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Group 24 - Cyclo HBB Parallel Shaft Helical Gearbox with Cyclo Reducer Input

Introduction:

During gate three we chose and analyzed a few different components within the gearbox. As part of the analysis we discussed different factors that could have influenced the design and decision making behind the components in the gear box. Our analysis explores the component function, component form, the manufacturing methods, and the complexity of each component that we chose. We also chose three of the components and created three dimensional computer models for them in order to showcase them in a partial assembly. We finish by making three suggestions for design revisions that could be benefit the products versatility of performance.

Project Management: Coordination Review

Cause for Corrective Action

Resolved Challenges:

Our group has conquered quite a few challenges and met quite a few obstacles in the past few months. Without a doubt our single largest challenge over the course of the semester has been the enormous amount of work and and incredible expectations that are required for this course. For many of us, the work load in this course alone has overshadowed all of the other courses in our schedules. However, as the semester continues to role on we have continually been able to meet and exceed all of the challenges that have been thrown at us and we will continue to do so until this course is over. Our plan to deal with the pressure, ambiguity, and extremely high standards from this course is to persistently meet with the professors in order to seek direction, gain clarity, and express discontent when needed.

When we were faced with enormous difficulties during the dissection of our product we were able to use the extra time that we had integrate into our work plan in order to receive advice from our professor and find the resources that we needed to finish the job. If we had not of started that gate early, we would not have been able to finish it before the due date.

In gate 3 our group was faced with enormous pressure from other courses. To address this pressure and account for this project we all sat down and looked at our schedules. It quickly became obvious that,there was going to be an enormous amount of pressure for all of us. We all agreed that this was necessary and that we would do everything that needed to be done to finish the gate in time. We have always been able to band together and finish the job despite the challenges that have been thrown at us.

Unresolved Challenges:

Most of the members of our group are working together very well. However, we are having problems coordinating and communicating at times. This is resulting in undeserved higher workloads for some of the members during peak work hours.

Our solution to communicate more clearly and more quickly in the coming gates. We are planning to make a schedule so that meetings will be more predictable. We will meet directly after class on Monday, November 29th in order to assign specific roles and plan specific times for meetings in order to finish the upcoming gate. In this way, the meetings will not surprise anyone. We will make sure to agree upon dates that everyone can attend.

Product Archaeology: Product Evaluation

Component Summary

Component	Quantity	Function	Material Used	Manufacturing Process
Casing/Gearbox	1	Housing of all components and oil used for lubrication to maintain efficiency	Ductile Iron	Die Cast
Cover	1	Allow access to inside of Casing without having to disassemble	Ductile Iron	Die Cast
Gear	1	Transfers rotational energy to the output	Ferrous Alloy	Die Cast & Milling (key slot)
Hex Head Bolt	8	Secures the Cover to the Casing	Iron	Rolling
Spring Washer	8	Distributes the load of the Hex Head Bolt evenly	Iron	Forge
Ball Bearing	2	Reduces rotational friction around the Shaft to provide near frictionless rotation	Steel	Race: Cold Heading & Grinding Balls: Cold Heading
Retaining Ring (Internal)	2	Ensures that the Ball Bearings stay in place and close to the Shaft	Iron	Forged
Oil Seal	4	Seals oil within the Casing	Nitrile Rubber	Emulsion
Taper Grip Bushing	1	Shaft attachment specifically for Sumitomo Speed Reducers' Gear Motors	Steel	Lathe
Bushing Screw	6	Applies force to Thrust Plate to secure Taper Grip Bushing to Shaft	Iron	Forge
Thrust Plate	1	Secures Taper Grip Bushing to Shaft with force from Bushing Screws	Steel	Forge
Pinion Shaft Spacer	2	Ensures that the Pinion stays vertical at a 90 degree angle with the Gear	Steel	Milling
Retaining Ring	1	Ensures that the Pinion stays within the Casing	Iron	Forge
Hex Socket Head Plug	1	Provides access to relubricate the Pinion Shaft	Iron	Forge
Ball Bearing	1	Reduces friction around the Pinion Shaft to provide near frictionless rotation	Steel	Race: Cold Heading & Grinding Balls: Cold Heading
Oil Seal	2	Separates the pinion and gearbox oil chambers	Nitrile Rubber	Emulsion
Pinion Shaft	1	Pinion helical gear and input shaft	Steel	Milling
Retaining Ring (Internal)	1	Maintains the position of the Pinion Shaft and ensures that no movement occurs	Iron	Forge
Retaining Ring (External)	1	Maintains the position of the Pinion Shaft and ensures that no movement occurs	Iron	Forge
Seal Cap	1	Prevents the parts along the Pinion axis from sliding out and protects them from outside contaminants	Aluminum	Milling
Key (Squared End)	1	Prevents rotation between the Gear and the Shaft	Steel	Milling
Input HUB	1	HUB point that provides the energy that powers the Reducer as a whole	Steel	Milling

Component	Quantity	Function	Material Used	Manufacturing Process
Cyclo Ring Gear Housing Pins	1	Stabilizer	Steel	Milling
Cyclo Ring Gear Housing Rollers	1	Reduce friction	Steel	Milling
Gasket Set	1	Stabilizer	Iron	Mold
Cyclo Ring Gear Housing	1	Provides a casing for the reducers components	Cast Iron	Die Cast
Snap Ring	1	Retainer	Iron	Forge
High-Speed Shaft A Bearing	1	Reduce Friction	Steel	Cold Heading
Spacer	1	Stabilize and maintain space between components	Steel	Milling
Cycloid Disc Spacer	1	Stabilize and maintain space between components	Steel/Iron	Milling
Cyclo Eccentric Cam Assembly Spacer	1	Stabilize and maintain space between components	Steel	Milling/Molding
High Speed Shaft B Bearing	1	Reduce Friction	Steel	Cold Heading
Cyclo High-Speed End Shield	1	Prevents entry by dust and debris and prevents oil leaking out	Iron	Cold Heading/Milling
Eccentric Key	1	Locks in components and prevents them from rotation freely	Steel	Milling
High Speed Shaft Oil Seal Collar	1	Prevents oil from leaking out of subsystem	Nitrile Rubber	Emulsion
High Speed Shaft Oil Seal	1	Prevents oil from leaking out of subsystem	Nitrile Rubber	Emulsion
High Speed Shaft	1	Provide the rotational energy that is transferred to the various components	Steel	Rotating Lather/Milling
Cycloid Discs	2	Reduce speed by rotating off a cam	Steel	Milling
Snap Ring	1	Retainer	Steel	Forge
Pin Carrier Rollers	8	Reduce rotational friction	Steel	Milling
Pin Carrier Rollers	1	Reduce rotational friction	Steel	Milling
Cyclo Housing Bolt/Washers/Nut set	1	Stabilizer	Steel/Iron	Milling/ Rolling Thread
Pinion Shat B Bearing	1	Reduce rotational friction	Steel	Cold Heading

Product Analysis

Complexity	Component Form	Component Interactions
Not Complex	The component required only 1 manufacturing step to create.	The component had only 1 or 2 interactions.
Somewhat Complex	The component required 2 manufacturing steps to create.	The component had 3 interactions.
Complex	The component required 3 manufacturing steps to create.	The component had 4 interactions.
Very Complex	The component required 4 manufacturing steps to create.	The component had 5 interactions.
Extremely Complex	The component required 5 or more manufacturing steps to create.	The component had 6 or more interactions.

Cyclo Single Reducer

Function:

Picture 1: Reducer

The main function of the Cyclo Single Reducer is to reduce the RPM’s from a motor into torque as an output. It achieves this using two identical gears that spin offset from one and other. There are bearings on both the inside and outside radius of the gears in order to allow for efficient rotation. In fact, according to the product catalogue, these “high performance steel gearing components deliver 85-90% efficiency.” The single reducer receives rotational input from a motor, using a love joi connection, and converts it to torque through the offset gear rotations. The rotational energy is then converted directly to the taper grip bushing. This is achieved because the eight holes in the lower gear (shown in photo 1) lock into place with the eight pins protruding from the surface of the bushing.

The component only serves to convert rotational energy into torque. It serves no other purpose.

There are no flows associated with this component. It functions directly through the transfer of rotational energy using friction.

This component operates in a stressful industrial environment. It was designed to work for long periods of time while periodically experiencing high levels of torque from heavy loads. As the gears of this component rotate it experiences a lot of friction, but the design is meant to minimize this friction.

Component Form:

Picture 2: Reducer - Exploded View of Internal Reducer Assembly

The shell of the component is in the shape of a cylinder, but inside of the cylinder there were two gears pressed into a set of offset ball bearings (shown in picture 2). This set of gears and offset bearings were pressed onto a central cylindrical shaft along with two additional ball bearings. This system of gears and ball bearings allows for the efficient transfer of rotational energy. The rod is has a slot for a woodruff key designed specifically to lock the assembly together during operation (shown in picture 2). Also, you’ll notice that there is a section of the rod that has a larger radius than the rest of it. This is designed to separate the gears from the casing when the reducer assembly is fit together (shown in picture 2). Otherwise the gears would be free to make contact with the shell of the casing, causing enormous friction and probable failure. Furthermore, the inside radius of the cylindrical shell is lined with bearings (shown in picture 2). These bearings allow the gears to efficiently rotate around each of their axes.

Each piece of the reducer component is, for the most part, axially symmetric. The main exceptions to this rule are the woodruff key slot on the central shaft and the fact that the gears are designed to rotate on offset axes from one and other. This complex process is designed specifically to allow for the reduction of rpm’s into torque.

This component acts in all three dimensions. It rotates along its length and its width, and it stacks pieces along its height in order to transfer rotational energy. This process could not be achieved in anything less than three dimensions.

This component is roughly 15cm in diameter and 3.4 centimeters in height and it weighs about 6lbs. Most of the pieces of this component are made of steel, but the casing and the cap were made out of ductile iron.

The components shape is specifically designed out of functionality. The axially symmetric pieces allow consistent rotation around each of the axes. The gears being laid out on offset axes allows for an initial reduction of RPM’s into torque. The holes in the bottom gear are designed only to interlock with the pins on the Taper Grip Bushing.

The company chose to produce the internal pieces to this component out of steel so that it would be able to operate without failing under a stressful environment. It is also important to point out that one of the bearing cases in this product is plastic. During the dissection this bearing case broke on us. The fact that Sumitomo used a material that would easily break indicates that the plastic bearing case is not subject to very much force during operation.

Steel is a material that is relatively easy to work in a manufacturing environment. It can easily be milled, machined, or even shaped using a die cast mold. Other materials that could have been used instead may have been much harder to manage during the manufacturing process.

Sumitomo created the important pieces of this component out of steel because these pieces require a high level of structural integrity during operation. Cheaper materials like aluminum could not offer the strength that steel offers.

Picture 3: Outside of Reducer Casing

Economic considerations most definitely affected the choice of material for this component. The casing was made out of ductile iron because it was cheaper and easier to work with. The internal components, which need structural integrity, were all made of steel. The steel pieces are strong enough to perform the job but relatively cheaper than other materials that could have been used to handle the stress that the component would be put under. Also, steel is relatively easy to work with compared to other materials, like titanium, that could have been used instead. This will save the company money during the machining and development process. Finally, the choice to use plastic to create the offset bearing case was economic because plastic is much cheaper and easier to work with then steel. Seeing as though this piece is not subject to much force during operation, the decision to use plastic was clearly economic.

Global considerations for the choice of material would come from the availability of the resource in different parts of the world. They can easily outsource the manufacturing of this component because steel is resource that is a widely available. Furthermore, steel is relatively easy to work with so there are many plants around the world that would have the capacity to manufacture the product for them.

The primary societal consideration for the choice of steel for the components. If they had chosen a cheaper metal, like aluminum, the product would be in danger of failing and injuring an employee at the plant. This is a risk that Sumitomo was not willing to take so they manufactured the pieces out of steel.

The external face of this component has a very simple finish, while the internal and functional pieces of this component are just machined steel.

Picture 4: Inside of Reducer Casing

This component was designed for use in an industrial setting and it is clear that there were no aesthetic considerations made when the component was designed.

The grey finish on the outside of the component is just to protect the steel from corrosion and there was no aesthetic consideration. The shiny finish on the internal pieces indicates machined steel and demonstrates a need for higher tolerances in those pieces.

The surface of the internal components was shiny and very precisely finished. These parts were originally pressed into each other and it is clear that there surfaces are strictly out of a need for high tolerances.

Manufacturing Methods:

Picture 5: Reducer Gear

Each of these components was made using a different manufacturing process. The main shell of the component was most likely milled. The cap to the shell of the reducer was die cast. The internal pieces to this component were created using milling or CNC machining. Finally, the plastic bearing case was manufactured using injection molding.

Evidence supporting that it was milled it is shaped in a way in which it would be impossible to machine with a standard CNC machine. It would have to be milled because of the two lips on the top and the bottom surface of the product (shown in picture 4). There is no evidence of tool marks around the surface of the product because of the finish that was applied to it’s surface.

Evidence supporting that the cap to the shell was created using die casting is that it has a rough external surface and a complex shape that would difficult to create (shown in picture 3). This component does not have any riser marks or separation marks because they have been milled off in the completion of the part. We can tell that the part was finished using milling because of the extreme precision that was needed (shown in picture 4). Unfortunately, due to wear and tear over years of use, we cannot see the tool marks that might have been left on it’s surface.

Each of the gears was either milled or cut by a CNC machine. Despite the fact that the gears are axially symmetric there is no indication that a turn was used for the main shape. In fact, the shape of these gears is not conducive for a turning process. Most of the detail is machined in parallel to the axis of symmetry, not parallel to the axis of symmetry. Thus we can conclude that a lathe was not used. Next you’ll notice that this part was manufactured to a very high level of precision. The finish on the surface of the gear is very smooth and demonstrates a high level of tolerance. This evidence supports that either a mill or a CNC machine was used to manufacture this part. Unfortunately the only marks remaining on the surface of the gears are friction marks made during years of operation (shown in picture 5).

Evidence that injection molding was used to manufacture the bearing casing is that, first of all, the shape of the casing is intricate and would be difficult to machine. Secondly the company would be producing many of these parts quickly and would not want to spend the money machining each of these out. Injection molding satisfies both of these needs easily, and considering that the part is plastic we know that it would be injection molding rather than die casting.

GSEE Manufacturing Factors:

The main factors that indicated the material decisions when making this product were economic; however global considerations may have been made as well. There were no environmental or societal factors that went into the manufacturing decision making process.

Main Casing:

The economic factors stem from the fact that die casting is the cheapest and most effective way to create a shape that would otherwise require a lot of time and energy to machine. The shell of the casing encourages die casting, because otherwise a tremendous amount of material would have to be removed from the center increasing machining costs in a number of different ways. For one, the machining time would increase dramatically. Secondly, unnecessarily machining that material would wear out the machines and drill bits quicker. Using die casting is an easy way to avoid these costs.

Bearing Casing:

Next, using a CNC Machine for the production of the gears increases the precision obtained and it reduces the machine time necessary for a person to machine it. This allows the company to create more of the pieces quicker and helps to reduce costs during the manufacturing process.

Main Rod:

Milling was chosen to manufacture the main rod for similar reasons. The intricacy and the precision needed when manufacturing this rod encourage the use of the CNC Mill. It would be too cost ineffective to try to manufacture this product in any other way.

Bearing Case:

Injection molding is the most cost effective method that could be used to manufacture the intricate bearing case. The time and energy that would be needed to manufacture this case would be enormous if they had used any other machining process.

Global Factors:

The global factors for the manufacturing of each of these components are the same. The company needs to make sure that the areas in which they are looking to outsource have the technical capability to manufacture these pieces. Seeing as though these are common manufacturing methods Sumitomo could feel safe to export the manufacturing of this component while expecting good results.

Environmental Factors:

The environmental factors for the machining of these components would only be related to the disposal of the waste material. They would not consider other environmental issues during the manufacturing.

Component Form Complexity:

This component has a 5 star complexity rating because of the number of internal pieces, the complexity of the internal interaction, and the sheer number of manufacturing steps used to create the component.

This component operates in a very complex way. The two gears that rotate on offset axes do so in a very specific way in order to convert the rpm’s from the input into higher torque for the output. Furthermore, the component contains four sets of bearings and the shell has eleven linear bearings along its inside edge. The gears then rotate smoothly along this complex geometry. The complexity of this component is directly related to its function and the form necessary to accomplish that function. The manufacturing methods did nothing to increase the complexity of this component.

Without a doubt, the component function had the largest impact on the complexity of all of the components in this product.

Component Interaction Complexity:

This component received an interaction complexity of 1 star because it’s only purpose is to transfer rotational energy from one component to another using friction.

The interactions between this component and the other components are relatively simple. A motor interacts with the reducer through the use of a love joi connection on the outside of the reducer. When the motor is operating it spins the love joi connection rotating the gears inside of the reducer. This rotational energy is then passed along to the pinion has eight pins that lock into the eight holes on the lower gear in the reducer.

Taper Grip Bushing

Component Function:

The Taper Grip Bushing is designed to transfer rotational energy directly from the reducer component to the pinion. There are eight pins that come off of the Taper Grip Bushing that lock into eight circular holes in the gear that’s part of the reducing component. As the reducing gear spins, the Taper Grip Bushing will spin at the same rate. The Bushing then transfers this rotational energy directly to the pinion. The pinion and the Taper Grip Bushing lock together using a series of grooves. As the Taper Grip Bushing rotates, the pinion also rotates at the exact same speed.

The main purpose of the Taper Grip Bushing is to transfer the rotational energy from the reducer to the pinion. However, it also serves to shift the rotational energy in the z direction, allowing for extra space in order to obtain more connection possibilities further on.
This component has no flows associated with it. It simply transfers rotational energy directly using friction.

This component operates in a stressful industrial environment. It was designed to work for long periods of time while periodically experiencing high levels of torque from heavy loads.

Component Form:

Picture 6: Taper Grip Bushing

The Taper Grip Bushing is basically composed of two different sections. The first being a large cylinder, with eight axially symmetric pins aligned in a circular pattern protruding from the top surface (shown in picture 6). Secondly, the bottom half is a smaller radius cylinder that has a cylinder with grooves cut out of its center (shown in picture 6). These grooves are designed to lock in place with the matching grooves on the pinion (shown in picture 7). The pinion is designed to slide into this slot and lock into place with the Taper Grip Bushing.

The Taper Grip Bushing is an axially symmetric component.

This is a three dimensional component. It rotates along the axis that runs down its height and the teeth of its gears wrap around its circumference composed of its length and width. Its height also shifts that rotation further away from the reducer. There is no way that this function could be achieved in a two dimensional environment.

This component was roughly 8cm in diameter, 7cm tall, and it weighed about 3lb.

The components shape is directly coupled with the function that it needs to perform. It is designed specifically to transfer rotational energy from the wider reducer to the thin pinion. The pins along the top are specifically designed to lock into place with the reducer and the grooves in the slot on the bottom are specifically designed to lock into place with the pinion. The component is axially symmetric in order to provide constant, uninterrupted, rotation around the axis of symmetry.

Sumitomo chose to make this piece out of steel because it is an integral part of the operation. This piece needs to operate in a very stressful environment for long periods of time without failing. Steel was the best choice for the problem at hand.

Manufacturing techniques could have influenced the decision to use steel because die casting can be used and steel is relatively easy to machine compared to other, more durable, metals. The shape of this component is relatively conducive to die casting because of the intricate grooves that lock with the pinion.

This component operates in a stressful environment for long periods of time. It needs to withstand this stress without wearing down and failing. This is one of the main reasons that the company would have chosen steel over another metal like aluminum. Aluminum would not have held up as well given the operating environment that this product works in.

An economic reason that steel was chosen is that it is relatively cheap compared to other metals that could perform the same function given the operating environment. Not only is steel more cost effective than materials like titanium, it is easier to work with and more readily available than titanium saving them time and money in manufacturing.

A global concern that influenced the decision to use steel is that because it allows the company to outsource the manufacturing of the product to areas that may not be able to work with titanium. This also doubles as an economic reason because they would be able to save costs by outsourcing the manufacturing.

Finally, a societal influence that impacted the decision to use steel was safety. Steel has the capability of functioning under the giving stresses without failing. If the product were to fail it could cause harm to the employees of the plant, making it a liability and a safety issue.

The Taper Grip Bushing is a silver component with shiny smooth surfaces. However the grooves on the inside of the circumference of this part are rough and dull.

There were no aesthetic considerations while this component was being designed.

For the most part the component is shiny silver because it is machined steel. Once again, the company used steel because it was strong enough to withstand the forces that this part would be exposed too. There was no need to change the appearance of the component after machining it.

This component has a very smooth surface because it was machined to a high level of precision. This level of precision was demanded strictly out of functional need because it was pressed into other pieces. Furthermore this part was designed to be continuously rotating and the smooth surfaces helped to reduce friction during its operation.

There were no aesthetic considerations made during the development of this component. Any aesthetics are strictly out of functional necessity.

Manufacturing Methods:

The main shape of this component was manufactured using die casting. Much of the evidence to support this has been machined off during the finishing of the part, but it is still clear that the component was created using a mold.

First of all you can see that the grooves are Tapered, an aspect common to the die casting manufacturing method. The Tapering allows the component to be easily removable from the mold. Next, the grooves have a rough surface finish. This indicates that they were not machined.

The choice to use steel also encourages die casting in this circumstance because die casting is a common manufacturing method for steel components.

The shape of the part most certainly impacted the manufacturing methods used to create it. It is complicated enough to justify using a die cast rather than simply machining the part from scratch. The grooves on the inside wall of the smaller cylinder of the component would be very expensive to machine from scratch as there is no need for very high tolerances here.

The rest of the component was finished using a combination of milling and turning.

You can tell that the component was machined because of the small circular rings left by the tools that were used. (Unfortunately our camera could not capture the concentric rings in a photo but they are visible to the naked eye.) Also, the surface finish is much smoother and has a much higher tolerance. This level of precision cannot be obtained from a cast and is a clear indication that a machining process was used.

The choice to use steel allows for relatively easy milling and machining relative to other, more exotic materials. This gave Sumitomo more freedom when deciding on a manufacturing process.

Finally, the general shape of the he cylinder itself would most easily machine using a lathe because it is axially symmetric over a sizable length. The pins on the top, however, were milled or machined using a CNC machine. There are eight different axis of symmetry between those pins and it would be impossible to manufacture that pattern using a lathe.

GSEE Manufacturing Factors:

Economic Factors:

Sumitomo most definitely made economic considerations when deciding how to manufacture this component. First of all, the shape of the product is too complicated to justify strictly using machining methods. It would be too cost ineffective to individually machine each of the grooves, used to lock with the pinion, considering that a high level of precision is not necessary. Secondly, using a mold has a high initial cost but saves money over the course of production. Seeing as though they are producing many of these components it makes sense that they would use a die cast mold, rather than investment casting, because it can be reused easily and would be quicker than machining each part.

Global Factors:

The global factors for the manufacturing of each of these components are the same. The company needs to make sure that the areas in which they are looking to outsource have the technical capability to manufacture these pieces. Seeing as though these are common manufacturing methods Sumitomo could feel safe to export the manufacturing of this component while expecting good results.

Environmental Factors:

The environmental factors for the machining of these components would only be related to the disposal of the waste material from the plant. They would not consider other environmental issues during the manufacturing.

Component Complexity:

This component has a 3 star complexity rating because of the fact that there were three machining methods used to manufacture this part.

Initially the main shape of the Taper Grip Bushing looks relatively complex. It has a high level of surface finish, there are eight pins along the top surface of the component, and there are inside grooves along the inside surface of the smaller cylinder. This component would take some time and planning to manufacture due to the different aspects and requirements of each section. In total there were three manufacturing methods used to finish this part. However, despite its complexity, the components shape serves only to perform very simple interactions between other components.

Without a doubt, the component function had the largest impact on the complexity of all of the components in this product.

Component Interaction Complexity:

This component received an interaction complexity of 1 star because it’s only purpose is to transfer rotational energy from one component to another using friction.

The Taper Grip Bushing interactions are not very complex at all. This component is designed only to transfer rotational energy along an axis. It does not change the torque or the rotational velocity at all, and the shape is only so that it can easily lock into place with the other components. Its high level of surface finish is used specifically to reduce the amount of friction inhibiting the performance during operation.

Pinion

Component Function:

The Pinion transfers rotation energy directly to the helical gear from the Taper Grip Bushing using friction. It does this because the teeth of the Pinion interlock with the teeth on the gear. Therefore when the Pinion is rotated by the Taper Grip Bushing the gear also rotates.

The purpose of the Pinion is twofold. First, it converts a higher rotational velocity into a greater torque through the gear ratio. Second, it transfers the rotation to an offset axis allowing for more installation possibilities in the plant.

There are no flows associated with this component.

Component Form:

Picture 7: Pinion & Taper Grip Bushing

This component is basically a cylinder with helical gears wrapping around the middle portion. The top portion, which connects to the Taper Grip Bushing, has grooves that lock to the in place with the grooves on the bushing and allow for rotation.

This component is axially symmetric along the axis of rotation.

The Pinion is a component that acts in three dimensions. The height of the pinion shifts the rotational energy further way from the Taper Grip Bushing. Then the pinion rotates around its central axis producing force along the length and the width of the component. The pinion could not operate in a two dimensional environment.

The pinion is approximately 12cm tall, 4cm in diameter, and weighs about 2lbs.

The components shape is directly coupled to the function that the component performs. It is designed to translate rotational energy from one axis to another axis. The helical gear teeth connect with the helical gear, as the output, in order to provide this rotation. The rotation at the input stems directly from the interlocking teeth between the Pinion and the Taper Grip Bushing (shown in picture 7).

The Pinion was manufactured out of steel out of considerations for component function, manufacturing techniques, and GSEE factors.

The fact that steel is relatively easy to machine is a manufacturing consideration that was made when deciding on the material to create the product. Also, the fact that steel components can be created using die casting also testifies as a manufacturing consideration for this component.

The Pinion is made of steel because steel is strong enough to perform the necessary function in the stressful operating environment that it functions in.

An economic reason that steel was chosen is that it is relatively cheap compared to other metals that could perform the same function given the operating environment. Not only is steel more cost effective than materials like titanium, it is easier to work with and more readily available than titanium saving them time and money in manufacturing.

A global concern that influenced the decision to use steel is that because it allows the company to outsource the manufacturing of the product to areas that may not be able to work with titanium. This also doubles as an economic reason because they would be able to save costs by outsourcing the manufacturing.

Finally, a societal influence that impacted the decision to use steel was safety. Steel has the capability of functioning under the giving stresses without failing. If the product were to fail it could cause harm to the employees of the plant, making it a liability and a safety issue.

The Pinion is a shiny silver cylinder that contains rough looking gears around its middle portion. The surfaces on the cylindrical portion are smooth and very precise.

There are no aesthetic properties for this component. It was designed solely out of economic and functional needs.

The component is silver because it is machined steel that had no other aesthetic alterations done to it.

The cylindrical portion of the pinion has a very smooth shiny silver face.

The smooth finish on this component is purely functional. It indicates that high tolerances were needed for the production of this component. This is supported by the fact that it was pressed into other pieces. There was no aesthetic consideration when this product was machined.

Manufacturing Methods:

This part was created using a combination of techniques. The main shape of the Pinion was created using a die cast, and then the smooth finish and fine detail was done through a turning process.

We can tell that the main shape of the component was created using a die cast for a few different reasons. First of all, the material is steel thus it cannot be injection molding. Secondly, it would not be cost effective to use investment casting for a component like this. Thirdly, the shape of the gear teeth and the notches encourages the use of a mold because it would be very difficult and expensive to machine using standard processes. . Finally, you can see that the gear teeth and slot grooves are tapered in order to allow for separation from the mold. Unfortunately there are no visible riser marks on this component because they have all been away during production.

We know that this component was finished using a lathe because of the smooth concentric rings along the surfaces of the part. These rings are marks left by turning process. Also, the finished surfaces of the part require high tolerances that cannot be achieved through casting. These finishes are achieved using machining processes which are much more precise than die casting. In fact, the product may have even been grinded and polished for an even higher tolerance to improve performance. Finally, we can see that the surfaces are much shinier than the unfinished surfaces from the die cast sections of the component. This indicates that a machining process was used to create the smooth surface.

GSEE Manufacturing Factors:

Economic Factors:

There were most certainly economic factors used during the production of this component. The shape of the product is too complicated to justify strictly using machining methods. It would be too cost ineffective to individually machine each of the grooves, used to lock with the Taper Grip Bushing, considering that a high level of precision is not necessary.

Global Factors:

The global factors for the manufacturing of each of these components are the same. The company needs to make sure that the areas in which they are looking to outsource have the technical capability to manufacture these pieces. Seeing as though these are common manufacturing methods Sumitomo could feel safe to export the manufacturing of this component while expecting good results.

Environmental Factors:

The environmental factors for the machining of these components would only be related to the disposal of the waste material from the plant. They would not consider other environmental issues during the manufacturing.

Component Complexity:

This component has a 2 star complexity rating because of the fact that there were two machining methods used to manufacture this part.

The Pinion is a fairly simply cylindrical part that has a pretty complex helical gear pattern around its center. There is also a set of notches around the top of the Pinion used to lock it into place with the Taper Grip Bushing. The gear teeth and the notches on this part are what gave it a complexity rating, otherwise it would just be a simple cylinder.

Without a doubt, the component function had the largest impact on the complexity of all of the components in this product.

Component Interaction Complexity:

This component received an interaction complexity of 1 star because it’s only purpose is to transfer rotational energy from one component to another using friction.

The Pinion has only two very simple interactions as a component. It is designed only to transfer the rotational energy from the Taper Grip Bushing to the helical Gear using the friction generated by the notches and the gear teeth along its surfaces. It is not a complicated process at all.

Helical Gear

Component Function:

The gear is designed to perform the simple function of transferring the rotational energy provided by the pinion and transferring that energy to the output taper bushing. As the pinion spins the helical shaped teeth near the bottom of the shaft grip onto the helical shaped teeth of the gear. This rotation happens at the same exact rate as the pinion.

It is important to note that there are no other flows associated with this component and energy is transferred simply through friction.

The gear is the main component within the gear box and is surrounded by oil that simply acts as lubrication to maintain efficiency during the long operational cycles that this system must endure.

Component Form:

Picture 8: Helical Gear

The gear is a disc with a key slot located on the rim of the inner diameter that locks onto the output shaft. Along the outer rim are teeth that are angled in a helical pattern.

The gear weighs about 8 lbs. with an outer diameter of 20.5 cm and an inner diameter of 9.2 cm which allows the shaft to fit snugly.

The use of helical teeth rather than spur teeth allows for a quitter functioning mechanism due to the surface of each tooth connecting a little at a time versus all at once while simultaneously allowing each tooth to handle a higher tolerance. There is a loss of efficiency due to the design.

The components material is made up of a Ferrous Alloy or steel. This assumption is justified due to the nature of the manufacturer. Since the product was made in Japan the use of the Japanese Industry Standard is used for most material, including metal. The etched in description “G38” can be referenced to the JIS index and the material used can thus be determined.

The helical gear was most likely machined using a hobbing manufacturing process (special type of milling) (shown in picture 8). This would give the rough unfinished template of the gear. The teeth would then be refined and hardened (heat treated) to withstand the stresses of impact and then grinded to a finish.

Steel was used to make this component due to its importance in the system. The SM Cyclo must be efficient and effective for long hours of operation. Thus meaning that a strong and durable material must be used. Globally and economically steel is a wise decision. It’s easily accessible worldwide thus making it rather easy to manufacture in a very cost effective manner simply by outsourcing the manufacturing of most components, which makes sense since Sumitomo is a global corporation with design and manufacturing sites worldwide.

The gears aesthetic properties are not features of design. The gear would not be visible while functioning and the consumer would not need access to the gear. The smooth appearance of the gear may be simply due to the hobbing process while making the gear and finishing it so that it snugly fits around the shaft and inside of the gear box.

Manufacturing Methods:

The helical gear was manufactured using a hobbing process which is a process using a specially designed milling machine and the teeth are created with a cutting tool called a hob. The key slot on the inside diameter was also most likely milled due to the precision needed (shown in picture 8). The precision of the angle necessary on each helical tooth must be extremely precise for this component to effectively function and casting, which may be the only other realistic solution, does not give the precision and accuracy that a mill can provide.

GSEE Manufacturing Factors:

Economic Factors:

Economic considerations were made when this component was manufactured. First of all, the shape of the product is too complicated to justify standard machining methods. In this case a hobbing process was used to cut out the teeth and a mill was used for finish the rest of the product. Sumitomo chose to manufacture the gear in this way to save time and money during the manufacturing process.

Global Factors:

The global factors for the manufacturing of each of these components are the same. The company needs to make sure that the areas in which they are looking to outsource have the technical capability to manufacture these pieces. Seeing as though these are common manufacturing methods Sumitomo could feel safe to export the manufacturing of this component while expecting good results.

Environmental Factors:

The environmental factors for the machining of these components would only be related to the disposal of the waste material from the plant. They would not consider other environmental issues during the manufacturing.

Component Complexity:

This component has a 2 star complexity rating because of the fact that there were two machining methods used to manufacture this part.

The gear is a simple component within the system as its primary and only function is to transfer energy from the pinion to the attached shaft.

The three categories above impact the complexity of the design due to the fact that it provides the challenge of designing a highly effective and efficient component that must be durable and easily accessible if repair is. Though component form is the most influential factor that leading to the complexity level of this component.

Component Interaction Complexity

This component received an interaction complexity of 2 stars because, with the help of another component, it transfers the rotational energy from the Pinion to the main shaft using friction.

The helical gear interacts with three other components during operation. It receives rotational energy from the rotating pinion and it transfers this energy to the main shaft of the HBB Gearbox. It achieves this transfer of energy with the help of a woodruff key that forces the main shaft to rotate at the same time as the gear.

Ball Bearings

Picture 9: Ball Bearing

Component Function:

Ball Bearings allow co-axial parts on the same xy-plane to move very smoothly. Ball bearings are balls encased between two hollow discs; they go in between the two co-axial parts. The balls roll so less contact friction is created compared to just the two co-axial parts rubbing up against each other.

The only purpose the ball bearings serve is to reduce friction.
No flows are existent in the ball bearings, although they are filled with oil and grease, especially.

Ball Bearings are in constant motion and stress, as they are moving and being pressed up against parts on their inner and outer radii. They are also lubed up with oil and grease.

Component Form:

Ball Bearings are balls between two hollow discs. As a whole, they look like discs with an inner and outer radius.

The discs themselves are axially symmetric, while the definition of a ball or sphere is a 3D object that has the same radius around a point in three-space.
This mechanism could be produced in two dimensions, where the discs are inner and outer circles, and then balls are circles in between them. It is interesting to note that the balls could also be replaced by cylinders in three-space; however, this wouldn’t be as efficient due to more friction.
The ball bearings as a whole are throughout the product in three different sizes (D = outer diameter, d = inner diameter, h = height):
- Small ball bearings – In the reducer – D = 4.5 cm, d = 1.8 cm, h = 1.3 cm, about .25 lb
- Medium ball bearings – Around the pinion – D = 7.9 cm, d = 4.2 cm, h = 1.7 cm, about 1 lb
- Large ball bearings – Around the shaft – D – 13.3 cm, d = 9.9 cm, h = 2.2 cm, about 3 lb

The shape of the ball bearing is what makes it work in this situation. Their cylindrical shape allows co-axial parts on the same xy-plane to move in a circular motion about the z-axis. The balls roll as opposed to rubbing, which produces less friction. Since the components are under constant motion and stress, they need to be durable. Therefore, one can infer that the bearings were made from steel, like the rest of the parts Sumitomo made that were under those conditions.

It is possible material choice was impacted by manufacturing decisions. Steel is an easy metal to work with and could be cheaper than other metals that can also handle the same amount of stress
The material used needed to be durable to withstand the constant motion stress and prolonged use for years at a time.
An economic factor that led to choosing steel was its cost; it was the cheapest material with the properties Sumitomo needed.
A global influence that resulted with steel as the choice was the ability to outsource the components for maximum profitability, due to steel being very common globally.
A societal reason steel was chosen is safety. Had the material being used not been durable under the conditions, a system failure could possibly injure an employee, a risk no buying or selling company wants to take.

Aesthetics were not important at all in the production of the ball bearings since they were all internal anyway.

The color of the steel was left the same after the materials were shaped in the manufacturing process.
The surfaces of the bearings are polished but that’s only to reduce friction, not for looks.

Manufacturing Methods:

The outer and inner discs are axially symmetric, meaning turning is the most probable method they used for manufacturing them. The balls, on the other hand, were most likely die casted as they don’t have any axially symmetric lines and the sheer number of them used indicates die casting several at a time into a mold would save lots of time and money in their production.

Material choice didn’t impact the manufacturing method, since both the balls and the discs were made out of steel, yet they required different manufacturing processes.
Shape was the reason the balls and the discs had to be manufactured the way they were, along with the number of balls that were needed; they were produced in the most efficient way possible for their shape.

GSEE Manufacturing Factors

Economic Factors:

Turning is a faster and cheaper way to manufacture a steel component that is axially symmetric than using a CNC machine or a mill. Die casting is a faster and cheaper way to produce masses of small simple objects, as opposed to trying to make them with a lathe.

Global Factors:

Since steel is the material being used, outsourcing is possible due to steel’s high availability. This is an economical benefit as well.

Environmental Factors:

The only environmental factors that would be involved in such a manufacturing process is the waste produced by the factory.

Component Complexity

This was given a three out of five because it needed two different manufacturing processes to create the balls and the discs, then they had to be put together.

Component Interactions

This was given a two out of five because of the way the balls move while the discs are orientated around them.

Shaft

Picture 10: Taper Shaft

Component Function:

As the gear notched into the shaft spins, the shaft itself also spins, thus turning the taper bushing which is threaded into it. The shaft also has two sets of ball bearings around it—one above the gear, one below—to allow a smoother spin and reduce friction.

Basically, the shaft indirectly connects the taper bushing to the gear, while reducing friction with the two sets of ball bearings.
There is oil lying around the whole encasing of the product but no fluid of any type is being circulated.

The outside of the shaft is inside of the gear box, with the ball bearings and helical gear around it also. Meanwhile, while the inner partof the shaft holds the taper bushing. As a result, the shaft is put under lots of stress. This function ultimately influenced what material the shaft was made out of.

Component Form:

The shaft is a hollow cylinder at its most basic description. Its diameter gets bigger where the gear is slotted into it.

It’s nearly axially symmetric. The features that make it non-axially symmetric are its internal threads for the taper bushing, the key slot of the outside for the gear, and four notches—two on top, two on the bottom—which are most likely for installation purposes.
The hollow shaft cannot be envisioned in anything other than three dimensions, as it creates a hollow circle in xy-plane, while rotating about the z-axis.
Ignoring the threads, the inner diameter of the shaft is 6.8 cm. The outer diameter is 8.4 cm, increasing to 9.0 cm only where the gear goes around it. The height is 13.3 cm.
This hollow cylinder shape is particularly useful: the hollow circle it creates in the xy-plane allows it to rotate around the z-axis; the inside is hollow and threaded so the taper bushing can screw into it; and in this case, the cylinder was designed to be long so the ball bearings could fit around the outside of it, along with the gear.
It weighs approximately 8-10 lb.

The shaft is made out of steel and for good reason.

Manufacturing didn’t play a role in the choice of the material; it was predetermined.
Sumitomo decided to make all the parts that were under a stressful environment, including the shaft, out of steel so they lasted under the hard conditions.
An economic reason that steel was used is that its cost is relatively lower than that of other metals that could fit the durable niche needed to perform its function.
A global influence that impacted the decision to use steel was that it is a readily availability material and can be outsourced to other areas for production, also creating an economic benefit.
Safety was a societal reason steel was chosen. Steel is strong under high stress; had the choice been a weaker material, product failure could have possibly injured someone.

This component was created solely for efficiency/performance so aesthetics weren’t important in its design.

The color of the steel was left the same, as color didn’t impact the performance of the part.
The component is smooth and polished, which is more for efficiency purposes regarding friction than aesthetics.

Picture 11: Taper Shaft: Threading

Manufacturing Methods:

The shaft was manufactured using a lathe, then a mill to do the rest.

Taking note of the circular lines along the top of the shaft, one can infer it began as a wide cylindrical ingot. Then, as most of the shaft is axially symmetric, a lathe most likely produced the hollow cylinder shape, along with the internal threads. All that’s left to do is add a key slot and notches on the top and bottom, a job easily performed by a mill.
The shape of the shaft, not the material it was made of, was really the only important deciding factor that led to this type of manufacturing method.
The shaft needed to be axially symmetric with minor non-axially symmetric design factors added in. These necessities call for a lathe and a mill.

GSEE Manufacturing Factors:

Economic Factors:

Creating the threads for the shaft using a lathe is much more time efficient than making them with a CNC machine for example. Producing more of a component in a given time allows for more sales, resulting in more profits.

Global Factors:

All the components have the same global manufacturing factors. The company needs to check that the areas they plan to outsource to have the technology to create them. Sumitomo is a global company and seeing as steel is commonly manufactured around the world, Sumitomo could easily find the cheapest place to create the steel parts.

Environmental Factors:

The only factor being considered here would be how the waste is disposed of at the plant.

Component Complexity:

This was given a two out of five because the shaft itself isn't a relatively complicated piece. However, two different machines were needed to create it efficiently.
The only GSEE manufacturing factor that comes into play when talking about the creation of the specific geometry of the shaft is economics; there may be a way to create the part with only one machine but it would probably take longer and be more expensive.

Component Interaction Complexity:

This was given a two out of five because the shaft has the ball bearings on it which allow it to spin nicely but at the end of the day, the shaft is really just transferring rotational energy from one part to another on the same axis (helical gear to the taper bushing).

Taper Bushing

Component Function:

The taper bushing acts as the output of the rotational energy in the part. There are six holes on it so that it can apply forces to the other parts.

The components only other function is to form a connection between the input of another device and the HBB Buddybox.

There are no flows associated with this component.

Component Form:

Picture 12: Taper Bushing

The taper bushing is axis- symmetric. Generally, it is formed by two cylinders. One of them has a smaller diameter at the bottom and another has a larger diameter at the top.

This component is axially symmetric along the axis of rotation.

The small cylinder has diameter of 6cm and thickness of 12.5cm. The bigger cylinder has diameter of 10cm and thickness of 2.5cm. There is a hole, with a diameter of 5.6cm, through the center of the cylinder. The component roughly weighs three pounds.

The six holes are located at the larger cylinder, on the extra diameter surface. With this design, the extruded components of the other parts can slide into the holes and receive rotational energy from the HBB Buddybox.

The Pinion was manufactured out of steel out of considerations for component function, manufacturing techniques, and GSEE factors.

The fact that steel is relatively easy to machine is a manufacturing consideration that was made when deciding on the material to create the product.

The taper bushing is made of steel because steel is strong enough to perform the necessary function in the stressful operating environment that it functions in.

An economic reason that steel was chosen is that it is relatively cheap compared to other metals that could perform the same function given the operating environment.

A global concern that influenced the decision to use steel is that because it allows the company to outsource the manufacturing of the product to areas that may not be able to work with titanium. This also doubles as an economic reason because they would be able to save costs by outsourcing the manufacturing.

Finally, a societal influence that impacted the decision to use steel was safety. Steel has the capability of functioning under the giving stresses without failing. If the product were to fail it could cause harm to the employees of the plant, making it a liability and a safety issue.

The Taper Bushing is a shiny silver cylinder that with smooth surfaces that were machined to high tolerances.

There are no aesthetic properties for this component. It was designed solely out of economic and functional needs.

The component is silver because it is machined steel that had no other aesthetic alterations done to it.

The cylindrical portion of the pinion has a very smooth shiny silver face.

The smooth finish on this component is purely functional. It indicates that high tolerances were needed for the production of this component. This is supported by the fact that it was pressed into other pieces. There was no aesthetic consideration when this product was machined.

Manufacturing Methods:

Milling is being used to manufacture this taper bushing. The evidence is that there are radial milling traces on the component itself. Besides that, the component itself is axial-symmetrical, which is perfect prerequisite for milling. The material choice did have an impact on the manufacturing methods. Steel, which is the material of the taper busing, is a good choice for milling.

GSEE Manufacturing Factors:

Economic Factors:

There were most certainly economic factors used during the production of this component. The shape of the product would be very easy to machine with a mill, and the the threads were very simple to create using a thread roller. Sumitomo chose these two combinations of tools to create this part because they were the most cost effective combination. It would have been too burdensome and difficult to machine the threads using a lathe.

Global Factors:

The global factors for the manufacturing of each of these components are the same. The company needs to make sure that the areas in which they are looking to outsource have the technical capability to manufacture these pieces. Seeing as though these are common manufacturing methods Sumitomo could feel safe to export the manufacturing of this component while expecting good results.

Environmental Factors:

The environmental factors for the machining of these components would only be related to the disposal of the waste material from the plant. They would not consider other environmental issues during the manufacturing.

Component Complexity

This component has a 2 star complexity rating because of the fact that there were two machining methods used to manufacture this part.

The taper bushing is a fairly simple component comprised of a cylinder with a lip that has axially symmetric holes on it, designed for mounting to anything that could use rotational energy to function. More specifically, this component was mounted to a conveyor belt. However, the manufacturing that went into this component is not nearly as simple. The intricate threading on the outside of this shaft was created using a roller threaded.

Without a doubt, the component function had the largest impact on the complexity of all of the components in this product.

Component Interaction Complexity:

This component received an interaction complexity of 1 star because it’s only purpose is to transfer rotational energy from one component to another using friction.

This component has only one component interaction within the HBB Buddybox and two component interactions if you include the conveyor belt that it was intended to attach to. The component interactions for this component are very simple. The rotational energy that the busing receives from the main shaft is transferred directly into the conveyor belt to which the HBB Buddy Box is attached.

Gear Box or Casing

Picture 13: Assembled Casing: Top View

Component Function:

The gear box encloses the gears and holds the parts in the assembly at the right orientation so they move properly. It also stores oil so the assembly can move at the speed it wants with minor heat creation from friction.

Nothing in the casing is flowing. However, oil plugs on the sides can be removed to add more oil the system.

The casing itself is the environment for the assembly. However, the casing would be oriented onto a section of a conveyor belt assembly as a component itself.

Component Form:

The gear box could literally be referred to as a box shape, as in the name it’s referred to as; however, a box still isn’t a very accurate description of it shape, even for a basic description.

It has two holes that go all the way through it, one for the reducer and one for the shaft. Its edges aren’t squared off either. On the top, the spots where the holes are have elevated cylinder shapes around them, the reducer one being taller and skinnier compared to that for the shaft.
This type of component can only exist in three dimensions since it is enclosing three-dimensional objects.
The casing is 23.2 cm in width, 10.2 cm in height, and 28.0 cm in length, weighing in at a heavy 60 – 75 lbs.

The gear box’s shape was designed specifically to help enclose the assembly, therefore using dimensions from the other parts in its creation. It also has to spots where it can be bolted to the rest of the conveyor belt system.

The gear box is made of cast iron

Manufacturing didn’t affect the material choice; a steel body could have been produced in the same manner.
The material needed to be able to handle heat, if any was produced from friction, and be long-lasting.
A global influence that caused the gearbox to be cast iron was its ability to be outsourced to other locations due to its common occurrence.
In addition to profiting from outsourcing, another economic factor for cast iron being the chosen material is its cost vs. durability; iron is long lasting and cheaper than other materials, such as steel.
A societal factor that led to the use of cast iron was safety. If the material wasn’t strong enough to hold the parts together and the material broke, extremely fast and heavy materials would be spewed all over, being very dangerous, one thing that wants to be avoided at all costs.

The only aesthetics involved for this component is its color, which isn’t even that important.

The component is seen every day so it’s colored/painted red in case it rusts; that way it wouldn’t be a sore eye, since the rust would blend to the red color.

Picture 14: Dissected Casing: Bottom View

Manufacturing Methods:

Die Casting is the most probable method in which the gear box was manufactured

Since iron is hard to trim, something that strong would be easier manufactured if it was heated and then molded.
Something designed to the gearbox’s specifications and made out of iron would be hard to do any other way.

GSEE Manufacturing Factors:

Economic Factors:

Die Casting is a cheap, quick and easy way to manufacture a component like this; anything else would be very time consuming.

Global Factors:

Outsourcing is a major economic advantage, making the need for global plants or factories that can use the die casting process.

Environmental Factors:

Waste from the factories are the only environmental factors that are important in this situation.

Component Complexity:

This component was given a four out of five due to its complex shape and material properties needed for it to function correctly.

Component Interactions:

This component was given a three out of five since it holds the whole entire system together but nothing moving is directly touching it.

Solid Model Assembly

For the solid model assembly we chose to develop the Taper Grip Bushing, the Pinion, and the Helical gear of the HBB Gearbox. We chose these three components because the interact directly with one an other, they were interesting, and they are each central to the function of the Gearbox. We chose to create these components using Creo design software because one of our group members has taken MAE 377: Product Design in CAD and has experience using this design package.

First is our three dimensional drawing of the Taper Grip Bushing:

Taper Grip Bushing: Three Dimensional Drawing

Second is our three dimensional drawing of the Pinion:

Pinion: Three Dimensional Drawing

Third is our three dimensional drawing of the Helical Gear:

Helical Gear: Three Dimensional Drawing

Fourth is the separated assembly of the Taper Grip Bushing, the Pinion, and the Helical Gear:

Component Assembly: Separated

Fifth is the joined assembly of the Taper Grip Bushing, the Pinion, and the Helical Gear:

Component Assembly: Joined

Engineering Analysis

We wanted to better understand why the design of the gear called for helical teeth rather than spur teeth, considering that creating a spur gear is much more efficient and economical to manufacture. The helical gear requires a certain level of testing and design for it to be effective. The angle(fig-1) at which the teeth must be manufactured is an essential variable to the design. This can be found with further analysis. The advantages of a helical gear are a quieter operating sound at high velocities and higher stress tolerances can be handled when compared to spur gears. In other words, the teeth on a helical gear can handle more since helical gear teeth are effectively larger due to its diagonally place position.

It’s clear that if a consumer wants a quieter working gearbox with significantly greater load capacity at the sacrifice of efficiency than a helical gear would be the most sensible choice.

Problem Statement:

The question that then arises is at which angle the teeth should be set for maximum efficiency for a needed application? How thick should each tooth be? The size of the lead? What should the Normal Diametral Pitch be set at? What is the allowable tooth load depending on the material used to manufacture the gear?

Diagram:

Figure 1 (Boston Gear)

Governing Equations:

The following equations can then be used to find these variables.

Equation Sheet (Boston Gear)

Calculations:

Once these factors are found we can then determine the allowable maximum amount of torque that our system can handle and in return the horse power it can provide.

Discussion:

If these solutions do not meet our standards then one may need to readjust the size of the tooth face or the helical angle to either increase or decrease the torque and horsepower respectively.

Design Revisions

Revision 1: Spurred gear with ceramic ball bearings

When this product was received we assumed that due to a broken seal, this product then becomes useless and “irreparable”. Our assumption was correct due to the time and cost needed to repair a broken seal isn’t worth the downtime of a large operation. The actual failure was due to the fragmenting of steel due to a ball bearing failure. With this revision we would not only change the shape of the gears used within the gearbox, but also the material used to create the ball bearings.

Spurred gears are far more efficient and much cheaper to make than the complicated design of a helical gear. Ceramic ball bearings are more expensive but can operate at much higher temperatures after being treated. This increase in stability decreases the chance of failure.

These saving in cost can then be transferred over to the use of ceramic ball bearing instead of steel ones thus, decreasing the chance of failure. Further analysis would need to be taken understand the specification changes needed for these saving to be maximized.

Revision 2: Belt Drive

This product revision call for the use of a belt drive to replace the gears used within the casing. By using a high strength chain or Nitrile rubber and looping each end around fixed axial cylinders with varying diameters (dependent on ratio of speed that is needed to be reduced) a belt drive may be extremely cost effective.

Although the percentage of failure is increased with this new system, maintenance of this device would be almost negligible in comparison to the SMCyclo HBB by allowing access to movable parts much easier to achieve thus making it easier to replace these failed components. This will allow the company to save more than 10x the cost, at about $150.00 dollars and 15 minutes of down time per repair v.s. over $1,000 and over 3 hours of downtime to replace a gear box.

Revision 3: Syncronous Belt Drive

Synchronous belt drives remain at an energy efficiency of 98-99% over the life of the belt. A proven, viable alternative to standard belt drives, V-belt drives, and roller-chain drives, they are generating savings across a variety of industrial applications.

Again,as a belt drive system, although the percentage of failure is increased with this new system, maintenance of this device would be almost negligible in comparison to the SMCyclo HBB by allowing access to movable parts much easier to achieve thus making it easier to replace these failed components. This will allow the company to save more than 10x the cost, at about $150.00 dollars and 15 minutes of down time per repair v.s. over $1,000 and over 3 hours of downtime to replace a gear box.

Revision 4: Roller Chain Drive

Roller chain or bush roller chain is the type of chain drive most commonly used for transmission of mechanical power on many kinds of domestic, industrial and agricultural machinery, including conveyors, wire and tubedrawing machines, printing presses, cars, motorcycles, and bicycles. It consists of a series of short cylindrical rollers held together by side links. It is driven by a toothed wheel called a sprocket. It is a simple, reliable, and efficient means of power transmission.

Though chains have a shorter life span than gears it is similar to belt systems in that it allows for easier access for repairs. This opens up the opportunity to repair the component rather than replacing it. Saving more than 10x the cost, at about $200.00 dollars and 15 minutes of down time per repair v.s. over $1,000 and over 3 hours of downtime to replace a gear box.

Gate 3 - Product Analysis (Group 24)

Latest revision as of 19:44, 6 December 2012

Contents

Project Management: Coordination Review

Cause for Corrective Action

Product Archaeology: Product Evaluation

Component Summary

Product Analysis

Cyclo Single Reducer

Taper Grip Bushing

Pinion

Helical Gear

Ball Bearings

Shaft

Taper Bushing

Gear Box or Casing

Solid Model Assembly

Engineering Analysis

Design Revisions

Views

Personal tools

Navigation

Search

Toolbox

@@ Line 36: / Line 36: @@
 |-
-|Casting
+|Casing/Gearbox
 |1
 |Housing of all components and oil used for lubrication to maintain efficiency
@@ Line 56: / Line 56: @@
 |Transfers rotational energy to the output
 |Ferrous Alloy
-|Die Cast/Milling (key slot)
+|Die Cast & Milling (key slot)
 |-
@@ Line 107: / Line 107: @@
 |Lathe
 |-
 |Bushing Screw
@@ Line 134: / Line 135: @@
 |Retaining Ring
 |1
-|Ensures that the PinionPrevents oil from leaking out of subsystem
+|Ensures that the Pinion stays within the Casing
-|Nitrile Rubber
+|Iron
-|Emulsion
+|Forge
 |-
@@ Line 150: / Line 151: @@
 |Ball Bearing
 |1
-|reduces friction around the Pinion Shaft to provide near frictionless rotation
+|Reduces friction around the Pinion Shaft to provide near frictionless rotation
 |Steel
-|Rotating Lather/Milling
+|Race: Cold Heading & Grinding
+Balls: Cold Heading
+|-
+|Oil Seal
+|2
+|Separates the pinion and gearbox oil chambers
+|Nitrile Rubber
+|Emulsion
 |-
-|Cycloid Discs
+|Pinion Shaft
-|2
+|1
-|Reduce speed by rotating off a cam
+|Pinion helical gear and input shaft
 |Steel
 |Milling
 |-
-|Snap Ring
+|Retaining Ring (Internal)
 |1
-|Retainer
+|Maintains the position of the Pinion Shaft and ensures that no movement occurs
-|Steel
+|Iron
 |Forge
 |-
-|Pin Carrier Rollers
+|Retaining Ring (External)
-|8
+|1
-|Reduce rotational friction
+|Maintains the position of the Pinion Shaft and ensures that no movement occurs
-|Steel
+|Iron
-|Milling
+|Forge
 |-
-|Pin Carrier Rollers
+|Seal Cap
 |1
-|Reduce rotational friction
+|Prevents the parts along the Pinion axis from sliding out and protects them from outside contaminants
-|Steel
+|Aluminum
 |Milling
 |-
-|Cyclo Housing Bolt/Washers/Nut set
+|Key (Squared End)
 |1
-|Stabilizer
+|Prevents rotation between the Gear and the Shaft
-|Steel/Iron
+|Steel
-|Milling/ Rolling Thread
+|Milling
 |-
-|Pinion Shat B Bearing
+|Input HUB
 |1
-|Reduce rotational friction
+|HUB point that provides the energy that powers the Reducer as a whole
 |Steel
-|Cold Heading
+|Milling
+|-
 |}
@@ Line 225: / Line 229: @@
 |Steel
 |Milling
 |-
@@ Line 234: / Line 237: @@
 |Steel
 |Milling
 |-
@@ Line 244: / Line 245: @@
 |Iron
 |Mold
 |-
@@ Line 254: / Line 253: @@
 |Cast Iron
 |Die Cast
 |-
@@ Line 264: / Line 261: @@
 |Iron
 |Forge
 |-
@@ Line 274: / Line 269: @@
 |Steel
 |Cold Heading
 |-
@@ Line 283: / Line 277: @@
 |Steel
 |Milling
 |-
@@ Line 292: / Line 285: @@
 |Steel/Iron
 |Milling
 |-
@@ Line 301: / Line 293: @@
 |Steel
 |Milling/Molding
 |-
@@ Line 310: / Line 301: @@
 |Steel
 |Cold Heading
 |-
@@ Line 319: / Line 309: @@
 |Iron
 |Cold Heading/Milling
 |-
@@ Line 329: / Line 317: @@
 |Steel
 |Milling
 |-
@@ Line 338: / Line 325: @@
 |Nitrile Rubber
 |Emulsion
 |-
@@ Line 347: / Line 333: @@
 |Nitrile Rubber
 |Emulsion
 |-
@@ Line 356: / Line 341: @@
 |Steel
 |Rotating Lather/Milling
 |-
@@ Line 366: / Line 349: @@
 |Steel
 |Milling
 |-
@@ Line 375: / Line 357: @@
 |Steel
 |Forge
 |-
@@ Line 384: / Line 365: @@
 |Steel
 |Milling
 |-
@@ Line 393: / Line 373: @@
 |Steel
 |Milling
 |-
@@ Line 402: / Line 381: @@
 |Steel/Iron
 |Milling/ Rolling Thread
 |-