Group 19 - Honda Engine

Revision as of 21:45, 15 December 2009

Group 19: Gate 1

Work Proposal

Our group, Group 19, has been tasked with disassembling a Honda engine. Our engine is an inline four cylinder. This means that it contains four cylinders and pistons adjacent to one another. We plan to start disassembly at the top in the air filter and work downward. This seems like the easiest approach, as the air filter will yield way to the cylinders of the engine. Figure 1 shows the top view of the engine. We then plan to disassemble the cylinders and make way through to the crank shaft. There are a widespread number of tools that may be necessary to help disassemble the engine. The outermost parts of the engine are simple enough to disassemble. Standard screw drivers and a ratchet can mostly be used to remove casings, and pliers can be used to remove most hoses without a problem. For the internal parts, vice grips and WD-40 may be used to remove some jammed components that are better set into place. Figure 2 shows a more detailed breakdown of the tools and possible uses.

Figure 2:

This dissection is expected to take approximately 10 hours. Five hours would be used to disassemble the product. Two and a half hours would be dedicated to understanding the internal components and their functions. The final two and a half hours would be spent reassembling the engine properly.

There are several large challenges involved in the disassembly of the engine. Firstly, there are many small parts and components that we are unfamiliar with. This will make it difficult to understand how it works. Additionally, we found that the engine itself has a highly intricate design. This coincides with the first obstacle, meaning that the high degree of complication will make understanding the inner workings of the engine difficult. The last impediment we found was that the engine is heavy. Being unable to physically manipulate the entire product makes dissection difficult, as some components may be in hard to reach places.

Our group has a small arrangement of capabilities among our members. John Burkhart has some limited solid modeling experience that will need to be supplemented to complete the project. All members are able to operate a computer, as well as most tools and equipment we will be using to disassemble the engine. In addition, all members of our group have AutoCAD experience, and are able to use that as a possible presentation tool.

Our group also has several disadvantages. No members of our group have ever made a Wiki, meaning that someone will have to take time to learn how to develop and maintain one. Also, none of our group members have any automotive experience. This lack of knowledge will hinder our group in identifying the components of the engine.

Management Proposal

Our group will be constructing a Gantt chart with specific instructions and timelines for when to complete each component of the project. The Gantt chart will consist of the deadlines and tasks that will need to be completed throughout the course of the project. We will maximize our group time in the lad, disassembling and analyzing each component’s function. We will be taking detailed written and visual records and posting them on our wiki site regularly to keep group members updated on our progress. We plan on meeting in front of Student Union before our scheduled lab times, 2 to 3 times a week. Our meeting times will be Tuesdays 4:15pm – 6:30pm and Wednesdays 5:00pm-8:00pm for the next several weeks.

The progress of our group depends on dedication and alertness to our work schedule as displayed in our Gantt chart. Each member has responsibilities that must be accounted for in order to keep the project moving forward and complete each component on time. Our Communication liaison will ensure that all group members are updated regularly on meeting times and everyone is always caught up on the task at hand at any given day.

The roles of each of our group members are defined as follows:

Project Manager: Salman Iqbal

The project manager’s job is to oversee all processes of the project, from the initial product assessment to the final delivery. He is responsible for making sure that all the work done during the lab hours is safe, substantial and detailed. He is to assess each group member’s work, making sure that each member is working diligently and is able to get the required amount of work done as prescribed by the Gantt chart. The project manager is also responsible of ensuring the quality of work done by every member and optimizing meeting times to match the schedule of the Gantt chart.

Technical Expert: Jonathan Burkhart

The technical expert is responsible for familiarizing himself with various technical aspects of the project. Such aspects include 3-D Modeling (Rhinoceros NURBS modeling for Windows and AutoCAD 2009), expert knowledge of the required tools and dissection procedures and ensuring that the dissection process is on pace with the Gantt chart and is done with the proper safety precautions.

Communication Liaison: David Holewka

The primary responsibility of the communication liaison is to maintain contact between the professor and the teaching assistants. Also, in the case that a member of group is unable to attend a meeting, the communication liaison is to bring that member up to date on any progress that has been made so far. He is also in charge of sending meeting reminder e-mails after each meeting and preparing the times and reviewing the Gantt chart for the subsequent meeting.

Wikipedia Manager: Andrew Carroll

The Wikipedia Manager maintains and updates the group’s Wikipedia page with photos, video and up to date developments on the project. He is also accountable for making sure that all necessary information such as the entire detailed dissection is posted on the wiki along with corresponding pictures. This will be followed by clear and comprehensive reports of the Preliminary Project Review, Coordination Review, Critical Project Review and Final Delivery. The Wikipedia manager will be expected to complete these assignments before each respective delivery date.

Technical and Communication Support: Rusty Donlon

The Technical and Communication Support will be accountable for assisting all group members with their respective tasks. His main objective is to take visual records (i.e. pictures, videos) of each step of the product dissection and assembly and assist the Wikipedia Manager in updating the wiki page. He will also assist the Technical Expert in creating 3-D models of certain parts that require more attention and making these parts available to the entire group.

Initial Product Assessment

After receiving our product, the entire group analyzed the various components and concluded that we had a HONDA motorcycle engine. Our general product dissection plan consists of taking apart the air intake and filter, moving down to the pistons and finishing at the crank shaft, all the while working towards the bottom of the engine. On each step, we will take detailed notes on all the components of our product and constantly update our wiki page while optimizing our work time in the lab.

Intended Use:

The intended use of our product is to produce power through a combustion process that takes place inside the engine block. It is part of a motorcycle that can be used both professionally and recreationally. The functions of our product include supplying power to the mechanical components of a motorcycle resulting is the turning of the wheels and creating motion. The engine’s alternator, when functional, provides energy to the battery which in turn provides electricity to power the electronic components of the motorcycle.

How it Works:

The engine process starts by taking in air and gas through the air intakes. Within the engine, there is a combustion reaction which converts the chemical energy of the gases into mechanical energy. This energy propels the pistons and turns the crankshaft which results in the rotation of the wheels and movement of the motorcycle. Meanwhile, frictional forces inside the engine act on various components creating thermal energy. The alternator provides electrical energy which in turn charges the battery enabling many electronic functions on the motorcycle.

Complexity:

This product is extremely complex consisting of many different sized components, each of which involves the use of smaller parts resulting in various functions. The engine is able to conduct many different processes simultaneously with each part moving at extremely rapid speeds. It is able to convert one form of energy into another continuously, providing this energy to the drive train and the alternator.

Materials:

The engine is composed of various metals such as steel, copper and aluminum creating the major components of the engine block. There are also rubber and plastic tubes present as well as grease, glue, oil and solder.

User Feedback:

This engine provides sufficient power to propel a motorcycle and optimize mileage. It creates high amounts of vibrations and outputs a significant amount of heat and sound. When installed, the system functions efficiently providing enough power to the drive train to propel a motorcycle. Despite its effortless operation, the engine is difficult to maintain without proper knowledge of all of its systems and parts.

Alternatives:

Some alternatives to this product are electric motors and hybrid motors. Electric motors are more expensive to purchase but are cheaper to operate. Hybrid motors are also more expensive than our current engine and are also cheaper to operate and maintain. However, our product is less expensive, outputs more power to the drive train and is much more universal for a mechanic to work on.

Group 19: Gate 2

Product Dissection Plan

The Honda engine is a product that is not intended to be taken apart easily. Many of the parts are put together by machines that exert a massive amount of force on those parts. This way, the engine is able to sustain high temperatures as well as very high pressures. However, for our disassembly plan, we had to use a variety of smaller tools ranging from Philips head screwdrivers to socket wrenches. These tools and their functions are labeled in the following table.

We established a difficulty scale to measure the ease of each step. The scale utilizes two components in the form of “A/B.” “A” denotes simplicity ranging from one to five. One being a very easy step to perform and five requiring multiple attempts and tools. “B” denotes how obvious the steps were, ranging from one to two. One being easy to see the step and two being thought intensive. For example, a difficulty of “4/2” represents a step that is complicated and requires thought.

The steps taken in the dissection process as well the tools required for each step are outlined in Table 1 and Table 2. Any obstacles that we faced are also documented on the following pages.

Figure 1:

OBSTACLE: The group needed larger allen keys to remove the valves from the pistons. We went to the machine shop to obtain the proper tools but the machine shop was closed. We decided that it would be easier to flip the engine over and work from the bottom. This way, we were able to get to the transmission easily.

Figure 2:

OBSTACLE: The group debated on how the transmission system works. We looked at all the dissected parts and talked about how the movement of the gears affects each part resulting in the movement of the motorcycle. We recorded a video on how we think this process takes place.

Causes For Corrective Action

As we progressed through our Work and Management plans, we encountered several problems. These problems led to obstacles in our dissection procedure that needed to be addressed. While our original plan was to start at the top of the engine and take it apart piece by piece, we found that an easier way to access the transmission was by inverting the engine. Getting a better understanding of how the transmission worked took longer than expected, due to the fact that we have very little knowledge of motorcycle engines. To account for this, we extended our meeting times so that we could spend more time in the lab and improve our understanding of the transmission. We finally determined how the transmission functions through a series of different trials. Each trial consisted of us turning a different part of the transmission until the gear pieces would shift or slide in one direction or another. From the knowledge we have of transmissions, we were able to decide what gears were neutral, first, second, etcetera.

We also noted an inaccuracy in our Gantt chart. Our time slot for the “Causes for Corrective Action” step was placed too early for us to complete. It should have been placed in a time slot after the “Disassembly” process was to be finished.

Although there were some problems and obstacles in our Work and Management plans, things went as smoothly as possible. Our Gantt chart provided an accurate time line that helped keep us on top of what needed to be done. Being able to meet as a group two to three times a week allowed our group leader to keep us organized and on track. As stated in our Management Proposal, we had allotted seven and a half hours for the dissection and understanding of the engine, “The dissection is expected to take approximately ten hours. Five hours would be used to disassemble the product. Two and half hours would be dedicated to understanding the internal components and their functions” (Management Proposal). However, the actual Disassembly process took us three hours to complete, leaving us with ample time to focus on the engine transmission. Up to this point, we are on schedule to complete the project on time.

For problems we will face in the future, we will need to find quick ways to resolve them without putting a delay on the other processes outlined in our Gantt chart. One problem that we may face is that the reassembly process may take longer than we expect. This is due to the fact that there are many different size screws and parts to the engine. To resolve this issue, we will extend our meetings to accommodate enough time to reassemble the engine. The notes and pictures that we have taken during the disassembly procedure will help guide us to correctly pull together the engine. Also, with scheduling conflicts and exams, some group members will not be able to attend all the meetings. The group members that are available will meet and keep the other members updated through e-mails. Since there is limited space in the lab and an excess of groups working at once, some small parts such as screws, nuts and bolts may have been misplaced during the dissection process. The Technical Expert of our group, Jonathan Burkhart will be responsible for documenting any missing parts. Our Communication Liaison, David Holewka will contact Phil Cormier or Erich Devendorf and inform them of any missing parts.

Group 19: Gate 3

Product Documentation and Analysis

This is the second major project review conducted by our group. We have finished analyzing the product and divided the components of the engine in to three main categories. These categories consist of the clutch, the gearshift/drum and the transmission. We have further sub-divided these categories into individual components and analyzed the function, composition, shape and complexity of each of these components.

Causes for Corrective Action:

Our group did encounter an issue with scheduling and meeting minutes. All of the members of our group were not able to meet at the same time due to conflicting schedules with each other. We were also not always able to meet as a group during lab hours. At first, this hindered our progress towards outlining the components of the product as we were not all on the same page. To resolve this issue, we took detailed notes of everything and sent these notes via email to the members of the group who were not present at all the meetings. This allowed all of us to stay on pace with Gate 3: Coordination Review and receive important updates regarding project assignments per member. This plan has worked very well for our group despite the fact that the entire group is unavailable to be at all of the meetings. If our schedules continue as they had, we plan on executing this plan of e-mailing each member of the notes taken on any meeting day and stay up to date with the progress of the assignment.

Component Summary

Blanket Statements:

Complexity: 1-3: 1 – item is very simple and clear, has a basic shape. 2 – Item is rather simple, has a basic shape but perhaps some sort of pattern to it. 3 – Item is complex, with no predictable pattern or doesn’t have a particular shape.

Different materials are chosen for different parts because of strength requirements, malleability, durability, and cost. Heavier parts that have forces exerted on them that are not meant to bend or change shape are made of steel, while smaller parts that are movable seem to be made out of aluminum. Within this section there are many different components that are manufactured differently, and made from different materials. In addition to this, the weight of different components is a major factor in choosing the material. The component summaries are listed on the following pages.

A. Clutch:

a. Clutch

i. Mechanical forces of about 50 N are applied to this part.

ii. For this part the material choice is steel. This is the chosen material because it is strong and durable. Using steel as the material affects the manufacturing process because different tools and processes have to be used to form the shape desired.

iii. When manufacturing certain parts different processes are used to form different parts. For this part is looks as if they used die casting and milling to create the desired shape.

iv. Die Casting was used to because this is a small/medium part, has a lot of detail, and has a fine surface. The milling process was used for dimensional precision and a good surface finish. Also the teeth on the gear are cut using milling. These processes were necessary for this because if parts in the transmission are dimensionally inaccurate there could be problems that cause the whole clutch to fail.

v. This component is functional. This part is necessary for the translation of mechanical energy from the engine to the wheels.

vi. We think that the chosen processes were used because of the need for high precision and good finish of the surface.

vii. On the scale stated above this part is a 3. It is very complex and has multiple shapes incorporated into it.

b. Sprocket

i. Mechanical forces of about 50 N are applied to this part.

ii. For this part the material choice is steel. This is the chosen material because it is strong and durable. Using steel as the material affects the manufacturing process because different tools and processes have to be used to form the shape desired.

iii. When manufacturing certain parts different processes are used to form different parts. For this part is looks as if they used die casting and milling to create the desired shape.

iv. Die Casting was used to because this is a small/medium part, has a lot of detail, and has a fine surface. The milling process was used for dimensional precision and a good surface finish. Also the teeth on the gear are cut using milling. These processes were necessary for this because if parts in the transmission are dimensionally inaccurate there could be problems that cause the whole clutch to fail.

v. This component is functional. This part is necessary for the translation of mechanical energy from the engine to the wheels.

vi. We think that the chosen processes were used because of the need for high precision and good finish of the surface.

vii. On the scale stated above this part is a 3. It is very complex and has multiple shapes incorporated into it.

c. Clutch spring

i. Mechanical forces of about 50 N are applied to this part.

ii. For this part the material choice is steel. This is the chosen material because it is strong and durable. Using steel as the material affects the manufacturing process because different tools and processes have to be used to form the shape desired.

iii. When manufacturing certain parts different processes are used to form different parts. For this part is looks as if they used die casting to create the desired shape.

iv. Die Casting was used to because this is a small/medium part and has a fine surface. This process is necessary because if parts in the transmission are dimensionally inconsistent there could be problems that cause the whole clutch to fail.

v. This component is functional. This part is necessary for the translation of mechanical energy from the engine to the wheels.

vi. We think that the chosen processes were used because of the need for consistent dimensions and good finish of the surface.

vii. On the scale stated above this part is a 1. It is not very complex and has a simple spring shape.

d. Bearing: 4x

i. Mechanical forces are applied to these parts.

ii. For these parts the material choice is steel. This is the chosen material because it is strong and durable. Using steel as the material affects the manufacturing process because different tools and processes have to be used to form the shape desired.

iii. When manufacturing certain parts different processes are used to form different parts. For these parts ir looks as if they used die casting, milling, and drilling to create the desired shape.

iv. The milling process was used for dimensional precision and a good surface finish. The casting process is used to create the ring that the bearings sit in. Also casting along with polishing is used to create the bearings. These processes were necessary for this because if parts in the transmission are dimensionally inaccurate there could be problems that cause the whole clutch to fail.

v. These components are functional. These parts are necessary for the translation of mechanical energy from the engine to the gears to the wheels and to reduce friction between moving parts.

vi. We think that the chosen processes were used because of the need for high precision and good finish of the surface.

vii. On the scale stated above these parts are a 2. They are somewhat complex components.

e. Clutch plates

i. Mechanical forces of about 50 N are applied to this part.

ii. For these parts the material choice is steel. This is the chosen material because it is strong and durable. Using steel as the material affects the manufacturing process because different tools and processes have to be used to form the shape desired.

iii. When manufacturing certain parts different processes are used to form different parts. For these parts it looks as if they used die casting and milling to create the desired shape.

iv. Die Casting was used to because these are small/medium parts with a lot of detail and they have a fine surface. The milling process was used for dimensional precision and a good surface finish. These processes are necessary for this because if parts in the transmission are dimensionally inaccurate there could be problems that cause the whole clutch to fail.

v. These components are functional. These parts are necessary for the translation of mechanical energy from the engine to the gears the wheels.

vi. We think that the chosen processes were used because of the need for high precision and good finish of the surface.

vii. On the scale stated above these parts are a 2. They are somewhat complex and have multiple shapes incorporated into it.

B. Gearshift – Drum:

f. Fork

i. Function: To move gears back and forth.

ii. Material: It is made out of steel.

iii. Manufacturing Process: It is die casted

iv. Part Number: 50219-001

v. Used once

vi. Steel was chosen because it is strong and lightweight.

vii. An estimated 20 lbs of force is applied to the forks. The shape and material both come into play when manufacturing. Die casting was chosen for this part because it creates many of the same precise part. This component is shaped like a rounded “Y” so it can fit around the gear shaft. The component is functional. The component is rated a 1 for complexity because of how simple it is.

g. Right gearshift fork

i. Function: To move gears back and forth.

ii. Material: It is made out of steel.

iii. Manufacturing Process: It is die casted.

iv. Part Number: 50383-001

v. Used once

vi. Steel was chosen because it is strong and lightweight.

vii. An estimated 20 lbs of force is applied to the forks. The shape and material both come into play when manufacturing. Die casting was chosen for this part because it creates many of the same precise part. This component is shaped like a rounded “Y” so it can fit around the gear shaft. The component is functional. The component is rated a 1 for complexity because of its basic shape.

h. Left gearshift fork

i. Function: To move gears back and forth.

ii. Material: Steel

iii. Manufacturing Process: Die casting

iv. Part Number: 50290-001

v. Used once

vi. Steel was chosen because it is strong and lightweight.

vii. An estimated 20 lbs of force is applied to the forks. The shape and material both come into play when manufacturing. Die casting was chosen for this part because it creates many of the same precise part. This component is shaped like a rounded “Y” so it can fit around the gear shaft. The component is functional. The component is rated a 1 for complexity because of how simple it is.

i. Gearshift spindle

i. Function: To mount the gearshift drum to the transmission housing and connect the drum to the shifter

ii. Material: Steel

iii. Manufacturing Process: Die casted

iv. Part Number: 178443-001

v. Used once

vi. An estimated 20 lbs are applied to this part. The material choice and shape affect the manufacturing process. Die casting was chosen because of the objects simplicity and the need to produce many. This component is a simple rod, and is given a complexity rating of 1. This component is meant to be functional.

j. Shift drum

i. Function: To move the forks to make the transmission shift gears.

ii. Material: Steel

iii. Manufacturing Process: Die casting, machining

iv. Part Number: 49970-001

v. Used once

vi. An estimated 20 lbs is applied to the shift drum. Steel was chosen for its strength and light weight. The material choice and shape of the item both affect the manufacturing process. This complex shape and sharp corners require some machining. The component has the basic shape of a cylinder, but has grooves cut in it that seem random. This earns it a complexity rating of 3. The component is purely functional.

k. Shift return spring

i. Function: To return the shifter to the original upright position after the gears have moved.

ii. Material: Aluminum

iii. Manufacturing process: Machining, Forming

iv. Part Number: 176655-001

v. Used twice

vi. An estimated 20 lbs of force are applied to the spring. The material choice and shape affect the manufacturing process. Machining was used to cut the piece, and the piece of metal was formed into its spring position. This component is shaped into a spring, and earns a complexity rating of 2. The component is functional.

C. Transmission

a. Gears:

i. 11 different types of gears

ii. Different sizes and number of teeth

iii. Similar composition

iv. Different functionality

• Function-to transmit torque to the transmission, each of the gears are known as spur gears

• Material-steel

• Manufacturing Process-mold casting

• Part numbers-61570-001, 61629-001, 180191-001, 180439-001, 178963-001, 179410-001, 179644-001, 179828-001, 179951-001, 178879-001

• Number of gears in transmission-11

• Forces applied-the forces applied to the gears are either from the main shaft of other gears

• Does material affect process-steel shouldn’t affect the mold casting

• Functional or cosmetic-clearly functional being the basic parts of every transmission

• Complexity-2 because each spur gear comes in a different size so that it alters the amount of torque

b. Main shaft

i. Function-holds the gears into place as well as giving torque to them to move the crankshaft

ii. Material-steel

iii. Manufacturing Process-mold casting

iv. Part number- 62667-001

v. Amount-1

vi. Forces applied-the forces applied to the main shaft are from the gears that are attached to it

vii. Does material affect process-steel shouldn’t affect the mold casting

viii. Functional or cosmetic-clearly functional being one of the basic part of every transmission

ix. Complexity-2 because different parts of the shaft have to have different grooves according to the gear that will be placed in that specific location

c. Bearings (8x)

i. Function-permits constrained relative motion on the shafts of the transmission

ii. Material-steel

iii. Manufacturing Process-mold casting

iv. Part numbers- 241763-001, 241788-001, 242121-001, 242151-001, 242571-001

v. Amount-5

vi. Forces applied-under perfect conditions it wouldn’t move at all but slight friction always occurs

vii. Does material affect process-steel shouldn’t affect the mold casting

viii. Functional or cosmetic-clearly functional being one of the basic part of every transmission

ix. Complexity-3 because not just a simple component, if the friction is off by just a little the entire engine can overheat

d. Washers (9x)

i. Function-used to distribute the load between gears

ii. Material-steel

iii. Manufacturing Process-mold casting

iv. Part numbers- 238086-001, 238156-001, 238309-001, 238376-001, 238415-001, 238446-001, 238479-001, 238499-001, 238548-001

v. Amount-9

vi. Forces applied-only real force is created by the gears pushing on the sides

vii. Does material affect process-steel shouldn’t affect the mold casting

viii. Functional or cosmetic-clearly functional being one of the basic part of every transmission as well as any mechanical device

ix. Complexity-1 because the washer is about as simple as it gets for this transmission, given that they are different radiuses and thicknesses.

Design Revisions

1.) Remove top gear. One can then adjust gearing so that the motorcycle will achieve a faster acceleration. This will also decrease weight, since fewer components will be included in the transmission, and also make it cheaper. This will result in a slight decrease in fuel economy. Since there are fewer moving parts, this also decreases the chance of mechanical failure.

2.) Using a better lubricant will allow the moving parts to be more frictionless. This may increase cost, but it will decrease the frictional force between the parts, making them move smoother and removing lost forces from the engine. Less friction means less heat and general wear and tear, meaning that the life of the transmission lengthens.

3.) Replace the steel parts with newer, lighter alloys of titanium. This may increase the cost but lighten the transmission. This means that less force from the engine will be wasted moving the transmission and will put that power to the wheels. The new alloy will be stronger and decrease the chance of mechanical failure.

Solid Model Assembly

For our solid modeling assembly we chose group member Jonathan Burkhart to create a computer generated image of the Honda engine Transmission. Jonathan was picked to do this part of the assignment due to his prior knowledge of solid modeling. The program that was used is called Rhinoceros 4.0. This program was chosen because Jonathan has used this program before and is most familiar with the techniques needed to make the model. Although the solid model assembly looks comparatively close to the actual transmission, it is not an identical image. The parts that were chosen to be modeled were the clutch, the transmission gears, and the Gearshift drum. These three components are the most essential parts to the transmission assembly and are the most visible parts. Some Parts were also left out of the due to their extreme detail, their lack of significance to the assembly, or they were not a major component of the transmission.

The corresponding images of the solid model assembly are shown below. They consist of various images of the gears, the clutch and a complete breakdown of the transmission.

To view more pictures of the solid modeling, please click this link: http://s1010.photobucket.com/albums/af230/chiefhockey10/?action=view&current=render2.jpg

Engineering Analysis

The group chose to analyze the force exerted on the transmission by a sudden stop after the motorcycle was travelling at a speed of 8m/s. We chose this scenario to analyze because given the assumptions; we were able to easily calculate the force that was exerted on the transmission. The engineering analysis applied in this problem clearly outlines a design process that can be used to perform analysis on the transmission.

a) Problem Statement:

What if the force applied to the transmission when the motorcycle is shifted straight to Park?

b) Assumptions:

• The motorcycle stops instantaneously

• The motorcycle stops instantaneously

• Neglect friction

• Stiff suspension to prevent rotation of wheel after stopping

• Radius of wheel: R= 0.33m

• Velocity before stopping: V= 8m/s

• Weight of motorcycle: m= 200kg

• 50-50 weight distribution on the wheels

c) Governing Equations:

Centripetal force: F=1/2 mAc

Centripetal acceleration: Ac=V^2/R

Centripetal force on one wheel: F=1/2 m V²/R

d) Calculations:

F= 1/2(100kg)((8m/s)²)/0.33m

F=9696.97 kN

e) Solution Check:

My answer of 19384 N is reasonable because I assumed that the velocity of the motorcycle was 8m/s. Carrying out the calculations with a 50-50 mass distribution on both wheels, after abruptly stopping the motorcycle would result in an enormous centripetal force on the wheel. The unit on my answer; Newton is a force unit is correct and it is generated by multiplying the mass of the motorcycle in kilograms by the velocity of the motorcycle given in meters²/seconds² and dividing my meters to obtain a unit of force.

The unit analysis is carried out below:

kgm/s² = N = kgm/s²

f) Discussion:

We are only analyzing the back wheel because it is the only one that produces torque for the motorcycle to move forward. This allowed us to calculate the centripetal force generated by the wheel. This force is then transferred to the transmission and results in the breakage of gears as analyzed in this problem. We assumed there was a 50-50 weight distribution of the motorcycle on each wheel. This means that with the assumed 200kg of the motorcycle, each wheel had a mass of 100kg. I assumed that the motorcycle stops instantly which allows me to not have to calculate the frictional force that exists not just between the wheel and the surface, but also between the wheel and the chain system and the chain and transmission system. We picked a radius and velocity that would be reasonable with the radius and velocity of the motorcycle at some arbitrary time. Another assumption we made was that the wheel-chain-transmission system is lubricated very well and so therefore there is no heat generated by the grinding of the gears and chain. This allowed us to calculate only the force generated by the stopping of the wheel.

Group 19: Gate 4

Product Reassembly

This is the final review of the product before the submission of the project. By now, we have finished the reassembly of our product and restored it to the condition as it was received. Like our previous gates, we focused on the transmission of the engine as the primary component of our reassembly. This involved the process of putting together the clutch, the gear-shift drum, the starting motor and various gears that make up the transmission. Once the transmission was secured, we had to wait for Group 31 to finish their part of the reassembly which included various internal components of the engine such as spark plugs, the crankshaft, the alternator and generator as well as the carburetor. After this step, we continued with the remainder of the reassembly process by putting the covers on the clutch, the carburetor and the alternator. We also reattached the camshafts, the cylinder head covers, the starting motor and the air cleaner.

A major challenge that halted our progress towards completing the reassembly process on time was the academic scheduling of our group members and Group 31’s members. Also, the office hours were not able to compensate for our busy schedules which made it very difficult to reassemble the engine on time. To resolve this problem, we communicated with Professor Devendorf and explained our situation. By giving us an extension on the reassembly process, we were able to complete the product reassembly in one sitting and prepare our notes for Gate 4.

Our product reassembly process is listed in the following table, Table 1: Product Reassembly, accompanied by the tools used for each step. We have created a new difficulty scale for the reassembly process as our previous one was tough to understand.

The difficulty scale ranges from 1 to 5. “One” represents a component that was effortless to reassemble and “Five” represents a component that was more challenging to reassemble due to the number of parts and location of the component.

Table 1: Product Reassembly

For an easier visual of each reassembly process, Table 2: Step-Picture-Part is available on the following page to further explain and help visualize the processes of Table 1: Product Reassembly.

Table 2: Step-Picture-Part

STEP	PICTURE	PART
1		Cam Chain and cam chain tensioner
2		Alternator cap
3		Starter motor
4		Clutch Cover
5		Crankcase cover
6		Cylinder head cover
7		Air cleaner housing
8		Carburetor cap
9		Air cleaner cover
10		Water pump
11		Back casing

Reassembly vs. Dissection

We did not completely reassemble the engine by ourselves. The engine was assigned to us with Group 31. We faced many scheduling conflicts during dissection as well as during reassembly. We were not able to work with Group 31 on dissection or reassembly at all during the course of the project, therefore, communication was always carried out by e-mail. This made it much more difficult to meet the deadlines on time, as stated in the introductory paragraph of this document.

The reassembly was different than the dissection in regards to the difficulty of the processes. Reassembling the engine and the transmission was much easier than taking it apart because we took great dissection notes to help us with the reassembly. We also referenced many of the dissection pictures we took to help recognize various parts and their locations when putting them back together. The most laborious part of the reassembly process was putting the correct part on first. The engine is not meant to be put together by untrained hands and therefore many parts are extremely difficult to fit in their proper positions without first putting together the correct part that should already be in that location. This elongated our reassembly process but by referencing our dissection notes and pictures, we were able to meet our extended deadline.

Functionality

Our product was a 1994 Honda 599CC engine. We decided to focus on understanding and breaking down the transmission. After the dissection, we were able to see that the transmission on our engine functioned very well. We have embedded a video of the transmission on our wiki page as well as an explanation of how the gearshift drum forks shift the gears as the rider steps on the shift lever. We were able to understand exactly what kind of gear would be reached depending on how the rider steps on the shift lever. This shifting mechanism is explained in the video.

Even though the transmission was fully functional on its own, the engine was far from it. A lot of the electrical equipment such as the alternator, the battery and the starter motor could not be tested. The exhaust, fuel and air systems were also not functioning. The functionality of our engine is very limited unless it is attached to the proper bike and all of the electrical components are connected in their proper places.

To see how our transmission works, click this link: http://www.youtube.com/watch?v=QTXUX-DPgsY

Recommendations

1) Removing the top gear allows an adjustment to the gearing so that the motorcycle will achieve a faster acceleration. This will also decrease the weight of the transmission, since fewer components will be used. It will make manufacturing cheaper; however this will result in a slight decrease in fuel economy. Since there are fewer moving parts the chance of mechanical failure seems less likely of a hazard.

2) Using a better lubricant will allow the moving parts to be more frictionless. This may increase the cost, but it will decrease the frictional force between the parts, making them move smoother and removing lost forces from the engine. Less friction means less heat and general wear and tear, meaning that the life of the transmission lengthens.

3) Replacing the steel parts with newer, lighter alloys of titanium will greatly lighten the transmission. This means that less force from the engine will be wasted moving the transmission and that extra energy will be put to power the wheels. The new alloy will be stronger and decrease the chance of mechanical failure. However, the alloys will increase the overall cost of the engine and its various components. It will also take much longer to manufacture the parts composed of the new alloys.

4) A universal screw head would make the dissection and the reassembly process much easier. This would eliminate the need for the 5 torx screws that are currently on the engine. Manufacturing a universal screw head would be cheaper in the long run because it would eliminate the need to manufacture various tools used for the dissection and reassembly.