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| | == Introduction == | | == Introduction == |
| − | A requirement for MAE277, taught by Erich Devendorf, the Reverse Engineering Project is designed to help students familiarize themselves with the assembly of a product. Over the course of the semester, the students will work on five gates which will showcase the ongoing analysis of their products. This project will reinforce key skills that engineers utilize everyday.
| + | MAE277 is a requirement for Aerospace and Mechanical Engineering at the University at Buffalo, taught by Erich Devendorf. The main purpose of this course is to familiarize students with design processes and methods. The Reverse Engineering Project is a prime example of what they should learn from the class. Throughout the project, students will learn how products are assembled by disassembling a specific product and analyzing its components. Over the length of the semester, students will work on five gates which will showcase the ongoing analysis of their products and test their knowledge of their products’ designs. It will reinforce key skills that engineers utilize daily. |
| | | | |
| − | Groups 25 and 26 were assigned a pressure washer. Rather than share entire product between two groups, the product was divided into two, with group 25 analyzing the compressor and with group 26 analyzing the engine. | + | Groups 25 and 26 were assigned a pressure washer. Rather than share the entire product between two groups, the product was divided into two. Group 25 is analyzing the compressor while group 26 analyzes the engine. |
| | + | |
| | + | == Executive Summary == |
| | + | |
| | + | For our dissection Group 26, in conjunction with group 25 received a power washer. Group 26 dissected the engine and |
| | + | this dissection and analysis is detailed in this wiki page. |
| | + | |
| | + | Gate 1: Request for Proposal. This gate consists of the work proposal, in which we plan out our analysis, the |
| | + | management proposal, in which we lay out the management of our group, and the initial product assessment, where we |
| | + | analyze our product before dissecting it. |
| | + | |
| | + | Gate 2: Preliminary Design Review. For this gate, the product was disassembled. For this portion of the project, we had causes for |
| | + | corrective action, where we assess our work and management plans. We also provide a product dissection plan which |
| | + | consists of step by step instructions on how the engine was disassembled. |
| | + | |
| | + | Gate 3: Coordination Review. In the component summary, we list all of the components of the engine including |
| | + | their functions, compositions, and manufacturing. We provide three Design Revisions which we believe would |
| | + | improve the product as well. A solid model of a section of the engine is included, in addition to an analysis of a specific |
| | + | section. |
| | + | |
| | + | Gate 4: Product Reassembly Plan. In this gate we describe the reassembly of our engine. |
| | + | |
| | + | Gate 5: Delivery. For this gate this wiki page was completed as well as a compliance matrix. Our group also |
| | + | presented our dissection and analysis to the rest of the class. |
| | + | |
| | + | We were successful in disassembling and reassembling our engine as well as analyzing it with only minor issues. The details of our work can be found below. |
| | | | |
| | == Gate 1: Request for Proposal == | | == Gate 1: Request for Proposal == |
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| | [[Product Dissection Plan for Group 26|Product Dissection Plan]]<br> | | [[Product Dissection Plan for Group 26|Product Dissection Plan]]<br> |
| | | | |
| − | ==Gate 3== | + | ==Gate 3: Coordination Review== |
| − | ===Component Summary===
| + | [[Component Summary for Group 26|Component Summary]]<br> |
| − | '''8mm Bolts (x11)'''
| + | [[Design Revisions for Group 26|Design Revisions]]<br> |
| − | :Function: Hold things together and prevent bigger parts from sliding or moving.
| + | [[Solid Modeled Assembly for Group 26|Solid Modeled Assembly]]<br> |
| − | :Material: Brass Plated Steel
| + | [[Engineering Analysis for Group 26|Engineering Analysis]]<br> |
| − | :Manufacturing Process: Heading, Thread Rolling, and Blackening or Galvanization
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because it is not very appealing to the eye. It is brass plated but this is to prevent corrosion, not to make it look any better. The true purpose is to hold everything tight.
| + | |
| − | | + | |
| − | '''10mm Bolts (x10)'''
| + | |
| − | :Function: Hold things together and prevent bigger parts from sliding or moving.
| + | |
| − | :Material: Brass Plated Steel
| + | |
| − | :Manufacturing Process: Heading, Thread Rolling, and Blackening or Galvanization
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because it is not very appealing to the eye. It is brass plated but this is to prevent corrosion, not to make it look any better. The true purpose is to hold everything tight.
| + | |
| − | | + | |
| − | '''10mm Nuts (x4)'''
| + | |
| − | :Function: Hold things together and prevent bigger parts from sliding or moving.
| + | |
| − | :Material: Brass Plated Steel
| + | |
| − | :Manufacturing Process: Upsetting, Heading, and Extrusion
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because it is not very appealing to the eye. It is brass plated but this is to prevent corrosion, not to make it look any better. The true purpose is to hold everything tight.
| + | |
| − | | + | |
| − | '''12mm Bolts (x4)'''
| + | |
| − | :Function: Hold things together and prevent bigger parts from sliding or moving.
| + | |
| − | :Material: Brass Plated Steel
| + | |
| − | :Manufacturing Process: Heading, Thread Rolling, and Blackening or Galvanization
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because it is not very appealing to the eye. It is brass plated but this is to prevent corrosion, not to make it look any better. The true purpose is to hold everything tight.
| + | |
| − | | + | |
| − | '''13mm Nuts (x2)'''
| + | |
| − | :Function: Hold things together and prevent bigger parts from sliding or moving.
| + | |
| − | :Material: Brass Plated Steel
| + | |
| − | :Manufacturing Process: Upsetting, Heading, and Extrusion
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because it is not very appealing to the eye. It is brass plated but this is to prevent corrosion, not to make it look any better. The true purpose is to hold everything tight.
| + | |
| − | | + | |
| − | '''22mm Nut (x1)'''
| + | |
| − | :Function: Hold things together and prevent bigger parts from sliding or moving.
| + | |
| − | :Material: Brass Plated Steel
| + | |
| − | :Manufacturing Process: Upsetting, Heading, and Extrusion
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because it is not very appealing to the eye. It is brass plated but this is to prevent corrosion, not to make it look any better. The true purpose is to hold everything tight.
| + | |
| − | | + | |
| − | '''Rubber Hoses (x2)'''
| + | |
| − | :Function: Carry gas to engine without leaking, and carry oil to carburetor without leaking.
| + | |
| − | :Material: Rubber
| + | |
| − | :Manufacturing Process: Die cutting and Extrusion
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because it is just a rubber hose and it is not glossy or painted any other color.
| + | |
| − | | + | |
| − | '''Pressure Spring Clamps (x2)'''
| + | |
| − | :Function: Hold hoses onto the inserts in the engine and gas tank.
| + | |
| − | :Material: Steel
| + | |
| − | :Manufacturing Process: Rolling, Stamping/Forming, Hardening and Tempering, and Surface Coating
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because it is just a steel clamp meant to keep the hose attached so there are no leaks. It is not shiny or bright so it is not cosmetic.
| + | |
| − | | + | |
| − | '''Spark Plug (x1)'''
| + | |
| − | :Function: To provide an electric spark that is hot enough to ignite the air/fuel mixture inside the combustion chamber which is done when a high voltage current arcs across a gap on the spark plug.
| + | |
| − | :Material: Ceramic, Nickel Alloy, and Steel
| + | |
| − | :Manufacturing Process: Extrusion, Machining, Welding, Surface Coating, Casting, and Machine Trimmed
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because it is just an ordinary spark plug to make sure the engine starts without any problems. It is not decorated or made to look good.
| + | |
| − | | + | |
| − | '''Metal Guard (Flywheel)'''
| + | |
| − | :Function: Guard the flywheel from debris
| + | |
| − | :Material: Aluminum
| + | |
| − | :Manufacturing Process: Casting
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? It is a combination of the two, it is functional because it protects the fly wheel while it also looks good.
| + | |
| − | | + | |
| − | '''Springs'''
| + | |
| − | :Function: To signal the release of gas for more power when power washer handle is squeezed.
| + | |
| − | :Material: Steel
| + | |
| − | :Manufacturing Process: Rolling, Stamping/Forming, Hardening and Tempering, and Surface Coating
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because it is just doing its job and is not painted or shiny.
| + | |
| − | | + | |
| − | '''Flywheel Shield'''
| + | |
| − | :Function: Protect the Flywheel
| + | |
| − | :Material: Steel
| + | |
| − | :Manufacturing Process: Stamping/Forming, Hardening and Tempering
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional and cosmetic because this part is visible during normal use of the pressure washer. It is painted black and has a glossy finish but it also does its job of keeping dirt out of the flywheel and letting air in to cool down the engine.
| + | |
| − | | + | |
| − | '''Carburetor'''
| + | |
| − | :Function: Blends air and fuel for the engine.
| + | |
| − | :Material: Iron, Brass, Rubber, and Plastic
| + | |
| − | :Manufacturing Process: Casting
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional and cosmetic because this part is visible during normal use of the pressure washer. It is painted black and has a glossy finish but it also does its’ job of blending air and fuel for the engine.
| + | |
| − | | + | |
| − | '''Engine Block'''
| + | |
| − | :Function: To hold all the components of an engine secure and to hold the fluid inside without allowing dirt or impurities inside.
| + | |
| − | :Material: Aluminum Alloy
| + | |
| − | :Manufacturing Process: Casting
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional and cosmetic because this part is semi-visible during normal use of the pressure washer. It is not painted but has a nice smooth finish which makes it look nice. It is functional because it also does its’ job of holding the components of the engine secure and holding in the oil without letting dirt inside.
| + | |
| − | | + | |
| − | '''10mm Studded Bolts (x2)'''
| + | |
| − | :Function: Hold things together and prevent bigger parts from sliding or moving.
| + | |
| − | :Material: Steel
| + | |
| − | :Manufacturing Process: Heading, Thread Rolling, and Glackening or Galvanization
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because this part is not visible during normal use of the pressure washer. The bolts are just normal steel and do the job of keeping the bigger parts from moving or sliding.
| + | |
| − | | + | |
| − | '''Gaskets (x6)'''
| + | |
| − | :Function: Make an air tight seal between the two components so oil or air do not leak out.
| + | |
| − | :Material: Rubber
| + | |
| − | :Manufacturing Process: Casting
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because this part is not visible during normal use of the pressure washer. The gaskets just create an airtight seal for connecting parts of the engine so there are no leaks.
| + | |
| − | | + | |
| − | '''Exhaust'''
| + | |
| − | :Function: Removes the exhaust fumes from the engine block out of the engine.
| + | |
| − | :Material: Steel
| + | |
| − | :Manufacturing Process: Casting
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional and cosmetic because this part is visible during normal use of the pressure washer. It is painted black and has a glossy finish but it also does its job of releasing fumes produced by the engine but keeps the fumes less toxic and the sound is quieter.
| + | |
| − | | + | |
| − | '''Valve Cover'''
| + | |
| − | :Function: Protect the intake and exhaust valves from outside air, dust, weather, and anything else that could harm the engine.
| + | |
| − | :Material: Aluminum Alloy
| + | |
| − | :Manufacturing Process: Casting
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional and cosmetic because this part is semi-visible during normal use of the pressure washer. Like the engine block it has a smooth finish but it also does its job of keeping dirt out of the intake and exhaust valves.
| + | |
| − | | + | |
| − | '''Engine Cover'''
| + | |
| − | :Function: Protect the gears the camshaft the crankshaft and the piston from dirt and keep the oil in the engine.
| + | |
| − | :Material: Aluminum Alloy
| + | |
| − | :Manufacturing Process: Casting
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional and cosmetic because this part is semi-visible during normal use of the pressure washer. Like the engine block it has a smooth finish but it also does its job of protecting the camshaft, crankshaft and the piston from dirt and it keeps the oil in the engine.
| + | |
| − | | + | |
| − | '''Rocker Arms (x2)'''
| + | |
| − | :Function: When the pushrod is pushed up from the lifters the rocker arm compresses the spring and opens the valve.
| + | |
| − | :Material: Steel
| + | |
| − | :Manufacturing Process: Forging
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because this part is not visible during normal use of the pressure washer. It is just normal steel and does the job of opening valves when acted upon by the pushrod.
| + | |
| − | | + | |
| − | '''Valve Springs (x2)'''
| + | |
| − | :Function: Keeps valves closed unless pushrod applies force and the rocker arm compresses the spring to open a valve.
| + | |
| − | :Material: Steel
| + | |
| − | :Manufacturing Process: Rolling, Stamping/Forming, Hardening, Tempering, and Surface Coating
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because this part is not visible during normal use of the pressure washer. The springs just do their job of opening the valve when acted upon by the rocker arm.
| + | |
| − | | + | |
| − | '''Pushrods (x2)'''
| + | |
| − | :Function: They open and close the valves by pushing the rocker arms and compressing the springs.
| + | |
| − | :Material: Steel
| + | |
| − | :Manufacturing Process: Hardening and Welding
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because this part is not visible during normal use of the pressure washer. They are just plain steel and do the job of pushing the rocker arm when acted upon by the lifters.
| + | |
| − | | + | |
| − | '''Valves (x2)'''
| + | |
| − | :Function: They let the air and fuel mixture in and out of the cylinder head.
| + | |
| − | :Material: Titanium Alloy
| + | |
| − | :Manufacturing Process: Upset Forging
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because this part is not visible during normal use of the pressure washer. The valves just allow the air and fuel mixture in and out of the cylinder head.
| + | |
| − | | + | |
| − | '''Camshaft'''
| + | |
| − | :Function: Controls the lifters which push the pushrods which will eventually open and close the valves.
| + | |
| − | :Material: Chilled Iron
| + | |
| − | :Manufacturing Process: Roll-forging, Casting and Grinding
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because this part is not visible during normal use of the pressure washer. The camshaft just does the job of moving the lifters to eventually allow the valves to open and close.
| + | |
| − | | + | |
| − | '''Flywheel'''
| + | |
| − | :Function: Stores up rotational energy during the combustions to keep a fairly constant rotational velocity to keep the crankshaft moving at a constant speed. This allows the engine to run smoothly and not rock.
| + | |
| − | :Material: Steel
| + | |
| − | :Manufacturing Process: Forged
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because this part is not visible during normal use of the pressure washer. The flywheel is just steel that does the job of storing rotational energy and allowing the engine to run smoothly.
| + | |
| − | | + | |
| − | '''Lifters (x2)'''
| + | |
| − | :Function: When pushed by the camshaft it will push the pushrod which will eventually open a valve.
| + | |
| − | :Material: Titanium Alloy
| + | |
| − | :Manufacturing Process: Upset Forging
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because this part is not visible during normal use of the pressure washer. The lifters look a lot like the valves and there only purpose is to push the pushrod when acted upon by the camshaft.
| + | |
| − | | + | |
| − | '''Piston'''
| + | |
| − | :Function: To expand and combust air and fuel mixtures and transfer the force produced to the crankshaft.
| + | |
| − | :Material: Aluminum Alloy
| + | |
| − | :Manufacturing Process: Casting, Boring, Turning, Grinding, and Reaming
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because this part is not visible during normal use of the pressure washer. The piston just does the job of transferring force produced to the crankshaft.
| + | |
| − | | + | |
| − | '''Piston Rings'''
| + | |
| − | :Function: Provide an airtight seal for the combustion/expansion chamber. It allows for heat transfer from the piston to the cylinder wall. They also regulate the amount of engine oil consumed.
| + | |
| − | :Material: Cast Iron and Steel
| + | |
| − | :Manufacturing Process: Casting
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because this part is not visible during normal use of the pressure washer. Piston rings just provide an airtight seal for the combustion/expansion chamber, allows for heat transfer from the piston to the cylinder wall, and regulates the amount of engine oil consumed.
| + | |
| − | | + | |
| − | '''Crankshaft'''
| + | |
| − | :Function: It transfers linear energy from the piston explosions to rotational energy.
| + | |
| − | :Material: Steel
| + | |
| − | :Manufacturing Process: Roll-forging, Casting, and Hardening
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because this part is not visible during normal use of the pressure washer. The crankshaft just transfers linear energy from the piston explosion to rotational energy.
| + | |
| − | | + | |
| − | '''Flywheel Fan'''
| + | |
| − | :Function: Produces a cooling airflow to keep engine from overheating.
| + | |
| − | :Material: Plastic
| + | |
| − | :Manufacturing Process: Injection Molding
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because this part is not visible during normal use of the pressure washer. The flywheel fan is black plastic but it doesn’t make it look good and it just does the job of cooling down the engine.
| + | |
| − | | + | |
| − | '''Ball Bearings'''
| + | |
| − | :Function: Circular motion with the least amount of friction
| + | |
| − | :Material: Aluminum
| + | |
| − | :Manufacturing Process: Molding
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because it reduces the friction in the rotational movement so it can move more smoothly.
| + | |
| − | | + | |
| − | '''Connecting Rod'''
| + | |
| − | :Function: To connect the piston to the crankshaft. This allows the transfer of energy from the piston to the crankshaft.
| + | |
| − | :Material: Aluminum
| + | |
| − | :Manufacturing Process: Forging
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional because this part is not visible during normal use of the pressure washer. The connecting rod is just plain aluminum which does the job of connecting the piston to the crankshaft and allowing the transfer of energy from the piston to the crankshaft.
| + | |
| − | | + | |
| − | '''Cylinder Head'''
| + | |
| − | :Function: To keep dirt out of cylinder bore to prevent scratched in the cylinder bore. The head is also there to separate the valves from the piston and form an expansion combustion chamber.
| + | |
| − | :Material: Aluminum Alloy
| + | |
| − | :Manufacturing Process: Casting
| + | |
| − | :Is the component functional, cosmetic, or a combination of the two? The component is functional and cosmetic because this part is semi-visible during normal use of the pressure washer. Like the engine block it has a smooth finish and does the job of keeping dirt out of the cylinder bore while separating the valves from the piston and creating an expansion/combustion chamber.
| + | |
| − | | + | |
| − | '''What forces are applied to the components?'''
| + | |
| − | :Centripetal forces are applied to the crank shaft, flywheel, and cam shaft. Linear forces on piston, connecting rod, lifters, push rods, rockers, valves, springs, and piston rings. Shear forces are applied to the engine block.
| + | |
| − | | + | |
| − | '''Does the material choice affect the manufacturing process?'''
| + | |
| − | :Yes different types of materials may not be able to be manufactured like others. For instance die casting aluminum is normal but not for iron. Certain metals are more ductile then other which allows them to be manufactured differently. Some have higher than average melting points, this makes it very difficult to melt and mold or cast. Injection molding is made for plastics because it cannot be done with metals. Each process has pros and cons for each metal and sometimes a con is that it cannot be done. Sometimes a process can be done on certain materials but the end result is undesired because it might make the product weaker. This can sometimes be a good thing if it doesn’t need to be as strong and it is cheaper.
| + | |
| − | | + | |
| − | '''Why were different materials selected for different components?'''
| + | |
| − | :Different materials were selected for different components for many reasons. Some reasons would include that the shape desired could only be done by certain processes and those processes could only be done with certain materials. Another reason would be the cost efficiency, if strength was not needed in a certain area than a weaker metal could be used for less money. Another possible reason could be that a certain material was needed to perform a task such as conducting electricity like nickel alloy.
| + | |
| − | | + | |
| − | '''Does the material choice affect the manufacturing process?'''
| + | |
| − | :Yes it does. Every material has its different properties. Some are harder then others and require a different way to manufacture. Some you can mold very easily others you have to forge.
| + | |
| − | | + | |
| − | '''Does the shape affect the manufacturing process?'''
| + | |
| − | :Yes the shape does affect the manufacturing process, the more complex the shape the longer and more difficult it will be to make.
| + | |
| − | | + | |
| − | '''Why was each manufacturing process chosen for the component, and how complex is the component?'''
| + | |
| − | '''8mm Bolts:''' are manufactured by galvanization to make them stronger and less likely to rust and fail.
| + | |
| − | :Complexity: not complex at all a simple cylindrical design with threads
| + | |
| − | | + | |
| − | '''10mm Bolts:''' are manufactured by galvanization to make them stronger and less likely to rust and fail.
| + | |
| − | :Complexity: not complex at all a simple cylindrical design with threads
| + | |
| − | | + | |
| − | '''12mm Bolts:''' are manufactured by galvanization to make them stronger and less likely to rust and fail.
| + | |
| − | :Complexity: not complex at all a simple cylindrical design with threads
| + | |
| − | | + | |
| − | '''10mm Nuts:''' heading is used for the nuts to make them stronger so they don’t fail.
| + | |
| − | :Complexity: not complex at all a simple hexagonal design with threads.
| + | |
| − | | + | |
| − | '''13mm Nuts:''' heading is used for the nuts to make them stronger so they don’t fail.
| + | |
| − | :Complexity: not complex at all a simple hexagonal design with threads.
| + | |
| − | | + | |
| − | '''22mm Nuts:''' heading is used for the nuts to make them stronger so they don’t fail.
| + | |
| − | :Complexity: not complex at all a simple hexagonal design with threads.
| + | |
| − | | + | |
| − | '''Rubber Hoses:''' extrusion is used to create the rubber hoses because it is easier to make tubular shapes with heading and it makes it a lot easier to form hoses.
| + | |
| − | :Complexity: not complex at all a simple tubular design made of rubber.
| + | |
| − | | + | |
| − | '''Spring Clamps:''' Rolling increases the tensile strength while giving it a cylindrical shape. Hardening, tempering, and surface coating all make it so the clamps are stronger and won’t rust.
| + | |
| − | :Complexity: not complex at all a simple piece of metal that is bent to hold down the rubber hosing.
| + | |
| − | | + | |
| − | '''Spark Plug:''' the part is machined then welded because its impossible to create the part in one piece. So they machine 2 parts then weld them together and put a protective coating on the surface of it to make it stronger.
| + | |
| − | :Complexity: It is a pretty complex design that uses many components to creates a small spark that ignites the fumes inside the cylinder to start the cycle.
| + | |
| − | | + | |
| − | '''Springs:''' Rolling increases the tensile strength while giving it a cylindrical shape. Hardening, tempering, and surface coating all make it so the clamps are stronger and won’t rust.
| + | |
| − | :Complexity: not complex at all a simple spring design that has been used for many years.
| + | |
| − | | + | |
| − | '''Flywheel Shield:''' Hardening, tempering, and surface coating all make it so the clamps are stronger and won’t rust.
| + | |
| − | :Complexity: not complex at all a simple design that is made out of metal shaped to cover the flywheel.
| + | |
| − | | + | |
| − | '''Carburetor:''' is casted out of one part because it’s a larger part then can be made out of one large piece of metal.
| + | |
| − | :Complexity: a very complex component that creates the perfect mixture of air and gas and delivers it into the engine.
| + | |
| − | | + | |
| − | '''Engine Block:''' is casted because it is a large part with a rather simple design.
| + | |
| − | :Complexity: the engine block itself is not a very complex design by itself but all the components working together inside it creates a complex system.
| + | |
| − | | + | |
| − | '''Exhaust:''' is casted because it is a large part with a rather simple design.
| + | |
| − | :Complexity: not complex at all a simple tubular design that removes the fumes from the cylinder out of the engine so the cycle and continue..
| + | |
| − | | + | |
| − | '''Valve Cover:''' is casted because it is a large part with a rather simple design.
| + | |
| − | :Complexity: not complex at all it is only a metal cover that goes over the valves.
| + | |
| − | | + | |
| − | '''Engine Cover:''' is casted because it is a large part with a rather simple design.
| + | |
| − | :Complexity: not complex at all it is only a metal cover that goes over the engine.
| + | |
| − | | + | |
| − | '''Rockers:''' They are forged because the rocker undergoes a lot of stress inside the engine and the forging process increases the strength of the metal that the rocker is made out of.
| + | |
| − | :Complexity: not complex at all it simple metal design that attaches to the cylinder heads.
| + | |
| − | | + | |
| − | '''Metal Guard (Flywheel):''' because it is a very simple part and the easiest way to manufacture it is through casting.
| + | |
| − | :Complexity: not complex at all its piece of metal shaped to cover the flywheel.
| + | |
| − | | + | |
| − | '''Valve Spring:''' Rolling increases the tensile strength while giving it a cylindrical shape. Hardening, tempering, and surface coating all make it so the clamps are stronger and won’t rust.
| + | |
| − | :Complexity: not complex at all, simple spring design that has been used for many years
| + | |
| − | | + | |
| − | '''Pushrods:''' the hardening makes the metal stronger and the welding is because it’s impossible for the component to be made in one piece so two pieces are created then welded together.
| + | |
| − | :Complexity: not complex at all, simple design of a long thin rod.
| + | |
| − | | + | |
| − | '''Valve:''' the valve goes through tremendous amounts of strain that require it to be really strong. Forging increases the strength of the metal.
| + | |
| − | :Complexity: not complex at all, simple design of a thin rod with a conical shape at the bottom of it.
| + | |
| − | | + | |
| − | '''Camshaft:''' the camshaft is forged for strength then grinded and casted to create the angle notches.
| + | |
| − | :Complexity: a very complex rod that has angled notches on it that have to hit the lifters at a certain time to time the cycle.
| + | |
| − | | + | |
| − | '''Flywheel:''' the flywheel is forged for extra strength.
| + | |
| − | :Complexity: not complex at all it simple circular design.
| + | |
| − | | + | |
| − | '''Lifters:''' the lifters are forged for extra strength.
| + | |
| − | :Complexity: not complex at all it simple metal design that is a similar to the valve design but flat.
| + | |
| − | | + | |
| − | '''Piston:''' The pistons are casted because it is a rather simplistic shape and it’s easier to create the shape using casting. It is also bored and grinded to get the final shape of the piston.
| + | |
| − | :Complexity: not complex at all it simple design that is a cylindrical shape.
| + | |
| − | | + | |
| − | '''Piston Ring:''' is casted because it is a very simplistic part that doesn’t require great amounts of strength.
| + | |
| − | :Complexity: not complex at all it simple circular design.
| + | |
| − | | + | |
| − | '''Crankshaft:''' is forged for strength and casted for the simpler parts of it. It is then hardened to make it stronger.
| + | |
| − | :Complexity: very complex rod that has gears and notches in it for the connecting rod to screw in.
| + | |
| − | | + | |
| − | '''Flywheel Fan:''' is injected molded because it is made out of hard plastic. It is the easiest way to create a simple design out of plastic
| + | |
| − | :Complexity: very simple plastic design of a circular fan.
| + | |
| − | | + | |
| − | '''Ball Bearings:''' are molded because it is a very simple design and many of them have to made, so it is also the quickest way to manufacture them.
| + | |
| − | :Complexity: simple spherical design.
| + | |
| − | | + | |
| − | '''Connecting Rod:''' is forged because of the amount of stress it undergoes it needs an excess amount of strength to withstand those stresses.
| + | |
| − | :Complexity: simple arm shape that connects to the piston.
| + | |
| − | | + | |
| − | '''Cylinder Head:''' is casted because it is a rather simple part and it is easier to manufacture that way.
| + | |
| − | :Complexity: very complex component that has notches and holes in it for the valves rods and springs.
| + | |
| − | | + | |
| − | '''Do any components have a particular shape? Why?'''
| + | |
| − | :There are many shapes that have a particular shape, for example the pistons. They have to be the same circular shape of the cylinder walls. The exhaust has to match the holes of the exhaust manifold for the exhaust to be vented out properly.
| + | |
| − | | + | |
| − | ===Design Revisions===
| + | |
| − | *A design revision that could prove to be useful is adding an electrical starter. A pull starter demands much more physical activity out of its users that could lead to fatigue and muscle strain. Users that are not physically fit may not be able to start the motor at all. The amount of activity needed is also dependent on the conditions of the motor - the less maintained the motor is, the more effort is needed to start the engine. The temperature of the unit is also a factor - the colder it is, the longer it will take to for the engine to start. The electrical starter would allow users to start the engine without much hassle, and keeping the pull starter on the engine would give users an additional way to start it in case the electrical starter fails.
| + | |
| − | | + | |
| − | :Using this revision would increase the cost of the pressure washer; it would, however, improve the usability of the product.
| + | |
| − | | + | |
| − | *Another design revision that would be useful is encasing the the engine in a hard plastic similar to a car engine. Since the pressure washer deals primarily with water and chemicals, rust is constantly a problem. Encasing the engine in plastic would prevent water from entering the engine, prolonging the life of the product.
| + | |
| − | | + | |
| − | :Using this revision would increase the cost of the pressure washer slightly; since it would prevent rust from forming in the engine, its reliability would improve and its maintenance would decrease.
| + | |
| − | | + | |
| − | *A third revision that would be beneficial to its users would be a self-propulsion system. The product is heavy, making it unwieldy for many to move around efficiently. Using a self-propulsion system would allow users to move the washer easily and effortlessly.
| + | |
| − | | + | |
| − | :Using this revision would increase the cost of the product; its usability would increase greatly, as would its functionality.
| + | |
| − | | + | |
| − | ===Solid Modeled Assembly===
| + | |
| − | :For our modeling we chose the main components of the intake/outlet valves which includes the valve itself (A), a spring (B), a push rod (C), a threaded rod (D), a connecting plate (E), an a pair of plates to secure the spring (F). We chose these components because, as a subsystem, they show quite well how a few relatively minor and simple pieces can perform a vital function well.
| + | |
| − | | + | |
| − | :The CAD package we used was Autodesk Inventor. Inventor is a powerful and fairly easy to understand package, with the added benefit of having a full version trial available for students.
| + | |
| − | | + | |
| − | [[Image:Valve_1.PNG|thumb|center|200x200px|Top View of Valve]] [[Image:Valve_2.PNG|thumb|center|200x200px|Front View of Valve]] [[Image:Valve_3.PNG|thumb|center|200x200px|Side View of Valve]]
| + | |
| − | | + | |
| − | ===Engineering Analysis===
| + | |
| − | :During the analysis of the engine the many parts made it difficult to choose which to use. After the analysis problem, the key component of the engine that would require a lot of analysis is the Piston and Cylinder of the engine. There are many important parts that require discussion about the chosen design and testing that would need to be done to make this part work efficiently.
| + | |
| − | | + | |
| − | :As an engine runs the piston moves up and down the cylinder constantly driving the camshaft and converting chemical energy into usable mechanical energy. As the gas expands in the chamber a large amount of pressure is exerted onto the piston forcing it down. Despite this large pressure none of the gas leaks around the sides of the piston thanks to the piston rings. Because of the sizable force pushing the piston down the piston rings must fit tightly against the sides of the cylinder. This tight fit causes friction along the sides of the cylinder. This is a place where some of the largest energy loss occurs.
| + | |
| − | | + | |
| − | :The equation for friction ( Ff=μ*Fn ) shows that the force of the piston pushing into the wall (Fn) greatly affects the amount of friction. One way to test Fn is to measure the force needed to pull the piston out of the cylinder. Once you find the force of movement using the equation F=ma it is possible to solve and find Ff (friction force). After this data tables readily supply the coefficient of friction (μ) and it is simple to solve for Fn. As can be seen a large amount of force can be lost from the system due to friction.
| + | |
| − | | + | |
| − | :Two ways in which to decrease the Ff are usually the easiest to pursue. The most obvious is to decrease the coefficient of friction by changing the material or adding oil into the system. The other way to decrease Ff is to change the Fn which can be done by decreasing the pressure of the piston rings.
| + | |
| − | | + | |
| − | :The point of these tests is to bring the efficiency of the engine closer to that of a perfect engine that does not lose energy due to friction.
| + | |
| − | | + | |
| − | == Gate 4: Product Reassembly Plan ==
| + | |
| − | | + | |
| − | After re-assembly the engine continues to move with hand cranking as it did when we received it. The only difference being a lack of oil which was removed and disposed of during dis-assembly. Getting the product into a working state should be as simple as adding new oil into it.
| + | |
| − | | + | |
| | | | |
| − | One design change which would increase the life of the pressure washer would be to have any exposed metals either covered with plastic shielding, or coated with a highly durable paint. This would reduce rusting and other damage to the engine and washer in general, extending its operational lifetime.
| + | == Gate 4: Critical Project Review == |
| | + | [[Product Reassembly Plan for Group 26|Product Reassembly Plan]]<br> |
| | + | ==Gate 5: Delivery == |
| | + | [[References for Group 26|References]]<br> |
MAE277 is a requirement for Aerospace and Mechanical Engineering at the University at Buffalo, taught by Erich Devendorf. The main purpose of this course is to familiarize students with design processes and methods. The Reverse Engineering Project is a prime example of what they should learn from the class. Throughout the project, students will learn how products are assembled by disassembling a specific product and analyzing its components. Over the length of the semester, students will work on five gates which will showcase the ongoing analysis of their products and test their knowledge of their products’ designs. It will reinforce key skills that engineers utilize daily.
Groups 25 and 26 were assigned a pressure washer. Rather than share the entire product between two groups, the product was divided into two. Group 25 is analyzing the compressor while group 26 analyzes the engine.
For our dissection Group 26, in conjunction with group 25 received a power washer. Group 26 dissected the engine and
this dissection and analysis is detailed in this wiki page.
Gate 1: Request for Proposal. This gate consists of the work proposal, in which we plan out our analysis, the
management proposal, in which we lay out the management of our group, and the initial product assessment, where we
analyze our product before dissecting it.
Gate 2: Preliminary Design Review. For this gate, the product was disassembled. For this portion of the project, we had causes for
corrective action, where we assess our work and management plans. We also provide a product dissection plan which
consists of step by step instructions on how the engine was disassembled.
Gate 3: Coordination Review. In the component summary, we list all of the components of the engine including
their functions, compositions, and manufacturing. We provide three Design Revisions which we believe would
improve the product as well. A solid model of a section of the engine is included, in addition to an analysis of a specific
section.
Gate 4: Product Reassembly Plan. In this gate we describe the reassembly of our engine.
Gate 5: Delivery. For this gate this wiki page was completed as well as a compliance matrix. Our group also
presented our dissection and analysis to the rest of the class.
We were successful in disassembling and reassembling our engine as well as analyzing it with only minor issues. The details of our work can be found below.
This portion of the Reverse Engineering Project is designed to help the group become familiarized with the product, a pressure washer. A general work outline for the semester will be developed and will contain the following items: a work proposal, a management proposal, and an initial product assessment.
