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.