final paper project icarus

7/29/2019 Final Paper Project Icarus

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Lindsay Davis

Michelle Brown

Design and Analysis of Drive Assembly

December 2012

Submitted to R. Scott Pierce


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TABLE OF CONTENTSTABLE OF CONTENTS............................................................................................................................................................ 2

OVERVIEW ................................................................................................................................................................................. 3

GEARMOTOR ............................................................................................................................................................................. 3

GEARPASS ................................................................................................................................................................................... 4

WHEEL SHAFT .......................................................................................................................................................................... 4

BEARINGS ................................................................................................................................................................................... 8

SUPPORT STRUCTURE ........................................................................................................................................................ 10

CONCLUSION ........................................................................................................................................................................... 11

APPENDIX ................................................................................................................................................................................. 12

DRAWING FILES ................................................................................................................................................................ 12

SUPPORT STRUCTURE .............................................................................................................................................. 12

WHEEL SHAFT .............................................................................................................................................................. 15

BEARING ASSEMBLY .................................................................................................................................................. 16

FINITE ELEMENT ANALYSIS ....................................................................................................................................... 19

SUPPORT STRUCTURE .............................................................................................................................................. 19

WHEEL SHAFT .............................................................................................................................................................. 20

ADDITIONAL IMAGES ..................................................................................................................................................... 22


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OVERVIEW

While considering the drive assembly, we analyzed and engineered how it will drive

PED's up the mountain safely and efficiently. The drive assembly needed to use a drive wheel

with the same diameter as the idler wheel and have a drive shaft that transfers torque from the

gear reducer to the wheel. The drive assembly must have bearings that support the wheel and

drive shaft and are mounted into a support structure. The support structure supports all of the

drive components and is within our safety standards. The gear reducer and drive shaft need to

be coupled together. This report will only discuss the drive wheel portion of the slope, not the

idler wheel portion.

GEARMOTOR

Using the Diequa Corporation Catalog we found a helical bevel gearmotor that fit our

previously calculated horsepower. We chose a KUA

136A 251 gearmotor that has a max rpm of 53,

therefore allowing us to adjust accordingly. This

gearbox produces a maximum torque of 144,388 in-

lbs. This low torque allows us to use a gear pass to

increase the gearmotor's maximum torque to what our drive wheel needs. See below for

images of the gearmotor to gain a better understanding.


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GEARPASS

Due to the large size of the slope we are working with, we have a colossal amount of

weight to pull up the hill and gargantuan required torque. The amount of torque we require is

not easily and cheaply found so to reduce costs we added an extra gear pass to multiply the

output torque of the motor.

This will also reduce our

revolutions per minute to

our desired velocity. The

gear pass is simply a smaller

gear that is attached on to the output shaft of the gearmotor, and then engages a gear a little

more than two times larger than the smaller gear. The larger gear engages the drive shaft and

increases the torque by a little more than double and halves the revolutions per minute. This is

a cost-effective and efficient way of using such a large slope to support more customers.

WHEEL SHAFT

We analyzed the wheel shaft for bending, stress due to

torsion, and shear due to bending. We found Von Mises stress

by analyzing eight stress squares on the surface of the shaft.

The shaft is made of 4130 AISI steel.


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We found the factor of safety for the bending to be

We found the factor of safety for the stress due to torsion to be

We found the factor of safety for the shear due to bending to be

We found the factor of safety for the Von Mises stress to be

The hand drawn calculations below explain in depth how we came to these factor of safeties.

(Units are shown separate column)


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BEARINGS

Two bearings were chosen to support the bull wheel because one bearing cannot

support a moment alone, and therefore another bearing had to be utilized. The top bearing is

smaller and can

support and radial

and trust load caused

by the tension in the

cable. The bottom

bearing is larger and

supports only a radial

load. It also creates a

force in the opposite

direction as the top bearing, equalizing the forces on the shaft of the wheel. Using the Timken

catalog these bearings were chosen to support the loads required. Each bearing was chosen to

withstand a load greater than what is anticipated. Please see the bearing calculations directly

below, these explain the L10 life and the minimum dynamic load rating need for each bearing.

Reference Appendix Page 16.


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SUPPORT STRUCTURE

We analyzed the support structure for buckling because this is the most likely form of

failure for this design. The support structure is made of 4130 AISI steel. The support structure

holds the wheel and wheel

shaft weight off the gear

pass and gearmotor. The

two bearings sit inside the

support structure and allow

the wheel to turn

smoothly. The bearings are

press-fitted inside the

structure and have little

risk of falling out.

We found the factor of safety for

the buckling on the support

structure

to be


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CONCLUSION

This proposal is superior to others because it entails a larger slope, which leads to more

patrons. When more patrons are on your ski lift more profit will be generated. We have a highly

efficient gearmotor at an up to standard price. Our underground cable maximizes safety while

being extremely functional and aesthetically pleasing to your patrons. Overall this design is

exceedingly gainful, eye-catching, and well-designed.


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APPENDIX DRAWING FILES

SUPPORT STRUCTURE

BY MICHELLE


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WHEEL SHAFT

BY LINDSAY


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BEARING ASSEMBLY


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FINITE ELEMENT ANALYSIS

SUPPORT STRUCTURE


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VON MISES

FACTOR OF SAFETY


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ADDITIONAL IMAGES


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