machine design final project presentation
TRANSCRIPT
INME 4012, Group 6 Final Presentation Fall 2014
Members: Jeromi Lopez Miguel Mora Bryan Ramirez Fabio Rodriguez
Drivetrain Arrangement
Legend:
1= CVT Shaft
2= Intermediate Shaft
3= Dead Axle
A= C – between the CVT and the Dead Axel=16.12”
B = C – Between the CVT and the intermediate Shaft=8.06”
Red Circle = 17 teeth ANSI No. 40-2 sprocket
Blue Circle = 52 teeth ANSI No. 40-2 sprocket
Yellow Circle = 17 teeth ANSI No. 50-2 sprocket
Green Circle = 54 teeth ANSI No. 50-2 sprocket
Figure 1: Shafts and Sprockets Arrangement
Figure 2: 3D Representation of the arrangement 2
Preliminary Work
Ø Forces acting on the vehicle:
ü Rolling Resistance = 14.7 lbf
ü Weight component in the plane direction = 346.48 lbf
ü Drag Force = 17.76 lbf
Ø Torque needed at the Dead Axle = 555.77 lbf-‐ft.
Ø Motor Torque = 20 lbf-‐ft.
Ø Ratio needed from the motor to the Dead Axle = 27.79:1
Ø CVT Ratio = 3:1
Ø Ratio needed after CVT = 9.26:1 3
Figure 3: Vehicle free body diagram
Sprockets and Roller Chains
Ø Chains pitch and length
ü From CVT Shaft to Middle Shaft: 0.5 in. (ANSI No. 40-‐2) – 2.86 feet
ü From Middle Shaft to Dead Axle: 0.625 in. (ANSI No. 50-‐2) – 3.33 feet
Ø Driver Sprockets fixed at 17 teeth
Ø Sprockets Ratios
ü From CVT Shaft to Middle Shaft: 3.059:1
ü From Middle Shaft to Dead Axle: 3.176:1
Ø Driven Sprockets teeth
ü Middle Shaft: 52
ü Dead Axle: 54
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Shafts
Ø Static Analysis
ü This will give the Minimum Static Shafts Diameters as:
ü CVT Shaft = 1in ü Middle Shaft = 1.25 in
ü Dead Axle Shaft = 1.25in.
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Shafts Dynamic Stress Calculations
6 6
Table 1: Values for the modified Goodman theory calculation
Table 2: Values of the minimum diameter, chosen diameter and safety factor of each shaft
Bearings
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Table 3: Design life & Basic load rating results
Table 4: Chosen Bearings
Brakes
Ê The normal force exerted by the vehicle (rear shaft):
Ê The required braking force:
Ê The required braking torque:
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Brakes
Ê The force provided by the brakes:
Ê The torque provided by the brakes:
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Brakes
Ê These values were determined with a 30-‐70 weight ratio.
Ê Normal force exerted in the rear part: 343 lbf
Ê Required force for braking: 240.1 lbf
Ê Required torque for braking: 320.13 lbf-‐ft
Ê Force provided by the brakes: 268.875 lbf
Ê Torque provided by the brakes: 358.5 lbf-‐ft
Ê The percentage of difference was approximately 12%.
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Acceleration
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
CVT Middle Dead
Inertia
(lb-‐ft^2
)
Shaft
0 1 2 3 4 5 6 7 8 9 10
CVT Middle Dead
Line
ar Acceleration (ft/s^2)
Shaft
0.00
20.00
40.00
60.00
80.00
100.00
120.00
CVT Middle Dead Ang
ular Acceleration (rad
/s^2
)
Shaft
Figure 4: Inertia of the shafts Figure 5: Angular acceleration of the shafts
Figure 6: Linear acceleration of the shafts
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Analysis Results
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Ê Weight of Drivetrain: 206.55 lbs
Ê Maximum Linear Acceleration at Dead Axle: 9.34 ft/s^2
Ê Acceleration time for 100 ft. (assuming constant acceleration) :4.63 seconds
Ê Theoretical top speed: 29.5 mph
Ê Highest grade that the can climb is 45°
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Item # Description Supplier Manufacturer Part Number Units Quantity Cost Final Price Weight per unit[lb] Total weight[lb]1 CVT CVTech-‐IBC CVTech-‐IBC each 1 $175.55 $175.55 22 222 Chain-‐ ANSI No. 40-‐2 Motion Industries Martin's 151461 ft 3 $20.95 $62.85 0.86 2.583 Chain-‐ ANSI No. 50-‐2 Motion Industries Martin's 151798 ft 4 $26.12 $104.48 1.38 5.524 Sprocket 17 teeth -‐ ANSI No. 40-‐2 Motion Industries Martin's 2168361 each 1 $104.10 $104.10 1.9 1.95 Sprocket 17 teeth -‐ANSI No. 50-‐2 Motion Industries Martin's 2168393 each 1 $134.61 $134.61 3.4 3.46 Sprocket 52 teeth -‐ ANSI No. 40-‐2 Motion Industries Martin's 2168381 each 1 $240.45 $240.45 16.1 16.17 Sprocket 54 teeth -‐ ANSI No. 50-‐2 Motion Industries Martin's 2167526 each 1 $392.55 $392.55 26.8 26.88 1-‐1/2" 4130 Rod Online Metals Online Metals ft 1.5 $16.43 $24.65 5.99 8.9859 2" 4130 Rod Online Metals Online Metals ft 3 $29.34 $88.02 10.66 31.9810 CVT-‐Bearings McMASTER-‐CARR McMASTER-‐CARR 2722T36 each 2 $163.88 $327.76 3.5 711 MiddleAxle-‐Bearings McMASTER-‐CARR McMASTER-‐CARR 2773T4 each 2 $95.06 $190.12 3.53 7.0612 DeadAxle-‐Bearings McMASTER-‐CARR McMASTER-‐CARR 2433K32 each 2 $246.13 $492.26 7 1413 Grade 8 Bolts Bolt Depot Not Available 632 each 12 $0.57 $6.84 0.994 11.92814 Grade 8 Nuts Bolt Depot Not Available 2678 each 12 $0.14 $1.68 0.03315 Lock Washers Bolt Depot Not Available 3040 each 12 $0.09 $1.08 0.225 2.716 Flat Washers Bolt Depot Not Available 3050 each 12 $0.20 $2.40 0.158 1.89617 Roller Chain Lube Ebay Schaeffer's 227 each 1 $12.99 $12.99 0 018 Asm. Caliper, LH (1.188" Bore) Polaris Polaris 1911150 each 1 $83.00 $83.00 5.6 5.619 Asm. Caliper, RH (1.188" Bore) Polaris Polaris 1911151 each 1 $83.00 $83.00 5.6 5.620 Asm. Caliper, Brake, Rear (1.5" Bore) Polaris Polaris 1911063 each 1 $83.00 $83.00 6.5 6.521 Brake Rotor -‐ Front and Rear (9.56" OD) Polaris Polaris 5250205 each 1 $22.00 $22.00 20 2022Rear Master Cylinder Assembly (3/4" Bore)Polaris Polaris 2203283 each 1 $54.00 $54.00 4 423 Brake Pad Kit Polaris Polaris 2202412 each 1 $25.00 $25.00 1 1
2712.385 Total 206.549
BOMTable 5 : Bill of Materials
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Conclusion
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Ê Torque at the wheel is 582.92 blf-‐ft
Ê Acceleration of the system is 9.34 ft/s^2
Ê Sprockets and Chain with ANSI No. 40-‐2 and 50-‐2
Ê Total price: $2712.39
Ê Total weight: 206.55 lbs
Ê The drivetrain weights 57.38% of the whole car weight
Assembly
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Sprockets
16
Shafts
17
CVT Shaft
Middle Shaft
Dead Axle
18
Shaft Assemblies
19
Full Assembly
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