Parametric modelling, Kinematic Simulation and FEA of

Differential Gear for an Automotive.

Name Student ID

Arvind Dalal 6582141

Prakul Mittal 6562353

Sambhu Kumar Gupta 7143947

MECH 6451 Computer Aided Design

Professor: Dr. Chevy Chen

PROJECT OUTLINE

Differential Overview

Definition of our technical task

Design calculation for Differential Gear

Tangential tooth load

Dynamic load

Static tooth load

Wear load

Force acting

Parametric Modeling using Catia V5

Parametric design for straight teeth bevel gear

Kinematic simulation of Differential Gear

When vehicle moves straight

While turning

Finite Elements Analysis using ANSYS 14.5

Structural analysis by design Operational load

Product failure load estimation

DIFFERENTIAL OVERVIEW

When turning, the inner and outer wheels have

arcs of different turning radii.

Consequently, the inner wheels travel less

distance than the outer wheels.

Because the turning paths of the inner and outer

wheels are different, the wheels on both axles

need to be able to spin independently of each

other

A differential is used to allow the wheels to spin

at different speeds

DIFFERENTIAL OVERVIEW

DESIGN CALCULATIONS

Differential gear assembly for a vehicle transmit power at different speeds at 2400 rpm.

Material used Aluminum Alloy.

For Crown Wheel

Diameter of crown gear = DG= 800 mm

Number of teeth gear = TG = 80

Number of teeth on Pinion= TP = 20

Module = m=DG/TP= 800/20= 10

Diameter of pinion DP=m TP = 10*20 = 200mm

Velocity ratio (V.R) = TG/ TP= DG/DP= NG/NP

So Velocity ratio is (V.R) = 80/40 = 4

Since the shafts are at right angles therefore pitch angle for the pinion

θp1=tan-1(1/v.r) = tan-1(1/4) = 14.04

Pitch angle of gear

θp2 = 90 - θp1 = 75.96

WEAR LOAD (WW)

WW

DP b q k

cos P1

180

2.601 104

N

Where K = load stress factor k es2

sin 20

180

EG EP

EP EG

1.4 0.721 N/mm2

FORCE ACTING

WN=normal load=WT/ COSØ

WT=tangential force

Where WT = T/ RM (RM = Mean radius)

Axial force acting on the pinion shaft

WRH =WT tan 20 sin ϴP1

WRH = 478.24N

Radial force acting on the pinion shaft

WRH =WTT tan 20 cos ϴP1

WRH = 1912.37 N

DESIGN CALCULATIONS

EP=young’s modulus for material of pinion in N/mm2=70300 N/mm2

EG=young’s modulus for material of gear in N/mm2= 70300N/mm2

PARAMETRIC MODELING USING CATIA V5

PARAMETRIC DESIGN

• Created 5 points to generate involute

teeth profile by parametric equation

• Connected the points by use of Spline.

• Scaled he tooth profile and projected

• Projected the involute profile on

the cone.

FINAL PRODUCT

Later surface was transferred in Part

workbench to create solid par.

PARAMETRIC DESIGN

KINEMATIC SIMULATION While vehicle is Turning

FINITE ELEMENT ANALYSIS USING ANSYS 14.5

MESH GENERATION

• Mesh Generated in Design Modeler

• Type: Coarse , Size: 1.5166e-004m

• We got total nodes= 6459 And

Elements = 3532

LOAD & FIXTURE APPLIED

• We applied fixed support

base of crown gear , and

frictionless at hole.

• Under setup sub tab.

DEFORMATION