Main functions of helical bevel gears in automobiles

1.Transfer the power output from the engine to the driving wheels via the transmission and the main drive.

2.Change the direction of rotation output by the longitudinally configured engine so that the driving wheel can rotate in the same direction as the driving direction of the vehicle.

3.Reduce the rotating speed of engine output and increase the torque of engine output so as to obtain sufficient traction for driving wheels.

The automotive industry usually refers to helical bevel gears as reduction gears and the assemblies composed of them are called reduction gear assemblies.CA1092 automobile uses two-pole main drive, one pair of helical bevel gears to achieve first-stage deceleration and one pair of helical cylindrical gears to achieve second-stage deceleration.

Spiral bevel gears have four speeds: 11:25, 12:25, 13:25, 9:25.

Helical cylindrical gears have two speed ratios: 14:47, 15:46.

Drive axles consist of four gear ratios:

25/1147/14=7.63, 25/1246/15=6.39, 25/1346/15=5.897, 25/947/14=9.33.

The driving condition of a vehicle changes instantaneously with external conditions, so the operation of helical bevel gears is extremely complex.The linear speed of spiral bevel gears of medium duty trucks can reach up to 17m/s, which requires that the tooth surfaces have the properties of wear resistance, impact resistance and bending resistance.High hardness of the tooth surface and good wayfulness of the heart are usually required.

Through the analysis of spiral bevel gear drive wheel in CA1092 automobile drive axle, the machining process specification and special machine tool fixture design of spiral bevel gear are carried out.In this paper, the general design method, universal machine tool and universal fixture are used to design only the fixture for milling teeth.