Classification and structure of constant speed drive shaft and universal joint

1. Review of constant speed drive shaft and universal joint

Constant velocity universal joint is an important part of car transmission system, which connects two axes which do not coincide with each other and makes them transfer motion at the same angular speed.

Its function is to transfer the power of the engine from the transmission (differential) to the driving wheel of the car, meet the requirements of the outer end corner of the car drive shaft, compensate the beating of the inner end suspension of the car, and drive the car to run at high speed.

There are many types of constant velocity universal joints for cars, among which the most widely used is the ball cage type constant velocity universal joint and three groove type constant velocity universal joint, inclined raceway type constant velocity universal joint, it is mainly composed of ball cage, ball cage and half shaft.

Due to the constant speed universal joint transmission of heavy driving torque,  heavy load, high transmission accuracy, great demand, and is safety parts, so its main parts are processed by fine forging.

2. Classification of constant velocity universal joint

1)  Constant speed Universal Joint Assembly- CV AXLE

A mechanical component that transmits motion and torque between a differential or an end reduction gear and a wheel and consists of two or one set of constant speed universal joints, intermediate shafts and other parts.

2)  Constant velocity universal joint -CVJ Constant Velocity joint

The output axis and the input axis share instantaneous angular velocity equal to 1 over the universal joint of transfer motion.

3)  Center Fixed type constant velocity universal joint-Fixed joint

That is a constant velocity universal joint which can only change the Angle of operation.

4)  Telescopic constant velocity universal Joint-Plunging Joint

That is a constant velocity universal joint which can change working Angle and slip movement.

3. Central fixed constant velocity universal joint:

1) BJ universal joint- Ball Fixed Joint

Rzeppa fixed section is called by Japan, South Korea and other countries. It was successfully developed by British Birfield Group in 1958.

The raceway is oval in radial section, and the ball and raceway are fixed central constant velocity universal joints with four point contact.

2) RF type universal joint

German abbreviation for single arc raceway fixed joint.

The raceway is round in radial section, and the ball and the raceway are fixed central constant velocity universal joints with two point contact.

3) GE universal joint-Glaenzerexterieurtripod

The three pin frame is fixed in the coat, and the ball ring installed on the three pin frame and the fork shaft form the central fixed constant velocity universal joint at the working Angle

4) AC universal joint-Angular Contact joint

For fixed end, the shape of the fairway section is elliptical or Gaussian curve (double arc)

AC universal joint is widely used in cars and light buses.It has the maximum swing Angle of 47°, and fullymeets the movement requirements of vehicle steering and suspension system.Itis the most widely used wheel end constant speed universal joint.

4. Expansion type constant velocity universal joint

1) Axially movable ball cage universal joint: DOJ type

Japan toyo bearing co., Ltd. developed successfully in 1965, also known as double compensation type.

There are 6 steel balls, 6 straight raceways for inner sleeve and outer jacket respectively, the radial section of raceway is oval, and the steel ball and raceway are four-point contact type.

Because of the DOJ expansion joint use straight raceway so the manufacturing is simple and low cost.

2) Three ball pin universal joint: TJ

Jacket raceway is closed and jacket chamber contains three pin stand assembly.

3) VL inclined raceway universal joint-VerschiebegelenkLobro

There are 6 steel balls, and 6 straight raceways for inner sleeve and coat respectively. The steel balls are held by a cage with an outer sphere at the intersection of straight raceways on the inner and coat, and the two adjacent straight raceways are reversely inclined along the axial direction at an equal Angle.

The VL joint is usually used as the inner universal joint of the rear wheel drive half shaft. The maximum swing Angle is 22 degrees and the maximum sliding distance is 50 mm. It is suitable for the occasion of large swing Angle and low axial force.

4) GI universal joint-Glaenzerinterieur tripod

The three-pin frame housing is open for the three-pin universal joint on the differential side. GI section is widely used in the transmission side of the mobile section, the maximum swing Angle of 23°, moving distance of 50mm. GI joints are especially suitable for medium swing Angle occasions, small slip resistance, jacket cavity can be with compression springs, can produce good NVH performance.

5) DO double offset universal joint-Double offset

DO joint is similar to VL joint. It has two structural forms, which can achieve 26° and 30° swing angles respectively, and their moving distance is 50mm. DO section is also suitable for large swing Angle, small axial force occasions.

6) AAR universal joint- Angular adjusted roller（GKN）

Ball ring adjustable Angle, used for differential side, with small slippage resistance, large swing Angle, good NVH performance.

AAR sections can ensure excellent NVH and durability of vehicles at large mounting angles.

Compared with GI joint, AAR joint has less sliding resistance and axial force, and better NVH performance, so it is more suitable for the occasion of large swing Angle.

The AAR section has a maximum swing Angle of 26 degrees and a maximum sliding distance of 50 mm.

7) SIO Universal joint (GKN)

Used for the gearbox side, it adopts the relative fairway principle, and the advantage is high transmission efficiency and small peripheral size.

SIO universal joint is the best solution to solve the problem of large mounting Angle and large shift of SUV vehicles.

8) UF type root-free cutting fixed joint-- undercut-free fixed joint （GKN）

On the outside end of the fairway into a straight line, the maximum swing Angle up to 50 degrees.

The UF section provides the same strength and durability as the AC section, with a maximum swing Angle of 50°, making the geometry of the steering mechanism more flexible and convenient, enabling a smaller vehicle turning radius.