Different Kinds of Universal Joints

There are many types of precision universal joint on the market, which can be simply divided into constant velocity joints and non-constant velocity joints. These two types of universal joints can be distinguished by simple analysis.

The first type is the Hook universal joint. When the input and output of the cross shaft are not on the same axis, the input and output angular speeds do not want to wait. For the automotive transmission system, this phenomenon of unequal angular speeds will affect the car ride. The comfort of it will also affect the service life of other parts, so most of the steering drive wheels that use cross-shaft universal joints, only a small part will use such universal joints.

The second type is a telescopic ball cage universal joint. The biggest feature of this type of universal joint is that it has the center of the two balls above and below. The plane is the symmetry plane of the joint, and the radius of the center of the ball is on the input shaft. It is equal to the output shaft. Whether it is an input shaft or an output shaft, its angular velocity is always equal. This universal shaft is a constant velocity universal joint.

The third type is a three-pin universal joint. It is paired with a cross shaft universal joint. It is a constant velocity universal joint formed by combining two universal joints. Its input and output angular velocities are also equal. The three-pin universal joint shortens the intermediate shaft to the minimum, but the three-pin universal joint is hardly used in vehicles because of its limited load-carrying capacity, relatively complicated manufacturing process and high production cost. The fourth type is the double joint. This type of joint occupies a large space and is difficult to achieve balance. It has the smallest error between the input and output angles of the universal joint, which is infinitely close to ninety degrees. It is not suitable for those who require high comfort and compact structure of the car.

The asymmetry of the two axes of the cross-axis universal joint, that is, the angle between the two is not equal, will bring about speed pulsation. Constant velocity universal joints are extremely rare in real life. The non-constant speed of the cross shaft universal joint is not suitable for cars, and its spatial arrangement is not accepted by cars. In comparison, the double cross shaft universal joint cross with a very short intermediate shaft is relatively low-cost, high-performance, and cost-effective.