For a car of a friend, the car has penetrated into all aspects of life, and the owner will also take care of their car on a plus, but the chassis side of vehicle maintenance is often overlooked part. Car chassis is in addition to the nearest part of the tire from the ground, mounted on a suspension system in which the traveling vehicles and driving experience has a very important role. I do not know if you have not thought about this question: why the car when the power steering is still able to export it to the wheel in order to understand this issue, we should start talking about the gimbal?.

In order to cope with a variety of road conditions, the vehicle needs to change the trajectory of the steering wheel, but also need to ensure that the power is still able to pass onto the wheels, so the festival came into being universal. The so-called universal joint refers to the use ball like means to achieve different directions of the shaft power output means. It sounds a bit complicated, in order to better understand the role of the universal joint.

A joint representation in the reverse direction if there is a clear elastic, can be divided into rigid and flexible joints joints. Steel joints can be divided into non-constant velocity joints, quasi-constant velocity joints and constant velocity joints of three.

The flexible joint is to rely on the elastic deformation of the elastic member to ensure that no mechanical interference occurs between the two when the shaft drive is generally used for two-axis angle of not more than 3 �� ~ 5 �� or trace axial displacement of the drive case, so here temporarily no introduction, let us start with the cross shaft universal joint, not CVJ cross shaft universal joint is widely used on the car, which allows a maximum of two adjacent shaft angle of 15 to 20 �b �b.

By a cross shaft universal joint cross-axis, two universal joints fork and four needle bearings and other components. Twenty thousand holes on the fork are set on two pairs of cross shaft journal. So that when the driving shaft rotates, the driven shaft can rotate therewith, but also swinging about the center of the cross shaft in any direction, thus adapted to the angle and distance while changing needs. Between the cross shaft journal and Yokes hole mounted needle roller bearings, needle roller bearing outer ring axial positioning by card.

Although the high cross shaft universal joint transmission efficiency of simple structure, but it also has a very significant drawback: in the case of two-axis angle is not zero, you can not pass isometric rotation speed, which is not cross-axis gimbal constant velocity. In simple terms, if the initiative, such as the angular velocity of the rotation axis, from the shaft when the fast slowly, and the two-axis angle, the greater the speed, the drive shaft is not constant worse. This feature makes it noise and life is not ideal, so rarely used in the steering mechanism, but after the car on the drive shaft on the application, but more. For example, the drive shaft on the E46 BMW 3 Series on the use of the cross shaft universal joint.

Cage-type universal joint

Cage-type universal joint structure shown below. Within the star sets connected to the drive shaft spline outer surface has six curved groove formed in the raceway. The inner surface of the spherical shell corresponding six arcuate recess, forming the outer raceway. Six balls were installed in six groups from inside and outside the raceway of the space, and is limited to the cage in the same plane. Powered by the drive shaft through the ball reached the spherical shell output.