万向节技术解析！

Universal joint technology analysis!

万向节是实现转轴之间变角度传递动力的部件。

The universal joint is a component which can transfer power from one shaft to another.

如果万向节在扭转方向没有弹性、动力靠零件的铰链式连接传递，是刚性万向节，刚性万向节又分为不等速万向节（如十字轴式万向节）、准等速万向节（如双联式、三销轴式等）和等速万向节（如球叉式、球笼式等）。

If the universal joint has no elasticity in the torsion direction, and the power is transmitted by the hinge connection of the parts, it is a rigid universal joint. The rigid universal joint can be divided into non constant velocity universal joint (such as cross shaft universal joint), quasi constant velocity universal joint (such as double joint, triple pin shaft type, etc.) and constant velocity universal joint (such as ball fork type, ball cage type, etc.).

如果万向节在扭转方向有一定弹性、动力靠弹性零件传递、且有缓冲减振作用，是弹性万向节。

If the universal joint has a certain elasticity in the torsion direction, the power is transmitted by the elastic parts, and the damping effect is buffered, it is an elastic universal joint.

汽车上应用较多的是刚性万向节。

Rigid universal joint is widely used in automobiles.

一、十字轴式刚性万向节

1、 Cross shaft type rigid universal joint

十字轴式刚性万向节结构简单、工作可靠、且允许所连接的两轴之间有较大交角，在汽车上应用最为普遍。

The cross axle type rigid universal joint has the advantages of simple structure, reliable operation and large angle of intersection between the two connected shafts, so it is widely used in automobiles.

1．构造及润滑

1. Structure and lubrication

2．十字轴式刚性万向节传动的不等速特性

2. The non-uniform speed characteristics of cross shaft rigid universal joint transmission

单个十字轴式刚性万向节在输入轴和输出轴有夹角的情况下，其两轴的角速度是不相等的，两轴夹角α越大，转角差（Φ1-Φ2）越大，万向节的不等速特性越严重。

When there is an angle between the input shaft and the output shaft of a single cross shaft rigid universal joint, the angular velocity of the two shafts is not equal. The greater the angle α between the two shafts and the greater the angle difference (Φ 1 - Φ 2), the more serious the non-uniform velocity characteristic of the universal joint is.

万向节传动的不等速特性将使从动轴及与其相连的传动部件产生扭转振动，从而产生附加的交变载荷，影响传动部件的寿命。

The non-uniform speed characteristics of universal joint drive will make the driven shaft and its connected transmission components produce torsional vibration, which will produce additional alternating load and affect the service life of transmission components.

3．十字轴式万向节传动的等速条件

3. Constant speed condition of cross axle universal joint transmission

（1）采用双万向节传动；

(1) Double universal joint transmission is adopted;

（2）第一万向节两轴间的夹角α1与第二万向节两轴间的夹角α2 相等；

(2) The angle α 1 between the two shafts of the first universal joint is equal to the angle α 2 between the two shafts of the second universal joint;

（3）第一万向节的从动叉与第二万向节的主动叉在同一平面内。

(3) The driven fork of the first universal joint is in the same plane as the driving fork of the second universal joint.