Listen to the technical engineers explain the working principle of the universal joint coupling

As a key member of the coupling family, the universal joint coupling has the advantage of being able to withstand operating conditions where the angle between two shaft axes is as high as 45°. It is widely used in modern industrial fields such as machine tools, automobiles, precision machinery, and heavy machinery. Next, we will delve into the working principle of the universal joint coupling, with professional explanations provided by Xinde's technical engineers.

Physical Structure of the Universal Joint Coupling
The universal joint coupling is primarily composed of a cross shaft, two universal joint yokes, and four needle roller bearings. Its unique feature is that the rotation centers (axes) of all the revolving pairs intersect at a single point O, with an angle α between the two shafts. This design allows the universal joint coupling to efficiently transmit motion between two intersecting shafts with varying angles.

Working Principle of the Universal Joint Coupling
Transmission Ratio Characteristics: When Shaft I completes one full rotation, Shaft II also completes one full rotation, with an average transmission ratio of 1 between the two shafts. However, the instantaneous transmission ratio is not constant but fluctuates periodically. This characteristic is known as the non-uniformity of the instantaneous transmission ratio.

Non-uniform Velocity Analysis: For a single universal joint, when there is an angle between the input and output shafts, the angular velocities of the two shafts will not be equal, meaning the universal joint exhibits non-uniform velocity. As the angle α between the two shafts increases, the speed fluctuation of the driven shaft becomes more pronounced. Therefore, to ensure smooth transmission, the angle α should ideally be controlled between 35° and 45°.

Advantages of Paired Use: To eliminate the drawback of variable-speed transmission in the driven shaft of a universal joint, it is typically used in pairs to prevent unequal angular velocities between the driving and driven shafts.

The working principle of the universal joint coupling is actually not complex and is relatively easy to understand. As one of the most widely used types of couplings today, with the rapid advancement of China's industrial strength, the market demand for universal joint couplings is also growing. Domestic manufacturers of universal joint couplings have made significant progress in both scale and technology, and Xinde has also achieved rapid growth in these years of industrial development. If you have procurement needs, please feel free to contact us.