Research on Long-Life Technical Control and Maintenance Strategies for Shaft Universal Joint Couplin

The universal joint coupling is the most commonly used type of coupling. Utilizing its structural characteristics, it enables two shafts that are not on the same axis, have a large angular offset, or experience significant axial movement to rotate at equal angular velocities in a continuous manner, while reliably transmitting torque and motion. It is widely applied in the mechanical shaft systems of industries such as metallurgy, lifting, engineering transportation, mining, petroleum, shipping, coal, rubber, papermaking machinery, and other heavy machinery sectors for torque transmission.

A coupling is a critical component connecting the prime mover to the working machine. Its failure can cause machine downtime and even affect the entire production line, so its reliability requirements are extremely high. However, the operating conditions for cross-type universal couplings are often harsh. For example, in rolling mill drives, due to limitations on the diameter of the connected rolls, the rotational diameter of the coupling is also restricted. The actual torque during rolling often approaches the coupling's fatigue torque, and even exceeds it under improper conditions. If such overloading occurs frequently, it will significantly reduce the fatigue life, leading to premature failure or damage. Additionally, the spatial geometric position requirements for cross-shaft universal couplings are also high. Improper alignment can result in additional torque, which also reduces its lifespan and affects its transmission efficiency. For large couplings, inadequate maintenance techniques and improper adjustment of the balancing system can also introduce additional loads equivalent to or even exceeding the torque level, with some cases resulting in the breakage of the cardan shaft. Therefore, for such a critical component, comprehensive technical control measures must be implemented to ensure its service life.