Welded Universal Joint Coupling

Welded universal joint coupling is a mechanical transmission device that connects components through welding technology. It is mainly used to connect two shafts on different axes, achieving effective transmission of torque and rotational motion. Its core lies in the ability to compensate for relative displacement between two axes, including axial, radial, and angular deviations. This type of coupling, through its unique structural design, allows the driving shaft and the driven shaft to maintain constant angular velocity and continuous rotation even in the presence of an axial angle.

The cross axis structure is a common design form of welded universal joint, consisting of two welded fork heads and a cross axis. The four necks of the cross shaft are connected to two fork heads through needle roller bearings, forming a hinged structure. When one axis is fixed, the other axis can be tilted at a certain angle. This structure enables the coupling to adapt to various complex installation conditions and working environments. In practical applications, to eliminate speed fluctuations, a double coupling form is usually used, which connects two universal couplings through an intermediate shaft to form a universal transmission shaft system.

The material selection of welded cardan shaft directly affects its performance and service life. Common materials include 45 steel, 45 forged steel, 40 chromium alloy steel, and 35CrMo. These materials have undergone quenching and high-frequency quenching processes to meet the strength requirements under different working conditions. For example, fork components are often quenched and tempered with 35CrMo alloy steel, while spline shafts undergo high-frequency quenching to improve wear resistance and load-bearing capacity.

Compared with traditional flange or bolted universal couplings, welded design has the advantages of compact structure, light weight, and high reliability. Due to the elimination of flanges and connecting bolts, the potential risk of loosening is reduced, making it particularly suitable for high-speed and heavy-duty working conditions. At the same time, the welding structure eliminates the connection gap, improves the transmission accuracy, and performs excellently in strict requirements such as metallurgical rolling mills and heavy machinery. However, the welded design also brings the limitation of non disassembly, and once damaged, it needs to be replaced as a whole, which is slightly insufficient in terms of maintenance convenience.