The transmission shaft assembly is composed of a shaft tube, an expansion sleeve and a universal joint. The telescopic sleeve can automatically adjust the distance between the transmission and the drive axle. The universal joint ensures the change of the included angle between the output shaft of the transmission and the input shaft of the drive axle, and realizes the constant angular speed transmission of the two shafts.

a universal coupling

Universal joint is the key component of automobile transmission shaft. A car is a moving object. On the rear drive vehicle, the engine, clutch and transmission are installed on the frame as a whole, and the drive axle is connected to the frame through the elastic suspension. There is a distance between the two and they need to be connected. When the vehicle is running, the road surface is uneven and jumps.

The universal joint is generally composed of a cross shaft, a cross bearing and a flange fork. Universal joint is the key component of automobile transmission shaft. On rear wheel drive vehicles with front engine, the universal joint transmission shaft is installed between the transmission output shaft and the input shaft of the drive axle main reducer; The front engine front wheel drive vehicle omits the transmission shaft, and the universal joint is installed between the front axle half shaft and the wheel, which is responsible for driving and steering. When the vehicle is running, the uneven road surface will produce runout, the load change or the installation position difference of the two assemblies will change the included angle and distance between the transmission output shaft and the input shaft of the drive axle main reducer. Therefore, a "variable strain" device should be used to solve this problem, so there is a universal joint.

Telescopic sleeve

The transmission shaft expansion sleeve with traditional structure is to weld the spline sleeve and the flange fork together, and weld the spline shaft on the transmission shaft tube. The new transmission shaft changes the traditional structure by welding the spline sleeve and the transmission shaft tube into a whole, and the transmission shaft makes the spline shaft and the flange fork into a whole. The rectangular tooth spline is changed into involute short tooth spline with large pressure angle, which not only increases the strength, but also facilitates extrusion forming and meets the needs of high torque working conditions. The tooth surfaces of the telescopic sleeve and spline shaft are coated with a layer of nylon material as a whole, which not only increases the wear resistance and self lubrication, but also reduces the damage of impact load to the transmission shaft and improves the cushioning capacity.

A tubular sealing protective sleeve is added outside the flange spline shaft of the transmission shaft, and two polyurethane rubber oil seals are set at the end of the protective sleeve, so that a fully sealed space is formed in the telescopic sleeve, so that the telescopic spline shaft is not eroded by external sand and dust, which is not only dust-proof but also rust proof. Therefore, when the spline shaft and the sleeve are coated with grease at one time during assembly, the use requirements can be fully met. There is no need to install a nozzle for lubrication, and the maintenance content is reduced.

Axial tube

It is designed to reduce the friction and wear when the shaft moves. Its basic purpose is the same as that of the bearing. It is relatively cheap, but the friction resistance is large, so it can only be used on some parts. Most shaft sleeves are made of copper, but there are also plastic shaft sleeves. The shaft sleeve is mostly placed in the shaft and supporting structure, and is very close to the supporting structure. Only the shaft can rotate on the shaft sleeve. When assembling the shaft and shaft sleeve, lubricant will be added between them to reduce the friction generated during rotation.