The drive shaft is composed of a shaft tube, a telescopic sleeve and a universal joint. The telescopic sleeve can automatically adjust the change in the distance between the transmission and the drive axle. The universal joint ensures the change in the angle between the transmission output shaft and the drive axle input shaft, and realizes the equal angular speed transmission of the two shafts.
In a car with a front engine and rear wheel drive (or all-wheel drive), due to the deformation of the suspension during the movement of the car, there is often relative movement between the input shaft of the drive shaft main reducer and the output shaft of the transmission (or transfer case). In addition, in order to effectively avoid certain mechanisms or devices (which cannot achieve linear transmission), there must be a device to achieve normal power transmission, so the universal joint transmission appeared. The universal joint transmission must have the following characteristics:
a. Ensure that the power can be transmitted reliably when the relative position of the two connected shafts changes within the expected range;
b. Ensure that the two connected shafts can operate evenly. The additional load, vibration and noise generated by the universal joint angle should be within the allowable range;
c. The transmission efficiency should be high, the service life should be long, the structure should be simple, the manufacturing should be convenient, and the maintenance should be easy. For automobiles, since the output shaft of a cross-axis universal joint rotates at an uneven speed relative to the input shaft (with a certain angle), a double universal joint (or multiple universal joints) transmission must be used, and the two universal joint forks connected to the drive shaft are arranged in the same plane, and the angles of the two universal joints are equal. This is very important. The angle of the universal joint should be minimized during design.
The traditional structure of the transmission shaft expansion sleeve is to weld the spline sleeve and the flange fork together, and weld the spline shaft to the transmission shaft tube. The new transmission shaft changes the traditional structure, welds the spline sleeve and the transmission shaft tube into one, and makes the spline shaft and the flange fork into one. And the rectangular tooth spline is changed to a large pressure angle involute short tooth spline, which not only increases the strength but also facilitates extrusion forming, and meets the needs of high torque working conditions. On the tooth surface of the expansion sleeve and the spline shaft, a layer of nylon material is coated as a whole, which not only increases the wear resistance and self-lubrication, but also reduces the damage to the transmission shaft caused by the impact load, and improves the buffering capacity.
This type of transmission shaft has a tubular sealing protective sleeve outside the flange spline shaft, and two polyurethane rubber oil seals are set at the end of the protective sleeve to form a completely sealed space inside the telescopic sleeve, so that the telescopic spline shaft is not eroded by external sand and dust, and is not only dust-proof but also rust-proof. Therefore, when assembling, applying grease once inside the spline shaft and the sleeve can fully meet the use requirements, and there is no need to install a grease nozzle for lubrication, which reduces the maintenance content.