What problems should be considered when selecting the bearing of the hydraulic motor pump? Dalan motor to help you solve!

The dimensions of the bearing directly matched with the hydraulic pump's dedicated motor include the inner ring diameter, outer ring diameter, and thickness. It involves bearing clearance, accuracy, and other specific properties such as heat and dust resistance. The overall performance of the motor plays a crucial role. Today, Dalan Motor Xiaobian focuses on the complex relationship between the bearing clearance and the motor.

First, affect the bearing clearance factor

Clearance is an important factor in bearing operation. Clearance is divided into axial play and radial play. Choosing the proper clearance allows the load to be reasonably distributed between the rolling elements of the bearing, limiting the axial and radial displacement of the shaft (or end cap), ensuring the accuracy of the shaft rotation and reducing vibration and noise. When selecting the bearing clearance, the following factors should be considered:

(1) When the bearing and the shaft and the end cap hole are in interference fit, the bearing clearance will be reduced;

(2) The requirements of the motor for the performance of the bearing, such as rotation accuracy, friction torque, vibration and noise, etc.;

(3) Working conditions of the bearing, such as load, temperature, and speed.

Second, the principle of selection of bearing clearance

Bearing clearance values ​​specified by the national standards of our country are divided into small clearance auxiliary groups (C1, C2 groups), basic groups (0 groups) and large clearance auxiliary groups (C3, C4, C5 groups). Under normal working conditions, the basic group should be preferred to facilitate the proper working clearance of the bearing. When the basic group cannot meet the requirements for use, auxiliary group play should be used.

Third, relatively appropriate work clearance

Work clearance refers to the bearing clearance under actual operating conditions; there is also a clearance called primary clearance, which refers to the clearance before the bearing is not installed (the original clearance is greater than the installation clearance). The choice of clearance is mainly the selection of a suitable working clearance.

Fourth, bearing selection and performance comparison

Generally, the bearing with small frictional torque and small heat output has good high-speed performance. The ball bearing has higher limit rotation speed than the roller bearing, so the ball bearing should be given priority in high speed. When the radial load is small, the deep groove ball bearing is selected; when the radial load is large, the cylindrical roller bearing is selected. For combined loads, when the load is small, angular contact ball bearings are used; when the load is large, tapered roller bearings or cylindrical roller bearings and angular contact ball bearings are selected.

Fifth, axial swimming performance

When the motor works, the shaft heats up due to the mechanical friction or working medium, resulting in thermal expansion and contraction. When selecting the type of bearing structure, the shaft should have the possibility of axial movement.

Source: Dalan oil pump motor