For screw bearings, flange type screw bearings are crucial and can directly affect the performance and service life of machine tools or spindles. Moreover, their correct installation is crucial. If installed improperly, it can cause damage to the shaft, and in severe cases, it can lead to damage to the bearings and equipment. Below, I will introduce how improper installation of flange type screw bearings can affect everyone.
Hazards of Improper Installation of Flange Type Screw Bearings
1. Generate axial clearance
Generally, the ball screw must be equipped with angular contact ball bearing, especially the bearing designed with high pressure angle is a better choice. When the ball screw bears axial load, the general deep groove ball bearing cannot eliminate its own backlash by preloading, so a fixed amount of axial clearance will be generated when installing this bearing. The conclusion is that the deep groove ball bearing is not suitable for this.
2. Generate back gap
If the flange type lead screw bearing is installed on the ball screw and the two do not fit tightly together, it will cause clearance under axial load. If this situation occurs, it may be caused by the shoulder of the lead screw being too long or too short, and the back clearance can be eliminated using a spacer ring.
3. Causes the bearing to tilt
If the perpendicularity between the bearing surface of the screw bearing and the V-shaped tooth axis of the locking nut is poor, or the parallelism between the locking nut surfaces in the two corresponding directions is not good, it will cause the bearing to tilt; Therefore, the V-shaped teeth of the locking nut on the shoulder of the lead screw and the bearing support surface must be processed simultaneously to ensure verticality, and grinding can also be used for better processing. Using two locking nuts and spring washers to secure the bearings can prevent them from loosening during operation.
4. Affects bed accuracy
If the surface parallelism or flatness of the support seat exceeds the tolerance range, the reproduction accuracy of the position during bed movement will be poor. Therefore, in equipment, thin gaskets can generally be used between the support seat and the machine body to achieve adjustment purposes.
Installation method of flange type screw bearing
1. Install the support unit on the side of the support seat: Insert the screw shaft into the single row bearing and fix it with a thrust ring, then insert the bearing into the support seat.
2. Adjustment accuracy: First, adjust the installation accuracy to within the reference value.
3. Install the screw onto the base: When using the fixed side support unit as the reference, adjust the outer diameter of the nut and the inner diameter of the workbench nut support to maintain a certain gap.
4. Install the lead screw on the workbench: When using the workbench as the reference, use thin washers to adjust the center height for square support units, and adjust the outer diameter of the nut and the inner diameter of the workbench nut to maintain a certain gap for flange type support units.
5. Tightening the bolts: After confirming that the accuracy is no problem, fully tighten the bolts to complete the installation of the lead screw, and then connect the motor to start trial operation.