Dynamic adjusting device and method for pre-tensioning force of main shaft bearing of machine tool

Abstract

The invention provides a dynamic adjusting device and method for pre-tensioning force of a main shaft bearing of a machine tool. The device comprises a force sensor, a fixed part, an electromagnet, an embedding sleeve, a moving part, an end cover, a spacer, a constant-pressure pre-tensioning spring and a supporting block, wherein the fixed part and the supporting block are connected with the main shaft; the electromagnet is fixedly connected with the embedding sleeve to form a combined body; the embedding sleeve sleeves a main shaft in an embedding manner and is connected with the fixed part; the spacer is mounted on an outer circle of a rear bearing; the moving part is inserted between the supporting block and the embedding sleeve, and two surfaces of the moving part are correspondingly in contact with the supporting block and the embedding sleeve; the constant-pressure pre-tensioning spring passes through a through hole of the fixed part; one end of the constant-pressure pre-tensioning spring is in contact with the spacer, and the other end of the constant-pressure pre-tensioning spring is in contact with the moving part; the end cover is connected with the housing; the force sensor is mounted on the outer circle of the rear bearing and is in contact with the spacer. According to the method, the electromagnetism can be changed by simply controlling the electrifying current of an electromagnet coil, and thus the pre-tensioning force of the bearing can be dynamically adjusted.

Description

technical field [0001] The invention relates to the field of performance testing of machine tool spindles, in particular to a dynamic adjustment device and a dynamic adjustment method for the pretightening force of machine tool spindle bearings. Background technique [0002] The pretightening force of the machine tool spindle bearing directly affects the static, thermodynamic and dynamic characteristics of the spindle system. In order to improve the rigidity and rotation accuracy grade of the spindle system, it is necessary to apply an initial preload to reduce the vibration and noise caused by the large clearance of the rolling bearing; however, when the stiffness of the rolling bearing is improved by increasing the preload, the high contact pressure of the balls and the inner and outer raceways It will damage the oil film and cause sticking, thereby reducing the life of the bearing, especially when the spindle rotates at high speed, due to the influence of centrifugal forc...

AI Technical Summary

Problems solved by technology

This method has a simple structural design, avoids external hydraulic adjustment devices, and has strong practicability, but this method can only rely on experience to qualitatively judge whether the pretightening force is appropriate under specific working conditions

Images