Method for evaluating pretightening force of spindle

Abstract

The invention discloses a method for evaluating the pretightening force of a spindle. The method comprises a step of performing load analysis on support bearings of the spindle and solving loads of the spindle bearings, a step of establishing a five-degree-of-freedom nonlinear finite element model of the machine tool spindle bearings and establishing a fitting relationship between the dynamic stiffness of the spindle bearings and the dynamic stiffness of the spindle, a step of calculating the dynamic stiffness of the spindle under different bearing pretightening forces and rotation speeds andestablishing a fitting relationship database between the dynamic stiffness of the spindle and the bearing pretightening forces and the rotation speeds, and a step of measuring the dynamic stiffness ofa spindle front end through a spindle dynamic stiffness measurement experiment and inquiring the obtained dynamic stiffness in the fitting relationship database between the dynamic stiffness of the spindle and the bearing pretightening forces and the rotation speeds to obtain the pretightening force of the machine tool spindle bearings.

Description

technical field [0001] The invention relates to the technical field of bearing processing technology, in particular to a method for evaluating the pretightening force of a main shaft. Background technique [0002] Preloading the rolling bearing of the machine tool spindle can eliminate the clearance of the rolling bearing during the manufacturing and assembly process, increase the stiffness of the bearing, and improve the rotation accuracy of the spindle. At the same time, due to the effect of the preload, the spindle The evaluation method of pretightening force can reduce the slipping phenomenon of bearing ball revolution, eliminate the gyro effect, and then improve the heating condition of the bearing, and the evaluation method of spindle pretightening force can prolong the service life of the bearing. [0003] The commonly used preloading method for machine tool spindles is constant pressure preloading, which is characterized by constant preloading force. The constant pr...

AI Technical Summary

Problems solved by technology

[0003] The commonly used preloading method for machine tool spindles is constant pressure preloading, which is characterized by constant preloading force. The constant pressure preloading method has obvious deficiencies in the evaluation method of the spindle preloading force: the preloading force is too small at low speed, which reduces the rigidity of the bearing, and the evaluation method of the spindle preloading force against forced vibration and self-excited vibration is weak. , resulting in a decrease in machining accuracy; the preload force is too large at high speed, which aggravates the temperature rise of the bearing, which restricts the evaluation method of the spindle preload force and hinders the high-speed spindle

[0004] At present, in addition to some simple preload estimation methods and evaluation methods for spindle preload for some occasions with low requirements in engineering, the method of determining bearing preload generally adopts the empirical method (hand feeling method), and this method The efficiency is low, and the evaluation method of the preload of the operating spindle is complex and only applicable to static

Images