Dynamic measurement method for radial stiffness and axial stiffness of bearing

Abstract

The invention belongs to the technical field of mechanical measurement and is applicable to measurement of radial stiffness and axial stiffness of bearings. The measurement principle is based on a relationship between the bearing stiffness and inherent vibration frequency of a shaft for test. The method comprises the following steps of: in the process of measuring the radial stiffness of the bearing, solving a function relationship between the radial stiffness of the bearing and the first-order transverse vibration frequency of a shaft for test, building a physical system among the shaft for test, a measured bearing and a rigid support, measuring the first-order radial vibration inherent frequency of the shaft for test, and finally, calculating the radial stiffness of the bearing according to a function relationship between the inherent vibration frequency and the radial stiffness of the bearing; and in the process of measuring the axial stiffness of the bearing, solving the mass of the shaft for test, building a physical system among the shaft for test, the measured bearing and the rigid support, measuring the first-order axial vibration inherent frequency of the shaft for test, and finally, calculating the axial stiffness of the bearing according to a relationship between the vibration inherent frequency and the axial stiffness of the bearing.

Description

technical field [0001] The invention belongs to the technical field of mechanical measurement and can be used for measuring radial stiffness and axial stiffness of rolling bearings and some sliding bearings. Background technique [0002] The measurement method of bearing stiffness is generally based on Hooke's theorem F=Kx, and the stiffness K is calculated by measuring the force F and the displacement x caused by the force. The latest patented technology on bearing stiffness testing, such as "Bearing Stiffness Testing Device" (application number: 200810137157), "air bearing stiffness testing device" (application number: 201010530570), are all testing devices based on Hooke's theorem improvements and inventions. [0003] The test method based on Hooke's theorem belongs to the statics method. Although the principle is simple, it has high requirements on the equipment. The reason is that the bearing stiffness K is generally large, and a large force F is applied but a small d...

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Problems solved by technology

[0003] The test method based on Hooke's theorem belongs to the statics method. Although the principle is simple, it has high requirements on the equipment. The reason is that the bearing stiffness K is generally large, and a large force F is applied but a small displacement x is generated, which leads to the test The equipment not only needs to generate and measure a large load force, but also needs to precisely measure the extremely small displacement generated by the force, which will easily lead to complex structure and high cost of the test device

[0004] In addition, according to the research results of recent scientific and technological papers, there are many factors that affect the stiffness of the bearing, mainly including preload force, deformation of the inner and outer rings, etc., and these factors are usually not considered by the test device based on Hooke's theorem, so it is not easy to measure. The stiffness of the bearing in the actual installation state

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