The motor bearing is an important part of the motor, and its preload and stiffness directly affect the running accuracy, stability and life of the motor. This paper will give a detailed introduction to the preload force and stiffness analysis of motor bearings to help readers better understand and choose suitable bearings.
What is preload?
Preload refers to the bearing installation, through a certain method to produce a certain pressure between the inner and outer rings of the bearing, in order to eliminate the bearing clearance, improve the bearing rigidity and operating accuracy.
The role of preload
The role of preload is mainly manifested in the following aspects:
(1) Improve the rigidity of the bearing: the preload can make the inner and outer rings of the bearing close contact, reduce the deformation and vibration of the bearing, so as to improve the rigidity of the bearing.
(2) Improve the running accuracy of the bearing: the preload can eliminate the bearing clearance, reduce the radial runout and axial movement of the bearing, so as to improve the running accuracy of the bearing.
(3) Improve the bearing stress condition: the preload can make the bearing inner and outer rings uniform stress, reduce stress concentration and wear, thus extending the service life of the bearing.
How to perform preload analysis?
The preload analysis can be performed in the following ways:
(1) Theoretical calculation: according to the structure and stress of the bearing, the size of the preload force is obtained through theoretical calculation.
(2) Experimental test: the rigidity and operating accuracy of bearings under different preloading forces are obtained through experimental tests, so as to determine the appropriate preloading force.
What is stiffness?
Stiffness refers to the ability of the object to resist deformation under the action of force, that is, the elastic modulus. For bearings, stiffness refers to their ability to resist radial and axial deformation under force.
Effect of stiffness
The role of stiffness is mainly manifested in the following aspects:
(1) Improve the bearing capacity: the higher the stiffness of the bearing can withstand greater radial and axial loads.
(2) Reduce the deformation and vibration of the bearing: the higher the stiffness of the bearing under the force, the smaller the deformation and vibration, so as to improve the operating accuracy and stability of the bearing.
(3) Protective bearings: Bearings with high stiffness can better withstand external shocks and vibrations, so as to protect bearings from damage.
How to perform stiffness analysis?
Stiffness analysis can be performed by:
(1) Theoretical calculation: according to the structure and material properties of the bearing, the stiffness of the bearing is obtained through theoretical calculation.
(2) Experimental test: the deformation and vibration parameters of the bearing under different loads are obtained through experimental test, so as to determine the stiffness of the bearing.
Relationship between preload and stiffness
There is a close relationship between preload and stiffness. The greater the preload, the higher the rigidity of the bearing, but at the same time will increase the bearing friction and temperature rise; The higher the stiffness of the bearing, the greater the preload force is required to achieve the same rigidity requirements. Therefore, the balance relationship between preload and stiffness needs to be considered when selecting bearings.
Influence of preload force and stiffness
The influence of preload and stiffness on motor bearings is mainly manifested in the following aspects:
(1) Affect the running accuracy and stability of the bearing: the higher the preload and stiffness, the better the running accuracy and stability of the bearing.
(2) Affect the bearing capacity and life of the bearing: the higher the preload force and stiffness, the longer the bearing capacity and life.
(3) Affect the energy consumption and temperature rise of the motor: the greater the preload force, the higher the friction and temperature rise of the bearing, thereby increasing the energy consumption and temperature rise of the motor. Therefore, it is necessary to consider the influence of preload force and stiffness comprehensively when selecting bearings, and select the appropriate preload force and stiffness.
This paper introduces the main contents of the analysis of preload force and stiffness of motor bearing, including the action of preload force, the action of stiffness and the relationship and influence between preload force and stiffness. The selection of appropriate preload force and stiffness is of great significance to ensure the normal operation of the motor bearing and improve the performance of the motor. Therefore, when selecting and using motor bearings, it is necessary to fully consider and analyze the preload force and stiffness. The future research direction can further explore the characteristics and differences of preload force and stiffness of bearings of different types, different structures and different materials, so as to provide a more accurate basis for the design and application of motor bearings.
