Research on the Equivalent Friction Force and Power Loss of a Magnetic Bearing

Compared with rolling bearing and sliding bearing, there is no mechanical friction and wear in magnetic bearing because there is no mechanical contact. But there is still a similar character with the mechanical friction force while magnetic bearing working. The force can be defined as an equivalent friction force for the similar to mechanical friction force. The equivalent friction force is studied and is used in calculation of power loss in magnetic bearing. It means that the power loss in magnetic bearing is equal to the equivalent friction force multiplied by the rotor speed. The definitions of the power loss in magnetic bearing and friction character are the same as those of rolling bearing and sliding bearing. A research method of equivalent friction force and power loss in magnetic bearing which is analogy of the conventional research method of rolling bearing and sliding bearing is put forward. A calculation method of power loss in magnetic bearing is presented. All of this will benefit the design of magnetic bearing system.