吃那么一天
There are at least six common principles of operation:plain bearing, also known by the specific styles: bushings, journal bearings, sleeve bearings, rifle bearingsrolling-element bearings such as ball bearings and roller bearingsjewel bearings, in which the load is carried by rolling the axle slightly off-centerfluid bearings, in which the load is carried by a gas or liquidmagnetic bearings, in which the load is carried by a magnetic fieldflexure bearings, in which the motion is supported by a load element which bends.
