Deep groove ball bearing is in common use rolling bearing. Its structure is put into use simplely, going to the lavatory. Need to be used to bear radial direction loading , have the function definitely contacting ball axle bearing piece , can bear the footpath , axial unity loading while but enhancing axle bearing radial direction end play. When height is inadvisable to adopt propulsive force ball axle bearing comparatively in the rotation rate, also available come to bear pure axial loading. Other type axle bearing being same as the dimension is parallel , this kind axle bearing friction coefficients are minor , the limit rotation rate is high. Only be not able to bear pound no proper bear heavy loading. After axle bearing installs deep ditch ball on the axis, may restrict the axis or axial outer covering two direction displacement , may therefore in axial two-way work allocation within axial axle bearing end play range. Besides, be kind axle bearing's turn to have the certain tune heart ability,