Since there is no inner ring, the surface of the matching journal is directly used as a rolling surface. With inner ring needle roller bearings NA, NKl type Because this kind of bearing has no ribs on the inner ring, the inner ring, outer ring, full set of needle rollers and cage can be installed separately, without limiting the Wholesale non-standard bearings axial displacement of the shaft or housing. They are also widely used when the shaft or housing has swing motion. When the main engine speed is high, the needle roller bearing with cage should be selected as far as possible. When there is an axial load, it should be used in combination with other bearings, it does not limit the axial displacement of the shaft or housing. They are suitable for components with restricted radial profile sizes. Needle roller bearings-generally can only bear radial load, not axial load. The limit speed of the needle roller bearing is low..Entity ferrule needle roller bearings are compact in structure, small in radial size and large in load capacity. Since the needle rollers are separated by a cage, friction is reduced, so it can be used in parts with higher speeds. Needle roller bearings without inner ring RNA, NK type Needle roller bearings without an inner ring are suitable for components with restricted radial dimensions. This type of bearing has a variety of structures and size series, requiring that the surface hardness, machining accuracy and surface roughness of the journal or shell rolling surface should be the same as the bearing ring.63μm. The surface hardness is required to be no less than HRC60, and the surface roughness Ra value is no more than 0. Assembled G2 level needle rollers, the group batch diameter variation is within 2μm, except for the full complement needle roller bearings, all adopt high rigid cage, which can correctly guide the needle rollers parallel to the axis. Compared with other types of rolling bearings, the load of the needle roller bearing is the same when the radial dimension is the same. The capacity is the largest, and its rigidity is higher, but the friction torque is also higher. This kind of bearing does not limit the axial displacement of the shaft or housing, and the limit speed is higher
