Collection: Combined needle roller / thrust ball bearings
These combine both the ball and needle roller bearing elements together within one bearing. By doing so, the bearings can accommodate both radial loads and an axial load in one direction and can be operated at high speeds. Because the two bearings are combined they are also require less space than other bearing types and so are particularly suitable for applications where space is at a premium. Some key features of combined needle roller / thrust ball bearings are :
- They accommodate both radial and axial loads
- They are suitable for operating at high speeds
- Low cross section and separable design
NX and NKX are types of combined needle roller bearings with thrust ball bearings
NX and NKX style bearings are supplied without an inner ring and are mostly used by mounting them directly on the shaft. Where the shaft cannot be used either because it is unground or the surface hardness is too soft then these bearings can be assembled with an inner ring
This bearing series can accommodate axial loads acting in one direction. This enables them to locate the shaft in one direction. For shorter shafts, two bearings can be used in a back-to-back arrangement. This is because the length of the smaller shaft is less susceptible to thermal expansion. When the bearings are used in a back-to-back arrangement it is recommended that the bearings are preloaded using spring washers as they help to prevent the bearings from skidding if one of the bearings doesn't have any load. The effect of preloading can also increase the bearing performance and reduce the noise level in operation.
Features of NX and NKX combined needle roller bearings
NX Series bearings
- They are suitable for applications with moderate radial loads and light single direction axial loads
- They are useful for applications such as multi-spindle drills
- To mount them, they can either sit against a shoulder in the bore of the housing to provide axial support or can be mounted with a snap ring to retain them. They have a snap ring groove in the outer ring to facilitate this.
- These bearings come with lubrication holes and can be lubricated with grease although they are most often oil lubricated and aren't supplied with grease as standards.
NKX Series bearings
- The thrust ball bearings contained within these bearings are identical to the 511XX series of bearing
- They are suitable for use at high speeds
- The outer ring flange enables the bearings to be located axially in one direction
- These bearings don't have lubrication holes so cannot be externally lubricated. They should be oil lubricated rather than grease lubricated as there is no facility within the bearing for grease retention.
Sealing combined needle roller bearings
Combined needle roller bearings can be supplied with a stamped steel cover over the thrust part of the bearing. These bearings have a suffix of Z on the part number to denote this. When supplied with the cover, it forms a gap seal which helps to retain grease within the bearings. There are no lubrication holes in these covers to aid re-lubrication.
Consideration needs to be given to the applications these Z suffixed bearings work on as some operation conditions such as very high speeds or temperatures can cause grease leakage. In such situations additional consideration needs to be given to either prevent grease leakage or to enable relubrication.
Other types of combined needle roller bearings
Our range of combined needle roller bearings includes :