Precision locknuts

Precision locknuts are used where high axial forces must be supported and high axial runout accuracy and rigidity are required.

The thread and the axial face of the locknut in contact with the rolling bearing are produced in a single clamping operation. This allows very high axial runout accuracy to be achieved.

The available precision locknuts AM, ZM and ZMA can be used several times if handled correctly.

Axial locking by segments

Precision locknuts AM with axial locking are divided into several segments for applying the locking forces. When the hexagonal socket grub screws are tightened, the segments are elastically deformed. As a result, the thread flanks of the segments are pressed against the flanks of the shaft thread and give a high frictional force that acts to prevent loosening of the nut. The axial runout of the nut is not affected by this method of locking.
 
Mounting clearance with locknut AM for axial locking

AM · ZKLF..-2RS

  Precision locknut AM

Locking by radial locking pegs

Precision locknuts  ZM and ZMA are secured against rotation by means of two radially acting locking pegs. ZMA is the heavy series.

The locking pegs are manufactured together with the internal thread of the locknut. They mesh like comb teeth in the thread of the shaft without affecting the axial runout or damaging the thread.

The locking pegs are secured by grub screws with a hexagonal socket arranged concentrically over the locking pegs.


Mounting clearance with locknut ZM, ZMA for radial locking

DRS · ZMA · ZARF..-L
  Precision locknut ZM or ZMA

  Locking peg
 
  Grub screw

Want to find out more about our Locknuts?

You will find detailed information in our knowledge center:

Locknuts and precision locknuts

Locknuts are suitable for locating bearings on cylindrical and tapered shafts, or on adapter sleeves, and for mounting and dismounting of bearings on withdrawal sleeves.

Locknuts have four or eight evenly spaced slots on the circumference. As a result, they can be tightened particularly easily with striking-face or hook wrenches. The locknuts are secured by means of tab washers or retaining brackets.

Precision locknuts
Precision locknuts are bearing accessories for screw drives. They are used to achieve a defined axial preload in axial angular contact ball bearings for screw drives and axial/radial roller bearings for screw drives.

Precision locknuts are also used in other applications where high axial forces must be supported and high axial runout accuracy and rigidity are required.

Precision locknut designs:

axial locking by segments (design AM)
securing by radial locking pegs (designs ZM, ZMA).

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