Functional Characterisitics:
A SCHAAF Hydraulic Nut of this design has a circular groove which is sealed to the exterior by an axially sliding ring piston and, thus, forms an annular hydraulic chamber. When pressurized, the ring piston is pushed out, contacts the counterface and generates an axial pressure force. Since the ring piston is self aligning it can, within certain limits, adapt to errors in run-out and to an uneven counterface. This characteristic offers a great advantage, in a lot of applications.
In the case of the Hydraulic Nuts, type A 4950, the pressure is generated by an external hand or motor pump or by the machine hydraulic system which is connected to the hydraulic connection bores. (3)

Note:
- Designed stroke is 10 mm max. (4 mm stroke: see model A 4954; bigger stroke on request)
- Clamping force is precisely monitored by the pressure gauge of the pump or control unit resp.
- Radial hydraulic connection bores with types A 4900 and A 4904