Wherever there is a need to connect shaft and hub securely and quickly, Hydraulic Shrink Disc from NMTG are used. NMTG has developed a hydraulically tensionable shrink disc type "NHSD", which is used everywhere in drive technology for frictional shaft-hub connections. Due to its quick and safe clamping, it is particularly suitable for assembly and repetitive clamping operations on the test bench.

The main function of a Hydraulic Shrink Disc is to securely connect a shaft to a hub by means of frictional locking. Shrink Discs are external clamping device for the backlash free fastening of hollow shafts or hubs to shafts. For example, between a drive shaft and a transmission hollow shaft. The Hydraulic Shrink Disc creates a backlash-free connection by pressing the hub onto the shaft. This type of connection is mainly used to transmit torque.

The basic principle of the mechanical shrink disc is retained. This theory has long been tried and tested. Here, the force-transmitting friction surfaces are strictly separated from the hydraulic system. This strict separation prevents oil contamination of these surfaces.

By applying the Hydraulic pressure, conical surfaces are pulled together generating radial forces; these forces press the hollow shaft on to the shaft. By using conical surfaces the inner diameter reduces and the radial pressure is built up. Torques or axial forces can be transmitted frictionally from the hollow shaft to the shaft. The radial clamping forces which act through the circumference of the hollow shaft also ensure an optimum centring to the shaft. After tightening the safety/Lock nut the Shrink disc will be locked mechanically and the hydraulic pressure will be removed.