Shrink Discs – find manufacturers and suppliers

Shrink discs

Shrink discs are a non-positive, flange-shaped connection between hub and shaft. This is mounted on a hollow shaft or hub from the outside (externally tensioned). It exerts pressure on the shaft by reducing its internal diameter. This is done via the pressing surfaces of the outer parts (tapered). Thus an interference fit is produced. This process is also known as "shrink fit". The fit between hub and shaft is completely frictionally engaged and backlash-free. This requires a preload. This is generated either hydraulically or via high-strength screws.

Types of shrink discs

These have an internal diameter of between 12 mm and 1000 mm. They provide the necessary frictional forces, but do not transmit any torque themselves. This is rather the exception with shaft-hub connections. The shrink disc is therefore outside the force flow!

There are also two-piece designs. These are similar to taper press fits. Three-piece versions with double cone and hydraulically tensionable shrink discs are further models. Shrink discs are not subject to any standard! However, manufacturers do pay attention to similar performance and dimensions in order to remain competitive. In addition, accuracy of fit, durability, ease of handling, etc. are still important selection criteria for manufacturers.

Shrink discs are used in combination with clutch parts and on hollow transmission shafts. They are thus used to transmit radial and axial loads, bending moments and torques. They are components of clamping sets.

Ring spring shrink discs

This is a very reliable alternative to the traditional connection. It still ensures a frictional, flanged shaft-hub connection. In this case, the torque is transmitted at the joining surface between hub and shaft. This is done without any intermediate elements! Ring spring shrink discs impress with their freedom from maintenance and wear. They are also easy to mount and dismount. They have excellent concentric running properties and continuous rotational fatigue strength! Ringfeder manufactures both to standard and to customer specifications. These can also be two- or three-piece designs or stainless steel.

In principle, shrink discs are available in "light", "standard" and "heavy" versions. The shaft diameter starts at 8 mm and goes up to 800 mm. The torques vary between one and 11 million nanometers. Shrink discs are particularly suitable for high speeds.

One of the most common shrink discs - the RfN 4061

- has a slotted inner ring, which results in low loss forces. The thrust rings are forged and therefore have the highest strength. This guarantees maximum safety against breakage. The material can therefore be optimally utilised. It provides the best clamping distribution. The pretensioning force can be adjusted precisely to the corresponding application.

What other advantages do shrink discs have?

The press fit prevents the penetration of dirt. This makes the connection insensitive to dirt. The high surface pressure prevents crevice corrosion. Since there are no moving parts, there is also no wear. The greatest advantage is that shrink discs can be easily loosened and replaced even after years of the hardest continuous use. The absolute freedom from play comes into its own especially during reversing operation.

What should I pay particular attention to when choosing a manufacturer?

Shrink discs and clamping sets are complex technical units. Precision and durability are particularly important for these. High-quality workmanship materials are also decisive, but not paramount. Perfect fit is in the foreground here! Each of the German manufacturers has many years of worldwide experience. Customized manufacturing is therefore of particular importance. For tricky cases, an on-site visit is also recommended to get a better idea of the conditions of later use.