RfN 4091

Heavy-duty series for maximum torques

Shrink discs are one of the latest methods of establishing clamping connections. Depending on the design, they essentially consist of one or two conical thrust rings and an inner ring. These elements are pressed against each other axially using clamping screws. The main difference, compared to other internal clamping connections, is that the contact pressure is exerted on the hub from the outside. This means that the shrink disc is not subjected to the main force. Instead, the torque is transmitted frictionally at the contact surface between the shaft and the hub without using an intermediate element. Thus, a shrink disc represents a straightforward and cost-effective way of creating a force fit (shrink fit) for highly stressed shaft-hub connections.

This offers considerable advantages over conventional methods of the past, when press fits could only be achieved with complex calculations, tight manufacturing tolerances and tricky assembly and disassembly processes. In addition, this approach enables replacement and centring to be carried out easily in the event of repairs. This shaft-hub connection is unrivalled in terms of its fatigue resistance under alternating torsional stresses and its radial run-out accuracy.

• Unlimited applications – RINGFEDER shrink discs are suitable for mounting hub bodies of any kind on shafts and axles. They can be used in place of shrink fits, wedge connections, keyway or polygonal connections, and splined shafts, among others. They provide a completely reliable means of securing gear wheels and sprockets, levers, cams, cam discs, belt pulleys, brake discs, flywheels, couplings, slip-on gears, flanges, rope pulleys and running wheels.
• Heavy-duty version – for maximum transmission values.
• Slitted inner ring – low loss forces and contact pressures exerted on shaft and hub.
• Compensation of small tolerance errors.
• Maximum reliability – suitable for static, dynamic and impact loads.
• Simple manufacturing of components – only minimal requirements have to be met by the functional surfaces of the components being joined.
• Easily replaceable – the RINGFEDER shrink discs do not involve any kind of positive locking.
• Easy mounting – no steps, keyways or pins are required. Can be mounted at any point on the shaft using standard screws and commercially available tools. No additional machining or fitting work is required.
• Easy removal – after loosening the clamping screws, the RINGFEDER shrink disc will self release and the hub will move freely on the shaft.
• Low susceptibility to contamination – a longer service life, as the functional contact surfaces are pressed firmly together when the clamping screws are tightened, thereby preventing the ingress of dirt and moisture.

Shrink discs GT (split)

With an arrangement of this type, longer clamping screws are required in accordance with dimension X. These must be ordered accordingly. If the “X” dimension you select is greater than 2 · L₁ (RfN 4091 standard series), you must be prepared for a reduction in the transmissible torque of up to 50% in the case of type GT.

Surface finishes

For shaft diameter d_w: Peak-to-valley height: R_a ≤ 3.2 μm