Shrink Disc RfN 4161 stainless steel

2-piece shrink disc made of stainless steel

The RfN 4161 stainless steel shrink discs are among the most advanced frictional connections. Depending on the design, they essentially consist of one or two conical pressure rings and an inner ring. These are axially clamped against each other using clamping screws. The key difference from internal clamping connections is that the pressure is applied externally to the hub. Thus, the shrink disc does not lie in the main power flow. Instead, the torque is transmitted through frictional engagement at the mating surface between the shaft and hub without any intermediate element. This makes it possible to create a press fit (shrink fit) for high-load shaft-hub connections in a simple and cost-effective manner.
Previously, press fits required complicated calculations, extremely tight manufacturing tolerances, and considerable effort during assembly and disassembly. Additionally, repairs often led to problems such as lack of interchangeability, positioning issues, or centering. No other shaft-hub connection type offers comparable properties in terms of torsional fatigue strength and excellent concentricity.

Product Features

• Unlimited application possibilities
  Shrink discs are suitable for mounting all types of hub components onto shafts and axles. They can be used wherever shrink fits, keyways, splines, polygonal, or multi-spline connections were previously applied. They ensure reliable fastening of gear and chain wheels, levers, cams, rollers, belt or brake discs, flywheels, couplings, shaft-mounted gear units, flanges, rope pulleys, and impellers.
• Standard series – for high torques
• Slotted inner ring – low loss forces and minimal pressure on shaft and hub
• Maximum reliability – suitable for static, dynamic, and shock loads
• Simple component manufacturing – low requirements on the functional surfaces of connected parts
• Easy replacement – RINGFEDER shrink discs operate entirely without form fit
• Simple installation – no shoulder, key, or pin required; can be installed anywhere on the shaft with standard screws and common tools
• Short assembly times – cost savings especially in series production
• Easy disassembly – after loosening the clamping screws, the shrink disc self-releases and can be freely moved along the shaft
• Low sensitivity to contamination – extended service life, as the contact surfaces are tightly pressed together after tightening the clamping screws, preventing dirt and moisture from reaching the functional area

Surfaces
For shaft diameter dw: surface roughness Ra ≤ 3.2 μm