Torque Limiters / Safety Couplings:
New Backlash-Free Overload Protection with Torque Limiting Clutches

For Torque-Limited Applications

One advantage of the ball-detent design torque limiter is the separation of the drive and the driven elements in milliseconds in the event of a torque overload. The further development and optimization of the well-established, backlash-free SK Series torque limiter has resulted in ideal designs for just about any application. The torque limit is accurately set to the customer’s specifications prior to shipment of the product, and the compact design of the R+W torque limiter is also great for use in applications with restricted installation spaces.

R+W torque limiters can be used in many mechanical power transmission and motion control applications, with torque limiters available for rated torques ranging from 0.1 to 2,800 Nm.

When a torque overload occurs, the torque limiter will disengage within milliseconds. The movement of the actuation ring can be sensed, and then used to control and shut down the machine. The machine will be available immediately after re-engagement of the torque limiter.

Increased Economic Efficiency

Optimized disc springs and carefully selected, high-grade materials used in producing the coupling allow for a compact and reliable design, better performance, and a lower mass. A long service life and maintenance-free operation are important features of R+W torque limiters.

R+W torque limiters have a profile approximately 1/3 smaller than comparable products, making it the most compact torque limiter available on the market. The smaller profile results in a light weight torque limiter, with a lower moment of inertia.

A Wide Variety

Machine designs with restricted installation spaces or difficult to access areas often require special solutions. The R+W product line offers several solutions to meet the need of just about any application. The hub type best suited for the application is selected and integrated for the ideal design.

The press-fit design developed by R+W uses the axial spring force of the metal bellows to pre-tension a tapered male segment into the corresponding female segment slightly. An axial pre-tensioning of the metal bellows of 0.2 millimeters assures backlash-free torque transmission. The self-adjusting tapered segment guarantees wear-free and maintenance-free operation.

Damping Torque Limiters / Safety Couplings

R+W’s new torque overload protection with damping properties, combining the well known elastomer coupling with the benefits of torque overload protection.

Between the clutch element with clamping hub and the other coupling hub, there is an elastomer insert made of thermoplastic polyurethane (TPU) absorbing the drive vibrations. Due to its elasticity, it is able to damp vibration and impacts, as well as compensate for axial, angular, and lateral misalignment. The high damping properties of R+W’s elastomer torque limiter can help improve the service life of the connected components during operation of machinery with frequent impacts or heavy vibration loads. This is especially true of the R+W Servomax® couplings, which are manufactured to a very high concentricity and fit with a precision-calibrated insert. Less concentrically machined couplings can transmit a pulsing radial load onto shaft bearings under similar misalignment conditions.

Choice of Different Shore Hardness

R+W offers a variety of elastomer inserts, including shore hardness 98 A, 64 D, and 80 A. The inserts are precisely calibrated in order to ensure a perfect fit between the coupling hubs. The industry standard high pretension of the inserts is thus reduced and the assembly is made much easier. Assembly is not the only concern since when the inserts are pressed in at too high a pretension, the radial forces occurring with lateral misalignment on the shafts will increase. The increased flexing of overly pretensioned inserts can lead to premature wear as well, making the calibrated insert from R+W the best choice for smooth, maintenance free operation.