The original Schnorr® bearing preload springs “K“ series
The optimal supplement for ball bearings
Two problems continually occupy design engineers using bearings, the reduction in noise and the elimination of play in ball bearings. A solution of both these problems has been achieved by Schnorr working in close cooperation with ball bearings manufacturers. The fitting of a special version of our disc springs effectively reduces both problems and frequently results in simpler designs.
Fitting of bearing preload springs
The drawing illustrates how the outer ring of the ball bearing usually is correctly preloaded using a disc spring “K“ series. Depending on the requirements of the design, one or more disc springs can be used. In some cases it is preferable to preload the inner ring of the bearing. That is why the bore holes of disc springs for ball bearings were chosen in such a way that they match the internal diameter of an other ball bearing size. That way, a disc spring suitable for pushing the external ring of the ball bearing 6302, for example, can also be used to pretension the inner rings of the ball bearings 6205 and 6305.
- Bearing preload spring
Key advantages speak for bearing preload springs
An important advantage of “K“ disc springs is their shape of a simple ring. That ensures an equal bearing surface when multiple discs are installed. As with standard disc springs, here it also applies that in alternating arrangement with the constant force the spring deflections add up, while in case of parallel layering (same laying in) with constant spring deflection the loads add up (see figure page 7). As all springs have a strongly digressive spring characteristic (great ho/t), the spring force continues to be almost constant over a large deflection range.
Apart from the compensation for play, this brings the following advantages:
- The tolerance built up in the assembly can be accomodated without significant change in preload.
- Length variations due to heat impact are absorbed
- Any subsequent axial movement of the assembly does not alter the preload significantly.