Original SCHNORR®

Bearing preload springs type “K“

Preloaded bearing springs have a smaller flank (ratio O_D / I_D) than standard disc springs due to the small installation space available.
Some ball bearing applications require a "softer deflection behaviour" at the beginning of deflection. This means a lot of deflection must generated with as little increase in spring force as possible. For this special case SCHNORR®  has developed the slotted bearing springs. Due to the slotted geometry these springs can precisely meet the requirement.

As a result of the very different dimensions of these springs compared with "normal" disc springs as defined in DIN EN 16983, the load and dimensional tolerances of disc springs designed for ball bearings do not coincide with the tolerance values in DIN EN 16983.

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 well-known 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.

Key advantages speak for bearing preload springs
An important advantage of “K“ disc springs is being round.
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. As all springs have a strongly digressive spring characteristic (great h_o/t), the spring force continues to be almost constant over a large deflection range.