Self-aligning roller bearings and spherical roller bearings are used in a large number of radially loaded applications in which an angle fault is to be compensated between the housing and shaft. It is possible to use these bearings for high loads by using the rolling element roller with line contact between the outer ring and inner ring. This bearing becomes problematical if the loading on the rolling bearing becomes too small, because the rows of rollers have the tendency that they no longer move in a rolling fashion but rather slide in the raceways. This sliding of the rolling elements in the raceways is then also associated with a drop in the rotational speed of the cage with the rolling elements. If the loading on the rolling bearing then suddenly increases, the rolling element which then engages between the outer ring and inner ring must accelerate the entire cage with all the other rolling elements to the correct rotational speed within fractions of a second. During this acceleration process, very high forces associated with a high sliding friction are generated which may damage the rolling elements and the raceways of the outer ring and the inner ring. This problem occurs, for example, in applications in which the rolling elements are subject only to a small load during normal operation. If an increase in the load occurs due to interference variables or load peaks, this leads to a situation in which the rolling bearings briefly experience a peak load, and the effect described above possibly occurs.
DE 8803970 U1 describes a radial rolling bearing in which both rollers and balls are used simultaneously together as rolling elements. The problem with this application is that the additional ball is intended to increase the basic bearing load rating of this combined self-aligning ball bearing. However, the problem of the sliding of the rolling elements and of the brief acceleration of an entire row of rollers is not solved with this embodiment.
Furthermore, DE 29 18 601 discloses a cylindrical roller bearing with cylindrical rollers and balls as the roller elements. The problem with this application is that the formation of a groove by the rolling elements is to be avoided when the outer ring and inner ring rotate at the same speed.
USPTO Backgrounds
USPTO Backgrounds