1. Field of the Invention
The invention relates to a bearing element with rolling bodies, with an inner raceway, an outer raceway and adjacent rolling bodies arranged rotatably between the inner and the outer raceways.
2. The Prior Art
Rotating machine parts generally move at a rotational speed with respect to the surroundings at which they are fastened. The connection is a rotatable bearing which, at high rotational speeds, is customarily a known type of rolling bearing. In order to maintain the rotatability over the long term, the bearings have to be lubricated. In most applications, the outer part of the bearing, the outer bearing ring, is fixed in the housing, and the rotating machine part, generally the shaft, rotates together with or without the inner bearing ring.
The differences in speed between the outer and inner bearing rings of the bearing result in a different pressure composition in air boundary layers close to the surface.
According to the continuity equation for flowing media (Bernoulli's law), a higher static pressure prevails at the outer bearing ring, which is a standstill or moves slowly, then at the inner bearing ring which rotates rapidly. This has the effect that, in the boundary layer region of the inner bearing ring, there is a suction effect in the bearing interior while the ambient pressure prevails in the boundary protection region of the outer bearing ring.
By means of the centrifugal force of the air layer rotating together with the inner bearing ring, reinforced by the rolling bodies which likewise rotate at the same time, a type of radial fan is formed, as a result of which the air is pressed counter to the pressure drop according to Bernoulli to the outer bearing ring and flows off to the outside.
At the laterally sealed bearing point, at which the lateral sealing disk bears tightly against the outer bearing ring, the air flows back radially again in the direction of the inner bearing ring such that a flow component forms in the bearing interior, this flow component, seen by itself, rotating in an opposed manner in the intermediate space between inner and outer bearing rings on both sides of the ring of rolling bodies, but rotating parallel to the axis of the shaft.
This flow is combined with the tangential component caused by the rotation, such that the starting point is a helical movement of air on both sides of the bearing point. This flow with the pressure differences associated therewith can be used for transporting lubricant in the bearing.