Patent ID: 7249932

Claim:
A method of shielding a bearing against undesirable matter, which bearing is mounted in a bearing casing including a side cover covering a side of the bearing casing and mounting a bearing seal, and which bearing supports a shaft for rotation, the method including laterally covering a side of the bearing and the bearing casing such as laterally to overlap or hood or cowl said side cover by means of a circumferential shield rotatably firmly attached to the shaft and having a peripheral rim at least partially overlapping the bearing casing; when the shaft is rotating, dilating said peripheral rim to provide running clearance, shielding the bearing casing from stray undesirable matter and flinging any such stray undesirable matter touching the shield centrifugally away from the bearing casing; when the shaft is stationary, contracting said peripheral rim to touch the bearing casing to provide a seal.