| 摘要 |
PROBLEM TO BE SOLVED: To provide a bearing unit for wheel support which prevents invasion of foreign matters, e.g., slurry, into the interior space of the bearing while constantly keeping the pressure of the interior space comparable to the atmospheric pressure.SOLUTION: A cap 5a has an outer plate part 21 and an inner plate part 22, and a communication space 26 is formed between the plate parts 21 and 22. In the lower part of the outer plate part 21, a discharge hole 25 communicating between the outside space and the communication space 26 is formed. In the central part of the inner plate part 22, an internal air hole 24 communicating between the communication space 26 and the internal space 11 is formed. Together with the rotation of a hub 2, a raschel blade 33 is rotated within the communication space 26 in such a state as to be opposite, in proximity, to the outside surface in the axial direction of the outer plate part 21, the inner peripheral surface of the outer plate part 21 and the inside surface in the axial direction of the inner plate part 22. |
