BEARING DEVICE ADAPTED FOR USE IN WHEEL AND HAVING ROTATIONAL SPEED DETECTION DEVICE

摘要

A bearing device adapted for use in a wheel and having a rotational speed detection device, in which a magnetic encoder is shielded and protected by a protective cover from the outside of a bearing and in which the protective cover is fixed so as not to move, thereby the bearing device has enhanced reliability of detection of rotational speed. A protective cover (19) is mounted to an outer member (2) and is constructed from a non-magnetic austenitic stainless steel plate by press working in a substantially L-shaped cross-section. The protective cover (19) has a hollow circular cylindrical fitting section (19a) having axially extending slits (24) formed therein and also has a circular plate-like shielding section (19b) extending radially inward from the fitting section (19a), and closes an opening present between the outer member (2) and an inner ring (5). An annular groove (20) having a V-shaped cross-section is formed in the outer periphery of an end of the outer member (2). An engaging section (21) having a V-shaped cross-section and projecting to the inner diameter side is formed on the fitting section (19a) and is engaged with the annular groove (20). The protective cover (19) is positioned and fixed to the outer member (2) with the shielding section (19b) making close contact with an end surface (2c) of the outer member (2).