| 摘要 |
To provide a compact bearing assembly equipped with a rotation sensor capable of detecting not only pulse signals for detecting the number of revolution, but also a home position signal, the bearing assembly equipped with the rotation sensor includes a rotatable member ( 2 ) and a non-rotatable member ( 3 ) with rolling elements ( 4 ) interposed between the rotatable and non-rotatable members ( 2 ) and ( 3 ) to permit the rotatable member ( 2 ) to be rotatable relative to the non-rotatable member ( 3 ). The rotatable member ( 2 ) is provided with a magnetic encoder ( 7 ) and the non-rotatable member ( 3 ) is provided with magnetic sensors ( 8 A) to ( 8 C). The magnetic encoder ( 7 ) includes first and second to-be-detected elements ( 7 A) and ( 7 B) each having a plurality of equally spaced, opposite magnetic poles defined therein so as to alternate with each other in a direction circumferentially thereof. The first to-be-detected element also has a magnetic characteristic disturbing element ( 15 ) provided at a predetermined site on a circumference of the magnetic encoder ( 7 ) for agitating a periodicity of the opposite magnetic poles. The two magnetic sensors ( 8 A) and ( 8 B) for detecting the first to-be-detected element ( 7 A) are spaced in a circumferential direction a distance greater than a circumferentially extending width of the disturbing element ( 15 ), and are so positioned as to be held in substantially phase-matched relation with a cycle of repetition of the opposite magnetic poles.
|
