Dynamic pressure fluid bearing
AssigneeCanon Kabushiki Kaisha
InventorsMasaki Nakaoka, Teruo Komatsu, Shinji Goto, Tsuyoshi Matsunaga
Life of this patent
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Abstract
A dynamic pressure fluid bearing, and particularly a dynamic pressure fluid bearing for effectively ensuring a minute gap between the shaft of the dynamic pressure fluid bearing and a bearing. More particularly, fluid intervenes between the shaft and the bearing and these two rotate relative to each other in a non-contact state, and a part or the whole of the bearing is formed of resin and the resin is endowed with electrical conductivity.
Claims2
A method for checking a dynamic pressure fluid bearing which comprises a support member and a rotary member rotating with fluid intervening between the support member and the rotary member so as to enable the rotary member to float in the thrust and the radial directions relative to the support member, said method comprising the steps of:
- providing such a bearing, with the support member and the rotary member so arranged relative to each other as to permit distinguish the thrust-direction electrical resistance value from the radial-direction electrical resistance value, said values being those occurring when the support member and the rotary member contact each other in the thrust direction and the radial direction, respectively;
- and
- electrically checking the floating conditions of the rotary member relative to the support member in the thrust and the radial directions by checking the electrical conduction therebetween in the thrust and the radial directions respectively.
A dynamic pressure fluid bearing comprising a support member, a rotating rotary member with fluid intervening between said support member and said rotary member, so as to cause said rotary member to float in the thrust and the radial directions relative to said support member, and a thrust receiving member receiving thrust loads of said rotary member while said rotary member is stationary or rotating at a low speed;
- said rotary member and said support member being electrically conductive, and said thrust receiving member being made of a conductive resin;
- said rotary member, said support member and said thrust receiving member being arranged such that a radial-direction electrical resistance value, when said rotary member and said support member are in contact with each other, is different from a thrust-direction electrical resistance value when said rotary member is not in contact with said support member, and such that said thrust receiving member receives said thrust loads;
- and
- means for electrically checking the floating conditions of said rotary member relative to said support member in the thrust and the radial directions by checking the electrical conduction between said rotary member and said support member.
Dependencies are inferred from the claim text.