| 摘要 |
PURPOSE:To provide serviceability under such environments as with much dust afloat by furnishing No.1 spiral groove, which is to send by pressure the lubricating air to the backmost in a bearing member, and No.2 spiral groove to send out the air to an open end at the mating surfaces of a rotary shaft or a bearing member, and by installing a filter on an air passage which is to put the boundary between the two grooves in communication with the outside. CONSTITUTION:Through the pumping action of No.1 spiral groove 5 associate with rotation of a rotary shaft 1, the lubricating air 3 between this rotary shaft and a bearing member 2 is sent by pressure toward the backmost in the bearing part so as to boost the pressure. The bearing effect is generated through wedge effect of the lubricating air 3 applied between the internal surface of the bearing member 2 and the external surface of rotary shaft 1. As the air is also sent off toward the open end of the bearing member 2 through the pumping action of No.2 spiral groove 6, external dust is prevented from intruding into gaps in the bearing. As the air at the atmospheric pressure with the dust removed by passing through a filter 9 is supplied to the boundary 7 of the two grooves, no obstacle will be generated for the load capacity of the bearing. |
