초록 ▼

An oil impregnated porous bearing unit includes an arrangement wherein an oil impregnated porous bearing containing ferro-fluid is fixed in a non-magnetizable housing, a ring shaped permanent magnet is disposed so that the ferro-fluid will exist in a gap between a rotary shaft, whereon the ring shap

An oil impregnated porous bearing unit includes an arrangement wherein an oil impregnated porous bearing containing ferro-fluid is fixed in a non-magnetizable housing, a ring shaped permanent magnet is disposed so that the ferro-fluid will exist in a gap between a rotary shaft, whereon the ring shaped permanent magnet is fixed, and the oil impregnated porous bearing, and the ferro-fluid circulates between a slide plane of the bearing and a body of the oil impregnated porous bearing with rotation of the rotary shaft by utilizing the magnetic attractive force of the permanent magnet and a capillary phenomenon in the oil impregnated porous bearing. In addition, a spiral groove may be provided in an exterior circumferential surface of the permanent magnet fixed to the rotary shaft or in an interior circumferential surface of the housing facing the above exterior circumferential surface of the permanent magnet in order to generate dynamic pressure at the spiral groove portion with rotation of the rotary shaft so as to supply ferro-fluid to the oil impregnated porous bearing.

대표청구항 ▼

[ What is claimed is:] [1.] An oil impregnated porous bearing unit for rotatably supporting a rotary shaft, with a ferro-fluid disposed between the rotary shaft and a bearing of the bearing unit, said bearing unit comprising:a rotary shaft;at least one ring shaped permanent magnet fixed to said rota

[ What is claimed is:] [1.] An oil impregnated porous bearing unit for rotatably supporting a rotary shaft, with a ferro-fluid disposed between the rotary shaft and a bearing of the bearing unit, said bearing unit comprising:a rotary shaft;at least one ring shaped permanent magnet fixed to said rotary shaft for rotation therewith;a housing encircling said permanent magnet and at least a portion of said rotary shaft;at least one porous bearing fixed inside said housing at a location axially adjacent to and facing said permanent magnet to define an axial gap between an end face of said permanent magnet and an end face of said porous bearing and an annular gap between an exterior circumferential surface of said rotary shaft and an interior circumferential surface of said porous bearing;a ferro-fluid within said axial gap and said annular gap, said ferro-fluid impregnating said porous bearing and surrounding said permanent magnet;one of said rotary shaft and said porous bearing being permeable, and the other of said rotary shaft and said porous bearing being non-magnetizable; andwhereby, upon rotation of the rotary shaft the ferro-fluid is urged by centrifugal force to exude through the axial gap and the annular gap so as to circulate between said end face of said permanent magnet and said end face of said porous bearing and between said exterior circumferential surface of said rotary shaft and said interior circumferential surface of said porous bearing.