Scroll fluid machine

Abstract

Lubricant is satisfactorily supplied to a bearing that supports an eccentric bush. A scroll compressor ( 100 ) includes a fixed scroll ( 122 ) fixed to a housing ( 140 ), an orbiting scroll ( 124 ) that orbits with respect to the fixed scroll, and a conversion mechanism ( 300 ) that mutually converts a rotary motion of a drive shaft ( 166 ) and an orbiting motion of the orbiting scroll. The converting mechanism includes an eccentric shaft ( 260 ) that is provided on an end surface of the drive shaft and is eccentric with respect to the drive shaft, an eccentric bush ( 270 ) having a through hole ( 271 ) into which the eccentric shaft is fitted, and a bearing ( 280 ) that is press-fitted into a boss portion ( 250 ) formed on the orbiting scroll and supports an outer peripheral surface ( 272 ) of the eccentric bush. A lubricant supply passage ( 350 ) for supplying lubricant to the bearing is penetratingly formed in the eccentric bush. An outlet ( 356 ) of the lubricant supply passage is disposed on the outer peripheral surface of the eccentric bush ( 272 ).

1 . A scroll fluid machine comprising, in a housing:
 a rotating main shaft that is rotatably provided;   a fixed scroll fixed to the housing;   an orbiting scroll that orbits with respect to the fixed scroll; and   a conversion mechanism that mutually converts a rotary motion of the rotating main shaft and an orbiting motion of the orbiting scroll,   wherein the conversion mechanism includes:
 an eccentric shaft that is provided on an end surface of the rotating main shaft and is eccentric with respect to the rotating main shaft; 
 an eccentric bush that has a though hole into which the eccentric shaft is fitted; and 
 a bearing that is press-fitted into a boss portion formed on the orbiting scroll and supports an outer peripheral surface of the eccentric bush, 
   wherein a lubricant supply passage for supplying a lubricant to the bearing is penetratingly formed in the eccentric bush, and   wherein an outlet of the lubricant supply passage is disposed on the outer peripheral surface of the eccentric bush.   
     
     
         2 . The scroll fluid machine according to  claim 1 , wherein the outlet of the lubricant supply passage faces an inner peripheral surface of the bearing. 
     
     
         3 . The scroll fluid machine according to  claim 1 ,
 wherein the lubricant supply passage includes an axial flow passage extending in an axial direction of the eccentric bush and a radial flow passage extending in a radial direction of the eccentric bush,   wherein the axial flow passage has an inlet of the lubricant supply passage, and   wherein the radial flow passage has the outlet of the lubricant supply passage.   
     
     
         4 . The scroll fluid machine according to  claim 1 , wherein the lubricant supply passage is further away than a central axis of the eccentric bush when viewed from a central axis of the rotating main shaft. 
     
     
         5 . The scroll fluid machine according to  claim 1 , wherein, when the eccentric bush is divided, by a virtual plane including a central axis of the rotating main shaft, into a first region and a second region, the first region includes a central axis of the eccentric bush, the lubricant supply passage, and the through hole positioned therein. 
     
     
         6 . The scroll fluid machine according to  claim 5 , wherein the lubricant supply passage is further away than the central axis of the eccentric bush when viewed from the virtual plane. 
     
     
         7 . The scroll fluid machine according to  claim 1 , further comprising a back pressure chamber that is formed on a back surface side of the orbiting scroll and generates a back pressure that presses and biases the orbiting scroll toward the fixed scroll, wherein
 an inlet of the lubricant supply passage communicates with the back pressure chamber.   
     
     
         8 . The scroll fluid machine according to  claim 1 , wherein an inlet of the lubricant supply passage is disposed on a concave portion formed on an end surface of the eccentric bush. 
     
     
         9 . The scroll fluid machine according to  claim 1 , wherein a sliding bearing is used as the bearing.