Scroll Type Compressor

Abstract

A scroll-type compressor, while adopting an Oldham mechanism as a rotation prevention mechanism, lubricates an Oldham ring by retaining a medium mixed with oil on a back surface of an orbiting scroll and maintains a compression mechanism in a compact shape. The Oldham ring is provided between the orbiting scroll and a block which supports a drive shaft. An annular thrust race which receives a load in the axial direction from the orbiting scroll is sandwiched between a fixed scroll and the block. An end surface of the circumference of the orbiting scroll is brought into contact with the race, and the race is brought into contact with an end surface of the block to an area outside a pair of key groove portions formed on the block in the radial direction. A retention space, defined by the orbiting scroll, the race, and the block, retains the medium.

1 . A scroll-type compressor comprising:
 a fixed scroll member whose movement in the rotational direction and the axial direction with respect to the inside of a housing is limited;   a drive shaft which transmits a rotational force;   an orbiting scroll member which is arranged to face the fixed scroll member in an opposed manner, and is connected to the drive shaft by way of an eccentric shaft which is eccentric with respect to the shaft center of the drive shaft so that the orbiting scroll member performs a orbiting movement about the shaft center of the drive shaft;   a block member which is provided on a side of the orbiting scroll member opposite to a side to which the fixed scroll member faces in an opposed manner, and pivotally supports the drive shaft; and   a rotation prevention member which is arranged between the orbiting scroll member and the block member, includes a plurality of key portions which are slidably engaged with a plurality of key groove portions formed on a back surface of the orbiting scroll member and a plurality of key portions which are slidably engaged with a plurality of key groove portions formed on an end surface of the block member which faces the orbiting scroll member in an opposed manner, and prevents the rotation of the orbiting scroll member by making the key portions engaged with the key groove portions corresponding to the key portions respectively,   wherein a medium is compressed by moving a compression chamber formed by the fixed scroll member and the orbiting scroll member toward a center side while reducing a volume of the compression chamber due to the orbiting movement of the orbiting scroll member, and wherein   an annular thrust race which receives the orbiting scroll member in the axial direction is sandwiched between the fixed scroll member and the block member,   the thrust race is slidably brought into close contact with the whole circumference of an end surface of the orbiting scroll member which faces the thrust race in an opposed manner, and the thrust race is brought into close contact with the end surface of the block member to an area outside the key groove portions formed on the block member in the radial direction, and   a retention space is defined by the orbiting scroll member, the thrust race and the block member, and the medium compressed in the compression chamber is supplied to and is retained in the retention space.   
     
     
         2 . The scroll-type compressor according to  claim 1 , wherein an annular slide surface with which the thrust race is brought into close contact is formed by forming a recessed portion on a back surface of an end plate of the orbiting scroll member, and the slide surface is formed such that the slide surface does not project from the thrust race. 
     
     
         3 . The scroll-type compressor according to  claim 1 , wherein a discharge region, where the medium which is retained in the retention space is discharged, is formed behind the fixed scroll member in the inside of the housing, and
 the discharge region and the retention space are communicated with each other through a pressure supply passage having a throttle formed in a middle portion thereof.   
     
     
         4 . The scroll-type compressor according to  claim 3 , wherein the retention space and an intake passage through which the medium is introduced into the compression chamber are communicated with each other through a pressure release passage, and a pressure regulating valve is arranged in the middle portion of the pressure release passage. 
     
     
         5 . The scroll-type compressor according to  claim 4 , wherein the rotation prevention member is arranged in an Oldham accommodating portion which is formed in the block portion, and comprises: a ring portion; a pair of key portions which is formed on the ring portion in a projecting manner, passes through the thrust race, and is slidably engaged with the pair of key groove portions formed on the back surface of the orbiting scroll member; and a pair of key portions which is formed on both sides of the ring portion in the radial direction in a projecting manner, and is slidably engaged with the pair of key groove portions formed on the block member,
 the Oldham accommodating portion comprises: a ring portion accommodating portion which accommodates the ring portion therein, and a pair of key groove portions which is communicated with the ring portion accommodating portion and with which the pair of key portions formed on both sides of the ring portion in the radial direction in a projecting manner is slidably engaged, and   the pressure supply passage is communicated with one of the pair of key groove portions formed on the block member, and the pressure release passage is communicated with the other of the pair of key groove portions formed on the block member.   
     
     
         6 . The scroll-type compressor according to  claim 2 , wherein a discharge region, where the medium which is retained in the retention space is discharged, is formed behind the fixed scroll member in the inside of the housing, and
 the discharge region and the retention space are communicated with each other through a pressure supply passage having a throttle formed in a middle portion thereof.   
     
     
         7 . The scroll-type compressor according to  claim 6 , wherein the retention space and an intake passage through which the medium is introduced into the compression chamber are communicated with each other through a pressure release passage, and a pressure regulating valve is arranged in the middle portion of the pressure release passage. 
     
     
         8 . The scroll-type compressor according to  claim 7 , wherein the rotation prevention member is arranged in an Oldham accommodating portion which is formed in the block portion, and comprises: a ring portion; a pair of key portions which is formed on the ring portion in a projecting manner, passes through the thrust race, and is slidably engaged with the pair of key groove portions formed on the back surface of the orbiting scroll member; and a pair of key portions which is formed on both sides of the ring portion in the radial direction in a projecting manner, and is slidably engaged with the pair of key groove portions formed on the block member,
 the Oldham accommodating portion comprises: a ring portion accommodating portion which accommodates the ring portion therein, and a pair of key groove portions which is communicated with the ring portion accommodating portion and with which the pair of key portions formed on both sides of the ring portion in the radial direction in a projecting manner is slidably engaged, and   the pressure supply passage is communicated with one of the pair of key groove portions formed on the block member, and the pressure release passage is communicated with the other of the pair of key groove portions formed on the block member.