Patent Publication Number: US-2019178249-A1

Title: Co-rotating scroll compressor

Description:
TECHNICAL FIELD 
     The present invention relates to a co-rotating scroll compressor. 
     BACKGROUND ART 
     Hitherto, a co-rotating scroll compressor is known (see PTL 1). The co-rotating scroll compressor includes a driving-side scroll and a driven-side scroll that rotates together with and in synchronization with the driving-side scroll. The co-rotating scroll compressor rotates the driving shaft and the driven shaft in the same direction at the same angular velocity by offsetting a driven shaft that supports the rotation of the driven-side scroll from a driving shaft that rotates the driving-side scroll by the turning radius. 
     CITATION LIST 
     Patent Literature 
     [PTL 1] 
     the Publication of Japanese Patent No. 5443132 
     SUMMARY OF INVENTION 
     Technical Problem 
     An outer peripheral ring portion is provided on the driven-side scroll in PTL 1, and this outer peripheral annular block portion has a shape that surrounds the outer periphery of the driven scroll. The outer peripheral annular block portion is advantage in that the rigidity of the driven scroll is enhanced and the deformation of an end plate is suppressed, but it becomes difficult to respond to high acceleration because the rotation inertia force increases. 
     The present invention has been made in view of the situation as above, and an object thereof is to provide a co-rotating scroll compressor that enables speed up and high acceleration. 
     Solution to Problem 
     In order to solve the abovementioned problem, a co-rotating scroll compressor of the present invention employs the following solutions. 
     That is, a co-rotating scroll compressor according to an aspect of the present invention includes: a driving-side scroll member driven by a drive unit so as to rotate, and including a plurality of spiral driving-side walls provided about a center of a driving-side end plate at predetermined angular intervals; a driven-side scroll member including spiral driven-side walls, the driven-side walls being provided about a center of a driven-side end plate at predetermined angular intervals and in a number corresponding to the driving-side walls, the driven-side walls being engaged with the corresponding driving-side walls so as to form a compression space; a synchronous driving mechanism that transmits driving force from the driving-side scroll member to the driven-side scroll member so that the driving-side scroll member and the driven-side scroll member rotationally move in a same direction at a same angular velocity; and a driving-side supporting member arranged across the driven-side end plate, fixed to a distal end side of the driving-side walls in an rotation direction, and rotated together with the driving-side scroll member, and/or a driven-side supporting member arranged across the driving-side end plate, fixed to a distal end side of the driven-side walls in an rotation direction, and rotated together with the driven-side scroll member, in which a fixing portion of each of the driving-side walls to which the driving-side supporting member is fixed is provided in a position close to a radially outside end portion of the driving-side wall and separated from the radially outside end portion in an inner circumferential direction of the driving-side wall, and/or a fixing portion of each of the driven-side walls to which the driven-side supporting member is fixed is provided in a position close to a radially outside end portion of the driven-side wall and separated from the radially outside end portion in an inner circumferential direction of the driven-side wall. 
     The driving-side walls arranged about the center of the end plate of the driving-side scroll member at predetermined angular intervals and the corresponding driven-side walls of the driven-side scroll member are engaged with each other. As a result, a plurality of pairs each formed by one driving-side wall and one driven-side are provided, and the scroll-type compressor including a plurality of lines of walls is formed. The driving-side scroll member is driven by the drive unit so as to rotate, and the driving force transmitted to the driving-side scroll member is transmitted to the driven-side scroll member via the synchronous driving mechanism. As a result, the driven-side scroll member rotationally moves in the same direction at the same angular velocity as the driving-side scroll member while rotating. As described above, the co-rotating scroll compressor in which both of the driving-side scroll member and the driven-side scroll member rotate is provided. 
     When the driving-side scroll member and the driven-side scroll member rotates and the number of revolutions increases, the distal ends of the walls provided on the end plates in the rotation axis direction are displaced to a radially outside place by centrifugal force, and the walls are deformed so as to be inclined. The radially outside end portions of the walls are in positions farthest from the centers of the end plates, and hence the centrifugal force becomes the largest. Therefore, the deformation of the walls becomes the largest at the radially outside end portions. Thus, by fixing the supporting members on the free end side of the walls, the rigidity of the walls is increased and the speed up can be responded to. 
     The fixing portions of the walls to which the supporting members are fixed has higher rigidity as compared to other regions of the walls. Therefore, it is conceived to be preferred that the fixing portions be provided on the radially outside end portions of the walls subjected to the largest centrifugal force. However, as a result of keen examination by the inventors and the like, it has been found that, when the fixing portions are provided on the radially outside end portions, the rigidity becomes higher but the stress caused by the centrifugal force increases on the contrary because the mass of the fixing portions becomes larger than the other wall regions. Thus, the fixing portions are provided in positions close to the radially outside end portions of the walls and separated from the radially outside end portions in the inner circumferential direction of the walls. As a result, as compared to a case where the fixing portions are placed on the radially outside end portions, the stress generated on the fixing portions can be reduced, and hence the speed up and the high acceleration can be responded to. 
     Further, in the co-rotating scroll compressor according to an aspect of the present invention, an angle formed by a line connecting a center of the driving-side wall and the radially outside end portion to each other and a line connecting the center of the driving-side wall and a middle of the fixing portion to each other is 10° or more and 50° or less when the driving-side wall is seen in planar view; and/or an angle formed by a line connecting a center of the driven-side wall and the radially outside end portion to each other and a line connecting the center of the driven-side wall and a middle of the fixing portion to each other is 10° or more and 50° or less when the driven-side wall is seen in planar view. 
     As the position close to the radially outside end portion of the wall in which the fixing portion is provided, the angle formed by the line connecting the center of the wall and the radially outside end portion to each other and the line connecting the center of the wall and the middle of the fixing portion to each other is preferably 10° or more and 50° or less. 
     Further, in the co-rotating scroll compressor according to an aspect of the present invention, the driving-side scroll member includes: a first driving-side scroll portion including a first driving-side end plate and a first driving-side wall, the first driving-side scroll portion being driven by the drive unit; a second driving-side scroll member including a second driving-side end plate and a second driving-side wall; and a wall fixing portion that performs fixing in a state in which distal ends of the first driving-side wall and the second driving-side wall in a rotation axis direction face each other; the driven-side scroll member includes: a first driven-side wall provided on one side surface of the driven-side end plate, the first driven-side wall being engaged with the first driving-side wall; and a second driven-side wall provided on another side surface of the driven-side end plate, the second driven-side wall being engaged with the second driving-side wall; and the driven-side supporting member includes: a first supporting member arranged across the first driving-side end plate, fixed on a distal end side of the first driven-side wall in a rotation axis direction, and rotated together with the first driven-side wall; and a second supporting member arranged across the second driving-side end plate, fixed to a distal end side of the second driven-side wall in a rotation axis direction, and rotated together with the second driven-side wall. 
     By engaging the first driving-side wall and the first driven-side wall with each other and engaging the second driving-side wall and the second driven-side wall with each other, the compression spaces are formed on both side surfaces of the driven-side end plate. Further, by providing the first supporting member fixed to the first driven-side wall and the second supporting member fixed to the second driven-side wall, the rigidity of the walls is increased. Further, as described above, the fixing portion is provided in a position close to the radially outside end portion of the wall and separated from the radially outside end portion in the inner circumferential direction of the wall. As a result, as compared to a case where the fixing portion is placed on the radially outside end portion, the weight increase can be suppressed and the stress generated on the fixing portion can be reduced. Therefore, the speed up and the high acceleration can be responded to. 
     Advantageous Effects of Invention 
     The fixing portion of the wall to which the supporting member is fixed is provided in a position close to the radially outside end portion of the wall and separated from the radially outside end portion in the inner circumferential direction of the wall. As a result, as compared to a case where the fixing portion is placed on the radially outside end portion, the stress generated on the fixing portion can be reduced, and hence the speed up and the high acceleration can be responded to. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a longitudinal cross-sectional view illustrating a co-rotating scroll compressor according to a first embodiment of the present invention. 
         FIG. 2  is a plan view illustrating a driving-side scroll member in  FIG. 1 . 
         FIG. 3  is a plan view illustrating a driven-side scroll member in  FIG. 1 . 
         FIG. 4  is a side view of a driving-side supporting member in  FIG. 1  seen from the exhaust side. 
         FIG. 5  is a side view of the driven-side supporting member in  FIG. 1  seen from the motor side. 
         FIG. 6  is a longitudinal cross-sectional view illustrating a co-rotating scroll compressor according to a second embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiments according to the present invention are described below with reference to the drawings. 
     First Embodiment 
     A first embodiment of the present invention is described below with reference to  FIG. 1  and the like. 
       FIG. 1  illustrates a co-rotating scroll compressor  1 A. The co-rotating scroll compressor  1 A can be used as a supercharger that compresses combustion air (fluid) to be supplied to an internal combustion engine such as a vehicle engine, for example. 
     The co-rotating scroll compressor  1 A includes a housing  3 , and a driving-side scroll member  7  and the driven-side scroll member  9  accommodated in the other end side of the housing  3 . 
     The housing  3  has a substantially cylindrical shape, and has one end (not shown) on which a motor accommodation portion that accommodates a drive unit such as an electric motor is provided. As illustrated in  FIG. 1 , a scroll accommodation portion  3   b  that accommodates the scroll members  7  and  9  are included on the other end. An exhaust opening  3   d  for exhausting air that has been compressed is formed in an end portion of the scroll accommodation portion  3   b . Note that, although not shown in  FIG. 1 , an air suction opening that sucks air is provided in the housing  3 . 
     The rotational driving force from a rotor of the motor is transmitted to a driving-side shaft portion  7   c  of the driving-side scroll member  7  that rotates about a driving rotational axis CL 1 . 
     The driving-side scroll member  7  includes a driving-side end plate  7   a , and a spiral driving-side wall  7   b  provided on one side of the driving-side end plate  7   a . The driving-side end plate  7   a  is connected to the driving-side shaft portion  7   c  connected to a driving shaft  6 , and extends in a direction orthogonal to the driving-side rotational axis CL 1 . The driving-side shaft portion  7   c  is provided so as to be rotatable with respect to the housing  3  via a driving-side bearing  11  that is a ball bearing. 
     The driving-side end plate  7   a  has a substantially disk-like shape when seen in planar view. As illustrated in  FIG. 2 , the driving-side scroll member  7  includes three spiral driving-side walls  7   b , that is, three lines of spiral driving-side walls  7   b . The three lines of driving-side walls  7   b  are provided about the driving-side rotational axis CL 1  at regular intervals. Radially outside end portions  7   e  of the driving-side walls  7   b  are not fixed to the other wall portions and are independent. That is, wall portions that connect the radially outside end portions  7   e  to each other so as to provide reinforcement are not provided. 
     Driving-side fixing portions  7   f  for fixing a driving-side supporting member  20  described below is provided near the radially outside end portions  7   e  of the driving-side walls  7   b . The driving-side fixing portion  7   f  is a bulging portion obtained by increasing the board thickness of the driving-side wall  7   b  radially outward. The forming position of the driving-side fixing portion  7   f  is a position separated from the radially outside end portion  7   e  in the inner circumferential direction (winding starting direction) of the driving-side wall  7   b . Specifically, an angle θ formed by the line connecting the driving-side rotational axis CL 1  and the radially outside end portion  7   e  to each other and the line connecting the driving-side rotational axis CL 1  and the middle of the driving-side fixing portion  7   f  (more specifically, the center of a fastening member  24   a ) to each other is 10° or more and 50° or less. 
     As illustrated in  FIG. 1 , the driven-side scroll member  9  is arranged so as to engage with the driving-side scroll member  7 , and includes a driven-side end plate  9   a  and a spiral driven-side wall  9   b  provided on one side of the driven-side end plate  9   a . A driven-side shaft portion  9   c  that extends in the direction of a driven-side rotational axis CL 2  is connected to the driven-side end plate  9   a . The driven-side shaft portion  9   c  is provided so as to be rotatable with respect to the housing  3  via a driven-side bearing  13  that is a double row ball bearing. 
     The driven-side end plate  9   a  has a substantially disk-like shape when seen in planar view. As illustrated in  FIG. 3 , three spiral driven-side walls  9   b , that is, three lines of spiral driven-side walls  9   b  are provided in the driven-side scroll member  9 . The three lines of driven-side walls  9   b  are arranged about the driven-side rotational axis CL 2  at regular intervals. An exhaust port  9   d  that exhausts air that has been compressed is formed in substantially the middle of the driven-side end plate  9   a . The exhaust port  9   d  communicates with the exhaust opening  3   d  formed in the housing  3 . Radially outside end portions  9   e  of the driven-side walls  9   b  are not fixed to the other wall portions and are independent. That is, wall portions that connect the radially outside end portions  9   e  to each other so as to provide reinforcement are not provided. 
     Driven-side fixing portions  9   f  for fixing a driven-side supporting member  22  described below is provided near the radially outside end portions  9   e  of the driven-side walls  9   b . The driven-side fixing portion  9   f  is a bulging portion obtained by increasing the board thickness of the driven-side wall  9   b  radially outward. The forming position of the driven-side fixing portion  9   f  is a position separated from the radially outside end portion  9   e  in the inner circumferential direction (winding starting direction) of the driven-side wall  9   b . Specifically, an angle θ formed by the line connecting the driven-side rotational axis CL 2  and the radially outside end portion  9   e  to each other and the line connecting the driven-side rotational axis CL 2  and the middle of the driven-side fixing portion  9   f  (more specifically, the center of a fastening member  24   b ) to each other is 10° or more and 50° or less. 
     As described above, as illustrated in  FIG. 1 , the driving-side scroll member  7  rotates about the driving-side rotational axis CL 1  and the driven-side scroll member  9  rotates about the driven-side rotational axis CL 2 . The driving-side rotational axis CL 1  and the driven-side rotational axis CL 2  are offset from each other by a distance with which a compression chamber can be formed. 
     As illustrated in  FIG. 1 , the driving-side supporting member  20  is fixed to the driving-side fixing portion  7   f  on the distal end (free end) of the driving-side wall  7   b  of the driving-side scroll member  7  via the fastening member  24   a  such as a pin or a bolt. The driven-side scroll member  9  is sandwiched between the driving-side supporting member  20  and the driving-side scroll member  7 . Therefore, the driven-side end plate  9   a  is arranged so as to be opposed to the driving-side supporting member  20 . 
     The driving-side supporting member  20  includes a shaft portion  20   a  on the center side. The shaft portion  20   a  is rotatably attached with respect to the housing  3  via a bearing  26  for the driving-side supporting member that is a ball bearing. As a result, the driving-side supporting member  20  rotates about the driving-side rotational axis CL 1  as with the driving-side scroll member  7 . 
     As illustrated in  FIG. 4 , the driving-side supporting member  20  includes a radially extending portion  20   b  that extends radially outward to the position of the outer periphery of the driving-side wall  7   b  for each position in which the distal end of the driving-side wall  7   b  is fixed by the fixing portion  7   f  (see  FIG. 2 ). The region between the radially extending portions  20   b  has a shape that does not extend to the outer periphery side of the driving-side wall  7   b , and saves weight. In this embodiment, the radially extending portions  20   b  are provided in three directions at equiangular intervals. Note that, in  FIG. 4 , the driving-side supporting member  20  and the driven-side scroll member  9  are illustrated and the driving-side scroll member  7  is not illustrated. 
     As illustrated in  FIG. 1 , a pin ring mechanism  15  is provided between the driving-side supporting member  20  and the driven-side end plate  9   a . The pin ring mechanism  15  is used as a synchronous driving mechanism that transmits driving force from the driving-side scroll member  7  to the driven-side scroll member  9  so that both of the scroll members  7  and  9  rotationally move in the same direction at the same angular velocity. That is, a ring member  15   a  that is a ball bearing is provided in the driven-side end plate  9   a , and a pin member  15   b  is provided in the driving-side supporting member  20 . As illustrated in  FIG. 4 , three pin members  15   b  are provided so as to correspond to the positions of the radially extending portions  20   b  of the driving-side supporting member  20 . 
     As illustrated in  FIG. 1 , the driven-side supporting member  22  is fixed to the distal end (free end) of the driven-side wall  9   b  of the driven-side scroll member  9  via the fastening member  24   b  such as a pin or a bolt. The driving-side scroll member  7  is sandwiched between the driven-side supporting member  22  and the driven-side scroll member  9 . Therefore, the driving-side end plate  7   a  is arranged so as to be opposed to the driven-side supporting member  22 . 
     The driven-side supporting member  22  includes a shaft portion  22   a  on the center side. The shaft portion  22   a  is rotatably attached with respect to the housing  3  via a bearing  28  for the driven-side supporting member that is a ball bearing. As a result, the driven-side supporting member  22  rotates about the driven-side rotational axis CL 2  as with the driven-side scroll member  9 . 
     As illustrated in  FIG. 5 , the driven-side supporting member  22  includes a radially extending portion  22   b  that extends radially outward to the position of the outer periphery of the driven-side wall  9   b  for each position in which the distal end of the driven-side wall  9   b  is fixed. The region between the radially extending portions  22   b  has a shape that does not extend to the outer periphery side of the driven-side wall  9   b , and saves weight. In this embodiment, the radially extending portions  22   b  are provided in three directions at equiangular intervals. Note that, in  FIG. 5 , the driven-side supporting member  22  and the driving-side scroll member  7  are illustrated and the driven-side scroll member  9  is not illustrated. 
     As illustrated in  FIG. 1 , the pin ring mechanism  15  is provided between the driven-side supporting member  22  and the driving-side end plate  7   a . The pin ring mechanism  15  is used as a synchronous driving mechanism that transmits driving force from the driving-side scroll member  7  to the driven-side scroll member  9  so that both of the scroll members  7  and  9  rotationally move in the same direction at the same angular velocity. That is, the ring member  15   a  is provided in the driving-side end plate  7   a , and the pin member  15   b  is provided in the driven-side supporting member  22 . As illustrated in  FIG. 5 , three pin members  15   b  are provided so as to correspond to the positions of the radially extending portions  22   b  of the driven-side supporting member  22 . 
     The co-rotating scroll compressor  1 A having the abovementioned configuration operates as follows. 
     When the driving shaft is rotated about the driving-side rotational axis CL 1  by the motor, the driving-side shaft portion  7   c  connected to the driving shaft also rotates. As a result, the driving-side scroll member  7  rotates about the driving-side rotational axis CL 1 . When the driving-side scroll member  7  rotates, the driving force is transmitted from the driving-side end plate  7   a  to the driven-side supporting member  22  via the pin ring mechanism  15 . Further, the driving force is transmitted from the driving-side supporting member  20  to the driven-side end plate  9   a  via the pin ring mechanism  15 . As a result, the driving force is transmitted to the driven-side scroll member  9 , and the driven-side scroll member  9  rotates about the driven-side rotational axis CL 2 . At this time, the pin member  15   b  of the pin ring mechanism  15  moves while being in contact with the ring member  15   a , and hence both of the scroll members  7  and  9  rotationally move in the same direction at the same angular velocity. 
     When both of the scroll members  7  and  9  rotationally move in the same direction at the same angular velocity, the air sucked from the suction opening in the housing  3  is sucked from the outer periphery side of both of the scroll members  7  and  9 , and is taken into the compression chamber formed by both of the scroll members  7  and  9 . The capacity of the compression chamber decreases as the compression chamber approaches the center side, and air is compressed accordingly. The air compressed as above flows through the exhaust port  9   d  in the driven-side scroll member  9  and is exhausted to the outside from the exhaust opening  3   d  in the housing  3 . The exhausted compressed air is guided to an internal combustion engine (not shown) and is used as combustion air. 
     The effects of this embodiment is as follows. 
     When the driving-side scroll member  7  and the driven-side scroll member  9  rotate and the number of revolutions increases, the distal ends of the walls  7   b  and  9   b  provided on the end plates  7   a  and  9   a  in the rotation axis direction are displaced to a radially outside place by centrifugal force, and the walls  7   b  and  9   b  are deformed so as to be inclined. The radially outside end portions  7   e  and  9   e  of the walls  7   b  and  9   b  are in positions farthest from the centers CL 1  and CL 2  of the end plates, and hence the centrifugal force becomes the largest. Therefore, the deformation of the walls  7   b  and  9   b  becomes the largest at the radially outside end portions  7   e  and  9   e . Thus, by fixing the supporting members  20  and  22  on the free end side of the walls  7   b  and  9   b , the rigidity of the walls  7   b  and  9   b  is increased and the speed up can be responded to. 
     The fixing portions  7   f  and  9   f  of the walls  7   b  and  9   b  to which the supporting members  20  and  22  are fixed have higher rigidity as compared to other regions of the walls  7   b  and  9   b . Therefore, it is conceived to be preferred that the fixing portions  7   f  and  9   f  be provided on the radially outside end portions  7   e  and  9   e  of the walls  7   b  and  9   b  subjected to the largest centrifugal force. However, as a result of keen examination by the inventors and the like, it has been found that, when the fixing portions  7   f  and  9   f  are provided on the radially outside end portions  7   e  and  9   e , the rigidity becomes higher but the stress caused by the centrifugal force increases on the contrary because the mass of the fixing portions  7   f  and  9   f  becomes larger than the other wall regions. Thus, the fixing portions  7   f  and  9   f  are provided in positions close to the radially outside end portions  7   e  and  9   e  of the walls  7   b  and  9   b  and separated from the radially outside end portions  7   e  and  9   e  in the inner circumferential direction of the walls  7   b  and  9   b . As a result, as compared to a case where the fixing portions  7   f  and  9   f  are placed on the radially outside end portions  7   e  and  9   e , the stress generated on the fixing portions  7   f  and  9   f  can be reduced, and hence the speed up and the high acceleration can be responded to. For example, the speed up of 10000 rotations per minute or more, preferably 15000 rotations or more can be responded to, and high acceleration that reaches to 10000 rotations in 0.5 seconds at the time of start-up can be responded to. 
     Second Embodiment 
     The arrangement and the structure of the fixing portions  7   f  and  9   f  described in the first embodiment can be also applied to a co-rotating scroll compressor described below. 
       FIG. 6  illustrates a co-rotating scroll compressor  1 B according to this embodiment. Note that structures similar to those in the co-rotating scroll compressor  1 A described with reference to  FIG. 1  are the same denoted by the same reference character, and the description thereof is omitted. 
     As illustrated in  FIG. 6 , the driving-side scroll member  70  includes a first driving-side scroll portion  71  on the motor side (the right side in  FIG. 6 ) and a second driving-side scroll portion  72  on the exhaust opening  3   d  side. 
     The first driving-side scroll portion  71  includes a first driving-side end plate  71   a  and a first driving-side wall  71   b . Three lines of first driving-side walls  71   b  are provided as with the abovementioned driving-side walls  7   b  (see  FIG. 2 ). 
     The second driving-side scroll portion  72  includes a second driving-side end plate  72   a  and a second driving-side wall  72   b . Three lines of second driving-side walls  72   b  are provided as with the abovementioned driving-side walls  7   b  (see  FIG. 2 ). A second driving-side shaft portion  72   c  that extends in the direction of the driving-side rotational axis CL 1  is connected to the second driving-side end plate  72   a . The second driving-side shaft portion  72   c  is provided so as to be rotatable with respect to the housing  3  via a second driving-side bearing  14  that is a ball bearing. An exhaust port  72   d  is formed in the second driving-side shaft portion  72   c  along the driving-side rotational axis CL 1 . 
     The first driving-side scroll portion  71  and the second driving-side scroll portion  72  are fixed in a state in which the distal ends (free ends) of the walls  71   b  and  72   b  are facing each other. The first driving-side scroll portion  71  and the second driving-side scroll portion  72  are fixed by a bolt (wall fixing portion)  31  fastened with respect to flange parts  73  provided in a plurality of places so as to protrude radially outward. 
     The driven-side scroll member  90  includes a driven-side end plate  90   a  provided in substantially the middle in the axial direction (the horizontal direction in  FIG. 6 ). A through hole (not shown) is formed in the middle of the driven-side end plate  90   a , and air that has been compressed flows to the exhaust port  72   d.    
     Driven-side walls  91   b  and  92   b  are provided on both sides of the driven-side end plate  90   a . The first driven-side wall  91   b  provided from the driven-side end plate  90   a  to the motor side is engaged with the first driving-side wall  71   b  of the first driving-side scroll portion  71 , and the second driven-side wall  92   b  provided from the driven-side end plate  90   a  to the exhaust opening  3   d  side is engaged with the second driving-side wall  72   b  of the second driving-side scroll portion  72 . 
     A first supporting member  33  and a second supporting member  35  are provided on both ends of the driven-side scroll member  90  in the axial direction (the horizontal direction in  FIG. 6 ). The first supporting member  33  is arranged on the motor side (the right side in  FIG. 6 ), and the second supporting member  35  is arranged on the exhaust opening  3   d  side. The first supporting member  33  is fixed to a first fixing portion  91   f  on the distal end (free end) of the first driven-side wall  91   b  by a fastening member  25   a  such as a pin or a bolt, and the second supporting member  35  is fixed to a second fixing portion  92   f  on the distal end (free end) of the second driven-side wall  92   b  by a fastening member  25   b  such as a pin or a bolt. As with the driven-side fixing portion  9   f  described with reference to  FIG. 3 , the fixing portions  91   f  and  92   f  provided on the driven-side walls  91   b  and  92   b  are bulging portions obtained by increasing the board thickness of the driven-side walls  91   b  and  92   b  radially outward, and are in positions separated from the radially outside end portions in the inner circumferential direction (winding starting direction) of the driven-side walls  91   b  and  92   b.    
     A shaft portion  33   a  is provided on the central axis side of the first supporting member  33 , and the shaft portion  33   a  is fixed to the housing  3  via a bearing  37  for the first supporting member. A shaft portion  35   a  is provided on the central axis side of the second supporting member  35 , and the shaft portion  35   a  is fixed to the housing  3  via a bearing  38  for the second supporting member. As a result, the driven-side scroll member  90  is rotated about the second center axis CL 2  via the supporting members  33  and  35 . Further, the shapes of the supporting members  33  and  35  are similar to that of the driven-side supporting member  22  in the first embodiment described with reference to  FIG. 5 . 
     The pin ring mechanism  15  is provided between the first supporting member  33  and the first driving-side end plate  71   a . That is, the ring member  15   a  is provided in the first driving-side end plate  71   a , and the pin member  15   b  is provided in the first supporting member  33 . As illustrated in  FIG. 5 , three pin members  15   b  are provided so as to correspond to the positions of the supporting portions of the first supporting member  33 . 
     The pin ring mechanism  15  is provided between the second supporting member  35  and the second driving-side end plate  72   a . That is, the ring member  15   a  is provided in the second driving-side end plate  72   a , and the pin member  15   b  is provided in the second supporting member  35 . As illustrated in  FIG. 5 , three pin members  15   b  are provided so as to correspond to the positions of the supporting portions of the second supporting member  35 . 
     The scroll accommodation portion  3   b  of the housing  3  is divided at the substantially middle portion of the scroll members  70  and  90  in the axial direction, and fixed by a bolt  32 . 
     The co-rotating scroll compressor  1 B having the abovementioned configuration operates as follows. 
     When the driving shaft connected to a rotor is rotated about the driving-side rotational axis CL 1  by a motor, the driving-side shaft portion  7   c  connected to the driving shaft also rotates. As a result, the driving-side scroll member  70  rotates about the driving-side rotational axis CL 1 . When the driving-side scroll member  70  rotates, the driving force is transmitted from the supporting members  33  and  35  to the driven-side scroll member  90  via the pin ring mechanism  15 , and the driven-side scroll member  90  rotates about the driven-side rotational axis CL 2 . At this time, the pin member  15   b  of the pin ring mechanism  15  moves while being in contact with the ring member  15   a , and hence both of the scroll members  70  and  90  rotationally move in the same direction at the same angular velocity. 
     When both of the scroll members  70  and  90  rotationally move in the same direction at the same angular velocity, the air sucked from the suction opening in the housing  3  is sucked from the outer periphery side of both of the scroll members  70  and  90 , and is taken into the compression chamber formed by both of the scroll members  70  and  90 . Further, the compression chamber formed by the first driving-side wall  71   b  and the first driven-side wall  91   b  and the compression chamber formed by the second driving-side wall  72   b  and the second driven-side wall  92   b  are separately compressed. The capacity of the compression chambers decreases as the compression chambers approach the center side, and the air is compressed accordingly. The air compressed by the first driving-side wall  71   b  and the first driven-side wall  91   b  flows through a through hole  90   h  formed in the driven-side end plate  90   a , and is merged with air compressed by the second driving-side wall  72   b  and the second driven-side wall  92   b . The merged air flows through the exhaust port  72   d  and is exhausted to the outside from the exhaust opening  3   d  in the housing  3 . The exhausted compressed air is guided to an internal combustion engine (not shown) and is used as combustion air. 
     Also in the co-rotating scroll compressor  1 B of this embodiment, as with the first embodiment, the fixing portions  91   f  and  92   f  are provided in places separated from the radially outside end portions of the driven-side walls  91   b  and  92   b  in the inner circumferential direction, and hence the stress generated on the fixing portions  91   f  and  92   f  can be reduced. As a result, the speed up and the high acceleration can be responded to. 
     Note that, in the abovementioned embodiments, the co-rotating scroll compressor is used as the supercharger, but the present invention is not limited thereto, and the co-rotating scroll compressor can be widely used as long as fluid is compressed. For example, the co-rotating scroll compressor can be used as a refrigerant compressor used in an air conditioning unit. 
     Further, as a “predetermined angular interval” by which the three lines of walls are separated about the center of the end plate, an equiangular interval that is 120° is preferred, but the present invention is not limited thereto. The angle tolerance for the equiangular interval is ±10°, and the interval may preferably be a substantially equiangular interval of which angle tolerance is ±1°. 
     Further, the pin ring mechanism  15  is used as a synchronous driving mechanism, but the present invention is not limited thereto, and the pin ring mechanism  15  may be used as a crank pin mechanism, for example. 
     REFERENCE SIGNS LIST 
     
         
           1 A,  1 B co-rotating scroll compressor 
           3  housing 
           3   b  scroll accommodation portion 
           3   d  exhaust opening 
           7  driving-side scroll member 
           7   a  driving-side end plate 
           7   b  driving-side wall 
           7   c  driving-side shaft portion 
           7   e  radially outside end portion 
           7   f  driving-side fixing portion 
           9  driven-side scroll member 
           9   a  driven-side end plate 
           9   b  driven-side wall 
           9   c  driven-side shaft portion 
           9   d  exhaust port 
           9   e  radially outside end portion 
           9   f  driven-side fixing portion 
           11  driving-side bearing 
           13  driven-side bearing 
           15  pin ring mechanism (synchronous driving mechanism) 
           15   a  ring member 
           15   b  pin member 
           20  driving-side supporting member 
           20   a  shaft portion 
           20   b  radially extending portion 
           22  driven-side supporting member 
           24   a  fastening member 
           24   b  fastening member 
           25   a  fastening member 
           25   b  fastening member 
           26  bearing for driving-side supporting member 
           28  bearing for driven-side supporting member 
           31  bolt (wall fixing portion) 
           32  bolt 
           33  first supporting member 
           33   a  shaft portion 
           35  second supporting member 
           35   a  shaft portion 
           37  bearing for first supporting member 
           38  bearing for second supporting member 
           70  driving-side scroll member 
           71  first driving-side scroll portion 
           71   a  first driving-side end plate 
           71   b  first driving-side wall 
           72  second driving-side scroll portion 
           72   a  second driving-side end plate 
           72   b  second driving-side wall 
           72   c  second driving-side shaft portion 
           72   d  exhaust port 
           73  flange part 
           90  driven-side scroll member 
           90   a  driven-side end plate 
           90   h  through hole 
           91   b  first driven-side wall 
           91   f  first fixing portion 
           92   b  second driven-side wall 
           92   f  second fixing portion