Patent Publication Number: US-8985974-B2

Title: Concentric multi-stage vane compressor

Description:
TECHNICAL FIELD 
     The present invention relates to a vane compressor that can be readily and inexpensively adapted to a multistage arrangement with a minimal number of components, in order to improve compression performance. 
     BACKGROUND ART 
     It is well known that vane compressors, which are employed as vacuum pumps and the like, are equipped with a rotor that undergoes eccentric rotation within a cylinder (a stator), and vanes that are slidably pressed against the inner peripheral surface of the cylinder or the outer peripheral surface of the rotor by spring force. In association with rotation of the rotor, a stroke to draw a fluid into compression chambers partitioned by the vanes, and a stroke to compress and discharge the drawn-in fluid, are repeated. In a case in which it is desired to enhance the compression performance of vane compressors, typical practice is to link the vane compressors in a multistage arrangement in their axial direction, so as to obtain a high-compression ratio fluid from the vane compressor of the final stage. 
     In Patent Document 1, there is proposed a multistage rotary compressor of vane design in an attempt at a concentric multistage arrangement. In the multistage rotary compressor disclosed therein, a cylindrical post is arranged in concentric fashion in the interior of a housing, and an orbiting ring rotates eccentrically between the circular inner peripheral surface of the housing and the circular outer peripheral surface of the post. A pair of vanes pressed by spring force against the circular inner peripheral surface of the orbiting ring are attached to the post situated towards the center, and a pair of vanes pressed by spring force against the circular outer peripheral surface of the orbiting ring are attached to the housing situated towards the outside. Through eccentric rotation of the orbiting ring, a fluid is repeatedly compressed through the agency of compression chambers formed to the outer peripheral side and the inner peripheral side thereof. 
     PRIOR ART DOCUMENT 
     Patent Document 
     [Patent Document 1] Japanese Laid-Open Patent Application 6-280766 
     DISCLOSURE OF THE INVENTION 
     Problems to be Solved by the Invention 
     The feature of a conventional vane compressor equipped with a plurality of concentrically arranged compression chambers is basically one in which single-stage vane compressors are arranged in a concentric arrangement. Consequently, in a manner similar to the case in which vane compressors are connected in the axial direction in a multistage design, the number of components increases, and the structure becomes more complex as well. Moreover, it is difficult to attempt a three-stage or greater multistage design in which the compression chambers are arrayed concentrically. 
     With the foregoing in view, it is an object of the present invention to propose a vane compressor in which the compression chambers can be concentrically arranged in multiple stages in a simple structure, while suppressing increase in number of components to the minimum level. 
     Means Used to Solve the Above-Mentioned Problems 
     In order to solve the above-mentioned problem, the vane compressor of the present invention is constituted as described below. The reference numerals in parentheses show corresponding regions in the embodiment of the present invention discussed hereinbelow, and being appended merely as an aid to understanding, are not intended to limit the present invention to the embodiment herein. 
     Specifically, according to the present invention, there is provided a vane compressor ( 1 A,  1 B) having a stator ( 2 ); a rotor ( 3 ); and vanes ( 4 ) for dividing an interstice between the stator ( 2 ) and the rotor ( 3 ) into a plurality of compression chambers ( 53 ,  54 ); characterized in that 
     the stator ( 2 ) is equipped, towards an outside from a center ( 2   a ) thereof, with a first circular inner peripheral surface ( 21   b ), a circular outer peripheral surface ( 21   a ), and a second circular inner peripheral surface ( 22   b ) arranged concentrically about the center ( 2   a ), an ring-shaped space ( 23 ) being formed between the circular outer peripheral surface ( 21   a ) and the second circular inner peripheral surface ( 22   b ); 
     the rotor ( 3 ) is equipped with a cylinder ( 35 ) centered about a center ( 3   a ) thereof, and with at least one pair of vane attachment grooves ( 37 ) that extend through the cylinder ( 35 ) in a radial direction thereof; 
     the cylinder ( 35 ) is arranged in an eccentric state in the ring-shaped space ( 23 ) of the stator ( 2 ), and divides the ring-shaped space ( 23 ) into an outer peripheral-side space ( 23   a ) and an inner peripheral-side space ( 23   b ); 
     the vanes ( 4 ) are slidably attached in the respective vane attachment grooves ( 37 ); 
     the vanes ( 4 ) are respectively equipped with first comb-tooth parts ( 41 ) and second comb-tooth parts ( 42 ) formed along a radial direction of the cylinder ( 35 ) of the rotor ( 3 ), at a predetermined distance from the center side thereof; 
     the first comb-tooth parts ( 41 ) are arranged to an inside of the first circular inner peripheral surface ( 21   b ), and the second comb-tooth parts ( 42 ) divide the outer peripheral-side space ( 23   a ) and the inner peripheral-side space ( 23   b ) respectively, into the plurality of compression chambers ( 53 ,  54 ) within the ring-shaped space ( 23 ); and 
     due to centrifugal force acting on the vanes ( 4 ) in association with rotation of the rotor ( 3 ), at least the first comb-tooth parts ( 41 ) become pressed against the facing first circular inner peripheral surface ( 21   b ), and the vanes ( 4 ), guided by the first circular inner peripheral surface ( 21   b ), experience reciprocating slide motion along the vane attachment grooves ( 37 ). 
     In the vane compressor ( 1 A,  1 B) according to the present invention, when the rotor ( 3 ) rotates, the vanes ( 4 ) attached to the vane attachment grooves ( 37 ) rotate together with the rotor ( 3 ) as well. Because rotation of the rotor ( 3 ) is centered at a position that is eccentric with respect to the stator ( 2 ), the vanes ( 4 ) which are slidably attached to the rotor ( 3 ) experience reciprocating slide motion in a radial direction along the vane attachment grooves ( 37 ), and the second comb-tooth parts ( 42 ) translate along the ring-shaped space through the ring-shaped space ( 23 ) of the stator ( 2 ). 
     Specifically, the comb-tooth parts ( 41 ,  42 ) of the vanes ( 4 ), together with the rotor ( 3 ), rotate along the first circular inner peripheral surface ( 21   b ), the circular outer peripheral surface ( 21   a ), and the second circular inner peripheral surface ( 22   b ) of the stator ( 2 ). The compression chambers ( 53 ,  54 ), which are divided by the comb-tooth parts ( 41 ,  42 ), repeatedly increase and decrease in volume in association with rotation of the rotor ( 3 ). Consequently, when the discharge portion of the outside compression chamber ( 53 ) communicates with the intake port of the inside compression chamber ( 54 ), fluid compressed by the outside compression chamber can be delivered to the inside compression chamber and further compressed. Therefore, a multistage vane compressor can be realized simply by increasing the number of ring-shaped spaces on the stator side, the number of cylinders on the rotor side, and the number of second comb-tooth parts of the vanes. Specifically, improved compression performance can be realized in simple fashion. 
     In the vane compressor ( 1 A,  1 B) according to the present invention, the vanes ( 4 ) are slidably attached in the vane attachment grooves ( 37 ), whereby the vanes ( 4 ) are subjected to the action of centrifugal force acting thereon outwardly in a radial direction in association with rotation of the rotor ( 3 ), rotating the vanes ( 4 ) while drawing them outwardly in a radial direction. Consequently, it is possible for only the comb-tooth parts situated on the center side and having the slowest peripheral speed, specifically, the first comb-tooth parts ( 41 ), to be pressed from the inside by centrifugal force against the first circular inner peripheral surface ( 21   b ) on the stator ( 2 ) side to control the position of the vane ( 4 ) in a radial direction, while the outside second comb-tooth parts ( 42 ) are retained in a state facing the circular outer peripheral surface ( 21   a ) across a small gap. 
     Specifically, the vane compressor ( 1 A,  1 B) according to the present invention is characterized in that, with the first comb-tooth parts ( 41 ) of the vane ( 4 ) abutting against the first circular inner peripheral surface ( 21   b ), the second comb-tooth parts ( 42 ) face the second circular inner peripheral surface ( 22   b ) in a non-contacting state. 
     In so doing, only the first comb-tooth parts ( 41 ) which are closest to the rotor rotation center ( 3 ), in other words, the first comb-tooth parts ( 41 ) which have the slowest peripheral speed, come into contact with the first circular inner peripheral surface ( 21   b ) on the stator ( 2 ) side. Therefore, the amount of wear of sliding parts can be reduced, as compared with the case in which the outside second comb-tooth parts ( 42 ) having faster peripheral speed slide along the second circular inner peripheral surface ( 22   b ) on the stator ( 2 ) side, so the life of the components can be extended. Moreover, because the sliding resistance can be reduced, loss power can be reduced. 
     Here, in order for the first comb-tooth parts ( 41 ) and the first circular inner peripheral surface ( 21   b ) to be maintained in a state of contact, and for the second comb-tooth parts ( 42 ), the circular outer peripheral surface ( 21   a ), and the second circular inner peripheral surface ( 22   b ) to be maintained in a non-contacting state of confrontation across unchanging small gaps, the shapes of the first circular inner peripheral surface ( 21   b ), the circular outer peripheral surface ( 21   a ), and the second circular inner peripheral surface ( 22   b ) are defined by the rotation trajectories of those regions of the first and second comb-tooth parts ( 41 ,  42 ) of the vanes ( 4 ) that face these surfaces, or by approximate curves of these rotation trajectories. The rotation trajectories of these comb-tooth parts are shaped like an ellipse slightly flattened with respect to a true circle. Consequently, the inner peripheral surfaces and outer peripheral surfaces which are defined by the rotation trajectories of the comb-tooth parts, or by approximate curves thereof, are herein expressed as “circular inner peripheral surfaces” and “circular outer peripheral surfaces”, respectively. 
     Next, according to the present invention, in order to further minimize wear between the vanes on the rotor side and the first circular inner peripheral surface on the stator side and minimize slide resistance between them to an even greater extent, a first cylindrical part ( 21 B) to which the first circular inner peripheral surface ( 21   b ) is equipped is rotatably supported about the center thereof by the stator ( 2 ). 
     Because the first cylindrical part ( 21 B), which functions as a vane guide that controls the reciprocating slide motion of the vanes ( 4 ), is rotatable, the part turns in tandem with the vanes in association with rotation of the vanes ( 4 ). Between the first cylindrical part ( 21 B) and the vanes ( 4 ), slip is generated in association with eccentric rotation of the rotor ( 3 ); however, the slip rate can be significantly lower, as compared with the case in which the vane guide is stationary. Therefore, wear and slide resistance between these parts can be significantly reduced. 
     Next, according to the present invention, there is provided a vane compressor ( 100 ,  100 A) having a stator ( 102 ); a rotor ( 103 ); and a vane ( 104 ) for dividing an interstice between the stator ( 102 ) and the rotor ( 103 ) into a plurality of compression chambers ( 153 - 156 ); characterized in that 
     the stator ( 102 ) is equipped, towards an outside from a center ( 102   a ) thereof, with a first circular outer peripheral surface ( 120   a ), a first circular inner peripheral surface ( 121   b ), a second circular outer peripheral surface ( 121   a ), and a second circular inner peripheral surface ( 122   b ) arranged concentrically about the center ( 102   a ), a first ring-shaped space ( 123 ) being formed between the first circular outer peripheral surface ( 120   a ) and the first circular inner peripheral surface ( 121   b ), and a second ring-shaped space ( 124 ) being formed between the second circular outer peripheral surface ( 121   a ) and the second circular inner peripheral surface ( 122   b ); 
     the rotor ( 103 ) is equipped, towards an outside from a center ( 103   a ) thereof, with a first cylinder ( 131 ) and a second cylinder ( 132 ) arranged concentrically and centered on the center ( 103   a ), and with at least one vane attachment groove ( 137 ) extending through the first and second cylinders ( 131 ,  132 ) in a diametrical direction thereof; 
     the first cylinder ( 131 ) is arranged in an eccentric state in the first ring-shaped space ( 123 ), and divides the first ring-shaped space ( 123 ) into an outer peripheral-side space ( 123   a ) and an inner peripheral-side space ( 123   b ); 
     the second cylinder ( 132 ) is arranged in an eccentric state in the second ring-shaped space ( 124 ), and divides the second ring-shaped space ( 124 ) into an outer peripheral-side space ( 124   a ) and an inner peripheral-side space ( 124   b ); 
     the vanes are equipped with a pair of first comb-tooth parts ( 141 ,  142 ) and a pair of second comb-tooth parts ( 143 ,  144 ) formed at point-symmetrical positions with respect to the center, towards either end from the center in a lengthwise direction thereof; 
     the first comb-tooth parts ( 141 ,  142 ) contact the first circular outer peripheral surface ( 120   a ) from both sides, as well as dividing the outer peripheral-side space ( 123   a ) and the inner peripheral-side space ( 123   b ) of the first ring-shaped space ( 123 ) into the plurality of compression chambers ( 155 ,  156 ); 
     the second comb-tooth parts ( 143 ,  144 ) divide the outer peripheral-side space ( 124   a ) and the inner peripheral-side space ( 124   b ) of the second ring-shaped space ( 124 ) into the plurality of compression chambers ( 153 ,  154 ); and 
     the vane ( 104 ) experiences reciprocating slide motion along the vane attachment grooves ( 137 ), due to sliding of the first comb-tooth parts ( 141 ,  142 ) of the vane ( 104 ) along the first circular outer peripheral surface ( 120   a ) in association with rotation of the rotor ( 103 ). 
     The stator ( 102 ) may be equipped with: a cylindrical or cylindrical solid vane guide ( 120 ) equipped with the first circular outer peripheral surface ( 120   a ); a first cylindrical part ( 121 ) arranged concentrically to an outside thereof, and equipped with the first circular inner peripheral surface ( 121   b ) and the second circular outer peripheral surface ( 121   a ); and a second cylindrical part ( 122 ) arranged concentrically to an outside thereof, and equipped with the second circular inner peripheral surface ( 122   b ). 
     In the vane compressor ( 100 ,  100 A) according to the present invention, the vane guide ( 120 ) is nestled between the pair of first comb-tooth parts ( 141 ,  142 ) of the vane ( 104 ), and there is accordingly no need to utilize centrifugal force to bring about reciprocating translation of the vane ( 104 ) and press them against the vane guide ( 120 ). Moreover, the center of gravity of the vane ( 104 ) is positioned close to the rotor rotation center ( 103 ), and the centrifugal force acting on the vane ( 104 ) is lower. Therefore, wear and sliding resistance between the vane ( 104 ) and the vane guide ( 120 ) can be significantly minimized. 
     Particularly in a case in which the vane guide ( 120 ) is a rotatably supported rotating vane guide, wear and sliding resistance between the vane ( 104 ) and the vane guide ( 120 ) can be reduced even more effectively. 
     Moreover, because the compression chambers ( 155 ,  156 ) are formed by the first comb-tooth part ( 141 ) of the vane ( 104 ) which is guided by the vane guide ( 120 ), the efficiency of utilization of space is high, and arrangement in multiple stages is easier. 
     Furthermore, in order to avoid disengagement of the first comb-tooth part ( 141 ) of the vane ( 104 ) from the first circular outer peripheral surface ( 120   a ), a width dimension (W) of an inside end surface of the first comb-tooth part ( 141 ) of the vane ( 104 ) abutting against the first circular outer peripheral surface ( 120   a ) of the vane guide ( 120 ) should be at least double the amount of eccentricity (Δ) between the rotor rotation center, and the center of the vane guide of the stator. 
     It is preferable that the stator ( 102 ) has an elastic member ( 176 ) that presses the vane guide ( 120 ) against the vane ( 104 ), along the direction of the center axis thereof. In so doing, appropriate positioning can be set in the axial direction for the vanes on the rotor side and the region on the stator side. 
     In the vane compressor ( 100 A) according to the present invention, it is also possible to adopt a feature whereby the rotor ( 103 ) is equipped with a pair of the vane attachment grooves ( 137 A,  137 B) that intersect at a right angle at the center ( 103   a ) thereof, and the vane ( 104 ) is slidably attached in the respective vane attachment grooves. 
     Effect of the Invention 
     In the vane compressor according to the present invention, cylinders on the rotor side are eccentrically arranged in a ring-shaped space formed on the stator side, and the ring-shaped space is divided into an outer peripheral-side space and an inner peripheral-side space. Moreover, the vanes are slidably attached in the vane attachment grooves furnished on the rotor side, and in association with rotation of the rotor, the vanes experience reciprocating slide motion along the vane attachment grooves, while undergoing translation in the circumferential direction along the ring-shaped space on the stator side. 
     According to this feature, through concentric arrangement of the ring-shaped space on the stator side and the cylinders on the rotor side in multiple stages, is it easy for the compression chambers to be concentrically arranged in multiple stages. Thus, the compression chambers can easily be arranged in multiple stages with a small number of components, and therefore a vane compressor having a high compression ratio can be realized inexpensively. Moreover, through implementation of the present invention in a vacuum dry pump, there can be obtained an inexpensive dry vacuum pump with excellent base pressure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  ( a ) is a simplified internal configuration diagram showing a vane compressor according to a first embodiment of the present invention, ( b ) is a simplified cross sectional view thereof, and ( c ) is a simplified cross sectional view take in cross section orthogonal to the cross section of ( b ); 
         FIGS. 2  ( a ) to  2  ( d ) are a descriptive diagram showing movement of the vane compressor of  FIG. 1 ; 
         FIG. 3  ( a ) is a simplified internal configuration diagram showing a vane compressor according to a second embodiment of the present invention, ( b ) is a simplified cross sectional view thereof, and ( c ) is a simplified cross sectional view take in cross section orthogonal to the cross section of ( b ); 
         FIG. 4  ( a ) is a simplified internal configuration diagram showing a vane compressor according to a third embodiment of the present invention, ( b ) is a simplified cross sectional view thereof, ( c ) is a simplified cross sectional view take in cross section orthogonal to the cross section of ( b ), and ( d ) is a descriptive diagram showing the width dimension of the vanes; 
         FIGS. 5  ( a ) to  5  ( d ) are a descriptive diagram showing movement of the vane compressor of  FIG. 4 ; 
         FIG. 6  ( a ) is a simplified internal configuration diagram showing a vane compressor according to a fourth embodiment of the present invention, ( b ) is a simplified cross sectional view thereof, and ( c ) is a simplified cross sectional view take in cross section orthogonal to the cross section of ( b ); and 
         FIG. 7  ( a ) and ( b ) are a plan view and a side view showing one of the vanes of the vane compressor of  FIG. 6  ( a ) and  FIG. 7  ( c ) and ( d ) are a plan view and a side view showing the other vane of the vane compressor of  FIG. 6  ( a ). 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     The embodiments of a vane compressor in which the present invention is applied are described below with reference to the drawings. 
     (First Embodiment) 
     The description of the vane compressor according to a first embodiment makes reference to  FIG. 1 . The vane compressor  1 A is equipped with a stator  2 , a rotor  3  rotatably supported inside the stator  2 , and a pair of vanes  4  that divide the space enclosed by the stator  2  and the rotor  3  into a plurality of compression chambers. The stator  2  is equipped with a holder  5  of cylindrical shape, and a stator plate  6  that closes off an opening at the front end side of the holder  5 . The pair of vanes  4  are attached to the rotor  3  so as to be slidable in a radial direction thereof. In the present example, the pair of vanes  4  are arranged at an angular distance of 180 degrees, specifically, on a single straight line in a diametrical direction. A motor  7  is coaxially mounted on the back end surface of the holder  5 , with rotation of the rotor  3  being driven by the motor  7 . 
     The back side of the holder  5  serves as a small-diameter cylindrical part  11 , and the front side serves as a large-diameter cylindrical part  12 . Via a mounting flange  7   a , the motor  7  is linked and fastened in a coaxial state to the back end surface of the small-diameter cylindrical part  11 . Inside the small-diameter cylindrical part  11 , a back side pivot shaft  14  of the rotor  3  is rotatably supported via a bearing  13 . Seals  15 ,  16  are mounted to the front and back of the bearing  13 , sealing off a zone between the back side pivot shaft  14  and the inner peripheral face of the cylindrical part  11  of the holder  5 . The axial end portion at the back side of the back side pivot shaft  14  is linked and fastened in a coaxial state, via a shaft coupling  17 , to the distal end portion of a motor rotating shaft  7   b  which is inserted from the back side. 
     The stator plate  6  is fastened in a coaxial state to the front end of the large-diameter cylindrical part  12  of the holder  5 . The stator plate  6  is shaped like a disk having a contour shape identical to that of the cylindrical part  12 , and a plurality of cylindrical parts (in the present example, a first cylindrical part  21  and a second cylindrical part  22 ) protrude concentrically from the inside end surface of the stator plate  6 . Between the inside first cylindrical part  21  and the second cylindrical part  22  to the outside thereof, and between the second cylindrical part  22  and the outside cylindrical part  12  (third cylindrical part), there are respectively formed ring-shaped spaces  23 ,  24 . The center  2   a  of the first cylindrical part  21 , the second cylindrical part  22 , and the cylindrical part  12  (the stator center) is eccentric by an unchanging amount of eccentricity Δ with respect to the rotor rotation center  3   a . Consequently, the ring-shaped spaces  23 ,  24  are also eccentric by an identical amount with respect to the rotor rotation center  3   a.    
     Next, the rotor  3  is equipped with a disk part  31 , this disk part  31  facing the stator plate  6  with an unchanging distance therebetween, and the circular end surface  31   a  thereof being faced across a small gap by the distal end faces of the first and second cylindrical parts  21 ,  22  formed on the stator plate  6  side. On the disk part  31 , the back side pivot shaft  14  is integrally formed on the back side thereof, and a front side pivot shaft  32  is integrally formed coaxially on the front side thereof. The axial distal end portion of the front side pivot shaft  32  is rotatably supported on the stator plate  6  side, via a bearing  33  mounted in a recessed portion formed on the inside end surface of the stator plate  6 . A zone between the front side pivot shaft  32  and the stator plate  6  is sealed off by a seal  34 . 
     On the circular end surface  31   a  of the disk part  31  of the rotor  3 , there are integrally formed a plurality of concentric cylinders (in the present example, two cylinders  35 ,  36 ) which are centered on the rotor rotation center  3   a . The inside cylinder  35  (first cylinder) projects into the inside ring-shaped space  23  on the stator  2  side, the ring-shaped distal end surface of this cylinder  35  facing the inside end surface  6   c  of the stator plate  6  across a small gap. Likewise, the outside cylinder  36  (second cylinder) projects into the outside ring-shaped space  24  on the stator  2  side, the ring-shaped distal end surface of this cylinder  36  facing the inside end surface  6   c  of the stator plate  6  across a small gap. The inside ring-shaped space  23  is thereby divided by the cylinder  35  into an inner peripheral-side space  23   b  and an outer peripheral-side space  23   a , while the outside ring-shaped space  24  is divided by the cylinder  36  into an inner peripheral-side space  24   b  and an outer peripheral-side space  24   a.    
     The cylinders  35 ,  36  on the rotor side are respectively inserted in a state of eccentricity, by an amount of eccentricity Δ, with respect to the ring-shaped spaces  23 ,  24  on the stator side. In the present example, as shown in  FIG. 1  ( a ), circular outer peripheral surfaces  35   a ,  36   a  of the cylinders  35 ,  36 , at a first end thereof in a single diametrical direction L, face the inner peripheral surface  22   b  of the cylindrical part  22  and the inner peripheral surface  12   b  of the cylindrical part  12  across small gaps, and at the end on the opposite side in the diametrical direction L, face the inner peripheral surfaces  22   b ,  12   b  of the cylindrical parts  22 ,  12  across maximum gaps. Consequently, the outer peripheral-side space  23   a  of the inside ring-shaped space  23  progressively increases in width along the circumferential direction going from the first end in the diametrical direction L towards the end on the opposite side; and, conversely, progressively decreases in width going from that end towards the other end. The width of the inner peripheral-side space  23   b  changes in the opposite manner along the circumferential direction. The width of the outer peripheral-side space  24   a  of the outside ring-shaped space  24  changes analogously to that of the outer peripheral-side space  23   a , and the width of the inner peripheral-side space  24   b  changes analogously to that of the inner peripheral-side space  23   b.    
     Next, a pair of vane attachment grooves  37  extending in a radial direction are formed on the rotor  3 . The vanes  4  are attached in these vane attachment grooves  37 , in a slidable state along the vane attachment grooves  37 . Each of the vane attachment grooves  37  is a groove of unchanging width extending outwardly in a straight line in a radial direction from a position in proximity to the rotor rotation center  3   a , and is equipped with a groove part  37   a  of unchanging depth formed on the circular end surface  31   a  of the disk part  31  of the rotor  3 , and slit parts  37   b ,  37   c  that pass in a radial direction through parts of the cylinders  35 ,  36  that face the groove part  37   a.    
     The vanes  4  which have been slidably attached in the vane attachment grooves  37  are equipped with a linking plate part  40  of unchanging width attached in the groove part  37   a  of the disk part  31 , and a plurality of comb-tooth parts (in the present example, three comb-tooth parts  41 ,  42 ,  43 ) that protrude at unchanging distance from this linking plate part  40 . 
     The comb-tooth parts  41  positioned to the rotor rotation center  3   a  side (the first comb-tooth parts) are positioned to the inner peripheral side of the inside cylindrical part  21 , with the distal end surfaces  41   c  thereof facing the inside end surface  6   c  on the stator plate  6  side across a small gap (non-contacting state), and with the outer peripheral-side end surfaces  41   a  thereof able to contact the inner peripheral surface  21   b  of the cylindrical part  21 . When the rotor  3  rotates, the vanes  4  are pushed outwardly due to centrifugal force, and slide outwardly along the vane attachment grooves  37 . As a result, the outer peripheral-side end surfaces  41   a  of the first comb-tooth parts  41  of the vane  4  are pressed against the inner peripheral surface  21   b  of the cylindrical part  21 , whereby the vanes  4  slide along the peripheral surface  21   b  in association with rotation of the rotor  3 . Stated another way, the peripheral surface  21   b  of the cylindrical part  21  functions as a vane guide surface, controlling the reciprocating slide motion of the vanes  4  in association with rotation of the rotor  3 . 
     In contrast to this, the comb-tooth parts  42  (the second comb-tooth parts) are positioned within the slit parts  37   b  of the inside cylinder  35  and the inside ring-shaped space  23 , with the distal end surfaces  42   c  thereof facing the inside end surface  6   c  on the stator plate  6  side across a small gap (non-contacting state). In a state in which the comb-tooth parts  41  (the first comb-tooth parts) are abutting against the inner peripheral surface  21   b  of the cylindrical part  21 , the outer peripheral-side end surfaces  42   a  of the comb-tooth parts  42  face the inner peripheral surface  22   b  of the cylindrical part  22  across small gaps (non-contacting state), while the inner peripheral-side end surfaces  42   b  thereof confronts the outer peripheral surface  21   a  of the cylindrical part  21  across small gaps (non-contacting state). 
     Likewise, the comb-tooth parts  43  positioned furthest to the outside are positioned within the slit parts  37   c  of the outside cylinder  36  and the outside ring-shaped space  24 , with the distal end surface  43   c  thereof facing the inside end surface  6   c  on the stator plate  6  side across a small gap (non-contacting state). Moreover, in a state in which the comb-tooth parts  41  are abutting against the inner peripheral surface  21   b  of the cylindrical part  21 , the outer peripheral-side end surfaces  43   a  of the comb-tooth parts  43  face the inner peripheral surface  12   b  of the cylindrical part  12  across small gaps (non-contacting state), while the inner peripheral-side end surfaces  43   b  thereof confronts the outer peripheral surface  22   a  of the cylindrical part  22  across small gaps (non-contacting state). 
     Here, in order to bring about rotation of the comb-tooth parts  42 ,  43  along the outer peripheral surfaces and inner peripheral surfaces of the cylindrical parts  21 ,  22 ,  12  while maintaining unchanging small distances, in the present example, the shapes of the inner peripheral surfaces and outer peripheral surfaces of the cylindrical parts  21 ,  22 , and of the inner peripheral surface of the cylindrical part  12 , are defined as follows. Specifically, the contour shape of the inner peripheral surface  21   b  of the cylindrical part  21  is defined by the rotation trajectory of the outer peripheral-side end surfaces  41   a  of the comb-tooth parts  41  of the vanes  4  in confrontation thereto, or by an approximate curve of the rotation trajectory. The contour shapes of the outer peripheral surface  21   a  of the cylindrical part  21  and the inner peripheral surface  22   b  of the cylindrical part  22  are defined by the rotation trajectories of the inner peripheral-side end surfaces  42   b  and the outer peripheral-side end surfaces  42   a  of the comb-tooth parts  42  of the vanes  4  in confrontation thereto, or by approximate curves of these rotation trajectories. Likewise, the contour shapes of the outer peripheral surface  22   a  of the cylindrical part  22  and the inner peripheral surface  12   b  of the cylindrical part  12  are defined by the rotation trajectories of the inner peripheral-side end surfaces  43   b  and the outer peripheral-side end surfaces  43   a  of the comb-tooth parts  43  in confrontation thereto, or by approximate curves of these rotation trajectories. 
     In the aforedescribed manner, the outer peripheral-side spaces  23   a ,  24   a  and the inner peripheral-side spaces  23   b ,  24   b  of the ring-shaped spaces  23 ,  24  are respectively divided into two compression chambers by the comb-tooth parts  42 ,  43  of the vanes  4 . Specifically, as shown in  FIG. 1  ( a ), the outer peripheral-side space  24   a  of the ring-shaped space  24  is divided into two first-stage compression chambers  51 , and the inner peripheral-side space  24   b  of the ring-shaped space  24  is divided into two second-stage compression chambers  52 , by the comb-tooth parts  43 . Moreover, the outer peripheral-side space  23   a  of the inside ring-shaped space  23  is divided into two third-stage compression chambers  53  by the comb-tooth parts  42 , and the inner peripheral-side space  23   b  is divided into two fourth-stage compression chambers  54  by the comb-tooth parts  42 . 
     In a region of the cylindrical part  12  within a range of rotation angles in which the volume of the first-stage compression chambers  51  progressively increases in association with the rotation of the rotor  3  (in the present example, in a region at an angular position rotated by 90 degrees with respect to the diametrical direction L), there is formed an intake port  55  for intake of fluid from the outside. In a region of the inside end surface  6   c  of the stator plate  6  within a range of rotation angles in which the volume of the first-stage compression chambers  51  progressively decreases in association with the rotation of the rotor  3  (in the present example, in a region rotated by 180 degrees with respect to the intake port  55 ), there is formed a communication port  56  communicating between the first-stage compression chambers  51  and the second-stage compression chambers  52 . Likewise, in the stator plate  6 , there are formed a communication port  57  for the second-stage compression chambers  52  and the third-stage compression chambers  53 , and a communication port  58  for the third-stage compression chambers  53  and the fourth-stage compression chambers  54 . Furthermore, a discharge port  59  for discharging the compressed fluid from the fourth-stage compression chambers  54  of the final stage is formed in the stator plate  6 . 
     The description of movement of the vane compressor  1 A will be made with reference to  FIG. 2 . When the rotor  3  is rotated by the motor  7 , the pair of vanes  4  rotate about the rotor rotation center  3   a , in unison with the rotor  3 . By virtue of being slidable in a radial direction with respect to the rotor  3 , the vanes  4  rotate while being pushed outwardly in a radial direction by the centrifugal force generated by rotation. Specifically, the comb-tooth parts  41  furthest towards the center side of the vane  4  slide along the inner peripheral surface  21   b  of the cylinder part  21  furthest towards the inside. Each time that the vanes  4  rotate, the first stage compression chambers  51  through fourth stage compression chambers  54  which are divided by the comb-tooth parts  42 ,  43  of the vanes  4  repeat a fluid intake stroke in association with increasing volume, and a fluid compression/discharge stroke in association with decreasing volume, the compressed fluid being delivered to the compression chambers of the next stage. The compressed fluid from the fourth-stage compression chambers  54  of the final stage is discharged from the discharge port  59 . 
     In the vane compressor  1 A of the present example, volume compression chambers can be furnished concentrically in multiple stages by increasing the number of the cylindrical parts  21 ,  22  of the stator  2 , the number of cylinders  35 ,  36  of the rotor  3 , and the number of comb-tooth parts  42 ,  43  (second comb-tooth parts) of the vanes  4 . Consequently, a vane compressor having high compression capability can be manufactured inexpensively in a simple structure, with a minimum number of components. Moreover, because the compression chambers of each stage are arrayed concentrically, the communication paths communicating between them can be formed in a simple manner. Consequently, the vane compressor  1 A can be employed as an inexpensive dry vacuum pump with excellent base pressure, or the like. 
     Moreover, as the vanes  4  are being pushed outwardly in a radial direction by centrifugal force, only the comb-tooth parts  41  on the center side, which have the slowest peripheral speed, slide along the inner peripheral face  21   b  of the cylindrical part  21  on the stationary side. Other parts rotate in a non-contacting state. Consequently, wear occurring between the vanes  4  and regions of the cylindrical part  12  against which they slide can be reduced, so the life of these components can be extended. Moreover, because the sliding resistance of the vanes  4  can be reduced, the loss power of the vane compressor  1 A can be reduced. 
     Furthermore, the outer peripheral surface shape of the cylindrical part  21 , the inner and outer peripheral surface shapes of the cylindrical part  22 , and the inner peripheral surface shape of the cylindrical part  12  are defined employing the rotation trajectories of those regions of the comb-tooth parts  41  to  43  of the vanes  4  that face these parts, or approximate curves of these rotation trajectories. In so doing, the comb-tooth parts  42 ,  43  and the cylindrical parts  21 ,  22 ,  12  can be maintained in confrontation in a non-contacting state, with an optimal unchanging small gap therebetween. In the present example, one pair of vanes  4  are equipped, but the number of vanes may be three or more. 
     (Second Embodiment) 
     A vane compressor according to a second embodiment will be described with reference to  FIG. 3 . The basic structure of the vane compressor  1 B is the same as that of the vane compressor  1 A according to the first embodiment; therefore corresponding parts have been assigned the same symbols, omitting description of these parts. 
     In place of the cylindrical part  21  positioned furthest to the inside on the stator side in the vane compressor  1 A, the vane compressor  1 B is equipped with a vane guide  21 B rotatably mounted on the stator plate  6  side. The vane guide  21 B is equipped with a pivot shaft part  61  that is rotatably supported, via a bearing  33 B, in a recessed portion formed in the center part of the stator plate  6 ; a disk part  62  integrally formed at an end of this pivot shaft part  61 ; and a cylindrical part  63  integrally formed in the outer peripheral edge part of the end surface of the disk part  62 . The distal end  63   c  of the cylindrical part  63  confronts a circular end surface  31   a  of the rotor  3  across a small gap. 
     The inner peripheral surface  63   b  of the cylindrical part  63  functions as a guide surface for the vanes  4 . Specifically, due to centrifugal force arising in association with rotation of the rotor  3 , the outer peripheral-side end surfaces  41   a  of the comb-tooth parts  41  (the first comb-tooth parts) of the vanes  4  slide against the inner peripheral surface  63   b  while being pressed thereagainst, controlling the reciprocating slide motion of the vanes  4 . 
     The vane guide  21 B is rotatably supported on the stator plate  6  side. Consequently, due to the vanes  4  rotating in association with rotation of the rotor  3 , the vane guide  21 B turns in tandem therewith. Because the rotor rotation center  3   a  (which is the center of rotation of the vanes  4 ) and the stator center  2   a  (which is the center of the vane guide  21 B) are offset by the amount of eccentricity Δ, slip is generated between the two members to a corresponding extent; however, the slip rate between the two members can be significantly reduced, as compared with the case in which the vane guide  21 B does not turn in tandem. Therefore, wear between these members can be significantly reduced, and slide resistance between these members can be significantly reduced as well. 
     In the vane compressor  1 B of the present example, the rotor  3  is supported in cantilever fashion by the holder  5 , and the disk part  31  of the rotor  3  is not equipped with the front side pivot shaft  32  in the vane compressor  1 A of the first embodiment. Consequently, the groove parts  37   a  of the pair of vane attachment grooves  37  formed in the disk part  31  are formed as a single continuous groove. 
     (Third Embodiment) 
     A vane compressor according to a third embodiment of the present invention is described with reference to  FIG. 4 . The vane compressor  100  is equipped with a stator  102 , a rotor  103  rotatably supported inside the stator  102 , and a vane  104  (an integral type vane) that divides the space enclosed by the stator  102  and the rotor  103  into a plurality of compression chambers. The stator  102  is equipped with a holder  105  of cylindrical shape, and a stator plate  106  that closes off an opening at the front end side of the holder  105 . The vane  104  is attached to the rotor  103  so as to be slidable in a diametrical direction thereof. A motor  107  is coaxially mounted on the back end surface of the holder  105 , with rotation of the rotor  103  being driven by the motor  107 . 
     The back side of the holder  105  serves as a small-diameter cylindrical part  111 , and the front side serves as a large-diameter cylindrical part  112 . Via a mounting flange  107   a , the motor  107  is linked and fastened in a coaxial state to the back end surface of the small-diameter cylindrical part  111 . Inside the small-diameter cylindrical part  111 , a back side pivot shaft  114  of the rotor  103  is rotatably supported via a pair of bearings  113 . Seals  115 ,  116  are mounted to the front and back of the bearings  113 , sealing off a zone between the back side pivot shaft  114  and the inner peripheral face of the cylindrical part  111  of the holder  105 . The axial end portion at the back side of the back side pivot shaft  114  is linked and fastened in a coaxial state, via a shaft coupling  117 , to the distal end portion of a motor rotating shaft  107   b  which is inserted from the back side. 
     The stator plate  106  is fastened coaxially to the front end of the large-diameter cylindrical part  112  of the holder  105 . The stator plate  106  is shaped like a disk having a contour shape identical to that of the cylindrical part  112 , and in the center portion of the inside end surface  106   c  of the stator plate  106 , a vane guide  120  of cylindrical shape for bringing about reciprocating slide motion of the vane  104  in a diametrical direction in association with rotation of the rotor  103  is mounted concentrically to the stator center  102   a . Moreover, on the inside end surface  106   c  there are formed a plurality of cylindrical parts (in the present example, a first cylindrical part  121  and a second cylindrical part  122 ) that concentrically encircle the vane guide  120 . Between the vane guide  120  and the inside first cylindrical part  121 , between the first cylindrical part  121  and the outside second cylindrical part  122 , and between the second cylindrical part  122  and the outside cylindrical part  112 , there are respectively formed ring-shaped spaces  123 ,  124 ,  125 . 
     The stator center  102   a  is eccentric by an amount of eccentricity Δ with respect to the rotor rotation center  103   a . Consequently, the ring-shaped spaces  123 ,  124 ,  125  are also eccentric by an unchanging amount of eccentricity Δ with respect to the rotor rotation center  103   a.    
     Next, as shown in  FIG. 4  ( c ), the rotor  103  is equipped with a disk part  130 , this disk part  130  facing the stator plate  106  with an unchanging distance therebetween. The circular end surface  130   a  of the disk part  130  is abutted by the end surface  120   c  of the vane guide  120  which is mounted on the stator plate  106  side, as well as being confronted across a small gap by the distal end faces  121   c ,  122   c  of the first and second cylindrical parts  121 ,  122 . The back side pivot shaft  114  is integrally formed on the back side of the disk part  130 . 
     On the circular end surface  130   a  of the disk part  130  of the rotor  103 , there are integrally formed a plurality of concentric cylinders (in the present example, three cylinders  131 ,  132 ,  133 ) which are centered on the rotor rotation center  103   a . The inside cylinder  131  projects into the inside ring-shaped space  123  on the stator  102  side, with the distal end surface thereof facing the end surface  106   c  of the stator plate  106  across a small gap. Likewise, the outside cylinders  132 ,  133  respectively project into the outside ring-shaped spaces  124 ,  125  on the stator  102  side, with the distal end surfaces thereof facing the inside end surface  106   c  of the stator plate  106  across a small gap. The ring-shaped spaces  123  to  125  are thereby respectively divided by the cylinders  131  to  133  into inner peripheral-side spaces  123   b ,  124   b ,  125   b , and outer peripheral-side spaces  123   a ,  124   a ,  125   a.    
     As shown in  FIG. 4  ( a ), circular outer peripheral surfaces  131   a  to  133   a  of the cylinders  131  to  133 , at a first end thereof in a single diametrical direction L, face the inner peripheral surfaces  121   b ,  122   b ,  112   b  of the cylindrical parts  121 ,  122 ,  112  across small gaps; and at the end on the opposite side in the diametrical direction L, face the inner peripheral surfaces  121   b ,  122   b ,  112   b  of the cylindrical parts  121 ,  122 ,  112  across maximum gaps. Consequently, the outer peripheral-side space  123   a  of the inside ring-shaped space  123  progressively increases in width along the circumferential direction going from the first end in the diametrical direction L towards the end on the opposite side; and, conversely, progressively decreases in width going from that other end towards the first end. The width of the inner peripheral-side space  123   b  changes in the opposite manner along the circumferential direction. The outer peripheral-side spaces  124   a ,  125   a  of the inside ring-shaped spaces  124 ,  125  change in width in comparable fashion to the outer peripheral-side space  123   a , and the inner peripheral-side spaces  124   b ,  125   b  change in width in comparable fashion to the inner peripheral-side space  123   b.    
     Next, a vane attachment groove  137  is formed extending in a diametrical direction in the rotor  103 . The vane  104  is attached in this vane attachment groove  137 , in a slidable state along the vane attachment groove  137 . The vane attachment groove  137  is a groove of unchanging width extending in a straight line in a diametrical direction through the rotor rotation center  103   a ; and is equipped with a groove part  137   a  of unchanging depth formed on the circular end surface  130   a  of the disk part  130  of the rotor  103 , and with slit parts  137   b ,  137   c ,  137   d  that pass in a radial direction through parts of the cylinders  131  to  133  that face the groove part  137   a.    
     The vane  104  which has been slidably attached in the vane attachment groove  137  is equipped with a linking plate part  140  of unchanging width attached in the groove part  137   a  of the disk part  130 , and a plurality of comb-tooth parts (in the present example, six comb-tooth parts  141  to  146 ) that protrude at unchanging distance from this linking plate part  140 . These comb-tooth parts  141  to  146  are formed point-symmetrically to either side of the rotor rotation center  103   a.    
     The pair of comb-tooth parts  141 ,  142  positioned to the rotor rotation center  103   a  side are positioned within the inside ring-shaped space  123 , with the distal end surfaces  141   c  thereof facing the inside end surface  106   c  on the stator plate  106  side across a small gap (non-contacting state), and with the inner peripheral-side end surfaces  141   b  thereof contacting the outer peripheral surface  120   a  of the vane guide  120 . When the rotor  103  rotates, because the vane guide  120  is sandwiched between the comb-tooth parts  141 ,  142  of the vane  104  which rotates in unison therewith, the vane  104  is guided by the outer peripheral surface  120   a  of the vane guide  120 , and rotates while undergoing reciprocating slide motion in a rotor diametrical direction along the vane attachment groove  137 . In contrast to this, the outer peripheral-side end surface  141   a  of the comb-tooth part  141  rotates while facing the inner peripheral surface  121   b  of the cylindrical part  121  across a small gap (non-contacting state). 
     The outside pair of comb-tooth parts  143 ,  144  are positioned within the ring-shaped space  124 , with the distal end surfaces  143   c ,  144   c  thereof facing the inside end surface  106   c  on the stator plate  106  side across a small gap (non-contacting state). Moreover, of these comb-tooth parts  143 ,  144 , the inner peripheral-side end surfaces  143   b ,  144   b  thereof face the outer peripheral surface  121   a  of the cylindrical part  121  across a small gap (non-contacting state), while the outer peripheral-side end surfaces  143   a ,  144   a  thereof face the inner peripheral surface  122   b  of the cylindrical part  122  across a small gap (non-contacting state). Likewise, the pair of comb-tooth parts  145 ,  146  positioned furthest to the outside are positioned within the ring-shaped space  125 , with the distal end surfaces  145   a ,  146   c  thereof facing the inside end surface  106   c  on the stator plate  106  side across a small gap (non-contacting state). Moreover, of these comb-tooth parts  145 ,  146 , the inner peripheral-side end surfaces  145   b ,  146   b  thereof face the outer peripheral surface  122   a  of the cylindrical part  122  across a small gap, while the outer peripheral-side end surfaces  145   a ,  146   a  thereof face the inner peripheral surface  112   b  of the cylindrical part  112  across a small gap. 
     Here, in order to bring about rotation of the comb-tooth parts  141  to  146  while maintaining an unchanging small distance with respect to the cylindrical parts  121 ,  122 ,  112  in the aforedescribed manner, in the present example, the shape of the outer peripheral surface  120   a  of the vane guide  120 , the shapes of the inner peripheral surfaces and outer peripheral surfaces of the cylindrical parts  121 ,  122 , and the shape of the inner peripheral surface of the cylindrical part  112 , are defined as follows. Specifically, the contour shape of the outer peripheral surface  120   a  of the vane guide  120  is defined by the rotation trajectory of the inner peripheral-side end surfaces  141   b ,  142   b  of the comb-tooth parts  141 ,  142  of the vane  104  in confrontation thereto, or by an approximate curve of the rotation trajectory. Likewise, the contour shapes of the inner peripheral surfaces  121   b ,  122   b  and the outer peripheral surface shapes  121   a ,  122   a  of the cylindrical parts  121 ,  122 , and of the inner peripheral surface  112   b  of the cylindrical part  112 , are defined by the rotation trajectories of the regions of the comb-tooth parts of the vane  4  in confrontation thereto, or by approximate curves of these rotation trajectories. 
     In the aforedescribed manner, the outer peripheral-side spaces  123   a ,  124   a ,  125   a  and the inner peripheral-side spaces  123   b ,  124   b ,  125   b  of the ring-shaped spaces  123 ,  124 ,  125  are respectively divided into two compression chambers by the comb-tooth parts  141  to  146  of the vane  104 . Specifically, as shown in  FIG. 4  ( a ), the outer peripheral-side space  125   a  of the ring-shaped space  125  is divided into two first-stage compression chambers  151  by the comb-tooth parts  146 ,  145 , and the inner peripheral-side space  125   b  thereof is divided into two second-stage compression chambers  152  by the comb-tooth parts  146 ,  145 . Moreover, the outer peripheral-side space  124   a  of the ring-shaped space  124  is divided into two third-stage compression chambers  153  by the comb-tooth parts  144 ,  143 , and the inner peripheral-side space  124   b  is divided into two fourth-stage compression chambers  154  by the comb-tooth parts  144 ,  143 . Further, the outer peripheral-side space  123   a  of the ring-shaped space  123  is divided into two fifth-stage compression chambers  155  by the comb-tooth parts  142 ,  141 , and the inner peripheral-side space  123   b  thereof is divided into two sixth-stage compression chambers  156  by the comb-tooth parts  142 ,  141 . 
     In a region of the cylindrical part  112  within the rotation angle range in which the volume of the first-stage compression chambers  151  progressively increases in association with the rotation of the rotor  103  (in the present example, in a region at an angular position rotated by 90 degrees with respect to the diametrical direction L), there is formed an intake port  161  for intake of fluid from the outside. In a region of the inside end surface  106   c  of the stator plate  106  within a range of rotation angles in which the volume of the first-stage compression chambers  151  progressively decreases in association with the rotation of the rotor  103  (in the present example, in a region rotated by 180 degrees with respect to the intake port  161 ), there is formed a communication port  162  communicating between the first-stage compression chambers  151  and the second-stage compression chambers  152 . Likewise, in the stator plate  106 , there are formed a communication port  163  for the second-stage compression chambers  152  and the third-stage compression chambers  153 , a communication port  164  for the third-stage compression chambers  153  and the fourth-stage compression chambers  154 , a communication port  165  for the fourth-stage compression chambers  154  and the fifth-stage compression chambers  155 , and a communication port  166  for the fifth-stage compression chambers  155  and the sixth-stage compression chambers  156 . Furthermore, a discharge port  167  for discharging the compressed fluid from the sixth-stage compression chambers  156  of the final stage is formed in the stator plate  106 . 
     The vane guide  120  of the present example is rotatably mounted onto the center portion of the stator plate  106 . The vane guide  120  is equipped with a cylindrical part  171 , and an integrally formed disk part  172  that closes off the end at the rotor side of this cylindrical part  171 , the end surface  120   c  of the disk part  172  contacting the circular end surface  130   a  of the disk part  130  of the rotor  103 . A shaft member  173 , which has been attached from the side situated towards the outside end surface  106   b  of the stator plate  106 , is inserted coaxially into the interior of the cylindrical part  171 . The cylindrical part  171  is rotatably supported by the shaft member  173  via a bearing  174 . The zone between the shaft member  173  and the cylindrical part  171  is sealed by a seal  175 . 
     Furthermore, a wave washer  176  (elastic member) is inserted between the end surface of the bearing  174  and the inside end surface of the disk part  172  of the vane guide  120 . The vane guide  120  is pressed against the circular end surface  130   a  of the disk part  130  of the rotor  103  by this wave washer  176 . Consequently, the linking plate part  140  of the vane  104 , which has been installed in the groove part  137   a  of the vane attachment groove  137  extending in a diametrical direction across the circular end surface  130   a , is pressed into the groove part  137   a  by the vane guide  120 . In this way, the rotor  103  and the vane  104  are pressed in the direction of the rotor center axis with respect to the holder  5 , defining the positions thereof in the direction of the rotor center axis. Therefore, the end surface  106   c  of the stator plate  106  and the distal end surfaces  131   c  to  133   c  of the cylinders  131  to  133  on the rotor side can be retained in a non-contacting state, with small gaps therebetween. Moreover, the circular end surface  130   a  of the disk part  130  on the rotor side and the distal end surfaces  121   c ,  122   c  of the cylindrical parts  121 ,  122  on the stator side can be retained in a non-contacting state, with small gaps therebetween. 
     In order to avoid disengagement of the comb-tooth parts  141 ,  142  of the vane  104  from outer peripheral surface  120   a  during rotation, the width dimension W of the inner peripheral-side end surfaces that in the first comb-tooth parts  141 ,  142  of the vane  104  abut against the outer peripheral surface  120   a  of the vane guide  120  should be at least double the amount of eccentricity Δ between the rotor rotation center  103   a  and the stator center  102   a , as shown in  FIG. 4  ( d ). 
     The following description of movement of the vane compressor  100  makes reference to  FIG. 5 . When the rotor  103  is rotated by the motor  107 , the vane  104  rotates about the rotor rotation center  103   a  in unison with the rotor  103 . The vane  104  is slidable in a diametrical direction with respect to the rotor  103 , and rotates while undergoing reciprocating slide motion in a diametrical direction, guided by the outer peripheral surface  120   a  of the vane guide  120  which is positioned at the rotor rotation center  103   a . As a result, the compression chambers  151  to  156  of the first to sixth stages, while in a state of being substantially sealed off by the comb-tooth parts  141  to  146  of the vane  104 , rotate together with the rotor  103 , with the volume thereof repeatedly increasing and decreasing each time that that rotor  103  rotates by 180 degrees. The fluid is thereby compressed in succession within the compression chambers  151  to  156 , and compressed fluid which has been compressed to a high compression ratio is then discharged from the compression chamber  156  of the final stage. 
     In the vane compressor  100  of the present example, volume compression chambers can be furnished concentrically in multiple stages by increasing the number of cylindrical parts on the stator side, the number of cylinders on the rotor side, and the number of comb-tooth parts of the vane. Consequently, a vane compressor having high compression capability can be manufactured inexpensively in a simple structure, with a minimum number of components. Moreover, because the compression chambers of each stage are arrayed concentrically, the communication paths communicating between them can be formed in a simple manner. Consequently, the vane compressor  100  can be employed as an inexpensive dry vacuum pump with excellent base pressure, or the like. 
     Moreover, because the vane guide  120  is sandwiched between the pair of comb-tooth parts  141 ,  142  of the vane  104 , there is no need, utilizing centrifugal force, to bring about reciprocating translation of the vane  104  and press it against the inner peripheral surface of the vane guide  120 . Moreover, the center of gravity of the vane  104  is positioned close to the rotation center of the rotor, and the centrifugal force acting on the vane  104  is lower. Therefore, wear and sliding resistance between the vane  104  and the vane guide  120  can be significantly minimized. In particular, in the present example, because the vane guide  120  is rotatably supported on the stator side, wear and sliding resistance between the vane and the vane guide can be reduced even more effectively. 
     Moreover, because the final-stage compression chamber  156  is formed by the comb-tooth parts  141 ,  142  of the vane  104  which is guided by the vane guide  120 , the efficiency of utilization of space is high, and arrangement in multiple stages is easy. 
     Furthermore, the rotor  103  and the vane guide  120  are pressed by the wave washer  176  along the direction of the center axis thereof, towards the side where the holder  105  of the stator  102  is situated. Consequently, the positions of the rotor  103  and the vane  104  with respect to the stator  102  in the center axis direction are defined, and the relative positions thereof in the axial direction can be set accurately. 
     (Fourth Embodiment) 
     A vane compressor according to a fourth embodiment of the present invention is described with reference to  FIG. 6 . The basic structure of the vane compressor  100 A of the present embodiment is the same as that of the vane compressor  100  according to the third embodiment; therefore portions corresponding to those of the vane compressor  100  have been assigned the same symbols, omitting description thereof. The vane compressor  100 A is equipped with two vanes  104 A,  104 B, the vane  104 A being slidably retained in a vane attachment groove  137 A, and the vane  104 B being slidably retained in a vane attachment groove  137 B. 
     Specifically, the vane attachment grooves  137 A,  137 B extend in directions orthogonal to one another, and are respectively formed passing through the center  103   a  of the rotor  103 . These vane attachment grooves  137 A,  137 B are respectively grooves of unchanging width extending in straight lines in diametrical directions through the rotor rotation center  103   a , and are basically identical to the vane attachment grooves  137  discussed previously. Consequently, the groove parts  137   a  of the vane attachment grooves  137 A,  137 B are formed to overlap at the centers thereof. 
     The following description of the vane  104 A which is slidably attached in the vane attachment groove  137 A and the vane  104 B which is slidably attached in the vane attachment groove  137 B makes reference to  FIG. 7  ( a ) to ( d ). As shown in the drawings, both of the vanes  104 A,  104 B have identical features overall, the features being basically identical to those of the vane  104  of the vane compressor  100  of the third embodiment. 
     The point of difference is that rectangular cutout portions  104   a ,  104   b  are formed so as to permit the vanes  104 A,  104 B to be attached in an orthogonal state in the vane attachment grooves  137 A,  137 B. Specifically, in one of the vanes  104 A, the rectangular cutout portion  104   a  is formed on the bottom side edge surface side in the lengthwise center part of the linking plate part  140  thereof, and in the other vane  104 B, the rectangular cutout portion  104   b  is formed from the top side edge surface side in the lengthwise center part of the linking plate part  140  thereof. 
     The comb-tooth parts  141  to  146  of the two vanes  104 A,  104 B disposed in the orthogonal state divide, into four compression chambers respectively, the outer peripheral-side spaces  123   a ,  124   a ,  125   a  and the inner peripheral-side spaces  123   b ,  124   b ,  125   b  of the ring-shaped spaces  123 ,  124 ,  125 . Specifically, as shown in  FIG. 6  ( a ), the outer peripheral-side space  125   a  of the outermost ring-shaped space  125  is divided into four first-stage compression chambers  151  by the comb-tooth parts  146 ,  145  of the vane  104 A and the comb-tooth parts  146 ,  145  of the vane  104 B. The inner peripheral-side space  125   b  of the ring-shaped space  125  is divided into four second-stage compression chambers  152  by the comb-tooth parts  146 ,  145  of the vane  104 A and the comb-tooth parts  146 ,  145  of the vane  104 B. 
     Likewise, the outer peripheral-side space  124   a  of the ring-shaped space  124  is divided into four third-stage compression chambers  153  by the pair of comb-tooth parts  144  and the pair of comb-tooth parts  143 . The inner peripheral-side space  124   b  of the ring-shaped space  124  is divided into four fourth-stage compression chambers  154  by the pair of comb-tooth parts  144  and the pair of comb-tooth parts  143 . The outer peripheral-side space  123   a  of the ring-shaped space  123  is divided into four fifth-stage compression chambers  155  by the pair of comb-tooth parts  142  and the pair of comb-tooth parts  141 , while the inner peripheral-side space  123   b  thereof is divided into four sixth-stage compression chambers  156  by the pair of comb-tooth parts  142  and the pair of comb-tooth parts  141 . 
     The intake port  161 , the communication ports  162  to  166 , and the discharge port  167  are formed at the same positions as in the vane compressor  100  discussed previously. 
     In the vane compressor  100 A having this feature, when the rotor  103  is rotated by the motor  107 , the pair of vanes  104 A,  104 B rotate in tandem with the rotor  103  about the rotor rotation center  103   a  while maintaining their orthogonal state. Because the vanes  104 A,  104 B are respectively slidable in orthogonal diametrical directions with respect to the rotor  103 , the vanes  104 A,  104 B, guided by the outside peripheral surface  120   a  of the vane guide  120  positioned at the rotor rotation center  103   a , rotate while undergoing reciprocating sliding motion in diametrical directions. 
     As a result, the compression chambers  151  to  156  of the first to sixth stages, while in a state of being substantially sealed off by the comb-tooth parts  141  to  146  of the vanes  104 A,  104 B, rotate together with the rotor  103 , with the volume thereof repeatedly increasing and decreasing each time that that rotor  103  rotates by 180 degrees. The fluid is thereby compressed in succession within the compression chambers  151  to  156 , and compressed fluid which has been compressed to a high compression ratio is then discharged from the compression chamber  156  of the final stage. The vane compressor  100 A thereby affords working effects comparable to the vane compressor  100  discussed previously.