Patent Publication Number: US-8985963-B2

Title: Stop mechanism for vane compressor

Description:
TECHNICAL FIELD 
     The present invention relates to a vane compressor. 
     BACKGROUND ART 
     A vane compressor includes a cylinder block in which a cylinder chamber having an ellipsoidal inner wall is formed, a rotor that is rotatably supported in the cylinder chamber and rotates by receiving a drive force, and plural vanes that are inserted in plural vane slots formed on an outer circumferential surface of the rotor, respectively. While the rotor rotates, the vanes are protruded by backpressure generated in backpressure spaces in the vane slots, so that end edges of the vanes are slidably contacted with the inner wall of the cylinder chamber and the vanes reciprocate in the vane slots. 
     Since the backpressure is generated by high-pressure refrigerant in the cylinder chamber in operation, the vanes are protruded from the vane slots and the end edges of the vanes are slidably contacted with the inner wall of the cylinder chamber, so that a volume of the backpressure spaces is kept almost constant. 
     On the other hand, pressure in the compressor becomes uniform while it is stopped, so that the backpressure to protrude the vanes doesn&#39;t act on the vanes. Therefore, a vane oriented vertically upward drops down in a vane slot while ejecting refrigerant and oil in the vane slot out through clearances between inner walls of the vane slot and the vane due to its own weight. Therefore, the volume of the backpressure spaces may gradually decrease if its stopped state continues. When the compressor is started up from this state, the volume of the backpressure spaces is small and a volume of the refrigerant and the oil flowing into the backpressure spaces through the clearances between the inner walls of the vane slot and the vane is small, so that the vane cannot protrude quickly even if a force for protruding the vane acts thereon due to a centrifugal force by the rotation of the rotor. Therefore, the backpressure spaces become negative pressure and the vane is difficult to protrude, so that the end edge of the vane is not sufficiently protruded to the inner wall surface of the cylinder chamber. As a result, the vane is repeatedly contacted-with and hit-back-from the inner wall surface of the cylinder chamber and thereby noises (chattering) may occur. 
     A Patent Document 1 listed below discloses a compressor that prevents chattering. In the compressor, a support plate is disposed on a bottom of a vane slot and pins are fixed on the support plate. Coil springs for biasing a vane in a protruding direction are inserted to the pins. As a result, the vane does not drop down in the vane slot in a stopped state of the compressor. When the compressor is started up, the vane is protruded from the vane slot by a biasing force of the coil springs and its end edge is slidably contacted with an inner wall of a cylinder chamber, so that chattering is prevented. 
     PRIOR ART DOCUMENT 
     Patent Document 
     
         
         Patent Document 1: Japanese Examined Utility Model Publication No. H8-538 
       
    
     SUMMARY OF INVENTION 
     However, in the compressor disclosed in the Patent Document 1 mentioned above, it is needed to provide the coil springs as extra parts. In addition, use of the coil springs increases assembling man-hours and thereby its costs. Further, working processes for the vanes become complicated due to the application of the coil springs. 
     An object of the present invention is to provide a vane compressor that can prevent chattering without extra workings on vanes or a rotor and without providing extra parts by reducing difference between a total volume of backpressure spaces while the compressor is operated and a total volume of the backpressure spaces while the compressor is stopped. 
     An aspect of the present invention provides a vane compressor that includes a cylinder block, a cylinder chamber that is formed in an inside of the cylinder block and has an ellipsoidal inner wall, a rotor that is rotatably supported in the cylinder chamber and whose outer circumferential surface is provided with a plurality of vane slots formed thereon, a drive source for rotating the rotor, and a plurality of vanes that is housed in the plurality of vane slots, respectively, wherein the rotor is rotated by the drive source while the vanes are protruded from the vane slots by backpressure generated in backpressure spaces in the vane slots to contact end edges of the vanes with the inner wall of the cylinder chamber, and the compressor further comprises a stop mechanism that makes the rotor stopped at a predetermined rotational position where a difference between a total volume of the backpressure spaces when operated and a total volume of the backpressure spaces when stopped becomes minimum. 
     According to the aspect, the rotor can be stopped at the predetermined rotational position where the difference between the total volume of the backpressure spaces when the compressor is operated and the total volume of the backpressure spaces when the compressor is stopped becomes minimum. As a result, chattering can be prevented without extra workings on the vane slots, the vanes or the rotor and without providing extra parts. 
     Here, it is preferable that the drive source is an electrical motor for rotationally driving the rotor while detecting a rotational position of the rotor, and the stop mechanism is a drive circuit for controlling the electrical motor so as to make the rotor stopped at the predetermined rotational position. 
     Alternatively, it is preferable that the stop mechanism is constituted of a clutch disposed between the rotor and the drive source, a plurality of rotor-side magnets mounted in the rotor along a circumferential direction at even intervals, and a plurality of cylinder-side magnets mounted in the inner wall of the cylinder chamber, and the stop mechanism disengages the clutch to make the rotor stopped at the predetermined rotational position due to a repulsive force and an attractive force acting between the rotor-side magnets and the cylinder-side magnets. 
     In addition, it is preferable that the compressor is arranged, when installed on a vehicle, such that an ellipsoidal major axis direction of the cylinder chamber is oriented in a horizontal direction. According to this, the difference between the total volume of the backpressure spaces when the compressor is operated and the total volume of the backpressure spaces when stopped becomes smaller. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is an overall cross-sectional view of a vane compressor  1  according to a first embodiment. 
         FIG. 2  is an enlarged cross-sectional view of a cylinder block  6  in the first embodiment. 
         FIG. 3  is a graph showing relationship between a rotor rotational angle and a volume fluctuation of backpressure spaces  14  when the compressor in the first embodiment is operated and stopped. 
         FIG. 4  ( a ) is an enlarged cross-sectional view of a cylinder block  6  in a second embodiment, and ( b ) is an enlarged cross-sectional view of a cylinder block  6  in a third embodiment. 
         FIG. 5  ( a ) is a graph showing relationship between a rotor rotational angle and a volume fluctuation of backpressure spaces  14  when the compressor in the second embodiment is operated and stopped, and ( b ) is a graph showing relationship between a rotor rotational angle and a volume fluctuation of backpressure spaces  14  when the compressor in the third embodiment is operated and stopped. 
         FIG. 6  is an enlarged cross-sectional view of a cylinder block  6  in a fourth embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, embodiments of a vane compressor will be explained with reference to the drawings. 
     First Embodiment 
     As shown in  FIG. 1 , a vane compressor  1  according to a first embodiment includes, a cylinder block  6 , a rotor  7 , and plural vanes  8 . A cylinder chamber  12  having an ellipsoidal inner wall is formed in the cylinder block  6 . The rotor  7  is rotatably supported in the cylinder chamber  12  and rotated by a drive force from a motor (a drive source)  3 . The vanes  8  are inserted in plural vane slots  13  formed on an outer circumferential surface of the rotor  7 , respectively. When the rotor  7  rotates, the vanes  8  are protruded by backpressure generated in backpressure spaces  14  in the vane slots  13 , so that end edges of the vanes  8  are slidably contacted with the inner wall of the cylinder chamber  12  and the vanes  8  reciprocate in the vane slots  13 . The compressor  1  according to the present embodiment is provided with a stop mechanism for stopping the rotor  7  at a rotational position where difference between a total volume of the backpressure spaces  14  when operated and a total volume of the backpressure spaces  14  when stopped becomes small. Especially in the embodiments explained hereinafter, the rotor  7  is made stopped at a rotational position where the above difference become minimum. The backpressure space(s)  14  will be explained in detail later. 
     Further, in the present embodiment, the motor (the electrical motor)  3  functions as the drive source for rotationally driving the rotor  7  while detecting its rotational position, and a drive circuit  18  for stopping the rotor  7  at the rotational position where the difference between the total volume of the backpressure spaces  14  when the compressor  1  is operated and the total volume of the backpressure spaces  14  when stopped becomes small functions as the stop mechanism. 
     Hereinafter, the compressor  1  will be explained in detail. 
     As shown in  FIG. 1 , in the compressor  1 , a compression section  2 , the motor (the drive source: the electrical motor)  3 , and an inverter  4  are housed in a cylindrical case  5 . The case  5  is constituted of a front case  5   a  that houses the inverter  4 , a middle case  5   b  that houses the compression section  2 , and a rear case  5   c  that houses the motor  3 . The front case  5   a , the middle case  5   b  and the rear case  5   c  are engaged with each other by bolts or the like, and a sealed chamber is formed in an inside of the case  5 . 
     The compression section  2  in the middle case  5   b  includes the cylindrical cylinder block  6 , a pair of side blocks  9  provided at both sides of the cylinder block  6 , and the columnar rotor  7 . The cylinder chamber  12  that has a smooth ellipsoidal inner wall surface  11  is formed in an inside of the cylinder block  6 . Both sides of the cylinder chamber  12  are closed by the pair of side blocks  9 . The rotor  7  is disposed at a center of the cylinder chamber  12 . In addition, a rotary shaft  10  coupled with a rotor shaft  17  of the motor  3  penetrates through the cylinder chamber  12 . The rotor  7  is supported by the rotary shaft  10 , and rotated in the cylinder chamber  12  by the rotational drive force of the rotor  7  via the rotary shaft  10 . 
     As shown in  FIG. 2 , the three vane slots  13  are formed on the outer circumferential surface of the rotor  7  along its circumferential direction at even intervals. The vane slots  13  are formed from the outer circumferential surface toward innards of the rotor  7 . The vane slot(s)  13  is constituted of a vane movable portion  13   b  that houses the planar vane  8  reciprocatably, and a pressure introduction portion  13   c  that has a circular cross-sectional shape and communicated with the vane movable portion  13   b . The pressure introduction portion  13   c  communicates with refrigerant paths in the side blocks  9 . The vane movable portion  13   b  and the pressure introduction portion  13   c  are formed along the rotary shaft  10  of the rotor  7 . In addition, the backpressure space  14  to which oil is supplied together with refrigerant is formed between a bottom  13   a  of the vane slot  13  and a rear edge Bb of the vane  8 . A volume of the backpressure space  14  varies along with a reciprocation of the vane  8 . 
     The vane(s)  8  is protruded from the vane slot  13  by an centrifugal force due to the rotation of the rotor  7  and a pressure of the oil and refrigerant supplied to the vane movable portion  13   b  and the pressure introduction portion  13   c  (i.e. the backpressure space  14 ). The vane  8  reciprocates in the vane slot  13  with its end edge  8   a  slidably contacted with the inner wall surface  11  of the cylinder chamber  12 . When the rotor  7  is rotated by the rotational drive force of the motor  3 , the refrigerant is compressed due to volume changes of compression chambers segmented by the inner wall surface  11  of the cylinder chamber  12  and the vanes  8 . 
     The motor  3  is an electrical motor, and, as shown in  FIG. 1 , constituted of plural coils  16  aligned along an internal circumferential surface of the rear case  5   c , a motor rotor  15  to be rotated by magnetism generated by the coils  16 , and the rotor shaft  17  fixed at a center of the motor rotor  15 . The rotor shaft  17  rotates along with the motor rotor  15 . Both ends of the rotor shaft  17  are rotatably supported by the rear case  5   c  and a partition wall arranged between the motor  3  and the side block  9  via bearings  19   a  and  19   b.    
     In addition, the motor  3  in the present embodiment is a so-called sensored electrical motor that can detect a rotational angle of the motor rotor  15 . The rotational angle of the motor rotor  15  is detected by a sensor not shown, and its detection result is transmitted to the drive circuit  18 . Note that, for example, the sensor detects the rotational angle of the motor rotor  15  by detecting a position of a magnet mounted in the motor rotor  15 . 
     In addition, the rotor shaft  17  coupled with the rotary shaft  10  is made stopped at a predetermined rotational angle in order to stop the rotor  7  at the predetermined rotational position (i.e. rotational position where the total volume of the backpressure spaces  14  when the compressor  1  is operated and the total volume of the backpressure spaces  14  when stopped becomes small). Therefore, the drive circuit  18  controls the rotor shaft  17  so as to stop it at the predetermined rotational angle based on the detection result of the rotational angle of the motor rotor  15 . 
     The inverter  4  is configured of a drive circuit housed in the front case  5   a , and controls power supply to the coils  16  based on the detection result of the rotational angle of the motor rotor  15   
     Next, volume fluctuations of the backpressure spaces  14  when the compressor  1  is operated and stopped will be explained with reference to  FIG. 3 . 
     A graph in  FIG. 3  shows the fluctuations of the total volume of the backpressure spaces  14  in a case of the compression section  2  (see  FIG. 2 ) with the tree vanes  8  in the first embodiment. Its horizontal axis indicates the rotational angle of the rotor  7 , and its vertical axis indicates the total volume of the backpressure spaces  14  (the total volume of the three backpressure spaces  14 ). 
     A curved line A indicates the fluctuation of the total volume of the backpressure spaces  14  when the compressor  1  is operated, and a curved line B indicates the fluctuation of the total volume of the backpressure spaces  14  when stopped. In an operated state shown by the curved line A, since all the end edges  8   a  of the vanes  8  contact with the inner wall surface  11  of the cylinder chamber  12 , the fluctuation of the total volume of the backpressure spaces  14  relative to the rotational angle of the rotor  7  is small and keeps an almost constant value. 
     On the other hand, a stopped state shown by the curved line B, the fluctuation of the total volume of the backpressure spaces  14  relative to the rotational angle of the rotor  7  varies significantly. Since one of the vanes  8  is oriented vertically upward when the rotor  7  is made stopped at a rotational angle (about 40°, about 150°, about 260° . . . ) indicated by points Q on the curved line B, the very vane  8  drops down in the vane slot  13  due to its own weight. As a result, the volume of the backpressure space  14  of the vane  8  oriented vertically upward decreases, so that the total volume of the backpressure spaces  14  becomes small (the difference relative to the total volume when operated is large [become maximum]). Alternatively, at a rotational angle (about 90°, about 210°, about 320° . . . ) indicated by points P on the curved line B, the rotor  7  stops at a position where a drop-down distance of the vane(s)  8  due to its own weight is small (see  FIG. 2 ). Therefore, the total volume of the backpressure spaces  14  becomes large (the difference relative to the total volume when operated is small [become minimum]). 
     From these curved lines A and B, it turns out that the total volume of the backpressure spaces  14  varies significantly according to the rotational angle (the rotational position) of the rotor  7  when the compressor  1  is stopped. Decrease of the total volume of the backpressure spaces  14  can be restricted by setting a stop position of the rotor  7  with the compressor  1  stopped to the predetermined rotational angel. 
     Therefore, in the present embodiment, the drive circuit  18  controls the rotational angle of the motor  3  so as to stop the rotor  7  at the rotational angle where the difference between the total volume of the backpressure spaces  14  indicated by the curved line A and the total volume of the backpressure spaces  14  indicated by the curved line B becomes small. 
     Next, the operation of the compressor  1  according to the present embodiment will be explained. 
     In the compressor  1 , electrical current is supplied to the coils  16  of the motor  3  from the drive circuit, so that the rotor shaft  17  is rotated together with the motor rotor  15 . When the rotor shaft  17  is rotated, the rotor  7  is rotated via the rotary shaft  10  coupled with an end of the rotor shaft  17 , and thereby refrigerant is compressed. The compressed refrigerant flows through the inside of the middle case  5   b  and the motor  3  in the rear case  5   c , and is discharged to an outside from a discharge port  21 . 
     When the compressor  1  is to be stopped, the drive circuit  18  stops the rotor  7  at the above-described predetermined rotational position (the rotational position where the difference between the total volume of the backpressure spaces  14  when operated of the compressor  1  and the total volume of the backpressure spaces  14  when stopped becomes small) by controlling the motor  3 . Namely, as shown in  FIG. 2 , the rotor  7  is made stopped at the rotational position where the drop-down distance of the vane(s)  8  due to its own weight is small. 
     As explained above, by stopping the rotor  7  at the position where the drop-down distance of the vane(s)  8  due to its own weight is small, the difference between the total volume of the backpressure spaces  14  when operated and the total volume of the backpressure spaces  14  when stopped can be made small without extra workings on the vane slots  13 , the vanes  8  or the rotor  7  and without providing extra parts. As a result, chattering upon starting-up can be prevented. 
     Note that, the motor  3  is a sensored electrical motor in the present embodiment, but it may be a sensorless motor. In a case of a sensorless motor, the rotor shaft  17  and the rotary shaft  10  are coupled with each other with a predetermined coupling angle (i.e. a rotational positional relation between the motor rotor  15  and the rotor  7  is fixed), the rotational angle of the rotor  7  is estimated based on electrical current flowing through the motor rotor  15 . It can be done to stop the rotor  7  at the above-described predetermined rotational position based on the estimated result. Note that the rotation of the motor rotor  15  is controlled by the drive circuit  18  also in this case. 
     In addition, the compressor  1  in the present embodiment is installed on a vehicle, and arranged, when installed on the vehicle, such that an ellipsoidal major axis direction of the cylinder chamber  12  perpendicularly intersects a horizontal direction (such that the ellipsoidal major axis direction extends along a vertical direction) as shown  FIG. 2 . 
     Second Embodiment 
     Next, a vane compressor according to a second embodiment will be explained with reference to  FIG. 4(   a ) and  FIG. 5(   a ). Note that redundant explanations for identical and similar components to those in the above-explained first embodiment will be omitted by adding identical reference numerals. 
     As shown in  FIG. 4(   a ), five vanes  8  are provided in a cylinder block  56  of the compression section  2 . When the compressor is installed on a vehicle, it is arranged such that the ellipsoidal major axis direction of the cylinder chamber  12  perpendicularly intersects a vertical direction (such that the ellipsoidal major axis direction extends along a horizontal direction). 
     Similarly to the first embodiment, the drive circuit  18  stops the rotor  7  at the above-described predetermined rotational position (the rotational position where the difference between the total volume of the backpressure spaces  14  when the compressor  1  is operated and the total volume of the backpressure spaces  14  when stopped becomes small) by controlling the motor  3  based on the detection result of the rotational angle of the motor rotor  15 . 
     A graph in  FIG. 5(   a ) shows fluctuations of the total volume of the backpressure spaces  14  in a case of the compression section  2  (see  FIG. 4(   a )) with the five vanes  8  in the second embodiment. Similarly to the graph in  FIG. 3 , its horizontal axis indicates the rotational angle of the rotor  7 , and its vertical axis indicates the total volume of the backpressure spaces  14  (the total volume of the five backpressure spaces  14 ). 
     Points Q on the curved line B indicate the rotational angles of the rotor  7  where the total volume of the backpressure spaces  14  when the compressor  1  is stopped becomes small (the difference relative to the total volume when operated is large [become maximum]). Points P indicate the rotational angles of the rotor  7  where the total volume of the backpressure spaces  14  when operated of the compressor  1  becomes large (the difference relative to the total volume when operated is small [become minimum]). 
     Therefore, by stopping the rotor  7  at the position where the difference between the total volume of the backpressure spaces  14  when the compressor  1  is operated and the total volume of the backpressure spaces  14  when stopped, chattering upon starting-up can be prevented. In the present embodiment, since the ellipsoidal major axis direction of the cylinder chamber  12  is arranged so as to intersect a vertical direction perpendicularly (the ellipsoidal major axis direction is arranged so as to extend along a horizontal direction), such a predetermined rotational position of the rotor  7  is a rotational position where a drop-down distance of the vane(s)  8  due to its own weight is small as shown in  FIG. 4(   a ). 
     In addition, since the rotor  7  is only controlled by the drive circuit  18  so as to stop at the above-described rotational angle, the difference between the total volume of the backpressure spaces  14  when operated and the total volume of the backpressure spaces  14  when stopped can be made small without extra workings on the vane slots  13 , the vanes  8  or the rotor  7  and without providing extra parts. As a result, chattering upon starting-up can be prevented. 
     Third Embodiment 
     Next, a vane compressor according to a third embodiment will be explained with reference to  FIG. 4(   b ) and  FIG. 5(   b ). Note that redundant explanations for identical and similar components to those in the above-explained first embodiment will be omitted by adding identical reference numerals. 
     As shown in  FIG. 4(   b ), three vanes  8  are provided in a cylinder block  66  of the compression section  2 . When the compressor is installed on a vehicle, it is arranged such that the ellipsoidal major axis direction of the cylinder chamber  12  perpendicularly intersects a vertical direction (such that the ellipsoidal major axis direction extends along a horizontal direction). 
     Similarly to the first embodiment, the drive circuit  18  stops the rotor  7  at the above-described predetermined rotational position (the rotational position where the difference between the total volume of the backpressure spaces  14  when the compressor  1  is operated and the total volume of the backpressure spaces  14  when stopped becomes small) by controlling the motor  3  based on the detection result of the rotational angle of the motor rotor  15 . 
     A graph in  FIG. 5(   b ) shows fluctuations of the total volume of the backpressure spaces  14  in a case of the compression section  2  (see  FIG. 4(   b )) with the three vanes  8  in the third embodiment. Similarly to the graph in  FIG. 3 , its horizontal axis indicates the rotational angle of the rotor  7 , and its vertical axis indicates the total volume of the backpressure spaces  14  (the total volume of the three backpressure spaces  14 ). 
     Points Q on the curved line B indicate the rotational angles of the rotor  7  where the total volume of the backpressure spaces  14  when the compressor  1  is stopped becomes small (the difference relative to the total volume when operated is large [become maximum]). Points P indicate the rotational angles of the rotor  7  where the total volume of the backpressure spaces  14  the compressor  1  is operated becomes large (the difference relative to the total volume when operated is small [become minimum]). In the present embodiment, at the rotational angles of the rotor  7  indicated by the points P, there is no difference between the total volume of the backpressure spaces  14  when the compressor  1  is operated and the total volume of the backpressure spaces  14  when stopped. Namely, at the rotational positions of the rotor  7  indicated by the points P, there is no difference in the total volume of the backpressure spaces  14  when the compressor  1  is operated and stopped. 
     Therefore, by stopping the rotor  7  at the position where the difference between the total volume of the backpressure spaces  14  when the compressor  1  is operated and the total volume of the backpressure spaces  14  when stopped, chattering upon starting-up can be prevented. In the present embodiment, since the ellipsoidal major axis direction of the cylinder chamber  12  is arranged so as to intersect a vertical direction perpendicularly (the ellipsoidal major axis direction is arranged so as to extend along a horizontal direction), such a predetermined rotational position of the rotor  7  is a rotational position where a drop-down distance of the vane(s)  8  due to its own weight is small as shown in  FIG. 4(   b ). 
     In addition, since the rotor  7  is only controlled by the drive circuit  18  so as to stop at the above-described rotational angle, the difference between the total volume of the backpressure spaces  14  when operated and the total volume of the backpressure spaces  14  when stopped can be made small without extra workings on the vane slots  13 , the vanes  8  or the rotor  7  and without providing extra parts. As a result, chattering upon starting-up can be prevented. 
     Fourth Embodiment 
     Next, a vane compressor according to a fourth embodiment will be explained with reference to  FIG. 6 . Note that redundant explanations for identical and similar components to those in the above-explained first embodiment will be omitted by adding identical reference numerals. 
     In the present embodiment, the rotor  7  in the cylinder chamber  12  of a cylinder block  76  is coupled with an internal engine (a drive source) via a clutch. The clutch is provided at a position of a member  20  shown in  FIG. 1 , for example, and a pulley or the like for receiving a drive force from the engine is attached thereto in stead of the motor  3  shown in  FIG. 1 . 
     A stop mechanism is constituted of N and S polar rotor-side magnets  77  and  78  mounted in the rotor  7  along its circumferential direction at even intervals, and N and S polar cylinder-side magnets  79  and  80  mounted in an inner wall of the cylinder chamber  12 . When the clutch is disengaged upon stopping the compressor, the rotor  7  is disengaged with the engine and the rotor  7  is made stopped at the above-described predetermined rotational position (the rotational position where the difference between the total volume of the backpressure spaces  14  when the compressor is operated and the total volume of the backpressure spaces  14  when stopped becomes small) due to a repulsive force and an attractive force acting between the rotor-side magnets  77  and  78  and the cylinder-side magnets  79  and  80 . 
     According to the present embodiment, a rotational drive force by the engine (the drive source) for the rotor  7  is transmitted to the rotor  7  via the clutch. When the compressor is stopped, the rotor  7  is made stopped at the above-described predetermined rotational position by the rotor-side magnets  77  and  78  and the cylinder-side magnets  79  and  80 . Therefore, since the difference between the total volume of the backpressure spaces  14  when operated and the total volume of the backpressure spaces  14  when stopped can be made small, chattering can be prevented. 
     In addition, the difference between the total volume of the backpressure spaces  14  when operated and the total volume of the backpressure spaces  14  when stopped can be made small without extra workings on the vane slots  13 , the vanes  8  or the rotor  7  and without providing extra parts, other than embedding the magnets  77  to  80  in the rotor  7  and the inner wall of the cylinder chamber  12 . As a result, chattering upon starting-up can be prevented. 
     Note that the present invention is appropriate for a horizontal vane compressor (in which an ellipsoidal major axis direction of a cylinder chamber  12  is extended along a horizontal direction) because a drop-off distance of an upwardly oriented vane(s)  8  due to its own weight can be made smaller in relation to a shape of the cylinder chamber  12 .