Patent Publication Number: US-9903369-B2

Title: Vane rotary compressor having hinge receiving portions formed on an outer peripheral surface of a rotor with a plurality of vanes including a hinge portion and a blade portion

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application is a United States national phase patent application based on PCT/KR2014/004653 filed May 26, 2014 which claims the benefit of Korean Patent Application No. 10-2014-0024520 filed Feb. 28, 2014. The entire disclosures of the above patent applications are hereby incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to a vane rotary compressor in which a fluid such as refrigerant is compressed while the volume of a compression chamber is reduced when a rotor rotates. 
     BACKGROUND OF THE INVENTION 
     A vane rotary compressor is used for an air conditioner and the like, and compresses a fluid such as refrigerant to supply the compressed fluid to the outside. 
       FIG. 1  is a cross-sectional view schematically illustrating a conventional vane rotary compressor disclosed in Japanese Patent Laid-open Publication No. 2010-31759 (Patent Document 1).  FIG. 2  is a cross-sectional view taken along line A-A in  FIG. 1 . 
     As illustrated in  FIG. 1 , the conventional vane rotary compressor, which is designated by reference numeral  10 , includes a housing H, which is configured of a rear housing  11  and a front housing  12  while defining the external appearance thereof, and a cylindrical cylinder  13  which is received within the rear housing  11 . 
     In this case, the cylinder  13  has an inner peripheral surface having an oval sectional shape as illustrated in  FIG. 2 . 
     In the inside of the rear housing  11 , a front cover  14  is coupled to the front of the cylinder  13  and a rear cover  15  is coupled to the rear of the cylinder  13 . A discharge space Da is defined between the outer peripheral surface of the cylinder  13 , the inner peripheral surface of the rear housing  11  facing the same, the front cover  14 , and the rear cover  15 . 
     A rotary shaft  17  is rotatably installed to the front cover  14  and the rear cover  15  through the cylinder  13 . The rotary shaft  17  is coupled with a cylindrical rotor  18 , and the rotor  18  rotates in the cylinder  13  along with the rotary shaft  17  when the rotary shaft  17  rotates. 
     As illustrated in  FIG. 2 , a plurality of slots  18   a  are radially formed on the outer peripheral surface of the rotor  18 , a linear type vane  20  is slidably received in each of the slots  18   a , and lubricant oil is supplied into the slot  18   a.    
     When the rotor  18  is rotated by the rotation of the rotary shaft  17 , a tip portion of the vane  20  protrudes outward from the slot  18   a  and comes into close contact with the inner peripheral surface of the cylinder  13 . In this case, a plurality of compression chambers  21  are divided and formed, each of which is defined by the outer peripheral surface of the rotor  18 , the inner peripheral surface of the cylinder  13 , a pair of adjacent vanes  20 , and a facing surface  14   a  of the front cover  14  and a facing surface  15   a  of the rear cover  15 , which face the cylinder  13 . 
     In the vane rotary compressor, an intake stoke is a stroke in which the volume of the compression chamber  21  is enlarged whereas a compression stroke is a stroke in which the volume of the compression chamber  21  is reduced, according to the rotation direction of the rotor  18 . 
     As illustrated in  FIG. 1 , a suction port  24  is formed at the upper portion of the front housing  12 , and a suction space Sa communicating with the suction port  24  is defined within the front housing  12 . 
     The front cover  14  is formed with an inlet  14   b  which communicates with the suction space Sa, and a suction passage  13   b , which communicates with the inlet  14   b , is formed to axially pass through the cylinder  13 . 
     As illustrated in  FIG. 2 , discharge chambers  13   d , which are recessed inwards, are formed at the opposite sides of the outer peripheral surface of the cylinder  13 . In this case, the pair of discharge chambers  13   d  communicate with the compression chambers  21  through associated discharge holes  13   a , and forms a portion of the discharge space Da. 
     The rear housing  11  is formed with a high-pressure chamber  30  which is divided by the rear cover  15  and into which a compressed refrigerant is introduced. That is, the inside of the rear housing  11  is divided into the discharge space Da and the high-pressure chamber  30  by the rear cover  15 . In this case, any one of the pair of discharge chambers  13   d  is formed with an outlet  15   e  which communicates with the high-pressure chamber  30 . 
     Accordingly, when the rotor  18  and the vanes  20  rotate along with the rotation of the rotary shaft  17 , a refrigerant is sucked from the suction space Sa via the inlet  14   b  and the suction passage  13   b  into each compression chamber  21 . The refrigerant compressed by the reduction in volume of the compression chamber  21  is discharged to the discharge chamber  13   d  through the associated discharge hole  13   a  to be introduced into the high-pressure chamber  30  through the outlet  15   e , and is then supplied to the outside through a discharge port  31 . 
     Meanwhile, the high-pressure chamber  30  is provided with an oil separator  40  for separating the lubricant oil from the compressed refrigerant introduced into the high-pressure chamber  30 . An oil separation pipe  43  is installed at the upper portion of a case  41 , and an oil separation chamber  42 , into which the separated oil is dropped, is formed in the lower portion of the oil separation pipe  43 . The oil in the oil separation chamber  42  flows down into an oil storage chamber  32 , which is formed in the lower portion of the high-pressure chamber  30 , through an oil passage  41   b.    
     The oil stored in the oil storage chamber  32  lubricates a sliding surface between the rear cover  15  and rotor  18  via a lubrication space of a bush, which supports the rear end of the rotary shaft  17 , through an oil supply passage  15   d . Subsequently, the oil is reintroduced into the outlet  15   e  through an oil return groove  45  by a difference in pressure between the discharge space Da and the high-pressure chamber  30 . 
     In the case of applying the linear type vane  20  to the conventional vane rotary compressor  10 , since the vane  20  protrudes outward of the rotor  18  along the slot  18   a , the tip portion of the vane  20  strikes the inner peripheral surface of the cylinder  13 , thereby causing strike noise. 
       FIG. 3  is a cross-sectional view schematically illustrating a curved blade type vane rotary compressor disclosed in Japanese Patent Laid-open Publication No. 2002-130169 (Patent Document 2). 
     The vane rotary compressor illustrated in  FIG. 3  includes a cylindrical cylinder  1 , a rotor  2 , and a drive shaft  3 . In this case, the cylinder  1  includes an inlet  1 A and an outlet  1 B and the rotor  2  is eccentrically installed in the cylinder  1 . 
     A plurality of curved blade type vanes  4  are provided on the outer peripheral surface of the rotor  2  so that a plurality of compression chambers  6  are divided and formed between the cylinder  1  and the rotor  2 . One side of each of the vanes  4  is hinge-coupled to the outer peripheral surface of the rotor  2  by a hinge pin  5 . 
     While the rotor  2  rotates by a predetermined angle from a time, at which a compression stroke ends when the vane  4  passes through the outlet  1 B, to a time, at which an intake stroke begins when the vane  4  passes through the inlet  1 A, the back portion of the vane  4  is pressed toward rotor  2  by the inner peripheral surface of the cylinder  1  as illustrated in the enlarged view of  FIG. 3 . In this case, the tip portion of the vane  4  is spaced apart from the inner peripheral surface of the cylinder  1 . 
     Subsequently, when the force applied to the back portion of the vane  4  is instantaneously removed as a gap between the outer peripheral surface of the rotor  2  and the inner peripheral surface of the cylinder  1  is increased by rotation of the rotor  2 , the tip portion of the vane  4  comes into contact with the inner peripheral surface of the cylinder  1  while the vane  4  pivots and is unfolded from the rotor  2 . 
     In this case, when the vane  4  folded by the rotor  2  is unfolded toward the inner peripheral surface of the cylinder  1  due to an increase in rotational moment of inertia of the vane  4  during the high-speed rotation of the rotor  2 , the tip portion of the vane  4  strikes the inner peripheral surface of the cylinder  1 , thereby causing strike noise. 
     In addition, the back portion of the vane  4  comes into contact with the inner peripheral surface of the cylinder  1  at the initial stage of the intake stroke and the vane  4  is rapidly unfolded from the rotor  2  after the intake stroke somewhat proceeds, so that the tip portion of the vane  4  is supported by the inner peripheral surface of the cylinder  1 . Therefore, the volume of the compression chamber  6  is not smoothly expanded, resulting in a reduction of suction flow rate. 
     This description will be given in more detail with reference to  FIG. 4 . 
       FIG. 4  is a partially enlarged view schematically illustrating forces acting on the curved blade type vane during the rotation of the rotor in  FIG. 3 . 
     In the vane rotary compressor illustrated in  FIGS. 3 and 4 , the vane  4  is unfolded from the outer peripheral surface of the rotor  2  during the rotation of the rotor  2 . In this case, the tip portion of the vane  4  comes into close contact with the inner peripheral surface of the cylinder  1  so that the compression chamber  6  is defined between the pair of adjacent vanes  4 . 
     The forces acting on the vane  4  will be described according to the action directions thereof with reference to  FIG. 4 . Centrifugal force A 1  according to the rotation of the rotor  2  and rotational moment A 2  according to a center of gravity M of the vane  4  act as forces of pushing and rotating the tip portion of the vane  4  toward the inner peripheral surface of the cylinder  1 . 
     On the contrary, hinge friction force B 1  of the vane  4 , rotational moment of inertia B 2 , fluid resistance B 3  in refrigerant of the compression chamber  6 , friction force B 4  between the vane  4  and the cylinder  1 , and viscosity B 5  of lubricant oil act as forces of pulling the tip portion of the vane  4  toward the outer peripheral surface of the rotor  2 . 
     In this case, when the forces B 1  to B 5  of pulling the tip portion of the vane  4  toward the outer peripheral surface of the rotor  2  are larger than the forces A 1  and A 2  of pushing the tip portion of the vane  4  toward the inner peripheral surface of the cylinder  1 , a gap is formed between the tip portion of the vane  4  and the inner peripheral surface of the cylinder  1 . 
     In this case, the compression chamber  6  is not fully sealed by the vane  4  and an inner leakage occurs between the compression chamber  6  and the adjacent compression chamber  6 , thereby causing a reduction of compression flow rate of the refrigerant. 
     In addition, the gap between the vane  4  and the cylinder  1  is gradually increased during a delay of rotation operation of the vane  4 . Accordingly, there is a problem in that strike noise is caused when the tip portion of the vane  4  instantaneously comes into contact with the inner peripheral surface of the cylinder  1  due to the centrifugal force A 1  according to the rotation of the rotor  2  and the rotational moment A 2  of the vane  4 . 
     In connection with the hinge friction force B 1  of the vane  4 , friction force is concentrated on a friction point Pf at which a hinge portion  4   a  of the vane  4  comes into contact with the outer peripheral surface of the rotor  2  when the vane  4  is unfolded. In this case, since an oil film  7  is formed only on one side of the friction point Pf, a reduction in friction force by lubricant oil may be decreased. 
     That is, when the hinge portion  4   a  of the vane  4  is hinge-coupled to a receiving groove  2   a  on the outer peripheral surface of the rotor  2 , a portion of the hinge portion  4   a  is exposed outward from the outer peripheral surface of the rotor  2 . Thus, the friction point Pf is formed on the sharp edge of the receiving groove  2   a  coming into contact with the hinge portion  4   a  during the rotation of the hinge portion  4   a , and the oil film  7  by lubricant oil is formed only in the front region of the hinge portion  4   a  in the rotation direction thereof on the basis of the friction point Pf. 
     [Patent Document 1] JP2010-031759A (Feb. 12, 2010) 
     [Patent Document 2] JP2002-130169A (May 9, 2002) 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention has been made in view of the above-mentioned problem, and an object thereof is to provide a vane rotary compressor capable of preventing strike noise due to a delay of rotation operation of a vane during the rotation of a rotor by reducing hinge friction force of the vane and of enhancing performance of the compressor by decreasing an inner leakage. 
     Technical Solution 
     In accordance with an aspect of the present invention, a vane rotary compressor includes a housing having a hollow cylinder therein, a rotor installed in the cylinder and rotating by receiving power of a drive source by a rotary shaft, a plurality of slots being formed on an outer peripheral surface of the rotor, and a plurality of vanes dividing a hollow of the cylinder into a plurality of compression chambers, each of the vanes including a hinge portion, hinge-coupled to one side of each of the slots, and a blade portion extending from the hinge portion to rotate toward an inner peripheral surface of the cylinder, wherein one side of the outer peripheral surface of the rotor is formed with a hinge receiving portion enclosing a circumference of the hinge portion, and the hinge portion is received inside the outer peripheral surface of the rotor by the hinge receiving portion. 
     Here, a friction point between the binge portion and the hinge receiving portion may be circumferentially inwardly spaced apart from an end of an inner peripheral surface of the hinge receiving portion. 
     In addition, an end portion of the binge receiving portion may pass an extension line joining a central point of the rotor and a central point of the hinge portion and extend along the circumference of the hinge portion in a rotation direction of the rotor. 
     In this case, an angle formed by the central point of the rotor and the end of the inner peripheral surface of the hinge receiving portion with respect to the central point of the hinge portion may be between more than 180° and equal to or less than 230°. 
     In addition, on the basis of the friction point between the hinge portion and the hinge receiving portion, oil films may be formed in the front and rear of the hinge portion in a rotation direction thereof. 
     In this case, the oil films may be respectively formed in gaps between the hinge portion and the hinge receiving portion at both sides of the friction point. 
     In addition, a plurality of oil film formation spaces may be formed in a gap between the inner peripheral surface of the hinge receiving portion and an outer peripheral surface of the hinge portion, on the basis of the friction point. 
     In accordance with another aspect of the present invention, a vane rotary compressor includes a housing having a hollow cylinder therein, a rotor installed in the cylinder and rotating by receiving power of a drive source by a rotary shaft, a plurality of slots being formed on an outer peripheral surface of the rotor, and a plurality of vanes dividing a hollow of the cylinder into a plurality of compression chambers, each of the vanes including a hinge portion, hinge-coupled to one side of each of the slots, and a blade portion extending from the hinge portion to rotate toward an inner peripheral surface of the cylinder, wherein, during unfolding of the vanes, a friction point of the hinge portion is formed on an extension line joining a central point of the rotor and a central point of the hinge portion. 
     Here, one side of the outer peripheral surface of the rotor may be formed with a hinge receiving portion enclosing a circumference of the hinge portion, and the friction point may be a point at which one side of an outer peripheral surface of the hinge portion comes into contact with one side of an inner peripheral surface of the hinge receiving portion. 
     In addition, a plurality of oil film formation spaces may be formed in a gap between the inner peripheral surface of the hinge receiving portion and the outer peripheral surface of the hinge portion. 
     In this case, the oil film formation spaces may be separated from each other by the friction point. 
     In addition, at both sides of the friction point, oil films may be formed in gaps between the outer peripheral surface of the hinge portion and the inner peripheral surface of the hinge receiving portion. 
     In this case, a hinge portion imaginary circle, forming an outer peripheral surface of the hinge portion, may be formed in an inner region of a rotor imaginary circle forming the outer peripheral surface of the rotor. 
     In addition, a hinge portion imaginary circle, forming an outer peripheral surface of the hinge portion, may be formed in an outer region of a rotor imaginary circle forming the outer peripheral surface of the rotor. 
     In accordance with a further aspect of the present invention, a vane rotary compressor includes a housing having a hollow cylinder therein, a rotor installed in the cylinder and rotating by receiving power of a drive source by a rotary shaft, a plurality of slots being formed on an outer peripheral surface of the rotor, each of the slots having a hinge portion receiving groove, and a plurality of vanes dividing a hollow of the cylinder into a plurality of compression chambers, each of the vanes including a hinge portion, hinge-coupled to hinge portion receiving groove, and a blade portion extending from the hinge portion to rotate toward an inner peripheral surface of the cylinder, wherein the hinge portion receiving groove is radially inwardly spaced apart from the outer peripheral surface of the rotor such that a circumference of the hinge portion is received inside the outer peripheral surface of the rotor. 
     Here, a binge receiving portion may be extendedly formed on one side of the outer peripheral surface of the rotor so as to enclose the radially outward circumference of the hinge portion receiving groove. 
     In this case, during unfolding of the vanes, a friction point, at which the hinge portion comes into contact with the hinge receiving portion, may be formed on one side of an inner peripheral surface of the hinge receiving portion. 
     In addition, oil films may be formed in gaps between an outer peripheral surface of the hinge portion and the inner peripheral surface of the hinge receiving portion, and the oil films may be respectively formed on both sides of the friction point. 
     In this case, the friction point may be formed on an extension line joining a central point of the rotor and a central point of the hinge portion. 
     In this case, an angle formed by a central point of the rotor and an end of an inner peripheral surface of the hinge receiving portion with respect to a central point of the hinge portion may be between more than 180° and equal to or less than 230°. 
     Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a vertical cross-sectional view illustrating a conventional vane rotary compressor; 
         FIG. 2  is a cross-sectional view taken along line A-A in  FIG. 1 ; 
         FIG. 3  is a horizontal cross-sectional view illustrating a conventional curved blade type vane rotary compressor; 
         FIG. 4  is a partially enlarged view schematically illustrating forces acting on the vane during the rotation of a rotor in  FIG. 3 ; 
         FIG. 5  is a vertical cross-sectional view illustrating a vane rotary compressor according to an embodiment of the present invention; 
         FIG. 6  is a view schematically illustrating a hinge portion of a vane and a hinge receiving portion of a rotor according to the embodiment of the present invention; 
         FIG. 7  is a partially enlarged view illustrating a state in which oil films are formed on both sides of a friction point of the vane hinge portion in  FIG. 6  according to the embodiment of the present invention; and 
         FIG. 8  is a partial view schematically illustrating an example of a hinge receiving portion according to another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION 
     Hereinafter, a vane rotary compressor according to exemplary embodiments of the present invention will be described with reference to the accompanying drawings. In the description, the thickness of each line or the size of each component illustrated in the drawings may be exaggerated for convenience of description and clarity. 
     In addition, the terms used herein are terms defined in consideration of functions of the present invention, and these may vary with the intention or practice of a user or an operator. Therefore, such terms should be defined based on the entire content disclosed herein. 
     Moreover, the following embodiments are for the purposes of illustratively describing the components set forth in the appended claims only and are not intended to limit the spirit and scope of the invention. More particularly, various variations and modifications are possible in concrete constituent elements of the embodiments, and it is to be understood that differences relevant to the variations and modifications fall within the spirit and scope of the present disclosure defined in the appended claims. 
     Embodiments 
       FIG. 5  is a vertical cross-sectional view illustrating a vane rotary compressor according to an embodiment of the present invention. 
     As illustrated in  FIG. 5 , the overall external appearance of a vane rotary compressor, which is designated by reference numeral  100  (hereinafter, referred to as “a compressor”), according to an embodiment of the present invention is defined by coupling of a housing  200  and a rear head  500 . 
     The housing  200  includes a cylinder portion  210  which is formed therein with a space portion, and a front head portion  220  which closes the front of the space portion of the cylinder portion  210 . The front head portion  220  is integrally formed with the cylinder portion  210  in the axial front thereof. In accordance with another example of the present invention, a housing may be integrally formed by the cylinder portion  210  and the rear head  500  to be described later and a separate front head may also be coupled to the front of the housing. 
     The space portion of the cylinder portion  210  is equipped with a hollow cylinder  300 . In addition, the cylinder  300  is provided therein with a rotary shaft  310  which rotates by the power of a drive source (not shown), a rotor  400  which rotates along with the rotary shaft  310  by receiving torque from the rotary shaft  310 , and a plurality of vanes  600  which are hinge-coupled to the outer peripheral surface of the rotor  400  to be rotatable in the radial direction of the rotor  400 . 
     The rear head  500  is coupled to the axial rear of the housing  200  to close the rear of the space portion of the cylinder portion  210 . A mounting groove  510  is formed at the inside center of the rear head  500 , and the rear end of the rotary shaft  310  is inserted into and rotatably supported by the mounting groove  510 . The front end of the rotary shaft  310  is rotatably supported by the hollow of the front head portion  220 . 
     Meanwhile, the outer peripheral surface of the first head portion  220  of the housing  200  is provided with a suction port (not shown) for suction of a refrigerant from the outside and a discharge port (not shown) for discharge of a high-pressure refrigerant compressed within the cylinder  300  to the outside, which are circumferentially spaced apart from each other. 
     In addition, the front center of the first head portion  220  is extendedly formed with a pulley coupling portion  240  so as to couple a pulley  230  of an electronic clutch (not shown) thereto. 
       FIG. 6  is a view schematically illustrating a hinge portion  610  of the vane  600  and a hinge receiving portion  420  of the rotor  400  according to the embodiment of the present invention.  FIG. 7  is a partially enlarged view illustrating a state in which oil films  700  are formed on both sides of a friction point Pf of the vane hinge portion  610  in  FIG. 6  according to the embodiment of the present invention. 
     As illustrated in  FIG. 6 , the cylinder  300  is equipped therein with the rotary shaft  310  and the rotor  400  which are rotated by power of the drive source. 
     The rotor  400  is coupled to the rotary shaft  310 , which is connected to a clutch (not shown) driven by a drive motor (not shown) or an engine belt (not shown), to axially rotate along with the rotary shaft  310 . The rotary shaft  310  is mounted along the central axis of the cylinder  300 . 
     The vanes  600  are spaced apart from each other and are hinge-coupled to the outer peripheral surface of the rotor  400 . Each of the vanes  600  includes the hinge portion  610  which is hinge-coupled to one side of the outer peripheral surface of the rotor  400  and a blade portion  620  extending from one side of the hinge portion  610 . 
     In this case, each compression chamber  320  is divided and formed by a space defined by the pair of adjacent vanes  600 , the outer peripheral surface of the rotor  400 , and the inner peripheral surface of the cylinder  300 . The front and rear of the compression chamber  320  are sealed by the front head portion  220  (see  FIG. 5 ) and the rear head  500  (see  FIG. 5 ), respectively. 
     During the rotation of the rotor  400 , the tip of the blade portion  620  of each of the vanes  600  rotates together in the rotation direction of the rotor  400  along the hollow inner peripheral surface of the cylinder  300 . In this case, as the tip of the blade portion  620  of the vane  600  is close from an inlet (not shown) to an outlet (not shown), a gap between the outer peripheral surface of the rotor  400  and the hollow inner peripheral surface of the cylinder  300  is gradually narrowed, with the consequence that the volume of the compression chamber  320  is reduced and the refrigerant in the compression chamber  320  is compressed. For example, the hollow inner peripheral surface of the cylinder  300  may be formed in the form of an involute curve in which the width thereof is gradually decreased as being close from the inlet to the outlet. 
     In this case, in order to maximally reduce the volume of the compression chamber  320  during a compression stroke, one side of the outer peripheral surface of the rotor  400  preferably comes into close contact with the hollow inner peripheral surface of the cylinder  300  in the vicinity of the outlet. To this end, the outer peripheral surface of the rotor  400  is formed with a plurality of slots  410  which are formed in the same number as that of the vanes  600  to receive the vanes  600  and are spaced apart from each other in the circumferential direction. The vanes  600  are fully received in the slots  410  on the outer peripheral surface of the rotor  400  in the vicinity of the outlet. 
     Each of the slots  410  includes the hinge portion receiving groove  411  to which the hinge portion  610  of each vane  600  is hinge-coupled and a blade portion receiving groove  412  on which the blade portion  620  of the vane  600  is seated. 
     The hinge portion receiving groove  411  has a circular arc section shape such that the circle section shaped hinge portion  610  is inserted into and coupled to the hinge portion receiving groove  411 . The blade portion receiving groove  412  has a shape corresponding to the blade portion  620  and is recessed on the outer peripheral surface of the rotor  400 . 
     In accordance with the embodiment of the present invention, the hinge portion receiving groove  411  is radially inwardly spaced apart from the outer peripheral surface of the rotor  400 . Thus, the overall circumference of the hinge portion  610  of the vane  600 , which is hinge-coupled to the hinge portion receiving groove  411 , is received inside the outer peripheral surface of the rotor  400 . That is, a hinge portion imaginary circle Ch, which forms an outer peripheral surface of the hinge portion  610 , is formed in an inner region of a rotor imaginary circle Cr, which forms the outer peripheral surface of the rotor  400 , as illustrated in  FIG. 6 . 
     In this case, a hinge receiving portion  420  is extendedly formed on one side of the outer peripheral surface of the rotor  400  so as to enclose a radially outward circumference of the hinge portion receiving groove  411 . Accordingly, the hinge portion  610  of the vane  600  is received radially inward of the hinge receiving portion  420 . 
     Thus, the oil films  700  by oil viscosity are formed on both sides of the friction point, at which the hinge portion  610  comes into contact with the hinge receiving portion  420 , so as to reduce friction resistance applied to the hinge portion  610  of the vane  600 . Hereinafter, this description will be given in more detail. 
     When the vane  600  is unfolded during beginning of an intake stroke, the sum of forces acting on the vane  600  is concentrated on the friction point Pf at which the outer peripheral surface of the hinge portion  610  of the vane  600  comes into contact with the inner peripheral surface of the hinge portion receiving groove  411 . 
     In the related art, since the friction point Pf between the hinge portion  4   a  and the hinge portion receiving groove  2   a  is formed at the end of the inner peripheral surface of the hinge portion receiving groove  2   a  as illustrated in  FIG. 4 , it is difficult to form the oil film  7  by the sliding surface and friction resistance is increased. Accordingly, this causes rotation operation of the vane  4  through the sliding motion of the hinge portion  4   a  to be delayed. 
     In accordance with the embodiment of the present invention, the friction point Pf of the hinge portion  610  is formed on an imaginary extension line l joining a central point Mr of the rotor  400  and a central point Mh of the hinge portion  610 , and an end portion of the hinge receiving portion  420  passes the extension line l from one side of the outer peripheral surface of the rotor  400  in the rotation direction of the rotor  400  and extends to enclose the outside of the hinge portion  610 . 
     That is, the friction point Pf, at which the outer peripheral surface of the hinge portion  610  comes into contact with the inner peripheral surface of the hinge portion receiving groove  411 , is circumferentially inwardly spaced apart from an end Pe of the inner peripheral surface of the hinge portion receiving groove  411  by a predetermined interval. 
     In addition, a predetermined gap is formed between the outer peripheral surface of the hinge portion  610  and the inner peripheral surface of the hinge portion receiving groove  411 , and the gap is divided into a plurality of oil film formation spaces on the basis of the friction point Pf. 
     On the basis of the friction point Pf, lubricant oil is preferably introduced into gaps of the front and rear of the hinge portion  610  in the rotation direction thereof so as to respectively from the oil films  700  in the gaps. 
     That is, in accordance with the embodiment of the present invention, the oil films  700  are formed by viscosity of the sliding surfaces on both sides of the friction point Pf so that the hinge portion  610  may smoothly slide, thereby preventing rotation operation of the vane  600  from being delayed. 
     Meanwhile, an angle α, which is formed by the central point Mr of the rotor  400  and the end Pe of the inner peripheral surface of the hinge receiving portion  420  with respect to the central point Mb of the hinge portion  610 , is preferably an obtuse angle between more than 180° and equal to or less than 230°. This is because it is difficult to form the oil films on both sides of the friction point Pf when the angle α is equal to or less than 180° and a rotatable angle of the vane  600  is restricted by the hinge receiving portion  420  to reduce compression efficiency when the angle α is more than 230°. 
     As described above, in accordance with the embodiment of the present invention, since the hinge receiving portion  420  is formed to enclose the outside of the hinge portion  610 , the friction point Pf at which the outer peripheral surface of the hinge portion  610  comes into contact with the inner peripheral surface of the hinge portion receiving groove  411  is circumferentially inwardly spaced apart from the end Pe of the inner peripheral surface of the hinge portion receiving groove  411  by a predetermined interval. In this case, since the oil films  700  are respectively formed on both sides of the friction point Pf, the hinge portion  610  may smoothly slide and rotation operation of the vane  600  may be prevented from being delayed. 
     Meanwhile,  FIG. 8  is a partial view schematically illustrating an example of three binge receiving portion  420  according to another embodiment of the present invention. 
     In the above-mentioned embodiment, the overall region of the hinge portion  610  is received inside the outer peripheral surface of the rotor  400  and this state may be identified by the hinge portion imaginary circle Ch being formed in the inner region of the rotor imaginary circle Cr, as illustrated in  FIG. 6 . 
     In accordance with another embodiment of the present invention, the overall region of the hinge portion  610  may also be arranged outside the outer peripheral surface of the rotor  400  as illustrated in  FIG. 8 . That is, a hinge portion imaginary circle Ch may also be formed in an outer region of a rotor imaginary circle Cr′. In this case, the hinge receiving portion  420  protrudes outward from the outer peripheral surface of the rotor  400  and encloses the circumference of the hinge portion  610 . 
     In accordance with another embodiment of the present invention, the friction point Pf between the hinge portion  610  and the hinge receiving portion  420  is formed on the extension line l joining the central point Mr of the rotor  400  and the central point Mh of the hinge portion  610 . Accordingly, oil films are respectively formed in the front and rear of the hinge portion  610  in the rotation direction thereof on the basis of the friction point Pf, thereby enabling a reduction in the hinge friction force B 1  (see  FIG. 4 ) of the vane  600 . 
     INDUSTRIAL APPLICABILITY 
     In accordance with the vane rotary compressor  100  according to an embodiment of the present invention, the oil films  700  are formed on both sides of the friction point Pf between the hinge portion  610  of the vane  600  and the hinge receiving portion  420  of the rotor  400 . 
     In this case, since two sliding surfaces are formed on each of the both sides of the friction point Pf, it may be possible to reduce friction force by the oil films  700  and to prevent generation of strike noise due to a delay of rotation operation of the vane  600 . 
     Moreover, it may be possible to enhance performance of the compressor by preventing an inner leakage due to the delay of rotation operation of the vane. 
     Various embodiments have been described in the best mode for carrying out the invention. Although the present invention has been described with respect to the illustrative embodiments, it will be apparent to those skilled in the art that various variations and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.