Patent Publication Number: US-11644033-B2

Title: Scroll compressor

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     This patent application is a United States national phase patent application based on PCT/KR2020/000815 filed on Jan. 16, 2020, which claims the benefit of Korean Patent Application No. 10-2019-0007316 filed on Jan. 21, 2019, the entire contents of both of which are hereby incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a scroll compressor and more particularly to a scroll compressor capable of compressing a refrigerant by a fixed scroll and an orbiting scroll. 
     BACKGROUND ART 
     In general, a vehicle is equipped with an air conditioning (A/C) system for heating and cooling the interior of the vehicle. Such an air conditioning system includes a compressor as a component of the cooling system. The compressor compresses a low-temperature and low-pressure gaseous refrigerant introduced from an evaporator into a high-temperature and high-pressure gaseous refrigerant, and transfers it to a condenser. 
     There are two types of compressors, that is to say, a reciprocating type compressor which compresses a refrigerant according to a reciprocating motion of a piston and a rotary type compressor which compresses a refrigerant while performing a rotational motion. The reciprocating type compressor includes a crank type compressor which transmits a driving force of a driving source to a plurality of pistons by using a crank and a swash plate type compressor which transmits a driving force of a driving source to a rotating shaft with the swash plate installed therein, etc., in accordance with a transmission method of the driving source. The rotary type compressor includes a vane rotary type using a rotating shaft and a vane, and a scroll type compressor using an orbiting scroll and a fixed scroll. 
     The scroll compressor is widely used for refrigerant compression in air conditioners, etc., because the scroll compressor can obtain a relatively high compression ratio compared to other types of compressors and can obtain a stable torque thanks to smooth connection of the suction, compression, and discharge strokes of the refrigerant. 
       FIG.  1    is a cross-sectional view showing a conventional scroll compressor. 
     Referring to accompanying  FIG.  1   , a conventional scroll compressor includes a housing  10 , a motor  20  generating a rotational force within the housing  10 , a rotary shaft  30  which is rotated by the motor  20 , an orbiting scroll  50  which performs an orbiting motion by the rotary shaft  30 , and a fixed scroll  60  which is meshed with the orbiting scroll  50  to form a pair of two compression chambers C. 
     The housing  10  includes a center housing  12 , a front housing  14  which is fastened to the center housing  12  to form a first space S 1  in which the motor  20  is received, and a rear housing  16  is fastened to the center housing  12  on the opposite side of the front housing  14  on the basis of a center housing end plate  12   a  to form a second space S 2  in which the orbiting scroll  50  and the fixed scroll  60  are received. 
     The center housing  12  includes the center housing end plate  12   a  which supports the orbiting scroll  50  and a center housing side plate  12   b  which protrudes from the outer circumferential portion of the center housing end plate  12   a  toward the front housing  14 . 
     One end of the rotary shaft  30  passes through the center side of the center housing end plate  12   a.    
     The front housing  14  includes a front housing end plate  14   a  which is opposed to the center housing end plate  12   a  and supports the other end of the rotary shaft  30 , and a front housing side plate  14   b  which protrudes from the outer circumferential portion of the front housing end plate  14   a , is fastened to the center housing side plate  12   b , and supports the motor  20 . 
     Here, the center housing end plate  12   a , the center housing side plate  12   b , the front housing end plate  14   a , and the front housing side plate  14   b  form the first space S 1 . In order that the motor  20  can be inserted into the first space S 1 , the center housing  12  and the front housing  14  are formed separately and then fastened to each other. Here, since leakage may occur between the center housing  12  and the front housing  14 , a first sealing member  70  for sealing the first space S 1  from the outside of the housing  10  is interposed between the front housing side plate  14   b  and the center housing side plate  12   b.    
     The rear housing  16  includes a rear housing end plate  16   a  which faces the center housing end plate  12   a  and a rear housing side plate  16   b  which protrudes from the outer circumferential portion of the rear housing end plate  16   a  and is fastened to the outer circumferential portion of the center housing end plate  12   a.    
     Also, the rear housing  16  further includes a discharge chamber D which receives the refrigerant discharged from the compression chamber C. 
     Here, the center housing end plate  12   a , the rear housing end plate  16   a , and the rear housing side plate  16   b  form the second space S 2 . In order that the orbiting scroll  50  and the fixed scroll  60  can be inserted into the second space S 2 , the center housing  12  and the rear housing  16  are formed separately and then fastened to each other. Here, since leakage may occur between the center housing  12  and the rear housing  16 , a second sealing member  80  for sealing the second space S 2  from the outside of the housing  10  is interposed between the center housing end plate  12   a  and the rear housing side plate  16   b.    
     The motor  20  includes a stator which is fixed to the front housing side plate  14   b  and a rotor which is rotated within the stator by interaction with the stator. 
     The rotary shaft  30  is fastened to the rotor and passes through the central portion of the rotor, so that one end of the rotary shaft  30  passes through the center housing end plate  12   a  and is fastened to an eccentric bush  40  which causes the orbiting scroll  50  to orbit. The other end of the rotary shaft  30  is supported by the front housing end plate  14   a.    
     The orbiting scroll  50  includes a disk-shaped orbiting scroll end plate  52 , an orbiting scroll wrap  54  which protrudes from the center of the orbiting scroll end plate  52  toward the fixed scroll  60 , and an orbiting scroll boss  530  which protrudes from the orbiting scroll end plate  52  to the opposite side of the orbiting scroll wrap  54  and is fastened to the eccentric bush  40 . 
     The fixed scroll  60  includes a disk-shaped fixed scroll end plate  62 , a fixed scroll wrap  64  which protrudes from the center of the fixed scroll end plate  62  and is meshed with the orbiting scroll wrap  54 , and a fixed scroll side plate  66  which protrudes from the outer circumferential portion of the fixed scroll end plate  62  and is fastened to the center housing end plate  12   a.    
     Here, in order that noise generated in the compression chamber C is prevented from being emitted to the outside of the housing  10 , the orbiting scroll  50  and the fixed scroll  60  are received within the housing  10 , and the center housing end plate  12   a , the fixed scroll end plate  62 , and the fixed scroll side plate  66  form an orbiting space of the orbiting scroll  50 . The fixed scroll side plate  66  is interposed between the rear housing side plate  16   b  and the orbiting scroll  50 . 
     However, such a conventional scroll compressor had difficulty in increasing the discharge amount of the refrigerant in a state in which the orbiting scroll  50  and the fixed scroll  60  are received within the housing  10 . Specifically, in order to increase the refrigerant discharge amount, an orbiting radius of the orbiting scroll  50  must be increased or the height of the compression chamber C in the axial direction must be increased. However, as the fixed scroll side plate  66  is formed between the rear housing side plate  16   b  and the orbiting scroll  50 , it is difficult for the orbiting radius of the orbiting scroll  50  to be increased within the housing  10  which has a predetermined size. In particular, the fixed scroll side plate  66  includes a fastening hole (not shown) through which a fastening member (not shown) for fastening the fixed scroll  60  to the center housing end plate  12   a  passes. Also, the fixed scroll side plate  66  is formed thicker than the rear housing side plate  16   b  in order to prevent the reduction of rigidity of the fixed scroll side plate  66  due to the fastening hole (not shown). Therefore, it is more difficult for the orbiting radius of the orbiting scroll  50  to be increased. When a distance between the orbiting scroll end plate  52  and the fixed scroll end plate  62  is increased and when the height of the orbiting scroll wrap  54  and the height of the fixed scroll wrap  64  are increased, the durability of the orbiting scroll  50  and the fixed scroll  60  is significantly reduced, so that it is difficult for the height of the compression chamber C in the axial direction to be increased. 
     SUMMARY 
     Accordingly, the purpose of the present invention is to provide a scroll compressor capable of increasing the discharge amount of the refrigerant in a state in which the orbiting scroll and the fixed scroll are received within a casing. 
     One embodiment is a scroll compressor including: a casing; a motor which generates a rotational force within the casing; a rotary shaft which is rotated by the motor; an orbiting scroll which performs an orbiting motion by means of the rotary shaft; a fixed scroll which is meshed with the orbiting scroll and forms a pair of two compression chambers; and a main frame which supports the orbiting scroll. The fixed scroll includes a fixed scroll end plate and a fixed scroll wrap which protrudes from the fixed scroll end plate. The main frame includes a main frame end plate which is provided on the opposite side of the fixed scroll end plate on the basis of the orbiting scroll, and a main frame side plate which protrudes from an outer circumferential portion of the main frame end plate toward the fixed scroll. The fixed scroll end plate, the main frame end plate, and the main frame side plate form an orbiting space of the orbiting scroll. 
     The main frame side plate may be interposed between the casing and the orbiting scroll. The orbiting scroll may be formed to face the main frame side plate in a radial direction. 
     The main frame side plate may be formed thinner than the casing. 
     The fixed scroll may further include a fixed scroll flange which protrudes from an outer circumferential surface of the fixed scroll end plate in a radial direction and is fastened to the casing. 
     The main frame may further include a main frame flange which protrudes from an outer circumferential surface of the main frame side plate in a radial direction and is fastened to the casing. 
     The casing may include: a first casing which has a receiving space in which the motor, the rotary shaft, the orbiting scroll, the fixed scroll, and the main frame are received; and a second casing which is fastened to the first casing and covers the receiving space. 
     The first casing may include: a first casing end plate which supports an end of the rotary shaft; and a first casing side plate which protrudes from an outer circumferential portion of the first casing end plate toward the second casing and supports the motor, the main frame, and the fixed scroll. 
     The first casing side plate may include a flange insertion groove into which the fixed scroll flange and the main frame flange are inserted. 
     The flange insertion groove may include: a flange insertion groove basal surface which is bent from an inner circumferential surface of the first casing side plate; and a flange insertion groove inner circumferential surface which is bent from the flange insertion groove basal surface and extends to a front end surface of the first casing side plate. 
     The main frame flange may include: a main frame flange basal surface which contacts with the flange insertion groove basal surface; a main frame flange outer circumferential surface which is bent from the main frame flange basal surface and faces the flange insertion groove inner circumferential surface; and a main frame flange top surface which is bent from the main frame flange outer circumferential surface and forms a back side of the main frame flange basal surface. 
     The fixed scroll flange may include: a fixed scroll flange basal surface which contacts with the main frame flange top surface; a fixed scroll flange outer circumferential surface which is bent from the fixed scroll flange basal surface and faces the flange insertion groove inner circumferential surface; and a fixed scroll flange top surface which is bent from the fixed scroll flange outer circumferential surface and forms a back side of the fixed scroll flange basal surface. 
     The fixed scroll flange may include a first fastening hole which passes through the fixed scroll flange from the fixed scroll flange top surface to the fixed scroll flange basal surface. The main frame flange may include a second fastening hole which passes through the main frame flange from the main frame flange top surface to the main frame flange basal surface. The flange insertion groove may include a third fastening hole which is formed engraved from the flange insertion groove basal surface. The main frame flange and the fixed scroll flange may be fastened to the first casing side plate by a fastening member that is inserted into the first fastening hole, the second fastening hole, and the third fastening hole. 
     The motor, the rotary shaft, the orbiting scroll, the fixed scroll, and the main frame may be inserted from the second casing side into the first casing side, and then may be received in the receiving space. 
     The sealing member which seals the receiving space from the outside of the casing may be formed between the first casing and the second casing. The receiving space may be sealed only by the sealing member. 
     The scroll compressor may further include an oil recovery passage which recovers oil which is separated from a refrigerant discharged from the compression chamber. The oil recovery passage may be formed on the main frame side plate. 
     The scroll compressor according to the embodiment of the present invention includes a casing; a motor which generates a rotational force within the casing; a rotary shaft which is rotated by the motor; an orbiting scroll which performs an orbiting motion by means of the rotary shaft; a fixed scroll which is meshed with the orbiting scroll and forms a pair of two compression chambers; and a main frame which supports the orbiting scroll. The fixed scroll includes a fixed scroll end plate and a fixed scroll wrap which protrudes from the fixed scroll end plate. The main frame includes a main frame end plate which is provided on the opposite side of the fixed scroll end plate on the basis of the orbiting scroll, and a main frame side plate which protrudes from an outer circumferential portion of the main frame end plate toward the fixed scroll. The fixed scroll end plate, the main frame end plate, and the main frame side plate form an orbiting space of the orbiting scroll. Accordingly, the orbiting radius of the orbiting scroll is increased within the casing which has a predetermined size, and thus, the discharge amount of the refrigerant can be increased in a state in which the orbiting scroll and the fixed scroll are received within the casing. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG.  1    is a cross-sectional view showing a conventional scroll compressor; 
         FIG.  2    is a cross-sectional view showing a scroll compressor according to an embodiment of the present invention; 
         FIG.  3    is an enlarged view of a part “A” of  FIG.  2   ; 
         FIG.  4    is a cross sectional view showing the scroll compressor of  FIG.  2    cut in another direction; 
         FIG.  5    is a perspective view showing a first casing in the scroll compressor of  FIG.  2   ; 
         FIG.  6    is a perspective view showing a main frame in the scroll compressor of  FIG.  2   ; 
         FIG.  7    is a perspective view showing a fixed scroll in the scroll compressor of  FIG.  2   ; 
         FIG.  8    is a perspective view showing a back side of  FIG.  7   ; and 
         FIG.  9    is a perspective view showing that the main frame of  FIG.  6    and the fixed scroll of  FIG.  7    have been coupled. 
     
    
    
     DETAILED DESCRIPTION OF AN EMBODIMENT 
     Hereinafter, a scroll compressor according to the present disclosure will be described in detail with reference to the accompanying drawings. 
       FIG.  2    is a cross-sectional view showing a scroll compressor according to an embodiment of the present invention.  FIG.  3    is an enlarged view of a part “A” of  FIG.  2   .  FIG.  4    is a cross sectional view showing the scroll compressor of  FIG.  2    cut in another direction.  FIG.  5    is a perspective view showing a first casing in the scroll compressor of  FIG.  2   .  FIG.  6    is a perspective view showing a main frame in the scroll compressor of  FIG.  2   .  FIG.  7    is a perspective view showing a fixed scroll in the scroll compressor of  FIG.  2   .  FIG.  8    is a perspective view showing a back side of  FIG.  7   .  FIG.  9    is a perspective view showing that the main frame of  FIG.  6    and the fixed scroll of  FIG.  7    have been coupled.  FIG.  9    is a perspective view showing that the main frame of  FIG.  6    and the fixed scroll of  FIG.  7    have been coupled. 
     Referring to the attached  FIGS.  2  to  9   , the scroll compressor according to the embodiment of the present invention may include a casing  100 , a motor  200  which generates a rotational force within the casing  100 , a rotary shaft  300  which is rotated by the motor  200 , an orbiting scroll  500  which performs an orbiting motion by means of the rotary shaft  300 , a fixed scroll  600  which is meshed with the orbiting scroll  500  and forms a pair of two compression chambers C, and a main frame  700  which supports the orbiting scroll  500 . 
     The casing  100  may include a first casing  110  which has a receiving space S in which the motor  200 , the rotary shaft  300 , the orbiting scroll  500 , the fixed scroll  600 , and the main frame  700  are received, and a second casing  120  which is fastened to the first casing  110  and covers the receiving space S. 
     The first casing  110  may include a first casing end plate  112  which supports one end of the rotary shaft  300 , and a first casing side plate  114  which protrudes from an outer circumferential portion of the first casing end plate  112  toward the second casing  120  and supports the motor  200 , the main frame  700 , and the fixed scroll  600 . 
     The first casing end plate  112  may be formed in an approximate disk shape, and may include a rotary shaft support groove which is formed in an approximate disk shape and into which one end of the rotary shaft  300  is inserted on a center side of the first casing end plate  112 . 
     The first casing side plate  114  may be formed in an approximately annular shape, and may include a suction port (not shown) which communicates with a refrigerant suction pipe (not shown) that guides a refrigerant from the outside to the receiving space S (more precisely, a first space S 1  to be described later). 
     Also, a front end of the first casing side plate  114  may include a flange insertion groove  116  which is formed engraved from a front end surface of the first casing side plate  114  and an inner circumferential surface of the first casing side plate  114  such that a fixed scroll flange  630  and a main frame flange  730  which are described later are inserted into. 
     The flange insertion groove  116  may include a flange insertion groove basal surface  116   a  which is bent from the inner circumferential surface of the first casing side plate  114 , and a flange insertion groove inner circumferential surface  116   b  which is bent from the flange insertion groove basal surface  116   a  and extends to the front end surface of the first casing side plate  114 . 
     Also, the flange insertion groove  116  may include a third fastening hole H 3  which is formed engraved from the flange insertion groove basal surface  116   a  such that a fastening member  800  to be described later is inserted. 
     The second casing  120  may include a second casing end plate  122  which faces the fixed scroll  600  and a second casing side plate  124  which protrudes from an outer circumferential portion of the second casing end plate  122  and is fastened to the first casing side plate  114 . 
     The second casing end plate  122  may include a discharge chamber D which receives the refrigerant discharged from the compression chamber C. 
     Also, the second casing end plate  122  may include a discharge port (not shown) which communicates with a refrigerant discharge pipe (not shown) that guides the refrigerant in the discharge chamber D to the outside. 
     A front end surface of the second casing side plate  124  may be formed to face the front end surface of the first casing side plate  114  and a fixed scroll flange top surface  636  to be described later, such that the second casing side plate  124  can be fastened to the first casing side plate  114  and such that the fixed scroll flange  630  to be described later is prevented from being separated from the flange insertion groove  116 . That is, the outer diameter of the second casing side plate  124  may be formed at an equal level to the outer diameter of the first casing side plate  114 , and the inner diameter of the second casing side plate  124  may be formed smaller than the inner diameter of the flange insertion groove  116 . 
     Here, the first casing  110  is integrally formed. Since the main frame  700  is formed to be attachable to and detachable from the first casing  110 , even when the first casing  110  is integrally formed, the motor  200 , the rotary shaft  300 , the orbiting scroll  500 , and the fixed scroll  600  may be inserted from the second casing  120  side to the first casing  110  side and may be received in the receiving space S. That is, the motor  200  and the rotary shaft  300  may be first inserted into the receiving space S. Then, as the main frame  700  is inserted into the receiving space S, the receiving space S may be divided into the first space S 1  in which the motor  200  is received and a second space S 2  in which the orbiting scroll  500  and the fixed scroll  600  are received. Then, an eccentric bush  400  which causes the orbiting scroll  500  to orbit may be inserted into the receiving space S (more precisely, the second space S 2 ) and be fastened to the rotary shaft  300 , and the orbiting scroll  500  may be inserted into the receiving space S (more precisely, the second space S 2 ) and be fastened to the eccentric bush  400 . Then, the fixed scroll  600  may be inserted into the receiving space S (more precisely, the second space S 2 ). Then, the second casing  120  may be fastened to the first casing  110  to cover the receiving space S. 
     On the other hand, since leakage may occur between the front end surface of the first casing side plate  114  and the front end surface of the second casing side plate  124 , a sealing member  900  which seals the receiving space S from the outside of the casing  100  is formed between the front end surface of the first casing side plate  114  and the front end surface of the second casing side plate  124 . 
     The motor  200  may include a stator which is fixed to the first casing side plate  114  and a rotor which is rotated within the stator by interaction with the stator. 
     The rotary shaft  300  is fastened to the rotor and passes through the central portion of the rotor, so that one end of the rotary shaft  300  may pass through the main frame  700 , and the other end of the rotary shaft  300  may be supported by the first casing end plate  112 . 
     The orbiting scroll  500  may include a disk-shaped orbiting scroll end plate  510 , an orbiting scroll wrap  520  which protrudes from the center of the orbiting scroll end plate  510  toward the fixed scroll  600 , and an orbiting scroll boss  530  which protrudes from the center of the orbiting scroll end plate  510  to the opposite side of the orbiting scroll wrap  520  and is fastened to the eccentric bush  400 . 
     The fixed scroll  600  may include a disk-shaped fixed scroll end plate  610 , a fixed scroll wrap  620  which protrudes from the center of the fixed scroll end plate  610  and is meshed with the orbiting scroll wrap  520 , and a fixed scroll flange  630  which protrudes from the outer circumferential surface of the fixed scroll end plate  610  in a radial direction and is inserted into the flange insertion groove  116  of the first casing  110 . 
     Here, the fixed scroll end plate  610 , the fixed scroll wrap  620 , and the fixed scroll flange  630  may form the appearance of the fixed scroll  600 . 
     A discharge hole  612  which discharges the refrigerant in the compression chamber C to the discharge chamber D may be formed on the center side of the fixed scroll end plate  610 . 
     The fixed scroll flange  630  is for fastening the fixed scroll  600  to the first casing  110 , and may be formed to be fastened to the first casing  110  in a state of being inserted together with the main frame flange  730  to be described later into the flange insertion groove  116 . 
     Specifically, the fixed scroll flange  630  may include a fixed scroll flange basal surface  632  which contacts with a main frame flange top surface  736  to be described later, a fixed scroll flange outer circumferential surface  634  which is bent from the fixed scroll flange basal surface  632  and faces the flange insertion groove inner circumferential surface  116   b , a fixed scroll flange top surface  636  which is bent from the fixed scroll flange outer circumferential surface  634  and forms a back side of the fixed scroll flange basal surface  632 , and a first fastening hole H 1  which passes through the fixed scroll flange  630  from the fixed scroll flange top surface  636  to the fixed scroll flange basal surface  632 . 
     The main frame  700  may include a main frame end plate  710  which is provided on the opposite side of the fixed scroll end plate  610  on the basis of the orbiting scroll  500 , a main frame side plate  720  which protrudes from an outer circumferential portion of the main frame end plate  710  toward the fixed scroll  600 , and a main frame flange  730  which protrudes from an outer circumferential surface of the main frame side plate  720  in a radial direction and is insert6ed into the flange insertion groove  116  of the first casing  110 . 
     Here, the main frame end plate  710 , the main frame side plate  720 , and the main frame flange  730  may form the appearance of the main frame  700 . 
     The main frame end plate  710  may provide a shaft receiving hole  712  through which one end of the rotary shaft  300  passes, and a back pressure chamber  714  which provides a space in which the eccentric bush  400  which is fastened to the one end of the rotary shaft  300  can be rotated and presses the orbiting scroll  500  toward the fixed scroll  600 . 
     The main frame side plate  720  may provide a suction hole  722  which passes through the main frame side plate  720  in such a way as to guide the refrigerant introduced into the first space S 1  through the refrigerant suction pipe (not shown) to the compression chamber C, and communicates the first space S 1  and the second space S 2 . 
     The main frame flange  730  is for fastening the main frame  700  to the first casing  110 , and may be formed to be fastened to the first casing  110  in a state of being inserted together with the fixed scroll flange  630  into the flange insertion groove  116 . 
     Specifically, the main frame flange  730  may include a main frame flange basal surface  732  which contacts with the flange insertion groove basal surface  116   a , a main frame flange outer circumferential surface  734  which is bent from the main frame flange basal surface  732  and faces the flange insertion groove inner circumferential surface  116   b , a main frame flange top surface  736  which is bent from the main frame flange outer circumferential surface  734  and forms a back side of the main frame flange basal surface  732 , and a second fastening hole H 2  which passes through the main frame flange  730  from the main frame flange top surface  736  to the main frame flange basal surface  732 . 
     Here, the main frame flange  730  and the fixed scroll flange  630  are fastened to the first casing side plate  114  by a fastening member  800  that is inserted into the first fastening hole H 1 , the second fastening hole H 2 , and the third fastening hole H 3 . 
     Hereinafter, the operation effects of the scroll compressor according to the present embodiment will be described. 
     That is, when the power is applied to the motor  200 , the rotary shaft  300  may rotate together with the rotor. 
     Also, the orbiting scroll  500  may be orbited by receiving a rotational force from the rotary shaft  300  through the eccentric bush  400 . 
     Accordingly, the volume of the compression chamber C may be reduced while continuously moving toward the center side. 
     Also, the refrigerant may flow into the second space S 2  through the refrigerant suction pipe (not shown), the first space S 1  and the suction hole  722 . 
     Also, the refrigerant introduced into the second space S 2  may be sucked into the compression chamber C. 
     Also, the refrigerant sucked into the compression chamber C may be compressed while being moved to the center side along the moving path of the compression chamber C and be discharged to the discharge chamber D through the discharge hole  612 . 
     Also, the refrigerant discharged to the discharge chamber D may be discharged to the outside of the compressor through the refrigerant discharge pipe (not shown). 
     Here, in the scroll compressor according to the embodiment of the present embodiment, as the orbiting scroll  500  and the fixed scroll  600  are received within the casing  100 , noise generated in the compression chamber C can be reduced by the casing. Accordingly, the noise generated in the compression chamber C can be prevented from being emitted to the outside of the casing  100 . 
     Also, the fixed scroll end plate  610 , the main frame end plate  710 , and the main frame side plate  720  form an orbiting space of the orbiting scroll  500 , and the main frame side plate  720  is interposed between the casing  100  and the orbiting scroll  500 . Therefore, the noise generated in the compression chamber C may also be reduced by the main frame side plate  720 . As a result of this, the noise generated in the compression chamber C can be further prevented from being emitted to the outside of the casing  100 . 
     On the other hand, as the fixed scroll end plate  610 , the main frame end plate  710 , and the main frame side plate  720  form the orbiting space of the orbiting scroll  500  and the main frame side plate  720  which is fastened to the first casing  110  through the main frame flange  730  is interposed between the casing  100  and the orbiting scroll  500 , an orbiting radius of the orbiting scroll  500  may increase. 
     Specifically, the main frame side plate  720  may not be directly fastened to the first casing  110 , but may be fastened to the first casing  110  through the main frame flange  730 . Accordingly, the main frame side plate  720  does not have a fastening hole into which the fastening member  800  is inserted. Accordingly, even though the main frame side plate  720  has a thin radial thickness, the rigidity of the main frame side plate  720  can be ensured. That is, for example, the radial thickness of the main frame side plate  720  may be smaller than that of the first casing side plate  114 . Accordingly, the orbiting radius of the orbiting scroll  500  may be formed to the maximum degree within a range in which the orbiting scroll  500  does not interfere with the main frame side plate  720 . 
     Accordingly, the discharge amount of the refrigerant may be increased while maintaining the height of the compression chamber C in the axial direction at a predetermined level. That is, the discharge amount of the refrigerant may be increased while maintaining the rigidity of the orbiting scroll wrap  520  and the fixed scroll wrap  620  at a predetermined level. 
     Alternatively, the outer diameter of the first casing side plate  114  may be reduced while maintaining the discharge amount of the refrigerant at a predetermined level. Accordingly, the weight and cost of the scroll compressor can be reduced and vehicle mountability can be improved. 
     Meanwhile, as the main frame  700  is formed to be attachable to and detachable from the casing  100 , the first casing  110  may be integrally formed. Accordingly, it is enough as long as the receiving space S is sealed only by the sealing member  900  interposed between the first casing  110  and the second casing  120 , so that the cost can be reduced and the risk of leakage can be significantly reduced. 
     Meanwhile, the scroll compressor according to the embodiment of the present embodiment can be formed such that oil flows together with a refrigerant within the casing  100  and various sliding portions can be lubricated. 
     Specifically, oil is stored in the first space S 1 . The oil in the first space S 1  flows, together with the refrigerant in the first space S 1 , into the compression chamber C, and the oil contained in the refrigerant discharged from compression chamber C to the discharge chamber D is separated in the discharge chamber D. The oil separated from the refrigerant in the discharge chamber D may flow into the first space S 1  and the back pressure chamber  714  through an oil recovery passage W. 
     The oil recovery passage W may include a first oil passage hole W 1  which passes through the fixed scroll end plate  610  and communicates with the discharge chamber D such that the oil in the discharge chamber D is introduced, a second oil passage hole W 2  which passes through the main frame side plate  720  and communicates with the first oil passage hole W 1  such that the oil in the first oil passage hole W 1  is introduced, a first decompression member R 1  which is provided within the second oil passage hole W 2  such that the pressure of the oil passing through the second oil passage hole W 2  is reduced from a discharge pressure to an intermediate pressure, a third oil passage hole W 3  which passes through the main frame end plate  710  and communicates the second oil passage hole W 2  and the first space S 1  such that a part of the oil which has passed through the second oil passage hole W 2  is guided to the first space S 1 , a second decompression member R 2  which is provided within the third oil passage hole W 3  such that the pressure of the oil passing through the third oil passage hole W 3  is reduced from the intermediate pressure to a suction pressure, and a fourth oil passage hole W 4  which passes through the main frame end plate  710  and communicates the second oil passage hole W 2  and the back pressure chamber  714  such that a part of the oil which has passed through the second oil passage hole W 2  is guided to the back pressure chamber  714 . 
     Here, in the present embodiment, since the main frame  700  includes the main frame side plate  720 , it may be easy to form the oil recovery passage W.