Scroll compressor

Abstract

The invention provides a scroll compressor capable of preventing breakage even if a rear bearing supporting a shaft has a larger outer diameter than a shaft seal. The scroll compressor is provided with a rear bearing (18) which is press-fitted and fixed to a center housing (6) and supports a shaft (14), and a shaft seal (58) which is disposed on the through-hole (17) side of the rear bearing (18), and enables a movable scroll (22) to revolve and rotate relative to a fixed scroll (21). The rear bearing (18) has a larger outer diameter than the shaft seal (58), and the shaft seal (58) and the rear bearing (18) are of a split structure. A shaft seal fixing plate (64) having a larger diameter than the shaft seal (58) is interposed between the rear bearing (18) and the shaft seal (58).

Description

Technical Field

[0001] The present invention relates to a scroll compressor in which a movable scroll is caused to orbit and rotate relative to a fixed scroll. Background Art

[0002] In the past, for example, a scroll compression mechanism constituting a refrigerant circuit of a vehicle air-conditioning device has a compression mechanism including a fixed scroll having a spiral wrap on the surface of an end plate, and a movable scroll having a spiral wrap on the surface of the end plate, wherein the wraps of each scroll are relative to each other, and a compression chamber is formed between the wraps. The movable scroll is caused to revolve and rotate relative to the fixed scroll by the shaft of a motor, thereby compressing the working fluid (refrigerant and lubricating oil) by the compression chamber.

[0003] In this case, a back pressure chamber is formed in a housing called a center housing on the back side of the end plate of the movable scroll, which pushes the movable scroll toward the fixed scroll in response to the compression reaction force from the compression chamber. In addition, the shaft passes through a through hole provided in the center housing, and is supported to rotate freely by a bearing called a rear bearing that is press-fitted and fixed in the center housing.

[0004] Furthermore, a shaft seal is provided in the center housing to prevent the working fluid from flowing out from the through hole, and is arranged to slidably contact the shaft (for the shaft seal, see, for example, Patent Document 1). Prior art literature Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2000-297757 Summary of the invention Technical Problems to be Solved by the Invention

[0006] In recent years, the operation range of the scroll compressor has been expanded, and the rear bearing supporting the shaft has become larger. In this case, the rear bearing has an outer diameter larger than the shaft seal. In the above-mentioned prior art, since the rear bearing and the shaft seal are integrated, there is no problem. However, in the case where the rear bearing and the shaft seal are separate structures, if the rear bearing has an outer diameter larger than the shaft seal, the end face of the shaft seal will contact with the ball sandwiched between the outer ring and the inner ring of the rear bearing, and there is a problem of damaging the rear bearing and the shaft seal.

[0007] The present invention has been made to solve the related conventional technical problems, and an object of the present invention is to provide a scroll compressor capable of preventing damage to a shaft seal even when a bearing supporting a shaft has an outer diameter larger than that of the shaft seal. Technical solutions for solving technical problems

[0008] In order to solve the above-mentioned problems, the scroll compressor of the present invention comprises: a compression mechanism, including a fixed scroll and a movable scroll; a casing; a back pressure chamber, formed between the casing and the movable scroll; a shaft, which passes through a through hole formed in a recessed portion of the casing to drive the movable scroll; a bearing, which is pressed into and fixed in the recessed portion of the casing to support the shaft so as to be rotatable; and a shaft seal, which is arranged in a recessed portion on the through hole side of the bearing and is used to prevent the working fluid from flowing out of the casing. The working fluid is compressed by making the movable scroll revolve and rotate relative to the fixed scroll by utilizing a motor equipped with a shaft. In the scroll compressor, the bearing has an outer diameter larger than that of the shaft seal, the shaft seal and the bearing are of a separate structure, and a shaft seal fixing plate having a larger diameter than that of the shaft seal is sandwiched in the recessed portion between the bearing and the shaft seal.

[0009] The scroll compressor of the second invention is characterized in that, in the above invention, it comprises: a thrust plate, which is arranged on the back pressure chamber side of the movable scroll; and at least one pair of positioning pins, which positions the thrust plate relative to the housing, and the outer diameter of the bearing is smaller than the interval between each positioning pin.

[0010] The scroll compressor of the third invention is characterized in that, in the first invention, the recess of the shell is in a stepped shape consisting of a small diameter recess and a large diameter recess, the through hole is formed in the small diameter recess, the shaft seal is arranged in the small diameter recess, the bearing is pressed and fixed in the large diameter recess, and the shaft seal fixing plate is arranged in the large diameter recess between the bearing and the shaft seal.

[0011] A scroll compressor according to a fourth aspect of the present invention is characterized in that, in the above-mentioned invention, the motor includes a balance weight located on the casing side, and the outer shape of the casing is a stepped shape along the stepped shape of the recessed portion.

[0012] The scroll compressor of the fifth invention is characterized in that, in the third or fourth invention, the bearing is a ball bearing having a ball arranged between an outer ring portion and an inner ring portion, the outer diameter dimension of the bearing is larger than the interval between at least a pair of rotation preventing pins of a movable scroll plate arranged on a thrust plate, and the shaft seal fixing plate has an outer diameter dimension substantially equal to the outer diameter dimension of the bearing and is sandwiched between the inner surface of the large diameter recess and the outer ring portion and the inner ring portion of the bearing. Effects of the Invention

[0013] According to the present invention, a scroll compressor comprises: a compression mechanism including a fixed scroll and a movable scroll; a casing; a back pressure chamber formed between the casing and the movable scroll; a shaft penetrating a through hole formed in a recessed portion of the casing to drive the movable scroll; a bearing pressed into and fixed in the recessed portion of the casing to rotatably support the shaft; and a shaft seal arranged in a recessed portion on the through hole side of the bearing to prevent a working fluid from flowing out of the casing, wherein the working fluid is compressed by causing the movable scroll to revolve and rotate relative to the fixed scroll using a motor mounted with a shaft. In the scroll compressor, a shaft seal fixing plate having a larger diameter than that of the shaft seal is sandwiched between the bearing and the shaft seal. Therefore, even when the bearing has an outer diameter larger than that of the shaft seal and the shaft seal and the bearing are of a separate structure, the undesirable situation that the shaft seal and the bearing are in contact with each other and thus the bearing and the shaft seal are damaged can be eliminated.

[0014] Thus, it is possible to avoid the undesirable situation that the working fluid flows out of the housing, and it is possible to eliminate the performance degradation of the scroll compressor. In addition, since it is possible to cope with the large-scale bearing, it is possible to extend the life even when the operating range of the scroll compressor is expanded. In addition, since it is a relatively simple structure in which a shaft seal fixing plate is sandwiched between the bearing and the shaft seal, the cost increase can be suppressed to a minimum.

[0015] In addition, since the shaft seal is not enlarged, the increase in the overall size of the scroll compressor caused by the extension of the shaft can be eliminated, and the risk of interference with the balance weight installed on the motor as in the fourth invention can be suppressed, and the undesirable situation of worsening vibration noise can be eliminated.

[0016] In addition, as in the second invention, a thrust plate is provided on the back pressure chamber side of the movable scroll disk, and at least a pair of positioning pins are provided for positioning the thrust plate relative to the casing, so that the outer diameter dimension of the bearing is smaller than the interval between the positioning pins, thereby avoiding the enlargement of the overall size of the scroll compressor due to excessive enlargement of the bearing.

[0017] In addition, as in the third invention, if the recessed portion of the housing is formed into a stepped shape consisting of a small-diameter recessed portion and a large-diameter recessed portion, a through hole is formed in the small-diameter recessed portion, the shaft seal is arranged in the small-diameter recessed portion, the bearing is press-fitted and fixed in the large-diameter recessed portion, and the shaft seal fixing plate is arranged in the large-diameter recessed portion between the bearing and the shaft seal, the bearing is press-fitted and fixed to the housing, and the shaft seal and the shaft seal fixing plate can be stably held.

[0018] Furthermore, as in the fourth invention, by making the outer shape of the housing into a stepped shape along the stepped shape of the recessed portion, it is possible to eliminate the undesirable interference between the housing and the balance weight located on the housing side of the motor without increasing the axial length of the shaft.

[0019] In addition, as in the fifth invention, if the outer diameter of the bearing is made larger than the interval between at least a pair of rotation preventing pins of the movable scroll plate arranged on the thrust plate, and the outer diameter of the shaft seal fixing plate is made approximately the same as the outer diameter of the bearing, and is clamped between the inner surface of the large diameter recess and the outer ring portion and the inner ring portion of the bearing, the shaft seal fixing plate can be more stably maintained in the housing, and interference between the shaft seal and the bearing can be reliably prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a cross-sectional view of a scroll compressor according to an embodiment of the present invention. Figure 2 yes Figure 1 An enlarged cross-sectional view of the rear bearing portion of a scroll compressor. DETAILED DESCRIPTION

[0021] Hereinafter, embodiments of the present invention will be described in detail based on the drawings. Figure 1 It is a schematic cross-sectional view of a scroll compressor 1 according to an embodiment of the present invention.

[0022] The scroll compressor 1 of the embodiment is a so-called horizontal scroll compressor, for example, used in the refrigerant circuit of an air-conditioning device for an electric vehicle, which sucks in a refrigerant (including lubricating oil) as a working fluid of the air-conditioning device, compresses it, and then discharges it to a discharge pipe, and has a three-phase motor 2 of the embodiment as a motor, an inverter 3 for operating the motor 2, and a scroll compression mechanism 4 driven by the motor 2.

[0023] The scroll compressor 1 of the embodiment comprises: a stator housing 7, inside which a motor 2 is housed, and a center housing 6 of the present invention as a housing; an inverter housing 8 installed on one end side of the stator housing 7 and inside which an inverter 3 is housed; and a rear housing 9 installed on the other end side of the stator housing 7.

[0024] The center housing 6 , the stator housing 7 , the inverter housing 8 , and the rear housing 9 are all made of metal (aluminum in the embodiment), and are integrally joined to form a housing 11 of the scroll compressor 1 of the embodiment.

[0025] The stator housing 7 includes a motor chamber 12 for accommodating the motor 2, and one end face of the motor chamber 12 is closed. The other end face of the motor chamber 12 is open, and the motor 2 is accommodated in the opening, and then the center housing 6 is accommodated. In addition, a front bearing 16 is mounted on the inner surface of the wall on one end side of the stator housing 7 (motor chamber 12 side), and the front bearing 16 supports one end of the shaft 14 mounted on the motor 2 so that it can rotate.

[0026] The center housing 6 has an opening on the side opposite to the motor 2 (the other end side), and after a movable scroll 22 of the compression mechanism 4 described later is accommodated in the opening, a rear housing 9 to which a fixed scroll 21 of the compression mechanism 4 described later is fixed is fixed to the stator housing 7, thereby closing the opening.

[0027] In addition, the center housing 6 is provided with a through hole 17, and the other end of the shaft 14 of the motor 2 passes through the through hole 17. A rear bearing 18, which supports the other end of the shaft 14 as a rotatable bearing on the compression mechanism 4 side, is installed in the center housing 6 on the compression mechanism 4 side of the through hole 17.

[0028] The motor 2 is composed of a stator 25 on which a coil is wound and fixed to the inner side of the peripheral wall of the stator case 7, and a rotor 23 rotating inside the stator 25. In addition, a DC current from a battery (not shown) of a vehicle is converted into a three-phase AC current by an inverter 3, and supplied to the coil of the stator 25 of the motor 2, thereby rotating and driving the rotor 23. In addition, the shaft 14 is fixedly mounted on the rotor 23 of the motor 2. Reference numeral 51A is a balancing weight mounted on the end surface of the rotor 23 of the motor 2 at a position on the center case 6 side, and reference numeral 51B is a balancing weight mounted on the end surface on the opposite side.

[0029] In addition, a suction port 30 is formed in the stator housing 7. Figure 1 As shown by arrows in the figure, the low-temperature refrigerant sucked from the suction port 30 passes through the motor 2 in the stator housing 7, flows into the center housing 6, and is sucked into the suction portion 37 outside the compression mechanism 4. Thus, the motor 2 is cooled by the sucked refrigerant. In addition, the following structure is provided: the refrigerant compressed by the compression mechanism 4 is discharged from the discharge chamber 27 described later through the discharge port 20 formed in the rear housing 9 to the discharge piping of the refrigerant circuit (not shown) outside the housing 11 as shown by arrows in the figure.

[0030] The compression mechanism 4 is composed of the fixed scroll 21 and the movable scroll 22. The fixed scroll 21 is integrally provided with a disc-shaped end plate 23 and a spiral volute 24 formed of an involute or a curve similar thereto and erected on the surface (one surface) of the end plate 23, and the surface of the end plate 23 on which the volute 24 is erected is fixed to the rear housing 9 as the center housing 6 side.

[0031] A discharge hole 26 is formed at the center of the end plate 23 of the fixed scroll 21, and the discharge hole 26 communicates with a discharge chamber 27 in the rear housing 9. In the figure, reference numeral 28 is a discharge valve provided at an opening of the discharge hole 26 on the back side (the other side) of the end plate 23.

[0032] The movable scroll 22 is a scroll that revolves and rotates relative to the fixed scroll 21, and is integrally provided with a disc-shaped end plate 31, a spiral lap 32 formed of an involute or a curve similar thereto and erected on the surface (one surface) of the end plate 31, and a boss 33 protruding from the center of the back surface (the other surface) of the end plate 31. The movable scroll 22 is arranged so that the lap 32 protrudes toward the fixed scroll 21 side, and the lap 32 is opposite to the lap 24 of the fixed scroll 21, and is arranged in a mutually opposing and meshing manner, and a pressure chamber 34 is formed between each lap 24, 32.

[0033] That is, the volute 32 of the movable scroll 22 is opposite to the volute 24 of the fixed scroll 21, and meshes with each other in a manner that the front end of the volute 32 contacts the surface of the end plate 23, and the front end of the volute 24 contacts the surface of the end plate 31, and the eccentric portion 36 provided eccentrically from the axis at the other end of the shaft 14 is fitted into the boss 33 of the movable scroll 22. And it is configured so that if the shaft 14 rotates together with the rotor 23 of the motor 2, the movable scroll 22 does not rotate but revolves and rotates relative to the fixed scroll 21. In addition, reference numeral 52 is a balancing weight mounted on the other end of the shaft 14.

[0034] The movable scroll 22 revolves eccentrically relative to the fixed scroll 21, so the eccentric direction and contact position of each volute 24, 32 move while rotating, and the pressure chamber 34 that sucks the refrigerant (including oil) from the suction portion 37 on the outside moves toward the inside and gradually shrinks. The refrigerant is compressed, and finally the refrigerant is discharged from the discharge hole 26 in the center to the discharge chamber 27 via the discharge valve 28.

[0035] exist Figure 1 In the figure, reference numeral 38 is an annular thrust plate. The thrust plate 38 is used to divide the back pressure chamber 39 formed between the back surface of the end plate 31 of the movable scroll 22 and the center housing 6 and the suction portion 37 outside the compression mechanism 4, and is located outside the boss 33 and sandwiched between the center housing 6 and the movable scroll 22. That is, the thrust plate 38 is provided on the back pressure chamber 39 side of the movable scroll 22.

[0036] In addition, reference numeral 40 is a positioning pin for positioning the thrust plate 38 on the center housing 6, and is located at the end of the thrust plate 38, and at least one pair is provided. In addition, reference numeral 45 is a rotation preventing pin protruding from the thrust plate 38 toward the movable scroll 22 side. The rotation preventing pin 45 is also provided with at least one pair, and is slidably engaged with the back surface of the end plate 31 of the movable scroll 22, and plays a role in preventing the movable scroll 22 from rotating.

[0037] In addition, reference numeral 41 is a seal member which is mounted on the back side of the end plate 31 of the movable scroll 22 and abuts against the thrust plate 38, and the back pressure chamber 39 and the suction portion 37 are divided by the seal member 41 and the thrust plate 38. In addition, although only one side is shown in the figure, the actual seal member 41 is annular and is mounted on the back side peripheral portion of the end plate 31.

[0038] In addition, reference numeral 48 denotes a centrifugal oil separator provided in the rear housing 9 (housing 11). The oil separator 48 separates the lubricating oil mixed in the refrigerant discharged from the compression mechanism 4 to the discharge chamber 27 from the refrigerant. The oil separator 48 is formed with an inlet 49, and the refrigerant containing oil flowing in from the inlet 49 rotates in the oil separator 48. The oil is separated by the centrifugal force at this time, and the refrigerant is discharged from the outflow port at the upper end toward the discharge port 20 to the discharge pipe as described above.

[0039] An oil storage chamber 44 is formed in the rear housing 9 below the oil separator 48, and the oil separated from the refrigerant by the oil separator 48 flows into the oil storage chamber 44 from the lower end of the oil separator 48. In the figure, reference numeral 43 is a back pressure passage formed from the rear housing 9 to the center housing 6. The back pressure passage 43 is a path that connects the oil separator 48 in the discharge chamber 27 (discharge side of the compression mechanism 4) in the rear housing 9 with the back pressure chamber 39, and has a throttle hole 50 in the embodiment. Thus, it is configured that the discharge pressure adjusted by the throttle hole 50 of the back pressure passage 43 is supplied to the back pressure chamber 39 together with the oil in the oil storage chamber 44 separated by the oil separator 48.

[0040] The pressure (back pressure) in the back pressure chamber 39 generates a back pressure load that pushes the movable scroll 22 toward the fixed scroll 21. The back pressure load is used to push the movable scroll 22 toward the fixed scroll 21 against the compression reaction force from the pressure chamber 34 of the compression mechanism 4, and the contact between the laps 24, 32 and the end plates 31, 23 is maintained, so that the refrigerant can be compressed through the pressure chamber 34.

[0041] On the other hand, the inverter case 8 includes a case body 10 constituting an inverter housing portion 13 for housing the inverter 3 therein, and a cover member 15 for closing an opening of one end surface of the case body 10. After the inverter 3 is housed in the inverter housing portion 13, the cover member 15 is attached to the case body 10.

[0042] A sealing pin 53 is attached to a wall on one end side of the stator case 7. One end side of the sealing pin 53 is electrically connected to the inverter 3. The other end side of the sealing pin 53 is connected to the coil of the stator 25 of the motor 2.

[0043] Next, refer to Figure 2The detailed structure around the rear bearing 18 is described with reference to an enlarged view of FIG. A recessed portion 54 is formed in the center housing 6, which is recessed toward one end side, that is, the side opposite to the opening of the other end side. The recessed portion 54 is in a stepped shape consisting of a small-diameter recessed portion 56 located at one end of the center housing 6 and a large-diameter recessed portion 57 having a larger diameter than the small-diameter recessed portion 56, and the through hole 17 is formed through the small-diameter recessed portion 56. In addition, the outer shape of the center housing 6 is in a stepped shape along the stepped shape of the recessed portion 54.

[0044] Furthermore, an annular shaft seal 58 is disposed in the small-diameter recess 56. In this case, the depth dimension of the inner side of the small-diameter recess 56 (the dimension in the axial direction of the shaft 14) is substantially equal to the thickness dimension of the shaft seal 58, and the shaft seal 58 is accommodated in the small-diameter recess 56 substantially without any gap. The shaft seal 58 is disposed on the through-hole 17 side of the rear bearing 18, and its inner peripheral edge portion is slidably in contact with the outer peripheral surface of the shaft 14, thereby preventing oil and refrigerant (working fluid) from flowing out from the through-hole 17 to the motor chamber 12 outside the center housing 6 ( Figure 2 indicated by arrows).

[0045] On the other hand, the rear bearing 18 is pressed into and fixed in the large diameter recess 57. The rear bearing 18 is a ball bearing composed of an outer ring portion 61 and an inner ring portion 62, and a plurality of balls 63 arranged therebetween, the outer surface of the outer ring portion 61 is pressed into the inner surface of the large diameter recess 57, and the shaft 14 is pressed into the inner surface of the inner ring portion 62.

[0046] The rear bearing 18 used in the present invention is enlarged in diameter compared with the conventional ones in order to cope with the expansion of the operating range of the scroll compressor 1, and has an outer diameter larger than the shaft seal 58. In the case of the embodiment, the outer diameter of the rear bearing 18 is enlarged to a value larger than the interval between the rotation preventing pins 45 of the thrust plate 38. However, the outer diameter of the rear bearing 18 of the embodiment is limited to a value smaller than the interval between the positioning pins 40 of the thrust plate 38. Therefore, as Figure 2 As shown, the outer peripheral edge of the shaft seal 58 of the embodiment just reaches a position corresponding to the ball 63 between the outer ring portion 61 and the inner ring portion 62 of the rear bearing 18 in the axial direction.

[0047] In addition, the rear bearing 18 and the shaft seal 58 are separate structures, and a predetermined gap is formed in the large diameter recess 57 on the shaft seal 58 side of the rear bearing 18. In addition, the shaft seal fixing plate 64 of the present invention is arranged in the gap of the large diameter recess 57 between the rear bearing 18 and the shaft seal 58, and the shaft seal fixing plate 64 is interposed between the rear bearing 18 and the shaft seal 58.

[0048] The shaft seal fixing plate 64 of the embodiment is larger than the diameter of the shaft seal 58 and has an outer diameter dimension substantially equal to the outer diameter dimension of the rear bearing 18. The shaft seal fixing plate 64 is sandwiched between the inner surface of the large diameter recess 57 at the step portion between the large diameter recess 57 and the small diameter recess 56 and the outer ring portion 61 and the inner ring portion 62 of the rear bearing 18.

[0049] Next, the procedure for installing the rear bearing 18, the shaft seal 58, and the shaft seal fixing plate 64 will be described. First, the shaft seal 58 is arranged in the small diameter recess 56 of the recess 54 of the center housing 6. Then, the shaft seal fixing plate 64 is arranged in the large diameter recess 57 of the step portion between the large diameter recess 57 and the small diameter recess 56. Finally, the rear bearing 18 is pressed into the large diameter recess 57.

[0050] Here, if the diameter of the rear bearing 18 is increased, the outer peripheral edge of the shaft seal 58 will come to a position corresponding to the ball 63 of the rear bearing 18 as described above. Therefore, if there is no shaft seal fixing plate 64, the shaft seal 58, which is a separate structure from the rear bearing 18, moves in the axial direction, and its outer peripheral edge contacts the ball 63 and the inner ring portion 62 of the rotating rear bearing 18, causing the rear bearing 18 and the shaft seal 58 to be damaged.

[0051] If the rear bearing 18 is damaged, the shaft 14 cannot be supported smoothly, thereby hindering the rotation. In addition, if the shaft seal 58 is damaged, the oil, refrigerant (working fluid) and the like are damaged. Figure 2 As shown by the arrow in FIG. 1 , the air leaks to the low-pressure motor chamber 12 outside the center case 6 , so the back pressure of the back pressure chamber 39 decreases, the compression mechanism 4 suffers from compression failure, and the refrigeration capacity decreases.

[0052] However, by configuring a shaft seal fixing plate 64 between the rear bearing 18 and the shaft seal 58 as in the present invention, even if the rear bearing 18 has an outer diameter larger than the shaft seal 58 and the shaft seal 58 and the rear bearing 18 are separate structures, it is possible to prevent the shaft seal 58 from contacting the ball 63 and the inner ring portion 62 of the rear bearing 18, thereby preventing the rear bearing 18 and the shaft seal 58 from being damaged.

[0053] Thus, it is possible to avoid the undesirable situation that oil and refrigerant (working fluid) flow out to the low-pressure motor chamber 12 outside the center housing 6, and it is possible to eliminate the performance degradation of the scroll compressor 1. In addition, it is possible to cope with the enlargement of the rear bearing 18 without any obstacles, so that even if the operating range of the scroll compressor 1 is expanded, the service life can be extended.

[0054] In addition, since the shaft seal fixing plate 64 is sandwiched between the rear bearing 18 and the shaft seal 58 in a relatively simple configuration, the cost increase can be suppressed to a minimum. In addition, since the shaft seal 58 is not enlarged, there is no need to extend the shaft 14 or the like to prevent interference with the balance weight 51A of the motor 2, and the increase in the overall size of the scroll compressor 1 can be avoided. In other words, there is no need to limit the size of the balance weight 51A, so the undesirable situation of worsening vibration noise can be avoided.

[0055] In the embodiment, since the outer diameter of the rear bearing 18 is smaller than the interval between the positioning pins 40 of the thrust plate 38 , it is possible to avoid an increase in the overall size of the scroll compressor 1 due to excessive increase in the size of the rear bearing 18 .

[0056] In addition, in the embodiment, the recess 54 of the center housing 6 is made into a stepped shape consisting of a small-diameter recess 56 and a large-diameter recess 57, a through hole 17 is formed in the small-diameter recess 56, the shaft seal 58 is arranged in the small-diameter recess 56, the rear bearing 18 is pressed and fixed in the large-diameter recess, and the shaft seal fixing plate 64 is arranged in the large-diameter recess 57 between the rear bearing 18 and the shaft seal 58. Therefore, by pressing and fixing the rear bearing 18 to the center housing 6, the shaft seal 58 and the shaft seal fixing plate 64 can be stably maintained.

[0057] In addition, in the embodiment, since the outer shape of the center housing 6 is made into a stepped shape along the stepped shape of the recessed portion 54, Figure 2 As shown, the small diameter recess 56 of the center case 6 is located inside the balance weight 51A of the motor 2. This can eliminate the problem of interference between the center case 6 and the balance weight 51A, and does not require the shaft 14 to be extended.

[0058] In addition, in the embodiment, the outer diameter dimension of the rear bearing 18 is made larger than the interval between the rotation preventing pins 45 of the movable scroll plate 2 arranged on the thrust plate 38, and the outer diameter dimension of the shaft seal fixing plate 64 is made to be approximately the same as the outer diameter dimension of the rear bearing 18, and is clamped between the inner surface of the large diameter recess 57 and the outer ring portion 61 and the inner ring portion 2 of the rear bearing 18, thereby making it possible to more stably maintain the shaft seal fixing plate 64 in the center housing 6, and reliably prevent interference between the shaft seal 58 and the rear bearing 18.

[0059] In addition, in the embodiment, the present invention is described using the scroll compressor 1 in which the center shell 6 is accommodated in the shell 11, but the specific structure of the shell 11 of the scroll compressor 1 is not limited to the embodiment and can of course be changed within the scope of the purpose of the present invention. Description of Reference Numerals

[0060] 1Scroll compressor 2 Motor 3 Inverter 4Compression mechanism 6 Center housing (housing) 7. Stator housing 11 Shell 12 Motor room 14 axis 17Through holes 18 rear bearing (bearing) 21 Fixed scroll 22 movable scroll 38 thrust plate 39 Back Pressure Chamber 40 positioning pin 45 Rotation prevention pin 51A balance weight 54 recess 56 small diameter recess 57 large diameter concave part 58 shaft seal 61 Outer ring 62 Inner ring 63 goals 64 Shaft seal retaining plate.

Claims

1. A scroll compressor, characterized in that: The scroll compressor comprises: a compression mechanism including a fixed scroll and a movable scroll; a housing; a back pressure chamber formed between the housing and the movable scroll; a shaft penetrating a through hole formed in a recessed portion of the housing to drive the movable scroll; a bearing pressed into and fixed in the recessed portion of the housing to rotatably support the shaft; and a shaft seal disposed in the recessed portion on the through hole side of the bearing to prevent the working fluid from flowing out of the housing. The working fluid is compressed by causing the movable scroll to orbit relative to the fixed scroll using a motor mounted on the shaft, In the scroll compressor, The bearing has a larger outer diameter than the shaft seal, The shaft seal and the bearing are separate structures, and A shaft seal fixing plate having a larger diameter than the shaft seal is interposed in the recessed portion between the bearing and the shaft seal.

2. The scroll compressor according to claim 1, characterized in that: The scroll compressor comprises: a thrust plate disposed on the back pressure chamber side of the movable scroll; and at least one pair of locating pins to position the thrust plate relative to the housing, The outer diameter of the bearing is smaller than the interval between the positioning pins.

3. The scroll compressor according to claim 1, characterized in that: The recessed portion of the housing is in a stepped shape consisting of a small-diameter recessed portion and a large-diameter recessed portion, and the through hole is formed in the small-diameter recessed portion. The shaft seal is arranged in the small diameter recess, the bearing is pressed and fixed in the large diameter recess, and The shaft seal fixing plate is arranged in the large-diameter recessed portion between the bearing and the shaft seal.

4. The scroll compressor according to claim 3, characterized in that: The motor has a balancing weight located on the housing side. The outer shape of the housing is a stepped shape along the stepped shape of the recessed portion.

5. The scroll compressor according to claim 3 or 4, characterized in that: The bearing is a ball bearing having a ball disposed between an outer ring portion and an inner ring portion. The outer diameter of the bearing is larger than the distance between at least one pair of rotation preventing pins of the movable scroll provided on the thrust plate. The shaft seal fixing plate has an outer diameter substantially equal to that of the bearing, and is sandwiched between the inner surface of the large-diameter recess and the outer ring portion and the inner ring portion of the bearing.

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