Double-rotating scroll compressor

Abstract

To suppress unstable behavior of a driving scroll and a driven scroll caused by compression load in a radial direction, of a driving axis.SOLUTION: When assuming a plane surface orthogonal to a driving axis X1, a middle point MP of a center of a driving-side base circle 34 and a center of a driven-side base circle 44 is defined as a point of action of compression load generating in a radial direction of the driving axis X1, a direction orthogonal to a virtual line VL connecting two of a first contact point P1 and a second contact point P2 where a side face of a driving spiral body 33 and a side face of a driven spiral body 43 are kept into contact with each other at an outermost peripheral side, is defined as a load direction LD of the compression load, a stator 13 defines a fixed axis FX in a housing 60 when a range of fluctuation of the load direction LD during one rotation of a driving scroll 30 is defined as a fluctuation range FR, and the driving axis X1 is defined by a rotor 14 and determined to be separated from the fixed axis FX in non-operation and to be agreed with or approach the fixed axis FX in operation, in the load direction LD included in the fluctuation range FR.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a double-rotating scroll compressor. [Background technology]

[0002] A conventional double-rotating scroll compressor (hereinafter simply referred to as a compressor) is disclosed in Patent Document 1. This compressor includes a drive mechanism, a drive scroll, a driven mechanism, a driven scroll, and a cylindrical housing.

[0003] The drive scroll is provided within the housing and is rotationally driven about a drive axis by a drive mechanism, and the driven scroll is provided within the housing and is rotationally driven by the drive scroll and the driven mechanism about a driven axis while being eccentric with respect to the drive scroll.

[0004] The drive scroll has a drive end plate and a drive scroll body. The drive end plate extends in a direction intersecting the drive axis. The drive scroll body protrudes from the drive end plate toward the driven scroll and has a spiral shape.

[0005] The driven scroll has a driven end plate and a driven volute, the driven end plate extending in a direction intersecting the driven axis, and the driven volute protrudes from the driven end plate toward the driving scroll and has a spiral shape.

[0006] The drive mechanism includes an electric motor disposed within a housing, the electric motor including a stator fixed to the housing, and a rotor disposed within the stator and rotatable together with the drive scroll.

[0007] The drive scroll and the driven scroll face each other to form a compression chamber, and the volume of the compression chamber is changed by the rotational driving and driven movement of the drive scroll and the driven scroll. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-310073 Summary of the Invention [Problem to be solved by the invention]

[0009] During operation of the compressor, a compressive load is generated by the refrigerant being compressed in the compression chamber. This compressive load acts mainly in the radial direction of the drive shaft rather than in the axial direction. Therefore, if the compressive load in the radial direction of the drive shaft acts on the rotor, for example, via the drive scroll, the behavior of the rotor may become unstable, and ultimately the behavior of the drive scroll and the driven scroll may also become unstable.

[0010] The present invention has been made in consideration of the above-mentioned conventional situation, and aims to solve the problem of preventing the behavior of the driving scroll and the driven scroll from becoming unstable due to the radial compressive load on the driving shaft core. [Means for solving the problem]

[0011] The double-rotating scroll compressor of the present invention comprises a drive mechanism, a drive scroll, a driven mechanism, a driven scroll, and a cylindrical housing, the driving scroll is provided in the housing and is driven to rotate about a drive axis by a driving mechanism; the driven scroll is provided in the housing and is rotated by the driving scroll and the driven mechanism around a driven axis while being eccentric with respect to the driving scroll; The drive scroll has a drive end plate extending in a direction intersecting the drive axis, and a drive scroll protruding from the drive end plate toward the driven scroll and having a spiral shape, The driven scroll has a driven end plate extending in a direction intersecting the driven axis, and a driven scroll body protruding from the driven end plate toward the drive scroll and having a spiral shape, the drive mechanism includes an electric motor having a stator fixed to the housing and a rotor disposed within the stator and rotatable together with the drive scroll; In a double rotary scroll compressor, the driving scroll and the driven scroll face each other to form a compression chamber, and the volume of the compression chamber is changed by the rotation driving and the rotation driven, When a plane perpendicular to the drive shaft is assumed, a midpoint between a center of a driving-side base circle forming the driving scroll and a center of a driven-side base circle forming the driven scroll is defined as a point of application of a compressive load generated in a radial direction of the drive shaft center by rotation of the driving scroll and the driven scroll; The load direction of the compressive load is defined as a direction perpendicular to an imaginary line connecting a first contact point where the outer surface of the drive spiral and the inner surface of the driven spiral meet at the outermost periphery side, and a second contact point where the inner surface of the drive spiral and the outer surface of the driven spiral meet at the outermost periphery side, and When the range in which the load direction changes during one rotation of the driving scroll and the driven scroll is defined as the fluctuation range, the stator defines a fixed axis within the housing; The drive axis is determined by the rotor and is set to be spaced apart from the fixed axis when not in operation, and to be aligned with or approach the fixed axis when in operation, in the load direction included in the fluctuation range.

[0012] In a double rotary scroll compressor, the refrigerant is compressed in the compression chamber, generating a compressive load that acts mainly in the radial direction of the drive shaft. In the following description, unless otherwise specified, the compressive load refers to the compressive load that acts in the radial direction of the drive shaft.

[0013] Even in a scroll compressor having a fixed scroll and an orbiting scroll, a compressive load acts in the radial direction of the rotating shaft that rotates the orbiting scroll. The direction of the compressive load acting in the radial direction of the rotating shaft rotates 360 degrees as the orbiting scroll orbits.

[0014] In contrast, in a double-rotating scroll compressor, the drive scroll and the driven scroll rotate eccentrically at the same angular velocity. Therefore, the direction of the compressive load does not change significantly in the circumferential direction of the drive shaft during operation of the compressor. In other words, the range of the compressive load generated during operation of the compressor is limited to a predetermined small angular range in the circumferential direction of the drive shaft. The inventors focused on this point and completed the present invention.

[0015] In other words, if the direction of the compressive load in the circumferential direction of the drive shaft does not change significantly during operation, the direction of the compressive load acting on, for example, the drive scroll will not change significantly either. Therefore, the drive scroll is constantly pushed in the direction of the compressive load during operation of the compressor. As a result, the rotor rotating with the drive scroll and the drive shaft defined by the rotor are also pushed in the direction of the compressive load and move slightly.

[0016] In the double-rotating scroll compressor of the present invention, a fixed axis defined by a stator fixed to a housing and a drive axis defined by a rotor rotating within the stator are set to have a predetermined relationship. That is, in the load direction within the specified fluctuation range, the drive axis is separated from the fixed axis when the compressor is not operating, and the drive axis is aligned with or approaches the fixed axis when the compressor is operating.

[0017] This prevents the drive shaft from moving in the direction of the compressive load during operation of the compressor, thereby preventing the rotor from becoming unstable due to the misalignment between the fixed shaft and the drive shaft, and thus prevents the behavior of the drive scroll and the driven scroll from becoming unstable.

[0018] Therefore, the double-rotating scroll compressor of the present invention can prevent the behavior of the driving scroll and the driven scroll from becoming unstable due to a compressive load in the radial direction of the drive shaft.

[0019] The housing preferably has a thin portion and a thick portion that is thicker than the thin portion in the circumferential direction of the fixed axis, and the thin portion is preferably provided within a range of variation.

[0020] When a stator is press-fitted into a cylindrical housing having a thin-walled portion and a thick-walled portion in the circumferential direction, the stator is fixed in a state where the axial center is slightly offset toward the thin-walled portion from the original axial center position of the stator due to the influence of the interference fit. The thin-walled portion is provided with a range of variation. The original axial center position of the stator is the position that coincides with the drive shaft center, which is the center of the rotor that is positioned in the correct position within the housing by a bearing or the like when the compressor is not operating.

[0021] Therefore, the stator is fixed to the housing with a slight axial deviation from its original axial position in the load direction included in the fluctuation range. In other words, the fixed axis defined by the stator fixed to the housing is slightly axially deviated from its original axial position in the load direction.

[0022] In this way, the direction of the axial misalignment of the fixed shaft center due to the influence of the interference fit is aligned with the load direction of the compressive load. Therefore, during operation of the compressor, the drive shaft center is pushed in the load direction of the compressive load and moves slightly in the direction of the axial misalignment of the fixed shaft center. This makes it possible to suppress the axial misalignment between the fixed shaft center and the drive shaft center during operation.

[0023] The stator is preferably fixed to the housing by an interference fit.

[0024] In this case, it is easy to set a predetermined interference when fixing by interference fit, and it is also easy to set the amount of axial misalignment of the fixed shaft center.

[0025] The drive mechanism preferably has an inverter circuit for driving the electric motor, and the inverter circuit is preferably provided in the thick portion.

[0026] By providing the inverter circuit in the thick-walled portion of the housing, it is possible to prevent the compressor from becoming larger in size in the direction of the drive shaft center, while suppressing axial misalignment between the fixed shaft center and the drive shaft center during operation.

[0027] The drive scroll is preferably contained within the rotor.

[0028] In this case, the electric motor, the drive scroll, and the driven scroll are aligned in the radial direction of the drive axis, so the compressor can be made smaller in the drive axis direction compared to when the electric motor is aligned in the drive axis direction with respect to the drive scroll and the driven scroll.

[0029] It is particularly preferable that the inverter circuit is provided in the thick-walled portion and the drive scroll is built into the rotor.

[0030] In this case, since the inverter circuit is disposed on the outer periphery of the stator, it is advantageous to simplify the wiring structure for supplying power from the inverter circuit to the stator. Furthermore, since the electric motor and the inverter circuit are aligned in the radial direction of the drive shaft relative to the driving scroll and the driven scroll, it is possible to integrate the inverter circuit into the compressor while avoiding an increase in the size of the compressor in the direction of the drive shaft. [Effects of the Invention]

[0031] The double-rotating scroll compressor of the present invention can prevent the behavior of the driving scroll and the driven scroll from becoming unstable due to a compressive load in the radial direction of the drive shaft. [Brief explanation of the drawings]

[0032] [Figure 1] FIG. 1 is a schematic cross-sectional view of a double-rotating scroll compressor according to an embodiment, showing a cross section of a portion other than an inverter case. [Figure 2]FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] FIG. 3 is a schematic diagram illustrating the direction of the compressive load in the double rotary scroll compressor of the embodiment, showing the moment when the compression chamber formed on the outermost peripheral side is closed (at the time of confinement). [Figure 4] FIG. 4 is a schematic diagram illustrating the direction of the compressive load in the double-rotation scroll compressor of the embodiment, showing the state when the compressor is rotated by 60 degrees from the closed position. [Figure 5] FIG. 5 is a schematic diagram illustrating the direction of the compressive load in the double-rotation scroll compressor of the embodiment, showing the state when the compressor is rotated 120 degrees from the closed state. [Figure 6] FIG. 6 is a schematic diagram illustrating the direction of the compressive load in the double-rotation scroll compressor of the embodiment, showing the state when rotated 180 degrees from the closed state. [Figure 7] FIG. 7 is a schematic diagram illustrating the direction of the compressive load in the double-rotation scroll compressor of the embodiment, showing the state when the compressor is rotated 240 degrees from the closed state. [Figure 8] FIG. 8 is a schematic diagram illustrating the direction of the compressive load in the double-rotation scroll compressor of the embodiment, showing the state when the compressor is rotated 300 degrees from the closed state. [Figure 9] FIG. 9 is a schematic diagram illustrating the direction of the compressive load in the double-rotating scroll compressor of the embodiment, showing the state immediately before 360-degree rotation from the closed position. [Figure 10] FIG. 10 is a schematic diagram illustrating the range of variation in the load direction of the compressive load in the double rotary scroll compressor of the embodiment. [Figure 11] FIG. 11 is a cross-sectional view of a housing body for explaining shrink fitting of a stator into a housing of a double rotary scroll compressor according to an embodiment. [Figure 12] FIG. 12 is a cross-sectional view illustrating the state in which the stator is shrink-fitted to the housing body in the double rotary scroll compressor of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0033] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

[0034] (Example) As shown in Fig. 1, a double-rotating scroll compressor 1 (hereinafter simply referred to as compressor 1) of this embodiment is an example of a specific aspect of the present invention. Compressor 1 includes a housing 60. Housing 60 includes a housing main body 61 and a cover 65.

[0035] The housing body 61 is a bottomed cylindrical member having an outer peripheral wall 62 and a bottom wall 63. The outer peripheral wall 62 has a cylindrical inner peripheral surface 62C centered on the drive axis X1. The bottom wall 63 extends in a generally circular flat plate shape perpendicular to the drive axis X1.

[0036] The outer peripheral edge of the bottom wall 63 is connected to the base end of the outer peripheral wall 62 that is remote from the cover 65. A cylindrical bearing portion 64 is provided in a protruding manner at the center of the inner surface of the bottom wall 63, the bearing portion 64 being centered on the drive axis X1. The outer ring of a bearing 71 is fitted into the bearing portion 64.

[0037] The cover 65 extends in a generally circular, flat plate shape perpendicular to the drive axis X1. The cover 65 closes the housing body 61 by fastening it to the outer peripheral wall 62 with bolts (not shown) with its outer peripheral edge abutting against the tip of the outer peripheral wall 62 of the housing body 61.

[0038] A cylindrical support portion 66 is provided in a protruding position on the center of the inner surface of the cover 65, with its center on the driven axis X2. The driven axis X2 extends parallel to the drive axis X1 while being eccentric with respect to the drive axis X1 by a predetermined amount. The outer ring of a needle bearing 72 is fitted into the support portion 66.

[0039] The cover 65 has an intake hole 67 and an exhaust hole 68. The intake hole 67 is located between the outer peripheral edge of the cover 65 and the journal portion 66, and passes through the cover 65 in a direction parallel to the drive axis X1. The exhaust hole 68 is located in the center of the cover 65, and passes through the cover 65 in a direction parallel to the drive axis X1.

[0040] As shown in FIGS. 1 and 2, the compressor 1 includes a drive mechanism 10, a driven mechanism 20, a drive scroll 30, and a driven scroll 40.

[0041] The drive mechanism 10 drives the drive scroll 30 to rotate around a drive axis X1. The drive mechanism 10 includes an electric motor 11 and an inverter circuit 12 that drives the electric motor 11. The electric motor 11 includes a stator 13 and a rotor 14.

[0042] The inverter circuit 12 is provided on the outer peripheral side surface of the cylindrical housing main body 61, i.e., on the outer peripheral surface of the outer peripheral wall 62. The inverter circuit 12 is housed in the inverter case 15. In the circumferential direction of the outer peripheral wall 62, the portion of the outer peripheral wall 62 in the range where the inverter case 15 is attached is a thick-walled portion 62A that is thicker than the remaining thin-walled general portion 62B. The outer surface of this thick-walled portion 62A, which is the mounting surface of the inverter case 15, is a flat surface 62D. The inverter case 15 is fixed to the flat surface 62D with bolts (not shown). The inverter board that constitutes the inverter circuit 12 is arranged approximately parallel to the flat surface 62D.

[0043] 2, the inverter case 15 is arranged in a direction perpendicular (or nearly perpendicular) to the direction in which the drive axis X1 and the driven axis X2 are aligned, i.e., the direction of a straight line connecting the drive axis X1 and the driven axis X2, in the circumferential direction of the drive axis X1 and the driven axis X2. Note that the inverter case 15 is arranged in a direction perpendicular (or nearly perpendicular) to the direction of an imaginary line VL, which will be described later, in the circumferential direction of the drive axis X1 and the driven axis X2. As will be described later, the inverter case 15 is arranged in a direction opposite to the load direction LD, which is included in the fluctuation range FR of the load direction LD of the compressive load, in the circumferential direction of the drive axis X1 and the driven axis X2, avoiding the fluctuation range FR of the load direction LD.

[0044] The stator 13 is cylindrical and has a center on the drive axis X1, and has windings 16. The stator 13 is fitted onto an inner peripheral surface 62C of an outer peripheral wall 62 of the housing main body 61, and is thereby fixed to the housing 60 around the drive axis X1.

[0045] The rotor 14 is cylindrical and oriented around the drive shaft X1. The rotor 14 is made up of a plurality of permanent magnets (not shown) that correspond to the stator 13 and laminated steel plates (not shown) that secure the permanent magnets. The rotor 14 is disposed on the inner periphery of the stator 13 and is rotatable within the stator 13.

[0046] The rotor 14 incorporates a drive scroll 30. A drive peripheral wall 32 (described later) of the drive scroll 30 is fitted onto the inner peripheral surface 14A of the rotor 14. This allows the rotor 14 and the drive scroll 30 to rotate integrally. In this way, the drive scroll 30 is driven to rotate around the drive axis X1 by the drive mechanism 10.

[0047] As shown in FIG. 1, the driving scroll 30 includes a driving end plate 31 , a driving peripheral wall 32 , and a driving scroll 33 .

[0048] The drive end plate 31 extends in a generally circular, flat plate shape perpendicular to the drive axis X1. A cylindrical supported portion 34 is provided in a protruding position at the center of the surface of the drive end plate 31 facing the bottom wall 63 of the housing body 61, with its center on the drive axis X1.

[0049] An inner ring of a bearing 71 is fitted onto the supported portion 34. As a result, the driving scroll 30 is supported by the housing body 61 so as to be rotatable around the driving axis X1.

[0050] The driving peripheral wall 32 protrudes from the outer peripheral edge 31F of the driving end plate 31 toward the driven scroll 40 in parallel with the driving axis X1, and is cylindrical around the driving axis X1.

[0051] 1 and 2, the drive scroll 33 is located radially inward of the drive axis X1 relative to the drive peripheral wall 32. The drive scroll 33 protrudes from the drive end plate 31 toward the driven scroll 40 in parallel with the drive axis X1, and forms a spiral shape around the drive axis X1.

[0052] The driven scroll 40 has a driven end plate 41 and a driven scroll 43 .

[0053] The driven end plate 41 extends in a generally circular flat plate shape perpendicular to the driven axis X2. A cylindrical supported portion 44 is provided in a protruding manner at the center of the surface of the driven end plate 41 facing the cover 65, with the center on the driven axis X2.

[0054] An inner ring of a needle bearing 72 is fitted onto the supported portion 44. As a result, the driven scroll 40 is supported by the cover 65 so as to be rotatable around the driven axis X2.

[0055] The driven end plate 41 has an intake port 47 (see FIG. 2) and an exhaust port 48 .

[0056] The suction port 47 is located radially outward of the outer peripheral surface of the journal portion 66 from the driven axis X2, and penetrates the driven end plate 41 in a direction parallel to the driven axis X2. Two suction ports 47 are formed in the driven end plate 41 with a phase difference of 180 degrees.

[0057] The discharge port 48 is located radially inward of the inner circumferential surface of the supported portion 44 with respect to the driven axis X2, and penetrates the driven end plate 41 in a direction parallel to the driven axis X2.

[0058] The space surrounded by the inner peripheral surface of the supported portion 44 and sandwiched between the cover 65 and the driven end plate 41 forms a discharge chamber 55 .

[0059] The driven end plate 41 is provided with a discharge valve 58 located on the discharge chamber 55 side for opening and closing the discharge port 48, and a retainer 59 for restricting the opening degree of the discharge valve 58.

[0060] As shown in FIGS. 1 and 2, the driven scroll 43 protrudes from the driven end plate 41 toward the driving scroll 30 in parallel with the driven axis X2, and forms a spiral shape around the driven axis X2.

[0061] The drive scroll 30 and the driven scroll 40 face each other, and the drive scroll 33 and the driven scroll 43 mesh with each other to form a compression chamber 50 .

[0062] The driven mechanism 20 includes a plurality of pairs (three or more pairs in the case of a pin-ring system) of pins 21 and rings 22. Each pair of pins 21 and rings 22 transmits driving force from the driving scroll 30 to the driven scroll 40.

[0063] The pins 21 are cylindrical members that protrude from the tip of the driving peripheral wall 32 toward the driven end plate 41 at appropriate intervals in the circumferential direction of the driving axis X1.

[0064] Each ring 22 is provided on the driven end plate 41 side so as to face each pin 21. Each ring 22 is fitted into a circular hole with a bottom recessed in the driven end plate 41. Each pin 21 is movable while in sliding contact with the inner circumferential surface of each ring 22.

[0065] When the driving scroll 30 is driven to rotate around the drive axis X1 by the drive mechanism 10, each pin 21 slides against the inner peripheral surface of each ring 22, causing each ring 22 to rotate relatively around the center of each pin 21, thereby transmitting the torque of the driving scroll 30 to the driven scroll 40. The orbiting radius of the ring 22 is set equal to the eccentricity of the driven axis X2 of the driven scroll 40 relative to the driving axis X1 of the driving scroll 30.

[0066] As a result, the driven scroll 40 is rotated by the driving scroll 30 and the driven mechanism 20 around a driven axis X2 parallel to the drive axis X1 while being eccentric with respect to the driving scroll 30. The driving scroll 30 and the driven scroll 40 rotate and follow each other, causing the driven scroll 40 to revolve around the drive axis X1 relative to the driving scroll 30, thereby changing the volume of the compression chamber 50.

[0067] Although not shown in the figure, the compressor 1, together with an evaporator, an expansion valve, and a condenser, constitutes a refrigeration circuit of a vehicle air conditioner. The evaporator is connected to the suction port 67 by piping. The condenser is connected to the discharge port 68 by piping. The expansion valve is connected to the evaporator and the condenser by piping.

[0068] Refrigerant supplied from the evaporator flows into the housing 60 through the suction hole 67 and is introduced into the compression chamber 50 via the suction port 47. The refrigerant compressed to discharge pressure in the compression chamber 50 is discharged into the discharge chamber 55 via the discharge port 48 and then discharged to the condenser through the discharge hole 68. In this manner, the air conditioning of the vehicle air conditioner is performed.

[0069] <Shrink-fitting the stator into the housing> In this compressor 1, the stator 13 is fixed to the housing 60 by shrink fitting. Specifically, the stator 13 is fixed to the inner peripheral surface 62C of the outer peripheral wall 62 of the housing body 61 by shrink fitting with a predetermined interference.

[0070] Fig. 11 is a cross-sectional view perpendicular to the drive axis X1 of the housing main body 61. In Fig. 11, center point O indicates the center position of the circular inner peripheral surface 62C of the outer peripheral wall 62. This center point O coincides with the position of the drive axis X1, which is determined by the center of the rotor 14 supported in a predetermined normal position by bearings 71 or the like within the housing 60 when the compressor 1 is not operating.

[0071] 12 is a cross-sectional view showing a state in which the stator 13 is fixed by shrink fitting to the inner peripheral surface 62C of the outer peripheral wall 62. As shown in Fig. 12, the fixed axis FX defined by the center point of the stator 13 is slightly offset from the center point O. This is because the outer peripheral wall 62 of the housing main body 61 has a thick-walled portion 62A and a thin-walled general portion 62B in the circumferential direction, and the stator 13 is fixed offset toward the thin-walled general portion 62B due to the effect of the interference fit during shrink fitting.

[0072] The direction of displacement of the fixed axis FX from the center point O due to shrink fitting is a direction perpendicular to the flat surface 62D of the thick portion 62A, and is a direction from the thick portion 62A toward the thin general portion 62B.

[0073] In this way, the stator 13 is fixed with a predetermined amount of axial offset in the direction from the thick-walled portion 62A of the outer wall 62 toward the thin-walled general portion 62B with respect to the drive axis X1 defined by the rotor 14 supported in the correct position within the housing 60 when the compressor 1 is not operating.

[0074] <Load direction variation range> During operation of the compressor 1, a compressive load is generated within the compression chamber 50 due to the rotation of the driving scroll 30 and the driven scroll 40.

[0075] 3 to 10 are diagrams assuming a plane perpendicular to the drive axis X1 and the driven axis X2. Figures 3 to 9 show the load direction LD of the compressive load generated in the compression chamber 50 during approximately one rotation of the drive scroll 30 and the driven scroll 40 during operation of the compressor 1, in increments of 60 degrees of rotation angle.

[0076] 3 to 10 schematically show the drive scroll 33 and the driven scroll 43 of the drive scroll 30 and the driven scroll 40, respectively, only for the portions that substantially contribute to the formation of the compression chamber 50. FIGS. 3 to 9 show a drive-side base circle (a base circle of an involute curve) 34 that forms the outer surface 33A and the inner surface 33B of the drive scroll 33, and a driven-side base circle (a base circle of an involute curve) 44 that forms the outer surface 43A and the inner surface 43B of the driven scroll 43. Of the circles indicated by the two-dot chain line, the upper one in the figure is the drive-side base circle 34, and the lower one in the figure is the driven-side base circle 44. The centers of the drive-side base circle 34 and the driven-side base circle 44 are offset by a predetermined amount in a direction perpendicular to the drive axis X1. 3 to 9, the central black circle of the three black circles is the midpoint MP between the center of the drive-side base circle 34 and the center of the driven-side base circle 44. In Fig. 3, the upper of the two white circles indicates the position of the drive axis X1, and the lower one indicates the position of the driven axis X2. In Figs. 4 to 9, the position of the drive axis X1 is shown, but the driven axis X2 is omitted.

[0077] 3 shows the moment when the two compression chambers 50, 50 are closed on the outermost side (closed, 0°). At this time, the outer surface 33A of the drive spiral 33 and the inner surface 43B of the driven spiral 43 come into contact at a first contact point P1 on the outermost side, and the inner surface 33B of the drive spiral 33 and the outer surface 43A of the driven spiral 43 come into contact at a second contact point P2 on the outermost side.

[0078] An imaginary line VL is defined that connects a first contact point P1 and a second contact point P2, which are two contact points where the drive spiral 33 and the driven spiral 43 meet on the outermost side. The length of the imaginary line VL can be considered to be the radial width RW of the entire two compression chambers 50. The midpoint MP can be considered to be the center of the entire two compression chambers 50. A surface that includes the imaginary line VL and extends in the axial direction of the drive axis X1 and the driven axis X2 is defined as the pressure-receiving surface of the compressive load. The midpoint MP between the center of the drive-side base circle 34 and the center of the driven-side base circle 44 is defined as the point of application of the compressive load. The direction perpendicular to the imaginary line VL in a plane perpendicular to the drive axis X1 and the driven axis X2 is defined as the load direction (direction of action) LD of the compressive load.

[0079] The first contact point P1 is located on one tangent line that touches both the drive-side base circle 34 and the driven-side base circle 44. The second contact point P2 is located on the other tangent line that touches both the drive-side base circle 34 and the driven-side base circle 44. These tangent lines extend parallel to the imaginary line VL.

[0080] Fig. 4 is a diagram of the device rotated 60 degrees from the time of confinement. Fig. 5 is a diagram of the device rotated 120 degrees from the time of confinement. Fig. 6 is a diagram of the device rotated 180 degrees from the time of confinement. Fig. 7 is a diagram of the device rotated 240 degrees from the time of confinement. Fig. 8 is a diagram of the device rotated 300 degrees from the time of confinement. Fig. 9 is a diagram immediately before rotating 360 degrees from the time of confinement.

[0081] 4 to 9, as the rotation of the drive scroll 30 and the driven scroll 40 progresses, the first contact point P1 and the second contact point P2 are displaced toward the inner periphery side. Accordingly, the length of the imaginary line VL, i.e., the radial width RW of the entire two compression chambers 50, also gradually decreases.

[0082] The drive axis X1 of the drive scroll 30 and the driven axis X2 of the driven scroll 40 are eccentric by a predetermined amount. As the drive scroll 30 and the driven scroll 40 rotate, the first contact point P1 and the second contact point P2 move, and the load direction LD of the compressive load with the midpoint MP as the point of application also fluctuates. The range within which the load direction LD fluctuates during one rotation of the drive scroll 30 and the driven scroll 40 is defined as the fluctuation range FR.

[0083] 3 to 9, a horizontal line is assumed, and the angle of the load direction LD with respect to the horizontal line is defined as the load angle θ. The minimum load angle θmin is when the device is closed as shown in Fig. 3, and the maximum load angle θmax is when the device is about to rotate 360 ​​degrees from the closed state as shown in Fig. 9.

[0084] As shown in Fig. 10, the fluctuation range FR of the load direction LD is the angle range of the difference between the minimum load angle θmin and the maximum load angle θmax. In Fig. 10, the load direction LD at the time of confinement is indicated by a solid arrow, and the load direction LD immediately before rotating 360 degrees from the time of confinement is indicated by a two-dot chain line.

[0085] 2, in this compressor 1, the inverter case 15 incorporating the inverter circuit 12 is disposed at a predetermined position in the circumferential direction of the outer peripheral wall 62. That is, the thin-walled general portion 62B of the outer peripheral wall 62 is provided so as to include the fluctuation range FR of the load direction LD, and the thick-walled portion 62A to which the inverter case 15 is attached is disposed in a direction opposite to the load direction LD, avoiding the fluctuation range FR of the load direction LD.

[0086] <Action and effect> In the outer peripheral wall 62, a flat surface 62D of the thick portion 62A to which the inverter case 15 is attached is perpendicular (or nearly perpendicular) to the load direction LD of the compressive load during the above-described confinement state shown in Fig. 3. As described above, the fixed axis FX defined by the stator 13 shrink-fitted to the outer peripheral wall 62 is misaligned by a predetermined amount from the thick portion 62A toward the thin general portion 62B in the direction perpendicular to the flat surface 62D with respect to the drive axis X1 defined by the rotor 14 supported in the correct position within the housing 60 when the compressor 1 is not operating.

[0087] That is, in a plane perpendicular to the drive axis X1, the drive axis X1, which is the center point of the rotor 14, is separated a predetermined amount from the fixed axis FX defined by the stator 13 when the compressor 1 is not operating. This separation direction is the same as (or nearly the same as) the load direction LD of the compressive load at the time of confinement shown in FIG. 3, which is included in the fluctuation range FR, and is the direction from the thick portion 62A to the thin general portion 62B. In other words, the drive axis X1 defined by the rotor 14 is separated a predetermined amount from the fixed axis FX defined by the stator 13 when the compressor 1 is not operating, in the load direction LD at the time of confinement, which is included in the fluctuation range FR, and the separation direction is opposite to the load direction LD.

[0088] When the compressor 1 is operating, a compressive load is generated in the compression chamber 50. The load direction LD of the compressive load during operation of the compressor 1 varies only within the extremely narrow range of variation FR. Therefore, the rotor 14, to which the compressive load acts via the driving scroll 30, is pushed in the direction of the compressive load LD, which is included in the range of variation FR.

[0089] In the load direction LD, when the compressor 1 is not operating, the drive axis X1 of the rotor 14 is misaligned with the fixed axis FX of the stator 13 in the opposite direction to the load direction LD. However, when the compressor 1 is operating, the drive axis X1 of the rotor 14 is pushed toward the load direction LD by the compressive load. Therefore, when the compressor 1 is operating, the drive axis X1 of the rotor 14 coincides with or approaches the fixed axis FX of the stator 13. Therefore, when the compressor 1 is operating, axial misalignment between the stator 13 and the rotor 14 due to the compressive load can be suppressed, and the behavior of the driving scroll 30 and the driven scroll 40 can be prevented from becoming unstable.

[0090] Therefore, the double rotary scroll compressor 1 of the embodiment can prevent the behavior of the driving scroll 30 and the driven scroll 40 from becoming unstable due to the compressive load in the radial direction of the drive axis X1.

[0091] In this compressor 1, the stator 13 is fixed by shrink fitting to the outer peripheral wall 62 of the housing 60. In this case, it is easy to set a predetermined interference during shrink fitting, and it is also easy to set the amount of axial misalignment of the fixed axis FX.

[0092] Furthermore, the inverter circuit 12 is provided in the thick portion 62A of the outer peripheral wall 62, and the driving scroll 30 is built into the rotor 14. In this case, the electric motor 11 and the inverter circuit 12 are aligned with the driving scroll 30 and the driven scroll 40 in the radial direction of the drive axis X1, so the compressor 1 can be made smaller in size in the direction of the drive axis X1 than when the electric motor 11 and the inverter circuit 12 are aligned with the driving scroll 30 and the driven scroll 40 in the direction of the drive axis X1.

[0093] Therefore, it is possible to suppress axial misalignment between the fixed axis FX and the drive axis X1 during operation while avoiding an increase in size of the compressor 1 in the direction of the drive axis X1, and it is also possible to integrate the inverter circuit 12 into the compressor 1. Furthermore, since the inverter circuit 12 is disposed on the outer periphery of the stator 13, this is advantageous in simplifying the wiring structure for feeding power from the inverter circuit 12 to the stator 13.

[0094] Furthermore, inverter case 15 is disposed in the circumferential direction of drive axis X1 and driven axis X2, avoiding the fluctuation range FR of the load direction LD of the compressive load, in the direction opposite to the load direction LD included in this fluctuation range FR. Therefore, even if housing 60 and the like vibrate due to the influence of the compressive load generated in compression chamber 50, it is possible to suppress the amplification of vibration by inverter case 15 and inverter circuit 12. Therefore, it is possible to suppress vibration of housing 60 and the like caused by the compressive load.

[0095] Although the present invention has been described above with reference to the examples, it goes without saying that the present invention is not limited to the above examples and can be modified and applied as appropriate within the scope of the invention.

[0096] In the embodiment, the inverter case 15 is attached to the thick portion 62A of the outer peripheral wall 62, but the present invention is not limited to this configuration. Components other than the inverter case 15 may be attached to the thick portion 62A, or nothing may be attached to the thick portion 62A. The shape of the thick portion 62A can also be set appropriately depending on the components to be attached to the thick portion 62A.

[0097] In the embodiment, a part of the outer peripheral wall 62 is the thick portion 62A, and the thick portion 62A is integrated with the housing 60, but this is not limiting, and the thick portion 62A may be separate from the housing 60.

[0098] In the embodiment, the electric motor 11 and the inverter circuit 12 are aligned radially relative to the driving scroll 30 and the driven scroll 40 about the drive axis X1, but the present invention is not limited to this configuration. For example, only the electric motor 11 may be aligned radially relative to the driving scroll 30 and the driven scroll 40 about the drive axis X1, and the inverter circuit 12 may be aligned in the direction of the drive axis X1. Alternatively, the electric motor 11 and the inverter circuit 12 may be aligned radially relative to the driving scroll 30 and the driven scroll 40 about the drive axis X1. Alternatively, only the electric motor 11 may be aligned radially relative to the driving scroll 30 and the driven scroll 40 about the drive axis X1, and the inverter circuit 12 may be disposed on the outer peripheral surface of the housing 60 at a position offset in the direction of the drive axis X1.

[0099] In the embodiment, the drive spiral 33 and the driven spiral 43 each have just under two turns, but the number of turns of the drive spiral 33 and the driven spiral 43 is not limited to this. For example, the number of turns of the drive spiral 33 and the driven spiral 43 may be increased to increase the number of compression chambers 50. The number of turns of the drive spiral 33 and the driven spiral 43 may also be different. Even in this case, the moment when the two compression chambers 50 on the outermost side are closed can be considered the above-mentioned confinement time of 0 degrees.

[0100] In the embodiment, with respect to the fluctuation range FR, the load angle θmin is at its minimum when the scroll is closed, and is at its maximum when the scroll is just about to rotate 360 ​​degrees from the time of closing. However, depending on the scroll shape, the time when the minimum load angle θmin occurs may differ from the time of closing, or the time when the maximum load angle θmax occurs may differ from the time just before the scroll is just about to rotate 360 ​​degrees from the time of closing.

[0101] In the embodiment, the stator 13 is fixed to the outer peripheral wall 62 of the housing 60 by shrink fitting, but the method of fixing the stator 13 to the housing 60 is not limited to this. For example, the stator 13 may be fixed to the outer peripheral wall 62 of the housing 60 by cold fitting or press fitting.

[0102] In the embodiment, the driven mechanism 20 is composed of a pin 21 and a ring 22, but the present invention is not limited to this configuration. For example, the driven mechanism 20 may be composed of a pin-ring-pin system in which two pins slide against the inner peripheral surface of one free ring, a pin-pin system in which the outer peripheral surfaces of two pins slide against each other, a system using an Oldham coupling, or the like. [Industrial Applicability]

[0103] The present invention can be used, for example, in an air conditioning system for a vehicle. [Explanation of symbols]

[0104] 1...Double-rotating scroll compressor 10...Drive mechanism 11...Electric motor 12...Inverter circuit 13...Stator 14...Rotor 20…Following mechanism 30...Drive scroll 31...Drive end plate 33...Driven spiral 34...Drive side base circle 40...Driven scroll 41…Driven end plate 43...Driven spiral 44...Driven side base circle 50...Compression chamber 60…Housing 62A…Thick wall part 62B…Thin wall general part (thin wall part) X1: Drive shaft center X2…driven shaft center MP…Middle point P1: First contact P2…Second contact VL...Virtual line LD: Load direction FR...Fluctuation range FX…Fixed axis center

Claims

1. a drive mechanism, a drive scroll, a driven mechanism, a driven scroll, and a cylindrical housing; the driving scroll is provided in the housing and is driven to rotate about a drive axis by a driving mechanism; the driven scroll is provided in the housing and is rotated by the driving scroll and the driven mechanism around a driven axis while being eccentric with respect to the driving scroll; The drive scroll has a drive end plate extending in a direction intersecting the drive axis, and a drive scroll protruding from the drive end plate toward the driven scroll and having a spiral shape, The driven scroll has a driven end plate extending in a direction intersecting the driven axis, and a driven scroll body protruding from the driven end plate toward the drive scroll and having a spiral shape, the drive mechanism includes an electric motor having a stator fixed to the housing and a rotor disposed within the stator and rotatable together with the drive scroll; In a double rotary scroll compressor, the driving scroll and the driven scroll face each other to form a compression chamber, and the volume of the compression chamber is changed by the rotation driving and the rotation driven, When a plane perpendicular to the drive shaft is assumed, a midpoint between a center of a driving-side base circle forming the driving scroll and a center of a driven-side base circle forming the driven scroll is defined as a point of application of a compressive load generated in a radial direction of the drive shaft center by rotation of the driving scroll and the driven scroll; The load direction of the compressive load is defined as a direction perpendicular to an imaginary line connecting a first contact point where the outer surface of the drive scroll and the inner surface of the driven scroll meet at the outermost periphery side, and a second contact point where the inner surface of the drive scroll and the outer surface of the driven scroll meet at the outermost periphery side, and When the range in which the load direction changes during one rotation of the driving scroll and the driven scroll is defined as the fluctuation range, the stator defines a fixed axis within the housing; the drive axis is determined by the rotor, and is set to be spaced apart from the fixed axis when the rotor is not in operation, and to be aligned with or approach the fixed axis when the rotor is in operation, in the load direction included in the fluctuation range.

2. the housing has a thin portion and a thick portion that is thicker than the thin portion in a circumferential direction of the fixed axis, 2. The double-rotary scroll compressor according to claim 1, wherein the thin-walled portion is provided so as to include the range of variation.

3. 3. A double-rotating scroll compressor according to claim 2, wherein said stator is fixed to said housing by interference fit.

4. the drive mechanism has an inverter circuit that drives the electric motor, 4. A double-rotary scroll compressor according to claim 2, wherein the inverter circuit is provided in the thick-walled portion.

5. 5. A double-rotating scroll compressor according to claim 1, wherein the driving scroll is built into the rotor.

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