Electric Compressor

Abstract

To improve the efficiency of a motor by sufficiently cooling a stator using refrigerant.SOLUTION: A motor compressor 100E includes a housing, a compressor, and a motor. The motor includes a stator 41 arranged inside the housing, and a rotor arranged on the inner periphery side of the stator 41. The stator 41 has a refrigerant flow path 46 formed therein to distribute the refrigerant from an inflow port 46d to an outflow port 46e. The refrigerant flow path 46 has: an inflow flow path part 46a formed on one end side along an axis line X so that a distance in a radial direction RD from the axis line X is gradually shorter from one end side to the other end side along the axis line X; and an outflow flow path part 46b formed on the other end side along the axis line X and communicating with the inflow flow path part 46a so that a distance in the radial direction RD from the axis line X is gradually shorter from the other end side to one end side.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present disclosure relates to an electric compressor. [Background technology]

[0002] In an electric compressor, a motor for driving a compression mechanism is built into a housing having a sealed structure together with the compression mechanism (see, for example, Patent Documents 1 and 2). Patent Document 1 discloses a structure in which an insertion hole for inserting a fastening bolt is formed in a stator, and the tip of the fastening bolt inserted into the insertion hole is fastened to a fastening hole formed in the housing to fix the stator to the housing. Patent Document 2 discloses that a refrigerant is circulated between the housing and the stator to suppress a rise in temperature of the stator. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-92889 A [Patent Document 2] JP 2017-99173 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the electric compressor disclosed in Patent Document 1, the length of the insertion hole formed in the stator to fix the stator to the housing is set to be the same as the overall length of the stator in the drive shaft direction of the motor (the motor stacking thickness). Therefore, if the overall length of the stator is increased to improve the output of the motor, the overall lengths of the insertion hole and the fastening bolts inserted into the insertion hole will also increase accordingly.

[0005] In this case, the contact position between the stator and the housing is at the end of the stator in the drive shaft direction, so the distance in the drive shaft direction between the contact position and the center of gravity of the motor becomes long. As a result, the moment acting on the motor due to vibration caused by the operation of the electric compressor and external forces acting on the electric compressor becomes larger according to the distance in the drive shaft direction between the contact position and the center of gravity of the motor. This increases the vibration generated in the electric compressor, making the fastening bolts more likely to loosen or break.

[0006] Furthermore, the electric compressor disclosed in Patent Document 2 suppresses temperature rise of the stator by circulating a refrigerant between the housing and the outer circumferential surface of the stator. However, since the area where the refrigerant flows is separated from the coil wound around the stator, the stator may not be sufficiently cooled by the refrigerant, resulting in reduced motor efficiency.

[0007] The present disclosure has been made in consideration of the above circumstances, and has an object to provide an electric compressor that is capable of sufficiently cooling the stator with a refrigerant to improve motor efficiency. [Means for solving the problem]

[0008] According to one aspect of the present disclosure, there is provided an electric compressor comprising: a housing formed in a cylindrical shape extending along an axis; a compressor disposed inside the housing and rotating about the axis to compress a refrigerant; and a motor that rotationally drives the compressor about the axis, wherein the motor comprises a stator disposed inside the housing; and a rotor disposed on an inner circumferential side of the stator, wherein a refrigerant flow path is formed inside the stator to circulate a refrigerant from an inlet provided at one end along the axis to an outlet provided at the other end along the axis, and the refrigerant flow path has: a first flow path portion formed at the one end along the axis and having a radial distance from the axis gradually shortened from the one end to the other end; and a second flow path portion formed at the other end along the axis, communicating with the first flow path portion, and having a radial distance from the axis gradually shortened from the other end to the one end. The inlet is provided near an outer circumferential surface of the stator, and the other end of the first flow passage portion and the one end of the second flow passage portion are formed in teeth of the stator around which a coil winding is wound. . Effect of the Invention

[0009] According to the present disclosure, it is possible to provide an electric compressor that is capable of sufficiently cooling the stator with a refrigerant to improve motor efficiency. [Brief description of the drawings]

[0010] [Figure 1] 1 is a partial vertical cross-sectional view showing an electric compressor according to a first embodiment of the present disclosure. [Diagram 2] 2 is a cross-sectional view taken along the line AA of the electric compressor shown in FIG. [Diagram 3] 2 is a cross-sectional view taken along the line BB of the electric compressor shown in FIG. 1. [Figure 4] FIG. 4 is a partial vertical sectional view showing an electric compressor of a comparative example. [Diagram 5] FIG. 4 is a partial vertical sectional view showing a modified electric compressor of the first embodiment. [Figure 6] FIG. 6 is a partial vertical cross-sectional view showing an electric compressor according to a second embodiment of the present disclosure. [Figure 7] 7 is a cross-sectional view taken along line EE of the electric compressor shown in FIG. 6. [Figure 8] FIG. 11 is a partial vertical cross-sectional view showing an electric compressor according to a third embodiment of the present disclosure. [Figure 9] FIG. 11 is a partial cross-sectional view showing an electric compressor according to a fourth embodiment of the present disclosure. [Figure 10] 10 is a cross-sectional view of the stator shown in FIG. 9 taken along the line GG. [Figure 11] 11 is a cross-sectional view of the stator shown in FIG. 10 taken along the arrow HH. [Figure 12] FIG. 13 is a partial cross-sectional view showing an electric compressor according to a first modified example of the fourth embodiment. [Figure 13] 13 is a cross-sectional view of the stator shown in FIG. 12 taken along the arrow JJ. [Figure 14] 14 is a cross-sectional view of the stator shown in FIG. 13 taken along the line KK. [Figure 15] FIG. 13 is a partial cross-sectional view showing an electric compressor according to a second modified example of the fourth embodiment. [Figure 16] 16 is a cross-sectional view of the stator shown in FIG. 15 taken along the arrow MM. [Figure 17] 17 is a cross-sectional view of the stator shown in FIG. 16 taken along the line NN. [Figure 18] FIG. 13 is a partial cross-sectional view showing an electric compressor according to a third modified example of the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] [First embodiment] Hereinafter, an electric compressor 100 according to a first embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a partial vertical cross-sectional view showing the electric compressor according to this embodiment. Fig. 2 is a cross-sectional view taken along line AA of the electric compressor 100 shown in Fig. 1. Fig. 3 is a cross-sectional view taken along line BB of the electric compressor 100 shown in Fig. 1. The cross-sectional view shown in Fig. 1 corresponds to a cross-sectional view taken along line CC of Fig. 2. Similarly, the cross-sectional view shown in Fig. 1 corresponds to a cross-sectional view taken along line DD of Fig. 3.

[0012] The electric compressor 100 of this embodiment is a device that compresses a refrigerant (fluid) sucked through a suction port P1 and discharges the refrigerant from a discharge port P2 to the outside. As shown in Fig. 1, the electric compressor 100 of this embodiment includes a housing 10, an end housing (sealing member) 20, a compressor 30, a motor 40, a fastening bolt 50, a first bearing 60, a second bearing 70, a retaining portion 80, and an inverter 90.

[0013] The housing 10 is a member formed in a substantially cylindrical shape extending along the axis X, and accommodates the compressor 30 and the motor 40 therein. The housing 10 is formed of a metal material such as an aluminum alloy. The housing 10 has an opening 11 sealed by the end housing 20 at an end on the end housing 20 side in the direction of the axis X.

[0014] 1, a suction port P1 is provided on the outer peripheral surface of the housing 10 near the bottom 12. The refrigerant supplied from the outside is introduced into the housing 10 from the suction port P1. The refrigerant introduced into the housing 10 flows along the axis X from the bottom 12 toward the opening 11.

[0015] The end housing 20 is a member that seals the opening 11 of the housing 10 when the compressor 30 and the motor 40 are inserted into the housing 10 through the opening 11. The end housing 20 is fixed to the housing 10 by fastening fastening bolts 21 into fastening holes (not shown) formed in the opening 11 of the housing 10. The opening 11, which is located at the end of the housing 10 on the compressor 30 side along the axis X, is sealed by the end housing 20.

[0016] The compressor 30 is a device that is disposed inside the housing 10 and rotates about the axis X to compress a fluid. The compressor 30 includes, for example, a scroll compression mechanism that compresses a refrigerant by causing an orbiting scroll (not shown) combined with a fixed scroll (not shown) fixed to the housing 10 to make an orbital motion about the axis X.

[0017] The compressor 30 sucks in and compresses the refrigerant introduced into the housing 10 from the suction port P1, and guides the compressed refrigerant to a discharge port P2 provided in the end housing 20. The refrigerant guided to the discharge port P2 is supplied to the outside via a pipe (not shown) connected to the discharge port P2.

[0018] The motor 40 is a device that drives the compressor 30 to rotate about the axis X. The motor 40 has a stator 41, a rotor 42, a drive shaft 43, and a bobbin 44 and a bobbin 45.

[0019] Stator 41 is formed by laminating a predetermined number of electromagnetic steel sheets that have been punched into an annular shape. As shown in Figures 2 and 3, a plurality of teeth 41a are provided on the inner periphery of stator 41. Coil windings (not shown) are wound around each of the plurality of teeth 41a of stator 41 via bobbins 44 and 45.

[0020] As shown in Fig. 1, the stator 41 is disposed inside the housing 10 and has a length L1 (first length) along the axis X from a position X1 at an end on the bottom 12 side to a position X2 at an end on the compressor 30 side. The stator 41 has a plurality of positioning portions 41b having a length L2 (second length) along the axis X that is shorter than the length L1. The positioning portions 41b are portions that have insertion holes 41b1 into which fastening bolts 50 are inserted. As shown in Fig. 2, the positioning portions 41b are disposed at a plurality of locations along a circumferential direction CD about the axis X.

[0021] 1 and 3, a plurality of grooves 41c extending along the axis X are formed on the outer peripheral surface of the stator 41 at positions in the circumferential direction CD where the plurality of positioning portions 41b are arranged. A plurality of protrusions 15 received in the plurality of grooves 41c and extending along the axis X are formed on the inner peripheral surface of the housing 10 at positions in the circumferential direction CD where the plurality of grooves 41c are arranged.

[0022] A space through which the refrigerant flows is provided between the inner peripheral surface of the housing 10 and the outer peripheral surface of the stator 41. When the refrigerant passes through this space, the heat of the stator 41 is transferred to the refrigerant via the outer peripheral surface of the stator 41, thereby cooling the stator 41. Here, in order to improve the heat transfer characteristics of the stator 41, an uneven shape may be provided on the outer peripheral surface of the stator 41 on which the groove portion 41c is formed. By providing the uneven shape, the contact area of ​​the stator 41 and the refrigerant is increased, and the efficiency of cooling the stator 41 by the refrigerant can be improved.

[0023] 1 and 3, a fastening hole 51 into which a fastening bolt 50 is fastened is formed in the end face of the protruding portion 15 of the housing 10 on the compressor 30 side. The end face of the protruding portion 15 of the housing 10 on the compressor 30 side is an end face that faces the end face of the positioning portion 41b on the bottom 12 side. The fastening hole 51 is formed in the end face of the protruding portion 15 that faces the positioning portion 41b.

[0024] The stator 41 is fixed inside the housing 10 by fastening fastening bolts 50, which are inserted into insertion holes 41b1 formed in the positioning portions 41b, to fastening holes 51. The multiple fastening bolts 50 fix the stator 41 of the motor 40 inside the housing 10 at multiple points in the circumferential direction CD.

[0025] The rotor 42 is disposed with a predetermined gap provided on the inner peripheral side of the stator 41. The rotor 42 is formed by laminating a predetermined number of electromagnetic steel sheets that are punched and formed into an annular shape.

[0026] The drive shaft 43 is inserted into a through hole formed in the center of the rotor 42, connected to the rotor 42, and is a member disposed on the axis X. The drive shaft 43 rotates integrally with the rotor 42 about the axis X, and transmits a driving force for rotating about the axis X to the compressor 30. An end of the drive shaft 43 on the opening 11 side is supported by a first bearing 60 so as to be rotatable about the axis X. An end of the drive shaft 43 on the bottom 12 side is supported by a second bearing 70 so as to be rotatable about the axis X.

[0027] The retaining portion 80 is a member that is fixed to the housing 10 and retains the first bearing 60. An end face of the retaining portion 80 on the bottom 12 side contacts the step portion 13 of the housing 10, and an end face on the opening 11 side contacts the compressor 30. By fixing the end housing 20 to the housing 10, the retaining portion 80 is sandwiched between the housing 10 and the compressor 30, and its position in the direction of the axis X is fixed.

[0028] The inverter 90 is a device that converts DC power supplied from an external power source into AC power and applies the AC power to the motor 40 to rotate the motor 40. The inverter 90 is disposed in a space isolated from the sealed space formed inside the housing 10.

[0029] Next, the moment acting on the motor 40 due to vibrations caused by the operation of the electric compressor 100 and external forces acting on the electric compressor 100 will be described with reference to a comparative example. Fig. 4 is a partial vertical cross-sectional view showing an electric compressor 100A of the comparative example. In the electric compressor 100A of the comparative example, the length of an insertion hole 41b1 formed in the stator 41 for fixing the stator 41 to the housing 10 is set to a length L1 that is the same as the overall length of the stator 41 in the direction along the axis X of the motor 40.

[0030] 1 and 4, the center of gravity of the motor 40 in the direction of the axis X is position Xg. In the electric compressor 100 of this embodiment, the contact position where the housing 10 and the positioning portion 41b of the stator 41 contact each other coincides with position Xg on the axis X. On the other hand, in the electric compressor 100A of the comparative example, the contact position where the housing 10 and the stator 41 contact each other is position X1 where the end of the stator 41 on the bottom 12 side is disposed.

[0031] In the electric compressor 100A of the comparative example, the contact position X1 where the housing 10 and the stator 41 contact each other is spaced from the position X1 where the housing 10 and the stator 41 contact each other by a length L3 to the position Xg where the center of gravity is located. On the other hand, in the electric compressor 100 of this embodiment, the contact position where the housing 10 and the stator 41 contact each other coincides with the position Xg where the center of gravity is located. That is, in the electric compressor 100 of this embodiment, the distance from the contact position where the housing 10 and the stator 41 contact each other to the center of gravity is shorter than in the electric compressor 100A of the comparative example.

[0032] According to the electric compressor 100 of this embodiment, the vibration caused by the operation of the electric compressor 100 and the moment acting on the motor 40 due to an external force acting on the electric compressor 100 are smaller than when the position of the stator 41 in the housing 10 is the position of the end face along the axis X of the stator 41. Therefore, it is possible to provide an electric compressor 100 that can suppress the occurrence of vibration and the loosening or breakage of the fastening bolts that fasten the stator 41 to the housing 10.

[0033] In the electric compressor 100 of the present embodiment, the contact position where the housing 10 and the stator 41 contact each other coincides with the position Xg, which is the center of gravity, but other configurations are also possible. For example, the contact position where the housing 10 and the stator 41 contact each other does not have to coincide with the position Xg as long as it is a position closer to the center of gravity of the motor 40 than the position of the end face of the stator 41 along the axis X.

[0034] Fig. 5 is a partial cross-sectional view showing an electric compressor 100B according to a modified example of the present embodiment. In the electric compressor 100B shown in Fig. 5, the contact position between the housing 10 and the stator 41 is set to a position X3 closer to the position Xg, which is the center of gravity of the motor 40, than to a position X2 of the end face of the stator 41 along the axis X.

[0035] 5, the stator 41 is disposed inside the housing 10 and has a length L1 along the axis X from a position X1 at an end on the bottom 12 side to a position X2 at an end on the compressor 30 side. The stator 41 has a plurality of positioning portions 41b having a length L2 along the axis X that is shorter than the length L1.

[0036] 5, the positioning portion 41b is provided at an end of the stator 41 close to the compressor 30 in the direction along the axis X. In the electric compressor 100B, the contact position between the housing 10 and the stator 41 is separated by a length L4 from the position Xg, which is the center of gravity. The length L4 is shorter than the length L3.

[0037] Next, the positions of the fastening holes 51 formed in the housing 10 of the electric compressor 100 will be described. As shown in Fig. 1, in the electric compressor 100 of this embodiment, the length from the opening 11 of the housing 10 to the contact position where the stator 41 and the housing 10 contact each other is a length L5. On the other hand, as shown in Fig. 4, in the electric compressor 100A of the comparative example, the length from the opening 11 of the housing 10 to the contact position where the stator 41 and the housing 10 contact each other is a length L6 that is longer than the length L5.

[0038] When forming fastening holes 51 in the end face of housing 10 with which stator 41 contacts, it is necessary to insert the tip of a tool from opening 11 and abut against the end face of housing 10. In electric compressor 100 of this embodiment, the length from opening 11 to the contact position where stator 41 and housing 10 contact each other is shorter than in electric compressor 100A of the comparative example. This improves the workability when inserting a tool from opening 11 of housing 10 to form fastening holes 51 in housing 10.

[0039] 5, the length from the opening 11 of the housing 10 to the contact position where the stator 41 and the housing 10 contact each other is length L7, which is shorter than length L5. In the electric compressor 100B of the modified example, the length from the opening 11 to the contact position where the stator 41 and the housing 10 contact each other is even shorter than in the electric compressor 100 of this embodiment. This further improves the ease of processing when inserting a tool through the opening 11 of the housing 10 to form the fastening holes 51 in the housing 10.

[0040] The electric compressor 100 of the present embodiment described above provides the following functions and effects. In the electric compressor 100 according to this embodiment, fastening bolts 50 are inserted into insertion holes 41b1 formed in a plurality of positioning portions 41b of the stator 41, and fastened to fastening holes 51 formed in the housing 10. A length L2 of the positioning portions 41b of the stator 41 along the axis X is shorter than a length L1 which is the entire length of the stator 41. Therefore, the contact position where the housing 10 and the positioning portions 41b come into contact with each other is closer to the center of gravity of the motor than the position of the end face of the stator 41 along the axis X.

[0041] This reduces the vibration caused by the operation of the electric compressor and the moment acting on the motor due to external forces acting on the electric compressor, compared to when the position of the stator relative to the housing or another member is the position of the end face along the axis of the stator. Therefore, it is possible to provide an electric compressor that can suppress the generation of vibration and the loosening or damage of the fastening bolts that fasten the stator to the housing.

[0042] Moreover, according to the electric compressor 100 of this embodiment, a plurality of protrusions 15 protruding from the inner peripheral surface of the housing 10 are accommodated in a plurality of grooves 41c formed on the outer peripheral surface of the stator 41, and fastening bolts 50 inserted into positioning portions 41b of the stator 41 are fastened to fastening holes 51 formed on end surfaces of the protrusions 15. Since the positioning portions 41b are shaped not to protrude from the outer peripheral surface of the stator 41, it is possible to suppress the occurrence of vibration and the loosening or breakage of the fastening bolts 50 without increasing the outer diameter of the electric compressor 100. Furthermore, since the protrusions 15 of the housing 10 are accommodated in the grooves 41c of the stator 41, it is possible to appropriately restrict the rotation of the motor 40 in the circumferential direction CD relative to the housing 10.

[0043] Furthermore, according to the electric compressor 100 of this embodiment, the positioning portion 41b is provided at an end portion of the stator 41 that is close to the compressor 30 in the direction along the axis X. Therefore, compared to a case where the stator 41 is positioned in the housing at an end portion of the stator 41 that is remote from the compressor 30, the distance along the axis X from the opening 11 of the housing to the position where the fastening hole 51 is formed can be shortened. Therefore, the workability is improved when a tool is inserted through the opening 11 of the housing 10 to form the fastening hole 51 in the housing 10.

[0044] Furthermore, according to the electric compressor 100 of this embodiment, the end face of the positioning portion 41b is fixed to the housing 10 in the vicinity of the center of gravity of the motor 40. Therefore, it is possible to reduce the moment acting on the motor 40 due to vibrations caused by the operation of the electric compressor 100 and external forces acting on the electric compressor 100.

[0045] Second Embodiment Next, an electric compressor 100C according to a second embodiment of the present disclosure will be described with reference to the drawings. Fig. 6 is a partial vertical cross-sectional view showing the electric compressor 100C according to this embodiment. Fig. 7 is a cross-sectional view taken along the line EE of the electric compressor 100C shown in Fig. 6. This embodiment is a modified example of the first embodiment, and is the same as the first embodiment except as otherwise specifically described below, and therefore further description will be omitted.

[0046] In the electric compressors 100 and 100B of the first embodiment, the protruding portion 15 of the housing 10 is housed in a groove portion 41c formed in the outer peripheral surface of the stator 41, and fastening holes 51 are formed in the end surface of the protruding portion 15. In contrast, in the electric compressor 100C of the present embodiment, the fastening holes 51 are formed in a step portion 14 of the housing 10 that faces a positioning portion 41b protruding from the outer peripheral surface of the stator 41.

[0047] 6, the stator 41 is disposed inside the housing 10 and has a length L1 along the axis X from a position X1 at an end on the bottom 12 side to a position X2 at an end on the compressor 30 side. The stator 41 has a plurality of positioning portions 41b having a length L2 along the axis X that is shorter than the length L1.

[0048] 6, the positioning portion 41b is provided at an end of the stator 41 close to the compressor 30 in the direction along the axis X. In the electric compressor 100C, the contact position between the housing 10 and the stator 41 is separated by a length L4 from the position Xg, which is the center of gravity. The length L4 is shorter than the length L3.

[0049] 6 and 7, in the electric compressor 100C of this embodiment, the positioning portion 41b protrudes from the outer peripheral surface of the stator 41. A step portion 14 is formed on the inner peripheral surface of the housing 10, connecting a first region R1 having a first inner diameter ID1 larger than the outer diameter of the positioning portion 41b and a second region R2 having a second inner diameter ID2 smaller than the outer diameter of the positioning portion 41b. A fastening hole 51 is formed in an end face of the step portion 14 facing the positioning portion 41b.

[0050] According to the electric compressor 100C of this embodiment, the positioning portion 41b protrudes from the outer peripheral surface of the stator 41, and the fastening bolt 50 inserted into the positioning portion 41b of the stator 41 is fastened to the fastening hole 51 formed in the end surface of the step portion 14 of the housing 10. Because the positioning portion 41b has a shape that protrudes from the outer peripheral surface of the stator 41, it is possible to suppress the occurrence of vibration and the loosening or breakage of the fastening bolt 50 that fastens the stator 41 to the housing 10 without weakening the magnetic force of the stator 41.

[0051] Third Embodiment Next, an electric compressor 100D according to a third embodiment of the present disclosure will be described with reference to the drawings. Fig. 8 is a partial vertical cross-sectional view showing the electric compressor 100D according to this embodiment. This embodiment is a modification of the first embodiment, and is the same as the first embodiment except as otherwise specifically described below, and therefore the description below will be omitted.

[0052] In the electric compressors 100 and 100B of the first embodiment and the electric compressor 100C of the second embodiment, the fastening holes 51 are formed in the housing 10. In contrast, in the electric compressor 100D of the present embodiment, the fastening holes 51 are formed in a member other than the housing 10.

[0053] 8, in the electric compressor 100D of the present embodiment, the fastening hole 51 is formed in the holding portion 80 which is a member different from the housing 10. The fastening hole 51 is formed in an end surface of the holding portion 80 facing the positioning portion 41b.

[0054] According to the electric compressor 100D of the present embodiment, the first bearing 60 supporting the drive shaft 43 connected to the rotor 42 is held by the holding portion 80, and the fastening holes 51 are formed in an end surface of the holding portion 80 facing the positioning portion 41b. The fastening holes 51 can be formed in advance in the holding portion 80 before it is fixed to the housing 10. Therefore, compared to the case where the fastening holes 51 are formed by inserting a tool into the housing 10, the workability in forming the fastening holes 51 is improved.

[0055] [Fourth embodiment] Next, an electric compressor 100E according to a fourth embodiment of the present disclosure will be described with reference to the drawings. Fig. 9 is a partial cross-sectional view showing the electric compressor 100E according to this embodiment. Fig. 10 is a cross-sectional view taken along the line GG of the stator 41 shown in Fig. 9. Fig. 11 is a cross-sectional view taken along the line HH of the stator 41 shown in Fig. 10. Fig. 9 is a cross-sectional view taken along the line II of Fig. 10.

[0056] This embodiment is a modified example of the first embodiment, and is the same as the first embodiment except where specifically described below, and therefore the description below will be omitted.

[0057] 9 to 11, a refrigerant flow path 46 for circulating a refrigerant is formed inside the stator 41 of the electric compressor 100E of this embodiment. The refrigerant flow path 46 is a flow path for circulating the refrigerant from an inlet 46d provided at one end side along the axis X (the bottom 12 side of the housing 10) to an outlet 46e provided at the other end side along the axis X (the opening 11 side of the housing 10).

[0058] 9 and 11, the inlet 46d is provided near the outer circumferential surface of the stator 41, which is closer to the housing 10 in the radial direction RD than the rotor 42. The flow rate of the refrigerant that has flowed into the housing 10 is greater on the outer circumferential side closer to the housing 10 than on the inner circumferential side in the radial direction RD. By providing the inlet 46d near the outer circumferential surface of the stator 41, the flow rate of the refrigerant flowing into the inlet 46d can be increased.

[0059] 10 and 11, the refrigerant flow path 46 has an inlet flow path portion (first flow path portion) 46a, an outlet flow path portion (second flow path portion) 46b, and a communicating flow path portion 46c. The inlet flow path portion 46a is formed on the inlet 46d side along the axis X, and is a flow path whose distance in the radial direction RD from the axis X gradually decreases from the inlet 46d to the outlet 46e.

[0060] The outlet flow passage portion 46b is a flow passage formed on the outlet port 46e side along the axis X, and the distance in the radial direction RD from the axis X gradually decreases from the outlet port 46e toward the inlet port 46d. The communicating flow passage portion 46c is a flow passage that communicates the inlet flow passage portion 46a and the outlet flow passage portion 46b, and is a flow passage in which the distance in the radial direction RD from the axis X is constant at each position along the axis X. The communicating flow passage portion 46c circulates the refrigerant on the inner peripheral side of the stator 41 (the side closer to the axis X) than the inlet flow passage portion 46a and the outlet flow passage portion 46b.

[0061] In the electric compressor 100E of this embodiment, the refrigerant flow passage 46 formed inside the stator 41 has an inflow flow passage portion 46a whose distance in the radial direction RD from the axis X gradually decreases from the inlet 46d to the outlet 46e, and an outflow flow passage portion 46b whose distance in the radial direction RD from the axis X gradually decreases from the outlet 46e to the inlet 46d. The refrigerant that flows in from the inlet 46d is guided from the outer periphery side to the inner periphery side in the radial direction RD by the inflow flow passage portion 46a.

[0062] Therefore, compared to the case where the refrigerant flows on the outer periphery side in the radial direction RD, it is possible to improve the cooling efficiency of the heating region on the inner periphery side of the stator 41. Also, the refrigerant guided to the inner periphery side in the radial direction RD can be guided from the inner periphery side to the outer periphery side in the radial direction RD by the outflow passage portion 46b. Therefore, it is possible to provide the electric compressor 100E that can sufficiently cool the stator 41 with the refrigerant and improve the motor efficiency.

[0063] The refrigerant flow path 46 of the electric compressor 100E described above is a flow path that extends linearly along the axis X and circulates through the same position in the circumferential direction CD about the axis X, but may be in other forms. For example, like the electric compressor 100F of the first modified example of this embodiment, the refrigerant flow path 46 may have a swirling flow path portion 46f that swirls in the circumferential direction CD.

[0064] Fig. 12 is a partial cross-sectional view showing an electric compressor 100F according to a first modified example of the present embodiment. Fig. 13 is a cross-sectional view taken along the line JJ of the stator 41 shown in Fig. 12. Fig. 14 is a cross-sectional view taken along the line KK of the stator 41 shown in Fig. 13. Fig. 12 is a cross-sectional view taken along the line LL of Fig. 13.

[0065] As shown in Figures 12 to 14, the refrigerant flow path 46 formed inside the stator 41 of the electric compressor 100F of the first modified example is a flow path that allows the refrigerant to flow from an inlet 46d provided at one end side along the axis X (the bottom 12 side of the housing 10) to an outlet 46e provided at the other end side along the axis X (the opening 11 side of the housing 10).

[0066] 13 and 14, the refrigerant flow path 46 has an inflow flow path portion (first flow path portion) 46a, an outflow flow path portion (second flow path portion) 46b, and a swirling flow path portion (third flow path portion) 46f. The inflow flow path portion 46a is formed closer to the inlet 46d along the axis X than the outflow flow path portion 46b, and the distance in the radial direction RD from the axis X gradually decreases from the inlet 46d to the outlet 46e.

[0067] The outlet flow passage portion 46b is formed closer to the outlet port 46e along the axis X than the inlet flow passage portion 46a, and the distance in the radial direction RD from the axis X to the inlet port 46d gradually decreases from the outlet port 46e.

[0068] The swirling passage portion 46f is a passage that is connected to the inlet 46d, swirls from the inlet 46d side toward the outlet 46e side in the circumferential direction CD about the axis line X, and communicates with the inlet passage portion 46a. As shown in Fig. 14, the distance of the swirling passage portion 46f from the axis line X in the radial direction RD is constant at each position along the axis line X.

[0069] According to the electric compressor 100F of the present embodiment, even if the inlet 46d is disposed at a position different from the positions at which the inlet passage portion 46a and the outlet passage portion 46b are disposed in the circumferential direction CD about the axis X, the refrigerant flowing in from the inlet 46d can be guided to the inlet passage portion 46a and then to the outlet 46e via the outlet passage portion 46b. For example, when the refrigerant with the lowest temperature flows between the teeth 41a of the stator 41, the refrigerant with the lowest temperature can be taken in from the inlet 46d and guided to the refrigerant passage formed in the teeth 41a.

[0070] The refrigerant flow path 46 of the electric compressor 100F of the first modified example described above has the swirl flow path portion 46f that swirls in only one direction, the circumferential direction CD, but may have other configurations. For example, like the refrigerant flow path 46 of the electric compressor 100G of the second modified example, the refrigerant flow path 46 may have a branch flow path portion 46g that branches so as to swirl in only two directions, the circumferential direction CD.

[0071] Fig. 15 is a partial cross-sectional view showing an electric compressor 100G according to a second modified example of the present embodiment. Fig. 16 is a cross-sectional view taken along the line MM of the stator 41 shown in Fig. 15. Fig. 17 is a cross-sectional view taken along the line NN of the stator 41 shown in Fig. 14. Fig. 15 is a cross-sectional view taken along the line OO of Fig. 14.

[0072] 15 to 17, a refrigerant flow path 46 formed inside a stator 41 of an electric compressor 100G of the second modified example is a flow path that circulates a refrigerant from an inlet 46d provided at one end side (the bottom 12 side of the housing 10) along the axis X to an outlet 46e provided at the other end side (the opening 11 side of the housing 10) along the axis X. The refrigerant flow path 46 shown in Fig. 16 branches the refrigerant flowing in from one inlet 46d to two outlets 46e and flows out.

[0073] 16 and 17, the refrigerant flow path 46 has an inflow flow path portion (first flow path portion) 46a, an outflow flow path portion (second flow path portion) 46b, and a branch flow path portion (third flow path portion) 46g. The inflow flow path portion 46a is formed closer to the inlet 46d along the axis X than the outflow flow path portion 46b, and the distance in the radial direction RD from the axis X gradually decreases from the inlet 46d to the outlet 46e.

[0074] The outlet flow passage portion 46b is formed closer to the outlet port 46e along the axis X than the inlet flow passage portion 46a, and the distance in the radial direction RD from the axis X to the inlet port 46d gradually decreases from the outlet port 46e.

[0075] The branch flow passage portion 46g is a flow passage that is connected to the inlet 46d, turns in the circumferential direction CD about the axis line X from the inlet 46d side toward the outlet 46e side, and communicates with the two inlet flow passage portions 46a. As shown in Fig. 17, the branch flow passage portion 46g has a constant distance from the axis line X in the radial direction RD at each position along the axis line X. The branch flow passage portion 46g branches the refrigerant that has flowed in from the inlet 46d into a first branch flow passage 46g1 on one side in the circumferential direction CD and a second branch flow passage 46g2 on the other side in the circumferential direction CD.

[0076] According to the electric compressor 100G of this embodiment, even if there are few locations where the inlet 46d is provided, the refrigerant flowing in from the inlet 46d can be branched into the first branch flow path 46g1 and the second branch flow path 46g2, thereby appropriately cooling different areas of the stator 41 in the circumferential direction CD.

[0077] In the electric compressor of the present embodiment described above, the cross-sectional shape of the refrigerant flow path 46 perpendicular to the axis X is circular as shown in Fig. 9, but other shapes are also possible. For example, the cross-sectional shape of the refrigerant flow path 46 perpendicular to the axis X may be other shapes such as a rectangle other than a circle.

[0078] Fig. 18 is a partial cross-sectional view showing an electric compressor 100H according to a third modified example of the fourth embodiment. As shown in Fig. 18, the cross-sectional shape perpendicular to the axis X of the refrigerant flow passage 46 formed in the stator 41 of the electric compressor 100H according to the third modified example is a triangular shape in which the circumferential flow passage width is narrower on the inner peripheral side than on the outer peripheral side in the radial direction.

[0079] The cross-sectional shape of the coolant flow passage 46 perpendicular to the axis X may be a shape other than a triangular shape. For example, a shape having a rectangular outer periphery and a semicircular inner periphery may be adopted. In addition, it is preferable that the circumferential flow passage width is narrower on the inner periphery side than on the outer periphery side in the radial direction. By making the flow passage width on the inner periphery side of the coolant flow passage 46 narrower than the flow passage width on the outer periphery side, it is possible to suppress a decrease in the magnetic flux density in the iron core of the stator 41 compared to when the flow passage widths on the inner periphery side and the outer periphery side are the same.

[0080] The electric compressor according to the present embodiment described above can be understood, for example, as follows. The electric compressor (100) according to the present disclosure includes a housing (10) formed in a cylindrical shape extending along an axis (X), a compressor (30) disposed inside the housing and rotating about the axis to compress a fluid, a motor (40) that rotationally drives the compressor about the axis, and a plurality of fastening bolts (50) that fix the motor inside the housing, and the motor includes a stator (41) disposed inside the housing and having a first length (L1) along the axis, and a plurality of fastening bolts (50) disposed on the inner peripheral side of the stator. and a rotor (42), the stator has a plurality of positioning portions (41b) that are arranged along a circumferential direction (CD) about the axis and have a second length (L2) along the axis that is shorter than the first length, and fastening holes (51) into which the fastening bolts are fastened are formed in the housing or another member (80) fixed to the housing, and the stator is fixed inside the housing by fastening the fastening bolts, which are inserted into insertion holes (41b1) formed in the positioning portions, to the fastening holes.

[0081] In the electric compressor according to the present disclosure, the stator is fastened to a fastening hole formed in a housing or another member fixed to the housing by inserting a fastening bolt into an insertion hole formed in a plurality of positioning portions of the stator. The second length of the positioning portions of the stator along the axis is shorter than the first length, which is the entire length of the stator. Therefore, the contact position where the positioning portions come into contact with the housing or another member is closer to the center of gravity of the motor than the position of the end face along the axis of the stator.

[0082] This reduces the vibration caused by the operation of the electric compressor and the moment acting on the motor due to external forces acting on the electric compressor, compared to when the position of the stator relative to the housing or another member is the position of the end face along the axis of the stator. Therefore, it is possible to provide an electric compressor that can suppress the generation of vibration and the loosening or damage of the fastening bolts that fasten the stator to the housing.

[0083] In the electric compressor of the present disclosure, a configuration may be adopted in which a plurality of groove portions (41c) extending along the axis (X) are formed on the outer peripheral surface of the stator at each position in the circumferential direction (CD) where the plurality of positioning portions are arranged, a plurality of protrusion portions (15) accommodated in the plurality of groove portions and extending along the axis are formed on the inner peripheral surface of the housing, and the fastening holes are formed in the end faces of the protrusions that face the positioning portions.

[0084] According to the electric compressor of this configuration, a plurality of protrusions protruding from the inner peripheral surface of the housing are accommodated in a plurality of grooves formed in the outer peripheral surface of the stator, and fastening bolts inserted into the positioning portions of the stator are fastened to fastening holes formed in the end faces of the protrusions. Because the positioning portions are shaped not to protrude from the outer peripheral surface of the stator, it is possible to suppress the generation of vibrations and the loosening or breakage of the fastening bolts fastening the stator to the housing without increasing the outer diameter of the electric compressor. In addition, because the protrusions of the housing are accommodated in the grooves of the stator, it is possible to appropriately restrict the circumferential rotation of the motor relative to the housing.

[0085] In the electric compressor of the present disclosure, the positioning portion protrudes from the outer peripheral surface of the stator, and a step portion (14) is formed on the inner peripheral surface of the housing, connecting a first region (R1) having a first inner diameter (ID1) larger than the outer diameter of the positioning portion and a second region (R2) having a second inner diameter (ID2) smaller than the outer diameter of the positioning portion, and the fastening hole may be formed in an end face of the step portion facing the positioning portion.

[0086] In the electric compressor having this configuration, the positioning portion protrudes from the outer circumferential surface of the stator, and the fastening bolt inserted into the positioning portion of the stator is fastened to the fastening hole formed in the end face of the step portion of the housing. Because the positioning portion protrudes from the outer circumferential surface of the stator, it is possible to suppress the generation of vibration and the loosening or damage of the fastening bolt that fastens the stator to the housing without weakening the magnetic force of the stator.

[0087] In the electric compressor having the above configuration, the housing may have an opening (11) sealed by a sealing member (20) at an end portion on the compressor side along the axis (X), and the positioning portion may be provided at an end portion of the stator adjacent to the compressor in a direction along the axis.

[0088] In the electric compressor having this configuration, the positioning portion is provided at the end of the stator that is close to the compressor in the axial direction. Therefore, the distance along the axis from the opening of the housing to the position where the fastening hole is formed can be shortened compared to when the stator is positioned in the housing at the end of the stator that is remote from the compressor. Therefore, the workability is improved when inserting a tool through the opening of the housing to form the fastening hole in the housing.

[0089] In the electric compressor having the aforementioned configuration, an end surface of the positioning portion fixed to the housing may be arranged in the vicinity of a center of gravity of the motor in a direction along the axis. In the electric compressor having this configuration, the end face of the positioning part is fixed to the housing or another member near the center of gravity of the motor, which makes it possible to reduce the moment acting on the motor due to vibrations caused by the operation of the electric compressor or external forces acting on the electric compressor.

[0090] In the electric compressor of the present disclosure, the motor may have a drive shaft (43) connected to the rotor and arranged on the axis, and a bearing (60, 70) supporting the drive shaft for free rotation, and the other member may be a retaining portion (80) fixed to the housing and holding the bearing, and the fastening hole may be formed in an end face of the retaining portion facing the positioning portion.

[0091] In the electric compressor having this configuration, the bearing that supports the drive shaft connected to the rotor is held by the holding portion, and the fastening hole is formed in the end face of the holding portion that faces the positioning portion. The fastening hole can be formed in advance in the holding portion before it is fixed to the housing. Therefore, compared to the case where the fastening hole is formed by inserting a tool into the housing, the workability in forming the fastening hole is improved.

[0092] The electric compressor according to the present disclosure includes a housing formed in a cylindrical shape extending along an axis, a compressor disposed inside the housing and rotating about the axis to compress a refrigerant, and a motor that rotates the compressor about the axis, the motor including a stator disposed inside the housing and a rotor disposed on an inner circumferential side of the stator, a refrigerant flow path is formed inside the stator to circulate a refrigerant from an inlet (46d) provided at one end along the axis to an outlet (46e) provided at the other end along the axis, the refrigerant flow path including a first flow path portion (46a) formed at the one end along the axis and having a radial distance from the axis gradually shortened from the one end to the other end, and a second flow path portion (46b) formed at the other end along the axis, connected to the first flow path portion, and having a radial distance from the axis gradually shortened from the other end to the one end.

[0093] According to the electric compressor of the present disclosure, the refrigerant flow passage formed inside the stator has a first flow passage portion in which the radial distance from the axis gradually decreases from one end side to the other end side, and a second flow passage portion in which the radial distance from the axis gradually decreases from the other end side to the one end side. The refrigerant flowing in from the inlet is guided from the outer circumferential side to the inner circumferential side in the radial direction by the first flow passage portion. Therefore, compared to the case where the refrigerant is circulated on the outer circumferential side in the radial direction, the cooling efficiency of the heating region on the inner circumferential side of the stator can be improved. In addition, the refrigerant guided to the inner circumferential side in the radial direction can be guided from the inner circumferential side to the outer circumferential side in the radial direction by the second flow passage portion. Therefore, it is possible to provide an electric compressor that can sufficiently cool the stator with the refrigerant and improve motor efficiency.

[0094] In the electric compressor according to the present disclosure, the refrigerant flow path may be configured to have a third flow path (46f, 46g) that is connected to the inlet, rotates circumferentially about the axis from the one end side to the other end side, and communicates with the first flow path portion. According to the electric compressor of this configuration, even if the inlet is disposed at a position different from the positions at which the first and second flow passages are disposed in the circumferential direction about the axis, the refrigerant flowing in from the inlet can be guided to the first flow passage and then to the outlet via the second flow passage. For example, when the refrigerant with the lowest temperature flows between the teeth of the stator, the refrigerant with the lowest temperature can be taken in from the inlet and guided to the refrigerant flow passages formed in the teeth.

[0095] In the electric compressor having the above configuration, the third flow path may be configured to branch the refrigerant flowing in from the inlet into a first branch flow path (46g1) on one side in the circumferential direction and a second branch flow path (46g2) on the other side. According to the electric compressor of this configuration, even if there are only a few locations where inlets are provided, the refrigerant flowing in from the inlet can be branched into the first branch flow path and the second branch flow path, thereby appropriately cooling different circumferential areas of the stator.

[0096] In the electric compressor according to the present disclosure, the inlet may be provided in the vicinity of an outer circumferential surface of the stator. In the electric compressor of this configuration, the inlet is located near the outer peripheral surface of the stator, so that sufficient refrigerant can be taken in from near the outer peripheral surface of the stator, where a large amount of refrigerant flows, into the inlet, and the inner peripheral area of ​​the stator can be reliably cooled.

[0097] In the electric compressor according to the present disclosure, a cross-sectional shape of the refrigerant flow path perpendicular to the axis may be configured such that a flow path width in the circumferential direction is narrower on an inner peripheral side than on an outer peripheral side in the radial direction. In the electric compressor having this configuration, the flow passage width on the inner circumference side of the refrigerant flow passage is narrower than the flow passage width on the outer circumference side, so that the reduction in magnetic flux density of the stator can be suppressed compared to when the flow passage widths on both sides are the same. [Explanation of symbols]

[0098] 10. Housing 11 Opening 12 Bottom 13,14 Stepped section 15 Protrusion 20 End housing 21 Fastening bolt 30 Compressor 40 Motor 41 Stator 41a Teeth 41b Positioning part 41b1 Insertion hole 41c Groove 42 Rotor 43 Drive shaft 44,45 Bobbin 46 Coolant flow path 46a Inlet passage section 46b Outlet passage section 46c Connecting passage section 46d Inlet 46e Outlet 46f Swirling flow path section 46g Branch flow passage section 46g1 First branch flow path 46g2 Second branch flow path 50 Fastening bolt 51 Fastening holes 60 No. 1 bearing 70 No. 2 bearing 80 Holding part 90 Inverter 100, 100A, 100B, 100C, 100D, 100E, 100F, 100G, 100H Electric compressor CD circumferential direction ID1 First inner diameter ID2 2nd inner diameter P1 Intake port P2 discharge port R1 First Region R2 Second Region RD Radial Direction X Axis

Claims

1. A housing formed in a cylindrical shape extending along an axis; a compressor disposed inside the housing and rotating about the axis to compress a refrigerant; a motor that drives the compressor to rotate about the axis, The motor is a stator disposed inside the housing; a rotor disposed on an inner circumferential side of the stator, a refrigerant flow path is formed inside the stator, through which a refrigerant flows from an inlet provided at one end along the axis to an outlet provided at the other end along the axis, the refrigerant flow path includes a first flow path portion formed at the one end side along the axis and having a radial distance from the axis gradually shortening from the one end side to the other end side, and a second flow path portion formed at the other end side along the axis and communicating with the first flow path portion, and having a radial distance from the axis gradually shortening from the other end side to the one end side, The inlet is provided near an outer circumferential surface of the stator, An electric compressor, wherein the other end of the first flow passage portion and the one end of the second flow passage portion are formed on teeth of the stator around which a coil winding is wound.

2. 2. The electric compressor according to claim 1, wherein the refrigerant flow path includes a third flow path that is connected to the inlet, rotates around the axis from the one end side to the other end side, and communicates with the first flow path portion.

3. The electric compressor according to claim 2 , wherein the third flow passage branches the refrigerant flowing in from the inlet into a first branch flow passage on one side in the circumferential direction and a second branch flow passage on the other side.

4. The electric compressor according to claim 1 , wherein the outlet is provided in the vicinity of an outer circumferential surface of the stator.

5. 4. The electric compressor according to claim 1, wherein a cross-sectional shape of the refrigerant flow path perpendicular to the axis is such that a flow path width in a circumferential direction about the axis is narrower on an inner peripheral side than on an outer peripheral side in the radial direction.

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