JP6654414B2 - Electric compressor - Google Patents

Description

  The present invention relates to an electric compressor.

  For example, an electric compressor having a compressor driven by the driving force of an electric motor is used for a car air conditioner, for example, because it can be driven when necessary even if an engine of an automobile is stopped. In such an electric compressor, for example, when the amount of circulating refrigerant is small and the rotation speed of the electric motor is low, or when the load on the electric motor is high, it becomes difficult to sufficiently cool the electric motor.

  For example, Patent Literature 1 discloses a technique in which a bobbin cover is provided with an air hole in order to suppress a rise in coil temperature during operation of an electric motor.

JP 2002-044896 A

  SUMMARY OF THE INVENTION It is an object of the present invention to provide an electric compressor that can prevent a temperature rise of a motor, suppress a decrease in efficiency of an electric motor, and prevent damage due to heat generation of the motor.

According to a first aspect of the present invention, an electric compressor includes a housing extending in an axial direction, a compressor provided in the housing, and rotating around an axis to compress a fluid; A stator provided so as to have a gap between the inner peripheral surface of the housing and a laminated body formed by a plurality of thin steel plates laminated in the axial direction, the outer peripheral surface of the cylindrical shape A stator core body having, a large recess formed on the outer peripheral surface of the stator core body so as to extend in the axial direction and serving as a fluid flow path, and a plurality of small recesses formed on an outer surface of the large recess. a stator having a stator core, a having, having a rotor disposed radially inner periphery of the stator, and a motor for rotating said compressor to said axis line, wherein the fluid Flows from the serial motor side to the compressor side, the stator further comprises a coil end bobbin penetrating portion is formed on the downstream side in the flow direction of the fluid.

  According to such a configuration, the heat transfer area of the stator core is increased by the plurality of small recesses. Thereby, the cooling efficiency of the stator by the fluid can be improved, and the temperature rise of the stator can be suppressed. Since the rise in the temperature of the stator and the rise in the temperature of the coil are suppressed, the efficiency of the electric motor constituting the electric compressor can be improved, and damage to the motor can be prevented.

  In the above electric compressor, the stator may have a plurality of small recesses formed on an outer peripheral surface of the stator core body.

  In the electric compressor, the stator core main body has a plurality of teeth formed on an inner peripheral side, the stator is formed of an insulating material, and is provided at one end and the other end of the stator core in the axial direction. A ring portion having a cylindrical shape, a hook portion protruding toward the inner peripheral side of the ring portion and disposed at an axial end of the teeth, and a plurality of through portions penetrating in a radial direction of the ring portion, And a coil wound around the plurality of teeth and the hook portion.

  According to such a configuration, it is possible to suppress a temperature rise of the coil due to the passage of the fluid through the through portion.

  In the above electric compressor, the through portion may be connected to an edge of the ring portion.

  According to the present invention, the heat transfer area of the stator core is increased by the plurality of small recesses. Thereby, the cooling efficiency of the stator by the fluid can be improved, and the temperature rise of the stator can be suppressed. By suppressing the rise in temperature of the stator, the efficiency of the electric motor constituting the electric compressor can be improved, and damage to the motor can be prevented.

It is a longitudinal section of an electric compressor of an embodiment of the present invention. It is a front view of the stator and the rotor of the electric compressor of the embodiment of the present invention. It is a perspective view of the 1st coil end bobbin of the electric compressor of an embodiment of the present invention. It is a perspective view of the 1st coil end bobbin of the electric compressor of the modification of an embodiment of the present invention.

Hereinafter, an electric compressor according to an embodiment of the present invention will be described in detail with reference to the drawings.
The electric compressor of the present embodiment is a relatively small electric compressor used for an air conditioner (car air conditioner) of an automobile. However, the subject of the present invention is not limited to such an electric compressor.
As shown in FIG. 1, an electric compressor 1 of the present embodiment includes a housing 2 forming an outer shell, an electric motor 7 provided in the housing 2, a compressor 22 provided in the housing 2, And an inverter device 33 provided in the control unit. The electric compressor 1 of the present embodiment is an inverter-integrated electric compressor 1 in which an inverter device 33 is integrally mounted. The electric motor 7 and the compressor 22 are sealed inside the housing 2.

  The electric compressor 1 is connected to a refrigerant circuit (not shown). That is, the electric compressor 1 is a machine that is incorporated in a refrigerant circuit having a condenser, an expansion valve, an evaporator, and the like, and compresses a refrigerant flowing in piping of the refrigerant circuit.

  In the following description, the direction in which the axis A of the rotating shaft 8 of the electric motor 7 extends is referred to as an axial direction Da. A direction perpendicular to the axis A is defined as a radial direction Dr, a side of the radial direction Dr that is away from the axis A is referred to as a radially outer side, and a side of the radial direction Dr approaching the axis A is referred to as a radially inner side. In the axial direction Da, the compressor 22 side is referred to as an axial first side Da1, and the electric motor 7 side is referred to as an axial second side Da2.

The inverter device 33 converts a direct current supplied from a storage battery outside the electric compressor 1 into a three-phase alternating current and supplies the three-phase alternating current to the electric motor 7. The inverter device 33 controls the operation of the motor 7 by controlling the current supply to the motor 7.
The terminal case 14 is arranged between the inverter device 33 and the electric motor 7. The terminal case 14 accommodates a terminal portion for connecting the external power line and the internal power line of the electric motor 7.

  The housing 2 is formed of a metal such as an aluminum alloy. The housing 2 includes a main housing 3 that extends in the axial direction Da and is formed in a substantially cylindrical shape, a first end housing 4 coupled to the first axial direction Da1 of the main housing 3, A second end housing 5 coupled to the second axial side Da2. The end housings 4 and 5 are fixed to the main housing 3 by bolts 6.

The housing 2 is formed with a refrigerant inlet 40 that is a refrigerant inlet. The coolant inlet 40 is provided near an end of the second axial side Da2 of the housing 2. The refrigerant inlet 40 is formed so as to introduce refrigerant from the second axial side Da2 of the electric motor 7.
The housing 2 is formed with a refrigerant outlet 41 that is a refrigerant outlet. The refrigerant outlet 41 is provided near an end of the first axial direction Da1 of the housing 2.

The electric motor 7 has a stator 9 and a cylindrical rotor 27 rotatably arranged inside the stator 9 with a predetermined space therebetween. The outer surface of the stator 9 has a cylindrical shape, and has a predetermined gap G between itself and the inner peripheral surface 3 a of the main housing 3.
The electric motor 7 receives the electric power from the inverter device 33 and generates a rotational force. The electric motor 7 is connected to the orbiting scroll 24 of the compressor 22 via the rotating shaft 8, and drives the orbiting scroll 24 to rotate around the axis A with the generated rotational force.
The compressor 22 is provided in the housing 2 and has a fixed scroll 23 and an orbiting scroll 24.

  The rotating shaft 8 of the electric motor 7 is rotatably supported by the housing 2 via a bearing 34. The end of the first axial side Da1 of the rotating shaft 8 is coupled to the shaft 25 of the orbiting scroll 24 of the compressor 22, and drives the orbiting scroll 24 to rotate. The compressor 22 is a scroll-type mechanism that compresses the refrigerant (fluid) drawn from the refrigerant inlet 40 by the orbiting motion of the fixed scroll 23 and the orbiting scroll 24 while being eccentric.

  The stator 9 includes an annular stator core 10, a first coil end bobbin 15 disposed on the first axial side Da1 of the stator core 10 (compressor 22 side), and a second axial end Da2 of the stator core 10. And a coil 13 (winding) wound around the teeth 12 of the stator core 10 (see FIG. 2) and the coil end bobbins 15, 16.

  The rotor 27 has a cylindrical rotor core 28 (rotor core) formed by laminating a required number of punched and formed thin electromagnetic steel sheets (thin steel sheets). As shown in FIG. 2, a rotation shaft through hole 29 into which the rotation shaft 8 is fitted is formed in the center of the rotor core 28. The rotor core 28 is provided with magnet holes 30 for magnet embedding corresponding to the number of poles of the electric motor 7 (six poles in the present embodiment) so as to surround the rotation shaft through hole 29 along the outer peripheral portion thereof. A permanent magnet 31 is embedded in each magnet hole 30.

  The stator core 10 is a laminated body formed by laminating a required number of electromagnetic steel sheets formed by punching in an annular shape, and includes a stator core body 11 having a cylindrical outer peripheral surface and an outer peripheral surface 11a of the stator core body 11 in an axial direction Da. And a plurality of small recesses 35 formed on the outer surface 35 a of the large recess 35 and the outer peripheral surface 11 a of the stator core main body 11. .

  A tooth 12 for winding a coil 13 is formed on the inner peripheral side of the stator core body 11. In the case of this embodiment, the teeth 12 are provided at nine locations at substantially equal intervals on the inner peripheral side of the stator core 10, and the coils 13 can be wound around the teeth 12 by punching out slots 32 between the respective teeth 12. It has been.

  Three large concave portions 35 are formed on the outer peripheral surface 11a of the stator core main body 11 at equal intervals in the circumferential direction. The large concave portion 35 is a cutout having a circular arc shape convex toward the radially inner circumferential side when viewed from the axial direction Da. The shape of the large concave portion 35 may be not only an arc shape but also a rectangular shape. The circumferential position of the large concave portion 35 is the same as the circumferential position of any of the teeth 12. The number of the large recesses 35 and the depth of the large recesses 35 in the radial direction Dr can be appropriately changed according to the amount of the refrigerant and the like.

The small recesses 36 are rectangular grooves formed on the outer surface 35 a of the large recess 35 and the outer peripheral surface 11 a of the stator core body 11. The small recesses 36 are formed in all the magnetic steel sheets constituting the stator core body 11 in the same manner, but need not necessarily be formed in all the magnetic steel sheets. The small recess 36 may be not only rectangular but also semi-circular or trapezoidal.
Further, it is preferable that the small concave portion 36 is not provided in a narrow portion where the magnetic flux density is concentrated as indicated by the reference numeral B in FIG.

Next, the detailed structure of the first coil end bobbin 15 will be described.
As shown in FIG. 3, the first coil end bobbin 15 includes a cylindrical ring portion 17 and a plurality of hook portions 18 provided on the inner peripheral side of the ring portion 17 at substantially equal intervals in the circumferential direction. Have. The outer diameter of the first coil end bobbin 15 is slightly smaller than the outer diameter of the stator core 10, and the inner diameter of the first coil end bobbin 15 is slightly larger than the inner diameter of the stator core 10. The number and the circumferential position of the hook portions 18 correspond to the teeth 12.

The first coil end bobbin 15 is formed of a material having an insulating property, for example, polybutylene terephthalate resin.
The hook portion 18 has a plate shape, and includes a hook body portion 19 that projects radially inward from an end portion of the ring portion 17 on the second axial side Da2, and a radially inner end portion of the hook body portion 19. And a coil holding portion 20 protruding on the first side Da1 in the axial direction. That is, the ring portion 17 and the hook portion constituting the first coil end bobbin 15 are U-shaped when viewed from the circumferential direction.

  The outer diameter of the ring portion 17 is slightly smaller than the outer diameter of the stator core 10. The width of the ring portion 17 in the axial direction Da is set by the number of turns of the coil 13. As shown in FIG. 1, the width of the ring portion 17 in the axial direction Da is a length such that the coil 13 does not protrude beyond the end of the ring portion 17 on the first axial side Da1 in the wound state. It is.

  The coil holding portion 20 has a plate shape curved so as to be parallel to the ring portion 17 when viewed from the axial direction Da. The distal end side of the coil holding portion 20 (the opposite side to the hook body portion 19, the first axial direction side Da1) is formed so that the width in the axial direction Da gradually decreases toward both ends in the circumferential direction. . An inclined surface 21 is formed on an end side of the distal end side of the coil holding portion 20 so that the width in the axial direction Da gradually decreases toward the end in the circumferential direction.

A plurality of through grooves 37 (through portions) are formed in the ring portion 17 of the first coil end bobbin 15. The through groove 37 is a groove that penetrates in the radial direction Dr. The through groove 37 is formed at a position different from the hook 18 in the circumferential direction of the ring 17. The through groove 37 is formed at an intermediate position between the hook portions 18 adjacent in the circumferential direction. The through groove 37 is connected to the edge 17a of the ring portion 17 on the first side Da1 in the axial direction.
The through groove 37 has a pair of groove slopes 38 and a bottom 39 connecting the pair of groove slopes 38. The depth L of the bottom portion 39 (the depth of the ring portion 17 from the edge portion 17a on the first axial side Da1) is approximately の of the width W of the ring portion 17 in the axial direction Da. The aperture ratio of the through groove 37, that is, the ratio of the area of the plurality of through grooves 37 to the area of the ring portion 17 where the through groove 37 is not formed can be 20% to 40%.

  The second coil end bobbin 16 has the same shape as the first coil end bobbin 15 except for the presence or absence of the through groove 37.

Next, the flow of the refrigerant will be described.
The refrigerant sucked from the refrigerant inlet 40 reaches the compressor 22 while cooling the electric motor 7 in the sealed housing 2, is compressed by the compressor 22, and is discharged from the refrigerant outlet 41. Most of the refrigerant flows through the large recess 35 when passing through the electric motor 7.

  According to the above embodiment, the heat transfer area of the stator core 10 is increased by the plurality of small recesses 36. Thereby, the cooling efficiency of the stator 9 by the refrigerant can be improved and the temperature rise of the stator 9 can be suppressed.

Further, since the through groove 37 formed in the first coil end bobbin 15 is formed, the refrigerant easily flows to the coil 13 side. Thereby, the cooling performance of the coil 13 can be improved.
In addition, since the through groove 37 is formed in the first coil end bobbin 15 on the downstream side in the flow direction of the refrigerant, the coil end whose temperature rises more rapidly can be cooled.
Further, since the position of the through groove 37 in the circumferential direction is different from the position of the coil 13, insulation of the coil 13 can be ensured.

Next, an electric compressor according to a modification of the present embodiment will be described.
As shown in FIG. 4, a through hole 43 is formed in the first coil end bobbin 15B of the electric compressor according to a modification of the present embodiment, instead of the through groove 37 (see FIG. 3) of the embodiment. . The through hole 43 is an elliptical hole formed near the center of the ring portion 17 in the axial direction Da. That is, the through hole 43 is not connected to the edge 17 a on the first axial side Da1 of the ring portion 17.
With the first coil end bobbin 15B having such a shape, the strength of the first coil end bobbin 15B can be improved.

Although the embodiments of the present invention have been described in detail above, various changes can be made without departing from the technical idea of the present invention.
For example, the small concave portion 36 of the present embodiment is formed over the entire circumference, but is not limited to this, and may be formed only on a part according to the heat generation state of the stator core 10.
Further, the mounting position of the inverter device 33 is not limited to the position shown in FIG. For example, it may be provided above the electric compressor 1.

DESCRIPTION OF SYMBOLS 1 Electric compressor 2 Housing 3 Main housing 3a Inner peripheral surface 4 First end housing 5 Second end housing 6 Bolt 7 Electric motor 8 Rotating shaft 9 Stator 10 Stator core 11 Stator core main body 11a Outer peripheral surface 12 Teeth 13 Coil 14 Terminal case 15 1st coil end bobbin 16 2nd coil end bobbin 17 Ring part 17a Edge part 18 Hook part 19 Hook body part 20 Coil holding part 21 Slope 22 Compressor 23 Fixed scroll 24 Orbiting scroll 25 Shaft part 27 Rotor core 29 Rotor shaft penetration Hole 30 Magnet hole 31 Permanent magnet 32 Slot 33 Inverter device 34 Bearing 35 Large recess 35a Outer surface 36 Small recess 37 Through groove (through portion)
38 Groove slope 39 Bottom 40 Refrigerant inlet 41 Refrigerant outlet 43 Through hole (penetrating part)
A axis line Da axis direction Dr radial direction

Claims (4)

An axially extending housing;
A compressor provided in the housing and configured to compress a fluid by rotating about an axis;
A stator provided in the housing so as to have a gap between the housing and an inner peripheral surface of the housing,
A stator core body which is a laminate formed by a plurality of thin steel plates laminated in the axial direction, and has a cylindrical outer peripheral surface,
A large recess formed on the outer peripheral surface of the stator core body so as to extend in the axial direction and serving as a fluid flow path;
A stator core having a plurality of small recesses formed on the outer surface of the large recess,
A stator having
A rotor arranged on the radially inner peripheral side of the stator,
An electric motor that rotationally drives the compressor around the axis,
The fluid flows from the motor side to the compressor side,
The electric compressor , wherein the stator further includes a coil end bobbin having a through portion formed on a downstream side in a flow direction of the fluid .   The electric compressor according to claim 1, wherein the stator has a plurality of small recesses formed on an outer peripheral surface of the stator core body. The stator core body has a plurality of teeth formed on the inner peripheral side,
The stator is
It is formed of a material having an insulating property, and is provided at one end and the other end in the axial direction of the stator core,
A cylindrical ring portion,
A hook portion protruding inward of the ring portion and disposed at an axial end of the tooth;
A coil end bobbin having a plurality of penetrating portions penetrating in the radial direction of the ring portion,
3. The electric compressor according to claim 1, further comprising the plurality of teeth and a coil wound around the hook portion. 4.   The electric compressor according to claim 3, wherein the through portion is connected to an edge of the ring portion.

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