JP2020150619A - Motor, and motor compressor - Google Patents

Abstract

To provide a motor and a motor compressor in which deformation is less likely to occur in a stator having a two-split structure having an inner core and an outer core, even if the inner core is press-fitted into the outer core.SOLUTION: A stator of a motor includes: an inner core 462 having a plurality of projection portions 462B extending radially outward from an outer peripheral surface of a cylindrical shaped cylindrical portion 462A; and a cylindrical shaped outer core 464 having an inner peripheral surface to which a tip of the projecting portion 462B of the inner core 462 is press-fitted. And at least one through-hole TH that penetrates from one surface of the inner core 462 in an axial direction to the other is formed at the tip of the projecting portion 462B of the inner core 462.SELECTED DRAWING: Figure 5

Description

The present invention relates to a motor used in a compressor or the like that compresses a fluid, and an electric compressor equipped with this motor.

As the stator of the motor, as described in Japanese Patent Application Laid-Open No. 11-98724 (Patent Document 1), a cylindrical inner core having a plurality of protrusions extending radially outward from the radius and a protrusion of the inner core. A two-part structure having a cylindrical outer core in which the tip of the portion is press-fitted is proposed. A groove extending in the axial direction of the inner core is formed on the tip surface of the protruding portion of the inner core so that the outer core is not deformed when the inner core is press-fitted into the outer core.

Japanese Unexamined Patent Publication No. 11-9724

However, if a groove is formed on the tip surface of the protruding portion of the inner core, when the groove is press-fitted into the outer core, for example, the tip of the protruding portion of the inner core is turned over and deformed to obtain desired dimensional accuracy. It may not be possible.

Therefore, the present invention provides a motor having a two-divided structure having an inner core and an outer core, which is less likely to be deformed even when the inner core is press-fitted into the outer core, and an electric compressor equipped with the motor. The purpose.

Therefore, the motor includes a drive shaft that transmits a rotational driving force, a rotor that rotates integrally with the drive shaft, and a stator that is arranged on the outer periphery of the rotor. The stator has a cylindrical shape with an inner core having a plurality of projecting portions extending outward from the outer peripheral surface of the cylindrical cylindrical portion and an inner peripheral surface into which the tip of the projecting portion of the inner core is press-fitted. It has an outer core. Then, at least one through hole is formed at the tip of the projecting portion of the inner core from one surface in the axial direction of the inner core to the other surface. Further, the electric compressor is equipped with a motor configured in this way.

According to the present invention, in a stator having a two-part structure having an inner core and an outer core, even if the inner core is press-fitted into the outer core, deformation can be made less likely to occur.

It is a vertical sectional view which shows an example of a scroll type compressor. It is a block diagram explaining the flow of a gaseous refrigerant and a lubricating oil. It is a perspective view which shows an example of the stator of the two-part structure. It is a perspective view which shows an example of the stator which attached the bobbin. It is explanatory drawing of the through hole which suppresses the deformation of a stator. It is explanatory drawing of the deformation amount of the outer core which does not have a through hole. It is explanatory drawing of the deformation amount of the outer core which has a through hole.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the attached drawings.
FIG. 1 shows an example of a scroll type compressor 100 in which a motor according to the present embodiment is incorporated. Here, the scroll type compressor 100 is given as an example of an electric compressor.

The scroll type compressor 100 is incorporated into, for example, a refrigerant circuit of a vehicle air conditioner, and compresses and discharges a gaseous refrigerant (fluid) sucked from the low pressure side of the refrigerant circuit. The scroll type compressor 100 includes a housing 200, a scroll unit 300 that compresses a low-pressure gaseous refrigerant, a motor 400 that drives the scroll unit 300, an inverter 500 that controls the motor 400, and one end of a drive shaft 420 of the motor 400. A support member 600 for freely rotating the portion is provided. Here, as the refrigerant of the refrigerant circuit, for example, a CO ₂ (carbon dioxide) refrigerant can be used. Further, as the scroll type compressor 100, an inverter integrated type is given as an example, but an inverter separate type may be used.

The housing 200 is fastened to the front casing 220 that houses the scroll unit 300, the motor 400, the inverter 500, and the support member 600, the rear housing 240 that is fastened to one end side of the front casing 220, and the other end side of the front casing 220. The inverter cover 260 and the like are included. The front casing 220, the rear housing 240, and the inverter cover 260 are integrally fastened by a plurality of fasteners 700 including, for example, bolts and washers to form the housing 200 of the scroll compressor 100. There is.

The front casing 220 is configured to include a cylindrical peripheral wall portion 222 and a disk-shaped partition wall portion 224 that divides the internal space of the peripheral wall portion 222 into two in the axial direction. Here, the cylindrical shape may be such that it can be visually recognized as a cylindrical shape, and for example, a rib for reinforcement, a boss for mounting, or the like may be formed on the outer peripheral surface thereof (the shape is the same below). ). The internal space of the front casing 220 is partitioned by the partition wall portion 224 into a first space 220A accommodating the scroll unit 300, the motor 400 and the support member 600, and a second space 220B accommodating the inverter 500.

The opening on one end side of the peripheral wall portion 222 is closed by the disc-shaped rear housing 240. Further, the opening on the other end side of the peripheral wall portion 222 is closed by the inverter cover 260. At the center of one surface of the partition wall portion 224, a cylindrical support portion 224A extending from here toward one end of the peripheral wall portion 222 is formed. The other end of the drive shaft 420 of the motor 400 is rotatably supported by the support portion 224A via a bearing 720 press-fitted into the inner peripheral surface thereof.

Further, a suction port P1 for a gas refrigerant is formed in the peripheral wall portion 222. The gaseous refrigerant from the low pressure side of the refrigerant circuit is sucked into the first space 220A of the front casing 220 via the suction port P1. Therefore, the first space 220A of the front casing 220 functions as a suction chamber H1 for the gaseous refrigerant. In the suction chamber H1, the gas refrigerant circulates around the motor 400 to cool the motor 400. The first space 220A located on one side of the motor 400 in the axial direction communicates with the first space 220A located on the other side to form one suction chamber H1. In the suction chamber H1, the gaseous refrigerant flows as a mixed fluid containing a trace amount of lubricating oil.

The rear housing 240 is fastened to the open end located on one end side of the peripheral wall portion 222 of the front casing 220 by a plurality of fasteners 700. Then, the rear housing 240 closes the opening on one end side of the front casing 220. Further, the rear housing 240 is formed with a discharge port P2 that discharges the gaseous refrigerant compressed by the scroll unit 300 to the high pressure side of the refrigerant circuit. Inside the rear housing 240, an oil separator 740 that separates the lubricating oil from the gaseous refrigerant compressed by the scroll unit 300 is incorporated. The gaseous refrigerant from which the lubricating oil is separated by the oil separator 740 (including the gaseous refrigerant in which a small amount of lubricating oil remains) is discharged to the high pressure side of the refrigerant circuit via the discharge port P2. On the other hand, the lubricating oil separated by the oil separator 740 is guided to the back pressure supply passage L1, which will be described in detail later.

The scroll unit 300 is housed on one end side of the front casing 220. Specifically, the scroll unit 300 includes a fixed scroll 320 fixed to one surface of the rear housing 240 and a swivel scroll 340 arranged on the opposite side of the rear housing 240 with the fixed scroll 320 interposed therebetween. ing.

The fixed scroll 320 includes a disk-shaped bottom plate 322 fixed to one surface of the rear housing 240, and an involute curved wrap (spiral-shaped blade) 324 extending from one surface of the bottom plate 322 toward the swivel scroll 340. It is composed of. The swivel scroll 340 includes a disc-shaped bottom plate 342 arranged to face the bottom plate 322 of the fixed scroll 320, and an involute curve wrap 344 extending from one side of the bottom plate 342 toward the fixed scroll 320. It is configured.

Then, the fixed scroll 320 and the swivel scroll 340 are meshed so that the side walls of the laps 324 and 344 are partially in contact with each other in a state where the circumferential angles of the laps 324 and 344 are deviated from each other. Therefore, in the scroll unit 300, a crescent-shaped closed space, that is, a compression chamber H2 for compressing the gaseous refrigerant is partitioned between the fixed scroll 320 and the swivel scroll 340.

At the center of the bottom plate 322 of the fixed scroll 320, a discharge passage L2 for discharging the gaseous refrigerant compressed by the compression chamber H2 is formed. Further, in the central portion of the other surface of the bottom plate 322, a discharge chamber H3 formed of a cylindrical recess is formed to temporarily store the gas refrigerant discharged from the compression chamber H2 via the discharge passage L2. Further, the other surface of the bottom plate 322 allows the flow of the gaseous refrigerant from the compression chamber H2 to the discharge chamber H3, while blocking the flow of the gaseous refrigerant from the discharge chamber H3 to the compression chamber H2, for example, from a reed valve. A one-way valve 326 is attached.

The motor 400 is composed of, for example, a three-phase AC motor, and includes a drive shaft 420, a rotor 440, and a stator 460 arranged on the radial outer side of the rotor 440. Then, the direct current from the vehicle battery (not shown) is converted into an alternating current by the inverter 500 and supplied to the stator 460 of the motor 400.

The drive shaft 420 is connected to the swivel scroll 340 via a crank mechanism described later, and transmits the rotational driving force of the motor 400 to the swivel scroll 340. One end of the drive shaft 420, that is, the end on the swivel scroll 340 side, penetrates the through hole 600A formed in the support member 600 and is rotatably supported by the bearing 760 fixed to the support member 600. As described above, the other end of the drive shaft 420 is rotatably supported by the bearing 720 press-fitted into the support portion 224A of the front casing 220.

The rotor 440 is rotatably supported inside the stator 460 via a drive shaft 420 fitted (for example, press-fitted) into a shaft hole formed at the center thereof in the radial direction. When a magnetic field is generated in the stator 460 by the power supply from the inverter 500, a rotational force acts on the rotor 440 to rotationally drive the drive shaft 420.

The support member 600 has a bottomed cylindrical shape having the same outer diameter as the bottom plate 322 of the fixed scroll 320, and has a stepped cylindrical inner peripheral surface whose diameter is reduced in two steps from the opening side toward the back. There is. Then, the swivel scroll 340 of the scroll unit 300 is housed in the space partitioned by the inner peripheral surface on the large diameter side of the support member 600. The open end surface of the support member 600 is fastened to one surface of the bottom plate 322 of the fixed scroll 320 by, for example, a fastener (not shown). Therefore, the opening of the support member 600 is closed by the fixed scroll 320, and the back pressure chamber H4 that presses the swivel scroll 340 against the fixed scroll 320 is partitioned.

A bearing 760 that freely rotates one end of the drive shaft 420 of the motor 400 is fitted on the inner peripheral surface of the support member 600 on the small diameter side. Further, a through hole 600A is formed in the radial center portion of the bottom wall located at the innermost portion of the support member 600 so as to penetrate one end portion of the drive shaft 420. A sealing member 780 is arranged between the bearing 760 and the bottom wall to ensure the airtightness of the back pressure chamber H4.

An annular thrust plate 800 is arranged between the stepped portion of the small diameter portion and the large diameter portion and the bottom plate 342 of the swivel scroll 340 in the space defined by the inner peripheral surface on the large diameter side of the support member 600. Will be done. The step portion of the support member 600 receives the thrust force from the swivel scroll 340 via the thrust plate 800. A seal member 820 for ensuring the airtightness of the back pressure chamber H4 is provided at each of the step portion of the support member 600 and the portion of the bottom plate 342 of the swivel scroll 340 that comes into contact with the thrust plate 800.

Back pressure supply to the rear housing 240, the fixed scroll 320, and the support member 600 is to supply the lubricating oil separated by the oil separator 740 incorporated in the rear housing 240 to the back pressure chamber H4 partitioned by the support member 600. The passage L1 is formed. Therefore, the lubricating oil supplied from the oil separator 740 to the back pressure chamber H4 is used as the back pressure for pressing the swivel scroll 340 against the fixed scroll 320. An orifice 840 that limits the flow rate of the lubricating oil is provided in the middle of the back pressure supply passage L1.

A back pressure control valve 860 that operates according to the back pressure Pm of the back pressure chamber H4 and the suction pressure Ps of the suction chamber H1 and adjusts the back pressure Pm of the back pressure chamber H4 is attached to the small diameter portion of the support member 600. Has been done. That is, the back pressure control valve 860 opens when the back pressure Pm of the back pressure chamber H4 rises above the target pressure, and discharges the lubricating oil of the back pressure chamber H4 to the suction chamber H1 to discharge the back pressure chamber H4 into the back pressure chamber H4. Reduces back pressure Pm. On the other hand, the back pressure control valve 860 closes when the back pressure Pm of the back pressure chamber H4 drops below the target pressure, and stops the discharge of the lubricating oil from the back pressure chamber H4 to the suction chamber H1 to stop the discharge of the lubricating oil from the back pressure chamber H1 to the back pressure chamber H1. The back pressure Pm of H4 is increased. In this way, the back pressure control valve 860 adjusts the back pressure Pm of the back pressure chamber H4 to the target pressure.

Between the inner peripheral surface of the peripheral wall portion 222 of the front casing 220 and the outer peripheral surface of the support member 600, the suction chamber H1 and the space H5 located on the outer peripheral portion of the scroll unit 300 are communicated with each other, and the suction chamber H1 to the space H5 are communicated with each other. A refrigerant introduction passage L3 for introducing a gaseous refrigerant into the air is formed. Therefore, the pressure in the space H5 is equal to the pressure in the suction chamber H1.

The crank mechanism includes a cylindrical boss portion 880 protruding from the other surface of the bottom plate 342 of the swivel scroll 340, a crank pin 882 eccentrically erected on one end surface of the drive shaft 420, and an eccentric crank pin 882. It is configured to include an eccentric bush 884 attached in the state and a slide bearing 886 fitted to the boss portion 880. The eccentric bush 884 is supported by the boss portion 880 so as to be relatively rotatable via the sliding bearing 886. A balancer weight 888 that opposes the centrifugal force of the swivel scroll 340 is attached to one end of the drive shaft 420. Further, although not shown, a rotation prevention mechanism for preventing the rotation of the turning scroll 340 is provided. Therefore, the swivel scroll 340 can revolve around the axis of the fixed scroll 320 via the crank mechanism in a state where its rotation is prevented.

FIG. 2 is a block diagram illustrating the flow of the gaseous refrigerant and the lubricating oil.
The gaseous refrigerant from the low pressure side of the refrigerant circuit is introduced into the suction chamber H1 via the suction port P1 and then guided to the space H5 located on the outer peripheral portion of the scroll unit 300 via the refrigerant introduction passage L3. Then, the gaseous refrigerant guided to the space H5 is taken into the compression chamber H2 of the scroll unit 300 and compressed by the volume change of the compression chamber H2. The gaseous refrigerant compressed in the compression chamber H2 is discharged to the discharge chamber H3 via the discharge passage L2 and the one-way valve 326, and then is guided to the oil separator 740. The gaseous refrigerant from which the lubricating oil is separated by the oil separator 740 is discharged to the high pressure side of the refrigerant circuit via the discharge port P2. Further, the lubricating oil separated by the oil separator 740 is supplied to the back pressure chamber H4 via the back pressure supply passage L1 in a state where the flow rate is limited by the orifice 840. The lubricating oil supplied to the back pressure chamber H4 is discharged to the suction chamber H1 via the back pressure control valve 860.

As shown in FIG. 3, the stator 460 of the motor 400 adopts a two-part structure in which the inner core 462 and the outer core 464 are integrated by press fitting, for example, for the purpose of improving the space factor of the winding. There is. The inner core 462 is an iron core in which a cylindrical cylindrical portion 462A and a plurality of projecting portions 462B extending radially outward from the outer peripheral surface of the cylindrical portion 462A are integrated. A rotor 440 is rotatably inserted inside the radius of the cylindrical portion 462A with an air gap at a predetermined interval. Further, the projecting portion 462B is a rectangular parallelepiped member arranged at an equal angle around the central axis of the cylindrical portion 462A, and as shown in FIG. 4, is wound from the outside of the tip thereof (not shown). ) Is wound around the bobbin 466 and is fixed. The winding may be wound directly around the projecting portion 462B without using the bobbin 466. In the illustrated example, 12 projecting portions 462B are provided on the outer peripheral surface of the cylindrical portion 462A, but the number of projecting portions 462B is determined in consideration of, for example, the required characteristics of the motor 400. It can be set arbitrarily.

The outer core 464 is a cylindrical iron core, and a plurality of groove portions 464A into which the tip of the protruding portion 462B of the inner core 462 is press-fitted are formed on the inner peripheral surface thereof. The groove portion 464A is formed from one surface of the outer core 464 in the axial direction to the other surface, and the tip of the protrusion 462B of the inner core 462 is press-fitted into the groove portion 464A from the width of the tip of the protrusion 462B. Also has a slightly smaller width. Therefore, the inner core 462 and the outer core 464 can be firmly integrated by suppressing the relative displacement in the circumferential direction by press-fitting the tip of the projecting portion 462B into the groove portion 464A. If relative displacement in the circumferential direction is unlikely to occur depending on the degree of press fitting, it is not necessary to form the groove portion 464A on the inner peripheral surface of the outer core 464.

As shown in FIG. 5, at least one through hole TH is formed at the tip of the projecting portion 462B of the inner core 462 so as to penetrate from one surface to the other surface in the axial direction of the inner core 462. In the illustrated example, a pair of left and right through holes TH are formed at the tip of the protruding portion 462B of the inner core 462. The pair of left and right through holes TH are formed as elongated holes that extend diagonally in the left-right direction toward the outer radius of the inner core 462. However, the through hole TH is not limited to the elongated hole, and may be a circular hole or the like. When a plurality of through holes TH are formed at the tip of the projecting portion 462B of the inner core 462, they are formed symmetrically at the tip of the projecting portion 462B so that the rigidity of the projecting portion 462B in the left-right direction is line-symmetrical. It is preferable to do so. Here, it is preferable that at least one through hole TH has a cross-sectional area that does not exceed 1/3 of the cross-sectional area of the projecting portion 462B so that the magnetic flux of the projecting portion 462B can be secured.

In this way, when the inner core 462 and the outer core 464 are integrated by press fitting, the rigidity of the tip of the protruding portion 462B of the inner core 462 is reduced by the through hole TH, so that the protruding portion 462B The tip of the is elastically deformed. Therefore, the force acting on the outer core 464 from the projecting portion 462B is reduced, and the deformation of the outer core 464 can be suppressed. Further, since a groove or the like is not formed on the tip surface of the projecting portion 462B, the tip of the projecting portion 462B is less likely to be turned over when the inner core 462 is press-fitted into the outer core 464, and desired dimensional accuracy can be obtained. it can.

When a stator 460 in which a through hole TH is not formed at the tip of a protruding portion 462B of the inner core 462 is simulated under predetermined conditions, as shown in FIG. 6, the maximum amount of deformation that occurs on the outer peripheral surface of the outer core 464 is the maximum amount. Was 30 μm. On the other hand, when simulating the stator 460 in which a pair of left and right through holes TH are formed at the tip of the projecting portion 462B under the same predetermined conditions, as shown in FIG. 7, the maximum amount generated on the outer peripheral surface of the outer core 464 is maximum. The amount of deformation was 25 μm. Therefore, by forming a pair of left and right through holes TH at the tip of the projecting portion 462B, the maximum amount of deformation generated on the outer peripheral surface of the outer core 464 is reduced from 30 μm to 25 μm, and the maximum amount of deformation is reduced by about 17%. was gotten.

It should be noted that the result of such a decrease in the maximum deformation amount changes depending on the number of through holes TH formed at the tip of the projecting portion 462B of the inner core 462, the cross-sectional shape, the cross-sectional area, the position, and the like. Anyone skilled in the art will easily understand. Therefore, it will be obvious to those skilled in the art that it is preferable to determine the optimum number of through holes TH, cross-sectional shape, cross-sectional area, position, etc., for example, through experiments and simulations.

Although the embodiments for carrying out the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and modifications are made based on the technical idea as shown in the following examples. Is possible.

The electric compressor is not limited to the scroll type compressor 100, for example, a centrifugal compressor, an axial flow compressor, a reciprocal compressor, a swash plate compressor, a diaphragm compressor, a screw compressor, a rotary compressor, and a rotary. It may be a piston type compressor, a slide vane type compressor, or the like. Further, the back pressure control valve 860 may adjust the back pressure Pm of the back pressure chamber H4 to the target pressure by increasing or decreasing the flow rate of the lubricating oil supplied to the back pressure chamber H4.

100 scroll type compressor (electric compressor)
400 Motor 420 Drive Shaft 440 Rotor 460 Stator 462 Inner Core 462A Cylindrical Part 462B Protruding Part 464 Outer Core 464A Groove TH Through Hole

Claims (7)

A motor including a drive shaft that transmits rotational driving force, a rotor that rotates integrally with the drive shaft, and a stator that is arranged on the outer circumference of the rotor.
The stator is a cylinder having an inner core having a plurality of projecting portions extending outward in radius from the outer peripheral surface of the cylindrical cylindrical portion and an inner peripheral surface into which the tip of the projecting portion of the inner core is press-fitted. It has an outer core having a shape, and at least one through hole is formed at the tip of a protruding portion of the inner core so as to penetrate from one surface to the other surface in the axial direction of the inner core.
motor. A plurality of grooves are formed on the inner peripheral surface of the outer core so that the tip of the protruding portion of the inner core is press-fitted.
The motor according to claim 1. A plurality of the through holes are formed at the tip of the protruding portion of the inner core.
The motor according to claim 1 or 2. The through hole was formed symmetrically at the tip of the protruding portion of the inner core.
The motor according to claim 3. The through hole is composed of an elongated hole.
The motor according to any one of claims 1 to 4. The through hole is composed of a circular hole.
The motor according to any one of claims 1 to 4. An electric compressor equipped with the motor according to any one of claims 1 to 6.