JP2019126133A - Rotary electric machine - Google Patents

Abstract

To provide a rotary electric machine capable of exhibiting exerting excellent cooling performance with a simple configuration.SOLUTION: A rotary electric machine comprises a cylindrical stator 3 including a coil 12 and a status core 11 on which the coil 12 is mounted, and a coolant passage 51 which extends in a shaft direction of the stator 3 and through which a coolant circulates. In the coolant passage 51, coil supply ports 55a and 55b which supply a coolant to the coil 12 are formed in the position overlapping the coil 12 in the shaft direction. In the coolant passage 51, a core supply port 56 which supplies the coolant to the status core 11 is formed in the position overlapping the status core 11 in the shaft direction. The core supply port 56 is provided with an on-off valve 61 whose aperture increases as a pressure of the coolant passing the coolant passage 51 increases.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a rotating electrical machine.

  In a rotating electric machine mounted on a hybrid car or an electric car, a magnetic field is formed in the stator core by supplying current to the coil, and a magnetic attractive force or repulsive force is generated between the permanent magnet of the rotor and the stator core. . This causes the rotor to rotate relative to the stator.

  In the above-described rotating electrical machine, when heat is generated with driving, there is a possibility that performance may be reduced. Therefore, various configurations for cooling the rotating electrical machine have been studied. For example, Patent Document 1 below discloses a configuration in which a control valve for adjusting the opening area of the supply port is provided at the supply port of the refrigerant formed in the refrigerant flow path. According to this configuration, by adjusting the opening area of the supply port according to the flow direction of the refrigerant, the difference between the supply amount of the refrigerant between the upstream supply port and the downstream supply port can be reduced. .

JP, 2013-51830, A

By the way, in a rotating electrical machine, since the copper loss increases in a high rotation state, the coil tends to easily generate heat. On the other hand, in the low rotation speed state, the core loss tends to increase, so the stator core tends to generate heat.
However, in the above-described prior art, there is still room for improvement in that the refrigerant is supplied to the appropriate place according to the rotation speed with a simple configuration.

  An object of the present invention is to provide a rotating electrical machine that can exhibit excellent cooling performance with a simple configuration.

(1) In order to achieve the above object, a rotating electrical machine according to an aspect of the present invention includes a coil (for example, a coil 12 in the embodiment) and a stator core on which the coil is mounted (for example, a stator core 11 in the embodiment) A cylindrical stator (for example, the stator 3 in the embodiment), and a refrigerant flow path (for example, the refrigerant flow path 51 in the embodiment) which extends in the axial direction of the stator and through which the refrigerant flows In the refrigerant flow path, coil supply ports (for example, coil supply ports 55a and 55b in the embodiment) for supplying the refrigerant to the coil are formed at positions overlapping the coil in the axial direction, and in the refrigerant flow path A core supply port for supplying the refrigerant to the stator core at a position overlapping the stator core in the axial direction (for example, core supply in the embodiment) 56) is formed, the said core supply port, in accordance with the pressure of the refrigerant increases flowing in the refrigerant flow path on-off valve (e.g., on-off valve 61 in the embodiment) is provided which opening is increased.

(2) In the rotating electrical machine according to the above aspect (1), the coil includes a pair of coil end portions (for example, coil end portions 12b and 12c in the embodiment) projecting on both sides in the axial direction with respect to the stator core. The coil supply port may be provided on both sides in the axial direction with respect to the stator core.

(3) In the rotary electric machine according to the aspect of the above (1) or (2), the on-off valve may be configured to be elastically deformable.

(4) In the rotating electrical machine according to any one of the above (1) to (3), a rotor (for example, the rotor 4 in the embodiment) configured to be rotatable in the radial direction with respect to the stator; A refrigerant pump may be provided that delivers the refrigerant to the refrigerant flow path in conjunction with the rotation of the rotor.

(5) In the rotary electric machine according to any one of the modes (1) to (4), the opening area of the core supply port may be larger than the opening area of the coil supply port.

According to the aspect of the above (1), by reducing the pressure in the refrigerant flow path at the time of low rotation, the opening degree of the on-off valve can be made small (or the on-off valve can be closed). Thus, the amount of refrigerant discharged from the core supply port can be reduced, and the amount of refrigerant discharged from the coil supply port can be secured. Thus, the refrigerant can be actively supplied to the coil through the coil supply port, and the coil can be actively cooled. On the other hand, the opening degree of the on-off valve can be increased by increasing the pressure in the refrigerant flow channel at the time of high rotation. Thus, the refrigerant can be discharged through the core supply port, and the stator core can be actively cooled.
As described above, since the portion of the stator that is to be actively cooled can be changed according to the pressure in the refrigerant flow path, excellent cooling performance can be exhibited with a simple configuration.

  According to the above aspect (2), since the coil supply ports are provided on both sides in the axial direction with respect to the stator core, the refrigerant can be effectively supplied to each coil end portion.

  According to the above aspect (3), since the on-off valve is configured to be elastically deformable, the core supply port is opened and closed according to the pressure of the refrigerant. Thereby, the above-mentioned effect is produced with a simpler configuration.

  According to the above aspect (4), it is possible to increase or decrease the pressure of the refrigerant in the refrigerant flow path in conjunction with the rotational speed of the rotor. This eliminates the need for separate control and the like for adjusting the pressure of the refrigerant, so that further simplification can be achieved.

  According to the above aspect (5), in the open state (high rotation state) of the on-off valve, the pressure loss when passing through the core supply port can be reduced, and the refrigerant can be positively supplied to the stator core through the core supply port. .

BRIEF DESCRIPTION OF THE DRAWINGS The fragmentary sectional view which follows the axial direction of the rotary electric machine which concerns on embodiment. FIG. 2 is a partial cross-sectional view along the radial direction of the rotating electrical machine according to the embodiment. The schematic bottom view of a refrigerant | coolant supply mechanism. Explanatory drawing for demonstrating the effect | action of a rotary electric machine. Explanatory drawing for demonstrating the effect | action of a rotary electric machine. Explanatory drawing for demonstrating the effect | action of a rotary electric machine. Sectional drawing of the refrigerant | coolant supply mechanism which concerns on a modification. Sectional drawing of the refrigerant | coolant supply mechanism which concerns on a modification.

Hereinafter, embodiments of the present invention will be described based on the drawings.
[Electric rotating machine]
FIG. 1 is a cross-sectional view along an axial direction of a rotary electric machine 1 according to the embodiment.
The rotary electric machine 1 shown in FIG. 1 is, for example, a traveling motor mounted on a vehicle such as a hybrid car or an electric car. However, the configuration of the present invention is applicable not only to the drive motor, but also to a generator motor, a motor for other applications, and a rotating electrical machine (including a generator) other than for a vehicle.

  The rotary electric machine 1 includes a stator 3, a rotor 4, an output shaft 5, and a refrigerant supply mechanism 6. The stator 3, the rotor 4, the output shaft 5 and the refrigerant supply mechanism 6 are integrally housed in a case (not shown). A refrigerant (not shown) is accommodated in the case. The stator 3 described above is disposed in the case in a state where a part thereof is immersed in the refrigerant. In addition, as a refrigerant | coolant, ATF (Automatic Transmission Fluid) etc. which are hydraulic fluid used for the lubrication of a transmission, power transmission, etc. are used suitably.

  The output shaft 5 is rotatably supported by the case. In the following description, the direction along the axis C of the output shaft 5 is simply referred to as the axial direction, the direction orthogonal to the axis C may be referred to as the radial direction, and the direction around the axis C may be referred to as the circumferential direction. In the present embodiment, the rotary electric machine 1 is mounted on a vehicle in a state in which the axial direction is in the vehicle width direction.

FIG. 2 is a partial cross-sectional view along the radial direction of the rotary electric machine 1.
As shown in FIG. 2, the stator 3 includes a stator core 11 and a coil 12 mounted on the stator core 11.
The stator core 11 has a tubular shape coaxially arranged with the axis C. The stator core 11 is fixed to the inner circumferential surface of the case. The stator core 11 is configured by laminating electromagnetic steel sheets in the axial direction. The stator core 11 may be a so-called dust core.

The stator core 11 has a back yoke portion 21 and a plurality of teeth portions 22.
The back yoke portion 21 is formed in a cylindrical shape coaxially disposed with the axis C. On the outer peripheral surface of the back yoke portion 21, a mounting piece 24 that protrudes outward in the radial direction is formed. The mounting piece 24 is fixed to the case via a bolt. A plurality of mounting pieces 24 are formed at intervals in the circumferential direction. The number, the position, and the like of the mounting pieces 24 can be changed as appropriate.

  Each tooth portion 22 projects radially inward from the inner peripheral surface of the back yoke portion 21. A plurality of teeth portions 22 are formed at intervals in the circumferential direction. Between the teeth portions 22 adjacent in the circumferential direction, a slot 23 through which the coil 12 is inserted is formed. The slots 23 penetrate the stator core 11 in the axial direction.

  The coil 12 is attached to the stator core 11. The coil 12 has a U-phase coil, a V-phase coil and a W-phase coil which are arranged with a phase difference of 120 ° with respect to the circumferential direction. As shown in FIG. 1, the coil 12 has an insertion portion 12 a inserted into a slot (not shown) of the stator core 11 and coil end portions 12 b and 12 c axially protruding from the stator core 11. A magnetic field is generated in the stator core 11 when a current flows through the coil 12.

  The rotor 4 is disposed radially inward of the stator 3 at an interval. The rotor 4 is fixed to the output shaft 5 and is configured to be rotatable around the axis C integrally with the output shaft 5. Specifically, the rotor 4 mainly includes a rotor core 31 and a permanent magnet 32.

  The rotor core 31 is formed in a cylindrical shape coaxially arranged with the axis C. The output shaft 5 is press-fitted and fixed to the inside of the rotor core 31. The rotor core 31 may be formed by laminating electromagnetic steel plates in the axial direction in the same manner as the stator core 11, or may be a dust core.

  A magnet holding hole 35 penetrating the rotor core 31 in the axial direction is formed in an outer peripheral portion of the rotor core 31. A plurality of magnet holding holes 35 are formed at intervals in the circumferential direction. Permanent magnets 32 are inserted into the respective magnet holding holes 35.

<Refrigerant supply mechanism>
The refrigerant supply mechanism 6 selectively supplies the refrigerant delivered by the drive of the refrigerant pump to each part of the stator 3. The refrigerant pump is, for example, a so-called mechanical pump driven in conjunction with the rotation of the output shaft 5. However, the refrigerant pump may be an electric pump which is driven independently with respect to the rotation of the output shaft 5.

  As shown in FIG. 2, the refrigerant supply mechanism 6 has a plurality of refrigerant channels 51. In the present embodiment, the refrigerant flow path 51 is disposed between the adjacent mounting pieces 24 in a portion positioned above (outside in the radial direction) the back yoke portion 21. The number, the position, and the like of the refrigerant channels 51 can be changed as appropriate. Each of the refrigerant channels 51 has the same configuration. Therefore, in the following description, one refrigerant channel 51 will be described as an example.

  The refrigerant channel 51 extends in the axial direction. In the coolant channel 51, the coolant delivered by the above-described coolant pump flows along the axial direction. The coolant channel 51 may be provided in the case, or may be provided separately from the case between the inner peripheral surface of the case and the stator core 11.

FIG. 3 is a schematic bottom view of the refrigerant supply mechanism 6.
As shown in FIGS. 2 and 3, in the coolant channel 51, a coil supply port (a first coil supply port 55a and a second coil supply port 55b) and a core supply port 56 are formed.
The first coil supply port 55 a is formed at a position overlapping the coil end portion 12 b in the axial direction in the refrigerant flow path 51. The first coil supply port 55 a is opened at a position of the refrigerant flow path 51 facing the coil end portion 12 b in the radial direction. In the present embodiment, a plurality of (for example, two) first coil supply ports 55a are formed at intervals in the circumferential direction.

  The second coil supply port 55 b is formed at a position overlapping the coil end portion 12 c in the axial direction in the refrigerant flow path 51. The second coil supply port 55 b is opened at a position of the refrigerant flow path 51 that is opposed to the coil end portion 12 b in the radial direction. In the present embodiment, a plurality of (for example, two) second coil supply ports 55b are formed at intervals in the circumferential direction.

The coil supply ports 55a and 55b may be formed, for example, at intervals in the axial direction. The number of each coil supply port 55a, 55b may be one or more than two.
If the coil supply port 55a (the coil supply port 55b) is formed at a position where at least a part of the refrigerant flow path 51 axially overlaps the coil end portion 12b (the coil end portion 12c), the coil supply port 55a, The opening direction of 55b can be changed as appropriate. The axial positions of the coil supply ports 55 a and 55 b may be different between the refrigerant channels 51.

  The core supply port 56 is formed at a position overlapping the stator core 11 in the axial direction in the refrigerant flow path 51. The core supply port 56 is opened at a position of the refrigerant flow path 51 facing the stator core 11 (back yoke portion 21) in the radial direction. In the present embodiment, the inner diameter of the core supply port 56 is larger than the inner diameter of the coil supply ports 55a and 55b. However, the inner diameters (opening areas) of the supply ports 55a, 55b, and 56 can be changed as appropriate.

  In the present embodiment, the core supply port 56 is located at the axial center of the stator core 11. However, the position, the number, and the like of the core supply ports 56 can be changed as appropriate.

  The core supply port 56 is provided with an on-off valve 61 that switches communication between the inside and the outside of the refrigerant flow path 51 through the core supply port 56. In the present embodiment, the on-off valve 61 is, for example, a slit valve. The on-off valve 61 is configured by being divided by a plurality of elastic connection pieces 64 by slits 63 in which closing portions 62 for closing the core supply port 56 are radially formed.

  The elastic connection piece 64 elastically deforms due to the pressure of the refrigerant flowing in the refrigerant channel 51, thereby expanding and contracting the slit 63. Specifically, the on-off valve 61 is in a valve closed state in which the slits 63 are closed by bringing the peripheries of the elastic connection pieces 64 into contact with each other, and the slits 63 are opened by separating the peripheries of the elastic connection pieces 64. The valve is opened. That is, the opening degree of the on-off valve 61 increases as the pressure in the refrigerant channel 51 increases, and the core supply port 56 is opened. In addition, it is possible to adjust the valve-opening timing of the on-off valve 61 by adjusting the thickness and length (opening area of the core supply port 56) of the elastic connection piece 64, and the like. That is, the valve opening timing of the on-off valve 61 is lowered by decreasing the thickness of the elastic connection piece 64 or lengthening the length of the elastic connection piece 64 (increasing the opening area of the core supply port 56). It is possible.

[Effect]
Next, the operation of the above-described rotary electric machine 1 will be described. 4 to 6 are explanatory diagrams for explaining the operation of the rotary electric machine 1.
First, the flow of the refrigerant in the low rotation (and high torque) state will be described.
As shown in FIG. 4, the refrigerant delivered by the refrigerant pump flows in the refrigerant flow path 51 along the axial direction. The refrigerant is discharged from the refrigerant channel 51 through the coil supply ports 55 a and 55 b in the process of flowing in the refrigerant channel 51. The refrigerant discharged from the first coil supply port 55a is mainly supplied to the coil end portion 12b. The refrigerant discharged from the second coil supply port 55b is mainly supplied to the coil end portion 12c. Thereby, the coil 12 is cooled.

  In the low rotation state of the rotary electric machine 1, the pressure of the refrigerant in the refrigerant flow path 51 is relatively low. In this case, the on-off valve 61 maintains the closed state. Thereby, all the refrigerant | coolants among the refrigerant | coolants which flow through the refrigerant | coolant flow path 51 are supplied to the coil 12 (coil end part 12b, 12c). Thereby, the coil 12 can be actively cooled in the low rotation state.

  As shown in FIG. 5, when the rotational speed of the rotor 4 increases and the pressure in the refrigerant channel 51 increases, the elastic connection piece 64 is elastically deformed by the pressure of the refrigerant. Thereby, the slit 63 of the on-off valve 61 spreads, and the on-off valve 61 is opened. When the on-off valve 61 is opened, a part of the refrigerant flowing through the refrigerant flow path 51 is discharged from the refrigerant flow path 51 through the slit 63 (core supply port 56). The refrigerant discharged from the slits 63 is supplied to the stator core 11. Thereby, the stator core 11 is cooled. Since the coil supply ports 55a and 55b are always open, the refrigerant is always discharged regardless of the rotational speed of the rotor 4.

  As shown in FIG. 6, when the rotation speed of the rotor 4 further increases and the pressure in the refrigerant channel 51 increases, the amount of deformation of the elastic connection piece 64 increases. Thereby, the opening area of the slit 63 (the opening degree of the on-off valve 61) is increased, and the discharge amount of the refrigerant discharged through the slit 63 (core supply port 56) is increased. That is, in the refrigerant supply mechanism 6 of the present embodiment, the supply amount of the refrigerant to the stator core 11 increases as the rotation speed of the rotor 4 increases.

As described above, in the present embodiment, the core supply port 56 is provided with the on-off valve 61 that opens the core supply port 56 as the pressure of the refrigerant flowing through the refrigerant channel 51 increases.
According to this configuration, the opening degree of the on-off valve 61 can be made smaller by reducing the pressure in the refrigerant flow path 51 at the time of low rotation. Thus, the amount of refrigerant discharged from the core supply port 56 can be reduced, and the amount of refrigerant discharged from the coil supply ports 55a and 55b can be secured. Thus, the refrigerant can be actively supplied to the coil 12 (the coil end portions 12b and 12c) through the coil supply ports 55a and 55b, and the coil 12 can be actively cooled. On the other hand, by increasing the pressure in the refrigerant channel 51 at the time of high rotation, the on-off valve 61 can be opened. Thus, the refrigerant can be discharged through the core supply port 56, and the stator core 11 can be actively cooled.
Thus, since the supply position of the refrigerant in the stator 3 can be changed according to the pressure in the refrigerant flow path 51, excellent cooling performance can be exhibited with a simple configuration.

  In the present embodiment, since the coil supply ports 55a and 55b are provided on both sides in the axial direction with respect to the stator core 11, the refrigerant can be effectively supplied to the coil end portions 12b and 12c.

  In the present embodiment, since the on-off valve 61 is configured to be elastically deformable, the core supply port 56 is opened and closed according to the pressure of the refrigerant. Thereby, the above-mentioned effect is produced with a simpler configuration.

In the present embodiment, it is configured to include a refrigerant pump that delivers the refrigerant to the refrigerant passage 51 in conjunction with the rotation of the rotor 4.
According to this configuration, it is possible to increase or decrease the pressure of the refrigerant in the refrigerant flow path 51 in conjunction with the rotational speed of the rotor 4. This eliminates the need for separate control and the like for adjusting the pressure of the refrigerant, so that further simplification can be achieved.

In the present embodiment, the opening area of the core supply port 56 is larger than the opening area of the coil supply ports 55a and 55b.
According to this configuration, in the open state (high rotation state) of the on-off valve 61, the pressure loss when passing through the core supply port 56 can be reduced, and the refrigerant can be positively supplied to the stator core 11 through the core supply port 56 .

(Modification)
Next, a modification of the present embodiment will be described. 7 and 8 are cross-sectional views of the refrigerant supply mechanism 6 according to the modification.
As shown in FIG. 7, the on-off valve 100 according to the present modification includes a lid portion 101 and a biasing member 102.

The lid portion 101 opens and closes the core supply port 56.
The biasing member 102 is interposed between the lid portion 101 and the coolant channel 51. The biasing member 102 biases the lid portion 101 in the closing direction.

  According to this configuration, when the pressure acting on the lid portion 101 increases as the rotational speed of the rotor 4 increases, the lid portion 101 separates from the core supply port 56 against the biasing force of the biasing member 102. Displace in the direction. Thereby, the lid part 101 and the refrigerant flow path 51 are separated, and the core supply port 56 is opened (valve open state). As a result, the refrigerant discharged from the refrigerant flow path 51 through the core supply port 56 is supplied to the stator core 11 through the gap between the refrigerant flow path 51 and the lid portion 101.

  Thereafter, when the rotational speed of the rotor 4 decreases, the lid portion 101 is displaced in the direction approaching the core supply port 56 by the biasing force of the biasing member 102. As a result, the lid portion 101 is in close contact with the coolant channel 51, and the core supply port 56 is closed (valve closed state). As a result, the discharge of the refrigerant through the core supply port 56 is stopped.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Additions, omissions, substitutions, and other modifications of the configuration are possible without departing from the spirit of the present invention. The invention is not limited by the foregoing description, but is only limited by the scope of the appended claims.
In the embodiment described above, the on-off valve 61 is configured to open and close the core supply port 56 by being elastically deformed by the pressure in the refrigerant channel 51. However, the present invention is not limited to this configuration.
Although the embodiment described above describes the configuration in which the opening area of the core supply port 56 is larger than the opening area of the coil supply ports 55a and 55b, the present invention is not limited to this configuration. That is, the opening area of the core supply port 56 may be equal to or less than the opening area of the coil supply ports 55a and 55b.
In the embodiment described above, the configuration in which the on-off valve 61 is provided only on the core supply port 56 has been described.

  In addition, it is possible to replace components in the above-described embodiment with known components as appropriate without departing from the spirit of the present invention, and the above-described modifications may be combined as appropriate.

DESCRIPTION OF SYMBOLS 1 ... rotary electric machine 3 ... stator 4 ... rotor 6 ... refrigerant supply mechanism 11 ... stator core 12 ... coil 12b ... coil end part 12c ... coil end part 51 ... refrigerant channel 55a ... 1st coil supply port (coil supply port)
55b ... 2nd coil supply port (coil supply port)
56 ... core supply port 61, 100 ... on-off valve

Claims (5)

A cylindrical stator having a coil and a stator core on which the coil is mounted;
A coolant flow path extending in the axial direction of the stator and through which the coolant flows;
In the refrigerant flow path, a coil supply port for supplying the refrigerant to the coil is formed at a position overlapping the coil in the axial direction;
A core supply port for supplying the refrigerant to the stator core is formed at a position overlapping the stator core in the axial direction in the refrigerant flow path,
The rotary electric machine is provided with an open / close valve whose opening degree is increased as the pressure of the refrigerant flowing through the refrigerant flow passage is increased in the core supply port. The coil has a pair of coil end portions projecting on both sides in the axial direction with respect to the stator core,
The rotating electrical machine according to claim 1, wherein the coil supply port is provided on both sides in the axial direction with respect to the stator core.   The rotating electrical machine according to claim 1, wherein the on-off valve is configured to be elastically deformable. A rotor configured to be rotatable inward in a radial direction with respect to the stator;
The rotary electric machine according to any one of claims 1 to 3, further comprising: a refrigerant pump that delivers a refrigerant to the refrigerant flow path in conjunction with the rotation of the rotor.   The rotary electric machine according to any one of claims 1 to 4, wherein an opening area of the core supply port is larger than an opening area of the coil supply port.

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