JP2018107865A - Rotating electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotating electric machine capable of reducing a difference between a refrigerant temperature after passing through a temperature sensor and a refrigerant temperature supplied to a stator. A rotating electric machine (1) is a stator (5) and a cooling pipe (7) radially facing the stator (5) and extending along the stator (5), which is arranged on one side of the cooling pipe (7) in the axial direction. One or more through holes including the end side through hole provided on the side wall of the cooling pipe 7 so as to face the stator 5 in the radial direction, and the tip opening on one side in the axial direction of the cooling pipe 7. A sealing member 8 for closing the cooling pipe, a temperature sensor 10 attached to the sealing member 8 and at least a part of which is arranged in the cooling pipe 7, and a coolant is supplied into the cooling pipe 7 and discharged from the through hole to the stator 5 side. And a pump 11 for allowing the pump 11 to operate. [Selection diagram] Figure 1

Description

  The present invention relates to a rotating electrical machine.

  Conventionally, as described in Patent Document 1, as a rotating electrical machine, a stator, a rotor disposed on the inner peripheral side of the stator, and cooling disposed on the outer peripheral side of the stator so as to face the stator in the radial direction Some pumps have a pipe and a pump that takes the refrigerant into the cooling pipe. The stator includes a stator core and a coil wound around the teeth of the stator core, and the cooling pipe extends in the axial direction of the stator along the stator. In addition, the cooling pipe is provided with a plurality of through-holes that communicate between the inside and the outside and have openings that are radially opposed to the stator. When the pump is driven, the refrigerant in the case is taken into the cooling pipe and discharged toward the stator through the plurality of through holes. In a rotating electrical machine, when a current flows through a coil when the rotor rotates, the stator core and the coil generate heat. Such heat generation affects the magnetic flux penetrating the inside of the rotating electrical machine, and decreases the operation efficiency (rotation efficiency, power generation efficiency). In this rotating electrical machine, the stator core and the coil are cooled by discharging the refrigerant to the stator core and the coil, thereby suppressing a decrease in operating efficiency.

No. 2015-089314

  In the rotating electrical machine that performs cooling of the stator, there is a demand to install a temperature sensor that measures the refrigerant temperature in order to detect the cooling performance. However, depending on the mounting position of the temperature sensor, there is a difference between the refrigerant temperature after passing through the temperature sensor and the refrigerant temperature supplied to the stator, and it is difficult to perform proper motor protection control.

  Therefore, an object of the present invention is to provide a rotating electrical machine that can reduce the difference between the refrigerant temperature after passing through the temperature sensor and the refrigerant temperature supplied to the stator.

  A rotating electrical machine according to the present invention includes a stator including an annular stator core, a coil wound around the teeth of the stator core, and faces the stator in the radial direction of the stator core, and extends along the stator. One or more through holes including an end side through hole disposed on one side of the cooling pipe in the axial direction are provided on a side wall of the cooling pipe so as to face the stator in the radial direction. A cooling pipe provided; a sealing member that seals the opening on one end of the cooling pipe in the axial direction; and a temperature sensor that is attached to the sealing member and at least partially disposed in the cooling pipe; And a refrigerant supply device that supplies the refrigerant into the cooling pipe and discharges the refrigerant to the stator side from the through hole.

  In the present invention, the sealing member is formed with a concave portion extending in the axial direction at a central portion, the temperature sensor is disposed in the concave portion, and one end face of the temperature sensor is the cooling pipe. It is preferable to be exposed inside.

  In the present invention, it is preferable that the wiring from the temperature sensor passes through the sealing member and is led out of the cooling pipe.

  According to the rotating electrical machine according to the present invention, the cooling pipe is provided along the stator, and the refrigerant supply device causes the refrigerant to pass through the one or more through holes from the inside of the cooling pipe and be discharged to the stator side. Further, the one or more through holes include an end side through hole disposed on one side in the axial direction of the cooling pipe, and the temperature sensor is provided in a sealing member that seals one side in the axial direction of the cooling pipe, and at least partly Is placed in the cooling pipe. Therefore, since the temperature sensor is disposed at a position close to the end side through hole, the refrigerant temperature immediately before the temperature sensor passes through the end side through hole can be measured. Therefore, the difference between the refrigerant temperature after passing through the temperature sensor and the refrigerant temperature supplied to the stator can be reduced, the refrigerant temperature estimation accuracy is improved, and appropriate motor protection control can be executed.

It is sectional drawing of the axial direction of the rotary electric machine which concerns on one Embodiment of this invention. It is an expanded sectional view around a cooling pipe in the rotating electrical machine.

  Embodiments according to the present invention will be described below in detail with reference to the accompanying drawings. In the following, when a plurality of embodiments and modifications are included, it is assumed from the beginning that a new embodiment is constructed by appropriately combining those characteristic portions. In the following description and drawings, the Z direction coincides with the vertical direction, and in FIGS. 1 and 2, the upper side of the drawing indicates the upper side in the vertical direction.

  FIG. 1 is a cross-sectional view of a rotating electrical machine 1 according to an embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view around a cooling pipe 7 in the rotating electrical machine 1. As shown in FIG. 1, the rotary electric machine 1 includes a case 2 and an electric machine main body 3 disposed in the case 2. The case 2 includes a case main body 21 and an upper cover 22, and the case main body 21 is open on the upper side in the Z direction, and the opening is covered with the upper cover 22. The upper cover 22 is fixed to the opening periphery of the case body 21 with bolts 23. On the other hand, the electric machine main body 3 includes a stator 5, a rotor 6, a cooling pipe 7, a sealing member 8, a temperature sensor 10, and a pump 11 as an example of a refrigerant supply device. The stator 5 includes an annular stator core 51 and a stator coil 52. The stator core 51 extends in the Z direction. The stator core 51 is a magnetic component and is configured by, for example, laminating a plurality of silicon steel plates (electromagnetic steel plates), but may be configured by pressing a resin binder and magnetic material powder. The stator core 51 has an annular yoke 53 disposed on the outer peripheral side and a plurality of teeth 54. The plurality of teeth 54 are arranged at intervals in the circumferential direction, and each tooth 54 protrudes from the yoke 53 inward in the radial direction. The stator coil 52 includes three-phase coils of U, V, and W. For example, the stator coil 52 is configured by Y-connecting three-phase coils of U, V, and W. Each of the three-phase coils is inserted into a slot (not shown) that is a space between adjacent teeth 54 and wound around the teeth 54.

  The rotor 6 is disposed on the inner peripheral side of the stator 5 with a space from the stator 5, and the center of the rotor 6 coincides with the center of the stator 5. The rotor 6 includes an annular rotor core 61 and a shaft 62 inserted and fixed in a through hole of the rotor core 61. The rotor core 61 extends in the Z direction. The rotor core 61 is a magnetic part, and is configured by, for example, laminating a plurality of annular silicon steel plates (electromagnetic steel plates). For example, a plurality of permanent magnets are embedded in the rotor core 61 at intervals in the circumferential direction. The shaft 62 extends in the Z direction and is rotatably attached to the inner peripheral surface of the case 2 via bearings 32a and 32b.

  The cooling pipe 7 is a hollow pipe and extends in the Z direction. The cooling pipe 7 is arranged on the outer peripheral side of the stator 5 so as to face the radial direction of the stator core 51 and along the stator 5. In the cooling pipe 7, the front end opening of the upper end portion 71 is blocked by the blocking member 8, while the opening of the lower end portion 72 is opened and communicates with the passage 27 provided in the case 2. The lower end 72 of the cooling pipe 7 has a disk-shaped flange 7a. The lower end 72 of the cooling pipe 7 is press-fitted into the press-fitting hole 2 a provided in the case 2 until the flange 7 a comes into contact with the wall surface of the case 2 and is fixed to the case 2.

  The sealing member 8 is made of, for example, a resin material. As shown in FIG. 2, the sealing member 8 has a disk-shaped lid portion 81 and a columnar press-fit portion 82. The central axis of the lid portion 81 coincides with the central axis of the press-fit portion 82, and the outer diameter of the lid portion 81 is larger than the outer diameter of the upper end portion of the cooling pipe 7. The press-fit portion 82 is press-fitted into the cooling pipe 7 until the lower surface of the lid portion 81 contacts the upper end surface of the cooling pipe 7, and the sealing member 8 is fixed to the cooling pipe 7 by such press-fitting.

  The rotating electrical machine 1 further includes a cylindrical rubber bush 88. Further, the sealing member 8 has a cylindrical portion 83 that protrudes upward from the lid portion 81. The rubber bushing 88 is attached to the upper surface of the cylindrical portion 83 with an adhesive or the like, for example, with its central axis substantially coinciding with the central axis of the cooling pipe 7, and the lower surface of the upper cover 22 of the case 2 and the cylindrical portion. 83 is disposed between the upper surface of 83. The integral structure composed of the cooling pipe 7, the sealing member 8, and the rubber bush 88 is sandwiched between the upper cover 22 of the case 2 and the case body 21 so as to receive a compressive load. As a result, the overall length of the rubber bush 88 in the axial direction is shorter than the natural length of the rubber bush 88, and the integrated structure is fixed to the case 2.

  The cooling pipe 7 is provided with a plurality of through holes 77 at intervals in the Z direction. The opening outside the cooling pipe in each through-hole 77 faces the stator 5 in the radial direction (the radial direction of the stator core 51), and more specifically, faces the coil end 52a of the stator coil 52 in the radial direction. The plurality of through-holes 77 include an end-side through-hole 77a disposed on one side (the upper side in the axial direction) of the cooling pipe 7 in the axial direction. Since the press-fit portion 82 of the sealing member 8 is press-fitted into one end portion (the upper end portion in the axial direction) of the cooling pipe 7, as a result, the end side through hole 77 a is close to the press-fit portion 82. Be placed. The end side through-hole 77 a is provided slightly below the Z direction from the lower end of the press-fit portion 82.

  The temperature sensor 10 includes a thermistor element 14 whose electric resistance varies depending on temperature. The thermistor element 14 is enclosed in a resin press-fit portion 82 and disposed in the cooling pipe 7. Specifically, the press-fit portion 82 of the sealing member 8 is formed with a concave portion 19 extending in the axial direction at the center portion, and the thermistor element 14 is disposed in the concave portion 19. The thermistor element 14 has an exposed portion 14 a exposed from the press-fit portion 82, and the exposed portion 14 a faces the refrigerant accommodating chamber 79 in the cooling pipe 7. The exposed portion 14 a is configured by one end face (lower end face) of the thermistor element 14. The thermistor element may protrude downward from the sealing member, and the exposed portion may include the side surface of the thermistor element. The thermistor element 14 is electrically connected to a control unit (not shown) outside the case via a lead wire 18 that is a wiring. More specifically, after passing through the sealing member 8, the lead wire 18 also passes through the case 2 and is electrically connected to the control unit. In the case 2, ATF (Automatic Transmission Fluid; not shown) as an example of a refrigerant is sealed. As will be described later, the exposed portion 14a of the thermistor element 14 contacts the ATF. When the temperature of the thermistor element 14 changes according to the temperature of the ATF, the resistance value of the thermistor element 14 changes and the current flowing through the lead wire 18 changes. The control unit detects the ATF temperature in contact with the thermistor element 14 by measuring the current flowing through the lead wire.

  Referring to FIG. 1 again, the pump 11 is housed in the pump housing chamber 2b on the lower side of the case. The pump housing chamber 2b communicates with the stator housing chamber 2c in which the stator 5 is housed through a space formed between the inner and outer rings of the lower bearing 32b, and the ATF is separated from the stator housing chamber 2c by the gravity. It is possible to flow to the side. The opening on the lower side which is not closed in the cooling pipe 7 communicates with the pump housing chamber 2b through the passage 27.

  In the above configuration, when rotating power is output, for example, after a direct current from a battery (not shown) is converted into a three-phase alternating current via an inverter (not shown), the three-phase alternating current is converted into the above-described U, V , W are supplied to a three-phase coil. By supplying the three-phase alternating current to the three-phase coils of U, V, and W, the teeth 54 are magnetized to become magnetic poles, and a rotating magnetic field is generated in which the position of the magnetic poles moves along the circumferential direction of the stator 5. Then, the rotor 6 rotates based on the rotating magnetic field, and rotational power is generated. On the other hand, when regenerating electric power, when the rotor 6 is rotated by external power, the permanent magnet embedded in the rotor 6 rotates around the rotor central axis. Then, an induced electromotive force based on the law of electromagnetic induction is induced in the three-phase coil of U, V, and W, and an alternating induction current flows through the three-phase coil of U, V, and W. Then, AC power from the three-phase coils of U, V, and W based on the induced current is converted into DC power by the inverter, and then supplied to the battery.

  Referring to FIG. 1, when the pump 11 is driven, the ATF accumulated in the pump storage chamber 2b below the case is passed from the lower side in the direction indicated by the arrow A into the cooling pipe 7 through the passage 27 by the pump 11. Pumped. The ATF pumped into the cooling pipe 7 is discharged from the through hole 77 toward the coil end 52 a of the stator 5 in the direction indicated by the arrow B. At that time, the ATF pumped to the upper side of the cooling pipe 7 comes into contact with the exposed portion 14a (see FIG. 2), and then is discharged toward the upper coil end 52a through the end side through hole 77a. The ATF blown to the upper coil end 52a travels down the stator coil 52 and the stator core 51 in the direction indicated by the arrow C due to gravity and moves downward while taking heat away from the members 51 and 52. It passes through the rolling element arrangement space (the space between the outer ring and the inner ring) of the bearing 32b and moves to the pump storage chamber 2b below the case. The wall surface portion 2d that defines the pump housing chamber 2b is made of, for example, a metal having excellent heat dissipation. The ATF comes into contact with the stator 5 and takes heat from the stator 5 and rises in temperature. Then, the ATF is cooled by releasing heat to the wall surface portion 2d in the pump housing chamber 2b. The cooled ATF is pumped again into the cooling pipe 7 by the pump 11. As the ATF is circulated, the cooled ATF is discharged from the cooling pipe 7 toward the stator 5 as needed, so that the stator 5 is cooled.

  According to the above embodiment, the cooling pipe 7 is provided along the stator 5, and the pump 11 causes the ATF to be discharged from the cooling pipe 7 through the one or more through holes 77 to the stator 5 side. One or more through-holes 77 include an end-side through-hole 77 a disposed on one side in the axial direction of the cooling pipe 7, and the temperature sensor 10 is attached to the sealing member 8 that seals one side in the axial direction of the cooling pipe 7. Provided, and at least a part thereof is disposed in the cooling pipe 7. Therefore, since the temperature sensor 10 is disposed at a position close to the end side through hole 77a, the temperature of the ATF immediately before the temperature sensor 10 passes through the end side through hole 77a can be measured. Therefore, the difference between the ATF temperature after passing through the temperature sensor 10 and the ATF temperature supplied to the stator 5 can be reduced, the estimation accuracy of the ATF temperature is improved, and appropriate motor protection control can be executed.

  Further, since the temperature sensor 10 is incorporated in the sealing member 8 for attaching the cooling pipe 7 to the case 2, a dedicated part for mounting the temperature sensor for disposing the temperature sensor 10 around the ATF (for example, a sensor bracket (Japanese Patent Laid-Open No. 2014) -178258))) can be omitted. Therefore, the manufacturing cost of the rotary electric machine 1 can be reduced.

  Furthermore, not only a dedicated part for attaching the temperature sensor is not necessary, but also the temperature sensor 10 is mounted in the dead space on the tip side of the cooling pipe 7. Therefore, even if the temperature sensor 10 is mounted, the rotating electrical machine 1 is hardly increased in size. Therefore, the rotary electric machine 1 including the temperature sensor 10 can be configured in a compact manner, and the mountability of the rotary electric machine 1 including the temperature sensor 10 on a vehicle or the like can be improved.

  The present invention is not limited to the above-described embodiment and its modifications, and various improvements and modifications can be made within the matters described in the claims of the present application and their equivalent ranges.

  For example, in the above-described embodiment, the case where the cooling pipe 7 extends in parallel to the axial direction of the stator core 51 has been described. However, the cooling pipe may extend in a direction inclined in the axial direction of the stator core. Further, the case where the cooling pipe 7 has only the through hole 77 facing the coil end 52a in the radial direction of the stator core 51 has been described. However, the cooling pipe may have one or more through holes opposed to the stator core in the radial direction in addition to one or more through holes opposed to the coil end in the radial direction of the stator core. Alternatively, the cooling pipe may have only one or more through holes opposed to the stator core in the radial direction without having a through hole opposed to the coil end in the radial direction of the stator core. Moreover, although the case where all the thermistor elements 14 of the temperature sensor 10 are disposed in the cooling pipe 7 has been described, only a part of the thermistor elements of the temperature sensor may be disposed in the cooling pipe. Further, the case where the thermistor element 14 constituting the temperature sensor 10 has the exposed portion 14a exposed in the cooling pipe 7 and the exposed portion 14a directly contacts the ATF has been described. However, all of the thermistor elements are disposed in the sealing member, and the thermistor element does not have an exposed portion exposed in the cooling pipe, and the thermistor element indirectly receives heat from the ATF via the sealing member. It may be configured. Moreover, although the case where a refrigerant | coolant was ATF was demonstrated, various refrigerant | coolants may be sufficient as a refrigerant | coolant, and it may be comprised with a washing | cleaning liquid etc. Further, although the case where the refrigerant supply device is the pump 11 has been described, the refrigerant supply device may be configured by a ring gear or the like that scoops up and flows the refrigerant.

  DESCRIPTION OF SYMBOLS 1 Rotating electrical machine, 5 Stator, 7 Cooling pipe, 8 Sealing member, 10 Temperature sensor, 11 Pump, 51 Stator core, 52 Stator coil, 54 Teeth, 77 Through-hole, 77a End side through-hole

Claims (1)

A stator including an annular stator core and a coil wound around the teeth of the stator core;
One or more cooling pipes facing the stator in the radial direction of the stator core and extending along the stator, including an end-side through-hole disposed on one side in the axial direction of the cooling pipe A cooling pipe provided on a side wall of the cooling pipe so that a through-hole faces the stator in the radial direction;
A sealing member for sealing a tip opening on one side of the cooling pipe in the axial direction;
A temperature sensor attached to the sealing member and at least partially disposed within the cooling pipe;
A refrigerant supply device for supplying a refrigerant into the cooling pipe and discharging the refrigerant to the stator side from the through hole;
A rotating electrical machine.

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