JP2016063628A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of the components of a signal slip ring for measuring the temperatures of a plurality of parts of a rotor coil of a rotary electric machine and to reduce the friction of a brush disposed in contact with the signal slip ring.SOLUTION: A rotary electric machine 101 comprises: a first thermistor mounted on a first coil 12 and having a first conducting wire 81 and a second conducting wire 83a; a second thermistor 86 having the first conducting wire 82 and the second conducting wire 83b; a signal slip ring 71 connected to the first thermistor 85 and second thermistor 86; and brushes 54a, 54b disposed in contact with the signal slip ring 71. The second conducting wires 83a, 83b are connected to a common conducting wire 84. The signal slip ring 71 is divided into a first separated body 71a and second separate body 71b connected to the first conducting wires 81, 82, respectively, and a third separate body 71c connected to a common conducting wire 84.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a rotating electric machine, and more particularly to a double rotor type rotating electric machine mounted on a hybrid vehicle.

  Generally, a rotating electrical machine mounted on a hybrid vehicle includes an inner rotor that is rotationally driven by an engine, an outer rotor that is rotatably disposed around the inner rotor, and a stator that is disposed around the outer rotor. A three-phase alternating current is supplied from the inverter to the stator coil, and the outer rotor is rotated by the rotating magnetic field generated thereby, and the wheels of the vehicle are driven through the axle that is mechanically connected to the outer rotor. On the other hand, when the charging rate of the storage battery that supplies electric power to the stator decreases, the inner rotor as the rotor is driven to rotate by the engine and generates electric power.

  Here, when the temperature of the coil of the inner rotor is measured while the rotating electrical machine is being driven, temperature detection means such as a thermistor or a thermocouple must be provided in the coil, and a signal from the temperature detection means must be taken out to the outside. In such a case, in addition to the power slip ring used for the exchange of power between the inner rotor and the outside, a signal slip ring for taking out the signal of the temperature detecting means to the outside is required. In general, two signal slip rings for temperature measurement are provided for one temperature detecting means, as shown in FIG. Specifically, in the rotating electric machine 201 of FIG. 6, two signal slip rings 171 are provided adjacent to three power slip rings 170 corresponding to the U phase, the V phase, and the W phase, respectively. Yes. The two signal slip rings 171 correspond to the temperature detecting means 186 attached to the coil 112 of the inner rotor 110.

  Here, in order to grasp the coil temperature distribution or the like, the temperature at two or more locations of the coil may be measured. In such a case, the number of signal slip rings is two according to the number of temperature detecting means. It will increase in the axial direction. Therefore, there is a problem that the rotating electrical machine becomes larger in the axial direction as the number of signal slip rings increases.

  Therefore, in the rotating electrical machine described in Patent Document 1, a temperature measurement slip ring that is divided into four divided bodies in the circumferential direction is used in measuring the temperature at two locations of the coil. The four split members of the temperature measuring slip ring are each connected to two conductors of two thermistors, that is, a total of four conductors are electrically connected to each other. Thus, a temperature measurement signal can be taken out from the two thermistors.

JP 2000-146713 A

  However, in the rotating electric machine of Patent Document 1, since the temperature measurement slip ring is divided by a multiple of the number of thermistors in the circumferential direction, the number of parts per slip ring increases. In addition, since there is a gap at the connection location between the adjacent divided bodies, the tip of the brush may be caught in the gap at the connection location, and the wear of the brush may be accelerated.

  The present invention has been made to solve such a problem, and reduces the number of parts of the signal slip ring for measuring the temperature at a plurality of locations of the rotor coil, thereby reducing the wear of the brush contacting the signal slip ring. It is an object of the present invention to provide a rotating electrical machine that can be used.

In order to solve the above-described problems, a rotating electrical machine according to the present invention is attached to a rotor, a rotating shaft that supports the rotor so as to be integrally rotatable, a rotor coil provided in the rotor, and the rotor coil. And a plurality of temperature detecting means each having a first conducting wire and a second conducting wire, a signal slip ring which is attached to the rotary shaft so as to be integrally rotatable and electrically connected to the temperature detecting means, and a signal slip ring A pair of brushes in contact with each other, the second conductors of the plurality of temperature detecting means are connected to one common conductor, and the signal slip ring is divided into a plurality of divided bodies in the circumferential direction. One of the divided bodies is electrically connected to the common conducting wire, and each of the other divided bodies is electrically connected to each of the first conducting wires.
Thereby, the number of the divided bodies is reduced and the gap between the divided bodies is also reduced. Therefore, the frequency with which the brush contacts the gap between the divided bodies decreases, and the degree of wear of the brush decreases.

  The plurality of temperature detection means of the rotating electrical machine according to the present invention includes a first temperature detection means and a second temperature detection means, and the plurality of divided bodies are a first divided body, a second divided body, and It is composed of a third divided body, the first divided body is electrically connected to the first conductor of the first temperature detecting means, the second divided body is electrically connected to the second conductor of the second temperature detecting means, The third divided body may be electrically connected to the common conductor.

  According to the rotating electrical machine of the present invention, it is possible to suppress the number of parts of the signal slip ring for measuring the temperature at a plurality of locations of the rotor coil, and to reduce the wear of the brush contacting the signal slip ring. .

1 is a sectional side view showing a structure of a rotating electrical machine according to an embodiment of the present invention. In the rotary electric machine shown in FIG. 1, it is a figure which shows typically the mode of the electrical connection of a 1st thermistor, a 2nd thermistor, a signal slip ring, and an inverter. FIG. 3I is a diagram illustrating a state in which the contact state between the split body of the signal slip ring and the brush changes as the rotating electrical machine illustrated in FIG. 1 is driven. FIG. 3 (ii) is a table showing the connection relationship between the terminals A and B of the inverter and the wiring on the signal slip ring side, which changes with the change in the connection state shown in FIG. 3 (i). . The electrical connection relationship between the inverter and the first thermistor or the second thermistor in the rotating electrical machine shown in FIG. 1 corresponds to the contact state between the signal slip ring split body and the brush shown in FIG. It is a figure showing each typically. It is a graph which shows the change of the electric potential difference Vth between the terminal A of an inverter, and the terminal B with the change of the contact state of the division body of a signal slip ring shown in FIG.3 (i), and a brush. It is a figure which shows typically the structure of the rotary electric machine by the conventional example.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Referring to FIG. 1, the rotating electrical machine 101 includes a housing 1 and a metal rotating shaft 40 that penetrates the housing 1 and extends at both ends to the outside. The rotating shaft 40 is rotatably supported by the housing 1. One end 40a of the rotating shaft 40 is mechanically connected to an engine (not shown). The rotating electrical machine 101 includes an inner rotor 10, an outer rotor 20, and a stator 30. The inner rotor 10, the outer rotor 20, and the stator 30 each have a substantially cylindrical shape, and are arranged concentrically in order from the inside toward the outside. The inner rotor 10 is supported on the rotary shaft 40 so as to be integrally rotatable. That is, the inner rotor 10 can be mechanically connected to the vehicle engine via the rotary shaft 40 and can be driven to rotate as the engine is driven. The inner rotor 10 includes a first core 11 that is fixed to the rotary shaft 40 and first coils 12 that are disposed at both ends of the first core 11 along the circumferential direction thereof. Here, a first thermistor 85 and a second thermistor 86 are attached to the inside of the first coil 12 at positions facing each other with the rotary shaft 40 interposed therebetween. The first thermistor 85 detects the temperature of the U phase in the first coil 12, and the second thermistor 86 detects the temperature of the V phase in the first coil 12. The first thermistor 85 has a first conductor 81 and a second conductor 83a, and the second thermistor 86 has a first conductor 82 and a second conductor 83b. The first conducting wires 81 and 82 and the second conducting wires 83a and 83b extend through the inside of the rotary shaft 40. Here, the second conducting wire 83 a of the first thermistor 85 and the second conducting wire 83 b of the second thermistor 86 are connected to one common conducting wire 84 inside the rotating shaft 40. The first conductors 81 and 82 and the common conductor 84 extend inside the rotary shaft 40 toward the end 40b and are connected to a signal slip ring 71 described later.
The inner rotor 10 constitutes a rotor. The first coil 12 constitutes a rotor coil. The first thermistor 85 constitutes a first temperature detection means, and the second thermistor 86 constitutes a second temperature detection means. That is, the temperature detection means is composed of a first thermistor 85 as the first temperature detection means and a second thermistor 86 as the second temperature detection means.

  The outer rotor 20 includes a second core 21, a pair of permanent magnets 22 and 23 embedded in the second core 21 in an annular shape along the circumferential direction thereof, and a pair of dish-shaped members that sandwich and support the second core 21 from both ends. Rotor brackets 24 and 25. The outer rotor 20 is rotatably attached to the rotary shaft 40 via the rotor brackets 24 and 25. Therefore, the outer rotor 20 is provided so as to face the inner rotor 10 and be relatively rotatable. The permanent magnet 22 is disposed on the inner peripheral portion of the second core 21 so as to face the inner rotor 10, and the permanent magnet 23 is disposed on the outer peripheral portion of the second core 21 so as to face the stator 30. . The rotor bracket 25 is connected to a substantially cylindrical output shaft 60 provided so as to surround the periphery of the rotary shaft 40. The pinion gear 5 is fixedly connected to the output shaft 60 so as to rotate integrally therewith, and the pinion gear 5 is mechanically coupled to an axle (not shown) that drives a vehicle wheel (not shown). To do.

  The stator 30 is provided to face the outer rotor 20 and is attached to the inside of the housing 1 so as not to rotate. The stator 30 includes a stator core 31 and second coils 32 disposed at both ends of the stator core 31 along the circumferential direction thereof.

Further, outside the housing 1, a power slip ring part 70 and a signal slip ring 71 are attached to an end part 40 b of the rotary shaft 40 so as to be integrally rotatable. The power slip ring portion 70 includes three power slip rings 70a, 70b, and 70c that are sequentially arranged toward the housing 1 side. The power slip rings 70 a, 70 b and 70 c are electrically connected to the first coil 12 of the inner rotor 10. Further, brushes 51, 52 and 53 are in contact with these power slip rings 70a, 70b and 70c, respectively. The power slip rings 70a, 70b, 70c and the brushes 51, 52, 53 correspond to the U-phase, V-phase, and W-phase of the three-phase AC current, respectively.
Further, the signal slip ring 71 is provided adjacent to the housing 1 side of the power slip ring 70 c closest to the housing 1 in the power slip ring portion 70. The signal slip ring 71 is in contact with a pair of brushes 54a and 54b facing each other with a spacing of 180 degrees. The signal slip ring 71 is connected to the first conductor 81 of the first thermistor 85, the first conductor 82 of the second thermistor 86, and the common conductor 84. The second thermistor 86 is electrically connected.
Here, the inverter 6 is electrically connected to each of the brushes 51, 52, 53, 54a and 54b. That is, the first coil 12 of the inner rotor 10 is electrically connected to the inverter 6 via the power slip ring part 70 and the brushes 51, 52, 53. Further, the first thermistor 85 and the second thermistor 86 are also electrically connected to the inverter 6 via the signal slip ring 71 and the brushes 54a and 54b, respectively. The inverter 6 is electrically connected to the second coil 32 of the stator 30, the storage battery 7, and the ECU 3.

Next, the detailed structure of the signal slip ring 71 will be described with reference to FIG.
The signal slip ring 71 includes three divided bodies arranged adjacent to each other so as to occupy a range of about 120 degrees in the circumferential direction, a first divided body 71a, a second divided body 71b, and a third divided body. The body 71c is divided. Here, the boundary between the first divided body 71 a and the second divided body 71 b is a connection location 72. In addition, the boundary between the second divided body 71b and the third divided body 71c is a connection point 73. Further, the boundary between the third divided body 71 c and the first divided body 71 a is a connection point 74. There is a slight gap between the connection points 72 to 74.

The first conducting wire 81 of the first thermistor 85 is connected to the first divided body 71a. The first conductor 82 of the second thermistor 86 is connected to the second divided body 71b. Furthermore, the common conducting wire 84 of the first thermistor 85 and the second thermistor 86 is connected to the third divided body 71c.
Further, the brushes 54a and 54b always come into contact with at least two divided bodies among the three divided bodies 71a to 71c. Further, the brush 54 a is electrically connected to the terminal A of the inverter 6, and the brush 54 b is electrically connected to the terminal B of the inverter 6. In the inverter 6, the terminal B is grounded. Here, the potential difference between the terminal B and the terminal A is a voltage Vth.
In the following description, the first conductor 81 that electrically connects the first divided body 71a and the first thermistor 85 is referred to as a wiring α. Similarly, the first conductor 82 that electrically connects the second divided body 71b and the second thermistor 86 is defined as a wiring β. Furthermore, the second conductors 83a and 83b and the common conductor 84 that electrically connect the third divided body 71c, the first thermistor 85, and the second thermistor 86 are defined as a wiring γ.

Next, the overall operation of the rotating electrical machine 101 will be described with reference to FIG. In the following description, traveling of the vehicle when the rotating electrical machine 101 is driving the wheels without generating power is referred to as EV mode traveling. In addition, traveling of the vehicle when the rotating electrical machine 101 generates power and simultaneously drives the wheels is referred to as RE (range extended) mode traveling.
First, the operation of the rotating electrical machine 101 when the vehicle is traveling in the EV mode will be described.
A three-phase alternating current flows from the storage battery 7 to the second coil 32 of the stator 30 via the inverter 6. As a result, a rotating magnetic field is generated between the second coil 32 and the permanent magnet 23 of the outer rotor 20. The outer rotor 20 starts to rotate due to a rotating magnetic field generated between the second coil 32 of the stator 30 and the permanent magnet 23 of the outer rotor 20, and the vehicle wheels are rotated via the output shaft 60 and the pinion gear 5. Driven.

Next, the operation of the rotating electrical machine 101 when the vehicle is traveling in the RE mode will be described. The vehicle travels in the RE mode when the charging rate of the storage battery 7 becomes a certain value or less.
When a three-phase alternating current is supplied from the storage battery 7 to the second coil 32 of the stator 30 via the inverter 6, a rotating magnetic field is generated between the second coil 32 and the permanent magnet 32 of the outer rotor 20. By this rotating magnetic field, the outer rotor 20 rotates in the same manner as during EV mode traveling, and drives the wheels of the vehicle via the output shaft 60 and the pinion gear 5. On the other hand, the inner rotor 10 is rotationally driven by the engine via the rotating shaft 40. Therefore, an induced current is generated in the first coil 12 of the inner rotor 10 that rotates to face the permanent magnet 22 of the outer rotor 20. The electric power generated in the first coil 12 is stored in the storage battery 7 via the power slip ring part 70, the brushes 51, 52, 53 and the inverter 6.

Next, a method for measuring the temperature of the first coil 12 of the inner rotor 10 using the first thermistor 85 and the second thermistor 86 will be described with reference to FIGS.
First, as the rotary shaft 40 rotates, the contact position between the signal slip ring 71 and the brushes 54a and 54b changes as shown in states R1 to R6 in FIG. For example, in the state R1, the brush 54a contacts the third divided body 71c of the signal slip ring 71, and the brush 54b contacts the second divided body 71b. Therefore, as shown in the table of FIG. 3 (ii), the terminal A of the inverter 6 is electrically connected to the wiring γ, and the terminal B is electrically connected to the wiring β. Next, when the rotary shaft 40 rotates about 60 degrees clockwise and moves to the state R2, the brush 54a contacts the third divided body 71c, and the brush 54b contacts the first divided body 71a. That is, as shown in FIG. 3 (ii), the terminal A of the inverter 6 is connected to the wiring γ, and the terminal B is connected to the wiring α. Next, when the state R3 is entered, the brush 54a contacts the second divided body 71b, and the brush 54b contacts the first divided body 71a. That is, as shown in FIG. 3 (ii), the terminal A of the inverter 6 is connected to the wiring β, and the terminal B is connected to the wiring α. Similarly, in the state R4, the terminal A of the inverter 6 is connected to the wiring β, and the terminal B is connected to the wiring γ. Next, in the state R5, the terminal A of the inverter 6 is connected to the wiring α, and the terminal B is connected to the wiring γ. Next, in the state R6, the terminal A of the inverter 6 is connected to the wiring α, and the terminal B is connected to the wiring β.

Further, changes in the connection state between the first thermistor 85 or the second thermistor 86 and the terminals A and B of the inverter 6 will be described with reference to FIGS.
First, when the signal slip ring 71 and the brushes 54a and 54b are in the contact position of the state R1 or R4 shown in FIG. 3 (i), the terminal A and the terminal B of the inverter 6 are as shown in FIG. 4 (a). The second thermistor 86 is electrically connected. When the signal slip ring 71 and the brushes 54a and 54b are in the contact position in the state R2 or R5, the terminal A and the terminal B of the inverter 6 are connected to the first thermistor 85 as shown in FIG. Electrically connected. Further, in the state R3 or R6, as shown in FIG. 4C, the first thermistor 85 and the second thermistor 86 are arranged in series with each other and are electrically connected to the terminal A and the terminal B of the inverter 6. ing.

  Accordingly, the voltage Vth changes as shown in FIG. 5 in accordance with the change in the contact position between the signal slip ring 71 and the brushes 54a and 54b as in the states R1 to R6 shown in FIG. Here, the ECU 3 calculates the U-phase temperature of the first coil 12 detected by the first thermistor 85 based on the voltages Vth of the states R2 and R5. Further, the ECU 3 calculates the temperature of the V phase of the first coil 12 detected by the second thermistor 86 based on the voltages Vth of the states R1 and R4. In the states R3 and R6, the first thermistor 85 and the second thermistor 86 are connected in series via the signal slip ring 71 as shown in FIG. Cannot be measured based on the voltage Vth. In the states R3 and R6, the voltage Vth rapidly increases as shown in FIG. Therefore, the ECU 3 ignores the voltage Vth in a range where the voltage Vth takes a value that cannot normally be reached, that is, in the states R3 and R6.

As described above, in the rotary electric machine 101 according to the first embodiment, the signal slip ring 71 is divided into the plurality of divided bodies 71a to 71c. The first divided body 71a is the first conductor 81 of the first thermistor 85, the second divided body 71b is the first conductor 82 of the second thermistor 86, and the third divided body 71c is the first thermistor 85 and the second thermistor. 86 common conductors 84 are connected to each other. Thereby, the temperature of two places corresponding to the U-phase and V-phase of the first coil 12 of the inner rotor 10 can be measured by one signal slip ring 71. Therefore, when the temperature of only the U-phase or the V-phase of the first coil 12 rapidly increases, it can be detected that an abnormality has occurred in the driving of the rotating electrical machine 101. Further, the temperature distribution of the first coil 12 can also be grasped. Specifically, it can be determined whether the higher temperature of the two temperatures of the first coil 12 to which the first thermistor 85 and the second thermistor 86 are attached does not exceed the allowable temperature.
The second conductor 83a of the first thermistor 85 and the second conductor 83b of the second thermistor 86 are connected to one common conductor 84, and the common conductor 84 is connected to only one third divided body 71c. Therefore, conventionally, the number of divided bodies of the signal slip ring 71 is four corresponding to each of the first conductor and the second conductor of the first thermistor 85 and the second thermistor 86. The temperature of two places of the first coil 12 can be measured by the divided body. Therefore, the number of parts of the rotating electrical machine 101 can be reduced. In addition, since the number of connection points between the divided bodies is reduced, the frequency at which the tip portions of the brushes 54a and 54b are caught in the gaps existing in the connection points 72, 73, and 74 between the divided bodies 71a to 71c is reduced, and the brushes 54a and 54b. Wear is reduced.

In the embodiment, the thermistor is used as the temperature detecting means, but the present invention is not limited to this, and a thermocouple may be used.
Further, the location of the first coil 12 detected by the temperature detecting means is not limited to the portion corresponding to the U phase and the V phase, and may be a location corresponding to any two phases of the U phase, the V phase, and the W phase. That's fine. Further, temperature detecting means may be provided at three or more locations of the first coil 12, and the signal slip ring 71 may be divided into four or more divided bodies.

  DESCRIPTION OF SYMBOLS 10 Inner rotor (rotor), 12 1st coil (rotor coil), 40 rotation shaft, 54a, 54b brush, 71 signal slip ring, 71a 1st division body (division body), 71b 2nd division body (division) Body), 71c third divided body (divided body), 81, 82 first conductor, 83a, 83b second conductor, 84 common conductor, 85 first thermistor (first temperature detecting means), 86 second thermistor (second) Temperature detecting means), 101 rotating electric machine.

Claims (2)

A rotor,
A rotating shaft that supports the rotor so as to be integrally rotatable;
A rotor coil provided in the rotor;
A plurality of temperature detecting means attached to the rotor coil and each having a first conductor and a second conductor;
A signal slip ring which is attached to the rotary shaft so as to be integrally rotatable, and is electrically connected to the temperature detecting means;
A pair of brushes in contact with the signal slip ring,
The second conductors of the plurality of temperature detecting means are connected to one common conductor;
The signal slip ring is divided into a plurality of divided bodies in the circumferential direction,
One rotating body among the plurality of divided bodies is electrically connected to the common conducting wire, and each of the other divided bodies is electrically connected to each of the first conducting wires. The plurality of temperature detection means includes a first temperature detection means and a second temperature detection means,
The plurality of divided bodies are composed of a first divided body, a second divided body, and a third divided body that are adjacent to each other.
The first divided body is electrically connected to the first conductor of the first temperature detecting means,
The second divided body is electrically connected to the second conducting wire of the second temperature detecting means,
The rotating electrical machine according to claim 1, wherein the third divided body is electrically connected to the common conducting wire.

Images