JP2016193681A - Cooling device of rotary electric machine for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device of a rotary electric machine for a vehicle which efficiently cools the rotary electric machine without operating an engine even during EV traveling when a mechanical cooling fluid pump is adopted to cool the rotary electric machine in a hybrid system using the rotary electric machine and the engine.SOLUTION: A gear 16 is provided at a drive shaft 11 of a diesel engine 10, and a gear 17 and a gear 18 mesh with the gear 16 and a gear 15 provided at an arm 12 respectively. The gears 17 and 18 are respectively connected to a drive shaft 63 of a cooling fluid pump 72 through a first one-way clutch 61 and a second one-way clutch 62. The first one-way clutch 61 allows only power transmission from the drive shaft 11 to the drive shaft 63. Meanwhile, the second one-way clutch 62 allows only power transmission from the arm 12 to the drive shaft 63.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cooling device for a rotating electrical machine for a vehicle.

  A hybrid vehicle having an engine and a rotating electric machine as a power source is usually provided with a cooling system for the rotating electric machine. This cooling system includes an oil circulation path for cooling the rotating electrical machine and a pump for circulating the oil. Patent Document 1 describes a mechanical oil pump that is driven by the power of an engine.

JP 2014-83907 A

  However, in a hybrid vehicle capable of intermittently stopping the engine, when the engine stops, the oil pump is not driven, and therefore the oil circulation to the rotating electrical machine is stopped. Therefore, when the temperature of the rotating electrical machine becomes high, it is necessary to circulate oil by driving the engine for cooling the rotating electrical machine. That is, there is a problem that the engine needs to be driven to cool the rotating electrical machine during EV traveling where only the rotating electrical machine travels, and the fuel consumption of the hybrid vehicle is deteriorated.

  The present invention has been made to solve such problems, and in a hybrid system using a rotating electrical machine and an engine, when a mechanical cooling fluid pump is used for cooling the rotating electrical machine, the EV is provided. An object of the present invention is to provide a cooling device for a rotating electrical machine for a vehicle that can efficiently cool the rotating electrical machine without operating the engine even during traveling.

A cooling apparatus for a rotating electrical machine for a vehicle according to the present invention includes an engine, a first rotor coupled to the engine, a second rotor disposed on a radially outer side of the first rotor and coupled to an axle. And a cooling fluid pump that is driven by transmission of power from the first rotor and the second rotor and supplies a cooling fluid to the rotating electrical machine, and the first rotor and the cooling fluid pump are connected to each other. In addition, the first one-way clutch that only allows transmission of power from the first rotor to the cooling fluid pump is connected to the second rotor and the cooling fluid pump, and the cooling fluid is supplied from the second rotor to the cooling fluid. A second one-way clutch that only allows transmission of power to the pump.
A battery for supplying electric power for driving the rotating electric machine to charge the electric power generated by the rotating electric machine, a charge amount detecting means for detecting a charge amount of the battery, and a control device for controlling the operation of the engine The control device may increase the engine speed when the detection value by the charge amount detection means is less than a predetermined value preset in the control device.
The control device incorporates an engine efficiency map of the engine, and when the detected value by the charge amount detecting means is less than a predetermined value, the control device can increase the engine speed based on the engine efficiency map. You may decide.

  According to this invention, the first one-way clutch that allows only the transmission of power from the first rotor to the cooling fluid pump, and the second that allows only the transmission of power from the second rotor to the cooling fluid pump. By providing the one-way clutch, the power is transmitted from the second rotor to the cooling fluid pump via the second one-way clutch even when the engine is stopped and the EV is running with only the rotating electrical machine. Since the cooling fluid pump can be driven, the rotating electrical machine can be efficiently cooled without operating the engine.

It is a figure which shows the structure of the cooling device of the rotary electric machine for vehicles which concerns on embodiment of this invention. It is a flowchart which shows operation | movement of the cooling device of the rotary electric machine for vehicles which concerns on this embodiment. It is an engine efficiency map of a hybrid vehicle provided with a cooling device for a rotating electrical machine for a vehicle according to this embodiment.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 shows the configuration of a cooling apparatus 100 for a vehicular rotating electrical machine according to an embodiment of the present invention. The cooling device 100 is provided in a hybrid vehicle including a diesel engine 10 that is an engine that generates light by burning light oil inside, and a double rotor motor 20 that is a rotating electrical machine that operates by three-phase AC power as a power source. ing. The double rotor motor 20 is mechanically coupled to the drive shaft 11 of the diesel engine 10 and is disposed on the radially outer side of the inner rotor 21 of the first rotor that rotates integrally with the drive shaft 11. The outer rotor 22 of the second rotor that is mechanically connected to the axle 14 via the arm 12 and the gear 15 provided on the arm 12 and the differential 13, and the motor casing 24 that is disposed radially outside the outer rotor 22. And a stator 23 fixed to the head.

  The inner rotor 21 is provided with a first coil 25, and the stator 23 is provided with a second coil 26. A magnet (not shown) is provided on the inner peripheral side of the outer rotor 22 so as to face the first coil 25 of the inner rotor 21, and the second coil of the stator 23 is provided on the outer peripheral side of the outer rotor 22. A magnet (not shown) is provided so as to face 26. The second coil 26 is provided with a temperature sensor 37 as temperature detecting means. In this embodiment, the detected value of the temperature sensor 37, that is, the temperature of the second coil 26 is defined as the temperature of the double rotor motor 20.

  The cooling device 100 includes a battery 30 that is power supply means capable of charging and discharging DC power, and a first inverter 31 and a second inverter 32 that convert DC power output from the battery 30 into three-phase AC power. The first inverter 31 and the second inverter 32 are controlled by the ECU 50 that is a control device. The ECU 50 detects the charge amount of the battery 30 from the voltage of the battery 30 or the like. Here, the ECU 50 constitutes a charge amount detection means for detecting the charge amount of the battery 30.

  The three-phase AC power output from the first inverter 31 is supplied to the second coil 26 of the stator 23. On the other hand, the three-phase AC power output from the second inverter 32 is transmitted to a conductive wire (not shown) wired along the drive shaft 11 via the slip ring mechanism 40 and passes through the conductive wire of the inner rotor 21. It is supplied to the first coil 25.

  The cooling device 100 is provided with a rotating electrical machine cooling system 70 that cools the double rotor motor 20. The rotating electrical machine cooling system 70 includes a cooling fluid circulation path 71 through which oil, which is a cooling fluid that cools the double rotor motor 20, particularly the first coil 25 and the second coil 26, and a cooling fluid pump 72 that circulates oil. A water circulation path 73 through which water circulates, a water pump 74 through which water circulates, a heat exchanger 75 through which heat is exchanged between oil through the cooling fluid circulation path 71 and water through the water circulation path 73, and a water circulation path A radiator 76 and a fan 77 which are cooling means 78 for cooling the water circulating through 73 are provided. Driving and stopping of the water pump 74 and the fan 77 are controlled by the ECU 50. The water circulation path 73 is arranged so that the circulating water can cool the first inverter 31 and the second inverter 32.

  A gear 16 is provided on the drive shaft 11 of the diesel engine 10, and a gear 17 and a gear 18 are engaged with the gear 16 and the gear 15 provided on the arm 12, respectively. The gears 17 and 18 are connected to the drive shaft 63 of the cooling fluid pump 72 via the first one-way clutch 61 and the second one-way clutch 62, respectively. The first one-way clutch 61 only allows transmission of power from the drive shaft 11, that is, from the inner rotor 21 to the drive shaft 63. On the other hand, the second one-way clutch 62 only allows transmission of power from the arm 12, that is, from the outer rotor 22 to the drive shaft 63.

  The temperature sensor 37 and the ECU 50 are electrically connected, and the detection value of the temperature sensor 37 is transmitted to the ECU 50. Electric power is supplied from the battery 30 to the water pump 74 and the fan 77 via a wiring (not shown).

Next, the operation of the cooling device 100 according to this embodiment will be described.
As shown in FIG. 1, when the hybrid vehicle travels with the power of the double rotor motor 20, the ECU 50 controls the first inverter 31 and the second inverter 32, respectively, so that the second coil of the stator 23 from the battery 30. 26 and the first coil 25 of the inner rotor 21 are supplied with three-phase AC power. Then, torque is generated between the first coil 25 of the inner rotor 21 and the magnet on the inner peripheral side of the outer rotor 22, and between the second coil 26 of the stator 23 and the magnet on the outer peripheral side of the outer rotor 22. Torque is also generated. When the outer rotor 22 rotates in response to these torques, this rotation is transmitted to the axle 14 via the arm 12 and the differential 13, and the hybrid vehicle travels.

  When the arm 12 is rotated by rotating the outer rotor 22, the gear 15 and the gear 18 are rotated. The second one-way clutch 62 transmits the rotation of the gear 18 to the drive shaft 63. As a result, the cooling fluid pump 72 is driven and oil circulates through the cooling fluid circulation path 71. When the cooling fluid pump 72 is activated, the ECU 50 activates the water pump 74 and the fan 77. When oil circulates through the cooling fluid circulation path 71, the double rotor motor 20, particularly the first coil 25 and the second coil 26, are cooled by the oil. The temperature of the oil rises as the first coil 25 and the second coil 26 are cooled. In the heat exchanger 75, the oil and the water circulating in the water circulation path 73 are exchanged by the water pump 74. This cools the oil. Although the temperature of the water rises as the oil is cooled, in the radiator 76, the water is cooled by the air blown by the fan 77.

  On the other hand, when the hybrid vehicle travels with the power of the diesel engine 10, the inner rotor 21 is rotated by the power of the diesel engine 10, and when a rotational speed difference is generated between the inner rotor 21 and the outer rotor 22, An induced current flows in the first coil 25 by the magnetic field generated by the inner peripheral magnet acting on the first coil 25 of the inner rotor 21, and this induced current and the magnetic field of the inner peripheral magnet of the outer rotor 22 Due to the interaction, torque is generated between the inner rotor 21 and the outer rotor 22. When the outer rotor 22 rotates upon receiving this torque, this rotation is transmitted to the axle 14 via the arm 12 and the differential 13 and the hybrid vehicle travels. In this case, the rotation of the gear 15 and the gear 16 is transmitted to the gear 17 and the gear 18, respectively, and the rotation of the gear 17 and the gear 18 is transmitted to the drive shaft 63 by the first one-way clutch 61 and the second one-way clutch 62, respectively. Then, the cooling fluid pump 72 is driven. The subsequent cooling operation of the double rotor motor 20 is the same as when the hybrid vehicle travels with the power of the double rotor motor 20.

Next, the operation of the cooling device 100 when the double rotor motor 20 generates excessive heat while the hybrid vehicle is running will be described with reference to the flowchart of FIG.
While the hybrid vehicle is running by driving either the diesel engine 10 or the double rotor motor 20, the ECU 50 determines whether the detected value T by the temperature sensor 37 is equal to or greater than a threshold value Ta set in advance in the ECU 50 (step S1). ). If T <Ta, repeat step S1. On the other hand, when T ≧ Ta, the ECU 50 increases the rotational speed of the fan 77 (step S2). When the rotational speed of the fan 77 increases, the temperature of the water circulating in the water circulation path 73 decreases, and as a result, the temperature of the oil circulating in the cooling fluid circulation path 71 also decreases, so the cooling capacity of the double rotor motor 20 is large. Become.

  Subsequently, the ECU 50 determines whether or not the rotational speed Nf of the fan 77 has reached the upper limit rotational speed Nfa (step S3). If Nf <Nfa, the process returns to step S1. On the other hand, if Nf = Nfa, the ECU 50 increases the rotational speed of the water pump 74 (step S4). When the rotation speed of the water pump 74 is increased, the flow rate of the water circulating in the water circulation path 73 is increased, so that the oil cooling capacity is increased, and as a result, the oil temperature is decreased. For this reason, the cooling capacity of the double rotor motor 20 is increased.

  Further, the ECU 50 determines whether or not the rotational speed Nw of the water pump 74 has reached the upper limit rotational speed Nwa (step S5). If Nw <Nwa, the process returns to step S1. On the other hand, if Nw = Nwa, the ECU 50 determines whether the rotational speed of the diesel engine 10 can be increased (step S6). Although the determination method in step S6 will be described later, when it is determined in step S6 that the rotational speed of the diesel engine 10 can be increased, when the hybrid vehicle runs with the power of the diesel engine 10, the ECU 50 determines the rotational speed of the diesel engine 10. When the hybrid vehicle travels with the power of the double rotor motor 20, the ECU 50 starts the diesel engine 10 and increases the rotational speed of the diesel engine 10 (step S7).

When the hybrid vehicle is running with the power of the diesel engine 10, when the rotational speed of the diesel engine 10 increases, the rotational speed of the drive shaft 11 becomes larger than the rotational speed of the arm 12, and the drive shaft 63 is The diesel engine 10 is rotated by the power. In this case, the rotational speed of the drive shaft 63 increases and the flow rate of the oil circulating through the cooling fluid circulation path 71 increases, so that the cooling capacity of the double rotor motor 20 increases.
On the other hand, when the hybrid vehicle is running with the power of the double rotor motor 20, when the diesel engine 10 starts and the rotational speed of the diesel engine 10 increases, the rotational speed of the drive shaft 11 becomes the rotational speed of the arm 12. The drive shaft 63 is rotated by the power of the diesel engine 10. In this case, the rotational speed of the drive shaft 63 increases and the flow rate of the oil circulating through the cooling fluid circulation path 71 increases, so that the cooling capacity of the double rotor motor 20 increases. After completing the operation in step S7, the process returns to step S1.

  On the other hand, if it is determined in step S6 that the rotational speed of the diesel engine 10 cannot be increased, the ECU 50 limits the output of the double rotor motor 20 (step S8). As a result, the temperature of the double rotor motor 20 gradually decreases. After completing the operation in step S8, the process returns to step S1.

  Next, the determination method in step S6 will be described. When the rotational speed of the diesel engine 10 is increased in step S7, a part of the increase in the power of the diesel engine 10 is used to drive the cooling fluid pump 72. The remainder of the increase is a double rotor motor. Used for power generation at 20. Since the electric power generated by the double rotor motor 20 is charged in the battery 30, the battery 30 needs a surplus charge capacity to determine that the rotational speed of the diesel engine 10 can be increased in step S <b> 6. Therefore, the ECU 50 detects the amount of charge of the battery 30 and determines whether it is greater than or less than a predetermined value preset in the ECU 50. If the detected charge amount is less than the predetermined value, the battery 30 has sufficient charge capacity, and therefore it is determined in step S6 that the rotational speed of the diesel engine 10 can be increased. On the contrary, when the detected charge amount is equal to or greater than the predetermined value, it is determined in step S6 that the rotational speed of the diesel engine 10 cannot be increased because the battery 30 has no remaining charge capacity.

  In order to determine whether the rotational speed of the diesel engine 10 can be increased in step S6, a determination method as described below may be added. That is, when the charge amount of the battery 30 is less than the predetermined value, the ECU 50 increases the rotational speed of the diesel engine 10 based on the engine efficiency map of the diesel engine 10 as shown in FIG. Then, it is determined whether or not the vehicle departs from an efficient area.

  For example, as shown in FIG. 3, in the engine efficiency map, the horizontal axis represents the rotational speed of the diesel engine 10, and the vertical axis represents the torque of the diesel engine 10. In the engine efficiency map, an iso-efficiency line connecting points having the same efficiency of the diesel engine 10 is drawn with a thin solid line, and the upper limit of the operating range is shown with a thick broken line. Further, in the engine efficiency map, the relationship between the rotational speed and torque of the diesel engine 10 at the same output is drawn by a thin broken line (equal output line) for each output, and the optimum operation which is the optimum condition for each output. The optimal operation line connecting the dots is drawn with a thick solid line. The efficient area is an area on the optimum operating line. If the engine 50 does not deviate significantly from the optimum operating line even if the rotational speed of the diesel engine 10 is increased, the ECU 50 determines that it does not deviate from the efficient area. In step S6, it is determined that the rotational speed of the diesel engine 10 can be increased. On the other hand, if the rotational speed of the diesel engine 10 is increased and greatly deviates from the optimum operating line, the ECU 50 determines that the speed deviates from the efficient region and determines that the rotational speed of the diesel engine 10 cannot be increased in step S6. To do.

As described above, the first one-way clutch 61 that allows only power transmission from the inner rotor 21 to the cooling fluid pump 72 and the second one-way that allows only power transmission from the outer rotor 22 to the cooling fluid pump 72. By providing the clutch 62, the diesel engine 10 stops and the cooling fluid pump 72 passes from the outer rotor 22 to the cooling fluid pump 72 via the second one-way clutch 62 even during EV traveling where only the double rotor motor 20 is traveling. Since the power is transmitted and the cooling fluid pump 72 can be driven, the double rotor motor 20 can be efficiently cooled without operating the diesel engine 10.
In particular, when the outer rotor 22 is driven for a long time in the state of low rotation and high torque during EV traveling, when the resistance increases due to damage or deterioration of the first coil 25 and the second coil 26, Since the cooling fluid pump 72 can be driven when the double rotor motor 20 generates excessive heat, such as when the heat dissipation performance is reduced due to the rise or damage or deterioration of the heat dissipation mechanism, the double rotor motor can be efficiently driven. 20 can be cooled.

  In this embodiment, when the detected value T by the temperature sensor 37 is equal to or greater than the threshold value Ta in step S1, the rotational speed of the water pump 74 is increased after the rotational speed of the fan 77 is increased (steps S2 and S3). (Steps S4 and S5), but the rotational speed of the fan 77 may be increased after the rotational speed of the water pump 74 is increased. That is, in the flowchart of FIG. 2, the order of steps S2 and S3 and steps S4 and S5 may be interchanged.

  In this embodiment, the detected value of the temperature sensor 37 inserted into the second coil 26 wound around the stator 23, that is, the temperature of the second coil 26 is set as the temperature of the double rotor motor 20. Not what you want. A temperature sensor may be provided in the first coil 25, and the detected value may be used as the temperature of the double rotor motor 20, or a temperature sensor may be provided in both the first coil 25 and the second coil 26 to double the detected values. The temperature of the rotor motor 20 may be used.

  In this embodiment, the rotating electrical machine is the double rotor motor 20 having the inner rotor 21, the outer rotor 22, and the stator 23, but may be a double rotor motor that does not have the stator 23.

  In this embodiment, the engine is the diesel engine 10, but it may be a gasoline engine. In this embodiment, the cooling fluid is oil, and the fluid that cools the oil is water. However, the present invention is not limited to this configuration, and a known fluid that can be used for cooling may be used.

  DESCRIPTION OF SYMBOLS 10 Diesel engine (engine), 20 Double rotor motor (rotary electrical machine), 21 Inner rotor (1st rotor), 22 Outer rotor (2nd rotor), 30 Battery, 50 ECU (control apparatus, charge amount detection means) 61 First one-way clutch, 62 Second one-way clutch, 72 Cooling fluid pump, 100 Cooling device.

Claims (3)

Engine,
A rotating electrical machine including a first rotor coupled to the engine and a second rotor disposed radially outside the first rotor and coupled to an axle;
A cooling fluid pump that is driven by transmission of power from the first rotor and the second rotor and supplies a cooling fluid to the rotating electrical machine;
A first one-way clutch that couples the first rotor and the cooling fluid pump and allows only power transmission from the first rotor to the cooling fluid pump;
A rotating electrical machine for a vehicle comprising: a second one-way clutch that connects the second rotor and the cooling fluid pump and allows only power transmission from the second rotor to the cooling fluid pump. Cooling system. A battery for supplying electric power for driving the rotating electric machine to the rotating electric machine and charging the electric power generated by the rotating electric machine;
Charge amount detection means for detecting the charge amount of the battery;
A control device for controlling the operation of the engine,
2. The vehicular rotating electrical machine according to claim 1, wherein the control device increases the number of revolutions of the engine when a value detected by the charge amount detection unit is less than a predetermined value preset in the control device. Cooling system. The control device incorporates an engine efficiency map of the engine,
The control device according to claim 2, wherein when the detection value by the charge amount detection means is less than the predetermined value, the control device determines whether or not the engine speed can be increased based on the engine efficiency map. A cooling device for a rotating electrical machine for a vehicle.

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