JP2016163399A - Driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving device capable of starting oil cooling at an early stage.SOLUTION: A driving device includes: a motor housing 15 for housing a motor 12; a speed reducer 13 which is disposed in the motor housing 15 so as to reduce the speed of the rotation of a rotary shaft 21 of the motor 12 by meshing of a plurality of gears 29, 30, and 31; and an inverter device for controlling the motor 12. The motor housing 15 includes an oil tank and a catch tank 35 for dropping oil O of the oil tank scraped up according to rotation of the gears 29, 30, and 31 of the speed reducer 13 to a heat generating point of the motor 12. The inverter device switches control for deteriorating efficiency according to a flow rate of the oil O of the catch tank 35 detected by a flow rate sensor, the rotation number of the motor 12 and a torque of the motor 12 and normal control.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a drive device.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique for controlling the warming-up of a motor when a motor is housed in a motor housing and a gear that transmits a driving force of the motor to wheels is housed in a gear housing. Specifically, the friction torque of the gear is estimated from the temperature at a predetermined position and the number of rotations of the motor, and the correction torque is calculated by adding the friction torque to the torque actually requested by the driver, and according to the correction torque. The current is supplied to the motor to raise the temperature of the lubricating oil while ensuring the stepping torque.

JP2011-125121A

  By the way, as a cooling structure in a vehicle driving motor in which a speed reducer is integrated, oil is circulated by rotation of a gear incorporated in a motor housing and used for cooling a motor and lubricating a bearing. However, the oil could only be circulated at a high motor speed. In particular, in a system in which oil is lifted with a gear, when the gear is vertically arranged or the lift is large, when the oil temperature is low, the viscosity is high and it is necessary to increase the rotation speed of the gear in order to stir the oil. Insufficient cooling and lubrication at low speed and high torque range. In other words, qualitatively, the cooling oil is sufficiently secured on the high speed side of the oil cooling region, so there is often room in terms of thermal performance, but the motor is in the high torque region at the rotation speed before oil cooling starts. The heat removal becomes insufficient for the loss and the thermal performance becomes severe.

  The objective of this invention is providing the drive device which can start oil cooling at an early stage.

  According to the first aspect of the present invention, a motor housing that houses a motor, a speed reducer that is disposed in the motor housing and decelerates rotation of the rotation shaft of the motor by meshing a plurality of gears, and the motor is controlled. The motor housing has an oil tank, and a catch tank that drops the oil in the oil tank, which has been lifted along with the rotation of the gear of the speed reducer, onto the heat generating portion of the motor. The gist of the invention is that the control device switches between the control for deteriorating the efficiency and the normal control in accordance with the flow rate of the oil in the catch tank detected by the flow rate sensor, the rotational speed of the motor, and the torque of the motor.

  According to the first aspect of the present invention, the control device switches between the control for deteriorating the efficiency and the normal control according to the oil flow rate of the catch tank detected by the flow rate sensor, the motor rotation speed, and the motor torque. It is done. Therefore, the oil cooling can be started early by deteriorating the motor efficiency by controlling the deterioration of the efficiency at the operation point operation near the start of the oil lifting based on the oil flow rate. Can be expanded.

  According to a second aspect of the present invention, in the driving device according to the first aspect, when the control device exceeds a continuously operable region without oil cooling, the efficiency deterioration control is performed during a period in which the flow rate of the oil is less than a threshold value. It is good to do.

  According to a third aspect of the present invention, in the drive device according to the second aspect of the present invention, the drive device includes an oil cooling mechanism that cools the oil by lifting and a water cooling mechanism that cools by circulating the cooling water. When the cooling by the oil cooling mechanism is not performed and the continuous operation possible region of only the cooling by the water cooling mechanism is exceeded, the efficiency deterioration control may be performed during a period in which the flow rate of the oil is less than a threshold.

  The drive device according to any one of claims 1 to 3, wherein the motor is a permanent magnet synchronous motor, and the control device controls the current advance angle. It is recommended to perform efficiency deterioration control.

  The drive device according to any one of claims 1 to 3, wherein the motor is an induction motor, and the control device is efficient by controlling a slip frequency and a current. Deterioration control should be performed.

  According to the present invention, oil cooling can be started early.

The schematic diagram of the drive device of embodiment. The perspective view of a drive device. Sectional drawing of a drive device (sectional drawing in the site | part corresponding to the AA line of FIG. 5). The left view of the drive device in the state where the left cover member was removed. The right view of the drive device in the state where the right cover member was removed. The exploded perspective view seen from the back side of a drive device. The perspective view seen from the front side of a drive device. The exploded perspective view seen from the front side of a drive device. The circuit block diagram of a control apparatus. Rotation speed-torque characteristic diagram. The partial enlarged view of a rotation speed-torque characteristic.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the driving device 10 is mounted on a vehicle 11 and attached to a vehicle body. As shown in FIG. 3, the drive device 10 includes a motor 12 and a speed reducer 13. In the drive device 10, a motor 12 and a speed reducer 13 are integrated, and the output of the motor 12 is decelerated by the speed reducer 13 and transmitted to the axle 14 to be used for traveling of the vehicle 11. The motor 12 is a permanent magnet synchronous motor.

  As shown in FIG. 3, the driving device 10 includes a motor housing 15 that forms the outer shape thereof. The motor housing 15 is made of a material having heat conductivity, and is made of, for example, a metal material (for example, aluminum). As shown in FIG. 2, the motor housing 15 is provided with an axle hole 16 that penetrates in the left-right direction X of the vehicle and through which the axle 14 is inserted.

  As shown in FIG. 3, the motor housing 15 includes a main body portion 17 that opens in the vehicle left-right direction X, and a right cover member 18 and a left cover member 19 that are attached to the main body portion 17 from the vehicle left-right direction X. Yes. A sealed space is formed by assembling the main body 17 and the cover members 18 and 19. 4 is a left side view with the left cover member 19 removed, and FIG. 5 is a right side view with the right cover member 18 removed.

  As shown in FIG. 3, the right cover member 18 of the motor housing 15 has a mounting protrusion 18 a at the top. The mounting protrusion 18a has a horizontally extending plate shape and protrudes to the right. Similarly, the left cover member 19 of the motor housing 15 has a mounting projection 19a at the top. The mounting protrusion 19a has a horizontally extending plate shape and protrudes to the left.

As shown in FIG. 3, the motor housing 15 has a motor housing portion 20. The motor 12 is accommodated in the motor accommodating portion 20.
As shown in FIG. 3, the motor 12 has a columnar shape with the vehicle left-right direction X as an axial direction as a whole. The motor 12 includes a rotor (rotor) 22 that rotates integrally with the rotating shaft 21, and a stator (stator) 23 provided on the outer peripheral side of the rotor 22. The rotor 22 is a rotor in which a permanent magnet Mg is embedded. The rotating shaft 21 extends in the vehicle left-right direction X and is supported by the motor housing 15 via a bearing 24 provided in the motor housing portion 20. For this reason, the rotation shaft 21 is rotatable about the vehicle left-right direction X, and the rotor 22 is disposed in a state of being rotatably supported in the motor housing 15.

  The stator 23 includes a cylindrical stator core 25 and a winding 26 wound around teeth, and has a cylindrical shape as a whole. In the stator 23, a winding 26 is wound around a stator core 25 fixed in the motor housing 15, and coil ends 27 a and 27 b protrude from end surfaces 25 a and 25 b of the stator core 25. The stator 23 is disposed at a position where the inner peripheral surface of the stator core 25 faces the outer peripheral surface of the rotor 22. In this case, the end surfaces 25 a and 25 b of the stator core 25 in the vehicle left-right direction X are opposed to the cover members 18 and 19 of the motor housing 15. The vehicle longitudinal direction Y is a direction orthogonal to the axial direction of the stator 23 and the vertical direction Z. Further, there is a slight gap between the inner peripheral surface of the stator core 25 and the outer peripheral surface of the rotor 22.

  As shown in FIGS. 3 and 4, the coil end 27 a protrudes from the end face 25 a on the counter-output side of the rotating shaft 21 in the stator core 25. The coil end 27 a is disposed below the base portion of the mounting projection 19 a extending in the axial direction of the rotor 22. As shown in FIG. 3, the coil end 27 b protrudes from the end face 25 b on the output side of the rotating shaft 21 in the stator core 25.

  The stator core 25 is fixed to the motor housing 15 by screwing the bolt 28 into a screw hole provided in the motor housing 15 with the bolt 28 (see FIG. 3) inserted. Although only one bolt 28 is shown in FIG. 3, the three bolts 28 are provided approximately evenly in the circumferential direction.

  A reduction gear 13 is arranged in the motor housing 15. The reduction gear 13 is a three-axis vertical transmission, and includes an input gear 29, a counter gear 30, and a diff ring gear 31. The gears 29, 30, and 31 are arranged in the vertical direction (up and down) while being rotatably supported by bearings. The input gear 29 is attached to the output end of the rotating shaft 21 that protrudes outside the motor housing portion 20. The input gear 29 is engaged with the first gear 30 a of the counter gear 30. A diff ring gear 31 is engaged with the second gear 30 b of the counter gear 30. The differential ring gear 31 is attached to the axle 14.

  The gears 29, 30, and 31 are rotated by the rotation of the rotating shaft 21 of the motor 12, and the rotation is decelerated and transmitted to the axle 14. That is, the speed reducer 13 decelerates the rotating shaft 21 (output) of the motor 12 by meshing the three gears 29, 30, and 31.

  The drive device 10 of this embodiment includes an oil cooling mechanism 32 and a water cooling mechanism 33 in order to cool the stator 23 and the like. The oil cooling mechanism 32 cools by oil scooping. The water cooling mechanism 33 is cooled by circulating antifreeze as cooling water.

First, the oil cooling mechanism 32 will be described.
As shown in FIG. 4, the motor housing 15 has an oil tank 34 and a catch tank 35. The oil tank 34 is disposed below the motor housing 20 and stores oil (cooling oil) O. The motor housing 20 and the tanks 34 and 35 are integrated.

  As shown in FIG. 5, a part of the diff ring gear 31 is immersed in the oil O of the oil tank 34. For this reason, when each gear 29,30,31 rotates, the oil O of the oil tank 34 is lifted up.

  In addition, in the motor housing 15, a guide channel 37 that guides the oil O that has been lifted up to the motor housing 20 is provided. In FIG. 5, the guide passage 37 is disposed in the vehicle front direction of the first gear 30 a and the input gear 29, and communicates to the upper side of the motor housing portion 20. Guide to the top of the.

  The catch tank 35 is formed in the upper part of the motor housing part 20 of the motor housing 15. As shown in FIG. 3, the catch tank 35 extends in the left-right direction X of the vehicle, and oil O is supplied from the guide passage 37 to the right end. The catch tank 35 has oil O supply holes (cooling oil dropping holes) 36 a and 36 b derived from the oil tank 34. The supply holes 36 a and 36 b are opened in the ceiling surface 20 a of the motor housing portion 20.

  As shown in FIG. 3, the motor housing portion 20 is provided with an oil reservoir 38 in which the oil O that has flowed down is stored. The oil reservoir 38 is partitioned by a partition wall 38 a that separates the motor housing portion 20 and the oil tank 34. A part of the stator 23, specifically, a part of the stator core 25 and a part of the winding 26 are immersed in the oil O stored in the oil reservoir 38.

  As shown in FIG. 4, the oil tank 34 is disposed below the stator 23 and the oil reservoir 38. The motor housing 15 is connected to the oil reservoir 38 and the oil tank 34, and is provided with a bypass passage 39 (see FIG. 3) through which the oil O flows. The bypass channel 39 is provided in the left cover member 19 and extends in the vertical direction Z. Oil O flows from the oil reservoir 38 to the oil tank 34 through the bypass passage 39.

  Also, as shown in FIG. 3, a plurality of fins 40 are arranged side by side below the oil tank 34 in the motor housing 15. These fins 40 cool the oil O stored in the oil tank 34.

  When the oil O in the oil tank 34 is lifted by the rotation of the gears 29, 30, and 31, the oil O that has been lifted flows through the guide passage 37, and supplies the supply holes 36 a and 36 a of the catch tank 35. It is dripped in the motor accommodating part 20 from 36b.

  As shown in FIG. 3, the supply hole 36a of the catch tank 35 is provided above the coil end 27a protruding from the end face 25a of the stator core 25, and the oil O is dropped onto the coil end 27a. The supply hole 36b of the catch tank 35 is provided above the coil end 27b protruding from the end face 25b of the stator core 25, and oil O is dropped onto the coil end 27b.

In this way, the catch tank 35 drops the oil O of the oil tank 34 that has been lifted along with the rotation of the gears 29, 30, and 31 of the speed reducer 13 onto the heat generating portion of the motor 12.
Next, the water cooling mechanism 33 will be described.

  As shown in FIGS. 2 and 6, the driving device 10 includes a cover 41 provided outside the motor housing 15 and a protrusion 20 b on the outer surface of the motor housing portion 20 of the motor housing 15. A cover 41 is fixed to the frame-shaped protrusion 20b by a bolt B1 (see FIG. 2). A water jacket (cooling water flow path) 42 is defined between the cover 41 and a region surrounded by the protrusion 20 b on the outer surface of the stator arrangement portion of the motor housing 15. As shown in FIG. 2, an antifreeze liquid (LCC) L as cooling water flows through the water jacket 42.

  As shown in FIG. 6, the cover 41 and the protrusion 20 b are L-shaped as a whole, and the antifreeze L flows through the L-shaped water jacket 42. An inlet portion 43 is formed below the cover 41 and an outlet portion 44 is formed above the protrusion 20b. And the antifreeze L flows in from the inlet part 43, and the antifreeze L is discharged | emitted from the exit part 44, as shown in FIG.

  Further, as shown in FIG. 2, the outlet portion 44 of the water jacket 42 in FIG. 6 communicates with one end of a connection flow path 45 formed in the motor housing 15. The other end side of the connection channel 45 extends obliquely downward so as to pass near the center of the motor 12.

  As shown in FIGS. 7 and 8, the drive device 10 includes a cover 46 provided on the outside of the motor housing 15 and a protrusion 20 c on the outer surface of the motor housing portion 20 of the motor housing 15. A cover 46 is fixed to the square frame-shaped protrusion 20c by a bolt B2 (see FIG. 7). A water jacket (cooling water flow path) 47 is defined between the cover 46 and a region surrounded by the protrusion 20 c on the outer surface of the stator arrangement portion of the motor housing 15. As shown in FIG. 7, the antifreeze (LCC) L from the connection channel 45 flows through the water jacket 47.

  As shown in FIG. 8, a reverse S-shaped channel is formed in the water jacket 42, and the antifreeze liquid L flows while meandering. An inlet 48 is formed below the protrusion 20c, and an outlet 49 is formed above the protrusion 20c. The inlet 48 communicates with the other end of the connection channel 45 as shown in FIG. Then, the antifreeze liquid L flows from the inlet 48 and the antifreeze L is discharged from the outlet 49.

The antifreeze liquid L is circulated through a pump and a heat exchanger.
Thus, as shown in FIG. 4, the water jackets 42, 47 are arranged at positions facing the vehicle longitudinal direction Y via the stator 23. A plurality of water jackets (outer peripheral flow paths) 42 and 47 that are spaced apart from each other in the circumferential direction of the stator 23 extend along the outer surface of the stator arrangement portion of the motor housing 15.

FIG. 9 shows a configuration of an inverter device 70 as a control device provided in the drive device 10, and the motor 12 is controlled by the inverter device 70.
As shown in FIG. 9, the inverter device 70 includes an inverter circuit 71 and an inverter control device 72. The inverter control device 72 includes a drive circuit 73 and a PWM control unit 74.

  The inverter circuit 71 has six switching elements Q1 to Q6 and six diodes D1 to D6. IGBTs are used as the switching elements Q1 to Q6. A switching element Q1 constituting the U-phase upper arm and a switching element Q2 constituting the U-phase lower arm are connected in series between the positive electrode bus and the negative electrode bus. A switching element Q3 constituting the V-phase upper arm and a switching element Q4 constituting the V-phase lower arm are connected in series between the positive electrode bus and the negative electrode bus. Between the positive electrode bus and the negative electrode bus, a switching element Q5 constituting the W-phase upper arm and a switching element Q6 constituting the W-phase lower arm are connected in series. Diodes D1 to D6 are connected in reverse parallel to the switching elements Q1 to Q6. A battery 76 as a DC power source is connected to the positive and negative buses via a smoothing capacitor 75.

  The U-phase terminal of the motor 12 is connected between the switching element Q1 and the switching element Q2. The switching element Q3 and the switching element Q4 are connected to the V-phase terminal of the motor 12. The switching element Q5 and the switching element Q6 are connected to the W-phase terminal of the motor 12. The inverter circuit 71 having the switching elements Q1 to Q6 constituting the upper and lower arms can convert the DC voltage that is the voltage of the battery 76 into an AC voltage and supply it to the motor 12 in accordance with the switching operation of the switching elements Q1 to Q6. It can be done.

  A drive circuit 73 is connected to the gate terminals of the switching elements Q1 to Q6. Drive circuit 73 performs switching operation of switching elements Q1 to Q6 of inverter circuit 71 based on the control signal.

  The motor 12 is provided with a position detector 77, and the position detector 77 detects the electrical angle θ as the rotational position of the motor 12. The current sensor 78 detects the U-phase actual current value Iu of the motor 12. The current sensor 79 detects the W-phase actual current value Iw of the motor 12.

  The PWM control unit 74 includes a torque / command current value conversion unit 80, subtraction units 81 and 82, a current control unit 83, coordinate conversion units 84 and 85, a PWM generation unit 86, and an advance angle control unit 87. I have.

  The coordinate conversion unit 84 obtains the V-phase actual current value Iv of the motor 12 from the U-phase actual current value Iu and the W-phase actual current value Iw obtained by the current sensors 78 and 79, and sets the electrical angle θ detected by the position detection unit 77. Based on the U-phase actual current value Iu, the V-phase actual current value Iv, and the W-phase actual current value Iw to the d-axis actual current value (excitation component current value) Id and the q-axis actual current value (torque component current value) Iq. Convert. The d-axis actual current value (excitation component current value) Id is a current vector component for generating a field in the current flowing through the motor 12, and the q-axis actual current value (torque component current value) Iq is the motor 12. Is a current vector component for generating torque.

  The torque / command current value converter 80 converts a torque command value Tref input from the outside into a d-axis command current value Id * and a q-axis command current value Iq *. For example, the torque / command current value conversion unit 80 is a table in which a torque command value Tref, a d-axis command current value Id *, and a q-axis command current value Iq * stored in advance in a storage unit (not shown) are associated with each other. Is used to convert torque / command current value.

  The subtraction unit 81 calculates a difference ΔId between the d-axis command current value Id * and the d-axis actual current value Id. The subtracting unit 82 calculates a difference ΔIq between the q-axis command current value Iq * and the q-axis actual current value Iq. Current controller 83 calculates d-axis command voltage value Vd * and q-axis command voltage value Vq * as control values based on difference ΔId and difference ΔIq. The coordinate conversion unit 85 converts the d-axis command voltage value Vd * and the q-axis command voltage value Vq * into command voltage values Vu *, Vv *, and Vw * based on the electrical angle θ detected by the position detection unit 77. To do.

  The PWM generator 86 turns on and off the switching elements Q1 to Q6 of the inverter circuit 71 based on the comparison result between the triangular wave that is a reference and the command voltage values Vu *, Vv *, and Vw * by PWM control. A PWM control signal is output.

  That is, the PWM control unit 74 determines the d-axis actual current value (excitation component current value) in the motor 12 based on the current of each phase of U, V, and W (actual current values Iu, Iv, Iw) flowing through the motor 12. The switching elements Q1 to Q6 provided in the current path of the motor 12 are controlled so that the q-axis actual current value (torque component current value) becomes the target value. A signal from the PWM generator 86 is sent to the drive circuit 73.

  The advance angle controller 87 is connected to an oil flow rate sensor (oil amount sensor) 88. The flow rate sensor 88 is attached to the oil passage of the catch tank 35 and detects the oil flow rate of the catch tank 35. The advance control unit 87 obtains the V-phase actual current value Iv of the motor 12 from the U-phase actual current value Iu and the W-phase actual current value Iw by the current sensors 78 and 79, and calculates the motor torque from the current values Iu, Iv, and Iw. calculate. The advance angle controller 87 detects the motor rotation speed based on the electrical angle θ detected by the position detector 77. The advance angle controller 87 is connected to the torque / command current value converter 80, and the advance angle controller 87 outputs an advance angle command to the torque / command current value converter 80. The torque / command current value converter 80 adjusts the current advance angle (phase of the current vector) by this advance command.

  The advance angle control unit 87 switches between the control for deteriorating the efficiency and the normal control according to the flow rate of the oil O in the catch tank 35 detected by the flow rate sensor 88, the rotational speed of the motor 12, and the torque of the motor 12. Specifically, before the oil cooling, the motor is operated on a continuous NT line without oil cooling (see FIG. 10). The current and the advance angle are obtained from the torque and the motor rotation speed, and the efficiency deterioration control is performed (the advance angle control unit 87 performs the efficiency deterioration control by controlling the current advance angle). That is, the d-axis current is increased and the q-axis current is increased so that a predetermined torque is generated. By performing this efficiency deterioration control, although the efficiency is poor, the motor current increases, and the oil temperature is quickly raised to reduce the oil viscosity, thereby making it easy to lift up the oil. When oil comes in the catch tank 35 or deviates from the output expansion region of FIG. 10, normal oil cooling maximum efficiency control (see L1 in FIG. 10) is performed. It should be noted that once the oil is lifted, the efficiency can be ensured by returning to the normal maximum torque control.

Next, the operation of the driving device 10 will be described.
The drive device 10 is an integrated power take-off unit (transaxle unit) in which the motor 12 and the speed reducer 13 are integrated. The drive device 10 includes a motor 12, a speed reducer 13, an oil cooling mechanism 32 having an oil tank 34 and a catch tank 35, and a water cooling mechanism 33 (water jackets 42 and 47) as functional configurations.

  Water passages (water jackets 42 and 47) for cooling the motor 12 are formed in the motor housing 15, and the antifreeze liquid L flows to cool the motor 12 as shown by the one-dot chain line in FIG. 2 and the one-dot chain line in FIG. Provided. Further, a reduction gear 13 for reducing the motor output is disposed inside the motor housing 15, and as shown in FIG. 5, oil O is filled up to the vicinity of the central axis of the diff ring gear 31, and the gears 29, 30, By the rotation of 31, the oil O is stirred, and the motor 12 is cooled and the bearing 24 is lubricated.

The stirring of the oil O is performed by the rotation of the gears 29, 30 and 31 of the speed reducer 13 provided in the driving device 10.
In the drive device 10 of FIG. 3, the stirring flow of the oil (cooling oil) O is shown by a one-dot chain line, and the stirring path of the oil O is shown by a one-dot chain line in FIG.

  The oil O in the oil tank 34 is lifted up to the catch tank 35 as the gears 29, 30, 31 rotate, and the oil O in the catch tank 35 is suspended from the supply holes 36 a, 36 b to be used for cooling the motor 12. Is done. That is, in FIG. 5, the oil O charged to the vicinity of the center of the diff ring gear 31 is stirred clockwise (CW direction) as the diff ring gear 31 rotates, and is filled in the oil tank 50 in the counter gear chamber. This oil O is agitated counterclockwise (CCW direction) as the counter gear 30 rotates, and is sent to the catch tank 35 located at the upper part of the driving device 10. The oil O sent to the catch tank 35 is supplied to the motor coil ends 27a and 27b and the motor 12 is cooled and the bearing 24 is lubricated.

  Thus, when the speed reducer 13 has a three-axis vertical arrangement, when oil cooling is started from the situation where the oil-cooled continuous NT line in FIG. Therefore, the oil circulation cannot be carried out unless the speed of the speed reducer 13 is large. Therefore, as shown in FIG. 10, the operating point (N1) of the continuous rotational speed immediately before the oil cooling starts thermally becomes most severe.

  9 advances the efficiency according to the flow rate of oil O in the catch tank 35 detected by the flow rate sensor 88, the rotational speed of the motor 12, and the torque of the motor 12. Switch between control and normal control. Specifically, the advance angle control unit 87 performs efficiency deterioration control in a period in which the oil flow rate is less than the threshold when exceeding the continuously operable region without oil cooling. In particular, when the oil cooling mechanism 32 does not perform cooling, the advance angle control unit 87 exceeds the continuous operation possible region where only the water cooling mechanism 33 performs cooling, and the oil flow rate is a threshold value when the motor operating point is in the output expansion region. The efficiency deterioration control is performed in a shorter period.

  Specifically, the flow rate of the oil O in the catch tank 35 is smaller than a threshold (for example, no oil has come), and the rotation speed N of the motor 12 and the torque T of the motor 12 enter the output expansion region of FIG. If so, the control for deteriorating the motor efficiency is executed. Further, when the flow rate of the oil O in the catch tank 35 is larger than a threshold (for example, oil has come), or when the rotational speed N of the motor 12 and the torque T of the motor 12 deviate from the output expansion region of FIG. Execute control.

This will be described in detail below.
The motor 12 is a permanent magnet synchronous motor and controls the current advance angle.
FIG. 10 shows the NT characteristic of the motor (electric motor). In FIG. 10, the horizontal axis represents the motor rotation speed N, and the vertical axis represents the motor torque T. FIG. 11 is a partially enlarged view of FIG.

  In FIG. 10, the output of the motor is defined as a maximum NT line without oil cooling and a continuous NT line without oil cooling, and the maximum NT line without oil cooling is output in a short time (for example, several seconds). Guaranteed value, oil-cooled continuous NT line is a long-time output guaranteed value. Specifically, the current of the continuous NT line without oil cooling is reduced with respect to the current of the maximum NT line without oil cooling, for example, about 50%. In addition, since oil agitation is inevitably performed when a predetermined number of revolutions is reached, the oil-free non-NT line referred to here is an imaginary case where there is no oil filling in the transaxle and only water cooling is performed. Is the output line.

  The regulation of continuous output is limited by the motor temperature (mainly winding) from the viewpoint of protecting the motor insulation performance. In the drive device 10 including the oil cooling structure by the gears 29, 30, and 31, the output of the motor 12 is improved by improving the cooling performance by oil cooling.

  The armature current increases in the order of I1, I2, and I3 (I1 <I2 <I3). The armature current advance angle increases in the order of β1, β2, and β3 (β1 <β2 <β3). The oil temperature increases in the order of t1, t2, and t3 (t1 <t2 <t3).

  10 and 11, an oil cooling maximum efficiency control line with an advance angle β1 (oil temperature t1) in continuous operation (continuous NT line) is shown at L1, and an armature current I1 flows. Since there is a line on the high rotation side from the t1 oil cooling start line, oil cooling has started, and the oil cooling maximum efficiency line can pass a larger current than the continuous NT line without oil cooling, and it has a larger continuous It can be operated with output. The torque of the oil-cooled maximum efficiency control line L1 is not always a constant value, but the advance angle is increased (β1 <β2 <β3) to suppress the back electromotive force of the motor as the rotational speed N rises. Perform field-weakening control. In the oil cooling weakening magnetic field control by the advance angle β2 (> β1), the armature current I2 (> I1) flows, and the oil temperature becomes t2. In the oil cooling weakening magnetic field control by the advance angle β3 (> β2> β1), the armature current I3 (> I2> I1) flows and the oil temperature becomes t3. If the oil temperature rises, the oil cooling start line shifts to the low rotation side, and lines (L2 and L3) that can continuously operate with the advance angle β and current I also shift to the low rotation side.

  When oil cooling is started, the heat balance that has been balanced by water cooling until then becomes large, so that the operating point on the continuous NT line without oil cooling is changed to oil as shown in FIG. The rotation speed (= N1) at the intersection with the cold maximum efficiency control line L1 can be increased to the rotation speed (= Nmin) at the intersection with the efficiency deterioration weakening field control maximum advance angle βmax line.

  The oil cooling start area is indicated by the t1 oil cooling start line, the t2 oil cooling start line, and the t3 oil cooling start line in FIG. 10, and if the temperature is low, the oil cooling can be started unless the rotational speed is increased. Can not. In other words, the oil cooling start line shifts to the higher speed side as the oil temperature becomes lower due to the torque reduction, because the energization current decreases due to the torque reduction and the oil temperature decreases, so the viscosity of the oil increases. This is because the oil cannot be lifted up unless the rotation speed is higher.

  Here, in this embodiment, the operating point is shifted from the oil cooling maximum efficiency control to the field weakening control (β2> β1), so that a continuous N at the start of oil cooling is used by using an output expansion region that is an expansion of the oil cooling region. -Increase the output on the T line and increase the armature current (I2> I1) to reduce motor efficiency. Along with this, the oil is warmed by heat generation (t2> t1), and the oil viscosity is lowered.

  That is, the flow rate sensor 88 is disposed in the oil passage of the catch tank 35 and field weakening control is performed only in the output expansion region. Specifically, in FIG. 11, the area surrounded by L1, the continuous NT line without oil cooling, and the time of βmax (line) is the output expansion area, and the advance angle control unit 87 of the inverter device 70 is detected. When the flow rate Q of the oil O in the catch tank 35 is smaller than the threshold value, the corresponding advance angle and current are set if the output range is entered from the rotational speed N of the motor 12 and the torque T of the motor 12. That is, if field weakening control is not performed, it can be used only up to L1 (up to N1). However, by using field weakening control, oil circulates at a lower rotational speed than N1, and therefore the oil cooling region increases.

  In this way, in the oil frying system, the catch tank 35 at the top of the motor 12 and the flow sensor 88 disposed there are combined to shift the motor drive operating point from maximum efficiency control to field weakening control. Thereby, the oil cooling area | region can be expanded and the cooling performance of the motor 12 can be improved.

Here, the oil-cooling method will be described while comparing an oil bath and fried food.
In the oil bath, the temperature of the portion where the motor is bathed is low, but the temperature of the portion where the motor is not high is increased, resulting in a large temperature distribution. Therefore, since the thermal performance of the motor is dragged to the highest temperature portion of the motor, a very effective heat removal effect cannot be expected.

  On the other hand, in the filing, the heat of the entire motor can be received evenly, and the heat removal effect is increased. Furthermore, the motor winding temperature is often the part where the motor power line is pulled out, and this part is generally located at the top of the motor structure. The method is effective. In other words, in the filing, even if the winding oil bath is small, the temperature of the oil can be increased effectively.

  In such a rafting system, the flow rate sensor detects whether or not the oil is coming to the catch tank, and when the oil is not coming to the catch tank, control is performed to reduce the efficiency and the oil is lifted to the catch tank. When oil comes to the catch tank, return to normal control. As a result, the oil cooling mode can be entered quickly. That is, the operation range can be expanded by starting the oil scooping start (circulation start) from a low motor speed. Thereby, oil cooling can be made easy and oil cooling can be started at an early stage.

  In particular, when the motor temperature reaches the threshold temperature due to the limiter function, even when no further current is passed, the control is performed to deteriorate the efficiency of the present embodiment, so that the oil is output even in the situation where the output is increased and the limiter is applied. The motor can be operated without limiting the current by the limiter by cooling the motor by circulating the motor.

According to the above embodiment, the following effects can be obtained.
(1) As a configuration of the driving device 10, a motor housing 15 housing the motor 12 and the motor housing 15 are arranged in the motor housing 15. A reduction gear 13 that performs the control, and an inverter device 70 that serves as a control device that controls the motor 12. The motor housing 15 includes an oil tank 34 and a catch tank 35 that drops the oil O of the oil tank 34 that has been lifted along with the rotation of the gears 29, 30, and 31 of the speed reducer 13 onto the heat generating portion of the motor 12. The inverter device 70 (advance control unit 87) performs control and normal control for deteriorating efficiency in accordance with the flow rate of the oil O in the catch tank 35 detected by the flow rate sensor 88, the rotational speed of the motor 12, and the torque of the motor 12. Switch. Therefore, the oil cooling can be started early by deteriorating the motor efficiency by controlling the deterioration of the efficiency at the operation point operation near the start of the oil lifting based on the oil flow rate. Can be expanded.

(2) The advance angle control unit 87 of the inverter device 70 is practical because it performs efficiency deterioration control during a period in which the flow rate of the oil O is less than the threshold when exceeding the continuously operable region without oil cooling.
(3) In particular, the oil cooling mechanism 32 that cools the oil O by scooping up the oil O and the water cooling mechanism 33 that cools by circulating the antifreeze liquid L as the cooling water are provided. When the cooling by the mechanism 32 is not performed and the continuous operation possible region of only the cooling by the water cooling mechanism 33 is exceeded, the efficiency deterioration control is performed in a period when the flow rate of the oil O is less than the threshold value. Therefore, efficiency is good.

  (4) The motor 12 is a permanent magnet synchronous motor, and the advance angle control unit 87 of the inverter device 70 performs efficiency deterioration control by controlling the current advance angle. Therefore, the output can be easily increased.

  (5) Since control is performed according to the amount of oil in the catch tank 35, when the oil temperature fluctuates (increases) due to factors other than the rotational speed and torque of the motor 12 and the oil amount increases, the control is switched to normal control. Deterioration control can be minimized.

  (6) Since efficiency deterioration control is performed using not only the oil amount but also the rotation speed and torque of the motor 12, efficiency deterioration control is performed in a region other than the output expansion region (operation range that can be expanded by efficiency deterioration control). There is nothing. Therefore, efficiency deterioration control can be minimized.

The embodiment is not limited to the above, and may be embodied as follows, for example.
In the above embodiment, the water cooling mechanism 33 (water jackets 42 and 47) is provided, but the present invention can also be applied to a drive device that does not have the water cooling mechanism 33.

The threshold value of the flow rate of the oil O is not fixed and may be changed according to the rotation speed and torque of the motor 12. You may have it as a map in advance.
In the above embodiment, a permanent magnet synchronous motor is used to control the current advance angle. However, instead of this, the “slip” may be shifted using an induction machine to change the operating point. That is, the motor may be an induction motor, and the control device may perform efficiency deterioration control by controlling the slip frequency and current.

  DESCRIPTION OF SYMBOLS 10 ... Drive device, 12 ... Motor, 13 ... Reduction gear, 15 ... Motor housing, 21 ... Rotating shaft, 29 ... Gear, 30 ... Gear, 31 ... Gear, 32 ... Oil cooling mechanism, 33 ... Water cooling mechanism, 34 ... Oil Tank, 35 ... catch tank, 70 ... inverter device, 87 ... advance angle control unit, 88 ... flow rate sensor, L ... antifreeze, O ... oil.

Claims (5)

A motor housing containing the motor;
A speed reducer disposed within the motor housing and decelerating rotation of the rotation shaft of the motor by meshing a plurality of gears;
A control device for controlling the motor;
With
The motor housing has an oil tank, and a catch tank that drops the oil in the oil tank that has been lifted with the rotation of the gear of the speed reducer onto a heat generation point of the motor,
The control device switches between a control for deteriorating efficiency and a normal control according to a flow rate of oil in the catch tank detected by a flow rate sensor, a rotation speed of the motor, and a torque of the motor. .   2. The drive device according to claim 1, wherein the control device performs efficiency deterioration control in a period in which the flow rate of the oil is less than a threshold when exceeding a continuously operable region without oil cooling. An oil cooling mechanism that cools by scooping up the oil, and a water cooling mechanism that cools by circulating cooling water,
The control device performs efficiency deterioration control during a period in which the flow rate of the oil is less than a threshold value when the oil cooling mechanism exceeds a continuously operable region where only the cooling by the water cooling mechanism is not performed. Item 3. The driving device according to Item 2. The motor is a permanent magnet synchronous motor,
The drive device according to any one of claims 1 to 3, wherein the control device performs efficiency deterioration control by controlling a current advance angle. The motor is an induction motor;
The drive device according to any one of claims 1 to 3, wherein the control device performs efficiency deterioration control by controlling a slip frequency and a current.