JP5369634B2 - Drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive unit improved in the cooling performance of a mounted rotating electric machine while suppressing an increase of a capacity of the drive unit and a rise of manufacturing cost. <P>SOLUTION: The drive unit 200 includes: a motor generator MG2; a differential mechanism which includes a rotatably-arranged gear, and can transmit power to drive wheels; a casing 600 which accommodates the motor generator MG2 and the differential mechanism, and in which a refrigerant is stored at its bottom; and a catch tank 613 for receiving the refrigerant which is squeezed up by the gear. A stator 222 includes a stator core 222A and a stator coil 222B wound to the stator core 222A, a refrigerant passage 285 through which the refrigerant can pass is formed at a rotor 221, the refrigerant is fed to the refrigerant passage 285 from the catch tank 613, and a discharge port 284 is formed at the refrigerant passage 285 so that the refrigerant in the refrigerant passage 285 is discharged toward the stator coil 222B. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a drive device, and more particularly, to a drive device that includes a rotating electrical machine including a rotor and a stator and that is improved in cooling of the rotating electrical machine.

  Conventionally, various types of rotating electrical machines in which stator coil ends and the like are cooled have been proposed. For example, a built-in motor described in Japanese Patent Application Laid-Open No. 9-154257 corresponds to a housing, a spindle rotatably supported in the housing, a stator disposed in the housing, and the stator. And a rotor disposed on the spindle.

A cooling liquid supply port is disposed near the spindle in the housing, and the cooling liquid is ejected from the supply port toward at least one of the stator, the rotor, and the spindle.
JP-A-9-154257

  However, in the drive device equipped with the built-in motor, it is necessary to mount a pump in order to spray the cooling liquid onto the stator, the rotor, or the like. If such a pump is provided in the drive device, the volume of the drive device itself increases, and the manufacturing cost of the drive device also increases.

  The present invention has been made in view of the above-described problems, and its object is to improve the cooling of the mounted rotating electrical machine while suppressing an increase in the volume of the drive device and an increase in manufacturing cost. A drive device is provided.

  A drive device according to the present invention includes a stator, a rotating electrical machine including a rotor provided rotatably around a central axis, a gear mechanism including a gear provided rotatably and capable of transmitting power to drive wheels. And a housing case that houses the rotating electrical machine and the gear mechanism and that stores the refrigerant at the bottom, and a catch tank that receives the refrigerant that has been scooped up by the gear. The stator includes an annular stator core disposed around the rotor and a coil attached to the stator core. Further, the rotor is formed with a refrigerant passage through which refrigerant can flow, the refrigerant passage is supplied with refrigerant from a catch tank, and the refrigerant passage discharges the refrigerant in the refrigerant passage toward the coil. Is provided.

  Preferably, the rotor includes a rotating shaft, a rotor core fixed to the rotating shaft, and an end plate provided on an end surface in the axial direction of the rotor core. A supply port for supplying the refrigerant from the catch tank to the refrigerant passage is formed in the end plate, and the catch tank is positioned above the supply port. Further, the catch tank is formed with a flow-down port through which the refrigerant in the catch tank flows down toward the supply port.

  Preferably, the rotary shaft is formed so as to protrude from a peripheral surface of the rotary shaft, and a flange portion is formed to support the end plate. And the said collar part is formed with the notch part extended toward a radial inside from an outer peripheral edge part, and a supply port is located in a notch part.

  Preferably, the housing case is provided with a bearing portion that rotatably supports the rotating shaft, the bearing portion is positioned below the catch tank, and the refrigerant flowing down from the catch tank reaches the bearing portion. Preferably, the rotor includes a rotor core and a magnet provided on the rotor core, and the refrigerant passage passes through the magnet. Preferably, the rotor includes a rotating shaft and a rotor core fixed to the rotating shaft, and the rotor core is provided with a plurality of cavities provided at intervals in the circumferential direction and extending in the central axis direction. Communicates with the refrigerant passage.

  Preferably, the rotor includes a magnet provided on the rotor core, the hollow portion is positioned radially inward from the magnet, and the rotor core is formed by stacking a plurality of steel plates. Preferably, the rotor core is formed with a magnet accommodation hole for accommodating a magnet, the magnet is fixed by a resin filled in the magnet accommodation hole, and the resin is outside the radial direction of the rotor in the circumferential surface of the magnet. A portion located on the radial side and located on the radially inner side of the peripheral surface of the magnet is exposed from the resin.

  Preferably, the refrigerant passage includes a liquid reservoir having a height higher than the height of the discharge port in the central axis direction, and the discharge port is connected to the liquid reservoir.

  With the drive device according to the present invention, it is possible to improve the cooling of the mounted rotating electrical machine while suppressing an increase in the volume of the drive device and an increase in manufacturing cost.

  A drive device according to the present embodiment and a vehicle equipped with the drive device will be described with reference to FIGS.

  Note that in the embodiments described below, when referring to the number, amount, and the like, the scope of the present invention is not necessarily limited to the number, amount, and the like unless otherwise specified. In the following embodiments, each component is not necessarily essential for the present invention unless otherwise specified. In addition, when there are a plurality of embodiments below, it is planned from the beginning to appropriately combine the features of each embodiment unless otherwise specified.

  FIG. 1 is a schematic diagram schematically showing a drive device 200 mounted on a hybrid vehicle. The hybrid vehicle includes a driving device 200 that rotates driving wheels. The driving device 200 includes an engine 100, motor generators MG1 and MG2, a power split mechanism 300, a differential mechanism (gear mechanism) 400, and a casing 600. Including. In casing 600, a storage chamber 610 that stores motor generator MG2, a storage chamber 611 that stores power split mechanism 300, counter gear 350, and differential mechanism 400, and a storage chamber 612 that stores motor generator MG1 are formed. ing. Motor generators MG1 and MG2 include rotors 211 and 221 and stators 212 and 222, respectively. The power split mechanism 300 includes planetary gears 310 and 320. Planetary gears 310 and 320 include sun gears 311 and 321, pinion gears 312 and 322, planetary carriers 313 and 323, and ring gears 314 and 324, respectively.

  Crankshaft 110 of engine 100, rotor 211 of motor generator MG1, and rotor 221 of motor generator MG2 rotate about the same axis.

  The sun gear 311 in the planetary gear 310 is coupled to a hollow sun gear shaft that passes through the center of the crankshaft 110. The ring gear 314 is supported so as to be rotatable coaxially with the crankshaft 110. The pinion gear 312 is disposed between the sun gear 311 and the ring gear 314 and revolves while rotating on the outer periphery of the sun gear 311. Planetary carrier 313 is coupled to the end of crankshaft 110 and supports the rotation shaft of each pinion gear 312.

  A counter drive gear for taking out power from the power split mechanism 300 rotates integrally with the ring gear 314. The counter drive gear is connected to the counter gear 350. Power is transmitted between the counter drive gear and the counter gear 350. The counter gear 350 drives the differential mechanism 400. On the downhill or the like, wheel rotation is transmitted to the differential mechanism 400, and the counter gear 350 is driven by the differential mechanism 400.

  Motor generator MG1 mainly operates as a generator that generates electromotive force at both ends of the three-phase coil by the interaction between the magnetic field generated by the permanent magnet and the rotation of rotor 211.

  Rotor 221 of motor generator MG2 is coupled to a ring gear case that rotates integrally with ring gear 314 of planetary gear 310 via planetary gear 320 as a speed reducer.

  Motor generator MG2 operates as an electric motor that rotationally drives rotor 221 by the interaction between a magnetic field generated by a permanent magnet embedded in rotor 221 and a magnetic field formed by a three-phase coil wound around stator 222. Motor generator MG2 also operates as a generator that generates electromotive force at both ends of the three-phase coil by the interaction between the magnetic field generated by the permanent magnet and the rotation of rotor 221.

  The planetary gear 320 performs speed reduction by a structure in which a planetary carrier 323 that is one of rotating elements is fixed to a case of a vehicle drive device. That is, planetary gear 320 meshes with sun gear 321 coupled to the shaft of rotor 221, ring gear 324 that rotates integrally with ring gear 314, ring gear 324 and sun gear 321, and pinion gear 322 that transmits the rotation of sun gear 321 to ring gear 324. Including.

  FIG. 2 is a circuit diagram showing a configuration of a main part of PCU 500 that drives and controls motor generators MG1 and MG2. Referring to FIG. 2, PCU 500 includes a converter 510, inverters 520 and 530, a control device 540, a filter capacitor C1, and a smoothing capacitor C2. Converter 510 is connected between battery B and inverters 520 and 530, and inverters 520 and 530 are connected to motor generators MG1 and MG2, respectively.

  Converter 510 includes power transistors Q1 and Q2, diodes D1 and D2, and a reactor L. Converter 510 boosts the DC voltage received from battery B using reactor L, and supplies the boosted voltage to power supply line PL2. Converter 510 steps down DC voltage received from inverters 520 and 530 to charge battery B.

  Inverters 520 and 530 include U-phase arms 521U and 531U, V-phase arms 521V and 531V, and W-phase arms 521W and 531W, respectively. U-phase arm 521U, V-phase arm 521V and W-phase arm 521W are connected in parallel between nodes N1 and N2. Similarly, U-phase arm 531U, V-phase arm 531V, and W-phase arm 531W are connected in parallel between nodes N1 and N2.

  U-phase arm 521U includes two power transistors Q3 and Q4 connected in series. Similarly, U-phase arm 531U, V-phase arms 521V and 531V, and W-phase arms 521W and 531W each include two power transistors Q5 to Q14 connected in series. Further, diodes D3 to D14 that flow current from the emitter side to the collector side are connected between the collector and emitter of each of the power transistors Q3 to Q14.

  Intermediate points of the respective phase arms of inverters 520 and 530 are connected to the respective phase ends of the respective phase coils of motor generators MG1 and MG2. In motor generators MG1 and MG2, one end of three coils of U, V, and W phases is commonly connected to the middle point.

  Filter capacitor C1 is connected between power supply lines PL1 and PL3, and smoothes the voltage level of power supply line PL1. Smoothing capacitor C2 is connected between power supply lines PL2 and PL3, and smoothes the voltage level of power supply line PL2.

  Inverters 520 and 530 convert DC voltage from smoothing capacitor C2 into AC voltage based on a drive signal from control device 540, and drive motor generators MG1 and MG2.

  Control device 540 calculates each phase coil voltage of motor generators MG1 and MG2 based on the motor torque command value, each phase current value of motor generators MG1 and MG2, and the input voltage of inverters 520 and 530, and the calculation result Based on this, a PWM (Pulse Width Modulation) signal for turning on / off the power transistors Q3 to Q14 is generated and output to the inverters 520 and 530.

  Control device 540 calculates the duty ratio of power transistors Q1 and Q2 for optimizing the input voltage of inverters 520 and 530 based on the motor torque command value and the motor rotation speed described above, and based on the calculation result. Thus, a PWM signal for turning on / off the power transistors Q1 and Q2 is generated and output to the converter 510.

  Further, control device 540 controls switching operations of power transistors Q1 to Q14 in converter 510 and inverters 520 and 530 in order to charge battery B by converting AC power generated by motor generators MG1 and MG2 into DC power. To do.

  FIG. 3 is a cross-sectional view showing a configuration of motor generator MG2 and its surroundings. As shown in FIG. 3, the motor generator MG2 includes a stator 222 formed in an annular shape, and a rotor 221 disposed in the stator 222 and provided to be rotatable around a rotation center line O. . The motor generator MG2 is accommodated in the accommodation chamber 610.

  The stator 222 includes an annularly formed stator core 222A, a stator coil 222B attached to the stator core 222A, and a fastening member 222C that fixes the stator core 222A to the casing 600.

  A catch tank 613 is formed in the storage chamber 611 in which the differential mechanism 400 is stored. The catch tank 613 is formed in a partition wall 228 between the storage chamber 610 and the storage chamber 611. Differential mechanism 400 includes a drive pinion gear, a ring gear, a differential pinion gear, a side gear, and a differential case (not shown). The drive pinion gear extends in the vehicle front-rear direction, and its front end is connected to a propeller shaft (not shown). The drive pinion gear is located on the front side of the vehicle with respect to the ring gear. The ring gear is fastened to the differential case using a fastening member such as a bolt. The ring gear is arranged to mesh with the drive pinion gear. When the rotation of the drive pinion gear is transmitted to the ring gear, the ring gear and the differential case are integrally rotated about the central axis of the drive shaft. The differential case and the drive shaft are provided with a pinion gear and a side gear, respectively. The differential case transmits equal rotational torque to both wheels while changing the rotational speed of the left and right drive shafts when the vehicle is turning by meshing the pinion gear and the side gear.

  Oil is stored at the bottom of the storage chamber 611. When the ring gear of the differential mechanism 400 rotates, the oil is lifted up and enters the catch tank 613. A flow-down port 216 is formed at the bottom of the catch tank 613 so that the oil in the catch tank 613 drips into the storage chamber 610.

  A coolant passage 285 is formed in the rotor 221, and a supply port 281 is formed in the coolant passage 285. The oil flowing down from the catch tank 613 enters the refrigerant passage 285 from the supply port 281.

  A discharge port 284 is formed in the refrigerant passage 285, and the oil in the refrigerant passage 285 can be discharged toward the stator coil 222B by rotating the rotor 221.

  Thus, the stator coil 222B can be cooled by spraying oil onto the stator coil 222B. Furthermore, the rotor 221 can be cooled by the refrigerant flowing through the refrigerant passage 285, and the cooling of the permanent magnet 253 can be improved.

  In this driving device 200, the oil staying at the bottom of the storage chamber 611 is pumped up by the ring gear, and the pumped up oil is supplied to the refrigerant passage 285. For this reason, an oil pump for supplying oil to the refrigerant passage 285 is not required, and the drive device 200 itself can be made compact and low in cost.

  Further, the partition wall 228 is provided with a bearing 260 that rotatably supports the rotary shaft 230. The bearing 260 is also located below the flow-down port 216, and the oil dripping from the flow-down port 216 is also supplied to the bearing 260, and the lubrication of the bearing 260 is ensured.

  Thus, by providing the refrigerant passage 285 in the portion of the rotor 221 located on the partition wall 228 side, the oil stored in the catch tank 613 is used for lubricating the bearing 260 and cooling the rotor 211 and the stator coil 222B. Can be used.

  In FIG. 3, the rotor 221 includes a rotation shaft 230 provided to be rotatable around a rotation center line O, a rotor core 251 fixed to the rotation shaft 230, and an end plate 252 provided on an end surface of the rotor core 251. And a permanent magnet 253 provided on the rotor core 251. The end plate 252 is provided on the axial end surface of the rotor core 251 arranged in the rotation center line O direction. In particular, the end plate 252 that forms the refrigerant passage 285 is provided on the axial end surface located on the partition wall 228 side of the axial end surface of the rotor core 251.

  The refrigerant passage 285 is defined by the end plate 252 and the axial end surface of the rotor core 251. A supply port 281 is formed in the end plate 252, and the catch tank 613 and the flow-down port 216 are located above the supply port 281.

  For this reason, the oil discharged from the downflow port 216 flows down along the partition wall 228 and enters the refrigerant passage 285 from the supply port 281. A part of the oil flowing down from the flow down port 216 reaches a portion of the end plate 252 adjacent to the supply port 281. When the rotor 221 rotates, the oil moves along the surface of the end plate 252 by centrifugal force and moves to the outer peripheral edge side of the end plate 252. Then, it is scattered toward the coil end of the stator coil 222B. As described above, the oil transmitted on the outer peripheral surface of the end plate 252 also contributes to cooling of the stator coil 222B. Furthermore, the oil flows through the front and back surfaces of the end plate 252 so that the end plate 252 can be cooled. The end plate 252 is supported by a flange 286 formed on the rotary shaft 230.

  FIG. 4 is a cross-sectional view showing the configuration of the refrigerant passage 285 and its surroundings. As shown in FIG. 4, the refrigerant passage 285 is disposed so as to pass through the end surface in the axial direction of the permanent magnet 253, and the permanent magnet 253 can be cooled by the oil flowing through the refrigerant passage 285. . By cooling the permanent magnet 253, demagnetization of the permanent magnet 253 can be suppressed.

  The refrigerant passage 285 communicates with a supply port 281 formed on the inner peripheral edge side of the end plate 252, a passage 282 communicating with the supply port 281, an oil reservoir 283 communicating with the passage 282, and an oil reservoir 283. And a discharge port 284 to be used.

  The height of the oil reservoir 283 in the direction of the rotation center line O is higher than the height of the discharge port 284 and the passage 282 in the direction of the rotation center line O. For this reason, oil can be stored in the oil reservoir 283, and oil can be continuously blown from the discharge port 284.

  Further, the oil staying in the oil reservoir 283 is pressurized by centrifugal force and then blown out through the narrow discharge port 284. For this reason, the blowing speed of the oil blown from the discharge port 284 is fast, and the oil blown from the discharge port 284 reaches the stator coil 222B. The axial end surface of the permanent magnet 253 reaches the oil reservoir 283.

  A plurality of hollow portions 290 are formed in the rotor core 251. A plurality of the hollow portions 290 extend in the direction of the rotation center line O and are formed at intervals in the circumferential direction. The hollow portion 290 reaches the refrigerant passage 285, and the oil flowing through the refrigerant passage 285 enters the hollow portion 290. The rotor core 251 can be cooled by the oil entering the cavity 290. FIG. 5 is a plan view showing an axial end surface of the rotor core 251. As shown in FIG. 5, the cavity 290 is formed on the radially inner side of the rotor core 251 with respect to the permanent magnet 253, and the rotor core 251 is formed by laminating a plurality of electromagnetic steel plates 270. . For this reason, when the rotor 221 rotates, part of the oil that has entered the cavity 290 enters between the electromagnetic steel sheets 270. The oil that has entered between the electromagnetic steel sheets 270 is blown out from the outer peripheral surface of the rotor core 251 toward the inner peripheral surface of the stator 222.

  Thus, the oil flows between the electromagnetic steel sheets 270, so that the rotor core 251 can be cooled well. By improving the cooling efficiency of the rotor core 251, the heat of the permanent magnet 253 can be radiated to the rotor core 251, and demagnetization of the permanent magnet 253 can be suppressed.

  A plurality of hollow portions 290 are formed at equal intervals in the circumferential direction. The oil that has entered each cavity 290 functions as a balancer of the rotor core 251. For example, when the rotor core 251 is eccentric, the oil gathers in a direction opposite to the eccentricity to correct the eccentric amount.

  As shown in FIG. 5, each permanent magnet 253 is accommodated in a magnet insertion hole 291 formed in the rotor core 251. The permanent magnet 253 is fixed by a resin 292 filled in the magnet insertion hole 291. As the resin 292, for example, an epoxy foam adhesive, urethane, or the like can be used.

  The resin 292 is filled between the side surface located on the radially outer side of the peripheral surface of the permanent magnet 253 and the inner peripheral surface of the magnet insertion hole 291. The resin 292 is not formed on the radially inner side surface of the peripheral surface of the permanent magnet 253, and the radially inner side surface is exposed from the resin 292. Then, the oil in the cavity 290 passes between the electromagnetic steel plates 270 and reaches the side surface on the radially inner side of the permanent magnet 253. Thereby, the side surface of the permanent magnet 253 is directly cooled by oil.

  As shown by the broken line in FIG. 5, a plurality of leg portions 289 that contact the end surface of the rotor core 251 in the axial direction are formed on the outer peripheral edge portion of the end plate 252. A discharge port 284 is formed between the leg portions 289.

  6 is a side view showing a configuration of the flange portion 286 that supports the end plate 252 and its surroundings, and FIG. 7 is a plan view of the end plate 252 and the flange portion 286 in plan view from the direction of the rotation center line O. .

  As shown in FIGS. 6 and 7, the collar portion 286 is formed with a plurality of notches 288 at intervals in the circumferential direction. The notch 288 extends radially inward from the outer peripheral edge of the flange 286. The supply port 281 formed in the end plate 252 is located in the notch 288.

  The oil flowing down from above is received by the notch 288 and guided to the supply port 281. As described above, even if the oil is caused to flow down from above, the oil can be satisfactorily supplied into the refrigerant passage 285. A protrusion 287 is formed between the notches 288.

  Although the embodiment of the present invention has been described above, it should be considered that the embodiment disclosed this time is illustrative and not restrictive in all respects. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims. Furthermore, the above numerical values are examples, and are not limited to the above numerical values and ranges.

  The present invention can be applied to a drive device provided with a rotating electrical machine, and is particularly suitable for a vehicle drive device.

It is a schematic diagram which shows typically the drive device mounted in the hybrid vehicle. It is a circuit diagram which shows the structure of the principal part of PCU which drives and controls a motor generator. It is sectional drawing which shows a motor generator and the surrounding structure. It is sectional drawing which shows a refrigerant path and the surrounding structure. It is a top view which shows the axial direction end surface of a rotor core. It is a side view which shows the collar part which supports an end plate, and the structure of the circumference | surroundings. It is the top view which planarly viewed the end plate and the collar part from the rotation center line direction.

Explanation of symbols

  100 Engine, 110 Crankshaft, 200 Drive unit, 211, 221 Rotor, 212, 222 Stator, 216 Downflow, 222A Stator core, 222B Stator coil, 222C Fastening member, 228 Bulkhead, 230 Rotating shaft, 251 Rotor core, 252 End plate 253 Permanent magnet, 260 Bearing, 270 Magnetic steel plate, 281 Supply port, 282 Passage, 283 Oil reservoir, 284 Discharge port, 285 Refrigerant passage, 286 Hook, 287 Projection, 288 Notch, 289 Leg, 290 Cavity Part, 291 magnet insertion hole, 292 resin, 400 differential mechanism.

Claims (7)

A rotating electrical machine including a stator and a rotor provided to be rotatable about a central axis;
A gear mechanism including a gear provided rotatably;
A housing case for housing the rotating electrical machine and the gear mechanism, and storing a refrigerant at a bottom;
A catch tank for receiving the refrigerant pumped up by the gear;
With
The stator includes an annular stator core disposed around the rotor and a coil attached to the stator core;
A refrigerant passage through which the refrigerant can flow is formed in the rotor, the refrigerant is supplied from the catch tank to the refrigerant passage, and the refrigerant in the refrigerant passage is discharged toward the coil into the refrigerant passage. So that the outlet is provided ,
The rotor includes a rotation shaft, a rotor core fixed to the rotation shaft, and an end plate provided on an axial end surface of the rotor core,
A supply port for supplying the refrigerant from the catch tank to the refrigerant passage is formed in the end plate,
The catch tank is located above the supply port;
The drive device in which the catch tank is formed with a flow-down port through which the refrigerant in the catch tank flows down toward the supply port . The rotating shaft is formed so as to protrude from the peripheral surface of the rotating shaft, and a collar portion for supporting the end plate is formed,
The drive device according to claim 1 , wherein the flange portion is formed with a notch portion extending radially inward from the outer peripheral edge portion, and the supply port is located in the notch portion. The housing case is provided with a bearing portion that rotatably supports the rotating shaft,
The bearing portion is positioned from below the catch tank, the refrigerant flowing down from the catch tank reaches the bearing unit, the driving device according to claim 1 or claim 2. The drive device according to any one of claims 1 to 3 , wherein the rotor includes a rotor core and a magnet provided in the rotor core, and the refrigerant passage passes through the magnet. The rotor includes a rotation shaft and a rotor core fixed to the rotation shaft. The rotor core is provided with a plurality of cavities provided at intervals in the circumferential direction and extending in the central axis direction. parts are communicated with the refrigerant passage, the driving device according to any one of claims 1 to 4. Said rotor includes a magnet provided on the rotor core, the cavity is located radially inward from the magnet, the rotor core is formed by laminating a plurality of steel plates, according to claim 5 The drive device described in 1. The rotor core is formed with a magnet housing hole for housing the magnet,
The magnet is fixed by a resin filled in the magnet accommodation hole,
The resin is formed on a portion of the peripheral surface of the magnet that is positioned on the radially outer side of the rotor, and a portion of the peripheral surface of the magnet that is positioned on the radially inner side is exposed from the resin. The drive device according to claim 6 .

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