JP2010273504A - Rotor, rotary electric machine, and vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor which is high in the efficiency of cooling a magnet embedded in the vicinity of an outer peripheral surface of a rotor core, and to provide a rotary electric machine and a vehicle with the same. <P>SOLUTION: A guide 213A which guides a coolant supplied to a space along the radial direction of an end plate 213 is formed at the end plate 213 so provided as to form the space on an axial edge of a rotor core together with the axial edge. The guide 213A includes a first end 213A1 communicating with a coolant passage 230A, and a second end 213A2 located outside in the radial direction to the first end 213A1. The end plate 213 includes a first discharge port 213B1 located on the inner side in the radial direction than the magnet 212 and capable of discharging the coolant in the space, and a second discharge port 213B2 formed so as to be disposed side by side with the magnet 212 in the circumferential direction and capable of discharging the coolant in the space. The discharge amount of the coolant capable of being discharged from the second discharge port 213B2 is smaller than that capable of being discharged from the first discharge port 213B1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rotor, a rotating electrical machine, and a vehicle, and more particularly, to a rotor that is supplied with a refrigerant on an axial end surface of a rotor core, and a rotating electrical machine and a vehicle including the rotor.

  Japanese Patent Laying-Open No. 2005-6429 (Patent Document 1) discloses that the cooling oil supplied from the rotor shaft is circulated in the gap between the rotor and the end plate. Here, the cooling oil is discharged from a discharge port on the outer peripheral surface of the end plate.

  Japanese Patent Laid-Open No. 2008-178243 (Patent Document 2) discloses that an oil passage is provided in the rotor and the magnet is cooled by the oil flow.

JP 2005-6429 A JP 2008-178243 A

  When flowing a refrigerant on the end plate, there is a demand for supplying sufficient refrigerant on a magnet embedded in the vicinity of the outer peripheral surface of the rotor core. This requirement increases as the rotational speed of the rotor increases. The rotors described in Patent Documents 1 and 2 cannot sufficiently solve the above problems.

  The present invention has been made in view of the above problems, and an object of the present invention is a rotor with high cooling efficiency of a magnet embedded in the vicinity of the outer peripheral surface of a rotor core, and a rotating electrical machine and a vehicle including the same. Is to provide.

  The rotor according to the present invention supplies a refrigerant to the rotor core, a magnet embedded in the rotor core, an end plate provided on the axial end surface of the rotor core so as to form a space between the axial end surface, and the space. And a guide part that guides the refrigerant supplied to the space along the radial direction of the end plate, and the guide part communicates with the first end part that communicates with the refrigerant path, and the first end part. And an end plate located radially inward from the magnet, and a first discharge port through which the refrigerant in the space can be discharged, and the magnet in the circumferential direction. A second discharge port that is formed so as to be lined up or positioned radially outward from the magnet and capable of discharging the refrigerant in the space, and the discharge amount of the refrigerant that can be discharged from the second discharge port is The amount of refrigerant discharged from the first outlet is smaller.

  According to the above configuration, the flow of the refrigerant is also formed on the magnet by having the second discharge port formed so as to be aligned with the magnet in the circumferential direction or positioned radially outward from the magnet. Therefore, the magnet embedded in the rotor core can be efficiently cooled. Further, since the amount of refrigerant that can be discharged from the second discharge port is smaller than the amount of refrigerant that can be discharged from the first discharge port, as the rotor rotates at a higher speed, the amount of refrigerant between the first and second discharge ports becomes smaller. The refrigerant can be stored so that the oil level is located. As a result, the cooling performance of the magnet is further improved.

  In the above rotor, as one example, when the rotor is rotating at low speed, the refrigerant is discharged from only the first outlet among the first and second outlets, and when the rotor is rotating at high speed, the refrigerant is discharged from the first and second outlets. The refrigerant is discharged from both sides. In this case, when the rotor is rotating at a low speed, a refrigerant flow can be formed above the magnet, and for a high rotation of the rotor, an excessive refrigerant can be discharged from the first discharge port while forming a refrigerant flow above the magnet.

  In the rotor, as one example, the end plate and the guide portion are integrally formed. In this case, the guide portion can be easily formed without increasing the number of parts.

  In the above rotor, as an example, a plurality of magnets are embedded in the vicinity of the outer peripheral surface of the rotor core and are arranged in a row in the circumferential direction of the rotor core.

  In the rotor, as an example, a plurality of guide portions are formed along the circumferential direction of the rotor core.

  The rotating electrical machine according to the present invention includes the rotor described above. A vehicle according to the present invention includes a drive unit including the rotating electric machine.

  ADVANTAGE OF THE INVENTION According to this invention, the cooling efficiency of the magnet embed | buried under the outer peripheral surface of a rotor core can be improved.

1 is a schematic diagram showing a configuration of a hybrid vehicle to which a rotor according to one embodiment of the present invention is applied. It is the schematic which shows the structure of the drive unit of the vehicle containing the rotor which concerns on one embodiment of this invention. It is sectional drawing which shows the rotary electric machine containing the rotor which concerns on one embodiment of this invention. It is a figure which shows the end plate contained in the rotor which concerns on one embodiment of this invention. It is a figure for demonstrating the flow of the refrigerant | coolant on the end plate in the rotor which concerns on one embodiment of this invention. It is a figure for demonstrating the flow of the refrigerant | coolant on the end plate in the rotor which concerns on a comparative example.

  Embodiments of the present invention will be described below. Note that the same or corresponding portions are denoted by the same reference numerals, and the description thereof may not be repeated.

  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.

  FIG. 1 is a schematic diagram illustrating a configuration of a hybrid vehicle to which a vehicle drive unit according to an embodiment of the present invention is applied. Referring to FIG. 1, the hybrid vehicle according to the present embodiment includes an engine 1, a drive unit 2, a PCU 3, and a battery 4. The drive unit 2 is electrically connected to the PCU 3 via the cable 3A. The PCU 3 is electrically connected to the battery 4 via the cable 4A.

  The engine 1 that is an internal combustion engine may be a gasoline engine or a diesel engine. The drive unit 2 generates a driving force for driving the vehicle together with the engine 1. Both the engine 1 and the drive unit 2 are provided in the engine room of the hybrid vehicle. The PCU 3 is a control device that controls the operation of the drive unit 2.

  FIG. 2 is a schematic diagram for explaining the internal structure of the drive unit 2. Referring to FIG. 2, drive unit 2 includes motor generators 100 and 200, power split mechanism 300, counter gear 400, and differential gear 500.

  Motor generators 100 and 200 are rotating electrical machines having at least one function of an electric motor and a generator. Power split device 300 is provided between motor generators 100 and 200. Counter gear 400 is provided between power split device 300 and differential gear 500. Differential gear 500 is connected to the drive shaft via a drive shaft receiving portion. Motor generators 100 and 200, power split device 300, counter gear 400 and differential gear 500 are housed in a casing.

  Motor generators 100 and 200 are electrically connected to cable 3A. The other end of the cable 3A is connected to the PCU 3 as shown in FIG. Thereby, battery 4 and motor generators 100 and 200 are electrically connected via PCU 3 and cables 3A and 4A.

  Motor generators 100 and 200 include rotors 110 and 210 and stators 120 and 220, respectively. Stator 120 and 220 include stator cores 121 and 221 and stator coils 122 and 222 wound around stator cores 121 and 221.

  Power split device 300 is configured to include 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.

  The crankshaft 1A of the engine 1, the rotor 110 of the motor generator 100, and the rotor 210 of the motor generator 200 rotate about the same axis.

The sun gear 311 in the planetary gear 310 is coupled to a hollow sun gear shaft that penetrates the center of the crankshaft 1A. The ring gear 314 is rotatably supported coaxially with the crankshaft 1A. 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 1 </ b> A and supports the rotation shaft of each pinion gear 312.

  The rotor 220 of the motor generator 200 is coupled to a ring gear case that rotates integrally with the ring gear 314 of the planetary gear 310 via a planetary gear 320 as a speed reducer.

  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 210, 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.

  When the vehicle travels, the power output from the engine 1 is transmitted to the crankshaft 1A and divided into two paths by the power split mechanism 300.

  One of the two paths is a path that is transmitted from the counter gear 400 to the drive shaft via the differential gear 500. The driving force transmitted to the drive shaft is transmitted as a rotational force to the drive wheels, and causes the vehicle to travel.

  The other is a path for driving the motor generator 100 to generate power. Motor generator 100 generates power using the power of engine 1 distributed by power split device 300. The electric power generated by the motor generator 100 is properly used according to the traveling state of the vehicle and the state of the battery 4. For example, during normal traveling and sudden acceleration of the vehicle, the electric power generated by motor generator 100 becomes the electric power for driving motor generator 200 as it is. On the other hand, under the conditions determined in battery 4, the electric power generated by motor generator 100 is stored in battery 4 through an inverter and a converter provided in PCU 3.

  Motor generator 200 is driven by at least one of the electric power stored in battery 4 and the electric power generated by motor generator 100. The driving force of the motor generator 200 is transmitted from the counter gear 400 to the drive shaft via the differential gear 500. By doing so, the driving force of the engine 1 can be assisted by the driving force from the motor generator 200, or the vehicle can be driven only by the driving force from the motor generator 200.

  On the other hand, during regenerative braking of the vehicle, the driving wheels are rotated by the inertial force of the vehicle body. Motor generator 200 is driven through the drive shaft, differential gear 500 and counter gear 400 by the rotational force from the drive wheels. At this time, the motor generator 200 operates as a generator. Thus, motor generator 200 acts as a regenerative brake that converts braking energy into electric power. The electric power generated by the motor generator 200 is stored in the battery 4 via an inverter provided in the PCU 3.

  FIG. 3 is a cross-sectional view showing motor generator 200. As shown in FIG. 3, the rotor 210 and the stator 220 included in the motor generator 200 are housed in the casing 2A. Rotor 210 includes a rotor core 211, a magnet 212, and an end plate 213. Stator 220 includes a stator core 221 and a stator coil 222.

  The rotor core 211 is configured by laminating electromagnetic steel plates, for example. The magnet 212 is embedded in a hole provided in the rotor core 211. The magnet 212 is embedded in the vicinity of the outer peripheral surface of the rotor core 211. The end plates 213 are provided on both end surfaces of the rotor core 211 in the axial direction.

  Stator core 221 is formed by laminating electromagnetic steel sheets, for example. The stator coil 222 is wound around the stator core 221.

  The rotor core 211 is fixed to the rotating shaft 230. The rotating shaft 230 is rotatably supported by the casing 2A. Therefore, the rotor core 211 is rotatable in the casing 2A.

  A refrigerant passage 230 </ b> A is formed at the center of the rotating shaft 230. Oil circulating in the casing 2A is supplied to the refrigerant passage 230A. This oil functions as a refrigerant that cools each part of the motor generator 200.

  In the refrigerant passage 230A, the refrigerant flows in the direction of the arrow DR230A. In other words, the refrigerant supplied to the refrigerant passage 230 </ b> A extending in the axial direction of the rotating shaft 230 is supplied to the space formed between the rotor core 211 and the end plate 213 by the centrifugal force accompanying the rotation of the rotor 210. . Thereby, the magnet 212 cooled by the rotor 210, especially the rotor core 211 is cooled.

  FIG. 4 is a top view showing the end plate 213. Referring to FIG. 4, end plate 213 has a guide portion 213 </ b> A that guides the refrigerant supplied between rotor core 211 and end plate 213 in the radial direction of end plate 213. The guide portion 213A is provided integrally with the end plate 213, and is formed so as to protrude from the main surface of the end plate 213 facing the rotor core 211 toward the rotor core 211. The guide part 213 is formed so as to extend in the radial direction of the end plate 213. As shown in FIG. 4, the supplied refrigerant can be guided in the radial direction by forming the two protruding portions substantially in parallel. In the example of FIG. 4, four guide portions are formed at positions separated by 90 ° in the circumferential direction. Each guide portion has a first end 213A1 positioned radially inward and a second end 213A2 positioned radially outward. The first end 213A1 communicates with a refrigerant passage 230A formed in the rotary shaft 230. The refrigerant supplied to the first end 213A1 is brought to the second end 213A2 by the centrifugal force accompanying the rotation of the rotor 210, and is supplied from the second end 213A2 to a region other than the guide part 213A. . By providing the guide portion 213 </ b> A, the refrigerant supplied from the refrigerant passage 230 </ b> A of the rotating shaft 230 can be guided to the vicinity of the outer peripheral surface of the rotor core 211, so that the magnet 212 embedded in the vicinity of the outer peripheral surface of the rotor core 211. Cooling can be promoted.

  Note that the magnet 142 made of rare earth or the like has temperature characteristics and tends to be demagnetized additionally and reversely as the temperature becomes higher, and the performance of the rotating electrical machine tends to deteriorate. Therefore, it is important to efficiently cool the magnet 142 embedded in the rotor core 141.

  FIG. 5 is a diagram for explaining the flow of the refrigerant on the end plate 213 in the rotor 210 according to the present embodiment.

  Referring to FIG. 5, the refrigerant guided in the radial direction (arrow DR0 direction) along guide portion 213 </ b> A flows in the circumferential direction from the vicinity of the outer peripheral surface of rotor core 211. In the rotating electrical machine according to the present embodiment, the end plate 213 is provided with a discharge port 213 </ b> B for discharging the refrigerant from the space between the rotor core 221 and the end plate 213. The discharge port 213B includes a first discharge port 213B1 and a second discharge port 213B2. The first outlet 213B1 is provided radially inward of the magnet 212, the first outlet 213B2 is radially outward of the first outlet 213B1, that is, the magnet 212 It is provided in the area immediately above. The refrigerant flow rate that can be discharged from the second discharge port 213B2 is smaller than the refrigerant flow rate that can be discharged from the first discharge port 213B1.

The diameter (D ₀ ) of the second discharge port 213B2 (orifice) is determined by the following equation.
D ₀ = K × √ {Q / (N × √R ₀ ² −R ² )}
K: Constant Q: Flow rate N: Number of revolutions (preferably at high revolutions, for example, about 15000 rpm)
R ₀ : Position of the second discharge port 213B2 R: Diameter of the refrigerant passage 230A By setting the above K (constant) to a predetermined range, a refrigerant pool is formed in a region immediately above the magnet 212, and the refrigerant is The cooling efficiency of the magnet 212 can be improved by flowing at a constant speed.

  The refrigerant that flows in the direction of the arrow DR0 along the guide part 213A flows out from the guide part 213A and then flows toward the two discharge ports 213B1. That is, one is a flow (arrow DR1) toward the first discharge port 213B1, and the other is a flow (arrow DR2) that passes immediately above the magnet 212 and toward the second discharge port 213B2. . Note that the flow of both arrows DR1 and DR2 shown in FIG. 5 is formed when the rotor 220 is rotating at a relatively high rotation, and when the rotor 220 is rotating at a relatively low rotation, that is, the guide portion. When the amount of refrigerant supplied from 213A is relatively small, only the flow indicated by the arrow DR2 toward the second discharge port 213B2 is formed.

  FIG. 6 is a diagram for explaining the flow of the refrigerant on the end plate in the rotor according to the comparative example. Referring to FIG. 6, in this comparative example, the second discharge port 213B2 shown in FIG. 5 is not formed, and only the first discharge port 213B1 positioned radially inward from the magnet 212 is provided. .

  In this comparative example, since only the first discharge port 213B1 is provided, the refrigerant flow along the arrow DR2 shown in FIG. 5 is not formed, and only the flow along the arrow DR1 toward the first discharge port 213B1 is formed. Is formed. In this comparative example, in the region immediately above the magnet 212, although the refrigerant is supplied and the refrigerant pool is formed, the flow in the direction of the arrow DR2 described above is not formed, so the replacement of the refrigerant is not promoted, The magnet 212 cannot be cooled efficiently.

  On the other hand, according to the rotor according to the present embodiment, as shown in FIG. 5, by having the second discharge port 213B2 formed so as to be aligned with the magnet 212 in the circumferential direction, Since the refrigerant flow (arrow DR2) can be formed, the magnet 212 embedded in the rotor core 211 can be efficiently cooled. Further, since the amount of refrigerant that can be discharged from the second discharge port 213B2 is smaller than the amount of refrigerant that can be discharged from the first discharge port 213B1, the first discharge port 213B1 and the second discharge port are increased as the rotor 210 is rotated at a higher speed. The refrigerant can be stored so that the oil level is positioned between 213B2. As a result, the cooling performance of the magnet 212 is further improved.

  Further, when the rotor 210 is rotating at a low speed, the refrigerant is discharged only from the first discharge port 213B1, and when the rotor 210 is rotating at a high speed, the refrigerant is discharged from both the first and second discharge ports 213B1 and 213B2. At the time of rotation, a refrigerant flow is formed above the magnet 212, and when the rotor 210 is rotated at a high speed, excess refrigerant can be discharged from the first discharge port 213B1 while forming a refrigerant flow above the magnet 212.

  Further, by integrally forming the end plate 213 and the guide portion 213A, the guide portion 213A can be easily formed without increasing the number of parts.

  The above contents are summarized as follows. That is, the rotor according to the present embodiment is an end provided so as to form a space between the rotor core 211, the magnet 212 embedded in the rotor core 211, and the axial end surface of the rotor core 211. The plate 213 includes a refrigerant passage 230A that supplies the refrigerant to the space, and a guide portion 213A that guides the refrigerant supplied to the space along the radial direction of the end plate 213. The guide portion 213A includes the refrigerant passage 230A. A first end portion 213A1 communicating with the first end portion 213A1 and a second end portion 213A2 positioned radially outward from the first end portion 213A1. The end plate 213 is positioned radially inward from the magnet 212. The first exhaust port 213B1 that can discharge the refrigerant in the space and the magnet 212 are arranged in the circumferential direction, and the refrigerant in the space can be discharged. And a second discharge port 213B2, emissions of the refrigerant can be discharged from the second discharge port 213B2 is smaller than the emissions of the refrigerant can be discharged from the first discharge port 213B1. When the rotor 210 is rotating at a low speed, the refrigerant is discharged only from the first outlet 213B1 of the first and second outlets 213B1 and 213B2. When the rotor 210 is rotating at a high speed, both the first and second outlets 213B1 and 213B2 are discharged. The refrigerant is discharged from.

  Note that the second discharge port 213B2 may be formed to be positioned radially outward from the magnet 212.

  Although the embodiments of the present invention have been described above, the embodiments disclosed this time should be considered as illustrative in all points and not restrictive. 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.

  1 engine, 1A crankshaft, 2 drive shaft, 2A casing, 3 PCU, 3A, 4A cable, 4 battery, 100, 200 motor generator, 110, 210 rotor, 211 rotor core, 212 magnet, 213 end plate, 213A guide part, 213A1 first end, 213A2 second end, 120, 220 stator, 230 rotating shaft, 300 power split mechanism, 310, 320 planetary gear, 311, 321 sun gear, 312, 322 pinion gear, 313, 323 planetary carrier, 314, 324 Ring gear, 400 counter gear, 500 differential gear.

Claims (7)

Rotor core,
A magnet embedded in the rotor core;
An end plate provided on the axial end face of the rotor core so as to form a space between the axial end face;
A refrigerant passage for supplying refrigerant to the space;
A guide portion that guides the refrigerant supplied to the space along the radial direction of the end plate;
The guide portion has a first end communicating with the refrigerant passage, and a second end located radially outward with respect to the first end,
The end plate is positioned radially inward from the magnet, and is arranged in a circumferential direction with the first discharge port capable of discharging the refrigerant in the space, or radially outward from the magnet. And a second discharge port capable of discharging the refrigerant in the space,
The rotor has a discharge amount of refrigerant that can be discharged from the second discharge port smaller than a discharge amount of refrigerant that can be discharged from the first discharge port. At the time of low rotation of the rotor, the refrigerant is discharged from only the first discharge port among the first and second discharge ports,
The rotor according to claim 1, wherein the refrigerant is discharged from both the first and second discharge ports when the rotor rotates at a high speed.   The rotor according to claim 1, wherein the end plate and the guide portion are integrally formed.   The rotor according to any one of claims 1 to 3, wherein a plurality of the magnets are embedded in the vicinity of an outer peripheral surface of the rotor core and are arranged in a row in a circumferential direction of the rotor core.   The rotor according to any one of claims 1 to 4, wherein a plurality of the guide portions are formed along a circumferential direction of the rotor core.   A rotating electrical machine comprising the rotor according to any one of claims 1 to 5.   A vehicle comprising a drive unit including the rotating electrical machine according to claim 6.

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