JP2006158105A - Apparatus and method for cooling motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and method for cooling a motor capable of achieving reductions in size and weight of a cooling system by self-circulating coolant. <P>SOLUTION: This cooling motor has a reservoir tank 11, a coolant supply passage 12 for communicating a passage 3P in a rotor, a passage 4P in a stator, respective inlet ports 3Pin, 4Pin for the respective passages 3P, 4P, and the reservoir tank 11, a coolant circulating passage 13 for communicating respective outlet ports 3Pout, 4Pout of the respective passages 3P, 4P and the reservoir tank 11, check valves 14, 15 which stop counterflow toward the coolant supply passage 12 direction by being disposed adjacent to the respective inlet ports 3Pin, 4Pin of the passages 3P, 4P, and an exhaust heat mechanism 16 which is disposed at the coolant circulating passage 13. The reservoir tank 11 is disposed at more upper position than the respective passages 3P, 4P in a vertical direction. With this constitution, the coolant M in a liquid phase is vaporized by heat generation of the rotor 3 portion during passing through the respective passages 3P, 4P, therefore, it is possible to perform efficient cooling with the vaporized coolant M, and to self-circulate the coolant M, thus providing reduction in the size of the cooling device 10. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a motor cooling device and a cooling method thereof.

  As an electric vehicle drive system, an in-wheel drive system in which a motor is inserted into a tire wheel has been proposed. This in-wheel drive system expands the effective use space in the vehicle interior and independently drives each wheel. It has the feature that the driving sensation different from the conventional car can be obtained.

  In order to realize such a drive system, it is essential to reduce the size of the motor. However, if the motor volume is reduced, the area that dissipates the heat generated by the loss also decreases, so the temperature rises significantly. Cooling is a big problem.

  Liquid cooling method and air cooling method are known for this cooling, but liquid cooling method can be expected to have high cooling efficiency, but circulation devices such as pumps and piping for circulating refrigerant liquid to the motor attached to the tire wheel Parts are required, and in this case, a refrigerant liquid heat exchanger is generally provided in the vicinity of the front grille, and this heat exchanger and the motor are connected by a long pipe, which increases the size of the entire cooling system. .

On the other hand, there is a hermetic type electric compressor in which a tube for circulating hot water is wound around the outer wall of the motor housing so that the sucked refrigerant is circulated in the motor housing. In this case, the refrigerant is circulated. The pump is assembled integrally (see, for example, Patent Document 1).
JP 2001-12352 A (page 3, FIG. 2)

  However, in such a conventional hermetic electric compressor, even when a pump for circulating the refrigerant is assembled integrally, the water in the hot water supply tube for cooling the refrigerant needs to be circulated by external power. In this case, the cooling system becomes larger, and the circulation of the refrigerant is integrated, but a pump is still necessary, and the motor must be enlarged even when the electric compressor is applied to the motor. Is done.

  Therefore, the present invention provides a motor cooling device and a cooling method thereof that can achieve a reduction in size and weight of a cooling system by self-circulation of a refrigerant.

  In the motor cooling device of the present invention, in a motor including a rotating shaft, a rotor coupled to the rotating shaft, and a stator surrounding the outer periphery of the rotor, the heat generated from the motor causes gas to escape from the liquid phase. A reservoir tank in which refrigerant changing in phase is stored; a rotor inner passage and a stator inner passage formed in each of the rotor and the stator; an inlet of the rotor inner passage and the stator inner passage; and the reservoir tank A refrigerant supply passage that communicates with each other, a refrigerant return passage that communicates with each outlet of the rotor passage and the stator passage, and the reservoir tank, and in the vicinity of each inlet of the rotor passage and the stator passage. A check valve for preventing a reverse flow in the direction of the refrigerant supply passage and the refrigerant return passage to dissipate the heat of the refrigerant in the refrigerant return passage outward. A heat removal mechanism, the provided is a most important feature that the reservoir tank is arranged in a vertical position above the rotor passage and the stator passage.

  In the motor cooling method of the present invention, the refrigerant stored in the reservoir tank in the motor including the rotating shaft, the rotor coupled to the rotating shaft, and the stator surrounding the outer periphery of the rotor. Is supplied to the rotor inner passage and the stator inner passage formed in each of the rotor and the stator through the refrigerant supply passage through check valves provided in the vicinity of the respective inlets. The refrigerant tank is returned to the reservoir tank through a refrigerant recirculation passage provided with a heat exhaust mechanism and circulated, and the reservoir tank is disposed at a position vertically above the rotor inner passage and the stator inner passage.

  According to the motor cooling device and the cooling method therefor of the present invention, the refrigerant is supplied from the reservoir tank disposed vertically above to the rotor inner passage and the stator inner passage through the refrigerant supply passage by gravity, and passes through these passages. In the meantime, the liquid-phase refrigerant is vaporized by heat generated by iron loss and copper loss of the rotor and stator portions, and the rotor and stator can be efficiently cooled by this vaporized refrigerant.

  At this time, the refrigerant that has become a gas phase in the rotor inner passage and the stator inner passage is prevented from flowing back to the refrigerant supply passage by the check valve, and the gas phase refrigerant that has cooled the rotor and stator is the refrigerant. It flows into the reflux passage and is returned from the gas phase to the liquid phase by the exhaust heat mechanism, and this liquid phase refrigerant can be self-circulated to the reservoir tank by the pressure of the gas phase refrigerant upstream of the exhaust heat mechanism, It is not necessary to provide a refrigerant moving device such as a pump in the refrigerant circulation path, and the cooling device can be made compact.

  Further, the heat of vaporization when the refrigerant is vaporized in the rotor inner passage and the stator inner passage can be used for cooling the rotor and the stator to improve the cooling efficiency, and the amount of refrigerant in the rotor inner passage and the stator inner passage Compared with the case of cooling in the phase state, it can be greatly reduced, and the weight of the entire system can be reduced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  1 to 4 show a first embodiment of a motor cooling apparatus and cooling method according to the present invention, FIG. 1 is a sectional view of the motor, FIG. 2 is a sectional view taken along line AA in FIG. FIG. 3 is a block diagram showing the refrigerant flow path of the cooling device, and FIG. 4 is an explanatory diagram showing the time variation of the refrigerant pressure in a graph.

  The motor of the present invention is applied to, for example, an in-wheel drive type electric vehicle, and is mounted on the vehicle body side in a state where the motor is inserted into a central recess formed on the back side of the tire wheel, and the wheel is directly driven by the rotation shaft of the motor. It is supposed to be.

  As shown in FIGS. 1 and 2, the motor 1 of this embodiment includes a rotating shaft 2, a rotor 3 coupled to the rotating shaft 2, and a stator 4 surrounding the outer periphery of the rotor 3. These are accommodated in the housing 5.

  The rotary shaft 2 is integrated with the rotor 3, and both end portions are rotatably supported by end plates 5 e at both ends of the housing 5 via bearings 6. A plurality (four in this embodiment) of rotor magnets 7 are arranged at equal intervals in the circumferential direction along the axial direction.

  The stator 4 is fixed to the inner periphery of the housing 5, and a plurality (six in this embodiment) of stator convex pole portions 4 </ b> S are provided on the inner periphery of the stator 4 at equal intervals in the circumferential direction. A coil 8 is wound around the pole portion 4S.

  As shown in FIG. 1, the cooling device 10 includes a reservoir tank 11 that stores a refrigerant M that changes from a liquid phase to a gas phase due to heat generated by the motor 1, and a rotor formed inside each of the rotor 3 and the stator 4. An internal passage 3P and the stator internal passage 4P, a refrigerant supply passage 12 for communicating the inlets 3Pin and 4Pin of the rotor internal passage 3P and the stator internal passage 4P with the reservoir tank 11, the rotor internal passage 3P and the rotor internal passage 3P. A refrigerant recirculation passage 13 for communicating the outlets 3Pout, 4Pout of the stator internal passage 4P and the reservoir tank 11 is provided, and is disposed in the vicinity of the inlets 3Pin, 4Pin of the rotor internal passage 3P and the stator internal passage 4P. These cooling valves are arranged in check valves 14 and 15 for preventing a reverse flow in the direction of the refrigerant supply passage 12 and the refrigerant return passage 13. And a condenser 16 as a heat exhaust mechanism for radiating the heat of the refrigerant in the recirculation passage 13 to the outside, and the reservoir tank 11 is located vertically above the rotor passage 3P and the stator passage 4P. In place.

  Further, in the method for cooling the motor 1 of the present embodiment, the refrigerant M in the motor 1 is formed in each of the rotor 3 and the stator 4 via the refrigerant supply passage 12 in the reservoir tank 11. After the rotor passage 3P and the stator passage 4P are supplied through check valves 14 and 15 provided in the vicinity of the respective inlets 3Pin and 4Pin, the refrigerant M is passed through a refrigerant return passage 13 provided with a capacitor 16. The reservoir tank 11 is circulated back to the reservoir tank 11 and disposed at a position vertically above the rotor inner passage 3P and the stator inner passage 4P.

  At this time, a main chamber 17 having a cross-sectional area larger than that of the passage 13 is provided upstream of the condenser 16 in the refrigerant recirculation passage 13 (upper side in the figure), and the main chamber 17 is interposed between the condenser 16 and the main chamber 17. A check valve 18 for preventing the flow in the direction of the main chamber 17 is provided.

  An air release port 11 c is formed in the upper end surface 11 b of the reservoir tank 11, and the start end portion of the refrigerant supply passage 12 and the end portion of the refrigerant return passage 13 are connected to the bottom portion 11 a of the reservoir tank 11. In addition, a sub chamber 19 for introducing the discharge pressure of the rotor inner passage 3P is provided at a position closer to the outlet 3Pout side of the rotor inner passage 3P than the main chamber 17 is.

  As shown in FIG. 2, the rotor inner passage 3P is formed at four substantially equal intervals in the circumferential direction corresponding to the arrangement positions of the four rotor magnets 7, and the stator inner passage 4P includes six stator protrusions. Six locations are formed at substantially equal intervals in the circumferential direction corresponding to the projecting portions of the pole portion 4S.

  As shown in FIG. 1, the rotor passage 3P is formed in the vicinity of the outer periphery of the rotor 3, while the introduction passage 2a for supplying the refrigerant from the refrigerant supply passage 12 to the rotor passage 3P is rotated around the rotor center. A branch passage 2b formed in the shaft 2 and extending from the introduction passage 2a to the rotor inner passage 3P is provided in the radial direction.

  That is, the refrigerant introduction side (the right side in FIG. 1) of the rotor inner passage 3P is connected to the introduction passage 2a formed at one end of the rotating shaft 2 as shown in FIG. The refrigerant supply passage 12 communicates with the branch passage 2b formed to be inclined in the radial direction, and the refrigerant discharge side (the left side in FIG. 1) of the rotor inner passage 3P is connected to the rotary shaft 2 from the rotor 3. The sub-chamber 19 communicates with a branch passage 2c formed over the other end and a discharge passage 2d formed at the other end of the rotating shaft 2.

  The refrigerant introduction side (right side in FIG. 1) of the stator inner passage 4P communicates with the refrigerant supply passage 12 via an annular passage 5a formed in the end plate 5e on one end side of the housing 5 as shown in FIG. The refrigerant discharge side (left side in FIG. 1) of the stator inner passage 4P communicates with the refrigerant recirculation passage 13 via an annular passage 5b formed in the end plate 5e on the other end side of the housing 5.

  The sub-chamber 19 communicates with a portion where the upstream portion 13A of the refrigerant recirculation passage 13 communicates with the main chamber 17 through a passage 19a, and the refrigerant M in the rotor inner passage 3P discharged to the sub-chamber 19 and the refrigerant recirculation. The refrigerant M in the stator inner passage 4 </ b> P discharged into the passage 13 joins and is introduced into the main chamber 17.

  Therefore, as shown in FIG. 3, the flow of the refrigerant M in the reservoir tank 11 flows from the refrigerant supply passage 12 (flow F1) through the introduction passage 2a (flow F2) and the branch passage 2b (flow F3). 3P (flow F4) is supplied to the stator inner passage 4P (flow F6) via the annular passage 5a (flow F5), and the refrigerant M in the rotor inner passage 3P flows into the branch passage 2c (flow F7). ) And the discharge passage 2d (flow F8), the refrigerant M in the stator inner passage 4P flows through the annular passage 5b (flow F9) to the upstream portion 13A (flow) of the refrigerant recirculation passage 13. F10).

  The refrigerant M discharged to the subchamber 19 and the upstream portion 13A of the annular passage 5a is introduced into the main chamber 17 (flow F11), and the refrigerant M introduced into the main chamber 17 is the check valve. After passing through the condenser 16 through 18 (flow F12), it returns to the reservoir tank 11 through the downstream portion 13B of the refrigerant recirculation passage 13 (flow F13).

  With the above configuration, according to the motor cooling device 10 and the cooling method thereof according to the present embodiment, the refrigerant M flows from the reservoir tank 11 arranged in the vertically upper position through the refrigerant supply passage 12 by gravity and passes through the rotor passage 3P and the stator. While being supplied to the passage 4P and passing through these passages 3P, 4P, the liquid-phase refrigerant is vaporized due to heat generated by iron loss or copper loss of the rotor 3, and the rotor 3 and the stator 4 are efficiently used by the vaporized refrigerant M. Can be cooled.

  At this time, the refrigerant in the gas phase in the rotor inner passage 3P and the stator inner passage 4P is prevented from flowing back to the refrigerant supply passage 12 side by the check valves 14 and 15, and the rotor 3 and the stator 4 are cooled. The gas-phase refrigerant M flows into the refrigerant recirculation passage 13 and is returned from the gas phase to the liquid phase by the capacitor 16. The liquid-phase refrigerant M is caused by the pressure of the gas-phase refrigerant M upstream of the capacitor 16. The refrigerant tank 11 can be self-circulated, and it is not necessary to use a refrigerant transfer device such as a pump in the circulation path of the refrigerant M, so that the cooling device 10 can be made compact.

  Further, the heat of vaporization when the refrigerant M is vaporized in the rotor inner passage 3P and the stator inner passage 4P can be used for cooling the rotor 3 and the stator 4 to improve the cooling efficiency, and the rotor inner passage 3P and the stator inner passage 4P. The amount of the refrigerant in the inside can be greatly reduced as compared with the case of cooling in the liquid phase state, and the weight of the entire cooling device 10 can be reduced.

  Therefore, the motor 1 can be made compact and light, so that it can be easily incorporated into the tire wheel in the case of the in-wheel drive system, and the cooling efficiency of the cooling device 10 is increased, thereby increasing the temperature of the motor 1. It can suppress and can maintain the driving | running state in a high load state for a long time.

  In the present embodiment, in addition to the above-described effects, a main chamber 17 is provided upstream of the condenser 16 provided in the refrigerant recirculation passage 13, and a check valve 18 is provided between the condenser 16 and the main chamber 17. Since the main chamber 17 is provided, the rapid pressure rise when the refrigerant M is vaporized in the rotor inner passage 3P and the stator inner passage 4P by the main chamber 17 can be reduced, and the pressure of the refrigerant M supplied to the capacitor 16 can be stabilized. In addition, the check valve 18 can prevent the liquid-phase refrigerant M from flowing back from the condenser 16 to the main chamber 17 due to the pressure fluctuation of the refrigerant M that has become a gas phase due to vaporization.

  That is, when the rotor 3 and the stator 4 are cooled to a temperature at which the refrigerant M is not vaporized, the pressure in the rotor inner passage 3P and the stator inner passage 4P is lowered, and then the temperature of the rotor 3 and the stator 4 starts to rise. Then, when there is a state in which the cycle in which the refrigerant M evaporates continues, if the peak value of the pressure increase is too high, the refrigerant M is not sufficiently exchanged by the condenser 16 and is returned to the reservoir tank 11 in a gas phase state. However, pressure fluctuation can be suppressed by the main chamber 17.

  At this time, in this embodiment, since the sub chamber 19 is provided on the rotor passage 3P side in addition to the main chamber 17, the pressure fluctuation suppression efficiency can be further increased by the both chambers 17 and 19.

  Therefore, when the time variation of the gas pressure P in the cooling device 10 in the case where the chambers 17 and 19 are not provided and in the case where the chambers 17 and 19 are provided is shown in FIG. 4, P1 configures the cooling device 10 without providing the chambers 17 and 19. In this case, P2 is a case where the cooling device 10 is configured by providing the chambers 17 and 19, and when the chambers 17 and 19 are provided, it is understood that the liquid-phase refrigerant M can alleviate a rapid pressure increase due to vaporization. In the figure, P3 will be described in a second embodiment described later.

  Further, the rotor inner passage 3P is formed in the vicinity of the outer peripheral portion of the rotor 3, while the introduction passage 2a for supplying the refrigerant from the refrigerant supply passage 12 to the rotor inner passage 3P is formed in the rotary shaft 2, and the rotor from the introduction passage 2a to the rotor. Since the branch passage 2b leading to the inner passage 3P is provided in the radial direction, the centrifugal force at the time of rotation of the rotor 3 acts on the liquid-phase refrigerant M present in the radial branch passage 2b. Since the refrigerant M in the refrigerant supply passage 12 can be supplied to the rotor internal passage 3P, the diameter of the rotor internal passage 3P can be made smaller than the stator internal passage 4P that supplies the refrigerant M only by gravity. Therefore, the amount of the refrigerant M in the rotor 3 can be reduced correspondingly, and as a result, the rotational resistance of the rotor 3 due to the weight of the refrigerant M can be reduced.

  FIG. 5 shows a second embodiment of the present invention, in which the same components as those in the first embodiment are denoted by the same reference numerals and redundant description is omitted, and FIG. 5 shows the refrigerant flow path of the cooling device. FIG.

  As shown in FIG. 5, the cooling device 10A of the present embodiment has basically the same configuration as that of the first embodiment, and includes a reservoir tank 11 in which the refrigerant M is stored, the rotor inner passage 3P, and the stator inner passage 4P. A refrigerant supply passage 12, a refrigerant recirculation passage 13, check valves 14 and 15 disposed in the vicinity of the respective inlets 3Pin and 4Pin, and a capacitor 16 disposed in the refrigerant recirculation passage 13, and the reservoir The tank 11 is disposed vertically above the rotor inner passage 3P and the stator inner passage 4P.

  A main chamber 17 having a check valve 18 is provided upstream of the condenser 16 in the refrigerant recirculation passage 13 and a sub chamber 19 for introducing the discharge pressure of the rotor internal passage 3P is provided.

  In this embodiment, the main chamber 17 is provided with an accumulator 20 that absorbs fluctuations in its internal pressure.

  Further, when the accumulator 20 is provided, the main chamber 17 and the accumulator 20 are communicated with each other through the two communication paths 21 and 22, and one of the plurality of communication paths 21 and 22 is connected to the accumulator 20. A check valve 23 for preventing the flow in the direction of the main chamber 17 is provided.

  As shown in FIG. 5, the accumulator 20 is provided with a piston 20b that slidably moves up and down in the sealed container 20a, and a spring 20c that presses the piston 20b downward, and is separated by the piston 20b. The lower chamber is a pressure adjusting chamber 20d, and the pressure adjusting chamber 20d and the upper portion of the main chamber 17 are communicated with each other through the communication passages 21 and 22.

  One communication path 21 of the communication paths 21 and 22 is a part of the upstream portion 13A of the refrigerant recirculation path 13 shown in the first embodiment, and the other communication path 22 is newly provided in the present embodiment. The check valve 23 is provided in the communication passage 22.

  When the gas pressure in the main chamber 17 increases as the vaporization of the refrigerant M is promoted in the rotor inner passage 3P and the stator inner passage 4P and the pressure of the gas-phase refrigerant M increases, the main chamber 17 The internal pressure is introduced into the pressure adjustment chamber 20d of the accumulator 20 through the communication passages 21 and 22, and the volume of the pressure adjustment chamber 20d is expanded.

  On the other hand, when the vaporization of the refrigerant M in the rotor inner passage 3P and the stator inner passage 4P slows down and the pressure in the main chamber 17 decreases, the piston 20b of the accumulator 20 descends by the urging force of the spring 20c, and the pressure adjusting chamber 20d The indoor volume is reduced, and the pressure in the pressure adjusting chamber 20 d is introduced into the main chamber 17 through the communication path 21.

  Therefore, according to the present embodiment, when the pressure in the main chamber 17 increases, a rapid pressure increase in the main chamber 17 can be suppressed by expanding the volume of the pressure adjusting chamber 20d of the accumulator 20, while the pressure in the main chamber 17 is increased. Is reduced, the rapid pressure drop of the main chamber 17 can be suppressed by reducing the volume of the pressure adjusting chamber 20d of the accumulator 20.

  In particular, in this embodiment, the main chamber 17 and the accumulator 20 are communicated with each other via two communication paths 21 and 22, and the check valve 23 is provided in one communication path 22. When the pressure is introduced, the gas-phase refrigerant M is introduced into the accumulator 20 through the two communication passages 21 and 22, so that the pressure increase in the main chamber 17 can be quickly suppressed, and the accumulator 20 When the pressure is returned to the main chamber 17, since the gas-phase refrigerant M is introduced into the main chamber 17 through only one communication path 21, it is possible to suppress a rapid pressure increase in the main chamber 17. it can.

  Therefore, the time variation of the gas pressure P in the cooling device 10 according to the present embodiment becomes a gradual variation as indicated by P3 in FIG. 4, and the refrigerant M is liquefied stably and efficiently in the capacitor 16. Can do.

Thus, in the present embodiment, the refrigerant liquid does not flow back to the chamber 23, the rotor, and the stator passage without a special pump. Then, there is a state in which a cycle in which the refrigerant liquid is again supplied into the passage and evaporation again occurs, but according to the calculation by the present applicant, 10% of the motor with an output of 20 kW is caused by heat loss in the motor. Then, there will be a heat loss of 2 kW. At this time, if the refrigerant is water, the pressure around the motor is atmospheric pressure, and the height H of the flow path located at the lowest part vertically downward among the liquid surface and flow path in the reservoir tank is 1 m, the maximum position head ρgH by the refrigerant is If the condenser outlet water temperature is 50 ° C., ρgH = 988 × 9.8 × 1 = 9682 N / m ² , which is less than 10% of atmospheric pressure (101.3 kN / m ² ) In this case, the refrigerant liquid can return to the reservoir tank if the pressure in the rotor and stator passages is at least atmospheric pressure + ρgH = 111 kN / m ² or more. The saturation temperature when the saturation pressure of water is 111 kN / m ² is about 102.3 ° C., and the strength of the configuration realizing the present invention can be sufficiently achieved. On the other hand, in order to make saturated water into steam with 2 kW exotherm, the latent heat of vaporization at a saturation temperature of 102.3 ° C. is 2251 kJ / kg, so 2 (kW) / 2251 (kJ / kg) / 998 (kg / m ³ ) = 8.99 × 10 ⁻⁷ (m ³ / s) = 540 × 10 ⁻² (1 / min). If a very small amount of 54 cc of cooling water is supplied, the maximum temperature around the channel is The temperature is kept at a few hundred degrees, and the cooling water can be sufficiently supplied even with the pressure from the position head.

  6 and 7 show a third embodiment of the present invention, in which the same components as in the first embodiment are denoted by the same reference numerals and redundant description is omitted, and FIG. 6 is a refrigerant flow of the cooling device. The principal part block diagram which shows a path | route, FIG. 7: is a principal part block diagram which shows the operating state of the refrigerant | coolant flow path of a cooling device.

  As shown in FIGS. 6 and 7, the cooling device 10 </ b> B of the present embodiment basically includes a reservoir tank 11 in which a refrigerant M is stored, a main chamber 17, and a sub chamber 19, substantially the same as in the first embodiment. The black box B1 in the figure is the same as that of the first embodiment, and is provided with a refrigerant supply passage 12, a rotor inner passage 3P, and a stator inner passage 4P.

  And in this embodiment, the lower capacitor | condenser 30 as a lower heat exhausting mechanism in which the communication position to the said main chamber 17 becomes a vertically downward position, and the upper condenser 31 as an upper heat exhausting mechanism in which the said communication position becomes a vertically upward position. And a check valve 32 is provided between the lower condenser 30 and the main chamber 17 to prevent the flow in the direction of the main chamber 17. It is.

  At this time, the lower capacitor 30 communicates with the bottom surface of the main chamber 17 in the same manner as the capacitor 16 of the first embodiment, while the upper capacitor 31 is connected to the main chamber 17 via an opening 17 a formed on the side surface of the main chamber 17. Communicate with.

  The lower capacitor 30 and the check valve 32 of the present embodiment can be regarded as the same configuration as the capacitor 16 and the check valve 18 shown in the first and second embodiments, and the refrigerant of the upper capacitor 31. The discharge side is connected to the downstream portion 13B of the refrigerant recirculation passage 13 in the same manner as the refrigerant discharge side of the lower capacitor 30.

  Further, the flow resistance of the refrigerant M in the upper capacitor 31 is made smaller than that of the lower capacitor 30 by making the flow path diameter of the upper capacitor 31 smaller than that of the lower capacitor 30 or providing a resistor such as a throttle valve in the flow path. Is also larger.

  FIG. 6 shows a case where the gas phase refrigerant Mg and the liquid phase refrigerant Ml are mixed in the main chamber 17 and the liquid level of the liquid phase refrigerant Ml is positioned above the opening 17a of the upper capacitor 31. The liquid phase refrigerant Ml in the main chamber 17 returns to the reservoir tank 11 from the downstream portion 13B of the refrigerant recirculation passage 13 after flowing through both the lower condenser 30 and the upper condenser 31.

  FIG. 7 shows the case where the pressure in the main chamber 17 is increased and the liquid level of the liquid-phase refrigerant Ml is located below the opening 17a of the upper condenser 31, and the gas-phase refrigerant Mg is contained in the upper condenser 31. To flow into.

  Therefore, according to this embodiment, when the pressure in the main chamber 17 increases, the pressure of the refrigerant Mg flows into the upper condenser 31 due to the difference in flow resistance as shown in FIG. 7, and from this state, the main chamber 17 When the internal pressure decreases, the gas-phase refrigerant Mg in the upper condenser 31 flows into the main chamber 17 from the opening 17a.

  For this reason, the flow (F14) of the refrigerant M in the upper condenser 31 has a different flow direction depending on the pressure in the main chamber 17, and can suppress a sudden pressure increase and decrease in the main chamber 17, which in turn. The time variation of the gas pressure P in the cooling device 10 becomes a gradual variation as indicated by P3 in FIG. 4 as in the second embodiment, and the liquefaction of the refrigerant M in the condenser 16 is stably and efficiently performed. It can be carried out.

  In particular, when returning from the state of FIG. 7 to the state of FIG. 6, the refrigerant M that has once passed through the upper condenser 31 and has fallen in temperature is again heat-exchanged by the upper condenser 31, so that the refrigerant M returned to the reservoir tank 11 is returned. The temperature of can be lowered further.

  FIG. 8 shows a fourth embodiment of the present invention, in which the same components as those in the third embodiment are denoted by the same reference numerals and redundant description is omitted, and FIG. 8 shows the refrigerant flow path of the cooling device. It is a principal part block diagram shown.

  As shown in FIG. 8, the cooling device 10C of the present embodiment basically has the same configuration as that of the third embodiment, and includes a lower condenser 30 whose communication position to the main chamber 17 is a vertically lower position, and a communication position that is the same. An upper capacitor 31 that is positioned vertically upward is provided, and a check valve 32 that prevents the flow in the direction of the main chamber 17 is provided between the lower capacitor 30 and the main chamber 17.

  Moreover, it has the reservoir tank 11 which stored the refrigerant | coolant M substantially like 1st Embodiment, the main chamber 17, and the subchamber 19, and the black box B2 in the same figure is 1st Embodiment. Similarly, the refrigerant supply passage 12, the rotor inner passage 3P, and the stator inner passage 4P are provided.

  In the present embodiment, the lower condenser 30 and the upper condenser 31 serving as a heat removal mechanism are arranged at an upper position in the vertical direction with respect to the refrigerant liquid level L of the reservoir tank 11.

  Therefore, according to the present embodiment, the same effect as that of the third embodiment can be obtained. In particular, the lower capacitor 30 and the upper capacitor 31 are arranged in a direction perpendicular to the refrigerant liquid level L of the reservoir tank 11. Since the refrigerant M flowing through the rotor inner passage 3P and the stator inner passage 4P and flowing into the main chamber 17 is in a gas phase, the refrigerant M in a liquid phase in the lower condenser 30 and the upper condenser 31 is disposed at the upper position. Thus, the pressure for returning the gas to the reservoir tank 11 becomes unnecessary, and the refrigerant M can be circulated at a lower pressure than the refrigerant M vaporized in the rotor inner passage 3P and the stator inner passage 4P.

  Of course, this embodiment can also be applied to the case where the single capacitor 16 of the first and second embodiments is provided.

  FIG. 9 shows a fifth embodiment of the present invention, in which the same components as those in the first embodiment are denoted by the same reference numerals and redundant description is omitted, and FIG. 9 shows the refrigerant flow path of the cooling device. It is a principal part block diagram shown.

  As shown in FIG. 9, the cooling device 10D of the present embodiment has basically the same configuration as that of the first embodiment, and includes a reservoir tank 11 in which a refrigerant M is stored, a condenser 16, a main chamber 17, and a sub chamber. 19, and the black box B3 in the figure is the same as that of the first embodiment, and is provided with the refrigerant supply passage 12, the rotor inner passage 3P, and the stator inner passage 4P.

  In the present embodiment, the capacitor 16 is disposed vertically above the upper end surface 11 b of the reservoir tank 11, and the capacitor 16 communicates with the upper end surface 11 b of the reservoir tank 11.

  Therefore, according to the present embodiment, the same effect as in the first and second embodiments provided with the capacitor 16 is obtained, and in particular, the capacitor 16 is more vertically disposed than the upper end surface 11 b of the reservoir tank 11. Since the condenser 16 is disposed at the upper position and communicated with the upper end surface 11b of the reservoir tank 11, the refrigerant M flowing into the main chamber 17 through the rotor passage 3P and the stator passage 4P is in the gas phase. Thus, the pressure for returning the liquid phase refrigerant M in the condenser 16 to the reservoir tank 11 is not required, and the refrigerant M that is vaporized in the rotor inner passage 3P and the stator inner passage 4P is circulated at a lower pressure. It becomes possible.

  In addition, since the condenser 16 is arranged at a position vertically above the upper end surface 11b of the reservoir tank 11, the pressure of the water head with respect to the refrigerant liquid level L in the reservoir tank 11 does not act on the condenser 16, and therefore, compared with the fourth embodiment. Therefore, the refrigerant M can be circulated with a smaller pressure.

  Of course, this embodiment can also be applied to the case where the single capacitor 16 of the first and second embodiments is provided, and the case where the two capacitors 30 and 31 of the third embodiment are provided.

  By the way, in the first to fifth embodiments, the refrigerant M used in the cooling devices 10 to 10D has the main chamber 17 pressure p, the liquid density ρ of the refrigerant M, the gravitational acceleration g, and the refrigerant in the reservoir tank 11. When the height of the liquid surface L and the vertical passage 4P in the lowermost position of the stator is H (see FIGS. 3, 5 to 8), p> ρ · g · H (1) is satisfied. The one with the physical property values to be used is used.

  3 and 5 to 7, when the vertically lowermost position of the refrigerant recirculation passage 13 is below the stator inner passage 4P, H is the refrigerant recirculation passage 13 indicated by the broken line. And the level of the refrigerant liquid L of the reservoir tank 11.

  Therefore, when the physical property value of the refrigerant M satisfies the expression (1), the refrigerant M is not pumped even when the refrigerant M exists in a liquid phase in any flow path of the cooling device 10. It can be returned to the reservoir tank 11.

  In the first to fifth embodiments, the capacitor 16 and the capacitors 30 and 31 are schematically shown in a state in which one straight pipe is arranged. Of course, the refrigerant is supplied to a plurality of straight pipes as in a normal heat exchanger. Needless to say, the refrigerant may be allowed to pass through, or the refrigerant passage pipe may be meandered.

  Furthermore, as shown in FIG. 2, the case where four rotor passages 3P and six stator passages 4P are provided is shown, but the number of these rotor passages 3P and stator passages 4P formed is not limited to this, The number of motors 1 that can be effectively cooled can be set.

  Of course, the motor cooling device of the present invention has been described by taking the first to fifth embodiments as an example. However, the present invention is not limited to these embodiments, and various other embodiments are adopted without departing from the scope of the present invention. For example, the motor 1 is not limited to an in-wheel drive type electric vehicle, and the present invention can also be applied to a normal motor.

It is sectional drawing of the motor with which the cooling device of this invention is applied. It is sectional drawing along the AA line in FIG. It is a block diagram which shows the refrigerant | coolant distribution route of the cooling device in 1st Embodiment of this invention. It is explanatory drawing which shows the time fluctuation of the refrigerant | coolant pressure in the cooling device of this invention with a graph. It is a block diagram which shows the refrigerant | coolant distribution route of the cooling device in 2nd Embodiment of this invention. It is a principal part block diagram which shows the refrigerant | coolant flow path of the cooling device in 3rd Embodiment of this invention. It is a principal part block diagram which shows the operating state of the refrigerant | coolant flow path of the cooling device in 3rd Embodiment of this invention. It is a principal part block diagram which shows the refrigerant | coolant flow path of the cooling device in 4th Embodiment of this invention. It is a principal part block diagram which shows the refrigerant | coolant flow path of the cooling device in 5th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Rotating shaft 2a Introduction passage 2b Branch passage 3 Rotor 3P Rotor passage 3Pin Rotor passage 3Pout Rotor passage 4 Stator 4P Stator passage 4Pin Stator passage 4Pout Stator passage 10, 10A , 10B, 10C, 10D Cooling device 11 Reservoir tank 11b Upper end surface of reservoir tank 12 Refrigerant supply passage 13 Refrigerant return passage 14, 15 Check valve 16 Condenser (exhaust heat mechanism)
17 Main chamber 18 Check valve 20 Accumulator 21, 22 Communication path 23 Check valve 30 Lower condenser (lower heat exhaust mechanism)
31 Upper condenser (Upper heat exhaust mechanism)
32 Check valve M Refrigerant L Refrigerant liquid level

Claims (9)

In a motor comprising a rotating shaft, a rotor coupled to the rotating shaft, and a stator surrounding the outer periphery of the rotor,
A reservoir tank that stores a refrigerant that changes from a liquid phase to a gas phase by the heat generated by the motor;
A rotor internal passage and a stator internal passage formed in each of the rotor and the stator, and
A refrigerant supply passage communicating the inlets of the rotor passage and the stator passage with the reservoir tank;
A refrigerant recirculation passage that communicates each outlet of the rotor passage and the stator passage with the reservoir tank;
A check valve that is disposed in the vicinity of each inlet of the rotor inner passage and the stator inner passage and prevents a reverse flow in the direction of the refrigerant supply passage;
An exhaust heat mechanism disposed in the refrigerant recirculation passage to dissipate heat of the refrigerant in the refrigerant recirculation passage outward;
The motor cooling apparatus according to claim 1, wherein the reservoir tank is arranged at a position vertically above the rotor inner passage and the stator inner passage.   A chamber having a larger cross-sectional area than that of the passage is provided in the refrigerant recirculation passage upstream of the exhaust heat mechanism, and a check valve is provided between the exhaust heat mechanism and the chamber to prevent a flow in the chamber direction. The motor cooling device according to claim 1, wherein the motor cooling device is provided.   The rotor internal passage is formed near the outer periphery of the rotor, while the introduction passage for supplying the refrigerant from the refrigerant supply passage to the rotor internal passage is formed in the rotor central portion, and the branch passage extending from the introduction passage to the rotor internal passage has a diameter. The motor cooling device according to claim 1, wherein the motor cooling device is provided in a direction.   4. The motor cooling apparatus according to claim 2, wherein an accumulator for absorbing fluctuations in the internal pressure is provided in the chamber.   The chamber and the accumulator communicate with each other through a plurality of communication passages, and a check valve for preventing the flow from the accumulator in the chamber direction is provided in the communication passage excluding at least one of the plurality of communication passages. The motor cooling device according to claim 4.   A chamber having a larger cross-sectional area than the passage is provided on the upstream side of the exhaust heat mechanism of the refrigerant recirculation passage, and the exhaust heat mechanism includes a plurality of communication positions different from each other in the vertical direction. The refrigerant flow resistance of the lower heat exhaust mechanism becomes larger than the refrigerant flow resistance of the upper heat exhaust mechanism whose communication position is the vertically upper position, and the flow in the chamber direction is made between the lower heat exhaust mechanism and the chamber. The motor cooling device according to claim 1, further comprising a check valve for blocking.   The motor cooling device according to any one of claims 1 to 6, wherein the exhaust heat mechanism is arranged at a position above the refrigerant liquid level of the reservoir tank in a vertical direction.   7. The exhaust heat mechanism is disposed vertically above the upper end surface of the reservoir tank, and the exhaust heat mechanism communicates with the upper end surface of the reservoir tank. Motor cooling device. In a motor comprising a rotating shaft, a rotor coupled to the rotating shaft, and a stator surrounding the outer periphery of the rotor,
The refrigerant stored in the reservoir tank is supplied to the rotor inner passage formed in the rotor and the stator and the stator inner passage through the refrigerant supply passage through check valves provided in the vicinity of the respective inlets. After that, the refrigerant is circulated back to the reservoir tank through the refrigerant recirculation passage provided with the exhaust heat mechanism, and the reservoir tank is disposed vertically above the rotor inner passage and the stator inner passage. A motor cooling method as a feature.

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