JP4816884B2 - Motor cooling device and cooling method. - Google Patents

Description

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

  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 cooling the motor, but high cooling efficiency can be expected with the liquid cooling method, but a circulating device such as a pump for circulating refrigerant liquid to the motor attached to the tire wheel In this case, a refrigerant liquid heat exchanger is generally installed 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. End up.

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.

  Accordingly, the present invention provides a motor cooling device and a cooling method capable of reducing the size of the cooling system by self-circulating the refrigerant and improving the cooling effect by improving the circulation efficiency of the refrigerant.

A motor cooling device according to the present invention includes a rotating shaft, a rotor coupled to the rotating shaft, and a stator that surrounds the outer periphery of the rotor. A cooling flow path for circulating a refrigerant that changes from a liquid phase to a gas phase; a reservoir tank that is disposed vertically above the cooling flow path and supplies the cooling flow to the cooling flow path while preventing the reverse flow; and the cooling flow An exhaust heat mechanism that is arranged in a refrigerant return flow path for returning the refrigerant discharged from the passage to the reservoir tank and liquefies the refrigerant vaporized in the cooling flow path, and reaches the reservoir tank from the cooling flow path The main feature of the present invention is that the refrigerant return channel further includes a pressurizing unit that further pressurizes the discharge pressure of the cooling channel, and the pressurizing unit is provided on the upstream side of the exhaust heat mechanism .

In the motor cooling method of the present invention, a refrigerant that changes from a liquid phase to a gas phase at a predetermined temperature is circulated through a cooling flow path provided in a heat generating part of the motor to cool the heat generating part, and The discharged vaporized refrigerant is converted into a liquid phase by an exhaust heat mechanism and returned to the reservoir tank, and the reservoir tank is disposed vertically above the cooling flow path to allow the refrigerant to self-circulate, while the exhaust heat The discharge pressure of the cooling flow path is further increased by a pressurizing means provided on the upstream side of the mechanism, and the pressure for pushing out the liquid phase refrigerant by the exhaust heat mechanism is further increased.

  According to the motor cooling device and the cooling method of the present invention, the refrigerant is supplied to the cooling flow path by gravity from the reservoir tank arranged vertically above, and the liquid-phase refrigerant passes through the cooling flow path within the motor. A gas phase is generated in the heat generating portion, and the stator and the rotor can be efficiently cooled with the vaporized refrigerant.

  Further, when the refrigerant vaporized in the cooling flow path is returned to the reservoir tank, it is made into a liquid phase by a heat exhaust mechanism arranged in the refrigerant return flow path. Since the liquid phase refrigerant is pushed out by the refrigerant pressure that has been vaporized and expanded in the cooling flow path, the liquid phase refrigerant can be pumped back to the reservoir tank.

  Accordingly, in combination with the fact that the refrigerant can be supplied to the cooling flow path by its own weight from the reservoir tank disposed vertically above, the refrigerant can be circulated by itself, and a refrigerant moving device such as a pump is provided in the refrigerant circulation path. Since it is not necessary, the cooling device can be made compact and light.

In addition, since the refrigerant return flow path is provided with a pressurizing means upstream of the exhaust heat mechanism to further increase the discharge pressure of the cooling flow path, the refrigerant that has become liquid phase by the exhaust heat mechanism Since the pressure can be pushed back to the reservoir tank with a large pressure, the circulation efficiency of the refrigerant can be further increased, and as a result, the cooling efficiency of the motor can be increased.

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

  1 to 6 show a first embodiment of a motor cooling device according to the present invention, FIG. 1 is a perspective view of a suspension device showing a motor mounting state to which the present invention is applied, and FIG. 2 is a cooling device. FIG. 3 is an overall configuration diagram showing a refrigerant circulation path of the cooling device, and FIG. 4 is a sectional view taken along line AA in FIG.

  5 is an enlarged perspective view of the motor inverter, and FIG. 6 is an enlarged cross-sectional view taken along line BB in FIG.

  The motor 1 to which the cooling device 20 of the present invention is applied is applied to, for example, an in-wheel drive type electric vehicle as shown in FIG. 1, and the motor 1 is inserted into a central recess Wh formed on the back side of the tire wheel W. In this state, the tire wheel W is directly driven by the rotating shaft of the motor 1.

  The tire wheel W is supported on the vehicle body by a double wishbone suspension device S including an upper link L1, a lower link L2 and a shock absorber Sa. In particular, the suspension device S is limited to this double wishbone method. It is not a thing.

  As shown in FIGS. 2 and 4, the motor 1 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. The rotor 3 and the stator 4 are accommodated in the housing 5.

  The rotating shaft 2 is integrated with the rotor 3, and both end portions are rotatably supported by end plates 5 e 1, 5 e 2 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.

  Further, the motor 1 is provided with a motor inverter 10 for converting DC power into AC power outside the housing 5 as shown in FIG.

  As shown in FIG. 5, the motor inverter 10 includes a rectangular parallelepiped main body portion 11 having six surfaces 11a to 11f, and a plurality of electronic elements 12 such as thyristor elements for inverter control are provided on an upper surface 11c of the main body portion 11. Configured by being installed.

  The motor 1 is cooled by a cooling device 20, and this cooling device 20 is provided in a heat generating part due to copper loss such as a coil 8 of the motor 1 or a bus bar outside the figure as shown in FIGS. And a cooling flow path 21 through which a refrigerant that changes from a liquid phase to a gas phase at a predetermined temperature is circulated, and is arranged vertically above the cooling flow path 21 and supplied to the cooling flow path 21 while preventing backflow of the refrigerant. The exhaust tank is disposed in the reservoir tank 22 that performs the cooling, and is disposed in the refrigerant return channel 23 that returns the refrigerant discharged from the cooling channel 21 to the reservoir tank 22. A condenser 24 as a mechanism and a motor inverter 10 as pressurizing means for further pressurizing the discharge pressure of the cooling channel 21 are provided in the refrigerant return channel 23 extending from the cooling channel 21 to the reservoir tank 22. And Aru.

  As shown in FIGS. 5 and 6, the motor inverter 10 is formed with an inverter cooling flow path 13 for introducing the refrigerant from the reservoir tank 22 through the check valve 29 while preventing the reverse flow. The refrigerant outlet 13out of the passage 13 is communicated with a refrigerant return passage 23 extending from the cooling passage 21 to the reservoir tank 22.

  In particular, in the present embodiment, the refrigerant outlet 13out of the inverter cooling flow path 13 communicates with the refrigerant return flow path 23 upstream of the capacitor 24.

  That is, the cooling flow path 21 is constituted by a plurality of stator internal passages 21a to 21f formed along the axial direction of the rotary shaft 2 in the outer peripheral portion of the stator 4 as shown in FIG. As shown in FIG. 4, 21 a to 21 f are formed at approximately equal intervals in the circumferential direction corresponding to the projecting portions of the stator salient pole portions 4 </ b> S.

  As shown in FIG. 4, the plurality of stator inner passages 21 a to 21 f are arranged with the stator inner passage 21 a at the uppermost portion of the stator 4, and the remaining stator inner passages 21 b to 21 f are sequentially arranged at equal intervals counterclockwise. Therefore, the stator inner passage 21d is arranged at the lowermost portion of the stator 4.

  As shown in FIG. 2, the stator inner passages 21 a to 21 f are communicated at their refrigerant introduction side (right side in the figure) by a first annular passage 5 a formed inside one end plate 5 e 1 of the housing 5. The discharge side (left side in the figure) is communicated by a second annular passage 5b formed inside the other end plate 5e2 of the housing 5.

  The reservoir tank 22 disposed vertically above the cooling flow path 21 has an air release port 22a formed at the upper end, and a first introduction flow path in which one end side 25a is connected to the lower side surface of the reservoir tank 22. 25, and the other end side 25b of the first introduction flow path 25 is connected to the first annular passage 5a via a check valve 26.

  The second annular passage 5b is connected to one end side 23a of the refrigerant return flow path 23, and the other end side 23b of the refrigerant return flow path 23 passes through the capacitor 24 before the reservoir tank 22 Connected to the upper side.

  A check valve 27 is provided downstream of the condenser 24 to prevent refrigerant from flowing into the condenser 24 from the reservoir tank 22 side.

  The capacitor 24 is disclosed in the state where fins are provided in one straight pipe in the figure, but it is not necessarily one straight pipe, and may be a plurality of straight pipes or meandering pipes. Good.

  The reservoir tank 22 is disposed above and separated from the motor 1, but in this embodiment, when the motor 1 is configured as an in-wheel drive system as shown in FIG. It can attach to the rear side member used as the skeleton member of both sides.

  The reservoir tank 22 is provided with a second introduction flow path 28 having one end side 28 a connected to the bottom thereof, and the other end side 28 a of the second introduction flow path 28 is cooled by the inverter via a check valve 29. It is connected to the refrigerant introduction pipe 13 a of the flow path 13.

  The inverter cooling flow path 13 is formed in the main body part 11 of the motor inverter 10, and the refrigerant introduction pipe 13a is provided on one end surface 11a in the longitudinal direction of the main body part 11 formed in a rectangular parallelepiped shape. A refrigerant discharge pipe 13b is provided on the other end surface 11b in the longitudinal direction of the main body portion 11, and a tip of the refrigerant discharge pipe 13b serves as the refrigerant discharge port 13out.

  As shown in FIG. 6, the inverter cooling flow path 13 is formed by a passage having a rectangular cross section surrounded by upper and lower surfaces 11c and 11e and left and right side surfaces 11d and 11f of the main body portion 11.

  At this time, the inverter cooling flow path 13 is formed of a porous material 30 as a porous material.

  Therefore, in the cooling device 20 of the present embodiment, the refrigerant flow in the reservoir tank 22 flows from the first introduction passage 25 (flow F1) through the check valve 26 to the first annular passage 5a as shown in FIG. The refrigerant introduced into the first annular passage 5a is distributed to the stator inner passages 21a to 21f and flows through the stator 4 (flow F2).

  Then, the refrigerant that has passed through the stator inner passages 21a to 21f joins in the second annular passage 5b, and is then discharged (flow F3) to the refrigerant return passage 23. The condenser 24 provided in the middle of the refrigerant return passage 23 After passing through the check valve 27 (flow F4), it is returned to the reservoir tank 22.

  Further, the refrigerant in the reservoir tank 22 is introduced from the second introduction flow path 28 (flow F5) to the inverter cooling flow path 13 of the motor inverter 10 through the check valve 29 and flows through the inverter cooling flow path 13. After (flow F6), the refrigerant flows into the upstream portion of the refrigerant return passage 23 from the refrigerant discharge port 13out (flow F7).

  And in the cooling method of the motor 1 using the cooling device 20 comprised in this way, it changes from a liquid phase to a gaseous phase at the predetermined temperature in the cooling flow path 21 (21a-21f) provided in the heat generating part of the motor 1. The refrigerant is circulated to cool the heat generating portion, and the vaporized refrigerant discharged from the cooling flow path 21 is liquefied by the condenser 24 which is a heat exhaust mechanism and returned to the reservoir tank 22. Is disposed vertically above the cooling flow path 21 to allow the refrigerant to self-circulate, while the discharge pressure of the cooling flow path 21 is further increased, and the liquid phase refrigerant in the condenser 24 is supplied to the reservoir tank 22. Increase the pressure to push out.

  With the above configuration, according to the cooling device 20 and the cooling method of the present embodiment, the refrigerant in the liquid phase state in the reservoir tank 22 arranged in the vertically upper position is fed from the first introduction flow path 25 to the check valve 26 by gravity. Is supplied to the first annular passage 5a and the stator inner passages 21a to 21f, and the liquid phase refrigerant is vaporized and expanded in the heat generating portion of the motor 1 while passing through the stator inner passages 21a to 21f, and the gas phase The heat generating part can be efficiently cooled with the refrigerant in the state.

  At this time, when the state changes from the liquid phase to the gas phase, the pressure in the flow path becomes larger than that in the liquid phase due to the expansion pressure, but the refrigerant gasified by the check valve 26 becomes the first annular passage. Backflow in the 5a direction is prevented.

  Therefore, the refrigerant that has become a gas phase in the stator inner passages 21 a to 21 f is prevented from flowing back to the first introduction passage 25 by the check valve 26, and the refrigerant return passage 23 through the second recirculation passage 5 b. To be discharged.

  Then, the discharged refrigerant in the gas phase state is cooled and liquefied by the condenser 24 provided in the middle of the refrigerant return passage 23, and the refrigerant in the liquid phase state is reversely provided on the downstream side of the condenser 24. While the backflow is blocked by the stop valve 27, it is pushed downstream by the expansion pressure of the refrigerant in the gas phase state upstream of the condenser 24.

  For this reason, since the refrigerant liquidified by the condenser 24 is sequentially pumped back to the reservoir tank 22 and returned, the refrigerant is supplied from the reservoir tank 22 by its own weight to the stator passages 21a to 21f as described above. Thus, the refrigerant can be self-circulated in the cooling device 20.

  Therefore, it is not necessary to use a refrigerant moving device such as a pump in the refrigerant circulation path, the cooling device 20 can be made compact, and the heat of vaporization when the refrigerant is vaporized in the stator inner passages 21a to 21f can be reduced. The cooling efficiency can be improved by using the cooling of the heat generating part of the heater, and the amount of refrigerant in the stator passages 21a to 21f can be greatly reduced as compared with the case of cooling in the liquid phase state, and the weight of the entire cooling device 20 Can be reduced.

  In addition, since the motor 1 can be made compact and lightweight, it can be easily incorporated into the tire wheel W in the case of the in-wheel drive system, and the cooling efficiency of the cooling device 20 is increased, thereby increasing the temperature of the motor 1. And the operation state in the high load state can be maintained for a longer time.

  By the way, when the expansion pressure when the liquid phase refrigerant is vaporized in the stator internal passages 21 a to 21 f is not sufficient, the refrigerant in the refrigerant return passage 23 liquefied by the capacitor 24 is transferred to the reservoir tank 22. Since the pressure for pushing out is insufficient, the refrigerant stagnates in the circulation path.

  Therefore, the liquid passage state refrigerant is not sufficiently supplied from the first introduction passage 25 to the stator passages 21a to 21f, and as a result, the temperature in the stator passages 21a to 21f exceeds the allowable design range. A so-called dry-out phenomenon occurs in which the temperature is increased.

  Therefore, in order to prevent the occurrence of the dry-out phenomenon, it is necessary to positively return the liquid-phase refrigerant present in the condenser 23 and the refrigerant return passage 23 downstream thereof to the reservoir tank 22.

  That is, by returning the liquid-phase refrigerant in the refrigerant return passage 23 to the reservoir tank 22, the pressure in the stator inner passages 21a to 21f is reduced, so that the check valve 26 can be opened. Since the liquid-phase refrigerant is supplied from the introduction flow path 25 to the stator inner passages 21a to 21f, the dry-out phenomenon can be prevented.

Here, considering the open / closed state of the check valve 26, as shown in FIG. 3, the pressure Pin at the upstream position S1 of the check valve 26 is:
Pin = Pt + ρi · g · Hi (1)

  Here, Pt is the pressure applied to the refrigerant level in the reservoir tank 22, ρi is the density of the liquid phase refrigerant at the upstream position S1, g is the gravitational acceleration, and Hi is from the upstream position S1 to the refrigerant level in the reservoir tank 22. It is height.

On the other hand, the pressure Pout at the downstream position S2 of the check valve 26 is
Pout = Pt + ΔPls + ρo · g · Ho (2)

  Here, ρo is the density of the liquid-phase refrigerant in the downstream portion of the condenser 24 in the refrigerant return channel 23, Ho is the height from the downstream position S2 to the position where the refrigerant return channel 23 is connected to the reservoir tank 22, and ΔPls is the flow Resistance pressure in the road.

  Accordingly, if the check valve 26 ignores this resistance, Pin ≧ Pout, that is, if ρi · g · Hi ≧ ΔPls + ρo · g · Ho, the check valve 26 opens and Pin <Pout If so, it will be closed.

Here, assuming that the coolant is water, the water temperature at the upstream position S1 and the water temperature downstream of the coolant return passage 23 are 50 ° C., and Hi is 0.5 m and Ho is 0.6 m,
ρi, g, Hi = 988 x 9.8 x 0.5 = 4.84 kPa (kN / m ² )
ρo · g · Ho = 988 × 9.8 × 0.6 = 5.81 kPa (kN / m ² ).

At this time, if Pt is standard atmospheric pressure (101.3kPa),
Pt + ρo · g · Ho = 107.1 kPa, and the saturation temperature for a water saturation pressure of 107.1 kPa is about 101.3 ° C. According to the experimental results, the saturation temperature is about 102 ° C., and according to the saturated steam table of water, the saturation pressure for the saturation temperature of 102 ° C. is 109.6 kPa.

These results
ΔPls = 109.6−107.1 = 2.5 kPa, and ΔPls has the same order value as ρo · g · Ho.

  Therefore, if the liquid-phase refrigerant in the refrigerant return passage 23 returning from the capacitor 24 to the reservoir tank 22 is sent to the reservoir tank 22 using an external heat source as in the present embodiment, Pin ≧ Pout can be achieved. The check valve 26 opens even during dryout.

  For this reason, in the present embodiment, the motor inverter 10 is used to supply liquid phase refrigerant from the reservoir tank 22 to the inverter cooling flow path 13 formed in the motor inverter 10 via the second introduction flow path 28. Thus, the liquid-phase refrigerant in the refrigerant return channel 23 is forcibly returned to the reservoir tank 22 using the pressure of the refrigerant vaporized in the inverter cooling channel 13.

  That is, the liquid-phase refrigerant introduced from the second introduction passage 28 into the inverter cooling passage 13 through the check valve 29 is disposed on the upper surface 11c of the main body portion 11 as shown in FIGS. The generated heat of the electronic element 12 is transferred to a gas phase and expanded, and the expansion pressure is discharged from the refrigerant discharge pipe 13b and supplied to the upstream side of the refrigerant return flow path 23 through which the refrigerant discharge port 13out communicates. The

  Then, on the upstream side of the condenser 24 in the refrigerant return passage 23, the pressure in the inverter cooling passage 13 acts in addition to the pressure in the inverter passages 21 a to 21 f, so that a larger pressure is applied on the upstream side of the capacitor 24. The liquid-phase refrigerant in the refrigerant return passage 23 can be forcibly returned to the reservoir tank 22 with the large pressure.

  Therefore, the circulation efficiency of the refrigerant can be further increased to prevent the dry-out phenomenon, and thus the cooling efficiency of the motor 1 can be increased. In addition, the cooling of the motor inverter 10 can be performed by circulating the refrigerant through the inverter cooling flow path 13. It can be carried out.

  Further, since the motor inverter 10 is used as the pressurizing means, the motor inverter 10 is an existing part, and it is not necessary to newly provide the pressurizing means, so that a significant increase in cost can be suppressed.

  Furthermore, in the present embodiment, the inverter cooling flow path 13 is formed of a porous material 30 as a porous material, so that the heat transfer area in the inverter cooling flow path 13 is increased, and thus the electronic element 12 generates heat. The amount of heat is easily transferred to the refrigerant passing through the porous material 30.

  Furthermore, since the flow resistance of the refrigerant passing through the porous material 30 is increased, the pressure in the inverter cooling flow path 13 is higher than the pressure in the stator internal passages 21a to 21f, and a larger pressure is generated. Thus, the pressure on the upstream side of the condenser 24 in the refrigerant return passage 23 can be increased, and the liquid phase refrigerant in the refrigerant return passage 23 can be returned to the reservoir tank 22 more reliably.

  7 to 9 show 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. FIG. 8 is an enlarged perspective view of the motor inverter, and FIG. 9 is an enlarged sectional view taken along the line CC in FIG.

  The cooling device 20A according to the present embodiment basically has the same configuration as the cooling device 20 according to the first embodiment. The motor inverter 10 is used to form a pressurizing unit, and an inverter cooling flow formed in the motor inverter 10 is used. A refrigerant in a liquid phase state is supplied to the passage 13 from the reservoir tank 22 through the second introduction passage 28, and the refrigerant return passage 23 is used by using the pressure of the refrigerant vaporized in the inverter cooling passage 13. The pressure on the upstream side is increased.

  Here, in the present embodiment, two first and second sub-cooling passages 14 and 15 are provided in the motor inverter 10 to circulate the refrigerant in the vicinity of the inverter cooling passage 13.

  That is, as shown in FIG. 8, the motor inverter 10 is provided with a plurality of inverter control electronic elements 12 on an upper surface 11c of a rectangular parallelepiped body portion 11 having six surfaces 11a to 11f as in the first embodiment. The first and second sub cooling channels 14 and 15 are arranged on both sides of the inverter cooling channel 13 in a state of being partitioned by partition walls 16a and 16b, respectively, as shown in FIG.

  The first and second sub-cooling channels 14 and 15 are formed as a rectangular cross-section like the inverter cooling channel 13, but the sub-cooling channels 14 and 15 are hollow. It is formed.

  As shown in FIG. 7, the inverter cooling passage 13 has a second introduction passage 28 connected to the refrigerant introduction tube 13a as in the first embodiment, and a refrigerant discharge port at the tip of the refrigerant discharge tube 13b. 13out is communicated to the upstream side of the condenser 24 in the refrigerant return passage 23, and the inverter cooling passage 13 is formed of the porous material 30 even in the present embodiment.

  The first sub-cooling flow path 14 is provided with a refrigerant introduction pipe 14a on the side where the refrigerant discharge pipe 13b of the inverter cooling flow path 13 is disposed (left side in FIG. 8), and the refrigerant introduction of the inverter cooling flow path 13 is performed. A refrigerant discharge pipe 14b is provided on the side where the pipe 13a is arranged (right side in FIG. 8), and the second sub cooling channel 15 is the side where the refrigerant introduction pipe 13a of the inverter cooling channel 13 is arranged. A refrigerant introduction pipe 15a is provided on the right side in FIG. 8 and a refrigerant discharge pipe 15b is provided on the side (left side in FIG. 8) where the refrigerant discharge pipe 13b of the inverter cooling flow path 13 is disposed.

  The refrigerant discharge pipe 14b of the first sub cooling channel 14 and the refrigerant introduction pipe 15a of the second sub cooling channel 15 are communicated with each other as shown in FIG.

  On the other hand, the downstream side of the refrigerant return channel 23 from the check valve 27 is divided in the middle, and the divided upstream return channel 23 c is connected to the refrigerant introduction pipe 14 a of the first sub-cooling channel 14. The divided downstream return flow path 23 d is connected to the refrigerant discharge pipe 15 b of the second sub cooling flow path 15.

  According to the motor cooling device 20A of the present embodiment having the above configuration, the refrigerant is introduced into the inverter cooling passage 13 of the motor inverter 10 from the second introduction passage 28 as in the first embodiment, and this inverter cooling is performed. By supplying the high-pressure refrigerant generated in the porous material 30 of the flow path 13 to the upstream side of the refrigerant return flow path 23, the circulation efficiency of the refrigerant can be improved and the dry-out phenomenon of the stator internal passages 21a to 21f can be prevented. However, in this case, it is necessary to adjust the diameter of the inverter cooling flow path 13 and the diameters of the refrigerant introduction / discharge pipes 13a and 13b before and after the inverter cooling flow path 13 so that high-pressure steam is generated in the inverter cooling flow path 13. .

  However, under the condition that the refrigerant is vaporized in the inverter cooling flow path 13, the heat removal performance of the plurality of electronic elements 12 may not be obtained. In the present embodiment, the inverter is included in the motor inverter 10. Two first and second sub-cooling channels 14 and 15 for circulating the refrigerant are provided in the vicinity of the cooling channel 13, and one of the first sub-cooling channels 14 is connected to the reservoir tank 22 from the refrigerant return channel 23. After the liquid phase refrigerant to be returned is introduced and circulated, the refrigerant is introduced into the other second sub-cooling flow path 15 and circulated, and then returned to the reservoir tank 22.

  Therefore, since the motor inverter 10 can be cooled by circulating the liquid-phase refrigerant returned to the reservoir tank 22 through the first and second sub-cooling channels 14 and 15 in this way, the inverter formed of the porous material 30 While the cooling flow path 13 is exclusively configured to promote the vaporization of the refrigerant, the heat removal performance of the electronic element 12 is improved by the liquid-phase refrigerant flowing through the first and second sub cooling flow paths 14 and 15. Can be secured.

  For this reason, it is possible to avoid the dry-out of the heat generating part of the motor 1, and the cooling of the electronic element 12 of the motor inverter 10 ensures a wider range of heat removal performance. Dry-out can be prevented even when force other than gravity acting on is applied.

  FIG. 10 shows a third embodiment of the present invention, in which the same components as those in the above-described embodiments are denoted by the same reference numerals and redundant description is omitted, and FIG. 10 shows a refrigerant circulation path of the cooling device. FIG.

  The cooling device 20B of the present embodiment basically has the same configuration as the cooling device 20 of the first embodiment, and the cooling flow path 21 is arranged on the outer periphery of the stator 4 as shown in FIG. A plurality of in-stator passages 21a to 21f formed along the direction, and the refrigerant introduced from the first introduction passage 25 is circulated through the respective in-stator passages 21a to 21f, and then the refrigerant return passage. 23 is discharged.

  As in the second embodiment, the motor inverter 10 is provided with first and second sub-cooling channels 14 and 15 in addition to the inverter cooling channel 13, and returns to the reservoir tank 22 from the refrigerant return channel 23. The refrigerant is circulated through the first and second sub-cooling channels 14 and 15.

  And in this embodiment, the refrigerant | coolant passage amount equalization means 31 which makes each refrigerant | coolant passage amount of these stator internal passages 21a-21f substantially equal according to the height (water head) from the liquid level of the reservoir tank 22 is provided. Yes.

  That is, when the diameters Da to Df of the stator inner passages 21a to 21f are equal, the refrigerant flows as the height from the liquid surface (water head) increases due to the influence of the position water head from the liquid surface of the reservoir tank 22. Since it becomes easy, a difference arises in a dryout situation by the up-and-down position of each passage 21a-21f in stator.

  For this reason, in this embodiment, the diameters Da to Df of the stator inner passages 21a to 21f are made smaller as the height (water head) from the liquid surface of the reservoir tank 22 becomes higher, thereby making the refrigerant passage amount equalizing means 31. Is configured.

  As shown in FIG. 4, the stator inner passages 21a to 21f are arranged such that the stator inner passage 21a is disposed at the uppermost portion of the stator 4 and the stator inner passage 21d is disposed at the lowermost portion of the stator 4. Stator internal passages 21b and 21f are arranged in the upper part between the stator internal passages 21a and 21d, and stator internal passages 21c and 21e are arranged in the lower part between the stator internal passages 21a and 21d.

Therefore, the diameters Da to Df of the stator inner passages 21a to 21f are
Da> (Db = Df)> (Dc = De)> Dd.

  With the above configuration, according to the cooling device 10B of the present embodiment, the diameters Da to Df of the stator inner passages 21a to 21f are reduced as the height (water head) from the liquid level of the reservoir tank 22 is increased. The passage amount of the refrigerant flowing through the stator inner passages 21a to 21f can be made substantially equal.

  Therefore, since the heat removal states of the plurality of stator inner passages 21a to 21f can be made substantially uniform, it is possible to prevent a difference in the respective dry-out situations, and thus control for removing the dry-out phenomenon. It becomes easy to do.

  In the present embodiment, the diameters Da to Df of the stator inner passages 21a to 21f are changed to make the respective refrigerant passage amounts substantially equal. However, orifices satisfying the above-described relationship are provided in the respective stator inner passages 21a to 21f. The purpose can also be achieved by providing.

  11 and 12 show a fourth embodiment of the present invention, in which the same components as those of the above-described embodiments are denoted by the same reference numerals and redundant description is omitted, and FIG. 11 is a refrigerant circulation of the cooling device. FIG. 12 is an explanatory diagram showing the switching state of the switching valve on the discharge side of the inverter cooling flow path in order of (a) and (b).

  The cooling device 20C of the present embodiment basically has the same configuration as the cooling device 20 of the first embodiment as shown in FIG. 11, and configures a pressurizing means using the motor inverter 10, Similar to the second embodiment, the motor inverter 10 includes, in addition to the inverter cooling flow path 13, first and second sub-cooling flow paths 14 through which liquid phase refrigerant returning from the refrigerant return flow path 23 to the reservoir tank 22 circulates. 15 is provided.

  In this embodiment, the refrigerant outlet 13out of the inverter cooling passage 13 is located downstream of the condenser 24 in the refrigerant return passage 23 when the refrigerant temperature in the cooling passage 21 is higher than a predetermined value. To communicate with.

  That is, in the present embodiment, the refrigerant discharge pipe 13b of the inverter cooling flow path 13 is branched into two paths of a main discharge pipe 13c and a sub discharge pipe 13d, and the refrigerant discharge port 13out provided at the tip of the main discharge pipe 13c is changed to the first. As in the first embodiment, the refrigerant return channel 23 communicates with the upstream side of the condenser 24.

  Further, a branch flow path 23e connected to the sub discharge pipe 13d is provided on the downstream side of the condenser 24 in the refrigerant return flow path 23. The branch flow path 23e and the main discharge pipe 13c are crossed, and A switching valve 33 that switches between the communication state of the main discharge pipe 13c shown in FIG. 12A and the communication state of the branch flow path 23e and the sub discharge pipe 13d shown in FIG. Is provided.

  On the other hand, a temperature sensor 34 is installed in the cooling flow path 21 (passage 21a in the stator), a detection signal from the temperature sensor 34 is output to the controller 35, the switching timing of the switching valve 33 is calculated, and the result is calculated as the actuator. The switching valve 33 is controlled to be switched.

  That is, the switching valve 33 shuts off the branch flow path 23e when the main discharge pipe 13c is in communication as shown in FIG. 12A, and the branch flow path 23e and the auxiliary discharge as shown in FIG. 12B. The main discharge pipe 13c is cut off in a communication state with the pipe 13d.

  In the communication state of the main discharge pipe 13c, the tip of the main discharge pipe 13c serves as the refrigerant discharge port 13out, and the refrigerant discharge port 13out is more than the capacitor 24 in the refrigerant return flow path 23, as in the above embodiments. While communicating with the upstream side, and in a communication state between the branch flow path 23e and the sub discharge pipe 13d, the tip of the sub discharge pipe 13d becomes the refrigerant discharge port 13out, and the refrigerant discharge port 13out is connected to the branch flow path 23e. Communicate.

  When the detected temperature T of the temperature sensor 34 is lower than a preset value Td (T <Td), the switching valve 33 is in the state shown in FIG. 12A, and the detected temperature T is preset. When the value is higher than the value Td (T ≧ Td), the switching valve 33 is in the state shown in FIG.

  The set temperature Td is equal to or higher than the saturation temperature Tsat in the cooling flow path 21 obtained by experiments or the like (Td ≧ Tsat), and when the allowable temperature limit of the motor 1 is Tm, Td = α · Td ( α <1). For example, when α = 0.8, when T ≧ Td, the cooling flow path 21 is in a dry-out state, and the motor 1 temperature is in a dangerous temperature range.

  With the above configuration, according to the cooling device 10C of the present embodiment, when T <Td, it is determined that the temperature is below the dangerous temperature range, and the main discharge pipe 13c is communicated with the switching valve 33 in the state of FIG. By setting the state, the configuration is the same as that of the cooling device 10A of the second embodiment, and the operational effects thereof are the same as those of the second embodiment.

  On the other hand, when T ≧ Td, it is determined that the temperature is within the dangerous temperature range, and the switching valve 33 is set in the state shown in FIG. 12B, so that the branch flow path 23e and the sub discharge pipe 13d are in communication.

  Then, the high-pressure refrigerant in the gas phase generated in the inverter cooling flow path 13 is supplied from the branch flow path 23 e to the upstream return flow path 23 c and pushes the liquid-phase refrigerant in the refrigerant return flow path 23 to the reservoir tank 22.

  In this case, since the high-pressure refrigerant in the inverter cooling flow path 13 is supplied to the downstream side of the condenser 24 in the refrigerant return flow path 23, the liquid phase in the return flow path 23 at a lower pressure without receiving the flow resistance of the capacitor 24. The refrigerant can be sent to the reservoir tank 22.

  That is, the height Hd from the position where the branch flow path 23e branches from the refrigerant return flow path 23 to the position where the refrigerant return flow path 23e connects to the reservoir tank 22 is expressed as the refrigerant return flow from the downstream position S2 of the check valve 26. When the path 23 is set lower than the height Ho (see FIG. 3) up to the position where it connects to the reservoir tank 22, the position head for ρo · g · (Ho−Hd) is reduced. In combination with the disappearance of the flow resistance, the liquid-phase refrigerant in the refrigerant return channel 23 returning to the reservoir tank 22 can be pushed out at a lower pressure.

  In the present embodiment, the case where the branch flow path 23e is branched from the upstream return flow path 23c has been disclosed. However, the present invention is not limited to this, and the same may be true even if the branch flow path 23e is branched from the downstream return flow path 23d. An effect can be produced.

  Further, in this embodiment, the cooling device 10A of the second embodiment, that is, the motor inverter 10 is provided with the first and second sub cooling channels 14 and 15, and the refrigerant return channel is provided in the sub cooling channels 14 and 15. 23, a case where the present invention is applied to the cooling device 10A in which the upstream return flow path 23c and the downstream return flow path 23d are connected is disclosed, but the first and second sub cooling flow paths 14 and 15 are not provided in the motor inverter 10. Even one embodiment can be applied.

  FIGS. 13 and 14 show a fifth embodiment of the present invention, in which the same components as in the fourth embodiment are denoted by the same reference numerals and redundant description is omitted, and FIG. FIG. 14 is an explanatory diagram showing the switching state of the open / close valve for opening and closing the refrigerant introduction flow path to the inverter cooling flow path in order of (a) and (b).

  As shown in FIG. 13, the cooling device 20D of the present embodiment basically has the same configuration as the cooling device 20C of the fourth embodiment, and the refrigerant discharge pipe 13b of the inverter cooling flow path 13 is connected to the main discharge pipe 13c and the sub discharge. The temperature sensor 34 provided in the cooling flow path 21 is provided with a switching valve 33 which branches into two paths of the pipe 13d and is provided at the intersection of the main discharge pipe 13c and the branch flow path 23e of the refrigerant return flow path 23. 35 and the actuator 32 are used for switching.

  By the way, the refrigerant in the reservoir tank 22 is introduced into the inverter cooling flow path 13 via the second introduction flow path 28. At that time, a large amount of liquid-phase refrigerant is generated in the inverter cooling flow path 13. When present, there is a possibility that a subcool phenomenon occurs in which the refrigerant vaporized in the inverter cooling flow path 13 immediately returns to the liquid phase state.

  Therefore, in the present embodiment, as shown in FIG. 13, the amount of refrigerant introduced from the reservoir tank 22 to the inverter cooling flow path 13 is reduced when the temperature in the inverter cooling flow path 13 is low, while the inverter cooling flow path is reduced. An open / close valve 36 is provided as a refrigerant amount control means for increasing when the temperature in 13 is high.

  That is, the opening / closing valve 36 is provided on the upstream side of the check valve 29 of the second introduction passage 28 for introducing the refrigerant in the reservoir tank 22 into the inverter cooling passage 13, and is opened and closed by the actuator 32. It has become.

  The switching control of the opening / closing valve 36 is performed by inputting a detection signal of a temperature sensor 37 installed in the inverter cooling flow path 13 to the controller 35, calculating a switching timing, and outputting the result to the actuator 32. .

  That is, when the temperature T1 in the inverter cooling flow path 13 is lower than the predetermined value Td1 (T1 <Td1), the switching valve 36 is closed as shown in FIG. On the other hand, when the temperature T1 is higher than the value Td1 (T1 ≧ Td1), the switching valve 36 is opened as shown in FIG. A liquid phase refrigerant can be introduced into the inverter cooling flow path 13.

  At this time, the Td1 is equal to or higher than the saturation temperature Tsat1 in the inverter cooling flow path 13 determined in advance by experiments or the like (Td1 ≧ Tsat1).

  With the above configuration, according to the cooling device 10D of the present embodiment, when the temperature in the inverter cooling flow path 13 is low, the open / close valve 36 is closed to reduce the amount of refrigerant introduced into the inverter cooling flow path 13. When the temperature in the inverter cooling flow path 13 is high, the open / close valve 36 is opened to increase the amount of refrigerant introduced into the inverter cooling flow path 13, thereby ensuring that the refrigerant is evacuated in the inverter cooling flow path 13. Since the refrigerant pressure can be increased by being phased, the dry-out phenomenon in the inverter cooling flow path 13 can be prevented.

  Of course, the cooling device 10D of the present embodiment can also be applied to the cooling device 10 of the first embodiment in which the first and second sub cooling channels 14 and 15 are not provided in the motor inverter 10.

  The motor cooling device of the present invention has been described by taking the first to fifth embodiments as examples. However, the present invention is not limited to these embodiments, and various other embodiments are employed without departing from the gist 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 be applied to a normal motor.

The perspective view of the suspension apparatus which shows the attachment state of the motor with which the cooling device of this invention is applied. Sectional drawing of the motor which assembled | attached the cooling device in 1st Embodiment of this invention. The whole block diagram which shows the refrigerant | coolant circulation path | route of the cooling device in 1st Embodiment of this invention. Sectional drawing along the AA line in FIG. The expansion perspective view of the motor inverter in a 1st embodiment of the present invention. The expanded sectional view along the BB line in FIG. Sectional drawing of the motor which assembled | attached the cooling device in 2nd Embodiment of this invention. The expansion perspective view of the motor inverter in a 2nd embodiment of the present invention. FIG. 9 is an enlarged cross-sectional view taken along line CC in FIG. 8. The whole block diagram which shows the refrigerant | coolant circulation path | route of the cooling device in 3rd Embodiment of this invention. The whole block diagram which shows the refrigerant | coolant circulation path | route of the cooling device in 4th Embodiment of this invention. Explanatory drawing which shows the switching state of the switching valve of the discharge | emission side of the inverter cooling flow path in 4th Embodiment of this invention later on to (a), (b) in order. The whole block diagram which shows the refrigerant | coolant circulation path of the cooling device in 5th Embodiment of this invention. Explanatory drawing which shows the switching state of the on-off valve which opens and closes the refrigerant | coolant introduction flow path to the inverter cooling flow path in 5th Embodiment of this invention later on to (a), (b).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Rotating shaft 3 Rotor 4 Stator 10 Motor inverter (pressurizing means)
DESCRIPTION OF SYMBOLS 12 Electronic element 13 Inverter cooling flow path 13out Refrigerant discharge port 14 1st subcooling flow path 15 2nd subcooling flow path 20, 20A, 20B, 20C, 20D Cooling device 21 Cooling flow path 21a-21f Stator internal path (cooling flow) Road)
22 Reservoir tank 23 Refrigerant return flow path 24 Condenser (exhaust heat mechanism)
30 Porous material 31 Refrigerant passage amount equalizing means 36 Open / close valve (refrigerant amount control means)

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 cooling flow path that is provided in the heat generating part of the motor and circulates a refrigerant that changes from a liquid phase to a gas phase at a predetermined temperature;
A reservoir tank that is arranged vertically above the cooling flow path and supplies the cooling flow path while preventing the refrigerant from flowing back;
An exhaust heat mechanism that is disposed in a refrigerant return channel that returns the refrigerant discharged from the cooling channel to the reservoir tank, and that converts the refrigerant gasified in the cooling channel into a liquid phase;
A pressure return means for further pressurizing the discharge pressure of the cooling flow path in the refrigerant return flow path from the cooling flow path to the reservoir tank ;
A motor cooling apparatus, wherein the pressurizing means is provided upstream of the exhaust heat mechanism .   The pressurizing means is a motor inverter formed with an inverter cooling flow path for introducing the refrigerant from the reservoir tank while preventing the reverse flow, and the refrigerant discharge port of the inverter cooling flow path extends from the cooling flow path to the reservoir tank. The motor cooling device according to claim 1, wherein the motor cooling device communicates with the refrigerant return flow path.   The motor cooling device according to claim 2, wherein a refrigerant discharge port of the inverter cooling flow path is communicated with an upstream side of the heat exhaust mechanism of the refrigerant return flow path.   4. The motor cooling device according to claim 2, wherein the inverter cooling flow path is formed of a porous material.   The motor cooling device according to any one of claims 2 to 4, wherein a sub-cooling flow path for circulating a refrigerant is provided in the motor inverter in the vicinity of the inverter cooling flow path.   A plurality of the cooling channels provided in the heat generating portion of the motor are formed at appropriate intervals in the circumferential direction of the motor, and the refrigerant passage amount of the plurality of cooling channels is set to a height from the liquid level of the reservoir tank. 6. The motor cooling device according to claim 1, further comprising a refrigerant passage amount equalizing unit that makes each substantially equal.   The refrigerant discharge port of the inverter cooling channel communicates with the downstream side of the exhaust heat mechanism of the refrigerant return channel when the refrigerant temperature in the cooling channel is higher than a predetermined value. The motor cooling device according to any one of claims 2 to 6.   There is provided a refrigerant amount control means for reducing the amount of refrigerant introduced from the reservoir tank into the inverter cooling channel when the temperature in the inverter cooling channel is low, and increasing when the temperature in the inverter cooling channel is high. The motor cooling device according to any one of claims 2 to 7, wherein A refrigerant changing from a liquid phase to a gas phase at a predetermined temperature is circulated through a cooling flow path provided in a heat generating part of the motor to cool the heat generating part, and the vaporized refrigerant discharged from the cooling flow path is exhausted. The liquid phase is returned to the reservoir tank by the mechanism, and the reservoir tank is arranged vertically above the cooling flow path to circulate the refrigerant by itself, while the pressurizing means provided on the upstream side of the exhaust heat mechanism. A method for cooling a motor, wherein the discharge pressure of the cooling channel is further increased to further increase the pressure for pushing out the refrigerant liquidified by the exhaust heat mechanism to a reservoir tank.

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