JP2009038940A - Motor cooling device, motor cooling method, and vehicle mounted with motor having motor cooling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor cooling device that achieves compactification and weight reduction of a cooling system by allowing a refrigerant to self-circulate, a motor cooling method, and a vehicle with a motor having the motor cooling device. <P>SOLUTION: The motor cooling device is configured by providing: a reservoir tank 11 reservoiring a refrigerant; a plurality of refrigerant evaporation passages 12a-12f juxtaposed inside a stator 4 that becomes a heat-generating part of a motor 1; refrigerant condensation passages 13a-13f respectively made to communicate with each downstream side of the plurality of refrigerant evaporation passages 12a-12f; a refrigerant supply passage 15 for supplying the refrigerant inside the reservoir tank 11 by distributing it to the refrigerant evaporation passages 12a-12f via an upstream-side check valve 14; and a refrigerant reflux passage 17 for collecting the refrigerant passing through the refrigerant condensation passages 13a-13f so as to return it to the reservoir tank 11 via a downstream-side check valve 16. The configuration achieves compactification of a cooling device 10 by reducing a flow rate of a liquid-phase refrigerant by generating an oscillating flow in the liquid-phase refrigerant by a minute bias of each passage while achieving the self-circulation of the refrigerant. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a motor cooling device, a cooling method, and a vehicle equipped with the motor with the cooling device.

  As an electric vehicle drive system, an in-wheel drive system in which a motor is incorporated in a tire wheel has been proposed. This in-wheel drive system expands the effective use space in the passenger compartment and drives each wheel independently. 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 make the motor compact. 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.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a motor cooling device and cooling method that can achieve a compact and lightweight cooling system by self-circulating the refrigerant, and a vehicle equipped with the motor with the cooling device.

  The motor cooling device of the present invention is a motor including a rotating shaft, a rotor coupled to the rotating shaft, and a stator surrounding the outer periphery of the rotor, and the motor generates heat to generate a gas phase from a liquid phase. And a plurality of refrigerant evaporating passages arranged in parallel to the heat generating portion of the motor, and a plurality of refrigerants communicating with the downstream side of the plurality of refrigerant evaporating passages and arranged in the low temperature portion A condensation passage, a refrigerant supply passage for distributing and supplying the refrigerant in the reservoir tank to the plurality of refrigerant evaporation passages via a first check valve, and the refrigerant that has passed through the plurality of refrigerant condensation passages. And a refrigerant recirculation passage that returns to the reservoir tank via a second check valve.

  According to the motor cooling device of the present invention, a closed loop is configured in which the refrigerant accumulated in the reservoir tank returns to the reservoir tank again through the refrigerant supply passage, the refrigerant evaporation passage, the refrigerant condensing passage, and the refrigerant recirculation passage. The action of pushing out the refrigerant that has been liquefied in the refrigerant condensing passage to the refrigerant recirculation passage with the pressure of the vapor generated by the vaporization of the refrigerant in the refrigerant evaporation passage, and the first and the first provided in the refrigerant supply passage and the refrigerant recirculation passage, respectively. The self-circulation of the refrigerant becomes possible by the action of the check valve 2 and the waste heat of the heat generating part of the motor is recovered as the latent heat of evaporation by the refrigerant in the refrigerant evaporation passage, and the recovered refrigerant is used as the refrigerant condensation passage. By being introduced into the inside, it is released as condensation latent heat, and the motor can be cooled. As a result, the cooling device can be made compact.

  In addition, a plurality of refrigerant evaporating passages are arranged in parallel, and a plurality of refrigerant condensing passages are connected to the refrigerant evaporating passage and arranged in parallel, so that the diameters and lengths of the plurality of refrigerant evaporating passages and the refrigerant condensing passages are the same. Even if it is formed, since there is a slight bias in each passage, the timing of evaporation in each passage will not be the same. That is, the evaporation timing in at least one of the passages can be varied. In this way, by varying the timing of evaporation, the pressure in the refrigerant evaporation passage where vaporization first occurs also affects other refrigerant evaporation passages, and the liquid flowing through the plurality of refrigerant evaporation passages and the refrigerant condensation passages. An oscillating flow can be generated in the phase refrigerant.

  Thus, by generating an oscillating flow, it is possible to reduce the amount of refrigerant flowing into each refrigerant evaporation passage in the liquid state, and thus to increase the condensation efficiency of the vaporized refrigerant in the refrigerant condensation passage. become able to. As a result, the capacity of the refrigerant condensing passage can be reduced, and further downsizing of the cooling device can be achieved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, a motor used in an in-wheel drive type electric vehicle will be described as an example.

(First embodiment)
1 to 8 show a first embodiment of a vehicle equipped with a motor cooling device and cooling method and a motor with the cooling device according to the present invention, and FIG. 1 shows a tire in which a motor is incorporated as an in-wheel drive system. It is a perspective view of a wheel.

  As shown in FIG. 1, the motor 1 to which the cooling device 10 of the present embodiment is applied is provided in the wheel axle WA as an in-wheel drive system. The motor 1 is mounted and supported on the wheel axle W / A on the housing side, and the drive shaft side of the motor 1 is inserted into the inner recess Wh of the tire wheel T / W to drive the wheel.

  In this embodiment, the wheel W is supported on the vehicle body side by a double wishbone suspension device S including an upper, a lower link L · U, L·L, and a shock absorber S · A. Is not limited to this double wishbone.

  2 is a longitudinal sectional view of a motor provided with a cooling device, and FIG. 3 is a sectional view taken along line AA in FIG. 2. As shown in FIGS. 2 and 3, the motor 1 includes a rotating shaft 2. And a rotor 3 coupled to the rotating shaft 2 and a stator 4 surrounding the outer periphery of the rotor 3. The rotating shaft 2, the rotor 3, and the stator 4 are accommodated in a cylindrical housing 5.

  The rotary shaft 2 is integrated with the rotor 3, and both end portions thereof are rotatably supported by end plates 5E1 and 5E2 that close both ends of the housing 5 via bearings 6A and 6B, and the rotor 3 is provided inside the peripheral portion of the rotor 3. The four rotor magnets 7 are arranged along the axial direction of the rotary shaft 2 at equal intervals in the circumferential direction (center angle 90 °).

  The stator 4 is fixed to the inner periphery of the housing 5, and six stator projecting pole portions 4 </ b> S are projected from the inner periphery of the stator 4 at equal intervals (center angle 60 °) in the circumferential direction. A motor coil 8 is wound around the portion 4S. The motor coil 8 generates heat when it is energized when the motor 1 is driven, and the heat generated by the motor coil 8 is conducted from the stator salient pole portion 4S to the entire stator 4, and as a result, the entire motor 1 is heated. .

  Here, as shown in FIGS. 2 and 3, the cooling device 10 includes a reservoir tank 11 that stores a refrigerant that changes from a liquid phase to a gas phase due to heat generated by the motor 1, and a stator 4 that serves as a heat generating portion of the motor 1. A plurality of (six) refrigerant evaporating passages 12a to 12f arranged in parallel with each other corresponding to the stator salient pole portion 4S, and a low temperature portion respectively connected to the downstream side of the plurality of refrigerant evaporating passages 12a to 12f. For example, a plurality of (six) refrigerant condensing passages 13a to 13f arranged on the outside of the housing 5 and the refrigerant in the reservoir tank 11 through the upstream check valve (first check valve) 14 are described above. A refrigerant supply passage 15 that is distributed and supplied to the plurality of refrigerant evaporation passages 12a to 12f and the refrigerant that has passed through the plurality of refrigerant condensation passages 13a to 13f are gathered to collect a downstream check valve (second check valve). 16 through the reservoir It includes a coolant recirculation passage 17 for returning the click 11.

  In this embodiment, the refrigerant stored in the reservoir tank 11 is distributed to a plurality of refrigerant evaporation passages 12a to 12f arranged in parallel with the heat generating portion (stator 4) of the motor 1 via the upstream check valve 14. After the supply, the refrigerant that has passed through the plurality of refrigerant evaporation passages 12a to 12f is introduced into the refrigerant condensation passages 13a to 13f provided on the downstream side of the respective refrigerant evaporation passages 12a to 12f, and the plurality of refrigerant condensation passages 13a. After collecting the refrigerant that has passed through 13 f, the refrigerant is returned to the reservoir tank 11 via the downstream check valve 16.

  As shown in FIG. 3, the refrigerant evaporating passages 12a to 12f are formed in a thickness corresponding to the stator salient pole portion 4S of the stator 4, and in this embodiment, the refrigerant evaporating passages 12a to 12f have the same diameter. Is formed.

  In addition, the refrigerant condensing passages 13a to 13f are configured by providing a large number of fins on the outer periphery of a pipe serving as a passage, and heat exchange between the outside air and the refrigerant in the passage is achieved through these fins. ing.

  4 is a right side view of the motor as viewed from the direction of arrow B in FIG. 2, and as shown in FIG. 2 and FIG. 2, the upstream end located at the inner end of the end plate 5E1 of the plurality of refrigerant evaporation passages 12a to 12f. Is communicated with the downstream end 15a of the refrigerant supply passage 15 formed as a single pipe via the branch passages 18a to 18f. An upstream check valve 14 is provided in the refrigerant supply passage 15.

  5 is a left side view of the motor as viewed from the direction of arrow C in FIG. 2, and as shown in FIG. 2 and FIG. 2, the downstream end located at the inner end of the end plate 5E2 of the plurality of refrigerant evaporation passages 12a to 12f. Are communicated with the upstream ends of the plurality of refrigerant condensing passages 13a to 13f via the corresponding communication passages 19a to 19f. The downstream ends of the refrigerant condensing passages 13a to 13f are communicated with the upstream end 17a of the refrigerant recirculation passage 17 formed by a single pipe via the collecting passage 20. Further, a downstream check valve 16 is provided in the refrigerant recirculation passage 17.

  Therefore, in the cooling device 10 according to the present embodiment, the refrigerant in the reservoir tank 11 includes the refrigerant supply passage 15 provided with the upstream check valve 14, the branch passages 18a to 18f, the refrigerant evaporation passages 12a to 12f, and the communication passage. A closed loop in which the refrigerant returns to the reservoir tank 11 through the refrigerant recirculation passage 17 provided with 19a to 19f, the refrigerant condensing passages 13a to 13f, the collecting passage 20 and the downstream check valve 16 is formed.

  In the refrigerant evaporating passages 12a to 12f, the refrigerant recovers the waste heat of the stator 4 serving as the heat generating portion of the motor 1 as latent heat of vaporization and is vaporized. On the other hand, in the refrigerant condensing passages 13a to 13f, The phased refrigerant is released as latent heat of condensation and becomes a liquid phase. As a result, the heat recovered in the refrigerant evaporating passages 12a to 12f is released to the outside from the refrigerant condensing passages 13a to 13f, and the motor 1 is cooled.

  Hereinafter, the operation of the cooling device 10 of the present embodiment will be described with reference to FIGS. 6, 7, and 8.

  FIG. 6A is a schematic diagram showing a simplified cooling device of the present embodiment, and FIG. 6B is a schematic diagram showing a simplified cooling device compared with the present embodiment.

  As shown in FIG. 6A, the cooling device 100 includes a reservoir tank 111, two refrigerant evaporation passages 112a and 112b arranged in parallel with the heat generating portion of the motor, and the downstream side of the refrigerant evaporation passages 112a and 112b. Two refrigerant condensing passages 113a and 113b communicated with each other, a refrigerant supply passage 115 for distributing and supplying the refrigerant in the reservoir tank 111 to the refrigerant evaporating passages 112a and 112b via the upstream check valve 114, A refrigerant recirculation passage 117 that collects the refrigerant that has passed through the refrigerant condensing passages 113a and 113b, communicates, and returns to the reservoir tank 111 via the downstream check valve 116 is schematically configured.

  In addition, the refrigerant supply passage 115 and the refrigerant evaporation passages 112a and 112b are communicated by branch passages 118a and 118b, and the refrigerant evaporation passages 112a and 112b and the refrigerant condensation passages 113a and 113b are communicated by communication passages 119a and 119b, respectively. In addition, the refrigerant condensing passages 113 a and 113 b and the refrigerant recirculation passage 117 are communicated with each other through the collecting passage 120.

  As described above, in the cooling device 100, the refrigerant evaporating passages 112a and 112b and the refrigerant condensing passages 113a and 113b are two, but even in the case of the cooling device 10 in which three or more of these passages are provided. The same action is the same.

  On the other hand, as shown in FIG. 6B, the cooling device 200 to be compared includes a reservoir tank 211, two refrigerant evaporation passages 212a and 212b arranged in series in the heat generating part of the motor, and a downstream refrigerant. A refrigerant condensing passage 213 communicated with the evaporation passage 212b, a refrigerant supply passage 215 for supplying the refrigerant in the reservoir tank 211 to the upstream refrigerant evaporating passage 212a via the upstream check valve 214, and a refrigerant condensing passage 213 And a refrigerant recirculation passage 217 for returning the refrigerant that has passed through the storage tank 211 to the reservoir tank 211 via the downstream check valve 216.

  The refrigerant supply passage 215 and the refrigerant evaporation passage 212a are communicated by a passage 218, the refrigerant evaporation passage 212b and the refrigerant condensation passage 213 are communicated by a communication passage 219, and the refrigerant condensation passage 213 and the refrigerant reflux passage 217 are connected. Are connected by a passage 220.

  That is, in the latter cooling device 200, the two refrigerant evaporation passages 212a and 212b are arranged in series. The refrigerant evaporating passages 212a and 212b have the same length as the refrigerant evaporating passages 112a and 112b of the former cooling device 100, respectively, and the refrigerant condensing passage 213 of the latter cooling device 200 is the same as the former cooling device. The two refrigerant condensing passages 113a and 113b of 100 are formed to have a combined length.

  In the cooling device 100, since a plurality of refrigerant evaporation passages 112a and 112b are provided in parallel, the liquid phase refrigerant existing in the refrigerant evaporation passages 112a and 112b reciprocates to generate an oscillating flow. Hereinafter, the reason why an oscillating flow is generated by providing a plurality of passages in parallel will be described with reference to FIG.

  FIG. 7 is an explanatory diagram illustrating, in the form of a graph, the time history of the temperature and pressure in the refrigerant evaporation passage and the flow rate in the refrigerant supply passage of the cooling device shown in FIG.

  First, when forming the cooling device 100, the refrigerant evaporating passages 112a and 112b and the refrigerant condensing passages 113a and 113b are symmetrical between the refrigerant supply passage 115 and the refrigerant recirculation passage 117, that is, the diameter and length are the same. However, in reality, there is a slight bias in each passage. For example, the refrigerant cooling performance due to subtle differences in the temperature and flow velocity of the cooling air contacting the refrigerant condensing passages 113a and 113b, the amount of heat from the heat generating portion (stator 4) of the motor 1, the refrigerant evaporation passages 112a and 112b, A deviation may occur in each passage due to a change in the distance from the heat generating portion or the like.

  Due to these biases, when one of the refrigerant evaporation passages 112a and 112b, for example, the refrigerant in the refrigerant evaporation passage 112a starts to evaporate first, the temperature and pressure at the center 112Ca of the refrigerant evaporation passage 112a are high. A liquid two-phase flow will flow. At this time, the gas-liquid two-phase flow flows into the refrigerant condensing passage 113a and also flows backward into the branch passages 118a and 118b and into the other refrigerant evaporating passage 112b, so that the temperature in the refrigerant evaporating passage 112b is lowered.

  7A and 7B, the temperature of the central portion 112Ca of one refrigerant evaporation passage 112a is the maximum value T1, the pressure is the maximum value P1, and the central portion 112Cb of the other refrigerant evaporation passage 112b. When the temperature reaches the minimum value T′1 and the pressure reaches the minimum value P′1, the gas-phase refrigerant introduced into one refrigerant condensing passage 113a condenses, so that the temperature and pressure at the central portion 112Ca begin to decrease.

  Thus, when the pressure at the center portion 112Ca decreases, the saturation pressure at the other center portion 112Cb also decreases, so that the refrigerant starts to evaporate in the refrigerant evaporation passage 112b and the liquid phase in the branch passages 118a and 118b. The refrigerant flows into one refrigerant evaporating passage 112a, and the temperature and pressure become maximum values T'2 and P'2 at the other center portion 112Cb, and the temperature becomes the minimum value T2 at one center portion 112Ca.

  When such an oscillating flow is repeated several times, the amount of liquid refrigerant in the branch passages 118a and 118b decreases, evaporation occurs in both refrigerant evaporation passages 112a and 112b, and the upstream check valve 114 opens. Then, as shown in FIG. 7C, the liquid phase refrigerant flows from the reservoir tank 111 into the refrigerant supply passage 115.

  Then, the liquid-phase refrigerant that has flowed into the refrigerant supply passage 115 is introduced into the refrigerant evaporation passages 112a and 112b from the branch passages 118a and 118b, and an oscillating flow is again generated in the refrigerant evaporation passages 112a and 112b as described above. Such a cycle is repeated.

  On the other hand, FIG. 8 is an explanatory diagram showing, in the form of graphs, time histories of the temperature and pressure in the refrigerant evaporation passage and the flow rate in the refrigerant supply passage of the cooling device shown in FIG. The temperature and pressure values at the center portion 212Ca of the refrigerant evaporation passage 212b on the downstream side of the cooling device 200 are similar in shape, and the center on the downstream side from the center portion 212Ca of the upstream refrigerant evaporation passage 212a. Since the graph is shifted by an amount corresponding to the flow path resistance up to the portion 212Cb and becomes complicated, the values of the temperature and pressure at the central portion 212Cb on the downstream side are omitted in FIG.

  In the cooling device 200, first, the upstream check valve 214 is opened, and the liquid-phase refrigerant from the reservoir tank 211 passes through the refrigerant supply passage 215 to the upstream refrigerant evaporation passage 212a and the downstream refrigerant evaporation passage 211b. When supplied, the liquid-phase refrigerant rises in temperature in the refrigerant evaporation passages 212a and 212b. And if it exceeds the value shown to T1 in Fig.8 (a) and P1 in FIG.8 (b), boiling will be started.

  When a part of the liquid-phase refrigerant evaporates and enters a gas-liquid mixed state in this way, the liquid-phase refrigerant present in the passage 219 and the refrigerant condensing passage 213 tends to be pushed out toward the downstream check valve 216. However, since the downstream check valve 216 does not open unless the pressure exceeds a predetermined value, the pressure and saturation temperature in the passage gradually increase, and eventually the pressure reaches the maximum value P2 and the saturation temperature. Becomes the maximum value T2.

  Then, when the pressure and saturation temperature rise, the downstream check valve 216 is opened, and the liquid-phase refrigerant present in the passage 219 and the refrigerant condensing passage 213 is pushed out, between T3 and T4 and between P3 and P4. As shown in between, the temperature and pressure are constant, and the liquid-phase refrigerant in the refrigerant evaporation passages 212a and 212b continues to evaporate. When the quality of the gas-liquid two-phase flow in the refrigerant condensing passage 213 increases, condensation occurs in the refrigerant condensing passage 213, the pressure in the refrigerant evaporating passages 212a and 212b decreases, and the upstream check valve 214 is opened, and the liquid-phase refrigerant is supplied to the refrigerant evaporation passages 212a and 212b.

  At this time, the temperature in the refrigerant evaporation passages 212a and 212b becomes the minimum value T5 due to the inflow of the liquid phase refrigerant. Thereafter, the above cycle is repeated. In addition, as shown to Fig.8 (a), the refrigerant | coolant in the refrigerant | coolant evaporation channel | path 212a, 212b is in a boiling state in T1-T4, and the refrigerant | coolant is in the state which is not boiling between T4-T6.

  As described above, unlike the cooling device 200, in the cooling device 100, an oscillating flow is generated in the liquid-phase refrigerant in the refrigerant evaporation passages 112a and 112b, so the upstream check valve 14 is opened and the refrigerant evaporates. The inflow amount of the liquid phase refrigerant flowing into the passages 112a and 112b can be significantly reduced as compared with the inflow amount of the liquid phase refrigerant flowing into the refrigerant evaporation passages 212a and 212b of the cooling device 200.

Here, the definition formula of the above-mentioned quality (the degree of cuteness) X is
Quality X = Gg / (Gg + Gl) (1)
It becomes.

Where Gg (= Wg / A): gas phase mass velocity, Gl (= Wl / A): liquid phase mass velocity, Wg: gas phase mass flow rate, Wl: liquid phase mass flow rate, A: channel cross-sectional area .

Also, if the cross-sectional area of the liquid phase condensing passage is constant,
X = Wg / (Wg + Wl) (2)
It becomes.

Here, if the heat removal amount is H and the latent heat is L, the generated steam amount is Gg = H / L, and if the average mass flow rate of the liquid-phase refrigerant flowing into the refrigerant evaporation passage is W01,
Wl = W01-Wg (3)
And quality X is
X = H / (L · W01) (4)
It becomes.

  Therefore, it is understood that the average mass flow rate of the liquid phase refrigerant flowing into the refrigerant evaporation passage may be reduced in order to increase the quality X.

  Further, as an approximate value estimation method of the heat transfer coefficient α in the condensation in the passage, there is a Shah equation described below.

α = αl {(1-X) ^0.8 + 3.8X ^0.76 (1-X) ^0.04 (Ps / Pcrt) ^−0.38 } (5)
However, αl is a heat transfer coefficient when it is assumed that only the liquid refrigerant flows in the passage, X: quality, Ps: saturation pressure, and Pcrt: critical pressure.

  The heat transfer coefficient α in the refrigerant condensing passage is a monotonically increasing function of X except for the vicinity of X = 1. Therefore, if the quality X of the fluid flowing into the refrigerant condensing passage increases, the heat transfer coefficient of the refrigerant condensing passage. As a result, the area of the refrigerant condensing passage can be reduced.

  Incidentally, in the cooling devices 100 and 200 of FIGS. 6A and 6B, the reservoir tanks 111 and 211 are opened to the atmosphere, the diameter of the cross section of all passages is set to 4 mm, and heat of 1.4 kW is removed. As a result, the average mass flow rates were 61 g / min and 183 g / min, respectively.

Further, when water is used as a refrigerant and the latent heat of vaporization near the saturation temperature of 100 ° C. is 2260 kJ / kg, the heat quantity of 1.4 kW is removed,
1.4 / 220 = 6.19 × 10 ⁻⁴ kg / s = 6.19 × 10 ⁻⁴ × 60 × 1000 = 37 g / min
Thus, it is sufficient to supply 37 g of water per minute. Conversely, this means that heat of 1.4 kW can be removed by converting 37 g of water into steam.

Therefore, the quality X of the flow path system of the cooling device 100 in FIG.
X = Wg / W01 = 37/61 = 0.61 (A)
It becomes. Moreover, the quality X of the flow path system of the cooling device 200 in FIG.
X = Wg / W01 = 37/183 = 0.20 (b)
It becomes.

For the qualities of 0.61 and 0.20 calculated in (i) and (b) above, when the condensation heat transfer coefficient is calculated using the Shah equation in (5), 13.5 kW / (m ² · K) and 6.4 kW / (m ² · K). However, for the sake of simplicity, the value of 1 atm (because the reservoir tank is open to the atmosphere) is used as the physical property value in the formula. Further, αl is assumed to be αl = 677 W / (m ² · K) from commonly used Nu (Nussell number) = 4, assuming the developed laminar flow heat transfer in the passage.

  Therefore, the refrigerant condensing passage of the flow path system of the cooling device 100 of FIG. 6A is 2.09 (= 13.5 / 6.4) compared to that of the flow path system of the cooling device 200 of FIG. 6B. ) Doubled. At this time, when the heat transfer coefficient of the refrigerant condensing passages 112a and 112b of the cooling device 100 is equal to the heat transfer coefficient of the refrigerant condensing passages 212a and 212b of the cooling device 200, according to the trial calculation, the cooling device 100 The total area of the refrigerant condensing passages 112a and 112b (in this case, the length of the condensing passage) can be eliminated by 20% (each 10% for each of the two refrigerant condensing passages 112a and 112b).

  Incidentally, the operation of the cooling device 10 shown in FIG. 2 of the present embodiment has been described using the simplified cooling device 100 shown in FIG. 6A for the sake of convenience. The same effect can be obtained only by increasing the number of the.

  According to the cooling device 10 and the cooling method of the motor 1 of the present embodiment having the above-described configuration, the refrigerant stored in the reservoir tank 11 is supplied to the cooling device 10 as the refrigerant supply passage 15, the refrigerant evaporation passages 12a to 12f, the refrigerant. A closed loop is formed in which the refrigerant returns to the reservoir tank 11 again through the condensing passages 13a to 13f and the refrigerant recirculation passage 17, and the refrigerant condensing passage 13a is generated by the pressure of the vapor generated by the vaporization of the refrigerant in the refrigerant evaporation passages 12a to 12f. The refrigerant that has been liquefied by ˜13f can be self-circulated by the action of pushing the refrigerant into the refrigerant recirculation passage 17 and the action of the check valves 14 and 16 provided in the refrigerant supply passage 15 and the refrigerant recirculation passage 17, respectively. At the same time, the waste heat of the heat generating part (stator 4) of the motor 1 is recovered by the refrigerant in the refrigerant evaporation passages 12a to 12f as latent heat of evaporation, and the heat is recovered. Refrigerant is discharged as latent heat of condensation by being introduced into the refrigerant condensing passages 13a~13f becomes possible to cool the motor 1. As a result, the cooling device 10 can be made compact.

  At this time, since a plurality of refrigerant evaporating passages 12a to 12f are arranged in parallel, a plurality of refrigerant condensing passages 13a to 13f are also arranged in parallel. In this way, by arranging a plurality of the refrigerant evaporation passages 12a to 12f and the refrigerant condensation passages 13a to 13f in parallel, the diameters of the plurality of refrigerant evaporation passages 12a to 12f and the refrigerant condensation passages 13a to 13f can be Even when the lengths are formed under the same conditions, there is a slight bias in each passage, so that the evaporation timing in each passage does not become the same. That is, the evaporation timing in at least one of the passages can be varied. Thus, by varying the timing of evaporation, the pressure in the refrigerant evaporation passages 12a to 12f where the vaporization has occurred first also affects the other refrigerant evaporation passages 12a to 12f, and a plurality of refrigerant evaporation passages 12a. ~ 12f and the refrigerant condensing passages 13a to 13f can generate an oscillating flow in the liquid phase refrigerant.

  Thus, since the flow rate of the liquid phase flowing through the closed loop constituting the cooling device 10 can be reduced by generating the oscillating flow, the amount of refrigerant flowing into each of the refrigerant evaporation passages 12a to 12f in the liquid phase is reduced. As a result, the condensing efficiency of the vaporized refrigerant in the refrigerant condensing passages 13a to 13f can be increased. As a result, the capacity | capacitance of the refrigerant | coolant condensing passages 13a-13f can be made small, and the further compactification of the cooling device 10 can be achieved.

  Further, by using the cooling device 10 made compact according to the present embodiment, the wheel driving motor 1 can be assembled to the tire wheel TW, and the motor 1 can be efficiently cooled. Therefore, an in-wheel drive vehicle equipped with the motor 1 that can withstand high loads can be obtained.

  By the way, in this embodiment, the reservoir tank 11 is arranged vertically below the refrigerant evaporation passages 12a to 12f without being arranged vertically above the position where the refrigerant evaporation passages 12a to 12f are formed as shown in FIG. The refrigerant condensing passages 13a to 13f can be installed at arbitrary positions. Further, the reservoir tank 11 may be opened to the atmosphere.

  Further, although the passage portions of the refrigerant condensing passages 13a to 13f are illustrated as straight pipes, they are not necessarily straight pipes, and can be formed by appropriately curved pipes or meandering pipes. Further, the number of refrigerant evaporating passages 12a to 12f is not limited to six, and the number and position thereof can be arbitrarily set so that heat recovery can be efficiently achieved in the motor 1.

(Second Embodiment)
FIG. 9 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. 9 is a diagram of a motor provided with a cooling device. It is a longitudinal cross-sectional view.

  As shown in FIG. 9, the cooling device 10 </ b> A according to the present embodiment basically has the same configuration as that of the cooling device 10 of the first embodiment, and a plurality (in parallel) of the reservoir tank 11 and the stator 4. 6) refrigerant evaporating passages 12a to 12f, a plurality (six) refrigerant condensing passages 13a to 13f communicating with the downstream sides of the respective refrigerant evaporating passages 12a to 12f, and an upstream check valve 14 are provided. A refrigerant supply passage 15 and a refrigerant recirculation passage 17 provided with a downstream check valve 16 are provided.

  The main difference between the present embodiment and the first embodiment is that at least one of the plurality of refrigerant evaporation passages 12a to 12f has a different diameter.

  In this embodiment, the diameter of the refrigerant evaporating passage 12a located at the uppermost vertical position is larger than the diameters of the other refrigerant evaporating passages 12b to 12f. At this time, the other refrigerant evaporating passages 12b to 12f have the same diameter.

Here, when the refrigerant evaporation passages 12a to 12f are filled with the liquid phase refrigerant at the temperature T0, the amount of heat Hs is added to the refrigerant evaporation passages 12a to 12f and the time τ until the saturation temperature Tsub is reached is
τ = (ρ · Cp · Ls · ΔTsub · A) / Hs (6)
It becomes.

  Where ρ: liquid phase refrigerant density, Cp: liquid phase refrigerant specific heat, Ls: length of refrigerant evaporation passage, ΔTsub = Tsub−T0, A: cross sectional area of refrigerant evaporation passage, Hs: applied heat quantity.

  When the cross-sectional area A is changed from the above equation (6), the time until the saturation temperature Tsub is reached, that is, the time until evaporation occurs in the liquid refrigerant changes.

  Therefore, according to the cooling device 10A of the present embodiment, the specific refrigerant evaporating passage 12a positioned at the uppermost vertical position has the same length Ls as the other refrigerant evaporating passages 12b to 12f, but has a large cross-sectional area A. Therefore, the refrigerant in the specific refrigerant evaporation passage 12a has a longer time until evaporation starts than the other refrigerant evaporation passages 12b to 12f.

  Therefore, by making at least one diameter of the refrigerant evaporating passages 12a to 12f different from the other diameters of the refrigerant evaporating passages 12a to 12f in this way, it is possible to positively generate an oscillating flow in the refrigerant flow path system. Thus, the condensation efficiency in the refrigerant condensing passages 13a to 13f can be further improved, and further downsizing of the cooling device 10A can be achieved.

(Third embodiment)
FIG. 10 shows a third 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. 10 shows a motor provided with a cooling device. It is a longitudinal cross-sectional view.

  As shown in FIG. 10, the cooling device 10 </ b> B of the present embodiment basically has the same configuration as the cooling device 10 of the first embodiment, and a plurality (6) of the reservoir tank 11 and the stator 4 are arranged in parallel. Main refrigerant evaporating passages 12a to 12f, a plurality of (six) refrigerant condensing passages 13a to 13f communicating with the downstream sides of the respective refrigerant evaporating passages 12a to 12f, and an upstream check valve 14. A supply passage 15 and a refrigerant recirculation passage 17 provided with a downstream check valve 16 are provided.

  The main difference between the present embodiment and the first embodiment is that the diameters Da to Df of the plurality of refrigerant evaporation passages 12a to 12f are increased as they are positioned vertically upward.

  That is, as shown in FIG. 10, the cooling device 10B of the present embodiment has a height H1 of the refrigerant evaporation passage 12a from the arbitrarily set reference position Bh, a height H2 of the refrigerant evaporation passages 12b and 12f, and a refrigerant. When the height of the evaporating passages 12c and 12e is H3 and the height of the refrigerant evaporating passage 12d is H4, H1> H2> H3> H4, and the diameter of the refrigerant evaporating passage 12a is Da, and the refrigerant evaporating passage When the diameters of 12b and 12f are Db and Df, the diameters of the refrigerant evaporating passages 12c and 12e are Dc and De, and the diameter of the refrigerant evaporating passage 12d is Dd, H1> H2> H3> H4, so Da> Db = Df> Dc = De> Dd.

  Therefore, in the present embodiment, the cross-sectional area A (で Da, Db, Dc, Dd, De, Df) changes in the equation (6) shown in the second embodiment, so that the refrigerant evaporation passage located vertically above The time until the liquid phase refrigerant evaporates is delayed.

  On the other hand, since the position head changes when the vertical height of the refrigerant evaporating passages 12a to 12f increases, the liquid phase refrigerant easily flows into the refrigerant evaporating passages 12a to 12f at lower positions.

  At this time, as described in the first embodiment, it is desirable that there is a difference in refrigerant inflow from the viewpoint of causing an oscillating flow in the refrigerant evaporation passages 12a to 12f, but if the difference in inflow is too large, the motor As a result, there is a significant difference in the cooling performance between the upper part and the lower part of 1. Therefore, in the present embodiment, by increasing the cross-sectional area of the refrigerant evaporation passages 12a to 12f located at higher positions, the amount of liquid-phase refrigerant flowing into each of the refrigerant evaporation passages 12a to 12f is made substantially uniform. ing. Further, by changing the cross-sectional areas of the refrigerant evaporation passages 12a to 12f and changing the time until the refrigerant evaporates, the vibration flow described in the first embodiment is easily caused.

  Therefore, according to the cooling device 10B of the present embodiment, the diameters Da to Df of the plurality of refrigerant evaporation passages 12a to 12f are increased as they are positioned vertically upward, so that the liquid to the refrigerant evaporation passages 12a to 12f is increased. The inflow amount of the phase refrigerant can be made uniform, and the oscillating flow can be generated by changing the cross-sectional area of the refrigerant evaporation passages 12a to 12f and changing the time until evaporation.

  As a result, the flow rate of the liquid-phase refrigerant flowing through the flow path system of the cooling device 10B can be reduced, so that the amount of refrigerant flowing into the refrigerant condensing passages 13a to 13f in the liquid phase is reduced, and thus the refrigerant condensing passage 13a. The condensation efficiency of ˜13f can be improved. As a result, the capacity of the refrigerant condensing passages 13a to 13f can be reduced, and the cooling device 10B can be further downsized.

(Fourth embodiment)
11 to 14 show a fourth 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. 11 is provided with a cooling device. FIG. 12 is a sectional view taken along line DD in FIG.

  As shown in FIGS. 11 and 12, the cooling device 10 </ b> C of this embodiment basically has the same configuration as the cooling device 10 of the first embodiment, and is arranged in parallel inside the reservoir tank 11 and the stator 4. A plurality (six) of refrigerant evaporating passages 12a to 12f, a plurality (six) of refrigerant condensing passages 13a to 13f communicating with the downstream sides of the respective refrigerant evaporating passages 12a to 12f, and an upstream check valve 14 are provided. A refrigerant supply passage 15 provided and a refrigerant recirculation passage 17 provided with a downstream check valve 16 are provided.

  The main difference between the present embodiment and the first embodiment is that at least one of the plurality of refrigerant evaporation passages 12a to 12f has a different length. In particular, in the present embodiment, when the lengths La to Lf of the plurality of refrigerant evaporating passages 12a to 12f are made different, the lengths La to Lf are made longer as they are positioned vertically upward.

  That is, in the cooling device 10C of this embodiment, as shown in FIG. 11, the height of the refrigerant evaporation passage 12a from the arbitrarily set reference position Bh is H1, the height of the refrigerant evaporation passages 12b and 12f is H2, and the refrigerant When the height of the evaporating passages 12c and 12e is H3 and the height of the refrigerant evaporating passage 12d is H4, H1> H2> H3> H4, so that the length of the refrigerant evaporating passage 12a> the length of the refrigerant evaporating passage 12b, The length of 12f> the length of the refrigerant evaporation passages 12c and 12e> the length of the refrigerant evaporation passage 12d.

  At this time, when changing the length of the refrigerant evaporating passages 12a to 12f, as shown in FIG. 12, the length of the longest refrigerant evaporating passage 12a is in the length direction of the stator 4 (left and right direction in the figure). The lengths of the refrigerant evaporating passages 12b and 12f, which are formed by meandering and reciprocating flow paths 12a1 to 12a4, and the next longer refrigerant evaporating passages 12b and 12f, The lengths of the refrigerant evaporating passages 12c and 12e, which are formed by the flow paths 12f1 to 12f3 and are next longer, are formed by the flow paths 12c1 and 12c2 and the flow paths 12e1 and 12e2 that are turned back and forth in the length direction of the stator 4. In addition, the length of the refrigerant evaporation passage 12d that is the shortest is formed by itself (12d) formed in the length direction of the stator 4.

  Therefore, the length of the refrigerant evaporation passage 12a having the height H1 is approximately four times the length of the refrigerant evaporation passage 12d positioned at the lowest vertical position, and the length of the refrigerant evaporation passages 12b and 12f having the height H2 is substantially the same. The length of the refrigerant evaporation passages 12c and 12e, which is three times the height H3, is approximately doubled.

  13 is a right side view of the motor viewed from the direction E of the arrow in FIG. 11, FIG. 14 is a left side view of the motor viewed from the direction of the arrow F in FIG. 11, and as shown in FIG. The branch passages 18a to 18f that connect the refrigerant evaporation passages 12a to 12f are arranged on the right end plate 5E1 side in the drawing as in the first embodiment. Of these branch passages 18a to 18f, the branch passages 18a is connected to the flow path 12a1 of the refrigerant evaporation passage 12a, the branch paths 18b and 18f are connected to the flow paths 12b1 and 12f1 of the refrigerant evaporation paths 12b and 12f, and the branch paths 18c and 18e are connected to the refrigerant evaporation paths 12c and 12e. Connected to the flow paths 12c1 and 12e1, the branch passage 18d is connected to the refrigerant evaporation passage 12d.

  On the other hand, among the communication passages 19a to 19f connecting the refrigerant evaporation passages 12a to 12f and the refrigerant condensation passages 13a to 13f, the communication passages 19a, 19c, and 19e are end plates 5E1 on the right side in the drawing as shown in FIG. The communication passages 19b, 19d, and 19f are arranged on the left end plate 5E2 side in the drawing as shown in FIG.

  As shown in FIG. 13, the communication path 19a is connected to the flow path 12a4 of the refrigerant evaporation path 12a, the communication path 19c is connected to the flow path 12c2 of the refrigerant evaporation path 12c, and the communication path 19e is connected to the refrigerant evaporation path 2e. As shown in FIG. 14, the communication path 19b is connected to the flow path 12b3 of the refrigerant evaporation path 12b, the communication path 19d is connected to the refrigerant evaporation path 12d, and the communication path 19f is connected to the flow path 12e2. It is connected to the flow path 12f3 of the passage 12f.

  In the present embodiment, the plurality of refrigerant evaporation passages 12b to 12f are provided with orifices 21b to 21f whose opening diameter increases as the position of the refrigerant evaporation passage becomes vertically upward.

  That is, as shown in FIG. 11, orifices 21b to 21f are provided in the vicinity of the end plate 5E1 that becomes the inlet portions of the remaining refrigerant evaporating passages 12b to 12f excluding the refrigerant evaporating passage 12a located at the uppermost vertical position, The orifices 21b to 21f are set so that the opening diameter becomes larger as the position of the refrigerant evaporation passage becomes vertically upward.

  At this time, it is formed so that the diameter of the refrigerant evaporation passage 12a> the opening diameter of the orifices 21b and 21f> the opening diameter of the orifices 21c and 21e> the opening diameter of the orifice 21d.

  Therefore, in the present embodiment, the length Ls changes in the expression (6) shown in the second embodiment, so that the time until the liquid-phase refrigerant evaporates is delayed as the refrigerant evaporating passage is positioned vertically upward. .

  On the other hand, since the position head changes when the vertical height of the refrigerant evaporating passages 12a to 12f increases, the liquid phase refrigerant easily flows into the refrigerant evaporating passages 12a to 12f at lower positions.

  At this time, as described in the first embodiment, it is desirable that there is a difference in refrigerant inflow from the viewpoint of causing an oscillating flow in the refrigerant evaporation passages 12a to 12f, but if the difference in inflow is too large, the motor As a result, there is a significant difference in the cooling performance between the upper part and the lower part of 1. Therefore, in this embodiment, the passage areas of the refrigerant evaporation passages 12a to 12f located at higher positions are large, that is, the diameter of the refrigerant evaporation passage 12a> the opening diameter of the orifices 21b and 21f> the opening diameter of the orifices 21c and 21e> the orifice. Since the opening diameter of the refrigerant evaporating passages 12a to 12f is substantially uniform, the refrigerant evaporating passages 12a to 12f are changed in flow area to change the refrigerant area. By changing the time until evaporates, the oscillating flow described in the first embodiment is easily caused.

  Therefore, according to the cooling device 10C of the present embodiment, since at least one of the plurality of refrigerant evaporation passages 12a to 12f has a different length, the refrigerant evaporation passages 12a to 12f having different lengths are used. Since the time required for the liquid-phase refrigerant to evaporate can be changed, an oscillating flow is generated in the refrigerant evaporation passages 12a to 12f as shown in the first embodiment, and the refrigerant condensation passages 13a to 13f Condensation efficiency can be improved and downsizing of the cooling device 10C can be achieved.

  In addition, when the lengths of the plurality of refrigerant evaporating passages 12a to 12f are made different from each other, the lengths of the refrigerant evaporating passages 12a to 12f that are positioned vertically upward are increased. It is possible to efficiently generate an oscillating flow by changing.

  Furthermore, the plurality of refrigerant evaporating passages 12a to 12f are provided with orifices 21b to 21f whose opening diameters increase as they are positioned vertically upward, so that the refrigerant evaporating passages 12a to 12f located at lower positions due to the difference in position heads. Although the liquid-phase refrigerant easily flows into 12f, the inflow amount of the liquid-phase refrigerant into each of the refrigerant evaporation passages 12a to 12f is increased by increasing the passage area of the refrigerant evaporation passages 12a to 12f as it is positioned vertically upward. While making it substantially uniform, the passage time of the refrigerant evaporating passages 12a to 12f can be changed to change the time until the refrigerant evaporates, thereby making it easier to cause an oscillating flow.

  In this embodiment, the orifice is excluded from the refrigerant evaporation passage 12a located at the uppermost vertical position, but the opening diameters of the orifices 21b and 21f provided in the refrigerant evaporation passages 12b and 12f are provided in the refrigerant evaporation passage 12a. Alternatively, an orifice having a larger opening diameter may be provided.

(Fifth embodiment)
15 and 16 show 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. 15 is provided with a cooling device. FIG. 16 is a right side view of the motor viewed from the arrow G in FIG.

  As shown in FIG. 15, the cooling device 10 </ b> D of the present embodiment has basically the same configuration as the cooling device 10 of the first embodiment, and a plurality (6) of the reservoir tank 11 and the stator 4 are arranged in parallel. Main refrigerant evaporating passages 12a to 12f, a plurality of (six) refrigerant condensing passages 13a to 13f communicating with the downstream sides of the respective refrigerant evaporating passages 12a to 12f, and an upstream check valve 14. A supply passage 15 and a refrigerant recirculation passage 17 provided with a downstream check valve 16 are provided.

  The main difference of the present embodiment from the first embodiment is that refrigerant cooling passages 22a to 22f are provided on the upstream side of the plurality of refrigerant evaporation passages 12a to 12f.

  The refrigerant evaporating passages 12a to 12f are connected to the refrigerant supply passage 15 via the branch passages 18a to 18f. In this embodiment, the refrigerant cooling passage 22a is provided between the branch passages 18a to 18f and the refrigerant supply passage 15. To 22f are interposed, and the refrigerant cooling passages 22a to 22f communicate with the upstream sides of the corresponding branch passages 18a to 18f, respectively.

  The refrigerant cooling passages 22a to 22f are configured by providing a large number of fins on the outer periphery of a pipe serving as a passage, similar to the refrigerant condensing passages 13a to 13f, and the outside air and the refrigerant in the passage through the fins. It is designed to exchange heat.

  Therefore, in this embodiment, since the liquid-phase refrigerant cooled by the refrigerant cooling passages 22a to 22f is supplied to the refrigerant evaporation passages 12a to 12f, in the equation (6) shown in the second embodiment, ΔTsub (= (Tsub-T0) increases. As a result, the time during which the oscillating flow described in the first embodiment is sustained is extended, and the flow rate at which the liquid phase refrigerant flows into the refrigerant evaporation passages 12a to 12f can be further reduced as compared with the first embodiment.

  As a result, even when the refrigerant cooling passages 22a to 22f are newly added by the cooling device 10D of the present embodiment, the total area obtained by adding all the refrigerant condensing passages 13a to 13f and the refrigerant cooling passages 22a to 22f is the first implementation. The total area of the refrigerant condensing passages 13a to 13f provided in the cooling device 10 of the embodiment can be made equal to or less, and further downsizing of the cooling device 10D can be further promoted.

  The motor cooling device of the present invention has been described with reference to the first to fifth embodiments. However, the present invention is not limited to these embodiments, and various other embodiments are employed without departing from the spirit of the present invention. For example, the motor 1 is not limited to being used in an in-wheel drive type electric vehicle, and the cooling device of the present invention can be applied to an ordinary motor.

The perspective view of the tire wheel which shows the incorporation state of a motor as an in-wheel drive system concerning 1st Embodiment of this invention. The longitudinal cross-sectional view of the motor which provided the cooling device concerning 1st Embodiment of this invention. Sectional drawing along the AA line in FIG. The right view of the motor seen from the arrow B direction in FIG. The left view of the motor seen from the arrow C direction in FIG. Schematic which simplifies and shows the cooling device of this invention in (a), and the cooling device compared with this invention in (b), respectively. Explanatory drawing which shows the time history of the refrigerant | coolant evaporation channel | path internal temperature of a cooling device shown to Fig.6 (a), a pressure, and the time log | history of the flow volume in a refrigerant | coolant supply channel, respectively. Explanatory drawing which shows the time history of the refrigerant | coolant evaporation channel | path internal temperature of a cooling device shown in FIG.6 (b), a pressure, and the time log | history of the flow volume in a refrigerant | coolant supply channel, respectively. The longitudinal cross-sectional view of the motor which provided the cooling device concerning 2nd Embodiment of this invention. The longitudinal cross-sectional view of the motor which provided the cooling device concerning 3rd Embodiment of this invention. The longitudinal cross-sectional view of the motor which provided the cooling device concerning 4th Embodiment of this invention. Sectional drawing along the DD line in FIG. The right view of the motor seen from the arrow E direction in FIG. The left view of the motor seen from the arrow F direction in FIG. The longitudinal cross-sectional view of the motor which provided the cooling device concerning 5th Embodiment of this invention. The right view of the motor seen from the arrow G in FIG.

Explanation of symbols

1 Motor 2 Rotating shaft 3 Rotor 4 Stator (heat generating part)
5 Housing 10, 10A, 10B, 10C, 10D Cooling device 11 Reservoir tank 12a-12f Refrigerant evaporation passage 13a-13f Refrigerant condensation passage 14 Check valve (first check valve)
15 Refrigerant supply passage 16 Check valve (second check valve)
17 Refrigerant recirculation passage 21b-21f Orifice 22a-22f Refrigerant cooling passage W / A Wheel axle

Claims (9)

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 plurality of refrigerant evaporating passages arranged in parallel in the heat generating part of the motor;
A plurality of refrigerant condensing passages which are respectively communicated to the downstream side of the plurality of refrigerant evaporating passages and are arranged in the low temperature part;
A refrigerant supply passage that distributes and supplies the refrigerant in the reservoir tank to the plurality of refrigerant evaporation passages via a first check valve;
A cooling device for a motor, comprising: a refrigerant recirculation passage that collects the refrigerant that has passed through the plurality of refrigerant condensation passages and returns the refrigerant to the reservoir tank via a second check valve.   The motor cooling device according to claim 1, wherein at least one of the plurality of refrigerant evaporation passages has a different diameter.   The motor cooling device according to claim 1, wherein each of the plurality of refrigerant evaporation passages has a larger diameter as it is positioned vertically upward.   The motor cooling device according to any one of claims 1 to 3, wherein at least one of the plurality of refrigerant evaporating passages has a different length.   The motor cooling device according to any one of claims 1 to 3, wherein each of the plurality of refrigerant evaporation passages has a longer length as it is positioned vertically upward.   The motor cooling device according to any one of claims 1 to 5, wherein the plurality of refrigerant evaporating passages are provided with orifices whose opening diameters increase as they are positioned vertically upward.   The motor cooling device according to any one of claims 1 to 6, wherein the plurality of refrigerant evaporating passages are provided with a refrigerant cooling passage on each upstream side. A motor comprising a rotating shaft, a rotor coupled to the rotating shaft, and a stator surrounding the outer periphery of the rotor,
After the refrigerant stored in the reservoir tank is distributed and supplied to the plurality of refrigerant evaporation passages arranged in parallel to the heat generating portion of the motor via the first check valve, the refrigerant that has passed through the plurality of refrigerant evaporation passages is supplied. The refrigerant is introduced into a refrigerant condensing passage provided on the downstream side of each refrigerant evaporating passage, the refrigerant passing through the plurality of refrigerant condensing passages is collected, and then returned to the reservoir tank via a second check valve. Motor cooling method. 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 plurality of refrigerant evaporating passages arranged in parallel in the heat generating part of the motor;
A plurality of refrigerant condensing passages which are respectively communicated to the downstream side of the plurality of refrigerant evaporating passages and are arranged in the low temperature part;
A refrigerant supply passage that distributes and supplies the refrigerant in the reservoir tank to the plurality of refrigerant evaporation passages via a first check valve;
The motor is provided with a cooling device including a refrigerant recirculation passage that collects the refrigerant that has passed through the plurality of refrigerant condensation passages and returns the refrigerant to the reservoir tank via a second check valve. A vehicle equipped with a motor with a cooling device, which is characterized by being incorporated in the vehicle.

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