JP2011024387A - Cooling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling device capable of achieving a high cooling effect and reducing failure at a heating part inside a casing due to the effect of foreign substance, by employing a structure in which a heating part of a motor coil or the like is cooled by using a cooling medium such as gas or liquid which is sealed up inside the casing and is agitated and heat exchanged. <P>SOLUTION: A casing 14 of a wheel 9 of an in-wheel motor 1 has a substantially sealed structure. Meanwhile, the cooling medium sealed up inside the casing 14 is heat exchanged by a heat exchanger 22 comprising a heat receiving fin 22A (cooling medium is made to flow by an agitator 23) and a heat radiation fin 22B (air is forcedly sent by a blower 25) to cool a heating part such as a coil 2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an apparatus for cooling a heat generating part disposed inside a casing, and more particularly to an apparatus for forcibly cooling a heat generating part with a cooling medium.

  In general, a motor includes a rotor (rotor) and a stator (stator) located on the outer periphery or inner periphery of the rotor. The rotor or stator is a copper having a circular cross section around an iron core. A structure in which a metal wire such as a wire is wound, that is, a coil is provided. In this motor, especially at the time of high load and low speed rotation, coils and the like generate heat, and it is necessary to cool these heat generating portions.

For example, among the motors, a so-called outer rotor type in-wheel motor in which the rotor is located on the outer periphery of the stator is shown in, for example, “IZA” developed by TEPCO, Patent Documents 1 to 3, and the like. Conventionally, a part of the wheel is opened, and a heat generating portion such as a motor coil is exposed to the outside air to cool it.
JP-A-1-298903 JP-A-11-187506 JP 2003-300420 A

  However, in the conventional cooling structure of the heat generating part, for example, the cooling effect is poor because a part of the wheel is opened and the heat generating part such as a coil is exposed to the atmosphere to cool by natural ventilation. In particular, in-wheel motors used in golf carts, construction vehicles, agricultural vehicles, and the like are used at low speeds, and therefore have a small natural ventilation amount and are inferior in cooling effect.

  In addition, since this cooling structure is inferior in the sealing performance of the wheel, in-wheel motors of golf carts that are often used in places with poor environmental conditions such as muddy water, dust, dust, iron powder, sand iron, etc. Since these foreign matters are likely to get on the wheel during traveling, and these foreign matters are likely to enter the inside together with the outside air, which adversely affects the coil and the like.

  The present invention has been made to solve the above-described problems, and uses a cooling medium such as a gas or liquid that is enclosed in a substantially sealed casing and stirred and heat-exchanged. It is possible to obtain a high cooling effect by cooling the heat generating part such as the coil of the coil, and the heat generating part inside the casing due to the influence of foreign matter such as muddy water, dust, dust, iron powder, sand iron, etc. An object of the present invention is to provide a cooling device that reduces the occurrence of failures.

  In order to solve the above-described problem, a cooling device according to a first aspect of the present invention is a device for cooling a heat generating portion disposed inside a casing, and the casing has a substantially hermetically sealed structure and is cooled inside. While enclosing the medium, the casing has an inner heat receiving portion that comes into contact with the cooling medium inside and receives heat from the cooling medium, and an outer heat release that comes into contact with outside air and releases the heat received by the heat receiving portion. And a heat exchanging means provided with a portion, and an agitating means for agitating the cooling medium is disposed inside the casing.

  The cooling device according to a second aspect of the invention is characterized in that the stirring means is a stirrer provided with a rotation driving means and a stirring fan that is rotationally driven by the rotation driving means.

  The cooling device according to a third aspect of the present invention is characterized in that a blowing means for blowing air for forcibly cooling the heat radiating portion is provided outside the casing.

  The cooling device of the invention according to claim 4 is characterized in that the heat generating portion is a heat generating portion of a motor including a stator and a rotor.

  According to a fifth aspect of the present invention, the motor includes an inner stator having a coil and an iron core, and an outer rotor having a permanent magnet and an iron core that is rotatably supported so as to be freely rotatable around the inner stator. And an outer rotor type motor.

  The cooling device of the invention according to claim 6 is an in-wheel motor of an electric vehicle in which the outer rotor type motor is fixedly attached to a wheel holding a tire, and the casing is formed on the wheel. It is characterized by that.

  The cooling device of the invention according to claim 7 is a wheel shaft in which a rotation center shaft of an in-wheel motor of the electric vehicle is fixed, and at least one of the stirring unit and the air blowing unit is attached to the wheel shaft. It is characterized by being able to.

  According to the cooling device of the first aspect of the present invention, the casing has a substantially hermetically sealed structure, while the cooling medium such as gas or liquid enclosed in the casing is provided with a heat receiving unit and a heat radiating unit. Thus, the heat generating part is cooled and the heat generating part is cooled. Therefore, the cooling effect is significantly superior to the cooling structure in which the heat generating part is exposed to the atmosphere and is naturally ventilated.

  In addition, since the agitating means is provided inside the casing, the cooling medium is agitated, and the cooling medium is agitated in this way, so that the cooling medium or the heat receiving part can easily flow, and the heat received by the cooling medium is received by the heat receiving part. Therefore, even if the inside of the casing has a substantially sealed structure, it is difficult for heat to be accumulated and the temperature is not easily raised, and efficient cooling can be performed.

  Further, since the casing has a substantially sealed structure, foreign matters such as muddy water, dust, dust, iron powder, and iron sand are difficult to enter the casing, and the occurrence of failures such as coils due to these foreign matters can be reduced.

  According to the cooling device of the second aspect of the present invention, the stirring means can be easily manufactured from a stirrer provided with a rotation driving means and a stirring fan.

  According to the cooling device of the third aspect of the invention, the external heat radiating portion is blown by the blowing means and is forcibly cooled, so that heat radiation is promoted.

  According to the cooling device of the inventions according to claims 4 and 5, the heat generating part such as a coil of a general motor or an outer rotor type motor can be effectively cooled.

  According to the cooling device of the invention according to claim 6, in-wheel motors used for golf carts, construction vehicles, agricultural vehicles, etc., are used at low speed rotation, but forcibly cooling with a cooling medium, In-wheel motors of these vehicles that are more effective and are often used in places with poor environmental conditions with foreign matters such as muddy water, dust, dust, iron powder, and sand iron, these foreign matters are wheeled while the vehicle is running. Although it is easy to get caught in, it is more effective because it is difficult for foreign matter to enter the wheel.

  According to the cooling device of the invention according to claim 7, since the agitating means and the air blowing means are attached to the fixed wheel shaft, there is no trouble with these attachment parts, and a stable attachment state is obtained. As a result, the stirring operation and the air blowing operation are also ensured.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. As shown in FIG. 1, the cooling device according to the present invention is a device that cools a heat generating portion B disposed inside a casing A. The casing A has a substantially sealed structure and a cooling medium is enclosed therein. On the other hand, the casing A releases the heat received by the heat receiving part C-1 in contact with the outside air and the inner heat receiving part C-1 that receives the heat of the cooling medium in contact with the internal cooling medium. A heat exchanging means C provided with an outer heat radiating part C-2, and a stirring means D for stirring the cooling medium is arranged inside the casing A. Is configured as follows.

  FIG. 2 shows an embodiment of an in-wheel motor cooling system for an electric vehicle as an example of a motor cooling system according to the present invention. That is, as shown in this figure, the in-wheel motor 1 is fixed to the body (not shown) side of an electric vehicle such as a golf cart used in a golf course, and has an inner stator having a coil 2 and an iron core 3. 4 and a motor unit which is supported on the vehicle body side so as to be freely rotatable around the inner stator 4 and includes an outer rotor 7 having a permanent magnet 5 and a rotor yoke 6 as an iron core. 9 is attached.

  A center shaft 10 is fixed to the vehicle body, and a hub 11 is fixed to the center shaft 10. The wheel shaft of the electric vehicle constitutes the rotation center axis of the motor, and the wheel shaft (rotation center axis) of the in-wheel motor 1 is constituted by the center shaft 10 and the hub 11 which are fixed shaft members. It is. Although not shown, the center shaft 10 is also connected to the other wheel.

  The wheel 9 includes a rim member 12 that holds the tire 8 and a casing 14 that is fastened to the rim member 12 with bolts 13 or the like, and is provided around the hub 11 so as to freely rotate. The casing 14 is fastened to the outer lid 14A with a bolt 15 or the like by closing the outer lid 14A on the inner peripheral surface of the outer lid 14A by a bolt 15 or the like. It consists of a substantially cylindrical inner lid 14B.

  The casing 14 of the wheel 9 having the structure described above is inserted around the hub 11 via the support groove 14a of the outer lid 14A and the support hole 14b of the inner lid 14B, and between the outer periphery of the hub 11 and the support groove 14a and the hub 11. It is rotatably supported around the hub 11 by bearings 16 and 17 interposed between the outer periphery and the support hole 14b.

  Further, a seal member 18 composed of a ring-shaped rubber packing or the like is mounted between the outer periphery of the hub 11 at a position close to the inside of the bearing 17 and the support hole 14b. Therefore, the casing 14 of the wheel 9 has a substantially sealed structure, and a cooling medium such as gas or liquid is enclosed therein.

  The inner stator 4 is formed in a ring shape and is provided with a coil 2 formed by winding metal wires around a plurality of winding portions of the iron core 3. The inner stator 4 is fitted on two ring-shaped stator fixing plates 19 and 20 which are fitted and inserted into the periphery of the hub 11 fixed to the center shaft 10 and both ends of the inner stator 4 are spaced apart and fixed to the outer periphery of the hub 11. Fastened by 21 or the like.

  The rotor yoke 6 of the outer rotor 7 is formed in a ring shape, and a large number of magnet grooves (not shown) that penetrate in the axial direction and are arranged at intervals in the inner peripheral surface of the rotor yoke 6. Are formed, and a large number of permanent magnets 5 provided in the magnet grooves are fitted and attached. The outer rotor 7 is assembled to the inner peripheral surface of the outer lid 14.

  Here, the casing 14 receives a large number of heat receiving fins 22A as inner heat receiving portions that come into contact with a cooling medium inside thereof and receive heat from the cooling medium, and heat received by the heat receiving fins 22A in contact with outside air. A heat exchanger 22 is provided as a heat exchanging means provided with a large number of radiating fins 22 </ b> B as outer radiating portions to be discharged.

  In this case, a large number of heat receiving fins 22 </ b> A are integrally formed on the inner surface of the end wall portion of the inner lid 14 </ b> B of the casing 14 in an axial direction, from the center portion to the outer peripheral portion, and in rows along the circumferential direction. Has been provided. On the other hand, a plurality of heat radiation fins 22B are provided on the outer surface of the end wall portion of the inner lid 14B so as to protrude in the axial direction, and are integrally formed in a row from the center portion to the outer peripheral portion and along the circumferential direction. ing.

  The casing 14 includes a plurality of agitators 23 each having a motor 23A as a rotation driving means and a stirring fan 23B that is rotationally driven by the motor 23A as agitation means for agitating the cooling medium inside the casing 14. Is provided.

  Such a stirrer 23 is disposed at a circumferential position in the circumferential direction of the hub 11 between the outer rotor 7 and the heat receiving fin 22A, and each motor 23A is attached to the hub 11 by a mounting member 24. Fan 23B is directed toward heat receiving fin 22A. In this case, the stirring fan 23B is set in a rotational direction such that the cooling medium flows toward the heat receiving fins 22A.

  Further, on the outside of the casing 14, as a blowing means for forcibly cooling the radiating fins 22B, a motor 25A which is a rotation driving means and a fan 25A for rotation driven by the motor 25A are provided. A plurality of blowers 25 provided are provided.

  The blower 25 is disposed at circumferential positions in the hub 11 projecting from the inner lid 14B at intervals along the circumferential direction. Each motor 25A is attached to the hub 11 by a mounting member 26, and the blower fan 25A dissipates heat. It is directed in the direction of the fin 22B. In this case, the blower fan 25A is set in a rotational direction such that air flows toward the heat radiating fins 22B.

  In an electric vehicle equipped with the in-wheel motor 1 having such a configuration, when the coil 2 of the inner stator 4 is energized and excited, the outer rotor 7 rotates around the inner stator 4 and the tire 8 passes through the wheel 9. Rotates and runs.

  Then, a cooling medium such as gas or liquid enclosed in the casing 14 spreads, for example, to a space between adjacent winding portions of the inner stator 4 and a heat generating portion such as between the outer rotor 7 and the inner stator 4, Heat is received by cooling them.

  The agitator 23 inside the casing 14 is driven to rotate the agitating fan 23B when the motor 23A is operated, so that the cooling medium inside the casing 14 is agitated. As the cooling medium is stirred in this manner, the cooling medium or the heat receiving fins 22A can easily flow, and the heat received by the cooling medium is forcibly transferred to the heat receiving fins 22A to facilitate heat conduction.

  The heat of the cooling medium conducted to the heat receiving fins 22A is conducted to the heat radiating fins 22B and radiated. In this case, the blower 25 outside the casing 14 is driven to rotate the blower fan 25B when the motor 25A is operated. Therefore, the blower fan 22B is blown to cool the heat sink fin 22B. Heat is dissipated efficiently.

  Therefore, such an operation is continuously performed, the cooling medium in the casing 14 is maintained at a low temperature by heat exchange, and the heat generating portion is always cooled by the cooling medium.

  In the above configuration, the casing 14 in the wheel 9 of the in-wheel motor 1 has a substantially hermetically sealed structure, while the cooling medium such as gas or liquid enclosed in the casing 14 includes the heat receiving fins 22A and the heat radiating fins 22B. Heat exchange is performed by the heat exchanger 22 provided to maintain the temperature at a low temperature. With this cooling medium, for example, an interval between adjacent winding portions of the inner stator 4 and a heat generating portion such as between the outer rotor 7 and the inner stator 4 are formed. The cooling has the following advantages.

  That is, the cooling effect is far superior to the conventional cooling structure in which the heat generating part is exposed to the atmosphere and naturally ventilated, and effective cooling can be obtained particularly when the in-wheel motor 1 is rotating at a low speed.

  In addition, since the stirrer 23 is provided inside the casing 14, the cooling medium is stirred, and the cooling medium is thus stirred, so that the cooling medium or the heat receiving fins 22A can easily flow as described above. The heat received by the heat transfer fins 22A is forcibly transferred to the heat receiving fins 22A, and heat conduction is facilitated. Therefore, even if the inside of the casing 14 has a substantially hermetic structure, heat is hardly trapped, and temperature rise inside the casing 14 is suppressed. Since the cooling medium can be maintained at a low temperature, efficient cooling can be performed.

  Further, since the external radiating fin 22B is forcedly cooled by being blown by the blower 25, even if the vehicle is traveling at a low speed and the wind generated when the wheel 9 rotates is small, the heat radiating fin 22B is radiated. Is promoted. In addition, when the cooling fin 22B can be sufficiently cooled only by the wind generated when the wheel 9 rotates, the blower 25 may not be provided separately.

  Furthermore, since the casing 14 has a substantially sealed structure, foreign matters such as muddy water, dust, dust, iron powder, and iron sand are less likely to enter the casing 14, and the occurrence of failure of the coil 2 and the like due to these foreign matters can be reduced.

  In the present embodiment, the stirrer 23 and the blower 25 are attached to the fixed wheel shaft (in the present embodiment, the hub 11). As a result, the agitation operation and the air blowing operation can be ensured.

  The stirrer 23 and the blower 25 are not limited to a plurality of units as shown in the embodiment, and may be installed only one unit, and the installation location and attachment site may be anywhere. Further, the positions of the heat receiving fins 22A and the heat radiating fins 22B in the heat exchanger 22 are not limited to the end wall portion of the inner lid 14B as in the embodiment, and may be anywhere in the casing 14, and the fins shown in the embodiment. Not only the form but also other forms of fins may be used. Furthermore, it is not limited to fins, but may be a heat receiving part or a heat radiating part having another structure.

  In addition, the present invention is applied to the outer rotor type in-wheel motor 1, but can be applied to all outer rotor type motors, and may be applied to all other motors.

  In-wheel motors used in golf carts, construction vehicles, agricultural vehicles, etc. are used at low speed, but are more advantageous because they are forcibly cooled by a cooling medium. If a blower is provided, heat can be effectively dissipated even at a low speed. In addition, in-wheel motors and the like of these vehicles that are often used in bad places with environmental conditions with foreign matters such as muddy water, dust, dust, iron powder, and iron sand, it is difficult for these foreign matters to enter the wheel while the vehicle is running. More advantageous.

FIG. 1 is a schematic view showing a cooling device according to the present invention. FIG. 2 is a front cross-sectional view showing an embodiment of a cooling device for an in-wheel motor of an electric vehicle as an example of the above cooling device.

A casing B heat generating part C heat exchanging means C-1 heat receiving part C-2 heat radiating part D stirring means 1 in-wheel motor 4 inner stator 7 outer rotor 9 wheel 14 casing 22A heat receiving fin 22B heat radiating fin 22 heat exchanger 23 stirrer 25 blower

Claims (7)

An apparatus for cooling a heat generating portion disposed inside a casing,
The casing has a substantially hermetically sealed structure, and a cooling medium is sealed in the casing, while the casing is in contact with the cooling medium in the casing and receives heat from the cooling medium, and is in contact with outside air. A heat exchanging means provided with an outer heat dissipating part for releasing the heat received by the heat receiving part, and a stirring means for stirring the cooling medium is provided inside the casing. apparatus.   2. The cooling device according to claim 1, wherein the stirring means is a stirrer including a rotation driving means and a stirring fan that is rotationally driven by the rotation driving means.   The cooling device according to claim 1 or 2, wherein a blowing means for blowing air for forcibly cooling the heat radiation portion is provided outside the casing.   The cooling device according to any one of claims 1 to 3, wherein the heat generating portion is a heat generating portion of a motor including a stator and a rotor.   The motor is an outer rotor type motor including an inner stator having a coil and an iron core, and an outer rotor having a permanent magnet and an iron core that are rotatably supported around the inner stator so as to be freely rotatable. The cooling device according to claim 4.   6. The cooling according to claim 5, wherein the outer rotor type motor is an in-wheel motor of an electric vehicle fixedly attached to a wheel holding a tire, and the casing is formed on the wheel. apparatus.   The rotation center shaft of the in-wheel motor of the electric vehicle is a fixed wheel shaft, and at least one of the stirring means and the air blowing means is attached to the wheel shaft. Cooling system.

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