JP2009148047A - Motor cooling system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor cooling system which can obtain a high cooling effect and can suppress the occurrence of a fault of a coil or the like caused by an influence of muddy water, dust, powdery particles or the like. <P>SOLUTION: Introduction passages (the inside of a center shaft 9, a hole 10a of a hub 10, a hole of 15a of a stator fixing plate 15, and an air space 19) are formed for introducing air fed from a blower 17 to internal surfaces of a coil 2 and an outer rotor 7, air is introduced to an interval between adjacent windings of an inner stator 4 and the internal surface of the outer rotor 7, respectively, the coil 2 and the outer rotor 7 are cooled, and derive-out passages (an air space 20 and a hole 11e of an outer lid 11b) are formed for deriving out air to the outside, thus enhancing the cooling effect of the motor cooling system, and further improving the sealing performance of a motor 1 compared with a prior art. Also, since air is discharged from the hole 11e to the outside, the muddy water, the dust, the powdery particles or the like hardly enters a wheel 8 together with outside air through the hole 11e, and as a result, the coil 2 is not imparted with an unfavorable influence, and the fault hardly occurs. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a system for cooling a heat generating part such as a coil of a motor, and more particularly to a system for cooling the heat generating part with a fluid that is forcibly sent.

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, a coil or the like generates 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 system, a part of the wheel is opened and the motor is cooled by natural ventilation, so that the cooling effect is poor and the sealing property of the wheel is poor. Since dust and the like easily enter the inside and adversely affect the coil and the like, there is a drawback that failure is likely to occur.

  In particular, in-wheel motors used for golf carts, construction vehicles, agricultural vehicles, and the like are used in places where environmental conditions such as muddy water, dust, and dust are bad, so these muddy water, dust, and dust while the vehicle is running. Etc. are easily applied to the wheel, and the above-mentioned drawbacks are more prominent.

  The present invention has been made in order to solve the above-described problems. The heat generating part such as the coil is cooled by a fluid such as air forcedly fed to the motor to obtain a high cooling effect. It is an object of the present invention to provide a motor cooling system that enhances hermeticity and reduces the occurrence of failures such as coils due to the influence of muddy water, dust, and dust.

  In order to solve the above-described problem, the motor cooling system of the invention according to claim 1 is a system for cooling a heat generating portion of a motor including a stator and a rotor, and includes means for supplying a cooling fluid, An introduction passage portion that introduces the cooling fluid supplied from the cooling fluid supply means into the heat generating portion, and a lead-out passage portion that guides the cooling fluid that has passed through the heat generating portion to the outside. And

  In the motor cooling system according to the second aspect of the present invention, the rotation center shaft of the motor is constituted by a fixed shaft member formed hollow, and a part of the introduction passage portion or the lead-out passage portion is formed from the fixed shaft member. It is characterized in that a part of is formed.

  According to a third aspect of the present invention, there is provided a motor cooling system including a fixed hollow shaft member that passes through a rotation center shaft of the motor, and a part of the introduction passage portion or a part of the outlet passage portion from the hollow shaft member Is formed.

  According to a fourth aspect of the present invention, in the motor cooling system, the hollow shaft member is inserted into the fixed shaft member so as to partition the fixed shaft member, and the hollow shaft member and the fixed shaft member are formed in a double structure. It is characterized by that.

  A motor cooling system according to a fifth aspect of the invention is characterized in that a part of the lead-out passage portion is formed from a hole formed in an end wall portion of a member covering the periphery of the motor.

  According to a sixth aspect of the present invention, there is provided a motor cooling system, wherein the motor has an inner stator having a coil and an iron core, and is rotatably supported so as to be freely rotatable around the inner stator, and has a permanent magnet and an iron core. It is an outer rotor type motor provided with an outer rotor.

  According to a seventh aspect of the present invention, there is provided a motor cooling system, wherein the outer rotor type motor is an in-wheel motor of an electric vehicle attached to a wheel holding a tire, and the rotation center axis of the motor is a wheel axis. And the wheel constitutes a member covering the periphery of the motor.

  The motor cooling system of the invention according to claim 8 is configured such that the wiring in the motor is housed inside either the fixed shaft member formed in the hollow or the hollow shaft member and taken out to the outside. It is characterized by.

  According to the motor cooling system of the first aspect of the present invention, a cooling fluid such as air is forcibly sent to cool a heat generating portion such as a coil, for example, so that the cooling effect is excellent. In addition, since it is not configured to cool the heating part by exposing it to the atmosphere, the motor has higher sealing performance than the conventional one, and since the cooling fluid is led out from the hole, etc. It is difficult for muddy water, dust, dust, and the like to enter with the outside air. Eventually, the coil and the like are not adversely affected, and failure is unlikely to occur.

  According to the motor cooling system of the second and third aspects of the present invention, a fixed shaft member and a hollow shaft member that can easily and surely manufacture a part of the introduction passage portion and that does not move are fixed. Since the cooling fluid is introduced and led out, the configuration for introducing and leading the cooling fluid is simple, and the cooling fluid supply means can be installed in a fixed state. Therefore, the configuration can be simplified.

  According to the motor cooling system of the invention of claim 4, the installation space in these motors can be reduced by forming the hollow shaft member and the fixed shaft member in a double structure inside and outside.

  According to the motor cooling system of the fifth aspect of the present invention, a part of the outlet passage portion can be manufactured easily and reliably.

  According to the motor cooling system of the sixth aspect of the present invention, the heat generating portion in the outer rotor type motor can be effectively cooled.

  According to the motor cooling system of the invention of claim 7, the cooling of the heat generating part in the in-wheel motor used in golf carts, construction vehicles, agricultural vehicles, etc., where muddy water, dust, dust, etc. are easily applied to the wheel. In addition to being able to perform more effectively, the rotation center axis of the motor can be easily configured by the wheel shaft, and the holes constituting the lead-out passage portion can be easily configured by the wheel covering the periphery of the motor.

  According to the motor cooling system of the eighth aspect of the present invention, there is no need to separately provide holes or grooves for leading the wires to the outside, the configuration can be simplified, and the sealing performance of the motor can be further improved. As a result, the cooling effect can be enhanced.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
A motor cooling system according to the present invention, that is, a system for cooling a heat generating portion of a motor including a stator and a rotor, as shown in FIG. 1, includes cooling fluid supply means, and from this cooling fluid supply means, An introduction passage portion for introducing the supplied cooling fluid into the heat generation portion of the motor, and a lead-out passage portion for deriving the cooling fluid that has passed through the heat generation portion to the outside. The configuration is as follows.

  FIG. 2 shows a first 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 (see FIG. 3) and an outer rotor 7 (see FIG. 4) that is pivotally supported on the vehicle body side so as to be freely rotatable around the inner stator 4 and has a permanent magnet 5 and a rotor yoke 6 as an iron core. The motor unit is attached to a wheel 8 (a member covering the periphery of the motor as referred to in the present invention) holding a tire (not shown).

  A hollow center shaft 9 is fixed to the vehicle body, and a substantially cylindrical hub 10 (see FIG. 5) is fitted and fixed to the outer peripheral surface of the center shaft 9. In addition, said wheel shaft comprises the rotation center axis | shaft of the motor said by this invention, and the wheel shaft (rotation center axis | shaft) of the in-wheel motor 1 is a fixed shaft member formed hollow. The center shaft 9 and the hub 10 are included.

  The wheel 8 is rotatably provided around the hub 10. The wheel 8 includes a body 11 (see FIG. 6) in which the outer rotor 7 is assembled on an inner peripheral surface, and an inner lid 12 (see FIG. 7) as an end wall portion that closes an opening of the body 11 on the vehicle body inner side. ).

  As shown in FIG. 6, the body 11 includes a cylindrical body wall portion 11a and an outer lid portion 11b as an end wall portion located on the outer side of the vehicle body, and the center of the outer lid portion 11b. A support groove 11c is formed on the inner surface of the part.

  As shown in FIG. 7, the inner lid 12 is formed in a plate shape, and an outer peripheral end portion is integrally formed with a flange portion 12a projecting outward perpendicular to the central axis, and a support hole is formed in the central portion. 12b is established. The inner lid 12 is assembled to the inner end surface of the body wall portion 11a of the body 11 and fastened with a bolt or the like.

  The wheel 8 having the structure described above is inserted around the hub 10 via the support groove 11c and the support hole 12b, and between the outer periphery of the hub 10 and the support groove 11c and between the outer periphery of the hub 10 and the support hole 12b. Are rotatably supported around the hub 10 by bearings 13 and 14 respectively interposed in the hub 10. Reference numeral 26 denotes an airtight seal composed of rubber packing or the like.

  As shown in FIG. 3, the inner stator 4 is formed in a ring shape and is provided with a coil 2 formed by winding a metal wire around a plurality of winding portions 3 a of the iron core 3. The inner stator 4 has two ring-shaped stator fixing plates 15 and 16 (see FIG. 8) which are fitted and inserted into the periphery of the hub 10 fixed to the center shaft 9 and located at both ends of the inner periphery. Fastened to both ends of the outer periphery of the hub 10 with bolts or the like.

  As shown in FIG. 4, the rotor yoke 6 of the outer rotor 7 is formed in a ring shape, and the inner surface of the rotor yoke 6 penetrates in the axial direction and is arranged for a large number of magnets arranged at intervals. Grooves 6a are formed, and a large number of permanent magnets 5 provided in the magnet grooves 6a are fitted and attached.

  The outer rotor 7 is assembled to the inner peripheral surface of the body wall portion 11a of the body 11. That is, as shown in FIG. 6, a step portion 11d is formed on the inner peripheral surface of the body wall portion 11a, and the outer rotor 7 set on the step portion 11d is connected to the body wall portion 11a of the body 11 as described above. It is pressed and fixed by the flange portion 12a of the inner lid 12 fastened with bolts or the like. Although not shown, the tire is disposed on the outer periphery of the wheel 8 and its inner inner peripheral end and outer outer peripheral end are pressed and fixed by a rim member (not shown).

  Here, in FIG. 2, the center shaft 9 is also connected to the wheel of the other wheel (not shown), and the cooling fluid is supplied to the inside from the intermediate portion in the longitudinal direction. In this case, a discharge port of an air supply blower 17 serving as a means for supplying a cooling fluid and a supply port 9a formed at, for example, an intermediate portion in the longitudinal direction of the center shaft 9 are connected via an air supply path 18. Is done.

  On the other hand, a portion of the hub 10 to which the inner stator 4 is attached is formed with a plurality of holes 10a penetrating the inner end thereof in communication with the inside of the center shaft 9 and opening the outer end at intervals in the circumferential direction. . The stator fixing plate 15 at the inner end of the inner stator 4 has an inner end communicating with the hole 10 a of the hub 10 and an outer end formed between the inner lid 12 and the inner end face of the inner stator 4. A plurality of holes 15a communicating with the space portion 19 are formed in the circumferential direction with a space therebetween.

  Further, the outer end of the outer lid portion 11b communicates with the space portion 20 formed between the outer lid portion 11b and the outer end surface of the inner stator 4 at the outer end, and the outer end is outside (the outer side of the wheel 8). A plurality of holes 11e opened in the circumferential direction are formed at intervals in the circumferential direction.

  Therefore, the introduction passage portion for introducing the air as the cooling fluid supplied from the blower 17 into the heat generating portion, that is, the inner peripheral surface of the coil 2 and the outer rotor 7 is provided inside the center shaft 9, the hole 10 a of the hub 10, The hub 10 and the inner stator 4, the hole 15 a of the stator fixing plate 15, and the space 19 are formed. The lead-out passage portion for leading the air that has passed through the coil 2 and the inner peripheral surface of the outer rotor 7 to the outside is composed of a space portion 20 and a hole 11e in the outer lid portion 11b.

  In the electric vehicle equipped with the in-wheel motor 1 having such a configuration, if the coil 2 of the inner stator 4 is energized to excite it, the outer rotor 7 rotates around the inner stator 4 and the tire passes through the wheel 8. Rotate and run.

  When the blower 17 is started, the air discharged from the blower 17 is supplied into the center shaft 9 through the air supply path 18 as indicated by an arrow A shown in FIG. The adjacent winding of the inner stator 4 reaches the hole 10a, the space between the hub 10 and the inner stator 4 and the hole 15a of the stator fixing plate 15, the space 19 between the inner lid 12 and the inner stator 4. The space between the portions 3a and between the outer rotor 7 and the inner stator 4 are introduced and cooled by passing through these. Then, the air discharged from the space between the winding portions 3a and between the outer rotor 7 and the inner stator 4 passes through the space portion 20 as shown by the arrow B shown in FIG. 2, and then the hole 11e of the outer lid portion 11b. Derived from the outside.

  Next, a second embodiment will be described with reference to FIG. In this embodiment, the air introduction direction and the derivation direction are opposite to the air introduction direction and the derivation direction shown in the first embodiment.

  That is, the inner end of the stator fixing plate 16 at the inner end of the inner peripheral portion of the inner stator 4 communicates with the hole 10 a of the hub 10, and the outer end is formed between the outer lid portion 11 b and the outer end face of the inner stator 4. A plurality of holes 16a communicating with the space 20 to be formed are formed through the circumferential direction at intervals. In addition, the outer end of the inner lid 12 communicates with a space portion 19 formed between the inner lid 12 and the inner end surface of the inner stator 4, and the outer end is arranged outside (inward direction of the wheel 8). A plurality of holes 12c that are opened in a circumferential direction are formed at intervals in the circumferential direction.

  Accordingly, the air discharged from the blower 17 (see FIG. 2) flows from the center shaft 9 into the hole 10a of the hub 10, between the hub 10 and the inner stator 4 and the stator as indicated by the arrow A shown in FIG. It reaches the hole 16a of the fixed plate 16 and the space 20 and is introduced between the adjacent winding portions 3a of the inner stator 4 and between the outer rotor 7 and the inner stator 4 to cool them. And the air discharged | emitted from these is derived | led-out outside from the hole 12c of the inner cover 12 through the space part 19, as the arrow B shown in FIG.

  Next, a third embodiment will be described with reference to FIG. This embodiment will be described later in place of the configuration in which cooling air is introduced from the center shaft 9 and the configuration in which the cooling air is led out from the outer lid portion 11b and the inner lid 12 as in the first and second embodiments. In this configuration, the hollow shaft 22 and the center shaft 9 are used to introduce and lead out cooling air.

  That is, the hub 21 is fixed to the center shaft 9, the wheel 8 is supported by the bearing 14, the hub divided body 21 a to which the inner stator 4 is fixed by the stator fixing plate 15, and the wheel 8 is supported by the bearing 13. And it is divided into two and divided into a hub divided body 21b to which the inner stator 4 is fixed by the stator fixing plate 16, and is arranged facing each other with a gap.

  Moreover, the hollow shaft 22 as a hollow shaft member which passes along the rotation center axis | shaft of the in-wheel motor 1 is provided, and it is comprised from the shaft part 22a and the flange part 22b integrally formed in the end. The shaft portion 22a of the hollow shaft 22 is inserted into the center shaft 9, and the flange portion 22b is disposed in the space between the hub divided body 21a and the hub divided body 21b so that the inner peripheral surface of the inner stator 4 Connected to In this embodiment, holes 15a and 16a are provided in both stator fixing plates 15 and 16.

  Accordingly, the hollow shaft 22 divides the inside of the center shaft 9 into the inner passage 9A and the outer passage 9B, and communicates the inside of the wheel 8 with the inner passage 9A and through the hole 16a of the stator fixing plate 16. The space portion 23 communicates with the outer passage 9 </ b> B, and the space portion 24 communicates via the hole 15 a of the stator fixing plate 15.

  On the other hand, a discharge port of the blower 17 (see FIG. 2) and a supply port (not shown) formed at, for example, an intermediate portion in the longitudinal direction of the hollow shaft 22 are connected to supply air to the inner passage 9A. The center shaft 9 is formed with an outlet 9b, and the outer passage 9B is opened to the atmosphere via the outlet 9b.

  The air discharged from the blower 17 (see FIG. 2) reaches the space portion 23 from the inner passage 9A and the hole 16a of the stator fixing plate 16 as indicated by an arrow A shown in FIG. The space | interval part of adjacent coil | winding parts and between the outer rotor 7 and the inner stator 4 are introduce | transduced, and these are cooled. And the air discharged | emitted from these passes along the space part 24 as shown by the arrow B shown in FIG. 10, reaches the outer channel | path 9B from the hole 15a of the fixing plate 15, and is derived | led-out outside from the exit 9b.

  In addition, you may arrange | position these separately, without inserting the hollow shaft 22 in the center shaft 9 inside. Further, the direction of air introduction and derivation may be opposite to those in the embodiment. That is, the center shaft 9 may be used for introducing air, and the hollow shaft 22 may be used for extracting air.

  In each of the embodiments described above, air is forcibly sent into the in-wheel motor 1, for example, the interval between adjacent winding portions 3 a of the inner stator 4, that is, the inner periphery of the coil 2 and the outer rotor 7, etc. The heat generating part is cooled so that the cooling effect is excellent. Further, for example, since the holes 11e and 12c for exhausting air are formed, and the heating part such as the coil 2 is not cooled by exposing it to the atmosphere, the sealing performance of the wheel 8 is conventionally Compared to the above, the air is exposed to the outside from the holes 11e, 12c, etc., so that muddy water, dust, dust and the like together with the outside air from these holes 11e, 12c are difficult to enter the wheel 8. It is difficult to cause a failure.

  In particular, the in-wheel motor 1 used in the golf cart, the construction vehicle, the agricultural vehicle, and the like employed in the present embodiment is used in a place that is bad for environmental conditions such as muddy water, dust, and dust. Although these muddy water, dust, dust and the like are likely to be applied to the wheel, the above-described configuration of the cooling system of the present invention is more effective because these muddy water, dust, dust and the like are less likely to enter the wheel 8.

  Moreover, in this embodiment, since the center shaft 9 and the hollow shaft 22 are used to constitute a part of the introduction passage part, a part of the introduction passage part can be easily and reliably manufactured. Moreover, since the air is introduced and led out using the center shaft 9 and the hollow shaft 22 that are fixed and do not move, the configuration for introducing and leading the air is simple, and the blower 17 and the like are also fixed. There is an advantage that it can be installed, and the configuration can be simplified.

  Furthermore, since a part of the outlet passage portion is formed by the holes 11e and 12c formed in the wheel 8, a part of the outlet passage portion can be easily and reliably manufactured. Further, in the third embodiment of FIG. 10, the hollow shaft 22 and the center shaft 9 are formed in a double structure inside and outside, so that there is an advantage that the installation space in these in-wheel motors 1 can be reduced. .

  In addition, it is good to set it as the structure which accommodates the wiring in the in-wheel motor 1 in either one of the center shaft 9 or the hollow shaft 22, and takes out outside (4th Embodiment).

  That is, as shown in FIG. 2, for example, the wiring 25 of the coil 2 is inserted into the center shaft 9 between the inner lid 12 and the inner stator 4, through the hole 15a of the stator fixing plate 15, and the hole 10a of the hub 10. And it is set as the structure taken out from here. In addition, it is good also as a structure which accommodates the wiring of a coil in the hollow shaft 22 shown in 3rd Embodiment of FIG. 10, and takes out outside. As a result, it is not necessary to separately provide holes or grooves for leading the wiring to the outside of the wheel 8 and the like, the structure can be simplified, and the sealing performance of the wheel 8 can be further improved. The cooling effect by air can be enhanced.

  In the above embodiment, the present invention is applied to the outer rotor type in-wheel motor 1. However, the present invention may be applied to all other motors, and the introduction passage portion and the discharge passage portion are shown in the embodiment. The configuration is not limited to that, and other configurations may be used. Furthermore, the cooling fluid is not limited to air, but may be other gas or liquid.

  The coil and other heat generating parts are cooled by air or other fluid that is forcibly sent to the motor to obtain a high cooling effect and to improve the motor's sealing performance. Since generation | occurrence | production can be reduced, it becomes advantageous to in-wheel motors, such as a golf cart used in a place with bad environmental conditions, a construction vehicle, and an agricultural vehicle.

FIG. 1 is a schematic diagram showing a motor cooling system according to the present invention. FIG. 2 is a front cross-sectional view showing first and fourth embodiments of an in-wheel motor cooling system for an electric vehicle as an example of a motor cooling system according to the present invention. FIG. 3 is a side view of an inner stator in the in-wheel motor same as above. FIG. 4 is a side view of the outer rotor in the in-wheel motor same as above. FIGS. 5A and 5B show a hub in the in-wheel motor same as above, wherein FIG. 5A is a left side view, FIG. 5B is a front view, and FIG. 5C is a right side view. FIG. 6 shows the body of the wheel in the in-wheel motor same as above, (a) is a left side view, and (b) is a front sectional view. FIG. 7 shows the inner lid of the wheel in the in-wheel motor same as above, (a) is a front sectional view, and (b) is a right side view. 8A and 8B are side views showing a stator fixing plate in the in-wheel motor same as above. FIG. 9 is a front cross-sectional view showing a second embodiment of the cooling system for the in-wheel motor of the electric vehicle. FIG. 10: is front sectional drawing which shows 3rd Embodiment of the cooling system of the in-wheel motor of an electric vehicle same as the above.

Explanation of symbols

1 in-wheel motor 4 inner stator 7 outer rotor 8 wheel 9 center shaft 9A inner passage 9B outer passage 9a supply port 9b outlet 10 hub 17 blower 10a hole 11b outer lid portion 11e hole 12 inner lid 12c hole 15 stator fixing plate 15a hole 16 Stator fixing plate 16a Hole 19 Space portion 20 Space portion 21a Hub divided body 21b Hub divided body 22 Hollow shaft 23 Space portion 24 Space portion 25 Wiring

Claims (8)

A system for cooling a heat generating part of a motor including a stator and a rotor,
A means for supplying a cooling fluid; an introduction passage portion for introducing the cooling fluid supplied from the cooling fluid supply means into the heat generating portion; and a derivation for extracting the cooling fluid that has passed through the heat generating portion to the outside. And a motor cooling system.   The rotation center shaft of the motor is constituted by a fixed shaft member formed hollow, and a part of the introduction passage portion or a part of the lead-out passage portion is formed from the fixed shaft member. The motor cooling system according to claim 1.   3. A fixed hollow shaft member that passes through a rotation center shaft of the motor is provided, and a part of the introduction passage part or a part of the lead-out passage part is formed from the hollow shaft member. The motor cooling system described.   4. The motor cooling according to claim 3, wherein the hollow shaft member is inserted into the fixed shaft member so as to partition the fixed shaft member, and the hollow shaft member and the fixed shaft member are formed in a double structure. system.   The motor cooling system according to any one of claims 1 to 4, wherein a part of the lead-out passage portion is formed from a hole formed in an end wall portion of a member that covers the periphery of the motor.   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 motor cooling system according to any one of claims 1 to 5, wherein:   The outer rotor type motor is an in-wheel motor of an electric vehicle attached to a wheel holding a tire, the rotation center axis of the motor is a wheel axis, and the wheel constitutes a member that covers the periphery of the motor The motor cooling system according to claim 6.   The wiring in the motor is configured to be housed in either the fixed shaft member formed in the hollow or the hollow shaft member and taken out to the outside. The motor cooling system according to one.

Images