JP5534934B2 - In-wheel motor cooling structure - Google Patents

Description

  The present invention relates to a cooling structure for an in-wheel motor that directly drives a vehicle wheel.

  2. Description of the Related Art Conventionally, an in-wheel motor is known as a vehicle driving device in which a motor is provided inside a wheel and the wheel is directly driven by the motor. In-wheel motors have a problem of energy loss due to heat generation in the motor at high speed and high load, and various measures are taken for cooling the motor. For example, in the one disclosed in Patent Document 1, in order to cool the motor, the shape of the under cover of the vehicle body is changed to form a duct, and the running wind is drawn into the in-wheel motor part through the duct to cool the motor by air cooling. It is cooling. In addition, in the device disclosed in Patent Document 2, a fan is provided beside a brake disk disposed adjacent to the in-wheel motor in order to cool the outer rotor type motor, and an air flow is supplied by the fan to cool the motor. ing.

Japanese Patent Laid-Open No. 2005-199828 JP 2006-57732 A

  However, in the technique disclosed in Patent Document 1, it is necessary to change the shape of the under cover (and suspension etc.) of the vehicle body in order to install the duct, leading to high costs. By providing the duct, the traveling wind can be guided to the in-wheel motor unit, but the wind flow around the in-wheel motor unit cannot be controlled. This limits the effect on cooling.

  Further, in the technique disclosed in Patent Document 2, since the fan is provided beside the brake disk, the mountability of the in-wheel motor may be deteriorated. In addition, the cost may increase due to an increase in the number of parts, and the running performance may be adversely affected due to an increase in unsprung weight.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a cooling structure for an in-wheel motor that has a simple structure and is low in cost, small and light, and has a high cooling effect.

In order to solve the above problems, the in-wheel motor cooling structure according to the first aspect of the present invention is characterized in that a casing that rotatably supports a wheel that constitutes an electric wheel of a vehicle is rotatably mounted, and the wheel is mounted in the casing and drives the wheel. An in-wheel motor cooling structure for cooling the motor of the electric wheel device comprising: a rotor support plate fixed to a rotor fixing portion formed on the wheel and supporting the brake rotor; and the rotor support plate A cylindrical portion that is formed separately from the rotor fixing portion and is fixed between the rotor support plate and a portion of the casing that is separated from the end face of the casing by a predetermined distance and surrounds the portion of the casing. And fixed to the inner peripheral surface of the cylindrical portion so as to face the casing, and contact the surface of the casing A blower for introducing a gas stream, is that with the.

The invention of the in-wheel motor cooling structure according to claim 2 is characterized in that, in claim 1, the air that allows passage of the air flow introduced by the blower to at least one of the cylindrical portion and the rotor fixing portion. hole is provided, is Rukoto introduced between said portion of said casing and said cylindrical portion and the part of the brake cooling air induced in the wheel by the blower to cool the brake rotor .

The in-wheel motor cooling structure according to claim 3 is characterized in that, in claim 1 or 2, the in-wheel motor cooling structure is disposed on the outer diameter side of the outer peripheral surface of the cylindrical portion and fixed to the vehicle body of the vehicle. A vehicle body side cylindrical member that rotatably supports the cylindrical portion via a ball bearing interposed between the cylindrical portion and the outer peripheral surface is provided .

  According to the first aspect of the present invention, the air flow is transmitted between the casing and the cylindrical portion by a small and low-cost air blower which can be mounted between the casing and the cylindrical portion surrounding the portion of the casing separated from the end face of the casing by a predetermined distance. The casing is actively introduced to cool the casing, and thus the motor mounted in the casing can be effectively cooled.

According to the invention of claim 2, since a part of the brake cooling air supplied to cool the brake can be introduced between the casing and the cylindrical portion and used, a sufficient amount of air can be secured and stably. The motor can be reliably cooled. At this time, when the air flow is introduced between the casing and the cylindrical portion by the blower, air can be effectively discharged from the air hole provided in at least one of the cylindrical portion and the rotor fixing portion. The flow is increased smoothly and the motor cooling effect is further improved.

According to the invention of claim 3, the vehicle body side cylindrical member rotatably supports the cylindrical portion, that is, the wheel to which the cylindrical portion is fixed, via the ball bearing. Thus, the wheel is supported and stabilized not only by the casing but also by the vehicle body side cylindrical member.

It is the schematic diagram (side view) which showed the structure of the electric wheel apparatus containing the cooling structure of the in-wheel motor which concerns on 1st Embodiment. It is a front view of the fan concerning this embodiment. It is the schematic diagram (side view) which showed the structure of the electric wheel apparatus containing the cooling structure of the in-wheel motor which concerns on 2nd Embodiment.

  Hereinafter, a first embodiment of an electric wheel device for a vehicle including an in-wheel motor cooling structure according to the present invention will be described based on a schematic diagram of FIG. As shown in FIG. 1, the electric wheel device 10 includes a wheel 11 that constitutes an electric wheel, a tire (not shown), a casing 24, a motor 30 that drives the wheel 11, a speed reducer 21, and a brake device 14. And an in-wheel motor cooling structure 20.

  The wheel 11 includes a wheel disc 12 and a wheel hub 13. The wheel 11 is rotatably supported by the casing 24, and a motor 30 and a speed reducer 21 are accommodated in the casing 24.

  The wheel disc 12 has a substantially cup shape and includes a disc portion 12a and a rim portion 12b. A tire (not shown) is fixed to the outer edge of the rim portion 12b. The wheel disc 12 has a disc portion 12a fastened to the wheel hub 13 by a hub bolt (not shown).

  The casing 24 is attached to a vehicle suspension mechanism (not shown) such that the wheel 11 faces the outside of the vehicle. The casing 24 is formed by two large and small cylindrical portions 26 and 27 having different diameters that are coaxially aligned in the axial direction extending in the left-right direction in FIG. The two cylindrical portions 26 and 27 have accommodation spaces 26a and 27a, respectively. Of the two cylindrical portions 26 and 27, a motor 30 is disposed in the accommodating space 26a of the cylindrical portion 26 having a large cylindrical diameter located on the right side in FIG. 1 so that the axis of the cylindrical portion 26 and the rotation axis are coaxial. The outer peripheral surface 30a is fixed to the cylindrical inner peripheral surface 26b of the cylindrical portion 26 by a predetermined means.

  As shown in FIG. 1, the motor 30 has a rotating shaft 32, a rotor 33, and a stator 34. The rotating shaft 32 is rotatably supported at both ends by an inner ring of a ball bearing 40 that is a bearing. Of the ball bearings 40 that support the rotating shaft 32, the outer ring of the right ball bearing 40 in FIG. 1 is fitted to the inner peripheral surface of a cylindrical protrusion 24c that protrudes leftward from the right side surface of the casing 24 in FIG. Has been.

  In FIG. 1, the outer ring of the left ball bearing 40 is fitted to the annular inner peripheral surface of the annular member 44 accommodated in the accommodating space 27 a of the cylindrical portion 27, and the annular outer peripheral surface of the annular member 44 is The cylindrical inner peripheral surface 27b is fitted.

  The stator 34 having the outer peripheral surface 30a of the motor 30 has a stator core 34a and a stator coil 34b. The stator core 34a has an outer peripheral surface 30a fixed to the inner peripheral surface 26b of the cylindrical portion 26 of the casing 24, and the stator coil 34b is wound around the stator core 34a. When motor 30 is a three-phase motor, stator coil 34b includes a U-phase coil, a V-phase coil, and a W-phase coil.

  Further, the rotor 33 is disposed on the inner diameter portion of the stator core 34a and the stator coil 34b and is formed integrally with the rotary shaft 32. The stator core 34a and the cylindrical portion 26 are each formed of a material having an appropriate thermal conductivity. Thereby, the heat generated in the motor 30 is quickly moved from the outer peripheral surface 30a of the stator core 34a to the casing 24 via the cylindrical inner peripheral surface 26b, and the motor 30 is efficiently cooled.

  Of the two cylindrical portions 26 and 27, the planetary gear mechanism 36, which is a reduction gear, is placed in the accommodating space 27 a of the cylindrical portion 27 having a small cylindrical diameter located on the left side in FIG. It is arranged to be coaxial.

  The planetary gear mechanism 36 is disposed between the motor 30 and the wheel hub 13. The planetary gear mechanism 36 decelerates the rotational speed of the motor 30 input by the rotary shaft 32 described above. The planetary gear mechanism 36 includes a sun gear 38, a ring gear 39, and a carrier 37 that rotatably supports a plurality of planetary gears 41.

  A sun gear shaft, which is a rotation shaft of the sun gear 38, is formed integrally with the rotation shaft 32 of the motor 30, and is rotatably supported by the ball bearing 40 on the cylindrical inner peripheral surface 27 b of the cylindrical portion 27. The sun gear 38 is integrally formed coaxially with the end of the rotating shaft 32 of the motor 30, and the ring gear 39 is coaxial with the sun gear 38 and is disposed on the outer peripheral side of the sun gear 38 and is formed on the cylindrical inner peripheral surface 27 b of the cylindrical portion 27. The outer periphery is fitted.

  The carrier 37 is constituted by a main body 37a and four rotating shafts 37c having one end fixed to the main body 37a. The main body 37a has a shaft portion 43 supported by a ball bearing 35. The ball bearing 35 has an outer ring fitted on the inner peripheral surface of a cylindrical opening 28 on the left side of the casing 24 in FIG. The portion 43 is rotatably supported.

  A planetary gear 41 that meshes with the sun gear 38 and the ring gear 39 is rotatably supported on each rotary shaft 37c via a bearing (not shown). The shaft portion 43 of the carrier 37 is an output shaft of the planetary gear mechanism 36.

  In the present embodiment, it has been described that four planetary gears 41 are provided on the outer periphery of the sun gear 38 at equal intervals, for example, but the number is not limited to this, and any number may be provided. An oil seal 47 is provided between the ball bearing 35 and the wheel hub 13. The oil seal 47 is provided between the shaft portion 43 and the inner peripheral surface of the opening portion 28 of the casing 24.

  The brake device 14 includes a brake rotor 14a and a brake caliper 14b. The brake rotor 14a is supported by a rotor support plate 17 having a cup shape with a hook in the axial cross section. The rotor support plate 17 includes a mounting wall 17a corresponding to the cup-shaped bottom surface, a side wall 17b corresponding to the cup-shaped side surface, and a rotor fixing wall 17c for fixing and supporting the brake rotor 14a corresponding to the flange portion. Yes. The mounting wall 17 a is fixed to the side surface 15 a on the wheel 11 side of the rotor fixing portion 15 formed in the wheel hub 13 constituting the wheel 11. The brake rotor 14 a is disposed so as to pass through the brake caliper 14 b and rotates with the rotation of the wheel 11.

  The brake caliper 14b is a part fixed to the vehicle body side, and a part thereof is fixed to the outer peripheral surface 26c of the casing 24 (not shown). The brake caliper 14b has a brake piston (not shown) and brake pads 14c and 14d. The brake pads 14c and 14d are provided to sandwich both surfaces of the brake rotor 14a. When brake oil is supplied to the brake caliper 14b, the brake pads 14c and 14d sandwich the both surfaces of the brake rotor 14a by applying the brake piston, and brake the brake rotor 14a, thereby braking the electric wheel.

  Next, the in-wheel motor cooling structure 20 according to the present invention will be described. The in-wheel motor cooling structure 20 surrounds the cylindrical portion 27 that is a portion of the casing 24 that is separated from the right end surface of the casing 24 leftward by a predetermined distance in FIG. 1 coaxially with the casing 24 and the cylindrical portion 27. A cylindrical portion 22 fixed to the rotor fixing portion 15, and a fan 23 as a blower fixed to the inner peripheral surface 22 a of the cylindrical portion 22 so as to face the outer peripheral surface 27 c of the cylindrical portion 27. The fan 23 is for introducing air, bringing the air into contact with the outer peripheral surface 27c of the cylindrical portion 27, and removing heat from the outer peripheral surface 27c. Since the fan 23 is provided on the inner peripheral surface of the cylindrical portion 22 rotated by the rotation of the motor 30 and is configured to generate an air flow by rotating together with the cylindrical portion 22, there is no need to provide a drive source independently. Only the rotor blade 23 which will be described later is provided, and the configuration can be reduced in size, weight and cost.

  The rotor fixing portion 15 to which the cylindrical portion 22 is fixed is formed on the wheel hub 13 constituting the wheel 11. The cylindrical portion 22 extends rearward on the right side in FIG. 1 with the rotor fixing portion 15 as a base point. The extending length of the cylindrical portion 22 is arbitrary, but the gap between the extended end point 22c of the cylindrical portion 22 and the connection wall 29 that connects the cylindrical portions 26 and 27 of the casing 24 is a predetermined value or more. It is desirable to be. Here, the predetermined value is a size of a gap that can supply a desired amount of air between the inner peripheral surface 22a of the cylindrical portion 22 and the outer peripheral surface 27c of the casing 24 by the operation of the fan 23. Find it.

  An air guide rod 31 having the end point 22c as a base point is provided from the end point 22c of the cylindrical part 22 over the entire circumference of the cylindrical part 22 in the circumferential direction. The air guide rod 31 is formed in a direction slightly away from the end line 22c of the cylindrical portion 22 from the axis of the cylindrical portion 22 and slightly rearward to the right in FIG. And the gap between the connection wall 29 and the wall surface of the air guide rod 31 facing the connection wall 29 is formed to have a predetermined value or more, like the gap between the end point 22c of the cylindrical portion 22 and the connection wall 29. ing. Thereby, in the vicinity of the cylindrical portion 22, a part of the brake cooling air W to be described later that moves from the right to the left in FIG. 1 in the axial direction of the cylindrical portion 22 collides with the wall surface of the air guide rod 31, Further, it is guided by the wall surface of the air guide rod 31 and moves in a direction approaching the axis, and is effectively introduced into the air passage 19 described later. In addition, even if the air guide rod 31 is not provided, a corresponding effect can be obtained, so that it is not necessary.

  The fan 23 as a blower is provided coaxially with the cylindrical portion 22 and at an arbitrary position in the axial direction of the cylindrical portion 22 over the entire circumference of the inner peripheral surface 22a. As shown in FIG. 2, the fan 23 includes a ring portion 23 a that is fitted and fixed to the inner peripheral surface 22 a of the cylindrical portion 22, and a plurality of rotor blades 23 b that are arranged at regular intervals on the inner peripheral portion of the ring portion 23 a. It has. In this embodiment, the fan 23 is a so-called axial flow type fan in which air flows in and out in parallel with the rotation axis when rotating around the rotation axis together with the cylindrical portion 22. As described above, the fan 23 as a blower device has a simple configuration, and can be made compact and lightweight at a low cost.

  In a state where the fan 23 is fixed to the inner peripheral surface 22 a of the cylindrical portion 22, the inner peripheral space of the fan 23, that is, the space closer to the rotating shaft than the tip of the rotary blade 23 b, and the casing 24 facing the fan 23 The aforementioned air passage 19 having a predetermined gap is formed between the outer peripheral surface 27c. In the air passage 19, fins 25 are provided on the outer peripheral surface 27 c of the cylindrical portion 27 in order to increase the surface area of the outer peripheral surface 27 c and improve the heat dissipation from the cylindrical portion 27. The fins 25 extend in the axial direction of the cylindrical portion 27, are erected in the air passage 19, and are formed at equal intervals over the entire circumference of the outer peripheral surface 27 c. As a result, the cooling performance of the cylindrical portion 27 and the motor 30 is improved. However, the fin shape is not limited to the shape of the present embodiment, and may be any shape as long as it increases the surface area of the outer peripheral surface 27c. For example, a large number of hemispherical protrusions may be provided, or conversely, a large number of hemispherical recesses may be provided to increase the surface area. Further, since the effect can be sufficiently obtained without providing the fin, it is not necessary to provide it.

  The cylindrical portion 22 and the rotor fixing portion 15 are provided with a plurality of air holes 22b and a plurality of air holes 15b. The air hole 22b is formed so that the inner peripheral side and the outer peripheral side of the cylindrical portion 22 communicate with each other. The air hole 15b is drilled at a predetermined position on the flat surface of the rotor fixing portion 15 in parallel with the axis of the cylindrical portion 22 or through a predetermined angle.

  A plurality of air holes 22b and air holes 15b may be provided anywhere, but in this embodiment, four air holes 22b are arranged every 90 degrees on the circumference around the axis (two of the four each). Is not shown). The air hole 22b and the air hole 15b are holes for allowing and discharging air appropriately so that the air moving in the rotor blade 23b portion of the fan 23 and the air passage 19 can smoothly flow. is there. Therefore, the total area of the air passage cross sections of the air hole 22b and the air hole 15b is desirably an area that allows a larger amount of air to flow than the flow rate of air flowing through the rotary blade 23b and the air passage 19.

  Note that only one of the air holes 22b and the air holes 15b may be provided. Further, the rotary blade 23b of the fan 23 is rotated in the opposite direction to the above, and the air hole 22b and the air hole 15b are used as the intake port, and the air flow is from left to right in FIG. You may make it flow toward. This also provides a reasonable effect.

  Two ball bearings 16 are arranged in the axial direction between the outer peripheral surface 22d of the cylindrical portion 22 and the vehicle body side cylindrical member 18 which is a vehicle body side member and is fixed to the vehicle body. That is, the inner ring 16 b of each ball bearing 16 is fitted to the outer peripheral surface 22 d of the cylindrical portion 22, and the outer ring 16 a of each ball bearing 16 is fitted to the inner peripheral surface 18 c of the vehicle body side cylindrical portion 18. The two ball bearings 16 are arranged on both sides of the air hole 22b in the rotation axis direction with the air hole 22b formed in the cylindrical portion 22 interposed therebetween. As described above, the wheel 11 is rotatably supported not only by the casing 24 but also by the ball bearings 16 and is stable.

  The vehicle body side cylindrical member 18 has a plurality of air holes 18a penetrating the cylindrical outer peripheral surface side and the cylindrical inner peripheral surface side. The plurality of air holes 18a may be provided anywhere, but in the present embodiment, four air holes 18a are arranged every 90 degrees on the circumference centered on the axis (two of the four are not shown). The two ball bearings 16 are arranged on both sides of the air hole 18a in the rotational axis direction so as to sandwich the air hole 18a formed in the vehicle body side cylindrical member 18. The air hole 18a is a discharge hole for allowing air to pass through the air hole 22b of the cylindrical portion 22 and discharging it smoothly.

  Further, a duct (not shown) having an inlet opening toward the front in the traveling direction when the vehicle travels is provided on the vehicle body side or the electric wheel device 10 side, and the outlet of the duct is directed toward the brake device 14. Suitable for. When the vehicle is traveling, the traveling wind is effectively collected at the duct inlet, and blown out in the direction of the braking device 14 as the cooling cooling air W to cool the braking device 14.

  Next, the operation of the in-wheel motor cooling structure 20 will be described. In the motor-driven wheel device 10 assembled to the vehicle via a mounting bracket (not shown), an alternating current is supplied to the stator coil 34b by a switching circuit (not shown) mounted on the vehicle, and the rotor 33 rotates. The motor 30 outputs a predetermined torque. The output torque of the motor 30 is transmitted to the planetary gear mechanism 36 serving as a speed reducer. The planetary gear mechanism 36 is shifted (decelerated) and output to the output shaft 43. The output shaft 43 rotates the wheel hub 13 and the wheel disc 12 at a predetermined rotation speed via a joint (not shown), and the electric wheel rotates at a predetermined rotation speed.

  Then, for example, a case where the operation of the electric wheel device 10 is continued and the motor 30 and each part of the sliding part generate heat will be described. At this time, the casing 24 that is fixed in contact with the motor 30 by members having an appropriate thermal conductivity sequentially receives heat from the motor 30 due to the heat generated by the motor 30 and rises in temperature.

  In such a state, the fan 23 that rotates in conjunction with the motor 30 is rotated in a predetermined direction as the cylindrical portion 22 rotates. As a result, air in the region P shown in FIG. 1 is sucked into the rotor blade 23b and flows in the rotor blade 23b from right to left in FIG. At the same time, the air drawn into the air passage 19 by the air flow flowing through the rotor blades 23 b flows from the right to the left while contacting the outer peripheral surface 27 c of the casing 24 and the fins 25 in the air passage 19. (See arrow in FIG. 1).

  The air introduced into the air passage 19 having a temperature lower than that of the casing 24 heated by the motor 30 flows while making contact with the outer peripheral surface 27c of the casing 24 and the fins 25 and effectively removing the heat of the casing 24. To go. The air flow that has been deprived of heat and heated up is smoothly discharged to the outside from the plurality of air holes 22b and air holes 15b provided in the cylindrical portion 22 and the rotor fixing portion 15, so that a large flow rate can be efficiently flowed. It is possible to introduce a large amount of low temperature fresh air sequentially. In this way, a large cooling capacity can be secured and the temperature rise of the casing 24 can be suppressed, so that the amount of heat generated by the motor 30 can be effectively moved sequentially from the motor 30 to the casing 24. As a result, the temperature rise of the motor 30 can be effectively suppressed.

  In the present embodiment, the brake cooling air W is supplied toward the brake device 14. The rotor fixing portion 15 constituting the brake device 14 is provided with the cylindrical portion 22 and the fan 23 according to the present invention. That is, when the brake cooling air W flows toward the brake device 14, it flows in the vicinity of the fan 23 and the cylindrical portion 22. Since the air guide rod 31 is provided at the end point 22c of the cylindrical portion 22 over the entire circumference of the cylindrical portion 22 in the cylindrical circumferential direction, a part of the brake cooling air W collides with the air guide rod 31 and is guided and rotated. The air is smoothly introduced into the blade 23 b and the air passage 19. As a result, even if the rotation of the motor 30 and the fan 23 that rotates in conjunction with the rotation of the motor 30 is increased and the required air flow rate is increased, a part of the brake cooling air W can always be used, and the air Since the air can be effectively introduced into the air passage 19 by the induction rod 31, the supply amount is not insufficient, and the motor 30 can be effectively cooled.

  As is clear from the above description, in the present embodiment, it can be mounted between the cylindrical portion 27 of the casing 24 located at a predetermined distance from the end surface of the casing 24 and the cylindrical portion 22 surrounding the cylindrical portion 27. The casing 24 is cooled by positively introducing an air flow between the cylindrical portion 27 and the cylindrical portion 22 by the fan 23 which is a small, lightweight and low-cost air blower, and mounted in the casing 24. Thus, the motor 30 can be cooled effectively. Further, since the fan 23 is small and light, the unsprung weight of the vehicle does not increase greatly, contributing to stable reliability.

  Further, in the present embodiment, when the air flow is introduced between the casing 24 and the cylindrical portion 22 by the fan 23, it is effective from the air hole provided in at least one of the cylindrical portion 22 and the rotor fixing portion 15. Since the air can be discharged, the air flow is smoothly introduced, the flow rate is increased, and the cooling effect of the motor 30 is further improved.

  Furthermore, in this embodiment, since a part of the brake cooling air W supplied to cool the brake can be introduced between the casing 24 and the cylindrical portion 22 and used, a sufficient amount of air can be secured, The motor 30 can be cooled stably and reliably.

Next, a reference example will be described with reference to FIG. In the first embodiment, two ball bearings 16 that support the wheel 11 are provided outside the casing 24 and coaxially with the casing 24 so as to surround the cylindrical portion 27, and the vehicle body side cylinder. It was arranged between the members 18. A fan 23 as a blower is fixed and arranged on the inner peripheral surface 22 a of the cylindrical portion 22.

However, in the reference example , the planetary gear mechanism 36 has a ball bearing 42 for supporting the wheel 11 as shown in FIG. 3, for example. The ball bearings 42 are respectively fitted and interposed between the outer peripheral surface of the carrier 37 of the planetary gear mechanism 36 and the cylindrical inner peripheral surface 56b of the cylindrical portion 56, and rotatably support the output shaft 43 and the wheel 11. Is.

Thereby, in the electric wheel device 50 of the reference example , the cylindrical portion 22 for supporting the ball bearing 16 and the vehicle body side cylindrical member 18 are not provided, and the rotor support plate 17 for supporting the brake rotor 14a is used as the cylindrical portion. A fan 53 is provided on the inner peripheral surface 17d of the side wall 17b. Since the first embodiment and the reference example are different only in the above points, only different portions will be described, and description of similar portions will be omitted. In addition, the same reference numerals are given to the same configuration and will be described.

The in-wheel motor cooling structure 60 according to the reference example has a cylindrical portion 56 that is a portion of the casing 65 that is a predetermined distance away from the right end face of the casing 65 leftward in FIG. A side wall 17b as a cylindrical portion of the rotor support plate 17 coaxially surrounding the portion 56, and a fan as an air blower fixed to the inner peripheral surface 17d of the cylindrical side wall 17b opposite to the outer peripheral surface 56a of the cylindrical portion 56 53 (see FIGS. 2 and 3). The fan 53 is brought into contact with the outer peripheral surface 56 a of the cylindrical portion 56 and the fin 55 erected on the outer peripheral surface 56 a to introduce an air flow for taking the temperature of the casing 65.

  The rotor fixing portion 15 to which the rotor support plate 17 is fixed is formed on the wheel hub 13 constituting the wheel 11. An air guide rod 62 having the end point 61 as a base point is provided at the end point 61 portion of the side wall 17b over the entire circumference in the circumferential direction of the side wall 17b. The air guide rod 62 is formed so as to be slightly inclined at an arbitrary angle in the direction away from the end point 61 of the side wall 17b from the rotation axis and to the rear, which is the right side in FIG. And the clearance gap between the connection wall 69 which the casing 65 has, and the wall surface of the air induction rod 62 which opposes the connection wall 69 is formed with the predetermined value or more having the same meaning as the predetermined value in 1st Embodiment. ing. As a result, a part of the brake cooling air W flowing from right to left in FIG. 3 toward the brake device 14 collides with the air guide rod 62 and is guided by the wall surface of the air guide rod 62 to move in a direction approaching the axis. Then, it is effectively introduced into an air passage 63 described later.

  In the state where the fan 53 is fixed to the inner peripheral surface 17 d of the side wall 17 b of the rotor support plate 17, the air passage 63 is formed in the inner peripheral space of the fan 53 and the outer peripheral surface of the cylindrical portion 56 of the casing 65 facing the fan 53. 56a and a predetermined gap.

  A plurality of air holes 66 and a plurality of air holes 15b that allow passage of air flowing through the air passage 63 are formed in the side wall 17b and the rotor fixing portion 15 so as to penetrate therethrough. Even in such a configuration, the same effect as in the first embodiment can be obtained.

In the present embodiment and the reference example , the speed reduction mechanism of the speed reducer 21 is the planetary gear mechanism 36. However, the speed reduction mechanism is not limited to this and may be any type of speed reduction mechanism.

  In addition, although the axial flow type fan is applied to the fans 23 and 53 that are the blower devices, the present invention is not limited to this, and a diagonal flow type fan is applied, and the air flow input in parallel to the rotation axis direction is applied in the axial direction. Alternatively, it may be configured to discharge at a predetermined angle and flow while colliding with the outer peripheral surfaces 27c and 56a of the cylindrical portions 27 and 56 of the casings 24 and 65 at a small angle. Thereby, the casings 24 and 65 can be air-cooled more effectively.

In the present embodiment and the reference example , the cylindrical portion 22, the side wall 17b, and the rotor fixing portion 15 are provided with a plurality of air holes 22b, air holes 66, and air holes 15b, one for each. You may provide each. Further, only one or more air holes may be provided in either the cylindrical portion 22 (or the side wall 17b) and the rotor fixing portion 15.

DESCRIPTION OF SYMBOLS 10, 50 ... Electric wheel apparatus, 11 ... Wheel, 12 ... Wheel disk, 12a ... Disk part, 12b ... Rim part, 13 ... Wheel hub, 14 ... Brake device , 15 ... Rotor fixing portion, 15b, 22b, 66 ... Air hole, 16, 35, 40, 42 ... Ball bearing, 17 ... Rotor support plate, 18 ... Car body side cylindrical member, 19, 63 ... Air passage, 20, 60 ... In-wheel motor cooling structure, 21 ... Reducer, 22 ... Cylindrical part, 23, 53 ... Blower (fan), 24, 65 ... Casing, 30 ... Motor, 31, 62 ... Air induction rod, 32 ... Rotating shaft, 33 ... Rotor, 34 ... Stator, 34a ... Stator core, 34b ... Stator coil, 43 ..Output shaft.

Claims (3)

A casing for rotatably supporting a wheel constituting the electric wheel of the vehicle;
An in-wheel motor cooling structure that cools the motor of the electric wheel device provided with a motor that is mounted in the casing and drives the wheel,
A rotor support plate fixed to a rotor fixing portion formed on the wheel and supporting the brake rotor;
The rotor support plate is formed separately and fixed to the rotor fixing portion, and is disposed between the rotor support plate and a portion of the casing that is separated from the end surface of the casing by a predetermined distance. A surrounding cylindrical part;
A blower that introduces an air flow that is fixed to the inner peripheral surface of the cylindrical portion so as to face the casing and contacts the surface of the casing;
An in-wheel motor cooling structure comprising: In claim 1,
At least one of the cylindrical portion and the rotor fixing portion is provided with an air hole that allows passage of the air flow introduced by the blower,
An in-wheel motor characterized in that a part of brake cooling air guided into the wheel for cooling the brake rotor is introduced between the cylindrical portion and the portion of the casing by the blower. Cooling structure. In claim 1 or 2,
Arranged on the outer diameter side of the outer peripheral surface of the cylindrical portion and fixed to the vehicle body of the vehicle, the cylindrical portion can be rotated via a ball bearing interposed between the inner peripheral surface and the outer peripheral surface of the cylindrical portion. An in-wheel motor cooling structure comprising a vehicle body-side cylindrical member that is supported on the vehicle body.

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