JP2023122099A - Rotary electric machine casing and motor - Google Patents

Abstract

To provide a casing without an increase in the number of components and intrusion of dust even if the casing is applied as an in-wheel motor.SOLUTION: A casing 10 of a rotary electric machine for storing a rotor inside thereof includes: a cylindrical side wall 12a; and end walls arranged on longitudinal both ends of the side wall 12a. The end wall includes first concave and convex fins 16a and 16c on side faces positioned on an inner side of the casing 10. The concave and convex fins 16a and 16c are radially arranged from a center side to an outer peripheral side of the end walls.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a rotating electrical machine, and more particularly to a casing for a rotating electrical machine with excellent cooling effect and a motor to which this casing is applied.

2. Description of the Related Art Among motors that constitute rotary electric machines, techniques disclosed in Patent Documents 1 and 2 are known as cooling techniques particularly for in-wheel motors. The technology disclosed in Patent Literature 1 has a configuration in which an opening is provided in the wheel and a fan that rotates together with the axle is provided on the outer side surface of the wheel. The fan is provided to suck air from the inner side of the wheel toward the outer side, and is equipped with a one-way clutch so that it can rotate even when the wheel stops rotating. there is With an in-wheel motor having such a configuration, air can be taken into and discharged from the inside of the wheel as the wheel rotates, so it is thought that a cooling effect can be obtained. However, in the in-wheel motor having such a configuration, the number of parts increases, and there is a possibility that dust may enter the inside of the wheel. In addition, since the fan continues to rotate even when the wheel stops rotating, there is a risk of injury in the event of accidental contact.

The technology disclosed in Patent Document 2 is a technology for cooling a control device that controls the rotation of an in-wheel motor, and uses a heat pipe routed from the control device to the outside of the casing for cooling. That's what it means. Moreover, Patent Document 2 describes that a heat sink may be provided at a portion of the heat pipe that is disposed outside the casing. Since the heat sink disclosed in Patent Document 2 is arranged on the outer peripheral side of the wheel, it is considered that the rotation of the wheel can efficiently obtain a cooling effect. However, since heat pipes and heat sinks are arranged on the outer periphery of the wheel, the weight balance tends to be disturbed and restrictions are imposed on the arrangement of the tires.

Further, the applicant of the present application has proposed a technique disclosed in Patent Document 3 as a technique for suppressing heat generation in a general motor. The cooling technique disclosed in Patent Document 3 is to provide unevenness on the inner peripheral portion of the side wall of a cylindrical casing facing the rotor. With such a configuration, the refrigerant enclosed inside is raked up by the rotation of the rotor and comes into contact with the inner peripheral surface of the side wall of the casing. By providing the unevenness on the inner peripheral surface of the casing, the contact area between the refrigerant and the casing increases, and the efficiency of heat transfer can be improved. Certainly, the casing having such a configuration can promote the heat dissipation of the motor. However, in order to promote the cooling effect with such a configuration, it is necessary that the side walls of the casing have a sufficient length so that many irregularities can be formed. Therefore, when applied to the casing of an in-wheel motor, which tends to be longer in the radial direction than in the axial direction, it may not be possible to obtain a sufficient cooling effect.

JP 2020-157837 A Japanese Patent Application Laid-Open No. 2021-146940 Japanese Patent Application Laid-Open No. 2021-112030

Therefore, in the present invention, even when applied as an in-wheel motor, there is no risk of an increase in the number of parts or contamination of dust, and the loss of weight balance is prevented. An object of the present invention is to provide a casing for a rotary electric machine with high cooling efficiency and a motor using this casing.

A casing for a rotating electrical machine according to the present invention for achieving the above object is a casing for a rotating electrical machine that accommodates a rotor therein, comprising a cylindrical side wall and arranged at both ends in the longitudinal direction of the side wall. The end wall has a first concave-convex fin on a side surface located on the inner side of the casing, and the first concave-convex fin extends from the center side to the outer peripheral side of the end wall. It is characterized by being arranged radially toward.

Further, in the casing for a rotary electric machine having the characteristics described above, the end wall includes second uneven fins on a side surface located on the outer side of the casing, and the second uneven fins also form the end wall. It is preferable that they are arranged radially from the center side of the to the outer peripheral side. With such characteristics, heat absorbed through the first uneven fins can be efficiently released through the second uneven fins.

Further, in the rotating electrical machine casing having the characteristics described above, the diameter of the end wall is preferably longer than the length of the side wall in the longitudinal direction. This feature increases the footprint of the end wall in the casing. Therefore, it is possible to enhance the heat absorption/radiation effect of the uneven fins on the end wall.

Further, in the rotating electrical machine casing having the features described above, the side wall expands the inner circumference from one of the end walls toward the other end wall. It is preferable to form a tapered surface having an inclination. According to such a feature, when the casing is rotated with the refrigerant put therein, the refrigerant gathers on the other end wall side due to the centrifugal force.

Further, in the casing for a rotating electric machine having the characteristics described above, at least a part of the wall surface located on the inner side of the casing is coated with an endothermic coating, and the wall surface located on the outer side of the casing is coated with heat absorbing coating. At least part of the wall surface is preferably coated with a heat-dissipating coating. By having such characteristics, it is possible to enhance the effect of exhausting the heat trapped inside the casing. In addition, it is desirable that none of the coating films have conductivity substantially.

Further, a motor according to the present invention for achieving the above objects employs any one of the casings for a rotary electric machine described above, the rotor is configured to rotate around a support shaft, and the casing is configured to rotate around the support shaft. is fixed, the rotor rotates due to the rotation of the rotor.

The motors according to the following embodiments are coreless type (cylindrical coil type) brushless in-wheel motors, in which a coil and a support shaft are fixed, and a yoke (either an inner yoke or an outer yoke, or At least one of the yokes is provided with a permanent magnet facing the coil, which may be referred to as a rotor in the following embodiments) and a casing (when the motor is used as a wheel, the outer ring of the wheel). Also, it may have tires on the circumference) rotates. The relationship between the casing and the rotor includes the case where the casing and the rotor are directly connected and the case where the rotation of the rotor is transmitted to the casing via a transmission gear such as a speed reducer, and the following embodiments are the latter. In the following embodiments, the transmission gear is directly connected to the rotor and is used as a part of the internal structure (rotating element) of the motor.

Further, in the motor having the characteristics described above, it is preferable that the casing contains a liquid refrigerant, and the amount of the refrigerant is such that it does not come into contact with the rotor when it spreads inside the side wall. . With such a feature, the rotor does not come into contact with the coolant that has spread inside the casing while the rotor is rotating, so there is no fear that the coolant will act as a resistance that hinders the rotation of the rotor.

Further, in the motor having the characteristics described above, a stator connected to the support shaft is arranged inside the casing, and the stator is provided with the refrigerant spreading inside the side wall of the rotating casing. Preferably, a coolant directing member is provided which contacts and directs the flow of a portion of the. With such features, the coolant can be guided to a desired location and circulated effectively, thereby enhancing the cooling effect.

Further, a motor according to the present invention for achieving the above object employs any one of the casings for a rotary electric machine described above, and when the casing extends inside the side wall, the rotor has a The rotor is configured to rotate around a support shaft, and the casing is configured to rotate due to the rotation of the rotor when the support shaft is fixed. , a stator connected to the support shaft is disposed inside the casing, and the stator is provided with a portion located on the side of the other end wall of the rotating casing inside the side wall of the rotating casing. It may be characterized by comprising a refrigerant guide member that comes into contact with a part of the refrigerant that spreads out and guides the flow of the refrigerant.

In the motor having the characteristics described above, the casing is provided with a substrate having a coil for operating the rotor and a circuit for controlling the coil. should be arranged in the direction in which is guided. The substrate, which has circuitry for controlling the coils, is one source of heat generation within the casing. Therefore, with the features as described above, the coolant can be reliably guided to the substrate, which is the heat source. Therefore, cooling efficiency can be improved.

Furthermore, in the motor having the characteristics described above, the coil is composed of coil elements forming a plurality of phases, and the circuit has a function of switching the connection of the plurality of coil elements in series and/or in parallel (parallel This function can switch the number of rotations, torque, etc. of the motor in several stages, including the case where there are multiple types of patterns and the case where series and parallel are mixed. With such characteristics, the amount of heat generated by the circuit mounted on the substrate is improved. Therefore, the cooling effect is enhanced by reliably guiding the coolant to the substrate. Further, in the following embodiments, the substrate for switching the connection of the coil is formed in a so-called donut-shaped ring. In addition, the substrate is disposed between the inner side of the casing end wall (the other end wall in the embodiment: the lid) and the inner structure such as the rotor or the end of the coil (for example, the coil base). placed almost parallel to the surface.

According to the rotary electric machine casing having the characteristics described above, even when it is applied as an in-wheel motor, it is possible to eliminate the risk of an increase in the number of parts and the contamination of dust. In addition, when the casing is used as a wheel, it is possible to prevent the weight balance from being disturbed and also to allow the arrangement of the tires to have a degree of freedom.

It is a front view showing the outline of the appearance composition of the casing concerning a 1st embodiment. It is a left side view showing the outline of the appearance composition of the casing concerning a 1st embodiment. It is a right side view showing the outline of the appearance composition of the casing concerning a 1st embodiment. FIG. 3 is a diagram showing a cross section taken along line AA in FIG. 2; It is a schematic diagram showing the configuration of the inner side surface of the case body in the first embodiment. It is the schematic which shows the structure of the internal side surface of the cover in 1st Embodiment. 1 is a schematic diagram showing a cross-sectional configuration of a motor according to an embodiment; FIG. It is a figure which shows an example of the form of the rectification|straightening member which concerns on embodiment. It is a reference perspective view showing a partial section of a motor concerning an embodiment. It is the schematic which shows the cross-sectional structure of the casing which concerns on 2nd Embodiment. It is a figure for demonstrating the cooling action by painting. 4 is a graph showing temperature changes during operation of a motor using a coated casing and a motor using an uncoated casing.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a casing for a rotary electric machine and a motor according to the present invention will be described in detail with reference to the drawings.
[First Embodiment: Configuration]
First, a motor according to a first embodiment will be described with reference to FIGS. 1 to 9. FIG. In the drawings, FIG. 1 is a front view showing an outline of the external configuration of the casing according to the embodiment, FIG. 2 is a left side view of the same, and FIG. 3 is a right side view of the same. 4 is a diagram showing a cross section taken along line AA in FIG. 2. As shown in FIG. FIG. 5 is a view showing the configuration of the inner side surface of the case main body, and FIG. 6 is a view showing the inner side surface of the lid. Also, FIG. 7 is a schematic diagram showing a cross-sectional configuration of the motor according to the embodiment. Moreover, FIG. 8 is a figure which shows an example of the form of the guide member which concerns on embodiment. Furthermore, FIG. 9 is a reference perspective view showing a partial cross section of the motor according to the embodiment.

A motor 100 according to the present embodiment is based on a casing 10, a support shaft 18 at least partially housed in the casing 10, a stator 22 housed inside the casing 10, and a rotating element 34. It is configured.

The casing 10 is basically composed of a cylindrical side wall 12a and end walls provided at both ends of the side wall 12a. In the examples shown in FIGS. 1 to 9, the side wall 12a and one end wall are integrally formed to form the casing body 12, and the other end wall is formed as a so-called lid body 14. It does not matter whether the end wall and the side wall 12a are integrated or separated.

In the casing 10 according to the embodiment, concave-convex cooling fins (hereinafter referred to as concave-convex fins 16a to 16d) are provided on the inner and outer side surfaces of the end walls. By providing the concave-convex fins 16a to 16d, the surface area of the inner side surface and the outer side surface of the end wall is increased, and the heat transfer efficiency can be improved. Therefore, when the internal temperature of the casing 10 rises, heat is absorbed from the concave-convex fins 16a and 16c on the inner side surface and radiated from the concave-convex fins 16b and 16d on the external side surface.

A plurality of uneven fins 16a to 16d are arranged radially from the center side to the outer peripheral side of the circular end wall. This is because, in the case of the end wall having a circular planar shape, the concave-convex fins 16a to 16d can be arranged in a uniform manner by arranging them radially. Further, in the motor 100 according to the present embodiment, the casing 10 rotates as the rotating element 34 rotates, as will be described later in detail. Therefore, the concave-convex fins 16a to 16d are arranged so as to have an inclination angle with respect to a perpendicular drawn from the center in the circumferential direction. By arranging the concave-convex fins 16a to 16d in such a configuration, there is an effect of causing the internal fluid (including air) such as coolant to flow from the center side of the circle to the outer circumference side. When the coolant flows, it flows along the side surfaces of the uneven fins 16a to 16d (groove portions formed by unevenness), so it is possible to improve the efficiency of heat exchange, that is, the cooling efficiency. . Further, by arranging the concave-convex fins 16a to 16d in such a configuration, it is possible to easily balance the weight and suppress shaking when the casing 10 itself rotates.

Moreover, the casing 10 according to the present embodiment is applied to an in-wheel motor. For this reason, the diameter of the end wall is configured to be longer than the longitudinal length of the side wall 12a (the distance between the opposing end walls). Therefore, by providing the uneven fins 16a to 16d on the end walls, it is possible to enhance the cooling effect. In the casing 10 according to the present embodiment, bearing holes 12b and 14a for inserting the support shaft 18 are provided in one end wall and the other end wall, respectively.

Furthermore, the casing 10 according to the present embodiment has a tapered surface with a slight inclination on the inner peripheral wall of the side wall 12a. In the case of the example shown in FIG. 4, the tapered surface is such that the thickness of the side wall 12a decreases from the proximal end side to the distal end side (the side where the lid body 14 is arranged) of the side wall 12a, that is, the diameter of the inner circumference of the casing 10 increases. is slanted so that With such a configuration, when the casing 10 is rotated in a state where the refrigerant 110 (see FIG. 7) is sealed inside the casing 10, the refrigerant 110 flows so as to gather toward the tip side of the side wall 12a. .

The support shaft 18 is a rod-shaped member that penetrates the casing 10 and is arranged in the bearing holes 12b and 14a provided in the side walls. In this embodiment, by fixing the support shaft 18 to a mobile body (for example, a wheelchair or a bicycle), the casing 10 rotates when a rotation element 34 (details of which will be described later) rotates. Therefore, bearings 20 are arranged between the support shaft 18 and the casing 10, respectively.

The stator 22 is an element that serves as a starting point for operating a rotating element 34 , which will be described later in detail. The coil 24 is an element for rotating a rotor 36 whose details will be described later, and is formed in a cylindrical shape in this embodiment. The coil base 26 is an element for cantilevering the coil 24 and is fixed to the support shaft 18 . Further, the coil 24 according to the embodiment is provided with a coil reinforcing ring 24a. The coil reinforcing ring 24a is an element that assists in maintaining the shape of the coil 24 formed in a cylindrical shape, and is provided on the tip side of the coil 24, that is, on the free end side. The coil ring 28 is an element for mounting the induction member 30, which will be described later in detail, and is provided along the coil base 26 in this embodiment.

The induction member 30 comes into contact with the coolant 110 filled in the casing 10 (the part indicated by the two-dot chain line indicates the amount of the coolant 110 during non-rotation), scrapes it, or moves it toward the substrate 32 (details will be described later). It is an element for guiding, and has at least one claw 30a on its outer circumference (three in the example shown in FIG. 8). The claw 30a is provided with an inclined surface (or an inclined groove) for guiding (flowing) the coolant 110 in contact with at least the tip thereof in a predetermined direction.

Since the guide member 30 plays a role of guiding the coolant 110 to the substrate 32 that generates a large amount of heat, it is preferably provided near the substrate 32 . In this embodiment, the induction member 30 is arranged on the outer circumference of the coil ring 28 . The refrigerant 110 filled in the casing 10 spreads over the inner peripheral surface of the side wall of the casing 10 due to the rotation of the rotating element 34 and the casing 10 . Here, since the side wall 12a of the casing 10 according to the embodiment forms a tapered surface, the coolant 110 gathers on the tip side (the side where the diameter of the inner circumference is large) of the side wall 12a. When the claws 30a of the guide member 30 come into contact with the collected coolant 110, the coolant 110 flows along the shape of the claws 30a.

In addition, the coils 24 constituting the motor 100 according to the embodiment are composed of coils forming a plurality of phases (hereafter referred to as coil elements to avoid confusion), and the substrate 32 is composed of the coils forming a plurality of phases. Equipped with a circuit to switch the connection relationship of elements between series and/or parallel (including multiple types of parallel patterns and mixed use of series and parallel). etc., can be switched in several steps). Therefore, since the substrate 32 can become one of the heat sources in the casing 10, it must be cooled down (reduced heat generation) in the same way as the coil 24. FIG.

The reason why the coolant 110 flows along the shape of the claw 30a is as follows. That is, when the tips of the claws 30 a are in contact with the coolant 110 , the coolant 110 is continuously supplied to the tips of the claws 30 a of the guide member 30 as the casing 10 rotates. Since the coolant 110 supplied first is pushed out by the coolant 110 to be supplied later, a flow of the coolant 110 is generated in the claw 30a. Further, since the claws 30a of the guide member 30 are provided with inclined surfaces for guiding the coolant 110, the coolant 110 supplied to the claws 30a is guided toward the substrate 32 side.

In this manner, the guide member 30 guides the coolant 110 to the substrate 32, which generates a large amount of heat, and scrapes or disturbs the coolant 110 from the side wall 12a depending on the rotational state of the casing 10. , the coolant 110 can be effectively circulated within the casing 10 to enhance the cooling effect. This cooling effect is particularly important when the substrate 32 having a coil connection switching function is incorporated in the coreless motor 100 using the cylindrical coil 24 as in the present embodiment.

For this reason, the guide member 30 may be arranged near the substrate 32 at a position where the coolant 110 gathers inside the rotating casing 10 so that at least the claws 30 a thereof come into contact with the coolant 110 . Therefore, the induction member 30 may be configured to guide at least part of the coolant 110 to the substrate 32 side. For example, as shown in FIG. 8, it may be configured to cover about one-third of the coil ring 28, and at least one claw 30a may be provided on the upper side. For example, when an in-wheel motor to which the motor 100 of this embodiment is applied is used for a wheel of a motorcycle, the cooling function is steadily exhibited. It should be noted that the induction member 30 may be arranged around the entire circumference of the coil ring 28 when the posture change of the motor is large.

The coolant 110 sealed inside the casing 10 may be any fluid that has a cooling effect, such as oil. Also, the amount of the coolant 110 should be such that the surface of the coolant 110 does not come into contact with the rotating element 34 when the rotating element 34 is rotated and spreads over the side wall 12a. This is because by adjusting the amount of the coolant 110 to such an amount, it is possible to avoid the coolant 110 from becoming a resistance that hinders the rotation of the rotating element 34 .

The substrate 32 is an element on which circuitry for controlling the current to the coil 24 is mounted. In this embodiment, the plate surface is arranged so as to be perpendicular to the support shaft 18 , that is, parallel to the cylindrical cross section of the coil 24 . By setting it as such an arrangement form, the whole motor 100 can be made compact.

Further, in the motor 100 of the present embodiment, the substrate 32 is positioned near the tip side of the side wall 12a, that is, near the side where the lid body 14 is arranged. With such a configuration, the substrate 32 is positioned near the portion (liquid pool) where the coolant 110 gathers when the casing 10 rotates, and the efficiency of supplying the coolant 110 by the induction member 30 can be improved. become able to.

Here, in the case of the motor 100 according to the embodiment, the substrate 32 is attached to the stator 22 and does not rotate. Therefore, the coolant 110 guided to the substrate 32 by the guide member 30 falls along the surface of the substrate 32 due to gravity while absorbing heat. Therefore, as described above, it is desirable that the claws 30a of the guide member 30 are positioned on the upper side when the motor 100 is placed.

In the embodiment, the slanted surface of the claw 30a is directed only toward the substrate 32, but the slanted surface of the claw 30a that guides the coolant 110 toward the coil 24 may be provided.

The rotating element 34 is a component that rotates around the support shaft 18 inside the casing 10. In this embodiment, a rotor 36 and a transmission gear 38 that rotates along with the rotor 36 are provided. Positioned as a rotating element 34 . The rotor 36 has an inner yoke 36a and an outer yoke 36b, each having a cylindrical shape and equipped with a permanent magnet. The inner yoke 36a is arranged on the inner peripheral side of the coil 24, the outer yoke 36b is arranged on the outer peripheral side of the coil 24, and they are connected by a bridge portion 36c arranged on the tip side of the coil 24. As shown in FIG.

The transmission gear 38 is an element for transmitting the rotational force generated by the rotor 36 to the casing 10. In the present embodiment, the transmission gear 38 reduces the rotation speed and improves the torque transmitted to the casing 10. ing. The inner peripheral side of the transmission gear 38 is supported via bearings 40 so as to be rotatable with respect to the support shaft 18 . On the other hand, the outer peripheral side of the transmission gear 38 is configured to have a gear connected to the rotor 36 described above or directly connected to the rotor 36, and rotational force is transmitted to the transmission gear 38 as the rotor 36 rotates. I'm trying The transmission gear 38 can have a plurality of stages of gears inside, and is configured to transmit power after shifting to a final gear 42 fixed to the casing 10 .

In the rotating element 34 having such a configuration, when power is supplied to the coil 24 , the rotor 36 rotates, and the rotational force of the rotor 36 is transmitted to the transmission gear 38 . Rotational speed and torque are converted by the transmission gear 38 and transmitted to the final gear 42 , thereby transmitting rotational force to the casing 10 . In the motor 100 according to the embodiment, the transmission gear 38 is included in the rotating element 34, and the entire unit constituting the transmission gear 38 is rotated. does not rotate, and the case where the rotating element 34 is only the rotor 36 that is the rotor (there is no transmission gear 38) is also included.

Further, when the gears rotate and mesh at high speed, the transmission gear 38 also becomes one of the heat sources inside the casing 10 . Therefore, as described above, when the claws 30a of the induction member 30 guide the refrigerant 110 to the coil 24 side as well, it becomes possible to cool the transmission gear 38 in addition to the coil 24. FIG.

[Action/effect]
According to the casing 10 having the above characteristics, since the casing 10 itself has a cooling effect, even if it is applied as the motor 100 (in-wheel motor), it is possible to prevent an increase in the number of parts for cooling. can be done. Moreover, since the casing 10 can be made to have a sealed structure, there is no risk of dust entering.

Furthermore, since the concave-convex fins 16a to 16d that improve the cooling efficiency are radially and evenly arranged from the center side of the end wall toward the outer peripheral side, it is possible to prevent loss of weight balance. Further, since no structure is provided on the outer circumference of the side wall 12a, when the casing 10 is used as a wheel, it is possible to give flexibility to the arrangement form of the tire.

In the present embodiment, the tapered surface is formed on the inner peripheral surface of the side wall 12a of the casing 10, thereby collecting the refrigerant on the side where the induction member 30 is arranged and forming a so-called liquid pool. However, a similar effect can be obtained by forming a deep portion in a part of the side wall 12a to facilitate the flow of the coolant 110. FIG. For this reason, the side wall 12a may be tapered by a partial inclination or recessed by a step, instead of being an inclined surface continuous in the longitudinal direction of the side wall 12a. may be fitted into the inner peripheral wall. This is because even with such a configuration, when the casing 10 is rotated, the coolant 110 will gather at the recessed stepped portion or tapered portion (the portion where the induction member 30 is arranged) formed in the side wall 12a. be.

[Second embodiment]
Next, a casing according to a second embodiment will be described with reference to FIGS. 10 and 11. FIG. Most of the configuration of the casing 10A according to this embodiment is the same as the casing 10 according to the first embodiment described above. Therefore, the parts having the same configuration are denoted by the same reference numerals in the drawings, and detailed description thereof will be omitted.

In the casing 10A according to the present embodiment, the heat-absorbing coating is applied to the inner peripheral surface of the side wall 12a of the casing body 12 to form the heat-absorbing coating 50, and the outer peripheral surface is coated with the heat-radiating coating to form the heat-radiating coating 52. Characterized by points. The inner peripheral surface of the casing 10A that constitutes the motor 100 is usually not painted, but with such a configuration, the heat radiation effect can be enhanced. Here, the inventor of the present application confirmed the effect by using the products of Shiobara Seisakusho Co., Ltd. for both the heat-absorbing paint and the heat-dissipating paint. All of these paints contain carbon nanotubes and silicon carbide. Therefore, it is conceivable that the heat-absorbing coating film 50 and the heat-dissipating coating film 52 composed of these coating materials can be made of the same system of components. In addition, it is desirable that none of the coating films have conductivity substantially.

The mechanism responsible for the heat absorption action and the heat dissipation action by the heat absorption coating film 50 and the heat radiation coating film 52 depends on the matters shown in FIG. 11 . That is, when the casing 10A is applied to the motor 100, the inside of the casing 10A becomes a high temperature region and the outside becomes a low temperature region. The heat generated in the internal region is absorbed by the heat absorbing coating film 50 and transferred to the casing 10A. Here, in this example, both the heat-absorbing coating 50 and the heat-dissipating coating 52 contain carbon nanotubes and silicon carbide. Since carbon nanotubes and silicon carbide have a high specific surface area, the contact area with each region increases at the portion where the paint is applied. Therefore, due to the temperature gradient in the contact area, the coating film on the high temperature side acts as the heat absorbing coating 50 and the coating film on the low temperature side acts as the heat radiation coating 52, resulting in a high heat dissipation effect for the entire motor 100. presumed to be working.

FIG. 12 shows temperature changes when a motor employing a casing coated with heat-absorbing paint 50 and heat-radiating paint 52 (hereinafter simply referred to as coated casing) is operated, and a casing not coated with paint (hereinafter simply referred to as 2 shows a graph comparing temperature changes when a motor employing a non-coated casing is operated. FIG. 12 shows temperature changes for the internal temperature of the casing, the surface temperature of the casing, and the temperature of the substrate, respectively.

According to FIG. 12, it can be read that there is not much difference in the surface temperature of the casing between the case of adopting the coated casing and the case of adopting the non-coated casing. On the other hand, it can be seen that there is a large temperature difference between the internal air temperature and the substrate temperature as compared with the surface temperature of the casing as the operating time elapses. This is because the heat-absorbing action of the heat-absorbing coating film 50 and the heat-dissipating action of the heat-dissipating coating film 52 continuously act on the casing having the same heat capacity, resulting in a great effect in discharging heat from the inside of the casing. it is conceivable that.

In the casing 10A shown in FIG. 10, the heat absorption coating 50 and the heat radiation coating 52 are applied only to the inner peripheral surface and the outer peripheral surface of the side wall 12a. It is also possible to form a coating film on the surface to obtain a greater heat absorbing effect and heat releasing effect.

In the above embodiments, the casings 10, 10A are applied to in-wheel motors, but the configuration of the casings 10, 10A according to the embodiments can also be applied to other motors.

10, 10A......casing, 12......casing main body, 12a......side wall, 12b......bearing hole, 14......cover, 14a......bearing hole, 16a to 16d......uneven fins . ……Guiding member, 30a……Claw, 32……Substrate, 34……Rotating element, 36……Rotor, 36a……Inner yoke, 36b……Outer yoke, 36c……Bridge Part, 38...Transmission gear, 40...Bearing, 42...Final gear, 50...Heat absorbing coating, 52...Radiating coating, 100...Motor, 110...Refrigerant.

Claims (11)

A rotating electrical machine casing containing a rotor therein, comprising:
having a cylindrical side wall and end walls disposed at both ends of the side wall in the longitudinal direction;
The end wall is provided with first uneven fins on a side surface located inside the casing, and the first uneven fins are radially arranged from the center side of the end wall toward the outer peripheral side. A casing for a rotating electrical machine, characterized by: The end wall has second concave-convex fins on a side surface located on the outer side of the casing, and the second concave-convex fins are also radially arranged from the center side of the end wall toward the outer peripheral side. The rotating electrical machine casing according to claim 1, characterized in that: 3. A casing for a rotary electric machine according to claim 1, wherein the diameter of said end wall is longer than the longitudinal length of said side wall. The side wall is characterized by forming a tapered surface with an inclination that expands the inner circumference from one of the end walls toward the other end wall. A rotating electrical machine casing according to any one of claims 1 to 3. an endothermic coating is applied to at least a part of the wall surface located on the inner side of the casing,
5. A casing for a rotary electric machine according to claim 1, wherein at least a part of a wall surface positioned on the outside of said casing is coated with a heat-dissipating coating. Employing the rotating electrical machine casing according to any one of claims 1 to 5,
The rotor is configured to rotate with a support shaft as a starting point,
A motor according to claim 1, wherein the casing rotates due to the rotation of the rotor when the support shaft is fixed. A liquid refrigerant is provided inside the casing,
7. The motor according to claim 6, wherein the amount of the coolant is such that it does not come into contact with the rotor when it spreads inside the side wall. A stator connected to the support shaft is disposed inside the casing, and the stator contacts and guides a portion of the refrigerant spreading inside the side wall of the rotating casing. 8. A motor as claimed in claim 7, characterized in that a coolant induction member is provided. The casing for a rotary electric machine according to claim 4 or claim 5 citing claim 4 is adopted, and a liquid is placed inside the casing in an amount that does not come into contact with the rotor when it spreads inside the side wall. of refrigerant,
The rotor is configured to rotate with a support shaft as a starting point,
The casing is configured to rotate due to the rotation of the rotor when the support shaft is fixed,
A stator connected to the support shaft is disposed inside the casing, and the stator is provided at a portion positioned on the side of the other end wall, inside the side wall of the rotating casing. A motor comprising a coolant guide member that contacts a portion of the spread coolant and guides the flow of the coolant. A substrate having a coil for operating the rotor and a circuit for controlling the coil is provided inside the casing,
10. The motor according to claim 8, wherein the substrate is arranged in a direction in which the coolant is guided by the coolant guide member. 11. The motor according to claim 10, wherein the coil is composed of coil elements forming a plurality of phases, and the circuit has a function of switching connection of the plurality of coil elements in series and/or in parallel. .

Images