Motor production method and motor

Abstract

Provided is a motor production method including: an attachment step of attaching an end plate, which is provided with a first end plate through-hole and a second end plate through-hole, to a housing storing a motor stator with a wound coil; a first injection step of pouring, after the attachment step, uncured resin from the first end plate through-hole into a motor rotor installation area of the housing storing the motor stator; and a second injection step of pouring uncured resin from the second end plate through-hole into the motor rotor installation area of the housing.

Description

Motor manufacturing method and motor

[0001] The present disclosure relates to a motor manufacturing method and a motor.

[0002] A motor includes a rotor, which is a rotating body, and a stator arranged around the rotor. The stator has a core and a coil wound around the core. The stator is sealed with resin to waterproof and rust-proof the coil, which is a conductor. Patent Documents 1 to 3 disclose motor-related technologies. For example, Patent Document 1 discloses a manufacturing method for a PM motor. In the manufacturing method disclosed in Patent Document 1, after the coil is placed on the inner diameter side of the stator core, resin is injected through a mold injection port. The injected resin is then hardened by heating or the like to form a mold resin layer that covers the stator core and coil. Patent Documents 2 and 3 disclose technologies for fixing magnets with resin.

[0003] JP 2022-184651 A JP 2018-130026 A International Publication No. 2021 / 200817

[0004] In recent years, technologies to improve motor output have been studied. To improve motor output, more current is applied to the coil. As a result, the amount of heat generated by the coil increases, making it important to cool the coil. Therefore, research is being conducted into using resin, which is used to waterproof and prevent rusting of coils, as a thermal path to remove heat from the coil.

[0005] Generally, resins with high thermal conductivity have high viscosity when uncured. If such uncured resin is poured into a structure in which a stator is placed in a housing, it takes a long time for the resin to permeate the gaps. Furthermore, if a resin with a short pot life is used, the resin may harden before the filling is complete.

[0006] To use the resin as a heat path, it is desirable that the resin be in contact with both the coil and the housing that houses the coil. Even if the resin is in contact with the coil, if it is not in contact with the housing, the gap between the resin and the housing will become thermal resistance. As a result, it will not function adequately as a heat path.

[0007] The present disclosure provides a method for manufacturing a motor that can easily dissipate heat to the outside in a short period of time, and a motor that can easily dissipate heat to the outside.

[0008] A motor manufacturing method according to one embodiment of the present disclosure includes an attachment step of attaching an end plate, which has a first end plate through hole and a second end plate through hole, to a housing containing a stator with a coil wound around it; a first injection step of pouring uncured resin into a stator placement area of ​​the housing containing the stator from the first end plate through hole, which allows a first portion of the coil to be visible from outside the housing, after the attachment step; and a second injection step of pouring uncured resin into the stator placement area of ​​the housing from the second end plate through hole, which allows a second portion of the coil, different from the first portion, to be visible from outside the housing.

[0009] In one embodiment of the motor manufacturing method, uncured resin is poured into the stator placement area after the end plates are attached. The uncured resin is poured into the stator placement area through a first end plate through-hole and a second end plate through-hole, separate from the first end plate through-hole. This reduces the time it takes for the uncured resin to spread throughout the stator placement area compared to pouring the uncured resin from a single location. Therefore, even if the resin is highly viscous and has high thermal conductivity, the time it takes for it to spread throughout the stator placement area can be reduced. As a result, a motor that easily dissipates heat can be manufactured in a short time.

[0010] In one embodiment of the motor manufacturing method, the first injection step and the second injection step may be repeated to expose uncured resin from at least one of the first end plate through hole and the second end plate through hole. When the uncured resin is exposed from at least one of the first end plate through hole and the second end plate through hole, the uncured resin is in contact with the back surface of the end plate. This ensures that a path for transferring heat from the coil to the end plate via the resin is formed.

[0011] A motor manufacturing method according to another aspect of the present disclosure includes a step of pouring uncured resin through an opening in a housing into a plurality of different locations in a stator arrangement region of the housing, the housing containing the stator around which a coil is wound, and a step of attaching end plates, each having a first end plate through hole and a second end plate through hole, after the pouring step. In the end plate attaching step, the end plates are pressed against the liquid surface of the uncured resin, thereby exposing the uncured resin from the first end plate through hole and / or the second end plate through hole.

[0012] In another embodiment of the motor manufacturing method, uncured resin is poured into the stator placement area from multiple different locations. This reduces the time it takes for the uncured resin to spread throughout the stator placement area compared to pouring the uncured resin from a single location. After pouring the uncured resin, the end plates are attached. When attaching the end plates, the end plates are pressed against the surface of the uncured resin, exposing the uncured resin through the first end plate through-holes and / or the second end plate through-holes. Pressing the end plates to expose the uncured resin through the first end plate through-holes and / or the second end plate through-holes means that the back surfaces of the end plates are in contact with the uncured resin. This allows for the rapid manufacture of a motor that easily dissipates heat.

[0013] In another embodiment of the motor manufacturing method, the injection step may involve continuously pouring in the uncured resin while rotating the housing and the device for supplying the uncured resin relatively around the axis of the housing. This step also shortens the time it takes for the uncured resin to spread throughout the stator placement area.

[0014] In another embodiment, the injection step of the motor manufacturing method may include the steps of pouring a predetermined amount of uncured resin into a first portion of the coil and pouring a predetermined amount of uncured resin into a second portion of the coil different from the first portion. This step also shortens the time it takes for the uncured resin to spread throughout the stator placement area.

[0015] A motor according to yet another embodiment of the present disclosure includes a stator wound with a coil, a rotor surrounded by the stator and rotating with a shaft, a housing that receives the stator and rotor through an opening and forms a stator placement area to accommodate the received stator, end plates attached to the housing opening, and a resin portion filled in the stator placement area. The resin portion contacts the coil and the end plates. The end plates include a plurality of end plate through-holes that expose the resin portion.

[0016] In yet another embodiment of the motor, the resin portion contacts both the coil and the end plate. This configuration ensures that a path for heat transfer from the coil to the end plate via the resin is formed, allowing the heat to be efficiently dissipated to the outside.

[0017] In yet another embodiment of the motor, the exposed surface of the resin portion exposed through the end plate through-hole may be located between the edge of the opening on the rear surface of the end plate and the edge of the opening on the main surface of the end plate, thereby achieving a structure in which the resin portion is in reliable contact with the rear surface of the end plate.

[0018] In yet another embodiment, the end plate of the motor may include an annular inner cylindrical portion including an end plate shaft insertion hole through which the shaft is inserted; an annular outer cylindrical portion circumferentially surrounding the inner cylindrical portion and having an inner diameter larger than the outer diameter of the inner cylindrical portion; and a plurality of connecting portions arranged at intervals around the axis of the shaft to connect the outer peripheral surface of the inner cylindrical portion to the inner peripheral surface of the outer cylindrical portion. The end plate through hole may be located between a pair of connecting portions adjacent to each other around the axis of the shaft. An end face of the inner cylindrical portion may protrude from the connecting portion along the axis of the shaft. This structure prevents uncured resin from adhering to the end face of the inner cylindrical portion, allowing the end face of the inner cylindrical portion to be used as an installation surface for components.

[0019] According to the motor manufacturing method of the present disclosure, a motor that easily dissipates heat to the outside can be manufactured in a short time. According to the motor of the present disclosure, heat can be suitably dissipated to the outside.

[0020] FIG. 1 is a cross-sectional view showing the structure of a motor according to the present disclosure. FIG. 2 is a cross-sectional perspective view showing a main portion of an end plate included in the motor shown in FIG. 1. FIG. 3 is a front view of the motor shown in FIG. 1. FIG. 4(a) is a cross-sectional view showing an example of an exposed resin surface. FIG. 4(b) is a cross-sectional view showing another example of an exposed resin surface. FIG. 5 is a flowchart of a method for manufacturing a first motor. FIG. 6(a) is a diagram showing a process for housing a motor assembly in a vacuum chamber. FIG. 6(b) is a diagram showing a process for pouring uncured resin through a first end plate through-hole. FIG. 7(a) is a diagram showing a process for pouring uncured resin through a second end plate through-hole. FIG. 7(b) is a diagram showing a state in which it has been determined that the exposed resin surface of the uncured resin material has reached a specified position. FIG. 8 is a flowchart of a method for manufacturing a second motor. FIG. 9 is a diagram showing examples of a first portion, a second portion, and a third portion.

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicated explanations will be omitted.

[0022] 1 is a cross-sectional view showing the structure of a motor 1 according to the present disclosure. The motor 1 is used, for example, in a vehicle supercharger. When the torque of a shaft 2 is insufficient, such as during vehicle acceleration, the motor 1 applies torque to the shaft 2 to compensate for the torque deficiency. In this case, an impeller (not shown) is attached to the end of the shaft 2.

[0023] The motor 1 is, for example, a brushless AC motor. The motor 1 includes a shaft 2, a motor rotor 3, a motor stator 4, a housing 5, and end plates 6. The vehicle's battery can be used as a driving source for the motor 1. When the vehicle decelerates, the motor 1 may generate power regeneratively using the rotational energy of the motor rotor 3. The motor 1 is capable of handling high-speed rotation of the shaft 2 (for example, 100,000 to 200,000 rpm).

[0024] The motor rotor 3, which is a so-called rotor, is disposed between a pair of bearings 21, 22 arranged along the direction of the axis A. The main element constituting the motor rotor 3 is a cylindrical magnet. The motor rotor 3 may include elements for transmitting torque acting on the magnet to the shaft 2 as needed. For example, the motor rotor 3 may include end rings disposed on both ends of the cylindrical magnet, or armoring that covers the outer circumferential surface of the magnet, as needed.

[0025] The motor stator 4, which is a so-called stator, is accommodated in a housing 5. The motor stator 4 is arranged to surround the motor rotor 3 in the circumferential direction. The motor stator 4 includes a core 4A and a coil 4B. When a current is supplied to the coil 4B, the coil 4B generates a magnetic field. This magnetic field acts on the magnet of the motor rotor 3 in the circumferential direction. As a result, torque is applied to the shaft 2.

[0026] The housing 5 forms an area that accommodates the motor rotor 3 and the motor stator 4. The housing 5 is a cylindrical member and has a cylindrical portion 51 and a bottom portion 52. One end of the housing 5, in the direction in which the axis of the shaft 2 extends, is open to accommodate components such as the motor rotor 3 and the motor stator 4. The housing 5 has a housing opening 51h. The housing 5 is equipped with structures for performing the functions of the motor 1, such as electrode portions for applying current to the coil 4B. However, the details of these structures are not shown in FIG. 1 and will not be described in detail in the description of the embodiment.

[0027] A motor stator arrangement area 511 (stator arrangement area) and a motor rotor arrangement area 512 are formed inside the housing 5. The motor stator arrangement area 511 is an area surrounded by the cylindrical portion 51. A cylindrical motor stator 4 is fixed to the inner peripheral surface of the cylindrical portion.

[0028] The housing opening 51h is closed by an end plate 6. "Closed" here means that the positions of the components housed inside the housing 5 are maintained. The disk-shaped end plate 6 is fixed to the end of the housing 5. A bearing 21 is fixed to the end plate 6.

[0029] <End Plate> The shape of the end plate 6 will be described in more detail. The end plate 6 is shaped like a substantially circular plate. The end plate 6 has an end plate main body 6A and an end plate flange 6F. The end plate main body 6A is fitted into the opening recess 51ha of the housing 5. The end plate flange 6F abuts against the housing opening end surface 51s. The end plate flange 6F is provided with several bolt through holes (not shown). Bolts inserted into the bolt through holes are screwed into threaded holes provided in the housing opening end surface 51s. As a result, the end plate 6 is fixed to the housing 5.

[0030] As shown in FIG. 2 , the end plate main body 6A has an outer peripheral cylindrical portion 61, spokes 62 (connecting portions), and an inner peripheral cylindrical portion 63. The outer peripheral cylindrical portion 61 is an integral portion with the end plate flange 6F. The outer peripheral cylindrical portion 61 has an outer peripheral annular portion 611 and an outer peripheral upright portion 612. The outer peripheral upright portion 612 stands upright from the outer peripheral annular portion main surface 611a of the outer peripheral annular portion 611 along the axis A. The end plate flange 6F extends radially from the outer peripheral upright portion outer surface 611d. The outer peripheral annular portion main surface 611a functions as a mounting surface for attaching another device to the motor 1. The outer peripheral annular portion main surface 611a may be defined as part of the end plate main surface 6a.

[0031] An outer circumferential step 613 is formed at the corner between the outer circumferential ring portion main surface 611a and the outer circumferential ring portion inner surface 611c. The outer circumferential step 613 includes an outer circumferential step main surface 613a and an outer circumferential step inner surface 613c. The outer circumferential step main surface 613a is recessed from the outer circumferential ring portion main surface 611a. The outer circumferential step inner surface 613c has a larger inner diameter than the outer circumferential ring portion inner surface 611c.

[0032] The resin part 7 is in contact with the back surface 611b of the outer ring portion (see FIG. 4A). Therefore, the back surface 611b of the outer ring portion constitutes part of the heat path. The back surface 611b of the outer ring portion may be defined as part of the back surface 6b of the end plate. The spokes 62 are connected to a part of the inner circumferential surface 611c of the outer ring portion.

[0033] The spokes 62 connect the inner cylindrical portion 63 to the outer cylindrical portion 61. In the example shown in Fig. 3, the end plate 6 has three spokes 62. The three spokes 62 may be arranged at equal intervals around the axis A.

[0034] As shown in Figure 3, the spaces between adjacent spokes 62 are defined as end plate through-holes 6P1, 6P2, and 6P3. For example, the end plate through-hole 6P1 may be an opening through which a first portion 40a (see Figure 9), which will be described later, can be seen. Similarly, the end plate through-holes 6P2 and 6P3 may be openings through which the second portion 40b and the third portion 40c, respectively, can be seen.

[0035] In the example shown in Figure 3, the end plate 6 has three end plate through holes 6P1, 6P2, and 6P3. The end plate through holes 6P1, 6P2, and 6P3 can be defined as areas surrounded by a portion of the inner circumferential surface 611c of the outer annular portion, a portion of the outer circumferential surface 63d of the inner cylindrical portion, and the spoke circumferential end surfaces 62c. The openings of the end plate through holes 6P1, 6P2, and 6P3 on the end plate main surface 6a side may be defined by edges included in the spoke circumferential end surfaces 62c. The length of the end plate through holes 6P along the axis A may be defined as the length from the end plate back surface 6b to the spoke main surfaces 62a.

[0036] As shown in FIG. 2 , the spokes 62 extend from the outer annular portion inner circumferential surface 611c to the inner cylindrical portion outer circumferential surface 63d. The spoke main surfaces 62a are not flush with the aforementioned outer annular portion main surface 611a. For example, when comparing the heights relative to the spoke back surfaces 62b, the height of the spoke main surfaces 62a is lower than the height of the outer annular portion main surface 611a. The spoke back surfaces 62b are flush with the outer annular portion back surface 611b. Like the outer annular portion back surface 611b, the spoke back surfaces 62b are also part of the end plate back surface 6b and constitute part of the heat path.

[0037] The inner cylindrical portion 63 has an inner cylindrical portion main surface 63a, an inner cylindrical portion back surface 63b, an inner cylindrical portion inner peripheral surface 63c, and an inner cylindrical portion outer peripheral surface 63d. The bearing 21 is disposed on the inner cylindrical portion main surface 63a. The inner cylindrical portion main surface 63a is a bearing disposition surface. The inner cylindrical portion main surface 63a may also be defined as being part of the end plate main surface 6a.

[0038] The inner cylindrical portion back surface 63b is flush with the outer annular portion back surface 611b and the spoke back surfaces 62b. Like the outer annular portion back surface 611b and the spoke back surfaces 62b, the inner cylindrical portion back surface 63b is part of the end plate back surface 6b and also constitutes part of the heat path. As described above, the spokes 62 are connected to part of the inner cylindrical portion outer surface 63d. Another part of the inner cylindrical portion outer surface 63d defines the end plate through holes 6P1, 6P2, and 6P3. The inner cylindrical portion inner surface 63c defines the end plate shaft insertion hole 6H through which the shaft 2 is inserted.

[0039] An inner step portion 633 is also formed at the corner between the inner cylindrical portion main surface 63a and the inner cylindrical portion inner peripheral surface 63c. The inner step portion 633 includes an inner step main surface 633a and an inner step outer peripheral surface 633d. The inner step main surface 633a is recessed from the inner cylindrical portion main surface 63a. The inner step outer peripheral surface 633d has a larger outer diameter than the inner cylindrical portion outer peripheral surface 63d. The inner step portion 633 can also be used, in cooperation with the outer step portion 613, as a portion against which a masking jig is abutted in a motor manufacturing method.

[0040] <Resin Portion> As shown in FIG. 1 , the motor 1 further includes a resin portion 7. The resin portion 7 is filled in the motor stator arrangement region 511 in which the motor stator 4 is arranged. The resin portion 7 covers the coil 4B. More specifically, the resin portion 7 covers the coil ends 41 protruding from the end faces of the core 4A. Such a resin portion 7 prevents the coil 4B from coming into direct contact with air. In other words, the resin portion 7 provides a waterproof function that protects the coil 4B from moisture, and also provides an anti-corrosion function that suppresses the formation of rust on the coil 4B.

[0041] The resin portion 7 is filled in the motor stator arrangement region 511. The resin portion 7 is not filled in the rotor arrangement region 311 where the motor rotor 3 is arranged. Therefore, the resin portion 7 may form an inner peripheral surface 7c that faces the motor rotor 3.

[0042] The resin portion 7 functions as a thermal path that dissipates heat generated in the coil 4B to the housing 5 and end plate 6. The resin portion 7 includes a portion 71 filled between the coil end outer peripheral surface 41b and the housing inner peripheral surface 5c. More specifically, this portion 71 contacts both the coil end outer peripheral surface 41b and the housing inner peripheral surface 5c. As a result, the thermal resistance from the coil end 41 to the housing 5 is dominated by the resin portion 7. Using a highly thermally conductive material for the resin portion 7 allows heat to be efficiently dissipated from the coil end 41 to the housing 5.

[0043] An example of such a resin is a two-component curing epoxy resin.

[0044] The resin portion 7 includes a portion 72 filled between the coil end end surface 41 a and the end plate back surface 6 b. More specifically, the portion 72 contacts both the coil end end surface 41 a and the end plate back surface 6 b. As a result, the thermal resistance from the coil end 41 to the end plate 6 is dominated by the resin portion 7, as described above.

[0045] As shown in FIG. 4A , the resin portion 7 further includes a portion 73 filled in the end plate through hole 6P. The surface of the resin portion 7 exposed from the end plate through hole 6P is referred to as the resin portion exposed surface 73s. The resin portion exposed surface 73s shown in FIG. 4A does not leak out of the end plate through hole 6P. Assume that the upper end of the end plate through hole 6P is defined by the opening edge 62as (the opening edge on the main surface side of the end plate) of the spoke main surface 62a. Assume also that the lower end of the end plate through hole 6P is defined by the opening edge 6bs (the opening edge on the back surface side of the end plate) of the end plate back surface 6b. Based on this assumption, the resin portion exposed surface 73s is located between the spoke main surface 62a and the end plate back surface 6b. Due to the position of the resin portion exposed surface 73s, the inner cylindrical portion main surface 63a protrudes from the resin portion exposed surface 73s. Therefore, the resin portion 7 does not adhere to the inner cylindrical portion main surface 63a. As a result, the bearing 21 can be attached to the inner peripheral cylindrical portion main surface 63a in a good condition.

[0046] The position of the resin portion exposed surface 73s may be at least closer to the motor stator 4 than the inner cylindrical portion main surface 63a. For example, as shown in FIG. 4B , the resin portion exposed surface 73s may be higher than the spoke main surfaces 62a and cover the spoke main surfaces 62a. Even in this case, the position of the resin portion exposed surface 73s is lower than the outer annular portion main surface 611a and / or the inner cylindrical portion main surface 63a. Therefore, the resin portion 7 does not adhere to the outer annular portion main surface 611a and / or the inner cylindrical portion main surface 63a. As a result, components such as the bearing 21 can be attached to the outer annular portion main surface 611a and / or the inner cylindrical portion main surface 63a with ease.

[0047] Next, we will explain a method for manufacturing the motor 1. The motor 1 can be manufactured by one of the two methods described below.

[0048] <Manufacturing Method of First Motor> Figure 5 is a diagram showing the main steps in the manufacturing method of the first motor. First, the motor stator 4 is placed in the housing 5. Next, the cylindrical member 101 (see Figure 6(a)) is placed in the area corresponding to the motor rotor placement area 512. This is to prevent uncured resin from filling the motor rotor placement area 512 when the step of filling the uncured resin is carried out. The end plate 6 is fixed to the housing 5 (S11: see Figure 6(a)). In the following explanation, for convenience of explanation, each part in the process of assembling the motor 1 in each manufacturing process will be referred to as the "motor assembly."

[0049] Next, the motor assembly is housed in the vacuum chamber 102 (S12: see FIG. 6A). The motor manufacturing method of this embodiment utilizes so-called vacuum filling to fill the uncured resin.

[0050] Next, uncured resin 7s is poured through the first end plate through-hole 6P1 (S13: see FIG. 6B). At this time, the motor assembly may be heated to a predetermined temperature to maintain the fluidity of the uncured resin 7s. After a predetermined amount of uncured resin 7s has been poured, the pouring of the uncured resin 7s is stopped.

[0051] At this time, the uncured resin 7s flows from the first end plate through hole 6P1 to the coil end 41, and then flows to the opposite coil end 41. However, because the viscosity of the uncured resin 7s is high, it takes a considerable amount of time for the poured uncured resin 7s to reach a static state. Here, "static state" refers to the state in which the tilted liquid surface of the uncured resin 7s reaches a horizontal position.

[0052] Next, before the uncured resin 7s poured through the first end plate through hole 6P1 reaches a static state, the injection of uncured resin 7s through the second end plate through hole 6P2 begins (S14: see FIG. 7(a)). This step S14 results in the state shown in FIG. 7(a). The uncured resin 7s poured through the second end plate through hole 6P2 flows into the area that the uncured resin 7s poured through the first end plate through hole 6P1 has not yet reached. Then, after a predetermined amount of uncured resin 7s has been poured, the injection of uncured resin 7s is stopped.

[0053] Similarly, before the uncured resin 7s poured through the second end plate through hole 6P2 reaches a static state, the injection of the uncured resin 7s through the third end plate through hole 6P3 begins (S15).

[0054] After step S15, it is confirmed whether the liquid levels of the uncured resin 7s poured through the end plate through-holes 6P1, 6P2, and 6P3 have reached a predetermined position (S16). This confirmation may be performed by visually checking the position of the liquid level 73k of the uncured resin 7s from the end plate through-holes 6P1, 6P2, and 6P3. For example, it may be determined that the liquid level 73k of the uncured resin 7s has reached the predetermined position when the liquid level 73k of the uncured resin 7s reaches the end plate through-holes 6P1, 6P2, and 6P3, as shown in FIG. 7B.

[0055] When it is determined that the liquid level 73k of the uncured resin 7s has reached a predetermined position, the injection of the uncured resin 7s is terminated. Then, the motor assembly is heated to a predetermined temperature. As a result, the uncured resin 7s becomes a solidified resin portion 7. After that, the motor rotor 3 and bearings 21 are attached to obtain the motor 1.

[0056] If it is not determined that the liquid surface 73k of the uncured resin 7s has reached the specified position, the uncured resin 7s is again injected through the first end plate through-hole 6P1 (S13).

[0057] Whether or not the liquid level 73k of the uncured resin 7s has reached the specified position may be checked at any time during each of steps S13 to S15 in which the uncured resin 7s is poured in. When it is determined that the liquid level 73k of the uncured resin 7s has reached the specified position, the repetition of steps S13 to S15 in which the uncured resin 7s is poured in may be terminated, and the process may proceed to the next manufacturing step.

[0058] According to the first motor manufacturing method, uncured resin 7s is poured until the liquid level of the uncured resin 7s reaches each of the end plate through-holes 6P1, 6P2, and 6P3. Reaching the uncured resin 7s into the end plate through-holes 6P1, 6P2, and 6P3 means that the uncured resin 7s has filled the holes until it contacts the end plate rear surface 6b. This ensures that the resin portion 7 is formed between the coil end 41 and the end plate rear surface 6b.

[0059] <Second Motor Manufacturing Method> In the first motor manufacturing method, the uncured resin 7s is poured in (S13, S14, S15) after the end plates 6 are attached to the housing 5 (S11). In the second motor manufacturing method, the uncured resin 7s is poured in and then the end plates 6 are attached.

[0060] 8 is a diagram showing the main steps included in the second motor manufacturing method. First, the motor stator 4 is placed in the housing 5. Next, the cylindrical member 101 is placed in the area corresponding to the rotor placement area 311. The motor assembly is then housed in the vacuum chamber 102 (S21). At this point, the end plates 6 are not attached to the motor assembly.

[0061] Next, uncured resin 7s is poured into the first portion 40a (see FIG. 9) (S22). The first portion 40a is any portion included in the motor stator arrangement area 511 exposed through the housing opening 51h (see FIG. 9). After a predetermined amount of uncured resin 7s has been poured, the pouring of the uncured resin 7s is stopped.

[0062] Next, uncured resin 7s is poured into second region 40b (see FIG. 9) (S23). Second region 40b is an arbitrary region of motor stator arrangement region 511 exposed through housing opening 51h, and is a region different from first region 40a. After a predetermined amount of uncured resin 7s has been poured, the pouring of uncured resin 7s is stopped.

[0063] Then, uncured resin 7s is poured into the third region 40c (see FIG. 9) (S24). The third region 40c is an arbitrary region of the motor stator arrangement region 511 exposed through the housing opening 51h, and is a region different from the first region 40a and the second region 40b. After a predetermined amount of uncured resin 7s has been poured, the pouring of the uncured resin 7s is stopped.

[0064] In the above description, when steps S22, S23, and S24 are performed, the injection of the uncured resin 7s is stopped after a predetermined amount of uncured resin 7s is poured into each portion. For example, the process may proceed to step S23 without stopping the injection of the uncured resin 7s in step S22. For example, while the uncured resin 7s is being poured from the supply device, the motor assembly may be rotated by a predetermined angle to change the pouring position from the supply device from the first portion 40a to the second portion 40b. The pouring position may also be changed from the first portion 40a to the second portion 40b by moving the supply device for the uncured resin 7s while the motor assembly is fixed.

[0065] After step S24, it is confirmed whether the liquid level of the uncured resin 7s has reached a predetermined position (S25). This confirmation may be performed by visually checking the position of the liquid level of the resin through the housing opening 51h.

[0066] When it is determined that the liquid level of the uncured resin 7s has reached a predetermined position, the injection of the uncured resin 7s is terminated. The motor assembly is then removed from the vacuum chamber 102. Next, the end plate 6 is fixed to the housing 5 (S26). At this time, the uncured resin 7s reaches the opening recess 51ha of the housing 5. When the end plate 6 is attached to the housing opening 51h, the uncured resin 7s that has reached the opening recess 51ha flows into the end plate through holes 6P1, 6P2, and 6P3 in response to the pressure applied by the end plate 6. The pressure applied to the uncured resin 7s is generated by the end plate rear surface 6b being in contact with the uncured resin 7s. In other words, the fact that the uncured resin 7s flows into the end plate through holes 6P1, 6P2, and 6P3 when the end plate 6 is attached means that there is no gap between the end plate rear surface 6b and the uncured resin 7s. In other words, the rear surface 6b of the end plate is in contact with the uncured resin 7s. The motor assembly is then heated to a predetermined temperature. After that, the motor rotor 3 and bearings 21 are attached to complete the motor 1.

[0067] If it is not determined that the liquid level of the uncured resin 7s has reached the specified position, the resin is again injected from the first portion 40a (S22).

[0068] As in the first motor manufacturing method, this step may be performed during the steps S22, S23, and S24 of pouring uncured resin.

[0069] <Operations and Effects> The background and problems of the conventional manufacturing method will be pointed out, followed by a description of the motor manufacturing method and the operations and effects of the motor according to the present disclosure.

[0070] Motor stators are equipped with a resin part that seals the entire assembly, including the core and wound coil, to ensure that the coil is waterproof and rust-proof. Furthermore, motors aiming for high power density may use a resin with high thermal conductivity, and by filling the gaps between the stator and the motor housing, which has a water-cooled structure, with resin, a structure is adopted in which the heat generated by the coil is efficiently transferred to the core and case. After the case and stator are assembled, the resin is poured into the opening of the case. The case is then heated to harden the resin. Two-part curing epoxy resin is often used as the resin.

[0071] The openings can be formed, for example, by pouring resin into one end plate before assembling it and then assembling the end plate after the poured resin has hardened. Another example of a method for forming the openings is by drilling holes in the end plate.

[0072] Because the end plates are assembled after the resin is cured, a gap forms between the surface of the cured resin and the end plate. Electric superchargers require resins with high thermal conductivity. However, such resins are highly viscous and prone to trapping air bubbles during pouring. Therefore, to minimize defects after curing, they are cast in a vacuum chamber. As a result, the resin surface bubbles during pouring. Therefore, precise control of pour height is difficult. Therefore, a certain gap (at least 2–3 mm) must be left between the end plate and the cured resin. Furthermore, a settling time (leveling time) is required for the resin surface to even out, resulting in an extremely long casting time. For these reasons, a high-viscosity resin cannot be used. A gap between the cured resin and the end plate can allow condensed water to accumulate in the gap. This penetration can lead to problems such as reduced insulation. It can also prevent heat from being removed from the coil from one end, resulting in performance degradation.

[0073] In view of the above background and problems, the motor manufacturing method and motor disclosed herein solve the problems by the following steps and configuration.

[0074] The manufacturing method of the first motor 1 includes an attachment step (S11) of attaching an end plate 6, which has a first end plate through hole 6P1 and a second end plate through hole 6P2, to a housing 5 that accommodates a motor stator 4 wound with a coil 4B; after the attachment step (S11), a first injection step (S13) of pouring uncured resin 7s into a motor rotor arrangement area 512 of the housing 5 that accommodates the motor stator 4 from the first end plate through hole 6P1, through which the first portion 40a of the coil 4B is visible from outside the housing 5; and a second injection step (S14) of pouring uncured resin 7s into the motor rotor arrangement area 512 of the housing 5 from the second end plate through hole 6P2, through which a second portion 40b, different from the first portion 40a of the coil 4B, is visible from outside the housing 5.

[0075] In the first motor 1 manufacturing method, uncured resin 7s is poured into the motor rotor placement area 512 after the end plate 6 is attached. The uncured resin 7s is poured into the motor rotor placement area 512 through a process (S13) of pouring through the first end plate through hole 6P1 and a process (S14) of pouring through a second end plate through hole 6P2, which is different from the first end plate through hole 6P1. This process shortens the time it takes for the uncured resin 7s to spread throughout the motor rotor placement area 512 compared to pouring the uncured resin 7s from a single location. Therefore, even if the resin portion 7 has high thermal conductivity and viscosity, it can be shortened in time for it to spread throughout the motor rotor placement area 512. As a result, a motor 1 that easily dissipates heat to the outside can be manufactured in a short time.

[0076] In the manufacturing method of the first motor 1, the first injection step (S13) and the second injection step (S14) are repeated to expose the uncured resin 7s from the first end plate through hole 6P1 and the second end plate through hole 6P2. When the uncured resin 7s is exposed from the first end plate through hole 6P1 and the second end plate through hole 6P2, the uncured resin 7s is in contact with the end plate back surface 6b. This ensures that a path for transferring heat from the coil 4B to the end plate 6 via the resin portion 7 is formed.

[0077] In short, in this motor manufacturing method, multiple openings are provided in the end plate 6. As mentioned above, the number of openings may be approximately three, depending on the size of the motor 1. After pouring uncured resin 7s through the first end plate through-hole 6P1, uncured resin 7s can be poured through the next second end plate through-hole 6P2 during the time required for the liquid level to level off, thereby reducing the leveling time. This improves the efficiency of motor manufacturing.

[0078] This motor manufacturing method allows for filling the end plate 6 with high-viscosity resin without gaps while maintaining a realistic takt time. The size of the end plate through-hole 6P, which is the opening, can be reduced. This allows for the mounting rigidity of the bearing housing provided in the end plate 6 and the heat extraction capacity from the end plate 6 side to be maintained.

[0079] When uncured resin 7s is poured from the first end plate through-hole 6P1, the liquid level 73k of the uncured resin 7s is leveled toward the second end plate through-hole 6P2 and the third end plate through-hole 6P3. When the liquid level 73k becomes uneven, uncured resin 7s is continuously poured from the second end plate through-hole 6P2. By repeating this process, the liquid can be poured while maintaining a uniform liquid level 73k. By minimizing the time that uncured resin 7s drips onto the spokes 62 connecting the end plate through-holes 6P, the risk of the uncured resin 7s overflowing can be reduced.

[0080] The manufacturing method of the second motor 1 includes an injection step (S22, S23, S24) of pouring uncured resin 7s through an opening in the housing 5 into different first, second, and third regions 40a, 40b, and 40c in a motor rotor arrangement region 512 of the housing 5, which accommodates the motor stator 4 wound with the coil 4B, and an attachment step (S26) of attaching an end plate 6 having a first end plate through hole 6P1 and a second end plate through hole 6P2 after the injection step (S22, S23, S24). In the attachment step (S28), the end plate 6 is pressed against the liquid surface of the uncured resin 7s, thereby exposing the uncured resin 7s from the first end plate through hole 6P1 and / or the second end plate through hole 6P2.

[0081] In the second motor 1 manufacturing method, uncured resin 7s is poured into the motor rotor placement area 512 from multiple different locations (S22, S23, S24). Therefore, the time required for the uncured resin 7s to spread throughout the motor rotor placement area 512 is shorter than when the uncured resin 7s is poured from a single location. After pouring the uncured resin 7s, the end plates 6 are attached (S26). When attaching the end plates 6, the end plates 6 are pressed against the liquid surface 73k of the uncured resin 7s, exposing the uncured resin 7s from the first end plate through-holes 6P1 and the second end plate through-holes 6P2. Exposing the uncured resin 7s from the first end plate through-holes 6P1 and the second end plate through-holes 6P2 by pressing the end plates 6 means that the end plate back surfaces 6b are in contact with the uncured resin 7s. This allows for the rapid manufacture of a motor 1 that easily dissipates heat.

[0082] In the injection steps (S22, S23, S24) of the second method for manufacturing the motor 1, the uncured resin 7 s is continuously poured in while the housing 5 and the device for supplying the uncured resin 7 s are rotated relatively around the axis A of the housing 5. This step also shortens the time it takes for the uncured resin 7 s to spread throughout the motor rotor arrangement area 512.

[0083] The injection steps (S22, S23, S24) of the second method for manufacturing the motor 1 include a step (S22) of pouring a predetermined amount of uncured resin 7 s into the first portion 40 a of the coil 4 B, and a step (S23) of pouring a predetermined amount of uncured resin 7 s into a second portion 40 b, different from the first portion 40 a, of the coil 4 B. This step also shortens the time it takes for the uncured resin 7 s to spread throughout the motor rotor arrangement area 512.

[0084] The motor 1 includes a motor stator 4 wound with a coil 4B, a motor rotor 3 surrounded by the motor stator 4 and rotating together with the shaft, a housing 5 that receives the motor stator 4 and the motor rotor 3 through an opening in the housing 5 and forms a motor rotor arrangement area 512 that accommodates the received motor stator 4, an end plate 6 attached to the housing opening 5h, and a resin portion 7 filled in the motor rotor arrangement area 512. The resin portion 7 contacts the coil 4B and the end plate 6, and the end plate 6 includes a plurality of end plate through-holes 6P that expose the resin portion 7.

[0085] The resin portion 7 of the motor 1 contacts the coil 4B and the end plate 6. This configuration ensures that a path for transferring heat from the coil 4B to the end plate 6 via the resin portion 7 is formed. As a result, heat can be efficiently released to the outside.

[0086] In the motor 1, the resin portion exposed surfaces 73s exposed from the plurality of end plate through-holes 6P are located between the opening edges 6bs on the rear surface 6b of the end plate and the opening edges 62as on the main surface 6a of the end plate. This configuration ensures that the resin portion 7 is in reliable contact with the rear surface 6b of the end plate.

[0087] The end plate 6 of the motor 1 includes an annular inner cylindrical portion 63 including an end plate shaft insertion hole 6H through which the shaft 2 is inserted; an annular outer cylindrical portion 61 circumferentially surrounding the inner cylindrical portion 63 and having an inner diameter larger than the outer diameter of the inner cylindrical portion 63; and a plurality of spokes 62 arranged at intervals around the axis A of the shaft 2 so as to connect an inner cylindrical portion outer surface 63d of the inner cylindrical portion 63 to an outer annular portion inner circumferential surface 611c of the outer cylindrical portion 61. Each of the plurality of end plate through holes 6P is a region sandwiched between a pair of spokes 62 adjacent to each other around the axis A of the shaft 2. The end face of the inner cylindrical portion 63 protrudes from the spokes 62 along the axial direction of the shaft 2. This structure prevents uncured resin 7s from adhering to the end face of the inner cylindrical portion 63, allowing the end face of the inner cylindrical portion 63 to be used as an installation surface for components.

[0088] In other words, each of the multiple end plate through holes 6P is defined by a spoke 62. The multiple end plate through holes 6P may be connected by a groove that is one step lower than the mounting surface of the other component so that the resin portion 7 may adhere thereto. Examples of the mounting surface of the other component include the outer annular portion main surface 611a and the inner cylindrical portion main surface 63a. Furthermore, a dedicated surface for applying a masking jig may be provided to prevent the liquid surface 73k of the foamed, uncured resin 7s from adhering to the mounting surface of the other component. Examples of the dedicated surface for applying a masking jig include the outer peripheral step portion 613 and the inner peripheral step portion 633.

[0089] The number of openings provided in the end plate 6 may be multiple. The resin portion 7 may be made of different types of resin materials. For example, a resin with high thermal conductivity may be poured until the coil 4B is hidden. Then, a resin with low viscosity and medium thermal conductivity may be poured near the end plate 6. This configuration allows for both control of the liquid level 73k and thermal conductivity. The resin may be poured without assembling the end plate, and then the end plate may be assembled before the resin hardens.

[0090] <Modifications> Examples of the motor manufacturing method and the motor have been described above. The motor manufacturing method and the motor are not limited to the above examples and may be implemented in various forms.

[0091] REFERENCE SIGNS LIST 1 Motor 2 Shaft 3 Motor rotor (rotor) 4 Motor stator (stator) 4A Core 4B Coil 5 Housing 6 End plate 6a End plate main surface 6b End plate back surface 6P1 First end plate through hole 6P2 Second end plate through hole 6P3 Third end plate through hole 62as Opening edge on end plate main surface side 6bs Opening edge on end plate back surface side 7 Resin part 51h Housing opening 61 Outer peripheral cylindrical part 62 Spoke (connecting part) 63 Inner peripheral cylindrical part 73s Exposed surface of resin part (exposed surface of resin part) A Axis

Claims

1. A method for manufacturing a motor, comprising: an attachment step of attaching an end plate, having a first end plate through hole and a second end plate through hole, to a housing containing a stator around which a coil is wound; a first injection step of pouring uncured resin into a stator arrangement area of ​​the housing containing the stator from the first end plate through hole, which allows a first portion of the coil to be visible from outside the housing, after the attachment step; and a second injection step of pouring the uncured resin into the stator arrangement area of ​​the housing from the second end plate through hole, which allows a second portion of the coil different from the first portion to be visible from outside the housing.

2. A method for manufacturing a motor as described in claim 1, wherein the uncured resin is exposed from the first end plate through hole and / or the second end plate through hole by repeating the first injection process and the second injection process.

3. A method for manufacturing a motor, comprising: an injection step of pouring uncured resin through an opening of a housing into a plurality of different locations in a stator arrangement area of ​​a housing containing a stator with a coil wound around it; and after the injection step, an attachment step of attaching an end plate having a first end plate through hole and a second end plate through hole, wherein in the attachment step, the end plate is pressed against the liquid surface of the uncured resin, thereby exposing the uncured resin from the first end plate through hole and / or the second end plate through hole.

4. A method for manufacturing a motor according to claim 3, wherein said injection step comprises continuously pouring in said uncured resin while rotating said housing and a device for supplying said uncured resin relatively about an axis of said housing.

5. A method for manufacturing a motor as described in claim 3, wherein the injection step includes the steps of: pouring a predetermined amount of the uncured resin into a first portion of the coil; and pouring a predetermined amount of the uncured resin into a second portion of the coil different from the first portion.

6. A motor comprising: a stator having a coil wound thereon; a rotor surrounded by the stator and rotating together with a shaft; a housing that receives the stator and the rotor through a housing opening and forms a stator arrangement area in which the received stator is accommodated; an end plate attached to the housing opening; and a resin portion filled in the stator arrangement area, wherein the resin portion contacts both the coil and the end plate, and the end plate includes a plurality of end plate through holes exposing the resin portion.

7. The motor according to claim 6, wherein an exposed surface of the resin portion exposed from the end plate through hole is located between an opening edge on the back surface side of the end plate and an opening edge on the main surface side of the end plate.

8. The motor described in claim 6, wherein the end plate includes: an inner cylindrical portion having an annular shape including an end plate shaft insertion hole through which the shaft is inserted; an outer cylindrical portion having an annular shape that circumferentially surrounds the inner cylindrical portion and has an inner diameter larger than the outer diameter of the inner cylindrical portion; and a plurality of connecting portions arranged at intervals from each other around the axis of the shaft so as to connect the outer peripheral surface of the inner cylindrical portion to the inner peripheral surface of the outer cylindrical portion, the end plate through hole being an area sandwiched between a pair of the connecting portions adjacent to each other around the axis of the shaft, and an end face of the inner cylindrical portion protrudes from the connecting portions along the axial direction of the shaft.