Rotating electrical machine

Abstract

A rotating electrical machine (100) comprises a stator (20) and a rotor (10) that rotates with the outer peripheral surface thereof facing the inner peripheral surface of the stator (20). The stator (20) comprises a cylindrical frame (24) and a bracket (60) that closes an opening (24Q) at the end of the frame (24) in the axial direction (Z). The rotating electrical machine (100) has a draining groove (63) that is recessed inward in the radial direction (X) and extends in the circumferential direction (Y) in at least one of the frame (24) and the bracket (60) of the fitting part between the frame (24) and the bracket (60).

Description

Rotating electric machines

[0001] The present disclosure relates to a rotating electric machine.

[0002] As a structure for completely waterproofing a rotating electrical machine such as a motor, an example of a structure in which a rubber gasket is placed on the mating surfaces of components is disclosed, as in Patent Document 1. Also, as a structure for preventing water from entering the motor and for draining water that does enter, a structure in which a drain hole is provided that opens vertically downward when the motor is installed is disclosed, as in Patent Document 2.

[0003] Patent No. 6492892 Patent No. 3168177

[0004] The rubber gasket used in Patent Document 1 has issues such as difficulty in dimensional control and variations in the crushing load due to the need to crush it before use, so it is necessary to ensure the dimensional accuracy, rigidity, and strength of the mating parts that come into contact with the gasket.

[0005] Furthermore, in environments where the water pressure applied to the motor is low, rubber seals may not be necessary, and a structure like that described in Patent Document 2 can be used. However, with a structure in which the end housing and yoke housing are fitted together, it is difficult to achieve stable, gap-free adhesion between the end housing and yoke housing due to dimensional variations in the components. In motors driven by inverter control, surge voltages are applied to the live parts, so it is necessary to keep moisture away from the live parts as much as possible. While this can be partially resolved by moving the live parts away from water intrusion paths, this increases the motor's size, making it difficult to fit into the equipment in which the motor is installed.

[0006] The present disclosure discloses a technique for solving the above-described problems, and aims to provide a rotating electric machine that has a compact structure while ensuring waterproof performance.

[0007] The rotating electric machine disclosed in the present disclosure is a rotating electric machine comprising a stator and a rotor that rotates with its outer peripheral surface facing the inner peripheral surface of the stator, wherein the stator comprises a cylindrical frame and a bracket that closes an opening at the axial end of the frame, and at least one of the frame and the bracket at the fitting portion between the frame and the bracket has a drain groove that is recessed radially inward and extends circumferentially.

[0008] According to the rotating electric machine disclosed in the present disclosure, it is possible to provide a rotating electric machine with a compact structure while ensuring waterproof performance.

[0009] 1. A cross-sectional view of a motor according to embodiment 1. A plan view of a bracket according to embodiment 1, as seen from the axial Z- side. A cross-sectional view taken along the line A-A in FIG. 2. A perspective view of a bracket according to embodiment 1. A perspective view of a stator according to embodiment 1. A cross-sectional view of a stator according to embodiment 1. An enlarged view of a main part of a motor according to embodiment 1. An enlarged view of a main part of a motor according to embodiment 1. A schematic cross-sectional view of a motor according to embodiment 1. A diagram showing a path along which water flows that has entered the motor from a screw hole in the bracket according to embodiment 1. A cross-sectional view showing another example of a motor according to embodiment 1. A diagram showing a fitting portion between a bracket and a stator according to embodiment 2. A diagram showing a fitting portion between a bracket and a stator according to embodiment 3. A diagram showing a fitting portion between a bracket and a stator according to embodiment 4. A perspective view of a stator according to embodiment 5. A perspective view showing the shape of a lead holder according to embodiment 5. A perspective view of a motor according to embodiment 5. An enlarged cross-sectional view of a main part of a motor according to embodiment 5. A diagram showing a cross section of the motor according to embodiment 5 near a drain outlet. A perspective view of a stator according to embodiment 6. A perspective view of a motor according to embodiment 6. FIG. 24 is an enlarged cross-sectional view of a main part showing an example of a motor provided with a plurality of drain grooves. FIG. 25 is an enlarged cross-sectional view of a main part showing an example of a motor provided with a plurality of drain grooves. FIG. 26 is an enlarged view of a main part of a motor according to embodiment 7. FIG. 27 is an enlarged view of a main part of FIG. 24. FIG. 28 is an enlarged view of a main part of a motor according to embodiment 7. FIG. 29 is a diagram showing another example of a base. FIG. 30 is a perspective view showing yet another example of a base according to embodiment 7. FIG. 31 is a diagram showing another fixing method of the bracket according to embodiment 1, showing the state before fixing. FIG. 32 is a diagram showing another fixing method of the bracket according to embodiment 1, showing the state after fixing.

[0010] First Embodiment. A rotating electric machine according to the first embodiment will now be described with reference to the drawings. FIG. 1 is a cross-sectional view of a motor 100 according to the first embodiment. As shown in FIG. 1, in the first embodiment, the motor 100, which is a rotating electric machine, is installed horizontally. However, as long as the tip of the shaft 11 is oriented between vertically upward and horizontally, a positional relationship is maintained in which the water intrusion path (described below) is above the installed motor 100 and the drainage path is below the installed motor 100, thereby achieving the waterproofing effect described below. In this specification, the axial direction of the motor 100 is referred to as the Z-axis direction, the load side (right side of FIG. 1) where the load is connected to the shaft 11 is referred to as the Z-axis direction, and the opposite side (left side of FIG. 1) is referred to as the Z+axis direction. The radial direction of the motor 100 is referred to as the X-axis direction, and the circumferential direction of the motor 100 is referred to as the Y-axis direction. Note that the term "fitting portion" used in the claims refers to the entire area where the stator frame and a bracket (described below) are fitted together.

[0011] The motor 100 includes a stator 20, a rotor 10 that rotates with its outer peripheral surface facing the inner peripheral surface of the stator 20, a shaft 11 that supports the rotor 10, a bearing Br that supports the load side of the shaft 11, a counter-load side housing 30 that supports the counter-load side bearing Br, a circuit board 40 that is disposed on the +axial Z side of the counter-load side housing 30 and controls the current flowing through the coil 21 of the stator 20, a bracket 60 that is disposed on the outside of the circuit board 40 in the axial Z direction via a heat dissipation sheet 50, and a lead wire WL that supplies power to the circuit board 40. The heat dissipation sheet 50 is disposed to dissipate heat generated in the circuit board 40 to the outside. The bracket 60 is also a lid that closes an opening 24Q at the counter-load side end of the resin frame 24 of the stator 20.

[0012] The stator 20 has a stator core 22 around which a coil 21 is wound via an insulator 23, and the outer periphery is molded with a molded resin to form a resin frame 24. The portion of the resin frame 24 that holds a bearing at the load-side end of the resin frame 24 is a load-side housing 24L. The end of the resin frame 24 on the non-load side is a first fitting portion 24K1 that fits with the outer periphery of the bracket 60. In addition, the resin frame 24 has a second fitting portion 24K2, which is located closer to the load side than the first fitting portion 24K1 and has an inner diameter smaller than that of the first fitting portion 24K1, that fits with the outer periphery of the non-load-side housing 30.

[0013] FIG. 2 is a plan view of the bracket 60 as viewed from the axial Z- side. FIG. 3 is a cross-sectional view taken along the line A-A in FIG. 2. FIG. 4 is a perspective view of the bracket 60. The bracket 60 is disk-shaped and has an outer fitting portion 61OUT on its outer peripheral surface that protrudes outward in the radial direction X like a flange and is fitted with the first fitting portion 24K1 of the resin frame 24. The bracket 60 also has an inner fitting portion 61IN on its outer peripheral surface that is closer to the axial Z-side of the outer fitting portion 61OUT and protrudes outward in the radial direction X with a smaller diameter than the outer fitting portion 61OUT. A drain groove 63 is formed between the outer fitting portion 61OUT and the inner fitting portion 61IN. The drain groove 63 extends around the entire periphery of the bracket 60 in the circumferential direction Y and has a smaller diameter than the inner fitting portion 61IN, recessed inward in the radial direction X.

[0014] The bracket 60 also has a flat board contact portion 41 that comes into contact with the board 40 via the heat dissipation sheet 50 to dissipate heat. If the bracket 60 is made of a metal such as aluminum alloy or steel, the drain grooves 63 can be easily formed by turning. If the bracket 60 is made of a resin, the drain grooves 63 can be formed by molding using a slide-type mold or by turning after molding.

[0015] Three screw holes 60H for fastening the bracket 60 with screws are opened in the axial Z direction radially inward from the minimum diameter portion of the drain groove 63. An end face 60S on the negative axial Z side of the bracket 60 is provided with a drainage channel 64. The drainage channel 64 is recessed toward the positive axial Z side so as to extend from a starting point 64S below the screw hole 60H that is located on the uppermost G+ side in the vertical direction G (upper side in FIG. 2 ) and on the inner side in the radial direction X, to the lower G- side in the vertical direction G and inward in the radial direction X from the starting point 64S. In other words, this drainage channel 64 starts between the screw hole 60H, which is located at the uppermost G+ side in the vertical direction G, and the substrate contact portion 41, extends further downward than the lower end of the substrate contact portion 41, and is connected to a water collection portion 64P formed on the end face 60S (inner surface) on the axial Z- side of the bracket 60, recessed toward the axial Z+ side (outside), and located radially inward in the radial direction X than the starting point 64S.

[0016] When water seeps into the inside of the motor 100 through the screw hole 60H, the drainage channel 64 serves to guide the infiltrating water via the water collection portion 64P to a drain outlet provided on the downward G- side in the vertical direction G, which will be described later. The drainage channel 64 is effective only when the screw hole 60H of the bracket 60 is located radially inward of the inner fitting portion 61IN, and is unnecessary when the screw hole 60H of the bracket 60 is located radially outward of the inner fitting portion 61IN. The drainage channel 64 is composed of an inclined groove 64K1 whose depth gradually deepens toward the axial Z+ side from the starting point 64S downward G-, and a guide groove 64K2 that connects to the lower end 64KU of the inclined groove 64K1 and connects to the water collection portion 64P at the same depth. That is, in the drainage channel 64, the bottom surface of the portion of the starting point 64S closest to the screw hole 60H of the bracket 60 is located furthest to the negative axial Z side, and as the distance from the screw hole 60H of the bracket 60 increases, the bottom surface of the inclined groove 64K1 that constitutes the drainage channel 64 inclines toward the positive axial Z side, and the depth of the inclined groove 64K1 in the axial Z direction increases. The lower end 64KU of the inclined groove 64K1 of the drainage channel 64 is connected to the upper end of the guide groove 64K2 of the drainage channel 64, which has the same depth over its entire length and whose bottom surface is not inclined in the axial Z direction. This allows water that enters through the screw hole 60H and flows downward to be collected by the Coanda effect.

[0017] FIG. 5 is a perspective view of the stator 20. FIG. 6 is a cross-sectional view of the stator 20. FIG. 7 is an enlarged view of a main portion of the motor 100. It is an enlarged view of the fitting portion between the bracket 60 and the resin frame 24. An outer fitting portion 24OUT having the same diameter as the outer fitting portion 61OUT of the bracket 60 is formed at the end of the resin frame 24 of the stator 20 on the + axial Z side, and an inner fitting portion 24IN having the same diameter as the inner fitting portion 61IN of the bracket 60 is formed on the - axial Z side of the outer fitting portion 24OUT. These fitting portions are fitted together when the bracket 60 is assembled to the stator 20. That is, a counterbore portion 24Z recessed in an annular shape toward the - axial Z side is formed at the end of the non-load side of the resin frame 24. The outer wall surface of the counterbore portion 24Z in the radial X direction is the outer fitting portion 24OUT, and the wall surface on the - axial Z side of the counterbore portion 24Z is the inner fitting portion 24IN.

[0018] As shown in FIG. 5 , the countersunk portion 24Z has a groove 27 at its end on the lower G- side in the vertical direction G, which, when combined with a bracket 60, serves as the drain outlet EX and outlet for the lead wires WL shown in FIG. 1 . The groove 27 is recessed in the axial direction Z- direction at the axial direction Z+ end of the resin frame 24, and the axial direction Z range of the groove 27 extends from the axial direction Z+ end to the axial direction Z- side of the bottom surface of the countersunk portion 24Z. Depending on the thickness and number of lead wires WL, multiple outlets for the drain outlets EX and lead wires WL may be provided as long as they are located on the vertically lower side. Separate outlets for the drain outlets EX and lead wires WL may also be provided. However, depending on the operating environment of the motor 100, splashes of water may enter from below, so it is preferable to have a small number of outlets for the drain outlets EX and lead wires WL.

[0019] Because only a very small amount of water will enter, the drain outlet EX only needs to be open enough to allow ventilation, and a part for fixing the lead wires WL may be fitted into the drain outlet EX / lead wire WL outlet, or a labyrinth structure (described later) may be used to allow the lead wires WL to be discharged as a countermeasure against water splashes from below. As shown in FIG. 6, the drain opening 27IN on the inside of the drain outlet EX / lead wire WL outlet communicates with the drain groove 63 of the bracket 60 as shown in FIG. 1. That is, the drain outlet EX communicates with the interior of the resin frame 24 on the axially negative side of the bracket 60, i.e., the interior on the axially opposite side of the first fitting portion 24K1 between the resin frame 24 and the bracket 60.

[0020] A bracket fixing screw hole 24H1 and a counter-load-side housing fixing screw hole 24H2 are provided radially inward of the inner fitting portion 24IN at positions corresponding to the screw holes 60H of the bracket 60. The bracket fixing screw hole 24H1 is positioned radially inward of the inner fitting portion 24IN in the X direction to make the motor 100 more compact, but if the size of the motor 100 allows, the bracket fixing screw hole 24H1 may be positioned radially outward of the inner fitting portion 24IN in the X direction. If the bracket fixing screw hole 24H1 is positioned radially outward of the inner fitting portion 24IN in the X direction, the drainage channel 64 of the bracket 60 described above does not need to be provided.

[0021] The outer fitting portions 61OUT, 24OUT and the inner fitting portions 61IN, 24IN provided on the bracket 60 and the stator 20 vary in geometric precision such as coaxiality and circularity, or in dimensional precision such as inner diameter and outer diameter, due to manufacturing variations, and if both fitting portions are interference-fitted, it will be difficult to assemble the bracket 60 to the stator 20. For this reason, one or both pairs of the outer fitting portions 61OUT, 24OUT and the inner fitting portions 61IN, 24IN are designed to have clearance fit dimensions that leave a gap between them.

[0022] Due to the relative mounting positions of the anti-load side housing 30 and the bracket 60, the positions of the base 24H1D of the bracket fixing screw hole 24H1 and the base 24H2D of the anti-load side housing fixing screw hole 24H2 are such that the base 24H1D of the bracket fixing screw hole 24H1 protrudes further toward the + axial Z direction than the other. Therefore, the base 24H1D of the bracket fixing screw hole 24H1, which is on the + axial Z direction when the motor 100 is installed, is provided with a base groove DM recessed in the - axial Z direction along the outer peripheral surface of the counterbore portion 24Z. The base groove DM is effective in preventing water retention, as described below.

[0023] Fig. 8 is an enlarged view of a main portion of the motor 100. Fig. 9 is a schematic cross-sectional view of the motor 100. Fig. 10 is a cross-sectional perspective view of a main portion of the motor 100. In Fig. 9, the circuit board 40 and the bracket 60 are depicted in their entirety. The arrows in Figs. 8 and 9 indicate the flow path of water that has entered through the fitting portion between the bracket 60 and the resin frame 24 of the stator 20.

[0024] As described above, because there is a minute gap between the outer fitting portion 61OUT of the bracket 60 and the outer fitting portion 24OUT of the resin frame 24, a small amount of water seeps into the motor 100 from the gap between the outer fitting portion 61OUT of the bracket 60 and the outer fitting portion 24OUT of the stator 20. The water that seeps in from there flows downward to the G- side in the vertical direction G, is trapped in the drain groove 63, branches within the drain groove 63 in the depth direction and the front direction in Figure 8, flows downward G- along the drain groove 63 recessed in the radial direction X as shown in Figure 9, and is discharged to the outside of the motor 100 through the drain outlet EX (which also serves as an outlet for the lead wires WL) formed by the bracket 60 and the groove 27 described above, which is connected to the drain groove 63.

[0025] To prevent water from entering the motor 100 further inside than the inner fitting portions 61IN and 24IN, i.e., on the negative axial Z side, the drain groove 63 needs to have sufficient drainage capacity. Therefore, the width W of the drain groove 63 in the axial Z direction and the depth H of the drain groove 63 in the radial X direction shown in Figure 8 are set as shown below. Even if the drainage capacity is sufficient, if the cross section of the drain groove 63 is too small, water may penetrate between the inner fitting portions 61IN and 24IN due to capillary action.

[0026] Here, the amount of rise in water level due to capillary action is expressed as h = 2T cos θ / ρgr (T: surface tension, θ: contact angle, ρ: density, g: gravitational acceleration, r: radius of the tube), so the inequality where r is replaced with W and h with H serves as a guide for determining H and W. Assuming that ρ = 1000 kg / m3 and g = 9.8 m / s2, the surface tension of water is in the range of T = 0.0589 to 0.0756 N / m depending on the temperature, and the contact angle of water is in the range of θ = 20° (glass), 70 to 89° (resin), or 40 to 80° (metal) depending on the surface roughness, the relationship between the depth H (mm) of the drain groove 63 and the width W (mm) of the drain groove 63 is expressed by the following equation. H・W≧11.3~14.5 (glass) H・W≧0.21~5.28 (resin) H・W≧2.09~11.8 (metal)

[0027] Figure 10 is a diagram showing the path of water that has entered the motor 100 from the screw holes 60H for the screws that secure the bracket 60 to the stator 20. In order to make clear the path of water that has entered, Figure 10 shows a cross section cut at the screw holes 60H of the stator 20, the bracket 60, and the substrate 40. For simplicity, the rotor, the stator core 22 inside the stator 20, the insulator 23, and the coils 21 are not shown. Of the three screws S, only the screws S in the portion where the cross section of the stator 20 remains are shown.

[0028] In the vicinity of the screw S, the axial force of the screw S tightly holds the bracket 60 and the resin frame 24 together, preventing water from entering, but in the unlikely event that a small amount of water does enter, the water will be drained out of the motor 100 by following the path indicated by the arrows in Figure 10. Water that enters through the threaded hole 60H for the screw S at the highest position flows down the drainage channel 64 provided in the bracket 60, passes through the water collection portion 64P, and is drained to the outside from the drain outlet EX.

[0029] In this way, the water is guided to the drain outlet EX so as not to approach the substrate 40. Furthermore, water that does not follow the drain path 64 is guided to the drain outlet EX along the base groove DM shown in FIG. 5 to prevent it from accumulating in the portion of the base 24H1D of the bracket fixing screw hole 24H1 on the lower side G- in the vertical direction G.

[0030] In this way, by providing a drain groove 63 on the surface where the bracket 60 and the stator 20 fit together and providing a drain outlet EX on the downward G- side of the motor 100 in the vertical direction G, a structure can be realized in which small amounts of water that have entered through the fitting portion between the resin frame 24 of the stator 20 and the bracket 60 can be drained outside the motor 100 without coming into contact with the substrate 40.

[0031] Furthermore, when the screws S for fastening the bracket 60 are positioned radially inward of the inner fitting portions 61IN and 24IN in the X direction to compact the motor 100, a groove-shaped drainage channel 64 extending from between the screw hole 60H and the board contact portion 41 downward in the vertical direction G toward the G- side and outward in the X direction can be provided in the bracket 60 to prevent the board 40 from getting wet. FIG. 28 is a diagram showing another method for fastening the bracket 60, illustrating the state before fastening. FIG. 29 is a diagram showing the state after fastening. Up to this point, a screw fastening structure that is advantageous for disassembly has been described as an example of a means for fastening the bracket 60. However, as shown in FIG. 28, a protrusion 24P protruding from the stator frame toward the + axial direction Z of the bracket 60 is inserted into the hole 60H2 of the bracket 60, and then, as shown in FIG. 29, the protrusion 24P may be inserted into the hole 60H2 of the bracket 60, and then the protrusion 24P may be crimped with a crimping tool TL having a thermal or mechanical means to form a head 24T, thereby fastening the bracket 60. For example, if the protruding portion 24P is made of resin, the head portion 24T can be formed by heat welding or ultrasonic welding, and if it is made of metal, rivet caulking or the like can be used.

[0032] Although the first embodiment has been described taking the example of preventing the circuit board 40 from getting wet, even in a motor that does not have a built-in circuit board 40, the structure of the first embodiment can be adopted to prevent the power terminals from getting wet by providing the drain groove 63 and the drain channel 64. In this case, the starting point 64S of the drain channel 64 is between the highest screw hole S and the terminal.

[0033] Furthermore, although the above has shown an example of the structure of the stator 20 covered with the resin frame 24, it goes without saying that the same effect can be obtained by using a structure in which the stator 20 core is press-fitted or shrink-fitted into a cylindrical or bowl-shaped frame, and by providing an outer fitting portion 24OUT and an inner fitting portion 24IN similar to those of this embodiment on the end faces of the frame in the axial direction Z.

[0034] Fig. 11 is a cross-sectional view showing another example of the motor 100. The motor 100 may have a configuration as shown in Fig. 11 in which the non-load side housing 30 is integrated with the bracket 60. In Fig. 11, the drain groove 63 of the bracket 60 is shown as having a rectangular cross section perpendicular to the circumferential direction Y, but the cross-sectional shape is not limited to this, and the effects of this embodiment can be achieved with a triangular or semicircular cross section as long as it is open outward in the radial direction X.

[0035] According to the rotating electric machine of embodiment 1, the rotating electric machine comprises a stator and a rotor that rotates with its outer peripheral surface facing the inner peripheral surface of the stator, wherein the stator comprises a cylindrical frame and a bracket that closes an opening at the axial end of the frame, and at least one of the frame and the bracket at the fitting portion between the frame and the bracket has a drain groove that is recessed radially inward and extends circumferentially, thereby making it possible to provide a rotating electric machine with a compact structure while ensuring waterproof performance.

[0036] In addition, when the rotating electric machine is installed, a drain hole is provided vertically downward for discharging water that has entered the interior, and the drain groove is connected to the drain hole, so that water that has entered through the fitting portion is guided along the outer peripheral surface of the fitting portion to the drain hole, thereby preventing water from seeping into the interior of the rotating electric machine. Furthermore, since the drain hole is connected to the interior of the frame on the axially opposite side of the bracket from the fitting portion side, water that has entered the bracket through the screw hole can be drained.

[0037] Furthermore, the drain port of the stator is formed in the opening of the frame of the stator and is formed by the bracket and a groove recessed toward the stator, so that the drain port can be formed easily.

[0038] Furthermore, since the lead wires connected to the substrate of the rotating electrical machine are led out from the drain outlet, there is no need to provide a separate lead wire outlet, which reduces the manufacturing costs of the rotating electrical machine.

[0039] Furthermore, when the axial width of the drain groove is W (mm) and the radial height is H (mm), if the material of the component in which the drain groove is provided is metal, H·W≧2.09 is satisfied, and if it is resin, H·W≧0.21 is satisfied, so sufficient drainage capacity can be ensured.

[0040] Furthermore, since no other members are disposed between the frame and the bracket, the manufacturing costs of the rotating electrical machine can be reduced.

[0041] In addition, the end face of the bracket on the opening side is provided with a drainage channel that extends downward and radially inward from a starting point on the radially inner side below the hole that is located vertically above the mounting portion in the installed posture of the rotating electric machine, and is recessed and connected to the drainage outlet, thereby preventing water entering through the screw hole from affecting the circuit board, etc.

[0042] The drainage channel has an inclined groove that gradually deepens from the starting point from above toward below in the vertical direction when the rotating electrical machine is installed, so that water that enters through the screw holes and flows downward can be collected by the Coanda effect. The drainage channel is also provided on the inner surface of the bracket and connected to a water collecting portion that is recessed outward in the axial direction, and the water collecting portion is connected to the drainage port, so that water that enters the interior of the rotating electrical machine from the bracket can be guided from the water collecting portion to the drainage port.

[0043] In this embodiment, the bracket 60 is provided on the anti-load side, but the present invention is also applicable to a type in which the resin frame 24 has an opening on the load side.

[0044] Second Embodiment. The following describes a rotating electric machine according to the second embodiment, focusing on differences from the first embodiment. Figure 12 is a diagram showing the fitting portion between bracket 260 and resin frame 224 of stator 220 according to the second embodiment, and is a diagram of a portion corresponding to Figure 8 of the first embodiment. In the second embodiment, counterbore portion 24Z, which is provided at the end portion of stator 20 on the + side in the axial direction Z in the first embodiment, is absent. Instead, a recess 260M is provided around the entire circumference of bracket 260 in the circumferential direction Y, recessing annularly from end face 260S on the - side in the axial direction Z to the + side in the axial direction Z. The end portion of resin frame 224 of stator 220 on the + side in the axial direction Z is fitted into this recess 260M.

[0045] That is, the outer peripheral surface of the end portion of resin frame 224 of stator 220 on the + axial direction Z side is outer fitting portion 224OUT, and the outer peripheral surface of recess 260M is outer fitting portion 261OUT. Also, the inner peripheral surface of resin frame 224 of stator 220 on the + axial direction Z side is inner fitting portion 224IN, and the inner peripheral surface of recess 260M is inner fitting portion 261IN. A drainage groove 263 recessed inward in the radial direction X of bracket 260 is formed on the inner peripheral surface of recess 260M over the entire circumference in the circumferential direction Y of bracket 260. The structure is otherwise the same as in embodiment 1.

[0046] As shown by the arrows in Figure 12, water that has entered between outer fitting portions 224OUT and 261OUT flows down drain groove 63 and is discharged from drain outlet EX to the outside of motor 100, just as in embodiment 1. In the case of embodiment 2, the structure makes it difficult for water to enter from the left side of Figure 12, which is effective when using motor 100 in an environment where the anti-load side is exposed to water.

[0047] According to the rotating electric machine of embodiment 2, the bracket has a ring-shaped recess in the end face on the stator side, the end of the frame on the opening side is fitted into the recess, and the drain groove is formed on the inner surface of the recess, so that the waterproof effect is high when the side is exposed to water.

[0048] Third Embodiment. The following describes a rotating electric machine according to the third embodiment, focusing on the differences from the first and second embodiments. Figure 13 is a diagram showing the structure of the fitting portion between a bracket 360 according to the third embodiment and a resin frame 324 of a stator 320, and is a diagram of a portion corresponding to Figure 8 of the first embodiment. In this embodiment, there is no outer fitting portion, and only an inner fitting portion is used, in which a portion of the outer peripheral surface of the bracket 360 fits into the inner peripheral surface of the stator 320. The inner peripheral surface of the end of the resin frame 324 of the stator 320 on the + axial direction Z side is an inner fitting portion 324IN, and the outer peripheral surface of the bracket 360 on the - axial direction Z side is an inner fitting portion 361IN formed with a smaller diameter than the end on the + axial direction Z side.

[0049] A drain groove 363 recessed radially inward is formed on the axial Z+ side of the inner fitting portion 361IN of the bracket 360, over the entire circumference in the circumferential direction Y of the bracket 360. The rest of the structure is the same as in the first embodiment.

[0050] 13, water that has entered between bracket 360 and resin frame 324 of stator 320 flows down drain groove 363 and is discharged from drain outlet EX to the outside of motor 100, as in embodiment 1. Although embodiment 3 has slightly lower waterproofing performance than embodiments 1 and 2, it has the advantage that, because there is no external fitting portion, there are fewer points requiring dimensional control during manufacturing, making it easier to produce motor 100.

[0051] According to the rotating electric machine of embodiment 3, the inner peripheral surface of the frame is fitted to the outer peripheral surface of the bracket, and the drain groove is formed on the outer peripheral surface of the bracket, thereby reducing the manufacturing costs of the rotating electric machine.

[0052] Embodiment 4. A rotating electric machine according to embodiment 4 will be described below, focusing on the differences from embodiment 2. Figure 14 is a diagram showing the fitting portion between bracket 460 and resin frame 424 of stator 420 according to embodiment 4, and is a diagram of the portion corresponding to Figure 12 of embodiment 2.

[0053] As in the second embodiment, a recess 460M recessed annularly in the +axial direction Z is provided on an end face 460S on the −axial direction Z side of disk-shaped bracket 460, over the entire circumference in the circumferential direction Y of bracket 460. An end of resin frame 424 of stator 420 on the +axial direction Z side is fitted into this recess 460M.

[0054] That is, the outer peripheral surface of the end portion of the resin frame 424 of the stator 420 on the + axial direction Z side is the outer fitting portion 424OUT, and the outer wall surface of the recess 460M in the radial direction X is the outer fitting portion 461OUT. Also, the inner peripheral surface of the end portion of the resin frame 424 on the + axial direction Z side of the stator 420 is the inner fitting portion 424IN, and the inner wall surface of the recess 460M in the radial direction X is the inner fitting portion 461IN. Furthermore, a drain groove 424M1 recessed toward the inside of the stator 420 in the radial direction X is formed in the outer fitting portion 424OUT, which is the outer peripheral surface of the resin frame 424, around the entire periphery of the resin frame 424 in the circumferential direction Y. The rest of the structure is the same as in the third embodiment.

[0055] As shown by the arrows in Figure 14, water that has entered between the outer fitting portions 424OUT and 461OUT flows down the drain groove 424M1 and is discharged from the drain outlet EX to the outside of the motor 100, just as in the first embodiment. In the case of the fourth embodiment, the structure also makes it difficult for water to enter from the left side in Figure 14, so this is effective for use in an environment where the anti-load side is exposed to water.

[0056] According to the rotating electric machine of embodiment 4, the bracket has a ring-shaped recess on the end face on the stator side, the end of the frame on the opening side is fitted into the recess, and the drain groove is formed on the outer peripheral surface of the end of the frame on the opening side, so that the waterproof effect is high when the opening side is exposed to water.

[0057] Fifth Embodiment A rotating electric machine according to a fifth embodiment will now be described, focusing on the differences from the first embodiment. Figure 15 is a perspective view of a stator 520. A resin frame 524 has a groove-shaped drain outlet EX and a lead holder fitting groove WHM below G- in the vertical direction G relative to the installation posture of the motor 100. The shapes of the parts other than the lead holder fitting groove WHM are the same as those of the other embodiments.

[0058] FIG. 16 is a perspective view showing the shape of the lead holder WH according to the fifth embodiment. FIG. 17 shows the motor 100 in a fully assembled state, with the bracket 560 shown in a see-through view to facilitate understanding of the internal structure. FIG. 18 is an enlarged cross-sectional view of a main portion of the motor 100. The lead wires WL are not shown. The lead holder WH has the function of holding the lead wires WL, has holes with the same diameter as the lead wires WL, and is shaped to fit into and be positioned in the lead holder fitting grooves WHM of the stator 520. Furthermore, the surface of the bracket 560 corresponding to the drain groove 63 is shaped so that the lead holder WH does not block the drain groove 63 when the bracket 560 is assembled to the stator 520.

[0059] The size relationship between the lead holder WH and the lead holder fitting groove WHM of the stator 520 can be set to a clearance fit dimensional relationship when ease of assembly is important, and the fitting gap can also be set so that water that has trickled down the drain groove 63 of the bracket 60 is discharged to the outside of the motor 100.

[0060] If it is desired to prevent the lead wire WL from getting wet, the material of the lead holder WH is made of a highly adhesive elastic material, and the dimensions of the lead holder WH and the lead holder fitting groove WHM of the stator 520 are tightly fitted together, so that water that has trickled down the drain groove 63 of the bracket 60 passes through the lead holder WH and is discharged from the drain outlet EX.

[0061] 19 is a cross-sectional view of the vicinity of the drain outlet EX of the motor 100. The drain groove 63 is directly connected to the drain outlet EX, but the drain outlet EX does not communicate with the interior of the motor 100, and is designed to withstand the intrusion of water caused by splashes from below. In addition, because the outlet for the lead wires WL and the drain outlet EX are separated, water from the drain groove 63 does not flow down the lead wires WL, which has the effect of making it difficult for water to enter the interior of the motor 100.

[0062] According to the rotating electric machine of embodiment 5, the drain outlet is connected only to the drain groove, so that, for example, in cases where the screw holes fastening the bracket to the resin frame do not communicate with the interior of the rotating electric machine, a drainage channel is not required, and the drainage structure can be simplified.

[0063] The device also includes a lead holder that holds lead wires connected to the circuit board of the rotating electric machine, the frame has a lead holder fitting groove that positions the lead holder, and the lead holder is shaped so as not to block the drain groove, so that the lead holder does not interfere with the drainage of water flowing through the drain groove.

[0064] Sixth Embodiment A rotating electric machine according to the sixth embodiment will now be described, focusing on the differences from the first embodiment. Figure 20 is a perspective view of a stator 620 according to the sixth embodiment. Figure 21 is a perspective view of a motor 100 according to the sixth embodiment, and, similar to Figure 17, is a view seen through a bracket 660. The drain outlet EX has a labyrinth structure in which a labyrinth inner wall 65IN is provided on the inside of the drain outlet EX that opens toward the bracket 60 in the axial direction, and a labyrinth outer wall 65OUT is provided on the outside. The labyrinth inner wall 65IN and the labyrinth outer wall 65OUT are positioned so as to overlap each other when viewed from the radial direction X, thereby preventing direct intrusion of water from below.

[0065] According to the rotating electric machine of the sixth embodiment, the drain outlet has a labyrinth structure, so that reverse intrusion of water through the drain outlet can be prevented.

[0066] Seventh Embodiment. A rotating electric machine according to the seventh embodiment will be described below, focusing on the differences from the first embodiment. FIG. 24 is an enlarged view of a main portion of a motor according to the seventh embodiment. It is a cross-sectional view of a portion corresponding to FIG. 7 of the first embodiment. FIG. 25 is an enlarged view of a main portion of FIG. 24. FIG. 26 is an enlarged view of a main portion of a motor according to the seventh embodiment. It is a diagram showing another example of a base. A bracket 760 according to the seventh embodiment has a screw hole 60H for fixing the bracket 760 to the resin frame 24 with a screw S. A cylindrical base 60H3D is provided at the edge of the entrance of the screw hole 60H, communicating with the screw hole 60H and protruding toward the + side in the axial direction Z. An outer diameter 60H3DL (outer diameter of the outermost periphery) of the base 60H3D (third base) is smaller than the outer diameter S1L of the head S1 of the screw S.

[0067] A drain groove 60SM1 having the same function as the above-mentioned drain groove 63 is formed between the back surface S1R of the head S1 of the screw S that abuts against the base 60H3D of the bracket 760, the outer surface 60H3DOUT of the base 60H3D, and the end face 60S2 on the axial Z+ side of the bracket 760.

[0068] In this way, a drain groove 60SM1 is formed around the fastening portion of each screw S, so that water droplets adhering around the drain groove 60SM1 can be easily discharged vertically downward, preventing water from entering the interior of the rotating electric machine through the screw hole 60H.

[0069] 24 and 25 show a structure in which end face 60S2 on the + axial direction Z of bracket 760 is flat, but as shown in Fig. 26, a drainage groove 60SM2 recessed in the - axial direction Z in an annular shape parallel to the edge of screw hole 60H in end face 60S2 on the + axial direction Z of bracket 760 may be formed, and a pedestal 60H4D having the same shape as pedestal 60H3D described using Fig. 24 may be provided inside this drainage groove SM2. A similar effect can be obtained if outer diameter 60H4DL of outer peripheral surface 60H4DOUT of cylindrical pedestal 60H4D is smaller than outer diameter S1L of head S1 of screw S.

[0070] Figure 27 is a perspective view showing yet another example of the pedestal. Furthermore, as long as the required area of ​​the bearing surface of the screw S can be secured, the shape of the pedestal 60H3D is not limited to a cylindrical shape. A partially cut-out cylindrical pedestal, as shown in Figure 27, or a polygonal shape such as an octagon, can also be used. As long as the outer diameter of the outermost periphery of the pedestal 60H3D is smaller than the outer diameter of the head S1 of the screw S, a similar drainage groove can be formed, thereby achieving the same effect. The inner diameter of the screw hole 60H is the same, including the pedestal 60H3D. This makes it easier to secure the required area of ​​the bearing surface of the screw S, preventing loosening of the screw due to sinking of the bearing surface, etc.

[0071] According to the rotating electric machine of the seventh embodiment, the bracket has a screw hole, and the screw hole is fixed to the frame with a screw. The screw hole has a pedestal that protrudes in the axial direction and communicates with the screw hole at the entrance edge of the screw hole. The pedestal is fixed by abutting against the head of the screw. Since the outer diameter of the outermost periphery of the pedestal is smaller than the outer diameter of the head of the screw, a drain groove recessed in the axial Z- direction is formed on the edge of the screw hole on the end face of the bracket on the + axial Z side, and water droplets adhering to the screw head can be guided into the drain groove and guided vertically downward. This prevents water from entering the rotating electric machine through screw holes, rivet holes, etc. Furthermore, since the pedestal of the bracket is cylindrical, water flowing around the pedestal can be smoothly guided vertically downward.

[0072] In each of the above embodiments, a radial gap motor with an inner rotor configuration has been described as an example, but in the case of an axial gap motor, a fitting portion can be provided between the stator and the bracket to form a drain groove, and the same effects as those of the respective embodiments can be obtained. Note that in the case of a radial gap motor with an outer rotor, the rotating portion is on the outside, and therefore it is outside the scope of this disclosure.

[0073] Although various exemplary embodiments and examples are described herein, the various features, aspects, and functions described in one or more embodiments are not limited to specific embodiments and may be applied to the embodiments individually or in various combinations. Accordingly, countless variations not illustrated are contemplated within the scope of the technology disclosed herein. For example, variations include modifying, adding, or omitting at least one component, or extracting at least one component and combining it with components from other embodiments. For example, as shown in FIG. 22 , the bracket 60 and the resin frame 24 may be provided with drainage grooves 63 and 424M1, respectively. Alternatively, as shown in FIG. 23 , multiple drainage grooves 63A and 63B may be provided only on the bracket 60, thereby achieving the same drainage function as the respective embodiments.

[0074] Various aspects of the present disclosure are summarized below as appendices.

[0075] (Supplementary Note 1) A rotating electric machine comprising a stator and a rotor that rotates with its outer peripheral surface facing the inner peripheral surface of the stator, wherein the stator comprises a cylindrical frame and a bracket that closes an opening at an axial end of the frame, and at least one of the frame and the bracket at a fitting portion between the frame and the bracket has a drain groove that is recessed radially inward and extends circumferentially. (Supplementary Note 2) The rotating electric machine according to Supplementary Note 1, wherein in an installed orientation of the rotating electric machine, the rotating electric machine has a drain port that is located vertically downward and discharges water that has entered the interior to the outside, and the drain groove communicates with the drain port. (Supplementary Note 3) The rotating electric machine according to Supplementary Note 2, wherein the drain port of the stator is formed by a groove that is formed in the opening of the frame of the stator and is recessed toward the stator, and the bracket. (Appendix 4) The rotating electric machine according to any one of Appendices 1 to 3, wherein the inner peripheral surface of the frame and the outer peripheral surface of the bracket are fitted together, and the drain groove is formed on the outer peripheral surface of the bracket. (Appendix 5) The rotating electric machine according to any one of Appendices 1 to 3, wherein the bracket has an annular recessed portion on its end surface facing the stator, an end of the frame on the opening side is fitted into the recess, and the drain groove is formed on the inner peripheral surface of the recess. (Appendix 6) The rotating electric machine according to any one of Appendices 1 to 3, wherein the bracket has an annular recessed portion on its end surface facing the stator, an end of the frame on the opening side is fitted into the recess, and the drain groove is formed on the outer peripheral surface of the end of the frame on the opening side. (Appendix 7) The rotating electric machine according to Appendices 2 or 3, wherein a lead wire connected to a circuit board of the rotating electric machine is led out from the drain outlet. (Supplementary Note 8) The rotating electric machine according to Supplementary Note 2, wherein the drain outlet is connected only to the drain groove. (Supplementary Note 9) The rotating electric machine according to any one of Supplementary Notes 1 to 8, wherein, when the axial width of the drain groove is W (mm) and the radial height of the drain groove is H (mm), if the material of the member in which the drain groove is provided is metal, H·W≧2.09 is satisfied, and if the material of the member in which the drain groove is provided is resin, H·W≧0.21 is satisfied.(Supplementary Note 10) The rotating electric machine according to any one of Supplementary Note 1 to Supplementary Note 6, comprising: a lead holder for holding lead wires connected to a circuit board of the rotating electric machine; the frame having a lead holder fitting groove for positioning the lead holder; and the lead holder having a shape that does not block the drain groove. (Supplementary Note 11) The rotating electric machine according to Supplementary Note 2, wherein the drain port has a labyrinth structure. (Supplementary Note 12) The rotating electric machine according to any one of Supplementary Note 1 to Supplementary Note 11, wherein no other member is arranged between the frame and the bracket. (Supplementary Note 13) The rotating electric machine according to Supplementary Note 2 or Supplementary Note 3, wherein an end face of the bracket on the opening side is provided with a drainage channel that extends downward and radially inward from a starting point below and radially inward of a screw hole that is located vertically above one of the screw holes for fixing the bracket in an installed attitude of the rotating electric machine, and that is recessed and connected to the drainage channel. (Supplementary Note 14) The rotating electric machine according to Supplementary Note 13, wherein the drainage channel has a groove depth that gradually increases from the top to the bottom in the vertical direction when the rotating electric machine is installed.

[0076] 100 motor, 10 rotor, 11 shaft, 20, 220, 320, 420, 520, 620 stator, 21 coil, 22 stator core, 23 insulator, 24, 224, 324, 424 resin frame, 24P protrusion, 24T head, 24IN, 224IN, 324IN, 424IN inner fitting portion, 24OUT, 224OUT, 424OUT outer fitting portion, 24H1D, 24H2D, 60H3D, 60H4D base, 24K1 first fitting portion, 24K2 second fitting portion, 24L load side housing, 24Z counterbore portion, 24Q opening, 27 groove, 27IN drain opening, 30 non-load side housing, 40 board, 41 board contact portion, 50 Heat dissipation sheet, 60, 260, 360, 460, 760 Bracket, 60H Screw hole, 60H2 Hole, 60S, 260S, 460S, 60S2 End face, 260M, 460M Recess, 60H3DOUT, 60H4DOUT Outer surface, 60H3DL, S1L Outer diameter, 61IN, 261IN, 361IN, 461IN Inner fitting portion, 61OUT, 261OUT, 461OUT Outer fitting portion, 63, 63A, 63B, 263, 424M1, 60SM1, 60SM2 Drain groove, 64 Drainage channel, 64K1 Inclined groove, 64K2 Guide groove, 64KU Lower end, 64P Water collection portion, 64S Starting point, 65IN Labyrinth inner wall, 65OUT Labyrinth outer wall, Br Bearing, DM Base groove, EX Drain port, G Vertical direction, WH Lead holder, WHM Lead holder fitting groove, WL Lead wire, S Screw, S1 Head, S1R Back surface, TL Crimping tool, X Radial direction, Y Circumferential direction, Z Axial direction.

Claims

1. A rotating electrical machine comprising a stator and a rotor that rotates with its outer peripheral surface facing the inner peripheral surface of the stator, wherein the stator includes a cylindrical frame and a bracket that closes an opening at an axial end of the frame, wherein at least one of the frame and the bracket at a fitting portion between the frame and the bracket has a drain groove that is recessed radially inward and extends circumferentially, wherein the bracket abuts against the entire axial end surface of the frame that continues to the fitting portion, wherein the drain groove is disposed radially inward of the axial end surface and is continuous with the axial end surface of the rotating electrical machine.

2. The fitting portion is provided on an outer peripheral surface of the frame or the bracket and has an outer fitting portion for fitting the frame and the bracket together, wherein the outer fitting portion communicates with the outside and is continuous with the axial end surface of the rotating electrical machine according to Claim 1.

3. A rotating electrical machine comprising a stator and a rotor that rotates with its outer peripheral surface facing the inner peripheral surface of the stator, wherein the stator includes a cylindrical frame and a bracket that closes an opening at an axial end of the frame, wherein at least one of the frame and the bracket at a fitting portion between the frame and the bracket has a drain groove that is recessed radially inward and extends circumferentially, wherein the bracket includes a recess that is annularly recessed in an end surface on the stator side, wherein an end portion of the frame on the opening side is fitted into the recess, wherein the drain groove is formed on an outer peripheral surface of an end portion of the frame on the opening side of the rotating electrical machine.

4. In the installation posture of the rotating electrical machine, there is a drain port that discharges water that has entered inside to the outside vertically downward, and the drain groove communicates with the drain port. The rotating electrical machine according to any one of Claims 1 to 3.

5. The drain port communicates with the inside of the frame on the side opposite to the fitting portion side with respect to the bracket in the axial direction. The rotating electrical machine according to Claim 4.

6. The drain port of the stator is formed in the opening of the frame of the stator, and is formed by a groove that is recessed on the stator side and the bracket. The rotating electrical machine according to Claim 4.

7. The outer fitting portion is formed by fitting the inner peripheral surface of the frame and the outer peripheral surface of the bracket together, and the drain groove is formed on the outer peripheral surface of the bracket. The rotating electrical machine according to Claim 2.

8. The bracket has a recess that is annularly recessed in the end face on the stator side, and an end of the frame on the opening side is fitted into the recess, wherein the drain groove is formed on the inner peripheral surface of the recess. The rotating electric machine according to any one of claims 1 to 3.

9. The rotating electric machine according to claim 4, wherein a lead wire connected to a substrate of the rotating electric machine is led out from the drain port.

10. The drain port does not communicate with the interior of the frame on the side opposite to the fitting portion in the axial direction with respect to the bracket, and is only connected to the drain groove. The rotating electric machine according to claim 4.

11. When the axial width of the drain groove is W (mm) and the radial height is H (mm), when the material of the member provided with the drain groove is metal, H·W≧2.09, and when it is resin, H·W≧0.

21. The rotating electric machine according to any one of claims 1 to 3.

12. The rotating electric machine includes a lead holder that holds a lead wire connected to a substrate of the rotating electric machine, the frame has a lead holder fitting groove for positioning the lead holder, and the lead holder has a shape that does not block the drain groove. The rotating electric machine according to any one of claims 1 to 3.

13. The drain port has a labyrinth structure. The rotating electric machine according to claim 4.

14. No other member is disposed between the frame and the bracket. The rotating electric machine according to any one of claims 1 to 3.

15. On the end face of the bracket on the opening side, among the holes provided on the inner side in the radial direction with respect to the fitting portion, below the hole on the upper side in the vertical direction in the installation posture of the rotating electric machine, and starting from the inner side in the radial direction, it extends downward and inward in the radial direction, and is recessed to form a drain passage that is connected to the drain port. The rotating electric machine according to claim 4.

16. The drain passage has an inclined groove in which the depth of the groove gradually increases from the starting point downward in the vertical direction in the installation posture of the rotating electric machine. The rotating electric machine according to claim 15.

17. The drain passage is provided on the inner surface of the bracket and is connected to a water collecting portion that is recessed outward in the axial direction, and the water collecting portion is connected to the drain port. The rotating electric machine according to claim 15.

18. A screw hole provided in the bracket, and at the edge of the entrance of the screw hole for fixing the bracket to the frame with a screw, a pedestal protruding in the axial direction and communicating with the screw hole is provided. The pedestal is fixed in contact with the head of the screw. The outer diameter of the outermost peripheral portion of the pedestal is smaller than the outer diameter of the head of the screw. The rotating electric machine according to any one of claims 1 to 3.

19. The pedestal of the bracket is cylindrical. The rotating electric machine according to claim 18.