Rotating electrical machine

Abstract

The present invention comprises: a stator (2) having a cylindrical frame (21) forming an outer peripheral surface; a bracket (9) fitted to the frame (21) and closing an opening of the frame (21); and a rotor (3) rotated with an outer peripheral surface thereof facing an inner peripheral surface of the stator (2). A water drainage groove (94) recessed radially inward is provided around the bracket (9). Of a first gap (16a) formed by the bracket (9) and the frame (21) and allowing water entering from the outside to flow into the water drainage groove (94) and second gaps (15a, 16b) formed by the bracket (9) and the frame (21) and allowing the water having flowed into the water drainage groove (94) to be discharged outside, a portion having the smallest cross-sectional area of the gap is formed in the first gap (16a), thereby suppressing defects such as short-circuiting of wiring with a structure that improves waterproofness and prevents the entry of small insects.

Description

Rotating electrical machine

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

[0002] As a structure for preventing water from entering the motor and draining the water that has entered the motor by chance, a structure is known in which a drain hole is formed in the vertically lower part of the motor installed as in Patent Document 1.

[0003] Japanese Patent No. 3168177

[0004] In an environment where the water pressure applied to the motor is low, a rubber seal may not be necessary, and the structure can be the same as that of Patent Document 1. However, in a structure in which the end housing and the yoke housing are fitted together, it is difficult to stably fit the end housing and the yoke housing without gaps due to variations in the dimensions of the parts. Further, in the case of a drain hole for draining the water that has entered the motor by chance, it is necessary to ensure a sufficient cross-sectional area. In that case, there is a risk of problems such as short-circuiting of the wiring on the substrate due to water leakage caused by a decrease in the waterproof performance of the drain hole and intrusion of small insects through the drain hole in an environment where intrusion of small insects is assumed.

[0005] The present disclosure has been made to solve the above-described problems, and an object thereof is to provide a rotating electrical machine having a structure capable of draining the water that has entered the motor by chance regardless of the size of the drain port while ensuring waterproof performance.

[0006] The rotating electrical machine according to the present disclosure includes a stator having a cylindrical frame forming an outer peripheral surface, a bracket fitted to the frame and closing an opening of the frame, and a rotor that rotates with an outer peripheral surface facing an inner peripheral surface of the stator. The bracket has a drainage groove recessed radially inward around the bracket, and a first gap formed by the bracket and the frame and allowing water that has entered from the outside to flow into the drainage groove, and a second gap formed by the bracket and the frame and discharging the water that has flowed into the drainage groove to the outside. Among them, the portion having the smallest cross-sectional area of the gap is formed in the first gap.

[0007] According to the rotating electrical machine according to the present disclosure, it is possible to drain the water that has entered the motor by chance regardless of the size of the drain port while ensuring waterproof performance.

[0008] This is a cross-sectional view of the rotating electric machine according to Embodiment 1. This is a plan view of the bracket of the rotating electric machine according to Embodiment 1. This is a cross-sectional view taken along line A-A in Figure 2. This is a perspective view of the stator of the rotating electric machine according to Embodiment 1. This is a cross-sectional view of the stator of the rotating electric machine according to Embodiment 1. This is a perspective view showing the shape of the lead holder of the rotating electric machine according to Embodiment 1. This is an enlarged cross-sectional view of the part of the rotating electric machine according to Embodiment 1 where the lead holder is attached. This is an enlarged view of the mating portion between the upper bracket and the stator in the installed state of the rotating electric machine according to Embodiment 1. This is an enlarged view of the mating portion between the lower bracket and the stator in the installed state of the rotating electric machine according to Embodiment 1. This is a cross-sectional view of the bracket of the rotating electric machine according to Embodiment 2. This is a perspective view of the stator of the rotating electric machine according to Embodiment 2. This is a perspective view showing the shape of the lead holder of the rotating electric machine according to Embodiment 2. This is an enlarged view of the mating portion between the upper bracket and the stator in the installed state of the rotating electric machine according to Embodiment 2. This is an enlarged view of the mating portion between the lower bracket and the stator in the installed state of the rotating electric machine according to Embodiment 2. This is an enlarged view of the mating portion between the upper bracket and the stator in the installed state of the rotating electric machine according to Embodiment 3. This is an enlarged view of the mating portion between the lower bracket and the stator in the installed state of the rotating electric machine according to Embodiment 3. This is an enlarged view of the mating portion between the upper bracket and the stator in the installed state of the rotating electric machine according to Embodiment 4. This is an enlarged view of the mating portion between the lower bracket and the stator in the installed state of the rotating electric machine according to Embodiment 4. This is a cross-sectional view of the rotating electric machine according to Embodiment 5. This is a cross-sectional view of the rotating electric machine according to Embodiment 6.

[0009] Embodiments of this disclosure will be described below with reference to the drawings. However, the embodiments described below are limited to technologies suitable for carrying out this disclosure, but the technical scope of this disclosure is not limited to the embodiments and drawings below. The same parts and components are denoted by the same reference numerals, and their detailed descriptions are omitted. Similarly, in subsequent embodiments, redundant descriptions of components denoted by the same reference numerals are omitted.

[0010] Embodiment 1. Figure 1 is a cross-sectional view of a motor 1, which is a rotating electric machine according to Embodiment 1. As shown in Figure 1, if the left-right direction of the paper in Figure 1 is the horizontal direction and the up-down direction of the paper is the vertical direction, then the motor 1 is shown to be installed horizontally. As long as the direction of the tip of the shaft 4 is between vertically upward and horizontally, the water intrusion path will be on the upper side of the motor 1 in the installed state (for example, above the shaft 4 which is the axis of rotation), and the drainage path will be on the lower side of the motor 1 in the installed state (for example, below the shaft 4 which is the axis of rotation), and the water will be drained as described below. Furthermore, the direction of the rotation axis of the motor 1 will be axial Z, the load side (right side in Figure 1) where the load is connected to the shaft 4 will be the axial Z- side, and the opposite side (left side in Figure 1) which is the non-load side will be the axial Z+ side. Furthermore, the radial direction of the motor 1 will be X, and the circumferential direction of the motor 1 will be Y. Furthermore, the direction perpendicular to the surface on which the motor 1 is mounted will be G.

[0011] The motor 1 includes a stator 2, a rotor 3 whose outer surface faces the inner surface of the stator 2 and which rotates around a shaft 4 as its axis of rotation, a bearing 5a that supports the load side of the shaft 4, a bearing 5b that supports the non-load side, a non-load side housing 6 that supports the bearing 5b, a wiring board 7 that is positioned on the axial Z+ side of the non-load side housing 6 and controls the current flowing to the coil 24 of the stator 2, a bracket 9 that is positioned on the axial Z+ side of the wiring board 7 via a heat dissipation sheet 8, lead wires 10, and a lead holder 11 that fixes the lead wires 10. The wiring board 7 and lead wires 10 are conductive and constitute part of the charging section for supplying power to the motor 1.

[0012] The heat dissipation sheet 8 is positioned to dissipate the heat generated on the wiring board 7 to the outside of the motor 1. The bracket 9 is a cover that closes the opening at the non-loaded end of the resin frame 21 of the stator 2.

[0013] The stator 2 has a coil 24 wound around a stator core 22 via an insulator 23, and its outer circumference is molded with molded resin to form a resin frame 21. A load-side housing 12 is formed at the load-side end of the resin frame 21 to hold a bearing 5a. The non-load-side end of the resin frame 21 is fitted with the outer surface of the bracket 9 at a first fitting portion 13. Further towards the load side than the first fitting portion 13, it is fitted with the outer surface of the non-load-side housing 6 at a second fitting portion 14, which has a smaller inner diameter than the first fitting portion 13.

[0014] Figures 2 and 3 show the shape of the bracket 9. Figure 2 is a plan view of the bracket as seen from the axial Z-side, and Figure 3 is a cross-sectional view taken along line A-A in Figure 2. The bracket 9 has a disc-like shape and has a stator combination portion 91 on its outer circumferential surface that protrudes radially outward in a flange-like manner, which is combined with the bracket combination portion 211 of the resin frame 21. The stator combination portion 91 has a stator-facing surface 92 on the axial Z-side that faces the resin frame 21 of the stator 2. It also has a stator fitting portion 93 on its outer circumferential surface that is smaller in diameter than the stator combination portion 91 and protrudes radially outward in the X-side, further axially outward than the stator combination portion 91. Between the stator-facing surface 92 and the stator fitting portion 93, a drainage groove 94 is formed that extends along the entire circumference of the bracket 9 in the circumferential Y direction and is smaller in diameter than the stator fitting portion 93, recessing radially inward in the X-side.

[0015] Furthermore, the bracket 9 is equipped with a planar substrate contact portion 95 that contacts the wiring board 7 via a heat dissipation sheet 8 for heat dissipation. If the material of the bracket 9 is a metal such as aluminum alloy or steel, the drainage groove 94 can be easily formed by turning. If the material of the bracket is resin, it can be formed by molding with a sliding mold or by turning after the bracket 9 has been molded.

[0016] Figure 4 is a perspective view of the stator 2, and Figure 5 is a cross-sectional view of the stator 2. The resin frame 21 of the stator 2 has a bracket combination portion 211 at the axial Z+ end, which is larger in diameter than the stator combination portion 91 of the bracket 9 and larger in diameter than the bracket fitting portion 213, which will be described later. In addition, a bracket fitting portion 213 with the same diameter as the stator fitting portion 93 of the bracket 9 is formed on the axial Z- side of the bracket combination portion 211, and is fitted when the bracket 9 is assembled to the stator 2.

[0017] When the motor 1 is installed above the mounting surface in the vertical direction G, for example, between the bracket combination portion 211 and the bracket fitting portion 213 located above the position of the shaft 4, a bracket opposing surface TOP 212a is formed that faces the stator opposing surface 92 of the bracket 9 in the axial direction. Between the bracket combination portion 211 and the bracket fitting portion 213 located below the position of the shaft 4, a bracket opposing surface BOT 212b is formed that is recessed in the axial direction Z-side compared to the bracket opposing surface TOP 212a.

[0018] The bracket opposing surface boundary 212c between the bracket opposing surface TOP 212a and the bracket opposing surface BOT 212b should be positioned on the G-side of the vertical direction from the center of the motor 1's diameter in the vertical direction G, for example, the position of the shaft 4. If this boundary is positioned on the G+ side of the vertical direction from the center of the motor 1's diameter in the vertical direction G, the drainage effect described later cannot be obtained. The further the bracket opposing surface boundary 212c is positioned on the G- side of the center of the motor 1's diameter in the vertical direction G, the more water intrusion from outside the motor 1 can be suppressed, and the closer it is to the center of the motor 1's diameter in the vertical direction G, the better the drainage effect. Therefore, it may be located vertically below the vertical lower end of the wiring board 7. Alternatively, the bracket opposing surface boundary 212c may be inclined to gradually recess axially Z-side from the center of the motor 1's diameter in the vertical direction G, without actively creating a stepped shape.

[0019] As shown in Figure 5, the bracket opposing surface 212, the bracket fitting portion 213, and the vertical G-side end of the bracket combination portion 211 have lead holder fitting grooves 214. The lead holder fitting grooves 214 are formed recessed in the axial Z- direction at the axial Z+ side end of the resin frame 21.

[0020] Figure 6 is a perspective view showing the shape of the lead holder 11, and Figure 7 is a partially enlarged cross-sectional view of the motor 1 to which the lead holder 11 is attached. The lead wires 10 are omitted in the figures. Note that the hatching indicating the cross-section in Figure 7 is omitted for explanatory purposes.

[0021] The lead holder 11 has the function of holding the lead wire 10 and has a hole 111 with the same diameter as the lead wire 10. It also has a fitting surface 112 that fits into and is positioned in the lead holder fitting groove 214 of the stator 2. A drain hole 113 is formed in the fitting surface 112. To countermeasures against water splashes from below the installed motor 1, the lead holder 11 and the lead holder fitting groove 214 have a labyrinth structure. The lead wire 10 is passed through the hole 111 and pulled out to the outside of the motor. The drain hole 113 also connects the water drainage groove 94 of the bracket 9 to the outside of the motor. In other words, the lead holder 11 fitted into the lead holder fitting groove 214 of the stator 2 can be said to be a drain port and lead wire outlet 115. The drain hole 113 has a smaller cross-sectional area than the hole 111.

[0022] If you want to prevent water from entering from the bottom of the installed motor 1, the lead holder 11 should be made of a highly elastic material and the size relationship between the lead holder 11 and the lead holder fitting groove 214 should be a tight fit. The drain hole 113 only needs to drain a small amount of water from the axial gap 16b formed by the stator-facing surface 92 of the bracket 9 and the bracket-facing surface BOT 212b, as shown in Figure 8 later, so it can be small. For example, in an environment where the entry of small insects is possible, it should be made small enough that small insects cannot pass through. Also, if ease of assembly is a priority, the dimensions should be a tight fit and the drain hole 113 may not be provided.

[0023] Figure 8 is an enlarged view of the fitting portion between the upper bracket 9 and the resin frame 21 of the stator 2 in the motor installation state. Figure 9 is an enlarged view of the fitting portion between the lower bracket 9 and the resin frame 21 of the stator 2 in the motor installation state. The arrows in Figures 8 and 9 indicate the flow path of water that enters from the joint between the bracket 9 and the resin frame 21.

[0024] As shown in Figure 8, in the motor-installed state, there is a gap 15a opening in the radial direction X (hereinafter referred to as the radial gap) between the stator assembly portion 91 of the bracket 9 and the bracket assembly portion 211 of the resin frame 21 on the upper side. In addition, the stator-facing surface 92 and the bracket-facing surface TOP 212a are assembled to be in contact facing each other in the axial direction, forming a gap 16a that opens slightly in the axial direction Z (hereinafter referred to as the axial gap). The radial gap 15a is minute, and the axial gap 16a is smaller than the radial gap 15a. In the motor-installed state, the cross-sectional area of ​​the axial gap 16a is smallest in the water flow path from the outside of the motor 1 to the drainage groove 94 on the upper side.

[0025] As shown in Figure 9, in the motor installation state, the lower side has a small radial gap 15a between the stator assembly portion 91 of the bracket 9 and the bracket assembly portion 211 of the resin frame 21, similar to the upper side shown in Figure 8. Also, the stator opposing surface 92 and the bracket opposing surface BOT 212b are assembled to face each other in the axial direction, forming an axial gap 16b. The axial gap 16b is smaller than the radial gap 15a, and in the motor installation state, the cross-sectional area of ​​the axial gap 16b is smallest in the water flow path from the outside of the motor 1 to the drainage groove 94. At this time, since the bracket opposing surface BOT 212b is recessed in the axial Z- direction compared to the bracket opposing surface TOP 212a, the cross-sectional area of ​​the axial gap 16b is larger than the cross-sectional area of ​​the axial gap 16a.

[0026] Next, the water flow in the drainage structure of Embodiment 1 described above will be explained. As mentioned above, there is a small radial gap 15a between the stator combination portion 91 of the bracket 9 and the bracket combination portion 211 of the resin frame 21, so as shown by the arrow in Figure 8, a small amount of water enters the inside of the motor 1 from the radial gap 15a. The water that enters flows in the vertical direction G-, is trapped in the drainage groove 94, and within the drainage groove 94, it branches in the depth direction and the front direction of the paper in Figure 8, and flows in the vertical direction G- along the drainage groove 94 which is recessed in the radial direction X.

[0027] As shown in Figure 9, water that flows along the drainage groove 94 towards the vertical G-side passes through the axial gap 16b, reaches the bottom of the vertical G-side, and is drained from the radial gap 15a. In the path from the outside of the motor 1 to the drainage groove 94, the axial gap 16b, which has the narrowest cross-sectional area at the bottom when the motor is installed, has a larger cross-sectional area than the axial gap 16a, which has the narrowest cross-sectional area at the top, so most of the small amount of water that enters can be drained. Any remaining trace amounts of water that cannot be drained are discharged to the outside of the motor 1 through the drainage hole 113 connected to the drainage groove 94.

[0028] In order to prevent water from entering the inside of the motor 1, i.e., the axial Z-side, beyond the stator fitting portion 93 and the bracket fitting portion 213, the drainage groove 94 needs to have sufficient drainage capacity. Therefore, the width W in the axial Z direction and the depth H in the radial X direction of the drainage groove 94 shown in Figure 8 are set as follows. Even if the drainage capacity is sufficient, if the cross-section of the drainage groove 94 is too small, water may penetrate between the stator fitting portion 93 and the bracket fitting portion 213 due to capillary action.

[0029] Here, the water level rise h due to capillary action is expressed as h = 2Tcosθ / ρgr (T: surface tension, θ: contact angle, ρ: density, g: acceleration due to gravity, r: radius of the pipe). Therefore, the inequality obtained by substituting the pipe radius r with the width W of the drainage groove 94 and the water level rise h with the height H of the drainage groove 94 serves as a guideline for determining the width W and height H. ρ = 1000 kg / m ３ g = 9.8 m / s ２Assuming that the surface tension of water ranges from T = 0.0589 to 0.0756 N / m depending on the temperature, and the contact angle of water ranges from θ = 20° (glass), 70 to 89° (resin), and 40 to 80° (metal), depending on the surface roughness, the threshold Hw_th that satisfies H・W ≥ Hw_th, which is determined based on the relationship between the depth H (mm) and width W (mm) of the drainage groove 94, is expressed by the following equation: H・W ≥ 11.3 to 14.5 (glass) H・W ≥ 0.21 to 5.28 (resin) H・W ≥ 2.09 to 11.8 (metal)

[0030] In Embodiment 1, the prevention of water damage to the wiring board 7 was explained as an example, but even in a motor 1 that does not have a built-in wiring board 7, the same effect can be obtained by adopting the above-described structure for the purpose of preventing water damage to the power supply terminals.

[0031] Furthermore, although the stator opposing surface 92 and the bracket opposing surface TOP 212a are assembled to face each other and be in contact in the axial direction, a similar effect can be obtained even if they are not in contact, as long as the narrowest cross-sectional area of ​​the lower path of the motor 1 is larger than the narrowest cross-sectional area of ​​the upper path of the motor 1 in the path from the outside of the motor 1 to the drainage groove 94.

[0032] In Embodiment 1, the axial gap 16b is larger than the radial gap 15a, and in the lower part of the motor installation state, the cross-sectional area of ​​the radial gap 15a may be the smallest in the path from the outside to the drainage groove 94a. In this case, the gap with the narrowest cross-sectional area will be formed by the axial gap 16a on the upper part of the motor installation state and the radial gap 15a on the lower part. In this case, if the cross-sectional area of ​​the narrowest radial gap 15a on the lower part of the motor installation state is larger than the cross-sectional area of ​​the narrowest axial gap 16a on the upper part, most of the water that enters can be drained.

[0033] Furthermore, the lead holder 11 is provided with a hole of the same diameter as the lead wire 10 for passing the lead wire 10 through. However, if the lead wire wiring work is to be simplified, the lead holder 11 may be divided into two axial sections, the lead wire 10 may be sandwiched between the divided lead holder 11, and the divided lead holder 11 may be held in place by a bracket 9 on the axial Z-side to hold the lead wire 10.

[0034] Furthermore, although an example of a stator 2 structure covered with a resin frame 21 has been shown, it goes without saying that a similar effect can be obtained if a cylindrical or bowl-shaped frame is used, and a stator core is press-fitted or shrink-fitted into it, and a drainage groove 94 is provided on the axial Z end face of the frame on the surface where the bracket 9 and the stator 2 fit together, similar to this embodiment, and the narrowest cross-sectional area of ​​the lower path of the motor 1 is larger than the narrowest cross-sectional area of ​​the upper path of the motor 1 in the path from the outside of the motor 1 to the drainage groove 94.

[0035] Furthermore, although the drainage groove 94 is shown with a rectangular cross-section perpendicular to the circumferential direction Y, the cross-sectional shape is not limited to this; any shape that opens outward in the radial direction X, such as a triangular or semicircular cross-section, will also achieve the effects of this embodiment. In this embodiment, the bracket 9 is provided on the non-load side, but this can also be applied to structures where the resin frame 21 has an opening on the load side.

[0036] In this way, a drainage groove 94 is provided on the surface where the bracket 9 and the stator 2 fit together, and in the path from the outside of the motor 1 to the drainage groove 94, the narrowest cross-sectional area of ​​the lower path of the motor 1 is formed to be larger than the narrowest cross-sectional area of ​​the upper path of the motor 1. This makes it possible to create a structure in which a small amount of water that enters from the joint between the resin frame 21 and the bracket 9 can be drained to the outside of the motor 1 without touching the wiring board 7, before reaching the bottom of the motor 1 in the vertical direction G. This promotes the discharge of water from the drainage groove 94 and reduces the cross-sectional area required for the drain at the bottom. This improves the waterproof performance from the drain and prevents the entry of small insects.

[0037] Furthermore, the drain port and lead wire outlet 115 located at the bottom only needs to be able to drain small amounts of water and can also serve as the outlet for the lead wires 10 connected to the wiring board 7. Therefore, there is no need to provide a separate outlet for the lead wires, which allows for space saving and miniaturization, and reduces the manufacturing cost of the rotating electric machine.

[0038] Furthermore, since the drain port / lead wire outlet 115 can be positioned at the bottom of the motor 1 on the vertical G-side, water intrusion will be in the direction most opposed to gravity, preventing water from entering through the drain port / lead wire outlet 115. Also, since the drainage direction through the drain hole 113 is the same as the direction of gravity, any small amount of water that could not be drained can be effectively discharged through the drain hole 113. In addition, the lead holder fitting groove 214 of the lead holder 11 and the stator 2 has a labyrinth structure, which prevents water from entering through the drain port / lead wire outlet 115.

[0039] Furthermore, when the axial width of the drainage groove 94 is W (mm) and the radial depth is H (mm), sufficient drainage capacity can be ensured by satisfying H・W ≥ 2.09 if the material of the member on which the drainage groove 94 is provided is metal, and by satisfying H・W ≥ 0.21 if the material is resin. In addition, since no other members are placed between the resin frame 21 and the bracket 9, the manufacturing cost of the rotating electric machine can be reduced.

[0040] Embodiment 2. Hereinafter, the rotating electric machine according to Embodiment 2 will be described, focusing on the parts that differ from those of Embodiment 1. Figure 10 is a cross-sectional view of the bracket 9, corresponding to the part shown in Figure 3 of Embodiment 1. Figure 11 is a perspective view of the stator 2, corresponding to the part shown in Figure 4 of Embodiment 1. Figure 12 is a perspective view showing the shape of the lead holder 11, corresponding to the part shown in Figure 6 of Embodiment 1. Figure 13 is an enlarged view of the fitting portion between the upper bracket 9 and the resin frame 21 of the stator 2 in the motor-installed state, corresponding to the part shown in Figure 8 of Embodiment 1. Figure 14 is an enlarged view of the fitting portion between the lower bracket 9 and the resin frame 21 in the motor-installed state, corresponding to the part shown in Figure 9 of Embodiment 1.

[0041] As shown in Figure 10, the bracket 9 of the second embodiment has a projection 96 that protrudes annularly in the axial direction Z- from the stator-facing surface 92a, extending along the entire circumference of the bracket 9 in the circumferential direction Y. The stator assembly portion 91a is located radially inward of this projection 96 in the direction X.

[0042] In the stator 2 of Embodiment 2, the bracket combination portion 211 provided at the end portion on the axial direction Z+ side of the stator 2 in Embodiment 1 does not exist. However, as shown in FIGS. 11 and 13, on the outer periphery of the resin frame 21 of the stator 2, outside the radial direction X of the bracket facing surface TOP212d, a bracket combination portion TOP215a having a smaller diameter than the stator combination portion 91a of the bracket 9 and facing the stator combination portion 91a in the radial direction is formed.

[0043] Further, as shown in FIGS. 11 and 14, within the range of the resin frame 21 where the bracket facing surface BOT212e is formed, a bracket combination portion BOT215b that is recessed inward in the radial direction from the bracket combination portion TOP215a is formed. The arrangement of the bracket facing surface boundary 212f and the bracket combination portion boundary 212g shown in FIG. 11 is the same as that of the bracket facing surface boundary 212c in Embodiment 1. Also, similar to the relationship between the bracket facing surface TOP212a and the bracket facing surface BOT212b in Embodiment 1, the bracket facing surface BOT212e is formed to be recessed toward the axial direction Z− side from the bracket facing surface TOP212d.

[0044] Further, as shown in FIG. 12, in the lead holder

[0045] 11a of Embodiment 2, the axial protrusion 114 provided at the end portion on the axial direction Z+ side in Embodiment 1 does not exist. Also, a bracket relief portion 116 is formed so as not to interfere with the protrusion 96 of the bracket 9.

[0045] As described above, as shown in FIG. 13, the stator combination portion 91a of the bracket 9 and the bracket combination portion TOP215a of the stator 2 face each other in the radial direction, and a radial gap 15b is formed. Also, the stator facing surface 92a and the bracket facing surface TOP212d face each other in the axial direction and are not in contact, and an axial gap 16c is formed. The radial gap 15b is smaller than the axial gap 16c, and in the upper side in the motor installation state, in the path from the outside of the motor 1 to the drain groove 94a, the cross-sectional area of the radial gap 15b is the smallest.

[0046] In FIG. 13, a bracket fitting portion 213a having the same diameter as the stator fitting portion 93a of the bracket 9 is formed and is fitted when the bracket 9 is assembled to the stator 2. However, as shown in FIG. 14, the stator combination portion 91a of the bracket 9 and the bracket combination portion BOT215b of the stator 2 face each other in the radial direction, and a radial gap 15c is formed. Further, the stator facing surface 92a and the bracket facing surface BOT212e are assembled so as to face each other in the axial direction, and an axial gap 16d is formed. The radial gap 15c is smaller than the axial gap 16d, and on the lower side in the motor installation state, in the path reaching from the outside to the drain groove 94a, the cross-sectional area of the radial gap 15c is the smallest.

[0047] At this time, since the bracket combination portion BOT215b is recessed more radially inward than the bracket combination portion TOP215a, the cross-sectional area of the radial gap 15b is larger than the cross-sectional area of the radial gap 15c. Other structures are the same as those in the first embodiment.

[0048] Next, the flow of water in the drainage structure of the second embodiment described above will be described. As shown in FIG. 13, a small amount of water enters from the radial gap 15b toward the inside of the motor 1. The water that has entered flows in the vertical direction G− side, is trapped in the drain groove 94a, branches in the depth direction and the front direction of the paper surface of FIG. 13 in the drain groove 94a, and flows in the vertical direction G− side along the drain groove 94a recessed in the radial direction X. As shown in FIG. 14, the water that has flowed in the vertical direction G− side along the drain groove 94a is drained from the radial gap 15c through the axial gap 16d before reaching the lowermost part on the vertical direction G− side of the motor 1. In the path from the outside of the motor 1 to the drain groove 94a, the radial gap 15c with the smallest cross-sectional area on the lower side in the motor installation state has a larger cross-sectional area than the radial gap 15b with the smallest cross-sectional area on the upper side, so that most of the small amount of water that has entered can be drained.

[0049] In Embodiment 2, the bracket opposing surface BOT212e is not formed recessed in the axial Z-side compared to the bracket opposing surface TOP212d. Even if it is on the same plane as the bracket opposing surface TOP212d, if the path from the outside of the motor 1 to the drainage groove has a larger path with the narrowest cross-sectional area at the bottom than the path with the narrowest cross-sectional area at the top, then almost all of the water that enters can be drained.

[0050] In Embodiment 2, the radial gap 15c is larger than the axial gap 16d, and in the lower part of the motor installation state, the cross-sectional area of ​​the axial gap 16d may be the smallest in the path from the outside to the drainage groove 94a. In this case, the gap with the narrowest cross-sectional area will be formed by the radial gap 15b on the upper part of the motor installation state and the axial gap 16d on the lower part. In this case, if the cross-sectional area of ​​the axial gap 16d with the narrowest cross-sectional area on the lower part of the motor installation state is larger than the cross-sectional area of ​​the radial gap 15b with the narrowest cross-sectional area on the upper part, then most of the water that enters can be drained.

[0051] In the case of Embodiment 2, in addition to the effects of Embodiment 1, the structure makes it difficult for water to enter from the left side of Figure 13, making it effective for use of the motor in environments where the non-load side is exposed to water.

[0052] Embodiment 3. Hereinafter, the rotating electric machine according to Embodiment 3 will be described, focusing on the parts that differ from Embodiment 1. Figure 15 is an enlarged view of the fitting portion between the upper bracket 9 and the resin frame 21 of the stator 2 in the motor installation state, and is a diagram of the part corresponding to Figure 8 of Embodiment 1. Figure 16 is an enlarged view of the fitting portion between the lower bracket 9 and the resin frame 21 of the stator 2 in the motor installation state, and is a diagram of the part corresponding to Figure 9 of Embodiment 1.

[0053] As shown in Figure 15, the bracket 9 of Embodiment 3 has a stator fitting portion 93c on the axial Z+ side of the drainage groove 94b, with the same diameter as the stator fitting portion 93 described in Embodiment 1. The stator 2 does not have a bracket opposing surface BOT 212b that is recessed in the axial Z- side than the bracket opposing surface TOP 212a described in Embodiment 1, and has a bracket opposing surface 212h that is on the same plane as the bracket opposing surface TOP 212a. Also, as shown in Figure 16, on the lower side in the motor installation state, the bracket fitting portion 213b of the stator 2 is retracted in the axial Z- side to a position where it does not contact the stator fitting portion 93c, and a counterbore portion 216 is formed by machining it in a stepped shape up to before reaching the bracket combination portion 211a formed on the radially outer side. The arrangement of the boundary between the upper side in the motor installation state and the lower side where the counterbore portion 216 is formed is the same as the arrangement of the bracket opposing surface boundary 212c in Embodiment 1.

[0054] As shown in Figure 15, on the upper side in the motor installation state, a radial gap 15d is formed by the stator combination portion 91b and the bracket combination portion 211a, and the stator fitting portions 93b and 93c of the bracket 9 fit together with the bracket fitting portion 213b of the stator 2, forming a radial gap 15e. Also, as described in Embodiment 1, the stator opposing surface 92b and the bracket opposing surface 212h are facing each other in the axial direction Z and are not in contact, forming an axial gap 16e. The axial gap 16e is smaller than the radial gap 15d and larger than the radial gap 15e. Therefore, on the upper side in the motor installation state, the cross-sectional area of ​​the radial gap 15e is smallest in the path from the outside of the motor 1 to the drainage groove 94b.

[0055] As shown in Figure 16, in the lower part of the motor installation state, a radial gap 15f is formed by the stator fitting portion 93c of the bracket 9 and the inner diameter portion 217 of the counterbore of the stator 2. The radial gap 15d formed by the stator combination portion 91b and the bracket combination portion 211a is smaller than the radial gap 15f and larger than the axial gap 16e. Therefore, in the lower part of the motor installation state, the cross-sectional area of ​​the axial gap 16e is smallest in the path from the outside of the motor 1 to the drainage groove 94b. Furthermore, the cross-sectional area of ​​the axial gap 16e is larger than the cross-sectional area of ​​the radial gap 15e. The rest of the structure is the same as in Embodiment 1.

[0056] Next, the water flow in the drainage structure of Embodiment 2 described above will be explained. As shown in Figure 15, a small amount of water enters the inside of the motor from the radial gap 15d. The water that enters flows in the vertical direction G-side and is trapped in the drainage groove 94b. Within the drainage groove 94b, it branches in the depth direction and the front direction of the paper in Figure 15, and flows in the vertical direction G-side along the drainage groove 94b which is recessed in the radial direction X. As shown in Figure 16, the water that has flowed in the vertical direction G-side along the drainage groove 94b passes through the radial gap 15f and the axial gap 16e before reaching the bottom of the motor on the vertical direction G-side, and is drained from the radial gap 15d. That is, in the path from the outside of the motor 1 to the drainage groove 94b, the radial gap 15d, which has the narrowest cross-sectional area at the bottom in the motor installation state, has a larger cross-sectional area than the radial gap 15e, which has the narrowest cross-sectional area at the top, so almost all of the small amount of water that enters can be drained.

[0057] In Embodiment 3, a counterbore 216 is formed in the bracket fitting portion 213b of the stator 2. However, even if the stator fitting portion 93c of the bracket 9 is formed only on the upper side in the motor-installed state, and the lower side in the motor-installed state is configured the same as shown in Figure 9, the radial gap 15d with the narrowest cross-sectional area on the lower side in the motor-installed state has a larger cross-sectional area than the radial gap 15e with the narrowest cross-sectional area on the upper side. Therefore, a similar effect can be obtained in which even small amounts of water that enter can be almost completely drained.

[0058] In this third embodiment, in addition to the effects of the first embodiment, a stator fitting portion 93c is provided on the axial Z+ side of the upper drainage groove 94b in the motor installation state. As a result, the waterproof performance can be improved in a motor in which the stator facing surface 92b and the bracket facing surface 212h face each other in the axial direction and do not come into contact.

[0059] Embodiment 4. Hereinafter, the motor 1 according to Embodiment 4 will be described, focusing on the parts that differ from those of Embodiment 1. Figure 17 is an enlarged view showing the fitting portion between the upper bracket 9 and the resin frame 21 of the stator 2 in the motor installation state, and is a diagram of the part corresponding to Figure 8 of Embodiment 1. Figure 18 is an enlarged view showing the fitting portion between the lower bracket 9 and the resin frame 21 of the stator 2 in the motor installation state, and is a diagram of the part corresponding to Figure 9 of Embodiment 1.

[0060] In this embodiment, the stator combination portion 91 of the bracket 9 and the bracket combination portion 211 of the stator 2, which were provided at the axial Z+ end of the stator 2 in Embodiment 1, are absent. The rest of the structure is the same as in Embodiment 1.

[0061] Next, the water flow in the drainage structure of Embodiment 4 described above will be explained. In Figure 17, as shown by the arrow, a small amount of water enters the inside of the motor 1 from the axial gap 16a. The water that enters flows in the vertical direction G-side, similar to Embodiment 1, and is trapped in the drainage groove 94. Within the drainage groove 94, it branches in the depth direction and the front direction of the paper in Figure 17, and flows in the vertical direction G-side along the drainage groove 94 which is recessed in the radial direction X. As shown in Figure 18, the water that flows in the vertical direction G-side along the drainage groove 94 is drained from the axial gap 16b before reaching the bottom of the motor on the vertical direction G-side. That is, in the path from the outside of the motor 1 to the drainage groove 94, the axial gap 16b, which has the narrowest cross-sectional area at the bottom in the motor installation state, has a larger cross-sectional area than the axial gap 16a, which has the narrowest cross-sectional area at the top, so almost all of the small amount of water that enters can be drained.

[0062] Embodiment 4 has a slightly lower effect compared to Embodiment 1 in terms of waterproofing performance and suppression of insect intrusion, but it has the advantage that the number of dimensional control points during manufacturing is reduced because the stator combination portion 91 of the bracket 9 and the bracket combination portion 211 of the stator 2 are absent, making it easier to produce the motor.

[0063] Embodiment 5. The motor 1 according to Embodiment 5 will be described below, focusing on the parts that differ from those of Embodiment 1. Figure 19 is a cross-sectional view of the motor 1a, which is a rotating electric machine according to Embodiment 5. Unlike the motor 1 of Embodiment 1, the wiring board 7, heat dissipation sheet 8, board contact portion 95, and lead holder 11 are not provided. Also, a hole is formed in the bracket 9, and a bush 25 is attached to this hole. The bush 25 is provided with a hole through which the lead wire 10a passes. As a result, the lead wire 10a, one end of which is connected to the power terminal portion 26, is led out from the hole in the bush 25 to the outside of the motor 1a on the axial Z+ side. The power terminal portion 26 and the lead wire 10a are conductive and constitute part of the charging portion for supplying power to the motor 1.

[0064] Because the lead holder 11 is not provided, the drainage paths such as the radial gap 15a, axial gaps 16a and 16b, and drainage groove 94 shown in Figures 8 and 9 are formed solely by the combination of the bracket 9 and the stator 2.

[0065] The power terminal section 26 is positioned vertically to the G+ side from the hole in the bracket 9, and the water outlet from the radial gap 15a, which continues from the axial gap 16b, is positioned vertically to the G- side from the hole in the bracket 9. Furthermore, the structural portion through which the lead wire 10a passes, which is composed of the bracket 9 and bush 25, maintains IP performance (Ingress Protection) and suppresses the intrusion of small insects and water. In addition, the bracket-facing surface boundary 212c described in Embodiment 1 may be located vertically below the vertically lower end of the power terminal section 26 in order to improve the drainage effect.

[0066] In this embodiment 5 configuration, the lead holder 11 is not placed between the bracket 9 and the stator 2, which reduces the number of dimensional control points during manufacturing and has the advantage of making it easier to produce the motor 1a.

[0067] Embodiment 6. The motor 1 according to Embodiment 6 will be described below, focusing on the parts that differ from those of Embodiment 1. Figure 20 is a cross-sectional view of the motor 1b, which is a rotating electric machine according to Embodiment 6. Unlike the motor 1 of Embodiment 1, the lead holder 11 is not provided. Also, a hole is formed in the bracket 9, and a bush 25a is attached to this hole. The bush 25a has a hole through which the lead wire 10b passes. As a result, the lead wire 10b that supplies power is led out from the hole in the bush 25a to the outside of the motor 1a on the axial Z+ side. The wiring board 7 and the lead wire 10b are conductive and constitute part of the charging section for supplying power to the motor 1.

[0068] Because the lead holder 11 is not provided, the drainage paths such as the radial gap 15a, axial gaps 16a and 16b, and drainage groove 94 shown in Figures 8 and 9 are formed solely by the combination of the bracket 9 and the stator 2.

[0069] The wiring board 7 is positioned vertically to the G+ side from the hole in the bracket 9, and the water outlet from the radial gap 15a, which continues from the axial gap 16b, is positioned vertically to the G- side from the hole in the bracket 9. Furthermore, the structural portion through which the lead wire 10b passes, formed by the bracket 9 and bush 25a, maintains IP performance (Ingress Protection) and suppresses the intrusion of small insects and water.

[0070] In this embodiment 6 configuration, the lead holder 11 is not placed between the bracket 9 and the stator 2, which reduces the number of dimensional control points during manufacturing and has the advantage of making it easier to produce the motor 1b.

[0071] While this disclosure describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but are applicable individually or in various combinations to the embodiments. Accordingly, countless variations not illustrated are envisioned within the scope of the technology disclosed herein. For example, these include modifying, adding or omitting at least one component, or extracting at least one component and combining it with a component from another embodiment.

[0072] 1, 1a, 1b: Motor, 2: Stator, 3: Rotor, 4: Shaft, 5a, 5b: Bearing, 6: Non-load side housing, 7: Wiring board, 8: Heat dissipation sheet, 9: Bracket, 10, 10a, 10b: Lead wires, 11, 11a: Lead holder, 12: Load side housing, 13: First mating part, 14: Second mating part, 15a, 15b, 15c, 15d, 1 5e, 15f: Radial clearance, 16a, 16b, 16c, 16d, 16e: Axial clearance, 21: Resin frame, 22: Stator core, 23: Insulator, 24: Coil, 25, 25a: Bushing, 26: Power terminal section, 91, 91a, 91b: Stator assembly section, 92, 92a, 92b: Stator opposing surface, 93, 93a, 93b, 93c: Stator fitting section ,94,94a,94b: drainage groove, 95: substrate contact part, 96: protrusion, 111: hole, 112: fitting surface, 113: drain hole, 114: axial protrusion, 115: drain port and lead wire outlet, 116: bracket relief part, 211,211a: bracket combination part, 212: bracket opposing surface, 212a,212d: bracket opposing surface TOP, 212b,212e: bracket opposing surface BOT, 212c,212f: bracket opposing surface boundary, 212g: bracket combination part boundary, 212h: bracket opposing surface, 213,213a,213b: bracket fitting part, 214: lead holder fitting groove, 215a: bracket combination part TOP, 215b: bracket combination part BOT, 216: counterbore part, 217: inner diameter part of counterbore part.

Claims

1. A rotating electric machine comprising a stator having a cylindrical frame forming an outer circumferential surface, a bracket fitted to the frame and closing an opening in the frame, and a rotor that rotates with its outer circumferential surface facing the inner circumferential surface of the stator, wherein the bracket has a drainage groove recessed radially inward around its circumference, and a first gap formed by the bracket and the frame into which water entering from the outside flows into the drainage groove, and a second gap formed by the bracket and the frame into which water flowing into the drainage groove is discharged to the outside, wherein the portion of the gap with the smallest cross-sectional area is formed in the first gap.

2. The rotating electric machine according to claim 1, characterized in that the first gap is formed by a first axial gap opening in the direction of the rotation axis of the rotor and extending in the radial direction of the bracket, and a first radial gap opening in the radial direction of the bracket and extending in the direction of the rotation axis, the second gap is formed by a second axial gap opening in the direction of the rotation axis of the rotor and extending in the radial direction of the bracket, and a second radial gap opening in the radial direction of the bracket and extending in the direction of the rotation axis, the cross-sectional area of ​​the first axial gap is smaller than that of the first radial gap, the cross-sectional area of ​​the second axial gap is smaller than that of the second radial gap, and the cross-sectional area of ​​the first axial gap is smaller than that of the second axial gap.

3. The rotating electric machine according to claim 1, characterized in that the first gap is formed by a first axial gap opening in the direction of the rotation axis of the rotor and extending in the radial direction of the bracket, and a first radial gap opening in the radial direction of the bracket and extending in the direction of the rotation axis, the second gap is formed by a second axial gap opening in the direction of the rotation axis of the rotor and extending in the radial direction of the bracket, and a second radial gap opening in the radial direction of the bracket and extending in the direction of the rotation axis, the cross-sectional area of ​​the first axial gap is smaller than that of the first radial gap, the cross-sectional area of ​​the second radial gap is smaller than that of the second axial gap, and the cross-sectional area of ​​the first axial gap is smaller than that of the second radial gap.

4. The rotating electric machine according to claim 1, wherein the first gap is formed by a first axial gap that opens in the direction of the rotation axis of the rotor and extends in the radial direction of the bracket, and a first radial gap that opens in the radial direction of the bracket and extends in the direction of the rotation axis, and the second gap is formed by a second axial gap that opens in the direction of the rotation axis of the rotor and extends in the radial direction of the bracket, and a second radial gap that opens in the radial direction of the bracket and extends in the direction of the rotation axis, wherein the cross-sectional area of ​​the first radial gap is smaller than that of the first axial gap, the cross-sectional area of ​​the second radial gap is smaller than that of the second axial gap, and the cross-sectional area of ​​the first radial gap is smaller than that of the second radial gap.

5. The rotating electric machine according to claim 1, wherein the first gap is formed by a first axial gap that opens in the direction of the rotation axis of the rotor and extends radially of the bracket, and a first radial gap that opens radially of the bracket and extends in the direction of the rotation axis, and the second gap is formed by a second axial gap that opens in the direction of the rotation axis of the rotor and extends radially of the bracket, and a second radial gap that opens radially of the bracket and extends in the direction of the rotation axis, wherein the cross-sectional area of ​​the first radial gap is smaller than that of the first axial gap, the cross-sectional area of ​​the second axial gap is smaller than that of the second radial gap, and the cross-sectional area of ​​the first radial gap is smaller than that of the second axial gap.

6. The rotating electric machine according to claim 1, characterized in that the boundary between the first gap between the opposing surfaces of the frame and the bracket that forms the first gap and the second gap between the opposing surfaces of the frame and the bracket that forms the second gap is located vertically below the center of the diameter of the rotating electric machine.

7. The rotating electric machine according to claim 6, further comprising a conductive charging part, wherein the boundary between the first interval and the second interval is located vertically below the vertically lower end of the charging part.

8. The rotating electric machine according to any one of claims 1 to 7, characterized in that, when the width of the drainage groove in the rotational axis direction of the rotor is W and the radial height of the bracket is H, the threshold Hw_th determined based on the material of the member forming the drainage groove and the amount of water level rise due to capillary action satisfies H・W ≥ Hw_th.

9. The rotating electric machine according to claim 8, characterized in that when the material of the member forming the drainage groove is metal, Hw_th is 2.09 or more.

10. The rotating electric machine according to claim 8, characterized in that when the material of the member forming the drainage groove is resin, Hw_th is 0.21 or more.

11. The rotating electric machine according to any one of claims 1 to 7, characterized in that a mating portion for positioning a lead holder that holds lead wires connected to a wiring board attached to the stator of the rotating electric machine, which is installed vertically above the mounting surface, is formed at the lowest vertical part of the frame.

12. The rotating electric machine according to claim 11, characterized in that the lead holder connects the drainage groove to the outside of the frame and has a drainage hole with a diameter smaller than that of the lead wire.

13. The rotating electric machine according to claim 11, characterized in that the mating portion has a labyrinth structure.

14. The rotating electric machine according to any one of claims 1 to 13, wherein no other member is disposed between the frame and the bracket.

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