JPH09261906A - Waterproofing structure for motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waterproofing structure for motor which can ensure prescribed waterproofing properties with a simple mechanical structure without using a sealing agent. SOLUTION: An end frame guide wall 6 is fitted at the inner wall 3c of a housing 3 so as to face its whole periphery, and at the lowest end part in a housing space 5 in the gravitational direction, a drain hole 12 is formed near a section where a flange 3 comes into pressure contact with an end frame 4. The water which enters the housing space 5 from a micro-clearance between the housing 3 and the end frame 4 runs downwards in the gravitational direction through the end frame guide wall 6, and discharged to the outside of the housing space 5 from the drain hole 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof structure for an electric motor, and is effective when used for an electric motor arranged in a place where the electric motor is not directly exposed to rain or the like, such as in a vehicle engine room.

[0002]

2. Description of the Related Art Conventionally, in a waterproof structure of an electric motor, a sealing agent such as a polyethylene-based liquid gasket is generally applied to a joint portion of each component to ensure waterproofness. That is,
As shown in FIG. 7, the rotor 1 is inserted through the opening 3a of the substantially cylindrical housing 3 having one end opened, and the brush holder 10 for closing the opening 3a and holding the brush 9 is assembled. The end frame 4 is pressure-bonded to the housing 3 by a coupling means such as caulking. Then, the above-mentioned sealing agent is applied to a pressure-contacting portion between the end frame 4 and the housing 3, and the sealing agent ensures waterproofness. In addition, 12a is a drain pipe for communicating the inside and outside of the electric motor.

[0003]

By the way, the above means requires a sealing agent and a coating step for coating the sealing agent, which has been an obstacle in reducing the manufacturing cost of the electric motor. In view of the above points, an object of the present invention is to provide a waterproof structure for an electric motor that does not use a sealant and can ensure a predetermined waterproof property with a simple mechanical structure.

[0004]

According to the present invention, attention is paid to the position of the drain hole which communicates the inside and outside of the housing space and the shape of the end frame which closes the opening of the housing, and both of them can be ensured to have a predetermined waterproof property. The following technical means will be described by devising the above to achieve the above object.

According to the first to sixth aspects of the invention, the housing space (5) of the end frame (4) partitioned by the housing (3) and the end frame (4).
On the side, an end frame guide wall (6) facing the inner wall (3c) of the housing (3) is provided over the entire circumference of the inner wall (3c) of the housing (3). Further, a drain hole (12) for communicating the inside and outside of the housing space (5) is formed on the radially outer side of the housing (3) with respect to the end frame guide wall (6). And this drain hole (1
2) is the lowest end of the housing space (5) in the direction of gravity, and is formed in the vicinity of the portion where the end frame (4) and the housing (3) are in pressure contact.

As a result, as will be described later, the water that has flooded into the housing space (5) through the minute gap between the housing (3) and the end frame (4) is pressed against the end frame guide wall (6). It flows down and flows downward in the direction of gravity,
The water is drained to the outside of the housing space (5) through a drain hole (12) formed at the lowermost end of the housing space (5) in the direction of gravity.

Also, the commutator (1a) and the brush (9)
Electrically important parts such as are arranged on the radially inner side of the housing (3) with respect to the end frame guide wall (6).
The inundated water is dammed by the end frame guide wall (6), and the commutator (1b) and the brush (9) are prevented from inundating. Therefore, the predetermined waterproofness can be ensured with a simple mechanical structure, so that the sealing agent applied to the joint portion of each part of the electric motor can be omitted. In addition, since the sealant and the coating step for coating the sealant are unnecessary, the manufacturing cost of the electric motor can be reduced.

The position of the drain hole (12) may be any position as long as it can exert a drainage function in relation to the water infiltrated into the housing space (5), and is simply physically located in the housing space (5). It is not limited to the lowermost part of the gravity direction. In the invention according to claim 2, the end frame (4)
A flange portion (3b) extending in the radial direction of the housing (3) is formed at an axial end portion of the housing (3) that is pressed against the.

As a result, the area of the portion where the end frame (4) and the housing (3) are in pressure contact with each other can be increased, so that the infiltration of water from the minute gap between the end frame (4) and the housing (3) is suppressed. can do. In the invention according to claim 3, the housing space (5)
Among the parts of the connector (15) located inside, a connector guide wall that is formed radially outward of the housing (3) with respect to the end frame guide wall (6) and faces the inner wall (3c) side of the housing (3). (16) is provided.

As a result, the water that has entered the gaps between the connector (15) and the housing (3) and the end frame (4) is dammed by the connector guide wall (16), and the commutator (1b) and the brush (9) are blocked. Etc. are prevented from flooding. Then, the dammed water flows to the connector guide wall (16) in the direction of gravity, flows from the end frame guide wall (6) to the radially outer side of the housing (3), and reaches the end frame guide wall (6). Flow in the direction of gravity,
The water is drained to the outside of the housing space 5 through the drain hole (12).

In the invention according to claim 4, among the parts of the connector (15) located in the housing space (5),
A groove (17) opening toward the housing space (5) on the radially outer side of the housing (3) from the connector guide wall (16).
Is formed. As a result, the water that has entered the gaps between the connector (15) and the housing (3) and the end frame (4) can be more reliably stopped and drained.

According to the invention of claim 5, the drain hole (1
Since the drain cover (13) for covering 2) is provided, direct infiltration of rainwater or the like from the drain hole (12) is suppressed. Therefore, it is possible to suppress direct intrusion of rainwater and the like with a simpler structure than the drain hole structure of the electric motor according to the related art, and thus it is possible to reduce the manufacturing cost of the electric motor.

In the invention described in claim 6, the connector (1
It is characterized in that a drop-out prevention mechanism (19, 21, 22) for preventing the drop-down of 5) from the terminal portion (14) is formed. In addition, the code in parentheses of each of the above means,
It shows the correspondence with specific means described in the embodiment described later.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; (First Embodiment) FIG. 1 is a sectional view showing a main part of an electric motor according to this embodiment, which is an electric motor for mounting on a vehicle. 1 is the rotor of the electric motor, 2 is the stator, 3
Is a metal housing which also serves as a yoke (yoke) of the electric motor and which houses the rotor 1. This housing 3
An opening 3a for inserting the rotor 1 into the housing 3 at the time of assembling the electric motor is formed at one axial end of the opening 3a, and the opening 3a is closed by the metal end frame 4. . The end frame 4 is
It may be integrally molded with resin together with the brush holder 10 described later.

The end frame 4 is in pressure contact with the housing 3 at one axial end of the housing 3 by a connecting means such as caulking.
A flange portion 3b extending outward in the radial direction of the housing 3 is formed at one axial end portion of the. The flange portion 3b is formed to facilitate the caulking connection between the end frame 4 and the housing 3, but
As will be described later, the waterproofness can be improved by making the flange portion 3b an appropriate size.

Incidentally, 5a is a stay for assembling the electric motor, which is connected to the housing 3 by a connecting means such as welding. On the side of the housing 3 and the housing space 5 that is partitioned by the end frame 4, an end frame guide wall 6 that faces the inner wall 3c of the housing 3 is formed over the entire inner wall 3c of the housing 3. (See (a) of FIG. 2). Reference numeral 7 denotes a bearing that rotatably supports one end side of the rotary shaft 1a of the rotor 1, and the bearing 7 is provided on a convex portion 4a formed so as to project to the outside of the housing space 5 at a substantially central portion of the end frame 4. It is press-fitted. Reference numeral 8 denotes a bearing that rotatably supports the other end side of the rotary shaft 1a of the rotor 1, and the bearing 8 projects out of the housing space 5 formed in the bottom portion 3d on the other end side in the axial direction of the housing 3. It is press-fitted into such a convex portion 3e.

Reference numeral 9 denotes a pair of brushes for supplying electric power from an external power source (not shown) to the commutator 1b of the rotor 1. The brushes 9 are made of resin for holding the brushes 9 as shown in FIG. Is arranged in the brush holder 10 and is pressed by the coil spring 11 toward the commutator 1b. The brush 9 and the brush holder 10 are arranged radially inward of the housing 3 with respect to the end frame guide wall 6. The brush holder 10 is continuously formed from the end frame guide wall 6 and is joined to a rib-like protrusion 6a that protrudes inward of the housing space 5 by a coupling means such as caulking (12a in FIG. 4). Located within the housing space 5.

Reference numeral 12 in FIG. 1 denotes a drain hole for communicating the inside and the outside of the housing space 5. The drain hole 12 is the lowermost end in the gravity direction of the housing space 5 on the radially outer side of the housing 3 with respect to the end frame guide wall 6. It is formed so as to be located in the vicinity of a portion where the end frame 4 and the housing 3 are in pressure contact with each other. That is, when the rotor 1 is arranged and used so that the rotation shaft 1a is substantially horizontal as in the present embodiment, the housing 3 near the flange portion 3b is used as shown in FIG. 1B. Alternatively, as shown in FIG. 3, it may be provided on the end frame 4 near the flange portion 3b. When the rotary shaft 1a is arranged and used so as to be substantially vertical, it may be provided on the end frame 4 in the vicinity of the flange portion 3b as in the case of FIG.

13 in FIG. 1 or FIG. 2 (b)
Is a drain cover that faces the drain hole 12 at a predetermined distance on the outside of the housing 3.
As shown in FIG. 1, 3 is an end frame 4 that covers the drain hole 12 while maintaining the communication state of the drain hole 12.
And are formed integrally. Although the drain covers are provided at two places, the drain cover 13 at the lowermost end in the gravity direction and the drain cover 13a at the uppermost end in the gravity direction, a plurality of drain covers may be provided around the rotary shaft 1a of the rotor 1. Good.

FIG. 4 shows a state in which the brush holder 10, the terminal portion 14 and the connector 15 which will be described later are mounted on the end frame 4. The terminal portion 14 is electrically connected to the brush 9, and the connector 15 is inserted into the terminal portion 14. Then, among the portions of the connector 15 located in the housing space 5, the connector guide wall 16 facing the inner wall 3c side of the housing 3 on the radially outer side of the housing 3 from the end frame guide wall 6 (see FIG.
2) is formed, and two grooves 17 that open to the housing space 5 side are formed on the radially outer side of the housing 3 from the connector guide wall 16 (see FIG. 5). The connector 15, the connector guide wall 16 and the groove 17 are integrally formed of resin.

Further, the connector 15 is provided with a detachment preventing mechanism for preventing the connector 15 from detaching from the terminal portion 14 as shown in FIGS.
A fall prevention claw mechanism as shown in FIG. That is, as shown in (a) or (b) of FIG. 5, which is an enlarged view of the portion B of FIG. Two claw portions 19 are formed so as to move away from the central axis of the connector 15 in the longitudinal direction as they go toward each other.

Of the insertion notches 20 (see FIG. 4B) into which the connector 15 formed in the housing 3 is inserted, both claws 19 are formed when the connector 15 is inserted.
The dimension between the parts that contact with each other is smaller than the maximum dimension between the claw portions 19. Therefore, when the connector 15 is completely inserted into the terminal portion 14, the claw portion 19 contacts the inner wall 3c of the housing, and the connector 15 is prevented from coming off. Further, as shown in FIG. 6 (enlarged view of portion C in FIG. 4), the end frame 4 and the connector 15 are provided with engaging portions 21 and 22 each having a triangular shape.

Next, the reason why the waterproof structure of the electric motor according to this embodiment ensures a predetermined waterproof property and the features thereof will be described. Hereinafter, as shown in FIG. 1, a case where the electric motor is exposed to a water receiving state in a state where the electric motor is arranged so that the rotating shaft 1a is substantially horizontal will be described as an example. As shown in FIG.
Even when the electric motor is arranged so that the rotary shaft 1a is substantially vertical, waterproofness can be obtained for the same reason as described below, and therefore description thereof is omitted.

That is, when the electric motor is exposed to water, water infiltrates into the housing space 5 through a minute gap in a portion where the housing 3 and the end frame 4 are in pressure contact with each other. Then, the flooded water flows along the end frame guide wall 6 downward in the gravity direction, and is drained to the outside of the housing space 5 through the drain hole 12 formed at the lowest end of the housing space 5 in the gravity direction.

In this embodiment, as shown in FIG.
A gap is formed between the end frame guide wall 6 and the inner wall 3c of the housing 3. This is provided to absorb a manufacturing error of the housing 3 and the end frame 4, and the end frame guide wall 6 The present invention can be implemented even if the inner wall 3c of the housing 3 and the inner wall 3c are in close contact with each other.
This is because, as described above, water infiltrates into the housing space 5 through the minute gap in the region where the housing 3 and the end frame 4 are in pressure contact with each other, so that a large flow does not flow in the housing space 5. Further, even when the end frame guide wall 6 and the inner wall 3c of the housing 3 are in close contact with each other, a minute gap always exists between them, so that the water that has infiltrated through this minute gap is gravitational It flows and is drained from the drain hole 12.

Further, since the electrically important parts such as the commutator 1b and the brush 9 are arranged on the radially inner side of the housing 3 with respect to the end frame guide wall 6, the inundated water is blocked by the end frame guide wall 6. Commutator 1b
Also, the brush 9 and the like are prevented from being flooded. Incidentally, in the electric motor according to the related art, the portion 61 corresponding to the end frame guide wall of the end frame 4 is, as shown in FIG. 7B, a portion where the brush is arranged,
Since the portion 61 corresponding to the end frame guide wall is not formed, if the sealant is omitted, the brush 9 and the commutator 1b will be flooded as shown by the arrow in the figure.

Further, since the end frame 4 and the housing 3 are in pressure contact with each other at the flange portion 3b, the pressure contact area can be increased. Therefore, since it is possible to suppress water from entering through the gap between the end frame 4 and the housing 3, it is possible to improve waterproofness. Further, among the parts of the connector 15 located in the housing space 5, on the radially outer side of the housing 3 from the end frame guide wall 6,
Connector guide wall 16 facing the inner wall 3c side of the housing 3
Since the water is infiltrated through the gap between the connector 15 and the housing 3 and the end frame 4, the water is dammed by the connector guide wall 16 and the commutator 1b, the brush 9 and the like are prevented from being inundated. The dammed water flows along the connector guide wall 16 in the direction of gravity, flows into the radially outer side of the housing 3 from the end frame guide wall 6, and joins with the water infiltrated from the gap between the housing 3 and the end frame 4. Then, the water is drained to the outside of the housing space 5 through the drain hole 12.

Further, on the radially outer side of the housing 3 with respect to the connector guide wall 16, the groove 1 opened to the housing space 5 side.
Since two 7 are formed, the water infiltrated from the gap between the connector 15 and the housing 3 and the end frame 4 can be more reliably stopped and drained.
Note that the inventors of the present invention conducted a test of test type S1 (test for examining the function of a component that receives direct wind and rain or water splash) based on the moisture resistance and water resistance test method (JIS D 0203) of automobile parts, It was confirmed that better waterproofness could be obtained than the waterproof structure of the electric motor.

As described above, since the predetermined waterproof property can be secured by the simple mechanical structure, it is possible to omit the sealant applied to the connecting portion of each part of the electric motor.
Therefore, the sealing agent and the coating step for coating the sealing agent are not necessary, so that the manufacturing cost of the electric motor can be reduced. Further, since the drain cover 13 covers the drain hole 12 with a predetermined distance from the drain hole 12 on the outer side of the housing 3, direct entry of rainwater or the like from the drain hole 12 is suppressed. Therefore, it is possible to suppress direct intrusion of rainwater and the like with a simpler structure than the drain hole structure of the electric motor according to the related art, and thus it is possible to reduce the manufacturing cost of the electric motor.

By the way, the portion where rainwater or splashes infiltrate the housing 3 at a substantially right angle to the gap between the housing 3 and the end frame 4 is higher than the other portions in the housing space 5. Is big. For this reason, for example, if rainwater or splashes are received from above the motor,
The flood pressure is highest at the uppermost part in the direction of gravity. However, in this embodiment, since the drain cover 13a at the uppermost end in the gravity direction is formed, this drain cover 13a is formed.
Plays a role like an umbrella and weakens the inundation pressure, and the inundated water is suppressed from entering the iron housing space 5 over the end frame guide wall 6.

Further, by providing a plurality of drain covers, even if the mounting state of the electric motor on the vehicle is changed, the existing end frame can be used and parts can be shared. For example, if the insertion notch 20 (see FIG. 4B) of the housing 3 is formed on the left side symmetrically with respect to the paper surface, the center of the end frame 4 is aligned with the rotation shaft 1a of the rotor 1. In this state, it can be rotated 180 ° and attached to the housing 3. That is,
In this embodiment, the insertion notch 2 of the housing 3 can be formed without changing the shape and structure of the end frame 4.
By changing the position of 0, the mounting position of the connector 15 can be changed.

Further, since the drain cover is provided on the entire circumference of the end frame 4 and the insertion notch 20 of the housing 3 is provided at an appropriate position, the connector 15 can be attached at a desired position. Therefore, it is possible to improve the productivity, and consequently to reduce the manufacturing cost of the electric motor. Further, according to the present embodiment, since the electrical connection between the external power source and the electric motor is made via the connector 15, the step of soldering the lead wire to the terminal of the electric motor can be omitted. As a result, in the manufacturing process of the electric motor in which the lead wire lengths of the electric motor are different from each other, after soldering the lead wire to the brush holder 5 assembled to the end frame as in the conventional case, the end frame is attached to the housing. The manufacturing process such as assembling can be eliminated.

That is, the steps of assembling the rotor 1, the stator 2, the housing 3, the end frame 4 and the like are standardized, and in the step of assembling the connector, the lead wire length is changed by changing the connector to be assembled. Individually different electric motors can be manufactured. Therefore, in the whole manufacturing process of the electric motor, the ratio of the commonized process increases, and the production efficiency is improved, so that the manufacturing cost of the electric motor can be reduced.

By the way, as described above, the position of the drain hole 12 may be any position as long as it can perform the drainage function in relation to the water that has entered the housing space 5, and is simply physically located in the housing space 5. It is not limited to the bottom end in the direction of gravity. Further, in the above-described embodiment, the flange portion 3b
Has been extended outward in the radial direction of the housing 3, but a predetermined waterproof property can be obtained even if the flange portion 3b is formed so as to be directed inward in the radial direction.

Further, in the above-described embodiment, the drain cover 13 is provided on the outside of the housing 3. However, if the drain cover 13 is provided inside the housing space 5, it is possible to prevent rainwater or the like from directly entering.

[Brief description of drawings]

FIG. 1A is a cross-sectional view of an electric motor according to the present invention,
(B) is an enlarged view of part A.

FIG. 2 is a view on arrow A of FIG.

FIG. 3 is a cross-sectional view showing a waterproof structure when a rotating shaft of an electric motor is arranged in a vertical direction.

FIG. 4 is a cross-sectional view showing a state where a connector is inserted in the electric motor according to the present invention.

FIG. 5 is an enlarged view of a portion B in FIG. 4;

FIG. 6 is an enlarged view of a portion C in FIG. 4;

FIG. 7 is a cross-sectional view showing a conventional electric motor.

[Explanation of symbols]

1 ... Rotor, 2 ... Stator, 3 ... Housing, 4 ... End frame, 5 ... Housing space, 6 ... End frame guide wall, 7, 8 ... Bearing, 9 ... Brush, 10 ... Brush holder, 11 ... Coil spring , 12 ... Drain hole, 13 ...
Drain cover, 14 ... Terminal part, 15 ... Connector, 16 ...
Connector guide wall, 17 ... Groove.

Claims (6)

[Claims] 1. A rotor (1) which rotates by receiving electric power from an external power source, and a housing (3) which houses the rotor (1) and has an opening (3a) at an axial end thereof. An end frame (4) that presses against the housing (3) at an axial end of the housing (3) and closes the opening (3a), and the housing (3) among the end frames (4). And an end provided on the housing space (5) side partitioned by the end frame (4) and facing the inner wall (3c) of the housing (3) over the entire circumference of the inner wall (3c) of the housing (3). A frame guide wall (6) and a brush (6) which is arranged radially inward of the housing (3) with respect to the end frame guide wall (6) and supplies electric power to the commutator (1a) of the rotor (1). 9), and A drain hole (12) formed radially outward of the housing (3) with respect to the drain frame guide wall (6) and communicating the inside and the outside of the housing space (5); The bottom end of the housing space (5) in the direction of gravity, and the end frame (4)
A waterproof structure for an electric motor, characterized in that the housing and the housing (3) are formed in the vicinity of a pressure contact portion. 2. A flange portion (3b) extending in a radial direction of the housing (3) is formed at an axial end portion of the housing (3) which is in pressure contact with the end frame (4). The waterproof structure for an electric motor according to claim 1. 3. A terminal part (1) provided in the housing space (5) and electrically coupled to the brush (9).
4), a connector (15) inserted into the terminal portion (14), and a part of the connector (15) located in the housing space (5) from the end frame guide wall (6). The electric motor according to claim 1 or 2, further comprising: a connector guide wall (16) formed on a radially outer side of the housing (3) and facing an inner wall (3c) side of the housing (3). Waterproof structure. 4. A portion of the connector (15) located in the housing space (5) is located radially outward of the housing (3) from the connector guide wall (16).
The waterproof structure for an electric motor according to claim 3, wherein a groove (17) opening to the housing space (5) side is formed. 5. A drain cover (13) facing the drain hole (12) at a predetermined interval is provided, and the drain cover (13) maintains the communication state of the drain hole (12). The waterproof structure for an electric motor according to any one of claims 1 to 4, wherein the drain hole (12) is covered with the waterproof structure. 6. The connector (15) prevents the connector (15) from falling out of the terminal portion (14) when the connector (15) is inserted in the terminal portion (14). The waterproof structure for an electric motor according to any one of claims 3 to 5, characterized in that a fall prevention mechanism (19, 21, 22) is formed.