JPH07322551A - Miniature motor - Google Patents

Abstract

PURPOSE:To facilitate the assembling work while preventing intrusion of water, oil, etc., into the inner space by bending and stopping a claw to a recess made at a position corresponding to a positioning protrusion on the outer periphery of an opening in the housing. CONSTITUTION:A bent fringe part 21 is formed around an end cap 6 integrally therewith and a stop claw 22, provided at a part, is engaged with a recess 23 made on the outer periphery of an opening made in the housing 1 thus securing the end cap 6. An arcuate protrusion 30a is formed simultaneously on the outer end face of the end cap 6 by halt punching and the outer periphery of the protrusion 30a is engaged with the opening in the housing 1 thus ensuring the coaxial setting. The inner diametral dimensions at the bent fringe part 21 of the end cap 6 are set larger than the outer diametral dimensions of the opening in the housing 1 and the gap between the fringe part 21 and the outer peripheral face at the opening is filled with a sealing material 24 thus sealing the motor hermetically. This structure prevents intrusion of water, oil, etc., into the inner space and facilitates the assembling work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small motor used to drive, for example, electric equipment for automobiles, hydraulic pumps, etc., and particularly to a rotor having an armature core, a commutator, etc. as constituent elements. Ensuring the sealing of the internal space to accommodate,
The present invention relates to a small-sized motor that prevents intrusion of water, oil, etc. and is easy to assemble.

[0002]

2. Description of the Related Art FIG. 11 is a vertical sectional front view of an essential part showing an example of a conventional small motor. In FIG. 11, reference numeral 1 denotes a housing, which is formed of a metal material such as soft iron into a hollow cylindrical shape with a bottom, and the permanent magnet 2 formed in an arc segment shape on the inner peripheral surface thereof, such as an adhesive or the like. It is fixed by the fixing means. The permanent magnet 2 may be formed, for example, in a hollow cylindrical shape and have a plurality of magnetic poles magnetized on its inner peripheral surface.

In the housing 1, the permanent magnet 2 is provided.
5 including an armature core 3 and a commutator 4 facing each other
It is configured to be able to intervene. Next, 6 is an end cap, which is made of the same metal material as the housing 1 and is fitted into the opening of the housing 1. A holder base 7 is made of an insulating material such as a resin material, and is fitted into the opening of the housing 1 together with the end cap 6.

Reference numeral 8 denotes a brush, which is made of a conductive material such as carbon and has a quadrangular cross section,
It is formed in the shape of a hollow square tube and is slidably inserted in a brush holder 9 provided on the inner end surface side of the holder base 7, and is slidably engaged with the outer peripheral surface of the commutator 4. Set up. A coil spring 10 is interposed in the brush holder 9 so as to press the brush 8 against the commutator 4 side.

Reference numeral 11 denotes a lead wire, which is a holder base 7.
It is connected to a conductive member (not shown) provided in the power source and supplied to the commutator 4 from the external DC power source (not shown) through the brush 8. Reference numeral 12 denotes a bearing, which is fixed to the central portion of the bottom portion (not shown) of the housing 1 and the end cap 6, and rotatably supports the shaft 13 constituting the rotor 5. The shaft 13 is formed so as to project outward from the bottom of the housing 1.

With the above-described structure, power is supplied to the winding of the armature core 3 from the lead wire 11 via the conductive member provided on the holder base 7 and the brush 8 via the commutator 4 constituting the rotor 5. By doing so, a rotational force is applied to the rotor 5 existing in the magnetic field formed by the permanent magnet 2 fixed to the inner peripheral surface of the housing 1, so that the rotor 5 can be rotated and the housing 1 An external device (not shown) can be driven via the shaft 13 protruding outward from the bottom.

When the small motor as described above is used for driving electrical equipment installed in a harsh environment such as an engine room of an automobile, water, oil or the like is stored in the inner space of the housing 1. In order to prevent undesired accidents due to invasion, there are many cases in which the waterproof cover 14 is fitted on the end cap 6 side of the housing 1. In this case, the waterproof cover 14 is formed of, for example, a rubber material in a hollow cylindrical shape with a bottom, and the inner diameter dimension thereof is substantially the same as the outer diameter dimension of the housing 1. Since a bearing (not shown) is provided at the bottom of the housing 1, a sealing means similar to the opening of the housing 1 is required. Normally, however, a separate sealing means is used together with a connecting means with an external device. Means have been applied.

[0008]

In the conventional small-sized motor having the above-mentioned structure, when the small-sized motor is attached to an external device, a through bolt which penetrates the inside of the housing 1 in the axial direction is usually used. It is necessary to temporarily remove the waterproof cover 14 from the housing 1 during the mounting work. Further, after the small motor is attached to the external device with the through bolt, the waterproof cover 14 must be attached to the opening of the housing 1 again, which causes a problem of low workability.

Further, when the waterproof cover 14 is attached to and removed from the housing 1, or when a small motor is attached by a through bolt, the waterproof cover 1 is erroneously attached.
4 may be damaged, and there is also a problem that the sealing property for waterproofing and oilproofing and the reliability are deteriorated.

Further, since the waterproof cover 14 must cover the opening of the housing including the end cap 6, not only the axial length of the entire small motor becomes large, but also the waterproof cover 14 is provided. However, there is a drawback that the manufacturing cost will increase as well.

In the assembling work of the small motor, first, the rotor 5 is inserted into the housing 1, and then the holder base 7 having the brush holder 9 and the brush 8 is fitted into the opening of the housing 1 and the end is finished. Cap 6
However, there is a problem that the work of fitting the holder base 7 is complicated. That is, the brush 8 biased toward the center by the coil spring 10 is attached to the holder base 7, and the inner diameter of the enclosing surface connecting the inner ends of the brush 8 is naturally smaller than the outer diameter of the commutator 4. This is because.

Therefore, the inner end of the brush 8 is previously moved outward by a jig to be fitted into the housing 1 with the inner diameter of the enclosing surface being sufficiently larger than the outer diameter of the commutator 4. There is a need. Then, after the holder base 7 is mounted and positioned, the jig is removed. Therefore, when positioning the holder base 7, it is necessary to perform the positioning with the jig for expanding the brush 8 interposed, and the workability is reduced.

The present invention solves the above-mentioned problems existing in the prior art, and provides a small motor that prevents water, oil, etc. from entering the internal space for housing the rotor and that is easy to assemble. The purpose is to

[0014]

In order to achieve the above object, according to the present invention, there is provided a housing formed of a metal material in the shape of a hollow cylinder with a bottom and having a permanent magnet fixed to an inner peripheral surface thereof, and the permanent magnet. A brush holder and a brush that hold a brush that is slidably engaged with the commutator on the holder base and an end cap that is fitted to the opening of the housing. A small motor having a pair of input terminals electrically connected thereto and rotatably supporting the rotor through a bearing provided on a bottom portion of the housing and an end cap. Is formed so as to penetrate the end cap and project outward, and a positioning projection is provided on the inner peripheral surface of the opening of the housing, and this projection is provided on the outer circumference of the holder base. Engage the positioning recesses to form a bent edge on the peripheral edge of the end cap, and make the inner diameter of this bent edge larger than the outer diameter of the opening in the housing. And a sealing material between the housing and the opening of the housing, and a locking claw is provided on a part of the bent edge of the end cap,
A technical means was adopted in which the locking claw is bent and locked in a recess provided on the outer periphery of the opening of the housing and in a portion corresponding to the positioning projection.

[0015]

With the above structure, the fitting portion between the opening of the housing and the end cap is completely sealed,
The waterproof property and the oil proof property are ensured, and the conventionally used waterproof cover is not required, so that the cost can be reduced. Further, the holder base can be easily attached to the housing and positioned.

[0016]

1 to 4 are a front view, a right side view, a left side view and a longitudinal sectional view of an essential part, respectively, showing an embodiment of the present invention.
2 is an enlarged cross-sectional view taken along the line AA in FIG. 2, and the same portions are denoted by the same reference numerals as those in FIG. 1 to 4, reference numeral 21 denotes a bent edge portion, which is integrally formed on the peripheral edge of the end cap 6. Next, a part of the bent edge portion 21 is provided with locking claws 22 at opposed positions of, for example, 180 °, and is bent and locked in a recess 23 provided on the outer periphery of the opening of the housing 1 as shown in FIG. As a result, the end cap 6 is fixed to the opening of the housing 1.

In this case, a so-called half punch is formed on the outer end surface of the end cap 6, for example, by using a molding die, to form an arcuate recess 30 having a depth dimension less than the plate thickness dimension of the material forming the end cap 6. By processing, arc-shaped protrusions 30a are simultaneously formed on the corresponding inner end faces, and the outer periphery of the protrusions 30a and the inner peripheral face of the opening of the housing 1 are engaged with each other so that the housing 1 and the end cap 6 are coaxial with each other. Secure.

The bent edge portion 21 of the end cap 6
Has an inner diameter larger than the outer diameter of the opening of the housing 1. Between the bent edge 21 and the outer peripheral surface of the opening of the housing 1, for example, a silicone rubber-based or butyl rubber-based non-lipophilic A sealing material 24 made of a non-hydrophilic material is filled and sealed. Axis 1 of rotor 5
The bearing 12 that supports the left end of the end cap 3 is fitted in the recess 25 formed in the outer end surface of the end cap 6.

The output shaft 13a is formed by penetrating the end cap 6 and projecting outward, and eccentric from the shaft center of the shaft 13 of the rotor 5 in the dimension e. Reference numeral 26 denotes a bolt hole, which is provided in the bottom portion of the housing 1 and the end cap 6, and allows a through bolt (not shown) for attachment to be inserted therethrough. Next, 27 is a pair of input terminals, which are provided in a connecting cylinder 28 provided at the lower end of the holder base 7 and are used for connection with an external DC power supply (not shown).

FIG. 6 is an end view of the opening of the housing 1, and FIG. 7 is a view in the direction of arrow B in FIG. 6, and the same parts are designated by the same reference numerals as those in FIGS. 6 and 7, reference numeral 29 denotes a positioning projection, which is provided so as to project from the inner peripheral surface of the opening of the housing 1 and is used for positioning the holder base 7 described later. That is, the protrusion 2
The inner end surface of 9 is formed in a plane parallel to the tangent line of the inner peripheral surface of the housing 1, both side surfaces of the protrusion 29 are substantially parallel to each other and substantially perpendicular to the inner end surface, and the opening portion of the protrusion 29 of the housing 1 is formed. The side end face is formed at right angles to the inner end face and both side faces.

It is preferable that the portion where the protrusion 29 is installed is provided at a portion corresponding to the concave portion 23 provided in the opening of the housing 1 as shown in FIG. By thus setting the concave portion 23 and the projection 29 at the corresponding portions, both can be simultaneously and highly accurately molded by a molding die utilizing press working, for example.

8 and 9 are a right side view and a left side view of the main part showing the holder base 7 in FIG. 4, respectively. FIG. 10 is a view of the main part in the direction of arrow C in FIG. The same reference numerals as those in FIGS. 1 to 4 are used. However, FIG. 8 shows a state in which the coil spring 10 shown in FIG. 4 is removed. 8 to 10, the holder base 7 is formed by integrally forming the hollow disk portion 7a and the connecting cylinder 28 with an insulating material such as a resin material.
The maximum outer diameter of a is formed to be substantially the same as the inner diameter of the opening of the housing 1 shown in FIGS.
The holder base 7 is formed so that it can be fitted into the opening of the housing 1.

Reference numerals 31 and 32 denote conductive members, which are fixed to the holder base 7 by bending the leg pieces 9a protruding from the brush holder 9. 33 is a pigtail wire, which is connected between the conductive members 31 and 32 and the brush 8. Reference numeral 34 is a positioning portion, which is a concave portion 35 for positioning.
Is provided. The size of the recess 35 is set to correspond to the size of the protrusion 29 shown in FIGS.
Can be engaged in the recess 35.

When assembling a small-sized motor having the above structure, first, the bearing 12, the end cap 6 and the holder base 7 on the output shaft 13a side shown in FIG. However, in this case, the coil spring 10 is not yet attached to the holder base 7 as shown in FIG. Next, the rotor 5 is mounted from the holder base 7 side, and the shaft 13 on the output shaft 13a side is fitted into the bearing 12. In this case, since the inner diameter of the enclosing surface connecting the inner ends of the brushes 8 is sufficiently larger than the outer diameter of the commutator 4, the brush 5 and the commutator 4 do not interfere with each other, and the rotor 5 can be easily mounted. Can be installed.

Next, the coil spring 10 is fitted from the outer end surface of the brush holder 9 to bring the brush 8 into contact with the commutator 4, and the locking piece 9d previously provided on the outer end surface of the brush holder 9 is attached to the coil spring 10. Bend to engage with and hold brush 8 and coil spring 10 in place. Then, the housing 1 is mounted with the bearing 12 mounted on the shaft 13 on the other side of the rotor 5.

When mounting the above housing 1, FIG.
7 to 7, the protrusion 29 protruding from the inner peripheral surface of the opening engages with the concave portion 35 provided on the outer periphery of the holder base 7 as shown in FIGS. Inner peripheral surface of opening and hollow disk portion 7 of holder base 7
The outer peripheral surface of the positioning portion 34 provided in a is engaged.
Therefore, the housing 1 and the holder base 7 are accurately positioned in the axial direction and the circumferential direction of the housing 1, and the coaxiality between the housing 1 and the holder base 7 is ensured.

After the housing 1, the holder base 7 and the end cap 6 are assembled as described above, the sealing material 24 is filled between the bent edge portion 21 of the end cap 6 and the outer peripheral surface of the opening portion of the housing 1. The locking claw 22 provided on the bent edge portion 21 of the end cap 6
5 is bent and locked in the recess 23 provided on the outer periphery of the opening of the housing 1 as shown in FIG. 5, the holder base 7 and the end cap 6 can be firmly fixed to the housing 1. The space can be sealed.

In the present embodiment, an example in which the shaft center of the output shaft 13a is eccentric with the shaft center of the shaft 13 of the rotor 5 has been described, but naturally the present invention can be applied to a small motor in which both are concentric. Is. The number of permanent magnets 2 to be fixed to the inner peripheral surface of the housing 1 and the number of brush holders 9 and brushes 8 to be provided on the holder base 7 can be appropriately selected according to the required specifications of the small motor.

The permanent magnet 2 may be formed in a hollow cylindrical shape and a predetermined number of magnetic poles may be provided on the inner peripheral surface thereof. Further, it goes without saying that the number of locking claws 22 and recesses 23 provided on the end cap 6 and the housing 1 can be appropriately selected. It is also possible to mount the housing 1 in a state where the sealing material 24 is applied in advance to the inner peripheral surface of the bent edge portion 21 of the end cap 6.

[0030]

EFFECTS OF THE INVENTION Since the present invention has the structure and operation as described above, the following effects can be obtained.

(1) It is possible to prevent water, oil, etc. from entering the internal space for accommodating the rotor.
Oil resistance can be improved. (2) Provide a locking claw on the bent edge of the end cap,
The end cap and the housing can be fixed to each other while securing the sealing property of the internal space by a simple means of bending and locking the locking claw in the recess provided on the outer peripheral surface of the opening of the housing, so that the assembly work is easy. Becomes

(3) Since the brush holder having the brush can be easily and accurately positioned in the housing,
Assembling work is further facilitated in connection with (2). (4) Since the conventionally used waterproof cover is unnecessary,
The work of attaching the small motor to the external device is facilitated, and the space occupied by the small motor in the axial direction can be reduced.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a right side view showing an embodiment of the present invention.

FIG. 3 is a left side view showing an embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of an essential part showing an embodiment of the present invention.

5 is an enlarged cross-sectional view of a main part taken along the line AA in FIG.

6 is an end view of the opening of the housing 1. FIG.

FIG. 7 is a view in the direction of arrow B in FIG.

8 is a right side view of an essential part showing the holder base 7 in FIG. 4. FIG.

9 is a left side view of an essential part showing a holder base 7 in FIG. 4. FIG.

10 is a main part C direction arrow view in FIG. 9;

FIG. 11 is a vertical sectional front view of an essential part showing an example of a conventional small motor.

[Explanation of symbols]

 1 Housing 6 End Cap 7 Holder Base 21 Bending Edge 22 Locking Claw 23, 35 Recess 29 Protrusion

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Tsutomu Saya Tsutomu Satoshi, Honpomura, Inba-gun, Chiba Prefecture 280 Mabuchi Motor Co., Ltd.Technical Center (72) Hiroaki Nakahashi 280 Ryugoji, Honpomura, Inba-gun Chiba Prefecture Mabuchi Motor Co., Ltd. Inside the technical center

Claims (1)

[Claims] 1. A housing (1) formed of a metallic material in the shape of a hollow cylinder having a bottom and having a permanent magnet (2) fixed to the inner peripheral surface thereof, and a rotor (5) facing the permanent magnet (2). )
And a holder base (7) and an end cap (6) fitted into the opening of the housing (1), and the holder base (7) is slidably engaged with the commutator (4). A brush holder (9) for holding the brush (8) and a pair of input terminals (27) electrically connected to the brush (8) are provided, and the bottom portion of the housing (1) and the end cap (6) are provided. In a small motor in which the rotor (5) is rotatably supported via a bearing (12) provided, the output shaft (13a) of the rotor (5) penetrates the end cap (6) to Projections (29) for positioning on the inner peripheral surface of the opening of the housing (1).
And a positioning recess (35) provided on the outer periphery of the holder base (7) is engaged with this projection (29) to form a bent edge (21) on the peripheral edge of the end cap (6). At the same time, the inner diameter of the bent edge (21) is made larger than the outer diameter of the opening of the housing (1).
A sealing material (24) is filled between the bent edge portion (21) of the end cap (6) and the opening portion of the housing (1), and is attached to a part of the bent edge portion (21) of the end cap (6). A locking claw (22) is provided, and the locking claw (22) is provided.
A recess (2) provided on the outer periphery of the opening of the housing (1) and at a portion corresponding to the positioning projection (29).
A small motor characterized by being bent and locked to 3).