JPH03117342A - Drain structure of motor - Google Patents

Abstract

PURPOSE:To smoothly discharge water in a housing externally and to prevent a foreign matter from entering the housing by covering a drain hole formed at the lower part of the housing with a water permeable member and mounting the member on the housing by mounting means. CONSTITUTION:In a drain structure of a motor, a housing 1 for containing a stator core 3 and a rotor 24 is formed of a base 1a and a case 1b, and a drain hole 25 is formed at the lower part of the case 1b. The hole 25 is covered with a cloth 27 as a water permeable member, and the cloth 27 is detachably mounted on the case 1b by a cap 26 as mounting means. Thus, water stored in the housing is smoothly discharged out of the housing through the member, introduction of the matter into the housing is effectively prevented, and leakage of a rotation sound out of the housing can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a drain structure for an electric motor, and particularly to a drain structure suitable for electric motors for various electric appliances installed outdoors.

[Prior Art] In general, electric motors whose housings have a sealed structure due to the necessity of waterproofing and rust prevention, have a drain hole formed in the housing so that moisture generated by condensation inside the housing can be discharged to the outside of the housing. It is configured as follows.

An example of a conventional electric motor drain structure having this type of drain hole is the technique disclosed in Japanese Utility Model Application Publication No. 61-205257.

FIG. 4 is a cutaway side view of essential parts showing the drain structure of the conventional electric motor disclosed in the above-mentioned publication.

In the figure, (31) is a housing that accommodates a stator core and a rotor (the path shown), and (32) is an output shaft coupled to the rotor. (33) is the output shaft (32)
This is a drain hole formed in the corner of the end face of the housing (31) on the opposite side.

In the conventional electric motor drain structure configured as described above, the drain hole (33) is formed at the corner of the end face of the housing (31), so the drain hole (33) is The housing (31) is always located at the lowest part of the motor so that water etc. accumulated inside the housing (31) can be discharged to the outside.

[Problems to be Solved by the Invention] However, according to the conventional drain structure of the electric motor, as described above, the housing (31) is open at the drain hole (33), so it is particularly difficult to install the motor outdoors. In electric motors for various electrical products, foreign matter such as rainwater, mud, and dust from the outside passes through the drain hole (33) and drains into the housing (31).
There was a risk that it could get inside. In addition, the rotating sound of the rotor generated inside the housing (31) is caused by the drain hole (
33) leaked to the outside, which was not desirable in terms of noise countermeasures.

Therefore, the object of the present invention is to develop a drain structure for an electric motor that can smoothly drain the water inside the nozzing to the outside, prevent foreign matter from entering the inside of the nozzle, and suppress the leakage of rotational noise. It is about providing.

[Means for Solving the Problems] In order to solve the above problems, the drain structure of the electric motor of the present invention is such that a drain hole is formed in the lower part of the housing that accommodates the stator core and the rotor, and the drain hole is inserted through the drain hole. The housing is covered with a water-based material, and the water-permeable material is mounted on the housing using a mounting means.

[Operation] In the drain structure of the electric motor of the present invention, water accumulated inside the nozzing is smoothly discharged to the outside of the housing through the water permeable member. Furthermore, since the drain hole is covered with a water-permeable member, entry of foreign matter into the housing is reliably prevented, and leakage of rotational noise to the outside of the housing is also suppressed.

[Example] Hereinafter, an example embodying the present invention will be described based on the drawings.

FIG. 1 is a fragmentary side view showing an embodiment of a drain structure for an electric motor according to the present invention.

In the figure, (1) is the housing of the electric motor, which is constructed in a sealed manner from a base body (1a) made of synthetic resin and a case body (1b) made of a metal cup. A flange portion (2) is provided protruding from the outer periphery of the base end of the base body (1a), and a center hole (8) is provided through the center portion. In addition, a stator core (
3), a winding (4), and a control circuit board (6) are molded and fixed, and an electronic component (5) is mounted on the control circuit board (6).
has been implemented.

The case body (1b) of the housing (1) covers the stator core (3) from the outside, and connects the flange portion (2) of the base body (1a) to the flange portion (2) of the base body (1a) via a packing (13) at the outer circumference of the base end thereof. It is fixed with screws (14). Case body (1
A bearing accommodating part (12) is protrudingly provided in the center part of b), and the first bearing (12) is provided in the bearing accommodating part (12).
15) is press-fitted.

(16) is a metal bracket joined to the outer surface of the base body (1a), and at its outer end, the base body (1a
) is fixed to the flange portion (2) by the screw (14). A bearing accommodating portion (17) is provided in a protruding manner at the center of the bracket throat (16), and a second bearing (18) is press-fitted into the bearing accommodating portion (17).

(7) is an output shaft inserted into the center hole (8) of the base body (1a), and its tip end is connected to the first bearing (
15), and the base end is the second bearing (18).
are each rotatably supported. A coupling screw (9) is provided at the tip of the output shaft (7), and an uneven portion (10) is formed in the intermediate portion. Furthermore, (19)
and (20) are locking rings that lock the first bearing (15) and the second bearing (18) on the output shaft (7).

(21) is a metal cup-shaped rotor support member disposed inside the case body (1b), and its central portion is fixedly connected to the uneven portion (10) of the output shaft (7). ,
(24) is a rotor made of an annular rubber magnet fixed to the inner peripheral surface of the rotor support member (21) so as to surround the stator core (3) with a predetermined minute gap therebetween.

(25) is a drain hole formed in the lower peripheral wall of the case body (1b) of the housing (1);
25), a synthetic resin cap (26) is removably inserted from the outside.

(27) is a cloth as a water passing member supported inside the cap (26) so as to cover the drain hole (25) from the outside.

As described above, the drain structure of the electric motor of this embodiment has a housing (
1) is composed of a base body (1a) made of synthetic resin and a case body (1b) made of a metal cup.
) A drain hole (25) is formed at the bottom of the drain hole (
25) is covered with a cloth (27) as a water-permeable member, and the cloth (27) is removably attached to the case body (1b) using a cap (26) as an attaching means.

Next, the operation of the drain structure of the electric motor of this embodiment configured as described above will be explained.

When this electric motor is installed in various electrical products installed outdoors, moisture due to condensation etc. will be generated inside the housing (1), but according to the drain structure of this embodiment, moisture will be generated inside the housing (1). The water is smoothly discharged to the outside of the housing (1) through a cloth (27) serving as a water-permeable member covering the drain hole (25). Further, foreign substances such as rainwater, mud, and dust are blocked by the cloth (27) and do not enter into the housing (1). Furthermore, the rotor (24
) is also blocked by the cloth (27), so leakage to the outside of the housing (1) is suppressed.

Moreover, in this embodiment, since the cloth (27) is removably attached to the case body (1b) by the cap (26) as attachment means, the clogged cloth (27) can be easily replaced. Furthermore, even if the electric motor is already installed, its drain structure can be easily repaired.

Further, according to the structure of this embodiment, the cloth (27) as a water-permeable member can be provided with a moisture draining function, a foreign matter intrusion prevention function, and a sound insulation function. It is possible to always maintain good operating characteristics of electric motors installed in various electrical products.

By the way, in the above embodiment, cloth (27
), but the present invention is not limited thereto, and the water permeable member can also be configured as shown in FIGS. 2 and 3.

2 and 3 are cross-sectional views showing another embodiment of the drain structure for a motor according to the present invention.

In the embodiment shown in FIG. 2, the water permeable member is composed of a plurality of capillaries (28). Each capillary tube (28) is bound by a ring-shaped cap (26) as a mounting means, and is removably inserted into the drain hole (25) of the case body (1a) by operating the cap (26). has been done.

Therefore, even with the configuration of this embodiment, each capillary (
28) exhibits a moisture discharge function, a foreign matter intrusion prevention function, and a sound insulation function, so that the same effects as in the above embodiment can be obtained.

In the embodiment shown in FIG. 3, the water-permeable member is made of open-cell urethane foam (29).

The urethane foam (29) is filled in the cap (26) as a mounting means, and
) is removably attached to the drain hole (25) of the case body (1a). This urethane foam (29) also provides the same effects as those of the above embodiment.

In the embodiment shown in FIG. 1, the cloth (27) is attached to the cap (2).
6), but it is attached to the case body (1b) by cloth (
27) may be attached to the outer surface of the case body (1b) using an adhesive or double-sided adhesive tape.

Further, in the embodiment shown in FIG. 1, the present invention is embodied in an outer rotor type electric motor, but even when the present invention is applied to an inner rotor type electric motor, the same effects as in the above embodiment can be obtained. Of course.

[Effects of the Invention] As described above, the drain structure of the electric motor of the present invention includes forming a drain hole in the lower part of the housing that accommodates the stator core and the rotor, and covering the drain hole with a water permeable member to improve the water permeability. Since the member is attached to the housing by the attachment means, moisture generated inside the housing can be smoothly discharged to the outside through the permeable member, and foreign matter can be reliably prevented from entering the housing. This has the effect of suppressing the leakage of rotational noise to the outside of the housing.

[Brief explanation of drawings]

FIG. 1 is a cutaway side view of essential parts showing one embodiment of a drain structure for an electric motor according to the present invention, FIGS. 2 and 3 are sectional views showing different embodiments of the drain structure, and FIG. 4 is a conventional one. FIG. 3 is a cutaway side view of main parts showing the drain structure of the electric motor. In the figure: 1: Housing 3: Stator core 24: Rotor 25: Drain hole 26: Cap 27:
Cloth 28: Capillary tube 29: Foamed urethane. In the drawings, the same reference numerals and the same symbols indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] A drain hole formed in a lower part of a housing that accommodates a stator core and a rotor, a water-permeable member that covers the drain hole, and a mounting means for mounting the water-permeable member on the housing. A drain structure for an electric motor characterized by the following.