JP2918594B2 - Bushing for molded motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a molded motor bushing in which a stator core and a winding are molded with a molding material containing a resin, and more specifically, leads from the winding. And a bushing for a molded electric motor drawn out by a bushing.

[Prior Art and Problems to be Solved by the Invention] Conventionally, a mold-type motor has been known as a small-sized motor having excellent mass productivity. This mold type electric motor usually has a stator core, and a winding wound around the stator core,
A housing that integrates the stator core and the entire winding. A rotating shaft rotatably supported by a pair of bearings is provided in the housing, and a rotor is mounted on the rotating shaft with a predetermined gap from a stator core.

The lead extending from the winding of the stator core is drawn out through a bushing partially embedded in the housing. FIG. 4 is an exploded perspective view showing a conventional bushing. The bushing (31) includes a pair of bushing members (31a) (31b), and each bushing member (31a) (31b) has a plurality of leads (33a) from a winding.
A plurality of mounting grooves (32a), (32b), and (32c) each having a curved cross section in which (33b) and (33c) are mounted are formed. On the opposing surface of each bushing member (31a) (31b), a projection (34) and a through-hole (35) that can be fitted to each other are formed.

Therefore, the leads (33a) (33b) (33) are inserted into the mounting grooves (32a) (32b) (32c) of the pair of bushing members (31a) (31b).
c) is mounted, each bushing member (31a) (31b) is fitted, the bushing members (31a) and (31b) are integrated, and pressed with a molding die to mold a housing (not shown). The bushing (31) can be embedded in the housing and integrated.

However, the leads (33a) (33b) (33c)
And the mounting groove ((32a) of the bushing member (31a) (31b))
Since a gap is formed between (32b) and (32c), moisture may enter the housing by capillary action. A general electric motor having a housing composed of a frame is generally air-permeable, so that moisture is volatilized by natural drying. However, unlike the above-described ordinary motor, the mold-type electric motor has high airtightness, so that the water once invading the housing is not diffused to the outside, but permeates and is retained in the housing. In particular, when the housing is formed of a molding material containing a synthetic resin and an inorganic filler, moisture easily permeates into the housing. Moisture retained in the housing reduces the insulation resistance of the housing,
Impairs the function as an electric motor.

Accordingly, an object of the present invention is to provide a bushing for a mold-type electric motor that can suppress the intrusion of moisture into a molded housing even when moisture enters the bushing.

[Means for Solving the Problems] In order to achieve the above object, the present invention comprises a pair of bushing members which are made of a hard electric insulating material and which can be fitted to each other, and are wound around a stator core. A plurality of leads connected to the windings are mounted in a plurality of mounting grooves of the bushing member, and the wound stator core and the bushing member are arranged in a mold and molded. In a bushing, a notch is formed between the plurality of adjacent mounting grooves, and a bushing for a molded electric motor is provided.

[Operation] In the bushing for a molded electric motor having the above-described configuration, the notch is formed between a plurality of adjacent mounting grooves of the bushing. Therefore, even if moisture enters the bushing along the lead due to the capillary phenomenon. In addition, the cut-in portion can retain the intruded moisture, and the intrusion of the moisture into the housing can be suppressed.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an exploded perspective view showing a bushing for a molded motor of the present invention, FIG. 2 is a sectional view showing a bushing molded in a housing, and FIG. 3 is a partial schematic sectional view showing a molded motor.

As shown in FIG. 3, this molded motor is
A stator core (1), a winding (2) wound around the stator core (1), and a housing (3) that integrates the entire stator core (1) and the winding (2). Have.

A rotating shaft (4) is disposed in the housing (3), and a rotor (5) is mounted on the rotating shaft (4) with a predetermined gap from the stator core (1). . The rotating shaft (4) is rotatably supported by a pair of bearings (6a) (6b), and a pair of brackets (7a) (7b) is fixed to both sides of the housing (3).

And a plurality of leads (2a) extending from the winding (2).
(2b) (2c) is drawn out by a bushing (8) partially embedded in the housing (3).

As shown in FIGS. 1 and 2, this bushing (8) is a pair of bushing members (8
a) (8b), and each of the bushing members (8a) (8b) has a lead (2a) (2
b) A plurality of mounting grooves (9
a) (9b) and (9c) are formed.

In this example, the mounting grooves (9a) (9b) (9c)
A plurality of notches (10a) are formed between the adjacent mounting grooves (9a), (9b), and (9c) to communicate with each other. In this example, notches (10b) are also formed in the walls of the mounting grooves (9a) (9c) on both sides.

In order to fit the pair of bushing members (8a) and (8b) closely together, a plurality of protrusions (11) are provided on the surface of one bushing member (8a) facing the other bushing member (8b). The other bushing member (8b) is formed with a plurality of through holes (12) into which the convex portions (11) are fitted. In the figure, reference numeral (13) is
It is a pin gate mark formed at the time of resin molding of each bushing member (8a) (8b).

The bushing (8) having such a structure is partially embedded in the housing (3), for example, as follows.
That is, as shown in FIG. 2, the mounting grooves (9a) (9
b) The leads (2a), (2b), and (2c) are attached to (9c), respectively, and the pair of bushing members (8a) (8b) are fitted together to be integrated. In addition, a bushing (8) is arranged at a predetermined position of the molding die, and is pressed by the molding die.
By injecting the molding material into the mold, a housing (3) in which the bushing (8) is partially embedded and integrated can be formed.

Even if moisture enters the bushing (8) from the outside through the leads (2a), (2b) and (2c), the entered moisture can be retained by the cutouts (10a) and (10b). It can be prevented from penetrating into the housing (3). Therefore, the insulation resistance of the housing (3) does not decrease, and the function of the motor does not deteriorate.

The moisture retained in the notches (10a) (10b) is transferred to the leads (2a) (2b) (2c) and the mounting groove (9) of the bushing (8).
a) Volatilizes to the outside by respiration through the gap between (9b) and (9c). In order to efficiently evaporate the moisture held in the notches (10a) (10b) to the outside, the diameter of the mounting grooves (9a) (9b) (9c) of the bushing (8) should be adjusted from the housing (3) side. Also, it is preferable to make the lead (2a), (2b), and (2c) larger on the lead-out side. In this case, the bushing (8)
At the drawer side of the lead (2a) (2b) (2c) and the mounting groove (9
a) Since a gap portion communicating with the outside air can be formed between (a), (9b), and (9c), the moisture held in the cutout portions (10a) (10b) can be efficiently volatilized to the outside.

In addition, the mounting groove (9a) (9b) of the bushing (8)
(9c) does not need to communicate with each other by the notch (10a), and may be formed on the peripheral wall of each mounting groove (9a) (9b) (9c). The notches (10) are provided in the mounting grooves (9a) and (9c) on both sides.
It is not necessary to form b). Further, at least one notch may be formed between the adjacent mounting grooves.

Further, the pair of bushing members (8a) and (8b) are not limited to the protrusion (11) and the through hole (12) of the above-described embodiment, but can be fitted to each other by protrusions and ridges, recesses and grooves. It may be. Further, in the illustrated example, three mounting grooves (2a) are formed in the bushing members (8a) (8b) so as to correspond to the three-phase motor.
(2b) (2c) is formed, but in the single-phase motor,
The number of mounting grooves may be two.

The bushing may be at least partially embedded in a housing formed by molding.

The bushing (8) only needs to be at least partially embedded in the housing (3) formed by molding, and is not limited to a synthetic resin, and may be formed of an electrically insulating material, for example, a ceramic.

As the molding material for forming the housing, a conventional material such as a thermosetting resin alone or a mixture of a thermosetting resin and an electrically insulating inorganic filler can be used.

The bushing for a mold type electric motor of the present invention is not limited to the internal rotation type electric motor as in the above embodiment, but can be applied to an external rotation type electric motor.

[Effects of the Invention] In the bushing for a molded electric motor of the present invention, a notch is formed between adjacent mounting grooves of a bushing embedded in a housing formed by molding, so that moisture that has entered from the outside can be removed. Can be held in the notch. Therefore, it is possible to prevent moisture from entering the housing, and to prevent a decrease in insulation resistance of the housing.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a bushing for a molded electric motor of the present invention, FIG. 2 is a sectional view showing a bushing molded in a housing, FIG. 3 is a partial schematic sectional view showing a molded electric motor, FIG. FIG. 2 is an exploded perspective view showing a conventional bushing. (2) ... winding, (2a) (2b) (2c) ... lead, (3) ...
Housing, (8) bushing, (8a) (8b) ... bushing member, (9a) (9b) (9c) ... mounting groove, (10a) (1
0b)… Notch

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H02K 5/22 H02K 5/08

Claims (1)

(57) [Claims] 1. A bushing comprising a pair of bushing members which are made of a hard electrically insulating material and which can be fitted to each other, and wherein a plurality of leads connected to a winding wound around a stator core are provided. In a motor bushing which is mounted in a plurality of mounting grooves of a member, and which is molded by arranging and winding the stator core and the bushing member in a mold, a notch is formed between the plurality of adjacent mounting grooves. A bushing for a mold-type electric motor, wherein a bushing is formed.