JPH02106153A - Brushless motor - Google Patents

Abstract

PURPOSE:To improve moisture resistance and dust resistance by providing an outer frame for burrying a stator and a substrate through resin molding and forming a fixing foot at a part of the outer frame. CONSTITUTION:A Hole element 9 and a drive circuit 10 are burried in an outer frame 15 molded of resin, and water drop adhered onto the outer frame 15 causes no trouble in the circuit. A lead wire 16 for feeding power to the circuit is also burried in the outer frame 15 and exhibits high water-proof performance. A rotor 6 is surrounded by the outer frame 15 having open section 15a closed with a cover 17, and thereby no dust intrudes between the stator 2 and the enclosed rotor 6. The fixing foot 15a is formed integrally with the outer frame 15 and used for securing the motor.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a brushless motor in which a rotor is disposed outside a stator.

[Conventional technology]

FIG. 3 is a longitudinal sectional view showing a conventional brushless motor disclosed in, for example, Japanese Utility Model Application Publication No. 52-140106.

In the figure, (1) is a cylindrical holder, (2) is a holder (1)
a stator fixed to the outer periphery of the stator and around which a coil (3) is wound;
(4) is a shaft supported on the inner periphery of the holder (11) via a bearing (5).

(6) is a bottomed cylindrical rotor fixed to the shaft (4),
A permanent magnet (7
) is stuck and gets stuck. (81 is a board fixed to the holder (IIK) and placed on the open side of the rotor (6), on which the Hall element (9) and the drive circuit α0 are mounted.

The conventional brushless motor is configured as described above, and the Hall element (9) detects the magnetic pole of the permanent magnet (7) of the rotor (6) and outputs a signal, and this signal causes the m-movement circuit α1 to move between the stator (2) By sequentially energizing the coils (3) of the rotor (6), the rotor (6) rotates and the shaft (4) generates mechanical output. The motor has 8 ports (
6) is placed outside the stator (2), and the substrate (81) is provided on the open side thereof, so the drive circuit a1 is vulnerable to humidity, and for example, water droplets may adhere to it and cause a short circuit. Also, since the rotor (6) is open on one side, dirt can easily enter the stator (2).
Dust may adhere between the rotor (2) and the permanent magnet (71).
There is also the problem that the rotation of ) may be restricted.

The present invention was made to solve the above problems, and an object of the present invention is to provide a brushless motor with improved moisture resistance.

In addition to the above object, another object of the present invention is to provide a brushless motor that can improve dust resistance.

[Means to solve the problem]

The brushless motor according to the present invention is provided with an outer frame in which the stator and the substrate are embedded together by resin molding, and also has mounting feet attached to a part of the outer frame. It was formed.

Moreover, a brushless motor according to another invention of the present invention includes:
In the above structure, the rotor is surrounded by an outer frame to form an opening in the axial direction of the rotor, and this opening is closed with a cover.

[Effect]

In this invention, since the stator and the substrate are integrated with resin, the drive circuit and the like are sealed from the outside world.

Further, in another aspect of the present invention, the open portion of the outer frame is closed with a cover, so that the rotor is sealed from the outside world.

〔Example〕

1 and 2 are views showing one embodiment of the present invention, in which FIG. 1 is a longitudinal cross-sectional view and FIG. 2 is a bottom view, and parts similar to those of the conventional apparatus are designated by the same reference numerals.

In the figure, α is the resin-molded outer frame, which is the stator (2).

The coil (3), the substrate (81, the Hall element (9), and the drive circuit α1 are all buried together, and has an opening (15a) on the bottom side of the rotor (6), with a part protruding outward. A leg (15b) is formed. (Le is a coil (
The lead wire 3) is similarly buried inside the outer frame and drawn from the side. αn is an outer frame a made of synthetic resin etc.
This is a cover that closes the opening (15a).

In the brushless motor configured as above,
Its operation is exactly the same as the conventional one, but the Hall element (91
and the drive circuit Q (I is buried in the outer frame 09 made of resin, so even if water droplets adhere, it will not cause any trouble to the circuit. Also, the lead wire αG that supplies power to the two circuits is also buried in the outer frame 09 made of resin. Because it is buried in the

Strong resistance to moisture.

On the other hand, the air gap between the stator (2) and rotor (6) is 1 usually 0
．． 5n, and if the rotor (6) is exposed to the outside world as in the conventional device, when used in an environment with a lot of dust, it is easy for dust and debris to enter the gap, causing the rotation of the rotor (6) to be slowed down. There is a risk of being detained. However, in the embodiment, the rotor (6) is surrounded by an outer frame (a), and the open portion (15a) of the outer frame (I) is closed with a cover αη.

Since the rotor (6) is sealed, the stator (2).

- Dust is prevented from entering between the ta (6).

Note that the mounting feet (15a) are integrally molded with the outer frame Q9, and are used to fix the motor with. In addition to providing an outer frame to be buried together, mounting feet were formed on a part of the outer frame.

The drive circuit and the like are sealed from the outside world, which has the effect of improving moisture resistance.

In another aspect of the present invention, the rotor is surrounded by an outer frame to form an opening in the axial direction of the rotor, and this opening is closed with a cover.

The rotor is sealed from the outside world, which has the effect of improving dust resistance.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a brushless motor according to the present invention, and FIG. 2 is a bottom view of FIG. 1. FIG. 3 is a longitudinal sectional view showing a conventional brushless motor. In the figure, (2) is a stator, (3) is a coil, (4) is a shaft, (6) is a rotor, (7) is a permanent magnet, (B) is a substrate,
(9) is the Hall element, αG is the drive circuit, α is the outer frame,
(1Sa) is an open part. (15b) is the mounting foot, and 07+ is the cover. Note that the same reference numerals in Figure 1 indicate the same parts.

Claims (2)

[Claims] (1) A rotor having permanent magnets is disposed outside a stator around which a coil is wound, a Hall element detects the magnetic pole of the permanent magnet, and a drive circuit controls the energization of the coil based on a signal from the Hall element. 1. A brushless motor having a board on which the stator and the board are mounted, including an outer frame in which the stator and the board are embedded together by resin molding, and mounting feet formed in a part of the outer frame. (2) A brushless motor according to claim 1, wherein the rotor is surrounded by an outer frame to form an opening in the axial direction of the rotor, and a cover is attached to the opening to close the opening.