JPH06327212A - Rotor of brushless motor - Google Patents

Abstract

PURPOSE:To provide the rotor of a brushless motor in which the variations of the fixation strength of a sensor magnet can be reduced and also the process of manufacture can be simplified. CONSTITUTION:A plurality of holes are provided in the end surface of a rotor iron core 2, and the positioning is performed with a projection provided in the abutting surface of the rotor iron core 2 of a sensor magnet 3. The inner diameter of a sensor magnet fixing boss 5 having an outer diameter molded so as to have nearly same dimensions as the inner diameter of the sensor magnet 3 is inserted by pressing into an axis 1 to abut on the sensor magnet 3, thereby providing the rotor of a brushless motor which can be fixed in the end surface of the rotor iron core 2 of the sensor magnet 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor of a brushless electric motor used as a drive source for a blower fan of a home air conditioner or the like.

[0002]

2. Description of the Related Art In recent years, in air conditioners such as home air conditioners, brushless electric motors having high efficiency and controllability have become the mainstream as a blowing drive source for indoor heat exchangers. It is also being used as a blower drive source for outdoor heat exchangers.

A conventional brushless motor is disclosed in Japanese Patent Laid-Open No. 1-916.
The structure was as described in Japanese Patent Laid-Open No. 44-44.

A conventional rotor of a brushless motor will be described below with reference to the drawings. FIG. 6 shows Japanese Patent Laid-Open No. 1-9164
It is a longitudinal cross-sectional view of the brushless electric motor shown in Japanese Patent Laid-Open No. 4 publication. The sensor magnet 12 is attached to the shaft 1 at a position facing the hall element 11.
It is fixed to the end surface of the rotor core 14 fixed to No. 3 by an adhesion method.

[0005]

However, in the above-mentioned conventional structure, it is necessary to use an adhesive jig having a radial positioning mechanism for the sensor magnet in order to fix the sensor magnet to the rotor core. Further, even in the drying process, it is necessary to fix the sensor magnet with the bonding jig provided so that the sensor magnet is not displaced, which causes a problem that the bonding jig is fixed. On the other hand, when a quick-drying adhesive is used, there is a risk that the sensor magnet may come off due to heat generation of the rotor at the environment of use of the electric motor or at a high load point due to variations in adhesive strength.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a rotor of a brushless electric motor which can be assembled by a simple construction method.

[0007]

In order to achieve the above object, the present invention provides a sensor magnet having a plurality of protrusions on its end face, and a plurality of sensor magnets at positions corresponding to the protrusions of the sensor magnet. It is configured to be inserted into a rotor iron core having a hole, and a resin-made boss molded into an outer diameter substantially the same as the inner diameter of the sensor magnet is press-fitted into the shaft.

[0008]

With this configuration, the protrusion of the sensor magnet and the hole of the rotor core enable positioning, and the sensor magnet can be fixed by pressing the boss into the shaft.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a rotor of a brushless electric motor according to the present invention. In FIG. 1, 1 is a shaft, 2 is a rotor core, 3 is a sensor magnet, 4 is a driving magnet fixed to the outer diameter of the rotor core 2, 5 is a sensor magnet fixing boss, and 6 is a thrust adjusting boss. Denoted by 7 are oil-draining washers for collecting lubricating oil that springs from a metal (not shown) for rotatably holding the rotor.

FIG. 2 is a perspective view of the rotor core 2, which is shown at 2a.
Is a hole provided in the end surface of the rotor core 2. FIG. 3 is a perspective view of the sensor magnet 3, and 3a is a protrusion to be inserted into a hole 2a provided in the end surface of the rotor core 2. FIG. 4 shows the sensor magnet 3
FIG. 4 is a perspective view seen from the side opposite to FIG. 3.

While inserting the projection 3a on the end surface of the sensor magnet 3 into the hole 2a in the end surface of the rotor core 2 fixed to the shaft 1, the sensor magnet 3 is brought into contact with the rotor core 2 for positioning.
At this time, the outer diameter of the protrusion 3a of the sensor magnet is formed to be slightly smaller than the outer diameter of the hole 2a of the rotor core.

After the sensor magnet 3 is positioned,
The sensor magnet 3 is formed while press-fitting the inner diameter 5a of the resin-made sensor magnet fixing boss 5 having the outer diameters 5b and 5c shown in FIG. 5, which are molded to be slightly smaller than the inner diameters 3b and 3c of the sensor magnet 3, into the shaft 1. The sensor magnet 3 is fixed at a predetermined position by bringing the outer diameters 5b and 5c into contact with the inner diameters 3b and 3c.

On the end surface of the rotor core 2 opposite to the sensor magnet 3, a thrust adjusting boss 6 and an oil draining washer 7 for collecting metal lubricating oil are fixed at predetermined positions.

[0015]

As is apparent from the above embodiments, according to the present invention, the sensor magnet and the rotor core can be easily fixed without using an adhesive, so that the manufacturing process is simplified and the productivity is improved. It is possible to omit the drying equipment and the like. Moreover, there is no variation in the fixing strength of the sensor magnet,
It can sufficiently cope with the usage environment of the electric motor and the heat generation of the rotor due to the high load point.

[Brief description of drawings]

FIG. 1 is a sectional view of a rotor of a brushless motor according to an embodiment of the present invention.

FIG. 2 is a perspective view of the rotor core of FIG.

3 is a perspective view of the sensor magnet of FIG. 1 viewed from a rotor contact side.

FIG. 4 is a perspective view of the sensor magnet as viewed from the side opposite to FIG.

5 is a perspective view of the boss for fixing the sensor magnet of FIG. 1 as seen from the contact side of the sensor magnet.

FIG. 6 is a vertical half sectional view of a conventional brushless electric motor.

[Explanation of symbols]

 1 axis 2 rotor core 3 sensor magnet 5 sensor magnet fixing boss

Claims (1)

[Claims] 1. A brushless motor having a sensor-dedicated magnet at a position facing a Hall element of a rotor core, wherein the sensor-dedicated magnet has a plurality of protrusions on an end surface of the magnet-dedicated magnet that abuts the rotor core, and the rotor core is in contact with the rotor core. Is provided with a plurality of holes of substantially the same shape into which the protrusions of the sensor-dedicated magnet are inserted, and a brushless electric motor having a resin boss formed to have an outer diameter substantially the same as the inner diameter of the sensor-dedicated magnet. Rotor.