JPH0614776B2 - Brushless motor stator - Google Patents

Description

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

2. Description of the Related Art In recent years, it has become mainstream to control the capacity of compressors in air conditioners such as home air conditioners. In response to this, it is also required to adjust the amount of air blown to the heat exchanger in a wide range and in multiple stages. Instead of the induction motor as a fan drive source that has been used conventionally to satisfy these demands, A method of operating a brushless motor whose speed is easily adjusted with a DC power source is being adopted.

One of the major features of the brushless motor is that the winding configuration is much simpler than the induction motor that has been used in the past, but on the other hand, the current flowing through the winding becomes discontinuous due to the drive method. Therefore, electromagnetic vibration is generated. As one measure to alleviate this point, it is adopted that the iron core and the winding are integrally resin-molded with a thermosetting resin to be solidified.

As a stator winding of a brushless motor, a method of winding a winding for each tooth of the stator core is often adopted. In this method, the winding is concentratedly wound around the teeth, so the coil end collapses to the inside or outside diameter of the stator core, especially the one where it collapses to the inside of the stator core. If you enter, it will interfere with the insertion and rotation of the rotor. As a measure against this point, it is customary to provide a winding shroud on each of the inner diameter side and the outer diameter side of each tooth portion of the stator core. On the other hand, the brushless motor usually has a position sensor as a means for detecting the position of the rotor. A hall element is often used as this position sensor, but since it must be installed on the stator side near the rotor, it does not extend beyond the inner diameter of the stator core on the inner diameter side of the inner diameter side winding shroud. Provide it at the position as close to the fixed iron core as possible. Therefore, the inner shroud on the side on which the position sensor is mounted has to guide the wall thickness by the thickness of the position sensor.

Problems to be Solved by the Invention With the configuration described above, the following can be considered.

(1) The inner shroud where the position sensor is located is
Since the wall thickness is thin, it deforms due to the pressure of the winding and falls toward the inner diameter side, making it difficult to mount the position sensor.

(2) For the above reasons, the dose and winding tension at the time of winding are limited, and it becomes difficult to design a large space factor in the slot.

(3) During resin molding after winding, the thin inner shroud is pressed and deformed by the fluid pressure of the molding resin.

Means for Solving the Problems The present invention takes the following means in order to solve the problems of the above conventional example. That is, of the inner shrouds, at least both of them are located on the end face of the stator core on the side where the printed circuit board is mounted, but both ends in the circumferential direction are made thicker than the other shroud parts.

With the above configuration, the shroud has the same effect as the addition of the reinforcing ribs, and can withstand the pressure during winding and the resin pressure during molding.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. 1 is a partial perspective view of an iron core insulation according to an embodiment of the present invention, FIG. 2 is a stator winding assembly state diagram of a brushless motor according to an embodiment of the present invention, and FIG. It is a longitudinal cross-sectional view of a brushless electric motor according to an embodiment of the invention.

In FIG. 1, a stator core 1 is provided with a core insulation 2 by integral molding. An inner shroud portion 2a and an outer shroud portion 2b are integrally formed for each tooth portion 1a of the stator core 1. A groove 2c for inserting a position sensor or a sensor fixing base is provided on the inner diameter surface of the inner shroud portion 2a on the side where the printed circuit board is mounted, and the thicknesses of the portions 2d on both sides of the groove 2c are different from those of the other portion. It is molded thicker. When the winding is applied to each tooth portion of the stator core obtained as described above, the result is as shown in FIG. The inner shroud 2a is prevented from being deformed toward the inner diameter side. As shown in FIG. 2, the sensor fixing base 5 mounted on the printed circuit board 4 is inserted into the groove 2c when the printed circuit board 4 is mounted on the stator core 1, and as a result, the position sensor 6 is It will be installed at the position closest to the fixed iron core 1. FIG. 3 shows a longitudinal section of a brushless electric motor obtained by mounting a rotor 8 and a bearing device 9 on a stator 7 obtained by solidifying these components.

Effects of the Invention With the above-mentioned configuration, the following effects can be obtained.

(1) Since the inner shroud becomes stronger, the amount of winding can be increased for winding, the space factor in the slot can be improved, and a compact brushless motor can be designed.

(2) In the same manner, the winding tension can be increased to perform the winding, and if the winding amount is the same, the winding can be made more compact.

(3) Since there is no fear of deformation or falling even during resin molding after the winding is completed, it is possible to reduce the defective rate in the molding.

[Brief description of drawings]

FIG. 1 is a partial perspective view of iron core insulation of the stator of the present invention, FIG.
FIG. 3 is an exploded perspective view showing an assembled state of the stator, and FIG. 3 is a vertical sectional view of a brushless electric motor according to the present invention. 1 ... Stator iron core, 2 ... Iron core insulation, 2a ... Inner shroud, 3 ... Winding, 4 ... Printed circuit board, 5 ... Sensor fixing base, 6 ... Position sensor.

Claims (1)

[Claims] 1. An annular stator iron core having a plurality of slots, an iron core insulation in which a slot insulation of the iron core and a shroud of a winding are integrally formed, and a winding formed for each tooth portion of the iron core, A printed circuit board with a position sensor mounted, at least, the inner shroud of the winding shroud located on the end surface of the stator core on the printed circuit board mounting side is formed thicker than other shroud portions at both circumferential ends thereof, Positioning the position sensor between the thick ends of the inner shroud and fixing the brushless motor by integrally molding and solidifying the iron core, the winding, and the printed circuit board with thermosetting resin having electrical insulation. Child.