JPH057945B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides a method in which a plurality of stator coils and a drive circuit for energizing the stator coils in an order according to the rotational position of a rotor are respectively disposed on a substrate. The present invention relates to a brushless motor, particularly an axial gap type brushless motor in which a stator coil and a rotor magnetic pole are opposed to each other in the axial direction.

[Technical background of the invention]

In the above type of axial gap type brushless motor, a plurality of stator coils are conventionally arranged on a board at equal intervals in a ring shape, and a part of the board is extended to the outer peripheral side of the stator coil. , it is common to arrange a drive circuit in this extended portion.

[Problems with background technology]

However, in the above conventional configuration, the portion of the board on which the drive circuit is installed protrudes in the radial direction, resulting in an increase in the size of the entire motor. There was also the problem that there was a risk of damage, making handling inconvenient.

[Purpose of the invention]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an axial gap type brushless brushless motor that can reduce the size of the entire motor, eliminate the need for its handling, and reduce output torque ripple. It is in providing the motor.

[Summary of the invention]

The present invention divides the stator coil into a plurality of groups and arranges them on the substrate with a predetermined space between each group and in a point symmetrical manner with respect to the rotational axis of the rotor, and also provides a plurality of stator coil groups. The components constituting the drive circuit are made of a magnetic material, and the structure is configured such that a positive torque is generated between the magnetic material and the rotor magnetic poles when the relative distance between the stator coils and the rotor magnetic poles is maximized. It is something.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 to 3, reference numeral 1 denotes an annular printed wiring board fixed to a base 2 via spacers 3 and screws 4, and a stator yoke 5 and a plurality of tubes are mounted on the upper and lower surfaces of the printed wiring board, respectively. 2n pieces (however, an integer of n≧3, n=3 in this example), that is, 6 flat stator coils 6, 7, 8, 9, 1
A stator 12 is constructed by arranging coils 0 and 11 (only the stator coil 6 is shown in FIG. 1). In this case, stator coils 6 to 1
1 has three phases and is arranged in the following arrangement. That is, each stator coil 6 to 1
1, the opening angle θ between the coil sides is set to 90°/n=30°, and the first group A consists of stator coils 6, 7, and 8, and the second group A consists of stator coils 9, 10, and 11. It is divided into B. Stator coils 6, 7, 8 and 9, 10, 1 of each group A and B
The arrangement pitch within each group is set to 120°/n=40°, and the first group A and the second group B are arranged point-symmetrically with respect to the rotational axis O of the rotor, which will be described later. Therefore, as a result, there is a predetermined space C, D between the first group A and the second group B on the substrate 1.
comes to exist.

On the other hand, 13 is a rotating shaft supported on the base 2 via a bearing (not shown), 14 is an annular rotor yoke attached to a boss 15 fitted and fixed to this rotating shaft 13 via screws 16; A rotor 18 is constructed by arranging a rotor magnetic pole 17 made of an annular permanent magnet on the upper surface of the rotor yoke 14 so as to face the stator coils 6 to 11 in the axial direction. In this case, the rotor magnetic pole 17 is 4n
= 12 poles, therefore rotor magnetic pole 17
The magnetization pitch is equal to the opening angle θ between the sides of the stator coils 6 to 11, which is 30°.

Therefore, stator coils 6 to 1 are shown in FIG.
1 and rotor magnetic poles 17 developed in the rotational direction of the rotor 18, as seen from the outside of the rotor 18. For example, in the state shown in Figure 4a,
When a current in the direction of the arrow is supplied to the first phase stator coils 6, 9 and the third phase stator coils 8, 11, there is a gap between the coil side of each stator coil 6, 8, 9, 11 and the rotor magnetic pole 17 as shown by the arrow E. A torque is generated in the direction. After this, when a current is supplied in the direction of the arrow to the first phase stator coils 6, 9 and the second phase stator coils 7, 10 in the state shown in FIG. 4b, the coil sides of each stator coil 6, 7, 9, 10 are A torque is generated in the direction of the arrow E between the and the rotor magnetic poles 17, and then, in the state shown in FIG. When supplying current in the direction, each stator coil 7, 8, 10, 1
Torques in the direction of arrow E are generated between the coil sides of 1 and the rotor magnetic poles 17, respectively. Therefore, if the stator coils 6 to 11 are energized in the order according to the rotational position of the rotor 18 as described above, the rotor 1
8 rotations are connected.

Now, in FIG. 2, 19 is a drive circuit for energizing the stator coils 6 to 11 in the order according to the rotational position of the rotor 18, and this is divided into spaces C and D on the substrate 1. It is located. This drive circuit 19 is connected to the rotor 18
Hall element 20a for detecting the rotational position of
20b, 20c and transistors 21a, 2 for switching on/off of stator coils 6 to 11;
1b, 21c and Hall elements 20a, 20b,
Transistors 21a, 2 based on the output of 20c
1b and 21c, and in this case, its height is set to be smaller than the height of the stator coils 6 to 11. Therefore, stator coil 6
11 to 11 and the rotor magnetic poles 17 can be minimized, thereby eliminating a drop in efficiency and reducing the size in the axial direction. In addition, the control IC 22, which is a component of the drive circuit 19, has its pins and chip base made of a magnetic material, and is in a state where the relative distance between the stator coils 6 to 11 and the rotor magnetic pole 17 is maximum, that is. A position where positive torque (torque in the direction of arrow E in FIG. 4) is generated between the magnetic body and the rotor magnetic pole 17 in a state where the torque acting between the stator coils 6 to 11 and the rotor magnetic pole 17 is minimum. It is located in That is, the output torque includes ripples as shown in FIG. 5, but when the control IC 22 is arranged as described above, the output torque increases at the valley between the ripples. As a result, the output torque ripple can be reduced with a simple configuration.

In the above embodiment, the spaces C and D on the substrate 1 are
The entire drive circuit 19 was arranged in
Only a part of the drive circuit 19 may be arranged in spaces C and D.

〔Effect of the invention〕

As explained above, the present invention divides the stator coil into a plurality of groups and arranges them on the substrate with a predetermined space between each group and in a point symmetrical manner with respect to the rotation axis of the rotor. At least a part of the drive circuit is arranged between the stator coil groups, and the parts constituting the drive circuit arranged in this way are made of a magnetic material, so that the relative distance between the stator coil and the rotor magnetic poles is maximized. Since the structure is configured so that positive torque is generated between the magnetic body and the rotor magnetic poles, the radial dimension of the board can be reduced, making it possible to downsize the entire motor. This has excellent effects in that it can eliminate the risk of damage and the inconvenience of handling it, and it can also reduce output torque ripple at the same time with a simple configuration.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a sectional view of the left half of the motor, Fig. 2 is a front view of the stator, Fig. 3 is a front view of the rotor, and Fig. 4 is a stator coil and rotor. Figure 5 showing the expanded state.
The figure is an output torque characteristic diagram. In the figure, 1 is a substrate, 6 to 11 are stator coils, 12 is a stator, 17 is a rotor magnetic pole, 18 is a rotor, 19 is a drive circuit, and 22 is a control IC (component).

Claims (1)

[Claims] 1. A plurality of stator coils arranged on a substrate, a rotor magnetic pole made of a permanent magnet arranged to face the stator coil in the axial direction, and a rotational position of the rotor arranged on the substrate. a drive circuit that energizes the stator coils in an order according to The stator coils are arranged point-symmetrically with respect to the rotation axis of the stator coils, and at least a part of the drive circuit is arranged in a space between the stator coil groups, and the parts constituting the drive circuit arranged in this way are made of a magnetic material. The axial gap type brushless brush is configured such that a positive torque is generated between the magnetic body and the rotor magnetic poles when the relative distance between the stator coils and the rotor magnetic poles is maximum. motor.