JPH0191641A - Dc motor - Google Patents

Abstract

PURPOSE:To improve holding torque in the direction of inverted rotation of a motor, when it is placed in a stable condition, by forming three grooves with a specific angular space on the point end peripheral surface of an armature core, in case of the four-pole five-coil DC motor. CONSTITUTION:In the case of a DC motor providing four field poles 2 and an armature core 3 having five radial toothed parts 131-135, three grooves A1, A2, A3-E1, E2, E3 are respectively provided in point end peripheral surfaces 231a-235a, opposed facing to the field pole, of each toothed part 131-135. These three grooves are provided with one of them on the open angle center line of a point end peripheral surface and the rest of two grooves in a position displaced about every 18 deg. before and after the groove on the center line of the peripheral surface. By the constitution thus obtained, the motor, when it is placed in a stable condition stopping applying driving voltage, enables holding torque for a direction of inverse rotation to be improved.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a DC motor, and relates to a functional component or product that operates using a DC motor, when no driving voltage is applied to the DC motor. It is also used in applications that require large holding torque. For example, in the field of automobile parts, it is used in DC FFI motors such as power window regulator systems, power seat systems, and sunroof systems.

(Prior Art) As a conventional DC motor, for example, as shown in Fig. 5,
A DC motor 50 is known that includes four field magnets 14i52 and an armature core 53 having five teeth 53b extending radially from a shaft portion 53a and facing the field 1g magnetic pole 52. This DC motor 50 is used, for example, in a transfer switching actuator for an automobile, as shown in FIG.

In this case, the power is transmitted by operating the DC motor 5o, whereby the rotational torque of the DC type 'ljJm 50 is transmitted from the worm 61 to the holding mechanism 63 via the worm wheel 62 and stored therein. Furthermore, the stored rotational torque is transferred to the rack and pinion 66.6 through reduction gears 64.65.
67, it is converted into a linear motion output. Here, the rotation angle sensor 68 senses the state in which rotational torque is stored in the holding mechanism section 63, and the power to the DC motor 50 is cut off. At this time, the rotational torque stored in the holding mechanism section 63 is in a state where rotational torque in the reverse direction is applied to the DC electric motor [50] via the worm 61 and the worm wheel 62. For this reason, the DC motor 50 is required to have a holding torque of 1 to 1 to overcome the rotational torque in the respective reverse direction.

[Problems to be Solved by the Invention] Since the above-mentioned conventional DC motor has a 4-pole, 5-coil concentrated winding configuration, only one of the five teeth is stable with respect to the four field magnetic poles. The structure is such that For this reason, there was a problem in that sufficient holding power to overcome the reversal direction stored in the rock support structure could not be obtained.

The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a DC motor with improved holding torque in the reverse direction when the application of drive voltage is stopped and current is not flowing through the coil. It is about providing.

[Structure of the Invention] (Means for Solving the Problems) The DC power lj1 machine of the present invention has four field magnetic poles and a five-circumferential tooth portion extending radially from the shaft portion and facing the field magnetic field 1if18i. In the il'j electrospinning machine, the ffi machine iron core teeth rotate on and from the opening angle center line of the outer peripheral surface facing the field magnetic pole. It is characterized by having grooves on a straight line that are angularly shifted by about 18 degrees back and forth, and which increase the air gap between them and the field magnetic pole.

The DC motor of the present invention is a 4-pole, 5-coil type DC motor that includes four field magnetic poles and an armature core having five teeth.

Two N-pole magnets and two S-pole magnets can be used as the field magnetic poles. The field magnetic poles are alternately arranged at approximately equal intervals on the same circumference. Various worlds 1i! It is preferable that each pole has the same shape, size, etc.

The armature core is placed inside the field poles.

This armature core has five teeth extending radially from the shaft at approximately equal intervals and facing the field vi1tnti. Grooves extending along the rotational axis are formed on the opening angle center line of the tip outer circumferential surface facing the field magnetic pole of each tooth and on a straight line shifted approximately 18 degrees forward and backward in rotation angle from the opening angle center line. ing.

Note that the opening angle center line refers to a line that passes through the center of the angle formed by both ends of the tip outer circumferential surface using the axis of the armature iron core, based on the arc method, and coincides with the extension center line of the tooth portion.

(Function) In the DC motor of the present invention, grooves are formed on the opening angle center line of the tip outer circumferential surface of each tooth portion and on a straight line that is shifted forward and backward by about 18 degrees from the opening angle center line. And drive
When no voltage is applied, the stable state is at a position where one of the N poles of the field magnetic pole and one tooth of the electron core face each other at the center. Further, the other N pole side located at a position 180 degrees out of phase faces approximately half of each of the two tooth portions of the armature core. In this state, at least one of the grooves formed on the outer peripheral surface of the tip of each tooth is connected to the field F41.
Grooves or spaces between the teeth are located at positions facing the poles and corresponding to both end portions of each field magnetic pole. As a result, a portion where the air gap becomes large due to the groove is formed between the outer peripheral surface of the tip and the opposing surface of the field magnetic pole.

(Example) Specific examples of the DC motor of the present invention will be described below based on the drawings. Here, Fig. 1 is a front view when the armature core is in a stable state with respect to the field magnetic poles, Fig. 2 is a longitudinal sectional view in the side direction of the DC motor, and Fig. 3 is a front view of the field magnetic poles. Fourth
The figure is a front view of the armature core.

The DC motor of this embodiment has a yaw 1, four field magnetic poles 2, an armature core 3, and a shaft 4 as main components.

Yoke 1G has a nearly cylindrical shape with a bottom, and the bottom 11
It has a cylindrical protrusion 12 that protrudes outward at its center. A shaft hole 12a is formed in the protrusion 12.
A metal bearing 4a that holds the shaft 4 inserted into the metal bearing 2a.
is installed. The yoke 1 is made of a carbon steel plate with a thickness of 1.61 mm, and the cylindrical part has a thickness of 35.7 mm.
The inner diameter φ1 is set to 47.2111 m. Also,
A ball bearing 4b that holds the shaft 4 is disposed on the other end of the shaft 4.

The field magnetic pole 2 includes two N-pole magnets 21, 23 and 2.
It consists of S Mj magnets 22 and 24. Each of the magnets 21 to 24 is fixed with an adhesive with the outer peripheral surface 21a to 24t) in close contact with the inner peripheral surface of the yoke 1, and different poles are alternately arranged with a phase shift of 90 degrees. . Therefore, the same poles face each other at 180 degrees. Each of the magnets 21 to 24 has a curved outer peripheral surface 21a to
24a and the inner peripheral surfaces 21b to 24b have a thickness of 5. They are formed into a curved flat plate with Qmm and length 1 of 26.5n++n, and are formed to have the same shape and size. Further, the diameter φ2 formed by the inner circumferential surfaces 21b to 24b of each magnet 21 to 24 is approximately 37 mm.
It is mm. Each of the magnets 21 to 24 has a width such that an angle α formed by both side surfaces 21 c to 25 c 121 d to 25 d by the arc method is 72 degrees, and an angle β formed by the adjacent side surfaces by the arc method is 18 degrees. They are placed at a certain distance apart. The magnets 21 to 24 in this example are manufactured by Tokyo Denki Kagaku Co., Ltd. ylrFB3.
I'm using BJ.

The armature core 3 has a shaft portion 30 and 5 shafts arranged at equal intervals from the shaft portion 30.
It is integrally formed with tooth portions 31 to 35 extending radially in the direction. The shaft portion 30 has a rotating shaft hole 30a at its center, into which the shaft 4 is inserted and fixed. Teeth 31
- 35 are extension parts 131 - 135 extending from the shaft part 30 with a constant width parallel to the extension center line, and each extension part 131 - 13 .
It consists of tip parts 231 to 235 formed at the tip of 5.

In this case, the angle θ formed by the extending center lines of the teeth 31 to 35 by the arc method is 72 degrees. Each of the tip portions 231 to 235 is formed wider than the width of the extension portions 131 to 135, and has a tip outer peripheral surface 231a to 235a.
is a curved surface on the circumference with a diameter of 36IllIIl. These tip outer circumferential surfaces 231a to 235a are spaced apart from the inner surfaces 21b to 24b of each magnet 21 to 24 at a constant interval (about 0
．． 511111). Also, the distance between adjacent tip portions 231 to 235 is approximately 2.511111
It becomes. And each tip outer peripheral surface 231a to 235a
The rotation shaft hole 30 is located on the opening angle center line (on the extension center line) and on a straight line that is 18 degrees forward and backward in rotation angle from the opening angle center line.
Grooves A1, A2, A3 to E1, E2 extending in the same direction as a.
E3 is provided. That is, each tip outer circumferential surface 231a-2
In the groove 35a, three grooves are formed at equal intervals of 18 degrees. Trench A1, A2, A3~E1, E2,
E3 is formed to have the same size with a depth d of 2, a width W of i, and 3+nm.

The length 5!2 of the electron core 3 in the direction of the rotation axis is approximately 17
It is formed at 11m.

The shift shaft 4 serves as a rotation axis of the armature core 3. This shaft 4 is fitted and fixed into a rotating shaft hole 30a of the armature core 3, and is supported by a metal bearing 4a of the yoke 1.

The DC motor of this embodiment is constructed as described above. In this DC motor, the tip outer peripheral surfaces 231a to 235a
The trapezoids A1, A2, A3 to E1, E2, and B3 provided in
and the spacing portions between the tip portions 231 to 235 are arranged at intervals of 18 degrees in terms of rotational angle. On the other hand, the magnets 21 to 24 are arranged at intervals of 18 degrees in rotation angle. Therefore, when the application of the drive voltage is stopped and the state is stable, the grooves △1, A2, A3 to
Any one of E1, E2, E3 or the interval between the tips 231 to 235 will be in position (-).An experiment was conducted to compare the improvement in the holding torque of this DC motor with the conventional one. I did it.

(Experiment) The holding torque of the DC motor of the above example and the conventional DC motor was measured at room temperature using a torque gauge. Note that the conventional DC motor differs from the DC motor of the embodiment only in that no groove is provided on the outer peripheral surface of the tip of the armature core facing the 11 field poles, and all other configuration conditions are the same. I used the one from

As a result, the holding torque of the conventional DC type vJn is 17
0 (JCm), whereas in the DC motor of the example, the holding torque was 320acm.

As is clear from this result, it was confirmed that the holding torque of the DC motor of the example increased significantly.

The reason why the holding torque of the DC motor of this embodiment increases significantly is as follows.

In FIG. 1, at J3C, the armature core 3 is in a stable state with respect to the field magnetic pole 2. In this case, the magnet 21 and the tooth 3
They are opposed to the tip outer circumferential surface 231a of No. 1 on their respective center lines. And both sides 21c, 21 of the magnet 21
At the position corresponding to d, there are spaced portions between the tip 231 of the tooth portion 31 and the tip portions 232 and 235 on both sides thereof.

On the other hand, the magnet 23 located on the opposite side in the 180 degree direction has two teeth 33.
4a are each half facing each other. That is, magnet 1
In the positions corresponding to both sides 2'3c and 23d of ~23,
Grooves C1 and Dl formed at the center of each tip outer circumferential surface 233a and 234a are located, respectively. A portion of the tip outer circumferential surface 233a faces the magnet 22, and a portion of the tip outer circumferential surface 234a faces the magnet 24. That is, a groove C3 is provided at a position corresponding to the side surface 22d of the magnet 22.
is located, and a groove D2 is located at a position corresponding to the side surface 24C of the magnet 24. In this case, magnet 23
Most of the magnetic flux flowing from the tip part 23 to the tooth part 33
Most of the magnetic flux flowing from the magnet 23 to the tooth portion 34 flows to the magnet 24 through the tip portion 234. As a result, the tooth portion 33 is
In the l 1i direction, the tooth portion 34 also absorbs a counterclockwise torque of 15, and both torques are balanced with approximately the same degree of force. However, as in the present invention, each tip outer circumferential surface 231a~
When iAl, A2, A3 to E1, [2, E3 are formed in 235a, grooves C1, C2, C3, Dl, C2, C
3 increases the air gap with the magnet 23 and forms a detour for the magnetic flux to pass through. As a result, the torque that tends to rotate both toothed portions 33.34 in directions facing each other is applied to the grooves C1, C2, C3, Dl,
Since C2 and C3 are balanced compared to the case where they are not present, the degree of instability is reduced accordingly. Note that the stability of the #1 portion 31, which is in a stable state with the tip outer peripheral surface 231a facing the magnet 21, is somewhat reduced by the groove A1.2.3. However, if the instability is reduced by the teeth 33 and 34, and the armature core 3 is considered as a whole, the stability will be improved and the holding torque will be improved.

[Effects of the Invention] In the DC motor of the present invention, each tooth portion of the armature core is on the opening angle center line of the outer peripheral surface facing the field magnetic pole and is deviated from the opening angle center line by about 18 degrees in rotation angle. Field in a straight line! !
It has a bulk that increases the air gap between it and the poles. Therefore, it is possible to significantly improve the holding torque in the reversal direction when the application of the drive voltage is stopped and the device is in a stable state.

[Brief explanation of the drawing]

Figures 1 to 4 relate to embodiments of the present invention, where Figure 1 is a front view when the armature core is in a stable state with respect to the field magnetic poles, and Figure 2 is a longitudinal section in the side direction of the DC motor. FIG. 3 is a front view showing the arrangement of field magnetic poles, and FIG. 4 is a front view of the armature core. 5 and 6 relate to a conventional DC electric machine, FIG. 5 is a front view corresponding to FIG. 1, and FIG. 6 is a perspective view of an automotive 1-transfer switching actuator. 1... Yoke, 2... To field magnetic pole 21 2
4...Magnet 3...Armature core 31-35...Tooth portion 23
1a to 235a...Tip outer peripheral surface AI, A2, A3 to E1, E2. , E3... Full patent applicant Aisin Seiki Co., Ltd.

Claims (1)

[Claims] (1) In a DC motor equipped with four field magnetic poles and an armature core having five teeth extending radially from the shaft and facing the field magnetic poles, each tooth of the armature core The air gap between the part and the field magnetic pole is large on the opening angle center line of the tip outer circumferential surface facing the field magnetic pole and on a straight line shifted approximately 18 degrees forward and backward from the opening angle center line in terms of rotation angle. A direct current motor characterized by having a groove.