JPH03107361A - Electromagnetic rotating device - Google Patents

Abstract

PURPOSE:To make the torque constant linear regardless of angle by passing the magnetic flux from the circular permanent magnet of a rotor through the main and auxiliary yokes of a stator so as to make air gap magnetic flux distribution constant. CONSTITUTION:The magnetic fluxes phi1 and phi2 coming out of the N pole of a permanent magnet 28 pass a main yoke 26 and an auxiliary yoke 27, respectively, and enter an S pole. When current I is let flow in the arrow D direction to an armature coil 24, torque occurs in the arrow D direction, and a rotor 25 rotates in the same direction. By the current control through a controller, the rotor 25 stops at a specified rotational position. The air gap magnetic flux distribution B(theta) by the circular permanent magnet 28 is at the fixed maximum value B0 regardless of the rotational angle, and also for current distribution, the armature coil 24 is of uniform distribution, and current I(theta) becomes uniform. Accordingly, the torque constant becomes linear by the current of the armature coil 24, regardless of angle, that is, the position of the rotor 25.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electromagnetic rotating device that is widely used in audio, video, office automation equipment, etc., and controls the rotation of a rotated body within a predetermined range.

[Conventional technology]

FIG. 6 is a side view of a conventional electromagnetic rotating device.

In the figure, l is a rotating body that incorporates a rotated object (not shown) such as a lens part of a video camera, and 2 is a rotating frame, o4 whose rotation is controlled to a predetermined range position by a driver 3. and 5 are a pair of fixed shafts fixed to the fixed frame 8;
A pair of mounting ears are attached to the rotating element of the driving machine 3 and are attached to the rotating frame 2 with mounting screws.

Reference numeral 9 denotes a base, to which the fixed frame 8 is attached using mounting screws 10.

6 and 1 are front and rear views of the apparatus shown in FIG.

The drive unit 3 is shown in FIG. 8 as a side view with the upper half sectioned, and FIG. 9 as a sectional view taken along the line -IX in FIG. 8. Reference numeral 11 denotes a stator of the driving machine 3, which is constructed as follows. A fixed side yoke 13 is attached to a boss 12 fixed to the fixed shaft 5.
is fixed, and four armature coils 14 & ~ 14 (1 is glued to this fixed side yoke 13. 15 is a drive unit 3
The rotating element is arranged axially opposite to the stator 11 with an air gap in between, and is constructed as follows. A boss 17 is rotatably supported on the fixed shaft 5 via a bearing 6.

A rotating side yoke 18 is fixed to the boss l), and a circular permanent magnet 19 magnetized into six poles is fixed to the rotating side yoke 18.

A mounting ear 6 is fixed to the boss 17. Numeral 31 is a fixing bolt that is screwed into the fixing frame 8 and fixes the inserted fixing shaft 6, and is secured by a locking nut 32.

FIG. 10 shows the air gap magnetic flux distribution between the stationary yoke 13 and the annular permanent magnet 19 shown in FIGS. 8 and 9. FIG.

θ indicates 360° in mechanical angle and is 4θ in electrical angle), and the coil side of armature coil 14& is 22.5 in mechanical angle.
(electrical angle 90), and this armature coil 14
The interaction between the current flowing through a and the magnetic flux generates a torque. Since this current always flows at a constant value, when the rotator 15 is rotated from the position shown in the figure, for example, the armature coil 1
When 4& is rotated by 60 degrees of electrical angle from the position of 90 degrees of electrical angle (15 degrees of mechanical angle) (indicated by the chain line in Fig. 1O), the torque is o.
It becomes 5. Bo is the maximum value of the air gap magnetic flux distribution, B(
θ) is the air gap magnetic flux distribution.

FIG. 5 shows a state in which the driving machine 3 is incorporated into a device as an element of a servo system, and the rotating body is to be controlled perpendicularly to the base 9.

As for the servo element, it is desirable that the relationship between torque and current, so-called torque constant, be linear.

[Problem to be solved by the invention]

In the conventional wl and fine rotation devices as described above, as is clear from the analysis results shown in FIG. 10, there is a problem in that the drive unit 3 is a nonlinear element and that h is not desirable.

This invention was made to solve these problems, and it is not affected by the rotating position of the rotor with respect to the armature of the stator, and the torque constant is linear due to the current of the wt armature coil. The purpose is to obtain a certain electromagnetic rotation device.

[Means to solve the problem]

In the electromagnetic rotation device according to the present invention, a stator is constructed by winding an electric coil in a toroidal shape through the inner periphery of a fan-shaped hole of an arc-shaped winding frame fixed to a fixed shaft. An auxiliary yoke is fixed to the outer end of a main yoke that is rotatably supported on a fixed shaft and surrounds the stator, and an annular permanent magnet is installed inside the main yoke and passed through the armature coil with a gap. Both magnetic pole faces of a permanent magnet are magnetized to the same polarity, and the split cylindrical face is magnetized to the other polarity to form a rotating element, and the main yoke portion is coupled to a rotating frame.

[Effect]

In this invention, the magnetic flux distribution in the air gap between the main yoke and the auxiliary yoke due to the permanent magnet becomes uniform, and a linear torque constant that is independent of position is obtained by interaction with the current flowing through the armature coil. It will be done.

〔Example〕

FIG. 1 is a cross-sectional front view of the upper half of the drive unit showing an electromagnetic rotation device according to an embodiment of the present invention, and FIGS. 2 and 3 are taken along the line II-II in FIG. 1. and a sectional view taken along the line ■-■. In FIGS. 1 to 3, reference numeral 20 denotes a drive machine interposed between the fixed shaft 5 and the rotating frame 2 of the rotating body 1 (see FIG. 5).

21 is a stator of the driving machine zO, which is configured as follows. A cylindrical winding frame 22 is fixed to a fixed shaft 5 fixed to a fixed frame 8 (see FIG. 5), and is provided with a pair of fan-shaped holes 22&. Reference numeral 23 indicates a pair of arc-shaped winding frames made of band-shaped plates, and 23 indicates a pair of armature coils which are wound in a toroidal shape across the fan-shaped hole 22a of the winding frame 22 and the arc-shaped winding frame 23, and are fixed with adhesive. The split surface side is fan-shaped.

Reference numeral 25 denotes a rotor of the driving machine 20, which is constructed as follows. 26 is a main yoke rotatably supported by a fixed shaft 5 via a bearing 16, and a mounting seat 2 with a pitch of 180 is provided on the inner surface of the disc portion.
6& is provided. This main yoke 26 is provided with a pair of attachment portions 26b, which are attached to the rotating frame 2 with attachment screws. 2F is a disk-shaped auxiliary yoke fixed to the end of the main yoke 26; 28 is a circular permanent magnet fixed to a pair of mounting seats 26 & with mounting screws 29; It passes through with an opening, allowing for free rotation within a predetermined range. 28m is a pair of mounting screw holes. The magnetic pole surfaces of the annular permanent magnet 28 are both magnetized to N poles, and both cylindrical surfaces are magnetized to S poles.

In the device of the above embodiment, the magnetic fluxes ψ1 and ψ2 emitted from the N pole of the permanent magnet 28 pass through the main yoke 26 and the auxiliary yoke 27, respectively, and enter the S pole in the direction of the arrow 0 to the armature coil z4. When flowing, torque is generated in the direction of the arrow, and the rotor 25 rotates in the same direction.

The rotor 25 is controlled by current control by a control device (not shown).
stops at a predetermined rotational position.

As shown in FIG. 4, the air gap magnetic flux distribution B (θ) due to the annular permanent magnet 28 has a constant maximum value BQ regardless of the rotation angle, and the current distribution is also uniform in the armature coil z4. Since the current I(θ) becomes -like, the torque constant becomes linear regardless of the angular variation. [Effects of the Invention] As described above, according to the present invention, the cylindrical shape fixed to the fixed shaft The armature coil is wound around the winding frame in a toroidal shape to form the stator, and the auxiliary yoke is fixed to the outer end of the main yoke that is rotatably supported on a fixed shaft and surrounds the armature coil section. An annular permanent magnet is installed inside the yoke, both magnetic pole surfaces of this permanent magnet are magnetized with the same polarity, and both cylindrical surfaces are magnetized with the same other polarity, passing through the armature coil with a gap. Since the rotor is constructed and the main yoke portion is coupled to the rotating frame, a linear torque constant can be obtained by the armature coil current regardless of the rotational position of the rotor.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional front view of the upper half of the drive unit showing an electromagnetic rotating device according to an embodiment of the present invention, and FIGS. Sectional view along the line, 4th
The figure is an air gap magnetic flux density distribution diagram of the drive machine in Figure 3, Figure 6 is a side view of a conventional electromagnetic rotating device, and Figures 6 and 7 are
The figures are a front view and a rear view of the device shown in Fig. 5, Fig. 8 is a side view of the conventional drive unit shown in Fig. 10 is a sectional view of FIG.
FIG. 3 is an air gap magnetic flux density distribution diagram of the drive machine shown in the figure. In the figure, 2... rotating frame, 5... fixed shaft, 8...
・Fixed frame, 16...Bearing, 20...Driver, 21.
... Stator, 22... Cylindrical winding frame, 22a... Fan-shaped hole, 23... Arc-shaped winding frame, 24... Armature coil, 25... Rotator, 26...・Main yoke, 27...
Auxiliary yoke, 2nd day...A circular permanent magnet. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] A cylindrical winding frame fixed to a fixed shaft fixed to a fixed frame and provided with a fan-shaped hole, and an arc-shaped winding concentrically arranged on the winding frame at intervals in the radial direction. a stator comprising a frame, and an armature coil wound and fixed across the fan-shaped hole of the cylindrical winding frame and the arc-shaped winding frame, and having fan-shaped sides on both flat sides; a bearing on the fixed shaft; is supported rotatably through the stator, and surrounds one side of the stator and the outer circumference with a gap, and
A main yoke coupled to the rotation frame by a mounting portion, an auxiliary yoke fixed to the other end of the main yoke and surrounding the other side of the stator with a gap, and an auxiliary yoke mounted within one end of the main yoke. , a circle passed through the armature coil with a gap, one and the other magnetic pole surfaces facing the main yoke and the auxiliary yoke are magnetized to the same polarity, and both cylindrical surfaces are magnetized to the other polarity. An electromagnetic rotating device equipped with a rotating element consisting of an annular permanent magnet.