JPH08214536A - Electromagnetic clutch apparatus - Google Patents

Abstract

PURPOSE: To prevent the wear due to the clutching operation and to increase the useful time by transmitting a rotary torque according to the magnetic attraction force of salient pole faces of first and second rotors. CONSTITUTION: A salient pole C protrudes from the bottom of the left side of a circular cylinder 5. The cylinder 5 becomes a rotor. The rotary shaft 6a-1 of a rotor 6 having entirely the same structure as that of the rotor 5 is rotatably supported by ball bearings 4a, 4b provided at the left side face of an outer housing 1. A salient pole D protrudes from the bottom of the left side of the cylindrical rotor 6. The poles C and D are opposed via a small gap of 0.2mm or less. The shaft 5a-1 of the cylinder 5 is driven by a drive source A, and a load B is driven by the shaft 6a-1 of the cylinder 6. When an exciting coil 7a is energized, its magnetic flux becomes as shown by 7b. Thus, the pole C is magnetically coupled to the pole D, and a torque is transmitted from the pole C to the pole D. Since they are magnetically coupled, even if they are coupled by a clutch, it is not worn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is used as an electromagnetic clutch for continuing or discontinuing transmission of the rotational torque of a driving source to a load by controlling energization.

2. Description of the Related Art As a means for transmitting the rotational torque of a drive source to a load, the operation of pressing or separating two discs is performed by an electromagnetic force.

[0002]

In the known means in which the rotational torque transmitting means is performed through frictional force, the two discs serving as the transmitting medium are often worn, and the service life is limited. Further, there is a problem that torque transmission by the friction surface becomes unstable.

[0003]

A first rotating body having a plurality of salient poles projecting from the outer periphery of the bottom surface of a soft magnetic material cylinder having a rotating shaft with an equal width and an equal separation angle, and a first rotating body. The second rotating body having the same structure as the body, the salient poles of the first rotating body and the salient poles of the second rotating body face each other with a gap of 0.2 mm or less between them. An outer casing having a bearing that rotatably supports the rotation shaft of the second rotating body, and an annular soft magnetic body stator whose outer peripheral surface is fixed to the inside of the outer casing,
Means for holding the first and second protrusions on both sides of the stator so as to face the outer peripheral surfaces of the first and second rotors with a gap of about 0.2 mm or less; , Second
Of the exciting coil wound inside the protrusion of the first rotating body, a drive source for driving the rotating shaft of the first rotating body, a load driven by the rotating shaft of the second rotating body, and energization of the exciting coil And an energization control device that operates.

[0004]

The rotating torque is transmitted by the magnetic attraction force of the salient pole surfaces of the first and second rotors facing each other, so that no wear occurs. Therefore, there is an effect that the service life becomes long and the transmission force of torque transmission becomes stable.

[0005]

Embodiments of the present invention will be described with reference to FIG.
Since the same symbols in the drawings are the same members, duplicate description thereof will be omitted. FIG. 1 is an explanatory diagram showing the overall configuration. In FIG. 1, symbol 5 is a cylinder, which is made of mild steel.
Other materials may be used as long as they are soft magnetic materials. Rotation axis 5 of cylinder 5
A-1 is rotatably supported on the central portion of the side plate 2 of the outer casing 1 by ball bearings 3a and 3b. A salient pole 5a (the other salient pole is schematically shown by a dotted line C), which will be described in detail with reference to FIG.

The cylinder 5 serves as a rotor, and the rotary shaft 6a-1 of the rotor 6 having the same structure is rotatably supported by ball bearings 4a and 4b provided on the right side surface of the outer casing 1. A salient pole 6a (other salient poles are schematically shown by a dotted line D) is provided on the left bottom surface of the cylindrical rotor 6 so as to project. Salient pole 5
The a and C and the salient poles 6a and 6 are opposed to each other through a slight gap (about 0.2 mm or less). The rotary shaft 5a-1 is rotated by a drive source A, for example, an electric motor, which applies a rotary torque. The load B is driven by the rotating shaft 6a-1 of the cylinder 6. An outer side of a soft steel core (stator) having an annular shape and a U-shaped cross section is fixed to the inner side of the outer casing 1, and an exciting coil 7a is wound in the inner recess.

When the exciting coil 7a is energized, its magnetic flux becomes as shown by the dotted line 7b. Since the strength of this magnetic flux becomes the rotational torque transmission force, it is necessary to make the gap in the magnetic path as small as possible. Since there is no change in magnetic flux during rotation of the rotors 5 and 6, there is almost no loss due to iron loss. FIG. 2 is a development view of the cylinder 5 and the cylinder 6 which are rotating in opposition.

The salient poles of the cylinder 5 are designated by the symbols 5a, 5b, ..., And the salient pole width and its spacing angle are made equal. The salient poles of the cylinder 6 are also shown as symbols 6a, 6b, ... With the same configuration. Dotted lines 7 and 8 indicate portions where the salient poles described above are omitted. Since the gap between the opposing salient poles is small as described above, one means for accurately holding the gap is shown in FIG. In FIG. 3, symbols 5 and 6 indicate the cross sections of the cylinders 5 and 6, and the salient pole portions are omitted and not shown. Dotted line 18
Indicates the center lines of the rotating shafts 5a and 6a. Cylindrical protrusions 10 and 11 are provided at the central portions of the cylinders 5 and 6, and a steel ball 12 is fitted into the hemispherical concave portions of these opposing portions to inject oil.

With the above construction, when the cylinders 5, 6 are attracted to each other by the magnetic flux, the steel balls 12 cause the salient poles 5a, 5b, ... And the salient poles 6a, 6b ,. Held in. Torque is transmitted from the rotor 5 to the rotor 6 by the opposing salient poles,
The details of torque transmission will be described for the salient poles 5a and 6a with reference to FIG. The magnetic flux generated by energizing the exciting coil 7a is indicated by the arrow 1
As shown in 3, 14, and 15. If the void length is small,
The magnetic flux 13 is perpendicular to the extreme surface and does not contribute to torque transmission. The leakage magnetic fluxes 14 and 15 at both ends contribute to torque transmission.

When the salient pole 5a moves in the direction of arrow 20,
The salient pole 6a is driven in the direction of arrow 21 by the leakage magnetic fluxes 14 and 15. The same is true for the other salient poles, and torque is transmitted. If the excitation coil 7a is energized while the rotors 5 and 6 are stopped, there is no problem in the above-described torque transmission, but the excitation coil 7a is rotated while the rotor 5 is rotating.
When the energization of a is started, the torque is transmitted by the following initial operation. In FIG. 2, the rotor 5 has an arrow 20.
When the exciting coil 7a is energized while rapidly rotating in the direction of, the torque in the same direction is applied to the rotor 6 by the opposing salient poles, but the salient poles slip with each other, and at this time the arrows The torque in the direction of 20 and the torque in the opposite direction are alternately applied.

Accordingly, the torque oscillating to the left and right is applied to the rotor 6, but the time in which the torque in the direction of the arrow 20 is applied is longer than the time in which the torque in the opposite direction is applied. It rotates synchronously in the direction of. Therefore, the object of the present invention can be achieved. Next, FIG. 5 will be described. The horizontal axis in FIG. 5 represents the current flowing through the exciting coil 7a, and the vertical axis represents the magnetic attraction force in which the salient pole 6a is attracted and driven leftward by the salient pole 5a in FIG. The gap between salient poles is 0.
When 2 mm, the curve shown by the dotted line 17 becomes 0.
When it is 1 millimeter, it becomes a curve 16, becomes a straight line, and the suction force also increases. Therefore, when carrying out the present invention, it is an effective means to set the gap length to a value close to 0.1 millimeter.

EFFECTS OF THE INVENTION Since there is no wear even if the clutch is repeatedly operated, it is possible to obtain an electromagnetic clutch having a long service life. Since no magnet is used, the magnetic flux density can be increased. Therefore, a large transmission torque can be obtained, and the product can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a device of the present invention.

FIG. 2 is a development view of rotors 5 and 6.

FIG. 3 is a cross-sectional view of facing surfaces of rotors 5 and 6.

FIG. 4 is an explanatory diagram of magnetic flux of salient poles.

[Fig. 5] Graph of magnetic attraction force of salient poles

[Explanation of symbols]

 1 Outer casing 2 Side plates 3a, 3b, 4a, 4b Ball bearings 5a-1, 6a-1 Rotating shaft 7 Annular magnetic core (stator) 5a, 5b, ..., 6a, 6b, ... Salient poles 5, 6 Columns 7a Excitation coil 8,9 Salient pole 7b Magnetic field line A Drive source B Load 12 Steel ball 13,14,15 Magnetic field line 16,17 Magnetic attraction curve C, D Salient pole

Claims (1)

[Claims] 1. A first rotating body having a plurality of salient poles projecting from the outer circumference of the bottom surface of a soft magnetic cylinder having a rotation axis at an equal width and an equal separation angle, and exactly the same as the first rotating body. The first rotating body and the second rotating body so that the salient poles of the first rotating body and the salient poles of the second rotating body face each other with a gap of 0.2 mm or less between them. An outer casing having a bearing that rotatably supports a body rotation axis, an annular soft magnetic stator whose outer peripheral surface is fixed to the inside of the outer casing, and first and second members on both sides of the stator. The second projecting portion has means for holding the second projecting portion so as to be opposed to the outer peripheral surfaces of the first and second rotors with a gap of about 0.2 mm or less between the second projecting portion and the inner surface of the first and second projecting portions. The wound excitation coil, a drive source for driving the rotation shaft of the first rotating body, a load driven by the rotation shaft of the second rotating body, and an excitation coil. Electromagnetic clutch apparatus characterized by of the more configuration and electrification control apparatus for controlling the energization.