JP2924534B2 - Electromagnetic coupling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a micro electromagnetic coupling device used for OA equipment and the like.

[0002]

2. Description of the Related Art FIG. 4 is an axial sectional view showing a conventional electromagnetic coupling device disclosed in, for example, Japanese Utility Model Publication No. 63-29949, and FIG. 5 is a sectional view taken along line VV of FIG. In the drawing, 1 is an annular yoke, 2 is a coil built in the yoke 1, 3 is a shaft made of resin, 4 is a mating shaft 5.
, A rotor fixed to the shaft 3, and a lining 7 fixed to a side surface of the rotor 6. The yoke 1 and the shaft 3 are provided so as to be relatively rotatable. Reference numeral 8 denotes an armature that is provided with an axial gap g with the rotor 6 and is movable in the axial direction. The hub 10 having the gear 9a is a spring, and is fixed to the armature 8 and the hub 9 by rivets (not shown), respectively.
Usually, the armature 8 is pressed against the rotor 6 and is provided to be rotatable relative to the shaft 3. Reference numeral 11 denotes a retaining ring provided to prevent the hub 9 from coming off, and reference numeral 12 denotes a retaining ring for fixing the electromagnetic coupling device itself to the mating shaft 5.

[0003] The electromagnetic coupling device configured as described above operates as follows. That is, when a voltage is applied to the coil 2 from a power source (not shown), a magnetic flux Φ is generated in a magnetic path indicated by a dotted line, and the armature 8 overcomes the elastic force of the spring 10 and is attracted to the rotor 6 by the attraction force. Therefore, the power transmitted to the gear 9 a in contact with the lining 7 is transmitted to the mating shaft 5 via the hub 9, the spring 10, the armature 8, the lining 7, the rotor 6, and the D cut 4 of the shaft 3. When the voltage of the coil 2 is removed, the magnetic flux Φ disappears, the armature 8 returns to its original position by the elastic force of the spring 10, the gap g with the rotor 6 is maintained, and the transmission of power is stopped.

[0004]

In the conventional electromagnetic coupling device, since the shaft 3 made of resin is provided with the D cut 4 for power transmission as described above, the electromagnetic coupling device is frequently started and stopped. Was repeated, the D-cut 4 was sometimes damaged and became unusable. Further, the magnetic flux Φ hardly flows through the shaft 3 which is a non-magnetic material, and there is a problem that the specified torque is not reached unless the magnetomotive force of the coil 2 is increased. That made the whole bigger. Further, when the electromagnetic coupling device is fixed to the mating shaft 5, the number of components is increased because the retaining ring 12 is used, so that there is a problem that the cost is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to reduce the size of the apparatus itself, improve the strength of the shaft, and easily assemble the apparatus, and to manufacture the electromagnetic apparatus at a low cost. The aim is to obtain a coupling device.

[0006]

An electromagnetic coupling device according to the present invention includes a rotor and a rotor provided with a gap in an axial direction of the rotor.
Armature, this armature and the rotor
Coil to be pressed, yoke containing this coil,
And a first shaft supporting the rotor and the rotor;
Axially arranged and integrated with a first shaft of
And a second shaft for supporting the amateur.
Equipped with a mating shaft that supports these shafts,
And the first shaft is made of a magnetic material.
In the inner diameter part, the position in the rotation direction with respect to the mating shaft is
Is provided, and the second shaft is made of resin.
In the second shaft in the axial direction with the mating shaft
Inserted into the circumferential groove of the mating shaft to fix the position
The electromagnetic coupling device is provided with a claw .

[0007]

According to the electromagnetic coupling device of the present invention, the lower part of the yoke is an iron-based first shaft, the lower part of the armature is a resin-made second shaft, and the first shaft has a transmission such as a D-cut .
Since the delivery mechanism is provided and the claw is provided on the second shaft, it can be manufactured compactly and inexpensively.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. 1 is an axial sectional view, and FIG. 2 is a line II in FIG.
3 is a cross-sectional view taken along line III-III of FIG. 1. The same or corresponding parts as those of the conventional one are denoted by the same reference numerals, and description thereof is omitted. In the figure, reference numeral 13 denotes a shaft having a two-part structure including a first shaft 13A and a second shaft 13B, and both shafts 13A and 13B are integrated by press fitting or the like. The first shaft 13A is made of an iron-based material, and has a D cut 13a on the inner diameter. If the first shaft 13A is made of a sintered alloy, the mass productivity is good and the cost is low.
The second shaft 13B is formed by molding a resin material, and the second shaft 13B has a protrusion 13b for preventing the hub 9 from coming off.
And a claw 13c provided to fit into the groove 14a of the mating shaft 14.

As described above, since the first shafts 13 and 13A made of iron are provided on the inner periphery of the yoke 1, the magnetic resistance is greatly reduced, and the coil 2 can be reduced in size. Become. Further, the first shaft 13A
Since the D-cut 13a is provided, there is no problem in terms of strength, and there is no trouble such as breakage, and the reliability is greatly improved. Further, since the second shaft 13B is made of a resin which is a non-magnetic material, the magnetic flux Φ does not leak to this portion. Further, since the resin has elasticity, it is possible to provide the claw 13c, and if the claw 13c is inserted into the groove 14a of the mating shaft 14 like a snap fit, it is possible to prevent the axial movement of the coupling device itself. As a result, the conventional retaining ring can be eliminated, the assembly becomes easy, and the cost can be greatly reduced.

Further, first and second shafts 13A, 13A
B, the second shaft 13B also has a protrusion 13
Since b can be provided and assembled, the retaining ring can be eliminated as described above. Further, the first shaft 13A is made of a sintered alloy, and the second shaft 13B can be manufactured by molding, so that the cost is not high. In addition, if the miniaturization is not considered, if the first shaft 13A is formed by molding, a snap fit is similarly provided, and the second shaft 13B is sintered and a D-cut for driving is provided, it can be easily mounted and inexpensive. And the effect is also great.

[0011]

As described above, according to the present invention, the shaft is divided into two parts, the first shaft below the yoke is iron-based, and a transmission mechanism such as a D-cut for transmitting power is provided. Because the shaft is made of resin, a claw that can be inserted into the groove of the mating shaft can be provided, so that the device itself can be reduced in size and easy to assemble, and the reliability is greatly improved. The effect is enormous.

[Brief description of the drawings]

FIG. 1 is an axial sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG. 1;

FIG. 4 is an axial sectional view showing a conventional device.

FIG. 5 is a sectional view taken along line VV of FIG. 4;

[Description of Signs] 1 Yoke 2 Coil 6 Rotor 7 Lining 8 Amateur 9 Hub 13 Shaft 13A First Shaft 13B Second Shaft 13a D-cut 13b Convex 13c Claw 14 Opposite Shaft 15 Opposite Shaft 14a Groove

Claims (1)

(57) [Claims] A rotor, an armature opposed to the axial direction of the rotor via a gap, a coil for pressing the armature against the rotor, a yoke containing the coil,
Comprising a first shaft, and a second shaft which are arranged side by side in the axial direction and is <br/> integrated supporting the armature to the first shaft for supporting the this yoke the rotor, these Equipped with a mating shaft that supports the shaft
In addition, the first shaft is made of a magnetic material, and has an inner diameter in a rotational direction with respect to the mating shaft.
A transmission mechanism for fixing the position is provided. The second shaft is made of resin, and is inserted into a circumferential groove of the mating shaft to fix the position of the second shaft in the axial direction with the mating shaft.
An electromagnetic coupling device comprising a claw that is provided.