JPH047383Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Industrial application field) The present invention relates to an electromagnetic coupling device.

(Prior Art) Conventionally, this type of electromagnetic coupling device has been constructed as shown in FIG. In Fig. 2, 1 is a hollow shaft connected to a driven shaft (not shown), 2 is a rotor with a U-shaped cross section and is a rotation transmission plate fixed to the shaft 1 by knurling, etc., and 3 is the rotor. It is a window for magnetic shielding formed on the side wall of 2, and a lining is arranged on the armature side. Reference numeral 4 denotes a drive rotation member that is loosely fitted to the shaft 1 adjacent to the rotor 2 so as to be relatively rotatable, 4a is a hub portion that constitutes the drive rotation member 4, and 4b is a drive source formed on the outer peripheral surface of the hub portion 4a. (not shown); 4c is an armature attached to the end face of the hub portion 4a via a leaf spring 4d so as to face the rotor 2 with a gap; 5 is an armature on the side of the rotor 2; This is an excitation device disposed in an annular yoke 5a that is press-fitted with a metal sleeve 6 and supported relatively rotatably on the shaft 1, an excitation coil 5b mounted in this yoke 5a, and a winding around the excitation coil 5b. 7 is a spacer inserted between the rotor 2, yoke 5a and metal sleeve 6, and 8 is a spacer inserted between the shaft 1 to prevent the hub 4a and yoke 5a from coming off in the axial direction. A retaining ring 9 is fixed to the yoke 5a, and a holder 9 is used to fix the yoke 5a in place to prevent it from rotating.

A conventional electromagnetic coupling device having such a configuration operates as follows. That is, when the excitation coil 5b is energized, a magnetic flux Φ is generated as shown in FIG. 2 to form a magnetic circuit, and the armature 4c is magnetically attracted to the rotor 2 against the elastic force of the leaf spring 4d. be done. As a result, the rotational force of the drive source (not shown) is transmitted to the driven shaft (not shown) via the gear 4b, hub portion 4a, leaf spring 4d, armature 4c, rotor 2, and shaft 1, and the driven shaft be rotated.

Furthermore, when the excitation coil 5b is deenergized, the magnetic flux Φ disappears, and the armature 4c is separated from the rotor 2 by the elastic force of the leaf spring 4d, and is opposed to the rotor 2 while maintaining a predetermined gap, thereby transmitting rotation to the drive rotating member 4. The connection with the rotor 2, which is a disk, is released, and the transmission path of rotational force is cut off.

Note that when the excitation coil 5b is energized, the yoke 5a
is also magnetically attracted to the rotor 2, but the metal sleeve 6 and the rotor 2 are separated in the axial direction by the spacer 7 and are press-fitted into the yoke 5a and the rotor 2.
and are in sliding contact with the spacer 7, respectively, to enable relative rotation.

(Problems to be solved by the invention) As mentioned above, the conventional electromagnetic coupling device uses a yoke 5 to form a durable sliding portion between the excitation device and the shaft.
An Fe-based metal sleeve 6 was press-fitted into the inner periphery of a. Therefore, since this metal sleeve 6 is fixed to the yoke 5a, it does not rotate, and is therefore prevented from seizing due to direct contact with the rotor 2, which rotates at high speed together with the shaft 1. The presence of spacer 7 was necessary.

By the way, this spacer 7 blocks the formation of a magnetic circuit from the yoke 5a and the metal sleeve 6 to the rotor 2, so the shaft 1 is made of iron or the like, and the magnetic circuit is connected from the yoke 5a to the metal sleeve 6, and then via the shaft 1. It formed a magnetic circuit that flows to the rotor 2. However, when using the shaft 1 as a part of the magnetic circuit in this way, in a small device where the shaft 1 is thin, it is not possible to secure the necessary magnetic path cross-sectional area for flowing magnetic flux, and the magnetic attraction force to the armature 4c is Doesn't come out,
As a result, there was a drawback that a predetermined transmission torque could not be obtained.

In addition, in the conventional electromagnetic coupling device, the metal sleeve 6 was press-fitted onto the inner circumference of the yoke 5a as described above, but this press-fitting work was done using a hydraulic press, and the work was very troublesome. It was hot.

In view of such conventional problems, the purpose of this invention is to
It is an object of the present invention to provide an electromagnetic coupling device that secures a necessary magnetic path cross-sectional area in a magnetic circuit, generates a predetermined transmission torque, and is easy to assemble.

(Means for Solving the Problems) The electromagnetic coupling device of the present invention has a metal sleeve loosely fitted to the shaft so as to be relatively rotatable, and its end is brought into contact with a rotation transmission board, and an excitation device is connected to the metal sleeve. The present invention is characterized in that a yoke is loosely fitted so as to be relatively rotatable, and a spacer is inserted between an end of the yoke and a rotation transmission plate.

(Function) According to the electromagnetic coupling device of the present invention, since the metal sleeve is loosely fitted to the shaft and the yoke of the excitation device is also loosely fitted to the metal sleeve, the armature is magnetically attracted to the rotation transmission plate and is separated from the drive rotating member. Even when transmitting rotational torque from the rotation transmission plate to the shaft, the metal sleeve rotates with the shaft. Therefore, even if one end of the metal sleeve is in direct contact with the rotation transmission plate, problems such as burnout and wear will not occur.In fact, due to the existence of this direct contact, even when using a thin shaft. Since the magnetic path area is compensated for by the narrowing, the magnetic path area necessary for the predetermined magnetic attraction force of the armature is secured.

(Embodiments) Hereinafter, the electromagnetic coupling device of the present invention will be described in more detail with reference to preferred embodiments shown in the accompanying drawings.

FIG. 1 shows an electromagnetic coupling device 10 according to an embodiment of the present invention. In FIG. 1 showing the electromagnetic coupling device 10 of this embodiment, parts that are the same as or corresponding to the components of the conventional electromagnetic coupling device shown in FIG. 2 are given the same reference numerals, and their explanations are omitted. .

In the electromagnetic coupling device 10 of this embodiment, a metal sleeve 11 is loosely fitted to the shaft 1 on the side of the rotor 2 (on the side opposite to the armature 4c) so as to be rotatable relative to the shaft 1. There is. One end of this metal sleeve 11 directly contacts the rotor 2, and a flange portion 11a for preventing the yoke from slipping off is formed around the outer periphery of the other end. In addition, the excitation device 12
The structure itself is similar to that shown in FIG. 1, and consists of a yoke 12c that houses a bobbin 12b wound with an excitation coil 12a, and its arrangement is similar to the conventional one, close to the rotor 2. It is fitted onto the metal sleeve 11. However, York 12
c is loosely fitted to the metal sleeve 11 so as to be relatively rotatable, and therefore both the inner peripheral surface and the outer peripheral surface of the metal sleeve 11 serve as sliding surfaces for the shaft 1 and the yoke 12c, respectively. There is. Further, a spacer 13 is disposed between the tip of the inner circumferential portion of the yoke 12c and the rotor 2 to prevent seizing due to direct contact since the yoke 12c is fixed in place by the holder 9.

In the electromagnetic coupling device 10 of the embodiment thus configured, when the excitation coil 12a is energized, the magnetic flux Φ is transmitted from the yoke 12c via the metal sleeve 11 and the shaft 1, similar to the conventional device shown in FIG. Flows to rotor 2. At this time, since one end of the metal sleeve 11 is in contact with the rotor 2, a part of the magnetic flux flows directly from the metal sleeve 11 to the rotor 2, as shown in FIG. Therefore, since the effective magnetic path area is large, the necessary magnetic path area is secured even if a thin shaft 1 is used, and as a result, the amount of magnetic flux is not limited, so a predetermined magnetic attraction force to the armature 4c can be obtained, and the required magnetic path area is secured. Generation of transmitted torque is guaranteed.

When the rotor 2 rotates in this way, the shaft 1 also rotates, but since the metal sleeve 11 is loosely fitted to the shaft 1 and the yoke 12c is also loosely fitted to the metal sleeve 11, the metal sleeve 11 rotates as axis 1 rotates. As a result, even if the metal sleeve 11 and the rotor 2 come into direct contact to form a magnetic circuit, problems such as burnout and wear will not occur. Furthermore, metal sleeve 1
1 is loosely fitted to both the shaft 1 and the yoke 12c so as to be relatively rotatable, and the purpose is to facilitate the assembly work. That is, when fitting the metal sleeve 11 loosely and slidably on both the inner and outer surfaces, there is no need to use a special assembly machine.
This is because it can be done by hand.

[Effect of idea]

As explained above, according to the electromagnetic coupling device of the present invention, when the yoke of the excitation device is attached to the shaft, the intervening metal sleeve is loosely fitted so as to be rotatable relative to the shaft, and also rotatable relative to the yoke. Since it is loosely inserted into the metal sleeve and its end is brought into direct contact with the rotor, the magnetic flux not only flows through the shaft to the rotor, but also directly from the metal sleeve to the rotor, without causing problems such as burnout or wear of the metal sleeve. Since a magnetic circuit can also be formed, the necessary magnetic path area can be secured even when a thin shaft is used, and a predetermined transmission torque can therefore be obtained.

Further, since the metal sleeve is loosely attached to both the shaft and the yoke, the assembly work is very easy and productivity can be increased.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an electromagnetic coupling device according to an embodiment of the present invention, with the upper half cut away from the central axis, and Fig. 2 is a sectional view similar to Fig. 1 showing a conventional electromagnetic coupling device. . 1... shaft, 2... rotation transmission plate (rotor), 4...
...Drive rotation member, 4a...hub, 4b...gear,
4c... Amachiure, 4d... Leaf spring, 10...
Electromagnetic coupling device, 11... Metal sleeve, 12...
...excitation device, 12c...yoke, 13...spacer. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] a shaft, a drive rotation member loosely fitted onto the shaft, a rotation transmission disk fixed to the shaft, and an end portion loosely fitted to the shaft on the side of the rotation transmission disk so as to be relatively rotatable; A metal sleeve in contact with the transmission disk, an armature attached to the drive rotation member via an elastic member, and a relative rotation to the metal sleeve to control the connection of the armature to the rotation transmission disk by magnetic attraction force. An electromagnetic coupling device comprising: an excitation device with a yoke that can be loosely fitted; and a spacer arranged between the yoke and the rotation transmission disk.