JPH0314584Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an electromagnetic coupling device used, for example, in a copying machine.

[Conventional technology]

Conventionally, as this type of electromagnetic coupling device, the one shown in Fig. 2 has been adopted, and this will be briefly explained based on the figure. 1 is a stator that houses an excitation coil 2, and 3 is a main body for coupling. A rotor is provided on a driven shaft 5 by a key 4. Reference numeral 6 denotes a hub having a gear 7, which is formed into a cylindrical shape and is rotatably provided on the driven shaft 5. Reference numeral 9 denotes a return leaf spring, which is fixed to the hub 6 by a screw 10 screwed into the screw hole 8. An armature 11 is fixed to a portion of the leaf spring 9 facing the rotor 3 by a rivet 12. A constant gap is maintained between this armature 11 and the rotor 3.

In the electromagnetic coupling device configured as described above, when a current is passed through the excitation coil 2, a magnetic flux Φ is generated as shown by the broken line in the figure, and a magnetic circuit is formed.
The armature 11 is attracted to the rotor 3 against the elastic force of the leaf spring 9. The rotation on the drive side is transmitted to the driven shaft 5 via the gear 7, hub 6, leaf spring 9, armature 11, rotor 3, and key 4.

On the other hand, when the current is cut off, the magnetic flux Φ disappears, and the armature 11 is separated from the rotor 3 by the elastic force of the leaf spring 9, and rotation is stopped.

[Problem that the invention attempts to solve]

In the electromagnetic coupling device as described above, since the hub 6 is made of resin, its contraction and expansion are large, which causes the screw 10 to loosen and the tightening force of the leaf spring 9 to be lost, causing the leaf spring 9 to be damaged. Otherwise, the elastic force of the leaf spring 9 no longer acts on the armature 11, resulting in the disadvantage that the armature 11 of the rotor 3 comes into contact with the armature 11 even though the excitation coil 2 is de-energized.

Therefore, it is conceivable to fix the leaf spring 9 to the hub 6 by using iron thread rivets instead of the screws 10, but this also has the disadvantage that the members on the hub 6 side may be damaged by the pressure of the rivets.

Further, in the case of the conventional device, the hub 6 and the leaf spring 9 need to be fixed together via the screws 10, resulting in a problem that the work process is complicated and productivity is poor.

This invention was devised to solve this problem, and aims to prevent damage to the leaf spring and loss of elastic force due to loosening of screws, and to obtain an electromagnetic coupling device with high reliability and excellent productivity. .

[Means for solving problems]

The electromagnetic coupling device according to this invention eliminates the conventional structure in which a leaf spring is fixed to a hub via a screw, and instead forms the spring and the hub integrally.

[Effect]

In this invention, the spring and the hub are integrally formed, which sufficiently contributes to the attraction and separation of the rotor and armature, which are the main bodies of connection, and enables rotational force transmission.

〔Example〕

FIG. 1 is a sectional view showing an embodiment of this invention, and numerals 1 to 5 are exactly the same as the conventional device described above. 6 is a resin hub having a gear 7 and integrally molded with a spring 6a. Reference numeral 11 denotes an armature facing the rotor 3, which is the main body of the connection, and is fixed to the spring 6a by ultrasonic welding or the like.

In the electromagnetic coupling device configured as described above, when a current is passed through the excitation coil 2, a magnetic flux Φ is generated as shown by the broken line in the figure, and a magnetic circuit is formed.
The armature 11 is attracted to the rotor 3 against the elastic force of the spring 6a. The rotation on the driving side is transmitted to the driven shaft 5 via the gear 7, the bubble 6, the spring 6a, the armature 11, the rotor 3, and the key 4.

On the other hand, when the current is cut off, the magnetic flux Φ disappears, the armature 11 is separated from the rotor 3 by the elastic force of the spring 6a, and rotation is stopped.

At this time, since the hub 6 and the spring 6a are integrally formed as described above, there is no need for the screws to loosen as in conventional devices, and the disadvantages of the spring 6a being damaged or losing elasticity are eliminated. Reliability is significantly improved.

Further, since the hub 6 and the spring 6a are integrally formed, fixing with screws is not necessary, and an electromagnetic coupling device with excellent productivity can be obtained.

Incidentally, in the above embodiment, the hub 6 was explained as being made of resin, but it goes without saying that this invention can be applied to cases where other members are used.

[Effect of idea]

As explained above, this invention makes it possible to obtain an electromagnetic coupling device with high reliability and excellent productivity by integrally forming the hub and the spring.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of this invention, and FIG. 2 is a sectional view showing a conventional electromagnetic coupling device. In the figure, 6 is a hub, and 6a is a spring. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] a connecting body; an armature that faces the connecting body in the axial direction with a gap therebetween; an excitation coil that attracts the armature to the connecting body; An electromagnetic coupling device comprising a spring for separating and a hub provided with one end of the spring, characterized in that the spring and the hub are integrally formed.