JPS5811945Y2 - electromagnetic spring clutch - Google Patents

Description

[Detailed description of the invention] This invention relates to a so-called electromagnetic spring clutch that utilizes the tightening force of a coil spring whose one end is hooked to an armature when transmitting torque from an input-side rotating member to an output-side rotating member. .

A conventional electromagnetic spring clutch, as shown in FIG. 1 in a vertical side view, is an output-side rotating member that is supported via a bearing 2 at the center of a field core 1 that is fixed to a device frame, etc. When magnetic flux is generated by energizing the rotor 3, the input hub 5 as an output side rotating member supported via a bearing 4 on the small diameter part of the output rotor, and the electromagnetic coil 6 built in the field core 1. , the armature 7 is magnetically attracted to the field core 1 side, and the armature 7 is magnetically attracted to the field core 1 side.
The tubular part 7A to be inserted into the inner diameter part of the field core 1
The flange portion 7B comes into contact with the end surface of the
An annular actual S having a predetermined width is formed between the inner circumferential surface of the tubular portion 7A and the outer circumferential surfaces of the boss portions 3A and 5A of the output rotor 3 and the input hub 5 having the same outer diameter. .

A coil spring 9 for seaming is inserted into the gap S.

One end of the coil spring 9 is shaped like an outward bent portion 9A that hooks into a notch 10 in the end of the tubular portion 7A of the armature 7, and the other end is shaped like an inner bent portion 9A that hooks into a hole 11 of the input hub 5. It is similar to the new song section 9B.

The inner diameter surface of the coil spring 9 faces both the outer circumferential surface of the boss portion 3A of the output rotor 3 and the outer circumferential surface of the boss portion 5A of the input hub 5.
A small gap is formed between them.

Now, as shown in the partially omitted enlarged longitudinal side view of FIG. 2, when the electromagnetic coil 6 is energized and a magnetic flux Φ is generated, the armature 7 is excited and magnetically attracted in the direction of the field core 1. Therefore, resistance is applied to the armature 7, which had been rotating together with the input hub 5, and the input hub 5 rotates in advance, so that the coil spring 9 is tightened.

Since the coiled spring 9 tightens the boss portion 5A of the input hub 5 and the boss portion 3A of the output rotor 3 at the same time, the output rotor 3 will rotate together with the input hub 5 from now on.

The above operation is performed in the same manner when the output rotor 3 is used as the input rotating member and the input hub 5 is used as the output side rotating member.

However, in any case, the coil spring 9
The coil spring 9 must be quite long because it transmits torque between the input and output side rotation members by tightening the equal diameter parts of the input side rotation member and the output side rotation member by tightening the coil spring 9. I don't get it.

The longer the coil spring 9 is, the longer it will take to complete the tightening process.If the input hub, which is the input-side rotating member, is rotating at a low speed, tightening the coil will take a long time, but in extreme cases. The seaming may be incomplete.

Furthermore, since the inner diameter surface of the coil spring 9, the boss portion 5A of the input hub 5, and the boss portion 3A of the output rotor 3 come into frictional contact to enable torque transmission between the input and output side rotating members, When the boss parts 5A and 3A of the output rotor 3 are tightly wound, a strong tensile force in the wire axis direction is applied to the coil spring 9 only on the part facing the boundary between the boss parts 5A and 3A. This part may break under repeated loads.

In addition, even if it does not break, the boss portion 5A is significantly worn and
If there is any misalignment or diameter difference in 3A, even if the amount is minute, the wear will be severe.

Therefore, in order to prevent fatigue of the coil spring 9 and reduce wear, the finishing accuracy of the boss portions 5A and 3A, especially the outer diameter dimensions and tolerances, must be made extremely strict.
There were problems such as increased processing costs and decreased production efficiency.

This idea is based on the above-mentioned points of view, and is easy to manufacture.
This provides an electromagnetic spring clutch that requires only a short coil spring and is less prone to wear.The inner surface of the coil spring 9 for tightening, which has one end 9A hooked to the armature 7, is connected to the output side or the input side. The coil spring can be wound only on the outer circumferential surface of the boss portion 3A of the rotating member 3, and one end 9C of this coil spring is held in contact with the input side or output side rotating member 5 that cannot be tightened by the coil spring. It is characterized by the fact that it is only

Next, the electromagnetic spring clutch of this invention will be explained by way of examples with reference to the drawings.

FIG. 3 shows an embodiment of the electromagnetic spring clutch of this invention in a longitudinal sectional side view in an unfastened state.

Note that the same reference numerals are used for common members and structures as in the conventional example explained in FIGS. 1 and 2.

As shown in the drawing, an input hub 5 as an input rotating member is supported on an output rotor 3 as an output rotating member supported via a bearing 2 at the center of the field core 1 via a bearing 4. It is.

The armature 7, which is magnetically attracted to the field core 1 side when a magnetic flux is generated by energizing the electromagnetic coil 6 provided inside the field core 1, has a tubular portion 7A inserted into the inner diameter of the field core 1, The inner peripheral surface of the tubular portion 7A forms an annular gap S of a predetermined width between the inner circumferential surface of the tubular portion 7A and the boss portion 3A of the output rotor 3. .

The boss portion 3A has a length such that the entire inner circumferential surface of the armature 7 is exposed, and furthermore, the tip portion thereof is connected to the small diameter portion 3C.
It is formed.

The input hub 5 is fitted into this small diameter portion 3C via a bearing 4, and the stepped end surface 3B between the end face of the flange portion 7B of the armature 7 in the non-excited state, the boss portion 3A of the output rotor 3, and the small diameter portion 3C. is in contact with the end surface of the boss portion 5A of the input hub 5.

The boss portion 5A of the input hub 5 has an outer diameter larger than the inner diameter of the armature 7, and a hole 1 is formed in the end surface of the boss portion 5A.
2 is formed.

A coil spring 9 for seaming is installed in the space S.

One end of this coil spring 9 has an outward bent portion 9A.
It is formed into a notch 10 formed at the end of the tubular part 7A of the armature 7, and the other end is formed into a bent part 9C which is bent in a direction parallel to the coil axis. It is inserted and latched into a hole 12 provided in the end face of the boss portion 5A of the input hub 5.

In the electromagnetic spring clutch of this invention having the above-described configuration, when the electromagnetic coil 6 is energized and magnetic flux is generated, the armature 7 is magnetically attracted toward the field core 1, and until then rotates together with the input hub 5 and the coil spring 9. Since the coil spring 9 is now in a state where resistance is applied, the coil spring 9 is tightened.

This operation is similar to that of a conventional electromagnetic spring clutch, but since the coil spring 9 tightens only the boss portion 3A of the output rotor 3, the coupling force between the coil spring 9 and the boss portion 3A is It will be extremely large.

In addition, unlike conventional electromagnetic spring clutches, two members are not tightened, so the number of turns of the coil spring can be reduced.
Since no tensile force is applied in the axial direction of the wire at the intermediate portion of the coil spring, fatigue of the coil spring is reduced.

Therefore, the electromagnetic spring clutch of this invention has a simplified structure, and in particular, the machining accuracy of the part tightened by the coil spring can be considerably reduced, which can significantly reduce production costs and streamline production. It has excellent advantages such as being able to do

[Brief explanation of the drawing]

Fig. 1 is a longitudinal side view showing an example of a conventional electromagnetic spring clutch, Fig. 2 is an enlarged longitudinal side view showing the state of tightening of a coil spring in an electromagnetic spring clutch having the same structure as Fig. 1, and Fig. 3 is an enlarged longitudinal side view of this electromagnetic spring clutch. FIG. 2 is a longitudinal sectional side view showing an embodiment of the electromagnetic spring clutch of the invention. In the drawing, 1... field core, 3...
...Output rotor, 3A...Boss part, 3B.
...Step end face, 3C...Small diameter part, 5...
...Input hub, 5A...Boss part, 6...
... Electromagnetic coil, 7 ... Armature, 7A
......Tubular part, 7B...Flange part, 9
・・・・・・Coil spring, 9A, 9B, 9C...
...Bending portion, 10...Notch, 11...
...hole, 12...hole.

Claims (1)

[Scope of utility model registration request] A flange portion 7 directly facing the end surface of the annular field core 1
B, and a tubular part 7A coaxially integrated with this flange part, and has an armature 7 that is made up of a tubular part 7A that is concentric with the flange part, and has an armature 7 that is connected to the outer circumferential surface of the boss part 3A of the output or input side rotating member 3 inserted into the tubular part 7A and the tubular part 7A. A tightening coil spring 9 is inserted into an annular gap S between the inner circumferential surface of the coil spring 9, and an input or output side rotating member 5 having a boss portion 5A whose end face faces the open end of the gap S is inserted. , is supported on the small diameter portion 3C of the output side or input side rotating member 3 so as to freely rotate, one end 9A of the coil spring 9 is connected to the notch 10 of the tubular portion 7A of the armature 7, and the other end 9C is connected to the input side. Alternatively, an electromagnetic spring clutch is inserted and engaged in an axial hole 12 provided in the end face of the boss portion 5A of the output rotating member 5.