JPS6135788Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic clutch used, for example, to connect and disconnect power transmission from an engine to a refrigerant compressor of an automobile cooling system.

Conventionally, in electromagnetic clutches, dust, mud, and
There has been a problem with water intrusion, so in order to prevent this, there are some models in which the gap between the armature and the hub is made very small. However, when the gap is made smaller in this way, magnetic leakage from the armature to the hub occurs, resulting in a reduction in the effective magnetic flux from the armature to the rotor, resulting in a reduction in transmitted torque. Furthermore, in order to reduce the gap between the armature and the hub, it is necessary to make the armature or the hub larger than necessary, resulting in an increase in weight and cost.

The present invention has been developed in view of the above points, and includes making the space between the hub and the armature as large as possible structurally, and providing a non-magnetic cover formed in a shape that eliminates the gap between the hub and the armature. The purpose is to solve the above problems.

According to the present invention, since the non-magnetic portion between the hub and the armature is large, leakage magnetic flux that occurs between the hub and the armature is hardly generated, and a decrease in the transmitted torque can be prevented. Furthermore, the hub can be made smaller and lighter. Also, mud, water, dust, etc. that enter between the armature and the hub should be
Since the cover can extremely effectively prevent the intrusion of mud, etc., the life of the bearing will not be shortened.

The present invention will be described below with reference to embodiments shown in the drawings. The drawings show an example in which the present invention is applied to an electromagnetic clutch for a compressor for a car cooler. In FIGS. 1 and 2, reference numeral 1 denotes an excitation coil, which is connected to a lead wire 1b via a connector 1a. Reference numeral 2 denotes a yoke for housing the coil 1, which is made of magnetic iron material and formed into a ring shape with a U-shaped cross section. A resin material 3 such as epoxy resin is filled between the yoke 2 and the coil 1 to fix and hold the coil 1 in a state where it does not come into contact with the yoke 2. In addition, a ring-shaped iron fixing plate 4 is welded to the side surface of the yoke 2, and the inner peripheral part of this fixing plate 4 is connected to a stepped part 6 formed in the front housing 5 of the refrigerant compressor C, which is a driven device. is fitted and fixed.

A rotor 8 is disposed so as to fit with the outer and inner surfaces of the yoke 2 through a minute gap, and is made of iron, which is a magnetic material, and has an annular U-shaped cross section. The inner surface of the rotor 8 is rotatably supported by the cylindrical portion 5a of the front housing 5 via a bearing 9, and a pulley 10 that engages with a V-belt (not shown) is integrally formed on the outer surface.
Therefore, the rotor 8 receives the driving force of a vehicle engine (not shown) through the belt and rotates at all times. Note that 11 is a circlip that holds the inner race of the bearing 9 in the housing 5. Reference numeral 12 denotes a driven shaft that is directly connected to the rotating shaft of the driven device, and an iron hub 13 is fixed to this shaft with a nut 14 via a key (not shown). Reference numeral 15 denotes an armature made of magnetic material, which is connected to the hub 13 by a plurality of leaf springs 16.
is connected to. That is, one end of the leaf spring 16 is fixed to the armature 15 by a rivet 17, and the other end is fixed to the hub 13 by a rivet 19 that forms a connecting fixing member together with a cover 18 made of a non-magnetic material (aluminum in this example). It is attached firmly. This cover 18 has a shape that eliminates the space between the armature 15 and the hub 13.
To explain this point in more detail, the outer periphery 13a of the end of the hub 13 is formed into a substantially triangular shape in this example as shown in FIG. It is formed into a circular shape that fits, and the inner periphery is the outer periphery shape 1 of the end of the hub 13.
It has a triangular shape along line 3a. The specific shape of the cover 18 is as shown in FIGS. 3 to 5,
The cover 18 has three mounting pieces 18a sandwiched between the leaf spring 16 and the hub 13, and a hole 18b through which a rivet 19 passes.

Here, one end of the leaf spring 16 and the mounting piece 18a of the cover 18 are fixed by the rivets 19 near the three vertices of the outer circumference 13a of the hub 13, which is formed in a substantially triangular shape.

Note that the leaf spring 16 is integrally formed with a short side portion 16a, and the armature 1 is attached to this short side portion 16a.
A protruding portion 16b protruding toward the 5 side is integrally stamped and formed. By pressing the armature 15 toward the rotor 8 side by the protruding portion 16b and giving deflection to the long side body portion of the leaf spring 16, the armature 15 is held in a position separated from the rotor 8 under normal conditions. ing.

In the above configuration, when the excitation coil 1 is not energized, the armature 15 is held in a position separated from the rotor 8 by the action of the leaf spring 16, so that the rotational power transmitted from the V-belt to the rotor 8 The rotor 8 is idling on a bearing 9.

However, when the excitation coil 1 is energized, a magnetic flux is generated in the magnetic circuit shown by the broken line a, and an attractive force is generated between the friction surface of the rotor 8 and the friction surface of the armature 15.
The armature 15 is attracted and attracted to the friction surface of the rotor 8 against the spring force of the leaf spring 16. As a result, the rotational power transmitted from the V-belt to the rotor 8 is transmitted to the driven shaft 12 via the armature 15 → leaf spring 16 → hub 13, and the driven shaft 12 rotates.

Furthermore, since the armature 15 and the hub 13 are both made of magnetic materials, the leakage magnetic flux shown by the broken line b tends to flow, but since the cover 18 is provided between the armature 15 and the hub 13, both 13 and 15 can be made larger. In particular, in the hub 13 having a substantially triangular outer circumferential shape 13a, in the middle portion of the three triangular vertices, both 1
The gap between 3 and 15 can be made larger. Therefore, the leakage magnetic flux b becomes a very small value, the effective magnetic flux shown by the broken line a does not decrease, and the transmitted torque does not decrease.

Note that the present invention is not limited to the above-described embodiments and can be modified in various ways. For example, the cover 18 may be inserted between the leaf spring 16 and the hub 13 as in the above example, or may be fixed by adhesion or welding. It can also be fixed by caulking or other means.

Further, the cover 18 may not be fixed to the hub 13 but may be fixed to the armature 15 or similarly fixed to the leaf spring 16.

Further, the material of the cover 18 may be a non-magnetic metal other than aluminum, or a resin such as nylon.

6 to 10 show embodiments using the cover 18 made of the resin described above. In this example, a metal washer 20 is interposed between the leaf spring 18 and the hub 13, and a cover 18 made of resin is used. The cover 18 is integrally formed with a mounting piece 18c which is sandwiched between the leaf spring 16 and the hub 13 adjacent to the side of the outer peripheral surface of the washer 20.

When the cover 18 is made of resin as described above, the cover 18 can also be integrally molded onto the hub 13 and the armature 15.

As described above, according to the present invention, the cover 18 can close the gap between the armature 15 and the hub 13, thereby effectively preventing mud, water, dust, etc. from entering the bearing 9 of the rotor 8. This has the effect of being able to prevent

In addition, since the gap between the two members 13 and 15 is closed with a lightweight cover 18 made of non-magnetic material, there is no need to make the armature 15 or hub 13 larger than necessary, which helps to reduce the size and weight of these members. As a result, it is possible to reduce the weight of the electromagnetic clutch.

Furthermore, since the outer circumference of the hub 13 has a polygonal shape and the inner circumference of the cover 18 has a polygonal shape corresponding to the polygonal outer circumference of the hub 13, the outer circumference of the hub 13 has a polygonal apex. Armature 1 in the part between the vertex (edge part)
5 and the hub 13 can be increased,
This provides the effect of reducing leakage magnetic flux flowing from the armature 15 to the hub 13 side.

According to the present invention, by combining the above-mentioned effects, it is possible to provide an electromagnetic clutch that is extremely useful in practice.

[Brief explanation of the drawing]

Fig. 1 to Fig. 5 show one embodiment of the present invention, Fig. 1 is a front view of the electromagnetic clutch, Fig. 2 is a half cross-sectional view of the electromagnetic clutch. Fig. 3 is a front view of the cover 18 of the electromagnetic clutch, Fig. 4 is a cross-sectional view taken along the line A-A in Fig. 3, Fig. 5 is a rear view of the cover 18, Fig. 6 to Fig. 10 show other embodiments of the present invention, and correspond to Fig. 1 to Fig. 5. 1: Excitation coil, 8: Rotor, 9: Bearing, 12: Driven shaft, 13: Hub, 15:
... armature, 16... leaf spring, 18... cover, C... compressor which is the driven device.

Claims (1)

[Claims for Utility Model Registration] A rotor to which rotation from a drive source is transmitted and rotatably supported on a bearing, a hub connected to a driven shaft, and an armature connected to the hub via a leaf spring. and an excitation coil that attracts and attracts the armature to the rotor, the outer periphery of the hub is formed into a polygonal shape having the same number of vertices as the number of fixing members for connecting the leaf spring and the hub, On the other hand, between the armature and the hub, there is provided a non-magnetic material having a polygonal inner circumference corresponding to the polygonal outer circumference of the hub, and a circular outer circumference corresponding to the circular inner circumference of the armature. Electromagnetic clutch with a cover.