JP2000213560A - Electromagnetic clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a compact, lightweight electromagnetic clutch at a low cost by composing an annular yoke member for fixing an exciting coil, of a cylindrical part and a flange part protruded outside or inside of the cylindrical part so as to have L-shaped cross section, and making the exciting coil abut on the annular yoke member to fix the exciting coil. SOLUTION: An electromagnetic clutch has a rotor 7 rotatably supported to an equipment body 6 through a ball bearing 8, and an armature 10 of nearly disk shape disposed opposedly to the rotor 7. The rotor 7 and the armature 10 are magnetically connected by applying a current to an exciting coil 1. In this case, an annular yoke member 2 of the exciting coil 1 is formed of a cylindrical part and a flange part protruded outward from one end of the cylindrical part, and the exciting coil 1 is disposed to make the inner peripheral surface and one end face abut on the annular yoke member 2. A cover 4 is disposed to cover a part exposed from the annular yoke member 2 of the exciting coil 1, and a claw part 2c of the annular yoke part 2 is caulked to fix the exciting coil 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an electromagnetic clutch for transmitting / cutting power.

[0002]

2. Description of the Related Art An electromagnetic clutch is used for controlling transmission of driving force to a compressor attached to, for example, an air conditioner for a vehicle. The general structure of the electromagnetic clutch of an automotive air conditioner is shown in FIGS. A disc-shaped armature 10 is fixed to an end of the main shaft 14 with splines 15 and bolts 16. The annular rotor 7 is
It is rotatably connected to the device body via a radial ball bearing 8. A concentric pulley 7a is provided at a peripheral portion of the rotor 7. The rotor 7 is connected to the engine by a V-belt (both not shown), and rotates by the power of the engine.

[0003] The rotor 7 and the armature 10 are arranged with a slight gap (for example, about 0.5 mm). In the hollow portion 7b of the rotor 7, the annular yoke member 2 accommodating the exciting coil 1 is arranged concentrically with the main shaft 14. One end of the holding portion 5 is welded to the annular yoke member 2, and the other end is
Fixed to the device body.

Conventionally, an annular yoke member 2 for accommodating an exciting coil 1 includes a pair of concentric cylindrical members as shown in FIG. 3, and a bottomed portion formed in a space between the two cylindrical members. Thus, the exciting coil 1 was housed in the annular hollow portion. An insulating layer 21 made of resin is provided between the annular yoke member 2 and the exciting coil 1 housed in the annular yoke member 2 in order to ensure insulation. The insulating layer 21 is formed, for example, by housing the exciting coil 1 in the hollow portion of the annular yoke member 2 and then injecting resin into the hollow portion. Thus, the insulating layer 21
And the exciting coil 1 is fixed. Instead of resin injection molding, there is also a method in which an exciting coil is wrapped with a resin-made bobbin and a cover molded in advance, then inserted into the yoke member 1, and caulked and fixed. Also in this method, a yoke member having a similar shape is used.

[0005] The rotor 7 is connected to the engine by a V-belt (not shown).
It is supported rotatably. A stopper plate 17 is fixed to the other surface of the amateur 10. A dish-shaped damper case 18 is provided on the outer surface of the stopper plate 17.
Are fixed by welding. In the damper case 18,
A rubber damper 20 vulcanized and bonded to the rivet 19 is accommodated. The rubber damper 20 is press-fitted into the damper case 18 and then fixed by caulking.

Hereinafter, the operation of the electromagnetic clutch will be described with reference to the above conventional example. When a current is supplied to the exciting coil 1 from an external power supply (not shown), a magnetic circuit is formed as shown by a broken line in FIG. As a result, the armature 10 is sucked by the rotor 7, and the armature 10 and the rotor 7
Are friction bonded. Thus, the driving force of the rotor 7 is transmitted to the main shaft 14 via the armature 10. When the power supply to the exciting coil 1 is stopped, the attractive force between the armature 10 and the rotor 7 is lost. Further, the armature 10 is separated from the rotor 7 by the recovery force of the rubber damper 20. Thus, power transmission from the rotor 7 to the main shaft 14 is shut off.

In recent years, not only air conditioning equipment but also equipment miniaturization,
Lightening is desired. Particularly, in electromagnetic clutches of automotive air conditioners, such demands are persistent for the purpose of limiting the arrangement space and reducing the weight of the vehicle.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a small and lightweight electromagnetic clutch at low cost.

[0009]

According to the present invention, an annular yoke member having a U-shaped cross section is replaced with an L-shaped cross-section member.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An electromagnetic clutch according to the present invention is rotatably provided on an apparatus body via a radial ball bearing, and is fixed to a disk-shaped rotor which is rotated by an external driving force; A substantially disk-shaped armature whose surface is arranged opposite to one main surface of the rotor and an annular groove formed concentrically with the main shaft on the other main surface of the rotor, and the rotor and the armature are moved by electromagnetic force. A solenoid coil for frictional joining, and an annular yoke member for fixing and receiving the solenoid coil in the annular groove, wherein the annular yoke member has a cylindrical portion and one end of the cylindrical portion. A solenoid coil is accommodated in a container made of a resin molded product and is fixed to the annular yoke member.

In a conventional electromagnetic clutch, the sectional shape of the annular yoke member is U-shaped, whereas in the electromagnetic clutch of the present invention, the sectional shape of the annular yoke member is L-shaped and accommodated in a container. The excited excitation coil 1 is fixed to the annular yoke. For example, the outer peripheral surface wound around the bobbin is covered with a cover having an L-shaped cross section, and the exciting coil is wrapped around the cover and an annular yoke member. Thereby, a part of the annular yoke member of the conventional electromagnetic clutch can be replaced with a lightweight resin. Further, the insulating layer of the conventional exciting coil for an electric clutch can be replaced by a resin container. Therefore, the weight of the electromagnetic clutch can be reduced. Furthermore, one of the wall surfaces of the annular yoke member provided in pairs in the diameter direction of the rotor can be omitted, and the diameter of the pulley of the rotor can be reduced accordingly. Therefore, the size of the electromagnetic clutch can be reduced.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. Here, components having the same functions as those of the conventional example are denoted by the same reference numerals.

Embodiment 1 FIG. 1 shows an electromagnetic clutch of this embodiment. The annular yoke member used for this electromagnetic clutch is:
It has a cylindrical portion and a flange portion protruding outward from one end thereof. That is, as compared with the annular yoke member used in the conventional electromagnetic clutch shown in FIG. 4, the cylindrical portion on the outer diameter side is omitted. The exciting coil 1 is wound around a resin bobbin 3 having flanges at both end surfaces. The exciting coil 1 wound around the bobbin 3 is arranged such that the inner peripheral surface and one end surface thereof respectively contact the annular yoke member 2. Next, the cover 4 is arranged so as to cover a portion of the exciting coil 1 exposed from the annular yoke member 2. Then, the exciting coil 1 is fixed by caulking the claw 2c at the end of the annular yoke member 2.

As described above, the exciting coil 1 is connected to the bobbin 3
And the cover 4 covers and is protected. By fixing the protected excitation coil 1 to the annular yoke member 2 having an L-shaped cross section, the outer diameter of the rotor 7 can be reduced, and the size of the entire electromagnetic clutch can be reduced. Can be. In addition, the cost of the electromagnetic clutch can be reduced by using an annular yoke member having a simple shape.

Embodiment 2 FIG. 2 shows an electromagnetic clutch of this embodiment. The electromagnetic clutch has a flange portion projecting inward from an end of the tubular portion of the annular yoke member 2. The exciting coil 1 is wound around a resin bobbin 3 having flanges at both end surfaces. A cover 4 is attached to the exciting coil 1 wound around the bobbin 3 so as to cover the exposed outer peripheral surface. Next, the exciting coil 1 is arranged such that the outer peripheral surface and the end surface thereof are in contact with the annular yoke member 2. Thereafter, the exciting coil 1 is fixed by caulking the claw 2d at the end of the annular yoke member 2.

[0016]

According to the present invention, the annular yoke member for fixing the exciting coil is constituted by the cylindrical portion and the flange portion protruding outside or inside thereof, and the exciting coil is fixed so as to be in contact with them. A small and lightweight electromagnetic clutch can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an electromagnetic clutch according to one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of an electromagnetic clutch according to another embodiment.

FIG. 3 is a longitudinal sectional view of a conventional electromagnetic clutch.

FIG. 4 is a plan view of the same.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 excitation coil 2 annular yoke member 2 c, 2 d claw portion 3 bobbin 4 cover 6 device body 7 rotor 7 a pulley 7 b hollow portion 8 radial ball bearing 10 amateur 14 main shaft 15 spline 17 stopper plate 18 damper case 19 rivet 20 rubber damper 21 insulating layer

Claims (1)

[Claims] An electromagnetic clutch for transmitting an external driving force to a main shaft of an apparatus, wherein the electromagnetic clutch is rotatably fixed to a main body of the apparatus via a radial ball bearing, and rotates in a disk shape by an external driving force. A rotor, a substantially disc-shaped armature fixed to the main shaft, the main surface of which is arranged to face one main surface of the rotor, and the other main surface of the rotor is formed concentrically with the main shaft. A solenoid coil housed in the annular groove portion for frictionally joining the rotor and the armature by electromagnetic force, and an annular yoke member for fixing and housing the solenoid coil in the annular groove portion,
The annular yoke member includes a cylindrical portion and a flange portion protruding from one end of the cylindrical portion, and the solenoid coil is covered by a container formed of the annular yoke member and a resin molded product, An electromagnetic clutch in which one surface of the resin molded product faces one side surface of the annular groove.