JPH10196687A - Electromagnetic powder clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To excellently protect a coil in the case of heat generation by covering and sealing the outer circumference of a coil electric wire wound on a disc type core member with a cover member made of heat resistant inorganic material. SOLUTION: A clutch is connected when powder P between a yoke 2 and a rotor 4 is bound by means of magnetic flux generated by excitation to a coil 3. For protecting the coil 3, a heat resistant inorganic adhesive is injected from the outside via an injection hole in an outer circumference ring 12 while the coil 3 is arranged inside the yoke 2, and the injected adhesive serves as a cover member 15 covering and sealing the outer circumference of an electrical wire winding groove in a core member of a coil bobbin and the outside of an electric wire wound on its inside. That is, in the adhesive made of a mixture of alumina grains and a binder, for example, the alumina grains are bound together by means of the binder so as to be solidified when solvent such as methanol is evaporated in the inside, and an aggregation of the alumina grains forms the cover member 15 while covering and sealing the outer circumference of the electrical wire winding groove. In this way, heat resistance can be secured in the cover member 15, and an insulation function can be maintained excellently.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic powder clutch.

[0002]

2. Description of the Related Art Conventionally, an electromagnetic powder clutch has a structure in which powder is put between a yoke containing a coil and a rotor, and the power is supplied to the coil so that the powder is connected to fasten the yoke and the rotor. However, the coil is conventionally housed in the yoke in a state of being surrounded by the thermosetting resin, and when the thermosetting resin expands due to heat, there is no place for the coil to escape. There is a problem that a short circuit may occur, and the thermosetting resin is carbonized due to heat generation, thereby deteriorating the insulating function.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide an electromagnetic powder clutch which can protect a coil well when heat is generated. The first gist is such that a powder is put between an outer peripheral yoke in which a coil is provided and an inner rotor, and the power is supplied to the coil so that the powder is fastened to fasten the yoke and the rotor. In the electromagnetic powder clutch configured as described above, the coil is formed by winding an electric wire around the outer periphery of a disk-shaped core material, and further covering the outer periphery of the wound electric wire with a cover material,
The cover material is made of a heat-resistant inorganic material. A second gist is that the cover member is formed of an aggregate of ceramic particles poured together with an adhesive dissolved in a solvent and solidified by an adhesive in a yoke.

[0004]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway cross-sectional configuration view of an electromagnetic powder clutch, and FIG. 2 is an enlarged cross-sectional view of a main part. In the figure, an electromagnetic powder clutch 1 includes an outer yoke 2 and an inner rotor 4. The yoke 2 is mounted on a crankshaft of an engine (not shown) and is rotated by the crankshaft. An input shaft on the transmission side is fitted to a hub 5 at the center of the rotor 4.

The rotor 4 is rotatably provided on the main body 6 via a bearing 7, and a current is applied from the outside via a slip ring 10, and the current is supplied to the coil 3 so that the yoke 2 and the rotor 4 The powder P interposed between the rotor 2 and the yoke 2 and the rotor 4 are coupled by the generated magnetic flux.
And the driving force from the engine side is transmitted to the transmission side.

[0006] The coil 3 housed in the yoke 2 comprises:
An electric wire is wound around a core member 14 of a disc-shaped coil bobbin as shown in FIG. 4. In FIG. 4, the core member 14 of the coil bobbin is an electric wire wound with a U-shaped cross section open at the outer peripheral side. A groove 14a is formed, an electric wire is wound inside the electric wire winding groove 14a, and fitting protrusions 14b, 14b are formed on the side surface of the core member 14 so as to protrude outward. .

[0007] The yoke 2 includes a yoke ring 11.
, An outer ring 12 and an inner ring 13 are assembled, and a stainless steel blocking ring 17 shown in FIG. 7 is interposed between the yoke ring 11 and the inner ring 13. 3 has a structure as shown in a perspective view in FIG. 3, and has a substantially disk shape as a whole, and has an inner projection 11a formed on the inner peripheral side so as to protrude toward the side surface. An outer protrusion 11b is formed so as to protrude with a gap therebetween, and a coil groove 11c into which a coil is fitted is formed between the inner protrusion 11a and the outer protrusion 11b, and the coil groove 11c shown in FIG. Core material of coil bobbin 1
Numeral 4 is fitted with the electric wire wound around the outer periphery. The outer periphery of the yoke ring 11 is a ring gear attachment portion 11d for attaching a ring gear.

The outer peripheral ring 12 forming the yoke 2
Is formed in a ring shape as shown in a perspective view in FIG. 5, and a fitting projection 14 formed on the core material 14 of the coil bobbin.
Fitting holes 12a, 12a into which the b and 14b are fitted are formed to penetrate, and an injection hole 12b for injecting the heat-resistant inorganic adhesive is formed. In the assembled state, the wall surface contacts the outer protrusion 11b of the yoke ring 11 in FIG.
It is assembled so as to cover

Further, the inner peripheral ring 13 constituting the yoke 2 is formed in a ring shape as shown in a perspective view of FIG. Therefore, when assembling, the electric wire is wound in the electric wire winding groove 14a of the core material 14 of the coil bobbin shown in FIG. 4 and fitted into the coil groove 11c of the yoke ring 11 of FIG. The outer ring 12, the blocking ring 17 and the inner ring 13 shown in FIGS. 5, 7 and 6 are fitted into the yoke 2 from outside, and the screw 16 is tightened. In this assembled state, the outer peripheral ring 12 shown in FIG.
The heat-resistant inorganic adhesive was injected from the outside through the injection hole 12b, and the injected heat-resistant inorganic adhesive was wound inside by covering the outer periphery of the wire winding groove 14a of the core material of the coil bobbin in FIG. The cover material 15 covers the outside of the electric wire.

That is, the heat-resistant inorganic adhesive is composed of, for example, a mixture of alumina particles and a binder (adhesive), and the alumina particles and the binder are mixed and dissolved in a solvent such as methanol. When the solvent such as methanol evaporates inside the hole 12b, the alumina particles are bonded and solidified by the binder, and the aggregate of the alumina particles flows along the outer periphery of the wire winding groove 14a. The cover material 1 with the lid covered
5, the electric wire forming the coil 3 is fixed in the yoke 2 in a state of being completely surrounded by the core material 14 of the coil bobbin and the solidified cover material 15, The solidified cover material 15 fixes the yoke 2 and the core material 14 of the coil bobbin in an insulated state, and the electric wire is completely insulated in the yoke 2.

As described above, in this embodiment, since the cover member 15 is formed of an aggregate of ceramics such as alumina particles, the cover member 15 has good thermal conductivity even when the electromagnetic powder clutch generates heat. Thus, the electric wire of the coil 3 is less likely to generate heat, the electric wire can be protected well, and the cover material 15 does not expand even when the temperature becomes about 1400 ° C. or more because it is made of ceramics. It does not damage the electric wire constituting the coil 3 by expanding as in the conventional case, and also does not carbonize as in the conventional case, without lowering the insulation function, has excellent heat resistance, and has a good insulation function even at high temperatures. Can be maintained.

[0012]

According to the present invention, a powder is put between a yoke on the outer peripheral side containing a coil and a rotor on an inner peripheral side, and the power is supplied to the coil so that the powder is fastened to fasten the yoke and the rotor. In the electromagnetic powder clutch, the coil is formed by winding an electric wire around an outer periphery of a disk-shaped core material, and further covering the outer periphery of the wound electric wire with a cover material. Since the material is composed of a heat-resistant inorganic material, the cover material is 1
Even when heat is generated at 400 ° C. or more, heat resistance is ensured, the insulating function can be maintained well, and the heat conductivity is good, so that heat can be satisfactorily dissipated and without thermal expansion, Therefore, there is an effect that an electromagnetic powder clutch having excellent heat resistance and durability can be formed by protecting the coil satisfactorily without breaking the electric wire of the coil at the time of heat generation unlike the related art.

The cover material is poured together with an adhesive dissolved in a solvent, and is composed of an aggregate of ceramic particles solidified by the adhesive in the yoke, so that the electromagnetic powder clutch can be assembled. Dissolve the ceramic particles and adhesive with a solvent from the outside and pour in,
The cover material can be formed by solidifying it well in the yoke, and since the cover material is an aggregate of ceramic particles, it has excellent heat resistance and can maintain a good insulating function even when heat is generated. Has the effect of satisfactorily dissipating the heat of the coil, preventing thermal expansion as in the prior art, satisfactorily protecting the electric wire of the coil, and forming a durable electromagnetic powder clutch.

[Brief description of the drawings]

FIG. 1 is a partially cut-away configuration view of an electromagnetic powder clutch.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is a perspective configuration diagram of a yoke ring constituting the yoke.

FIG. 4 is a perspective configuration diagram of a core material of a coil bobbin constituting a coil.

FIG. 5 is a perspective configuration diagram of an outer peripheral ring constituting the yoke.

FIG. 6 is a perspective configuration diagram of an inner peripheral ring constituting the yoke.

FIG. 7 is a perspective configuration diagram of a blocking ring constituting the yoke.

[Explanation of symbols]

 Reference Signs List 1 electromagnetic powder clutch 2 yoke 3 coil 4 rotor 11 yoke ring 11c coil groove 12 outer ring 12a fitting hole 12b injection hole 13 inner circumferential ring 14 core material of coil bobbin 14a wire winding groove 14b fitting protrusion 15 cover material

Claims (2)

[Claims] 1. A structure in which powder is inserted between an outer yoke on which an inner coil is mounted and an inner rotor, and the coil is energized so that the powder is fastened to fasten the yoke and the rotor. In the electromagnetic powder clutch, the coil is formed by winding an electric wire around an outer periphery of a disk-shaped core material, and further covering the outer periphery of the wound electric wire with a cover material. An electromagnetic powder clutch comprising a conductive inorganic material. 2. The electromagnetic powder clutch according to claim 1, wherein the cover material is formed of an aggregate of ceramic particles poured together with an adhesive dissolved in a solvent and solidified by the adhesive in a yoke.