Abstract: An electromagnetic clutch has an electromagnetic coil and a coil housing for accommodating the coil. The coil is inserted into the coil housing together with insulating members made of readily deformable insulating material. The insulating members are pressed downwardly by the coil and deformed according to an inner shape of the coil housing. As a result, the coil and the insulating members are accommodated in the coil housing with a preset gap between a surface of the coil and an inside surface of the coil housing, formed by the insulating members. The gap is filled with melted resin so that the coil is firmly secured in the coil housing. Thus, the coil can be readily secured in and insulated from the coil housing at a low cost.

Abstract: A multi-stepped pulley, and a method and apparatus for manufacturing the same, wherein the mechanical strength is increased while keeping down an increase of mass and a rise of manufacturing costs by pressing against portions of a surface of a hollow metal material having a circular cross-section corresponding to a connection portion of a plurality of pulleys by pressing rollers and simultaneously crushing the material in an axial direction so as to integrally form first and second rims, first and second webs, and a connection portion thereof.

Abstract: A workpiece W2 is grasped by inserting a first jig into a concave portion which is formed in a rotor forming process, and by interfitting a second jig to a convex portion which is also formed in the rotor forming process. Thereby, the workpiece W2 is firmly grasped, and a groove-forming roller can be strongly pressed into the workpiece W2. A time for forming a pulley groove is shortened, and a manufacturing cost thereof is reduced.

Abstract: An electromagnetic clutch for a compressor in an air conditioning system, having a rotor 2 for receiving a rotating movement from its source, a hub 12 in connection with a rotating shaft of the compressor, a coil housing 4 for storing a coil spool 14 on which an electromagnetic coil is wound, and an armature 8 which is attracted to a frictional surface 2a of the rotor 2 under the effect of an electromagnetic attracting force generated by the electromagnetic coil 5. The coil spool 14 has an inclined surface at an inner corner location which is located adjacent the frictional surface 2a of the rotor 2. The coil spool has a recess at a location where the inclined surface is formed, in which recess a temperature fuse is arranged. The temperature fuse is broken under a condition that the temperature is higher than a predetermined value, thereby de-energizing the electromagnetic coil 5.

Abstract: A transparent adhesive layer 3 with good permeability to laser light is provided on a base sheet 4, a colored layer 2 with good absorption of laser light is provided on the transparent adhesive layer 3, and a transparent layer 1 with good permeability to laser light is provided on the colored layer 2. Laser light 6 is irradiated from the side of the transparent layer 1 to form marked sections 5 at prescribed areas of the colored layer 2. To paste the marking sheet A onto the outer surface of a product, the base sheet 4 is peeled off and the transparent adhesive layer 3 is pasted onto the outer surface of the product. The color of the outer surface of the product may then be seen through the marked sections 5. Thus, satisfactory displays may be provided using only the marked sections 5 formed by laser light irradiation, without any additional special painting step.

Abstract: A magnetic clutch includes a rotor and an armature facing to each other for establishing a coupling connection. A serpentine magnetic circuit is formed in the rotor and the armature. A method for manufacturing a rotor of a magnetic clutch of the invention comprises the step of deforming a single ring-shaped plate of a magnetic material, by a plastic deformation process such as cold forging, into a ring-shaped element comprising generally concentric inner and outer cylindrical walls, and a ring-shaped bottom wall. Prior to or after or simultaneously with this step, ring grooves are formed on the bottom wall. A nonmagnetic material is then filled in the ring grooves, and the bottom surface of the bottom wall is cut to form a friction surface. By this cutting, the nonmagnetic material is exposed at the friction surface.

Abstract: A first body is formed from a first cylindrical member. The first body includes a restricted portion which extends circumferentially along the first body and has an inner diameter smaller than that of the first cylindrical member, a V-shaped groove on the outer surface of the restricted portion, opposite cylindrical end portions which have a diameter substantially equal to that of the first cylindrical member, and a pair of annular connecting portions which connect the end portions to the respective ends of the restricted portion. Further, a second body is formed from a second cylindrical member which has a diameter smaller than that of the first cylindrical member.

Abstract: An electromagnetic clutch has an electromagnetic coil 3, an armature 5, and a rotor 1 of a substantially C-cross section, which is constructed by an outer ring 21 arranged outside of the coil 3, an inner ring 22 arranged inside of the coil 3, and a friction face 23 for connecting the inner and the outer rings 21 and 22. The outer ring has an inner periphery of a reduced diameter located nearer to the friction face, so that a thick wall portion 27 is created at a location adjacent the friction face 23. As a result, the magnetic resistance of the outer ring 21 is reduced at a location adjacent the friction wall 23, thereby increasing the total magnetic force of the magnetic circuit, thereby increasing an engaging face between the rotor and the armature.

Abstract: An electromagnetic clutch capable of reducing a noise generated upon contact of an armature with rotor. Connecting member 20 for connecting inner and outer rings 5a and 5b of the armature are integrally formed with arms 19 extending radially inwardly from locations where the connection members 20 are connected to the inner ring 5a by rivets 12. The arms 17 are in face to face contact with an elastic member 18 made of rubber, which is held by the inner hub 7 by means of a retainer 19. Upon the movement of the armature 5 toward to rotor 4 by means of an electromagnetic force, just before the contact of the armature 5 with the rotor 4, a steep increase in a force for opposing the movement of the armature 5 with respect to the rotor 4 is obtained, thereby reducing an impact upon the contact, and reducing the noise.

Abstract: An electromagnetic coupling selectively transmits power from an automobile engine to a supercharger. The electromagnetic coupling includes a rotor having excitation coils thereon and rotatable by the drive source, an armature magnetically attractable in a direction toward the rotor for rotation therewith in response to energization of the excitation coils, an outer holder plate mounted on the armature and having a first flange, an inner holder plate connected to the supercharger and disposed radially inwardly of the outer holder plate, the inner holder plate having a second flange positioned concentrically with and spaced from the first flange, and an elastomeric member disposed between and joined to the first and second flanges. The elastomeric member has a thickness in the direction toward the rotor which is progressively increased from the second flange toward the first flange.