Abstract: Provided is an electromagnetic clutch, in which a plurality of magnetic flux shielding slits extending in the axial direction and arcuately in the circumferential direction are formed individually in a rotor and an armature, and in which the magnetic flux by the excitation of a coil inserted on the anti-armature side of the rotor is passed from the non-slit portion of the rotor to the non-slit portion of the armature and from the non-slit portion of the armature to the non-slit portion of the rotor, so that a magnetic attraction is generated to bring two frictional faces into press contact with each other and so that the two frictional faces are separated by the demagnetization of the coil. The slits of at least one of the rotor and the armature are formed to change in such a taper shape that the slit width at the frictional face side may be smaller than that at the anti-frictional face side.

Abstract: An electromagnetic clutch (20) capable of connecting and disconnecting a driving power source and a rotary shaft (22) includes a rotor (25) rotated by the driving power source, and an armature (40) capable of being attracted to the rotor (25) by electromagnetic force to produce a transmission force transmitted from the rotor (25) to the rotary shaft (22). The electromagnetic clutch (20) further includes leaf springs (52) urging the armature (40) in such a direction as to separate the armature from the rotor (25). The leaf springs (52) each assume an orientation such that a boost force assisting the attractive force acting upon the armature (40) is produced based on the transmission force when the armature (40) is attracted to the rotor (40).

Abstract: An electromagnetic clutch for separably coupling a drive source and a rotary shaft has a rotor to be disposed in the outside of the rotary shaft concentrically therewith. The rotor is rotated by a drive source and accommodates an electromagnetic coil. The electromagnetic clutch has an armature plate that is attracted toward the rotor by an electromagnetic force generated by the electromagnetic coil so as to adhere to the rotor. Furthermore, the electromagnetic clutch has a coupler for coupling the armature plate and the rotary shaft to each other. The coupler includes a center part to be coupled to the rotary shaft and an elastically-deformable outer part for coupling the center part to the armature plate, the outer part being extended from the center part and elastically deformed when the armature plate is attracted to the rotor.

Abstract: In an electromagnetic clutch, an electromagnetic coil is energized to couple a rotor and an armature plate to each other. Each leaf spring extends in a direction so as to intersect at an obtuse angle with the rotating direction of the armature plate, and accordingly, when the power of the driving source is transmitted to the armature plate through the rotor, a compressive force acts upon the leaf spring. The leaf spring has an inclined portion, and the armature plate is pressed against the rotor by the compressive force. Each leaf spring has a first extended portion located between the first coupling portion and inclined portion thereof and a second extended portion located between the second coupling portion and inclined portion thereof.

Abstract: An electromagnetic clutch (20) capable of connecting and disconnecting a driving power source and a rotary shaft (22) includes a rotor (25) rotated by the driving power source, and an armature (40) capable of being attracted to the rotor (25) by electromagnetic force to produce a transmission force transmitted from the rotor (25) to the rotary shaft (22). The electromagnetic clutch (20) further includes leaf springs (52) urging the armature (40) in such a direction as to separate the armature from the rotor (25). The leaf springs (52) each assume an orientation such that a boost force assisting the attractive force acting upon the armature (40) is produced based on the transmission force when the armature (40) is attracted to the rotor (40).

Abstract: An electromagnetic coil is energized to couple a rotor and an armature plate to each other. Each leaf spring extends in a direction so as to intersect at an obtuse angle with the rotating direction of the armature plate, and accordingly, when the power of the driving source is transmitted to the armature plate through the rotor, a compressive force acts upon the leaf spring. The leaf spring has an inclined portion, and the armature plate is pressed against the rotor by the compressive force. Each leaf spring has a first extended portion located between the first coupling portion and inclined portion thereof and a second extended portion located between the second coupling portion and inclined portion thereof. The compressive force applied per unit area can therefore be reduced by an amount corresponding to the increase in length of the leaf spring, making it unnecessary to thicken the leaf spring.

Abstract: An electromagnetic clutch for separably coupling a drive source and a rotary shaft has a rotor to be disposed in the outside of the rotary shaft concentrically therewith. The rotor is rotated by a drive source and accommodates an electromagnetic coil. The electromagnetic clutch has an armature plate that is attracted toward the rotor by an electromagnetic force generated by the electromagnetic coil so as to adhere to the rotor. Furthermore, the electromagnetic clutch has a coupler for coupling the armature plate and the rotary shaft to each other. The coupler includes a center part to be coupled to the rotary shaft and an elastically-deformable outer part for coupling the center part to the armature plate, the outer part being extended from the center part and elastically deformed when the armature plate is attracted to the rotor.

Abstract: An electromagnetic spring-wound clutch is disclosed. An armature plate member to which one end of a coil wound spring is connected is flexibly connected to a guide member rotatably supported on a cover plate by a plurality of leaf springs. The cover plate has a bent portion at its axial terminal end and the guide member is closely fitted against the bent portion to maintained its axial position thereon. Thus, the armature plate is fitted against an axial end of the bent portion due to the recoil strength of the coil wound spring.

Abstract: An electromagnetic clutch for selectively transmitting the rotation of a magnetic pulley to a rotatable shaft by the magnetic attraction of an annular magnetic armature plate elastically supported on the shaft to an axial end of the pulley produced by the energization of an electromagnet stationarily disposed in a radial hollow portion of the pulley. A radial inner wall defining the hollow portion of the pulley is partially thicker in the radial thickness at an axial extent between the axial end of the pulley and the electromagnet, thereby to decrease the magnetic resistance through the axial extent and to strengthen the magnetic attraction force between the pulley and the armature without increasing the outer diameter of the clutch. A magnetic ring may be partially fitted to the inner wall to substantially increase the radial thickness in place of the partial increase of the radial thickness of the inner wall itself.

Abstract: An electromagnetic clutch wherein a rotational force is transmitted between a first rotatable member and a second rotatable member by a magnetic attraction of an armature supported on one of the first and second rotatable members to the other member. The armature is rotatable with respect to the member upon which it is mounted within a limited extent. At least one arcuate spring member is provided to connect the armature and the supporting member. The inner surface of the arcuate member faces the annular surface of a portion of the other rotatable member. When the armature is magnetically attracted to, and rotated together with, the other rotatable member, the inner surface of the arcuate spring member comes into contact with an annular surface of the other rotatable member so that the transmission of the rotational force is effected through the arcuate spring in addition to the magentic attraction of the armature.

Abstract: An annular armature plate of an electromagnetic clutch is provided with circular grooves in an axial end surface corresponding to the location of concentric slits of a cooperating clutch element made of a magnetic materials to define magnetic pole pieces. The armature plate further includes corresponding press-formed circular projections on the opposite end surface thereof, in order to strengthen the magnetic attraction between the armature plate and the cooperating clutch element. The armature plate may be supported on and joined to a rotatable member by leaf springs and may be provided with pin-like projections formed on the axial end surface thereof to fix the leaf springs to the armature plate. A radial flange of the rotatable member supporting the armature plate may be provided with projections with flat end surfaces on which the leaf springs are fixed without the use of washers.