A driving force transmission control apparatus includes: a driving force transmission device that includes an electromagnetic clutch mechanism configured to generate a frictional force between clutch plates by energization of an electromagnetic coil and transmits a driving force by actuating the electromagnetic clutch mechanism; and a control device that controls the driving force transmission device. The control device includes a storage unit storing a hysteresis value representing the difference between a current value required to transmit a predetermined torque when an energization current to the electromagnetic coil is gradually increased and a current value required to transmit the predetermined torque when the energization current is gradually reduced, a torque command value calculator that calculates a torque command value, and a current command value calculator that calculates a current command value representing a target value of a current to be supplied to the electromagnetic coil based on the torque command value and the hysteresis value.

A disconnect assembly for translating torque to shafts of a driveline. A clutch is disposed in torque translating relationship between the shafts and is movable between an engaged configuration wherein torque is translated, and a disengaged configuration wherein torque is interrupted. An actuator includes a coil that generates a first magnetic field. A slider is movable between a first stable position and a second stable position, with an armature operatively attached to the slider. The armature has a magnetic polarity pattern defined by a plurality of north and south magnetic pole regions facing the coil. The pattern configured such that predetermined changes in the magnetic field generated by the coil urge the slider from one of the stable positions to the other of the stable positions so as to cause corresponding movement of the clutch assembly between the configurations to selectively translate rotational torque between the shafts of the driveline.

An electromagnetic clutch assembly includes a rotor assembly operable to rotate about an axis. The electromagnetic clutch assembly also includes an armature assembly operable to rotate about the axis. The electromagnetic clutch assembly also includes an electromagnetic coupling system operable to generate a magnetic field. The magnetic field induces the rotor assembly and the armature assembly against one another along the axis for frictional engagement such that the rotor assembly and the armature assembly rotate together. The electromagnetic clutch assembly also includes an air gap defined between the rotor assembly and the armature assembly when the rotor assembly and the armature assembly are in frictional engagement. In another implementation, at least one plate is positioned between the rotor assembly and the armature assembly such that magnetic flux passes through the at least one plate. The plate is formed from a mixture of powdered metal and solid lubricant.

A magnetorheological fluid clutch apparatus comprises an input rotor adapted to be coupled to a power input, the input rotor having a first set of at least one input shear surface, and a second set of at least one output shear surface. An output rotor is rotatably mounted about the input rotor for rotating about a common axis with the input rotor, the output rotor having a first set of at least one output shear surface, and a second set of at least one output shear surface, the first sets of the input rotor and the output rotor separated by at least a first annular space and forming a first transmission set, the second sets of the input rotor and the output rotor separated by at least a second annular space and forming a second transmission set. Magnetorheological fluid is in each of the annular spaces, the MR fluid configured to generate a variable amount of torque transmission between the sets of input rotor and output rotor when subjected to a magnetic field. A pair of electromagnets are configured to deliver a magnetic field through the MR fluid, the electromagnets configured to vary the strength of the magnetic field, whereby actuation of at least one of the pair of electromagnets results in torque transmission from the at least one input rotor to the output rotor.

A steering system includes a two-way clutch, a worm wheel that is rotatable together with an input shaft, and a coil that generates a drive force for the two-way clutch to couple/decouple the input shaft and an output shaft to/from each other. The worm wheel has a center circular plate portion fixed to the input shaft, a radial ring portion that projects forward from a peripheral edge of the center circular plate portion, and a toothed portion that projects outward in the radial direction from the radial ring portion. The two-way clutch is disposed in a space surrounded by the center circular plate portion and the radial ring portion and formed on the front side with respect to the center circular plate portion. The coil surrounds an outer peripheral surface of the radial ring portion.

A magnetic clutch device having improved durability and reliability without increasing a size in an axial direction. A fixed member, the first engagement element, and a second engagement element are arranged concentrically to one another in order from a rotational center axis. The first engagement element comprises a first magnet. The fixed member comprises a second magnet in which a polarity is switched between a straight polarity and a reversed polarity, and a coil that switches the polarity of the second magnet depending on a direction of the current applied thereto.

An electromagnetic clutch assembly includes a rotor assembly operable to rotate about an axis. The electromagnetic clutch assembly also includes an armature assembly operable to rotate about the axis. The electromagnetic clutch assembly also includes an electromagnetic coupling system operable to generate a magnetic field. The magnetic field induces the rotor assembly and the armature assembly against one another along the axis for frictional engagement such that the rotor assembly and the armature assembly rotate together. The electromagnetic clutch assembly also includes an air gap defined between the rotor assembly and the armature assembly when the rotor assembly and the armature assembly are in frictional engagement. In another implementation, at least one plate is positioned between the rotor assembly and the armature assembly such that magnetic flux passes through the at least one plate. The plate is formed from a mixture of powdered metal and solid lubricant.

A bistable electromagnetic clutch is provided that includes a first part, a second part and an spring part. The first part includes a yoke with a plurality of iron cores, and an electromagnetic coil on each of the iron cores. The second part includes a moving carrier disc and a magnetic conductive disc that is fixed on a side of the moving carrier disc that is away from the yoke. Several magnets are fixed on the moving carrier disc, and the iron cores and the magnets are provided in a correspondence relation. The spring part is configured to keep the moving carrier disc and the yoke in normally separated positions. Two adjacent electromagnetic coils form a group, two electromagnetic coils in a same group are wound to form a group of windings with identical magnetic polarities, and corresponding two magnets form a group of magnetomotive forces with identical magnetic polarities.

This application pertains to an electromagnetic dog clutch, including a movable gear sleeve and a fixed toothed sleeve that are engaged to transmit power. The movable gear sleeve is provided with contrate transmission teeth or tooth spaces, and the fixed toothed sleeve is correspondingly provided with contrate tooth spaces or transmission teeth. The transmission teeth have a uniform thickness in a direction of tooth length, tooth spaces that engage with the transmission teeth have a sector-shape in a direction of tooth space length, and the width of two sides of the tooth spaces gradually increases outwardly along the radial direction of the fixed toothed sleeve and gradually decreases inwardly along the radial direction of the fixed toothed sleeve. By employing the engagement of transmission teeth of uniform thickness and sector-shaped tooth spaces, the transmission teeth can more easily engage with the tooth spaces, and more easily realize surface contact.

An inner peripheral surface of an outer cylindrical tubular portion and an outer peripheral surface of an inner cylindrical tubular portion of a rotor are respectively shaped into a stepped form. A radial distance between the outer cylindrical tubular portion and the inner cylindrical tubular portion at a counter-armature side location is larger than that of an armature side location in the rotor. An outer peripheral surface of an outer cylindrical tubular portion and an inner peripheral surface of an inner cylindrical tubular portion of a stator are respectively shaped into a stepped form. A radial distance between the outer peripheral surface of the outer cylindrical tubular portion and the inner peripheral surface of the inner cylindrical tubular portion at the counter-armature side location is larger than that of the armature side location in the stator.