A drive plate of an electromagnetic-fan clutch comprises: a body of the drive plate provided with magnetic-insulation air holes, connection ribs, and magnetic conductive layers. The magnetic-insulation air holes and the magnetic conductive layers are arranged alternatively along a radial direction of the body of the drive plate. A friction-increasing groove is opened on the magnetic conductive layer. The thickness of the magnetic insulation air holes and the thickness of the connection ribs are less than the thickness of the magnetic conductive layers. Six connection ribs are distributed uniformly between the magnetic conductive layers, and the connection ribs at two sides of the magnetic conductive layer are distributed along the radial direction of the body of the drive plate at an interval of 30 degrees. A drive plate through hole is opened in the body of the drive plate, and accommodation walls are disposed on the magnetic conductive layers.

A drive plate of an electromagnetic-fan clutch comprises: a body of the drive plate provided with magnetic-insulation air holes, connection ribs, and magnetic conductive layers. The magnetic-insulation air holes and the magnetic conductive layers are arranged alternatively along a radial direction of the body of the drive plate. A friction-increasing groove is opened on the magnetic conductive layer. The thickness of the magnetic insulation air holes and the thickness of the connection ribs are less than the thickness of the magnetic conductive layers. Six connection ribs are distributed uniformly between the magnetic conductive layers, and the connection ribs at two sides of the magnetic conductive layer are distributed along the radial direction of the body of the drive plate at an interval of 30 degrees. A drive plate through hole is opened in the body of the drive plate, and accommodation walls are disposed on the magnetic conductive layers.

An engagement device includes: an engaged body configured to rotate in conjunction with a rotary shaft; an engaging body arranged coaxially with the engaged body and configured to engage with the engaged body by movement in an axial direction; a power source configured to provide thrust to the engaging body in the axial direction; and a hub member configured to couple the engaging body to a torque receiver which receives torque transmitted from the engaged body at a time the engaging body engages with the engaged body. The engaged body, the engaging body, and the power source are accommodated in a closed space, and the hub member is at least a part of an outer shell forming the closed space.

An engagement device includes: an engaged body configured to rotate in conjunction with a rotary shaft; an engaging body arranged coaxially with the engaged body and configured to engage with the engaged body by movement in an axial direction; a power source configured to provide thrust to the engaging body in the axial direction; and a hub member configured to couple the engaging body to a torque receiver which receives torque transmitted from the engaged body at a time the engaging body engages with the engaged body. The engaged body, the engaging body, and the power source are accommodated in a closed space, and the hub member is at least a part of an outer shell forming the closed space.

A fail-safe friction clutch assembly for a vehicle accessory, particularly to drive a vehicle cooling pump, and more particularly as part of a dual mode drive for a cooling pump, together with an electric motor. The friction clutch assembly includes a friction plate member connected to a central rotatable shaft member used for operating the vehicle accessory. A pair of friction lining members are positioned on opposite sides of the friction plate member. An armature member is spring biased to axially force the friction plate member and friction lining member against a housing or cover which is rotating at input speed. A solenoid assembly is used to overcome the spring bias and pull the armature and friction plate member away from the housing.

A fail-safe friction clutch assembly for a vehicle accessory, particularly to drive a vehicle cooling pump, and more particularly as part of a dual mode drive for a cooling pump, together with an electric motor. The friction clutch assembly includes a friction plate member connected to a central rotatable shaft member used for operating the vehicle accessory. A pair of friction lining members are positioned on opposite sides of the friction plate member. An armature member is spring biased to axially force the friction plate member and friction lining member against a housing or cover which is rotating at input speed. A solenoid assembly is used to overcome the spring bias and pull the armature and friction plate member away from the housing.

A system is configured to control a clutch that connects a first rotating body and a second rotating body. The system includes a biasing portion, an actuator, an energization device, and a control unit. The biasing portion permanently biases the clutch in a connecting direction. The actuator drives the clutch in a disconnecting direction. The energization device energizes the actuator. The control unit controls the energization device. The energization device outputs a first current value to the actuator when a connection of the clutch is detected even if a condition for permitting a disconnection is satisfied. The energization device outputs a second current value lower than the first current value when the condition for permitting the disconnection is satisfied and a disconnection of the clutch is detected.

A system is configured to control a clutch that connects a first rotating body and a second rotating body. The system includes a biasing portion, an actuator, an energization device, and a control unit. The biasing portion permanently biases the clutch in a connecting direction. The actuator drives the clutch in a disconnecting direction. The energization device energizes the actuator. The control unit controls the energization device. The energization device outputs a first current value to the actuator when a connection of the clutch is detected even if a condition for permitting a disconnection is satisfied. The energization device outputs a second current value lower than the first current value when the condition for permitting the disconnection is satisfied and a disconnection of the clutch is detected.

A bidirectional magnetic clutch for an additive manufacturing system, comprising a concentric arrangement of an inner drive member (2) and an outer drive member (3) enclosing the inner drive member (2), the inner and outer drive members (2,3) being rotatable relative to each other. The inner drive member (2) comprises at least two outward facing recesses (5, 6) and the outer drive member (3) comprises at least two inward facing recesses (8,9). Each outward facing recess (5,6) comprises a radially moveable roller member (10,11) of ferromagnetic material. The inner drive member (2) further comprises a magnetic biasing system (12) configured to magnetically bias the roller members (10,11) into the outward facing recesses (5,6). The bidirectional magnetic clutch further comprises a magnet actuator (13) at least partially circumferentially arranged around the outer drive member (3) and configured to maintain an engaged state or disengaged state of the bidirectional magnetic clutch.

A bidirectional magnetic clutch for an additive manufacturing system, comprising a concentric arrangement of an inner drive member (2) and an outer drive member (3) enclosing the inner drive member (2), the inner and outer drive members (2,3) being rotatable relative to each other. The inner drive member (2) comprises at least two outward facing recesses (5, 6) and the outer drive member (3) comprises at least two inward facing recesses (8,9). Each outward facing recess (5,6) comprises a radially moveable roller member (10,11) of ferromagnetic material. The inner drive member (2) further comprises a magnetic biasing system (12) configured to magnetically bias the roller members (10,11) into the outward facing recesses (5,6). The bidirectional magnetic clutch further comprises a magnet actuator (13) at least partially circumferentially arranged around the outer drive member (3) and configured to maintain an engaged state or disengaged state of the bidirectional magnetic clutch.