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 system for assisting a user in moving a device relative to a structure comprises a magnetorheological (MR) fluid actuator unit including at least one torque source and at least one MR fluid clutch apparatus having an input coupled to the at least one torque source to receive torque from the at least one torque source, the MR fluid clutch apparatus controllable to transmit a variable amount of assistance force via an output thereof. An interface is configured for coupling the output of the at least one MR fluid clutch apparatus to the device or surrounding structure. At least one sensor provides information about a movement of the device. A processor unit for controlling the at least one MR fluid clutch apparatus in exerting the variable amount of assistance force as a function of said information, wherein the system is configured for one of the MR fluid actuator unit and the interface to be coupled to the structure, and for the other of the MR fluid actuator unit and the interface to be coupled to the device for the assistance force from the MR fluid actuator unit to assist in moving the device.

A control system is provided for controlling movements of an end effector connected to a clutch output of at least one magnetorheological (MR) fluid clutch apparatus. A clutch driver is configured to drive the at least one MR fluid clutch apparatus between a controlled slippage mode, in which slippage between a clutch input and the clutch output of the MR fluid clutch apparatus varies, and a lock mode, in which said slippage between the clutch input and the clutch output is maintained below a given threshold, the clutch output transmitting movement to the end effector. A motor driver is configured to control a motor output of at least one motor, the motor output coupled to the clutch input. A mode selector module is configured to receive signals representative of at least one movement parameter of the end effector, the mode selector module selecting a mode between the controlled slippage mode and the lock mode of the clutch driver based on the signals, and switching the selected mode based on the signals. A movement controller controls the clutch driver and the motor driver to displace the end effector based on at least one of the selected mode and on commanded movements of the end effector for the end effector to achieve the commanded movements. A method for controlling movements of an end effector connected to the MR fluid clutch apparatus is also provided.

A rheological lock apparatus includes a fluid chamber formed within a housing between a pair of seals. The fluid chamber contains a rheological fluid. An inner surface of the housing has a first plurality of splines projecting into the fluid chamber and extending longitudinally along a longitudinal dimension of the chamber. A driveshaft extends axially through the chamber such that the pair of seals are sealed against the driveshaft. The driveshaft includes a second plurality of splines. A field generator is coupled to one of the driveshaft or the housing to generate a field through the rheological fluid during times when the housing is substantially immobile in a borehole.

A blind riveting apparatus (1) comprises a motor (3), and a clamp (31) for gripping the mandrel of a blind rivet, the clamp being movable substantially along the axis of the rivet. The apparatus further comprises a first transmission (51) configured to transfer rotary motion of the motor (3) to the clamp (31) when engaged; and a second transmission (52) configured to convert rotary motion of the motor (3) to linear motion of the clamp (31), and thereby retract the clamp (31) to pull on the mandrel, when engaged. A transmission control apparatus is arranged to selectively adjust the degree of engagement of at least one of the first (51) and second (52) transmissions, the transmission control apparatus comprising a variable-influence brake or clutch (58). Methods of blind riveting, and further pieces of blind riveting apparatus, are also disclosed.

A method of making a wet friction material layer includes adding a media in liquid form to a material base including filler particles embedded in a matrix of fibers; drying the media to solidify the media on the filler particles such that the media plugs holes in the filler particles; adding a binder to the material base; and unplugging at least some of the holes in the filler particles by removing at least some of the media from the material base.

A method of making a wet friction material layer includes adding a media in liquid form to a material base including filler particles embedded in a matrix of fibers; drying the media to solidify the media on the filler particles such that the media plugs holes in the filler particles; adding a binder to the material base; and unplugging at least some of the holes in the filler particles by removing at least some of the media from the material base.

An active suspension system comprises at least one biasing device configured to support a body from a structure, and at least one motor. A magnetorheological (MR) fluid clutch apparatus(es) is coupled to the at least one motor to receive torque from the motor, the MR fluid clutch apparatus controllable to transmit a variable amount of torque. A mechanism is between the at least one MR fluid clutch apparatus and the body to convert the torque received from the at least one MR fluid clutch apparatus into a force on the body. Sensor(s) provide information indicative of a state of the body or structure. A controller receives the information indicative of the state of the body or structure and for outputting a signal to control the at least one MR fluid clutch apparatus in exerting a desired force on the body to control movement of the body according to a desired movement behavior.

The present disclosure is a high-stability and large-torque magnetorheological fluid clutch. Firstly, in order to prevent sedimentation of the magnetorheological fluid, blades are installed on the disc body of an input disc. When the clutch operates in a power interruption mode, the blades can stir the magnetorheological fluid, so that the sedimented magnetorheological fluid is uniformly mixed. Secondly, in order to improve the maximum transmission torque of the magnetorheological fluid clutch, an excitation magnetic field is increased in a mode that a permanent magnet and an electromagnet are connected in series. Meanwhile, a third electric push rod is used for pushing the input disc, and the magnetorheological fluid works in a shearing-extruding working mode, so that the yield stress of the magnetorheological fluid is improved. Therefore, the maximum transmission torque of the magnetorheological fluid clutch is improved.

A system for assisting a user in moving a device relative to a structure comprises a magnetorheological (MR) fluid actuator unit including at least one torque source and at least one MR fluid clutch apparatus having an input coupled to the at least one torque source to receive torque from the at least one torque source, the MR fluid clutch apparatus controllable to transmit a variable amount of assistance force via an output thereof. An interface is configured for coupling the output of the at least one MR fluid clutch apparatus to the device or surrounding structure. At least one sensor provides information about a movement of the device. A processor unit for controlling the at least one MR fluid clutch apparatus in exerting the variable amount of assistance force as a function of said information, wherein the system is configured for one of the MR fluid actuator unit and the interface to be coupled to the structure, and for the other of the MR fluid actuator unit and the interface to be coupled to the device for the assistance force from the MR fluid actuator unit to assist in moving the device.