The present invention discloses a brake-by-wire actuator based on motor-magnetorheological fluid clutch. The system includes a motor, a transmission mechanism and a floating-caliper disc mechanism. The transmission mechanism includes a magnetorheological fluid clutch, a planetary gear set and a ball screw set. The ball screw set includes balls, a ball screw and a sleeve. The floating-caliper disc mechanism includes a brake pad back plate, left and right brake pads, a caliper body, a brake disc and a guide rail. The motor and the magnetorheological fluid clutch cascaded in series, the linear motion of the sleeve of the ball screw set is achieved by the magnetorheological fluid clutch and the transmission mechanism. The sleeve pushes forward the brake pad back plate of the floating-caliper disc mechanism to clamp the brake disc by left and right brake pads, which accomplishes braking. The present invention uses a brake-by-wire actuator based on motor-magnetorheological fluid clutch, which not only has the advantages of fast response and improved braking security, but also solves the problem of the motor stalling during long time braking.

A tensioning set comprises an output member. A magnetorheological fluid clutch apparatus is configured to receive a degree of actuation (DOA) and connected to the output member, the magnetorheological fluid clutch apparatus being actuatable to selectively transmit the received DOA through the output member by controlled slippage. A tensioning member is connected to the output member so as to be pulled by the output member upon actuation of the magnetorheological fluid clutch apparatus, a free end of the tensioning member adapted to exert a pulling action transmitted to an output when being pulled by the output member. The tensioning set, or a comparable compressing set, may be used in systems and robotic arms. A method for controlling movements of an output driven by the tensioning set or compressing set is also provided.

A magnetorheological fluid clutch apparatus comprises a stator having at least an annular wall; a first rotor rotatably mounted to the stator, the first rotor having at least one first shear surface; a second rotor rotatably mounted to the stator for rotating about a common axis with the first rotor, the second rotor having at least one second shear surface opposite the at least one first shear surface, the shear surfaces separated by at least one annular space. A magnetorheological (MR) fluid is in an MR fluid chamber including the at least one annular space, the MR fluid configured to generate a variable amount of torque transmission between the rotors when subjected to a magnetic field. An inner magnetic core and an outer magnetic core with an annular cavity therebetween receive the annular wall of the stator, the inner magnetic core and the outer magnetic core connected to at least one of the rotors to rotate therewith so as to be rotatably mounted to the stator. Outer and inner fluid gaps are between the inner magnetic core and the annular wall, and between the outer magnetic core and the annular wall, the outer and inner fluid gaps filled with at least one fluid. At least one coil is supported by the annular wall and actuatable to deliver a magnetic field through the MR fluid, the magnetic field following a path comprising the annular wall, the outer fluid gap, the outer magnetic core, the at least one first shear surface and the at least one second shear surface, the inner magnetic core and the inner fluid gap, wherein one of the rotors is adapted to be coupled to a power input and the other of the rotors is adapted to be connected to an output whereby actuation of the at least one coil results in a variation of torque transmission between the rotors.

An aircraft steering system includes an electric actuator, a clutch, at least one plasma actuator, and a controller. The electric actuator is configured to vary an angle of a flight control surface of an aircraft. The clutch is configured to cut off torque by driving of the electric actuator. The torque is to be transmitted to the flight control surface. The at least one plasma actuator is configured to form a flow of air on a surface of the flight control surface when the torque is cut off. The controller is configured to control the electric actuator, the clutch, and the at least one plasma actuator.

A spot-joining apparatus comprises a motor, a punch for driving a fastener or performing a clinching or friction stir spot welding operation, a first transmission, a second transmission and a transmission control apparatus. The first transmission is configured to transfer rotary motion of the motor to the punch when engaged. The second transmission is configured to convert rotary motion of the motor to linear motion of the punch, and thereby drive the punch towards a workpiece, when engaged. The transmission control apparatus is arranged to selectively adjust the degree of engagement of at least one of the first and second transmissions. Further apparatus for spot joining, and methods of spot-joining, are also disclosed.

In one aspect, there is provided a damper control system for a reciprocating pump assembly according to which control signals are sent to electromagnets. In another aspect, there is provided a method of dampening vibrations in a pump drivetrain according to which a beginning of torque variation is detected and at least a portion of the torque variation is negated. In another aspect, signals or data associated with pump characteristics are received from sensors, torque characteristics and damper response voltages per degree of crank angle are calculated, and control signals are sent to electromagnets. In another aspect, a damper system includes a fluid chamber configured to receive a magnetorheological fluid; a flywheel disposed at least partially within the fluid chamber and adapted to be operably coupled to a fluid pump crankshaft; and a magnetic device proximate the flywheel. The magnetic device applies a variable drag force to the flywheel.

A system comprises magnetorheological fluid clutch apparatuses, each magnetorheological fluid clutch apparatus including a first rotor having at least one first shear surface, a second rotor rotating about a common axis with the first rotor, the second rotor having at least one second shear surface opposite the at least one first shear surface, the shear surfaces separated by at least one annular space, magnetorheological (MR) fluid in an MR fluid chamber including the at least one annular space, the MR fluid configured to generate a variable amount of torque transmission between the rotors when subjected to a magnetic field, and coil(s) actuatable to deliver a magnetic field through the MR fluid such that each said magnetorheological fluid clutch apparatus is actuatable to selectively transmit actuation by controlled slippage of the rotors with respect to one another. The MR fluid chambers of the second magnetorheological fluid clutch apparatuses are in fluid communication for the MR fluid to circulate between the magnetorheological fluid clutch apparatuses.

In one aspect, there is provided a damper control system for a reciprocating pump assembly according to which control signals are sent to electromagnets. In another aspect, there is provided a method of dampening vibrations in a pump drivetrain according to which a beginning of torque variation is detected and at least a portion of the torque variation is negated. In another aspect, signals or data associated with pump characteristics are received from sensors, torque characteristics and damper response voltages per degree of crank angle are calculated, and control signals are sent to electromagnets. In another aspect, a damper system includes a fluid chamber configured to receive a magnetorheological fluid; a flywheel disposed at least partially within the fluid chamber and adapted to be operably coupled to a fluid pump crankshaft; and a magnetic device proximate the flywheel. The magnetic device applies a variable drag force to the flywheel.

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 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.