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 fluid pump includes an input shaft, a pumping unit comprising a pump rotor, and a clutch arranged between the input shaft and the pump rotor. The clutch comprises at least two input clutch disks, at least two output clutch disks, a permanent magnet element, and an actuator. The at least two input clutch disks and the at least two output clutch discs together define at least two clutch liquid gaps which are filled with a magneto-rheological clutch liquid. The permanent magnet element shifts between an engaged position wherein a magnetic field of the permanent magnet element penetrates the at least two clutch liquid gaps with a high magnetic flux, and a disengaged position wherein the magnetic field of the permanent magnet element is less than in the engaged position. The actuator moves the permanent magnet element between the engaged position and the disengaged position.

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 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.

A mechanical combustion-engine-driven fluid pump includes an input shaft driven by a combustion engine, a pumping unit comprising a pump rotor, and a clutch arranged between the input shaft and the pump rotor. The clutch comprises an input clutch body, an output clutch body, an electroconductive element, a permanent magnet element, and an actuator. The clutch transfers a rotation of the input clutch body to the output clutch body in an engaged clutch state. The closed clutch liquid gap is formed between the input clutch body and the output clutch body, and is filled with a magneto-rheological clutch liquid. The electroconductive element co-rotates with the output clutch body. The permanent magnet element co-rotates with the input clutch body and is shiftable between an engaged position and a disengaged position. The actuator moves the permanent magnet element between the engaged position and the disengaged position.

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.

In some embodiments, a rotorcraft flight control actuator includes a driving member configured to receive mechanical energy from a power source, a driven member, a magnetorheological (MR) fluid disposed between the driving member and the driven member and configured to transmit a variable amount of mechanical energy from the driving member to the driven member, an output member configured to be coupled between the driven member and a flight control device of a rotor system, and a magnetic circuit configured to deliver a magnetic field towards the MR fluid, the magnetic circuit configured to vary the strength of the magnetic field in response to inputs.

A system for controlling a tension of a tether between an object and a load tethered to the object comprises magnetorheological (MR) fluid actuator unit(s) including at least one torque source and at least one MR fluid clutch apparatus 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 torque via an output of the MR fluid actuator unit. A tensioning member is connected to the output 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 when being pulled by the output member. Sensor(s) provide information indicative of a relation between the object and the load tethered to the object. A controller controls the at least one MR fluid clutch apparatus in exerting the pulling action based on said information.

In some embodiments, a redundant control system includes first and second control systems, having first and second clutches, and a shared clutch system. The shared clutch system may include a shared shaft configured to receive mechanical energy from a shared power source, a first shared clutch corresponding to the first clutch and configured to receive mechanical energy from the shared shaft, and a second shared clutch corresponding to the second clutch and configured to receive mechanical energy from the shared shaft. A first linkage provides mechanical communication between an output of the first clutch, an output of the first shared clutch, and a first output device in mechanical communication with the rotor system. A second linkage provides mechanical communication between an output of the second clutch, an output of the second shared clutch, and a second output device in mechanical communication with the rotor system.

In some embodiments, an actuation system includes a plurality of threaded member portions, a plurality of roller nuts, a driving member configured to receive mechanical energy from a power source, a plurality of driven members, and a magnetorheological (MR) fluid disposed between the plurality of driven members and at least one braking surface. An output member may be coupled between the rotor system and either the plurality of threaded member portions or the plurality of roller nuts and configured to translate linearly in response to the threaded member portions advancing or receding within the roller nuts.