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 exemplary apparatus includes a common movable driving member for actuating a plurality of flight control surfaces; a first power transfer device configured to variably adjust power transfer from the common movable driving member to a first of the plurality of flight control surfaces; and a second power transfer device configured to variably adjust power transfer from the common movable driving member to a second of the plurality of flight control surfaces. The power transferred to the second flight control surface may be adjusted independently of the power transferred to the first flight control surface. Apparatus and methods for actuating flight control surfaces using magneto-rheological fluid or electro-rheological fluid are also disclosed.

An electroadhesive clutch that establishes a quick, electrically-controllable connection of two components capable of transmitting complex loading across the connection. The quick connection is comprised of at least two electrodes separated by a dielectric material, where one of the electrodes is flexible. The dielectric material may coat or otherwise be attached to one or several electrodes or, alternatively, be placed between opposing electrodes.

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.

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.

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.

Systems and techniques for controlling a power distribution of a hybrid powertrain system using magnetorheological (MR) clutches. In embodiments, MR clutches may be used to control the power transfer from a mechanical power source to a plurality of loads. For example, mechanical power produced by a mechanical power source (e.g., an internal combustion engine (ICE)) may be transferred to each load of the plurality of loads using an MR clutch respectively connected to each load. In this example, the amount of mechanical power transferred from the mechanical power source to each of the loads of the plurality of loads may be controlled and/or managed using the MR clutch connected to each respective load. In embodiments, a load may be engaged or disengaged from the mechanical power source gradually, such as by ramping up or ramping down the amount of mechanical power transferred via the MR clutch to the load.

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.