A system for operating at least one magnetorheological fluid clutch apparatus may, in a first mode, vary an amount of torque transmission between a driving member and a driven member in the at least one magnetorheological fluid clutch apparatus by actuating at least one coil in the at least one magnetorheological fluid clutch apparatus. In a second mode, the system may cause torque transmission between the driven member and the driving member by setting a desired remanent magnetization level in a magnetic component of the at least one magnetorheological fluid clutch apparatus by actuating the at least one coil in the at least one magnetorheological fluid clutch apparatus.

A magnetorheological fluid clutch apparatus comprises an input(s) having an input shear surface(s). An output(s) is rotatably mounted about the input for rotating about a common axis with the input, the output(s) having output shear surface(s), the input shear surface and the output shear surface separated annular space(s), with magnetorheological 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. An electromagnet(s) delivers a magnetic field through the magnetorheological fluid, the electromagnet configured to vary the strength of the magnetic field, whereby actuation of the electromagnet results in torque transmission from the input to the output. A member(s) defining at least one of the shear surfaces is made of a low-permeability material.

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.

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.

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 for operating at least one magnetorheological fluid clutch apparatus may, in a first mode, vary an amount of torque transmission between a driving member and a driven member in the at least one magnetorheological fluid clutch apparatus by actuating at least one coil in the at least one magnetorheological fluid clutch apparatus. In a second mode, the system may cause torque transmission between the driven member and the driving member by setting a desired remanent magnetization level in a magnetic component of the at least one magnetorheological fluid clutch apparatus by actuating the at least one coil in the at least one magnetorheological fluid clutch apparatus.

A torque generating device includes a magnetic disk configured to rotate around a rotation axis, first and second yokes located on opposite sides across the magnetic disk, a coil disposed to overlap the magnetic disk along a direction of the rotation axis, a third yoke of which at least a region proximity to the magnetic disk is located outside the magnetic disk and the coil and that makes up a magnetic path of a magnetic field generated by the coil with the first and second yokes, and a magnetic viscous fluid filled between the magnetic disk and the first and second yokes. The third yoke has a magnetic gap between the third and first yokes. The magnetic gap is formed at a position outside an outer peripheral edge of the magnetic disk or overlapping the outer peripheral edge of the magnetic disk along the direction of the rotation axis.

A magnetorheological fluid clutch apparatus comprises an input(s) having an input shear surface(s). An output(s) is rotatably mounted about the input for rotating about a common axis with the input, the output(s) having output shear surface(s), the input shear surface and the output shear surface separated annular space(s). with magnetorheological 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. An electromagnet(s) delivers a magnetic field through the magnetorheological fluid, the electromagnet configured to vary the strength of the magnetic field, whereby actuation of the electromagnet results in torque transmission from the input to the output. A member(s) defining at least one of the shear surfaces is made of a low-permeability material.

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.

A mechanical actuator system has variable and controllable mechanical impedance. Such a mechanical actuator system may be used to effectuate a degree of freedom in a robot, i.e., to control speed, output torque and direction of movement of a robotic component, such as a joint, wheel, arm, wrist or grabber. Mechanical impedance, i.e., an amount of “resistance” the robot presents to a human user, can be controlled for safety and rehabilitation purposes. The mechanical actuator system includes a mechanical differential and two adjustable-engagement clutches driven by motor. Advantageously, the motor may turn at a constant speed and direction, yet the mechanical actuator system can be controlled to turn in either direction and at a desired speed. The adjustable-engagement clutches may be electrorheological (ER) fluid clutches, magnetorheological (MR) fluid clutches, conventional dry friction clutches or any other type of clutch whose degrees of engagement can be controlled.