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 hydraulic fluid system is disclosed and that utilizes a hydraulic motor or gear pump and a magneto-rheological fluid (MRF) brake that is interconnected with an output of the hydraulic motor. The MRF brake may utilize a rotatable rotor that is disposed within a magneto-rheological fluid and that is interconnected with an output (e.g., a rotatable output shaft) of the hydraulic motor. An electrical control signal may be provided to the MRF brake (e.g., to a magnetic coil) to adjust the viscosity of the magneto-rheological fluid, and thereby a braking torque exerted on the output of the hydraulic motor.

A hydraulic fluid system is disclosed herein. The hydraulic fluid system includes a hydraulic motor including an output shaft, a reduction gear box having a first side and an opposing second side, the reduction gear box being coupled to the output shaft at the first side and coupled to a reduction shaft at the second side, and a magneto-rheological fluid brake (MRF) brake coupled to the reduction shaft.

A magnetorheological braking device with a fixed holder and a first and second braking component. One of the braking components is connected to the holder and does not rotate relative thereto. The two braking components are continuously rotatable relative to one another. The first braking component extends axially, and the second braking component has a hollow shell part extending around the first braking component. A peripheral gap, filled with a magnetorheological medium, is formed between the first and second braking component. The first braking component has an electric coil and a magnetically conductive core extending axially. Magnetic field concentrators, on the core and/or the shell part, protrude into the gap, creating variable gap height. The electric coil is wound around a section of the core. A magnetic field of the electric coil runs through the core, magnetic field concentrators, and the gap into a wall of the shell part.

This disclosure relates to a magnetorheological (MR) brake. The MR brake includes a rotor constructed at least partially of a ferromagnetic material, and a housing that supports the rotor such that the rotor and the housing are rotatable relative to each other about an axis, wherein the housing and rotor are configured such that a fluid gap is defined between the housing and the rotor, and wherein portions of the housing adjacent the rotor are constructed at least partially of a ferromagnetic material. An MR fluid is disposed in the fluid gap. A current-carrying coil is excitable to generate a magnetic field within ferromagnetic portions of the rotor and the housing and acts on the MR fluid. At least one element constructed of a material having low magnetic permeability is configured route the lines of magnetic flux through surrounding higher permeability material on opposite sides of the fluid gap.

A tactile feedback device (TFD) drum brake has a drum rotor that creates at least two gaps and at least four shear surfaces. Magnetically responsive (MR) material is disposed within the gaps. The TFD drum brake further has an upper and lower magnetic seal to prevent the migration of the MR material from the gaps. The drum rotor is thin and rapidly saturates when a magnetic flux is generated. Controllable torque is created when the drum rotor is saturated. The controllable torque provides feedback to an operator of vehicle with the TFD drum brake installed.

Described are various embodiments of a haptic braking device and parallel hybrid actuator system using same. In one embodiment, the braking device comprises a fixed elongated shaft member having a first end directly or indirectly affixed to a non-rotating surface, the fixed elongated shaft member comprising a driving member coupled along a length thereof configured to drive a change a rheological property of a damping substance. A rotatable brake housing is configured to be rotationally coupled to a motor shaft via a transmission, comprises an elongated aperture defined within fittingly receiving said shaft member therethrough and configured to allow said housing to rotate around said shaft member. A channel defined within the housing filled with the damping substance is in physical contact with the shaft member and the driving member upon activation increases a frictional resistance to a rotational motion of the housing around said shaft member.

A magnetorheological braking device has two braking components that are continuously rotatable relative to one another. A first braking component extends in the axial direction and the second braking component includes a hollow casing extending around the first braking component. A peripheral gap is filled with a magnetorheological medium. The first braking component has an electric coil and a magnetically conductive core which extends in the axial direction. A star contour with magnetic field concentrators on the core and/or on the shell part project into the gap, which results in a peripheral gap region with a variable gap height. The electric coil is wound around the core such that a magnetic field runs through the core and the magnetic field concentrators and through the gap into a wall of the casing. A star contour is formed by a stack of star plates.

A rotational resistance apparatus includes a rotational shaft member including a first shaft portion, a second shaft portion, and a third shaft portion disposed between the first and second shaft portions and having a diameter larger than that of each of the first and second shaft portions, and the rotational shaft member being made of a magnetic material, a housing member configured to hold the rotational shaft member and made of a magnetic material, a first coil disposed between an outer circumferential surface of the first shaft portion and an inner circumferential surface of the housing member, a second coil disposed between an outer circumferential surface of the second shaft portion and the inner circumferential surface of the housing member, and a magnetic viscose fluid disposed between an outer circumferential surface of the third shaft portion and the inner circumferential surface of the housing member.

A haptic operating device having a magnetorheological braking device, a stationary holder, and two brake components. One of the brake components is connected to the holder for fixed rotation therewith. The brake components can be continuously rotated relative to one another about a rotation axis. A first brake component extends along the rotation axis and has a magnetically conductive core. The second brake component has a hollow casing part extending around the first brake component. Axially spaced apart peripheral braking gap portions formed between the first and second brake components are at least partially filled with a magnetorheological medium. At least one third braking gap portion is located axially between a first and a second braking gap portion. A first electric coil is assigned to the first braking gap portion and a separately controllable second electric coil is assigned to the second braking gap portion.