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.

The present device relates to means for the individual training of highly-qualified athletes in cyclic sports. The technical result is the more reliable transfer of power from a drive to a working mechanism with the possibility of smoothing out ultrashort fluctuations (0.3-0.7 seconds) in force. The athlete training device comprises two spaced-apart bases, each having a pulley attached thereto for rotation in a single plane. An annular cable track is fastened between the pulleys, to which track a lanyard is secured by one end, the other end of the lanyard being fastened to a device for attaching the athlete. With the aid of a motor, a rotation rate is transmitted to one of the pulleys via a shaft. The shaft, which consists of a driving part and a driven part, has mounted thereon an adjustable transmission for controlling torque. The adjustable transmission is in the form of an electromagnetic powder clutch, consisting of a driving part, connected to the driving part of the shaft, and a driven part, connected to the driven part of the shaft. The driving and driven parts of the clutch are configured in the form of steel cylinders. An annular groove in the driven part contains an excitation winding, which is connected via slip rings and brushes to a dc power supply. The driven part of the clutch is mounted with clearance in a coaxial cavity in the driving part, the clearance gap between the driving part and the driven part of the clutch containing a ferromagnetic powder, the viscosity of which is adjusted by a clutch controller.

A rheological lock apparatus includes a fluid chamber formed within a housing between a pair of seals. The fluid chamber contains a rheological fluid. An inner surface of the housing has a first plurality of splines projecting into the fluid chamber and extending longitudinally along a longitudinal dimension of the chamber. A driveshaft extends axially through the chamber such that the pair of seals are sealed against the driveshaft. The driveshaft includes a second plurality of splines. A field generator is coupled to one of the driveshaft or the housing to generate a field through the rheological fluid during times when the housing is substantially immobile in a borehole.

Electronic devices, such as consumer electronics devices and constrol systems in vehicles are controlled by way of a haptic operating device with a rotating unit. Selectable menu items are displayed on a display unit, and a menu item is selected by rotating the rotating unit. The rotating unit latches at a number of haptically perceptible latching points during rotation. The number and rotational position of the haptically perceptible latching points is dynamically changed in accordance with a specific menu item selected by the user.