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 servovalve includes a supply port and a control port; a moveable valve spool arranged to regulate flow of fluid from the supply port to the control port in response to a control signal and a drive assembly configured to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow; wherein the drive assembly comprises a first fluid channel providing a flow path for fluid from the supply port to a first end of the spool and provided with a first flow control orifice. The assembly also includes a second fluid channel providing a rotating element provided with a cam profile located between the first flow control orifice and the second flow control orifice. The assembly also includes drive means arranged to rotate the rotating element.

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 apparatus configured to supply track-setting devices for producing a cross-country skiing trail; the apparatus comprising: a first inlet configured to receive a fluid; a first outlet and a second outlet configured to release two flows of fluid; a first hydraulic coupling motor having a second inlet, a third outlet and a first shaft; and a second hydraulic coupling motor having a third inlet, a fourth outlet and a second shaft; wherein the second inlet and the third inlet are connected to the first inlet, and the first shaft and the second shaft are integrally connected to each other, the third outlet being connected to the first outlet, and the fourth outlet being connected to the second outlet.

A servovalve includes a supply port and a control port; a moveable valve spool arranged to regulate flow of fluid from the supply port to the control port in response to a control signal and a drive assembly configured to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow; wherein the drive assembly comprises a first fluid channel providing a flow path for fluid from the supply port to a first end of the spool and provided with a first flow control orifice. The assembly also includes a second fluid channel providing a rotating element provided with a cam profile located between the first flow control orifice and the second flow control orifice. The assembly also includes drive means arranged to rotate the rotating element.

A servovalve includes a fluid transfer valve assembly comprising a supply port and a control port a moveable valve spool arranged to regulate flow of fluid from the supply port to the control port in response to a control signal; and a jet pipe assembly configured to direct fluid to the ends of the spool to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow. The jet pipe assembly includes a jet pipe and a connector header fluidly connecting the jet pipe to a nozzle via which fluid is directed to the spool ends. One or more openings is provided in the spool such that fluid from the supply port flows into the interior of the spool and into the jet pipe and to the nozzle via the connector header.

A flow divider assembly for use with a hydraulic pump provides flow to separate drive motors for use in a vehicle or other application. A pair of flow divider motors may be mounted on a block and have a common axis of rotation. The ratio between the two may be controlled by adjustment of the angles of the respective thrust bearings of the flow divider motors. A valve may connect the outlet of one of the flow divider motors or the outlet of the other flow divider motor. passage to the second outlet passage. Additional bypass valves may be provided to permit direct connection between the hydraulic pump and the separate drive motors.

A flow divider assembly for use with a hydraulic pump provides fluid flow to separate drive motors for use in a vehicle or other application. Flow may be provided alternatively to a first fluid side and second fluid side. First and second flow divider motors are in communication with an output of a shuttle valve. A first bypass valve is connected to the first fluid side and a second bypass valve is connected to the second fluid side, and both bypass valves have an open position and a closed position. A multi-position, pilot operated valve is operably connected to both flow divider motors and to both bypass valves. An embodiment permits the output of the system to be driven in either forward or reverse directions.

A hydraulic apparatus configured to supply track-setting devices for producing a cross-country skiing trail; the apparatus comprising: a first inlet configured to receive a fluid; a first outlet and a second outlet configured to release two flows of fluid; a first hydraulic coupling motor having a second inlet, a third outlet and a first shaft; and a second hydraulic coupling motor having a third inlet, a fourth outlet and a second shaft; wherein the second inlet and the third inlet are connected to the first inlet, and the first shaft and the second shaft are integrally connected to each other, the third outlet being connected to the first outlet, and the fourth outlet being connected to the second outlet.

A servovalve includes a fluid transfer valve assembly comprising a supply port and a control port a moveable valve spool arranged to regulate flow of fluid from the supply port to the control port in response to a control signal; and a jet pipe assembly configured to direct fluid to the ends of the spool to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow. The jet pipe assembly includes a jet pipe and a connector header fluidly connecting the jet pipe to a nozzle via which fluid is directed to the spool ends. One or more openings is provided in the spool such that fluid from the supply port flows into the interior of the spool and into the jet pipe and to the nozzle via the connector header.