A propel system of an agricultural vehicle has an active pump displacement control system for equalizing or balancing pressure output of hydrostatic pumps of a tandem pump propel arrangement. The active pump displacement control system may include a pressure sensor(s) for determining output pressure of hydrostatic pumps and use the output pressure values within a feedback loop to provide coil input values of coils that control displacement of the hydrostatic pumps so that the pressure outputted by the hydrostatic pumps can be equalized in real-time while on the go during use of the agricultural vehicle.

A method for executing straight tracking control may include receiving an input command(s) associated with controlling the operation of a first-side drive system and/or a second-side drive system of a hydrostatic transmission of a work vehicle to drive the vehicle along a straight path. The method may also include receiving first and second speed signals associated with the output speeds of the drive systems, and modifying the first speed signal or the second speed signal based on a speed scaling factor to generate a corrected speed signal. In addition, the method may include determining an adjusted control command for controlling the operation of the hydrostatic transmission as a function of the input command(s) and a control output determined based on the corrected speed signal. Further, the method may include controlling the operation of the hydrostatic transmission based at least in part on the adjusted control command.

A method for executing straight tracking control may include receiving an input command(s) associated with controlling the operation of a first-side drive system and/or a second-side drive system of a hydrostatic transmission of a work vehicle to drive the vehicle along a straight path. The method may also include receiving first and second speed signals associated with the output speeds of the drive systems, and modifying the first speed signal or the second speed signal based on a speed scaling factor to generate a corrected speed signal. In addition, the method may include determining an adjusted control command for controlling the operation of the hydrostatic transmission as a function of the input command(s) and a control output determined based on the corrected speed signal. Further, the method may include controlling the operation of the hydrostatic transmission based at least in part on the adjusted control command.

This disclosure generally relates to an automatic bicycle, particularly to a hydraulic automatic transmission bicycle which can automatically and adaptively change gear ratios. More particularly, this disclosure relates to those hydraulic automatic transmission bicycles which use fluid pressure to change such gear ratios, and which include various hydraulic automatic transmissions which may be provided in various configurations and may operate in various methods and sequences to provide automatic and infinitely variable gear ratios.

This disclosure generally relates to an automatic bicycle, particularly to a hydraulic automatic transmission bicycle which can automatically and adaptively change gear ratios. More particularly, this disclosure relates to those hydraulic automatic transmission bicycles which use fluid pressure to change such gear ratios, and which include various hydraulic automatic transmissions which may be provided in various configurations and may operate in various methods and sequences to provide automatic and infinitely variable gear ratios.

This disclosure generally relates to an automatic bicycle, particularly to a hydraulic automatic transmission bicycle which can automatically and adaptively change gear ratios. More particularly, this disclosure relates to those hydraulic automatic transmission bicycles which use fluid pressure to change such gear ratios, and which include various hydraulic automatic transmissions which may be provided in various configurations and may operate in various methods and sequences to provide automatic and infinitely variable gear ratios.

This disclosure generally relates to an automatic bicycle, particularly to a hydraulic automatic transmission bicycle which can automatically and adaptively change gear ratios. More particularly, this disclosure relates to those hydraulic automatic transmission bicycles which use fluid pressure to change such gear ratios, and which include various hydraulic automatic transmissions which may be provided in various configurations and may operate in various methods and sequences to provide automatic and infinitely variable gear ratios.

In one aspect, a system for controlling the torsional output of a hydrostatic transmission of a work vehicle may include pilot-operated first and second valves. The first valve configured to be actuated to a closed position to occlude fluid flow through a first fluid conduit when a pressure within such conduit at a location downstream of the first valve drops below a first threshold. Moreover, the second valve configured to be actuated to a closed position to occlude fluid flow when a pressure within the second fluid conduit at a location downstream of the second valve drops below a second threshold. As such, when one of the first or second valves is actuated to the closed position, an increased flow of fluid is delivered through the other of the first valve or the second valve to increase a torsional output of an associated hydraulic motor.

In one aspect, a system for controlling the torsional output of a hydrostatic transmission of a work vehicle may include pilot-operated first and second valves. The first valve configured to be actuated to a closed position to occlude fluid flow through a first fluid conduit when a pressure within such conduit at a location downstream of the first valve drops below a first threshold. Moreover, the second valve configured to be actuated to a closed position to occlude fluid flow when a pressure within the second fluid conduit at a location downstream of the second valve drops below a second threshold. As such, when one of the first or second valves is actuated to the closed position, an increased flow of fluid is delivered through the other of the first valve or the second valve to increase a torsional output of an associated hydraulic motor.

A hydraulic fracturing system for fracturing a subterranean formation is described according to various embodiments. In an embodiment, the system can include a multi-plunger hydraulic fracturing pump fluidly connected to a well associated with the subterranean formation, the multi-plunger pump configured to pump fluid into a wellbore associated with the well at a high pressure so that the fluid passes from the wellbore into the subterranean formation and fractures the subterranean formation. In an embodiment, a plurality of motors can be positioned to power the multi-plunger pump, and a planetary gear train can have a plurality of pinion gears in rotational contact with each of the plurality of motors. In an embodiment, a gear ratio of the planetary gear train and a speed at which the plurality of motors operates can be selected so as to limit a maximum pump speed associated with the multi-plunger pump.