A system including a gearbox and a hydraulic machine connected by a working fluid circuit. The gearbox including a gearbox housing having first and second gearbox fluid passages integrated into the gearbox housing. The hydraulic machine including a case having first and second hydraulic machine fluid passages, the first and second hydraulic machine fluid passages being integrated into the case. A set of rotating elements enclosed within the case. The first gearbox fluid passage and the first hydraulic machine fluid passage align to form a feed passage to conduct fluid at a first pressure from a first source to the set of rotating elements. The second gearbox fluid passage and the second hydraulic machine fluid passage align to form a charge passage to conduct fluid at a second pressure from a second source to the set of rotating elements. The first pressure being less than the second pressure.

A system including a gearbox and a hydraulic machine connected by a working fluid circuit. The gearbox including a gearbox housing having first and second gearbox fluid passages integrated into the gearbox housing. The hydraulic machine including a case having first and second hydraulic machine fluid passages, the first and second hydraulic machine fluid passages being integrated into the case. A set of rotating elements enclosed within the case. The first gearbox fluid passage and the first hydraulic machine fluid passage align to form a feed passage to conduct fluid at a first pressure from a first source to the set of rotating elements. The second gearbox fluid passage and the second hydraulic machine fluid passage align to form a charge passage to conduct fluid at a second pressure from a second source to the set of rotating elements. The first pressure being less than the second pressure.

An HST circuit has a hydraulic pump that converts a drive force of an engine into energy of oil, and a hydraulic motor that converts the energy of the oil converted by the hydraulic pump into drive energy. Pressure sensors detect a pressure of the oil within the HST circuit. A variable charge pump replenishes the oil into the HST circuit. A controller controls a capacity of the variable charge pump based on the pressure of the oil within the HST circuit detected by the pressure sensors.

A transmission system for a feed mixer including a continuously variable transmission (CVT) is provided. The CVT includes a mechanical loop and a hydrostatic loop. The CVT is operated so that the mechanical portion of the CVT is prevented from overtaking the hydrostatic portion of the CVT at start up of the CVT.

Provided is a work vehicle capable of attaining a maximum vehicle speed specification value set in advance for each vehicle body even in the case where a device constituting an HST traveling drive system has deteriorated over time. In a wheel loader 1 equipped with an HST traveling drive system, a controller 5 is configured to, in the case where a detection pressure value P is equal to or less than a switching pressure value Ps corresponding to a switching point in the HST motor 42 between a maximum displacement volume qmax and a minimum displacement volume qmin, and a detection vehicle speed value V is less than an upper limit vehicle speed specification value Vmaxs, limit the minimum displacement volume qmin of the HST motor 42 to a first minimum displacement volume value qmin1 less than a minimum displacement volume specification value qmins that is associated with the upper limit vehicle speed specification value Vmaxs.

A control system for a hydrostatic drive system can include a hydraulic charge pump circuit having a hydraulic load and a tank. The hydraulic charge pump can be in fluid communication with the hydraulic charge pump circuit. A bypass line can extend to the tank from a junction between the hydraulic charge pump and the hydraulic load. A charge bypass valve can be disposed to control flow through the bypass line. The control system can include a control device configured to determine one or more operational parameters for the power machine and control the charge bypass valve to allow flow through the bypass line, from the hydraulic charge pump to the tank, based on the determined operational parameters during a starting operation.

A control system for a hydrostatic drive system can include a hydraulic charge pump circuit having a hydraulic load and a tank. The hydraulic charge pump can be in fluid communication with the hydraulic charge pump circuit. A bypass line can extend to the tank from a junction between the hydraulic charge pump and the hydraulic load. A charge bypass valve can be disposed to control flow through the bypass line. The control system can include a control device configured to determine one or more operational parameters for the power machine and control the charge bypass valve to allow flow through the bypass line, from the hydraulic charge pump to the tank, based on the determined operational parameters during a starting operation.

A control system for a hydrostatic drive system can include a hydraulic charge pump circuit having a hydraulic load and a tank. The hydraulic charge pump can be in fluid communication with the hydraulic charge pump circuit. A bypass line can extend to the tank from a junction between the hydraulic charge pump and the hydraulic load. A charge bypass valve can be disposed to control flow through the bypass line. The control system can include a control device configured to determine one or more operational parameters for the power machine and control the charge bypass valve to allow flow through the bypass line, from the hydraulic charge pump to the tank, based on the determined operational parameters during a starting operation.

A harvester is provided with a draper head that has a frame extending substantially across a working width of the draper head. Cutting elements are arranged at a front side of the draper head and connected to the frame. Conveying surfaces and conveying members transport cut crop from the cutting elements to a discharge location of the draper head. A reel extends transversely to a working direction of the draper head across the working width of the draper head. Reel support arms are pivotably supported on the frame and support the reel. A hydraulic adjusting drive is operatively connected to the reel support arms to pivot the reel support arms to carry out a height adjustment of the reel. A hydraulic circuit is operatively connected to the hydraulic adjusting drive and has a hydraulic valve that is able to lock the hydraulic circuit.

A transmission system includes a power take-off for driving an implement and a hydrostatic unit for transmitting power from the engine to the power take-off. The hydrostatic unit includes a first hydraulic power unit having a first connection line and a second connection line, and a second hydraulic power unit having a first connection line and a second connection line. The hydrostatic unit also includes a valve for connecting the first hydraulic power unit and the second hydraulic power unit, the valve being positionable at least in a first position a first position and in a second position.