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.

A system includes a variable displacement pump (VDP) with an inlet and an outlet, a fixed displacement motor (FDM) with an inlet and an outlet. A first line connects the outlet of the VDP to the inlet of the FDM. A second line connects the outlet of the FDM to the inlet of the VDP. A crossover line is in fluid communication between the first and second lines, with a valving system in the crossover line configured so that the flow through the crossover line can switch directions to allow a change in power flow direction between the FDM and the VDP.

The invention relates to a self-maintenance system (1) for a vehicle hydraulic assistance device (2), the said device (2) comprising a hydraulic machine (21, 23), the said hydraulic machine (21, 23) being configured to be brought into operation, or deactivated, alternately, the bringing-into-operation and the deactivation being afforded by movement of bringing-into-operation moving parts (211, 231), and the engagement and disengagement of the assistance being operable on command, the system (1) comprising a control module (11) configured to command the bringing into operation of the hydraulic machine (21, 23) for a predetermined length of time and then command deactivation of the hydraulic machine (21, 23) so as to flush all or part of the hydraulic machine (21, 23), the said commands being independent of a command to engage and disengage the assistance.

The invention relates to a self-maintenance system (1) for a vehicle hydraulic assistance device (2), the said device (2) comprising a hydraulic machine (21, 23), the said hydraulic machine (21, 23) being configured to be brought into operation, or deactivated, alternately, the bringing-into-operation and the deactivation being afforded by movement of bringing-into-operation moving parts (211, 231), and the engagement and disengagement of the assistance being operable on command, the system (1) comprising a control module (11) configured to command the bringing into operation of the hydraulic machine (21, 23) for a predetermined length of time and then command deactivation of the hydraulic machine (21, 23) so as to flush all or part of the hydraulic machine (21, 23), the said commands being independent of a command to engage and disengage the assistance.

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.

A sickle knife drive for an agricultural vehicle generally includes a first pump, a first motor, a second motor and a drive manifold having a plurality of connections used for connecting to other devices of the sickle knife drive and/or to devices outside of the sickle knife drive. Operation of the first pump in a forward direction causes the first motor to drive a sickle knife gearbox to cut a crop. During the forward direction, the second motor provides cooling to the fluid circuit. When the first pump direction is reversed, the agricultural vehicle supplements a fluid flow to the fluid circuit to clear any jammed crop from the sickle knives.

The aim of the invention of for the hydrostatic drive to enable a lowering of the feed pressure provided by the feed pump and, at the same time, to effect a supply of the adjustment unit of the drive that is proper with respect to the pressure and the delivery rate. This aim is achieved in that the adjustment unit (5) of the drive is supplied with hydraulic energy by an electrohydraulic supply unit (6), wherein the supply unit (6) consists of an electric motor (7) and an auxiliary pump (8) coupled thereto and wherein the outlet of the auxiliary pump (8) is connected to the adjustment unit (5) directly or by means of a check valve (18). Hydrostatic drives according to the invention are used, for example, in self-propelled working machines.

The aim of the invention of for the hydrostatic drive to enable a lowering of the feed pressure provided by the feed pump and, at the same time, to effect a supply of the adjustment unit of the drive that is proper with respect to the pressure and the delivery rate. This aim is achieved in that the adjustment unit (5) of the drive is supplied with hydraulic energy by an electrohydraulic supply unit (6), wherein the supply unit (6) consists of an electric motor (7) and an auxiliary pump (8) coupled thereto and wherein the outlet of the auxiliary pump (8) is connected to the adjustment unit (5) directly or by means of a check valve (18). Hydrostatic drives according to the invention are used, for example, in self-propelled working machines.

A drive, which permits a lowering in the feed pressure provided by the feed pump and, at the same time, effects a supply to the displacement unit of the drive which meets the demand with regard to pressure and delivery volume. This is achieved in that the displacement unit (5) is supplied with hydraulic energy by an electro-hydraulic supply unit (6) wherein the supply unit (6) comprises a hydraulic reservoir (9) and a non-return valve (18) and is connected to the feed pressure limiting valve (12), which is implemented as an electrically adjustable pressure limiting valve, wherein the hydraulic reservoir (9) is also connected to an electro-hydraulic pressure sensor (10), which outputs the electric signal thereof to an electric auxiliary controller (11), and wherein the electric auxiliary controller (11) drives the feed pressure limiting valve (12). These hydraulic drives are used for example, in self-propelled working machines.

A drive, which permits a lowering in the feed pressure provided by the feed pump and, at the same time, effects a supply to the displacement unit of the drive which meets the demand with regard to pressure and delivery volume. This is achieved in that the displacement unit (5) is supplied with hydraulic energy by an electro-hydraulic supply unit (6) wherein the supply unit (6) comprises a hydraulic reservoir (9) and a non-return valve (18) and is connected to the feed pressure limiting valve (12), which is implemented as an electrically adjustable pressure limiting valve, wherein the hydraulic reservoir (9) is also connected to an electro-hydraulic pressure sensor (10), which outputs the electric signal thereof to an electric auxiliary controller (11), and wherein the electric auxiliary controller (11) drives the feed pressure limiting valve (12). These hydraulic drives are used for example, in self-propelled working machines.