A hybrid system, consisting of an internal combustion engine (1) with added-on and/or integrated hydraulic pumps (2) to supply consumers (5) and/or the drive unit (12), at least one engine control unit (3) for electronic engine regulation and/or fuel-injection regulation, at least one hydraulic control unit (4) to control at least one hydraulic consumer (5), at least one pressure sustaining valve (6), at least one reversing valve (7) and at least one hydraulic pressure accumulator (8).

A series hydraulic hybrid driveline for a vehicle, having a hydraulic circuit with a first hydraulic displacement unit in fluid communication with a second hydraulic displacement unit, the first hydraulic displacement unit having a variable hydraulic displacement and the first hydraulic displacement unit being drivingly engaged with an internal combustion engine. A hydraulic accumulator assembly selectively fluidly connected to the hydraulic circuit, the hydraulic accumulator assembly having a high pressure hydraulic accumulator and a low pressure hydraulic accumulator. And a hydraulic actuator adapted to control the hydraulic displacement of the first hydraulic displacement unit, the hydraulic actuator being in fluid communication with the hydraulic accumulator assembly and/or with the hydraulic circuit. A method of shutting down an engine of a series hydraulic hybrid driveline and of re-starting the engine of a series hydraulic hybrid driveline using energy stored in a hydraulic accumulator assembly is also described.

Systems and apparatuses are disclosed that include a plurality of hydraulic vaned devices arranged in-line with one another such as along a drive line of a vehicle. Various system operation modes achieved by such devices in the in-line arrangement are also disclosed.

A variable displacement hydrostatic power unit (7) is in a drive connection with an internal combustion engine (2). When operated as a pump, the power unit (7) delivers hydraulic fluid to at least one consumer (V). When operated as a motor, the power unit (7) is a hydraulic starter for the internal combustion engine (2) and is supplied with hydraulic fluid from a hydraulic accumulator (25). The displacement volume of the power unit (7) is set by a displacement volume control device (50) actuated by a positioning device (52). The displacement volume control device (50) is displaced into a position with maximum displacement volume by a corresponding actuation of the positioning device (52) chronologically prior to the shutoff of the internal combustion engine (2). A securing device (60) holds the displacement volume control device (50) in the maximum displacement volume position when the internal combustion engine (2) is shut off.

A work vehicle includes a control unit having a motor switch control unit and a motor command determining unit. The motor switch control unit controls a motor switching mechanism so that a third motor connects to a first motor when a first rotation speed is less than a second rotation speed. The first rotation speed is the rotation speed of the first motor corresponding to that of a rotating shaft of the third motor. The second rotation speed is the rotation speed of the second motor corresponding to that of a rotating shaft of the third motor. When the third motor is connected to the first motor, the motor command determining unit determines a command torque for the first motor and the third motor so that the command torque for the third motor is no more than the command torque for the first motor.

A hydrostatic power unit (2) comprises a variable displacement machine with a continuously variable displacement volume and is operated as a pump and motor and is in a drive connection with an internal combustion engine (3). When operated as a pump, the power unit sucks hydraulic fluid out of a tank (9) and delivers into a delivery side (P), and, when operated as a motor, functions as a hydraulic starter to start the internal combustion engine (3). When operated as a motor, the power unit is supplied with hydraulic fluid from a hydraulic accumulator (30). The displacement volume of the power unit (2) is set by a displacement volume control device (60) actuated by a positioning piston device (61) supplied with hydraulic fluid from a charging pressure circuit (23). The power unit (2) includes a supplemental positioning piston device (80) in an operative connection with the displacement volume control device (60) and which is actuated directly by the pressure present in the hydraulic accumulator (30). By means of a connection of the supplemental positioning piston device (80) with the hydraulic accumulator, the power unit (2) can be adjusted to increase the displacement volume to start the internal combustion engine (3).

A vehicle having a device that uses an input provided from a first hydraulic system to charge one or more other hydraulic systems. The first hydraulic system can be a vehicle brake system or a hydraulic system having an electrically operated pump. The hydraulic systems to be charged could include an engine lubrication system and/or a transmission hydraulic control system.

An implement system is disclosed for use with a machine having an engine. The implement system may have a pump driven by the engine, a first actuator configured to receive pressurized fluid from the pump during operation of the engine, and at least a second actuator configure to receive pressurized fluid from the pump during operation of the engine. The implement system may also have an accumulator configured to receive pressurized fluid from the first actuator during operation of the engine, and to discharge fluid to the first actuator and to the at least a second actuator when the engine is shut down.

Method for controlling a refilling motor (2) that drives a hydraulic pump (4) that refills at least one pressure accumulator (8), this accumulator thereafter delivering the hydraulic pressure (P) to a hydraulic traction machine (20) of a hybrid vehicle, characterized in that it takes account both of the rate of discharge of the pressure accumulator (8) and of the time to start (i) the refilling motor (2) so as to manage this start in such a way that this accumulator more or less reaches its minimum operating pressure level (PI) at the end of this start (t1).