The present invention provides a zero-steering hydraulic drive axle, which includes: a housing, and the housing is internally provided with a first drive assembly. One end of the first drive assembly is connected to an external power input device for power input, and the other end of the first drive assembly is connected to an external rotation output device. The first drive assembly includes: a plunger pump and a plunger motor. One end of the plunger pump is matched with the power input device, and the other end of the plunger pump is connected to an external oil pipe for oil feeding or supplementing. The plunger motor is matched with the rotation output device. The present invention is simple in overall structure, stable in power output, capable of realizing stepless speed change and pivot steering and turning, and wider in application scene range.

A drive train configuration is disclosed. The drive train incorporates an engine having hydraulic pumps contained substantially inside the engine housing and with an engine shaft driving the hydraulic pumps. A porting block or center section is mounted to the engine housing to provide hydraulic communication between the hydraulic pumps located inside the engine housing and hydraulic motors located outside the engine housing. The hydraulic motor output shafts drive gears connected to axles to propel a vehicle.

A hydrostatic driveline has a power source and a hydrostatic pump in driving engagement with the power source; a primary driveline shaft in driving engagement with the power source. The driveline also has a first transmission portion and a second transmission portion in driving engagement with the first transmission portion. A hydrostatic motor is in fluid communication with the hydrostatic pump and is in driving engagement with the first transmission portion. A vehicle output is in driving engagement with the second transmission portion. The primary driveline shaft is also in driving engagement with the second transmission portion. The hydrostatic driveline may be operated in a hydrostatic mode or in a direct drive mode using the primary driveline shaft and the second transmission portion.

A drive assembly having a housing forming an internal sump for a transmission, and an accumulator chamber formed in the housing and in fluid communication with the sump. A piston chamber in the housing is in fluid communication with the accumulator chamber. The transmission includes a pump, a pump running surface and an internal porting system in a center section, and a pump swash plate. A piston divides the piston chamber into first and second portions. The piston is biased by a spring force to pressurize hydraulic fluid in the piston chamber and thereby pressurize the hydraulic fluid in the internal sump when pressure in the piston chamber decreases below a set level. A second transmission may also be located in the housing.

A dual drive driveline for a vehicle has a power source, a hydrostatic pump drivingly engaged with the power source, a first axle, a second axle, and a first hydrostatic unit in fluid communication with the hydrostatic pump. The first hydrostatic unit is drivingly engaged or selectively drivingly engaged with the first axle, and the first hydrostatic unit is not drivingly engageable with the second axle. A second hydrostatic unit in fluid communication with the hydrostatic pump, the second hydrostatic unit being drivingly engaged or selectively drivingly engaged with the second axle, and the second hydrostatic unit not being drivingly engageable with the first axle. A control unit is adapted to control a hydraulic displacement of at least one of the hydrostatic pump, the first hydrostatic unit and the second hydrostatic unit.

The invention relates to a dual motor hydraulic hybrid transmission. The transmission comprises a power source, a hydraulic circuit including a pump drivingly engaged with the power source and two displacement units, a hydraulic accumulator assembly including high and low pressure accumulators, one or more control valves, and an output shaft drivingly engaged with the first hydraulic displacement unit. The displacement units are in fluid communication with the hydraulic pump. The accumulators are in fluid communication with the hydraulic circuit. The second hydraulic displacement unit is drivingly engaged with the output shaft. The control valves are configured to selectively fluidly connect the hydraulic pump to the first hydraulic displacement unit while fluidly disconnecting the hydraulic pump from the second hydraulic displacement unit; and, simultaneously, fluidly connect the hydraulic accumulator assembly to the second hydraulic displacement unit while fluidly disconnecting the hydraulic accumulator assembly from first hydraulic displacement unit.

A working vehicle includes a first hydraulic pump (e.g., a variable displacement pump) with a delivery flow rate controlled by load sensing control, a second hydraulic pump (e.g., a fixed displacement pump), at least one working-machine-related control valve to control at least one working-machine-related hydraulic actuator, a power shift valve to control at least one traveling-power-transmission-related hydraulic actuator, and a power steering controller to control a steering-related hydraulic actuator. The at least one working-machine-related control valve is provided in a first hydraulic system supplied with hydraulic fluid by the first hydraulic pump, and at least one of the power shift valve or the power steering controller is provided in a second hydraulic system supplied with hydraulic fluid by the second hydraulic pump.

A transmission combination includes a hydrostatic transmission and a mechanical transmission having a clutch and a control device for calibrating a grinding point of the clutch. A traction drive includes the transmission combination. A method includes calibrating the clutch.

A transmission device with secondarily coupled power splitting, having hydrostatic and mechanical branches which can be summed by a summing gear system provided in the area of a central transmission shaft. At least two transmission ratio ranges, in the forward and reverse driving directions, can be obtained such that within the transmission ratio ranges the transmission ratio can, in each case, be varied continuously by a hydrostatic variator in the area of the hydrostatic branch. On the transmission input side, the central transmission shaft can directly couple a drive engine and functionally connect to both an auxiliary drive output shaft and a hydrostatic shaft of the variator, in the form of countershafts, and also to hydraulic pumps in the area of the transmission input. In the area of the transmission output, the central transmission shaft is coupled to a further hydrostatic shaft in the form of a countershaft.

A hydrostatic driveline and method of operating a hydrostatic driveline is provided. The hydrostatic driveline comprises a power source, hydrostatic pump, a hydrostatic motor, a direct drive link, a first transmission portion, and a second transmission portion. The direct drive link is in driving engagement with at least one of the power source and the hydrostatic pump. The first transmission portion is in driving engagement with a vehicle output and the hydrostatic motor. The second transmission portion is in driving engagement with the direct drive link and at least one of the vehicle output and the first transmission portion. The hydrostatic pump, the hydrostatic motor, and the first transmission portion form a first power path for the hydrostatic driveline and the direct drive link and the second transmission portion form a second power path for the hydrostatic driveline.