A hydro-mechanical hybrid transmission device with two hydraulic transmission mechanisms includes an input member, a second hydraulic transmission mechanism, a rear planetary gear mechanism, an output member, a first hydraulic transmission mechanism, a front planetary gear mechanism, a clutch assembly, and a brake assembly. The clutch assembly connects the input member to the front planetary gear mechanism, the second hydraulic transmission mechanism, and the first hydraulic transmission mechanism, connects an output end of the first hydraulic transmission mechanism to the front planetary gear mechanism, connects the rear planetary gear mechanism to an output end of the second hydraulic transmission mechanism and the front planetary gear mechanism, and connects the rear planetary gear mechanism to the output member. The clutch assembly and the brake assembly provide a continuous transmission ratio between the input member and the output member.

A hydraulic system according to the present invention includes a rotational shaft, a hydraulic rotor supported by the rotational shaft so as to be incapable of relative rotation, an output adjuster varying a volume of the hydraulic rotor, a control shaft tilting the output adjuster, a drive motor operating the control shaft around the axis, a drive shaft disposed on a reference axis same as the axis of the control shaft and operably driven around the axis by the drive motor, a deceleration mechanism decelerating rotary power input from the drive shaft and outputs the decelerated rotary power toward the control shaft, and a housing accommodating the hydraulic rotor, the output adjuster, and the deceleration mechanism, wherein the deceleration mechanism has a hypocycloid-type deceleration mechanism disposed on the reference axis.

A transmission device (1) with secondarily coupled power splitting in which part of an applied torque can be conducted, in a first power branch (3) at least by way of a hydrostatic system (4), and the other part of the torque can be conducted in a second power branch (5) via mechanical system (6), located between a transmission input (7) and a transmission output (8). The hydrostatic system (4) of the first power branch (3) includes at least one pump (12) and at least one motor (13) that is functionally connected to the pump by way of a hydraulic circuit, and both of the pump and motor are adjustable. The two power paths (3, 5) can be summed by a summing gear system (9). The pump (12) is made smaller than the motor (13).

In a hydraulic motor and a hydrostatic traction drive with such a hydraulic motor, the regulating of the displacement of the hydraulic motor is done via a pilot-operated pressure regulator. The feedforward controller calculates an estimated motor displacement and relays this to the pressure regulator.

A hydro-mechanical hybrid transmission device with two hydraulic transmission mechanisms includes an input member, a second hydraulic transmission mechanism, a rear planetary gear mechanism, an output member, a first hydraulic transmission mechanism, a front planetary gear mechanism, a clutch assembly, and a brake assembly. The clutch assembly connects the input member to the front planetary gear mechanism, the second hydraulic transmission mechanism, and the first hydraulic transmission mechanism, connects an output end of the first hydraulic transmission mechanism to the front planetary gear mechanism, connects the rear planetary gear mechanism to an output end of the second hydraulic transmission mechanism and the front planetary gear mechanism, and connects the rear planetary gear mechanism to the output member. The clutch assembly and the brake assembly provide a continuous transmission ratio between the input member and the output member.

In a hydraulic motor and a hydrostatic traction drive with such a hydraulic motor, the regulating of the displacement of the hydraulic motor is done via a pilot-operated pressure regulator. The feedforward controller calculates an estimated motor displacement and relays this to the pressure regulator.

A hydrostatic traction drive includes a hydraulic pump for supplying pressure medium to a hydraulic motor of the traction drive. The hydraulic pump has an actuation cylinder with at least one cylinder space and a swept volume which can be adjusted thereby. At least one electrically actuable pressure valve is provided, by means of which an actuation pressure which has an adjusting effect can be applied to the cylinder space. In addition, the traction drive has a device by means of which a pressure of the hydraulic pump can be limited by influencing the actuation pressure.

A hydraulic system according to the present invention includes a rotational shaft, a hydraulic rotor supported by the rotational shaft so as to be incapable of relative rotation, an output adjuster varying a volume of the hydraulic rotor, a control shaft tilting the output adjuster, a drive motor operating the control shaft around the axis, a drive shaft disposed on a reference axis same as the axis of the control shaft and operably driven around the axis by the drive motor, a deceleration mechanism decelerating rotary power input from the drive shaft and outputs the decelerated rotary power toward the control shaft, and a housing accommodating the hydraulic rotor, the output adjuster, and the deceleration mechanism, wherein the deceleration mechanism has a hypocycloid-type deceleration mechanism disposed on the reference axis.

A load cancelling hydrostatic system is disclosed comprising at least two hydrostatic modules coupled in parallel. Each hydrostatic module comprises input and output hydraulic piston drive units, each of which is coupled to its respective unit in the other module by common drive shafts. The pistons in a hydraulic piston drive unit of one module are coupled together with those in the respective unit of the other module with a timing angle of about 0. The design advantageously cancels any axial imbalances and allows for use of radial drive shaft bearings which support an essentially purely radial load. In turn, greater power density and system efficiency can be obtained.

A power split transmission has a drive shaft with a first mechanical branch comprising a planetary gear arrangement with at least two sun gears, a first ring gear and a planetary web, on which double planetary gears are arranged, which mesh with the sun gears and with the first ring gear, at least one of the sun gears being coupled to the drive shaft, with a continuously adjustable second branch, which can be connected at least partially to the first, mechanical branch via the planetary gear arrangement and comprises at least two adjustable hydraulic units which can be energetically coupled to one another and can be operated in each case in both directions as a motor or pump, and with an output shaft which can be coupled to the drive shaft via the first, mechanical branch and the second branch, the planetary gear arrangement being assigned a planetary reversing gear by means of which the direction of rotation of the first, mechanical branch can be reversed.