Abstract:
Saturation of a secondary system pressure circuit (18) of a hydraulic system (4) of a motor vehicle transmission is earlier, in that an excess amount of oil from a primary system pressure circuit (16) of the hydraulic system (4) is not directed to a suction charging (40), but rather into the secondary system pressure circuit (18). This can take place via a system pressure valve (9) for the primary system pressure circuit (16), which is configured for this function.
Abstract:
A hydraulic arrangement (10) to increase a motor load is described. The hydraulic arrangement comprises a hydraulic consumer (28), a load pressure-controlled hydraulic pump (24), a hydraulic tank (26), and a hydraulic control circuit (30), connected with the hydraulic consumer (28), with which a volume flow conveyed by the hydraulic pump (24) can be changed, wherein the hydraulic control circuit (30) comprises an excess pressure valve (42) and an electronically controllable control valve (36). In order to ensure a prioritization of the hydraulic consumer with a simultaneous increase of the motor bad, a proposal is made that the hydraulic control circuit (30) comprise a load pressure-controlled pressure compensator (38) between the excess pressure valve (42) and the control valve (36).
Abstract:
A multifunction relief valve includes a relief chamber having an introduction port and a relief port for introducing and relieving pressure fluid; a back pressure chamber formed on one end side of the relief chamber; a piston which is movably provided in the back pressure chamber and divides the back pressure chamber into a first back pressure chamber and a second back pressure chamber; a first spring which is provided in the first back pressure chamber and exerts a biasing force in a direction in which the relief port is closed; a second spring which is provided in the second back pressure chamber and biases the piston in the direction in which the relief port is closed; and a pilot pressure supply port formed in the first back pressure chamber. The pressure fluid introduced into the first back pressure chamber via the pilot pressure supply port changes the relief pressure.
Abstract:
A hydraulic drive system has a variable displacement hydraulic pump; a prime mover driving the hydraulic pump; a variable displacement hydraulic motor fed hydraulic fluid by the hydraulic pump, the hydraulic motor having internal torque control and speed modulation via the variable displacement; and a shaft driven by the hydraulic motor. The prime mover is either an electric motor or an internal combustion engine, advantageously a diesel engine. The system is either an open loop hydraulic system or a closed loop hydraulic system. With the system, relatively low output prime movers are used without reduction in the systems maximum torque output.
Abstract:
A hydraulic system 10 provides a positive supply of hydraulic fluid at a controlled pressure to plurality of pumps. The system comprises a fluid reservoir 15 having outlet means to supply fluid to an auxiliary pump 30. A pressure chamber 16 communicates with a reservoir 15 and has outlet means to supply fluid to a plurality of working pumps 11, 12, 13. An inlet manifold 18 is provided for receiving fluid returned from the working and auxiliary pumps.
Abstract:
Systems and methods for electrohydraulic valve calibration are provided. In one aspect, a calibration circuit includes a calibration conduit isolated from a supply conduit, a first calibration orifice configured to provide fluid communication between the calibration conduit and a fluid source, and a second calibration orifice arranged in series with the first calibration orifice. The second calibration orifice is on a spool of a electrohydraulic control valve and is configured to selectively provide fluid communication between the calibration conduit and a low pressure source. The calibration circuit further includes a pressure sensor configured to measure a pressure in the calibration conduit between the first calibration orifice and the second calibration orifice. The second calibration orifice is isolated from the at least one workport of the electrohydraulic control valve.
Abstract:
A mixer drum driving apparatus includes an auxiliary fluid pressure pump that is provided independently of a fluid pressure pump and is capable of supplying a working fluid to a fluid pressure motor so as to cause a mixer drum to perform agitation rotation, a plurality of motors configured to drive the auxiliary fluid pressure pump to rotate, and a control unit that controls rotation of the mixer drum. When an engine is stopped during the agitation rotation of the mixer drum, the control unit drives the auxiliary fluid pressure pump to rotate by operating the plurality of motors selectively in accordance with a load of the mixer drum.
Abstract:
A hydraulic pressure supply system of an automatic transmission for a vehicle is provided. The system divides a hydraulic pressure generated from first and second pump chambers of a hydraulic pump into a high-pressure and low-pressure part. The system includes first and second input lines that guide oil of an oil pan to the first and second pump chambers. First and second discharge lines discharge the hydraulic pressure generated from the first and second pump chambers. A high-pressure switch valve selectively supplies or recycles the hydraulic pressure supplied from the first discharge line to the high-pressure hydraulic path into the high-pressure part. A pressure accumulator is disposed on a high-pressure hydraulic path between the high-pressure switch valve and the high-pressure part and a low-pressure switch valve selectively supplies or recycles the hydraulic pressure supplied from the second discharge line to the low pressure hydraulic path into the low-pressure part.
Abstract:
A control system for a hybrid construction machine includes first and second main pumps, first and second supply passages, first and second circuit systems, a hydraulic motor, a motor generator, an assist pump, a joint passage connected to the assist pump and branching off, first and second logic valves, and a switching valve. The switching valve switches between a state where the assist pump is connected to the second supply passage and a state where the second main pump is connected to the hydraulic motor. A bypass passage branches off from the other branch passage at the downstream of the switching valve. The bypass passage is connected to the second supply passage on the downstream side of the second logic valve.