The present disclosure relates to a control circuit and a control method for boom energy regeneration, and the control circuit for boom energy regeneration includes: a control unit which controls a discharge amount control valve, such that the amount of oil, which is discharged from a head of a boom cylinder, is supplied to a regeneration device or a rod of the boom cylinder through a hydraulic regeneration line, and when the regeneration device has an abnormality, the amount of oil, which is discharged from the head of the boom cylinder, is supplied to the main control valve through a hydraulic discharge line.

A pressurized fluid supply system for a vehicle transmission is provided. The fluid supply system has a pump with at least high and low pressure outputs that supplies high and low pressure components via a directional valve. The pressurized fluid supply system minimizes the parasitic loss upon a vehicle engine.

A system and method for machinery performing work with hydraulic actuators. Radial hydraulic pumps are aligned end-to-end along a common driveshaft axis to form a multi-pump assembly having a plurality of piston/cylinder units extending in a radial direction. Two or more piston/cylinder units are associated with one another to form multiple piston/cylinder groups. A plurality of control valves combines individual output flows from the two or more associated piston/cylinder units into respective common output flows for each respective piston/cylinder group. A plurality of flow control devices varies the common output flow from each respective piston/cylinder group by throttling inlet flow to the two or more associated piston/cylinder units in each respective piston/cylinder group. Each respective common output flow is directed from each respective piston/cylinder group to a hydraulic actuator on the heavy machinery to control its direction of movement.

A drum unloader may include a pump assembly, a motor, a plate, a piston-cylinder assembly, and a sensor. The motor drives the pump assembly. The plate is mounted to the pump assembly and includes an inlet to the pump assembly. The piston-cylinder assembly includes a housing, a piston, and a piston rod. The housing defines a bore. The piston is received within the bore and cooperates with the housing to define a first cavity and a second cavity. The piston rod is attached to and extends from the piston such that the piston rod extends through the first cavity. The piston rod is coupled to the pump assembly, the motor and the plate such that movement of the piston within the bore causes corresponding movement of the pump assembly, the motor and the plate relative to the housing. The sensor measures a pressure within the second cavity.

A cylinder driving apparatus includes a first passage connecting a first chamber of a cylinder to a first port of a pump; a second passage connecting a second chamber of the cylinder to a tank; a third passage connecting a second port of the pump to the tank; a throttle configured to apply resistance to a working fluid flowing through the third passage; and an operated check valve provided in the first passage to allow the working fluid to flow from the pump into the first chamber. The operated check valve is configured to allow the working fluid to flow from the first chamber into the pump in accordance with a fluid pressure of the working fluid in the third passage between the pump and the throttle.

A hydraulic unit includes two pressure connections for supplying devices, in particular hydraulic rescue devices, including a first hydraulic circuit with a first pump arrangement and a first pressure connection and a second hydraulic circuit with a second pump arrangement and a second pressure connection, wherein the pump arrangements are driven at the same time by a common drive, and wherein by a first valve switch the first hydraulic circuit can be connected to the second hydraulic circuit and by a second valve switch the second hydraulic circuit can be connected to the first hydraulic circuit. The valve switches include a spring acting in the direction of an initial position and from the first hydraulic circuit or from the second hydraulic circuit a first control line runs to the first valve switch and from the second hydraulic circuit or from the first hydraulic circuit a second control line runs to the second valve switch.

An adaptor is used to couple a prime mover to an actuator. The adaptor includes a first portion that attaches to the prime mover and a second portion that attaches to the actuator. The outer surface of the first portion is defined by at least one flat portion connected by at least one arcuate portion. The second portion has a bore configured to accept the first portion, with an inner surface shaped to complement the outer surface of the first portion. A bore through the first portion accepts a drive shaft of the prime mover therethrough where the drive shaft is configured to engage the actuator.

A hydraulic control system of an automatic transmission for a vehicle provided with an ISG system is disclosed. The hydraulic control system may include: a mechanical hydraulic pump driven by an engine; a linear solenoid valve to control hydraulic pressure generated by the mechanical hydraulic pump; a first switch valve to selectively supply or not to supply controlled hydraulic pressure to one of friction members; an electric hydraulic pump driven by electric energy; and a second switch valve to selectively supply the hydraulic pressure, generated by the electric hydraulic pump, to the one friction member or to the linear solenoid valve. The hydraulic control system supplies the hydraulic pressure to one of the friction members operated at a gear stage where starting control is performed.

A hybrid shovel includes an engine that is controlled at a constant revolution speed, a motor generator that assists the engine, a control part that controls a drive of the motor generator, and a hydraulic pump that is driven by the engine. The control part causes the motor generator to assist the engine when a revolution speed of the engine is lower than the constant revolution speed due to a load of the hydraulic pump. The control part causes the motor generator to decrease an assist output to said engine before the revolution speed of the engine returns to the constant revolution speed.

A multi-control hydraulic circuit supplies receivers with hydraulic fluid delivered by a pump with an output controlled by the pressure of a control line depending on a load pressure of the receivers, and delivers the hydraulic fluid at a regulated pressure. The hydraulic circuit consists of hydraulic modules each associated with a receiver having a distributor which regulates the variable output supplying the receiver via a pressure compensator connected at its inlet to the outlet of the variable choke of the distributor, and at its outlet. The plunger manages the connection between its inlet and its outlet. The pressure compensator has a fluid link equipped with a choke and connects the outlet to the control line, irrespective of the position of the plunger.