A hydraulic system for a working machine, the system comprising: an electric machine connected to a first hydraulic machine and to a second hydraulic machine via a common axle, an output side of the second hydraulic machine being connected to an input side of the first hydraulic machine, wherein the first hydraulic machine is a variable displacement hydraulic machine with unidirectional flow; at least one hydraulic consumer hydraulically coupled to an output side of the first hydraulic machine via a supply line and configured to be powered by the first hydraulic machine; a first return line hydraulically coupling the hydraulic consumer to the input side of the first hydraulic machine.

A hydraulic drive unit for a stretcher has a hydraulic circuit with a differential cylinder, a pump, a tank and a valve assembly. The differential cylinder includes a rod working chamber and a piston working chamber. The valve assembly is switchable into at least a first state and a second state, wherein the rod working chamber is connected to the tank in the first state and to the pump in the second state, and wherein the piston working chamber is connected to the pump in the first state and to the tank in the second state. The tank is a tank separated from the atmosphere with a variable tank volume, so that the hydraulic circuit is configured as a closed hydraulic circuit. A stretcher having such a hydraulic drive unit is also provided.

A time delay valve includes a switching valve that switches between a first position and a second position; an urging member that urges the switching valve toward the first position; a driving mechanism that urges the switching valve toward the second position located opposite the first position in the presence of the pressure of a pilot fluid being supplied: a pilot flow channel that introduces the pilot fluid to the driving mechanism; and a delaying mechanism that delays the switching timing of the switching valve. The delaying mechanism includes a first throttle valve provided on the pilot flow channel, a compensation mechanism that urges the switching valve toward the first position in the presence of the pressure of the pilot fluid being supplied, and a compensation flow channel that is branched from the pilot flow channel to introduce a portion of the pilot fluid to the compensation mechanism.

A hydraulic system for operating a rear gate of a baler implement includes a hydraulic cylinder having a housing that defines an interior, and a piston that is moveably disposed within the interior of the housing. The housing includes a first fluid port and a second fluid port, each disposed in fluid communication with a first fluid volume of the hydraulic cylinder. A flow rate control valve is moveable between a first position for directing fluid to or from the first fluid port at a first flow rate, and a second position for directing fluid to or from the second fluid port at a second flow rate. The second flow rate is different than the first flow rate.

An example valve includes: a plurality of ports comprising: a first port, a second port, and a third port; a spool configured to block fluid flow from the first port to the third port while allowing fluid flow from the third port to the second port when the valve is in an unactuated state; a spring applying a biasing force on the spool in a proximal direction, wherein when the valve is actuated, the spool moves in a distal direction against the spring, thereby allowing fluid flow from the first port to the third port while blocking fluid flow from the third port to the second port; and a turbine configured to rotate as fluid flows from the first port to the third port when the valve is in an actuated state.

A main flow path that introduces high-pressure air to an air cylinder, or discharges exhaust air therefrom, includes a sub flow path provided alongside the main flow path; an exhaust flow rate adjustment unit that suppresses the operation speed of the air cylinder by adjusting the flow rate of the exhaust air flowing through the sub flow path; and a switching valve that is connected between the air cylinder, the main flow path and the sub flow path, and that connects the main flow path and the sub flow path to the air cylinder in a switching manner. The switching valve is constituted by a spool valve.

The present invention pertains to an air cylinder (10) in which flow rate controllers (24, 24A) are built into a head cover (14) and a rod cover (16), said flow rate controllers (24, 24A) being provided with a first flow rate adjustment part (28) connected between a port (14a, 16a) and a cylinder chamber (12c), a second flow rate adjustment part (32) provided adjacent to the first flow rate adjustment part (28), and a pilot check valve (38) connected in series to the second flow rate adjustment part (32). In response to the pressure of pilot air, the pilot check valve (38) switches between a state in which the passage of exhaust air from the cylinder chamber (12c) is permitted and a state in which the passage of exhaust air is prevented.

A flow rate controller and a drive device are provided with a cylinder flow passage connected to an air cylinder; a main flow passage for supplying air to and discharging air from the air cylinder; an auxiliary flow passage that has a first throttle valve and through which exhaust air discharged from the air cylinder passes with a smaller flow rate than that of the main flow passage; a switch valve that switches between a first position in which the cylinder flow passage communicates with the main flow passage and a second position in which the cylinder flow passage communicates with the auxiliary flow passage; and a pilot air adjustment part that guides a portion of the exhaust air from the air cylinder as pilot air to the switch valve.

An air cylinder in which a flow rate controller is built in, has a head cover and a rod cover. A pilot air adjustment unit guides exhaust air to a switch valve of the flow rate controller as pilot air, and the switch valve is switched by an increase in the pressure of the pilot air.

A flow rate controller and a drive device are provided with a first flow passage connected between an operation switching valve and an air cylinder, and that supplies air to and discharges air from a cylinder chamber of the air cylinder; a first flow rate adjustment part provided in the first flow passage; a second flow passage adjacent to the first flow passage; a pilot check valve provided at a point along the second flow passage; a second flow rate adjustment part connected in series to the pilot check valve at a point along the second flow passage; a pilot air flow passage, one end of which communicates with the operation switching valve and the other end of which is connected to a pilot port of the pilot check valve; and a third flow rate adjustment part provided in the pilot air flow passage.