A pneumatic circuit for controlling the activation of a robot with inflatable chambers includes at least one ring oscillator formed from a plurality of valves connected in series to selectively admit fluid pressure to inflate and deflate the chambers. Sequential actuation of the valves induces sequential bending and rotation of combinations of the chambers to effect motion. A switching valve changes the actuation sequence of the oscillator valves to change the direction of motion.

Device for recovering hydraulic energy in a machine comprising at least a first differential cylinder-piston assembly having a differential cylinder with a separate rod and base side, at least a second differential cylinder-piston assembly having a differential cylinder with a separate rod and base side, and at least one hydraulic accumulator that can be hydraulically connected to at least one of the differential cylinder-piston assemblies, wherein the differential cylinder-piston assemblies are mechanically coupled to one another, and wherein the potential energy of at least one of the differential cylinder-piston assemblies retracting under a compressive load can at least partially be stored in the hydraulic accumulator.

In the hydraulic pump according to the present invention, a straight path among the paths, through which the fluid flows within the hydraulic pump, and a connection point on the straight path are formed to have curvatures, so that it is possible to prevent stress from being concentrated to the connection point, thereby improving durability, and it is possible to manufacture the hydraulic pump by forming a casting shape with a curvature in advance, thereby decreasing additional machining and decreasing costs of a product.

The present disclosure relates to a hydraulic system for a construction machine, and more particularly, to a hydraulic system for a construction machine including a plurality of actuators, in which each of the actuators includes a pump/motor, is operated under a control of a corresponding pump/motor, and stores working oil in an accumulator or receives the working oil supplemented from the accumulator in accordance with a difference between a flow rate entering the actuator and a flow rate discharged from the actuator.

A lifting mechanism has a descending mode including an energy-regeneration mode and a non-energy-regeneration mode. The lifting mechanism includes: a battery, an electric machine, a hydraulic pump, an oil tank, a hydraulic cylinder, a work platform and a flow limiting valve. In the energy-regeneration mode, the hydraulic fluid drives the hydraulic pump to operate as a hydraulic motor, thus in turn driving the electric machine to operate as a generator and charge the battery. In the non-energy-regeneration mode, the flow limiting valve limits the maximum of the descending speed of the work platform. In the present application, the flow limiting valve is used to provide throttling resistance to limit the maximum of the descending speed of the hydraulic fluid, thus in turn defining the maximum of the descending speed of the work platform. Therefore, in the present application, by using the flow limiting valve to define the maximum of the descending speed of the work platform, the safety problem due to an accelerated descent during descending of the work platform may be solved, and thus the safety of the lifting mechanism may be ensured.

According to one embodiment, an actuator includes a plurality of channel members each having at least one first port into which fluid flows and at least one second port from which the fluid flows out. At least one of the channel members includes a different number of second ports from a number of first ports. The channel members are joined with each other to form at least one channel component.

A method of operating a variable displacement pump in a pressurized fluid supply system for an agricultural vehicle, including maintaining a constant displacement of the pump as rotational speed of the input drive to the pump increases to a first value of 1500 rpm and thereafter adjusting the displacement of the pump to maintain a constant output fluid flow 230 L/min or reduced flow as rotational speed of the input drive to the pump increases beyond the first value to a maximum value of 2100 rpm.

The lifting mechanism includes a battery, an electric machine, a hydraulic pump, an oil tank, a hydraulic cylinder, a work platform and a proportional valve or switch valve. In the energy-regeneration mode, the hydraulic fluid drives the hydraulic pump to operate as a hydraulic motor, thus in turn driving the electric machine to operate as a generator and charge the battery. In the present application, the hydraulic pump operates to increase a pressure in a hydraulic line between the hydraulic pump and the proportional valve or switch valve before the proportional valve or switch valve is switched from a unidirectional communication position to a bidirectional communication position. When the proportional valve or switch valve is switched from the unidirectional communication position to the bidirectional communication position, by increasing the pressure in the hydraulic line, it could be avoided that the volume of hydraulic fluid has low pressure is compressed because the hydraulic fluid has low pressure is communicated with hydraulic fluid has high pressure; therefore a state of sudden drop of the work platform is avoided, and safety performance and operating experience of the lifting mechanism is improved.

A hydraulic system for a construction machine having a protection device is disclosed, which can limit a flow rate of hydraulic fluid that is discharged from a hydraulic pump in accordance with a hydraulic fluid temperature and notify an operator of information on the hydraulic fluid temperature. The hydraulic system for a construction machine includes a hydraulic actuator operated by hydraulic fluid that is supplied from a hydraulic pump; a control valve installed in a flow path between the hydraulic pump and the hydraulic actuator to control a flow rate of the hydraulic fluid that is supplied from the hydraulic pump to the hydraulic actuator; an oil cooler installed in a return flow path from the control valve to an hydraulic fluid tank to cool the hydraulic fluid; a hydraulic fluid temperature sensor detecting in real time a hydraulic fluid temperature of the hydraulic fluid tank; a hydraulic pump regulator controlling a discharge flow rate of the hydraulic pump through adjustment of an inclination angle of a swash plate of the hydraulic pump; and a controller comparing the hydraulic fluid temperature detected by the hydraulic fluid temperature sensor with a predetermined hydraulic fluid temperature, and outputting a control signal to the hydraulic pump regulator so as to limit the discharge flow rate of the hydraulic pump to or below a predetermined flow rate if the detected hydraulic fluid temperature is equal to or lower than a predetermined lower limit value, or equal to or higher than a predetermined upper limit value.

An aircraft with a fuselage and with wings connected thereto, wherein a support strut extends between the fuselage and each of the wings, which support strut is connected both to the fuselage and to the wing. The support strut has a hydraulic working cylinder, which can be pressurized with hydraulic fluid in a controlled manner for the purpose of pivoting the wing.