The present disclosure provides an aircraft thermal management system. The aircraft thermal management system includes a first hydraulic system for circulating a first hydraulic fluid, a second hydraulic system for circulating a second hydraulic fluid, and a third hydraulic system for circulating a third hydraulic fluid. The aircraft thermal management system also includes a controller configured to: (i) determine a temperature of the first hydraulic fluid, a temperature of the second hydraulic fluid, and a temperature of the third hydraulic fluid, and (ii) based on the determined temperature of the first hydraulic fluid, utilize the second hydraulic fluid and/or the third hydraulic fluid to modify an operational temperature of the first hydraulic fluid.

A hydraulic forging press machine and a control method, whereby surging of the forging load or dead zones where the forging speed goes to zero is suppressed, and forging is performed with high precision throughout a wider range than the prior art, from low to high load. Pressure cylinders have a main pressure cylinder configured so working fluid is supplied during forging, and secondary pressure cylinders are configured so supplying and stopping of the supply of working fluid thereto are switched in response to the forging load, head-side hydraulic chambers of the secondary pressure cylinders being connected to a head-side hydraulic chamber of the main pressure cylinder via electromagnetic switching valves. Only the main pressure cylinder is used until the forging load exceeds a set load, and the number of secondary pressure cylinders used is sequentially increased as the forging load increases after the forging load exceeds the set load.

A control system of a hybrid construction machine includes fluid pressure pumps, a regeneration motor, a rotating electric motor coupled to the regeneration motor, a storage battery configured to store electric power generated by the rotating electric motor, an assist pump provided coaxially to the regeneration motor to be driven by the rotating electric motor, the assist pump being configured to supply a working fluid to a fluid pressure actuator, and load adjusting units configured to change a load of the assist pump in accordance with a state of the storage battery.

An hydraulic system for a working machine, the system comprising an engine, and an engine speed sensor configured to detect the engine speed; a travel pump configured to actuate a travel actuator, and a travel pump pressure sensor configured to detect the travel pump pressure; a service pump configured to actuate a service actuator, and a service pump pressure sensor configured to detect the service pump pressure; and a micro-controller unit configured to receive input values from each sensor, and configured to determine whether each input value is within a predetermined range where the engine will not stall. The micro-controller unit is configured to provide an output when at least one input value is outside the predetermined range.

A method is provided for detecting and quantifying leaks in a gas network under pressure or vacuum. The gas network may have a sensor(s) capable of recording the status of a source(s), consumers, consumer areas or applications. The method includes: a start-up phase; a training or estimation phase; and an operational phase. The operational phase includes: reading out the first group of sensors; calculating or determining the value of a second group of sensors from the readings from the first group of sensors; comparing the calculated or determined values of the second group of sensors with the read values of the second group of sensors and determining the difference between them; determining, on the basis of a residual value analysis, whether there is a leak in the gas network; generating an alarm and/or generating a leakage rate and/or generating the corresponding leakage cost if a leak is detected.

A method is provided for detecting and quantifying obstructions in a gas network under pressure or vacuum. The gas network may be provided with a sensor(s) capable of recording the status of a source(s), consumers, or consumer areas. The method includes: a possible start-up phase; a baseline or zero phase; and an operational phase. The operational phase includes: reading out the first group and second group of sensors; re-estimating, determining or calculating the physical model or mathematical relationship on the basis of the read measurements from the sensors; determining or calculating of the existence of an obstruction in the system based on the difference and/or its derivatives between the parameters of the physical model or mathematical relationship as determined during the baseline or zero phase and the operational phase; generating an alarm and/or generating a degree of obstruction and/or generating the corresponding obstruction if an obstruction is detected.

A hydraulic system includes: a cylinder in which an interior of a tube is divided by a piston into a first pressure chamber and a second pressure chamber; a first bidirectional pump connected to the first pressure chamber by a first supply/discharge line; a second bidirectional pump connected to the second pressure chamber by a second supply/discharge line and coupled to the first bidirectional pump in a manner enabling torque to be transmitted between the first and second bidirectional pumps; a relay line connecting the first and second bidirectional pumps such that a hydraulic liquid discharged from one of the first and second bidirectional pumps is introduced into the other of the first and second bidirectional pumps; and an electric motor that drives the first or second bidirectional pump. At least one of the first and second bidirectional pumps is a variable displacement pump whose delivery capacity per rotation is freely variable.

A hydraulic system includes: hydraulic actuators; a control valve for controlling the hydraulic actuators; a tank for storing a hydraulic operation fluid; a variable displacement pump for supplying the hydraulic operation fluid to the hydraulic actuators; a regulator for controlling the variable displacement pump; a pilot pump for discharging a hydraulic pilot fluid; a load sensing system for maintaining a differential pressure to be a constant pressure, the differential pressure being obtained by subtracting a second signal pressure from a first signal pressure that is the discharge pressure of the variable displacement pump, the second signal pressure being the maximum one of the load pressures generated in the hydraulic actuators; a signal tube for sending the second signal pressure to the regulator; a throttle provided on the signal tube; and a warm-up circuit for supplying the hydraulic pilot fluid to a downstream side of the throttle.

Provided is a construction machine on which a hydraulic closed circuit for driving a single rod-type hydraulic cylinder and a swing hydraulic motor is mounted and that has good swing deceleration responsiveness. In this construction machine that drives each of a single rod-type hydraulic cylinder and a swing hydraulic motor in a closed circuit, a minimum passage area from a second flushing valve to a tank in a case the second flushing valve is fully open is smaller than a minimum passage area from a first flushing valve to the tank in a case the first flushing valve is fully open.

A bi-directional pump connected to a motor by a pair of supply/discharge lines; a regulator changes the bi-directional pump tilting angle; and a controller controls the regulator based on a turning signal outputted from a turning operation valve. At the turning acceleration, at which the signal increases, the controller calculates a motor flow rate passing through the motor and an instruction flow rate determined based on the turning signal. If the instruction flow rate is greater than a reference flow rate obtained by adding a predetermined value to the motor flow rate, the controller controls the regulator so the bi-directional pump tilting angle is adjusted to a tilting angle realizing the reference flow rate. If the instruction flow rate is not greater than the reference flow rate, the controller controls the regulator so the bi-directional pump tilting angle is adjusted to a tilting angle realizing the instruction flow rate.