This disclosure relates to a hydraulic system for a hydro-mechanical machine comprising a rotary mechanism. The hydraulic system includes a primary accumulator configured to receive and store high-pressure fluid in response to stopping of the rotary mechanism. A control system coupled to the primary accumulator through a hydraulic supply circuit is configured to enable passage of the high-pressure fluid stored in the primary accumulator to a rotary control valve configured to control the rotary mechanism, through the hydraulic supply circuit, based on a predefined pressure threshold associated with the primary accumulator. A secondary accumulator coupled to the primary accumulator and the control system via the hydraulic supply circuit is configured to store surplus high-pressure fluid provided by the primary accumulator through the hydraulic supply circuit.

A system for delivering fluid in a machine is provided. The system includes a pump, a first valve disposed downstream of the pump, a check valve disposed downstream of the first valve, at least one accumulator disposed downstream of the check valve, and an auxiliary system disposed upstream of the check valve. The system further includes a control unit configured to receive a signal indicative of a fluid demand from the auxiliary system. The control unit is also configured to selectively control the first valve in a first position to limit flow of the fluid from the pump to the auxiliary system, and in a second position to allow flow of the fluid from the pump to the auxiliary system based, at least in part, on the received signal. The check valve limits flow of a fluid from the at least one accumulator to the auxiliary system.

A controller (45) is provided with an elapse time measuring section (47A) that measures an elapse time (tx) elapsed since an initial use of an accumulator (29) based upon a reset signal from a reset switch (44), a number-of-operations measuring section (47B) that measures a number of operations of the accumulator (29), that is, a number (N) of boom lowering operations after a reset, based upon a detection signal from an accumulator side pressure sensor (39), a gas permeation amount estimating section (47C) that estimates an estimation gas permeation amount (Qloss) of the accumulator (29), a sealed gas pressure estimating section (47D) that finds an estimation sealed gas pressure (Pgs) of a gas chamber (29B) of the accumulator (29), and an accumulator degradation determining section (47E) that determines a degradation condition of the accumulator (29) and outputs the determination result.

A hydraulic circuit (11) of a hydraulic excavator (1) is provided with a main hydraulic circuit (11A) including a boom cylinder (5D), a pilot hydraulic circuit (11B) for operating the boom cylinder (5D) and a recovery hydraulic circuit (11C) including an accumulator (29). In this case, the recovery hydraulic circuit (11C) is provided with a recovery control valve (31) that recovers pressurized oil discharged from the boom cylinder (5D) to the accumulator (29), a main supply control valve (34) for supplying pressurized oil accumulated in the accumulator (29) to the main hydraulic circuit (11A) and a pilot supply control valve (37) for supplying pressurized oil accumulated in the accumulator (29) to the pilot hydraulic circuit (11B).

A pressure capsule/header assembly for a process fluid pressure transmitter is provided. An isolator plug has an isolation diaphragm at a first end thereof and a second end spaced from the first end. The isolator plug has a fill fluid passageway fluidically coupling the first end to the second end. A header has a first end configured to carry a pressure sensor and a second end spaced from the first end. The header has at least one electrical interconnect extending from the first end to the second end. A biaxial support ring is disposed about an outer surface of the header. The biaxial support ring and the header define a tapered interference interface therebetween. The header is welded to the isolator plug at a first weld and the biaxial support ring is welded to the isolator plug at a location that is spaced from the second end of the header.

This disclosure relates to a hydraulic system for a hydro-mechanical machine comprising a rotary mechanism. The hydraulic system includes a primary accumulator configured to receive and store high-pressure fluid in response to stopping of the rotary mechanism. A control system coupled to the primary accumulator through a hydraulic supply circuit is configured to enable passage of the high-pressure fluid stored in the primary accumulator to a rotary control valve configured to control the rotary mechanism, through the hydraulic supply circuit, based on a predefined pressure threshold associated with the primary accumulator. A secondary accumulator coupled to the primary accumulator and the control system via the hydraulic supply circuit is configured to store surplus high-pressure fluid provided by the primary accumulator through the hydraulic supply circuit.

Provided are an energy regeneration device which can regenerate energy of a working fluid discharged from an actuator while controlling a flow rate of the working fluid, and a work machine including the foregoing device. The regeneration device (100) includes a boom cylinder (20), an inertial fluid container (102), an oil tank (110), an accumulator (105), a low-pressure-side opening/closing device (103), and a high-pressure-side opening/closing device (104). A calculation unit (151) calculates a duty ratio for opening/closing the low-pressure-side opening/closing device (103) and the high-pressure-side opening/closing device (104) in accordance with a desired flow rate of a working fluid discharged from the boom cylinder (20). A regeneration control unit (153) selects alternately the low-pressure-side opening/closing device (103) and the high-pressure-side opening/closing device (104) as a destination with which the inertial fluid container (102) communicates in accordance with the calculated duty ratio, and supplies a discharged working fluid to an accumulator (105).

A first valve mechanism is a valve mechanism provided in a flow path coupled to a liquid ejecting head that ejects a liquid, and including a valve that opens/closes the flow path, a first communication liquid chamber that communicates with the flow path, and a first pressure receiving body that converts a pressure difference between a pressure of the first communication liquid chamber and a reference pressure into an operating force of the valve, in which a threshold pressure of the first communication liquid chamber for determining opening/closing of the valve is variable.

The present disclosure relates to the technical field of cranes, and in particular to a crane hydraulic control system and a crane. The crane hydraulic control system of the present disclosure includes a prime mover, an execution control mechanism, a hydraulic baking device, a running energy recycling device and an operation energy recycling device. By means of cooperation among the operation energy recycling device, the energy recovery device and the hydraulic energy conversion device, kinetic energy in a driving braking process of the crane and the potential energy in a load lowering process are respectively converted into hydraulic energy for recovery, storage and reuse, therefore, the present disclosure can achieve the recovery of the superstructure energy and the lower vehicle energy of the crane so as to effectively reduce the energy waste.

An exemplary embodiment of the present disclosure relates to a construction machine starting assist system including: an engine of a construction machine; an input unit which receives a key-on signal and a key-off signal of the engine; a hydraulic pump which is operated by the engine; an actuator which is operated by hydraulic oil discharged from the hydraulic pump; a regeneration valve which is switched so that a part or an entirety of the hydraulic oil returned from the actuator; an accumulator which is charged with the hydraulic oil supplied from the regeneration valve; a charging valve which is controlled so that the hydraulic oil is discharged from the accumulator when the key-on signal is inputted into the input unit; and a hydraulic motor connected to the engine and configured to assist in starting the engine.