A hybrid power unit of a work machine includes an engine and an energy storage device. The engine includes a crankshaft for driving a load and the crankshaft is attached to an energy storage device via a clutch. The energy storage device can be charged by the engine to store energy, that may be used to provide, when required, a boost to engine performance. The clutch may engage/disengage the energy storage device from the engine and/or control a clutch pressure. The clutch protects the crankshaft from shock loading and can slip to prevent over-torqueing of the crankshaft.

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 compensator device includes a hydraulic cylinder with a first end, a second end and an inner cylinder rod extending axially from the second end; and a piston rod with a piston movable axially within the cylinder. The inner cylinder rod has an end with a blocking diameter. The piston rod is generally hollow and includes a cavity to receive the blocking diameter of the inner cylinder rod.

Disclosed are a damping system for a movable arm of a loading machine and an operation machinery, which comprise a multi-way valve, a movable arm oil cylinder, a movable arm damping valve, and a damping lock. The multi-way valve comprises a movable arm valve core and a bucket valve core, a first movable arm oil port of the movable arm valve core communicates with a rod cavity of the movable arm oil cylinder, a second movable arm oil port of the movable arm valve core communicates with a rodless cavity of the movable arm oil cylinder, the rod cavity of the movable arm oil cylinder communicates with the movable arm damping valve, the rodless cavity of the movable arm oil cylinder communicates, via the damping lock, with the movable arm damping valve; a switching oil port of the damping lock communicates with an unloading position of the bucket valve core.

This hydraulic drive system includes: a hydraulic pump that supplies a working fluid to a hydraulic actuator; a meter-in control valve that controls a flow rate of the working fluid flowing from the hydraulic pump to the hydraulic actuator; a meter-out control valve that controls a flow rate of the working fluid being drained from the hydraulic actuator into a tank; and a regeneration valve that supplies, to the hydraulic actuator, the working fluid drained from the hydraulic actuator. The meter-out control valve is connected to the hydraulic actuator in parallel with the regeneration valve.

The present invention is related to a construction machine, the construction machine including: a main pump; a swing motor operated by receiving a hydraulic oil from the main pump; a swing valve configured to control flow of the hydraulic oil by the main pump to supply the hydraulic oil to the swing motor and to control the flow of the hydraulic oil having been discharged from the swing motor; a hydraulic oil control valve unit provided between the swing motor and the swing valve and configured to control the flow of the hydraulic oil according to a pressure of the hydraulic oil at opposite ends; a first accumulator configured to store the hydraulic oil having passed through the hydraulic oil control valve unit when the swing motor is decelerated; a regeneration control valve provided between the hydraulic oil control valve unit and the first accumulator; and a controller configured to control the hydraulic oil control valve unit and the regeneration control valve by determining acceleration or deceleration of the swing motor.

A hydraulic excavator drive system includes: a first pump that is connected to a head-side chamber of a boom cylinder by a head-side line and to a rod-side chamber of the boom cylinder by a rod-side line to form a closed circuit; and a second pump that supplies hydraulic oil to at least one of an arm cylinder or a bucket cylinder. The hydraulic excavator drive system further includes a switching valve located on a relay line that connects a supply line extending from the second pump to the rod-side line. The switching valve opens the relay line at a boom raising operation and blocks the relay line except at the boom raising operation.

A boom system including a hoist boom pivoted to a machine base; a stick boom having a proximal end pivoted to the hoist boom and a distal end configured to carry a working tool; at least one hydraulic hoist cylinder mounted between the machine base and the hoist boom; a first stick cylinder mounted between the hoist boom and the stick boom; a second stick cylinder mounted similarly and mechanically linked with the first stick cylinder; and a hydraulic circuit for supplying hydraulic fluid to the hoist cylinder and stick cylinders, wherein the hydraulic circuit includes a hydraulic conduit line connecting a base end of the at least one hoist cylinder with a base end of the second stick cylinder to allow hydraulic fluid to shunt between the base ends of the hoist cylinder and the second stick cylinder.

The present disclosure relates to a power distribution architecture for an off-road vehicle. The power distribution architecture includes a work circuit and a propel circuit and is configured for facilitating bi-directional power exchange between the work circuit and the propel circuit.

An excavator includes a traveling body, an upper turning body rotatably provided on the traveling body, an attachment which has a boom, an arm, and a bucket and is attached to the upper turning body, and a controller configured to perform a control of a cylinder of at least one shaft of the attachment so as to suppress a vibration of the traveling body or the upper turning body, which is caused by an aerial operation of the attachment.