A lift device and a method of controlling the lift device are provided. The lift device has an electric motor drivingly coupled to a traction device, and a traction battery. A hydraulic circuit has a pump with a pump motor, and a valve. In response to a voltage being above a threshold voltage while the electric motor is outputting a braking torque and providing electrical power to the battery, flow of the pump is increased and the valve is controlled to reduce a size of the valve opening and increase pressure in the pressure galley thereby reducing electrical power to the traction battery. The flow of the pump and the valve position are therefore controlled in response to a braking power output being greater than a threshold to dissipate braking power output into the hydraulic circuit and charge the traction battery with the remaining braking power output.

When a first control valve and a second control valve are in non-neutral positions, respectively, a fifth fluid passage and a second fluid passage are closed, thereby generating a first pressure within a fifth portion of the fifth fluid passage and a second pressure within a second portion of the second fluid passage, so that the first pressure is applied to a first valve through a fourth fluid passage to move the first valve to close the third fluid passage and a second pressure is applied to the confluence valve through a first fluid passage to move the confluence valve to a confluence position. When the confluence valve is in the confluence position, the confluence valve directs working fluid from a first working fluid supply to the second control valve.

An inlet section for use in a hydraulic distributor including a valve body and a slider with a first area and a second area. The inlet section further including said slider being longitudinally slidable within the valve body between a first position in which it prevents passage of fluid from a high pressure line to a low pressure line, and a second position in which it enables passage of fluid. The inlet section further including a main spring active on the second area of the slider in a direction consistent with action of the second pressure and a control device of the slider. The control device of the slider includes a mechanical actuator member selectively active on the slider in a direction consistent with the action of the first pressure on the first area of the slider so as to force the slider in the second position.

The invention relates to a pressure oil filter system for a hydraulic transmission, in particular for a motor vehicle transmission, comprising at least one oil pump which can be actuated as required and which has a pressure side and a suction side, a pressure line to a consumer and at least a first oil filter which is arranged at the pressure side of the oil pump in the pressure line, wherein means for damping pressure surges during intermittent operation of the oil pump are provided in the pressure line upstream of the first oil filter in the flow direction of the oil.

Problem to be solved: To provide a hydraulic circuit for the construction machine which enables to use the relief valve of low capacity in the work tool circuit. Solution: The hydraulic circuit 2 for a construction machine has: a hydraulic pump 4 of variable capacity, a work tool 6 operated by hydraulic oil delivered by the hydraulic pump 4, a work tool operating device 10 to output a signal for operating the work tool 6, a control valve 14 allowing the hydraulic pump 4 to supply the hydraulic oil to the work tool 6 based on the signal output from the work tool operating device 10, a tool's relief valve 44 to release the hydraulic oil flowing between the control valve 14 and the work tool 6, a pressure sensor 46 to detect a pressure of hydraulic oil flowing into the work tool 6, and a controller 48 to reduce a delivery rate from the hydraulic pump 4 when the pressure detected by the pressure sensor 46 exceeds a predetermined value.

A hydraulic circuit for a vehicle driving device includes an oil pump, a clutch oil passage, a cooling oil passage, a pressure regulating valve, and a shift valve. The cooling oil passage guides oil to a cooled portion of a vehicle. Supply of oil to the clutch oil passage and the cooling oil passage is switched by switching of the pressure regulating valve and the shift valve. The cooling oil passage includes: a shaft center cooling oil passage which supplies cooling oil to a shaft center of a rotation shaft of an electric motor mounted on the vehicle; and a cooling oil passage shift valve which switches presence/absence of supply of oil to the shaft center cooling oil passage.

A hydraulic circuit for a vehicle driving device includes an oil pump, a clutch oil passage, a cooling oil passage, a pressure regulating valve, and a shift valve. The cooling oil passage guides oil to a cooled portion of a vehicle. Supply of oil to the clutch oil passage and the cooling oil passage is switched by switching of the pressure regulating valve and the shift valve. The cooling oil passage includes: a shaft center cooling oil passage which supplies cooling oil to a shaft center of a rotation shaft of an electric motor mounted on the vehicle; and a cooling oil passage shift valve which switches presence/absence of supply of oil to the shaft center cooling oil passage.

A hydraulic system for a working machine includes a first electric machine connected to a first hydraulic machine; a second electric machine connected to a second hydraulic machine, an output side of the second hydraulic machine being connected to an input side of the first hydraulic machine; 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; and a valve arrangement arranged between the hydraulic consumer and the first and second hydraulic machines, wherein the valve arrangement is configured to control a return flow of hydraulic fluid from the hydraulic consumer to either the input side of the first hydraulic machine or an input side of the second hydraulic machine based on a requested output pressure from the first hydraulic machine.

A quick coupler circuit includes a cylinder to attach and/or detach an attachment to and/or from a construction machine by expansion and/or contraction, a flow pump to supply fluid to the cylinder, a valve through which fluid for operating the cylinder passes, a spool valve which includes a spool, to move along an axial direction, and to form a pressure at a node of the flow pump according to movement of the spool, an electronic proportional pressure reducing valve to control the spool valve, a switch to perform an ON/OFF operation, and a controller to output a control current to the electronic proportional pressure reducing valve in response to the operation of the switch. The controller is maintains control current which it outputs during the switch's ON operation for a predetermined period of time after the switch's OFF operation.

An assembly system for components of a pressurized fluid supply system for an agricultural vehicle includes a body having at least one fluid duct connectable at one end to a pressurized fluid supply and having a socket at the other end. A detachable component such as an accumulator or oil filter is connectable in releasable mechanical engagement with the body to receive pressurized fluid from the at least one fluid duct. The engagement results from insertion of at least a portion of the component into the socket and rotation of the component to a locked position. The body has at least one discharge duct extending therethrough. In a partially rotated position of the component portion within the socket, the component remains mechanically attached to the body and the fluid duct and discharge duct are in fluidic connection, discharging accumulated pressure in the fluid duct.