A strainer device includes a strainer element; a first lid member that covers an upper opening of the strainer element; a second lid member that covers a lower opening of the strainer element and has a fitting hole in a portion surrounded by the strainer element; a delivery pipe protruding upward inside a hydraulic oil tank in a state in which the delivery pipe is fitted into the fitting hole of the second lid member; and a check valve arranged at the first lid member. The check valve includes a valve main body having a valve passage whose one end opens to the internal space of the strainer element and whose other end opens to inside of the hydraulic oil tank; and a valve body which is arranged to be able to move in a vertical direction with respect to a valve seat provided in the valve passage.

A hydraulic fluid tank arrangement for a working machine is provided, the arrangement including a hydraulic fluid tank; an inlet portion for receiving hydraulic fluid into the hydraulic fluid tank; and an oil filter arranged in fluid communication with the inlet portion; wherein the hydraulic fluid tank arrangement further includes a gas removal device arranged in fluid communication with the oil filter downstream the inlet portion and upstream the oil filter for removing gas from the hydraulic fluid before the hydraulic fluid reaches the oil filter. A method for removing gas from hydraulic fluid contained in a hydraulic fluid tank arrangement is also provided.

A hydraulic system for a work machine includes a tank to store an operation fluid, a hydraulic device to be operated by the operation fluid, a control valve to control the hydraulic device, a first fluid tube connecting the hydraulic device and the control valve, the first fluid tube being to supply the operation fluid from the control valve to the hydraulic device, a second fluid tube branching from the first fluid tube and connected to the tank, a switch valve provided to the second fluid tube, the switch valve being to control a flow rate of the operation fluid, and an oil cooler provided to the second fluid tube between the switch valve and the tank.

The present invention relates to an oil tank ventilation device for a hydraulic brake unit of a tramcar, comprising a vent plug, a sealing ring, a gas guide hole and a gas guide pipe; the gas guide hole is a through-hole structure arranged at an upper end inside an integrated valve block; the communications of electrical element protection case, integrated valve block and the oil tank are realized by the gas guide pipe stretched into an air chamber of the oil tank and by the vent plug configured in the electrical element protection case. When the surface of the oil tank is covered with ice or snow, the rain or snow can be effectively prevent from falling on the vent plug body and the driving safety of the train is ensured.

The present invention relates to an oil tank ventilation device for a hydraulic brake unit of a tramcar, comprising a vent plug, a sealing ring, a gas guide hole and a gas guide pipe; the gas guide hole is a through-hole structure arranged at an upper end inside an integrated valve block; the communications of electrical element protection case, integrated valve block and the oil tank are realized by the gas guide pipe stretched into an air chamber of the oil tank and by the vent plug configured in the electrical element protection case. When the surface of the oil tank is covered with ice or snow, the rain or snow can be effectively prevent from falling on the vent plug body and the driving safety of the train is ensured.

A hydraulic fluid de-aeration device for a hydraulically actuated variable valve actuation system is provided. The device includes a de-aeration bridge having a first end and a second end. The device includes a conical de-aeration chamber having an outer wall and a generally vertical center axis. The second end of the de-aeration bridge is offset from the center axis of the de-aeration chamber such that hydraulic fluid flowing from the de-aeration bridge is directed towards the outer wall of the de-aeration chamber. The device includes a cover with a vent hole for air that is expelled from the hydraulic fluid. A passage connected to the de-aeration chamber supplies the hydraulic fluid to a hydraulic fluid gallery of the variable valve actuation system.

A valve arrangement for a fluidic supply of a fluid load, with several main valves designed for influencing fluid flows at the fluid ports, and with electrically controllable pilot valves designed for fluidic control of the main valves. A base body is assigned a connection plate lying opposite a connection face and having a fluid passage which leads into an operating port for the connection of a fluid load wherein, between the connection face and the connection plate there is provided a separate passage body which has at least one connection passage for a fluidically communicating link between at least one of the fluid ports and the operating port, and at least one connecting conduit for a fluidic coupling of at least two fluid ports.

A working medium circuit for a hydrodynamic machine. The working medium circuit includes a working medium container, an inflow line, an emptying line, and a heat exchanger. The working medium can be moved out of the working medium container into the working chamber for a first operating state, in particular the braking mode, and the working medium can be moved out of the working chamber back into the working medium container for a second operating state, in particular the non-braking mode. For aerating and ventilating, the working chamber is connected at least indirectly via a ventilating line to a chamber which has a ventilating device with respect to the surroundings and in which working medium can collect.

A hydraulic system for a work machine includes a first switch valve and a first return circuit. The first switch valve is switchable between a confluent position and an isolation position. The first switch valve is switched to the confluent position such that a first operation fluid tube is connected to a second operation fluid tube and a first transmission fluid tube is connected to a second transmission fluid tube. The first switch valve is switched to the isolation position such that the first operation fluid tube is disconnected from the second operation fluid tube and the first operation fluid tube is disconnected from the second operation fluid tube.

A filter (5) for a return line (L1, L2) for hydraulic oil to a hydraulic tank (2), which filter (5) has a filter element (11). The filter (5) is arranged to filter the hydraulic oil through the filter element (11) when the hydraulic oil is below a first oil level (H1) in the filter (5), and the filter (5) has an arrangement (15) to cause the hydraulic oil to bypass the filter element (11) when the oil level (H) in the filter (5) exceeds the first oil level (H) without causing any significant back pressure.