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.

This disclosure relates to a system for reducing cavitation at a surface that moves relatively with respect to a first fluid. The system comprises a degasser configured to at least partially degas a second fluid. The system also comprises a reservoir in communication with the degasser and configured to house the at least partially degassed second fluid, the reservoir having an outlet that is arranged for directing the second fluid towards the surface. The system is configured such that the directing of the at least partially degassed second fluid towards the surface forms a boundary layer at the surface. The boundary layer is adapted to at least partially increase the negative pressure required to initiate cavitation at the surface so as to reduce the occurrence of cavitation during such relative movement.

This disclosure relates to a system for reducing cavitation at a surface that moves relatively with respect to a first fluid. The system comprises a degasser configured to at least partially degas a second fluid. The system also comprises a reservoir in communication with the degasser and configured to house the at least partially degassed second fluid, the reservoir having an outlet that is arranged for directing the second fluid towards the surface. The system is configured such that the directing of the at least partially degassed second fluid towards the surface forms a boundary layer at the surface. The boundary layer is adapted to at least partially increase the negative pressure required to initiate cavitation at the surface so as to reduce the occurrence of cavitation during such relative movement.

Hydraulic circuit comprising a low-pressure circuit (6) fed by a booster pump (4) that draws from a very-low-pressure reservoir (2), characterized in that this very-low-pressure reservoir (2) is leaktight and has a device for placing the internal volume (12) under negative pressure with respect to atmospheric pressure.

A hydraulic unit includes a tank configured to be filled with a hydraulic fluid. The tank has at least one inflow connection and at least one outflow connection. A flow guide for the hydraulic fluid is formed between the inflow connection and the outflow connection. The flow guide is configured to have at least two 180° flow arcs configured to cool and calm the hydraulic fluid and to avoid dead zones.

A hydraulic unit includes a tank configured to be filled with a hydraulic fluid. The tank has at least one inflow connection and at least one outflow connection. A flow guide for the hydraulic fluid is formed between the inflow connection and the outflow connection. The flow guide is configured to have at least two 180° flow arcs configured to cool and calm the hydraulic fluid and to avoid dead zones.

A hydraulic machine includes: a power source; an assist motor including comprising an inlet port and an outlet port and assisting a torque of the power source; a tank; a collection line which is connected to the inlet port and allows a fluid to flow to the inlet port; a first return line which is connected to the tank and allows the fluid to flow to the tank; a self-priming line which connects the first return line to the inlet port and allows the fluid to flow from the first return line to the inlet port; and an anti-cavitation line which connects the outlet port to the self-priming line and allows the fluid to flow from the outlet port to the self-priming line.

An example valve includes a piston configured to block fluid flow from a first port of the valve to a second port of the valve when the valve is in a closed position; a relief mode spring applying a first biasing force on the piston in a distal direction; a reverse flow spring applying a second biasing force on the piston in a proximal direction, wherein the reverse flow spring is weaker than the relief mode spring; and a pressure setting spring applying a third biasing force on a check element in the distal direction, causing the check element to be seated when the valve is in the closed position.

A method is provided for determining a gas charge pressure P.sub.calcGC of a hydraulic accumulator within a hydraulic fluid system. The method includes receiving pressure decay data representing the pressure decay within a self-pressurizing hydraulic reservoir of the hydraulic fluid system as the self-pressurizing hydraulic reservoir depressurizes from an operating pressure of the self-pressurizing hydraulic reservoir towards atmospheric pressure. The method also includes calculating the gas charge pressure P.sub.calcGC of the hydraulic accumulator using the received pressure decay data of the self-pressurizing hydraulic reservoir.

An example valve includes: (i) a valve body comprising a supply port and an operating port; (ii) a sleeve comprising a first opening fluidly coupled to the supply port, a second opening fluidly coupled to the operating port, and a seat; (in) a spool configured to move axially within the sleeve, wherein the spool is configured to he seated on the seat of the sleeve when the valve is unactuated, and wherein when the valve is actuated, the spool moves such that a gap is formed at the seat; and (iv) a flow restriction disposed downstream of the gap, wherein when the valve is actuated, fluid is allowed to flow from the supply port through the first opening and the gap and through die flow′ restriction prior to flowing through the second opening to the operating port, such that the flow restriction generates an increased pressure level at the gap.