Disclosed embodiments include travel motor hydraulic circuits for controlling the provision of hydraulic fluid to a travel motor. The travel motor hydraulic circuits include a counterbalance valve configured to block the flow of hydraulic fluid when in a neutral position to prevent unintended movement of a power machine, and an anti-cavitation valve configured to direct flow of hydraulic fluid back to the travel motor to prevent cavitation.

A method for generating cavitation resistance in a liquid, a portion of which can be in contact with a surface is disclosed. The disclosed method can be carried out by pressure-treating the liquid, the liquid portion in contact with the surface, and/or the surface for a sufficient time to develop resistance to cavitation. The disclosed method can be carried out when the surface is made of a material having a surface roughness that is greater than the rc of the liquid. Suitable surfaces include borosilicate glass, drawn glass, copper, lead, steel, cast iron, metal alloys and concrete. The surfaces can be ship and boat propeller surfaces, the interior of fuel lines and fuel storage containers or any other surface where cavitation can occur.

A method for generating cavitation resistance in a liquid, a portion of which can be in contact with a surface is disclosed. The disclosed method can be carried out by pressure-treating the liquid, the liquid portion in contact with the surface, and/or the surface for a sufficient time to develop resistance to cavitation. The disclosed method can be carried out when the surface is made of a material having a surface roughness that is greater than the rc of the liquid. Suitable surfaces include borosilicate glass, drawn glass, copper, lead, steel, cast iron, metal alloys and concrete. The surfaces can be ship and boat propeller surfaces, the interior of fuel lines and fuel storage containers or any other surface where cavitation can occur.

A pressure-limiting valve with feed function includes a valve housing (20) having a working connection (A) and a tank connection (T). A spring-loaded pressure-limiting valve piston (22) is mounted and longitudinally movable in the valve housing (20). A spring-loaded non-return valve piston (56) for the implementation of the feed function is designed as a hollow piston and is mounted to be longitudinally movable in the valve housing (20).

The valve module can be installed regardless of an oil level, for example of an oil level of an oil sump of a motor vehicle. By means of a buffer volume having an overflow it is always guaranteed that a leakage flow conveyed past a valve piston includes no air but consists solely of hydraulic medium, since the overflow guarantees a level of hydraulic medium which lies above an upper face of the valve piston in a preferred installation position. As a result, foaming of the hydraulic medium can be prevented. The valve module can also be installed above the oil sump, for example in an upper region of a gearbox of the motor vehicle. In addition, the oil from the overflow can be used for cooling/lubrication of further drive train components.

A method and application for eliminating gaseous cavitation. The method allows for the determination of the types of problems that cause cavitation, such as RPM, temperature, differential pressure and flow rate, as well as the application of possible techniques for the permanent solution of gaseous cavitation in the power steering system in heavy-duty vehicles.

A fluid storage reservoir that creates a regenerative loop inside the reservoir to maintain a pressurized main suction chamber of the hydraulic fluid reservoir is provided. This reservoir includes two separate chambers which are operably fluidly connected by one or more check valves. In the main suction chamber, the design arranges the return flow larger than suction flow in order to pressurize this chamber. This pressure can be adjusted by the check valve setting. This regenerative reservoir can provide sufficient pressure when large system flow occurs.

A diffuser for a return line on a hydraulic tank may include a coupling portion configured for coupling in fluid communication with a return port of the hydraulic tank and for receiving return fluid along an incoming longitudinal direction. The diffuser may also include a dispersion portion in fluid communication with the coupling portion and configured for dispersing the return fluid radially. The diffuser may also include a manifold arranged around the dispersion portion and configured to direct the return fluid circumferentially and axially.

A diffuser for a return line on a hydraulic tank may include a coupling portion configured for coupling in fluid communication with a return port of the hydraulic tank and for receiving return fluid along an incoming longitudinal direction. The diffuser may also include a dispersion portion in fluid communication with the coupling portion and configured for dispersing the return fluid radially. The diffuser may also include a manifold arranged around the dispersion portion and configured to direct the return fluid circumferentially and axially.

A hydraulic machine includes an actuator, a tank, a directional control valve disposed between the actuator and the tank, and an adjustable return check valve disposed between the directional control valve and the tank. The directional control valve includes an attachment actuator directional control valve disposed between an attachment actuator of the actuator and the tank and a swing actuator directional control valve disposed between a swing actuator of the actuator and the tank. The adjustable return check valve allows fluid to flow from the attachment actuator directional control valve toward the tank while applying the low back pressure but blocks a flow, and allows fluid to flow from the swing actuator directional control valve toward the tank while applying the high back pressure but blocks a reverse flow.