A hydraulic steering arrangement (1) is described comprising a supply port arrangement (P, T) having a pressure port (P) and a tank port (T), a working port arrangement having two working ports (L, R), a main flow path (2) having a main orifice (A.sub.1), at least one further orifice (A.sub.2, A.sub.3, A.sub.4) downstream the main orifice (A.sub.1), and a measuring motor (3), the main flow path (2) being arranged between the pressure port (P) and the working port arrangement (L, R), a return flow path (4) arranged between the working port arrangement (L, R) and the tank port (T), an amplification flow path (6) having an amplification orifice (A.sub.U) and being arranged between the pressure port (P) and the working port arrangement (L, R), and an adjustable pressure source (9) connected to the pressure port (P) and having a load sensing port (18), wherein a main drain orifice (A.sub.md) is connected between the main flow path (2) downstream the main orifice (A.sub.1) and the return flow path (4). It should be possible to operate such a steering arrangement with a dynamic flow. To this end a flow divider (19) connects the load sensing port (18) with the main flow path (2) downstream the main orifice (A.sub.1) and the amplification flow path (6) downstream the amplification orifice (A.sub.U).

A steering device for a steerable machine, particularly a construction machine, comprising a steering element for manual input of steering commands, a steering actuator for driving a steering adjustment of a travel unit of the construction machine, and a transmission device, which is arranged between the steering element and the steering actuator, the transmission device including an actuator orbitrol for driving the steering actuator. Furthermore, the invention relates to a construction machine having such a steering device, as well as to a method for steering a steerable machine, particularly a construction machine.

A method (300) and control arrangement (210) for controlling a vehicle (100) to freewheel with engine off. The vehicle (100) has an engine (260) for propelling the vehicle (100) and a hydraulic power steering system (400). The hydraulic power steering system (400) comprises a primary power steering pump (270a) arranged to be driven by the engine (260) and a secondary power steering pump (270b). The method (300) includes: determining (301) when to start freewheeling the vehicle (100) with its engine off; and prior to starting the freewheeling of the vehicle (100) with engine off, determining (302) to start the secondary power steering pump (270b).

A steering gear includes a housing defining a chamber. A piston divides the chamber into first and second chamber portions. The piston is moveable along a linear axis relative to the housing upon pressurization of fluid in one of the first and second chamber portions. A pressure relief vents pressurized fluid from one of the first and second chamber portions to one other of the first and second chamber portions upon movement of the piston to a predetermined position. The pressure relief assembly includes a first valve at a first end of the pressure relief assembly and a second valve at a second end of the pressure relief assembly. The pressure relief assembly is axially movable relative to the piston to adjust the position of the first valve and the second valve relative to the piston.

A hydraulic steering unit is described comprising a housing (1) and a non-return valve (2) having a ball (3) and a valve seat (4) at an end of a channel (5) in the housing (1), wherein a movement of the ball (3) away from the valve seat (4) is limited by an abutment (7) in the channel (5). Such a steering unit should have a non-return valve which can be produced with low costs. To this end the abutment (7) extends transversely through the channel.

A steering system includes a drag link having a first support bushing opposite a second support bushing, a first steering hydraulic cylinder operably connected to the drag link, a second steering hydraulic cylinder operably connected to the drag link, a first tie rod operably connected to the drag link, and a second tie rod operably connected to the drag link. Each of the first and second cylinders and first and second tie rods are arranged to apply a corresponding radial force that is distributed between the first and second support bushings. One or more of the first and second steering cylinders and/or the first and second tie rods is positioned relative to the drag link to minimize a net summation of the first and second cylinder radial forces and the first and second tie rod radial forces that are applied to the first and second support bushings.

Hydraulic bi-directional flow switches are disclosed. A disclosed example apparatus includes a piston disposed in a fluid channel between a first fluid connection and a second fluid connection, where the first and second fluid connections define a fluid pathway for hydraulic steering fluid. The example apparatus also includes a detector to detect a movement of the piston away from a default position of the piston, where the piston is to displace from the default position when the hydraulic steering fluid flows along the fluid pathway.

A vortex reservoir for separation of an aerated portion of a hydraulic fluid includes an upper chamber and a lower chamber, in fluid communication with the upper chamber, having a lower chamber sidewall. The lower chamber includes a lower lower chamber and an upper lower chamber. The lower chamber includes a lower chamber partitioning plate. The lower chamber partitioning plate is located between the lower lower chamber and the upper lower chamber. The lower lower chamber is in fluid communication with the upper lower chamber via a gap between the lower chamber partitioning plate and the lower chamber sidewall.

A ball-nut steering system of a conventional vehicle includes a first and a second cylinder chamber for receiving a fluid, a first feed line for conducting fluid from a pump to the first cylinder chamber, and a device for damping and/or easing pulsations of the fluid. The device is arranged inside the first cylinder chamber and/or inside the first feed line. The first cylinder chamber has a smaller volume for receiving the fluid than the second cylinder chamber.

A system and method for detecting the functional state of a piloted or direct-operated isolation valve in a hydraulic circuit is presented. In some examples the hydraulic circuit is a steering circuit and the isolation valve provides selective isolation between a hydraulic actuator and one or more metering valves. In some examples, the isolation valve assembly is movable between a first position, in which fluid flow between the metering valve and the actuator is enabled, and a second position, in which fluid flow between the metering valve and the actuator is blocked. When the isolation valve assembly is moved to one of the first and second positions, an inlet port and a pressure sensing port of the isolation valve assembly are placed in fluid communication with each other. When the isolation valve assembly is moved to the other of the first or second position, a second inlet port and the pressure sensing port are placed in fluid communication.