Abstract: A hydraulic steering device is provided comprising a supply port arrangement having a pressure port (P) and a tank port (5), a working port arrangement having two working ports (L, R), a main flow path (14) between the pressure port (P) and the working port arrangement, a return flow path (16) between the working port arrangement and the tank port (5), flow meter means (15) being arranged in said main flow path (14), an amplification flow path (17) being arranged in parallel to said main flow path (14), said amplification flow path (17) being connected to said main flow path (14) downstream said flow meter means (15) in a direction from said pressure port (P) to said working port arrangement. A risk of dangerous situations in case of jamming of the flow meter should be reduced. To this end pressure increasing means are provided increasing a pressure over said flow meter means (15) in case a flow through said main flow path (14) is blocked by said flow meter (15).

Abstract: A hydraulic steering arrangement (1) is provided comprising a static steering unit (2) and an adjustable pressure source (3) connected to a pressure port (4) of said steering unit (2) and having a load sensing port (21). Such a steering unit should enable a fast reaction of the steering unit. To this end said pressure source (3) is a dynamic pressure source having an orifice (Adyn) outputting hydraulic fluid to said load sensing port (21), a load sensing line (22) connecting said load sensing port (21) and a low pressure port (11), a control valve (24) being arranged in said load sensing line (22) between said load sensing port (21) and said low pressure port (11), said control valve (24) being actuated by a control pressure within said steering unit (2) and throttling a flow through said load sensing line (22) depending on said control pressure.

Abstract: A hydraulic steering device is provided comprising a supply port arrangement having a pressure port (P) and a tank port (5), a working port arrangement having two working ports (L, R), a main flow path (14) between the pressure port (P) and the working port arrangement, a return flow path (16) between the working port arrangement and the tank port (5), flow meter means (15) being arranged in said main flow path (14), an amplification flow path (17) being arranged in parallel to said main flow path (14), said amplification flow path (17) being connected to said main flow path (14) downstream said flow meter means (15) in a direction from said pressure port (P) to said working port arrangement. A risk of dangerous situations in case of jamming of the flow meter should be reduced. To this end pressure increasing means are provided increasing a pressure over said flow meter means (15) in case a flow through said main flow path (14) is blocked by said flow meter (15).

Abstract: A hydraulic steering arrangement (1) is provided comprising a static steering unit (2) and an adjustable pressure source (3) connected to a pressure port (4) of said steering unit (2) and having a load sensing port (21). Such a steering unit should enable a fast reaction of the steering unit. To this end said pressure source (3) is a dynamic pressure source having an orifice (Adyn) outputting hydraulic fluid to said load sensing port (21), a load sensing line (22) connecting said load sensing port (21) and a low pressure port (11), a control valve (24) being arranged in said load sensing line (22) between said load sensing port (21) and said low pressure port (11), said control valve (24) being actuated by a control pressure within said steering unit (2) and throttling a flow through said load sensing line (22) depending on said control pressure.

Abstract: The invention concerns a hydraulic machine with a toothed set comprising a toothed ring with an inner toothing, whose circumferential surface extends in parallel with its axis, and a gear wheel (3) with an outer toothing, whose circumferential surface (24) extends in parallel with its axis, at least one tooth flank having an edge as an axial end of a section, which is located between the circumferential surface and a surface directed radially inwards. It is endeavored to reduce the wear. For this purpose it is ensured that in the radial direction an edge (22, 23) ends so as to be offset inwards in relation to the circumferential surface (24).

Abstract: The invention concerns a hydraulic machine with a toothed set comprising a toothed ring with an inner toothing, whose circumferential surface extends in parallel with its axis, and a gear wheel (3) with an outer toothing, whose circumferential surface (24) extends in parallel with its axis, at least one tooth flank having an edge as an axial end of a section, which is located between the circumferential surface and a surface directed radially inwards. It is endeavoured to reduce the wear. For this purpose it is ensured that in the radial direction an edge (22, 23) ends so as to be offset inwards in relation to the circumferential surface (24).

Abstract: The invention concerns a hydraulic machine with a set of teeth, having a toothed ring with an inner toothing and a gear wheel with an outer toothing, the gear wheel rotating and orbiting in the toothed ring, the inner toothing and the outer toothing touching each other in contact areas, thus separating pressure chambers, and with a valve arrangement controlling a connection between a connection arrangement having a high pressure connection and a low pressure connection, and the pressure chambers. It is endeavoured to achieve a stable operation, particularly with low speeds. For this purpose, each contact area is provided with an opening, which, at the time when a pressure chamber reaches an extreme value of its volume, produces a short-circuiting with the neighbouring pressure chamber.

Abstract: A hydraulic motor of the disc valve type has a disc valve with a plurality of commutation slots that can sequentially register with ports in a port plate as the disc valve is rotated with respect to the port plate. The commutation slots have a geometrical configuration that is complimentary in shape to a portion of the geometric configuration of the ports in the port plate to reduce the resistance to fluid flow through the ports and the slots when the complimentary shapes move into or from superimposed registering positions.

Abstract: A gerotor motor has a housing located adjacent a port plate. The housing has two fluid chambers on opposite sides of a disc valve. The disc valve is in sealing surface engagement with the port plate to prevent fluid from moving between the fluid chambers. The valve assembly has forward and rearward sides and has substantially equal volumes of material removed therefrom so as to balance the port plate against any torsional forces imposed on the valve assembly which might otherwise deflect the valve assembly to interfere with its sealing relationship with the port plate.