Abstract: A hydraulic steering unit (1) is described comprising a supply port arrangement having a pressure port (8) connected to a main flow path (6) and a tank port (T) connected to a tank flow path (7), a working port arrangement having a left working port (L) connected to a left working flow path (9) and a right working port (R) connected to a right working flow path (10), a bridge arrangement (14) of variable orifices having a first left orifice (A2L) connected to the main flow path (6) and to the left working flow path (9), a first right orifice (A2R) connected to the main flow path (6) and to the right working flow path (10), a second left orifice (A3L) connected to the left working flow path (9) and to the tank flow path (7), and a second right orifice (A3R) connected to the right working flow path (10) and to the tank flow path (7). Such a hydraulic steering unit should allow comfortable steering.

Abstract: A hydraulic steering unit (1) is described comprising a supply port arrangement having a pressure port (8) connected to a main flow path (2) and a tank port (5) connected to a tank flow path (3), a working port arrangement having a left working port (L) connected to a left working flow path (4) and a right working port (R) connected to a right working flow path (5), a variable first left orifice (A2L) connected to the main flow path (2) and to the left working flow path (4), a variable first right orifice (A2R) connected to the main flow path (2) and to the right working flow path (5), a variable second left orifice (A3L) connected to the left working flow path (4) and to the tank flow path (3), and a variable second right orifice (A3R) connected to the right working flow path (5) and to the tank flow path (3). Such a steering unit should allow comfortable steering. To this end a measuring motor (15) is arranged in one of the working flow parts (4, 5).

Abstract: A hydraulic steering unit (1) is described comprising a supply port arrangement having a pressure port (P) connected to a main flow path (2) and a tank port (T) connected to a tank flow path (3), a working port arrangement having a left working port (L) connected to a left working flow path (9) and a right working port (R) connected to a right working flow path (10), a bridge arrangement (15) of variable orifices having a first left orifice (A2L) connected to the main flow path (2) and to a left connecting point (16) at the left working flow path (9), a first right orifice (A2R) connected to the main flow path (2) and to a right connecting point (17) at the right working flow path (10), a second left orifice (A3L) connected to the left connecting point (16) at the left working flow path (9) and to the tank flow path (3), and a second right orifice (A3R) connected to the right connecting point (17) at the right working flow path (10) and to the tank flow path (3).

Abstract: A hydraulic steering arrangement (2) is described having a main flow path (8) with a flow meter (9) and an amplification flow path (10) opening into the main flow path (8) at a connecting point (11) located between the flow meter (9) and a working port arrangement (L, R). Such a steering arrangement should have in a simple way a large flow of the hydraulic fluid to the working port arrangement. To this end pressure increasing means (17) are arranged in the main flow path (8) upstream the connecting point (11).

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: A control device (1) for a hydrostatic steering motor comprises supply and return pump and tank connections (P, T), a slide valve arrangement in which inner and outer slide element sleeves are rotatable relative to each other to both sides of a neutral position through a limited small angle, said sleeves mutually forming controlled supply and return passages connected to said motor having supply and return throttles which are closed when said sleeves are in a neutral position, bypass throttle means (7) between said pump and tank connections (P, T) being open when said sleeves are in a neutral position, said bypass throttle means (7) having a set of at least two variable orifices connected in series. In such a device the noise should be reduced when a higher supply pressure of hydraulic fluid is used.

Abstract: A control device (1) for a hydrostatic steering motor comprises supply and return pump and tank connections (P, T), a slide valve arrangement in which inner and outer slide element sleeves are rotatable relative to each other to both sides of a neutral position through a limited small angle, said sleeves mutually forming controlled supply and return passages connected to said motor having supply and return throttles which are closed when said sleeves are in a neutral position, bypass throttle means (7) between said pump and tank connections (P, T) being open when said sleeves are in a neutral position, said bypass throttle means (7) having a set of at least two variable orifices connected in series. In such a device the noise should be reduced when a higher supply pressure of hydraulic fluid is used.

Abstract: The invention provides a fluid controller, e.g. for a hydrostatic power steering. The controller comprises a cylindrical valve member cooperating with a housing to define at least one fluid path from a pressure source to a steering cylinder. The valve member is rotatable in the housing and comprises a sleeve and a spool, wherein the spool is rotatable within the sleeve. The fluid flow is metered by a flow meter, and the valve member comprises a plurality of meter ports communicating the fluid between the valve member and the flow meter. To obtain less friction between the sleeve and the housing and between the sleeve and the spool, the meter ports are grouped in two groups in which groups the ports are in mutually fluid communication.

Abstract: The invention provides a fluid controller, e.g. for a hydrostatic power steering. The controller comprises a cylindrical valve member cooperating with a housing to define at least one fluid path from a pressure source to a steering cylinder. The valve member is rotatable in the housing and comprises a sleeve and a spool, wherein the spool is rotatable within the sleeve. The fluid flow is metered by a flow meter, and the valve member comprises a plurality of meter ports communicating the fluid between the valve member and the flow meter. To obtain less friction between the sleeve and the housing and between the sleeve and the spool, the meter ports are grouped in two groups in which groups the ports are in mutually fluid communication.

Abstract: A leakage compensation system in a control device (S) has a fully hydraulic steering system (1) with a supply connection arrangement having a high-pressure connection (P) and a low-pressure connection (T). A working connection arrangement has two working connections (CL, CR), a control section between the supply connection arrangement (P, T) and the working connection arrangement (CL, CR). A control element (2) for activating the control section, a steering member (3) and an auxiliary fluid path (12) has a valve arrangement (A6, A7), through which hydraulic fluid can be supplied or drained off.

Abstract: A leakage compensation system in a control device (S) has a fully hydraulic steering system (1) with a supply connection arrangement having a high-pressure connection (P) and a low-pressure connection (T). A working connection arrangement has two working connections (CL, CR), a control section between the supply connection arrangement (P, T) and the working connection arrangement (CL, CR). A control element (2) for activating the control section, a steering member (3) and an auxiliary fluid path (12) has a valve arrangement (A6, A7), through which hydraulic fluid can be supplied or drained off.

Abstract: A hydraulic steering device, in particular for vehicles, is disclosed, having a housing in which two sliders are arranged to move relative to one another and together form at least one adjustable throttle, a restoring device for restoring the two sliders to their neutral position being provided, one of the two sliders being driveable and the other of the two sliders being in operative connection with a measuring device. In such a steering device it is desirable to improve the correlation between steering torque and flow amplification; in particular it is desirable to linearize the relationship better. For that purpose the measuring device is arranged in a flow path closed in itself, and operates as a pump, while an open flow path runs past the closed flow path from an inlet connection arrangement to an outlet connection arrangement.

Abstract: In a device for controlling the pressure to be supplied to a hydrostatic steering unit (1) by means of a control signal (s), there is a rotary slide valve arrangement, one slide valve element of which is rotatable by means of a steering means (5) and the other side valve element of which is corrected by means of a measuring motor (16). Together with a series throttle (AV), a control throttle (AS) forms a series circuit independent of the intake path of the steering motor (4), which circuit is connected between a pressure source (CF) and the tank (6). The control throttle (AS) has a closing characteristic that extends substantially across the entire working range of the angle of rotation of the slide valve elements. The control signal (s) is tapped between the series throttle (AV) and the control throttle (AS). This provides a pressure control that is independent of load.

Abstract: In a hydraulic power steering control unit of the type having an inner steering wheel operated control member which has limited relative rotation movement with respect to outer control member which controls a conventional steering motor, passages are provided in these members to control the pressures therebetween to prevent jamming thereof.

Abstract: Clutch and brake apparatus that is operable by a compressible fluid, particularly pneumatically, includes input and output shafts mounted in a common housing that has a clutch chamber. A clutch plate and a clutch flange are mounted in the clutch chamber with the flange being fixed to the input shaft and the clutch plate dividing the clutch chamber into two operating chambers that are adapted to be at different fluid pressures. A friction lining is fixed to at least one of the clutch plate and clutch flange for engaging the other. A clutch plate is mounted to be axially displacable relative to the output shaft in every load condition while at least one torque plate is fixed to rotate with the output shaft and a peripheral portion of the clutch plate. The torque plate is subjected to the same fluid pressure on both sides. The apparatus is able to operated with a large pressure differences across the clutch plate without danger of damaging the clutch plate.

Abstract: The invention relates to a hydrostatic power steering unit of the type having a gerotor gear set forming a metering motor and a valve unit for routing pressurized fluid from an inlet port selectively via expansible chambers of the gerotor gear set to either one of two motor ports while connecting the other one of the motor ports to an outlet port. The housing of the valve unit, which has inner and outer rotary sleeve members, is arranged adjacent the gerotor gear set. A cardan shaft which connects the outer sleeve member to the gerotor star member has a gear head connected to the adjacent end of the outer sleeve member but the shaft itself is disposed mostly in the gerotor star member. The bore of the inner sleeve member has a smaller diameter than that of the shaft head connected to the outer sleeve member and the annularly and axially extending valving grooves of the inner valve member may thus have relatively greater radial depths and thereby relatively greater capacity.