Rotatable controller system
AssigneeZahnradfabrik Friedrichshafen AG
InventorWerner Tischer
Life of this patent
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Abstract
Axially spaced and aligned longitudinal distributor grooves are formed in the radially outer surface of a thin-walled tubular valve element in angularly spaced relation to internal grooving of the valve element for conducting pressurized fluid and establishing a torsional coupling in a hydrostatic controller associated with a power steering system. Obliquely orientated bores in the valve housing establish fluid communication between the longitudinal grooves adjacent opposite axial ends of the housing and axial passages in the housing.
Claims15
A power steering system, including a metering pump device having an internally toothed stator gear (1) and an externally toothed rotor gear (6) in mesh with said stator gear, a valve housing (3) fixed to the stator gear having a bore (3A) formed therein, a servomotor (26), a drive shaft (9), a hinge coupling (8) connecting the drive shaft to the rotor gear, a rotatable valve element (10) means mounting the valve element for axial displacement within said bore of the housing to control flow to and from said servomotor, drive pin means (11) coupling the valve element to the hinge coupling for rotation of the rotor gear in response to rotation of the valve element to control the metering pump device, said valve element having two systems (27 and 28) of axially limited, longitudinal distributor grooves (29 and 30) formed externally thereon, said housing further having a supply passage (18), two outlet ports (22, 23) connected to the servomotor and axial passages (35) formed therein, said distributor grooves of the respective systems being substantially aligned with each other in an axial direction within predetermined limits, and connecting passages (36, 37), formed in the housing establishing fluid communication between the distributor grooves at the bore and the axial passages.
In a fluid power operated system having a source of pressurized medium (17), a servomotor (26) and a fluid metering device (1-6) through which the pressurized medium is conducted to the servomotor, a controller comprising a housing (3) formed with a bore (3A), an axial passage (35) and inlet and outlet ports (16, 22, 23) in fluid communication with said bore, a tubular valve element (10), means operatively mounting said valve element in said bore for axial and angular displacements respectively controlling flow of the pressurized medium and operation of the fluid metering device, said valve element having radially outer and inner surfaces extending between opposite axial ends thereof and passage means through which said pressurized medium is conducted from the source, including axially aligned grooves (29 and 30) formed in the outer surface of the valve element adjacent said opposite ends, and connecting bores (36 and 37) extending through the housing between said axial passage and the grooves.
In a fluid power steering system having a source of pressurized fluid (17), a servomotor (26), a steering drive shaft (9), a fluid metering device including a rotor gear (6), and controller means driven by the drive shaft for controlling flow of the fluid along flow paths between said source and the servomotor through the metering device and operation of the metering device including a valve housing (3), a tubular valve element (10), and means operatively connecting the drive shaft to the valve element and the rotor gear for axial and angular displacements of the valve element to respectively control said flow of the fluid and said operation of the metering device, the improvement residing in internal groove means (31, 32, 33) formed internally of the tubular valve element for establishing a torsional coupling between the valve element and the rotor gear and form flow passages conducting said fluid along said flow paths and distributor groove means (29, 30) formed externally in the valve element in angularly spaced relation to the internal groove means for establishing said flow paths, whereby the flow paths and the torsional coupling are formed in the tubular valve element having a reduced radial thickness.
Dependencies are inferred from the claim text.