Danfoss A/s

Poul H Pedersen

Svend Erik Thomsen

Thorkild Christensen

Johannes V Baatrup

Ivar Rasmussen

Ole Vincentz So Slashedrensen

Niels G Karlberg

Hydraulic control arrangement

The handwheel of a vehicle is connected to a handwheel shaft which in turn is connected through a load torque isolating device (overrunning clutch) that acts in either of the two directions of rotation and is connected to a steering shaft that controls a hydraulic arrangement. The hydraulic arrangement controls a steering motor that in turn controls the direction of turning of the vehicle. A second motor is drivingly connected to the overrunning clutch to rotate the steering shaft when the second motor is operated but when the steering is controlled by the handwheel, movement of the second motor is prevented. The second motor is operable from a location remote from the vehicle. The overrunning clutch includes a hub connected to the steering shaft and is movable by the handwheel shaft, the hub being wedgable against the clutch housing for being driven by the second motor by two jamming rollers that each acts in one direction of rotation and can be released by rotating the handwheel shaft. In one embodiment, the load torque isolating device may be arranged between a planetary gear and the steering handwheel shaft arrangement. Sensors and a control circuit may be arranged to achieved a direct correlation between the position of the steering handwheel and the steering angle.

Steering arrangement

A control valve is opened (moved from its neutral position) by rotation of a steering wheel to conduct fluid from a pump to a steering meter device that controls the amount of fluid fed to a steering motor arrangement. When the steering motor piston has been displaced by a distance corresponding to the angle of rotation of the steering wheel, the control valve is moved by the steering meter device from its opened condition to its neutral position. A pilot valve controlled actuating device is provided to short circuit the steering meter device to permit continued fluid flow from the pump to the steering motor device and provide a mechanical braking force to the meter device to block rotation thereof and thereby the movement of the control valve to its neutral position. The braking mechanism is resiliently urged to a non-braking position.

Fully hydraulic steering arrangement for vehicles

The invention relates to a multi-groove and spline connection between a gear and cardan shaft of a rotary piston machine with an internal axis, wherein external toothing at the head of the cardan shaft engages internal toothing of the gear and an axial abutment co-operates with the end face of the head. The abutment is such that it is only contactable by the teeth of the head of the cardan shaft.

Multi-groove and spline connection between gear shaft of a rotary piston

A hydraulic sealing apparatus for sealing an annular gap between two members which are movable relatively to each other and one of which has an annular groove for receiving the sealing apparatus, the groove having a side wall at least on the low pressure side, comprising an elastic ring and a slide ring which consists of a slidable plastics material and has an annular sealing rib at its free circumferential surface.

Sealing apparatus with elastic seal ring and plastic slide ring

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 connects the outer sleeve member to the gerotor star member, a gear head connected to the adjacent end of the outer sleeve is disposed internally of the inner sleeve member. Supply and drain ports and motor ports connectable to an external servomotor are provided in a cover plate which is fastened to the gerotor gear set on the side thereof opposite from the valve unit. Some of the axial bores in the gerotor ring gear normally used as bolt holes are used as passages for connecting the supply port and the motor ports to the interior of the valve unit on the other side of the gerotor.

Control device for hydrostatic steering means

The invention relates to a reaction hydraulic control unit for use in steering systems of the type having a differential type servomotor. In steering systems of this type having a differential piston type servomotor there exists a condition during the piston centering operation when the unit is in neutral wherein the servomotor piston has a slower centering speed when the transfer of medium is from the nonrod side to the rod side of the servomotor. The unequal centering times causes annoyance to drivers because that condition is transmitted to the steering wheel. This problem is addressed by providing steering controlled valving for exhausting fluid from the nonrod chamber of the servomotor to the system tank after the control unit has returned to its neutral position and during the centering operation of the servomotor piston.

Reaction type hydraulic steering control unit

The invention relates to hydraulic steering apparatus of the type having valve gear for selectively directing pressurized fluid to and from opposite sides of a servomotor connected to vehicle wheels to be steered. This type of steering apparatus only requires pressurized fluid when actuated and may provide an auxiliary circuit with pressured fluid at times when it is not being actuated. Priority valves give priority to the steering apparatus. During extended intervals when pressured fluid is supplied to an auxiliary circuit, parts of the steering apparatus are subjected to substantial cooling. Then when the priority valve diverts hot pressurized fluid from the auxiliary circuit to the cooled steering apparatus the temperature differential causes an adverse effect on the steering apparatus by creating a tendency for binding of parts due to the unequal expansion of valve sleeves. A heat exchanger is provided having passages through which hot pressurized fluid to and from the priority valve is passed and the housing of the heat exchanger is in contact with the housing of the steering apparatus in the vicinity of the inlet and outlet ports of the steering apparatus. The heat exchanger prevents the steering apparatus parts from extensive cooling and the harmful uneven expansion of valve sleeve is avoided.

Growing community of inventors

Nordborg, Denmark

Poul H Pedersen