Abstract: A hydraulic pump system having a pump for pressurizing fluid and a hydraulic chamber for receiving fluid from the pump. An even flow of fluid is outputted from the chamber to a valve assembly. The chamber is formed from a resonator and a resonator cover that are attached in a fluid tight manner by elastic fasteners. The resonator cover acts as a pressure controller in that when the pressure of fluid is of sufficient magnitude, this force creates a gap for controlling fluid pressure output to the valve assembly.

Abstract: A shaft seal seals a shaft in a hydraulic steering valve. The seal is a sealing ring surrounding the shaft. The sealing ring has a sealing edge contacting the outer surface of the shaft to form a seal. The sealing edge extends circumferentially around the outer surface of the shaft in a sinusoidal fashion. The sealing ring has first and second surfaces which extend radially outward from the sealing edge and which diverge relative to each other as they extend radially outward from the sealing edge. The first and second surfaces extend entirely circumferentially around the outer surface of the shaft. The first surface extends at a constant first angle relative to said sealing edge throughout the entire circumferential extent of the first surface and the second surface extends at a constant second angle relative to the sealing edge throughout the entire circumferential extent of the second surface.

Abstract: In order to additionally develop a conventional steering valve in such a way that it has a simple and economical design and is insensitive to pressure pulsations, a conventional steering valve is additionally developed by arranging at least one essentially coaxial chamber that extends in the shape of an arc and can be charged with hydraulic pressure either directly or indirectly on the input shaft or the output shaft, with at least one piston element that is directly or indirectly connected to the other shaft being arranged in the aforementioned chamber such that it can be moved along an essentially arc-shaped path.

Abstract: In order to improve a steering valve of the relevant type such that it is of simple and economical design and without requiring increases in design length and so that it is not sensitive to rotational vibrations, a steering valve is designed to supply a servoelement with hydraulic pressure, consisting of an input shaft located in a housing, an output shaft, a centering spring element and a valve element, such that the steering valve has at least one chamber moving in a circular motion, essentially coaxial and supplied with hydraulic pressure, in which at least one piston element can move on an essentially circular path, where the chamber and/or the piston element form a portion of a bearing located between one of the shafts and the casing, or are connected axially parallel to it.