Abstract: An invention is disclosed in which a mechanical hydraulic component includes fluid-bearing passageways. The fluid-bearing passageways are defined by a pre-formed tubing cluster which resides within a block which is cast around the tubing cluster in order to define a solid body which is fuse-bonded to the tubing cluster. The present mechanical body is formed by providing hollow tubing which is bent to provide a tube member having a desired configuration. A number of tube members are secured in order to provide a tubing cluster which defines the preformed fluid-bearing passageways. After that, a castable material is cast around the tubing cluster so as to produce a solid block with the tubing cluster embedded therein. The block and tubing cluster are formed of predetermined materials which result in chemical infiltration in order to produce a low-porosity fusion bond.

Abstract: Compensation for friction affecting motion of moveable machine members is effected in servo control of the member actuators. An estimate of velocity is used in evaluation of a model of frictional force to produce compensation values. Alternative embodiments provide continuous models of estimated velocity and frictional forces and state models of estimated velocity and frictional forces. Compensation values determined according to either embodiment may be produced for application to servo control commands such as position or torque. The compensation accounts for step changes of friction upon reversal of direction of travel.

Abstract: A hydraulic pump is disclosed which uses a side-discharge valve plate. The present valve plate includes a valve plate body having front and back surfaces with a side defining the peripheral surface therebetween. First and second fluid passages are formed on at least one of said front and back surfaces for respectively defining a fluid inlet for supplying hydraulic fluid to a piston and a fluid outlet for receiving pressurized hydraulic fluid from a piston. At least one fluid access is formed in the side of the valve plate body, connecting with at least one of said fluid passages to define a fluid pathway therewith. The design of the present invention thereby permits a pump design have shorter axial length, permitting a smaller size pump which offers improved space considerations. Also, the present valve plate also has few contact surfaces, thereby reducing leakage and improving pump efficiency.

Abstract: A low noise hydraulic pump is disclosed which can be an piston pump or a vane pump, including a flow generation assembly with at least one pumping chamber for creating positive displacement of hydraulic fluid into a hydraulic system. The pump also includes a valve plate in fluid communication with the flow generation assembly, wherein the valve plate defines an inlet for admitting hydraulic fluid and also an outlet for receiving discharged hydraulic fluid. A check valve assembly is received within the valve plate for establishing a fluid passageway between the flow generation assembly and the outlet, wherein the check valve assembly reduces the pressure overshoot between the flow generation assembly and the outlet. The check valve assembly further comprises a check valve having a plurality of apertures, the apertures being sized so as to permit a predetermined flow of fluid through the check valve assembly, whereby the check valve assembly reduces noise generated by the pump.

Abstract: A control for machine members propelled at plural points along their length to move linearly transverse to member length determines and eliminates skew of the driven points. Skew is determined from position indicated by position transducers associated with the driven points. Various types of position transducers are accommodated, including encoders having outputs from which member position can be determined only with reference to marker outputs of the transducer. For such encoders, the control effects velocity controlled motion to detect position. Skew is eliminated by relatively moving the driven points by the magnitude of the skew.