Patent ID: 9194506
Filing Date: 2015-11-24
Classification: F01L,F16K,Y10T

Abstract:
1. A central valve for a pivot motor actuator, the central valve, comprising: a housing tube including a first operating connection, a supply connection, a second operating connection and a tank drain connection, wherein a respective radial recess is associated with each of the two operating connections, wherein the respective radial recess is coverable by a respective annular bar of a piston that is arranged within the housing tube and axially moveable relative to the housing tube, wherein the first operating connection is connected with the supply connection in a first position of the piston in that a first annular bar opens a first radial recess towards the supply connection, wherein the second operating connection is opened by a second annular bar towards the tank drain connection in the first position of the piston, wherein the piston is in a center position in a second position of the piston, wherein the second operating connection is connected with the supply connection in a third position of the piston in that the second annular bar opens the second radial recess towards the supply connection, wherein the first operating connection is opened by the first annular bar towards the tank drain connection in the third position of the piston, wherein the piston includes at least one first check valve on its outside wherein the at least one first check valve opens a flow path from the first operating connection to the second operating connection when the piston is in the third position and a pressure is provided at the first operating connection that exceeds a first threshold value and the piston includes at least one second check valve on its outside wherein the at least one second check valve opens a flow path from the second operating connection to the first operating connection when the piston is in the first position and a pressure is provided at the second operating connection which exceeds a second threshold value, wherein both radial recesses are covered by the annular bars towards the tank drain connection by overlaps in the center position of the piston, so that pressure spikes above the threshold values from the operating connections to the check valves are highly throttled.