Direct drive servovalve with rotary valve
AssigneeDavidson Textron Inc.
InventorDennis D. Johnson
Life of this patent
Estimating the term…
Abstract
An electrical force motor and servovalve combination has a rotary spool directly coupled to the motor shaft without requiring a rotary-to-linear motion convertor; the rotary spool is configured to have a cruciform metering section that cooperates with a flow sleeve having ports and slots configured to produce four-way flow patterns in a reduced length and volume valve package.
Claims10
In a motor driven four-way valve assembly including a drive motor connected to a rotary spool having lands thereon moveable with respect to metering passages for modulating pressure from a pressure source port in the valve housing to first and second control ports and for modulating pressure flow from the control ports to a return port the improvement comprising:
- a circular sleeve in said valve housing rotatably supporting the rotary spool and having a pair of pressure metering passages and having a pair of return metering passages;
- means for directing pressure to said pressure metering passages including a first groove formed in the outer circumference of said circular sleeve, means for returning pressure flow from said return metering passages including a second groove formed in the outer circumference of said circular sleeve, said first and second grooves each having an arcuate segment formed on a circle segment of said sleeve;
- said first and second grooves having spaced offset end segments therein communicating respectively with said pair of pressure metering passages and with said pair of return metering passages to equalize radial pressure on the rotary spool for reducing the force required to rotate the rotary spool with respect to the circular sleeve.
In a motor driven four-way valve assembly having a drive motor connected to a rotary spool having lands thereon moveable with respect to metering means for modulating pressure from a pressure source pot in the valve housing to first and second control ports and for modulating pressure flow from the control ports to a return port the improvement comprising:
- a circular sleeve in said valve housing rotatably supporting the rotary spool and having a first pair of pressure metering passages and having a second pair of return metering passages;
- means for directing pressure to said metering passages including overlapping grooves formed in the outer circumference of said circular sleeve, said overlapping grooves each having an arcuate segment formed on a circle segment of said sleeve;
- said overlapping grooves each having spaced offset end segments therein communicating with said metering passages to produce an equalized radial pressure on the rotary spool for reducing force required to rotate the rotary spool with respect to said circular sleeve.
Dependencies are inferred from the claim text.