High-flow direct-drive rotary servovalve

• US 5,597,014 A
• Filed: 11/08/1995
• Issued: 01/28/1997
• Est. Priority Date: 03/31/1994
• Status: Expired due to Term

• Current Assignee: Moog Incorporated
• Original Assignee: Moog Incorporated
• Inventors: Vick, Ralph L.
• Primary Examiner(s): Michalsky, Gerald A.
• Application Number:
  US08/555,574
• Time in Patent Office: 447 Days
• Field of Search: 137/625.22, 137/625.23, 251/283
• US Class Current: 137/625.23
• CPC Class Codes: F15B 15/12 of the oscillating-vane or curved-cylinder type
• CPC Class Codes: F15B 9/14 with rotary servomotors
• CPC Class Codes: Y10T 137/86654 For plural lines

Abstract

A rotary valve (10) is adapted to be associated with a fluid source (P) and a fluid return (R), and is adapted to control the flows of fluid (via control ports C₁ and C₂) with respect to the opposed chambers of a fluid-powered load. The valve has a body (11) provided with an elongated bore (12). The body has a plurality of passageways (23, 24, 25, 26) communicating spaced locations along the bore with the source, return and load control ports, respectively. A spool member (28) is rotatably mounted in the bore. The spool member has a passage adapted to cooperate with a body passageway so as to define at least one flow-metering port therebetween. The area of this flow-metering port or orifice (34) is a function of the angular displacement of the spool member relative to the body from a null position. The improvement comprises each of the upstream approach walls (32, 35) adjacent the orifice being relieved at an angle (β) of at least 21° with respect to a radial plane so as to cause the flow through the orifice, whether directed inwardly or outwardly, to be substantially radial, thereby to eliminate tangential Bernoulli reaction forces acting on the spool member.

Claims

1. In a rotary valve adapted to be associated with a fluid source and a fluid return, and adapted to control the flows of fluid through variable-area metering ports with respect to the opposed chambers of a fluid-powered load, said valve having a body provided with an elongated bore, said body having at least one passageway communicating at a location along said bore with said one of said source, return and load, said valve also having a spool member rotatably mounted in said bore, said spool member having a passage adapted to cooperate with said body passageway so as to selectively uncover a metering port therebetween, the orifice area of said metering port being a function of the angular position of said spool member relative to said body, wherein the improvement comprises:

said cooperative body passageway and spool passage being so configured and arranged so as to cause the flow through said metering port to be oriented such that the application of tangential reaction forces attributable to said flow to said spool member is eliminated, and wherein a wall of the passage or passageway located upstream of said orifice terminates in an edge of said metering port which is arranged in a plane containing the axis of said spool and said wall is relieved from said plane by art angle of at least 21°

such that the flow through said metering port is radial.

2. The improvement as set forth in claim 1 wherein said body includes a sleeve member surrounding said spool member and extending said body passage to cooperate with said spool passageway.

3. The improvement as set forth in claim 1 wherein said body passageway is substantially rectangular at the intersection of said bore.

4. The improvement as set forth in claim 1 wherein said spool member passage is substantially rectangular in the vicinity of said bore.

6. The improvement as set forth in claim 2 wherein said body includes a sleeve member surrounding said spool member and extending said body passage to cooperate with said spool passageway.

5. In a rotary valve adapted to be associated with a fluid source and a fluid return, and adapted to control the flows of fluid through variable-area metering ports with respect to the opposed chambers of a fluid-powered load, said valve having a body provided with an elongated bore, said body having a passageway communicating at a location along said bore, said valve also having an elongated spool member rotatably mounted in said bore, said spool member having a passage adapted to cooperate with said body passageway so as to selectively uncover a metering port therebetween, the orifice area of said metering port being a function of the angular position of said spool member relative to said body, and wherein the direction of fluid flow is inward from said one passageway to said spool member passage, the improvement which comprises:

said body passageway being so configured and arranged so as to cause the inward flow through said metering port to be substantially radial such that the application of tangential reaction forces attributable to said inward flow to said spool member is substantially eliminated, and wherein a wall of the passageway located upstream of said orifice terminates in an edge of said metering port which is arranged in a plane containing the axis of said spool and said wall is relieved from said plane by an angle of at least 21°

such that the flow through said metering port is substantially radial.

7. The improvement as set forth in claim 5 wherein said body passageway is substantially rectangular at the intersection of said bore.

8. The improvement as set forth in claim 5 wherein said spool member passage is substantially rectangular in the vicinity of said bore.

9. In a rotary valve adapted to be associated with a fluid source and a fluid return, and adapted to control the flows of fluid through variable-area metering ports with respect to the opposed chambers of a fluid-powered load, said valve having a body provided with an elongated bore, said body having two passageways communicating with said bore at spaced locations therealong, said valve also having an elongated spool member rotatably mounted in said bore, said spool member having two passages each adapted to cooperate with a respective one of said body passageway so as to selectively uncover two metering ports therebetween, the orifice areas of said metering ports being a function of the angular position of said spool member relative to said body, and wherein the direction of fluid flow is inward through one metering port and outward through the other metering port, the improvement which comprises:

said body passageways and said spool passages being so configured and arranged that the application of tangential reaction forces attributable to the flows through each of said metering ports to said spool member is substantially eliminated, and wherein a wall of each passageway or passage located upstream of an associated orifice terminates in an edge of said metering port which is arranged in a plane containing the axis of said spool and said wall is relieved from said plan by an angle of at least 21°

such that the flow through said metering port is substantially radial.

10. The improvement as set forth in claim 9 wherein said body includes a sleeve member surrounding said spool member and extending said body passage to cooperate with said spool passageway.

11. The improvement as set forth in claim 9 wherein said body passageway is substantially rectangular at the intersection of said bore.

12. The improvement as set forth in claim 9 wherein said spool member passage is substantially rectangular in the vicinity of said bore.