Dynamic ball valve sealing device for three-way valves

• US 7,712,724 B2
• Filed: 06/21/2007
• Issued: 05/11/2010
• Est. Priority Date: 06/21/2007
• Status: Active Grant

• Current Assignee: Schneider Electric Buildings Americas Incorporated (Schneider Electric SE)
• Original Assignee: Tac, LLC
• Inventors: Thomas, Kurt R.
• Primary Examiner(s): Fristoe, Jr.; John K
• Application Number:
  US11/766,611
• Publication Number:
  US 20080315144A1
• Time in Patent Office: 1,055 Days
• Field of Search: 251/315.01, 251/315.16, 251/314, 251/359, 137/625, 137/625.4, 137/625.41, 137/625.46, 137/602
• US Class Current: 251/314
• CPC Class Codes: F16K 11/0873 the plug being only rotatable around one spindle
• CPC Class Codes: F16K 5/201 with the housing or parts of the housing mechanically pressing the seal against the plug
• CPC Class Codes: Y10T 137/86823 Rotary valve
• CPC Class Codes: Y10T 137/86863 Rotary valve unit
• CPC Class Codes: Y10T 137/87571 Multiple inlet with single outlet

Abstract

A ball valve having improved sealing between the valve member and the valve body is presented. Improved sealing is realized by providing a sealing member that is allowed to float on the outer surface of the valve member in the closed position. By being able to float on the outer surface, the sealing member can compensate for any variations in the valve member as a result of machining tolerances or variations in position of the valve member due to changes in pressure within the valve, thereby providing dynamic sealing The dynamic sealing is also provided by configuring the valve member such that it causes the sealing member to be exposed to a higher biasing force in the closed position than in the open position.

Claims

1. A ball valve comprising:

a valve body defining a flow passage having a plurality of flow ports and a valve chamber thereinbetween;

a valve member disposed within the valve chamber and having a through passage therein defining through passage openings, the valve member selectively movable within the valve chamber between an open position and a closed position, the open position providing an in-fluid-communication alignment of the through passage with a first flow port of the plurality of flow ports and at least another one of the plurality of flow ports, and the closed position providing an out-of-fluid-communication alignment of the through passage with the first flow port for blocking flow between the first port and the through passage;

a seal including a seal member carried by the valve body in sealing contact with the first port, the seal member having, in the open position, a first end substantially aligned with a first one of the through passage openings and positioned a first distance from an axis of rotation of the valve member, and in the closed position, the seal member is aligned with and in sealing contact with a seal-off portion of the surface of the valve member and positioned a second distance from the axis of rotation, the second distance being greater than the first distance; and

a spring member biasing the dynamic seal member toward the valve member.

2. The ball valve of claim 1, wherein the seal-off portion of the surface of the valve member is imperforate.

3. The ball valve of claim 2, wherein the geometry of the valve member is configured such that voids are formed by deviations of the valve member from having a continuously rotation symmetric outer surface about the axis of rotation.

4. The ball valve of claim 3, wherein the surface of the valve member is generally spherical and the voids are defined by deviations in the spherical shape defined by the through passage openings intersecting the outer surface.

5. The ball valve of claim 4, wherein a diameter of a valve member end of the seal member is smaller than a diameter of at least one of the through passage openings.

6. The ball valve of claim 3, wherein the valve member end of the seal member penetrates one of the voids in the open position.

7. The ball valve of claim 3, wherein at least one void is formed by the valve member having an outer surface that surrounds the axis of rotation of the valve member that generally has minor and major axes, the voids being formed proximate the minor axis and at least one of the through passage openings is formed proximate a minor axis of the valve member.

8. The ball valve of claim 1, wherein the first flow port is substantially perpendicular to a second flow port of the plurality of flow ports.

9. The ball valve of claim 1, wherein the spring member is interposed between a retainer and the seal member.

10. The ball valve of claim 9, wherein the position of the retainer is variable.

11. The ball valve of claim 1, wherein the seal member is slidingly carried in the first port, and a valve chamber end of the seal member extends into the valve chamber.

12. The ball valve of claim 11, wherein the seal includes an auxiliary seal member, and the seal member includes a ramped back surface, the auxiliary seal interposed between the ramped back surface and the spring member and forming a seal between an inner surface of the first port and the ramped back surface.

13. The ball valve of claim 12, wherein the auxiliary seal member is an o-ring, and the spring member acts directly on the o-ring and thereby on the seal member, the o-ring being increasingly wedged between the ramped back surface and the inner surface of the first port to increase a sealing pressure on the inner surface of the first flow port and ramped back surface as the biasing force provided by the spring member increases.

14. The ball valve of claim 12, wherein the tapered back surface and the valve chamber end define opposite ends of the seal member, the seal member further includes an extension portion and a radial flange, the extension portion adjacent to and transitioning into the valve chamber end, the flange being interposed between the extension portion and the tapered back surface and extending outward beyond the extension portion, and the first flow port of the valve body includes a first bore having a first diameter and a second bore adjacent to the first bore having a second diameter, smaller than the first, the adjacent bores defining a shoulder, the second bore connecting the first bore with the valve chamber, at least part of the extension portion of the seal member slidingly carried in the second bore and being longer in length than the second bore.

15. The ball valve of claim 1, wherein transitioning the valve member from the open position to the closed position causes the spring member to provide a larger biasing force in the closed position than in the open position.

16. The ball valve of claim 1, wherein at least one of an outer surface of the seal member and an inner surface of the through passage openings includes a tapered region, the tapered region adapted assist biasing the seal member while transitioning the valve member from the open position to the closed position.

17. The ball valve of claim 1, wherein the seal member is out of contact with the valve member in the open position.