Crowned anti-rotation device for circumferential seals
An anti-rotation device is for a circumferential seal disposed within a housing and having an annular body and one or more openings with facing first and second sides. The device includes at least one and preferably a plurality of lugs each having a first axial end coupled with the housing, preferably through an annular carrier disposed within the housing, an opposing second axial end, inner and outer radial ends each extending axially between the first and second axial ends, and opposing first and second retainer surfaces extending axially between the first and second axial ends and radially between the inner and outer radial ends. At least one retainer surface is convexly curved and each lug is disposable within a seal opening such that the convexly curved retainer surface is contactable with one of the seal opening sides to prevent angular displacement of the seal with respect to the housing.
1. An anti-rotation device for a circumferential seal, the seal being disposed within a housing and having an annular body with a central axis, opposing axial ends and at least one opening extending generally axially between the axial ends and having facing first and second sides, the device comprising:
at least one lug having a first axial end coupled with the housing, an opposing second, free axial end, inner and outer radial ends each extending axially between the first and second axial ends, and opposing first and second retainer surfaces extending axially between the first and second axial ends and radially between the inner and outer radial ends, at least one of the first and second retainer surfaces being generally convexly curved, the at least one lug being disposable at least partially within the at least one seal opening such that the convexly curved retainer surface is contactable with one of the first and second seal opening sides to prevent angular displacement of the seal with respect to the housing.
2. The anti-rotation device as recited in claim 1 wherein the at least one lug is configured such that an axially-extending central section of the at least one convexly curved retainer surface engages against the one of the first and second seal opening sides while the remainder of the curved retainer surface is spaced circumferentially from the one seal opening side.
3. The anti-rotation device as recited in claim 1 wherein the at least one lug has a thickness between the first and second retainer surfaces, the thickness varying radially between a least value proximal to at least one of the first and second radial ends and a greatest value at a central position between the first and second radial ends.
4. The anti-rotation device as recited in claim 1 wherein the lug has a centerline extending between the lug first and second axial ends and the at least one convexly curved retainer surface is formed as a portion of a generally cylindrical surface having a radius extending from an axis spaced from the lug centerline.
5. The anti-rotation device as recited in claim 4 wherein the lug has a height between the lug inner and outer radial ends and the lug is formed such that a ratio of the radius of the retainer surface to the lug height is within the range of between about 2.4 and about 2.8.
6. The anti-rotation device as recited in claim 1 wherein each one of the first and second retainer surfaces is convexly curved.
7. The anti-rotation device as recited in claim 6 wherein the at least one lug has a centerline extending between the first and second axial ends and each one first and second retainer surfaces extend outwardly from the centerline in opposing circumferential directions with respect to the seal axis.
8. The anti-rotation device as recited in claim 1 wherein the first axial end of the at least one lug is directly connected with the housing or with a carrier disposed within the housing.
9. The anti-rotation device as recited in claim 1 wherein the at least one lug includes a generally rectangular body.
10. The anti-rotation device as recited in claim 1 further comprising a generally annular carrier disposed within the housing, the first axial end of the at least one lug being removably coupled with the carrier, permanently attached to the carrier or integrally formed with the carrier.
11. The anti-rotation device as recited in claim 1 wherein the at least one lug includes a plurality of the lugs spaced circumferentially about the central axis, each one of the plurality of lugs being disposed at least partially within a separate one of a plurality of seal openings.
12. An anti-rotation device for a circumferential seal, the seal being disposed within a housing and having an annular body with a central axis, opposing axial ends and at least one opening extending generally axially between the axial ends and having facing first and second sides, the device comprising:
a generally annular carrier disposed within the housing and spaced axially from the seal, the carrier having opposing first and second axial faces; and
at least one lug extending axially from the carrier first face, the lug having a first axial end coupled with the carrier, an opposing second, free axial end, inner and outer radial ends each extending axially between the first and second axial ends, and opposing first and second retainer surfaces extending axially between the first and second axial ends and radially between the inner and outer radial ends, at least one of the first and second retainer surfaces being generally convexly curved, the at least one lug being disposable at least partially within the at least one seal opening such that the convexly curved retainer surface is contactable with one of the first and second seal opening sides to prevent angular displacement of the seal with respect to the housing.
13. The anti-rotation device as recited in claim 12 wherein the at least one lug is configured such that an axially-extending central section of the convexly curved retainer surface engages against the one of the first and second seal opening sides while the remainder of the curved retainer surface is spaced circumferentially from the one seal opening side.
14. The anti-rotation device as recited in claim 12 wherein the at least one lug has a thickness between the first and second retainer surfaces, the thickness varying radially between a least value proximal to one of the first and second radial ends and a greatest value at a central position between the first and second radial ends.
15. The anti-rotation device as recited in claim 12 wherein the at least one convexly curved retainer surface is formed as a generally cylindrical surface section.
16. The anti-rotation device as recited in claim 12 wherein each one of the first and second retainer surfaces is convexly curved.
17. The anti-rotation device as recited in claim 12 wherein the carrier includes a generally washer-like circular plate and the at least one lug includes a generally rectangular body.
18. The anti-rotation device as recited in claim 12 wherein the first axial end of the at least one lug is removably coupled with the carrier, permanently attached to the carrier or integrally formed with the carrier.
19. The anti-rotation device as recited in claim 12 wherein the at least one lug includes a plurality of the lugs spaced circumferentially about the central axis, each one of the plurality of lugs extending axially from the carrier first face and being disposed at least partially within a separate one of a plurality of seal openings.
20. The anti-rotation device as recited in claim 12 wherein the carrier first axial face provides a retention surface for an end of at least one spring for biasing the seal.