Pumping seal with aligned spring

Patent metadata

Field	Value
Publication number	US-9228658-B2
Application number	US-201214367084-A
Country	US
Kind code	B2
Filing date	Dec 14, 2012
Priority date	Dec 21, 2011
Publication date	Jan 5, 2016
Grant date	Jan 5, 2016

Abstract

A seal assembly for sealing a space between a housing and a rotary shaft includes a generally annular sealing member having a central axis and inner and outer circumferential surfaces extending about the axis, at least a portion of the inner surface providing a sealing surface engageable with the shaft outer surface so as to define a seal interface with opposing axial ends. The sealing surface is configured to direct substances entering the interface toward at least one of the axial ends. Further, an annular biasing member is disposed about the sealing member outer surface and configured to exert a radially-inwardly directed force on the sealing member so as to generate contact pressure within the seal interface. The biasing member is arranged on the sealing member such that at least a portion of the biasing member extends axially in general alignment with at least a portion of the sealing surface.

First claim

We claim:

1. A seal assembly for sealing a space between a housing and a rotary shaft having an outer surface and disposed at least partially within the housing, the seal assembly comprising:
a generally annular sealing member having a central axis and inner and outer circumferential surfaces extending about the axis, at least a portion of the inner surface providing a sealing surface engageable with the shaft outer surface so as to define a seal interface with opposing axial ends, the sealing surface being configured to direct substances entering the interface toward at least one of the axial ends; and
a generally annular biasing member disposed about the sealing member outer surface and configured to exert a radially-inwardly directed force on the sealing member so as to generate contact pressure within the seal interface, the biasing member being arranged on the sealing member such that at least a portion of the biasing member extends axially in general alignment with at least a portion of the sealing surface;
wherein one of:
the sealing surface is generally elliptical shaped and the biasing member extends in a generally elliptical pattern about the sealing member outer surface so as to be substantially aligned with and spaced radially outwardly from the sealing surface; and
the sealing surface is generally sinusoidal-shaped and the biasing member extends in a generally sinusoidal pattern about the sealing member outer surface so as to be substantially aligned with and spaced radially outwardly from the sealing surface.

2. The seal assembly as recited in claim 1 wherein the sealing member has an engagement portion extending radially inwardly from a remainder of the sealing member, the engagement portion having generally triangular-shaped axial cross-sections and an inner radial end providing the sealing surface, the engagement portion being formed such that the inner end extends one of generally elliptically about the central axis and generally sinusoidally about the central axis.

3. The seal assembly as recited in claim 1 wherein the sealing member inner surface has a generally cylindrical surface portion and the sealing member further has a projection extending radially inwardly from the cylindrical surface portion and having a free end providing the sealing surface, the projection extending one of generally elliptically about the central axis and generally sinusoidally about the central axis.

4. The seal assembly as recited in claim 1 wherein:
the sealing member further includes a plurality of projections extending generally radially outwardly from the outer surface and spaced circumferentially apart about the central axis, each projection having opposing first and second axial ends and the plurality of projections defining at least one first projection and at least one second projection; and
the biasing member has opposing first and second ends and is arranged on the sealing member with the biasing member first end contacting the second end of each first projection and the biasing member second end contacting the first end of each second projection such that the biasing member extends axially and circumferentially between the first and second projections such that the contact pressure extends at least partially axially between the seal interface ends.

5. The seal assembly as recited in claim 4 wherein the sealing surface extends generally elliptically about the central axis, the plurality of projections includes two projections spaced apart circumferentially by about one hundred eighty degrees and providing one first projection and one second projection, the biasing member being positioned by the projections so as to extend generally elliptically about the central axis such that the contact pressure is exerted generally along the sealing surface.

6. The seal assembly as recited in claim 4 wherein the sealing surface extends generally sinusoidally about the central axis, the plurality of projections includes at least four projections circumferentially spaced apart about the central axis and providing at least two first projections and at least two second projections, the biasing member being bended about each one of the projections so as to extend generally sinusoidally about the central axis such that the contact pressure is exerted generally along the sealing surface.

7. The seal assembly as recited in claim 6 wherein one of
the plurality of projections includes four projections circumferentially spaced apart by about ninety degrees and providing two first projections and two second projections; and
the plurality of projections includes six projections spaced circumferentially apart by about sixty degrees and providing three first projections and three second projections.

8. The seal assembly as recited in claim 4 wherein each projection is formed as a generally rectangular tab having opposing circumferentially-extending radial surfaces providing the first and second ends.

9. The seal assembly as recited in claim 1 wherein the sealing member includes a base portion coupleable with the housing and cantilever portion connected with the base portion and providing the inner circumferential sealing surface and the outer circumferential surface, the cantilever portion being deflectable relative to the base portion and the biasing member being configured to bias the cantilever portion generally radially inwardly so as to maintain contact between the sealing surface and the shaft outer surface.

10. The seal assembly as recited in claim 1 wherein the biasing member is one of a garter spring and an elastomeric ring.

11. The seal assembly as recited in claim 1 further comprising a generally annular casing having an interior cavity configured to receive the sealing member base and an outer circumferential surface engageable with an inner circumferential surface of the housing so as to couple the sealing member with the housing.

12. A method of pumping fluid with a seal assembly for sealing a space between a rotatable shaft and a housing, the pumping method comprising the steps of:
providing a generally annular sealing member having a central axis, inner and outer circumferential surfaces, at least a portion of the inner surface providing a sealing surface engageable with the shaft outer surface and so as to define a seal interface with opposing axial ends, the sealing surface being configured to direct substances entering the interface toward at least one of the axial ends; and
providing a generally annular biasing member configured to exert a radially-inwardly directed force when deflected radially outwardly;
mounting the sealing member on the shaft such that the sealing surface is engaged with the outer surface of the shaft;
mounting the biasing member on the sealing member such that the biasing member such that at least a portion of the biasing member extends axially in alignment with at least a portion of the sealing surface; and
rotating the shaft within the seal such that the sealing surface directs any fluid entering the seal interface toward a proximal one of the two axial ends of the sealing surface;
wherein one of:
the sealing surface is generally elliptical shaped and the biasing member extends in a generally elliptical pattern about the sealing member outer surface so as to be substantially aligned with and spaced radially outwardly from the sealing surface; and
the sealing surface is generally sinusoidal-shaped and the biasing member extends in a generally sinusoidal pattern about the sealing member outer surface so as to be substantially aligned with and spaced radially outwardly from the sealing surface.

Assignees

• Epshetsky Yefim
• Paykin Alex
• Skf Ab

Inventors

• Epshetsky Yefim
• Paykin Alex

Classifications

• F16J15/3244

  with hydrodynamic pumping action · CPC title

• F16J15/32 Primary

  with elastic sealings, e.g. O-rings · CPC title

• F16J15/3208 Primary

  provided with tension elements, e.g. elastic rings · CPC title

• F16J15/3212

  with metal springs · CPC title