High moisture environment seal assembly

1. A seal assembly, comprising:

an annular seal plate configured to be seated within a groove defined in an inside surface of a bearing case, the annular seal plate being radially-offset from a rotatable shaft and extending circumferentially thereabout;

a seal retainer mounted on the rotatable shaft and axially-offset from the annular seal plate, wherein the seal retainer is configured to be radially-offset from the inside surface of the bearing case; and

a seal arranged axially-adjacent the seal retainer and extending circumferentially about the rotatable shaft, the seal having a body and a flexible lip extending from the body and engaging the inside surface of the bearing case, wherein:

the flexible lip is configured to engage the inside surface of the bearing case when the rotatable shaft is at rest,

the flexible lip is configured to engage the annular seal plate while maintaining engagement with the inside surface of the bearing case when the rotatable shaft is operated at an intermediate rotational speed, and

the flexible lip is configured to disengage from the inside surface of the bearing case and the annular seal plate when the rotatable shaft is operated at a high rotational speed.

2. The seal assembly of claim 1 , wherein the seal is elastomeric.

3. The seal assembly of claim 1 , wherein the seal is a v-ring seal.

4. The seal assembly of claim 1 , wherein the seal is configured to isolate an interior cavity of the bearing case from an exterior environment.

5. The seal assembly of claim 1 , wherein the seal retainer is mounted to the rotatable shaft by one or more mechanical fasteners.

6. The seal assembly of claim 1 , wherein the seal retainer is mounted to the rotatable shaft by heat shrinking or welding.

7. The seal assembly of claim 1 , wherein the seal retainer is directly mounted on and fixedly attached to the rotatable shaft.

8. The seal assembly of claim 1 , wherein the seal retainer holds the seal in place in both radial and axial directions.

9. A method for sealing a bearing case, comprising:

seating an annular seal plate at least partially within a groove defined in an inside surface of the bearing case, the annular seal plate being radially-offset from a rotatable shaft and extending circumferentially thereabout;

mounting a seal retainer on the rotatable shaft, the seal retainer axially-offset from the annular seal plate and radially-offset from the inside surface of the bearing case;

seating a seal within a channel defined in the seal retainer, the seal having a body and a flexible lip extending from the body;

engaging the flexible lip with the inside surface of the bearing case when the rotatable shaft is at rest;

engaging the flexible lip with the annular seal plate while maintaining engagement of the flexible lip with the inside surface of the bearing case when the rotatable shaft is operated at an intermediate rotational speed; and

disengaging the flexible lip from the inside surface of the bearing case and the annular seal plate when the rotatable shaft is operated at a high rotational speed.

10. The method of claim 9 , further comprising isolating an interior cavity of the bearing case from an exterior environment.

11. The method of claim 9 , further comprising retaining the seal in place in both radial and axial directions with the seal retainer.

12. The method of claim 9 , wherein mounting the seal retainer on the rotatable shaft comprises using one or more mechanical fasteners, heat shrinking, or welding to mount the seal retainer on the rotatable shaft.

13. A seal assembly, comprising:

an annular seal plate configured to be at least partially seated within a groove defined in an inside surface of a bearing case, the annular seal plate being radially-offset from a rotatable shaft to define a clearance therebetween, wherein the clearance is configured to be in fluid communication with an interior cavity of the bearing case;

a seal retainer mounted on the rotatable shaft, the seal retainer axially-offset from the annular seal plate and defining a channel therebetween, wherein the seal retainer is configured to be radially-offset from the inside surface of the bearing case to define a gap therebetween that is in fluid communication with an exterior environment; and

a seal having a body mounted on the rotatable shaft and a flexible lip extending from the body, wherein:

the body is seated within the channel,

the flexible lip is configured to engage the inside surface of the bearing case when the rotatable shaft is at rest,

the flexible lip is configured to engage the annular seal plate while maintaining engagement with the inside surface of the bearing case when the rotatable shaft is operated at a first rotational speed, and

the flexible lip is configured to disengage from the inside surface of the bearing case and the annular seal plate when the rotatable shaft is operated at a second rotational speed relatively greater than the first rotational speed.

14. The seal assembly of claim 13 , wherein the seal is configured to isolate the interior cavity of the bearing case from the exterior environment.

15. The seal assembly of claim 13 , wherein the seal is elastomeric.

16. The seal assembly of claim 13 , wherein the seal is a v-ring seal.

17. The seal assembly of claim 13 , wherein the seal retainer is mounted to the rotatable shaft by one or more mechanical fasteners.

18. The seal assembly of claim 13 , wherein the seal retainer is mounted to the rotatable shaft by heat shrinking or welding.

19. The seal assembly of claim 13 , wherein the seal retainer is directly mounted on and fixedly attached to the rotatable shaft.

20. The seal assembly of claim 13 , wherein the seal retainer holds the seal in place in both radial and axial directions.