Screw conveyor shaft seal and related methods

Patent metadata

Field	Value
Publication number	US-12227364-B2
Application number	US-202117922357-A
Country	US
Kind code	B2
Filing date	Apr 30, 2021
Priority date	Apr 30, 2020
Publication date	Feb 18, 2025
Grant date	Feb 18, 2025

Abstract

The present disclosure provides a shaft seal for a screw conveyor. The shaft seal includes a housing that includes an outboard frame plate and an inboard frame plate. The shaft seal also includes an outboard compression plate and an inboard compression plate situated between the outboard frame plate and the inboard frame plate. A least three sealing devices are situated between the outboard compression plate and the inboard compression plate with an annular recess at least partially formed along at least one of the inboard compression plate and the outboard compression plate.

First claim

The invention claimed is:

1. A shaft seal for a screw conveyor, the shaft seal comprising:
a housing including an outboard frame plate and an inboard frame plate with a shaft aperture extending axially therethrough;
an outboard compression plate and an inboard compression plate situated between the outboard frame plate and the inboard frame plate;
a wear plate inboard of the inboard compression plate, the wear plate configured to limit wear of the inboard frame plate, the wear plate having an outer diameter and including a wear pin aperture formed in the wear plate through the outer diameter thereof;
a wear pin extending outboard from an inner surface of the inboard frame plate and into the wear pin aperture in the wear plate;
an annular recess at least partially formed along at least one of the inboard compression plate and the outboard compression plate;
an inboard sealing device disposed between the inboard frame plate and the inboard compression plate along the shaft aperture;
an outboard sealing device disposed between the outboard frame plate and the outboard compression plate along the shaft aperture; and,
at least three intermediate sealing devices situated between the outboard compression plate and the inboard compression plate, the at least three intermediate sealing devices disposed within the annular recess with the inboard sealing device spaced axially inboard of the at least three intermediate sealing devices and the outboard sealing device space axially outboard of the at least three intermediate sealing devices such that the inboard sealing device and the outboard sealing device provide redundant seals along an associated shaft in addition to the at least three intermediate sealing devices.

2. A shaft seal according to claim 1 , wherein the outboard compression plate and the inboard compression plate are at least partially formed from non-corrosive material.

3. A shaft seal according to claim 1 , wherein at least one of the outboard compression plate and the inboard compression plate includes an annular groove configured to contain a corresponding one of the inboard sealing device and the outboard sealing device.

4. A screw conveyor comprising:
a shaft seal according to claim 1 .

5. A screw conveyor according to claim 4 further comprising a shaft with a radially outer surface extending axially through the shaft aperture such that the inboard sealing device forms a seal along an axially-inboard portion of the radially outer surface, the outboard sealing device forms a seal along an axially-outboard portion of the radially outer surface, and the at least three intermediate sealing devices form a seal along an axially-intermediate portion of the radially outer surface.

6. A screw conveyor according to claim 4 , wherein the shaft seal is coupled to a backplate via a plurality of fasteners.

7. A method of assembling a shaft seal, the method comprising:
providing an inboard compression plate and an outboard compression plate with one of the inboard compression plate and the outboard compression plate at least partially defining an annular recess;
positioning at least three sealing devices within the annular recess and situating the inboard compression plate, the outboard compression plate and the at least three sealing devices such that a shaft aperture extends axially therethrough;
positioning an inboard sealing device along the shaft aperture axially between the inboard compression plate and an inboard frame plate such that the inboard sealing device is spaced axially inboard of the at least three intermediate sealing devices;
positioning an outboard sealing device along the shaft aperture axially between the outboard compression plate and an outboard frame plate such that the outboard sealing device is spaced axially outboard of the at least three intermediate sealing devices;
positioning a wear plate between the inboard compression plate and the inboard frame plate such that the wear plate is operative to limit wear of the inboard frame plate, the wear plate having an outer diameter and including a wear pin aperture formed in the wear plate through the outer diameter thereof;
extending a wear pin outboard from an inner surface of the inboard frame plate and into the wear pin aperture in the wear plate thereby inhibiting rotational movement of the wear plate relative to the inboard frame plate; and,
compressing the at least three sealing devices between the inboard compression plate and the outboard compression plate, the inboard sealing device between the inboard compression plate and the inboard frame plate, and the outboard sealing device between the outboard compression plate and the outboard frame plate such that the inboard sealing device and the outboard sealing device provide redundant seals in addition to the at least three intermediate sealing devices along a shaft extending axially through the shaft aperture.

8. A method according to claim 7 , wherein the inner surface of the inboard frame plate is a recess inner surface at least partially defining a frame plate recess within the inboard frame plate, and positioning the wear plate between the inboard compression plate and the inboard frame plate includes positioning the wear plate within the frame plate recess.

9. A method according to claim 8 , wherein the wear plate includes an inboard surface and an outboard surface, and positioning the wear plate within the frame plate recess includes positioning the inboard surface of the wear plate in abutting engagement with the recess inner surface and the outboard surface of the wear plate in abutting engagement with the inboard compression plate.

10. A method according to claim 7 , wherein the inner surface of the inboard frame plate is a recess inner surface at least partially defining an outboard-facing frame plate recess within the inboard frame plate, and the method further comprises positioning at least a portion of the inboard compression plate within the outboard-facing frame plate recess of the inboard frame plate.

11. A method according to claim 7 further comprising enclosing the inboard compression plate, the outboard compression plate, and the wear plate within a housing formed by the inboard frame plate and the outboard frame plate.

12. A screw conveyor comprising:
a backplate;
a rotatable shaft extending through the backplate and including a radially outer surface; and,
a shaft seal assembly secured along the backplate and sealingly engaging the rotatable shaft, the shaft seal assembly including:
an outboard frame plate and an inboard frame plate that together define a shaft aperture extending axially therethrough;
an outboard compression plate and an inboard compression plate situated between the outboard frame plate and the inboard frame plate;
a wear plate inboard of the inboard compression plate, the wear plate dimensioned to limit wear of the inboard frame plate, the wear plate having an outer diameter and including a wear pin aperture formed in the wear plate through the outer diameter thereof;
a wear pin extending outboard from an inner surface of the inboard frame plate and into the wear pin aperture in the wear plate;
an annular recess at least partially formed along at least one of the outboard compression plate and the inboard compression plate;
an inboard sealing device disposed between the inboard frame plate and the inboard compression plate along the shaft aperture;
an outboard sealing device disposed between the outboard frame plate and the outboard compression plate along the shaft aperture; and,
at least three intermediate sealing devices situated between the outboard compression plate and the inboard compr

Assignees

• Bridgestone Corp

Inventors

• Gaston Scott E

Classifications

• F16J15/26

  with stuffing-boxes for rigid sealing rings · CPC title

• F16J15/24 Primary

  with radially or tangentially compressed packing · CPC title

• F27D99/0073

  Seals · CPC title

• F16J15/3252

  with rigid casings or supports · CPC title

• F16J15/3256

  comprising two casing or support elements, one attached to each surface, e.g. cartridge or cassette seals · CPC title