Method and device for mounting shaft seals permitting eccentric motion
A device and method are taught for mounting an annular shaft seal between a bore and a shaft in which the shaft and bore may be subject to radial eccentricity. The device comprises an annular sealing case having a first end and a second end; a shaft sealing case having a first end and a second end; a flexible sealing linkage axially and sealingly connecting the second end of the annular sealing case to the first end of the shaft sealing case. The annular sealing case is shaped to receive a seal to seal against an interior surface of the bore, and the shaft sealing case is shaped to receive a seal to seal against an exterior surface of the shaft, and the flexible sealing linkage provides sealing between the annular sealing case and the shaft sealing case.
1. A device for housing seals between a bore and a shaft, in which the shaft and bore may be subject to radial eccentricity, comprising:
a. an annular sealing case having a first end and a second end;
b. a shaft sealing case having a first end and a second end; and
c. a flexible sealing linkage axially and sealingly connecting the second end of the annular sealing case to the first end of the shaft sealing case;
wherein, the annular sealing case is shaped to receive one or more seals to seal against an interior surface of the bore, and the shaft sealing case is shaped to receive one or more seals to seal against an exterior surface of the shaft, and the flexible sealing linkage provides sealing between the annular sealing case and the shaft sealing case and is translatable to accommodate radial eccentricity between the shaft and the bore while ensuring that the annular sealing case remains coaxial with the bore and the shaft sealing case remains coaxial with the shaft.
2. The device of claim 1 wherein the annular sealing case comprises a geometry to receive one or more seals on an exterior surface thereof to seal between the annular sealing case and the interior surface of the bore.
3. The device of claim 2 , wherein the device is retained in the bore by a retaining means.
4. The device of claim 3 wherein the retaining means is selected from the group consisting of (i) a captured gland, (ii) a split gland utilizing a snap ring (iii) a threaded mounting, (iv) a bolted flange mounting (v) a screwed flange mounting, (vi) a radial screw mounting.
5. The device of claim 3 , wherein the retaining means are integrally built into the device.
6. The device of claim 1 wherein the shaft sealing case comprises geometry to receive one or more seals on an interior surface thereof to seal between the shaft sealing case and the exterior surface of the shaft.
7. The device of claim 1 wherein the flexible sealing linkage is selected from the group consisting of (i) An elastomeric section with or without convolutions, (ii) A polymeric section with or without convolutions, (iii) A convoluted metallic section.
8. The device of claim 6 wherein the flexible sealing linkage is connected to the annular sealing case and to the shaft sealing case by a method selected from the group consisting of (i) Direct bonding/vulcanization in the case of an elastomeric linkage, (ii) Welding in the case of a metallic linkage, and (iii) Clamping or swaging of the linkage.
9. The device of claim 7 , wherein the flexible sealing linkage, the annular sealing case and the shaft sealing case are constructed as a single body construction.
10. The device of claim 7 wherein the flexible sealing linkage allows lateral movement between the annular sealing case and shaft sealing case.