Viscous speed retarding device for rotary nozzles with internal piston for thermal expansion

Patent metadata

Field	Value
Publication number	US-RE49573-E
Application number	US-202117336102-A
Country	US
Kind code	E1
Filing date	Jun 1, 2021
Priority date	Oct 12, 2018
Publication date	Jul 11, 2023
Grant date	Jul 11, 2023

Abstract

A speed retarding device for a rotary nozzle includes a hollow cylindrical housing and a rotatable tubular shaft rotatably carried by the housing. The shaft has a central axial bore and an enlarged drag sleeve portion carried in the housing. A pair of support bearings support the drag sleeve portion of the shaft in the housing. An annular inner seal between each of the support bearings and the drag sleeve portion defines a cavity within the housing receiving a viscous fluid confined within the cavity. The drag sleeve portion includes a peripheral helical groove and a plurality of axial bores extending therethrough parallel to the central bore, one or more blind axial bores each having a closed end an open end, and a piston disposed in each of the one or more blind axial bores each defining an air space between the closed end and the piston.

First claim

What is claimed is:

1. A speed retarding device for a rotary component comprising:
a hollow cylindrical housing;
a rotatable tubular shaft having a central bore, the shaft being rotatably carried by the housing, the shaft having a cylindrical drag portion in the housing and having a shaft end extending through at least one end of the housing, wherein the shaft end is adapted to receive a reaction force rotary nozzle thereon, the drag portion having a plurality of bores therethrough parallel to the central bore and at least one blind bore having a closed end and opposite an open end, the open end carrying a piston therein defining an air a gas chamber between the closed end and the piston;
a pair of lubricated support bearings supporting the cylindrical drag portion of the shaft in the housing; and
a viscous fluid confined within the housing in a cavity formed between the shaft housing and the drag portion, wherein the piston in the blind bore moves within the blind bore parallel to the central bore to absorb thermal expansion of the viscous fluid in the cavity.

2. The retarding device according to claim 1 further comprising an annular axial inner seal between each of the support bearings and the cylindrical drag portion, wherein the inner seals sandwich the drag portion therebetween and isolate the drag portion from the support bearings.

3. The retarding device according to claim 2 further comprising an outer annular seal on the shaft adjacent to each support bearing whereby each support bearing is sandwiched between inner and outer annular seals in the housing and separated from the viscous fluid in the cavity.

4. The retarding device according to claim 1 wherein the viscous fluid is separated from the at least one blind before by the piston.

5. The retarding device according to claim 1 wherein the piston in the at least one blind before defines the gas chamber is a chamber between the closed end of the blind bore and the piston.

6. The retarding device according to claim 5 wherein the chamber is an air chamber further comprising a plurality of blind bores each carrying a piston therein defining an air chamber therein between the closed end and the piston therein.

7. The retarding device according to claim 5 1 further comprising four blind bores each carrying a piston therein and at least four through bores in the drag portion of the tubular shaft.

8. The retarding device according to claim 1 wherein the drag sleeve portion has an outer cylindrical surface and a peripheral helical groove in the outer cylindrical surface.

9. The retarding device according to claim 5 1 further comprising an outer annular seal on the shaft adjacent to each support bearing whereby each support bearing is sandwiched between inner and outer annular seals in the housing and separated from the viscous fluid in the cavity.

10. The retarding device according to claim 8 wherein the viscous fluid is separated from the at least one blind bore by the piston.

11. The retarding device according to claim 8 wherein the piston in the at least one blind bore defines gas chamber is an air chamber between the closed end of the blind bore and the piston.

12. The retarding device according to claim 11 further comprising four blind bores each carrying a piston therein and at least four through bores in the drag portion of the tubular shaft.

13. A speed retarding device for a rotary nozzle comprising:
a hollow cylindrical housing;
a rotatable tubular shaft rotatably carried by the housing, the shaft having a central bore and a drag portion in the housing and having a shaft end extending through at least one end of the housing;
a pair of lubricated support bearings supporting the drag portion of the shaft in the housing;
an annular inner seal between each of the support bearings and the drag portion, wherein the inner seals, the housing and the drag portion define a cavity within the housing;
the drag portion having a peripheral helical groove and plurality of bores therethrough parallel to the central bore and at least one blind bore parallel to the central bore having a closed end and opposite an open end, the open end carrying a piston therein closing the open end and forming an air chamber within the at least one blind bore between the closed end and the piston; and
a viscous fluid confined within the cavity, wherein the piston in the blind bore moves within the blind bore parallel to the central bore to absorb thermal expansion of the viscous fluid in the cavity.

14. The retarding device according to claim 13 further comprising an outer annular seal on the shaft adjacent to each support bearing whereby each support bearing is sandwiched between inner and outer annular seals in the housing and separated from the viscous fluid in the cavity.

15. A speed retarding device for a rotary component, the device comprising:
a hollow cylindrical housing;
a rotatable tubular shaft rotatably carried by the housing, the shaft having a central bore and a drag portion in the housing having a shaft end extending through at least one end of the housing;
a pair of lubricated support bearings supporting the drag portion of the shaft in the housing;
the drag portion having a plurality of bores therethrough parallel to the central bore of the tubular shaft and at least one blind bore parallel to the central bore having a closed end and opposite an open end, the open end carrying a movable piston therein closing the open end and forming an air chamber within the blind bore between the closed end and the piston; and
a viscous fluid confined within a cavity formed between the housing, the support bearings and an external surface of the drag portion, wherein the piston in the blind bore moves within the blind bore parallel to the central bore to absorb thermal expansion of the viscous fluid in the cavity.

16. The retarding device according to claim 15 further comprising an annular inner seal between each of the support bearings and the drag sleeve portion, wherein the inner seals, the housing and the drag portion restrict the cavity within the housing.

17. The retarding device according to claim 16 further comprising an outer annular seal on the shaft adjacent to each support bearing whereby each support bearing is sandwiched between one of the inner seals and one of the outer annular seals in the housing and separate the support bearings from the viscous fluid in the cavity.

18. The retarding device according to claim 16 wherein the drag sleeve portion has a cylindrical outer surface and a helical groove around the drag sleeve portion formed in the outer surface.

19. The retarding device according to claim 18 wherein the piston further comprises an annular O-ring seal therearound isolating the air chamber from the viscous fluid in the cavity.

Assignees

• Stoneage Inc

Inventors

• Schneider Joseph A

Classifications

• F16D57/00 Primary

  Liquid-resistance brakes; {Brakes using the internal friction of fluids or fluid-like media, e.g. powders (for braking drums, barrels or ropes of cranes, lift hoists or winches B66D5/026)} · CPC title

• F16F9/064

  Units characterised by the location or shape of the expansion chamber (F16F9/068, F16F9/08 take precedence) · CPC title

• F16F9/14

  Devices with one or more members, e.g. pistons, vanes, moving to and fro in chambers and using throttling effect · CPC title

• B05B3/1042

  Means for connecting, e.g. reversibly, the rotating spray member to its driving shaft · CPC title

• B05B3/06

  by jet reaction · CPC title