TENSIONED SUPPORT SHAFT AND OTHER MOLTEN METAL DEVICES

• US 20170198721A1
• Filed: 01/13/2017
• Published: 07/13/2017
• Est. Priority Date: 01/13/2016
• Status: Active Grant

• Current Assignee: Molten Metal Equipment Innovations Incorporated (Molten)
• Original Assignee: Molten Metal Equipment Innovations Incorporated (Molten)
• Inventors: Cooper, Paul V.
• Granted Patent: US 10,267,314 B2
• Time in Patent Office: Days
• CPC Class Codes: B22D 39/00 Equipment for supplying molten metal in rations
• CPC Class Codes: F04D 13/06 the pump being electrically driven
• CPC Class Codes: F04D 29/026 especially adapted for liquid pumps
• CPC Class Codes: F04D 29/043 Shafts
• CPC Class Codes: F04D 29/605 specially adapted for liquid pumps
• CPC Class Codes: F04D 29/628 especially adapted for liquid pumps
• CPC Class Codes: F04D 7/065 for liquid metal
• CPC Class Codes: F05D 2300/20 Oxide or non-oxide ceramics

Abstract

A vertical member, which is preferably a support post used in a molten metal pump, includes a ceramic tube and tensioning structures to add a compressive load to the tube along its longitudinal axis. This makes the tube less prone to breakage. A device, such as a pump, used in a molten metal bath includes one or more of such vertical members.

Claims

1. A support post, comprising:

a tube defining a hollow channel and having a first tube end and a second tube end;

a tension rod having a first rod end and a second rod end disposed within the hollow channel of the tube;

a bottom cap configured to receive the first tube end and operatively coupled to the first rod end; and

a top cap configured to receive the second tube end and operatively couple to a portion of the tension rod,

wherein the tension rod is configured to provide a compressive load to the tube in response to be operatively coupled to the bottom cap and the top cap.

2. The support post of claim 1, wherein the tube is a homogenous ceramic.

3. The support post of claim 1, wherein the tube comprises silicon carbide.

4. The support post of claim 1, wherein the tube comprises an interior surface, and wherein the tension rod is separated from the interior surface defining a gap between the tension rod and the interior surface.

5. The support post of claim 1, wherein the bottom cap is made of graphite.

6. The support post of claim 1, wherein the bottom cap and top cap are each comprised of one or more of graphite and silicon carbide.

7. The support post of claim 1, wherein the bottom comprises a two-piece assembly that is configured to isolate the tension rod from a molten metal environment.

8. The support post of claim 1, further comprising a spring disposed within the top cap and installable over the second rod end.

9. The support post of claim 1, wherein the second rod end is configured to protrude through the top cap.

10. A molten metal pump comprising:

a superstructure;

a motor having a motor post with a first post end connected to the motor and a second post end;

a rotor shaft operatively coupled to the second post end;

a support post comprising,

a tube defining a hollow channel; and

a tension rod having a first rod end and a second rod end disposed within the hollow channel of the tube;

a bottom cap operatively coupled to the first rod end; and

a top cap operatively coupled to a portion of the tension rod, wherein the tension rod is configured to load the tube in response to be operatively coupled to the bottom cap and the top cap; and

a base assembly coupled to the superstructure by the support post.

11. The molten metal pump of claim 10, further comprising a rotor coupled to the rotor shaft.

12. The molten metal pump of claim 10, further comprising an injection tube coupled to the superstructure.

13. A rotor shaft for use in a molten metal device, the rotor shaft comprising:

an outer tube having a first end, a second end, and an outer surface;

an inner rod having a first end and a second end;

a cap that threads onto the first end of the inner rod, and that has an upper portion configured to be connected to a coupling that drives the rotor shaft; and

a structure that retains the second end of the outer tube,

wherein when the cap is connected to the coupling and the coupling drives the rotor shaft, the rotor shaft moves in a direction that tightens the cap against the first end of the outer tube to apply axial pressure on the outer tube.

14. The rotor shaft of claim 13, wherein the outer tube is comprised of ceramic.

15. The rotor shaft of claim 14, wherein the ceramic is silicon carbide.

16. The rotor shaft of claim 13, wherein the structure that retains the second end of the outer tube is a nut threaded onto the second end.

17. The rotor shaft of claim 13, wherein the inner rod is formed of steel.

18. The rotor shaft of claim 13, wherein the upper portion of the cap includes one or more L-shaped openings to connect to the coupling.

19. The rotor shaft of claim 13, wherein the cap is formed of steel.

20. The rotor shaft of claim 13, wherein the rotor shaft attaches to a rotor.