Tensioned support shaft and other molten metal devices

• US 10,267,314 B2
• Filed: 01/13/2017
• Issued: 04/23/2019
• 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.
• Primary Examiner(s): Bertheaud, Peter J
• Application Number:
  US15/406,515
• Publication Number:
  US 20170198721A1
• Time in Patent Office: 830 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 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.

2. The rotor shaft of claim 1, wherein the outer tube is comprised of ceramic.

3. The rotor shaft of claim 2, wherein the ceramic is silicon carbide.

4. The rotor shaft of claim 1, wherein the structure that retains the second end of the outer tube is a nut threaded onto the second end.

5. The rotor shaft of claim 1, wherein the inner rod is formed of steel.

6. The rotor shaft of claim 1, wherein the upper portion of the cap includes one or more L-shaped openings to connect to the coupling.

7. The rotor shaft of claim 1, wherein the cap is formed of steel.

8. The rotor shaft of claim 1, wherein the rotor shaft is configured to attach to a rotor.

9. The rotor shaft of claim 1 is attached to a rotor.

10. The rotor shaft of claim 1 has a first end configured to be retained in the coupling and a second end configured to be connected to a rotor.

11. The rotor shaft of claim 10, wherein the second end of the rotor shaft is threaded.

12. A molten metal pump comprising the rotor shaft of claim 1.

13. The molten metal pump of claim 12 that further comprises a motor configured to rotate the rotor shaft, a rotor connected to an end of the rotor shaft, a base that includes a chamber and a discharge, wherein the rotor is positioned in the chamber, a superstructure that supports the motor, and one or more support posts that connect to the base and to the superstructure.