System for coupling a shaft to an outer shaft sleeve

A shaft system adapted for use in molten metal, the shaft system comprising:

• (a) a base shaft with an outer surface having a base shaft coefficient of expansion when subjected to a temperature delta;
• (b) a shaft sleeve composed of material adapted to be used in a molten metal environment, the shaft sleeve having an inner surface approximately corresponding in size to the outer surface of the base shaft and located approximately concentrically around the base shaft, and the shaft sleeve having a shaft sleeve coefficient of expansion when subjected to a temperature delta;
• and
• (c) a shaft coupler between the outer surface of the base shaft and the inner surface of the shaft sleeve, having a shaft coupler coefficient of expansion when subjected to a temperature delta;
• wherein the shaft sleeve is securely attached to the base shaft by the imposition of a temperature delta to the shaft sleeve, the base shaft and the shaft coupler.

A shaft system adapted for use in molten metal, the shaft system comprising:

• (a) a base shaft with an outer surface;
• (b) a shaft sleeve composed of material adapted to be used in a molten metal environment, the shaft sleeve having an inner surface approximately corresponding in size to the outer surface of the base shaft and located approximately concentrically around the base shaft;
• and
• (c) a shaft coupler between the outer surface of the base shaft and the inner surface of the shaft sleeve, the shaft coupler being a pressure based bonding agent between the base shaft and the shaft sleeve.

A submersible molten metal pump comprising:

• (a) a pump framework, including a motor mount and a pump base;
• (b) a pump motor mounted on the framework motor mount;
• (c) a pump shaft system operative coupled to the pump motor, the pump shaft system comprising:
• (i) a base shaft with an outer surface;
• (ii) a shaft sleeve composed of material adapted to be used in a molten metal environment, the shaft sleeve having an inner surface approximately corresponding in size to the outer surface of the base shaft and located approximately concentrically around the base shaft;
• and
• (iii) a shaft coupler between the outer surface of the base shaft and the inner surface of the shaft sleeve;
• wherein the shaft sleeve is attached to the base shaft by the expansion of the shaft coupler;
• and
• (d) an impeller operatively coupled to the pump shaft system.

A process for making a shaft system for use in molten metal, the process comprising the following steps:

• (a) providing a base shaft with an outer surface;
• (b) providing a shaft coupler and placing the shaft coupler generally around the outer surface of the base shaft;
• (c) providing a shaft sleeve composed of material adapted to be used in a molten metal environment, the shaft sleeve having an inner surface approximately corresponding in size to the outer surface of the base shaft;
• (d) placing the shaft sleeve around and in close proximity to the shaft coupler;
• (e) applying heat to the shaft system such that the shaft coupler expands sufficiently to securely affix the shaft sleeve to the base shaft.

A process for making a shaft system for use in molten metal, the process comprising the following steps:

• (a) providing a base shaft with an outer surface;
• (b) providing a shaft sleeve composed of material adapted to be used in a molten metal environment, the shaft sleeve having an inner surface approximately corresponding in size to the outer surface of the base shaft;
• (c) placing the shaft sleeve around the base shaft;
• (d) placing a shaft coupler between the outer surface of the base shaft and the inner surface of the shaft sleeve;
• and
• (e) applying heat to the shaft system such that the shaft coupler expands sufficiently to securely affix the shaft sleeve to the base shaft.