A molten metal rotor receives and retains an end of a molten metal rotor shaft. The rotor shaft has one or more projections at the end received in the rotor. The rotor has an inner cavity, a top surface with an opening leading to the inner cavity, and at least one abutment. The opening includes one or more portions for allowing each projection to pass through the opening and into the inner cavity. The rotor and/or shaft are then rotated so at least one of the outwardly-extending projections is under the top surface of the rotor and is against an abutment. A molten metal pump, rotary degasser scrap melter or other device used in molten metal may utilize a rotor/shaft combination as disclosed herein.

Embodiments of the invention are directed to a rotor for use in molten metal and devices including the rotor. The rotor has a rotor body and blades, wherein each blade includes a tip that is at least twice as hard as the rotor body.

A launder for use in moving molten metal includes at least one relatively narrow channel through which molten metal flows. Using a narrow, rather than broad, channel permits better control of the flow and helps prevent overflowing the launder or a structure adjacent the launder. A molten metal pumping or transfer system may utilize a launder as disclosed herein.

A system according to aspects of the invention includes a pump and a refractory casing that houses the pump or is in fluid communication with the pump. As the pump operates it moves molten metal upward through an uptake section of the casing until it reaches a rectangular outlet wherein it exits the vessel. The rectangular outlet is configured to be connected to, or may be attached to, a launder. Another system uses a wall to divide a cavity of the chamber into two portions. The wall has an opening and a pump pumps molten metal from a first portion into a second portion until the level in the second portion reaches an outlet and exits the vessel.

A system and method for filling a mold with molten aluminum includes a molten metal pump, a vessel configured to contain molten metal, a mold for receiving molten metal, and a conduit between the vessel and the mold. Molten metal is pumped in the vessel until it reaches a level at which it flows through the conduit and into the mold. The flow of molten metal into the mold is stabilized to maintain a level of molten metal in the mold. A skin of solid metal forms between the mold and the conduit, at which time the pumping of molten metal can cease. The mold with solid metal in it can be moved.

A smart molten metal pump system and method automatically controls the operating speed of the pump rather than requiring an operator to control the speed. The system includes a pump, a controller for controlling the speed of the pump and one or more vibration sensors (such as an accelerometer) to measure vibration. The controller receives input about the vibration of the pump or one or more pump components, and possibly other data, such as the temperature of the molten metal, and/or the depth of the molten metal, ad/or parameters related to the operation of the pump. The controller analyzes the one or more inputs to vary the speed of the pump, turn the pump off, and/or send a communication to an operator.

A pump for transferring molten metal includes an intake tube, a motor, a rotor positioned at least partially within the bottom end of the intake tube, a rotor shaft positioned at least partially in the intake tube, the rotor shaft having a first end attached to the motor and a second end attached to the rotor. An overflow conduit is attached to the intake tube. The pump does not include a pump housing and preferably does not include a superstructure, so it is relatively small, light and portable. In use, the motor drives the rotor shaft and rotor to generate a flow of molten metal upward into the intake tube and into the overflow conduit where it is discharged.

A coupling has an opening and a protrusion extending downward from the opening. The protrusion has threads that are preferably positioned outside of the opening. A rotor shaft that connects to the coupling has an internal bore with threads that receives and retains the protrusion, such as by a threaded connection between the two, so the protrusion applies driving force to the shaft.

A coupling has an opening and a protrusion extending downward from the opening. The protrusion has threads that are preferably positioned outside of the opening. A rotor shaft that connects to the coupling has an internal bore with threads that receives and retains the protrusion, such as by a threaded connection between the two, so the protrusion applies driving force to the shaft.

In accordance with one aspect of the present exemplary embodiment, a molten metal pump comprising a refractory material body defining an elongated chamber is provided. The chamber is configured to receive a shaft and impeller assembly. The chamber includes an open top through which the shaft passes and a bottom inlet. The impeller is located in or adjacent the inlet. The body further defines an elongated passage adjacent to the chamber. An opening provides fluid communication between the elongated passage and the elongated chamber. The elongated passage is in fluid communication with a discharge channel configured to direct molten metal at least substantially perpendicular to an elongated axis of the elongated chamber.