Mold pump assembly

Patent metadata

Field	Value
Publication number	US-10718336-B2
Application number	US-201815944184-A
Country	US
Kind code	B2
Filing date	Apr 3, 2018
Priority date	Apr 18, 2011
Publication date	Jul 21, 2020
Grant date	Jul 21, 2020

Abstract

A molten metal pump assembly and method to fill complex molds with molten metal, such as aluminum. The pump assembly includes an elongated shaft connecting a motor to an impeller. The impeller is housed within a chamber of a base member such that rotation of the impeller draws molten metal into the chamber at an inlet and forces molten aluminum through an outlet. A first bearing is adapted to support the rotation of the impeller at a first radial edge and a second bearing adapted to support the rotation of the impeller at a second radial edge. A bypass gap is interposed between the second bearing and the second radial edge. Molten metal leaks through the bypass gap at a predetermined rate to manipulate a flow rate and a head pressure of the molten metal such that precise control of the flow rate is achieved.

First claim

The invention claimed is:

1. A molten metal pump assembly to fill a mold with molten metal, the pump assembly comprising:
an elongated shaft connecting a motor to an impeller, the impeller being housed within a chamber of a base member such that rotation of the impeller draws molten metal into the chamber at an inlet and forces molten metal through an outlet of the chamber, the impeller including a first radial edge spaced from a second radial edge such that the first radial edge is proximate the elongated shaft; and
a bearing assembly surrounding the impeller within the chamber, the bearing assembly including:
a first bearing adapted to support the rotation of the impeller at the first radial edge;
a second bearing adapted to support the rotation of the impeller at the second radial edge; and
wherein at least one of the first and second bearings and the associated first and second radial edges is comprised of a plurality of posts positioned radially about a perimeter of the impeller, said posts defining apertures between the posts, said apertures allowing fluid communication between the chamber and an environment external to the pump, and wherein molten metal leaks through the apertures when the impeller is rotated to manipulate a flow rate and a head pressure of the molten metal passing through the outlet of the chamber.

2. The molten metal pump in accordance with claim 1 , wherein molten metal leaks from the chamber through the apertures at a predetermined rate as the impeller is rotated.

3. The molten metal pump in accordance with claim 1 , wherein the apertures are only between the second bearing and second radial edge.

4. The molten metal pump in accordance with claim 1 , wherein the base member is adapted to support the impeller, elongated shaft and the motor such that a second peripheral circumference of the impeller is adjacent to the second radial edge and is generally aligned with a bottom portion of the base member.

5. The molten metal pump in accordance with claim 1 , wherein the impeller includes a first peripheral circumference and a second peripheral circumference such that the elongated shaft is generally perpendicular to the first peripheral circumference of the impeller.

6. The molten metal pump in accordance with claim 5 , wherein the inlet is located at the first peripheral circumference, the inlet includes a plurality of apertures adapted to communicate molten metal to the chamber.

7. The molten metal pump in accordance with claim 6 , wherein said impeller comprises a plurality of bores extending from said first peripheral circumference to a side wall of the impeller.

8. The molten metal pump in accordance with claim 1 , wherein the molten metal leaking through the apertures reduces a head pressure of the associated molten metal at the outlet as the rotational rate of the impeller is increased.

9. A method of filling a mold with molten metal, the method comprising:
disposing the molten metal pump assembly of claim 1 in a bath of molten metal;
rotating the impeller;
transferring molten material through the impeller into the chamber;
leaking a predetermined portion of molten metal through the apertures to tune a head pressure relative to a rotational speed of the impeller; and
filling an associated mold with the molten metal.

10. The method of filling a mold with molten metal according to claim 9 , further comprises adjusting the rotational speed of the impeller while the associated mold is filled with molten metal.

11. The method of filling a mold with molten metal according to claim 9 , further comprising controlling a head pressure and flow rate of molten metal according to a programmable mold fill profile while the associated mold is filled with the molten metal.

Assignees

• Pyrotek Inc

Inventors

• Tipton Jon

Classifications

• F04D7/06

  the fluids being hot or corrosive, e.g. liquid metals · CPC title

• F04D29/047

  hydrostatic; hydrodynamic · CPC title

• F04D7/04 Primary

  the fluids being viscous or non-homogenous · CPC title

• B22D17/02 Primary

  Hot chamber machines, i.e. with heated press chamber in which metal is melted · CPC title

• F04D29/0473

  for radial pumps · CPC title