Mold pump assembly
First Claim
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 opposing the first radial edge;
a second bearing opposing the second radial edge; and
at least one bypass gap interposed between a portion of one of the first and second bearings and the associated first and second radial edges, a lubrication gap interposed between the other of the first and second bearing and the associated first and second radial edges, the bypass gap having a width greater than a width of the lubrication gap, said lubrication gap being configured such that the bearing supports rotation of the impeller, the bypass gap communicating between the chamber and an environment external to the pump assembly to leak molten metal from the pump assembly during operation and modify a flow rate and a head pressure of the molten metal as the molten metal exits the outlet of the chamber.
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Accused Products
Abstract
A molten metal pump assembly (10) and method to fill complex molds with molten metal, such as aluminum. The pump assembly includes an elongated shaft (16) connecting a motor (14) to an impeller (22). The impeller is housed within a chamber (18) of a base member such that rotation of the impeller draws molten metal into the chamber at an inlet (48) and forces molten aluminum through an outlet (50). A first bearing (36) is adapted to support the rotation of the impeller at a first radial edge (32) and a second bearing (38) is adapted to support the rotation of the impeller at a second radial edge. A bypass gap (60) 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.
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Citations
12 Claims
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1. A molten metal pump assembly to fill a mold with molten metal, the pump assembly comprising:
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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 opposing the first radial edge; a second bearing opposing the second radial edge; and at least one bypass gap interposed between a portion of one of the first and second bearings and the associated first and second radial edges, a lubrication gap interposed between the other of the first and second bearing and the associated first and second radial edges, the bypass gap having a width greater than a width of the lubrication gap, said lubrication gap being configured such that the bearing supports rotation of the impeller, the bypass gap communicating between the chamber and an environment external to the pump assembly to leak molten metal from the pump assembly during operation and modify a flow rate and a head pressure of the molten metal as the molten metal exits the outlet of the chamber. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification