Casting mold and method for reducing air inclusions in a cast article

Abstract

A mold includes a first gate defining a first annular chamber and a second gate defining a second annular chamber and spaced from the first gate. The mold includes a first end ring gate concentric with the first gate gate and defining a first end ring chamber in fluid communication with the first annular chamber, and a second end ring gate concentric with the second gate gate and defining a second end ring chamber in fluid communication with the second annular chamber. The mold includes runners interconnecting the first and second end ring gates. Each of the runners defines a conduction beam channel in fluid communication with the first and second end ring chambers.The mold includes an overflow gate disposed between the first and second sprue gates, the overflow gate defining an annular overflow chamber in fluid communication with the lead beam channel.

Description

introduction

[0001] The disclosure relates to a mold and a method for reducing air inclusions in a cast article.

[0002] Die casting is a metal casting process in which molten metal is poured into a mold cavity, causing the molten metal to solidify and take on the shape of the mold. This metal forming technique allows for great versatility in the size and shape of objects, even complex shapes with internal cavities or hollow profiles. Therefore, die casting can be useful for forming objects such as electric motor components.

[0003] Electric motors convert electrical energy into mechanical energy through the interaction of magnetic fields and current-carrying conductors and may include a rotating element about a central axis. The rotating element, such as a rotor, may be arranged coaxially with a static element, such as a stator. One type of rotor, a squirrel cage rotor, may have a cage-like shape and include multiple longitudinal conductor bars arranged between and connected to two end rings.

[0004] DE 10 2010 010 363 A1 describes a rotor for an induction motor and a method for preparing the same. The method comprises producing a squirrel cage rotor consisting of a cage and a lamination stack by forming a mold around the stack, heating the stack, and introducing molten metal into the mold such that the molten metal substantially fills a space defined in the stack corresponding to the cage. In one form, the space comprises grooves or associated channels formed in the stack, which, after filling with the molten metal, become longitudinally extending rods that form electrical current loops with end rings of the cage.By heating the stack and maintaining it at a temperature high enough to keep the molten metal in a substantially molten state at least long enough for it to flow through the stack grooves, premature freezing of the molten metal is avoided. Furthermore, by providing low pressure to the molten metal, combined with the elevated temperature within the stack, flow is promoted to ensure a substantially porosity-free, full-density cage for the rotor.

[0005] EP 3 866 316 A1 describes a method and a casting mold for producing a rotor for an electric machine, wherein the rotor is formed from a metal core, at least one lower short-circuit ring, one upper short-circuit ring, and lamellar conductors connecting the short-circuit rings, wherein the method is carried out using a casting machine and a casting mold, wherein a molten metal is applied to the metal core in the casting mold, wherein the metal is copper, aluminum, or silver, wherein the rotor is formed with its axis of rotation vertical relative to a horizontal plane of the casting mold, wherein the metal is introduced into the casting mold at a gate on the lower short-circuit ring and fills the conductors and the upper short-circuit ring, wherein the metal is introduced into a variable chamber on the upper short-circuit ring,whereby the metal in the chamber is subjected to pressure by means of a plunger and displaced into the upper short-circuit ring.

[0006] US 5,067,550 A describes a manufacturing method for a defect-free cast product. The method comprises the steps of forming a cavity surrounded by a plurality of molds, filling the cavity with molten conductive material, and applying pressure to the conductive material by means of pressure. The method selectively applies additional pressure to the portion of the conductive material that may have cavities due to a delay in solidification by utilizing the pressure exerted by the pressure and moving a portion of the molds relative to the conductive material as the conductive material solidifies and shrinks, thereby preventing cavities. Description

[0007] The invention is defined by the claims.

[0008] A mold includes a first gate defining a first annular chamber and a second gate defining a second annular chamber and spaced from the first gate along a central longitudinal axis. The mold further includes a first end ring gate concentric with the first gate and defining a first end ring chamber in fluid communication with the first annular chamber, and a second end ring gate concentric with the second gate and defining a second end ring chamber in fluid communication with the second annular chamber. The mold also includes a plurality of runners interconnecting the first end ring gate and the second end ring gate, each of the plurality of runners defining a conduction beam channel in fluid communication with the first end ring chamber and the second end ring chamber.Furthermore, the mold includes a spill gate disposed between the first gate and the second gate along the central longitudinal axis, the spill gate defining an annular spill chamber in fluid communication with the conduit beam channel of each of the plurality of runners.

[0009] In one aspect, the mold may further include an inlet gate defining an inlet chamber in fluid communication with the first annular chamber and the second annular chamber.

[0010] In another aspect, the inlet gate may be bifurcated and may include a first arm connected to the first gate gate at a first connection and a second arm connected to the second gate gate at a second connection.

[0011] In another aspect, the first gate gate may have a first width at the first connection and a second width at a point spaced from the first connection transverse to the central longitudinal axis that is less than the first width.

[0012] In another aspect, the first gate may include a projection spaced from the first connection and extending away from the central longitudinal axis.

[0013] In one aspect, the plurality of rotors may be arranged in a radial configuration about the central longitudinal axis.

[0014] In another aspect, the overflow gate may completely enclose the plurality of runners.

[0015] In another aspect, the overflow gate may include a collection container and a vent spaced from the collection container.

[0016] In another aspect, the mold may further include a first plurality of flow gates each interconnecting the first gate and the first end ring gate and radially spaced about the central longitudinal axis.

[0017] In one aspect, each of the first plurality of flow gates may define a first flow gate channel in fluid communication with the first annular chamber and the first end annular chamber.

[0018] In another aspect, the mold may further include a second plurality of flow gates each interconnecting the second gate gate and the second end ring gate and spaced radially apart about the central longitudinal axis.

[0019] In another aspect, each of the second plurality of flow gates may form a second flow gate channel in fluid communication with the second annular chamber and the second end annular chamber.

[0020] In another aspect, the first gate gate may completely enclose the first end ring gate and the second gate gate may completely enclose the second end ring gate.

[0021] In another aspect, the first gate gate may partially enclose the first end ring gate and the second gate gate may partially enclose the second end ring gate.

[0022] In another aspect, the first gate may include two dead end nodes spaced apart from each other and from the central longitudinal axis.

[0023] In one aspect, the first end ring gate may be configured to form a first end ring of a rotor, the second end ring gate may be configured to form a second end ring of the rotor, and the plurality of rotors may be configured to form a plurality of conduction beams of the rotor.

[0024] In another aspect, a motor vehicle may include a rotor formed by the mold.

[0025] In one embodiment, a mold includes a first gate defining a first annular chamber and a second gate defining a second annular chamber and spaced from the first gate along a central longitudinal axis. The mold also includes a first end ring gate concentric with the first gate and defining a first end ring chamber in fluid communication with the first annular chamber, and a second end ring gate concentric with the second gate and defining a second end ring chamber in fluid communication with the second annular chamber. The mold further includes a plurality of runners interconnecting the first end ring gate and the second end ring gate, each of the plurality of runners defining a conduction beam channel in fluid communication with the first end ring chamber and the second end ring chamber.Furthermore, the mold includes a spill gate disposed between the first gate and the second gate along the central longitudinal axis and surrounding the plurality of runners, the spill gate defining an annular spill chamber in fluid communication with the conduit bar channel of each of the plurality of runners. The mold includes an inlet gate defining an inlet chamber in fluid communication with the first annular chamber and the second annular chamber, the inlet gate being bifurcated and including a first arm connected to the first gate, a second arm connected to the second gate, and a body connected to the first arm and the second arm.The body is L-shaped and includes a first leg extending along a first axis substantially perpendicular to the central longitudinal axis and a second leg extending along a second axis oblique to the first axis and the central longitudinal axis.

[0026] A method for reducing air entrapment in a casting includes filling a mold with a metal. The mold includes a first gate defining a first annular chamber and a second gate defining a second annular chamber and spaced from the first gate along a central longitudinal axis. The mold also includes a first end ring gate concentric with the first gate and defining a first end ring chamber in fluid communication with the first annular chamber, and a second end ring gate concentric with the second gate and defining a second end ring chamber in fluid communication with the second annular chamber.The mold further includes a plurality of runners interconnecting the first end ring gate and the second end ring gate, each of the plurality of runners defining a conducting beam channel in fluid communication with the first end ring chamber and the second end ring chamber. Furthermore, the mold includes a spill gate disposed between the first gate gate and the second gate gate along the central longitudinal axis, the spill gate defining an annular spill chamber in fluid communication with the conducting beam channel of each of the plurality of runners. Filling includes introducing the metal into the first annular chamber and the second annular chamber substantially simultaneously such that the metal has a first entry velocity at the first end ring gate and a second entry velocity at the second end ring gate substantially equal to the first entry velocity.The method also includes replacing air in the conducting beam channel of each of the plurality of runners with the metal in a first portion of each of the plurality of runners between the first end ring gate and the overflow gate and in a second portion of the plurality of runners between the second end ring gate and the overflow gate substantially simultaneously to form the casting and thereby reduce entrapped air in the first end ring chamber, the second end ring chamber, and the conducting beam channel of each of the plurality of runners.

[0027] In one aspect, the method further comprises, after replacing air, removing the metal from the annular overflow chamber, removing the cast article from the mold.

[0028] The above features and advantages, as well as other features and associated advantages of this disclosure, will be readily apparent from the following detailed description of illustrative examples and modes for carrying out the present disclosure, taken in conjunction with the accompanying drawings and the appended claims. Furthermore, this disclosure expressly includes combinations and subcombinations of the elements and features presented above and below. Brief description of the drawings Fig. 1 is a schematic perspective view of a mold. Fig. Figure 2 is a schematic front view of another embodiment of the mold of Fig. 1. Fig. 3 is a schematic side view of the mold of Fig. 2. Fig. 4 is a schematic perspective view of the mold of Fig. 1, which is filled with a metal. Fig. Figure 5 is a schematic perspective view of a motor vehicle with a rotor formed by the mold of Fig. 1 is formed. Fig. Figure 6 is a schematic flow diagram of a method for reducing air inclusions in a cast article. Detailed description

[0029] Referring to the figures, wherein like reference numerals refer to like elements, there is generally shown a mold 10, 110 ( Fig. 1 and Fig. 2) and a procedure 12 ( Fig. 6) for reducing air inclusions in a cast article 14 ( Fig. 5). The mold 10, 110 and method 12 may be useful for applications requiring lightweight, strong cast articles 14, such as a rotor 114 ( Fig. 5), with minimal porosity and air entrapment after casting, thus improving structural integrity and performance. In particular, method 12 may be useful for reducing fill clearance and increasing metal feed during casting, as discussed in more detail below.

[0030] More specifically, the mold 10, 110 and the process 12 metal 16 (in Fig. 4 shown as shading) to secure both end rings 18, 20 ( Fig. 5) to form the rotor 114 substantially simultaneously while reducing porosity at all locations on the rotor 114. In particular, the mold 10, 110 and method 12 can form the rotor 114 by equalizing an entry velocity at two ends of the mold 10, 110 while simultaneously casting both end rings 18, 20. Furthermore, the rotor 114 is formed by filling the conduction beams 22 from each end of the mold 10, 110 toward a center of the conduction beams 22, as explained in more detail below. The mold 10, 110 and method 12 enable the production of cast articles 14 with complex shapes and excellent dimensional accuracy without excessive porosity.

[0031] Therefore, the mold 10, 110 and method 12 may be useful for automotive applications, such as, but not limited to, prototyping and manufacturing cast articles 14 such as rotors 114, e.g., cage rotors, and other vehicle components. For example, a motor vehicle 24 ( Fig. 5) the rotor 114, e.g., a squirrel cage for an electric motor, produced by the mold 10, 110 and method 12. Alternatively, the mold 10, 110 and method 12 may also be useful for non-automotive applications, such as, but not limited to, prototyping and manufacturing cast articles 14 and components for aerospace, marine, transportation, robotics, architecture, and industrial applications.

[0032] Now with reference to Fig. 1, the casting mold 10 includes a first gating gate 26 defining a first annular chamber 28. The first gating gate 26 may be configured to convey the metal 16 into the first annular chamber 28 during casting. Similarly, the casting mold 10 includes a second gating gate 30 defining a second annular chamber 32 and spaced from the first gating gate 26 along a central longitudinal axis 34. The second gating gate 30 may also be configured to convey the metal 16 into the second annular chamber 32 during casting.

[0033] The mold 10 also includes a first end ring gate 36 that is concentric with the first gate gate 26 and defines a first end ring chamber 38 that is in fluid communication with the first annular chamber 28. That is, as shown in the Fig. 1-3, the first end ring gate 36 and the first gating gate 26, 126 have the same center, i.e., along the central longitudinal axis 34, and the first gating gate 26, 126 surrounds the first end ring gate 36. The first annular chamber 28 and the first end ring chamber 38 are fluidly connected to one another so that the metal 16 can flow from the first annular chamber 28 into and through the first end ring chamber 38 during casting, as will be explained in more detail below.

[0034] More specifically, and as explained with reference to Fig. 1 and Fig. 4, the mold 10 may further include a first plurality of flow gates 40 ( Fig. 1) that each interconnect the first gate 26 and the first end ring 18 and are radially spaced apart from each other about the central longitudinal axis 34. That is, the first plurality of flow gates 40 may be spaced apart from each other and extend radially between the first gate 26 and the first end ring gate 36 about the central longitudinal axis 34. As shown in Fig. 2, each of the first plurality of flow gates 40 may form a first flow gate channel 42 in fluid communication with the first annular chamber 28 of the first gating gate 26 and the first end annular chamber 38 of the first end annular gate 36. Therefore, during casting, the metal 16 may flow from the first annular chamber 28 through the first flow gate channel 42 of each of the first plurality of flow gates 40 to the first end annular chamber 38.

[0035] With continued reference to the Fig. 1-4, the mold 10 further comprises a second end ring gate 44 ( Fig. 3), which is arranged concentrically with the second gate 30 and a second end ring chamber 46 ( Fig. 4) which is in fluid communication with the second annular chamber 32. That is, the second end ring gate 44 and the second gating gate 30 have the same center, i.e., along the central longitudinal axis 34, and the second gating gate 30 surrounds the second end ring gate 44. The second annular chamber 32 and the second end ring chamber 46 are fluidly connected to one another so that the metal 16 can flow from the second annular chamber 32 to and through the second end ring chamber 46 during casting, as will be explained in more detail below.

[0036] In particular, the mold 10, as shown in Fig. 4, a second plurality of flow gates 140 each interconnecting the second gate gate 30 and the second end ring gate 44 and radially spaced apart about the central longitudinal axis 34. That is, the second plurality of flow gates 140 may be spaced apart from each other and extend radially between the second gate gate 30 and the second end ring gate 44 about the central longitudinal axis 34. Further, each of the second plurality of flow gates 140 may form a second flow gate channel 48 in fluid communication with the second annular chamber 32 of the second gate gate 30 and the second end ring chamber 46 of the second end ring gate 44. Therefore, during casting, the metal 16 can flow from the second annular chamber 32 through the second flow gate channel 48 of each of the second plurality of flow gates 140 into the second end annular chamber 46.

[0037] Now with reference to the Fig. 3 and Fig. 4, the casting mold 10, 110 also includes a plurality of runners 50 interconnecting the first end ring gate 36 and the second end ring gate 44. Each of the plurality of runners 50 defines a conducting beam channel 52 in fluid communication with the first end ring chamber 38 and the second end ring chamber 46. For example, each of the plurality of runners 50 may be shaped as a bar, and the conducting beam channel 52 of each of the plurality of runners 50 is in fluid communication with both the first end ring chamber 38 of the first end ring gate 36 and the second end ring chamber 46 of the second end ring gate 44 so that metal 16 can flow from the first and second end ring gates 38, 46 into the conducting beam channels 52 during casting. As shown in Fig. 4, the plurality of rotors 50 may be arranged in a radial array about the central longitudinal axis 34. That is, the plurality of rotors 50 may form a cage-like shape about the central longitudinal axis 34.

[0038] Therefore, as explained with reference to Fig. 5, after casting, the first end ring gate 36 may be configured to form the first end ring 18 of the rotor 114, the second end ring gate 44 may be configured to form the second end ring 20 of the rotor 114, and the plurality of rotors 50 may be configured to form the plurality of conduction beams 22 of the rotor 114.

[0039] Again with reference to Fig. 4, the mold 10 also includes a spill gate 54 disposed between the first gate 26 and the second gate 30 along the central longitudinal axis 34. The spill gate 54 defines an annular spill chamber 56 in fluid communication with the conduit beam channel 52 of each of the plurality of runners 50.

[0040] For example, the overflow gate 54 may completely enclose or surround the plurality of runners 50 and be disposed substantially parallel to the first end ring gate 36 and the second end ring gate 44 along the central longitudinal axis 34. In one non-limiting example, the overflow gate 54 may be disposed approximately halfway between the first end ring gate 36 and the second end ring gate 44 along the central longitudinal axis 34 and may be in fluid communication with each of the plurality of runners 50 such that metal 16 may flow from the conduction beam channel 52 of each of the plurality of runners 50 into the annular overflow chamber 56 during pouring.

[0041] As in the Fig. 1 and Fig. 3, the overflow gate 54 ( Fig. 1) comprise a collection container 58 and a vent 60 spaced from the collection container 58. The collection container 58 and the vent 60 may be spaced apart along an axis 62 that is substantially perpendicular to the central longitudinal axis 34 of the mold 10, 110. The collection container 58 may be configured to collect excess or contaminated metal 64 ( Fig. 4) collects, e.g., metal 64 containing air or other contaminants that flow beyond the conduit beam channels 52 during pouring. For example, excess or contaminated metal 64 may overflow into the collection container 58 due to gravity.

[0042] After pouring, as described below, the excess or contaminated metal 64 may be removed from the overflow chamber 56 via the vent 60. For example, a vacuum source (not shown) may be connected to the vent 60 to remove the excess or contaminated metal 64.

[0043] Now with reference to the Fig. 1 and Fig. 2, the casting mold 10, 110 further includes an inlet gate 66 defining an inlet chamber 68 in fluid communication with the first annular chamber 28 and the second annular chamber 32. The inlet gate 66 may be configured to receive the metal 16 for pouring. That is, molten or otherwise flowable metal 16 may be introduced or supplied into the casting mold 10, 110 via the inlet gate 66, for example, with a pump, ladle, tube, or other conveying mechanism, such that the metal 16 may flow from the inlet chamber 68 of the inlet gate 66 into the first annular chamber 28 and the second annular chamber 32.

[0044] More specifically, as in Fig. 1, the inlet gate 66 may be bifurcated and include a first arm 70 connected at a first connection 72 to the first gate gate 26, and a second arm 74 connected at a second connection 76 to the second gate gate 30. That is, the inlet gate 66 may be bifurcated or split into the first arm 70 and the second arm 74 so that the first gate gate 26 and the second gate gate 30 may be supplied with metal 16 substantially simultaneously during casting. The first arm 70 and the second arm 74 may be hollow and include a first conduit 78 ( Fig. 4) or a second line 80 ( Fig. 4). The first conduit 78 may be in fluid communication with the first annular chamber 28 and the second conduit 80 may be in fluid communication with the second annular chamber 32 so that the metal 16 may flow to both the first end ring gate 36 and the second end ring gate 44 simultaneously during casting.

[0045] As with reference to Fig. 2, the inlet gate 66 may further include a body 82 connected to the first arm 70 and the second arm 74. The body 82 may be generally L-shaped and have a first leg 84 extending along a first axis 86 substantially perpendicular to the central longitudinal axis 34, and a second leg 88 extending along a second axis 90 oblique to the first axis 86 and the central longitudinal axis 34. That is, the body 82 may move such that the metal 16 is directed during pouring along a plane substantially parallel to an outer surface 92 ( Fig. 1 and Fig. 3) each of the first and second end ring gates 36, 44 ( Fig. 3) runs, can flow in a first direction (indicated by the first arrow 94 in Fig. 2). The metal 16 can then move in a second direction (indicated by the second arrow 96 in Fig. 2) which is substantially perpendicular to the first direction 94, and can move within the L-shaped body 82 in a third direction (indicated by the third arrow 98 in Fig. 2) continue in the second conduit 80 of the second leg 88 toward the first arm 70 and the second arm 74. Therefore, a single filling or introduction point for the metal 16 can feed both the first gating gate 26 and the second gating gate 30, and, accordingly, the first end ring gate 36 and the second end ring gate 44.

[0046] As in Fig. 2, the first gate 26, 126 may have a first width 100 at the first connection 72 and a second width 102 that is less than the first width 100 at a point 104 spaced from the first connection 72 transverse to the central longitudinal axis 34. That is, the first gate 26, 126 may be thicker in one section than in another section along the central longitudinal axis 34 to optimize metal flow during casting.

[0047] In an embodiment of the mold 10, which is described with reference to the Fig. 1 and Fig. 4, the first gate gate 26 may completely enclose the first end ring gate 36, and the second gate gate 30 may completely enclose the second end ring gate 44 ( Fig. 4). That is, the first annular chamber 28 and the second annular chamber 32 may each be continuous, allowing the metal 16 to flow around the entire first end ring gate 36 and second end ring gate 44, respectively.

[0048] In this embodiment, the first gate 26 may include a protrusion 106 spaced from the first connection 72 of the first arm 70—first gate 26—and extending away from the central longitudinal axis 34. Similarly, the second gate 30 may include another protrusion 106 spaced from the second connection 76 of the second arm 74—second gate 30—and extending away from the central longitudinal axis 34. Similar to the sump 58 of the overflow gate 54 described above, the protrusion 106 may be configured to collect excess or contaminated metal 64, e.g., metal 64 containing air or other contaminants, that overflows the first gate 26 and / or the second gate 30 during casting. For example, excess or contaminated metal 64 may overflow into the projection 106 under pressure.

[0049] In another embodiment of the mold 110, which is described with reference to Fig. 2, the first gate gate 126 may partially enclose the first end ring gate 36, and a second gate gate 130 may partially enclose the second end ring gate 44. That is, the first annular chamber 128 and the second annular chamber 132 may each be discontinuous, allowing the metal 16 to flow around less than the entirety of the first end ring gate 36 and the second end ring gate 44, respectively.

[0050] In this embodiment, as best seen in Fig. 3, the first gating gate 126 may include two dead end nodes 108 spaced apart from each other and from the central longitudinal axis 34. Similarly, the second gating gate 130 may include two additional dead end nodes 108 spaced apart from each other and from the central longitudinal axis 34. Similar to the above-described sump 58 of the overflow gate 54, the dead end nodes 108 may be configured to collect excess or contaminated metal 64, e.g., metal 64 containing air or other contaminants, that flows beyond the first gating gate 26 and / or the second gating gate 30 during casting. Excess or contaminated metal 64 may spill over into the dead end nodes 108, for example, under pressure.

[0051] With reference to Fig. 6, the method 12 for reducing air entrapment in the cast article 14 includes filling 112 the mold 10, 110 with the metal 16. The filling 112 comprises introducing the metal 16 into the first annular chamber 28 and the second annular chamber 32 substantially simultaneously such that the metal 16 has a first entry velocity at the first end ring gate 36 and a second entry velocity at the second end ring gate 44 that is substantially equal to the first entry velocity. That is, the filling 112 may include feeding the metal 16 to the first end ring gate 36 and to the second end ring gate 44 at substantially the same time such that the metal 16 is forced at equal rates and amounts from each respective end ring gate 36, 44 through the conduit beam channel 52 of each of the plurality of runners 50 and to the annular overflow chamber 56 of the overflow gate 54.

[0052] The method 12 also includes replacing 116 air in the conduction beam channel 52 of each of the plurality of runners 50 with the metal 16 in a first portion 118 ( Fig. 3) each of the plurality of runners 50 between the first end ring gate 36 and the overflow gate 54 and in a second section 120 ( Fig.3) the plurality of runners 50 between the second end ring gate 44 and the overflow gate 54 substantially simultaneously to form the cast article 14 and thereby reduce the air trapped in the first end ring chamber 38, the second end ring chamber 46, and the lead beam channel 52 of each of the plurality of runners 50. That is, replacing 116 air may include forcing any air present in the various chambers 28, 32, 38, 46, 56 and channels 42, 48, 52 out of the mold 10, 110, e.g., via the vent 60, or into the sump 58, the boss 106, or the dead end nodes 108 while the metal 16 flows through the mold 10.

[0053] The method 12 may also include, after the air exchange 116, removing the metal from the annular overflow chamber 56 and the cast article 14 from the mold 10, 110. That is, the removal 122 may include collecting the excess or contaminated metal 64, which may contain some trapped air, and venting the spent or excess or contaminated metal 64 from the annular overflow chamber 56. The removal 122 may also include unpacking the formed casting 14 from the mold 10, 110. The cast article 14 may then be further processed, e.g., by grinding or polishing.

[0054] Advantageously, the mold 10, 110 and method 12 reduce air entrapment in the casting 14. That is, because the bifurcated construction of the body 82 allows the metal 16 to flow into both the first end ring gate 36 and the second end ring gate 44 at a substantially equal entry velocity, the mold 10, 110 improves and controls the metal feed so that the cast article 14 has reduced or minimized porosity and excellent strength, structural integrity, and dimensional stability. The mold 10, 110 and method 12 enable reduced metal feed distances and optimized forming of the first end ring 18 and the second end ring 20 of a cast rotor 114 by casting each end ring 18, 20 substantially simultaneously.Furthermore, each conductor bar 22 of the cast rotor 114 may have reduced or minimized porosity because the metal 16 flows over half the length of the conductor bar before reaching the overflow gate 54. Therefore, the mold 10, 110, and method 12 may reduce scrap rates and optimize casting processes, and may be capable of producing strong, lightweight articles 14 with high dimensional accuracy, all without additional tooling investments.

[0055] The described embodiments of the present disclosure are intended to serve as non-limiting examples, and other embodiments may take various and alternative forms. Furthermore, the accompanying drawings are not necessarily to scale and may present a somewhat simplified representation of various features of the present disclosure, including, for example, specific dimensions, orientations, positions, and shapes. The details associated with these features will be determined in part by the intended application and environment of use of the described embodiments.

[0056] For the purposes of this description, the use of the singular includes the plural and vice versa, unless expressly excluded; the terms "and" and "or" apply both subjunctive and disjunctive; and the words "including," "containing," "comprising," "with," and the like mean "including without limitation." Furthermore, words of approximation such as "about," "almost," "substantially," "generally," "approximately," etc. may be used herein to mean "at, near, or almost at," or "within 0-5% of," or "within acceptable manufacturing tolerances," or logical combinations thereof. A component "configured" to perform a particular function is capable of performing the particular function without modification, rather than merely having the potential to perform the particular function after further modifications.In other words, if the described hardware is expressly configured to perform the specified function, it is specifically selected, created, implemented, used, programmed, and / or designed to perform the specified function. Furthermore, the use of ordinal terms such as "first," "second," and "third" does not necessarily imply a ranking, but can merely distinguish between multiple instances of an act or structure.

Claims

[1] Casting mold (10, 110), comprising: a first gate (26) forming a first annular chamber (28); a second gate (30) forming a second annular chamber (32) and spaced from the first gate (26) along a central longitudinal axis (34); a first end ring gate (36) concentric with the first gate gate (26) and defining a first end ring chamber (38) in fluid communication with the first annular chamber (28); a second end ring gate (44) concentric with the second gate gate (30) and defining a second end ring chamber (46) in fluid communication with the second annular chamber (32); a plurality of runners (50) interconnecting the first end ring gate (36) and the second end ring gate (44), each of the plurality of runners (50) defining a conduction beam channel (52) in fluid communication with the first end ring chamber (38) and the second end ring chamber (46); and an overflow gate (54) disposed between the first gate gate (26) and the second gate gate (30) along the central longitudinal axis (34), the overflow gate (54) defining an annular overflow chamber (56) in fluid communication with the conduit bar channel (52) of each of the plurality of runners (50). [2] The mold (10, 110) of claim 1, further including an inlet gate (66) defining an inlet chamber (68) in fluid communication with the first annular chamber (28) and the second annular chamber (32). [3] The mold (10, 110) of claim 2, wherein the inlet gate (66) is bifurcated and includes a first arm (70) connected to the first gate gate (26) at a first connection (72) and a second arm (74) connected to the second gate gate (26) at a second connection (76). [4] The mold (10, 110) of claim 1, wherein the overflow gate (54) includes a collection container (58) and a vent (60) spaced from the collection container (58). [5] The casting mold (10, 110) of claim 1, wherein the first gate gate (26) completely encloses the first end ring gate (36) and the second gate gate (30) completely encloses the second end ring gate (44). [6] The mold (10, 110) of claim 1, wherein the first gate (26) partially encloses the first end ring gate (36) and the second gate (30) partially encloses the second end ring gate (44). [7] A method (12) for reducing air inclusions in a cast article (14), the method (12) comprising: Filling (112) a casting mold (10, 110) with a metal (16), the casting mold (10, 110) comprising: a first gate (26) forming a first annular chamber (28); a second gate (30) forming a second annular chamber (32) and spaced from the first gate (26) along a central longitudinal axis (34); a first end ring gate (36) concentric with the first gate gate (26) and defining a first end ring chamber (38) in fluid communication with the first annular chamber (28); a second end ring gate (44) concentric with the second gate gate (30) and defining a second end ring chamber (46) in fluid communication with the second annular chamber (32); a plurality of runners (50) interconnecting the first end ring gate (36) and the second end ring gate (44), each of the plurality of runners (50) defining a conduction beam channel (52) in fluid communication with the first end ring chamber (38) and the second end ring chamber (46); and an overflow gate (54) disposed between the first gate gate (26) and the second gate gate (30) along the central longitudinal axis (34), the overflow gate (54) defining an annular overflow chamber (56) in fluid communication with the conduit bar channel (52) of each of the plurality of runners (50); wherein filling (112) comprises introducing the metal (16) into the first annular chamber (28) and the second annular chamber (30) substantially simultaneously such that the metal (16) has a first entry velocity at the first end ring gate (36) and a second entry velocity at the second end ring gate (44) substantially equal to the first entry velocity; and Replacing (116) air in the conducting beam channel (52) of each of the plurality of runners (50) with the metal (16) in a first portion (118) of each of the plurality of runners (50) between the first end ring gate (36) and the overflow gate (54) and in a second portion (120) of the plurality of runners (50) between the second end ring gate (44) and the overflow gate (54) substantially simultaneously to form the cast article (14) and thereby reduce entrapped air in the first end ring chamber (38), the second end ring chamber (46), and the conducting beam channel (52) of each of the plurality of runners (50).

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