One embodiment of the invention includes a product including an annular portion including a frictional surface and a first flange portion extending from the frictional surface, wherein the first flange portion comprises a first face, a second face, and a third face; and a hub portion and a second flange portion extending from the hub portion, wherein the second flange portion engages the first face, the second face, and the third face of the first flange portion.

TECHNICAL FIELD

The field to which the disclosure generally relates includes a product with an improved cast-in-place torsion joint and a method for producing the same.

BACKGROUND

A variety of parts such as rotors, pulleys, brake drums, transmission gears, and other parts are typically composed of single piece cast iron or steel to support heavy loads and to resist wear.

SUMMARY OF EXEMPLARY EMBODIMENTS OF THE INVENTION

One embodiment of the invention includes a product including an annular portion including a frictional surface and a first flange portion extending from the frictional surface, wherein the first flange portion comprises a first face, a second face, and a third face; and a hub portion and a second flange portion extending from the hub portion, wherein the second flange portion engages the first face, the second face, and the third face of the first flange portion.

Other exemplary embodiments of the invention will become apparent from the detailed description of exemplary embodiments provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the exemplary embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the claimed invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following description of the embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

FIG. 1Ashows a perspective view of a product10. The product10may be for example, but is not limited to, a transmission gear, a transmission gear assembly, a rotor, a pulley, or a sprocket. In one embodiment of the invention, the product10may be a brake drum10including an annular portion12. The annular portion12may include a first flange portion (annular flange portion)14and a frictional surface16, where the first flange portion14extends from the frictional surface16. In one embodiment, the frictional surface16may be located on the internal surface of the annular portion12, and brake friction pads (not shown) may push outward on the frictional surface16to stop the motion of an automobile or to prevent a stopped automobile from moving. The first flange portion14may comprise a plurality of teeth18which may assist in preventing damage to the product10when torque is applied thereto. In another embodiment, the first flange portion12may include through holes (not shown) and the through holes may be located in at least one of the plurality of teeth18. In the embodiment where the first flange portion12includes through holes, the first flange portion14may or may not include the plurality of teeth18.

In another embodiment, the product10may include a pulley20.FIG. 1Bshows a perspective view of a pulley20according to one embodiment of the invention. The pulley20includes an annular portion22. The annular portion22includes a frictional surface26and a first flange portion24, where the first flange portion24extends from the frictional surface26. In one embodiment, the frictional surface26may be ribbed. The frictional surface26may be adapted for engagement by a device such as a belt (not shown). In one embodiment, the frictional surface26may be engaged by a belt of any known type, for example a belt having a generally rectangular cross-section or a belt having a v-shaped or triangular cross-section. A belt having a v-shaped cross section may be implemented with a notched frictional surface (not shown). In another embodiment, the pulley20may include through holes28in the first flange portion24. In another embodiment, the first flange portion24may include a plurality of teeth (not shown) but no through holes28, as shown in U.S. patent application Ser. No. 11/440,919, which is assigned to the assignee of this application. In another embodiment, the first flange portion24may include a plurality of teeth (not shown) and the through holes28may be located in at least one of the plurality of teeth.

In another embodiment, the product10may include a vehicle disk brake rotor30.FIG. 1Cshows a perspective view of a rotor30according to one embodiment of the invention. The rotor30includes an annular portion32. The annular portion32includes a first portion which may include at least one of a first face66and a second face68, and a first flange portion34extending from the first portion. The faces66and68may be adapted for engagement by a brake pad (not shown). The first flange portion34may extend from the first face66. While the rotor30shown is vented, in other embodiments, the rotor30may be un-vented. In one embodiment where the rotor30is vented, the first face66and the second face68may be separated by a plurality of vanes70. In one embodiment, first flange portion34may include a plurality of teeth36. In another embodiment, the first flange portion34may include through holes38and the through holes38may be located in at least one of the plurality of teeth36. In another embodiment, the first flange portion34may include the through holes38but not include the plurality of teeth36. In another embodiment, the first flange portion34may include a plurality of teeth (not shown) but no through holes38, as shown in U.S. patent application Ser. No. 11/220,893, which is assigned to the assignee of this application. In another embodiment, the first flange portion34may include the plurality of teeth36but not the through holes38.

In another embodiment, the automobile component10includes a brake drum assembly40shown inFIG. 2A. The brake drum assembly40includes the annular portion12, the first flange portion14extending from the annular portion12, a hub portion42, and a second flange portion (hub flange portion)44extending from the hub portion42. The second flange portion44may be constructed and arranged to engage the first flange portion14and thereby prevent rotation of the hub portion42relative to the annular portion12. In an embodiment where the first flange portion14includes a plurality of teeth18(shown inFIG. 1A), the second flange portion44may also include a plurality of hub teeth (not shown) adapted to engage the complementary teeth18. The annular portion12may comprise a first material. The hub portion42and the second flange portion44may comprise a second material that is lighter by volume (i.e., less dense) than the first material. The first material may comprise one of cast iron or steel. In one embodiment the second material may comprise one of aluminum, magnesium, plastic, or composite material. Aluminum may have a density of 2,700 kg m3and magnesium may have a density of 1,738 kg/m3, which are significantly lighter by volume than, for example, iron having a density of 7874 kg/m3. Therefore, in one embodiment, the overall weight of the drum assembly40is less than that of a comparable drum assembly composed entirely of cast iron or steel. In another embodiment, the hub portion42may also include features to attach to a vehicle axle assembly, for example a center opening46and a bolt hole pattern48. In another embodiment the first material and second material are substantially the same.

In another embodiment, the product10includes a pulley assembly50shown inFIG. 2B. The pulley assembly50includes the annular portion22, the first flange portion24(shown inFIG. 1B) extending from the annular portion22, a hub portion52, and a second flange portion54extending from the hub portion52. The second flange portion54may be constructed and arranged to engage the first flange portion24(shown inFIG. 1B) and thereby prevent rotation of the hub portion52relative to the annular portion22. The through holes28in the first flange portion24(shown inFIG. 1B) may interface with the second flange portion54to receive a connecting post or interlocking portion or spline as described hereafter. In an embodiment where the first flange portion24includes a plurality of teeth (not shown), the second flange portion54may also include a plurality of hub teeth (not shown) adapted to engage the complementary teeth on the first flange portion24. The annular portion22may comprise the first material, as described above. The pulley assembly50may transfer rotational energy from one device to another. An energy transfer device such as a belt engaged with the pulley assembly50tends to wear the friction surface over time, and therefore the first material should provide good resistance to wear and be relatively inexpensive. The hub portion52and the second flange portion54may comprise the second material, as described above. In one embodiment, the overall weight of the pulley assembly50is less than that of a comparable pulley assembly composed entirely of cast iron or steel. In another embodiment, the hub portion52may also include features to facilitate the attachment of the pulley assembly to an accessory drive component such as a shaft. These features may include, for example, a central aperture56and a locking element58. The central aperture56may be a cylindrical or conical bored hole. The locking element58may be a keyhole. The features such as the central aperture56and the locking element58may be machined after the casting process.

In another embodiment, the product10includes a rotor assembly60shown inFIG. 2C. The rotor assembly60includes the annular portion32, the first flange portion34(shown inFIG. 1C) extending from the annular portion32, a hub portion62, and a second flange portion64extending from the hub portion62. The second flange portion64may be constructed and arranged to engage the first flange portion34and thereby to prevent rotation of the hub portion62relative to the annular portion32. In an embodiment where the first flange portion34includes a plurality of teeth36(shown inFIG. 1C), the second flange portion64may also include a plurality of hub teeth (not shown) adapted to engage the complementary teeth36. The annular portion32may comprise the first material, as described above. The hub portion62may comprise the second material, as described above. The first material may provide good resistance to thermal deformation, resist wear during engagement of the brake pad (not shown) with the frictional surfaces66and68, which generates heat, and be relatively inexpensive. In one embodiment, the overall weight of the rotor assembly60is less than that of a comparable rotor assembly composed entirely of cast iron or steel. In another embodiment, the hub portion62may also include features to attach the rotor assembly60to a vehicle axle assembly, for example a central aperture72and a plurality of bolt holes74.

Referring toFIG. 3A, a partial sectional view of the brake drum assembly40is shown. The second flange portion44is constructed and arranged to engage the first flange portion14. The first flange portion14may extend from a friction surface82. The first flange portion14may include a first face76, a second face78, and a third face80. In one embodiment, the second flange portion44engages the first face76, the second face78, and the third face80of the first flange portion14. The second flange portion44may include an outer second flange portion84and an inner second flange portion86. The outer second flange portion84may engage the first face76and the inner second flange portion86may engage the second face78. In one embodiment, the engagement of the second flange portion44with the first flange portion14may be described as the first flange14being trapped between the outer second flange portion84and the inner second flange portion86. However, according to an alternate embodiment of the present invention (not shown), the geometry of the first flange portion14may be replaced with that of second flange portion44and vice versa. In other words, the first flange portion14may include opposing portions (not shown) configured to trap the second flange portion44therebetween.

Referring toFIG. 3B, a partial sectional view of the pulley assembly50is shown, according to one embodiment of the invention. The hub52may include the central aperture56and the locking element58. The second flange portion54is constructed and arranged to engage the first flange portion22. The first flange portion22may include a first face88, a second face90, and a third face92. In one embodiment, the second flange portion54engages the first face88, the second face90, and the third face92of the first flange portion22. The second flange portion54may include an outer second flange portion94and an inner second flange portion96. The outer second flange portion94may engage the first face88and the inner second flange portion96may engage the second face90. In one embodiment, the second flange portion54also fills the through holes28to form connectors or connection posts (splines)98extending between the outer second flange portion94and the inner second flange portion96. In one embodiment, the connectors98may provide a mechanical interface between the hub portion52and the annular portion22that is capable of transmitting the torque required in the operation of the accessory drive system. In another embodiment, the connectors98may be metallurgically bonded to the annular portion22. In an alternative embodiments shown inFIGS. 3C and 3D, the connectors98may extend from the first face88or the second face90of the flange portion24into a through-hole29formed in at least one of the outer second flange portion94or the inner second flange portion96.

Another embodiment does not include the through holes28and so there are no connectors98, as shown in U.S. patent application Ser. No. 11/440,919, which is assigned to the assignee of this application. In one embodiment, the engagement of the second flange portion54with the first flange portion22may be described as the first flange portion22being trapped between the outer second flange portion94and the inner second flange portion96. However, according to an alternate embodiment of the present invention (not shown), the geometry of the first flange portion22may be replaced with that of second flange portion54and vice versa. In other words, the first flange portion22may include opposing portions (not shown) configured to trap the second flange portion54therebetween.

Referring now toFIG. 3E, a partial sectional view of the rotor assembly60is shown, according to one embodiment of the invention. The second flange portion64is constructed and arranged to engage the first flange portion34. The first flange portion34may include a first face100, a second face102, and a third face104. In one embodiment, the second flange portion64engages the first face100, the second face102, and the third face104of the first flange portion34. The second flange portion64may include an outer second flange portion106and an inner second flange portion108. The outer second flange portion106may engage the first face100and the inner second flange portion108may engage the second face102. The second flange portion64also fills the through holes38to form connectors110between the outer second flange portion106and the inner second flange portion108. The connectors110may provide a mechanical interface between the hub portion62and the annular portion32that is capable of transmitting the torque required. Another embodiment does not include the through holes38and so there are no connectors110, as shown in U.S. patent application Ser. No. 11/220,893, which is assigned to the assignee of this application. In one embodiment, the engagement of the second flange portion64with the first flange portion34may be described as the first flange portion34being trapped between the outer second flange portion106and the inner second flange portion108. However, according to an alternate embodiment of the present invention (not shown), the geometry of the first flange portion34may be replaced with that of second flange portion64and vice versa. In other words, the first flange portion34may include opposing portions (not shown) configured to trap the second flange portion64therebetween.

Referring now toFIG. 4A, a detailed partial sectional view of the interface of the annular portion22of the pulley assembly50and the hub portion52of the pulley assembly50is provided according to one embodiment of the invention. According to another embodiment of the invention,FIG. 4Bshows a detailed partial sectional view of the interface of the annular portion32of the rotor assembly60and the hub portion62of the rotor assembly.

Referring now toFIG. 5A, a method of producing the brake drum assembly40is shown according to one embodiment of the invention. A first tool112and a second tool114are configured to manufacture the brake drum assembly40and are shown in an open position. The first tool112includes a first tool surface116and a first sealing lip118. The first tool surface116may define the outer surfaces of the hub portion42. The first sealing lip118may define the edges of the outer second flange portion84. The second tool114includes a second tool surface120, a second sealing lip122, and an annular portion cavity124. The second tool surface120may define the inner surfaces of the hub portion42. The second sealing lip122may define the edges of the inner second flange portion86. The annular portion cavity124may be of a size and shape to readily accept the insertion of the annular portion12. The first tool112and the second tool114may be metallic.

As shown inFIG. 5B, the annular portion12is placed in the annular portion cavity124. The first tool112is then placed over the second tool114. A compressive force is applied to the first tool112and the second tool114, which in turn applies a compressive force clamping the first flange portion14between the first sealing lip118and the second sealing lip122. The sealing lips118and122may define the perimeter of a central cavity116that is formed between the first tool112and the second tool114. A material is then introduced into the central cavity116to form the hub portion42and the second flange portion54extending from the hub portion42. The material may be a molten substance, for example molten aluminum or magnesium. The material is transferred into the central cavity116, for example injected into the cavity116. In another embodiment, the material is a semi-solid material and may be introduced into the central cavity116in accordance with the well known semi-solid forging process. The sealing lips118and122may prevent the material from leaking out of the central cavity116. The material forms the hub portion42, as shown inFIG. 5B. In one embodiment, the molten material forms hub teeth (not shown) which mechanically interlock with the teeth18. In one embodiment, as the molten material comes into contact with the annular portion12, a welding or diffusion bonding process may occur at the interface between the hub portion42and the annular portion12to further prevent relative motion therebetween. In one embodiment, the first tool112, the second tool114, and the annular portion12are maintained at a predetermined elevated temperature before the material is transferred into the central cavity116, such that the material does not prematurely cool upon contact with a relatively cold surface. After the passing of a sufficient cooling time, the tools112and114would return to the open position as shown inFIG. 5Aand the brake drum assembly40would be removed for further processing. Further processing may include, for example, machining features into the hub portion42such as the center opening46or the bolt hole pattern48shown inFIG. 2A. When the tools112and114are returned to the open position, the next annular portion12would be inserted into the open tooling and the manufacturing process of the brake drum assembly40would repeat.

In another embodiment (not shown), the hub portion42may be positioned in the first tool112, the second tool114may be placed over the first tool112, and a material may be introduced into a cavity formed between the tools112and114to form the annular portion12.

Referring now toFIG. 6A, a method of producing the pulley assembly50is shown according to one embodiment of the invention. A first tool126and a second tool128are configured to manufacture the pulley assembly50and are shown in an open position. The first tool126includes a first tool surface130and a first sealing lip132. The first tool surface130may define the outer surfaces of the hub portion52(shown inFIG. 2Band inFIG. 3B). The first sealing lip132may define the edges of the outer second flange portion94(shown inFIG. 3B). The second tool128includes a second tool surface134, a second sealing lip136, and an annular portion cavity138. The second tool surface134may define the inner surfaces of the hub portion52. The second sealing lip136may define the edges of the inner second flange portion96(shown inFIG. 3B). The annular portion cavity138may be of a size and shape to readily accept the insertion of the annular portion26. The first tool126and the second tool128may be metallic.

As shown inFIG. 6B, the annular portion26is placed in the annular portion cavity138. The first tool126is then placed over the second tool128. A compressive force is applied to the first tool126and the second tool128, which in turn applies a compressive force clamping the first flange portion24between the first sealing lip118and the second sealing lip122. The sealing lips118and122may define the perimeter of a central cavity140that is formed between the first tool126and the second tool128. A material is then introduced into the central cavity140to form the hub portion52and the second flange portion54extending from the hub portion52. The material may be a molten substance, for example molten aluminum or magnesium. The material is transferred into the central cavity140, for example injected into the central cavity140. In another embodiment, the material is a semi-solid material and may be introduced into the central cavity140in accordance with the well known semi-solid forging process. The sealing lips118and122may prevent the material from leaking out of the central cavity140. The material forms the hub portion52and the second flange portion54, as shown inFIG. 6B. In one embodiment, the molten material forms hub teeth (not shown) which mechanically interlock with the complementary teeth on the first flange portion24. In one embodiment, as the molten material comes into contact with the annular portion26, a welding or diffusion bonding process may occur at the interface between the hub portion52and the annular portion26to further prevent relative motion therebetween. In one embodiment, the first tool126, the second tool128, and the annular portion26are maintained at a predetermined elevated temperature before the material is transferred into the central cavity140, such that the material does not prematurely cool upon contact with a relatively cold surface. After the passing of a sufficient cooling time, the tools126and128would return to the open position as shown inFIG. 6Aand the pulley assembly50would be removed for further processing. Further processing may include, for example, machining features into the hub portion52such as the central aperture56and the locking element58shown inFIG. 2B. When the tools126and128are returned to the open position, the next annular portion26would be inserted into the open tooling and the manufacturing process of the pulley assembly50would repeat.

In another embodiment (not shown), the hub portion52may be positioned in the first tool126, the second tool128may be placed over the first tool126, and a material may be introduced into a cavity formed between the tools126and128to form the annular portion26.

Referring now toFIG. 7A, a method of producing the rotor assembly60is shown according to one embodiment of the invention. A first tool142and a second tool144are configured to manufacture the rotor assembly60and are shown in an open position. The first tool142includes a first tool surface146and a first sealing lip148. The first tool surface146may define the outer surfaces of the hub portion62(shown inFIG. 2Cand inFIG. 3E). The first sealing lip148may define the edges of the outer second flange portion106(shown inFIG. 3E). In one embodiment, the first tool142also includes a generally cylindrical protrusion150configured to produce the central aperture72(shown inFIG. 2C). But in other embodiments, the central aperture72may be produced by a subsequent machining process. In one embodiment, the plurality of bolt holes74(shown inFIG. 2C) may be produced by a plurality of smaller protrusions (not shown) in the first tool142or by a subsequent machining process.

Still referring toFIG. 7A, the second tool144includes a second tool surface152, a second sealing lip154, and an annular portion cavity156. The second tool surface152may define the inner surfaces of the hub portion62. The second sealing lip154may define the edges of the inner second flange portion108(shown inFIG. 3E). The annular portion cavity156may be of a size and shape to readily accept the insertion of the annular portion32. The first tool142and the second tool144may be metallic.

As shown inFIG. 7B, the annular portion32is placed in the annular portion cavity156. The first tool142is then placed over the second tool144. A compressive force is applied to the first tool142and the second tool144, which in turn applies a compressive force clamping the first flange portion34between the first sealing lip148and the second sealing lip154. The sealing lips148and154may define the perimeter of a central cavity158that is formed between the first tool142and the second tool144. A material is then introduced into the central cavity158to form the hub portion62. The material may be a molten substance, for example molten aluminum or magnesium. The material is transferred into the central cavity158, for example injected into the central cavity158. In another embodiment, the material is a semi-solid material and may be introduced into the central cavity156in accordance with the well known semi-solid forging process. The sealing lips118and122may prevent the material from leaking out of the central cavity158. The material forms the hub portion62, as shown inFIG. 7B. In one embodiment, the molten material forms hub teeth (not shown) which mechanically interlock with the complementary teeth36. In one embodiment, as the molten material comes into contact with the annular portion32, a welding or diffusion bonding process may occur at the interface between the hub portion62and the annular portion32to further prevent relative motion therebetween. In one embodiment, the first tool142, the second tool144, and the annular portion32are maintained at a predetermined elevated temperature before the material is transferred into the central cavity158, such that the material does not prematurely cool upon contact with a relatively cold surface. After the passing of a sufficient cooling time, the tools142and144would return to the open position as shown inFIG. 7Aand the rotor assembly60would be removed for further processing. Further processing may include, for example, machining features into the hub portion62such as the central aperture72and the plurality of bolt holes74shown inFIG. 2C. When the tools142and144are returned to the open position, the next annular portion32would be inserted into the open tooling and the manufacturing process of the rotor assembly60would repeat.

In another embodiment (not shown), the hub portion62may be positioned in the first tool142, the second tool144may be placed over the first tool142, and a material may be introduced into a cavity formed between the tools142and144to form the annular portion32.

The above description of embodiments of the invention is merely exemplary in nature and, thus, variations thereof are not to be regarded as a departure from the spirit and scope of the invention.