Molded gearbox cover

Abstract

A compression-molded gearbox cover comprises a radially outer flange section for mounting to a gearbox housing, a convex section extending axially from the radially outer flange section, and a stepped projection arranged to receive a first bearing. The stepped projection may include a first cylindrical projection extending from the convex section and a circular ring extending radially inward from the first cylindrical projection. The stepped projection may also include a second cylindrical projection, coaxial with the first cylindrical projection and extending from the circular ring. The second cylindrical projection may include an opening for receiving an axle shaft.The first cylindrical projection can extend from the circular ring in a first axial direction, and the second cylindrical projection can extend from the circular ring in a second axial direction opposite to the first axial direction.

Description

CROSS-REFERENCE TO RELATED REGISTRATIONS

[0001] This application claims the benefit of the preliminary US patent application No. 63 / 521,203, filed on June 15, 2023, and the non-preliminary US patent application No. 18 / 543,435, filed on December 18, 2023, the entire disclosures of which are incorporated herein by reference. TECHNICAL AREA

[0002] The present disclosure relates generally to a gearbox cover and in particular to a compression-molded gearbox cover. BACKGROUND

[0003] Gearbox covers with integrated bearing cavities are known. An example is shown and described in US patent application 2023 / 0126628 entitled “BOLT THROUGH INTERMEDIATE SHAFT OF PARALLEL AXIS GEARBOX” by Labelle. SUMMARY

[0004] Exemplary aspects generally include a compression-molded gearbox cover comprising a radially outer flanged section for attachment to a gearbox housing, a convex section extending axially from the radially outer flanged section, and a stepped projection arranged to receive a first bearing. In some exemplary embodiments, the stepped projection includes a first cylindrical projection extending from the convex section and a circular ring extending radially inward from the first cylindrical projection. In some exemplary embodiments, the stepped projection further includes a second cylindrical projection, coaxial with the first cylindrical projection and extending from the circular ring. The second cylindrical projection includes an opening for receiving an axle shaft.In one exemplary embodiment, the second cylindrical projection is arranged to receive an axle shaft seal. In another exemplary embodiment, the first cylindrical projection extends from the circular ring in a first axial direction, and the second cylindrical projection extends from the circular ring in a second axial direction opposite to the first axial direction.

[0005] In some exemplary embodiments, the molded gearbox cover also includes a conical projection offset from the stepped projection. In one exemplary embodiment, the conical projection includes a conical ring and a circular disc. In some exemplary embodiments, the molded gearbox cover also includes a separate bearing bracket that is attached to the conical projection. In one exemplary embodiment, the conical projection and the separate bearing bracket each have conical surfaces in contact with each other. In one exemplary embodiment, the separate bearing bracket is attached to the conical projection. In one exemplary embodiment, the separate bearing bracket includes a third cylindrical projection arranged to receive a second bearing.In one exemplary embodiment, the separate bearing bracket comprises a "J"-shaped cross-section.

[0006] Other exemplary aspects include, broadly speaking, a transmission for a vehicle comprising a transmission housing, the molded transmission cover attached to the radially outer flange section of the transmission housing, and a first gear. In some exemplary embodiments, the transmission also includes a second gear meshing with the first gear. In some exemplary embodiments, the transmission also includes a first bearing located in the stepped projection and an axle shaft supported by the first bearing. In some exemplary embodiments, the transmission also includes a second bearing, the molded transmission cover further comprising a tapered projection offset from the stepped projection, and a separate bearing bracket secured in the tapered projection, with the second bearing located in the separate bearing bracket.In some exemplary embodiments, the transmission also includes a transmission shaft held by the second bearing. In some exemplary embodiments, the first gear is coaxial with the axle shaft, and the second gear is coaxial with the transmission shaft. In one exemplary embodiment, the transmission also includes an axle shaft seal located in the stepped projection for sealing the axle shaft against the molded transmission cover. BRIEF DESCRIPTION OF THE DRAWINGS The single figure illustrates a partial cross-sectional view of a gearbox incorporating a compression-molded gearbox cover according to an exemplary aspect of the present disclosure. DETAILED DESCRIPTION

[0007] Embodiments of the present disclosure are described herein. It should be clear that identical reference numbers appearing in different drawing views denote identical or functionally similar structural elements. Likewise, it is understood that the disclosed embodiments are merely examples and other embodiments may take different and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show detail of certain components. Therefore, certain design and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching the person skilled in the art to apply the embodiments in various ways.As experts will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to create embodiments not expressly illustrated or described. The illustrated combinations of features provide representative embodiments for typical applications. However, various combinations and modifications of the features, consistent with the teachings of this disclosure, may be desirable for specific applications or implementations.

[0008] The terminology used herein serves only to describe certain aspects and is not intended to limit the scope of protection of this disclosure. Unless otherwise defined, all technical and scientific terms used herein have the same meanings generally ascribed to them by a person skilled in the art in the field to which this disclosure belongs. Although any methods, devices, or materials similar or equivalent to those described herein may be used in the application or testing of the disclosure, the following are examples of such methods, devices, and materials.

[0009] The following description is given with reference to the single figure. The single figure illustrates a partial cross-sectional view of a gearbox 200, which includes a compression-molded gearbox cover 100. The compression-molded gearbox cover 100 includes a radially outer flanged section 102 for attachment to a gearbox housing (e.g., a gearbox housing 202, as described below), a convex section 104 extending axially from the radially outer flanged section, and a stepped projection 106 arranged for receiving a bearing (e.g., a bearing 204, as described below). The stepped projection 106 includes a cylindrical projection 108 extending from the convex section and a circular ring 110 extending radially inward from the cylindrical projection 108. The circular ring 110 forms, for example, an axial support for the bearing 204.

[0010] The stepped projection 106 also includes a cylindrical projection 112, which is coaxial with the cylindrical projection 108 and extends from the circular ring. The cylindrical projection 112 includes an opening 114 for receiving an axle shaft (e.g., an axle shaft 206, as described below). The cylindrical projection 112 is also arranged to receive an axle shaft seal (e.g., an axle shaft seal 208, as described below). As shown in the figure, the cylindrical projection 108 extends from the circular ring in the axial direction 116, and the cylindrical projection 112 extends from the circular ring in the axial direction 118, opposite to the axial direction 116.

[0011] The compression-molded gearbox cover 100 includes a conical projection 120 offset from the stepped projection. The conical projection includes a conical ring 122 and a circular disc 124. The compression-molded gearbox cover 100 includes a separate bearing bracket 126, which is attached to the conical projection. "Separate" means that the bearing bracket 126 is a separate component formed from a separate piece of material, in contrast to the features of the compression-molded gearbox cover discussed above (e.g., flanged section, domed section, stepped projection, conical projection), all of which are formed from a single piece of material by cold forming (e.g., compression molding). The conical projection 120 and the bearing bracket 126 each comprise conical surfaces in contact with each other. In other words, the bearing bracket rests against the conical ring of the conical projection.

[0012] The separate bearing bracket is attached to the conical projection (e.g., by welding, adhesives, soldering, press-fitting, bolting, riveting, or another fastening method). The bearing bracket 126 includes a cylindrical projection 128 arranged to receive a bearing (e.g., a bearing 210, as described below). As can be seen in the cross-sectional figure, the separate bearing bracket has a "J"-shaped cross-section, with an angled section 130 connected to the cylindrical projection 128 by a circular ring 132.

[0013] The gearbox 200 is intended for use in a vehicle. That is, the gearbox 200 could, for example, be an electric axle for a vehicle. The gearbox 200 comprises a gearbox housing 202, a molded gearbox cover 100 attached to the radially outer flange section of the gearbox housing, and a gear 212. As shown in the figure, the gear 212 is arranged in the curved section such that the entire gear 212 is positioned between the outer flange section 102 and a base of the curved section. The cover 100 can be positioned, for example, by pins (not shown) installed in the housing 202 that extend through openings in the cover 100. The cover 100 can also be fastened to the housing, for example, by screws that extend through separate openings in the cover. The gearbox 200 also includes a gear 214 that meshes with the gear 212.This means that the gear teeth of gears 212 and 214 are aligned such that a rotation of one gear rotates the other gear in a known manner. As shown in the figure, gear 214 is located in the curved section and the axes of rotation of the gears are radially offset, so that the two gears are NOT coaxial.

[0014] The gearbox 200 also includes the bearing 204, which is located in the stepped projection, and the axle shaft 206, which is held by the bearing 204. The bearing 204 may, for example, be pressed into the cylindrical projection 108 or pressed onto the axle shaft 206. It should be noted that the axle shaft 206 extends through the cover 100 to engage with a differential assembly 216, and that the gear 212 is attached to the differential assembly. Therefore, the bearing 204 also holds the gear 212 through the axle shaft. The gearbox 200 also includes an axle shaft 218, which is held by a bearing 220 installed in the housing 202. The axle shafts 206 and 218 extend axially outward from the housing and the cover toward the vehicle wheels (not shown) to provide drive to the vehicle. Gear 212 can, for example, be described as an axle drive gear.

[0015] The gearbox 200 also includes a bearing 210, which is arranged in the separate bearing holder 126, and a gearbox shaft 222, which is held by the bearing 210. Like the bearing 204 discussed above, the bearing 210 can, for example, be pressed into the bearing holder 126 or pressed onto the gearbox shaft 222. The gear 212 is coaxial with the axle shaft 206, and the gear 214 is coaxial with the gearbox shaft. As discussed above, the gear 212 is held by the axle shaft 206. Similarly, the gear 214 is held by the gearbox shaft 222. The gears 212 and 214 provide an axle ratio for the gearbox 200. The gearbox 200 also includes an axle shaft seal 208, which is arranged in the stepped projection for sealing the axle shaft against the molded gearbox cover.

[0016] The gearbox 200 can also include a bearing 224 arranged in the housing 202 for holding the gearbox shaft 222 and a gear 226 arranged on the gearbox shaft 222. The gears 214 and 226 are attached to the gearbox shaft 222 so that they rotate together. The gearbox 200 can include an electric motor 228 with a motor shaft 230 and a gear 232, which is attached to the motor shaft 230 and meshes with the gear 226. A bearing 234 arranged in the housing 202 holds the motor shaft 230.

[0017] Although exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the description are descriptive and not limiting, and it is understood that various modifications can be made without deviating from the fundamental idea and scope of protection of the disclosure. As previously described, the features of different embodiments can be combined to form further embodiments of the disclosure that may not be expressly described or illustrated.While various embodiments could have been described as advantageous or preferred over other embodiments or implementations according to the prior art with respect to one or more desired properties, those skilled in the art recognize that a compromise may be made with regard to one or more features or properties in order to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes may include, but are not limited to, cost, strength, durability, life cycle costs, marketability, appearance, packaging, size, usability, weight, manufacturability, ease of assembly, etc.To the extent that embodiments are described as less desirable than other embodiments or realizations according to the prior art with respect to one or more properties, these embodiments are therefore not outside the scope of protection of the disclosure and may be desirable for certain applications. Reference symbol list 100 Molded Gearbox Covers 102 Radial outer flange section 104 Vaulted Section 106 Graduated lead 108 Cylindrical projection (first) 110 Circular ring 112 Cylindrical protrusion (second) 114 Opening (cylindrical projection 112) 116 Axial direction (first) 118 Axial direction (second) 120 Conical Protrusion 122 Conical Ring 124 Circular disc 126 Bearing bracket 128 Cylindrical projection (third) 130 Angled section (bearing bracket) 132 Circular ring (bearing holder) 200 gearboxes 202 Gearbox housing 204 warehouses (first) 206 Axle shaft 208 Axle shaft seal 210 storage (second) 212 Gear (first) 214 Gear (second) 216 Differential assembly 218 Axle shaft 220 storage 222 Gear shaft 224 warehouses 226 gear 228 Electric motor 230 motor shaft 232 gear 234 warehouses QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 521.203

[0001] US 18 / 543,435

[0001] US 2023 / 0126628

[0003]

Claims

[1] Molded gearbox cover, comprising: a radially outer flange section for attachment to a gearbox housing; a curved section extending axially from the radially outer flange section; and a stepped projection arranged to receive a first bearing. [2] Molded gearbox cover according to claim 1, wherein the stepped projection comprises: a first cylindrical projection extending from the arched section; and a circular ring extending radially inwards from the first cylindrical projection. [3] Molded gearbox cover according to claim 2, wherein the stepped projection further comprises a second cylindrical projection which is coaxial to the first cylindrical projection and extends from the circular ring, wherein the second cylindrical projection comprises an opening for receiving an axle shaft. [4] Molded gearbox cover according to claim 3, wherein the second cylindrical projection is arranged to receive an axle shaft seal. [5] Molded gearbox cover according to claim 3, wherein: the first cylindrical projection extends from the circular ring in a first axial direction; and the second cylindrical projection extends from the circular ring in a second axial direction opposite to the first axial direction. [6] Molded gearbox cover according to claim 1, further comprising a conical projection offset from the stepped projection. [7] Molded gearbox cover according to claim 6, wherein the conical projection comprises: a conical ring; and a circular disc. [8] Molded gearbox cover according to claim 6, further comprising a separate bearing support which is attached in the conical projection. [9] Molded gearbox cover according to claim 8, wherein the conical projection and the separate bearing support each comprise conical surfaces touching each other. [10] Molded gearbox cover according to claim 8, wherein the separate bearing holder is attached to the conical projection. [11] Molded gearbox cover according to claim 8, wherein the separate bearing holder comprises a third cylindrical projection arranged to receive a second bearing. [12] Molded gearbox cover according to claim 8, wherein the separate bearing support comprises a “J”-shaped cross-section. [13] Transmission for a vehicle, comprising: a gearbox housing; the molded gearbox cover according to claim 1, which is attached to the radially outer flange section on the gearbox housing; and a first gear. [14] Gearbox according to claim 13, further comprising a second gear which engages with the first gear. [15] Gearbox according to claim 14, further comprising: a first bearing arranged in the stepped projection; and an axle shaft that is held by the first bearing. [16] Gearbox according to claim 15, further comprising a second bearing, wherein: The molded gearbox cover also includes the following: a conical projection offset from the stepped projection; and a separate bearing bracket that is attached to the conical projection; and the second bearing is arranged in the separate bearing bracket. [17] Gearbox according to claim 16, further comprising a gearbox shaft which is held by the second bearing. [18] Gearbox according to claim 17, wherein the first gear is coaxial to the axle shaft and the second gear is coaxial to the transmission shaft. [19] Gearbox according to claim 18, further comprising an axle shaft seal which is arranged in the stepped projection for sealing the axle shaft against the molded gearbox cover.

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