Bolt passing through intermediate shaft of parallel shaft gearbox

Abstract

A parallel shaft gearbox for a vehicle is provided. The parallel shaft gearbox includes an input shaft having a first axis of rotation and an intermediate shaft having a second axis of rotation that is parallel to the first axis of rotation. The intermediate shaft includes an intermediate drive gear, an intermediate driven gear, and a longitudinal bore through the intermediate shaft. The intermediate driven gear is meshingly engaged with a first drive gear on the input shaft. The input shaft and the intermediate shaft are housed within and supported by a cover that is fixedly coupled with a housing. Bolts fixedly couple the cover with the housing and pass through the longitudinal bore of the intermediate shaft.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority and all benefits to U.S. Provisional Application 63 / 014,816, filed April 24, 2020, entitled “Bolt through the intermediate shaft of a parallel shaft gearbox,” the disclosure of which is incorporated herein by reference. Technical Field

[0003] This invention relates to an electric vehicle axle gearbox for a vehicle having a hollow intermediate shaft. More specifically, this invention relates to an electric vehicle axle gearbox housed in a cover and a housing and including a hollow intermediate shaft, wherein the cover is fixedly connected to the housing via the hollow intermediate shaft. Background Technology

[0004] In contrast to or in addition to internal combustion engines, many vehicles today feature electric drive systems, which include electric motors operatively coupled to axle gearboxes. Axle gearboxes operatively coupled to electric motors are typically described as electric axle gearboxes and / or eAxle gearboxes. eAxle gearboxes are typically operatively coupled to one or more wheels for propelling the vehicle.

[0005] One type of eAxle gearbox is a parallel-shaft gearbox. A parallel-shaft gearbox typically includes an input shaft, an intermediate shaft, a differential assembly, and first and second output-side shafts, each having its own axis of rotation parallel to the others. The input shaft is typically operatively coupled to an electric motor output shaft. Furthermore, the input shaft includes a first drive gear. Similarly, the intermediate shaft includes an intermediate drive gear. The first drive gear is fixedly coupled to the intermediate shaft and meshes with a drive gear on the input shaft. The first and second output-side shafts are rotatably coupled via the differential assembly to an annular driven gear that meshes with the intermediate drive gear.

[0006] Typically, a parallel-shaft gearbox includes a cover fixedly connected to a housing to house and support the internal components of the gearbox. Multiple mechanical fasteners are typically spaced around the outer periphery of the cover to attach it to the housing. The cover has increased axial stiffness near the mechanical fasteners. However, in the portion of the cover spaced from the mechanical fasteners, the stiffness of the cover is generally lower. Because the cover and housing house and support the internal components of the gearbox, the reduced stiffness of the cover in the axial direction of the intermediate shaft leads to increased deflection of the cover under load. Deflection of the cover under load causes misalignment between the meshing gears within the parallel-shaft gearbox. Furthermore, the input shaft, intermediate shaft, and differential assembly are all supported by bearings. These bearings can misalign due to the deflection of the cover under load. Misalignment between the meshing gears within the parallel-shaft gearbox increases gear wear and reduces gear durability. Additionally, bearing misalignment increases bearing wear and further reduces bearing durability.

[0007] Some parallel shaft gearboxes include an intermediate shaft having a longitudinal bore that extends at least partially through the intermediate shaft. An intermediate shaft with a longitudinal bore may alternatively be described as a hollow intermediate shaft.

[0008] Typically, the intermediate shaft is positioned spaced apart from the outer periphery of the cover of the parallel shaft gearbox. U.S. Patent 9,951,850 generally discloses a first known parallel shaft gear having an input shaft, an intermediate shaft, and first and second output shafts, each having a parallel axis of rotation. The input shaft is operatively coupled to an electric motor output shaft. Furthermore, the input shaft includes a first drive gear. Similarly, the intermediate shaft includes an intermediate drive gear. A longitudinal bore extends partially through the intermediate shaft. A first driven gear is fixedly coupled to the intermediate shaft and meshes with the first drive gear on the input shaft. The first and second output shafts are rotatably coupled via a differential assembly to an annular driven gear meshing with the intermediate drive gear.

[0009] The internal components of the first known parallel-shaft gearbox are supported and housed within a cover and a housing. Multiple mechanical fasteners attach the cover to the housing around its outer periphery. However, the cover has no mechanical fasteners near the intermediate shaft. Because the mechanical fasteners are spaced apart around the outer periphery of the cover, the cover has reduced axial stiffness under load near the intermediate shaft.

[0010] Chinese Patent 10894439 generally discloses a second known parallel-shaft gearbox having an input shaft, an intermediate shaft, and first and second output shafts, each having a parallel axis of rotation. The input shaft is operatively coupled to an output shaft of an electric motor. Furthermore, the input shaft includes a first drive gear. Similarly, the intermediate shaft includes an intermediate drive gear. Additionally, a longitudinal bore extends through the intermediate shaft. A first driven gear is fixedly coupled to the intermediate shaft and meshes with the first drive gear on the input shaft. The first and second output shafts are rotatably coupled via a differential assembly to an annular driven gear meshing with the intermediate drive gear.

[0011] The housing of a second known parallel-shaft gearbox includes a first channel opening for access to an intermediate shaft and a second channel opening for access to an input shaft. Furthermore, the first and second channel openings are each sealed by corresponding first and second covers. The outer peripheries of the first and second covers are fastened to the housing by mechanical fasteners. Compared to the first known parallel-shaft gearbox, in the second known parallel-shaft gearbox, the mechanical fasteners are closer to the intermediate shaft. However, in the second known parallel-shaft gearbox, the first cover for the intermediate shaft will deflect under load. Because the mechanical fasteners are spaced around the outer periphery of the first cover, the first cover has reduced axial stiffness near the axis of rotation of the intermediate shaft.

[0012] Therefore, it is desirable to reduce the possibility of meshing misalignment within the parallel shaft gearbox due to the deflection of the cover on the intermediate shaft under load. Furthermore, it is desirable to reduce the possibility of bearing misalignment by decreasing the likelihood of the cover deflecting under load. Additionally, it is desirable to increase the axial rigidity of the cover on the intermediate shaft. Furthermore, it is desirable to add a connection point between the cover and the housing via the intermediate shaft. Finally, it is desirable to mechanically fasten the cover to the housing via a longitudinal hole passing through the intermediate shaft to increase the axial rigidity of the cover. Summary of the Invention

[0013] This invention relates to a parallel-shaft gearbox for a vehicle. The parallel-shaft gearbox includes an input shaft having a first axis of rotation and an intermediate shaft having a second axis of rotation parallel to the first axis of rotation. The intermediate shaft includes an intermediate drive gear, an intermediate driven gear, and a longitudinal bore passing through the intermediate shaft. The intermediate driven gear meshes with a first drive gear on the input shaft. The input shaft and the intermediate shaft are housed within and supported by a cover, which is fixedly connected to a housing. Bolts secure the cover to the housing and pass through the longitudinal bore of the intermediate shaft. Attached Figure Description

[0014] The advantages of the invention will become readily apparent, and even more readily understood, when considered in conjunction with the accompanying drawings and with reference to the following detailed description, wherein,

[0015] Figure 1 This is a partially transparent view of a parallel shaft gearbox according to an embodiment of the present invention, the gearbox having an intermediate shaft supported and housed within a cover and a housing, the view showing bolts passing through a longitudinal hole in the intermediate shaft and securely connecting the cover to the housing;

[0016] Figure 2 It was cut along section line AA. Figure 1 An aligned sectional view of a parallel-shaft gearbox illustrates the first embodiment of the present invention;

[0017] Figure 3 It was cut along section line BB. Figure 1 An enlarged sectional view of the parallel shaft gearbox shows the bolts that securely connect the cover to the housing through a longitudinal hole passing through the intermediate shaft;

[0018] Figure 4 This is a partially transparent view of a known parallel shaft gearbox having an intermediate shaft supported and housed within a cover and a housing. The view shows mechanical fasteners spaced around the outer periphery of the cover and attaching the cover to the housing.

[0019] Figure 5 It was cut along section line CC. Figure 4 Aligned sectional view of a known parallel shaft gearbox, showing mechanical fasteners spaced apart from the intermediate shaft;

[0020] Figure 6 It was cut along section line BB. Figure 1 An enlarged sectional view of the parallel shaft gearbox shows the second embodiment of the present invention;

[0021] Figure 7 It was cut along section line BB. Figure 1 An enlarged cross-sectional view of the parallel shaft gearbox shows the third embodiment of the present invention. Detailed Implementation

[0022] Figure 1-3 Figures 6 and 7 illustrate a parallel shaft gearbox 10 according to an embodiment described herein, the parallel shaft gearbox 10 having bolts 14 that fasten a cover 18 to a housing 22 via an intermediate shaft 26. Orientation references used or shown in the specification, drawings, or claims, such as top, bottom, upper, lower, upward, downward, longitudinal, transverse, left, right, etc., are relative terms used for ease of description and are not intended to limit the scope of the invention in any way. Referring to the drawings, in several views, the same numbers denote the same or corresponding parts.

[0023] Figure 1 A partial transparent view of a parallel shaft gearbox 10 is shown, which has an intermediate shaft 26 supported and housed within a cover 18 and a housing 22. Figure 2 The section cut along section line AA is shown. Figure 1 Aligned sectional view of the parallel shaft gearbox 10. (Refer to...) Figure 2 The parallel shaft gearbox 10 includes an input shaft 30, an intermediate shaft 26, and first and second output side shafts 34 and 34'. The intermediate shaft 26, the input shaft 30, and the first and second output side shafts 34 and 34' each have rotation axes 26A, 30A, and 34A that are parallel to each other.

[0024] Reference Figure 2 The input shaft 30 has a first shaft end 38 configured for operative connection to the motor output shaft of an electrically driven motor. Furthermore, the input shaft 30 includes an integrally formed drive gear 42 spaced apart from a second shaft end 46. In other embodiments, the drive gear 42 is a separate component fixedly coupled to the input shaft 30. The first shaft end 38 of the input shaft 30 is supported and held by a lower bearing 50 located within a lower bearing cavity 54 of the housing 22. Similarly, the second shaft end 46 of the input shaft 30 is supported and held by an upper bearing 58 located within an upper bearing cavity 62 formed in the cover 18. Figure 2In the diagram, the lower bearing 50 and upper bearing 58 supporting the input shaft 30 are shown as deep groove ball bearings. However, alternative types of bearings and bearing mounting positions can be used without changing the scope of the invention. For example, if desired, the lower bearing 50 and upper bearing 58 can be individually housed within the housing 22.

[0025] Figure 2 The intermediate shaft 26 shown includes a first shaft end 66, a second shaft end 70, an integrally formed intermediate drive gear 74 adjacent to the first shaft end 66, and an intermediate driven gear 78 fixedly connected to the intermediate shaft 26 adjacent to the second shaft end 70. The intermediate driven gear 78 includes gear teeth 82 configured to mesh with the drive gear 42 of the input shaft 30. Furthermore, the intermediate driven gear 78 rotates about the rotation axis 26A of the intermediate shaft 26. The first shaft end 66 of the intermediate shaft 26 is supported and held by a lower intermediate bearing 86 located in a lower bearing cavity 90 formed in the cover 18. Similarly, the second shaft end 70 of the intermediate shaft 26 is supported and held by an upper intermediate bearing 94 located in an upper bearing cavity 98 formed in the cover 18. Figure 2 In the illustrated embodiment, the lower intermediate bearing 86 and the upper intermediate bearing 94 are tapered roller bearings; however, other types of bearings, such as deep groove ball bearings, may also be used without changing the scope of the invention. Furthermore, the lower intermediate bearing 86 and the upper intermediate bearing 94 can be supported and held within the housing 22 without changing the scope of the invention. Similarly, as... Figure 2 As shown, the intermediate shaft 26 includes a longitudinal hole 102 that extends between a first shaft end 66 and a second shaft end 70 and is aligned with the axis of rotation 26A of the intermediate shaft 26. The intermediate shaft 26 having the longitudinal hole 102 can also be described as a hollow intermediate shaft 26.

[0026] like Figure 2 As shown, the annular driven gear 106 is operatively connected between the intermediate drive gear 74 and the differential assembly 108. The annular driven gear 106 rotates about a rotation axis 34A of the first and second output-side shafts 34, 34'. Furthermore, the annular driven gear 106 includes gear teeth 110 configured to engage in a mating manner with the intermediate drive gear 74. Figure 2 In the embodiment shown, the annular driven gear 106 is fixedly connected to the first output side shaft 34, and the second output side shaft 34' is operatively connected to the first output side shaft 34 via the differential assembly 108.

[0027] Figure 2The differential assembly 108 shown includes at least a first side shaft gear 114 and a second side shaft gear 116 that mesh with a pinion 118. The first and second side shaft gears 114 and 116 are each fixedly connected to first and second output side shafts 34 and 34', respectively. The first and second side shaft gears 114 and 116, and the pinion 118, are typically bevel gears. Each of the first and second output side shafts 34 and 34' is supported by a first output bearing 122 and a second output bearing 126, respectively. It should be understood that the number, shape, size, and type of gears 42, 74, 78, 106, bearings 50, 58, 86, 94, 122, 126, shafts 26, 30, 34, 34', and other components within the parallel shaft gearbox 10, as well as components 114, 116, 118 of the differential assembly 108, can vary without changing the scope of the invention. Furthermore, it should be understood that the parallel shaft gearbox 10 may include more or fewer components without changing the scope of the invention.

[0028] exist Figure 2 In the illustrated embodiment, both the cover 18 and the housing 22 are formed of cast aluminum. However, it should be understood that the cover 18 and the housing 22 may be formed of other materials or using alternative forming methods without changing the scope of the invention. Preferably, both the cover 18 and the housing 22 are formed of metal. Moreover, it should be understood that the size and shape of the cover 18 and the housing 22 may be varied without changing the scope of the invention. Similarly, it should be understood that the size and shape of the cover 18 may vary, including one or more separate covers fixedly attached to different portions of the housing 22.

[0029] like Figure 1 and Figure 2 As shown, the cover 18 is securely connected to the housing 22 by a plurality of mechanical fasteners 130, which are spaced apart around the outer periphery 134 of the cover 18. (Refer to...) Figure 2 Each of the plurality of fasteners 130 includes a bolt shaft 138 protruding from a bolt head 142. Each bolt shaft 138 is sized and shaped to fit into a corresponding channel 146 in the cover 18. The bolt shaft 138 of each mechanical fastener 130 extends through the corresponding channel 146 in the cover 18 and into a corresponding cavity 150 in the housing 22. Typically, the size and shape of each bolt head 142 are such that each bolt head 142 is larger than the inner diameter 146A of the corresponding channel 146 in the cover 18. Furthermore, each bolt shaft 138 includes a threaded portion 154 configured to engage with a corresponding threaded cavity 150 in the housing 22.

[0030] Figure 3 It shows along Figure 1The sectional view of the parallel shaft gearbox 10, taken by section line BB, shows additional details of the bolts 14 that fasten the cover 18 to the housing 22 and pass through the longitudinal hole 102 of the intermediate shaft 26. (See also...) Figure 3 The longitudinal hole 102 passing through the intermediate shaft 26 has a first inner diameter 158 extending between a first hole opening 162 adjacent to a first shaft end 66 of the intermediate shaft 26 and a second hole opening 166 adjacent to a second shaft end 70 of the intermediate shaft 26. Furthermore, the longitudinal axis 102A of the longitudinal hole 102 is aligned with the rotation axis 26A of the intermediate shaft 26.

[0031] like Figure 3 As shown, a housing boss 170, having a generally cylindrical main portion 170A, extends from the housing 22. The size and shape of the housing boss 170 are such that when the housing 22 is assembled with the intermediate shaft 26, the longitudinal axis 170B of the housing boss 170 is substantially aligned with the axis of rotation 26A of the intermediate shaft 26. Figure 3 In the illustrated embodiment, the housing boss 170 is integrally formed with the housing 22, and both the housing 22 and the housing boss 170 are formed of cast aluminum. It should be understood that the housing 22 and the housing boss 170 can be formed of different types of metal and manufactured using alternative manufacturing methods without changing the scope of the invention. Furthermore, the outer diameter 174 of the housing boss 170 is smaller than the inner diameter 158 of the longitudinal hole 102 passing through the intermediate shaft 26. When the housing 22 is assembled with the intermediate shaft 26, the size and shape of the housing boss 170 are adapted to fit into the longitudinal hole 102 of the intermediate shaft 26. Additionally, the housing boss 170 includes a housing boss end face 178, which is substantially perpendicular to the longitudinal axis 170B of the housing boss 170.

[0032] like Figure 3 As shown, the housing boss cavity 182 extends axially from the opening 183 in the end face 178 of the housing boss 170 and terminates at the base surface 184 of the housing boss cavity 182. Furthermore, the housing boss cavity 182 has a minimum inner diameter 182A extending between the opening 183 and the base surface 184 of the housing boss cavity 182. Additionally, the housing boss cavity 182 has a longitudinal axis 182B aligned with the longitudinal axis 170B of the housing boss 170.

[0033] like Figure 3 As shown, a cover boss 186, having a generally cylindrical main portion 186A, extends from the cover 18. The size and shape of the cover boss 186 are such that when the cover 18 is assembled with the intermediate shaft 26, the longitudinal axis 186B of the cover boss 186 is substantially aligned with the axis of rotation 26A of the intermediate shaft 26. Figure 3In the illustrated embodiment, the cover boss 186 is integrally formed with the cover 18, and both the cover 18 and the cover boss 186 are formed of cast aluminum. It should be understood that the cover 18 and the cover boss 186 can be formed of different types of metal and can be manufactured using alternative manufacturing methods without changing the scope of the invention. Furthermore, the outer diameter 190 of the cover boss 186 is smaller than the inner diameter 158 of the longitudinal hole 102 passing through the intermediate shaft 26. When the cover 18 is assembled with the intermediate shaft 26, the size and shape of the cover boss 186 are adapted to fit into the longitudinal hole 102 of the intermediate shaft 26.

[0034] In addition, such as Figure 3 As shown, the cover boss 186 includes a cover boss end face 194 that is substantially perpendicular to the longitudinal axis 186B of the cover boss 186. A cover boss hole 198 extends axially through the cover boss 186. The longitudinal axis 198B of the cover boss hole 198 is substantially aligned with the longitudinal axis 186B of the cover boss 186. Furthermore, the inner diameter 200 of the cover boss hole 198 extends between a first opening 202 on the outer surface 18A of the cover 18 and a second opening 204 on the cover boss end face 194.

[0035] Reference Figure 3 The dimensions of the cover boss 186 and the housing boss 170 are such that when the cover 18 and the housing 22 are assembled as part of the parallel shaft gearbox 10, the end face 194 of the cover boss 186 is substantially parallel to the end face 178 of the housing boss, and the longitudinal axis 170B of the housing boss 170 is substantially aligned with the longitudinal axis 186B of the cover boss 186. Furthermore, after assembly, the cover boss hole 198 is substantially aligned with the housing boss cavity 182. Additionally, the end face 194 of the cover boss may optionally frictionally engage with the end face 178 of the housing boss.

[0036] Alternatively, such as Figure 3As shown, the dimensions and shapes of the cover boss 186 and the housing boss 170 are such that, after the parallel shaft gearbox 10 is assembled, the cover boss end face 194 is spaced apart from the housing boss end face 178. In some embodiments, a gasket 206 is optionally placed between the cover boss end face 194 and the housing boss end face 178. The gasket 206 is generally disk-shaped, having opposing upper surfaces 210 and lower surfaces 214, a channel 218 extending between the opposing upper surfaces 210 and lower surfaces 214, and an outer edge surface 222 extending between the opposing upper surfaces 210 and lower surfaces 214, the opposing upper and lower surfaces defining the thickness of the gasket 206. The gasket 206 is formed of metal, plastic, rubber, and / or combinations thereof. Alternative embodiments of the gasket include washers, selective mating washers, spring washers, sleeves, compressible seals, etc., and combinations of one or more gaskets 206. When shim 206 is assembled with cover boss 186 and housing boss 170 as part of parallel shaft gearbox 10, the longitudinal axis 218B of channel 218 is approximately aligned with the longitudinal axes 182B, 198B of housing boss cavity 182 and housing boss hole 198. During assembly, shim 206 is compressed when the bolts 14 connecting cover 18 and housing 22 are tightened. Therefore, in some embodiments, shim 206 is oversized to account for compression during assembly when all bolt torque is applied to bolt 14. A combination of one or more shims 206 can be used to obtain a desired preload on intermediate shaft 26 during assembly.

[0037] Similarly, Figure 3 As shown, bolt 14 has a bolt shaft 226 that extends from bolt head 230 and defines the longitudinal axis 14A of bolt 14. Bolt shaft 226 is substantially cylindrical and terminates at bolt end face 234. Furthermore, the dimensions and shape of bolt shaft 226 and the channel 218 through washer 206 allow bolt shaft 226 to be inserted through the channel 218 of washer 206. Moreover, the maximum outer diameter 238 of the outer surface 236 of bolt shaft 226 is generally less than or equal to the inner diameter 200 of cap boss hole 198. Figure 3 In the illustrated embodiment, the bolt shaft 226 includes a threaded portion 242 configured to engage with a threaded portion 246 of the housing boss cavity 182. The maximum outer diameter 238A of the threaded portion 242 of the bolt shaft 226 is equal to or greater than the minimum inner diameter 182A of the threaded portion 246 of the housing boss cavity 182. Optionally, the threaded portion 242 of the bolt shaft 226 is configured to cut mating threads in the housing boss cavity 182 during assembly.

[0038] Reference Figure 3The bolt head 230 of bolt 14 is sized and shaped such that it frictionally engages with the outer surface 18A of cover 18. Furthermore, bolt head 230 has an outer periphery 248 sized and shaped such that it does not completely pass through cover boss hole 198. In some embodiments, cover boss hole 198 includes an access cavity 250 adjacent to opening 202 of cover 18, the size and shape of which ensure that bolt head 230 is at least partially recessed into the access cavity 250 when assembled as part of parallel shaft gearbox 10. Optionally, during assembly, one or more of gaskets, washers, and / or compression seals may be included between bolt head 230 and cover 18.

[0039] like Figure 3 As shown, when bolt 14, cover 18, intermediate shaft 26, and housing 22 are assembled as part of parallel shaft gearbox 10, bolt 14 mechanically fastens housing 22 to housing 22 through longitudinal hole 102 in intermediate shaft 26. Furthermore, after assembly as part of parallel shaft gearbox 10, the longitudinal axes 14A, 26A, 102A, 170B, 182B, 186B, and 198B of bolt 14, intermediate shaft 26, longitudinal hole 102 in intermediate shaft 26, housing boss 170, housing boss cavity 182, cover boss 186, and cover boss hole 198 are substantially aligned.

[0040] Reference Figures 1 to 3 Bolts 14 passing through the longitudinal hole 102 of the intermediate shaft 26 securely connect the cover 18 to the housing 22. The addition of a connection point between the cover 18 and the housing 22 via the intermediate shaft 22 enhances the connection in the axial direction 26B of the intermediate shaft 26 (e.g., Figure 2 (As shown by arrow 26B) The stiffness of the cover portion 18C near the intermediate shaft 26. The enhanced stiffness of the cover portion 18C near the intermediate shaft 26 reduces the potential deflection of the cover 18 under load. Moreover, due to the enhanced stiffness of the cover portion 18C, the possibility of meshing misalignment between the intermediate driven gear 78 and the driven gear 42 of the input shaft 30 is reduced. In addition, the possibility of meshing misalignment between the intermediate drive gear 74 and the ring driven gear 106 is also reduced by the enhanced stiffness of the cover portion 18C. Furthermore, with Figure 4 and Figure 5 Compared to the known parallel shaft gearbox 10P shown, the possibility of misalignment between the lower intermediate bearing 86 and the upper intermediate bearing 94 is reduced.

[0041] Reference Figure 4 The known parallel shaft gearbox 10P includes a cover 18P, which is fixedly connected to the housing 22P by a plurality of mechanical fasteners 130P spaced apart around the outer periphery 134P of the cover 18P. Figure 5 The section cut along section line CC is shown. Figure 4A sectional view of the known parallel-shaft gearbox 10P. (Refer to...) Figure 5 The known parallel-shaft gearbox 10P includes an input shaft 30P, an intermediate shaft 26P, and first and second output shafts 34P and 34P'. The respective axes of rotation 26AP, 30AP, and 34AP of the intermediate shaft 26P, input shaft 30P, and first and second output shafts 34P and 34P' are parallel to each other. A first shaft end 38P of the input shaft 30P is configured to be operatively connected to the motor output shaft of an electric drive motor. Furthermore, the input shaft 30P includes an integrally formed drive gear 42P spaced apart from a second shaft end 46P.

[0042] Figure 5 The first shaft end 38P of the input shaft 30P of the known parallel shaft gearbox 10P is supported and held by a lower bearing 50P located within a lower bearing cavity 54P of the housing 22P. Similarly, the second shaft end 36P of the input shaft 30P is supported and held by an upper bearing 58P located within an upper bearing cavity 62P formed in the cover 18P of the known parallel shaft gearbox 10P.

[0043] Figure 5 The intermediate shaft 26P of the known parallel shaft gearbox shown includes a first shaft end 66P, a second shaft end 70P, an integrally formed intermediate drive gear 74P adjacent to the first shaft end 66P, and an intermediate driven gear 78P fixedly connected to the intermediate shaft 26P adjacent to the second shaft end 70P. The intermediate driven gear 78P includes gear teeth 82P configured to mesh with the drive gear 42P of the input shaft 30P. Moreover, the intermediate driven gear 78P rotates about the rotation axis 26AP of the intermediate shaft 26P. The first shaft end 66P of the intermediate shaft 26P is supported and held by a lower intermediate bearing 86P located in a lower bearing cavity 90P formed in the cover 18P. Similarly, the second shaft end 70P of the intermediate shaft 26P is supported and held by an upper intermediate bearing 94P located in an upper bearing cavity 98P formed in the cover 18.

[0044] like Figure 5 As shown, the intermediate shaft 26P of the known parallel shaft gearbox 10P includes a longitudinal hole 102P extending between a first shaft end 66P and a second shaft end 70P and aligned with the axis of rotation 26AP of the intermediate shaft 26P. Figure 5 The intermediate shaft 26P shown with longitudinal hole 102P is alternatively described as a hollow intermediate shaft 26P.

[0045] Figure 5The known parallel-shaft gearbox 10P shown includes an annular driven gear 106P operably connected between an intermediate drive gear 74P and a differential assembly 108P. The annular driven gear 106P rotates about a rotation axis 34AP of the first and second output-side shafts 34P, 34P'. Furthermore, the annular driven gear 106P includes gear teeth 11OP configured to mesh with the intermediate drive gear 74P. The differential assembly 108P includes at least a first side shaft gear 114P and a second side shaft gear 116P that mesh with a pinion 118P. Each of the first and second side shaft gears 114P, 116P is fixedly connected to the first and second output-side shafts 34P, 34P', respectively. Each of the first and second output-side shafts 34P, 34P' is supported by a first output bearing 122P and a second output bearing 126P, respectively.

[0046] like Figure 5 As shown, each of the plurality of mechanical fasteners 130P of the known parallel shaft gearbox 10P includes a bolt shaft 138P protruding from a bolt head 142P. The bolt shaft 138P of each mechanical fastener 130P extends through a channel 146P in the cover 18P and into a cavity 150P in the housing 22P. Typically, the bolt head 142P is sized and shaped such that it is larger than the channel 146P in the cover 18P. Furthermore, the bolt shaft 138P includes a threaded portion 154P configured to mechanically engage with the cavity 150P in the housing 22P.

[0047] Reference Figure 4 and Figure 5 In the known parallel shaft gearbox 10P, the cover 18P is fastened to the housing 22P only around the outer periphery 134P of the cover 18P. In contrast, Figures 1 to 3 The illustrated embodiment of the parallel shaft gearbox 10 includes bolts 14 that securely connect the cover 18 to the housing via an intermediate shaft 26. The only support between the cover 18P and the housing 22P of the known parallel shaft gearbox 10P is along the outer periphery 134P of the cover 18P, which results in the cover portion 18P' near the intermediate shaft 26P being 26BP in the axial direction of the intermediate shaft 26P. Figure 5 The stiffness of the portion 18P' of the cover 18P (indicated by the middle arrow 26BP) is less than that of the portion 18P' of the cover 18P near the mechanical fastener 130P. Therefore, the cover portion 18P' of the cover 18P has an increased tendency to deflect under load. The deflection of the cover portion 18P' near the intermediate shaft 26 under load increases the potential meshing misalignment between the intermediate driven gear 78P and the drive gear 42P of the input shaft 30P, and between the intermediate drive gear 74P and the ring driven gear 106P. Furthermore, the deflection of the cover 18P under load leads to an increase in bearing misalignment between the upper intermediate bearing 94P and the lower intermediate bearing 86P.

[0048] Compared to the known parallel shaft gearbox 10P, Figures 1 to 3 The embodiment of the parallel shaft gearbox 10 shown includes a connection point between the cover 18 and the housing 22. Bolts 14 (as shown) are added through the longitudinal hole 102 of the intermediate shaft 26. Figure 3 (As shown) The stiffness of the cover portion 18C near the intermediate shaft 26 is enhanced along the axial direction 26B. Due to the increased stiffness in the axial direction 26B at the connection point between the cover 18 and the housing 22 via the intermediate shaft 26, the durability of the gears and bearings is improved by reducing gear meshing misalignment and bearing misalignment. Furthermore, the enhanced stiffness of the cover 18 near the intermediate shaft 26 reduces the sensitivity to thermal expansion under preload because the deflection of the cover 18 under load is reduced.

[0049] exist Figure 3 In the illustrated embodiment, the cover 18 includes a mounting surface 18B configured to engage with a mounting surface 22B on the housing 22. An end face 194 of the cover boss 186 is spaced apart from the mounting surface 18B of the cover 18 by a first predetermined distance 258 in the axial direction 26B. Similarly, an end face 178 of the housing boss 170 is spaced apart from the mounting surface 22B of the housing 22 by a second predetermined distance 266 in the axial direction 26B. The sum of the first and second predetermined distances 258 and 266 is selected to accommodate a gasket 206 positioned between the end face 194 of the cover boss 186 and the end face 178 of the housing boss 170. In some embodiments, if the gasket 206 is compressed during assembly, the sum of the first and second predetermined distances 258 and 266 is less than the uncompressed thickness of the gasket 206. Figure 3 In the illustrated embodiment, the axial distance between the upper surface 210 and the lower surface 214 of the gasket 206 is less than the axial distance between the end face 194 of the cover boss 186 and the opening 202 of the cover boss hole 198 adjacent to the outer surface 18A of the cover 18. Furthermore, the axial distance between the upper and lower surfaces 210 and 214 of the gasket 206 is less than the axial distance between the end face 178 of the housing boss 170 and the outer surface 22A of the housing 22 adjacent to the intermediate shaft 26. It should be understood that the relative axial distances between the upper and lower surfaces of the gasket 206, between the end face 194 of the cover boss 186 and the opening 202 leading to the cover boss hole 198, and between the end face 178 of the housing boss 170 and the outer surface 22A of the housing 22 can vary without changing the scope of the invention.

[0050] Figure 6A second embodiment of the parallel shaft gearbox 10' is shown, having a cover 18' with an improved cover boss 186', a housing 22' with an improved housing boss 170', and a spacer 206' positioned between the improved cover boss 186' and the improved housing boss 170'. Like the first embodiment, the second embodiment includes an intermediate shaft 26 having a longitudinal bore 102 extending between a first intermediate shaft end 66 and a second intermediate shaft end 70, the longitudinal bore 102 being aligned with the axis of rotation 26A of the intermediate shaft 26. Furthermore, the longitudinal bore 102 has a first inner diameter 158 extending between a first hole opening 162 adjacent to the first shaft end 66 of the intermediate shaft 26 and a second hole opening 166 adjacent to the second shaft end 70 of the intermediate shaft 26.

[0051] Still as Figure 6 As shown, the first intermediate shaft end 66 and the second intermediate shaft end 70 are each supported and held by corresponding lower bearings 86 and upper bearings 94. The lower bearing 86 is held within the cavity 90 of the housing 22'. Furthermore, the upper bearing 94 is held within the cavity 98 of the cover 18'. In addition, the intermediate driven gear 78 is fixedly connected to the intermediate shaft 26. The intermediate drive gear 74 is integrally formed with the intermediate shaft 26.

[0052] like Figure 6 As shown, an improved housing boss 170', having a generally cylindrical main portion 170a', extends from the housing 22'. The dimensions and shape of the improved housing boss 170' are such that when the housing 22' is assembled with the intermediate shaft 26, the longitudinal axis 170B of the improved housing boss 170' is aligned with the rotation axis 26A of the intermediate shaft 26. Figure 6 In the second embodiment shown, the improved housing boss 170' is integrally formed with the housing 22', and both the housing 22' and the improved housing boss 170' are formed of cast aluminum. It should be understood that the housing 22' and the improved housing boss 170' can be formed of different kinds of metal and manufactured using alternative manufacturing methods without changing the scope of the invention. Furthermore, the outer diameter 174' of the improved housing boss 170' is smaller than the inner diameter 158 of the longitudinal hole 102 passing through the intermediate shaft 26. The size and shape of the improved housing boss 170' are such that when the housing 22' is assembled with the intermediate shaft 26, the improved housing boss 170' can enter the longitudinal hole 102 of the intermediate shaft 26. In addition, the improved housing boss 170' includes a housing boss end face 178', which is substantially perpendicular to the longitudinal axis 170B of the improved housing boss 170'.

[0053] like Figure 6As shown, the second embodiment includes a housing boss cavity 182', which extends axially from the opening 183' of the housing boss end face 178' and terminates at the base surface 184' of the housing boss cavity 182'. Furthermore, the dimensions and shape of the housing boss cavity 182' are matched to the threaded portion 242' of the bolt 14' passing through the intermediate shaft 26. Additionally, the longitudinal axis 182B of the housing boss cavity 182' is substantially aligned with the longitudinal axis 170B of the modified housing boss 170'.

[0054] Figure 6 The improved cover boss 186' of the second embodiment shown has a generally cylindrical main portion 186A' extending from the cover 18'. The dimensions and shape of the improved cover boss 186' are such that when the cover 18' is assembled with the intermediate shaft 26, the longitudinal axis 186B of the improved cover boss 186' is substantially aligned with the axis of rotation 26A of the intermediate shaft 26. Figure 6 In the illustrated embodiment, the improved cover boss 186' is integrally formed with the cover 18', and both the cover 18' and the improved cover boss 186' are formed of cast aluminum. It should be understood that the cover 18' and the improved cover boss 186' can be formed of different types of metal and can be manufactured using alternative manufacturing methods without changing the scope of the invention. Furthermore, the outer diameter 190' of the improved cover boss 186' is smaller than the inner diameter 158 of the longitudinal hole 102 passing through the intermediate shaft 26. The size and shape of the improved cover boss 186' allow it to enter the longitudinal hole 102 of the intermediate shaft 26 when the cover 18' is assembled with the intermediate shaft 26.

[0055] In addition, such as Figure 6 As shown, the improved cover boss 186' includes a cover boss end face 194', which is substantially perpendicular to the longitudinal axis 186B of the improved cover boss 186'. A cover boss hole 198' extends axially through the improved cover boss 186' between a first opening 202' on the outer surface 18A' of the cover 18' and a second opening 204' on the cover boss end face 194A'. The longitudinal axis 198B of the cover boss hole 198' is substantially aligned with the longitudinal axis 186B of the improved cover boss 186'.

[0056] Reference Figure 6 The dimensions of the improved cover boss 186' and the improved housing boss 170' are configured such that when the cover 18' and housing 22' are assembled as part of the parallel shaft gearbox 10', the end face 194' of the cover boss is substantially parallel to and spaced apart from the end face 178' of the housing boss, and the longitudinal axis 170B of the improved housing boss 170' is aligned with the longitudinal axis 186B of the improved cover boss 186'. Moreover, after assembly, the cover boss hole 198' is substantially aligned with the housing boss cavity 182'.

[0057] like Figure 6 As shown, spacer 206' is fitted between the improved cover boss end face 194' and the improved housing boss end face 178'. Figure 6 In the illustrated embodiment, the spacer 206' is a substantially cylindrical sleeve having opposing upper surfaces 210' and lower surfaces 214', a longitudinally extending channel 218' between the opposing upper surfaces 210' and lower surfaces 214', and an outer edge surface 222' extending between the opposing upper surfaces 210' and lower surfaces 214', the opposing upper and lower surfaces defining the length of the spacer 206'. As a non-limiting example, the spacer 206' is preferably formed of a metal such as steel or aluminum. Alternatively, as... Figure 3 One or more gaskets 206 can be assembled with spacer 206'. When spacer 206' is assembled with the modified cover boss 186' and the modified housing boss 170' as part of the parallel shaft gearbox 10', the longitudinal axis 218B of the channel 218' of spacer 206' is substantially aligned with the longitudinal axes 182B, 198B of the housing boss cavity 182' and the cover boss hole 198'. During assembly, tightening the bolts 14' connecting the cover 18' and the housing 22' compresses spacer 206'. Therefore, in some embodiments, spacer 206' is oversized to account for compression during assembly when all bolt torque is applied to bolts 14'. In addition to spacer 206', combinations of one or more gaskets 206 can be used to obtain the desired preload on intermediate shaft 26 during assembly.

[0058] Figure 6 As also shown, bolt 14' has a bolt shaft 226' extending from bolt head 230' and defining the longitudinal axis 14A of bolt 14'. Bolt shaft 226' is generally cylindrical and terminates at bolt end face 234'. Moreover, the maximum outer diameter 238' of the outer surface 236' of bolt shaft 226' is generally less than or equal to the inner diameter 200' of cover boss hole 198'. Furthermore, spacer 206' has a minimum inner diameter 218C, which is generally greater than the maximum outer diameter 238' of bolt shaft 226'. Moreover, the threaded portion 242' of bolt shaft 226' is configured to engage matingly with the threaded portion 246' of housing boss cavity 182'. Optionally, the threaded portion 242' of bolt shaft 226' is configured to cut mating threads in housing boss cavity 182' during assembly.

[0059] exist Figure 6In the second embodiment shown, the bolt head 230' of bolt 14' is sized and shaped such that bolt head 230' frictionally engages with the outer surface 18A' of cover 18'. Furthermore, bolt head 230' has an outer periphery 248' whose size and shape prevent it from completely passing through cover boss hole 198'. In some embodiments, cover boss hole 198' includes an access cavity 250' adjacent to opening 202' of cover 18', the size and shape of which ensure that bolt head 230' is at least partially recessed into access cavity 250' when bolt 14' is assembled as part of parallel shaft gearbox 10'. Optionally, during assembly, one or more of gaskets, washers, and / or compressible seals may be included between bolt head 230' and cover 18'.

[0060] like Figure 6 As shown, when bolt 14', cover 18', intermediate shaft 26, spacer 206', and housing 22' are assembled as part of parallel shaft gearbox 10', bolt 14' mechanically fastens cover 18' to housing 22' through longitudinal hole 102 in intermediate shaft 26. Furthermore, after assembly as part of parallel shaft gearbox 10', the longitudinal axes 14A, 26A, 102A, 170B, 182B, 186B, and 198B of bolt 14', intermediate shaft 26', longitudinal hole 102 through intermediate shaft, housing boss 170', housing boss cavity 182', cover boss 186', cover boss hole 198', and spacer 206' are substantially aligned.

[0061] exist Figure 6 In the second embodiment shown, the cover 18' has a mounting surface 18B' configured to engage matingly with the mounting surface 22B' of the housing 22'. The intermediate shaft 26 defines the axial direction 26B of the parallel shaft gearbox 10', as... Figure 6As indicated by the middle arrow 26B, the end face 194' of the modified cover boss 186' is spaced apart from the mounting surface 18B' of the cover 18' by a first predetermined distance 258' in the axial direction 26B. Similarly, the end face 178' of the housing boss 170' is spaced apart from the mounting surface 22B' of the housing 22' by a second predetermined distance 266' in the axial direction 26B. The sum of the first predetermined distance 258' and the second predetermined distance 266' is selected to accommodate the spacer 206' positioned between the end face 194' of the modified cover boss 186' and the end face 178' of the modified housing boss 170'. In some embodiments, if the spacer 206' is compressed during assembly, the sum of the first predetermined distance 258' and the second predetermined distance 266' is less than the uncompressed distance between the upper surface 210' and the lower surface 214' of the spacer 206'. In other embodiments, the total length of the spacer 206' is selected in part based on the sum of the first predetermined distance 258' and the second predetermined distance 266'. Furthermore, as a non-limiting example, one or more of supplementary gaskets, washers, compressible gaskets, spring washers, etc., may be selectively assembled with the spacer 206' to compensate for dimensional variations in the components.

[0062] Figure 6 The axial distance between the upper surface 210' and lower surface 214' of the spacer 206' shown is greater than the axial distance between the end face 194' of the modified cover boss 186' and the opening 202' of the cover boss hole 198' adjacent to the outer surface 18A' of the cover 18'. Furthermore, the axial distance between the upper surface 210' and lower surface 214' of the spacer 206' is greater than the axial distance between the end face 178' of the housing boss 170' and the outer surface 22A' of the housing 22'. It should be understood that the relative axial distances between the upper surface 210' and lower surface 214' of the spacer 206', the relative axial distances between the end face 194' of the modified cover boss 186' and the opening 202' of the cover boss hole 198', and the relative axial distances between the end face 178' of the modified housing boss 170' and the outer surface 22A' of the housing 22' can vary without changing the scope of the invention. Furthermore, it should be understood that the relative dimensions, shapes, and overall lengths of the improved cover boss 186', the improved housing boss 170', and the spacer 206' can vary without altering the scope of the invention.

[0063] Reference Figure 6 As shown, bolt 14' passes through the longitudinal hole 102 of intermediate shaft 26 to securely connect cover 18' to housing 22'. Because an intermediate shaft 26 adds a connection point between cover 18' and housing 22', in the axial direction 26B (e.g.) Figure 6(As shown by the middle arrow 26B) The stiffness of the cover portion 18C' near the intermediate shaft 26 is increased. This increased stiffness reduces the potential deflection of the cover 18' under load. Furthermore, due to the increased stiffness of the cover portion 18C', the possibility of misalignment between the intermediate driven gear 78 and the drive gear 42 is reduced. Additionally, the possibility of misalignment between the intermediate drive gear 74 and the ring driven gear 106 is also reduced due to the increased stiffness of the cover portion 18C'. Moreover, compared to the known parallel shaft gearbox 10P which lacks bolts 14' passing through the intermediate shaft 26, the possibility of misalignment between the lower intermediate bearing 86 and the upper intermediate bearing 94 is reduced.

[0064] Figure 7 A third embodiment of the parallel shaft gearbox 10” is shown. Figure 6 and Figure 7 The parallel shaft gearboxes 10' and 10" of the second and third embodiments shown respectively include an intermediate shaft sub-assembly 102S, which includes at least one intermediate shaft 26 with a longitudinal bore 102, a lower bearing 86 and an upper bearing 94, and an intermediate driven gear 78. Furthermore, both the second and third embodiments of the parallel shaft gearboxes 10' and 10" include an improved housing boss 170' protruding from the housing 22', and bolts 14" and spacers 206" inserted into the longitudinal bore 102 of the intermediate shaft 26. Additionally, the third embodiment includes a cover 18" having a mounting surface 18B" configured to be fixedly connected to the mounting surface 22B' of the housing 22'.

[0065] However, Figure 7 The third embodiment shown includes a cap 270 inserted into a channel 274 of the cap 18”, the channel providing an inlet to a cap bearing cup 278 that supports and retains an upper intermediate bearing 94. During assembly, the cap 270 abuts against the cap bearing cap 278. The cap 270 is configured to engage matingly with the channel 274 of the cap 18”. A groove 282 extends circumferentially around the cap 270 and is configured to support and retain a compressible seal 286. When the cap 270 is inserted into the channel 274, the compressible seal 286 abuts against the channel 274 in the cap 18”, thereby forming a tight seal between the cap 270 and the cap 18”.

[0066] also, Figure 7 The cap 270 shown includes a cap boss 186", which has a generally cylindrical main portion 186A extending from the cap 270. The size and shape of the cap boss 186" are such that when the cap 270 and the cap 18" are assembled with the intermediate shaft 26, the longitudinal axis of the cap boss 186" is aligned with the axis of rotation 26A of the intermediate shaft 26. Figure 7In the illustrated embodiment, the cap boss 186” is integrally formed with the cap 270 and is made of metals such as cast aluminum or steel. It should be understood that the cap 270 and the cap 18” can be formed of different kinds of metals and manufactured using alternative manufacturing methods without changing the scope of the invention. Figure 7 As shown, the cap boss 186” includes an end face 194”, which is generally perpendicular to the longitudinal axis 186B of the cap boss 186”. Moreover, when the cap 270 and the cover 18” are assembled with the intermediate shaft 26, the size and shape of the cap boss 186” are such that the end face 194” of the cap boss 186” will pass through the second hole opening 166 of the longitudinal hole 102.

[0067] Reference Figure 7 The cap boss hole 198” extends axially through the cap boss 186” between the first opening 202” on the outer surface 270A of the cap 270 and the second opening 204” on the cap boss end face 194”. The longitudinal axis 198B of the cap boss hole 198” is substantially aligned with the longitudinal axis 186B of the cap boss 186”.

[0068] like Figure 7 As shown, the dimensions and shapes of the cap boss 186” and the modified housing boss 170’ are such that when the cap 270, cover 18”, and housing 22’ are assembled as part of the parallel shaft gearbox 10”, the cap boss end face 194” is substantially parallel to and spaced apart from the modified housing boss end face 178’, and the longitudinal axis 170B of the modified housing boss 170’ is substantially aligned with the longitudinal axis 186B of the cap boss 186”. Moreover, after assembly, the cap boss hole 198” is substantially aligned with the housing boss cavity 182’.

[0069] like Figure 7 As shown, spacer 206” is assembled between cap boss end face 194” and modified housing boss end face 178”. Figure 7 In the illustrated embodiment, the spacer 206” is a generally cylindrical sleeve having opposing upper surfaces 210” and lower surfaces 214”, a channel 218” extending longitudinally between the opposing upper surfaces 210” and lower surfaces 214”, and an outer edge surface 222 extending between the opposing upper surfaces 210” and lower surfaces 214”, the upper surfaces 210” and lower surfaces 214” defining the length of the spacer 206”. As a non-limiting embodiment, the spacer 206” is preferably made of metal, such as steel, aluminum, etc. Alternatively, as Figure 3As shown, one or more shims 206 can be assembled with spacer 206". When spacer 206" is assembled with cap boss 186" and modified housing boss 170' to form parallel shaft gearbox 10", the channel 218" of spacer 206" has a longitudinal axis 218B that is substantially aligned with the longitudinal axis 182B of housing boss cavity 182' and the longitudinal axis 198B of cap boss hole 198". During assembly, tightening bolt 14" between cap 270 and housing 22' compresses spacer 206". Therefore, in some embodiments, spacer 206" is oversized, taking into account that spacer 206" is compressed during assembly when all bolt torque is applied to bolt 14". In addition to spacer 206", combinations of one or more shims 206 can be used to obtain the desired preload on intermediate shaft 26 during assembly.

[0070] Similarly, Figure 7 As shown, bolt 14” has a bolt shaft 226” extending from bolt head 230”, which defines the longitudinal axis 14A of bolt 14”. Bolt shaft 226” is generally cylindrical and terminates at bolt end face 234”. Moreover, the dimensions and shape of the outer surface 236” of bolt shaft 226” allow bolt shaft 226” to pass through cap boss hole 198” and through channel 218” of spacer 206”. In addition, bolt shaft 226” includes a threaded portion 242” which is configured to engage matingly with the threaded portion 246’ of housing boss cavity 182’. Optionally, the threaded portion 242” of bolt shaft 226” is configured to cut mating threads in housing boss cavity 182’ during assembly.

[0071] exist Figure 7 In the third embodiment shown, the bolt head 230” of bolt 14” is sized and shaped such that bolt head 230” frictionally engages the outer surface 270A of cap 270. Furthermore, the outer periphery 248” of bolt head 230” is sized and shaped such that bolt head 230” does not completely pass through cap boss hole 198. In some embodiments, cap boss hole 198” includes an inlet cavity 250” adjacent to the opening 202 of cap 270”, and the size and shape of inlet cavity 250” are such that when bolt 14” is assembled as part of parallel shaft gearbox 10”, bolt head 230” is at least partially recessed into inlet cavity 250”. Optionally, during assembly, one or more of gaskets, washers, and / or compressible seals may be included between bolt head 230” and cap 270”.

[0072] like Figure 7As shown, when bolt 14”, cap 18”, cap 270, intermediate shaft 26, spacer 206”, and housing 22’ are assembled into part of parallel shaft gearbox 10”, bolt 14” mechanically fastens cap 270 to housing 22’ through longitudinal hole 102 of intermediate shaft 26. Furthermore, after assembly into parallel shaft gearbox 10”, the longitudinal axes 14A, 26A, 102A, 170B, 182B, 186B, and 198B of bolt 14”, intermediate shaft 26, longitudinal hole 102 through intermediate shaft 26, modified housing boss 170’, housing boss cavity 182’, cap boss 186”, cap boss hole 198”, and spacer 206” are substantially aligned.

[0073] exist Figure 7 In the third embodiment shown, after the cap 270 and cover 18” are assembled, the end face 194” of the cap boss 186” is spaced apart from the mounting surface 18B” of the cover 18” by a first predetermined distance 258” in the axial direction 26B. Similarly, the end face 178” of the housing boss 170’ is spaced apart from the mounting surface 22B’ of the housing 22’ by a second predetermined distance 266” in the axial direction 26B. The sum of the first predetermined distance 258” and the second predetermined distance 266” is selected to accommodate the spacer 206” positioned between the end face 194” of the cap boss 186” and the end face 178” of the modified housing boss 170’. In some embodiments, if the spacer 206” is compressed during assembly, the sum of the first and second predetermined distances 158” and 266” is less than the uncompressed distance between the upper and lower surfaces 210” and 214” of the spacer 206”. In other embodiments, the total length of the spacer 206” is selected in part based on the sum of the first and second predetermined distances 258”, 266”. Furthermore, as a non-limiting example, one or more of supplementary gaskets, washers, compressible gaskets, spring washers, etc., may be selectively assembled with the spacer 206” to compensate for dimensional variations in the component.

[0074] Figure 7In the third embodiment shown, the axial distance between the upper and lower surfaces 210” and 214” of the spacer 206” is greater than the axial distance between the end face 194” of the cap boss 186” and the opening 202” of the cap boss hole 198” on the outer surface 270A' of the adjacent cap 270. Moreover, the axial distance between the upper and lower surfaces 210” and 214” of the spacer 206” is greater than the axial distance between the end face 178’ of the housing boss 179’ and the outer surface 22A’ of the housing 22’. It should be understood that the relative axial distances between the upper and lower surfaces 210” and 214” of the spacer 206”, between the end face 194” of the cap boss 186” and the opening 202” leading to the cap boss hole 198”, and between the end face 178’ of the improved housing boss 170’ and the outer surface 22A’ of the housing 22’ can be varied without changing the scope of the invention. Furthermore, it should be understood that the relative dimensions, shapes, and overall lengths of the cap boss 186”, the improved housing boss 170’, and the spacer 206” can be varied without changing the scope of the invention. Additionally, it should be understood that the overall length of the cap boss 186” and the improved housing boss 170’ can be increased, and the spacer 206” can be replaced by a gasket 206, such as… Figure 3 The first embodiment is shown.

[0075] Reference Figure 7 Bolts 14” passing through the longitudinal hole 102 of the intermediate shaft 26 securely connect cap 270 to housing 22'. The addition of a connection point between cap 270 and housing 22' via the intermediate shaft 26 enhances the axial stiffness of the cap portion 270B near the intermediate shaft 26. This enhanced stiffness near the intermediate shaft 26 reduces the potential deflection of cap 270 under load. Since the cap bearing cup 278 is effectively axially disengaged from cap 18”, bolts 14” do not provide additional stiffness to cap 18”. However, bolts 14” do provide additional stiffness to the intermediate shaft subassembly 102S.

[0076] One advantage of the bolts 14, 14', 14” passing through the intermediate shaft 26 of the parallel shaft gearboxes 10, 10' is that the intermediate shaft 26 increases the connection point between the housings 22, 22' and the covers 18, 18' / caps 270. A second advantage is that the axial stiffness of the covers 18, 18' / caps 270 is enhanced because the bolts 14, 14', 14” pass through the intermediate shaft 26 and are securely connected to the housings 22, 22'. A third advantage is that the bolts 14, 14', 14” passing through the intermediate shaft enhance the stiffness of the intermediate shaft assembly 102S. A fourth advantage is that the enhanced stiffness of the intermediate shaft assembly 102S and / or the enhanced stiffness of the covers 18, 18' reduces the possibility of meshing misalignment within the parallel shaft gearboxes 10, 10', 10”. The fifth benefit is that it reduces the possibility of bearing misalignment because the bolts 14, 14', 14" that connect the covers 18, 18' to the housings 22, 22' through the intermediate shaft 26 reduce the possibility of the covers 18, 18' flexing under load.

[0077] The invention has been described in an illustrative manner, and it should be understood that the terminology used is intended to be descriptive rather than limiting. Many modifications and variations can be made to the invention based on the foregoing teachings. Therefore, it should be understood that the invention can be practiced in ways other than those specifically described within the scope of the appended claims.

Claims

1. A parallel shaft gearbox for a vehicle, comprising: An input shaft having a first drive gear and a first axis of rotation; An intermediate shaft having an intermediate drive gear, an intermediate driven gear, and a longitudinal hole extending through the intermediate shaft, the intermediate driven gear engaging meshingly with the first drive gear of the input shaft, and the intermediate shaft having a second axis of rotation parallel to the first axis of rotation; A cover is fixedly connected to the housing, the cover and the housing accommodating and supporting the input shaft and the intermediate shaft; Bolts securely attach the cover to the housing, the bolts passing through the longitudinal hole of the intermediate shaft; The cover boss protrudes from the cover and terminates at the end face of the cover boss; The cover boss hole extends longitudinally through the cover boss between the first opening on the outer surface of the cover and the second opening on the end face of the cover boss; The housing boss protrudes from the housing and terminates at the end face of the housing boss; The housing boss cavity extends longitudinally from the end face of the housing boss between the third opening of the housing boss and terminates at the end face of the housing boss cavity. The bolt has a bolt shaft, the size and shape of which allow at least a portion of the bolt shaft to pass through the cover boss hole; as well as The bolt shaft has a threaded portion configured to be fixedly connected to the housing boss cavity when the bolt is assembled with the cover, the intermediate shaft and the housing.

2. The parallel shaft gearbox according to claim 1, wherein: A spacer is inserted into the longitudinal hole of the intermediate shaft, the spacer being sized and shaped to fit into the longitudinal hole, the spacer having a channel extending between opposite first and second ends of the spacer.

3. The parallel shaft gearbox according to claim 2, wherein: When the cover, the housing, the intermediate shaft, the spacer, and the bolt are assembled as part of the parallel shaft gearbox, at least a portion of the bolt shaft passes through the channel of the spacer.

4. The parallel shaft gearbox according to claim 3, wherein: The spacer includes one or more of a sleeve, gasket, washer, and seal.

5. The parallel shaft gearbox according to claim 4, wherein: During the assembly of the cover and the housing, the spacer is compressed between the cover boss and the housing boss.

6. The parallel shaft gearbox according to claim 5, wherein: The spacer is formed of one or more of metal, plastic, and rubber.

7. The parallel shaft gearbox according to claim 6, wherein: The cover and the housing are made of metal.

8. The parallel shaft gearbox according to claim 7, wherein: The annular driven gear meshes with the intermediate driven gear; as well as The first output shaft and the second output shaft are operatively connected to the annular driven gear via a differential assembly.

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