WO2024263597A1

WO2024263597A1 - Alternator shaft extender

Info

Publication number: WO2024263597A1
Application number: PCT/US2024/034543
Authority: WO
Inventors: Moayed El Gaml; Steven CVEJN
Original assignee: Daimler Truck North America Llc
Priority date: 2023-06-21
Filing date: 2024-06-18
Publication date: 2024-12-26

Abstract

An engine assembly can comprise an engine block and a front end accessory drive coupled to a front end portion of the engine block. The front end accessory drive can include a shaft extender assembly to accommodate and support accessory components. The system can include multiple belt layers, such as a first belt layer, a second belt layer disposed forward of the first belt layer, and a third belt layer disposed forward of the second belt layer. The third belt layer can comprise a drive belt, an alternator, and a shaft extension assembly coupled to the alternator, wherein the shaft extension assembly is configured to transmit mechanical power from the drive belt to the alternator assembly.

Description

ALTERNATOR SHAFT EXTENDER

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63/509,523, filed June 21, 2023, which is incorporated by reference herein in its entirety.

FIELD

[0002] This disclosure generally relates to alternator shaft extenders for motor vehicles.

BACKGROUND

[0003] A vehicle typically includes an engine assembly with an alternator for generating the electrical power required to operate various electrical components of the vehicle. As additional accessory components are added, the electrical power requirement of the vehicle also increases. Improvements to conventional alternators are desirable to meet the increasing power requirements of current and future vehicles.

SUMMARY

[0004] Described herein are engine assemblies, alternator assemblies, and shaft extension assemblies for vehicles and methods for installing such alternator assemblies and shaft extension assemblies. The disclosed engine assemblies, alternator assemblies, and shaft extension assemblies can, for example, help certain vehicles meet substantially increased power demands to enable autonomous driving and satisfy emissions standards. In one specific example, the disclosed engine assemblies, alternator assemblies, and shaft extension assemblies can allow for an alternator to be integrated to an engine of a vehicle, such that the alternator can be driven by a belt of the engine without interfering with preexisting components on the alternator, the engine, and/or the vehicle, thereby beneficially simplifying the integration of the alternator to the engine. However, in view of the many possible ways in which the principles of the disclosure may be applied, it should be recognized that the aforementioned exemplary potential benefits and exemplary potential applications of the disclosed engine assemblies, alternator assemblies, and shaft extension assemblies should not be taken as limiting the scope of the disclosure or the claims.

[0005] In some examples, an engine assembly can comprise an engine block and a front end accessory drive coupled to a front end portion of the engine block. [0006] In some examples, the front end accessory drive can comprise a first belt layer, a second belt layer disposed forward of the first belt layer and a third belt layer disposed forward of the second belt layer.

[0007] In some examples, the third belt layer can comprise a drive belt, an alternator, an alternator shaft extending therefrom, and a shaft extension assembly coupled to the alternator shaft.

[0008] In some examples, the shaft extension assembly can be engaged with the drive belt and coupled to the alternator shaft.

[0009] In some examples, the shaft extension assembly and the alternator shaft can be fixedly coupled in a circumferential direction.

[0010] In some examples, the shaft extension assembly can comprise a rotor comprising a first end portion and a second end portion.

[0011] In some examples, the first end portion can be coupled to the alternator shaft.

[0012] In some examples, the first end portion of the rotor and the alternator shaft can be fixedly coupled in the circumferential direction.

[0013] In some examples, the first end portion of the rotor can comprise a recess configured to accept an end portion of the alternator shaft therein.

[0014] In some examples, the rotor and the alternator shaft can form a sliding joint.

[0015] In some examples, the shaft extension assembly can comprise a clutch coupling the rotor to the alternator shaft.

[0016] In some examples, the clutch and the alternator shaft can be fixedly coupled in the circumferential direction.

[0017] In some examples, the second end portion can be coupled to an accessory pulley.

[0018] In some examples, the second end portion and the accessory pulley can be fixedly coupled in the circumferential direction.

[0019] In some examples, the accessory pulley can be configured to engage the drive belt of the third belt layer.

[0020] In some examples, the alternator is configured to generate at least 2 kW, at least 12 kW, or at least 20 kW of electrical power when engaged with the drive belt of the third belt layer.

[0021] In some examples, the shaft extension assembly can comprise a gearbox comprising an input shaft coupled to the rotor and an output shaft coupled to the alternator shaft. [0022] In some examples, the input shaft and the rotor can be fixedly coupled in the circumferential direction.

[0023] In some examples, the output shaft and the alternator shaft can be fixedly coupled in the circumferential direction.

[0024] In some examples, an intermediate bracket can be disposed between the alternator and the shaft extension assembly.

[0025] In some examples, the shaft extension assembly and the intermediate bracket can be integrated as a unitary structure.

[0026] In some examples, the engine assembly can comprise an integrated housing encasing the alternator and at least a portion of the shaft extension assembly therein.

[0027] In some examples, the shaft extension assembly can comprise an idler pulley configured to engage one of the first belt layer and the second belt layer.

[0028] In some examples, a method of constructing an engine assembly can comprise mounting a shaft extension assembly to an alternator to form an alternator assembly.

[0029] In some examples, the method can further comprise coupling the alternator assembly to an engine block of the engine assembly.

[0030] In some examples, the method can further comprise coupling the alternator assembly to a third drive belt of the engine assembly.

[0031] In some examples, the method can further comprise, prior to coupling the alternator assembly to a third drive belt of the engine assembly, coupling a third drive pulley to the engine assembly.

[0032] In some examples, the method can further comprise coupling a second alternator assembly to the third drive belt of the engine assembly.

[0033] In one representative example, an engine assembly can comprise an engine block and a front end accessory drive coupled to a front end portion of the engine block. The front end accessory drive can comprise a first belt layer, a second belt layer disposed forward of the first belt layer, and a third belt layer disposed forward of the second belt layer. The third belt layer can comprise a drive belt, an alternator, an alternator shaft extending therefrom, and a shaft extension assembly coupled to the alternator shaft. The shaft extension assembly can be engaged with the drive belt. The shaft extension assembly can be coupled to the alternator shaft. [0034] In one representative example, an alternator assembly can comprise an alternator housing, an alternator shaft extending from the alternator housing, and a shaft extension assembly coupled to the alternator shaft. The shaft extension assembly can comprise a rotor having a first end portion coupled to the alternator shaft and a second end portion opposite the first end portion and an accessory pulley coupled to the second end portion of the rotor.

[0035] In one representative example, a shaft extension assembly for an alternator can comprise a rotor and a stator circumferentially disposed around at least a portion of the rotor. The rotor can comprise a first end portion configured to be coupled to a shaft of the alternator and a second end portion disposed opposite the first end portion. The shaft extension assembly can further comprise an accessory pulley coupled to the second end portion of the rotor.

[0036] In one representative example, a method of constructing an engine assembly can comprise: mounting a shaft extension assembly to an alternator to form an alternator assembly, coupling the alternator assembly to an engine block of the engine assembly, and coupling the alternator assembly to a third drive belt of the engine assembly.

[0037] In some examples, an engine assembly, alternator assembly, and/or a shaft extension assembly can comprise one or more components as recited in examples 1-33 below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] FIG. 1 is a perspective view of an exemplary engine assembly.

[0039] FIG. 2 is a side view of an exemplary engine assembly.

[0040] FIG. 3 is a perspective view of a portion of an exemplary alternator assembly.

[0041] FIG. 4 is a cross-sectional view of an exemplary shaft extension assembly.

[0042] FIG. 5 is a perspective view of an exemplary alternator assembly.

[0043] FIG. 6 is a side view of an exemplary engine assembly.

[0044] FIG. 7 is a perspective view of a portion of an exemplary alternator assembly.

[0045] FIG. 8 is a cross-sectional view of an exemplary shaft extension assembly.

[0046] FIG. 9 is a cross-sectional view of an exemplary shaft extension assembly.

[0047] FIG. 10 is a cross-sectional view of an exemplary shaft extension assembly.

[0048] FIG. 11 is a cross-sectional view of an exemplary shaft extension assembly.

[0049] FIG. 12 is a cross-sectional view of an exemplary shaft extension assembly. [0050] FIG. 13 is a cross-sectional view of an exemplary shaft extension assembly.

[0051] FIG. 14 is a cross-sectional view of an exemplary shaft extension assembly.

[0052] FIG. 15 is a cross-sectional view of an exemplary shaft extension assembly.

[0053] FIG. 16 is a cross-sectional view of an exemplary shaft extension assembly.

[0054] FIG. 17 is a perspective view of an exemplary engine assembly.

[0055] FIG. 18 is a perspective view of a portion of an exemplary alternator assembly.

DETAILED DESCRIPTION

Explanation of Terms

[0056] For purposes of this description, certain aspects, advantages, and novel features of the embodiments of this disclosure are described herein. The disclosed methods, apparatus, and systems should not be construed as being limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub-combinations with one another. The methods, apparatus, and systems are not limited to any specific aspect or feature or combination thereof, nor do the disclosed embodiments require that any one or more specific advantages be present or problems be solved. The scope of this disclosure includes any features disclosed herein combined with any other features disclosed herein, unless physically impossible.

[0057] Although the operations of some of the disclosed embodiments are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses rearrangement, unless a particular ordering is required by specific language set forth below. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed methods can be used in conjunction with other methods.

[0058] As used in this disclosure and in the claims, the terms “belt layer” and “drive layer” are used to refer to an assembly comprising a drive pulley, a drivebelt coupled the drive pulley, and one or more components driven by the drive pulley via the drive belt.

[0059] As used in this disclosure and in the claims, the term “fixedly coupled in a circumferential direction” refers to a coupling between two components of an assembly configured such that the components to rotate in unison in the circumferential direction of the assembly (for example, a shaft extension assembly). The term does not require, but also does not preclude, the two components being fixed relative to each other in an axial direction and/or a radial direction of the assembly.

[0060] As used in this disclosure and in the claims, the singular forms “a,” “an,” and “the” include the plural forms unless the context clearly dictates otherwise. Additionally, the term “includes” means “comprises.” Further, the terms “coupled” and “associated” generally mean electrically, electromagnetically, and/or physically (e.g., mechanically or chemically) coupled or linked and does not exclude the presence of intermediate elements between the coupled or associated items absent specific contrary language.

[0061] In the description, certain terms may be used such as “forward,” “front,” “rear,” “up,” “down,” “upper,” “lower,” “horizontal,” “vertical,” “left,” “right,” and the like. These terms are used, where applicable, to provide some clarity of description when dealing with relative relationships. But these terms are not intended to imply absolute relationships, positions, and/or orientations. For example, with respect to an object, an “upper” surface can become a “lower” surface by turning the object over. Nevertheless, it is still the same object.

[0062] Similar components in different embodiments are described in the specification and illustrated in the figures with similar reference numbers for improved understanding and readability. However, it should be understood that this numbering convention is merely for convenience and is not intended to limit and/or exclude any claim scope.

[0063] Although there are alternatives for various components, parameters, operating conditions, etc., set forth herein, that does not mean that those alternatives are necessarily equivalent and/or perform equally well. Nor does it mean that the alternatives are listed in a preferred order unless stated otherwise.

Overview of the Disclosed Technology

[0064] A motor vehicle (such as a car, truck, semi-trailer truck, etc.) typically includes an engine assembly comprising an engine block and a front engine accessory drive (which is also referred to herein as a “FEAD”) disposed on a front portion of the engine block. The FEAD can comprise at least one belt layer (which is also referred to herein as a “front end accessory drive layer,” a “FEAD layer,” and/or a “layer”) that includes a drive pulley, a drive belt, and at least one accessory configured to be driven by the drive pulley via the drive belt. In some examples, a FEAD can comprise a first belt layer and a second belt layer disposed forward of the first belt layer. The belt layers described herein can be configured to drive any accessory or combination of accessories of the engine assembly and/or the vehicle. For example, a belt layer can be configured to drive at least one of a water pump to circulate coolant, an AC compressor to compress air conditioner refrigerant, an engine fan to cool the engine assembly, a pump for pumping water or other fluids, and an alternator configured to generate electrical power.

[0065] In some examples disclosed herein, motor vehicles can have high electrical power requirements that conventional belt-driven alternators coupled to the first or second belt layers cannot meet or otherwise cannot achieve as efficiently as the alternators described herein. Such electrical power requirements can help enable autonomous driving features or help satisfy emissions standards. Thus, there is a need for alternators capable of efficiently meeting such electrical power requirements.

[0066] Furthermore, since integrating an alternator to an engine can sometimes require a redesign of the alternator, engine, and/or motor vehicle, there is a need to facilitate the simple integration of an alternator to an engine assembly to beneficially reduce the amount of work needed to design and execute the integration.

Examples of the Disclosed Technology

[0067] FIG. 1 is a perspective view of an exemplary engine assembly 100. As shown, the engine assembly 100 comprises an engine block 102 and a front engine accessory drive 110 (“FEAD”) disposed on a front end portion thereof. The FEAD 110 can comprise a plurality of belt layers. As shown, the FEAD 110 comprises three belt layers: a first belt layer 120, a second belt layer 130 disposed forward of the first belt layer 120, and a third belt layer 140 disposed forward of the second belt layer 130. However, other exemplary front engine accessory drives can comprise any number of belt layers, such as one, two, four, five, or more than five belt layers.

[0068] The first belt layer 120 can comprise a first drive pulley (which is also referred to herein as a “first crankshaft pulley”), a first drive belt 124 coupled to the first drive pulley, and one or more first accessory pulleys 126 coupled to the first drive belt 124. The first drive pulley can be coupled to a crankshaft of the engine assembly 100. The first drive pulley can be configured to transfer mechanical power via the first drive belt 124 from the crankshaft to the first accessory pulleys 126, each of which can be coupled to a corresponding accessory (such as a compressor, a water pump, an alternator, a fan, etc.). In some examples, the first belt layer 120 can further comprise a first belt tensioner configured to tension the first drive belt 124. The first drive belt 124 is aligned with a first lateral plane 121 (see, e.g., FIG. 2).

[0069] The second belt layer 130 can comprise a second drive pulley (which is also referred to herein as a “second crankshaft pulley”), a second drive belt 134 coupled to the second drive pulley, and one or more second accessory pulleys 136 coupled to the second drive belt 134. The second drive pulley can be coupled to the crankshaft of the engine assembly 100 and can be disposed on the crankshaft forward of the first drive pulley of the first belt layer 120. Thus, the first drive pulley and the second drive pulley can be coupled to and coaxially aligned on the crankshaft of the engine assembly 100. The second drive pulley can be configured to transfer mechanical power via the second drive belt 134 from the crankshaft to the second accessory pulleys 136, each of which can be coupled to a corresponding accessory (such as a compressor, a water pump, an alternator, a fan, etc.). As shown, the second belt layer 130 further comprises a second belt tensioner 138 configured to tension the second drive belt 134. The second drive belt 134 is aligned with a second lateral plane 131 (see, e.g., FIG. 2) disposed forward of the first lateral plane 121.

[0070] As shown, the third belt layer 140 comprises a third drive pulley 142 (which is also referred to herein as a “third crankshaft pulley”) and a third drive belt 144 coupled to the third drive pulley 142. The third drive pulley 142 can be coupled to the crankshaft of the engine assembly 100 and can be disposed on the crankshaft forward of the second drive pulley of the second belt layer 130. Thus, the first drive pulley, the second drive pulley, and the third drive pulley can be coupled to and coaxially aligned on the crankshaft of the engine assembly 100. As shown, the third belt layer 140 further comprises a third belt tensioner 148 configured to tension the third drive belt 144. The third belt tensioner 148 is shown as mounted to an engine front legs bracket 150 coupled to the front end portion of the engine block 102. However, other examples of the third belt tensioner 148 can be coupled to the engine block 102 at different locations or using different brackets. The third drive belt 144 is aligned with a third lateral plane 141 see, e.g., FIG. 2) disposed forward of the second lateral plane 131.

[0071] As shown, the third belt layer 140 further comprises an alternator assembly 160. The alternator assembly 160 comprises an alternator 162 configured to be driven by the third drive belt 144 of the third belt layer 140. The alternator 162 can be configured to generate at least 2 kW of electrical energy when driven by the third drive belt 144. For example, the alternator 162 can be configured to generate at least 12 kW, at least 20 kW, 2 kW to 25 kW, 12 kW to 25 kW, and/or 20 kW to 25 kW of electrical energy when driven by the third drive belt 144. Thus, when coupled to the third drive belt 144, the alternator 162 can beneficially generate sufficient electrical power to meet the electrical power requirements of certain motor vehicles. For example, the alternator 162 can be configured to generate more electrical power than a conventional alternator, thereby beneficially result in greater electrical power output as compared to configurations with a conventional alternator. [0072] In some examples, the third belt layer 140 can comprise another accessory, such as a water pump to circulate coolant, an AC compressor to compress air conditioner refrigerant, an engine fan to cool the engine assembly 100, or any other engine accessory in addition to or in lieu of the alternator assembly 160.

[0073] As shown, the alternator assembly 160 can be mounted on a hot side 104 of the engine block 102. For example, the hot side 104 of the engine block 102 can be a lateral side of the engine block 102 on which an exhaust manifold is located and/or a lateral side of the engine block 102 configured to handle exhaust from the engine assembly 100. However, as further discussed below, some examples of the alternator assembly 160 can be mounted to a cold side (see, e.g., FIGS. 5-6) of the engine block 102. In some examples, the alternator assembly 160 can be a first alternator assembly mounted to the hot side 104 of the engine block 102 and a second alternator assembly can be mounted to the cold side of the engine block 102. In some examples, more than one assembly (e.g., a first alternator assembly and a second alternator assembly) can be mounted to the same side (e.g., the hot side 104 or the cold side) of the engine block 102. Such configurations can, for example, beneficially result in greater electrical power output as compared to configurations with one alternator assembly.

[0074] The alternator assembly 160 can be configured to engage multiple belt layers of the FEAD 110. For example, as shown, an idler pulley 190 (see, e.g., FIGS. 3-4) of the alternator assembly 160 can be configured to engage the first drive belt 124 of the first belt layer 120 and an accessory pulley 180 (see, e.g., FIGS. 3-4) of the alternator assembly 160 can be configured to engage the third drive belt 144 of the third belt layer 140. In some of these examples, since the idler pulley 190 does not transmit mechanical power to the alternator assembly 160, mechanical power can be transmitted to the alternator assembly 160 only through some of the drive belts. For example, mechanical power can be transmitted through the third drive belt 144 which engages the accessory pulley 180, but not the first drive belt 124 which engages the idler pulley 190. However, it should be understood that the alternator assembly 160 can engage any combination of belt layers of the FEAD 110 and mechanical power can be transmitted through any combination of the belt layers.

[0075] FIG. 2 is a side view of the engine assembly 100 and shows the first belt layer 120, the second belt layer 130, and the third belt layer 140 in profile. As shown, the first drive belt 124 of the first belt layer 120 is aligned with the first lateral plane 121, the second drive belt 134 of the second belt layer 130 is aligned with the second lateral plane 131 disposed forward of the first lateral plane 121, and the third drive belt 144 of the third belt layer 140 is aligned with the third lateral plane 141 disposed forward of the second lateral plane 131. [0076] FIG. 3 is a perspective view of a portion of the alternator assembly 160. As shown, the alternator assembly 160 comprises the alternator 162 and a shaft extension assembly 170 (which is also referred to herein as a “shaft extender” and/or an “alternator shaft extender”) coupled to the alternator 162. The first drive belt 124, which was previously shown in FIGS. 1-2 as engaging an idler pulley 190 of the shaft extension assembly 170, is omitted to better show the shaft extension assembly 170. For example, the shaft extension assembly 170 can beneficially allow for the alternator assembly 160 to be mounted to the engine block 102 such that the alternator 162 does not interfere with the first drive belt 124 of the first belt layer 120.

[0077] Although the shaft extension assembly 170 is presently illustrated as being used in conjunction with the alternator 162, the shaft extension assembly 170 may additionally or alternatively be used in conjunction with an engine fan, a compressor, a pump, and/or any other engine accessory configured to be driven by the FEAD 110.

[0078] FIG. 4 is a cross-sectional view of the shaft extension assembly 170 coupled to the alternator 162. The alternator 162 comprises an alternator housing 164 and an alternator shaft 166 extending from the alternator housing 164. A portion of the alternator shaft 166 having a length 166L extends from the alternator housing 164. The alternator shaft 166 can have a diameter 166d. For simplicity and convenience, only a portion of the alternator housing 164 and the alternator shaft 166 are shown in FIG. 4. The alternator housing 164 comprises one or more mounting holes 168 on a front portion thereof, wherein each of the mounting holes 168 is configured to accept a fastener (such as a screw 177) for coupling the shaft extension assembly 170 to the alternator housing 164.

[0079] The shaft extension assembly 170 comprises a rotor 172 extending along a central longitudinal axis 171 of the shaft extension assembly 170 and a stator 173 circumferentially surrounding at least a portion of the rotor 172. As shown, the rotor 172 comprises a rod or shaft oriented along the central longitudinal axis 171 with a first end portion 172a and a second end portion 172b. The rotor 172 is presently shown as comprising a hollow cavity extending in a longitudinal direction therethrough, wherein the hollow cavity has an internal diameter 172d. The internal diameter 172d can be from 5 mm to 30 mm, such as from 10 mm to 25 mm, 10 mm to 20 mm, and/or 10 mm to 15 mm. However, it should be understood that the rotor 172 (or any other rotor disclosed herein) can alternatively be a solid structure without a hollow cavity. The internal diameter 172d is presently shown as being less than a diameter 166d of the alternator shaft 166. However, in other examples, the internal diameter 172d can be greater than or equal to the diameter 166d of the alternator shaft 166. As shown, the radial thickness of the rotor 172 can change along the length (along central longitudinal axis 171) of the rotor 172. For example, the rotor 172 can be radially thicker at an intermediate portion 172c (between first and second end portions 172a and 172b) of the rotor 172 than at the first and second end portions 172a and 172b of the rotor 172. The rotor 172 can have a length 172L (along the central longitudinal axis 171) from 30 mm to 300 mm, from 60 mm to 270 mm, from 90 mm to 240 mm, from 120 mm to 210 mm, and/or from 120 mm to 180 mm. In some examples, the length 172L of the rotor 172 can be equal to or up to sixty times greater than the internal diameter 172d of the rotor 172. In some examples, the length 172L of the rotor 172 can be twice, three times, four times, etc. the length 166L of the portion of the alternator shaft 166 extending from the alternator housing 166 and/or extending into the recess of the rotor 172. In a similar manner, any other rotor length (for example, 272L, 372L, 472L, 572L, 672L, etc.) disclosed herein can be twice, three times, four times, etc. the length (for example, 272L, 372L, 472L, 572L, 672L, etc.) of a corresponding portion of an alternator shaft extending from an alternator housing and/or extending into the rotor.

[0080] The first end portion 172a of the rotor 172 is coaxial with and coupled to the alternator shaft 166 such that the rotor 172 can rotate in unison with and transfer torque to the alternator shaft 166. In some examples, the first end portion 172a of the rotor and the alternator shaft are fixedly coupled in a circumferential direction of the shaft extension assembly 170. For example, the first end portion 172a of the rotor 172 can comprise a recess in which an end portion of the alternator shaft 166 can be disposed. In some examples, the first end portion 172a of the rotor 172 and the alternator shaft 166 can be connected at a sliding joint, including but not limited to a keyed joint, a spline joint, or a polygonal joint. In some examples, the first end portion 172a of the rotor 172 and the alternator shaft 166 can be connected by a clutch. In some examples, the first end portion 172a of the rotor 172 and the alternator shaft 166 can be connected by a gearbox; thus, in such examples, the first end portion 172a of the rotor 172 can rotate at a different speed than the alternator shaft 166. In some examples, the coupling between the rotor 172 and the alternator shaft 166 is not constrained in the axial direction (along the central longitudinal axis 171) such that the rotor 172 can move in the axial direction relative to the alternator shaft 166, or vice versa. However, in some examples, the coupling between the rotor 172 and the alternator shaft 166 can be constrained in the axial direction (along the central longitudinal axis 171), such that the rotor 172 and alternator shaft 166 are fully constrained. The first end portion 172a of the rotor 172 can alternatively or additionally be coupled to the alternator shaft 166 using rivets, bolts, nuts, threaded portions, welds, adhesives, press fits, interference fits, or any combination thereof.

[0081] As shown, the stator 173 comprises a housing 174 comprising a first end portion 174a and a second end portion 174b axially opposite the first end portion 174a. The housing 174 of the stator 173 can be configured to accept at least a portion of the rotor 172 therein such that the housing 174 of the stator 173 circumferentially surrounds said portion of the rotor 172. The radial thickness of the housing 174 can change along the length (along central longitudinal axis 171) of the housing 174. For example, as shown, the housing 174 can be radially thicker at the first end portion 174a than at the second end portion 174b. Furthermore, as shown, the housing 174 is thicker at an intermediate portion 174c (between first and second end portions 174a and 174b) than at the second end portion 174b. Such a configuration can, in some examples, better withstand forces exerted on the housing 174 by idler pulley 190.

[0082] The stator 173 is shown as further comprising a mounting flange 175 that extends substantially perpendicularly from the first end portion 174a of the housing 174. As shown, the mounting flange 175 is a plate that tapers away from the housing 174. However, some examples of the mounting flange 175 can comprise a flat, non-tapering plate. The mounting flange 175 can facilitate the coupling or mounting of the stator 173 to the alternator housing 164. For example, the mounting flange 175 can comprise one or more through holes 176 which, when aligned with corresponding mounting holes 168 of the alternator housing 164, allow screws 177 to be inserted therethrough. However, other examples of the stator 173 can be coupled to the alternator housing 164 using one or more rivets, nuts, bolts, welds, adhesives, press fits, interference fits, or any combination thereof. In some examples, the housing 174 and the mounting flange 175 can be formed as a unitary structure. In some examples, the alternator housing 164 and the stator 173 can be formed as a unitary structure.

[0083] As shown, the shaft extension assembly 170 further comprises a first bearing 178 disposed radially between the rotor 172 and the stator 173. The first bearing 178 can be configured to support the rotor 172, minimize friction between the rotor 172 and the stator 173, and/or facilitate radial separation between the rotor 172 and the stator 173 as the rotor 172 rotates within the stator 173. In some examples, the first bearing 178 can be a “floating bearing” which can freely move in the axial direction (along central longitudinal axis 171) relative to the rotor 172.

[0084] As shown, the shaft extension assembly 170 comprises an optional second bearing 179 disposed radially between the rotor 172 and the stator 173. The second bearing 179 can be configured to further support the rotor 172, further minimize friction between the rotor 172 and the stator 173, and/or further facilitate radial separation between the rotor 172 and the stator 173 as the rotor 172 rotates within the stator 173. In some examples, the second bearing 179 can be a “fixed bearing” which maintains a fixed position in the axial direction (along central longitudinal axis 171) relative to the rotor 172. Since the rotor 172 can have a non-uniform diameter along its length 172L, some examples of the second bearing 179 can have a different diameter than the first bearing 178. However, since the second bearing 179 is optional, other examples of the shaft extension assembly 170 can lack the second bearing 179.

[0085] As shown, the shaft extension assembly 170 further comprises an accessory pulley 180 (which is also referred to herein as a “third accessory pulley”) coupled to the second end portion 172b of the rotor 172. In some examples, the accessory pulley 180 and the second end portion 172b of the rotor 172 can be fixedly coupled in the circumferential direction. The accessory pulley 180 comprises a wheel with a grooved rim 182 around which the third drive belt 144 passes when the alternator assembly 160 is driven by the third drive belt 144. The accessory pulley 180 is shown as having a diameter 180d, which can range from 30 mm to 120 mm (for example, from 45 mm to 105 mm, from 60 mm to 90 mm, etc.). The accessory pulley 180 can have a length 180L, which can range from 10 mm to 60 mm (for example, from 20 mm to 50 mm, from 30 mm to 40 mm, etc.). For example, the diameter 180d of the accessory pulley 180 can be 0.5 to 12 times (such as 1 to 11 times, 2 to 10 times, 3 to 9 times, 4 to 7 times, 5 to 6 times, etc.) greater than the length 180L of the accessory pulley 180. The diameter 180d can be greater than each of the diameters of the alternator shaft 166, the rotor 172, and the housing 174 of the stator 173. However, certain examples of the accessory pulley 180 can have a smaller diameter than any of these components.

As shown, a washer 184 and a screw 186 can be used to fasten the accessory pulley 180 to the rotor

172. However, the accessory pulley 180 can be coupled to the rotor 172 using a sliding joint, a rivet, threaded portion, nut, weld, adhesive, press fit, interference fit, or any combination thereof. In some examples, the rotor 172 and the accessory pulley 180 can be formed as a unitary structure. The rotor 172 is coupled to the accessory pulley 180 such that the rotor 172 and the accessory pulley 180 — and, by extension, the alternator shaft 166 coupled to the rotor 172 — can rotate in unison when the accessory pulley 180 is driven by the third drive belt 144.

[0086] As shown, the shaft extension assembly 170 further comprises a sleeve 188 and a shaft nut 189. The sleeve 188 comprises a cylindrical tube configured to circumferentially surround the rotor 172. The shaft nut 189 can be coupled to the rotor 172 (for example, the first end portion 172a of the rotor 172) such that the shaft nut 189 cannot move axially relative to the rotor 172. As shown, the sleeve 188 is axially disposed between the second bearing 179 and the shaft nut 189, both of which are axially fixed, to prevent axial movement of the rotor 172 relative to the stator

173.

[0087] As shown, the shaft extension assembly 170 further comprises an optional idler pulley 190 circumferentially disposed around the stator 173. The idler pulley 190 comprises a wheel with a grooved rim 192 around which the first drive belt 124 passes. The idler pulley 190 has a diameter 190d. As shown, the diameter 190d is greater than the diameter 180d of the accessory pulley 180. However, some examples of the accessory pulley 180 can have a greater diameter 180d than the diameter 190d of the idler pulley 190. The shaft extension assembly 170 further comprises a bearing 194 disposed radially between the idler pulley 190 and the stator 173 to facilitate the rotation of the idler pulley 190 around the stator 173. In some examples, such as the illustrated example, the idler pulley 190 can beneficially engage the first belt layer 120 to guide the first drive belt 124 around the shaft extension assembly 170, which can help prevent the shaft extension assembly 170 from interfering with the first drive belt 124 and can allow the alternator assembly 160 to be placed at locations on the engine block 102 that would otherwise interfere with the first drive belt 124. However, some examples of the shaft extension assembly 170 can lack the idler pulley 190. In some examples, the idler pulley 190 can be alternatively configured to engage the second belt layer 130 to guide the second drive belt 134 around the shaft extension assembly 170. In some examples in which the alternator assembly 160 is driven by the first drive belt 124 and/or the second drive belt 134, the idler pulley 190 can be additionally or alternatively configured to engage the third belt layer 140 to guide the third drive belt 144 around the shaft extension assembly 170. In some examples, the idler pulley 190 can be a first idler pulley configured to guide the first drive belt 124 around the shaft extension assembly 170 and the shaft extension assembly 170 can further comprise a second idler pulley to guide the second drive belt 134 around the shaft extension assembly 170.

[0088] FIG. 5 is a perspective view of an exemplary engine assembly 200. As described below, engine assembly 200 can be similar to engine assembly 100, but one exemplary difference is that alternator assembly 260 is mounted on a cold side 206 of the engine assembly 200 instead of a hot side. The FEAD 210 comprises a first belt layer 220, a second belt layer 230 disposed forward of the first belt layer 220, and a third belt layer 240 disposed forward of the second belt layer 230. The first belt layer 220 can comprise a first drive pulley, a first drive belt 224 engaged with the first drive pulley, and a first accessory pulley 226 coupled to the first drive belt 224. The second belt layer 230 can comprise a second drive pulley, a second drive belt 234 engaged with the second drive pulley, a second accessory pulley 236 coupled to the second drive belt 234, and a belt tensioner 238 engaged with the second drive belt 234. The third belt layer 240 of the FEAD 210 comprises a third drive pulley 242, a third drive belt 244 coupled to the third drive pulley 242, a belt tensioner 248 engaged with the third drive belt 244, and an alternator assembly 260 mounted to a cold side 206 of the engine block 202 and driven by the third drive belt 244. The cold side 206 of the engine block 202 can be opposite a hot side see, e.g. , FIG. 1) of the engine block 202. The engine assembly 200 can further comprise an engine front legs bracket 250 coupled to a front portion of the engine block 202.

[0089] FIG. 6 is a side view of the engine assembly 200 and shows the first belt layer 220, the second belt layer 230, and the third belt layer 240 in profile. One exemplary difference between FIG. 6 and FIG. 2 is that alternator assembly 260 is shown disposed on the cold side 206 of the engine block 202 rather than the hot side. However, it should be understood that some examples of the alternator assembly 260 can be configured for mounting on the hot side of the engine block 202. As shown, the engine assembly 200 comprises the first drive belt 224 of the first belt layer 220 aligned with a first lateral plane 221, the second drive belt 234 of the second belt layer 230 aligned with a second lateral plane 231 disposed forward of the first lateral plane 221, and the third belt layer 240 aligned with a third lateral plane 241 disposed forward of the second lateral plane 231. In some examples, the spacing between the second and lateral planes 231 and 241 can be similar to the spacing between the second and third lateral planes 131 and 141 shown in FIG. 2.

[0090] Another exemplary difference between FIG. 6 and FIG. 2 is that the alternator assembly 260 is shown as further comprising an optional rear cable bracket 263 to help route alternator cables 265a and 265b, which extend from the alternator assembly 260, thereby facilitating the simple integration of the alternator assembly 260 to the engine block 202. It should be understood that any other alternator assembly disclosed herein can comprise the rear cable bracket 263.

[0091] FIG. 7 is a perspective view of a portion of the alternator assembly 260. One exemplary difference between FIG. 7 and FIG. 3 is that alternator assembly 260 is configured to be disposed on the cold side 206 of the engine block 202 rather than the hot side. However, it should be understood that some examples of the alternator assembly 260 can be configured for mounting on the hot side of the engine block 202. The alternator assembly 260 comprises an alternator 262, the rear cable bracket 263, the alternator cables 265a and 265b, an ear mount bracket 267, and a shaft extension assembly 270 coupling the alternator 262 to the third drive belt 244 of the third belt layer 240. In some examples, the ear mount bracket 267 can be coupled to the engine block 202 and the shaft extension assembly 270 and can be configured to help stabilize the shaft extension assembly 270 relative to the engine block 202. In some examples, the ear mount bracket 267 can be configured to transmit bending forces from the shaft extension assembly 270 to the engine block 202 rather than to the alternator 262. In some examples, the ear mount bracket 267 can be coupled to any other fixation point on the vehicle. The shaft extension assembly 270 can beneficially allow the alternator 262 to be driven by the third drive belt 244. As shown, the alternator assembly 260 further comprises a mounting plate 261 disposed between the engine block 202 and the alternator 262 to facilitate the coupling of the alternator 262 to the engine block 202. However, other examples of the alternator assembly 260 can be directly mounted to the engine block 202 or any other fixation point without the use of the mounting plate 261.

[0092] FIG. 8 is a cross-sectional view of the shaft extension assembly 270 coupled to the alternator 262. One exemplary difference between the shaft extension assembly 270 and the shaft extension assembly 170 is that the shaft extension assembly 270 lacks an idler pulley. The alternator 262 comprises an alternator housing 264 and an alternator shaft 266 extending from the alternator housing 264. A portion of the alternator shaft 266 having a length 266L extends from the alternator housing 264. The alternator shaft 266 has a diameter 266d. For simplicity and convenience, only a portion of the alternator housing 264 and the alternator shaft 266 are shown in FIG. 8. The alternator housing 264 comprises one or more mounting holes 268 on a front portion thereof, wherein each of the mounting holes 268 is configured to accept a fastener (such as screw 277) for coupling the shaft extension assembly 270 to the alternator housing 264.

[0093] The shaft extension assembly 270 comprises a rotor 272 extending along a central longitudinal axis 271 of the shaft extension assembly 270 and coupled to the alternator shaft 266, a stator 273 circumferentially surrounding at least a portion of the rotor 272 and coupled to the alternator housing 264 using screws 277, first and second bearings 278 and 279 disposed radially between the rotor 272 and the stator 273, an accessory pulley 280 coupled to the rotor 272, a washer 284 and screw 286 coupling the accessory pulley 280 to the rotor 272, and a sleeve 288 and a shaft nut 289 which axially secure the rotor 272 relative to the stator 273.

[0094] As shown, the rotor 272 comprises a rod or shaft oriented along the central longitudinal axis 271 and having a first end portion 272a and a second end portion 272b. The rotor 272 is shown as comprising a hollow cavity extending in a longitudinal direction therethrough, wherein the hollow cavity has an internal diameter 272d. The internal diameter 272d can be from 5 mm to 30 mm, such as from 10 mm to 25 mm, 10 mm to 20 mm, and/or 10 mm to 15 mm. However, some examples of the rotor 272 can be solid structures without cavities. As shown, the radial thickness of the rotor 272 can change along the length (along central longitudinal axis 271) of the rotor 272. For example, the rotor 272 can be radially thicker at an intermediate portion 272c (between first and second end portions 272a and 272b) of the rotor 272 than at the first and second end portions 272a and 272b of the rotor 272. The rotor 272 can have a length 272L (along the central longitudinal axis 271). In some examples, the length 272L can be from 30 mm to 300 mm, from 60 mm to 270 mm, from 90 mm to 240 mm, from 120 mm to 210 mm, and/or from 120 mm to 180 mm. Thus, in some examples, the length 272L of the rotor 272 can be equal to or up to sixty times greater than the internal diameter 272d of the rotor 272.

[0095] Although the illustrated rotor 272 is radially thicker at the intermediate portion 272c than at the end portions 272a and 272b, the rotor 272 can alternatively be uniformly thick along its length 272L.

[0096] The first end portion 272a of the rotor 272 is coaxial with and coupled to the alternator shaft 266. In some examples, the first end portion 272a and the alternator shaft 266 can be fixedly coupled in the circumferential direction, such the first end portion 272a of the rotor 272 and the alternator shaft 266 can rotate in unison when torque is applied to the rotor 272. For example, the end portion of the alternator shaft 266 can be disposed within the first end portion 272a of the rotor 272 such that the components form a sliding joint, such as a keyed joint, a spline joint, or a polygonal joint. In some examples, a clutch can be used to couple the first end portion 272a of the rotor 272 and the alternator shaft 266. In some examples, a gearbox can be used to couple the first end portion 272a of the rotor 272 and the alternator shaft 266. In some examples, the joint formed by the rotor 272 and the alternator shaft 266 can slide in the axial direction (along the central longitudinal axis 271). In some examples, the joint formed by the rotor 272 and the alternator shaft 266 can be fully constrained, such that the rotor 272 is fixedly coupled to the alternator shaft 266 in both the axial and circumferential directions. However, the first end portion 272a of the rotor 272 can be coupled to the alternator shaft 266 using rivets, nuts, bolts, threaded portions, welds, adhesives, press fits, interference fits, or any combination thereof.

[0097] As shown, the stator 273 comprises a housing 274 comprising a first end portion 274a and a second end portion 274b opposite the first end portion 274a. The housing comprises a body tapering from the first end portion 274a to the second end portion 274b and a hollow cavity extending lengthwise through the housing 274.

[0098] The stator 273 is shown as further comprising a mounting flange 275 extending from the first end portion 274a of the housing 274. As shown, the mounting flange 275 is a plate comprising one or more through holes 276 which, when aligned with corresponding mounting holes 268 of the alternator housing 264, allow screws 277 to be inserted therethrough to couple the alternator housing 264 to the shaft extension assembly 270. However, other examples of the stator 273 can be coupled to the alternator housing 264 using one or more rivets, nuts, bolts, welds, adhesives, press fits, interference fits, or any combination thereof. In some examples, the housing 274 and the mounting flange 275 can be formed as a unitary structure. In some examples, the alternator housing 264 and the stator 273 can be formed as a unitary structure. [0099] As shown, the shaft extension assembly 270 further comprises the first bearing 278 disposed radially between the rotor 272 and the stator 273. In some examples, the first bearing 278 can be a “floating bearing” which can freely move in the axial direction (along central longitudinal axis 271) relative to the rotor 272.

[0100] As shown, the shaft extension assembly 270 comprises the optional second bearing 279 disposed radially between the rotor 272 and the stator 273. In some examples, the second bearing

279 is a “fixed bearing” which maintains a fixed position in the axial direction (along central longitudinal axis 271) relative to the rotor 272. Since the rotor 272 can have a non-uniform diameter along its length 272L, some examples of the second bearing 279 can have a different diameter than the first bearing 278. However, since the second bearing 279 is optional, other examples of the shaft extension assembly 270 can lack the second bearing 279.

[0101] As shown, the shaft extension assembly 270 further comprises the accessory pulley 280 coupled to the second end portion 272b of the rotor 272. In some examples, the accessory pulley

280 and the second end portion 272b of the rotor 272 can be fixedly coupled in the circumferential direction, such that the accessory pulley 280 and the rotor 272 rotate in unison when torque is applied to the accessory pulley 280. In some examples, the accessory pulley 280 can be coupled to the second end portion 272b of the rotor 272 via a sliding joint. The accessory pulley 280 comprises a wheel with a grooved rim 282 around which the third drive belt 244 passes when the alternator assembly 260 is driven by the third drive belt 244. The accessory pulley 280 is shown as having a diameter 280d and a length 280L. The diameter 280d can range from 30 mm to 120 mm (for example, from 45 mm to 105 mm, from 60 mm to 90 mm, etc.). The accessory pulley 280 can have a length 280L, which can range from 10 mm to 60 mm (for example, from 20 mm to 50 mm, from 30 mm to 40 mm, etc.). Thus, the diameter 280d of the accessory pulley 280 can be 0.5 to 12 times (such as 0.5 to 1 times, 1 to 11 times, 2 to 10 times, 3 to 9 times, 4 to 7 times, 5 to 6 times, etc.) greater than the length 280L of the accessory pulley 280. As shown, a washer 284 and a screw 286 can be used to fasten the accessory pulley 280 to the rotor 272. However, the accessory pulley 280 can be coupled to the rotor 272 using a rivet, threaded portion, nut, bolt, weld, adhesive, press fit, interference fit, or any combination thereof. In some examples, the rotor 272 and the accessory pulley 280 can be formed as a unitary structure. The rotor 272 is coupled to the accessory pulley 280 such that the rotor 272 and the accessory pulley 280 — and, by extension, the alternator shaft 266 coupled to the rotor 272 — can rotate in unison when the accessory pulley 280 is driven by the third drive belt 244. [0102] As shown, the shaft extension assembly 270 further comprises the sleeve 288 and the shaft nut 289. The sleeve 288 comprises a cylindrical tube configured to circumferentially surround the rotor 272. The shaft nut 289 can be coupled to the rotor 272 (for example, the first end portion 272a of the rotor 272) such that the shaft nut 289 cannot move axially relative to the rotor 272. As shown, the sleeve 288 is axially disposed between the second bearing 279 and the shaft nut 289, both of which are axially fixed, to prevent axial movement of the rotor 272 relative to the stator 273.

[0103] As shown in the figures, unlike the shaft extension assembly 170 illustrated in FIGS. 1-4, the shaft extension assembly 270 lacks an idler pulley (for example, idler pulley 190). However, other examples of the shaft extension assembly 270 can include an idler pulley.

[0104] FIG. 9 is a cross-sectional view of an alternator assembly 360 comprising a shaft extension assembly 370 coupled to an alternator 362. The alternator 362 comprises an alternator housing 364 and an alternator shaft 366 extending from the alternator housing 364. A portion of the alternator shaft 366 having a length 366L extends from the alternator housing 364. The alternator shaft 366 has a diameter 366d. For simplicity and convenience, only a portion of the alternator housing 364 and the alternator shaft 366 are shown in FIG. 9. The alternator housing 364 comprises one or more mounting holes 368 on a front portion thereof, wherein each of the mounting holes 368 is configured to accept a fastener (such as screw 377) for coupling the shaft extension assembly 370 to the alternator housing 364.

[0105] The shaft extension assembly 370 comprises a rotor 372 extending along a central longitudinal axis 371 of the shaft extension assembly 370 and coupled to the alternator shaft 366, a stator 373 circumferentially surrounding at least a portion of the rotor 372 and coupled to the alternator housing 364 using screws 377, a double bearing 378 disposed radially between the rotor 372 and the stator 373, an accessory pulley 380 coupled to the rotor 372, and a washer 384 and screw 386 coupling the accessory pulley 380 to the rotor 372.

[0106] As shown, the rotor 372 comprises a rod or shaft oriented along the central longitudinal axis

371 and having a first end portion 372a and a second end portion 372b. The rotor 372 is shown as comprising a hollow cavity extending in a longitudinal direction therethrough. The hollow cavity has an internal diameter 372d. The internal diameter 372d can be from 5 mm to 30 mm, such as from 10 mm to 25 mm, 10 mm to 20 mm, and/or 10 mm to 15 mm. However, some examples of the rotor 372 can be solid structures without cavities. As shown, the radial thickness of the rotor

372 can change along the length (along central longitudinal axis 371) of the rotor 372. For example, the rotor 372 can be radially thicker at an intermediate portion 372c (between first and second end portions 372a and 372b) of the rotor 372 than at the first and second end portions 372a and 372b of the rotor 372. The rotor 372 can have a length 372L (along the central longitudinal axis 371). In some examples, the length 372L can be from 30 mm to 300 mm, from 60 mm to 270 mm, from 90 mm to 240 mm, from 120 mm to 210 mm, and/or from 120 mm to 180 mm. In some examples, the length 372L of the rotor 372 can be equal to or up to sixty times greater than the internal diameter 372d of the rotor 372.

[0107] The first end portion 372a of the rotor 372 is coaxial with and coupled to the alternator shaft 366, such that the rotor 372 can rotate in unison with the alternator shaft 366. In some examples, the first end portion 372a of the rotor 372 and the alternator shaft 366 can be fixedly coupled in the circumferential direction. For example, the end portion of the alternator shaft 366 can be disposed within the first end portion 372a of the rotor 372 such that the components form a sliding joint, including but not limited to a keyed joint, a spline joint, or a polygonal joint. However, the first end portion 372a of the rotor 372 can be coupled to the alternator shaft 366 using rivets, welds, nuts, bolts, threaded portions, adhesives, press fits, interference fits, or any combination thereof.

[0108] As shown, the stator 373 comprises a housing 374 comprising a first end portion 374a and a second end portion 374b opposite the first end portion 374a. The housing comprises a body tapering from the first end portion 374a to the second end portion 374b and a hollow cavity extending lengthwise through the housing 374. At least a portion of the rotor 372 is disposed within the hollow cavity.

[0109] The stator 373 is shown as further comprising a mounting flange 375 extending from the first end portion 374a of the housing 374. As shown, the mounting flange 375 is a plate comprising one or more through holes 376 which, when aligned with corresponding mounting holes 368 of the alternator housing 364, allow screws 377 to be inserted therethrough to couple the alternator housing 364 to the shaft extension assembly 370. However, other examples of the stator 373 can be coupled to the alternator housing 364 using one or more rivets, nuts, bolts, welds, adhesives, press fits, interference fits, or any combination thereof. In some examples, the housing 374 and the mounting flange 375 can be formed as a unitary structure. In some examples, the alternator housing 364 and the stator 373 can be formed as a unitary structure.

[0110] As shown, the shaft extension assembly 370 further comprises the double bearing 378 disposed radially between the rotor 372 and the stator 373. In some examples, the double bearing 378 can beneficially be configured to withstand more force or torque than certain other bearings described herein. In some examples, the double bearing 378 can be coupled to the rotor 372 and the stator 373 such that the rotor 372 cannot move axially (along central longitudinal axis 371) relative to the stator 373 when the shaft extension assembly 370 is coupled to the alternator housing 364.

[0111] As shown, the shaft extension assembly 370 further comprises the accessory pulley 380 coupled to the second end portion 372b of the rotor 372. In some examples, the accessory pulley 380 and the second end portion 372b of the rotor 372 can be fixedly coupled in the circumferential direction. For example, the accessory pulley 380 can be coupled to the second end portion 372b of the rotor 372 via a sliding joint. The accessory pulley 380 comprises a wheel with a grooved rim 382 around which a third drive belt 344 passes when the alternator assembly 360 is driven by the third drive belt 344. The accessory pulley 380 is shown as having a diameter 380d and a length 380L. The diameter 380d can range from 30 mm to 120 mm (for example, from 45 mm to 105 mm, from 60 mm to 90 mm, etc.). The accessory pulley 380 can have a length 380L, which can range from 10 mm to 60 mm (for example, from 20 mm to 50 mm, from 30 mm to 40 mm, etc.). Thus, the diameter 380d of the accessory pulley 380 can be 0.5 to 12 times (such as 0.5 to 1 times, 1 to 11 times, 2 to 10 times, 3 to 9 times, 4 to 7 times, 5 to 6 times, etc.) greater than the length 380L of the accessory pulley 380. As shown, a washer 384 and a screw 386 can be used to fasten the accessory pulley 380 to the rotor 372. However, the accessory pulley 380 can be coupled to the rotor 372 using a rivet, threaded portion, nut, bolt, weld, adhesive, press fit, interference fit, or any combination thereof. In some examples, the rotor 372 and the accessory pulley 380 can be formed as a unitary structure. The rotor 372 is coupled to the accessory pulley 380 such that the rotor 372 and the accessory pulley 380 — and, by extension, the alternator shaft 366 coupled to the rotor 372 — can rotate in unison when the accessory pulley 380 is driven by the third drive belt 344.

[0112] As shown, unlike the shaft extension assembly 170 illustrated in FIGS. 1-4, the shaft extension assembly 370 lacks an idler pulley (for example, idler pulley 190). However, some examples of the shaft extension assembly 370 can include an idler pulley.

[0113] FIG. 10 is a cross-sectional view of an alternator assembly 460 comprising a shaft extension assembly 470 coupled to an alternator 462. The alternator 462 comprises an alternator housing 464 and an alternator shaft 466 extending from the alternator housing 464. A portion of the alternator shaft 466 having a length 466L extends from the alternator housing 464. The alternator shaft 466 has a diameter 466d. For simplicity and convenience, only a portion of the alternator housing 464 and the alternator shaft 466 are shown in FIG. 10.

[0114] The shaft extension assembly 470 comprises a rotor 472 extending along a central longitudinal axis 471 of the shaft extension assembly 470 and coupled to the alternator shaft 466, a stator 473 circumferentially surrounding at least a portion of the rotor 472 and coupled to the alternator housing 464, first and second bearings 478 and 479 disposed radially between the rotor 472 and the stator 473, an accessory pulley 480 coupled to the rotor 472, and a washer 484 and screw 486 coupling the accessory pulley 480 to the rotor 472.

[0115] As shown, the rotor 472 comprises a rod or shaft oriented along the central longitudinal axis 471 and having a first end portion 472a and a second end portion 472b. The rotor 472 is shown as comprising a hollow cavity extending in a longitudinal direction therethrough, wherein the hollow cavity has an internal diameter 472d. The internal diameter 472d can be from 5 mm to 30 mm, such as from 10 mm to 25 mm, 10 mm to 20 mm, and/or 10 mm to 15 mm. However, some examples of the rotor 472 can be solid structures without cavities. As shown, the radial thickness of the rotor 472 can change along the length (along central longitudinal axis 471) of the rotor 472. For example, the rotor 472 can be radially thicker at an intermediate portion 472c (between first and second end portions 472a and 472b) of the rotor 472 than at the first and second end portions 472a and 472b of the rotor 472. The rotor 472 can have a length 472L from 30 mm to 300 mm, from 60 mm to 270 mm, from 90 mm to 240 mm, from 120 mm to 210 mm, and/or from 120 mm to 180 mm. In some examples, the length 472L of the rotor 472 can be equal to or up to sixty times greater than the internal diameter 472d of the rotor 472.

[0116] The first end portion 472a of the rotor 472 is coaxial with and coupled to the alternator shaft 466. In some examples, the first end portion 472a and the alternator shaft 466 are fixedly coupled in the circumferential direction. For example, the end portion of the alternator shaft 466 can be disposed within the first end portion 472a of the rotor 472 such that the components form a sliding joint, including but not limited to a keyed joint, a spline joint, or a polygonal joint. The first end portion 472a of the rotor 472 can be coupled to the alternator shaft 466 using rivets, nuts, bolts, threaded portions, welds, adhesives, press fits, interference fits, or any combination thereof.

[0117] As shown, the stator 473 comprises a housing 474 comprising a first end portion 474a and a second end portion 474b opposite the first end portion 474a. The housing comprises a tube with at least a portion of the rotor 472 disposed therein. At least a portion of the rotor 472 is disposed within the stator 473.

[0118] The stator 473 is shown as further comprising a mounting flange 475 extending from the first end portion 474a of the housing 474. The mounting flange 475 is configured to facilitate the coupling of the alternator housing 364 to the shaft extension assembly 370, for example, using screws. However, other examples of the stator 473 can be coupled to the alternator housing 464 using one or more rivets, nuts, bolts, welds, adhesives, press fits, interference fits, or any combination thereof. In some examples, the housing 474 and the mounting flange 475 can be formed as a unitary structure. In some examples, the alternator housing 464 and the stator 473 can be formed as a unitary structure.

[0119] As shown, the shaft extension assembly 470 further comprises the first bearing 478 disposed radially between the rotor 472 and the stator 473. In some examples, the first bearing 478 can be a “floating bearing” which can freely move in the axial direction (along central longitudinal axis 471) relative to the rotor 472.

[0120] As shown, the shaft extension assembly 470 comprises the second bearing 479 disposed radially between the rotor 472 and the stator 473. In some examples, the second bearing 479 is a “fixed bearing” which maintains a fixed position in the axial direction (along central longitudinal axis 471) relative to the rotor 472.

[0121] As shown, the shaft extension assembly 470 further comprises the accessory pulley 480 coupled to the second end portion 472b of the rotor 472. In some examples, the accessory pulley 480 and the second end portion 472b of the rotor 472 can be fixedly coupled in the circumferential direction, for example, via a sliding joint. The accessory pulley 480 comprises a wheel with a grooved rim 482 around which a third drive belt 444 passes when the alternator assembly 460 is driven by the third drive belt 444. The accessory pulley 480 is shown as having a diameter 380d and a length 480L. The diameter 480d can range from 30 mm to 120 mm (for example, from 45 mm to 105 mm, from 60 mm to 90 mm, etc.). The length 480L can range from 10 mm to 60 mm (for example, from 20 mm to 50 mm, from 30 mm to 40 mm, etc.). Thus, the diameter 480d of the accessory pulley 480 can be 0.5 to 12 times (such as 0.5 to 1 times, 1 to 11 times, 2 to 10 times, 3 to 9 times, 4 to 7 times, 5 to 6 times, etc.) greater than the length 480L of the accessory pulley 480. As shown, a washer 484 and a screw 486 can be used to fasten the accessory pulley 480 to the rotor 472. However, the accessory pulley 480 can be coupled to the rotor 472 using a rivet, nut, bolt, threaded portion, weld, adhesive, press fit, interference fit, or any combination thereof. In some examples, the rotor 472 and the accessory pulley 480 can be formed as a unitary structure. The rotor 472 is coupled to the accessory pulley 480 such that the rotor 472 and the accessory pulley 480 — and, by extension, the alternator shaft 466 coupled to the rotor 472 — can rotate in unison when the accessory pulley 480 is driven by the third drive belt 444.

[0122] As shown, the shaft extension assembly 470 further comprises the sleeve 488 and the shaft nut 489. The sleeve 488 comprises a cylindrical tube configured to circumferentially surround the rotor 472. The shaft nut 489 can be coupled to the rotor 472 (for example, the first end portion 472a of the rotor 472) such that the shaft nut 289 cannot move axially relative to the rotor 472. As shown, the sleeve 488 is axially disposed between the second bearing 479 and the shaft nut 489, both of which are axially fixed, to prevent axial movement of the rotor 472 relative to the stator 473.

[0123] As shown, unlike the shaft extension assembly 170 illustrated in FIGS. 1-4, the shaft extension assembly 470 lacks an idler pulley (for example, idler pulley 190). However, some examples of the shaft extension assembly 470 can include an idler pulley.

[0124] FIG. 11 is a cross-sectional view of an alternator assembly 560. The alternator assembly 560 comprises an alternator 562 and a shaft extension assembly 570 coupled to the alternator 562. The alternator 562 comprises an alternator housing 564 and the alternator shaft 166 extending from the alternator housing 564. For convenience and simplicity, only the shaft extension assembly 570 and a portion of the alternator housing 564 are shown in cross-section. As shown, the alternator housing 564 comprises engine block mounting flanges 565 extending from the alternator housing

564. The engine block mounting flanges 565 are configured to facilitate the mounting of the alternator 562 to an engine block (for example, any of the engine blocks disclosed herein).

However, some examples of the alternator housing 564 can lack the engine block mounting flanges

565. The alternator housing 564 further comprises mounting holes 568 to facilitate the coupling of the shaft extension assembly 570 to the alternator housing 564 using screws 577.

[0125] The portion of the alternator shaft 566 extending from the alternator housing 564 has a length 566L and a diameter 566d.

[0126] As shown, the shaft extension assembly 570 comprises a rotor 572 coupled to the alternator shaft 566 and extending along central longitudinal axis 571, a stator 573 circumferentially disposed around at least a portion of the rotor 572, an accessory pulley 580 coupled to the rotor 572, a double bearing 578 disposed radially between the rotor 572 and the stator 573, and screws 577 coupling the stator 573 to the alternator housing 564.

[0127] As shown, the rotor 572 comprises a substantially cylindrical rod or shaft. However, certain examples of the rotor 572 can be tapered or otherwise non-cylindrical. The rotor 572 and the alternator shaft 566 can be fixedly coupled in the circumferential direction. The rotor 572 comprises a first end portion 572a having a recess configured to accept the alternator shaft 566 and a second end portion 572b coupled to the accessory pulley 580. The end portion of the alternator shaft 566 can be disposed within the first end portion 572a of the rotor 572 such that the components form a sliding joint, such as a keyed joint, a spline joint, or a polygonal joint that allow the alternator shaft 566 and rotor 572 to rotate in unison when torque is applied to the accessory pulley 580. However, the first end portion 572a of the rotor 572 can be coupled to the alternator shaft 566 using rivets, nuts, bolts, threaded portions, welds, adhesives, press fits, interference fits, or any combination thereof. The second end portion 572b is shown as coupled to the accessory pulley 180 using a screw 586. However, certain examples of the rotor 572 can be coupled to the accessory pulley 580 using rivets, nuts, bolts, threaded portions, welds, adhesives, press fits, interference fits, or any combination thereof. The rotor 572 is illustrated as being solid, but other examples of the rotor 572 can be hollow. The rotor 572 has a length 572L, which can range from 30 mm to 300 mm, from 60 mm to 270 mm, from 90 mm to 240 mm, from 120 mm to 210 mm, and/or from 120 mm to 180 mm. The rotor 572 has a diameter 572d.

[0128] As shown, the stator 573 comprises a substantially cylindrical tube 574 and a mounting flange 575 extending from a first end portion thereof. The mounting flange 575 comprises one or more through holes 576 which, when aligned with corresponding ones of the mounting holes 568 of the alternator housing 564, facilitate the coupling of the shaft extension assembly 570 to the alternator housing 564 using screws 577.

[0129] The double bearing 578 is disposed radially between the rotor 572 and the stator 573 to prevent radial movement of the rotor 572 relative to the stator 573. In certain examples, the double bearing 578 can be similar to the double bearing 378.

[0130] As shown, the shaft extension assembly 570 further comprises the accessory pulley 580 coupled to the second end portion 572b of the rotor 572. The accessory pulley 580 comprises a wheel with a grooved rim 582 around which a third drive belt 544 passes when the alternator assembly 560 is driven by the third drive belt 544. The accessory pulley 580 is shown as having a diameter 580d and a length 580L. The diameter 580d can range from 30 mm to 120 mm (for example, from 45 mm to 105 mm, from 60 mm to 90 mm, etc.). The length 580L can range from 10 mm to 60 mm (for example, from 20 mm to 50 mm, from 30 mm to 40 mm, etc.). Thus, the diameter 580d of the accessory pulley 580 can be 0.5 to 12 times (such as 0.5 to 1 times, 1 to 11 times, 2 to 10 times, 3 to 9 times, 4 to 7 times, 5 to 6 times, etc.) greater than the length 580L of the accessory pulley 580. As shown, a screw 586 can be used to fasten the accessory pulley 580 to the rotor 572. However, the accessory pulley 580 can be coupled to the rotor 572 using a rivet, nut, bolt, threaded portion, weld, adhesive, press fit, interference fit, or any combination thereof. In some examples, the rotor 572 and the accessory pulley 580 can be formed as a unitary structure. The rotor 572 is fixedly coupled in the circumferential direction to the accessory pulley 580 such that the rotor 572 and the accessory pulley 580 — and, by extension, the alternator shaft 566 coupled to the rotor 572 — can rotate in unison when the accessory pulley 580 is driven by the third drive belt 544. [0131] FIG. 12 is a cross-sectional view of a shaft extension assembly 670 of an alternator assembly 660. The alternator assembly 660 comprises the alternator 662, a shaft extension assembly 670, and an intermediate bracket 696 disposed between the alternator 662 and the shaft extension assembly 670.

[0132] The alternator 662 comprises an alternator housing 664 and the alternator shaft 666 extending from the alternator housing 664. The portion of the alternator shaft 666 extending from the alternator housing 664 has a length 666L and a diameter 666d. As shown, the alternator housing 664 comprises one or more intermediate bracket mounting flanges 665 extending from the alternator housing 664. The intermediate bracket mounting flanges 665 can be configured to facilitate the mounting of the intermediate bracket 696 to the alternator housing 664. Each of the intermediate bracket mounting flanges 665 comprises a through hole 668.

[0133] The intermediate bracket 696 comprises a plate with a first set of mounting holes 698a disposed on a first side of the plate and a second set of mounting holes 698b disposed on a second side of the plate. In certain examples, one or more of the first set of mounting holes 698a and one or more of the second set of mounting holes 698b can be threaded. Each of the first set of mounting holes 698a can be configured to accept a screw 677 for fastening the alternator 662 (more specifically, the intermediate bracket mounting flanges 665) to the intermediate bracket 696. Each of the second set of mounting holes 698b can be configured to accept a screw 677 for fastening the shaft extension assembly 670 (more specifically, a mounting flange 675 of the shaft extension assembly 670) to the intermediate bracket 696. The intermediate bracket 696 can be configured to be mounted to an engine block such that bending forces exerted on the shaft extension assembly 670 (for example, torque exerted by a third drive belt 644 on the shaft extension assembly 670) are transmitted to the engine block instead of to the alternator housing 664. In some examples, the intermediate bracket 696 is not affixed to the engine block and/or the power train and can instead be affixed to another portion of the vehicle. In some examples, transmitting bending forces to the engine block instead of the alternator housing 664 can beneficially reduce the need to redesign the alternator housing 664 to withstand such bending forces.

[0134] The shaft extension assembly 670 comprises a rotor 672 coupled to the alternator shaft 666, a stator 673 circumferentially surrounding the rotor 672, a first bearing 678 disposed radially between the rotor 672 and the stator 673, a second bearing 679 disposed radially between the rotor 672 and the stator 673, and an accessory pulley 680 coupled to the rotor 672.

[0135] The rotor 672 comprises a rod or shaft. The rotor 672 has a length 672L, which can range from 30 mm to 300 mm, from 60 mm to 270 mm, from 90 mm to 240 mm, from 120 mm to 210 mm, and/or from 120 mm to 180 mm. The rotor 672 has a diameter 672d. The rotor 672 is shown as being solid, but certain examples of the rotor 672 can be hollow. The rotor 672 is coupled at a first end portion 672a to the alternator shaft 666 and at a second end portion 672b to the accessory pulley 680. In some examples, the rotor 672 can be fixedly coupled in the circumferential direction to the alternator shaft 666 and/or the accessory pulley 680. For example, the end portion of the alternator shaft 666 can be disposed within the first end portion 672a of the rotor 672 such that the components form a sliding joint. However, the first end portion 672a of the rotor 672 can be coupled to the alternator shaft 666 using rivets, threaded portions, nuts, bolts, welds, adhesives, press fits, interference fits, or any combination thereof.

[0136] The stator 673 comprises a mounting flange 675 extending in a direction substantially perpendicular to the central longitudinal axis 671. The mounting flange 675 comprises one or more through holes 676 which, when aligned with a corresponding one of the second set of mounting holes 698b, can accept screws 677 therethrough for mounting the shaft extension assembly 670 to the intermediate bracket 696. In some examples, the stator 673 and the intermediate bracket 696 can be integrated as a single component.

[0137] As shown, the shaft extension assembly 670 further comprises the first bearing 678 disposed radially between the rotor 672 and the stator 673. In some examples, the first bearing 678 can be a “floating bearing” which can freely move in the axial direction (along central longitudinal axis 671) relative to the rotor 672.

[0138] As shown, the shaft extension assembly 670 comprises the second bearing 679 disposed radially between the rotor 672 and the stator 673. In some examples, the second bearing 679 can be a “fixed bearing” which maintains a fixed position in the axial direction (along central longitudinal axis 671) relative to the rotor 672.

[0139] As shown, the shaft extension assembly 670 further comprises the accessory pulley 680 coupled to the second end portion 672b of the rotor 672. The accessory pulley 680 comprises a wheel with a grooved rim 682 around which a third drive belt 644 passes when the alternator assembly 660 is driven by the third drive belt 644. The accessory pulley 680 is shown as having a diameter 680d and a length 680L. The diameter 680d can range from 30 mm to 120 mm (for example, from 45 mm to 105 mm, from 60 mm to 90 mm, etc.). The length 680L can range from 10 mm to 60 mm (for example, from 20 mm to 50 mm, from 30 mm to 40 mm, etc.). Thus, the diameter 680d of the accessory pulley 680 can be 0.5 to 12 times (such as 0.5 to 1 times, 1 to 11 times, 2 to 10 times, 3 to 9 times, 4 to 7 times, 5 to 6 times, etc.) greater than the length 680L of the accessory pulley 680. As shown, a screw 686 can be used to fasten the accessory pulley 680 to the rotor 672. However, the accessory pulley 680 can be coupled to the rotor 672 using a rivet, sliding joint, threaded portion, nut, bolt, weld, adhesive, press fit, interference fit, or any combination thereof. In some examples, the rotor 672 and the accessory pulley 680 can be formed as a unitary structure. The rotor 672 is coupled to the accessory pulley 680 such that the rotor 672 and the accessory pulley 680 — and, by extension, the alternator shaft 666 coupled to the rotor 672 — can rotate in unison when the accessory pulley 680 is driven by the third drive belt 644.

[0140] FIG. 13 is a cross-sectional view of an alternator assembly 760. The alternator assembly 760 comprises an alternator 762, a shaft extension assembly 770 coupled to the alternator 762, and an integrated altemator/shaft extension assembly housing 764 within which both the alternator 762 and at least a portion of the shaft extension assembly 770 are disposed.

[0141] As shown, the alternator 762 comprises an alternator shaft 766 extending in an axial direction (along central longitudinal axis 771) through a body of the alternator 762. The alternator shaft 766 has a length 766L and a diameter 766d.

[0142] As shown, the alternator assembly 760 further comprises alternator shaft bearings 769a and 769b disposed within the integrated alternator/shaft extension assembly housing 764 and on opposite axial sides of the body of the alternator 762. The alternator shaft bearings 769a and 769b can be similar to other bearings disclosed throughout this application. The alternator shaft bearings 769a and 769b can be configured to support opposite ends of the alternator shaft 766 and can help maintain alignment of the alternator shaft 766 relative to the shaft extension assembly 770.

[0143] As shown, the integrated altemator/shaft extension assembly housing 764 comprises a first portion 764a and a second portion 764b. The second portion 764b comprises a cylindrical tube 764c in which at least a portion of the shaft extension assembly 770 (for example, rotor 772) is disposed. In certain examples, the cylindrical tube 764c can have a similar function and shape as certain stators described throughout the present disclosure. The first portion 764a and the second portion 764b are coupled to each other using screws 767. Each of the first portion 764a and the second portion 764b comprise engine block mounting flanges 765 for mounting the alternator 762 to an engine block (for example, engine blocks similar to engine blocks 102 and 202). However, certain examples of the integrated altemator/shaft extension assembly housing 764 can lack the engine block mounting flanges 765. In some examples, packaging both the alternator 762 and the shaft extension assembly 770 in the integrated alternator/shaft extension assembly housing 764 can result in better alignment of the alternator 762 and the shaft extension assembly 770 and can provide for improved packaging of the alternator assembly 760. [0144] As shown, the shaft extension assembly 770 comprises a rotor 772, a first bearing 778 disposed radially between the rotor and the cylindrical tube 764c of the integrated altemator/shaft extension assembly housing 764, a second bearing 779 disposed radially between the rotor 772 and the cylindrical tube 764c of the integrated alternator/shaft extension assembly housing 764, and an accessory pulley 780 coupled to the rotor 772. One exemplary difference between the shaft extension assembly 770 and the shaft extension assemblies previously disclosed herein is that the shaft extension assembly 770 lacks a stator, which is replaced by the cylindrical tube 764c of the integrated alternator/shaft extension assembly housing 764.

[0145] The rotor 772 is coupled at a first end portion 772a to the alternator shaft 766 and at a second end portion 772b to the accessory pulley 780. The rotor 772 is shown as being solid, but certain examples of the rotor 772 can be hollow. The rotor 772 has a length 772L, which can range from 30 mm to 300 mm, from 60 mm to 270 mm, from 90 mm to 240 mm, from 120 mm to 210 mm, and/or 120 mm to 180 mm. The rotor 572 has a diameter 572d. and a diameter 772d.

[0146] As shown, the alternator assembly 760 further comprises a clutch 763 disposed between and coupling the alternator shaft 766 and the first end portion 772a of the rotor 772. The clutch 763 can couple the alternator shaft 766 and the rotor 772 such that torque can be transferred from the accessory pulley 780 to the alternator shaft 766. The second end portion 772b of the rotor 772 is coupled to the accessory pulley 780 using the screw 786.

[0147] As shown, the shaft extension assembly 770 further comprises the first bearing 778 disposed radially between the rotor 772 and the cylindrical tube 764c of the integrated alternator/shaft extension assembly housing 764. In some examples, the first bearing 778 can be a “floating bearing” which can freely move in the axial direction (along central longitudinal axis 771) relative to the rotor 772.

[0148] As shown, the shaft extension assembly 770 comprises the second bearing 779 disposed radially between the rotor 772 and the cylindrical tube 764c of the integrated altemator/shaft extension assembly housing 764. In some examples, the second bearing 779 can be a “floating bearing” which can freely move in the axial direction (along central longitudinal axis 771) relative to the rotor 772.

[0149] As shown, the shaft extension assembly 770 further comprises the accessory pulley 780 coupled to the second end portion 772b of the rotor 772. The accessory pulley 780 comprises a wheel with a grooved rim 782 around which a third drive belt 744 passes when the alternator assembly 760 is driven by the third drive belt 744. The accessory pulley 780 is shown as having a diameter 780d and a length 780L. The diameter 780d can range from 30 mm to 120 mm (for example, from 45 mm to 105 mm, from 60 mm to 90 mm, etc.). The length 780L can range from 10 mm to 60 mm (for example, from 20 mm to 50 mm, from 30 mm to 40 mm, etc.). Thus, the diameter 780d of the accessory pulley 780 can be 0.5 to 12 times (such as 0.5 to 1 times, 1 to 11 times, 2 to 10 times, 3 to 9 times, 4 to 7 times, 5 to 6 times, etc.) greater than the length 780L of the accessory pulley 780. As shown, a screw 786 can be used to fasten the accessory pulley 780 to the rotor 772. However, the accessory pulley 780 can be coupled to the rotor 772 using a rivet, threaded portion, nut, bolt, sliding joint, weld, adhesive, press fit, interference fit, or any combination thereof. In some examples, the rotor 772 and the accessory pulley 780 can be formed as a unitary structure. The rotor 772 is coupled to the accessory pulley 780 such that the rotor 772 and the accessory pulley 780 — and, by extension, the alternator shaft 766 coupled to the rotor 772 — can rotate in unison when the accessory pulley 780 is driven by the third drive belt 744.

[0150] FIG. 14 is a cross-sectional view of portion of an alternator assembly 860. The alternator assembly 860 comprises an alternator 862 and a shaft extension assembly 870 coupled to the alternator 862. For convenience and simplicity, only the shaft extension assembly 870 and a portion of the alternator 862 are shown in cross-section.

[0151] As shown, the alternator 862 comprises an alternator housing 864 and an alternator shaft 866 extending from the alternator housing 864. As shown, the alternator housing 864 comprises engine block mounting flanges 865 extending from the alternator housing 864. The engine block mounting flanges 865 are configured to facilitate the mounting of the alternator 862 to an engine block. However, some examples of the alternator housing 864 can lack the engine block mounting flanges 865. The portion of the alternator shaft 866 extending from the alternator housing 864 has a length 866L and a diameter 866d.

[0152] As shown, the shaft extension assembly 870 comprises a rotor 872 extending along central longitudinal axis 871 and coupled to the alternator shaft 866, a stator 873 circumferentially disposed around at least a portion of the rotor 872, the accessory pulley 880 coupled to the rotor

872, first and second bearings 878 and 879 disposed radially between the rotor 872 and the stator

873, and screws 877 coupling the stator 873 to the alternator housing 864.

[0153] As shown, the rotor 872 comprises a substantially cylindrical rod or shaft. However, certain examples of the rotor 872 can be tapered or otherwise non-cylindrical. The rotor 872 comprises a first end portion 872a coupled to the alternator shaft 866 via a clutch 863 and a second end portion 872b coupled to the accessory pulley 880. The second end portion 872b is shown as coupled to the accessory pulley 880 using a screw 886. However, certain examples of the rotor 872 can be coupled to the accessory pulley 880 using rivets, welds, threaded portions, nuts, bolts, sliding joints, adhesives, press fits, interference fits, or any combination thereof. The rotor 872 is illustrated as being solid, but other examples of the rotor 872 can be hollow. The rotor 872 has a length 872L, which can range from 30 mm to 300 mm, from 60 mm to 270 mm, from 90 mm to 240 mm, from 120 mm to 210 mm, and/or from 120 mm to 180 mm, and a diameter 872d.

[0154] As shown, the stator 873 comprises a substantially cylindrical tube 874 and a mounting flange 875 extending from a first end portion 874a thereof. The mounting flange 875 comprises one or more through holes 876 which, when aligned with corresponding ones of the mounting holes 868 of the alternator housing 864, facilitate the coupling of the shaft extension assembly 870 to the alternator housing 864 using screws 877.

[0155] As shown, the shaft extension assembly 870 further comprises the accessory pulley 880 coupled to the second end portion 872b of the rotor 872. The accessory pulley 880 comprises a wheel with a grooved rim 882 around which a third drive belt 844 passes when the alternator assembly 860 is driven by the third drive belt 844. The accessory pulley 880 is shown as having a diameter 880d and a length 880L. The diameter 880d can range from 30 mm to 120 mm (for example, from 45 mm to 105 mm, from 60 mm to 90 mm, etc.). The length 880L can range from 10 mm to 60 mm (for example, from 20 mm to 50 mm, from 30 mm to 40 mm, etc.). Thus, the diameter 880d of the accessory pulley 880 can be 0.5 to 12 times (such as 0.5 to 1 times, 1 to 11 times, 2 to 10 times, 3 to 9 times, 4 to 7 times, 5 to 6 times, etc.) greater than the length 880L of the accessory pulley 880. As shown, a screw 886 can be used to fasten the accessory pulley 880 to the rotor 872. However, the accessory pulley 880 can be coupled to the rotor 872 using a rivet, nut, bolt, threaded portion, sliding joint, weld, adhesive, press fit, interference fit, or any combination thereof. In some examples, the rotor 872 and the accessory pulley 880 can be formed as a unitary structure. The rotor 872 is coupled to the accessory pulley 880 such that the rotor 872 and the accessory pulley 880 — and, by extension, the alternator shaft 866 fixedly coupled to the rotor 872 — can rotate in unison when the accessory pulley 880 is driven by the third drive belt 844.

[0156] FIG. 15 is a cross-sectional view of portion of an alternator assembly 960. The alternator assembly 960 comprises an alternator 962 and a shaft extension assembly 970 coupled to the alternator 962. For convenience and simplicity, only the shaft extension assembly 970 and a portion of the alternator 962 are shown in cross-section.

[0157] As shown, the alternator 962 comprises an alternator housing 964 and an alternator shaft 966 extending from the alternator housing 964. The alternator housing 964 comprises engine block mounting flanges 965 for mounting the alternator assembly 960 to an engine block (for example, engine blocks similar to engine blocks 102 and 202). However, certain examples of the alternator housing 964 can lack the engine block mounting flanges 965. The portion of the alternator shaft 966 extending from the alternator housing 964 has a length 966L and a diameter 966d.

[0158] As shown, the shaft extension assembly 970 comprises a rotor 972, an in-line gearbox 963 disposed between the rotor 972 and the alternator shaft 966, a stator 973 circumferentially disposed around at least a portion of the rotor 972, an accessory pulley 980 coupled to the rotor 972, first and second bearings 978 and 979 disposed radially between the rotor 972 and the stator 973, and screws 977 coupling the stator 973 to the alternator housing 964.

[0159] One exemplary difference between the alternator assembly 960 and the alternator assembly 860 shown in FIG. 14 is that the shaft extension assembly 970 of the alternator assembly 960 comprises the in-line gearbox 963 disposed between the alternator shaft 966 and the rotor 972 instead of a clutch (such as clutch 863). The in-line gearbox 963 comprises an output shaft 963a and an input shaft 963b, both of which are aligned with a central longitudinal axis 971 of the alternator assembly 960. The in-line gearbox 963 is illustrated as a planetary gearbox in a planetary configuration, in which the input shaft 963b is coupled to a sun gear and the output shaft 963a is coupled to a carrier. However, other examples of the in-line gearbox 963 be a planetary gearbox in any other configuration (for example, a star or solar configuration). Furthermore, other examples of the in-line gearbox 963 are not limited to planetary gearboxes and can comprise any combination of spur gears, bevel gears, worm gears, spiral bevel gears, and/or internal toothing. In certain examples, incorporating the in-line gearbox 963 into the alternator assembly 960 can beneficially allow for the speed of the alternator shaft 966 or the torque on the alternator shaft 966 to be adjusted or controlled.

[0160] The output shaft 963a is coupled to the alternator shaft 966, for example, using a sliding joint. The alternator shaft 966 can comprise a recess (for example, a keyed recess) configured to accept a portion of the output shaft 1063a therein. However, the alternator shaft 966 and output shaft 963a can be coupled using rivets, nuts, bolts, threaded portions, welds, adhesives, press fits, interference fits, or any combination thereof.

[0161] As shown, the rotor 972 comprises a substantially cylindrical rod or shaft. However, certain examples of the rotor 972 can be tapered or otherwise non-cylindrical. The rotor 972 comprises a first end portion 972a coupled to the input shaft 963b of the in-line gearbox 963 and a second end portion 972b coupled to the accessory pulley 980. In some examples, the rotor 972 and the input shaft 963b can be fixedly coupled in the circumferential direction using a sliding joint. For example, the rotor 972 can comprise a recess (for example, a keyed recess) configured to accept a portion of the input shaft 963b therein. However, the rotor 972 and input shaft 963b can be coupled using rivets, welds, adhesives, press fits, interference fits, or any combination thereof. The second end portion 972b is shown as coupled to the accessory pulley 980 using a screw 986. However, certain examples of the rotor 972 can be coupled to the accessory pulley 980 using rivets, welds, adhesives, press fits, interference fits, or any combination thereof. The rotor 972 is illustrated as being solid, but other examples of the rotor 972 can be hollow. The rotor 972 has a length 972L, which can range from 30 mm to 300 mm, from 60 mm to 270 mm, from 90 mm to 240 mm, from 120 mm to 210 mm, and/or from 120 mm to 180 mm, and a diameter 972d.

[0162] As shown, the stator 973 comprises a substantially cylindrical tube 974 and a mounting flange 975 extending from a first end portion 974a thereof. The mounting flange 975 comprises one or more through holes 976 which, when aligned with corresponding ones of the mounting holes 968 of the alternator housing 964, facilitate the coupling of the shaft extension assembly 970 to the alternator housing 964 using screws 977.

[0163] As shown, the shaft extension assembly 970 further comprises the accessory pulley 980 coupled to the second end portion 972b of the rotor 972. The accessory pulley 980 comprises a wheel with a grooved rim 982 around which a third drive belt 944 passes when the alternator assembly 960 is driven by the third drive belt 944. The accessory pulley 980 is shown as having a diameter 980d and a length 980L. The diameter 980d can range from 30 mm to 120 mm (for example, from 45 mm to 105 mm, from 60 mm to 90 mm, etc.). The length 980L can range from 10 mm to 60 mm (for example, from 20 mm to 50 mm, from 30 mm to 40 mm, etc.). Thus, the diameter 980d of the accessory pulley 980 can be 0.5 to 12 times (such as 0.5 to 1 times, 1 to 11 times, 2 to 10 times, 3 to 9 times, 4 to 7 times, 5 to 6 times, etc.) greater than the length 980L of the accessory pulley 980. As shown, a screw 986 can be used to fasten the accessory pulley 980 to the rotor 972. However, the accessory pulley 980 can be coupled to the rotor 972 using a rivet, weld, sliding joint, nut, bolt, threaded portion, adhesive, press fit, interference fit, or any combination thereof. In some examples, the rotor 972 and the accessory pulley 980 can be formed as a unitary structure. The rotor 972 is coupled to the accessory pulley 980 such that the rotor 972 and the accessory pulley 980 — and, by extension, the alternator shaft 966 fixedly coupled to the rotor 972 — can rotate in unison when the accessory pulley 980 is driven by the third drive belt 944.

[0164] FIG. 16 is a cross-sectional view of an alternator assembly 1060. The alternator assembly 1060 comprises an alternator 1062 and a shaft extension assembly 1070 coupled to the alternator 1062. For convenience and simplicity, only the shaft extension assembly 1070 and a portion of the alternator 1062 are shown in cross-section. [0165] As shown, the alternator 1062 comprises an alternator housing 1064 and an alternator shaft 1066 extending from the alternator housing 1064. The portion of the alternator shaft 1066 extending from the alternator housing 1064 has a length 1066L and a diameter 1066d.

[0166] As shown, the alternator housing 1064 comprises engine block mounting flanges 1065 extending from the alternator housing 1064. The engine block mounting flanges 1065 are configured to facilitate the mounting of the alternator 1062 to an engine block. However, some examples of the alternator housing 1064 can lack the engine block mounting flanges 1065. The alternator housing 1064 further comprises mounting holes 1068 to facilitate the coupling of the shaft extension assembly 1070 to the alternator housing 1064 using screws 1077.

[0167] As shown, the shaft extension assembly 1070 comprises a rotor 1072, an offset gearbox 1063 disposed between the rotor 1072 and the alternator shaft 1066, a stator 1073 circumferentially disposed around at least a portion of the rotor 1072, an accessory pulley 1080 fixedly coupled to the rotor 1072, first and second bearings 1078 and 1079 disposed radially between the rotor 1072 and the stator 1073, and screws 1077 coupling the stator 1073 to the alternator housing 1064.

[0168] One exemplary difference between the alternator assembly 1060 and the alternator assembly 960 shown in FIG. 15 is that the shaft extension assembly 1070 of the alternator assembly 1060 comprises the offset gearbox 1063 disposed between the alternator shaft 1066 and the rotor 1072 instead of an in-line gearbox (for example, in-line gearbox 963). The offset gearbox 1063 comprises an output shaft 1063 a and an input shaft 1063b. The output shaft 1063 a is aligned with a first longitudinal axis 1071a and is coupled to the alternator shaft 1066. The alternator shaft 1066 can comprise a sliding joint, for example, a keyed recess configured to accept an end portion of the output shaft 1063a therein. However, the alternator shaft 1066 and output shaft 1063a can be coupled using rivets, welds, threaded portions, nuts, bolts, adhesives, press fits, interference fits, or any combination thereof. The input shaft 1063b is aligned with a second longitudinal axis 1071b and is = coupled to the rotor 1072. The rotor 1072 can comprise a sliding joint, for example, a keyed recess at a first end portion 1072a thereof configured to accept an end portion of the input shaft 1063b therein. However, the rotor 1072 and input shaft 1063b can be coupled using rivets, nuts, bolts, threaded portions, welds, adhesives, press fits, interference fits, or any combination thereof. Similar to the in-line gearbox 963, the offset gearbox 1063 can beneficially allow for the speed of the alternator shaft 1066 or the torque exerted on the alternator shaft 1066 to be adjusted or controlled.

[0169] As shown, the rotor 1072 comprises a substantially cylindrical rod or shaft. However, certain examples of the rotor 1072 can be tapered or otherwise non-cylindrical. The rotor 1072 comprises the first end portion 1072a coupled to the input shaft 1063b of the offset gearbox 1063 and a second end portion 1072b coupled to the accessory pulley 1080. The first end portion 1072a and the input shaft 1063b can be fixedly coupled in the circumferential direction, for example, using a sliding joint. The second end portion 1072b is shown as coupled to the accessory pulley 1080 using a screw 1086. However, certain examples of the rotor 1072 can be coupled to the accessory pulley 1080 using rivets, welds, adhesives, press fits, interference fits, or any combination thereof. The rotor 1072 is illustrated as being solid, but other examples of the rotor 1072 can be hollow. The rotor 1072 has a length 1072L, which can range from 30 mm to 300 mm, from 60 mm to 270 mm, from 90 mm to 240 mm, from 120 mm to 210 mm, and/or 120 mm to 180 mm, and a diameter 1072d.

[0170] As shown, the stator 1073 comprises a housing 1074 in which at least the offset gearbox 1063 and a portion of the rotor 1072 are disposed. The stator 1073 further comprises through holes 1076 which, when aligned with corresponding mounting holes 1068 of the alternator housing 1064, can facilitate the coupling of the alternator 1062 to the shaft extension assembly 1070.

[0171] As shown, the shaft extension assembly 1070 further comprises the accessory pulley 1080 fixedly coupled to the second end portion 1072b of the rotor 1072. The accessory pulley 1080 comprises a wheel with a grooved rim 1082 around which a third drive belt 1044 passes when the alternator assembly 1060 is driven by the third drive belt 1044. The accessory pulley 1080 is shown as having a diameter 1080d and a length 1080L. The diameter 1080d can range from 30 mm to 120 mm (for example, from 45 mm to 105 mm, from 60 mm to 90 mm, etc.). The length 1080L can range from 10 mm to 60 mm (for example, from 20 mm to 50 mm, from 30 mm to 40 mm, etc.). Thus, the diameter 1080d of the accessory pulley 1080 can be 0.5 to 12 times (such as 0.5 to 1 times, 1 to 11 times, 2 to 10 times, 3 to 9 times, 4 to 7 times, 5 to 6 times, etc.) greater than the length 1080L of the accessory pulley 1080. As shown, a screw 1086 can be used to fasten the accessory pulley 1080 to the rotor 1072. However, the accessory pulley 1080 can be coupled to the rotor 1072 using a rivet, nut, bolt, threaded portion, sliding joint, weld, adhesive, press fit, interference fit, or any combination thereof. In some examples, the rotor 1072 and the accessory pulley 1080 can be formed as a unitary structure. The rotor 1072 is coupled to the accessory pulley 1080 such that the rotor 1072 and the accessory pulley 1080 — and, by extension, the alternator shaft 1066 coupled to the rotor 1072 — can rotate in unison when the accessory pulley 1080 is driven by the third drive belt 1044.

[0172] In some examples, the engine assembly can be initially built to include any one or any combination of the alternator assemblies and/or shaft extension assemblies disclosed herein. [0173] FIG. 17 illustrates an engine assembly 1100 comprising an engine block 1102, a FEAD 1110 mounted to a front portion of the engine block 1102, and an alternator assembly 1160 mounted to a cold side 1106 of the engine block 1102.

[0174] The FEAD 1110 comprises a first belt layer 1120, a second belt layer 1130 disposed forward of the first belt layer 1120, and a third belt layer 1140 disposed forward of the second belt layer 1130. The first belt layer 1120 can comprise a first drive pulley, a first drive belt 1124 engaged with the first drive pulley, and a first accessory pulley 1126 coupled to the first drive belt 1124. The second belt layer 1130 can comprise a second drive pulley, a second drive belt 1134 engaged with the second drive pulley, a second accessory pulley 1136 coupled to the second drive belt 1134, and a belt tensioner 1138 engaged with the second drive belt 1134. The third belt layer 1140 of the FEAD 1110 comprises a third drive pulley 1142, a third drive belt 1144 coupled to the third drive pulley 1142, a belt tensioner 1148 engaged with the third drive belt 1144, and an alternator assembly 1160 mounted to the cold side 1106 of the engine block 1102 and driven by the third drive belt 1144. The engine assembly 1100 can further comprise an engine front legs bracket 1150 coupled to a front portion of the engine block 1102.

[0175] FIG. 18 is a perspective view of a portion of the alternator assembly 1160. The alternator assembly 1160 comprises an alternator 1162, a rear cable bracket 1163, alternator cables 1165a and 1165b extending from the alternator 1162 and coupled to the rear cable bracket 1163 , an ear mount bracket 1167, and a shaft extension assembly 1170 coupling the alternator 1162 to the third drive belt 1144 of the third belt layer 1140. The shaft extension assembly 1170 can be similar to other shaft extension assemblies disclosed herein (for example, shaft extension assembly 670). One exemplary difference between the ear mount bracket 1167 of FIG. 18 and the ear mount bracket 267 of FIG. 7 is that, similar to the intermediate bracket 696, the ear mount bracket 1167 is disposed between the shaft extension assembly 1170 and the alternator 1162. The ear mount bracket 1167 is shown as directly coupled to the engine block 1102, but some examples of the ear mount bracket 1167 can be coupled to any other fixation point on the engine assembly 1100. Such an ear mount bracket 1167 can beneficially help transfer bending stresses to the engine block 1102 instead of to the alternator 1162.

[0176] In some examples, an engine assembly can be initially constructed or subsequently retrofitted to include any one or any combination of the alternator assemblies and/or shaft extension assemblies disclosed herein. In some examples, an exemplary method of constructing or retrofitting an engine assembly can include: (1) mounting a shaft extension assembly to an alternator to form an alternator assembly, (2) coupling the alternator assembly to an engine block (such as engine block 102), and (3) coupling the alternator assembly to a third drive belt (such as third drive belt 144) of the engine assembly. In some examples in which the exemplary engine assembly lacks a third belt layer, the method can optionally include, prior to coupling the alternator assembly to the third drive belt, coupling a third drive pulley (such as drive pulley 144) to the engine block (for example, a crankshaft of engine block 102) and coupling a third drive belt (such as third drive belt 144) to the third drive pulley. In some examples, the method can optionally further include, prior to coupling the alternator assembly to the third drive belt, coupling a third belt tensioner (such as third belt tensioner 148) to the engine block 102. In some examples, the method can optionally further include, after coupling the alternator assembly to the third drive belt, coupling a second alternator assembly to the third drive belt. In some examples, constructing an engine assembly to add one or more of the disclosed alternator assemblies can beneficially allow the engine assembly to generate sufficient electrical power to meet certain electrical power requirements.

Additional Examples of the Disclosed Technology

[0177] In view of the above-described implementations of the disclosed subject matter, this application discloses the additional examples enumerated below. It should be noted that one feature of an example in isolation or more than one feature of the example taken in combination and, optionally, in combination with one or more features of one or more further examples are further examples also falling within the disclosure of this application.

[0178] Example 1. An engine assembly can comprise an engine block and a front end accessory drive coupled to a front end portion of the engine block. The front end accessory drive can comprise a first belt layer, a second belt layer disposed forward of the first belt layer; and a third belt layer disposed forward of the second belt layer. The third belt layer can comprise a drive belt, an alternator, an alternator shaft extending therefrom, and a shaft extension assembly coupled to the alternator shaft, wherein the shaft extension assembly is engaged with the drive belt and coupled to the alternator shaft.

[0179] Example 2. The engine assembly of any example herein, particularly example 1 , wherein the shaft extension assembly comprises a rotor comprising a first end portion coupled to the alternator shaft and a second end portion coupled to an accessory pulley, wherein the accessory pulley is configured to engage the drive belt.

[0180] Example 3. The engine assembly of any example herein, particularly example 2, wherein the first end portion of the rotor comprises a recess configured to accept an end portion of the alternator shaft therein. [0181] Example 4. The engine assembly of any example herein, particularly any one of examples 2-3, wherein the rotor and the alternator shaft form a sliding joint.

[0182] Example 5. The engine assembly of any example herein, example 2, wherein the shaft extension assembly further comprises a clutch coupling the rotor to the alternator shaft.

[0183] Example 6. The engine assembly of any example herein, particularly any one of examples 1-5, wherein the alternator is coupled to a cold side of the engine block.

[0184] Example 7. The engine assembly of any example herein, particularly any one of examples 1-5, wherein the alternator is coupled to a hot side of the engine block.

[0185] Example 8. The engine assembly of any example herein, particularly any one of examples 1-7, further comprising a mounting plate disposed between the alternator and the engine block.

[0186] Example 9. The engine assembly of any example herein, particularly any one of examples 1-8, wherein the alternator is configured to generate at least 12 kW of electrical power when driven by the drive belt of the third belt layer.

[0187] Example 10. The engine assembly of any example herein, particularly any one of examples 1-9, wherein the alternator is configured to generate at least 20 kW of electrical power when driven by the drive belt of the third belt layer.

[0188] Example 11. The engine assembly of any example herein, particularly any one of examples 1-10, wherein the shaft extension assembly comprises an idler pulley configured to engage at least one of the first belt layer and the second belt layer.

[0189] Example 12. The engine assembly of any example herein, particularly any one of examples 1-11, wherein the third belt layer further comprises a belt tensioner configured to tension the third belt layer.

[0190] Example 13. The engine assembly of any example herein, particularly example 12, further comprising an engine front legs bracket, wherein the belt tensioner is mounted to the engine front legs bracket.

[0191] Example 14. An alternator assembly can comprise an alternator housing, and alternator shaft extending from the alternator housing, a shaft extension assembly coupled to the alternator shaft, and an accessory pulley coupled to the second end portion of the rotor. The shaft extension assembly can comprise a rotor having a first end portion coupled to the alternator shaft and a second end portion opposite the first end portion. [0192] Example 15. The alternator assembly of any example herein, particularly example 14, wherein the first end portion of the rotor is fixedly coupled in a circumferential direction to the alternator shaft.

[0193] Example 16. The alternator assembly of any example herein, particularly any one of examples 14-15, wherein the first end portion of the rotor comprises a recess configured to accept an end portion of the alternator shaft therein.

[0194] Example 17. The alternator assembly of any example herein, particularly any one of examples 14-16, wherein the first end portion of the rotor and the alternator shaft form a sliding joint.

[0195] Example 18. The alternator assembly of any example herein, particularly example 14, further comprising a gearbox disposed between the rotor and the alternator shaft, the gearbox comprising an input shaft coupled to the rotor and an output shaft coupled to the alternator shaft.

[0196] Example 19. The alternator assembly of any example herein, particularly example 18, wherein the gearbox is an in-line gearbox.

[0197] Example 20. The alternator assembly of any example herein, particularly example 18, wherein the gearbox is an offset gearbox.

[0198] Example 21. The alternator assembly of any example herein, particularly any one of examples 14-20, further comprising an ear mount bracket disposed between the alternator housing and the shaft extension assembly.

[0199] Example 22. The alternator assembly of any example herein, particularly any one of examples 14-20, wherein the alternator housing is directly coupled to the shaft extension assembly.

[0200] Example 23. A shaft extension assembly for an alternator comprising a rotor, an accessory pulley, and a stator. The rotor can comprise a first end portion configured to be coupled to a shaft of the alternator and a second end portion disposed opposite the first end portion. The accessory pulley can be coupled to the second end portion of the rotor. The stator can be circumferentially disposed around at least a portion of the rotor.

[0201] Example 24. The shaft extension assembly of any example herein, particularly example

23, further comprising a first bearing disposed radially between the rotor and the stator.

[0202] Example 25. The shaft extension assembly of any example herein, particularly example

24, further comprising a second bearing disposed radially between the rotor and the stator. [0203] Example 26. The shaft extension assembly of any example herein, particularly any one of examples 23-25, further comprising an idler pulley circumferentially disposed around the stator.

[0204] Example 27. The shaft extension assembly of any example herein, particularly example 26, further comprising a bearing disposed radially between the idler pulley and the stator.

[0205] Example 28. The shaft extension assembly of any example herein, particularly any one of examples 23-27, wherein the stator comprises a first end portion and a second end portion opposite the first end portion, and wherein the stator tapers from the first end portion to the second end portion.

[0206] Example 29. The shaft extension assembly of any example herein, particularly any one of examples 23-28, wherein the first end portion of the rotor comprises a recess configured to accept the shaft of the alternator therein.

[0207] Example 30. The shaft extension assembly of any example herein, particularly example 29, wherein the recess is a keyed recess.

[0208] Example 31. A method of constructing an engine assembly comprising mounting a shaft extension assembly to an alternator to form an alternator assembly, coupling the alternator assembly to an engine block of the engine assembly, and coupling the alternator assembly to a third drive belt of the engine assembly.

[0209] Example 32. The method of any example herein, particularly example 31, further comprising, prior to coupling the alternator assembly to a third drive belt of the engine assembly, coupling a third drive pulley to the engine assembly and coupling the third drive belt to the third drive pulley.

[0210] Example 33. The method of any example herein, particularly examples 31-32, further comprising, after coupling the alternator to the third drive belt, coupling a second alternator assembly to the third drive belt of the engine assembly.

[0211] The features described herein with regard to any example can be combined with other features described in any one or more of the other examples, unless otherwise stated. For example, any one or more of the features of one engine assembly can be combined with any one or more features of another engine assembly. As another example, any one or more features of one alternator assembly can be combined with any one or more features of another alternator assembly. As another example, any one or more features of one shaft extension assembly can be combined with any one or more features of another shaft extension assembly. [0212] In view of the many possible ways in which the principles of the disclosure may be applied, it should be recognized that the illustrated configurations depict examples of the disclosed technology and should not be taken as limiting the scope of the disclosure nor the claims. Rather, the scope of the claimed subject matter is defined by the following claims and their equivalents.

Claims

We claim:

1. An engine assembly comprising: an engine block; and a front end accessory drive coupled to a front end portion of the engine block, the front end accessory drive comprising: a first belt layer; a second belt layer disposed forward of the first belt layer; and a third belt layer disposed forward of the second belt layer, the third belt layer comprising a drive belt, an alternator, an alternator shaft extending therefrom, and a shaft extension assembly coupled to the alternator shaft, wherein the shaft extension assembly is engaged with the drive belt and coupled to the alternator shaft.

2. The engine assembly of claim 1 , wherein the shaft extension assembly comprises a rotor comprising a first end portion coupled to the alternator shaft and a second end portion coupled to an accessory pulley, wherein the accessory pulley is configured to engage the drive belt of the third belt layer.

3. The engine assembly of claim 2, wherein the first end portion of the rotor comprises a recess configured to accept an end portion of the alternator shaft therein.

4. The engine assembly of claim 2, wherein the shaft extension assembly further comprises a clutch coupling the rotor to the alternator shaft.

5. The engine assembly of claim 1 , wherein the alternator is configured to generate at least 12 kW of electrical power when driven by the drive belt of the third belt layer.

6. The engine assembly of claim 1 , wherein the alternator is configured to generate at least 20 kW of electrical power when driven by the drive belt of the third belt layer.

7. The engine assembly of claim 1 , wherein the shaft extension assembly comprises an idler pulley configured to engage at least one of the first belt layer and the second belt layer.

8. An alternator assembly comprising: an alternator housing; an alternator shaft extending from the alternator housing; and a shaft extension assembly coupled to the alternator shaft, the shaft extension assembly comprising a rotor having a first end portion coupled to the alternator shaft and a second end portion opposite the first end portion, and an accessory pulley coupled to the second end portion of the rotor.

9. The alternator assembly of claim 8, wherein the first end portion of the rotor is fixedly coupled in a circumferential direction to the alternator shaft.

10. The alternator assembly of claim 8, wherein the first end portion of the rotor comprises a recess configured to accept an end portion of the alternator shaft therein.

11. The alternator assembly of claim 8, wherein the first end portion of the rotor and the alternator shaft form a sliding joint.

12. The alternator assembly of claim 8, further comprising a gearbox disposed between the rotor and the alternator shaft, the gearbox comprising an input shaft coupled to the rotor and an output shaft coupled to the alternator shaft.

13. The alternator assembly of claim 8, further comprising an ear mount bracket disposed between the alternator housing and the shaft extension assembly.

14. The alternator assembly of claim 8, wherein the alternator housing is directly coupled to the shaft extension assembly.

15. A shaft extension assembly for an alternator comprising: a rotor comprising: a first end portion configured to be coupled to a shaft of the alternator; and a second end portion disposed opposite the first end portion; an accessory pulley coupled to the second end portion of the rotor; and a stator circumferentially disposed around at least a portion of the rotor.

16. The shaft extension assembly of claim 15, further comprising a bearing disposed radially between the rotor and the stator.

17. The shaft extension assembly claim 15, further comprising an idler pulley circumferentially disposed around the stator.

18. The shaft extension assembly of claim 17, further comprising a bearing disposed radially between the idler pulley and the stator.

19. The shaft extension assembly of claim 15, wherein the stator comprises a first end portion and a second end portion opposite the first end portion, and wherein the stator tapers from the first end portion to the second end portion.

20. The shaft extension assembly of claim 15, wherein the first end portion of the rotor comprises a keyed recess configured to accept the shaft of the alternator therein.

21. A method of constructing an engine assembly comprising: mounting a shaft extension assembly to an alternator to form an alternator assembly; coupling the alternator assembly to an engine block of the engine assembly; and coupling the alternator assembly to a third drive belt of the engine assembly.

22. The method of claim 21 , further comprising, prior to coupling the alternator assembly to a third drive belt of the engine assembly: coupling a third drive pulley to the engine assembly; and coupling the third drive belt to the third drive pulley.

23. The method of claim 21 , further comprising, after coupling the alternator to the third drive belt: coupling a second alternator assembly to the third drive belt of the engine assembly.