Electric motors mounted on the final drive unit of tracked tractors

Abstract

A crawler tractor includes a frame housing defining an interior cavity extending to an exterior aperture, a motor module, and a final drive assembly. The motor module includes a motor housing having a flanged end, and a rotor shaft extending through the flanged end. The flanged end is mounted to an outer mounting surface of the frame housing surrounding the exterior aperture such that the motor module extends through the exterior aperture and is retained within the interior cavity of the frame housing. The final drive assembly is mounted to the flanged end and includes a gear set in operative engagement with the rotor shaft for motorized operation of the final drive assembly.

Description

Technical Field

[0001] The present invention relates generally to an electric motor module and, more particularly, to a frame-mounted electric motor module for a track-type work machine. Background Art

[0002] An electric drive unit may be used as a source of drive power in a vehicle, such as an off-road tracked work machine (e.g., a tracked tractor), a highway truck, or an automobile. The electric drive unit may supplement the drive power provided by an internal combustion engine, or the electric drive unit may provide all of the drive power for the vehicle. Using an electric drive unit to supplement or replace an internal combustion engine may reduce emissions generated during vehicle operation. In addition, the electric drive unit may increase the fuel efficiency of the vehicle. In operation, the electric drive motor typically generates an output torque that is transmitted to a ground engaging member on the machine, such as a track on a tracked tractor, using a final drive unit.

[0003] Some machines, such as track-type tractors, typically include a differential steering arrangement between an electric motor and ground engaging devices disposed on the machine. The differential steering arrangement is operable to vary the relative speeds of the ground engaging devices in order to steer the machine. For example, U.S. Patent Application Publication No. 2016 / 0096563 describes an electric drive retrofit kit that includes an electric motor module that is mountable in a frame housing and operably connected to a final drive assembly mounted on the frame housing via a planetary gear assembly that provides differential steering for a track-type tractor by allowing adjustment of the rotational speeds of the final drive assemblies relative to each other.

[0004] In other embodiments, multiple drive motors may be provided to individually drive opposing ground engaging devices. For example, U.S. Pat. No. 7,309,300 describes an electric drive system for a track-type work machine having multiple electric motors. However, the space requirements for the individual motors and drive devices are high and may limit the ability to modify or otherwise utilize a frame housing of the original size and configuration for a similar machine powertrain.

[0005] The foregoing background discussion is intended only to aid the reader. It is not intended to limit the innovations described herein, nor is it intended to limit or extend the prior art discussed. Therefore, the foregoing discussion should not be used to indicate that any particular element of an existing system is not suitable for use with the innovations described herein, nor is it intended to indicate that any element is necessary in implementing the innovations described herein. The implementation and application of the innovations described in the present invention are defined by the appended claims. Summary of the invention

[0006] An exemplary track-type tractor includes a frame housing defining an interior cavity extending to a first exterior aperture, a first motor module, and a first final drive assembly. The first motor module includes a first motor housing having a first flanged end, and a first rotor shaft extending through the first flanged end. The first flanged end is mounted to a first exterior mounting surface of the frame housing surrounding the first exterior aperture such that the first motor module extends through the first exterior aperture and is retained within the frame housing interior cavity. The first final drive assembly is mounted to the first flanged end and includes a gear set in operative engagement with the first rotor shaft for motorized operation of the first final drive assembly.

[0007] In an exemplary method of installing an electric drive system in a frame housing of a track-type tractor, a first motor housing of a first motor module is inserted through a first outer aperture in the frame housing such that the first motor housing extends into an interior cavity of the frame housing and a first rotor shaft of the first motor module extends outside the frame housing. A first flanged end of the first motor housing is mounted to a first outer mounting surface of the frame housing surrounding the first outer aperture. A first final drive assembly is mounted to the first flanged end such that the first final drive assembly is in operative engagement with the first rotor shaft for motorized operation of the first final drive assembly.

[0008] An exemplary electric drive system retrofit kit for a track-type tractor includes a motor module and a final drive assembly. The motor module includes a motor housing having a flanged end, and a rotor shaft extending through the flanged end, the flanged end including a first set of mounting holes arranged around an outer periphery. The final drive assembly includes a mounting flange and a gear set, wherein the mounting flange includes a second set of mounting holes, the second set of mounting holes being sized and positioned to align with the first set of mounting holes when the rotor shaft is engaged with the gear set, so that mounting fasteners installed through the aligned first and second sets of mounting holes can be installed in corresponding mounting holes in an outer wall of the track-type tractor for mounting of the motor module and the final drive assembly with the track-type tractor.

[0009] Other features and aspects of the present invention will become apparent from the following description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a side view of a crawler-type tractor according to an exemplary embodiment of the present invention;

[0011] Figure 2 is a cross-sectional view of a motor module and a final drive assembly externally mounted on a frame housing of a track-type tractor according to an exemplary embodiment of the present invention;

[0012] Figure 3 yes Figure 2an exploded perspective view of the components of the

[0013] Figure 4 is a cross-sectional view of an electric drive system including two motor modules and a final drive assembly externally mounted on a frame housing of a track-type tractor according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0014] The present invention relates to a mounting arrangement for an electric drive system for a crawler work machine, including a motor module having a flanged end configured to be fixed to an outer mounting surface of a frame housing. Reference will now be made in detail to specific embodiments or features, examples of which are shown in the accompanying drawings. Where possible, corresponding or similar reference numerals will be used throughout the accompanying drawings to refer to the same or corresponding parts. In addition, when there may be more than one element of the same type, references to the various elements described herein are made jointly or individually. However, these references are merely exemplary in nature. Therefore, it should be noted that, unless expressly stated in the appended claims, any such reference to an element in the singular should also be interpreted as involving the plural, and vice versa, without limiting the scope of the invention to the exact number or type of such elements.

[0015] The detailed description describes exemplary embodiments and is not intended to limit the scope of the claims in any way. In fact, the claimed invention is broader than the exemplary embodiments and is not limited by the exemplary embodiments, and the terms used in the claims have their full ordinary meanings. The features and components of an exemplary embodiment may be incorporated into other exemplary embodiments. Inventions within the scope of the present invention may include additional features, or may have fewer features than those shown in the exemplary embodiments.

[0016] Figure 1 A track-type work machine 100, such as a track-type tractor, is shown including a frame housing 110 that encloses a power source, such as an electric powertrain, as described in more detail below. A final drive assembly 140 is attached to each side 114 of the frame housing 110 to engage and support a corresponding track chain 105 (or other such track-type ground engaging member). The track-type tractor 100 is propelled by the movement of the track chain 105 driven by the rotation of the final drive assembly 140, as is known in the art.

[0017] Reference Figure 2 A partial cross-sectional view of Figure 3, the exemplary crawler-type tractor 100 includes at least one motor module 120 and a final drive assembly 140 mounted on the exterior of the frame housing 110. The motor module 120 includes a housing 121 having a substantially cylindrical body portion 122 and a flanged end portion 123. The body portion 122 is sized to be received in the interior cavity of the frame housing 110 through a final drive hole or outer hole 112 in the side of the frame housing, and the flanged end portion 123 is sized to abut against an outer mounting surface 113 of the frame housing surrounding the final drive hole 112. Mounting holes 126 disposed on the periphery of the flanged end portion may be sized and positioned to align with corresponding mounting holes 116 in the outer mounting surface 113 for mounting the motor module 120 to the frame housing 110 using mounting fasteners (e.g., bolts). As shown, the motor module housing 121 may be provided with an enlarged shoulder 127 behind the flanged end 123 to provide a tight or press-fit engagement between the motor module housing 121 and the final drive bore 112 .

[0018] The portion of the motor module 120 disposed outside the frame housing 110 may depend on the thickness of the flanged end 123. Although the flanged end 123 shown is relatively thin, a thicker or axially enlarged flanged end may be provided to position a larger portion of the motor module outside the frame housing, thereby reducing the space occupied by the motor module within the frame housing. Alternatively, a spacer may be installed between the flanged end and the outer mounting surface of the frame housing to position a larger portion of the motor module outside the frame housing.

[0019] A rotor shaft 125 in the motor module housing 121 extends beyond the flanged end 123 for operative rotational connection with a final drive assembly 140 for driving an external sprocket 147. In the example shown, the rotor shaft 125 engages a gear set 124 which is rotationally connected to an output shaft 145 in the final drive assembly which in turn is connected to the gear set 144. The final drive assembly 140 includes a support spindle 142 having a mounting flange 143 sized to align with the flanged end 123 of the motor module housing 121 and may have mounting holes 146 sized and positioned to align with the mounting holes 116, 126 in the frame housing and the motor module flanged end 123 so that a single set of fasteners can be used to mount the motor module 120 and the final drive assembly 140 to the frame housing 110. Although the mounting flange 143 of the final drive assembly 140 can be directly mounted to the flanged end 123 of the motor module housing 121, or directly engaged with the flanged end 123, in the illustrated embodiment, the brake assembly 150 is operable to reduce the rotational speed of the rotor shaft 125, sandwiched between the flanged end 123 of the motor module housing 121 and the mounting flange 143 of the final drive assembly 140 to receive and operably engage the adjacent ends of the rotor shaft 125 and the output shaft 145.

[0020] like Figure 4 As shown in the cross-sectional view of FIG. 1 , the track-type tractor 100 may include an electric drive train system having two motor modules 120, 120′, brake assemblies 150, 150′, and final drive assemblies 140, 140′ externally mounted on the frame housing 110. The second motor module 120′, brake assembly 150′, and final drive assembly 140′ may be constructed and mounted in substantially the same manner as the first motor module 120, brake assembly 150, and final drive assembly 140, as described in more detail above.

[0021] As shown, the housing body portions 122, 122' of the motor modules 120, 120' may be substantially unsupported within the frame housing 110, such that the motor modules are secured in a cantilevered state within the frame housing by attaching the flanged ends 123, 123' to the frame housing outer mounting surface 113. In other embodiments (not shown), the body portions 122, 122' of one or both of the motor modules 120, 120' may be supported by a portion of the frame housing 110 or by another motor module (e.g., by a bracket to which the body portions are attached).

[0022] Industrial Applicability

[0023] The mounting arrangement of the present invention is suitable for implementation and use in industrial environments (e.g., mining, agriculture, and construction). The described technology can be provided for use with an electrically powered crawler tractor, whether originally constructed or modified from an original machine-driven crawler tractor, and can also be applied to other work machines (e.g., wheel loaders, motor graders, excavators, articulated trucks, pipelayers, trenchers, bulldozers), on-road or off-road trucks, or automobiles).

[0024] The work machine frame housing 110 may be configured to house a machine or an electric powertrain assembly. For example, during assembly, the same frame housing may be used to construct both a machine and an electric-driven work machine by selecting and installing corresponding powertrain assemblies, thereby reducing construction and inventory costs. As another example, an existing machine-driven work machine may be retrofitted with an electric powertrain assembly to convert the work machine into an electric-driven work machine.

[0025] While a single motor of a conventional electric drive system may be sized to fit completely within the frame housing of a conventional machine-driven work machine, for other electric drive system arrangements that include multiple motor drive systems, the overall size or shape of the electric drive system prevents the electric system from fitting into the same space as the machine transmission being replaced. For example, fully enclosing multiple independently operable motor modules within a conventional sized work machine frame housing (e.g., configured to eliminate the need for a differential steering arrangement, e.g., to improve motor efficiency) may be limited or prevented by space constraints within the frame housing. By externally mounting the flanged ends 123 of one or more motor modules 120 to the outer mounting surface 113 of the frame housing 110, the space occupied by the motor modules within the frame housing is reduced, allowing the one or more motor modules to be accommodated in a smaller frame housing of the crawler tractor 100. By using conventional final drive apertures 112 for mounting the motor modules 120 and the outer mounting surface 113 of the conventional frame housing 110, it is possible to use an existing frame housing in an initial construction or retrofit assembly without modifying the frame housing.

[0026] In retrofitting an existing work machine 100 to replace the existing machine drive system with an electric drive system, as described herein, in an exemplary embodiment, the final drive assembly is disassembled from the frame housing mounting surface 113 and the machine drive system is removed from the frame housing 110. The main body 122 of the motor module housing 121 is inserted into the final drive device hole 112, and the flanged end 123 is engaged with the frame housing mounting surface 113. The brake assembly 150 is assembled to the flanged end 123 of the motor module housing 121, and the mounting flange 143 of the final drive assembly 140 is assembled to the brake assembly so that the rotor shaft 125 engages the gear set 124 within the housing 151 of the brake assembly 150, and the gear set 124 is rotationally connected to the output shaft 145 in the final drive assembly, which in turn is connected to the gear set 144. After aligning the mounting holes 116, 126, 146, 156 of the frame housing 110, the motor module 120, the final drive assembly 140, and the brake assembly 150, the fastening bolts are installed via the aligned mounting holes. In the illustrated embodiment, the final drive assembly 140 includes a spindle 142 that is configured to engage with the external brake assembly 150. Thus, the electric drive system retrofit kit may include the motor module 120, the brake assembly 150, and the final drive assembly 140, and may additionally include longer replacement fastening bolts to accommodate the attachment of the motor module, the brake assembly, and the final drive assembly to the frame housing 110. In other embodiments, the electric drive system may be configured to accommodate the final drive assembly and / or brake assembly of an existing machine drive system such that a new final drive assembly and / or brake assembly is not required.

[0027] Although various inventive aspects, concepts and features of the present invention may be described and illustrated herein as being implemented in combination in an exemplary embodiment, these various aspects, concepts and features may be used in many optional embodiments individually or in various combinations and sub-combinations thereof. Unless expressly excluded herein, all such combinations and sub-combinations are intended to fall within the scope of the present invention as determined based on the claims and any equivalents thereof. Further, although various optional embodiments of various aspects, concepts and features of the present invention may be described herein, such as optional materials, structures, configurations, methods, circuits, devices and components, software, hardware, control logic, and optional solutions for form, assembly and function, etc., these descriptions are not intended to be a complete or exhaustive list of available optional embodiments. A person skilled in the art may easily adopt one or more of the inventive aspects, concepts or features to additional embodiments and uses within the scope of the present invention, even if the embodiments are not explicitly disclosed herein. In addition, even if some features, concepts or aspects of the present invention may be described herein as preferred arrangements or methods, such descriptions are not intended to imply that such features are necessary or essential, unless explicitly stated as such. Further, exemplary or representative values ​​and ranges may be included to aid in understanding the present invention, however, such values ​​and ranges should not be interpreted as limiting and are determined as critical values ​​or ranges only when so explicitly stated. Unless otherwise expressly stated, parameters determined as "approximately" or "about" a specified value are intended to include both the specified value and the value within 10% of the specified value. In addition, it should be understood that the drawings of the present invention may, but need not be, to scale, and therefore may be understood to teach various proportions and ratios apparent in the drawings. In addition, although various aspects, features, and concepts may be explicitly identified herein as inventive or forming part of the invention, such identification is not intended to be exclusive, but there may be inventive aspects, concepts, and features that are fully described herein, but not explicitly identified as a specific invention itself or a part thereof, and the invention is not set forth in the appended claims. The description of an exemplary method or process is not limited to including all steps required in all cases, nor is it limited to the order in which the steps are presented being interpreted as required or necessary unless explicitly stated so.

[0028] As used herein, the articles "a" and "an" are intended to include one or more items and are used interchangeably with "one or more." Where only one item is intended, the term "one" or similar language is used. Furthermore, as used herein, the terms "has, have, having, etc." are intended to be open-ended terms. Furthermore, the phrase "based on" is intended to mean "based, at least in part, on," unless expressly stated otherwise.

Claims

1. A crawler tractor (100), comprising: A frame housing (110) of a track-type tractor defining an interior cavity extending to a first exterior aperture (112); a first motor module (120) comprising a first motor housing (121) having a first flanged end (123), and a first rotor shaft (125) extending through the first flanged end (123), the first flanged end (123) being mounted to a first outer mounting surface (113) of the frame housing (110) surrounding the first outer hole (112), such that the first motor module (120) extends through the first outer hole (112) and is retained within the frame housing interior cavity; as well as a first final drive assembly (140) mounted to the first flanged end (123) and including a gear set (144) in operative engagement with the first rotor shaft (125) for motorized operation of the first final drive assembly (140); Wherein the frame housing is also capable of accommodating machine powertrain components, the first final drive assembly is configured to engage and support a corresponding track chain.

2. The crawler-type tractor (100) of claim 1, wherein the first motor module (120) is cantilevered within the frame housing cavity.

3. The crawler tractor (100) according to claim 1 or 2, further comprising a second motor module (120'), the second motor module comprising a second motor housing (121') having a second flanged end (123'), and a second rotor shaft (125') extending through the second flanged end (123'), the second flanged end (123') being mounted to a second outer mounting surface (113') of the frame housing (110) surrounding a second outer hole (112'), so that the second motor module (120') extends through the second outer hole (112') and is retained within the inner cavity of the frame housing; and A second final drive assembly (140') mounted to the second flanged end (123') of the second motor housing (121') and in operative engagement with the rotor shaft (125') for motorized operation of the second final drive assembly (140'), wherein the second motor module (120') is cantilevered within the frame housing interior cavity.

4. The crawler tractor (100) according to any one of claims 1-3, further comprising a first brake assembly (150), wherein the first brake assembly (150) is mounted between the first flanged end (123) and the first final drive assembly (140).

5. The track-type tractor (100) of any one of claims 1-4, wherein the first final drive assembly (140) includes a first mounting flange (143) mounted to the first flanged end (123), and wherein the first outer mounting surface (113) is configured to accommodate direct mounting of the first mounting flange (143).

6. A method for installing an electric drive system in a frame housing (110) of a crawler tractor (100), the method comprising: Inserting a first motor housing (121) of a first motor module (120) through a first outer hole (112) in the frame housing (110) so that the first motor housing (121) extends into an inner cavity of the frame housing (110) and a first rotor shaft (125) of the first motor module (120) extends outside the frame housing (110); Mounting a first flanged end portion (123) of the first motor housing (121) to a first outer mounting surface (113) of the frame housing (110) surrounding the first outer hole (112); and mounting a first final drive assembly (140) to the first flanged end (123) such that the first final drive assembly (140) is in operative engagement with the first rotor shaft (125) for motorized operation of the first final drive assembly (140); Wherein the frame housing is also capable of accommodating machine powertrain components, the first final drive assembly is configured to engage and support a corresponding track chain.

7. The method of claim 6, wherein mounting the first flanged end (123) of the first motor housing (121) to the first outer mounting surface (113) includes securing the first motor module (120) in a cantilevered state within the frame housing cavity.

8. The method according to claim 6 or 7, further comprising: Inserting a second motor housing (121') of a second motor module (120') through a second outer hole (112') in the frame housing (110') so that the second motor housing (121') extends into an inner cavity of the frame housing (110') and a second rotor shaft (125') of the second motor module (120') extends outside the frame housing (110'); Mounting a second flanged end portion (123') of the second motor housing (121') to a second outer mounting surface (113') of the frame housing (110) surrounding the second outer hole (112'); as well as mounting a second final drive assembly (140') to the second flanged end (123') such that the second final drive assembly (140') is in operative engagement with the second rotor shaft (125') for motorized operation of the second final drive assembly (140'), Wherein, mounting the second flanged end (123') of the second motor housing (121') to the second outer mounting surface (113') includes fixing the second motor module (120') in a cantilevered state within the inner cavity of the frame housing.

9. The method of any one of claims 6-8, wherein mounting the first final drive assembly (140) to the first flanged end (123) includes mounting a first brake assembly (150) between the first flanged end (123) and the first final drive assembly (140).

10. The method of any one of claims 6-8, wherein mounting the first final drive assembly (140) to the first flanged end (123) comprises mounting a first mounting flange (143) of the first final drive assembly (140) to the first flanged end (123), wherein the first outer mounting surface (113) is configured to accommodate direct mounting of the first mounting flange (143).

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