Modular Robot Vehicle

Abstract

A robotic vehicle having modular track assemblies separable from a chassis, a drive unit is built into each track assembly along with a motor controller, a cooling system is provided in an exterior cover located above the tracks, a cooler for the cooling system is located aft of the motor and the motor controller, and the motor has a gearbox connected to the outside of the exterior cover inside the left track assembly for coupling the motor to a final drive that drives the tracks located above the final drive.

Description

[Technical field]

[0001] This application claims priority to U.S. Patent Application No. 17 / 562,847, filed December 27, 2021, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to autonomous vehicles, and more particularly, to modular tracked robotic vehicles. [Background technology]

[0003] There are many instances where autonomous vehicles are preferable over human-operated vehicles. Such autonomous vehicles are particularly advantageous when performing dangerous tasks or operating in dangerous conditions, such as those experienced by emergency responders or explosive ordnance disposal teams. They are also advantageous in situations where large fleets of vehicles are required, such as agriculture, where the amount of time allowed for farm work remains constant as the size of the farm increases. Whatever the situation, there is a need for autonomous vehicles that are readily available and robust enough to operate in any situation.

[0004] Thus, there is a need in the art for methods, systems, and / or apparatus that can assist humans in performing various tasks that can be used to reduce the time to perform a task, improve the conditions under which the task can be performed, reduce the amount of personnel required, and otherwise reduce the number of challenges associated with agriculture and other industries. Summary of the Invention

[0005] In one aspect of the invention, disclosed is a robotic vehicle having a modular, removable, interchangeable, and configurable track assembly. In one embodiment, the robotic vehicle comprises a chassis including a right side and a left side with a right track assembly separable from the right side of the chassis and a left track assembly separable from the left side of the chassis, each of the right track assembly and the left track assembly comprising a motor operably connected to the tracks. In this configuration, each track assembly is removable, interchangeable, and configurable from the chassis of the robotic vehicle such that the robotic vehicle can be configured as a dual track or single track robotic vehicle, with the motor, motor controller, and cooling system contained within each track assembly.

[0006] Each of the right and left track assemblies includes a track frame, a track link coupled to the track for rotation therewith, a sprocket engaged to the track link for rotating the track link and the track, at least one idler roller and at least one roller engaged to the track link for maintaining alignment of the track and distributing the weight of the track assembly throughout the track, and a final drive coupled to the sprocket and driven by a motor for rotating the track relative to the track frame.

[0007] To keep each modular track assembly compact, each of the right and left track assemblies further includes a gearbox assembly comprising a motor disposed vertically above the final drive. In this regard, the axis of rotation for the output of the motor is disposed above the axis of rotation of the final drive to raise the motor above the ground and keep the motor clean. A brake may also be connected to the gearbox on the opposite side of the motor and final drive to stop rotation of the output of the motor, the final drive, or both the motor and the final drive.

[0008] Such a compact configuration of the gearbox can be achieved by a unique assembly of the gearbox that can accommodate a motor gear mechanically coupled to the motor, a brake gear mechanically coupled to the brake and counter-rotatably engaged with the motor gear, and a final drive gear mechanically coupled to the final drive and counter-rotatably engaged with the brake gear, each of the motor gear, brake gear, and final drive gear can have axes of rotation that can all be aligned along a vertical plane.

[0009] More specifically, the gearbox comprises front and rear gearbox plates spaced apart by a center gearbox plate, a motor gear coupled to the motor by a motor shaft assembly substantially housed in a motor shaft housing attached to the outside of the front gearbox plate and to the motor, a brake gear coupled to the brake by a brake shaft assembly substantially housed in a brake shaft housing attached to the outside of the rear gearbox plate and to the brake, and a final drive gear coupled to the final drive by a final drive shaft assembly housed in a final drive shaft housing attached to the outside of the face of the front gearbox and to the final drive. This arrangement allows the overall thickness of the gearbox from the front gearbox plate to the rear gearbox plate to be relatively thin, on the order of a few inches thick.

[0010] Each of the right and left track assemblies of the robotic vehicle may advantageously include a motor controller electrically connectable to the battery unit and electrically connected to the motor for converting power from the battery unit for the motor. With the motor controller located in the modular track assemblies, the motor controller may be connected to a central unit of the robotic vehicle by a removable electrical connector, such that the motor and motor controller are retained within each track assembly. In one embodiment, the motor is an AC motor, and the motor controller converts power from the battery unit to variable frequency AC power for the motor. Depending on the circumstances, a DC motor with an appropriate motor control controller may be used.

[0011] It is also advantageous for each of the right and left track assemblies to include a cooling system operatively connected to the motor controller and motor for dissipating heat from the motor controller and motor. The cooling system may include a chiller and a pump that circulates coolant to the chiller around the controller and motor, the controller being located between the motor and the pump. To keep each track assembly modular and compact, the cooling system and motor controller may be located above the tracks. The chiller is located aft of the motor and final drive.

[0012] It is contemplated that each of the track assemblies may be configured differently. Each of the right and left track assemblies may include a track frame and a mounting mechanism for removably mounting the track frame to the chassis. In one embodiment, the mounting mechanism includes a pair of tubes coupled to the track frame and slidably coupled to the chassis, and an actuator coupled to the chassis and attached to at least one of the pair of tubes for driving the track frame toward and away from the chassis to increase or decrease the track width of the robotic vehicle. This is particularly useful for agricultural operations where furrow widths may vary. In another embodiment, the mounting mechanism may include a pair of angle arms attached at one end to the track frame and attached at the other end to the chassis to elevate the chassis above the ground and increase the track width of the robotic vehicle.

[0013] In either embodiment of the attachment mechanism, the left track assembly can be separated from the chassis by disconnecting the attachment mechanism from the chassis and disconnecting the electrical connectors, allowing each track assembly, along with its own contained motor, motor controller, and cooling system, to be completely isolated from the operating unit and battery unit. [Brief description of the drawings]

[0014] These and other features and advantages of the present invention may be better understood from the following detailed description taken in conjunction with the drawings.

[0015] [Figure 1] FIG. 1 is a perspective view of a robotic vehicle according to the present disclosure.

[0016] [Diagram 2] FIG. 2 is a perspective view of the robotic vehicle of FIG. 1 with the track assembly detached from the operational unit.

[0017] [Diagram 3] FIG. 2 is an exterior perspective view of the left track assembly of FIG.

[0018] [Figure 4] FIG. 2 is an inner perspective view of the left track assembly of FIG. 1.

[0019] [Diagram 5] FIG. 2 is an exploded perspective view of the operating unit of the left track assembly of FIG. 1.

[0020] [Figure 6] 1 is an alternative embodiment of a robotic vehicle having a wider base and higher ground clearance.

[0021] [Figure 7] FIG. 7 is a perspective view of the robotic vehicle of FIG. 6 with the track assembly detached from the operational unit.

[0022] [Figure 8] FIG. 7 is a perspective view of the exterior of the left track assembly of FIG.

[0023] [Figure 9] FIG. 7 is an inner perspective view of the left track assembly of FIG.

[0024] [Figure 10] FIG. 7 is a right side perspective view of a gearbox assembly for the track assembly of the robotic vehicle of FIGS. 1 and 6 .

[0025] [Figure 11] FIG. 7 is a left side perspective view of a gearbox assembly for the track assembly of the robotic vehicle of FIGS. 1 and 6 .

[0026] [Figure 12] FIG. 7 is a perspective view of the robotic vehicle of FIG. 6 with a dual track assembly unit.

[0027] [Figure 13] FIG. 7 is a right side perspective view of a cooling system for the track assembly of the robotic vehicle of FIGS. 1 and 6 .

[0028] [Figure 14] FIG. 7 is a left side perspective view of a cooling system for the track assembly of the robotic vehicle of FIGS. 1 and 6 .

[0029] [Figure 15A] FIG. 12 is a rear view of the gearbox of FIG.

[0030] [Figure 15B] FIG. 15B is a cross-sectional view taken along line AA in FIG. 15A.

[0031] [Figure 16] FIG. 12 is an exploded perspective view of the gearbox assembly of FIGS. 10 and 11 .

[0032] [Figure 17] FIG. 2 is a bottom view of the left track assembly and operating unit of FIG.

[0033] [Figure 18] FIG. 3 is a bottom view of the left track assembly and operational unit of FIG. 2 with the left track assembly extended from the operational unit.

[0034] [Figure 19] FIG. 7 is a perspective view of the inside of the left track assembly of FIG. 6 with the attachment mechanism exploded from the left track assembly.

[0035] [Figure 20] FIG. 2 is an electrical configuration diagram of the robot vehicle of FIG.

[0036] [Figure 21] FIG. 2 is a schematic diagram of a cooling system for the robotic vehicle of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] FIG. 1 is a perspective view of a robotic vehicle 100 according to the present disclosure. The robotic vehicle 100 is electrically powered and remotely operable to perform laborious or high-risk tasks without tiring or endangering the operator. The robotic vehicle 100 is rugged and robust to operate in harsh environments. Its low, forward center of gravity allows it to tow and carry equipment many times its weight. An easily replaceable battery pack allows the robotic vehicle 100 to operate for extended periods of time and then continue operation by quickly replacing the battery pack.

[0038] The robotic vehicle 100 comprises a central unit 101 having a chassis 102 having a front end 102a and a rear end 102b supported on a right track assembly 104 and a left track assembly 106. The right track assembly 104 and the left track assembly 106 each have their own motorized drive that is removably connectable to an operational unit 112 in which the circuitry and software required to operate the robotic vehicle 100 is located. A front hood 114 projects outwardly from the operational unit 112 of the central unit 101 and each motorized drive assembly 108 and on which auxiliary devices such as a camera 111 and lights 113 may be placed.

[0039] A battery unit 200 is provided below the front hood 114, above the chassis 102, and between the right and left track assemblies 104 and 106. The battery unit 200 may be 25-30% of the total weight of the robotic vehicle 100, which may weigh over 1500 pounds. Locating the battery unit 200 below the front hood 114 on the chassis 102 lowers and moves the center of gravity of the robotic vehicle 100 forward, improving traction and towing capacity. The battery unit 200 and chassis 102 are described in further detail in U.S. Patent Application No. 17 / 526,872, filed November 15, 2021, the contents of which are incorporated herein by reference.

[0040] The robotic vehicle 100 includes a right track assembly 104 and a left track assembly 106 that are each removably mountable from the chassis 102 of the central unit 101 of the robotic vehicle 100 to allow the robotic vehicle 100 to be easily configured for various applications. FIGS. 1-4 show one embodiment with a right track assembly 104 and a left track assembly 106 having a standard width and ground clearance. Also, FIGS. 6-9 show another embodiment with a larger width and ground clearance by replacing the frame mounting mechanism 120 described below. Furthermore, the robotic vehicle 100 can include more than one right track assembly 104 and left track assembly 106 when greater traction capacity is required, such as the embodiment shown in FIG. 12 having a dual track assembly unit including right track assemblies 104a, 104b and left track assemblies 106a, 106b.

[0041] 2, the right and left track assemblies 104, 106 are shown removed from the chassis 102 of the central unit 101. As shown, each of the right and left track assemblies 104, 106 is a modular, self-contained unit that is easily separable from the chassis 102 of the central unit 101 with only one connection, which is a frame mounting mechanism 120, shown in FIGS. 4, 7, 17 and 18, for removably coupling the respective right and left track assemblies 104, 106 to the chassis 102, and an electrical connector 121 for power from the battery unit 200 and data to and from the operating unit 112.

[0042] Figure 3 is a perspective view of the exterior of the left track assembly 106 of Figure 1, and Figure 4 is a perspective view of the interior of the left track assembly 106. Because the right track assembly 104 is functionally identical with the same components mirrored, only the left track assembly 106 will be described as though the right track assembly 104 were similarly constructed.

[0043] 5, the left track assembly 106 includes standard components of a tracked vehicle, including tracks 124 with track links 126, which may be in the form of a belt or chain, attached to the inside of the tracks. A sprocket 128, fixed to a final drive 152 (described below in connection with FIGS. 10 and 11 ), engages the track links 126 and drives the tracks 124 over the ground. A front idler roller 130, a rear idler roller 132, and one or more rollers 134 support the weight of the robotic vehicle 100 and maintain the alignment of the tracks 124. The front idler roller 130, the rear idler roller 132, and the rollers 134 are rotatably coupled to the track frame 123 by suspension members 138 to absorb some of the shocks as the robotic vehicle 100 travels over uneven terrain.

[0044] The frame attachment mechanism 120 attaches the left track assembly 106 to the chassis 102. In the embodiment shown in FIG. 4, the attachment mechanism is configured as a pair of tubes 122 coupled to the track frame 123 of the left track assembly 106, which are biased inwardly and outwardly relative to the chassis 102 by at least one actuator 125 shown in FIGS. 17 and 18. The pair of tubes 122 may each be configured as a single tube or as multiple telescopic tubes for greater expansion. Automatic width adjustment is preferred, but manual width adjustment by telescopic tubes is also acceptable. Depending on the terrain traveled, the width between the tracks can be increased or decreased. This is particularly advantageous for use in agricultural operations where the distance between crop rows varies, such as vineyards and produce. The actuator 125 is electrically connected to the battery unit 200 and the operation unit 112 via an electrical connector 121. In this manner, a command from the operation unit 112 can extend or retract one or both of the right track assembly 104 and the left track assembly 106. One end of the actuator 125 is fixed to the chassis 102 , and the rod of the actuator 125 is fixed to the tube 122 .

[0045] As shown in FIGS. 6-9 and 19, the frame mounting mechanism 120 may be configured as a pair of angle arms 140 attached at one end to a track plate 142 that is welded, bolted, or otherwise attached across the track frame 123 of the left track assembly 106 and attached at the other end to a chassis plate 144 that is attached across the chassis 102. A cable cover 146 may be added to cover the electrical connector 121 and corresponding cables. This arrangement of the pair of angle arms 140 effectively fixes the track width of the robotic vehicle 100 and increases the ground clearance of the chassis 102. This embodiment is useful when a more sturdy base and greater ground clearance are required. Otherwise, these embodiments shown in FIGS. 6-9 are the same as the embodiment shown in FIG. 1. Other implementations to increase ground clearance may include angled actuators that effectively raise the center unit 101 and chassis 102 for both the right track assembly 104 and the left track assembly 106.

[0046] As shown in FIG. 5, an exploded view of the left track assembly 106 is shown, which further includes a gearbox assembly 150 and a cooling system 190. Referring now to FIGS. 10-11, illustrated is the gearbox assembly 150 that drives the left track assembly 106. FIGS. 10-11 show the gearbox assembly 150 that drives the left track assembly 106. The gearbox assembly 150 includes a final drive 152 that is directly coupled to a sprocket 128 that engages the track link 126 of the left track assembly 106. The final drive 152 is driven to rotate by a motor 154 that is powered by a battery unit 200 and controlled by the operating unit 112. A brake 156 is mechanically coupled between the motor 154 and the final drive 152 to stop the rotation of the motor 154 and the final drive 152. All of these components are mechanically linked in an innovative arrangement where the motor 154 is elevated vertically above the final drive 152 with the output axis of rotation of the motor 154 above the axis of rotation of the final drive 152. This positions the motor 154 above the tracks 124 of the left track assembly 106 and out of the way of contamination. All of the mechanical parts connecting these components are isolated within a narrow, 2 inch thick gearbox 158.

[0047] The gearbox is best shown in FIG. 10, which is a front perspective view of gearbox 158, FIG. 11, which is a rear perspective view of gearbox 158, FIG. 15A, which is a rear view of the gearbox of FIG. 11, and FIG. 15B, which is a cross-sectional view taken along line AA of FIG. 15A, and FIG. 16, which is an exploded view of gearbox assembly 150. Gearbox 158 includes a front gearbox plate 160 and a rear gearbox plate 162 spaced apart by a center gearbox plate 161. Inside gearbox 158 is a motor gear 164 mechanically coupled to motor 154 by a motor shaft assembly 166, which is enclosed within motor shaft housing 168 and fixed and aligned to motor 154 by a motor mounting plate 170. Motor gear 164 counter-rotatably meshes with a brake gear 172 which is mechanically coupled to brake 156 by a brake shaft assembly 174 which is enclosed within and fixed to brake shaft housing 176 and aligned with motor 154. This causes the brake 156 to apply a counter rotating force to the brake gear 172, stopping the rotation of the motor gear 164. The brake gear is counter rotatably meshed with a final drive gear 178 that is mechanically coupled to the final drive 152 and sprocket 128 by a final drive shaft assembly 180 that is sealed and fixed within the final drive shaft housing and aligned with the final drive 152.

[0048] The motor gear 164, brake gear 172, and final drive gear 178 all have their respective axes aligned in the same vertical plane to reduce the required width of the gearbox 158. This also allows the gearbox 158 to have a thickness significantly less than standard gearboxes for electric drive robotic vehicles. The rear gearbox plate 162 also has a large surface area that provides mounting points for a cooling system 190.

[0049] 13-14 and 21, a cooling system 190 is shown connected to the motor 154 and a motor controller 192. In the case of the motor 154 configured as an AC motor, the motor controller 192 may be configured as an inverter to convert DC voltage from the battery unit 200 into variable frequency AC power for driving the motor 154. In the case of the motor 154 configured as a DC motor, the motor controller 192 may control the rotational speed and torque of the motor 154 by adjusting the current and voltage applied to the motor 154. In either example, the motor 154 and motor controller 192 may be cooled to maintain optimal operating conditions. The cooling system 190 includes a fan-integrated chiller 194 in fluid communication with a coolant reservoir 196 and a pump 198. The pump 198 circulates coolant from the coolant reservoir around the motor 154 and motor controller 192 through a series of hoses 199 to the chiller 194 where excess heat can be dissipated. Returning to FIG. 5, it can be seen that a cooler 194 with a built-in fan is uniquely positioned behind the gearbox assembly 150, near the rear of the robotic vehicle 100.

[0050] 1-4, it can be seen that the left track assembly 106 is a unit with the gearbox assembly 150, cooling system 190, motor 154, and motor controller 192 contained within an exterior cover 118 above the tracks 124 of the left track assembly 106. The exterior cover 118 includes an outer cover portion 118a and an inner cover portion 118b that may be directly connected to the gearbox 158. This allows one or more left track assemblies 106 to be added or removed by simply disconnecting the electrical connector 121 and frame mounting mechanism 120.

[0051] 20 is a high-level electrical schematic diagram of the robotic vehicle 100. The central unit 101 of the robotic vehicle 100 includes a battery unit 200 that is electrically connected to the operational unit 112, which contains the necessary software and hardware to drive and control the robotic vehicle 100. Each of the right and left track assemblies 104 and 106 is electrically connected to the operational unit 112 and the battery unit 200 by at least one electrical connector 121. Thus, power from the battery unit 200 and bidirectional control and response signals from the operational unit 112 are directly supplied to the motor controller 192, actuators 125, pump 198 and cooler 194. All of the positive and negative DC supply voltages, relay supplies, and bidirectional CAN and VCU connections for bidirectional control and response signals between the operational unit 112 and the motors 154 and motor controllers 192 may be electrically connected by at least one electrical connector 121 between the operational unit 112 and the corresponding right and left track assemblies 104 and 106. The operational unit 112 is configured to simultaneously control all of the track assemblies 104, 106 described in this disclosure.

[0052] Those skilled in the art will appreciate that the illustrated embodiment described above is exemplary. Other variations and modifications to the robotic vehicle 100 are contemplated in this disclosure. In an alternative embodiment, a single motor controller 192 can be located in the central unit 101 and configured to power the motors 154 for the left track assembly 106 and the right track assembly 104. Similarly, a single cooling system 190 can be located in the central unit 101 with additional quick release connections for hoses 199. While such a modification provides the modular benefits of the illustrated embodiment, it is currently believed to be disadvantageous due to the unavailability and cost of a single motor controller 192 to drive multiple motors 154.

[0053] Terms used in this disclosure are presumed to have their ordinary meaning to one of ordinary skill in the art unless a different meaning is given. Substantially, as used in this disclosure, means the standard dictionary definition of most, but not all, of what is specified.

[0054] While the principles of the invention have been described in this disclosure, those skilled in the art should understand that this description is made by way of example only and is not intended to limit the scope of the invention. Other embodiments are intended to be within the scope of the invention in addition to the exemplary embodiments shown and described in this disclosure. Modifications and substitutions made by those skilled in the art are deemed to be within the scope of the invention, which is not limited except by the claims.

Claims

1. a chassis having a right side and a left side; a right track assembly separable from a right side of the chassis; a left track assembly separable from a left side of the chassis; the right track assembly and the left track assembly each include a motor operably coupled to the tracks.

2. Each of the right and left track assemblies comprises: A track frame; a track link coupled to the track for rotation therewith; a sprocket engaged with the track link for rotating the track link and the track; at least one idler roller and at least one roller engaging the track links to maintain alignment of the track; The robotic vehicle of claim 1 , wherein a final drive is coupled to the sprocket and driven by the motor to rotate the tracks relative to the track frame.

3. 3. The robotic vehicle of claim 2, wherein the right track assembly and the left track assembly each further include a gearbox assembly including the motor disposed vertically above the final drive.

4. 4. The robotic vehicle of claim 3, wherein the motor output axis of rotation is located above and aligned with the axis of rotation of the final drive, thereby elevating the motor above the ground and keeping the motor free from contamination.

5. The robotic vehicle of claim 4 , wherein the gearbox assembly further comprises a brake that stops rotation of the output of the motor.

6. 6. The robotic vehicle of claim 5, wherein each of the gearbox assemblies further comprises a gearbox housing a motor gear mechanically coupled to the motor, a brake gear mechanically coupled to the brake and in counter-rotatable engagement with the motor gear, and a final drive gear mechanically coupled to the final drive and in counter-rotatable engagement with the brake gear, each of the motor gear, the brake gear, and the final drive gear having an axis of rotation aligned along a vertical plane.

7. 7. The robotic vehicle of claim 6, wherein each of the gearboxes further comprises front and rear gearbox plates separated by a center gearbox plate, the motor gear is coupled to the motor by a motor shaft assembly substantially housed in a motor shaft housing attached to an exterior of the front gearbox plate and to the motor, the brake gear is coupled to the brake by a brake shaft assembly substantially housed in a brake shaft housing attached to an exterior of the rear gearbox plate and to the brake, and the final drive gear is coupled to the final drive by a final drive shaft assembly housed in a final drive shaft housing attached to an exterior of the front gearbox plate and to the final drive.

8. 2. The robotic vehicle of claim 1, wherein each of the right and left track assemblies is electrically connectable to a battery unit and further comprises a motor controller electrically connected to the motor and converting power from the battery unit for the motor.

9. The robotic vehicle of claim 8 , wherein each of the motors is an AC motor, and each of the motor controllers converts power from the battery unit to variable frequency AC power for the motor.

10. 10. The robotic vehicle of claim 9, wherein each of the right and left track assemblies further comprises a cooling system operatively connected to the motor controllers and the motors for dissipating heat from the motor controllers and the motors.

11. 11. The robotic vehicle of claim 10, wherein the cooling system includes a cooler and a pump that circulates a coolant around the controller and the motor to the cooler, the controller being disposed between the motor and the pump.

12. The robotic vehicle of claim 11 , wherein each of the cooling systems and each of the motor controllers are disposed above the tracks.

13. The robotic vehicle of claim 12 , wherein each of the coolers is disposed aft of a corresponding one of the motors, and a final drive is coupled to the output of each of the motors.

14. 2. The robotic vehicle of claim 1, wherein the right and left track assemblies each further comprise a track frame and a mounting mechanism that removably mounts the track frame to the chassis.

15. 15. The robotic vehicle of claim 14, wherein each of the attachment mechanisms further comprises: a pair of tubes coupled to the track frame and slidably coupled to the chassis; and an actuator coupled to the chassis and attached to at least one of the pair of tubes for driving the track frame toward and away from the chassis to increase or decrease a track-to-track width of the robotic vehicle.

16. 15. The robotic vehicle of claim 14, further comprising a pair of angle arms, each of the mounting mechanisms having one end attached to the track frame and another end attached to the chassis, elevating the chassis above the ground and increasing a track-to-track width of the robotic vehicle.

17. 2. The robotic vehicle of claim 1 , wherein the left track assembly is (i) separable from the chassis by an attachment mechanism and electrical connectors, with the motor, motor controller, and cooling system being separable together with the left track assembly as a whole from a central unit including an operation unit and a battery unit coupled to the chassis, and (ii) an exterior cover is disposed above the tracks, the motor, motor controller, and cooling system all encased in the exterior cover, a cooler for the cooling system is disposed rearward of the motor and the motor controller at a front side of the robotic vehicle, coupled to an exterior cover inside the exterior cover and the left track assembly, and a gearbox coupling the motor to a final drive that drives the tracks, the gearbox being disposed above the final drive with an axis of rotation of the output of the motor vertically aligned and coplanar with an axis of rotation of the output of the final drive.

18. a chassis having a right side and a left side; An operation unit disposed at the rear of the chassis; A battery unit disposed in front of the chassis; a right track assembly separable from a right side of the chassis; a left track assembly separable from a left side of the chassis; each of the left and right track assemblies is separable from the chassis by an attachment mechanism and an electrical connector; Each of the right and left track assemblies comprises: a motor operably mounted to the battery unit on the chassis; a track frame removably attachable to the chassis; an endless track that can traverse a ground surface and rotate relative to the endless track frame; a track link coupled to the track for rotation therewith; a sprocket coupled to the motor and engaging the track link to rotate the track link and the track; at least one idler roller and at least one roller engaging the track links to maintain alignment of the track; the motor and motor controller being generally separable from the left track assembly, the manipulation unit and the battery unit.

19. Each of the right and left track assemblies further comprises a gearbox assembly including the motor positioned vertically above and engaging a final drive coupled to the sprocket, the motor output having an axis of rotation positioned above an axis of rotation of the final drive to raise the motor above the ground and keep the motor clean, the gearbox assembly further comprises a brake to stop rotation of the motor output, the gearbox assembly further comprises a gearbox housing a motor gear mechanically coupled to the motor, a brake gear mechanically coupled to the brake and counter-rotatably engaged with the motor gear, and a final drive gear mechanically coupled to the final drive and counter-rotatably engaged with the brake gear, each of the motor gear, the brake gear, and the final drive gear being arranged to be vertically above and engaged with the brake gear.

19. The robotic vehicle of claim 18, wherein the gearbox further comprises front and rear gearbox plates spaced apart by a center gearbox plate, the motor gear is coupled to the motor by a motor shaft assembly substantially housed in a motor shaft housing attached to an outside of the front gearbox plate and to the motor, the brake gear is coupled to the brake by a brake shaft assembly substantially housed in a brake shaft housing attached to an outside of the rear gearbox plate and to the brake, and the final drive gear is coupled to the final drive by a final drive shaft assembly housed in a final drive shaft housing attached to an outside of a face of the front gearbox and to the final drive.

20. 20. The robotic vehicle of claim 18, wherein each of the right and left track assemblies further comprises a motor controller electrically connectable to the battery unit and electrically connected to the motor for converting power from the battery unit for the motor, each of the right and left track assemblies further comprises a cooling system operably connected to the motor controller and the motor for dissipating heat from the motor controller and the motor, the cooling system comprising a chiller and a pump that circulates coolant around the motor controller and the motor to the chiller, the motor controller being disposed between the motor and the pump, the cooling system and the motor controller being disposed above the tracks, the chiller being disposed rearward of the motor and connected to the motor and further comprising a final drive coupled to the sprocket.

Images