Patent ID: 12240550

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

The disclosure and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments and examples that are described and/or illustrated in the accompanying drawings and detailed in the following description. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale, and features of one embodiment may be employed with other embodiments, as the skilled artisan would recognize, even if not explicitly stated herein.

Descriptions of well-known components and processing techniques may be omitted to not unnecessarily obscure the embodiments of the disclosure. The examples used herein are intended merely to facilitate an understanding of ways in which the disclosure may be practiced and to further enable those of skill in the art to practice the embodiments of the disclosure. Accordingly, the examples and embodiments herein should not be construed as limiting the scope of the disclosure. Moreover, it is noted that like reference numerals represent similar parts throughout the several views of the drawings.

It is desired to provide a mobile robot with a wheel drive assembly that can be easily removed and replaced with minimal time, skill and tooling. The concept described herein permits the motor drive assembly to be removed from the bottom of the robot by disconnecting wiring and removing several screws. The motor drive assembly described herein is also well-sealed to protect against entry of dust and contaminants into the components which may cause premature failure. Additionally, the design restricts access to the components of the motor drive assembly when it is installed on a robot which can prevent injuries, such as finger entrapment between the wheel and the wheel well.

An autonomous mobile robot100, according an embodiment of this disclosure, is shown inFIG.1. Mobile robot100includes a platform102for carrying items directly or for supporting a shelving unit or other form of tote and a mobile base104. The mobile robot may include a mast unit (not shown) for mounting a user input device, such as handheld computer like an ipad®. There is also an array of sensors106at the front of mobile base104, which may include laser radar (LIDAR) and vision cameras, used for navigation. Charging port108is included so the robot may autonomously dock at a charging station to recharge its batteries. Mobile base104also includes two removable wheel drive assemblies110and112(seeFIG.2) on either side of the mobile base104. Caster wheels114and116at the front and rear, respectively, of the mobile base104are shown inFIG.2.

One example of robot100is described in U.S. Pat. No. 10,019,015, for use in warehouse order fulfillment. The operation and application of robot100is not critical to the removable wheel drive assemblies described and claimed herein so they will not be described further. The removable wheel drive assemblies described and claimed herein may be used with various types of mobile robots designed for any suitable robot application.

Referring toFIGS.1and2, mobile base104may include a frame or chassis120on which are mounted removable wheel drive assemblies110and112and caster wheels114and116. There is an exterior cover122, which may comprise a number of exterior cover components, including upper wheel well cover131, including leg portions132aand132b, which are interconnected by an arch portion132c. Upper wheel well cover131forms part of upper wheel well member132, described below. Part of upper wheel well cover131disposed above leg portions132aand132bis label region134. Label region134may be used to display insignia, such as a logo or name/number associated with the robot. Lower wheel well cover portions130aand130bof wheel drive assembly110, mate with leg portions132aand132bof upper wheel well cover portion131when removable wheel drive assemblies110is installed. Together, these exterior cover components interconnect to form a part of the exterior cover122, as best shown inFIG.1.

As shown inFIG.2, removable wheel drive assembly110, includes mounting bracket140on which the components of the wheel drive assembly are mounted when installed within wheel drive region124. The mounting bracket140may be installed on mobile base104by means of fasteners (e.g. screws)142a-142dinserted through holes144a-144din the bottom of mounting bracket140and secured in holes146a-146din frame member126. The bottom of mounting bracket150of removable wheel drive assembly112is shown in the installed position. Other components disposed on mounting bracket140include wheel160on which is mounted tire162. There is also included a motor drive unit170.

An advantage of using a standard mounting bracket, like mounting brackets140/150, is that it can provide standard mounting platform that is easily installable and removable on the robot base, but can support different motor drive assemblies. This allows for diversity of suppliers or for field replacement of an obsolete drive assembly with updated units not directly providing identical mounting features. In other words, the mounting plate can serve as an adapter.

Referring now toFIG.3, a side perspective view of removable wheel drive assembly110is shown. In this view, motor drive unit170is shown to include an electric motor172integrated with a gear box unit174, which is interconnected to an axle (not shown). In turn, the axle is connected to the wheel160(also not shown in this view). Wheel drive assembly110is a right hand type drive with electric motor unit172, having a vertically oriented axis of rotation176, which at a right angle to the horizontally oriented axis of rotation178of the gear box unit174. While not a requirement of the wheel drive assembly disclosed herein, this type of drive unit is desirable as it is compact and readily mountable on mounting bracket140.

Continuing to refer toFIG.3and toFIGS.4A and4B, disposed on mounting bracket140is a lower wheel well member180positioned between gearbox174of the motor drive unit170and the wheel160/tire162. Wheel160is disposed on an axle (not shown) which passes through aperture182and connects gearbox174to wheel160. As described further below, upper wheel well member132mates with a lower wheel well member180on the removable wheel drive assembly110to form a sealed wheel well. The upper and lower wheel well member are designed to interconnect when removable wheel drive assembly110is mounted on mobile base104to form a seal to limit/prevent dust (and other matter) from entering the motor drive unit170, which may otherwise cause premature failure of motor drive unit170. The upper and lower wheel well members and external cover components also guard against safety issues, such as finger entrapment between wheel and wheel well. In addition to the connection between the upper and lower wheel well portions, the design also provides a minimized amount of clearance between the wheel well portions and the wheel160and tire162.

Referring toFIGS.5A and5B, the minimized clearances between the wheel well members and the wheel160and tire162are depicted. Wheel well cover portion130a, which forms part of lower wheel well member180, is spaced a very small distance from tire162, forming a minimized gap192, as shown inFIG.5A. In this example, the gap is approximately 3.5 mm from the tread surface190of tire162. This gap distance may be made smaller or larger, but typically gap192would be small enough to prevent insertion of a little (or “pinkie”) finger of a smaller sized person.

InFIG.5Ba bottom plan view of lower wheel well member180is shown. In this view, the connection of the base202of wheel well member180to mounting bracket140via bolt194is shown. A very small gap, gap196, between the front surface200of wheel well portion180and the edge of tire tread surface190of tire162is shown. In this example, the gap is approximately 1.625 mm, but the typical size gap196would be small enough prevent insertion of a little (or “pinkie”) finger of a smaller sized person.

Turning back toFIGS.4A and4B, the design of lower wheel well member180is further described. The remainder of the removable wheel drive assembly110(i.e. all but wheel well member180) is shown in phantom inFIGS.4A and4B, so the focus of these views and the description herein is on the wheel well member180. Lower wheel well member180includes a base portion202, which sits on and is connected to the mounting bracket140as indicated above with regard toFIG.5B. While the wheel well portion180is a single integrated component, for description purposes only, it is described in sections, which are divided by broken lines inFIG.4B. First, there is a central section210having an aperture182through which the axle (not shown) passes. Central section210has a curved or arched top surface212, which may be conformed to the curvature of wheel160/tire162. There is a first side section214extending in a first direction indicated by arrow215away from the central section210. There is a second side section216extending in a second direction indicated by arrow217away from the central section216. The second direction is opposite the first direction.

Extending from first side section214, in a direction perpendicular to front surface200(i.e. outwardly from the front surface), is a first curved fender220. First curved fender220has a curved surface221, which faces tread surface190of tire162and is in close proximity thereto, i.e. spaced by gap192ofFIG.5A. The curved surface221has a width approximately equal to the width of tread surface190. The curved surface221is conformed to the curvature of tread surface190of the tire160.

Extending from second side section216, in a direction perpendicular to front surface200(i.e. outwardly from the front surface), is a second curved fender240. Second curved fender240has a curved surface241, which faces tread surface190of tire162and is in close proximity thereto, i.e. spaced by gap192ofFIG.5A. Curved surface241has a width approximately equal to the width of tread surface190. Curved surface241is conformed to the curvature of tread surface190of the tire160.

Lower wheel well cover portions130aand130bofFIGS.1and2, are described with respect toFIGS.4A and4B. Lower wheel well cover portion130ahas a curved edge250affixed to and conforming with a curved edge of curved surface221of first fender220. The wheel well cover portion130aextends from curved edge250in a direction parallel to arrow215. Wheel well cover portion130bhas a curved edge252affixed to and conforming with a curved edge of curved surface241of second curved fender240. Wheel well cover portion130bextends from curved edge252in a direction parallel to arrow217.

As described further below with regard toFIG.6, upper wheel well member132mates with a lower wheel well member180on the removable wheel drive assembly110to form a sealed wheel well when removable wheel drive assembly110is installed on wheeled base104. The upper and lower wheel well members are designed to interconnect when removable wheel drive assembly110is mounted on mobile base104in wheel drive region124to form a seal to limit/prevent dust (and other matter) from entering the motor drive unit170, which may otherwise cause premature failure of motor drive unit170. In addition, wheel well cover portions130aand130bof lower wheel well member180mate with leg portions132aand132bof upper wheel well portion131to form a sealed external cover portion about wheel drive region124.

FIG.6shows a front perspective view of upper wheel well member132mounted on mobile base104mated with lower wheel well member180on the removable wheel drive assembly110. In this view, wheel160and tire162are not depicted, so the engagement of upper and lower wheel well members may be clearly seen. Moreover, base portion202of lower wheel well member180, which is normally connected to mounting bracket140of wheel drive assembly110, is shown to be disconnected. This is also to more clearly depict the engagement of upper wheel well member132and lower wheel well member180.

Forming part of upper wheel well132is a thin arched flange member300, which is part of frame portion302. Frame portion302is part of the mobile base frame120shown inFIG.1. Thus, upper wheel well member132comprises arched flange member300and upper wheel well portion131. Leg portions132aand132cand arch132cdefine an inner surface310, which act as an upper fender for tire162. The inner surface310has a surface width approximately the same width as surfaces221and241, respectively, of first and second fenders220and240. Thus, together the first and second fenders221and241and surface310form a fender for tire162with a very small gap between the tire surface and the fender as shown inFIG.5A. This design guards against safety issues, such as finger entrapment between wheel and wheel well.

When lower wheel well portion180is mated with upper wheel well portion132, curved or arched top surface212of central section210engages with complementarily curved/arched flange member300, together forming a closed or sealed surface bounded by fender surfaces240,241, and310. The only opening in the surface is aperture182through which the axle for mounting wheel160is disposed. The region in which wheel160and tire162are mounted is sealed to limit/prevent dust (and other matter) from entering the motor drive unit170.

Various embodiments of the present invention may be characterized by the potential claims listed in the paragraphs following this paragraph (and before the actual claims provided at the end of this application). These potential claims form a part of the written description of this application. Accordingly, subject matter of the following potential claims may be presented as actual claims in later proceedings involving this application or any application claiming priority based on this application. Inclusion of such potential claims should not be construed to mean that the actual claims do not cover the subject matter of the potential claims. Thus, a decision to not present these potential claims in later proceedings should not be construed as a donation of the subject matter to the public.

The embodiments of the invention described above are intended to be merely exemplary; numerous variations and modifications will be apparent to those skilled in the art. All such variations and modifications are intended to be within the scope of the present invention as defined in any appended claims.