Sprocket gearbox

Abstract

An assembly including a sprocket and a speed reducer, where the speed reducer assembly is contained within the sprocket. The sprocket has an outer surface and an inner surface, wherein the inner surface includes a toothed or grooved surface, and the speed reducer assembly includes one or more gears for engaging with the toothed or grooved surface of the inner surface of the sprocket.

Description

Filed via USPTO.gov on October 6, 2025 Attorney Docket No. 1755.006WOSPROCKET GEARBOXCLAIM OF BENEFIT OF FILING DATE

[0001] The present application claims the benefit of U.S. Provisional Application No. 63 / 707,336, filed on October 15, 2024, the content of which is hereby expressly incorporated by reference in its entirety for all purposes.FIELD

[0002] In general, the present teachings relate to a sprocket and gearbox, and more particularly to a sprocket with an integrated gearbox.BACKGROUND

[0003] Speed reducers, also known as gear boxes or gear reducers, are frequently used to reduce rotational speed while increasing torque. Such applications for speed reducers include machine tools and industrial equipment. Speed reducers are used in various industries such as automation, aerospace, industry, transportation, and medical. They boost performance, extend equipment life, allow for achieving necessary or desired rotational output needs, or a combination thereof. Conventional speed reducers use gears to reduce the speed of an input shaft and increase the torque on an output shaft.

[0004] Sprockets are used in vehicles or machinery to transmit rotary motion between two shafts where gears are unsuitable or are used to impart linear motion. As a sprocket rotates, it can be used to pull a linked chain, track, or belt. Sprockets use teeth to engage with or interlock with the chain, track, or belt.

[0005] Gears and sprockets are both used to transmit power or move items; however, the way they operate is different. Gears, such as a spur gear, also have teeth. These teeth interlock with other gears to transfer rotational movement.

[0006] In robotic applications, for example, there is a need for speed reducers in combination with gears and / or sprockets. Where a gear box is located at or near an end of a robot arm, there is a need for reduced mass and reduced size of the assembly. Thus, what is needed is a simplified assembly and / or lightweight assembly that combines the benefits of a gearbox (e.g. , decreases speed and increases the torque of an electric motor) and the benefits of a sprocket and / or gear. What is needed is an assembly that achieves these benefits with a relatively small footprint. What is needed is a compact assembly. What is needed is an assembly with a reduced mass that is still able to achieve the desired purpose.Filed via USPTO.gov on October 6, 2025 Attorney Docket No. 1755.006WOSUMMARY

[0007] The present teachings make use of a simple, yet elegant, construction approach by which relatively few components can be employed for achieving a sprocket with an integrated speed reducer or gearbox.

[0008] The present teachings envision an assembly having a sprocket and a speed reducer assembly contained within the sprocket. The sprocket may have an outer surface and an inner surface, where the inner surface includes a toothed or grooved surface. The outer surface of the sprocket may include a plurality of radial projections that may cover all or a portion of the outer surface. The speed reducer assembly includes one or more gears for engaging with the toothed or grooved surface of the inner surface of the sprocket. The assembly may have a gear reduction from about 6:1 to about 50:1 (e.g., about 14:1). The gears may be cycloid gears. The gears may be planetary gears. The assembly may include a motor that may include a motor shaft for driving the assembly. A mounting plate may be used to mount the sprocket to the motor. The mounting plate may include an extended portion (e.g., acting as a fin for heat transfer).

[0009] The assembly may include one or more sets of bearings. The bearings may be separate elements that are situated on or in other elements of the assembly. For example, the assembly may include two cycloid gears each having a central opening that receives a bearing. The size of the bearings may be the same. The size of the bearings may be different. In one example, a bearing within the cycloid gear adapted to be furthest from the motor may be smaller than the bearing of the cycloid gear adapted to be closer to the motor. The assembly may include an eccentric assembly having an eccentric with two or more eccentric portions. A bearing may be located on at least one of the eccentric portions. The bearing and the eccentric portion may be received within the central opening of a gear (e.g., the cycloid gear).

[0010] The bearings may be integrally formed with components of the assembly. The sprocket may form a raceway for one or more sets of rolling members. A support plate may form a raceway for one or more sets of rolling members. An outer plate may form a raceway for one or more sets of rolling members. The raceway of the sprocket may be an outer race and the raceway of the support plate may be an inner race with rolling elements therebetween to create a bearing. The raceway of the sprocket may be an outer race and the raceway of the outer plate may be an inner race with rolling elements therebetween to create a bearing.Filed via USPTO.gov on October 6, 2025 Attorney Docket No. 1755.006WO

[0011] The assembly may include a cap secured to the sprocket. The cap may act as a belt retainer. The assembly may include one or more rings (e.g., gasket, O-ring, spacer, lip seal). The assembly may include one or more grease input holes, one or more vent holes, or both. The assembly may include a support plate. The assembly may include an outer plate. The assembly may be held together via one or more assembly fasteners. The assembly fasteners may extend through an outer plate, cycloid gear, support plate and / or pins thereof, a mounting plate, or a combination thereof.

[0012] Thus, the present assembly is a simplified assembly that achieves the benefits and functions of both a sprocket and a speed reducer in one assembly.BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is an assembly including a motor, sprocket, and mounting plate in accordance with the present teachings.

[0014] FIG. 2 is an exploded view of an assembly in accordance with the present teachings.

[0015] FIG. 3 is a partial exploded view of a portion of the assembly including a speed reducer and a sprocket assembly in accordance with the present teachings.

[0016] FIG. 4 is a view of a portion of the assembly including a speed reducer and a sprocket in accordance with the present teachings.

[0017] FIG. 5 is a view of a portion of the assembly of FIG. 4 with the sprocket and cycloid gear assembly omitted.

[0018] FIGs. 6A and 6B illustrate an exemplary sprocket in accordance with the present teachings.

[0019] FIG. 7A illustrates an exemplary eccentric assembly in an assembled view in accordance with the present teachings.

[0020] FIG. 7B is an exploded view of the exemplary eccentric assembly of FIG. 7A.DETAILED DESCRIPTION

[0021] As required, details of the present teachings are disclosed herein; however, it is to be understood that the disclosed teachings are merely examples that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Some features may be omitted for clarity. Positions of some elements may be different than those shown in the figures. Therefore, specific structural and functional details disclosed herein are not to be interpretedFiled via USPTO.gov on October 6, 2025 Attorney Docket No. 1755.006WO as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present teachings.

[0022] The present teachings envision a simplified, elegant sprocket with an integrated gear box. A speed reducer assembly may be contained within a sprocket. The sprocket and speed reducer assembly may be mounted to a motor. The motor may be any motor that includes an elongated drive shaft or motor shaft capable of rotation. Exemplary motors include but are not limited to electric motors or servo motors.

[0023] The assembly of the present teachings contemplates a sprocket, a gear, or other rotational member. For simplicity, this is referred to hereinafter as a sprocket. The sprocket may have an outer surface and an inner surface. The sprocket may have a generally circular cross-section or generally circular profile. The sprocket may include one or more openings along an edge for receiving a fastener to secure a cap to the sprocket.

[0024] The sprocket may have radial projections extending from its outer surface. Radial projections may include bars, teeth, pins, grooves, or other textures. The radial projections may be adapted to engage with a chain, rack, belt, or other perforated or indented material. The sprocket may be a belt sprocket. The sprocket may be a gear sprocket. The radial projections may be equidistantly spaced relative to each other. The outer surface may be or may resemble a spur gear. The outer surface may be a double duty sprocket, hunting tooth sprocket, segmental rim sprocket, multiple strand sprocket, idler, sprocket, or the like. The radial projections may be located around the periphery of the outer surface of the sprocket. The radial projections may be located over the entire outer surface of the sprocket. The radial projections may be located over only a portion of the outer surface of the sprocket. At least a portion of the outer surface may be free of radial projections. This may allow for a ring (e.g., an O-ring) or other component to be added, to allow for connection of the sprocket to another element of the assembly, or both. For example, a band of smooth surface may be located on one portion of the outer surface (e.g., along the circumference of the outer surface of the sprocket at or near one edge of the sprocket), while an adjacent band of radial projections may be located on another portion of the outer surface (e.g., along the circumference of the outer surface of the sprocket at or near the opposing edge of the sprocket). An O-ring may be added on the smooth band and positioned adjacent the band of radial projections. The O-ring may act as a belt retainer and / or to contain grease within the assembly. The sprocket may have a frictional surface that engages with another surface. It is also contemplated that the sprocket may be a tire.

[0025] The inner surface of the sprocket may have an engagement surface with one or moreFiled via USPTO.gov on October 6, 2025 Attorney Docket No. 1755.006WO features adapted for engaging with one or more gears of the assembly. The inner surface of the sprocket may, for example, have a toothed surface, grooved surface, or interlocking surface to mesh with one or more gears (e.g., cycloid gears). The engagement surface may be located around the circumference of the inner surface. The engagement surface may be located over the entire inner surface of the sprocket. The engagement surface may be located over a portion of the inner surface of the sprocket. For example, the engagement surface may be located around the circumference of the inner surface where one or more gears will be positioned. The inner surface may be free of an engagement surface (e.g., free of teeth or grooves) in one or more areas. The inner surface may have one or more smooth surfaces.

[0026] The inner surface may include one or more smooth surfaces adapted to serve as an outer raceway for a bearing. The sprocket may form one or more bearings with one or more elements of the assembly (e.g., with a support plate, with an outer plate, or both). The inner surface may include one or more lips, inwardly projecting walls (e.g., toward the center of the circle when taken at a cross-section), and / or one or more walls oriented generally transverse to the outer raceway surface to retain rolling members (e.g., balls) of the integrated bearing.

[0027] For example, the sprocket may include smooth surfaces at or near each edge of the interior surface of the sprocket, with the engagement surface located therebetween. A bearing wall may project inwardly to separate the smooth surfaces and the engagement surface at or near each edge. A plurality of rolling members may be positioned at the bearing wall and smooth surface. The rolling members may be further retained to form a bearing with an outer plate at one edge of the sprocket and with a support plate at the opposing edge of the sprocket.

[0028] The assembly may include one or more gears. The gears may be cycloid gears. The assembly may include one or more cycloid gears. For example, the assembly may include two cycloid gears. Due to symmetrical load distribution, two cycloid gears may be offset (e.g., by about 180 degrees). The offset may provide compensation for unbalanced forces, resulting in smoother operations at high speeds. Two or more cycloid gears may be used to allow very high torques to be transmitted. The gears may be situated within the sprocket of the assembly. The gears may engage with the interior surface of the sprocket of the assembly.

[0029] A cycloid gear may include a central opening located generally at or toward the center of the cycloid gear. The central opening may be adapted to receive a motor shaft, an eccentric, a bearing, or a combination thereof.

[0030] A cycloid gear may include a plurality of pin openings. The pin openings may surround the central opening or may be radially disposed. The pin openings may be located between the centralFiled via USPTO.gov on October 6, 2025 Attorney Docket No. 1755.006WO opening and the teeth. The pin openings may be arranged to generally match the arrangement of the pins of the support plate. The pin openings may be generally round. The pin openings may be generally circular and have a diameter. The pin openings may be of sufficient size to receive the pins of the support plate. The pin openings may be of sufficient size to receive bushings or rollers on the pins of the support plate. The size of the pin openings may be dependent upon the size of the pins, bushings, rollers, or the like, the size of the cycloid gear relative to the size of the inner diameter of the sprocket, or a combination thereof.

[0031] The outer perimeter of the cycloid gear may include teeth, grooves, or other texture. The teeth, grooves, or other texture may be adapted to engage with an interior toothed, grooved, or textured surface of the sprocket.

[0032] The sprocket and speed reducer assembly may be mounted to a motor with a mounting plate. The mounting plate may be formed of one or more pieces. The mounting plate may include an opening for receiving the drive shaft or motor shaft. One or more assembly fasteners may be received within the mounting plate. For example, a plurality of assembly fasteners may be secured around the opening. The assembly fasteners may extend through or between multiple portions of the assembly (e.g., Outer plate, pins, cycloid gears, support plate) to contain the speed reducer assembly within the sprocket.

[0033] The mounting plate may include a raised surface generally surrounding the opening of the mounting plate and / or area receiving the assembly fasteners. The raised surface may act as a platform upon which a support plate may be affixed. A ring, such as a gasket, may be positioned around the raised surface and / or between the mounting plate and the support plate to ensure proper fitment between elements, reduce lash or rocking of components, seal mating surfaces, or a combination thereof.

[0034] The mounting plate may include an extended portion. The extended portion may extend in a direction generally transverse to the axis of the drive shaft or motor shaft. The extended portion may allow for securing the motor within another assembly. The extended portion may act as a fin for heat transfer to or from the assembly. The extended portion may include a plurality of openings. The openings may provide for various attachment positions, reduce weight, impact heat transfer, or a combination thereof. The extended portion may be integrally formed with the rest of the mounting plate. The extended portion may be attached to the portion of the mounting plate having the opening and / or raised surface.

[0035] The assembly may include a support plate. The support plate may be attached to or positioned on the mounting plate (e.g., at a raised portion). The support plate may remainFiled via USPTO.gov on October 6, 2025 Attorney Docket No. 1755.006WO generally fixed within the assembly such that it does not rotate. The support plate may have a generally circular profile. The support plate may include a central opening adapted to receive the motor shaft, a portion of an eccentric, a clamp, a bearing, or any combination thereof. The central opening may be generally aligned with the opening of the mounting plate.

[0036] The support plate may include one or more surfaces for supporting rolling members (e.g., balls). The support plate may have a surface serving as an inner raceway for a bearing. The support plate may include a portion that acts as a bearing wall to contain the rolling members. For example, the sprocket may include an outer race surface and a bearing wall. When the sprocket is assembled with the support plate, the support plate forms the inner race surface and an opposing bearing wall from the bearing wall of the sprocket, thus containing the rolling members and forming an integrated bearing within the assembly.

[0037] The support plate may include a plurality of extending members, such as pins extending from the face of the support plate. The pins may be positioned radially from the central opening. The pins may be positioned in alignment with openings of the mounting plate that receive the assembly fasteners. The pins may extend in a direction generally parallel to the motor shaft. The pins may be integrally formed with the support plate, attached to the support plate, or both. The pins may be generally cylindrical. The pins may be generally hollow. The pins may be adapted to receive assembly fasteners that extend to the mounting plate. The pins may have threads (e.g., if the assembly fasteners are threaded).

[0038] Bushings or rollers may be positioned on the pins (referred to hereinafter as bushings for simplicity). The bushings may act to reduce friction between the support plate pins and the gears (e.g., the walls defining the pin openings of a cycloid gear). The assembly may be free of bushings. A bushing may be combined with a pin in a single piece.

[0039] The assembly may include an outer plate that acts to contain the gear assembly. The outer plate may be positioned at an opposing edge of the sprocket from the support plate. The outer plate may have a face with one or more fastener openings adapted to receive the assembly fasteners. Thus, in one example, the assembly fasteners may extend from the outer plate to the mounting plate to secure the gear assembly within the sprocket.

[0040] The outer plate may have a generally circular profile. The outer plate may have a lip at, near, or around its circumference. The lip may act to at least partially contain a plurality of rolling members (e.g., by forming an inner raceway, forming a bearing wall, or both). The outer plate may form an inner raceway for a plurality of rolling members. For example, the outer plate may form an inner raceway and a bearing wall containing rolling members. The sprocket may form theFiled via USPTO.gov on October 6, 2025 Attorney Docket No. 1755.006WO outer raceway on its inner surface and may include a bearing wall generally opposite the bearing wall of the outer plate to form an integrated bearing between the sprocket and outer plate.

[0041] The assembly may include a cap. The cap may act to contain grease, keep out debris, contain the elements of the assembly, protect the elements of the assembly, or a combination thereof. The cap may act as a belt retainer. The cap may include one or more vent holes. The cap may include one or more grease input openings. The cap may be secured to the sprocket. The cap may include a plurality of openings for receiving fasteners for attaching the cap to the assembly (e.g., to the sprocket).

[0042] The assembly may include one or more rings. The rings may be gaskets, O-rings, spacers, lip seals, or the like. The rings may act to contain grease, reduce friction between elements, reduce lash between elements, reduce rocking or undesired movement or vibrations, ensure proper fitment between elements, create a proper seal between elements, or any combination thereof. For example, a ring may be located between the cap and the sprocket (e.g., an O-ring). A ring may be located between the toothed portion of the outer surface of the sprocket and a smooth part of the outer surface of the sprocket. This may be a lip seal to seal between the stationary support plate and the rotating sprocket. A ring may be located between the mounting plate and the support plate (e.g., a gasket).

[0043] The assembly may include an eccentric structure. The eccentric structure may function as an axle in the gear reduction mechanism. The eccentric structure may include an elongated bore extending therethrough for receiving a drive shaft, such as a motor shaft. The eccentric structure may include a plurality of eccentric portions that are out of phase with each other. For example, the eccentric structure may include two eccentric portions that are out of phase with each other. The eccentric portions may be adjoining. The eccentric portions may be spread apart from each other (e.g., they may be longitudinally spaced so that opposing faces may have a gap between them). The eccentric portions may be of different sizes or may have different sized diameters or largest dimensions. For example, an eccentric may have an eccentric portion having a larger diameter adjacent to an eccentric portion having a smaller diameter relative to the larger diameter.

[0044] In one exemplary eccentric, the eccentric may include a motor-facing end portion adapted to be situated on and secured to the drive shaft. At the opposing end may be a smaller eccentric portion. Located therebetween may be a larger eccentric portion. A bore may extend through the entirety of the eccentric for receiving the drive shaft. The bore may be off-center from the larger eccentric portion, smaller eccentric portion, or both. The larger eccentric portion and smaller eccentric portion may be offset from each other or out of phase with each other (e.g., about 180Filed via USPTO.gov on October 6, 2025 Attorney Docket No. 1755.006WO degrees out of phase with each other).

[0045] A clamp, strap, ring, fastener, or other member (referred to hereinafter as a clamp for simplicity) may be positioned on a portion of the eccentric. The clamp may act to secure the eccentric to a drive shaft or motor shaft. The clamp may prevent rotation of the eccentric separate from the rotation of the drive shaft. The clamp may engage with or be received within another portion of the assembly, such as walls defining an opening of a mounting plate, a support plate, or both. The clamp may act to reduce friction between the eccentric and other elements of the assembly. The clamp may include one or more fastener openings for receiving a fastener such as a screw, clip, pin, or the like. The clamp may allow for tightening of the fastener to clamp the eccentric. The clamp may be affixed to an end of the eccentric, such as the motor-facing end portion. The motor-facing end portion may include one or more features that engage with an interior surface of the clamp. The interior surface of the clamp, the motor-facing end portion, or both, may include one or more channels, corners, flat segments, keyed portions, or a combination thereof.

[0046] The eccentric may be received within one or more bearings. One or more bearings may be positioned on one or more portions of the eccentric. The bearings may be of different sizes depending on where the bearing is positioned on the eccentric. For example, one smaller diameter bearing may be positioned on a smaller eccentric portion. One larger diameter bearing may be positioned on a larger eccentric portion. In the assembly, the bearings may be positioned between the boundaries of a central opening of a gear (e.g., a cycloid gear) and the outer surface of a portion of the eccentric. The bearings may be ball bearings, roller bearings, or another suitable bearing for reducing friction between the gear (e.g., a cycloid gear) and the eccentric.

[0047] In operation, the motor shaft (e.g., with the eccentric secured thereto) may act to drive the cycloid gears within the assembly. For example, two cycloid gears may be positioned adjacent to each other in the assembly. The cycloid gears may be offset from each other. Each cycloid gear is driven to rotate around its axis of symmetry. The motor rotates its drive shaft about a drive shaft rotational axis (e.g., by way of the eccentric assembly), which, for example, may be aligned with or parallel to the axis of symmetry of each cycloid gear.

[0048] The support plate may remain fixed. The pins fixed to the support plate and any bushing or rollers thereon may extend into the pin openings of the cycloid gears arranged generally in a circle around the drive shaft and / or eccentric. As the cycloid gears rotate, walls defining the pin openings of the cycloid gear may contact and travel around the pins and / or bushings of the support plate. The cycloid gears may then engage with the teeth of the interior of the sprocket.Filed via USPTO.gov on October 6, 2025 Attorney Docket No. 1755.006WOThe sprocket may Be caused to rotate. Friction may be reduced due to the integrated bearings formed between the sprocket and outer plate, sprocket and support plate, or both.

[0049] The components of the assembly may be selected to achieve a desired gear reduction. A gear reduction of about 6:1 or greater, about 10:1 or greater, or about 12:1 or greater is contemplated. A gear reduction of about 50:1 or less, about 30:1 or less, or about 16:1 or less is contemplated. For example, the gear reduction may be 14:1.

[0050] Turning now to the figures, Figure 1 illustrates an exemplary assembly including a motor 10, a sprocket 90 containing a speed reducer assembly, and a mounting plate 40 mounting the sprocket 90 to the motor 10.

[0051] Figure 2 is an exploded view of an exemplary assembly. A motor 10 includes a motor shaft 12. An eccentric assembly 20 is situated on and driven by the motor shaft 12. An eccentric 22 is secured to the motor shaft 12 with a clamp 24. A larger diameter bearing 32 and a smaller diameter bearing 34 are adapted to be situated on the eccentric 22.

[0052] A mounting plate 40 is adapted to be secured to the motor 10 and has an opening 42 that receives the motor shaft 12. An extended portion 44 extends in a direction generally transverse to the motor shaft 12. A ring 50, shown as a gasket, is located between the mounting plate 40 and a support plate 60. The support plate 60 includes a plurality of pins 62 extending from its face. The pins 62 are at least partially threaded, hollow, or both. The pins 62 are adapted to receive assembly fasteners 110 that extend between an outer plate 100 and the mounting plate 40. A bushing 64 or roller is adapted to be situated on each pin 62. The bushings 64 and pins 62 are received within pin openings 84 of cycloid gears 80. It is also contemplated that the assembly may be free of bushings 64. For example, bushing 64 may be omitted. Pins 62 may be enlarged (e.g., if the bushing is omitted). A bushing may be combined with a pin in a single piece. The cycloid gears 80 include a central opening 82 for receiving at least a portion of the eccentric assembly 20.

[0053] The cycloid gears 80 engage with an interior surface of a sprocket 90. A ring 50, shown as a lip seal acting as a seal between the stationary support plate 60 and the rotating sprocket 90, is situated on, at, or near the open ends of the sprocket 90. A first set of a plurality rolling members 70 (shown as balls) are contained within the assembly between the support plate 60 and the sprocket 90. A second set of rolling members 70 (shown as balls) are located between the sprocket 90 and an outer plate 100. The outer plate 100 includes openings 104 (see Fig. 2) that receive the assembly fasteners 110 to contain the gear and bearings assembly within the sprocket 90. A cap 120 is secured to the sprocket 90 via a plurality of cap fasteners 122.Filed via USPTO.gov on October 6, 2025 Attorney Docket No. 1755.006WO

[0054] Figure 3 illustrates a partially exploded view of an assembly. For clarity, a motor and a cap, such as those shown in Fig. 2, have been omitted, though cap fasteners 122 are shown to illustrate where a cap may be attached to a sprocket 90 of the assembly. An outer plate 100 has been pulled away from the assembly to show certain elements within the assembly.

[0055] The outer plate 100 includes a face 102 having a plurality of fastener openings 104. A lip 106 is located around circumference of the outer plate 100.

[0056] Rolling elements 70 are located between the outer plate 100 and a portion of a sprocket 90. At least a portion of the outer plate 100 serves as an inner race 108 for the rolling elements, while at least a portion of the sprocket 90 serves as an outer race 98. The lip 106 of the outer plate 100 acts to at least partially contain the rolling elements. A bearing wall 96 of the sprocket 90 acts to at least partially contain the rolling elements.

[0057] A cycloid gear 80 is located within the interior of the sprocket 90. A second cycloid gear may be located behind the cycloid gear shown (see Fig. 4). Teeth 86 of the cycloid gear 80 are adapted to engage with an engagement surface, shown as an interior toothed surface 94 of the sprocket 90. The cycloid gear includes a central opening 82 that is adapted to receive a portion of a motor shaft 12, a portion of an eccentric 22, a smaller diameter bearing 34, or a combination thereof.

[0058] The assembly is secured to a mounting plate 40 via a plurality of assembly fasteners 110. The assembly fasteners 110 penetrate the fastener openings 104 of the outer plate 100 and extend through pins 62 of a support plate 60 to the mounting plate 40. The pins 62 are received within pin openings 84 of the cycloid gear 80. A bushing 64 is located on the pins 62.

[0059] The outer surface of the sprocket 90 includes radial projections 92. A ring 50, shown as an O-ring, is located on the outer surface of the sprocket adjacent the radial projections. The ring is located between the sprocket 90 and the cap 120.

[0060] Figure 4 illustrates an assembly with a cap, outer plate, and one cycloid gear removed. A cycloid gear 80 is located within a sprocket 90. Teeth 86 of the cycloid gear 80 are adapted to engage with an interior toothed surface 94 of the sprocket 90. The cycloid gear includes a central opening 82 adapted to receive a motor shaft 12 (not shown), an eccentric 22, a larger diameter bearing 32, or a combination thereof.

[0061] Figure 5 illustrates portions of an exemplary assembly with the cap, outer plate, cycloid gears, mounting plate, and sprocket removed for clarity. The assembly as shown includes a motor 10 with a motor shaft 12. A support plate 60 having a plurality of pins 62 extending therefrom is secured to the motor via a plurality of assembly fasteners 110. The pins 62 are generally hollowFiled via USPTO.gov on October 6, 2025 Attorney Docket No. 1755.006WO and / or threaded to receive the assembly fasteners 110. To illustrate this, some assembly fasteners have been omitted. A bushing 64 is located on each pin 62.

[0062] An eccentric assembly is secured to the motor shaft 12 with a clamp 24 and extends through the support plate 60, with an eccentric 22 supporting a pair of bearings, with a larger diameter bearing 32 located closer to the support plate 60 than a smaller diameter bearing 34.

[0063] The support plate 60 acts as an inner race 68 for rolling elements 70 (with only two shown as examples). A bearing wall 68 of the support plate 60 acts to at least partially contain the rolling elements.

[0064] Figures 6A and 6B illustrate an exemplary sprocket 90. Along at least a portion of its outer surface, radial projections 92 extend therefrom. The radial projections may be adapted to engage with a belt, chain, mesh, grooved surface, frictional surface, rack, the like, or a combination thereof. It is contemplated that a spur gear may be employed to engage with another gear or part of another assembly. A portion of the sprocket may be free of radial projections (e.g., may be a generally smooth surface). This area may receive or support another component of the assembly, such as flange (e.g., to act as a belt retainer).

[0065] The interior of the sprocket may have an interior toothed surface 94 or otherwise textured surface. The surface may be adapted to engage with one or more cycloid gears. The surface of the interior and / or number of teeth may be selected based on the desired gear reduction, transmission ratio, number of teeth or grooves on the cycloid gears, or a combination thereof.

[0066] The opposing ends of the sprocket 90 may create an outer race 98 for a plurality of rolling elements, thereby creating a portion of a bearing. A bearing wall 96 may extend inwardly, toward the center of the sprocket, and / or generally transverse to the surface of the outer race 98 to contain the rolling elements within the desired location. The rolling elements may be further contained by an inner race and bearing wall of another component within the assembly, such as an outer plate, support plate, or both. The sprocket may be adapted to receive one or more gaskets, spacers, O-rings, or the like for containing grease, for ensuring proper fit between other elements of the assembly, for reducing lash between elements, or a combination thereof.

[0067] Figures 7A and 7B illustrate an exemplary eccentric assembly 20, with Figure 7A showing the elements assembled and Figure 7B showing an exploded view. The eccentric assembly 20 includes an eccentric 22 having a bore 23 for receiving an input shaft such as a motor shaft 12 (see Fig. 5). The eccentric includes a motor-facing end 26 adapted to be situated toward the motor. On the opposing end of the eccentric is a smaller eccentric portion 30. A larger eccentric portion 28 is located therebetween, where the larger eccentric portion has a larger diameter orFiled via USPTO.gov on October 6, 2025 Attorney Docket No. 1755.006WO largest dimension than the diameter or largest diameter of the smaller eccentric portion. The smaller eccentric portion 30 is illustrated as being generally circular with the bore being offset from center. The larger eccentric portion 28 is illustrated as being generally circular with the bore being offset from center. The center of the larger eccentric portion is offset from the center of the smaller eccentric portion 30. While the eccentric portions are illustrated as being circular, other shapes, such as an oval or egg-shape are also contemplated.

[0068] A clamp 24 is positioned on the eccentric 22 at the motor-facing end. The clamp may function to secure the eccentric to the motor shaft, prevent rotation of the eccentric separate from rotation of the motor shaft, or both. A smaller diameter bearing 34 is positioned on the smaller eccentric portion 30. A larger diameter bearing 32 is positioned on the larger eccentric portion 28. The smaller and larger eccentric portions may be adapted to be received within a central opening of two adjacent cycloid gears, as shown in Figures 3 and 4.

[0069] While a cycloid gear assembly is described herein, other gear assemblies are also contemplated, such as a planetary gear assembly. The planetary gear assembly may include a centrally disposed sun gear and a plurality of radially disposed planet gears. The assembly may include a circumscribing ring gear. The interior of the sprocket may serve as the circumscribing ring gear. The planet gears may be adapted for rotation by way of a plurality of respective axles that are received within the gears and the planet carrier.

[0070] While ball bearings and roller bearings are described herein, other bearings are also contemplated, such as a plain bearing, needle bearing, taper bearing, cylinder bearing, angular bearing, spherical bearing, or a combination thereof. Separate bearings may be used instead of integrated bearings. For example, a separate bearing may be used instead of forming a bearing with rolling members, the sprocket, and the support plate and / or outer plate.

[0071] The present teachings may find use where speed reducers, gears, sprockets, or a combination are needed. The present teachings may find use where reduced mass and / or size are important. For example, but not limiting, the present teachings may be useful in robotics applications. A combined sprocket / gearbox could be located at the end of a robot arm.

[0072] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.Filed via USPTO.gov on October 6, 2025 Attorney Docket No. 1755.006WO

[0073] Any numerical values recited herein include all values from the lower value to the upper value in increments of one unit provided that there is a separation of at least 2 units between any lower value and any higher value. As an example, if it is stated that the amount of a component or a value of a process variable such as, for example, temperature, pressure, time and the like is, for example, from 1 to 90, preferably from 20 to 80, more preferably from 30 to 70, it is intended that values such as 15 to 85, 22 to 68, 43 to 51 , 30 to 32 etc. are expressly enumerated in this specification. For values which are less than one, one unit is considered to be 0.0001 , 0.001 , 0.01 or 0.1 as appropriate. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner.

[0074] Unless otherwise stated, all ranges include both endpoints and all numbers between the endpoints. The use of “about” or “approximately” in connection with a range applies to both ends of the range. Thus, “about 20 to 30” is intended to cover “about 20 to about 30”, inclusive of at least the specified endpoints.

[0075] The disclosures of all articles and references, including patent applications and publications, are incorporated by reference in their entireties for all purposes. The term “consisting essentially of” to describe a combination shall include the elements, ingredients, components or steps identified, and such other elements ingredients, components or steps that do not materially affect the basic and novel characteristics of the combination. The use of the terms “comprising” or “including” to describe combinations of elements, ingredients, components or steps herein also contemplates embodiments that consist essentially of, or even consisting of, the elements, ingredients, components or steps.

[0076] Plural elements, ingredients, components or steps can be provided by a single integrated element, ingredient, component or step. Alternatively, a single integrated element, ingredient, component or step might be divided into separate plural elements, ingredients, components or steps. The disclosure of “a” or “one” to describe an element, ingredient, component or step is not intended to foreclose additional elements, ingredients, components or steps.

[0077] Relative positional relationships of elements depicted in the drawings are part of the teachings herein, even if not verbally described. Further, geometries shown in the drawings (though not intended to be limiting) are also within the scope of the teachings, even if not verbally described.Filed via USPTO.gov on October 6, 2025 Attorney Docket No. 1755.006WOELEMENT LIST

Claims

Filed via USPTO.gov on October 6, 2025 Attorney Docket No. 1755.006WOCLAIMSWhat is claimed is:1 . An assembly comprising: a. a sprocket having an outer surface and an inner surface, wherein the inner surface includes a toothed or grooved surface; b. a speed reducer assembly contained within the sprocket, wherein the speed reducer assembly includes one or more gears for engaging with the toothed or grooved surface of the inner surface of the sprocket.

2. The assembly of claim 1 , wherein the outer surface of the sprocket includes a plurality of radial projections.

3. The assembly of any of the preceding claims, wherein the one or more gears are cycloid gears and / or planetary gears.

4. The assembly of claim 3, wherein the assembly includes two cycloid gears contained within the sprocket.

5. The assembly of claim 4, wherein the assembly includes two cycloid gears each having a central opening receiving a bearing; wherein the bearing within the cycloid gear adapted to be furthest from a motor is smaller than the bearing of the cycloid gear adapted to be closer to the motor.

6. The assembly of any of the preceding claims, wherein the assembly includes a mounting plate for mounting the assembly to a motor.

7. The assembly of any of the preceding claims, wherein the assembly includes a motor.

8. The assembly of claim 7, wherein the motor includes a motor shaft for driving the speed reducer assembly.

9. The assembly of any of the preceding claims, wherein the assembly includes one or more sets of bearings.Filed via USPTO.gov on October 6, 2025 Attorney Docket No. 1755.006WO10. The assembly of any of the preceding claims, wherein the assembly includes an eccentric assembly including an eccentric having two or more eccentric portions.

11. The assembly of claim 10, wherein the assembly includes a bearing on at least one of the eccentric portions.

12. The assembly of claim 11 , wherein the bearing and the eccentric portion are received within a central opening of a gear (e g., a cycloid gear).

13. The assembly of any of the preceding claims, wherein the sprocket forms a raceway for one or more sets of rolling members (e.g., balls).

14. The assembly of any of the preceding claims, wherein the assembly includes a support plate that forms a raceway for one or more sets of rolling members.

15. The assembly of any of the preceding claims, wherein the assembly includes an outer plate that forms a raceway for one or more sets of rolling members.

16. The assembly of claim 13 or 14, wherein the raceway of the sprocket is an outer race and the raceway of the support plate is an inner race with rolling elements therebetween to create a bearing.

17. The assembly of claim 13 or 15, wherein the raceway of the sprocket is an outer race and the raceway of the outer plate is an inner race with rolling elements therebetween to create a bearing.

18. The assembly of any of the preceding claims, wherein the assembly includes a cap secured to the sprocket.

19. The assembly of claim 18, wherein the cap acts as a belt retainer.

20. The assembly of any of the preceding claims, wherein the assembly includes one or more rings (e.g., gasket, O-ring, spacer).

21. The assembly of any of the preceding claims, wherein the assembly has a gear reduction from about 6:1 to about 50:1 (e.g., about 14:1).

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