SUNLESS PLANETARY GEAR AND METHOD FOR USE

Abstract

A gearbox is disclosed. The gearbox can have planetary gears. Each planetary gear can revolve around a rotational center of itself while concurrently revolving around a rotational center of the gear system as a whole. The gearbox can be used to deliver rotational output energy at a right (or other angle) from the direction of a received input energy.

Claims

1. A gearbox device comprising: planetary gears; no sun gear; a first ring gear; a second ring gear transversely spaced from the first ring gear; a flange between the first ring gear and second ring gear; and a frame, wherein the first ring gear is fixed to the frame; a gearbox central port through a radial center of the planetary gears a passing element extending across and through the gearbox central port, wherein the passing element comprises at least one of cooling fluid, fuel, wires, or cables.

2. The device of claim 1, wherein the planetary gears have a first external radius and a second external radius, and wherein the first external radius is constant along a first region of each planetary gear, and wherein the second external radius is constant along a second region of each planetary gear.

3. A gearbox device comprising: planetary gears; a first sun gear; and no ring gear.

4. The device of claim 3, wherein: the first sun gear has a first transverse position in the gearbox device; and the device further comprises a second sun gear having a second transverse position in the gearbox device separated from the first sun gear.

5. A gearbox device comprising: a planetary gear having a first tooth and a second tooth, wherein the first tooth and the second tooth are on the radial outside of the planetary gear, and wherein the first tooth has a larger radius from a planetary gear rotational center than the second tooth.

6. The device of claim 5, wherein the first tooth has a first top land, and wherein the first top land has a constant radius from the planetary gear rotational center along the length of the first tooth.

7. The device of claim 6, wherein the second tooth has a second top land, and wherein the second top land has a constant radius along the length of the second tooth.

8. The device of claim 5, wherein the second tooth has a second top land, and wherein the second top land has a constant radius along the length of the second tooth.

9. The device of claim 5, wherein the planetary gear further comprises a third tooth that has a third top land, and wherein the third top land has a constant radius from the planetary gear rotational center along the length of the third tooth.

10. The device of claim 9, wherein the first tooth is on a first longitudinal side of the second tooth, and wherein the third tooth is on a second longitudinal side of the second tooth, and wherein the third tooth has a radius from the rotational center of the planetary gear that is less than the radius of the second tooth from the rotational center of the planetary gear.

11. The device of claim 10, wherein the third tooth has a radius from the rotational center of the planetary gear that is equal to the radius of the first tooth from the rotational center of the planetary gear.

12. The device of claim 5, wherein the first planetary gear comprises a magnet.

13. The device of claim 12, wherein the magnet comprises an electro-magnet.

14. The device of claim 12, wherein the magnet comprises a permanent magnet.

15. The device of claim 5, wherein the first planetary gear comprises a toothless friction surface.

16. The device of claim 5, further comprising a ring gear.

17. The device of claim 5 wherein the device has no sun gear.

18. The device of claim 5, further comprising a sun gear.

19. The device of claim 5, wherein the device has no ring gear.

20. The device of claim 5, further comprising a slip ring.

21. The device of claim 5, further comprising a frameless motor and a planetary gear frame, wherein a center port radius of the frameless motor is equal to or greater than a center port of a planetary gear frame.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG. 1 illustrates a variation of a gearbox device.

[0015] FIGS. 2a and 2b are variations of cross-section A-A of the device of FIG. 1. (FIG. 2a does not show the planet gear axle and planet bearing for illustrative purposes.)

[0016] FIGS. 3a and 3b illustrate a variation of the planet gear.

[0017] FIG. 3c is a variation of cross-section B-B of the planet gear of FIG. 3b.

[0018] FIGS. 3d through 3h are simplified views of variations of the planet gears.

[0019] FIG. 4 illustrates a variation of the gearbox device.

[0020] FIG. 5a illustrates a variation of the gearbox device having a motor (the frame is not shown for illustrative purposes).

[0021] FIG. 5b illustrates a variation of the gearbox device (the frame is not shown for illustrative purposes).

[0022] FIG. 6a is a variation of cross-section C-C of the gearbox device of FIG. 4 with one planet gear not shown in cross-section and the planet gear axles not shown for illustrative purposes.

[0023] FIG. 6b is a variation of cross-section C-C of the gearbox device of FIG. 4.

[0024] FIG. 7 is a sectional view of a variation of selected internal elements of the gearbox device of FIG. 4.

[0025] FIG. 8a illustrates a variation of the gearbox device.

[0026] FIG. 8b is an end view of the gearbox device of FIG. 8a with one planet carrier and some ring gears removed for illustrative purposes.

[0027] FIG. 8c is a variation of a partial cross-section D-D of the gearbox device of FIG. 8a.

[0028] FIG. 8d illustrates a variation of a planet gear from the gearbox device of FIG. 8a.

[0029] FIG. 9a is a schematic view of a variation of the sunless planetary gear in use.

[0030] FIG. 9b is a schematic view of a variation of the ringless planetary gear in use.

DETAILED DESCRIPTION

[0031] FIGS. 1, 2a, and 2b illustrate that a variation of a planetary gearbox device that can have planet and ring gears. The gearbox device can have a gearbox frame or housing. The planetary gearbox device can have a planetary gearbox longitudinal axis. The gearbox frame can have a gearbox frame first side on a first longitudinal side of the gearbox and a gearbox frame second side on a second longitudinal side of the gearbox opposite to the first longitudinal side. The gearbox frame first side can be integrated with the gearbox frame second side (e.g., two sides of a single cast part). The gearbox frame first side can be separated and distinct from the gearbox frame second side. For example the gearbox frame first side can be fixed to a first longitudinal side of a gearbox frame spacer, and the gearbox second side can be fixed to a second longitudinal side of a side of the gearbox frame spacer.

[0032] The gearbox can have a gearbox mount, such as a flange extending off the gearbox frame. The gearbox mount can be attached to the remainder of the gearbox frame, such as by one or more gearbox mount screws. The gearbox mount can be fixedly attached to an external structure such as a car chassis or robotic arm or leg.

[0033] The gearbox device can have from about two (e.g., with “empty spots” where at least third and fourth planet gears would otherwise be between the two planet gears, the “empty spots” occupied by spacers, tubes or closed channels carrying fluids—the fluid can be agitated as the tube rotates around the gearbox device during use, impeller or fan for example to blow fluid through the gearbox such as for cooling, or combinations thereof) to about 1,000 planet gears, more narrowly from about six to 100 planet gears, even more narrowly from about ten to about twenty. For example, the gearbox can have a prime number of planet gears, such as seven, 11, 13, or 17 planet gears.

[0034] The radial outer surface of the planet gears can have planet gear teeth. The planet gears can have a stepped cylindrical shape, having cylindrical shapes of different radii with right angled steps between the regions with different radii, as shown in FIGS. 1-3. The planet gears can have varying conical shapes with differing constant angles away from the longitudinal axis. The planet gears can have steps and varying conical shapes.

[0035] The gearbox device can have a center port extending longitudinally through the radial center of the set of planet gears. The center port can be empty. Cables or wires can extend through the center port. A gearless tube or channel can extend through the central port. Fluid and/or solid elements, such as cooling fluid, fuel, wires, or cables, can extend or flow through the gearless tube or channel. The gearless tube or channel can have a large enough outer diameter to contact the planet gears or a small enough outer diameter to not contact the planet gears.

[0036] The radial inside surface of the gearbox frame first side at the center port can have, be fixedly attached to, or form a first (fixed) ring gear. The first ring gear can have first ring gear teeth. The radial inside surface of the gearbox frame second side at the center port can have, be fixedly attached to, or form a second (fixed) ring gear. The second ring gear can have second ring gear teeth.

[0037] The planet gear teeth can mesh, engage, or interface with the respective fixed ring gear teeth.

[0038] The planet gears each can have a bearing, shaft, or axle port extending through the length of the radial center of each planet gear. A planet gear bearing, shaft, or axle can extend through the planet gear axle port. Each planet gear can rotate around its respective planet gear axle which can extend along the planet gear longitudinal axis.

[0039] The gearbox device can have a carrier plate. The carrier plate can be cylindrical shaped with a hole in the radial middle aligned with the center port of the gearbox device. The carrier plate can have a carrier mount port for every planet gear (and “empty spots”, if any). The radial center of each carrier mount port can align with each planet gear longitudinal axis and any “empty spot” (e.g., tubes, channels) longitudinal axis.

[0040] The planet gears can be spaced apart from each other so there is a gap between the planet gears and they do not directly contact each other.

[0041] The planet gears can each rotate along the planet gear longitudinal axis with respect to the respective carrier mount ports, for example through bearings in the planet axle channel and/or in the carrier mount port, as shown in FIG. 2b. The planet gears can each have a planet axle channel that terminates at the planet axle ports. The radial center of each planet axle channel can align with the longitudinal axis of the planet gear and/or the carrier mount port.

[0042] Each planet gear can be translatably fixed and rotatably attached to a planet bearing. The planet bearing can be between the planet axle and the surface of the planet axle channel and/or between the planet axle and the radial surface of the carrier mount port. The planet bearing can have a bearing inner ring, a bearing outer ring radially outside of the bearing inner ring (with respect to the radial center of the planet axle) and bearing rollers or balls radially between the bearing inner ring and bearing outer ring (with respect to the radial center of the planet axle). The planet bearing can have a lubricant between the bearing outer ring and the bearing inner ring. The bearing outer ring and bearing inner ring can be permanent magnets repelling each other.

[0043] The planet gears can each be translatably fixed with respect to the respective carrier mount ports, for example via the planet gear shaft or axle that can extend through and out of the planet axle port and into the carrier mount port.

[0044] The gearbox device can have an output flange radially outside of the planetary gears The radial exterior of the output flange can have, be fixedly attached to, or form an output arm.

[0045] The radial inside of the output flange can have, be fixedly attached to, or form an output ring gear.

[0046] The planet gear teeth can mesh, engage, or interface with the respective output ring gear teeth.

[0047] The output ring gear, output flange, and output arm can be configured to rotate with respect to the longitudinal axis of the carrier or center port of the gearbox device and deliver output energy to an energy receiver, such as a robotic arm or leg, driveshaft for an impeller, propeller or turbofan (e.g., for pumps or airplanes), axle or wheel (e.g., for road vehicles, for example positioning the entire gearbox device and motor in or adjacent to a wheel), or combinations thereof.

[0048] The output gear can rotate in the opposite direction of the planet carrier.

[0049] The planetary gearbox device can have no sun gear.

[0050] Rotation of the planet carrier about a planet carrier longitudinal central axis can cause the rotation of each planet gears around its respective planet gear longitudinal axis and around the planet carrier longitudinal central axis. These two rotations of the planet gear can cause the rotation of the output ring gear around a central longitudinal axis of the planet ring gear (e.g., which can be collinear with the planet carrier longitudinal central axis).

[0051] FIGS. 3a through 3c illustrate that the planet gear can have a planet gear longitudinal axis. The planet gear can have a planet bearing, shaft, or axle ports that can be at the terminal longitudinal ends of a planet bearing, shaft or axle channel.

[0052] The planet gear can have multiple longitudinal engagement zones, areas, lengths or regions. The longitudinal engagement regions can be longitudinally sequential with each other. The planet gear can have a proximal, proximal-middle (proximal-central), distal-middle (or distal-central), and distal engagement regions that can have proximal, proximal-middle, distal-middle, and distal teeth, respectively that can engage and interface with teeth on a corresponding ring (or sun) gear.

[0053] The teeth on the different regions can have the same or different teeth dimensions as the teeth on the other regions, such as the pitch, the face width, addendum, dedendum, total depth, working depth, tooth thickness, fillet radii, tooth space, or combinations thereof. For example, regions that are longitudinally symmetrical about the longitudinal centerline plane can have identical teeth dimensions as each other, and non-symmetrically located regions can have different teeth dimensions from each other.

[0054] The different engagement regions can have the same or different outer radii. Engagement regions with different outer radii can have a gear ratio other than 1:1, for example driving more than one output flange or output gear.

[0055] The different engagement regions of a planetary gear can align and mesh/engage/interface with different regions of one or more ring gears, or each planetary gear engagement region can align with and interface an entirely different ring gear.

[0056] One or more non-engagement regions can be between and/or at the longitudinal ends of the engagement regions. For example, a planet gear can have non-engagement regions interspersed along and/or at the ends of the planet gear. For example, the non-engagement regions can have a smaller radius than needed to engage or contact the adjacent ring or sun gear, and/or the non-engagement regions can be toothless (e.g., if the engagement regions have teeth) and/or magnetless (e.g., if the engagement regions have magnets) and/or effectively frictionless (e.g., if the engagement regions are friction drive regions). The non-engagement region can be in contact with a roller (e.g., to measure angular position and/or rotational speed), reflective (e.g., to measure position and/or rotational speed with an optical sensor), have blades extending radially inwardly and/or outwardly (e.g., to control fluid flow around the planet gear and/or macerate or otherwise condition or stir material adjacent to the planet gear), or combinations thereof.

[0057] The distal and/or proximal engagement regions can have an outer radius D1 from about 5 mm to about 500 mm, more narrowly from about 10 mm to about 20 mm, for example about 10 mm, 15 mm, and 20 mm.

[0058] One or both of the middle engagement regions can have an outer radius D2 from about 5 mm to about 500 mm, more narrowly from about 10 mm to about 20 mm, for example about 10 mm, 15 mm, and 20 mm.

[0059] D2 can be larger or smaller than D1. The difference between D2 and D1 can be from D2 being about 50% smaller to about 100% larger (but not 0%) than D1, more narrowly from 1% larger to about 25% larger, for example 15% larger, 10% larger, or 5% larger. For example D2 can be about 115% of D1.

[0060] The gear ratio can directly correlate and scale with D1/(D2−D1). The gear ratio can also be influenced by other dimensions, such as the dimensions of the ring or sun gear.

[0061] Any engagement region can have an engagement region length (shown in FIG. 3b for the distal engagement region) D3 from about 25 mm to about 2500 mm, more narrowly from 50 mm to about 100 mm, for example about 50 mm, 75 mm, and 100 mm. The ratio of D3 to D1 can be about 5:1.

[0062] The engagement region lengths can be equal or differ between some or all of the engagement regions in a single planet gear. The outer radii of the distal and proximal engagement regions can be the same (as shown in FIG. 3b) or differ. The outer radius of the proximal-middle engagement regions can be the same or different from the outer radius of the distal-middle engagement region.

[0063] FIG. 3d illustrates that the planet gears can have one or more (e.g., all) engagement regions with radial outer surfaces that have slopes with respect to the planet gear longitudinal axis. The planet gears can have angled or sloped end engagement regions, and/or middle engagement regions. The sloped engagement regions can be sloped at the same or different angles.

[0064] The distal engagement region can have a radial outer surface with a distal engagement region angle with respect to the planet gear longitudinal axis. The distal-middle engagement region can have a radial outer surface with a distal-middle engagement region angle with respect to the planet gear longitudinal axis. The distal engagement region angle can be less (as shown in FIG. 3d), more, or equal to the distal-middle engagement region angle. The proximal-middle engagement region can have a proximal-middle engagement region angle that is less (shown as the negative of the distal-middle engagement region angle), more, or equal to the distal-middle engagement region angle.

[0065] A centerline ridge, rib or spine can be at the border between the proximal-middle engagement region and the distal-middle engagement region, as shown. An inter-region ridge, rib or spine can be at the border of adjacent engagement regions where the first engagement region with the smaller average outer radius has a larger engagement region angle than the adjacent second engagement region, or where adjacent engagement regions with equal radii have different engagement region angles, as shown between the middle engagement regions in FIG. 3d.

[0066] An inter-region crease, fold, valley, or gulley can be between the distal engagement region and the distal-middle engagement region, as shown. An inter-region crease can be at the border of adjacent regions where the first engagement region having a smaller average outer radius has a smaller engagement region angle than the adjacent second engagement region.

[0067] The planet gear can be symmetric (as shown) or asymmetric about the centerline plane (as shown in FIG. 3h) and/or about the planet gear longitudinal axis (e.g., a cammed lobe gear).

[0068] The planet gear can have a ridge, such as a centerline ridge (does not have to be at center or at a positive angle).

[0069] FIG. 3e illustrates that the planet gear can have five engagement regions. The planet gear can have a middle engagement region between the proximal-middle engagement region and the distal-middle engagement region. The engagement regions in a planet gear can each have the same engagement region lengths or one or more engagement regions can have different engagement region lengths. For example, as shown in FIG. 3e, the distal and proximal engagement region lengths can be larger than the middle engagement region length, and the middle engagement region length can be larger than the middle-proximal and middle-distal engagement region lengths.

[0070] The middle engagement region can have a cylindrical or flat (albeit possibly with teeth, texturing, or other non-flat interfacing feature) outer radial surface with respect to the planet gear longitudinal axis. The planet gear can have one or more angled or sloped engagement regions and one or more flat engagement regions.

[0071] FIG. 3f illustrates that the planet gear can have cylindrical or flat distal and/or proximal engagement regions and angled or sloped proximal-middle or distal-middle engagement regions.

[0072] FIG. 3g illustrates that the distal-middle engagement region can have a negative slope or angle and the proximal-middle engagement region can have a positive slope or angle. The centerline can be inverted as a centerline crease.

[0073] The distal and/or proximal engagement regions can have cylindrical or flat outer radial surfaces. The borders between the distal engagement region and the distal-middle engagement region and/or the proximal engagement region and the proximal-middle engagement region can each have a discrete radial step having a step wall face.

[0074] FIG. 3h illustrates that the planet gear can be longitudinally asymmetric. All or some of the longitudinally corresponding engagement regions can be asymmetric with respect to each other (as shown) and/or the lengths of the engagement regions can be irregular so there some or all of the engagement regions have no corresponding engagement region at the same longitudinal position opposite from the centerline.

[0075] For example, the proximal engagement region can be longitudinally symmetric with the distal engagement region, but the proximal-middle engagement region can have a different length and/or not the negative angle with respect to the distal-middle engagement region.

[0076] For the sake of not having an overly tedious detailed description, all other combinations and numbers of engagement regions having the outer radial surface configurations shown in FIGS. 3a through 3h are not illustrated but are considered to be disclosed herein to one having ordinary skill in the art.

[0077] FIG. 4 illustrates that the gearbox device can have one or more sun gears and planet gears. The gearbox housing or frame can have a radially outer portion or face that can encircle the sun gear(s) and planet gears and be fixed to the gearbox frame first side and/or gearbox frame second side. The housing radially outer portion can be radially spaced from the outer planetary gears. The housing frame can have housing assembly screw holes through which assembly screws can be attached to fix the housing radially outer portion to the proximal plate and/or the distal plate of the housing.

[0078] The planetary gearbox can have an output flange radially inside of the planet gears. The output flange can be attached to the one or more output sun gears. The output flange can have one or more flange screw holes or mount-holes that can be attached to and deliver output energy to an energy receiver,

[0079] FIGS. 5a, 5b, 6a, 6b and 7 illustrate that the gearbox device can have a motor longitudinally within the gearbox housing, that can deliver input energy to the planetary gears.

[0080] The motor can have a stator and rotor. The terminal radial outside surface of the stator can have, be attached to, or form the housing radially outer portion or face.

[0081] The rotor can be radially inside of the stator. The motor can have bearings (e.g., ball bearings) between the stator and rotor and/or the planet gears can act as bearings between the rotor and the stator. For example, if the rotor is fixed to the planet carrier, the motor can have no bearings positioned in the radial gap between the rotor and the stator.

[0082] The radially inside and/or longitudinal sides of the rotor can be fixedly attached or integrated with a proximal planet carrier and/or a distal planet carrier. For example, one or both of the distal planet carriers can be attached to (e.g. welded) or integrated with (e.g., cast) the rotor. The distal planet carrier can be longitudinally spaced apart from the proximal planet carrier. The planet carriers can be translatably fixed and rotatably attached to the respective ends of the planet gear shafts or axles.

[0083] The gearbox device can have a proximal (fixed) sun gear extending longitudinally inwardly from the gearbox housing/frame first side. The fixed sun gears can be radially (with respect to the gearbox housing) inside the planet gears. The gearbox device can have a distal (fixed) sun gear extending longitudinally inwardly from the gearbox housing/frame second side. The fixed sun gears can be fixed to the gearbox housing/frame.

[0084] The gearbox device can have one or more output sun gears radially (with respect to the gearbox housing) inside of the planet gears. The output sun gear can be longitudinally between the proximal sun gear and the distal sun gear. The output sun gear can have an outer radius larger or smaller than the outer radii of the proximal and distal sun gears. For example, the distal and proximal sun gears can have the same radii as each other.

[0085] The planet gear teeth can mesh, engage, or interface with the respective fixed sun gear teeth. For example, the planet gear distal teeth can longitudinally coincide or overlap with the distal sun gear teeth, the planet gear middle or central teeth can longitudinally coincide or overlap with the central (output) sun gear teeth, and the planet gear proximal teeth can longitudinally coincide or overlap with the proximal sun gear teeth.

[0086] The gearbox device can have no ring gears.

[0087] FIGS. 8a through 8d illustrate a sunless gearbox device that can have planet gears that can have multiple output ring gears that can concurrently deliver output energy at different rotational speeds and torques from each other through the single gearbox device.

[0088] For example, the gearbox device can have a fixed proximal and distal ring gears. The distal and proximal ring gears can be translationally and rotationally fixed to the case, frame or chassis. The gearbox device can have a proximal output ring gear and a distal output ring gear that can be connected and deliver output energy to the same or different first energy receivers. The proximal and distal output ring gears can have the same or different inner radii. The gearbox device can have a middle output ring gear that can be connected and deliver output energy to a second energy receiver different from the first energy receiver. During use, the middle output ring can rotate at a slower speed and deliver a higher output torque than the speed and torque of the proximal and distal output ring gears.

[0089] The proximal engagement region can be longitudinally symmetric about the planet gear's centerline plane and equal in outer radius to the distal engagement region (as shown), or can have different outer radii and/or be asymmetric with each other about the planet gear's centerline plane. The proximal-middle engagement region and the distal-middle engagement region can be longitudinally symmetric about the planet gear's centerline plane, equal in outer radius to each other, and have a larger outer radius than the proximal and distal engagement regions (as shown), or can have different outer radii and/or be asymmetric with each other about the planet gear's centerline plane and one or both can have a smaller outer radius than the proximal and/or distal engagement region. The middle engagement region can have a larger (as shown) or smaller outer radius than the distal-middle and/or proximal-middle engagement region.

[0090] FIG. 9a illustrates that when the sunless gearbox device is in use, an input rotational torque can be applied to the planet carrier. The planet carrier can rotate clockwise, as shown by planet carrier rotation arrow. The planet carrier can be translationally fixed to the planet gears. The centers of the planet gears can rotate clockwise (also shown by planet carrier rotation arrow) about the rotational center of the planet carrier. The rotational axis of the planet carrier can be collinear with the center axis of the fixed ring gear and/or output ring gear.

[0091] The planet gears can rotate about each of the planet gear's longitudinal axes, as shown by planet gear rotation arrow. For example, when the input rotational torque is transferred through the planet carrier to the planet gears and causes the planet gears to rotate with the planet carrier rotation, the fixed ring gear interface (between the planet gears and the fixed ring gear) can apply from the fixed ring gear to the planet gears a force opposing the planet gears' motion. This force can cause the planet gear rotation.

[0092] The planet gears can transfer the input rotational torque to the output ring gear. The planet gear rotation of the planet gears can rotate the output ring gear by transferring a force at the output ring gear interface. The output ring gear can then deliver the transferred force as an output torque and energy to an energy receiver.

[0093] FIG. 9b illustrates that when the ringless gearbox device is in use, an input rotational torque can be applied to the planet carrier. The planet carrier can rotate clockwise, as shown by planet carrier rotation arrow. The planet carrier can be translationally fixed to the planet gears. The centers of the planet gears can rotate clockwise (also shown by planet carrier rotation arrow) about the rotational center of the planet carrier. The rotational axis of the planet carrier can be collinear with the center axis of the fixed sun gear and/or output sun gear.

[0094] The planet gears can rotate about each of the planet gear's longitudinal axes, as shown by planet gear rotation arrow. For example, when the input rotational torque is transferred through the planet carrier to the planet gears and causes the planet gears to rotate with the planet carrier rotation, the fixed sun gear interface (between the planet gears and the fixed sun gear) can apply from the fixed sun gear to the planet gears a force opposing the planet gears' motion. This force can cause the planet gear rotation.

[0095] The planet gears can transfer the input rotational torque to the output sun gear. The planet gear rotation of the planet gears can rotate the output sun gear by transferring a force at the output ring gear interface. The output sun gear can then deliver the transferred force as an output torque and energy to an energy receiver.

[0096] The output flanges can be fixedly attached to clutches (e.g., to a compact automatic or manual transmission) and/or other power receiving elements.

[0097] The planet gears, ring gears, and sun gears can have teeth (as shown), can be toothless friction gears, magnetic-drive gears, or combinations thereof. For example, the gearbox can have longitudinally alternate between toothed and friction-drive gears and/or sections (e.g., having a toothed proximal sun gear, a toothless friction output (middle) sun gear, and a toothed distal sun gear, and planet gear with proximal teeth, distal teeth, and a middle toothless friction-drive section), and/or magnetic-drive gears and/or sections.

[0098] Magnetic drive sections can be toothed, friction drive, or neither. For example, the respective gears can have permanent and/or electromagnets (e.g., that can be turned off and on during use to activate and deactivate gears, for example to act as clutches for the respective output flange) that can attract or repel each other to transmit forces between gears. For example, the magnets on the proximal sun gear can transmit forces to the magnets in the proximal section of the planet gears. With the respectively connected gears and sections (e.g., the proximal sun gear and the planet gear proximal section) not being mechanically attached to each other, the magnetic respective interactions can reduce transmission of high impact or shock forces (i.e., acting as a mechanical damper or shock absorber.

[0099] Except for magnets or electrically conductive elements, any or all of the elements of the gearbox system disclosed herein can be made from metals, plastics (including resins), composites (e.g., resin and carbon fiber composites, metal matrix composites (e.g., carbon fiber reinforced aluminum), metal alloys), or combinations thereof. Permanent magnets can be made from permanent magnetic or ferromagnetic material. Electrically conductive elements (e.g., electromagnets) can be made from metals, electrically active plastics, conductive elastomers, or combinations thereof.

[0100] Any or all of the elements of the gearbox system disclosed herein can be made by injection molding, casting, three-dimensional printing, grinding, polishing, or combinations thereof.

[0101] Any and all references including patent applications and publications cited herein are incorporated herein by reference in their entirety and for all purposes to the same extent as if each individual publication or patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety for all purposes. Many modifications and variations of this disclosure can be made without departing from its spirit and scope, as will be apparent to those skilled in the art.

[0102] The specific variations described herein are offered by way of example only. The elements disclosed herein can be combined with each other in other variations than the specific variations disclosed herein. Any element described herein as being sole or singular can also be plural or multiple, and any element described herein as plural or multiple can also be sole or singular.