# US 10,371,237 B2 · Belt wave drives > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,371,237 B2 - Document ID: US10371237B2 - Status: Granted - Kind: B2 - Application number: 15/588,293 - Filed: 2017-05-05 - Published: 2017-08-24 - Granted: 2019-08-06 - Earliest claimed: 2014-06-23 - Assignees: SRI International - Applicants: SRI International - Inventors: Karen Shakespear Koenig; Pablo Eduardo Garcia Kilroy - Web page: https://patentgrep.com/patent/US10371237B2 ## CPC - F16H 9/26: with members having orbital motion - F16H 7/02: with belts; with V-belts - F16H 55/38: Means or measures for increasing adhesion - F16H 55/54: of which the bearing parts are radially adjustable - F16H 57/08: of gearings with members having orbital motion - F16H: GEARING ## Abstract A belt wave drive transmission system and method are shown involving a first rotor (10) having a first drum configured to rotate about its axis of rotation and a second rotor (20) having a second drum configured to rotate about its axis of rotation, where the first rotor (10) is constrained to orbit concentrically about the axis of rotation of the second drum. A belt (30) encircles the first and second drums to couple the first (10) and second (20) rotors such that the first rotor (10) moves concentrically around the second rotor (20) as the belt (30) advances about a circumference of the second drum. In further refinements, the system and method involve electrically controllably coupling at least one of the first and second rotors to the belt. ## Claims ### Claim 1 A variable transmission system, comprising: a first rotor configured to rotate about its axis of rotation; a second rotor comprising a drum configured to rotate about its axis of rotation, wherein the first rotor is constrained to orbit concentrically about the axis of rotation of the drum; and a belt encircling the first rotor and the drum, wherein the belt couples the first and second rotors such that as the first rotor moves concentrically around the drum the belt advances about a circumference of the drum, wherein the drum has a variable diameter that provides a variable gear ratio. ### Claim 2 (depends on 1) The variable transmission system of claim 1, wherein the first rotor comprises a rod coupled to a plate. ### Claim 3 (depends on 2) The variable transmission system of claim 2, wherein the plate is coupled to an axle driven by a motor. ### Claim 4 (depends on 1) The variable transmission system of claim 1, wherein the drum comprises a plurality of segments, and wherein the segments are adjustable to vary the diameter of the drum. ### Claim 5 (depends on 4) The variable transmission system of claim 4, wherein the plurality of segments is defined by a plurality of slits that run along a length of the drum. ### Claim 6 (depends on 1) The variable transmission system of claim 1, further comprising a diameter adaptor, wherein the diameter adaptor is coupled to the second rotor such that axial movement of the diameter adaptor varies the diameter of the drum. ### Claim 7 (depends on 1) The variable transmission system of claim 1, wherein the drum has a conical shape that provides the variable diameter. ### Claim 8 (depends on 1) The variable transmission system of claim 1, wherein a position of the first rotor relative to the axis of rotation of the drum is adjustable. ### Claim 9 (depends on 1) The variable transmission system of claim 1, wherein the belt and the drum are configured to be electrically coupled. ### Claim 10 (depends on 9) The variable transmission system of claim 9, wherein the belt and the first rotor are configured to be electrically coupled. ### Claim 11 (depends on 9) The variable transmission system of claim 9, wherein the belt and the drum are configured to be electrically coupled through an electrolaminate effect between the belt and an outer surface of the drum. ### Claim 12 A method for providing a variable gear ratio, comprising: providing a first rotor configured to rotate about its axis of rotation; providing a second rotor comprising a drum configured to rotate about its axis of rotation, wherein the first rotor is constrained to orbit concentrically about the axis of rotation of the drum, wherein the drum has a variable diameter that provides the variable gear ratio; coupling the first and second rotors with a belt, wherein the belt encircles the first rotor and the drum; adjusting a diameter of the drum; and moving the first rotor concentrically around the drum with the adjusted diameter to advance the belt about a circumference of the drum with the adjusted diameter. ### Claim 13 (depends on 12) The method of claim 12, wherein moving the first rotor concentrically around the drum comprising driving the first rotor by a motor. ### Claim 14 (depends on 13) The method of claim 13, wherein the first rotor comprises a rod coupled to a plate, and wherein the plate is coupled to an axle driven by the motor. ### Claim 15 (depends on 12) The method of claim 12, wherein the drum comprises a plurality of segments defined by a plurality of slits that run along a length of the drum, wherein adjusting the diameter of the drum comprises adjusting the plurality of segments. ### Claim 16 (depends on 12) The method of claim 12, wherein the second rotor is coupled to a diameter adaptor, wherein adjusting the diameter of the drum comprises moving the diameter adaptor in an axial direction. ### Claim 17 (depends on 12) The method of claim 12, further comprising: adjusting a position of the first rotor relative to the axis of rotation of the drum. ### Claim 18 (depends on 12) The method of claim 12, further comprising: electrically coupling the belt and the drum. ### Claim 19 (depends on 18) The method of claim 18, further comprising: electrically coupling the belt and the first rotor. ### Claim 20 (depends on 18) The method of claim 18, wherein electrically coupling the belt and the drum comprises electrically coupling the belt and the drum through an electrolaminate effect between the belt and an outer surface of the drum.