# US 2014/0150586 A1 · Internally-toothed gear unit with composite roller bearing, and wave gear device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0150586 A1 - Document ID: US20140150586A1 - Status: Published application - Kind: A1 - Application number: 14/131,894 - Filed: 2011-07-29 - Published: 2014-06-05 - Earliest claimed: 2011-07-29 - Assignees: Harmonic Drive Systems Inc. - Inventors: Satoru Kanai - Web page: https://patentgrep.com/patent/US20140150586A1 ## CPC - F16C 19/381: {with at least one row for radial load in combination with at least one row for axial load} - F16H 1/10: one of the members being internally toothed - F16H 49/001: {Wave gearings, e.g. harmonic drive transmissions} - Y10T 74/19647: Parallel axes or shafts - F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS - F16H: GEARING - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A wave gear device (30) uses, as a bearing which supports a first rigid internally-toothed gear (31) and a flexible externally-toothed gear (33) so as to be capable of rotation relative to each other, a composite roller bearing (38) equipped with a first roller (53) and second roller (54) for thrust bearing use and a third roller (55) for radial bearing use. Compared to a cross roller bearing or an angular bearing, the composite roller bearing (38) can be implemented as a highly rigid bearing in a small installation space. The first rigid internally-toothed gear (31) and the inner ring portion (51) of the composite roller bearing (38) are formed integrally as a single component, so an attachment part for connecting these members is not necessary. A highly rigid, flat wave gear device can be achieved. ## Claims ### Claim 1 An internally-toothed gear unit with composite roller bearing characterized in comprising: an internally-toothed gear and a composite roller bearing; wherein the internally-toothed gear has a first end surface and second end surface facing each other from a direction of a rotational center axis of the gear and extending in a direction perpendicular to the rotational center axis, and a circular external peripheral surface and circular internal peripheral surface positioned between the first end surface and the second end surface, internal teeth being formed in the circular internal peripheral surface; the composite roller bearing has an inner ring portion formed integrally with the internally-toothed gear, an outer ring, a plurality of first rolling objects, a plurality of second rolling objects, and a plurality of third rolling objects, with the first, second and third rolling objects being inserted in a rollable state between the inner ring portion and the outer ring; the inner ring portion has a first inner ring race surface formed in the first end surface of the internally-toothed gear, a second inner ring race surface formed in the second end surface of the internally-toothed gear, and a third inner ring race surface formed in the circular external peripheral surface of the internally-toothed gear; the outer ring has a first outer ring race surface facing the first inner ring race surface, a second outer ring race surface facing the second inner ring race surface, and a third outer ring race surface facing the third inner ring race surface; the first rolling objects for a thrust bearing are inserted between the first inner ring race surface and the first outer ring race surface; the second rolling objects for a thrust bearing are inserted between the second inner ring race surface and the second outer ring race surface; and the third rolling objects for a radial bearing are inserted between the third inner ring race surface and the third outer ring race surface. ### Claim 2 (depends on 1) The internally-toothed gear unit with composite roller bearing according to claim 1, wherein the outer ring comprises a first end plate having an end surface in which the first outer ring race surface is formed, a second end plate having an end surface in which the second outer ring race surface is formed, and a cylindrical member sandwiched between the first end plate and the second end plate and having a circular internal peripheral surface in which the third outer ring race surface is formed. ### Claim 3 (depends on 1) The internally-toothed gear unit with composite roller bearing according to claim 1, further comprising: a first retainer for a thrust bearing in which the first rolling objects are held between the first inner ring race surface and the first outer ring race surface in a rollable state; a second retainer for a thrust bearing in which the second rolling objects are held between the second inner ring race surface and the second outer ring race surface in a rollable state; and a pair of third retainer portions for a radial bearing which extend from ends of the first retainer and the second retainer to an area between the third inner ring race surface and the third outer ring race surface, the third rolling objects being held between the third inner ring race surface and the third outer ring race surface in a rollable state. ### Claim 4 (depends on 1) The internally-toothed gear unit with composite roller bearing according to claim 1, wherein columnar rollers are used as the first, second, and third rolling objects. ### Claim 5 A wave gear device characterized in comprising: an annular rigid internally-toothed gear; a flexible externally-toothed gear disposed coaxially on an inside of the rigid internally-toothed gear; a wave generator for causing the flexible externally-toothed gear to flex in a non-circular manner to partially mesh external teeth of the flexible externally-toothed gear with internal teeth of the rigid internally-toothed gear in the circumferential direction, and creating relative rotation between the gears by moving meshing positions of the gears in the circumferential direction; and a composite roller bearing for supporting the rigid internally-toothed gear and the flexible externally-toothed gear in a state that allows the two gears to rotate relative to each other; wherein the rigid internally-toothed gear has a first end surface and second end surface facing each other from a direction of a rotational center axis of the gear and extending in a direction perpendicular to the rotational center axis, and a circular external peripheral surface and circular internal peripheral surface positioned between the first end surface and the second end surface, internal teeth being formed in the circular internal peripheral surface; the composite roller bearing has an inner ring portion formed integrally with the internally-toothed gear, an outer ring, a plurality of first rolling objects, a plurality of second rolling objects, and a plurality of third rolling objects, with the first, second and third rolling objects being inserted in a rollable state between the inner ring portion and the outer ring; the inner ring portion has a first inner ring race surface formed in the first end surface of the internally-toothed gear, a second inner ring race surface formed in the second end surface of the internally-toothed gear, and a third inner ring race surface formed in the circular external peripheral surface of the internally-toothed gear; the outer ring has a first outer ring race surface facing the first inner ring race surface, a second outer ring race surface facing the second inner ring race surface, and a third outer ring race surface facing the third inner ring race surface; the first rolling objects for a thrust bearing are inserted between the first inner ring race surface and the first outer ring race surface; the second rolling objects for a thrust bearing are inserted between the second inner ring race surface and the second outer ring race surface; and the third rolling objects for a radial bearing are inserted between the third inner ring race surface and the third outer ring race surface. ### Claim 6 (depends on 5) The wave gear device according to claim 5, wherein the outer ring comprises a first end plate having an end surface in which the first outer ring race surface is formed, a second end plate having an end surface in which the second outer ring race surface is formed, and a cylindrical member sandwiched between the first end plate and the second end plate and having a circular internal peripheral surface in which the third outer ring race surface is formed. ### Claim 7 (depends on 5) The wave gear device according to claim 5, further comprising: a first retainer for a thrust bearing in which the first rolling objects are held between the first inner ring race surface and the first outer ring race surface in a rollable state; a second retainer for a thrust bearing in which the second rolling objects are held between the second inner ring race surface and the second outer ring race surface in a rollable state; and a pair of third retainer portions for a radial bearing which extend from ends of the first retainer and the second retainer to an area between the third inner ring race surface and the third outer ring race surface, the third rolling objects being held between the third inner ring race surface and the third outer ring race surface in a rollable state. ### Claim 8 (depends on 5) The wave gear device according to claim 5, wherein columnar rollers are used as the first, second, and third rolling objects. ### Claim 9 (depends on 6, 7, 8) The wave gear device according to any one of claims 6 to 8, wherein the flexible externally-toothed gear is a silk-hat-shaped gear comprising a cylindrical part capable of flexing in a radial direction, a discoid diaphragm widening outward in the radial direction from one end of the cylindrical part, an annular boss continuing from an external peripheral edge of the diaphragm, and the external teeth formed in an external peripheral surface portion at the other end of the cylindrical part; and the boss is fixed to either the first end plate or the second end plate of the composite roller bearing, or the boss is formed integrally as a part of either end plate. ### Claim 10 (depends on 6, 7, 8) The wave gear device according to any one of claims 6 to 8, wherein the flexible externally-toothed gear is a cup-shaped gear comprising a cylindrical part capable of flexing in a radial direction, a discoid diaphragm extending inward in the radial direction from one end of the cylindrical part, a discoid or annular boss continuing from an internal peripheral edge of the diaphragm, and the external teeth formed in an external peripheral surface portion at the other end of the cylindrical part; and the boss is fixed to either the first end plate or the second end plate of the composite roller bearing, or the boss is formed integrally as a part of either end plate. ### Claim 11 (depends on 6, 7, 8) The wave gear device according to any one of claims 6 to 8, further comprising: a second rigid internally-toothed gear disposed between the rigid internally-toothed gear and either the first endplate or the second endplate of the outer ring; wherein the flexible externally-toothed gear is of a cylindrical shape and has a cylindrical part flexible in a radial direction in which the external teeth are formed along a circular external peripheral surface of the cylindrical part; the second rigid internally-toothed gear is either fixed to the first or second end plate or formed integrally as part of the first or second end plate; the flexible externally-toothed gear has fewer teeth than the rigid internally-toothed gear and the same number of teeth as the second rigid internally-toothed gear; and the flexible externally-toothed gear is flexed in a non-circular manner by the wave generator and made to partially mesh with the rigid internally-toothed gear and the second rigid internally-toothed gear.