# US 12,766,620 B2 · Tool, gear machining apparatus, and method of machining gear > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,766,620 B2 - Document ID: US12766620B2 - Status: Granted - Kind: B2 - Application number: 18/841,786 - Filed: 2023-08-29 - Published: 2026-06-25 - Granted: 2026-10-20 - Earliest claimed: 2023-08-29 - Assignees: Jtekt Gear Systems Corporation - Applicants: Jtekt Gear Systems Corporation - Inventors: Kenichi Maruyama - Web page: https://patentgrep.com/patent/US12766620B2 ## CPC - B23F 19/06: Shaving the faces of gear teeth - B23F 19/10: Chamfering the end edges of gear teeth - B23F 19/12: by grinding - B23F 21/005: {with plural tools on a common axis} - B23F 21/02: Grinding discs; Grinding worms (truing grinding tools B24B; grinding tools in general B24D) - B23F 21/12: Milling tools - B23F 19/066: {with plural tools} - B23F 21/28: Shaving cutters - Y10T 407/17: Gear cutting tool - Y10T 407/1735: Rotary, gear shaving cutting tool - Y10T 407/1902: Gang - Y10T 409/101113: Gear chamfering or deburring - Y10T 409/10795: Process - B23F: MAKING GEARS OR TOOTHED RACKS (by stamping B21D; by rolling B21H; by forging or pressing B21K; by casting B22; arrangements for copying or controlling B23Q; machines or devices for grinding or polishing, in general B24B) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A tool includes a first tool member having first machining blades which are formed on an outer circumferential surface of a first tool body and which perform first machining on a workpiece gear and a second tool member having second machining blades which are formed on an outer circumferential surface of a second tool body and which perform second machining on the workpiece gear. The tool is formed such that, in a state in which the first tool member and the second tool member are combined, the first machining blades of the first tool member protrude toward the second tool member and the second machining blades of the second tool member are positioned at predetermined intervals in a circumferential direction relative to protruding portions of the first machining blades. ## Claims ### Claim 1 A tool comprising: a first tool member including first machining blades formed on an outer circumferential surface of a disk-shaped first tool body so as to be parallel to a rotation axis of the first tool body, the first machining blades performing first machining on a workpiece; and a second tool member including second machining blades which are formed on an outer circumferential surface of a disk-shaped second tool body so as to be twisted with respect to a rotation axis of the second tool body and which have a blade length along a direction of the rotation axis of the second tool body longer than that of the first machining blades, the second machining blades performing second machining on the workpiece, wherein, in a state in which the first tool member and the second tool member are combined such that the respective rotation axes of the first tool body and the second tool body are coaxial with each other, the machining blades of the first tool member are formed so as to protrude in the direction of the rotation axes from the first tool body toward the second tool member, and the machining blades of the second tool member are positioned at predetermined intervals in a circumferential direction relative to protruding portions of the machining blades of the first tool member. ### Claim 2 (depends on 1) The tool according to claim 1, wherein the first machining blades and the second machining blades are alternately arranged along an outer circumferential surface of the tool in a state in which the first tool member and the second tool member are combined. ### Claim 3 (depends on 1) The tool according to claim 1, wherein at least part of the machining blades of the first tool member has the protruding portions that protrude toward the second tool member, wherein the second tool member has circumferential gaps between adjacent ones of the second machining blades, and wherein the protruding portions respectively enter the circumferential gaps in a state in which the first tool member and the second tool member are combined. ### Claim 4 (depends on 3) The tool according to claim 3, wherein a formation circumferential pitch at which the first machining blades are formed in the first tool member and a formation circumferential pitch at which the second machining blades are formed in the second tool member are identical with each other. ### Claim 5 (depends on 1) The tool according to claim 1, wherein the number of the second machining blades of the second tool member is smaller than the number of the first tool blades of the first tool member. ### Claim 6 (depends on 5) The tool according to claim 5, wherein a circumferential formation pitch at which the second machining blades are formed in the second tool member is not less than twice a circumferential formation pitch at which the first machining blades are formed in the first tool member. ### Claim 7 (depends on 1) The tool according to claim 1, wherein a center axis of one of the first tool member and the second tool member is eccentric with respect to a center axis of the other of the first tool member and the second tool member. ### Claim 8 (depends on 7) The tool according to claim 7, wherein an outer diameter of the first tool body of the first tool member and an outer diameter of the second tool body of the second tool member are different from each other. ### Claim 9 (depends on 8) The tool according to claim 8, wherein the outer diameter of the first tool body is greater than the outer diameter of the second tool body. ### Claim 10 (depends on 1) The tool according to claim 1, wherein the first machining blades and the second machining blades have different blade heights each representing a height from a blade root to a blade tip. ### Claim 11 (depends on 10) The tool according to claim 10, wherein the blade height of the first machining blades is greater than that of the second machining blades. ### Claim 12 (depends on 1) The tool according to claim 1, wherein the workpiece is a workpiece gear, wherein each of the first machining blades is a phrasing blade that performs, as the first machining, phrasing machining to chamfer one end portion in a tooth trace direction of a tooth surface of the workpiece gear by meshing with the workpiece gear and pressing the one end portion, and wherein each of the second machining blades is a relief blade that performs, as the second machining, relief machining to remove a corner edge of one of four corner portions in the tooth trace direction of the tooth surface while meshing with the workpiece gear and pressing the one of the four corner portions. ### Claim 13 (depends on 1) The tool according to claim 1, wherein the workpiece is a workpiece gear, wherein each of the first machining blades is a phrasing blade that performs, as the first machining, phrasing machining to chamfer one end portion in a tooth trace direction of a tooth surface of the workpiece gear by meshing with the workpiece gear and pressing the one end portion, and wherein each of the second machining blades is a shaving blade that performs, as the second machining, shaving machining to remove irregularities of the tooth surface while meshing with the workpiece gear and contacting the tooth surface. ### Claim 14 (depends on 1) The tool according to claim 1, wherein a surface of each of at least the second machining blades is covered with a coating layer containing abrasive grains. ### Claim 15 (depends on 1) The tool according to claim 1, comprising: a first machining blade group including a plurality of ones of the first machining blades continuously arranged along the outer circumferential surface of the first tool body; and a second machining blade group including a plurality of ones of the second machining blades continuously arranged along the outer circumferential surface of the second tool body, wherein the first machining blade group and the second machining blade group are alternately arranged along an outer circumferential surface of the tool in a state in which the first tool member and the second tool member are combined. ### Claim 16 (depends on 1) The tool according to claim 1, wherein a first machining blade group including a plurality of ones of the first machining blades continuously arranged along the outer circumferential surface of the first tool body and one of the second machining blades are alternately arranged along an outer circumferential surface of the tool in a state in which the first tool member and the second tool member are combined. ### Claim 17 (depends on 1) The tool according to claim 1, wherein one of the first machining blades and a second machining blade group including a plurality of ones of the second machining blades continuously arranged along the outer circumferential surface of the second tool body are alternately arranged along an outer circumferential surface of the tool in a state in which the first tool member and the second tool member are combined. ### Claim 18 (depends on 1) A gear machining apparatus, comprising: the tool according to claim 1; a tool spindle configured to rotationally drive the tool; a workpiece spindle configured to rotationally drive a workpiece gear as the workpiece; and a moving device configured to move the workpiece spindle and the tool spindle relative to each other so as to enable the tool supported by the tool spindle and the workpiece gear supported by the workpiece spindle to be in mesh with each other, wherein the first machining and the second machining are repeatedly performed in one machining process. ### Claim 19 (depends on 18) The gear machining apparatus according to claim 18, wherein a surface of each of the second machining blades that perform the second machining is covered with a coating layer containing abrasive grains, and the second machining blades grind tooth surfaces of the workpiece gear. ### Claim 20 (depends on 1) A method of machining a gear, using: the tool according to claim 1; a tool spindle configured to rotationally drive the tool; a workpiece spindle configured to rotationally drive a workpiece gear as the workpiece; and a moving device configured to move the workpiece spindle and the tool spindle relative to each other so as to enable the tool supported by the tool spindle and the workpiece gear supported by the workpiece spindle to be in mesh with each other, wherein the method comprises continuously and repeatedly performing, in one machining process, the first machining and the second machining in order by performing the second machining following the first machining and performing the first machining following the second machining. ### Claim 21 (depends on 20) The method according to claim 20, wherein a surface of each of the second machining blades that perform the second machining is covered with a coating layer containing abrasive grains, and the second machining blades grind tooth surfaces of the workpiece gear.