# US 11,898,320 B2 · Circle drive system for a grading machine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,898,320 B2 - Document ID: US11898320B2 - Status: Granted - Kind: B2 - Application number: 16/664,090 - Filed: 2019-10-25 - Published: 2021-04-29 - Granted: 2024-02-13 - Earliest claimed: 2019-10-25 - Assignees: Caterpillar Inc. - Applicants: Caterpillar Inc. - Inventors: Bruce R. Vahling - Web page: https://patentgrep.com/patent/US11898320B2 ## CPC - E02F 3/844: {for positioning the blade, e.g. hydraulically} - E02F 3/7636: {Graders with the scraper blade mounted under the tractor chassis} - E02F 3/764: {with the scraper blade being pivotable about a vertical axis} - E02F 9/2079: {Control of mechanical transmission (for hydrostatic transmission or hydraulic torque converter E02F9/2253)} - E02F 9/2203: {Arrangements for controlling the attitude of actuators, e.g. speed, floating function} - E02F: DREDGING; SOIL-SHIFTING (winning peat E21C49/00) ## Abstract A grading machine includes a machine body, a grading blade supported by a circle, a drawbar connecting the grading blade and the circle to the machine body, and a circle drive system. The circle drive system includes a circle drive motor with a motor shaft, a gear box, a gear coupling, and a braking mechanism. The gear box is configured to engage with and rotate the circle relative to the drawbar around a circle axis. The braking mechanism is positioned between the circle drive motor and the gear coupling and is configured to selectively engage the motor shaft. ## Claims ### Claim 1 A grading machine, comprising a machine body; a grading blade supported by a circle; a drawbar connecting the grading blade and the circle to the machine body; and a circle drive system including a circle drive motor with a motor shaft, a gear box, a gear coupling, and a braking mechanism, wherein the gear box is configured to engage with and rotate the circle relative to the drawbar around a circle axis, wherein the gear coupling includes a worm and a worm gear, wherein the braking mechanism and the motor shaft are positioned between a housing of the circle drive motor and the worm, wherein the braking mechanism is configured to lock the housing of the circle drive motor and the motor shaft together when the braking mechanism is engaged, wherein one or more portions of the circle drive motor or the motor shaft include one or more grooves or notches, wherein the braking mechanism includes one or more locking elements that are configured to engage with the one or more grooves or notches to secure one or more of the circle drive motor or the motor shaft in a locked configuration, and wherein the one or more locking elements include one or more of ratcheted fingers, springs, or teeth. ### Claim 2 (depends on 1) The grading machine of claim 1, wherein the braking mechanism is a hydraulically actuated brake. ### Claim 3 (depends on 2) The grading machine of claim 2, wherein the hydraulically actuated brake is coupled to the circle drive motor. ### Claim 4 (depends on 1) The grading machine of claim 1, wherein the circle drive motor includes an axis of rotation that is perpendicular to the circle axis. ### Claim 5 (depends on 1) The grading machine of claim 1, wherein the worm includes an axis of rotation that is parallel to the axis of rotation of the circle drive motor and perpendicular to the circle axis. ### Claim 6 (depends on 1) The grading machine of claim 1, wherein the circle drive motor is a first circle drive motor, wherein the gear box is a first gear box, wherein the gear coupling is a first gear coupling, wherein the braking mechanism is a first braking mechanism, wherein the first gear box is configured to engage with a front portion of the circle to rotate the circle, wherein the circle drive system further includes a second circle drive motor, a second gear box, a second gear coupling, and a second braking mechanism positioned between the second circle drive motor and the second gear coupling, and wherein the second gear box is configured to engage with a rear portion of the circle and rotate the circle relative to the drawbar around the circle axis. ### Claim 7 (depends on 6) The grading machine of claim 6, wherein the first braking mechanism and the second braking mechanism are configured to be automatically engaged during a grading operation, and wherein the first braking mechanism and the second braking mechanism are configured to be automatically released during a blade positioning operation. ### Claim 8 (depends on 6) The grading machine of claim 6, wherein the first braking mechanism and the second braking mechanism are configured to be engaged based on a user input or a manual operation on an actuator positioned in an operator cab, and wherein the first braking mechanism and the second braking mechanism are configured to be released based on another user input or another manual operation on the actuator positioned in the operator cab. ### Claim 9 (depends on 1) The grading machine of claim 1, wherein the circle drive motor is a hydraulic motor. ### Claim 10 (depends on 1) The grading machine of claim 1, wherein the braking mechanism is further positioned between the housing of the circle drive motor and the motor shaft. ### Claim 11 A circle drive system for a grading machine, comprising: a circle drive motor that includes a motor shaft; a gear box configured to engage with and rotate a circle; a gear coupling including a worm and a worm gear coupling the circle drive motor to the gear box; and a braking mechanism, wherein the braking mechanism is positioned between a portion of the circle drive motor and the worm, wherein the braking mechanism includes one or more locking elements that are configured to engage with one or more portions of the circle drive motor or the motor shaft, and wherein the one or more locking elements include one or more of ratcheted fingers, springs, or teeth. ### Claim 12 (depends on 11) The circle drive system of claim 11, wherein the braking mechanism is configured to lock a rotation of at least a portion of the circle drive motor. ### Claim 13 (depends on 12) The circle drive system of claim 12, wherein the braking mechanism is configured to engage with and lock the rotation of the motor shaft. ### Claim 14 (depends on 11) The circle drive system of claim 11, wherein the circle drive motor is a first circle drive motor, wherein the gear box is a first gear box, wherein the gear coupling is a first gear coupling, wherein the braking mechanism is a first braking mechanism, and wherein the circle drive system further includes a second circle drive motor, a second gear box, a second gear coupling, and a second braking mechanism positioned between the second circle drive motor and the second gear coupling. ### Claim 15 (depends on 14) The circle drive system of claim 14, wherein the first gear box is configured to engage with a front portion of the circle to rotate the circle, and wherein the second gear box is configured to engage with a rear portion of the circle to rotate the circle. ### Claim 16 (depends on 14) The circle drive system of claim 14, wherein the first braking mechanism and the second braking mechanism are configured to be automatically engaged during a grading operation, and wherein the first braking mechanism and the second braking mechanism are configured to be automatically released during a blade positioning operation. ### Claim 17 (depends on 14) The circle drive system of claim 14, wherein the first braking mechanism and the second braking mechanism are configured to be engaged based on a user input or a manual operation on an actuator, and wherein the first braking mechanism and the second braking mechanism are configured to be released based on another user input or another manual operation on the actuator. ### Claim 18 A blade positioning system for a grading machine, comprising: a circle coupled to a grading blade, wherein the circle is rotatable around a circle axis; and a circle drive system, including: a circle drive motor including a motor shaft and having a motor axis; a gear coupling coupled to the circle drive motor and including a worm and a worm gear, wherein the worm includes a worm axis parallel to the motor axis; a gear box driven by the circle drive motor and the gear coupling, wherein the gear box includes a gear axis parallel to the circle axis, and wherein the gear box is configured to engage with and drive a rotation of the circle; and a braking mechanism configured to selectively lock the motor shaft from rotating, wherein the braking mechanism and the motor shaft are positioned between a portion of the circle drive motor and the worm, wherein the braking mechanism includes one or more locking elements that are configured to engage with one or more portions of the motor shaft to lock the motor shaft from rotating, and wherein the one or more locking elements include one or more of ratcheted fingers, springs, or teeth. ### Claim 19 (depends on 18) The blade positioning system of claim 18, wherein the braking mechanism is configured to be automatically engaged during a grading operation, and wherein the braking mechanism is configured to be automatically released during a blade positioning operation. ### Claim 20 (depends on 18) The blade positioning system of claim 18, wherein the circle drive motor is a first circle drive motor, wherein the gear coupling is a first gear coupling, wherein the gear box is a first gear box, wherein the braking mechanism is a first braking mechanism, wherein the first gear box is configured to engage with a front portion of the circle to rotate the circle, wherein the circle drive system further includes a second circle drive motor, a second gear coupling, a second gear box, and a second braking mechanism positioned between the second circle drive motor and the second gear coupling, and wherein the second gear box is configured to engage with a rear portion of the circle and rotate the circle.