# US 9,518,815 B2 · Rotary position encoder for rotatable shafts > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,518,815 B2 - Document ID: US9518815B2 - Status: Granted - Kind: B2 - Application number: 12/537,170 - Filed: 2009-08-06 - Published: 2010-02-11 - Granted: 2016-12-13 - Earliest claimed: 2008-08-06 - Assignees: Haas Automation, Inc. - Applicants: Thomas R. Velasquez; David E. Wolf; Cody J. Carothers; Brian J. Thoma - Inventors: Thomas R. Velasquez; David E. Wolf; Cody J. Carothers; Brian J. Thoma - Web page: https://patentgrep.com/patent/US9518815B2 ## CPC - G01B 7/30: for measuring angles or tapers; for testing the alignment of axes - G01D 5/3473: {Circular or rotary encoders} - G01D 11/245: {Housings for sensors} - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR ## Abstract A rotary position encoder is described that includes a hub configured to mount on an end of a rotatable shaft of a machine tool and rotate concurrently with the rotatable shaft. The hub includes a cup formed in a first end to receive the rotatable shaft, the cup having equally spaced axial grooves formed on an inner surface. A collar clamps the hub to the rotatable shaft by collapsing the cup around the rotatable shaft. The rotary position encoder further includes a sensor configured to detect a rotational position of the hub and a housing, wherein the sensor is mounted to the housing in a position opposite a second end of the hub. The hub is rotatably coupled to the housing via a bearing and a bracket is attached to the housing for mounting the rotary position encoder to the machine tool and preloading the bearing. ## Claims ### Claim 1 A rotary position encoder, comprising: a hub that directly mounts on an end of a rotatable shaft of a machine tool and that rotates concurrently with the rotatable shaft, wherein the hub comprises a cup formed in a first end to receive the rotatable shaft and a plurality of equally spaced axial grooves formed on an inner surface of the cup creating portions of the cup that are thinner than other portions of the cup; a collar configured to collapse the cup around the end of the rotatable shaft; a sensor configured to detect a rotational position of the hub; a housing, wherein the sensor is mounted to the housing in a position adjacent to the hub; one and only one bearing, wherein the hub is rotatably coupled to the housing via the one and only one bearing; and a bracket comprising a central portion attached to the housing and a plurality of flexible mounting tabs extending away from the central portion for mounting the rotary position encoder to the machine tool at a plurality of corresponding anchor points, wherein the central portion of the bracket defines an opening through which the hub extends away from the housing. ### Claim 2 (depends on 1) The rotary position encoder according to claim 1, wherein the collar comprises a pinch collar. ### Claim 3 (depends on 1) The rotary position encoder according to claim 1, wherein the collar comprises a clamping collar. ### Claim 4 (depends on 1) The rotary position encoder according to claim 1, wherein the rotary position encoder further comprises a magnet mounted on a second end of the hub opposite the sensor, wherein the sensor detects an angular position of the magnet. ### Claim 5 (depends on 4) The rotary position encoder according to claim 4, wherein the magnet is a diametrically polarized cylindrical magnet. ### Claim 6 (depends on 1) The rotary position encoder according to claim 1, the housing comprising: a body attached to the bracket, wherein the sensor is mounted to the body; and a cap attached to the body, wherein the body and the cap partially define a cavity containing the sensor. ### Claim 7 (depends on 1) The rotary position encoder according to claim 1, wherein the one and only one bearing comprises a rolling element bearing. ### Claim 8 (depends on 1) The rotary position encoder according to claim 1, wherein the one and only one bearing comprises a deep groove ball bearing. ### Claim 9 (depends on 1) The rotary position encoder according to claim 1, wherein the bracket comprises stainless steel having a thickness of 0.012 to 0.015 in. ### Claim 10 (depends on 1) The rotary position encoder according to claim 1, further comprising an interface for communicating rotational position information generated by the sensor to a controller. ### Claim 11 A rotary position encoder, comprising: a hub having a cup formed in a first end to receive and directly mount on an end of a rotatable shaft of a machine tool and that rotates concurrently with the rotatable shaft; a sensor configured to detect a rotational position of the hub; a housing, wherein the sensor is mounted to the housing in a position adjacent to the hub; one and only one bearing, wherein the hub is rotatably coupled to the housing via the one and only one bearing; and a flexible bracket comprising a central portion attached to the housing and a plurality of mounting tabs extending away from the central portion for mounting the rotary position encoder to the machine tool at a plurality of corresponding anchor points, wherein the central portion of the flexible bracket defines an opening through which the hub extends away from the housing. ### Claim 12 (depends on 11) The rotary position encoder according to claim 11, wherein the rotary position encoder further comprises a diametrically polarized cylindrical magnet mounted on a second end of the hub opposite the sensor, wherein the sensor detects an angular position of the magnet. ### Claim 13 (depends on 11) The rotary position encoder according to claim 11, the housing comprising: a body attached to the bracket, wherein the sensor is mounted to the body; and a cap attached to the body, wherein the body and the cap partially define a cavity containing the sensor. ### Claim 14 (depends on 11) The rotary position encoder according to claim 11, wherein the one and only one bearing comprises a rolling element bearing or a deep groove ball bearing. ### Claim 15 (depends on 11) The rotary position encoder according to claim 11, wherein the bracket comprises stainless steel having a thickness of 0.012 to 0.015 in. ### Claim 16 (depends on 11) The rotary position encoder according to claim 11, further comprising an interface for communicating rotational position information generated by the sensor to a controller.