# US 8,539,811 B2 · Rotary transducer with monitoring of the bearing wear and method therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,539,811 B2 - Document ID: US8539811B2 - Status: Granted - Kind: B2 - Application number: 12/669,942 - Filed: 2008-06-20 - Published: 2010-07-22 - Granted: 2013-09-24 - Earliest claimed: 2007-07-31 - Assignees: Baumer Hubner GmbH - Applicants: Lothar Wilhelmy; Bernhard Hiller; Jochen Wilhelmy - Inventors: Lothar Wilhelmy; Bernhard Hiller; Jochen Wilhelmy - Web page: https://patentgrep.com/patent/US8539811B2 ## CPC - G01D 3/08: with provision for safeguarding the apparatus, e.g. against abnormal operation, against breakdown - F16C 19/52: with devices affected by abnormal or undesired conditions - F16C 19/525: {related to temperature and heat, e.g. insulation} - F16C 41/007: {Encoders, e.g. parts with a plurality of alternating magnetic poles} - G01M 13/04: Bearings - G01P 3/481: of pulse signals - G01P 21/02: of speedometers - F16C 2233/00: Monitoring condition, e.g. temperature, load, vibration - 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 - F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS - G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR - G01P: MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT (measuring or recording blood flow A61B5/02, A61B8/06; monitoring speed or deceleration of electrically-propelled vehicles B60L3/00; vehicle lighting systems adapted to indicate speed B60Q1/54; determining position or course in navigation, measuring ground distance in geodesy or surveying G01C; combined measuring devices for measuring two or more variables of movement G01C23/00; measuring velocity of sound G01H; measuring velocity of light G01J7/00; measuring direction or velocity of solid objects by reception or emission of radiowaves or other waves and based on propagation effects, e.g. Doppler effect, propagation time, direction of propagation, G01S; measuring speed of nuclear radiation G01T; measuring acceleration of gravity G01V; {measuring or recording the speed of trains B61L23/00; speed indicators incorporated in motor vehicles B60K35/00; measuring frequency or phase G01R; traffic control G08G}) ## Abstract A rotary transducer has a detector device with a measurement sensor, used to generate a measurement signal representative of angular position and/or velocity of an object. The detector device has a rotary bearing and a material measure that can be rotated relative to the measurement sensor and is arranged in the measurement field of the latter. A monitoring device, connected to the measurement sensor, which can provide a state signal representative of the state of wear of the rotary transducer, is integrated in the rotary transducer. In order to be able to timely warn of mechanical failure of the rotary transducer, the monitoring device is provided with a register that can permanently store as value representative of the state of wear of the rotary bearing and is formed from the information relating to the angular position and/or velocity contained in the measurement signal. ## Claims ### Claim 1 A rotary encoder having integrated therein a detector device comprising at least one measurement sensor by which, during operation, a measurement signal can be generated that is representative of the angular position and/or velocity of an object which is connectable to the rotary encoder, at least one rotary bearing, and at least one material measure which is arranged rotatable relative to the measurement sensor in the measurement field thereof by means of the rotary bearing, and a monitoring device which is connected to the measurement sensor such that data are transmitted, wherein the monitoring device comprises a counter which can permanently store a value which is representative of the state of wear of the rotary bearing and is formed from the information contained in the measurement signal on the angular position and/or velocity. ### Claim 2 (depends on 1) The rotary encoder according to claim 1, wherein the rotary encoder comprises a housing in which the detector device and the monitoring device are accommodated. ### Claim 3 (depends on 1) The rotary encoder according to claim 1, wherein the counter comprises a non-volatile electronic memory. ### Claim 4 (depends on 1) The rotary encoder according to claim 1, wherein the counter comprises an adder in which at least during operation a revolution number formed from the measurement signal can be added up. ### Claim 5 (depends on 1) The rotary encoder according to claim 1, wherein the monitoring device comprises a comparator by which a value of the revolution number stored in the counter can be compared with a predeterminable limit value. ### Claim 6 (depends on 1) The rotary encoder according to claim 1, wherein the rotary encoder has integrated therein at least one temperature sensor by which a temperature representative of the rotary bearing can be sensed. ### Claim 7 (depends on 1) The rotary encoder according to claim 1, wherein the rotary encoder has integrated therein a structure-borne sound sensor by which a structure-borne sound produced by the rotary bearing during operation can be sensed. ### Claim 8 A method for monitoring wear of a rotary encoder which during operation senses the angular position and/or velocity of a rotating object connected to the rotary encoder and outputs it as a measurement signal, wherein a state variable representative of the wear condition of a rotary bearing of the rotary encoder is monitored on the basis of the information contained in the measurement signal on the angular position and/or velocity, and a state signal representative of the functional state of the rotary bearing is output by the rotary encoder. ### Claim 9 (depends on 8) The method according to claim 8, wherein the rotary encoder adds up the revolutions independently of the rotary direction as a state variable. ### Claim 10 (depends on 9) The method according to claim 9, wherein the rotary encoder directly provides the added-up number of revolutions as a state signal. ### Claim 11 (depends on 8) The method according to claim 8, wherein the rotary encoder internally senses the temperature of the rotary bearing as a state variable. ### Claim 12 (depends on 8) The method according to claim 8, wherein the rotary encoder internally senses the vibrations of the rotary bearing as a state variable. ### Claim 13 (depends on 8) The method according to claim 8, wherein the rotary encoder directly determines, on the basis of the measurement signal, the number of revolutions of the rotary bearing performed since the start of operation. ### Claim 14 (depends on 8) The method according to claim 8, wherein the rotary encoder compares the state variable with a previously stored value and generates the state signal in response to the result of said comparison. ### Claim 15 (depends on 14) The method according to claim 14, wherein the rotary encoder outputs the state signal whenever a residual life calculated on the basis of the state variable falls below a stored residual life. ### Claim 16 (depends on 15) The method according to claim 15, wherein the rotary encoder indicates a shortened rotary bearing life if the angular velocity determined from the measurement signal is below a first stored limit velocity and/or above a second stored limit velocity. ### Claim 17 (depends on 16) The method according to claim 16, wherein the rotary encoder indicates a shortened rotary bearing life if the monitored temperature is below a first stored limit temperature and/or above a second stored limit temperature. ### Claim 18 (depends on 15) The method according to claim 15, wherein the rotary encoder indicates a shortened rotary bearing life if the amplitude of the monitored vibrations are above a stored limit value. ### Claim 19 (depends on 8) The method according to claim 8, wherein in the rotary encoder the time progression of the at least one state variable is stored to be readable from outside the rotary encoder. ### Claim 20 (depends on 8) The method according to claim 8, wherein the rotary encoder monitors the function of the detector device and/or the monitoring device and outputs a state signal representative of the functional state thereof. ### Claim 21 (depends on 20) The method according to claim 20, wherein an alarm signal which is representative of a faulty operative state is output when during monitoring of the wear state the limit life is passed and/or the state signal representative of the function monitoring represents a malfunction. ### Claim 22 (depends on 8) The method according to claim 8, wherein, when an alarm limit value is exceeded by a monitored state variable, an alarm signal is output independently of the values of the other monitored state variables.