US 12,252,872 B2
Abnormality diagnosis device for planetary gear speed reducer and construction machine
Motoki Sato, Tokyo (JP); Makoto Henmi, Tokyo (JP); Masahiko Ono, Tokyo (JP); Hayato Masuda, Ibaraki (JP); Shinichi Sekido, Ibaraki (JP); Tomoharu Morita, Ibaraki (JP); and Tatsuya Ono, Ibaraki (JP)
Assigned to HITACHI CONSTRUCTION MACHINERY CO., LTD., Tokyo (JP)
Appl. No. 18/689,493
Filed by HITACHI CONSTRUCTION MACHINERY CO., LTD., Tokyo (JP)
PCT Filed Nov. 1, 2022, PCT No. PCT/JP2022/040934
§ 371(c)(1), (2) Date Mar. 6, 2024,
PCT Pub. No. WO2023/080140, PCT Pub. Date May 11, 2023.
Claims priority of application No. 2021-179175 (JP), filed on Nov. 2, 2021.
Prior Publication US 2025/0034845 A1, Jan. 30, 2025
Int. Cl. F16H 57/08 (2006.01); E02F 9/26 (2006.01); G01M 13/021 (2019.01); G01M 13/028 (2019.01); B60W 30/20 (2006.01)
CPC E02F 9/267 (2013.01) [F16H 57/08 (2013.01); G01M 13/021 (2013.01); G01M 13/028 (2013.01); B60W 30/20 (2013.01)] 5 Claims
OG exemplary drawing
 
1. An abnormality diagnosis device for a planetary gear speed reducer in a construction machine that is driven by a hydraulic motor and the planetary gear speed reducer coupled to an output shaft of the hydraulic motor, comprising:
a first vibration sensor attached to a speed reducer housing that is a housing of the planetary gear speed reducer and configured to sense vibration of the speed reducer housing;
a second vibration sensor attached to a motor housing that is a housing of the hydraulic motor and configured to sense vibration of the motor housing; and
a processor configured to determine presence or absence of abnormality in a plurality of gears included in the planetary gear speed reducer on a basis of sensing results acquired by the first vibration sensor and the second vibration sensor, wherein
the processor is configured to
compute a peak frequency corresponding to a peak period of vibration of the hydraulic motor and a speed of rotation of the hydraulic motor from second vibration data acquired by the second vibration sensor,
compute characteristic frequencies corresponding to respective rotation periods of the plurality of gears on a basis of the speed of rotation of the hydraulic motor, number of the plurality of gears, and number of teeth of each of the plurality of gears, and
determine presence or absence of abnormality in the plurality of gears on a basis of the peak frequency of the hydraulic motor and amplitudes at the characteristic frequencies of first vibration data acquired by the first vibration sensor.