US 11,656,216 B2
Monitoring process for a grease lubricated rotating system and corresponding system
Per-Erik Larsson, Lulea (SE); and Fredrik Sundquist, Luleå (SE)
Assigned to Aktiebolaget SKF, Gothenburg (SE)
Filed by Aktiebolaget SKF, Gothenburg (SE)
Filed on Jul. 1, 2021, as Appl. No. 17/365,031.
Claims priority of application No. 102020208701.6 (DE), filed on Jul. 13, 2020.
Prior Publication US 2022/0011289 A1, Jan. 13, 2022
Int. Cl. G01N 33/28 (2006.01); G01N 27/04 (2006.01); G08B 21/18 (2006.01)
CPC G01N 33/2847 (2013.01) [G01N 27/048 (2013.01); G01N 33/2888 (2013.01); G08B 21/182 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method for monitoring a grease used as a lubricant in a rotating system comprising:
providing an electrode configured to measure the lubricant;
providing a processing unit engaged with the electrode for measuring a water content within the grease;
determining by the processing unit if a learning period will be performed, the learning period comprising a predetermined period of time during which a plurality of measurements of the water content in the grease are recorded,
wherein when the learning period is performed by the processing unit, the processing unit determines an upper threshold and a lower threshold based on the mean value and the standard deviation of the plurality of measurements;
determining by the processing unit if a current measurement is greater than or equal to the upper threshold, when the current measurement is greater than or equal to the upper threshold then the processing unit determines a number of subsequent high measurements, the processing unit then compares the number of subsequent high measurements to a first predetermined limit and if the number of subsequent high measurements is greater than the first predetermined limit designating an occurrence of a first event,
determining by the processing unit if the current measurement is smaller than or equal to the lower threshold, when the current measurement is smaller than or equal to the lower threshold the processor then determines a number of subsequent low measurements, the processing unit then compares the number of subsequent low measurements to a second predetermined limit and if the number of subsequent low measurements exceeds the second predetermined limit designating the occurrence of a second event,
determining if the first event is designated and, if so, emitting a first event alarm function, and
determining if the second event is designated and, if so, emitting a second event alarm function.