Method and system of lubricating consumers to be monitored via their lubricant

Abstract

A method involves directing lubricant to different consumers which are to be monitored via their lubricant. The lubricant is drained through drain lines connected to the consumers and directed to a tank. At least some the lubricant in the drain lines or the consumers is extracted into extraction lines. Flow from the extraction lines is selectively directed to a measurement device, which then measures a characteristic of the lubricant. A system for carrying out such a method is also provided, wherein the system includes a multiplexer for selectively directing flow from the extraction lines.

1 . A method of lubricating different consumers whose lubricant is to be analyzed, comprising:
 directing lubricant to the different consumers;   draining the lubricant through drain lines connected to the consumers, the drain lines being connected to a tank so as to direct the lubricant to the tank;   extracting at least some lubricant from the drain lines or the consumers into extraction lines;   selectively directing flow from the extraction lines to a measurement device; and   measuring a characteristic of the lubricant directed to the measurement device.   
     
     
         2 . The method according to  claim 1 , wherein the measurement device is a particle counter such that measuring a characteristic of the lubricant comprises counting particles in the lubricant with the particle counter. 
     
     
         3 . The method according to  claim 2 , further comprising:
 collecting particles greater than a predetermined minimum size in a particle collector downstream from the particle counter.   
     
     
         4 . The method according to  claim 2 , wherein the particle counter is configured to count particles greater than 70 μm. 
     
     
         5 . The method according to  claim 1 , wherein selectively directing flow from the extraction lines to the measurement device comprises operating a multiplexer to which the extraction lines are connected, the multiplexer comprising a valve arrangement in which respective valves are associated with the extraction lines and a controller for selectively opening the valves. 
     
     
         6 . The method according to  claim 1 , wherein selectively directing flow from the extraction lines to the measurement device comprises switching between directing: a) a combined flow from the consumers into an output line, and b) from individual and/or subsets of consumers into the output line. 
     
     
         7 . The method according to  claim 6 , wherein the drain lines converge before connecting to the tank, and further wherein the combined flow is from a common extraction line downstream from where the drain lines converge. 
     
     
         8 . The method according to  claim 6 , wherein the combined flow is the result of all extraction lines being open to the output line. 
     
     
         9 . The method according to  claim 6 , wherein the measurement device is a particle counter and selectively directing flow from the extraction lines comprises:
 directing flow from all consumers into the output line until the particle counter detects a predetermined minimum particle size; and   searching for which consumer is the source of the detected particles by:   switching to direct flow from a first extraction line into the output line; and   switching to direct flow from a different extraction line into the output line if the particle counter does not detect the predetermined minimum particle size after a set period of time.   
     
     
         10 . The method according to  claim 1 , further comprising:
 drawing lubricant from the extraction lines to the measurement device with a pump or by gravity.   
     
     
         11 . The method according to  claim 1 , wherein measuring a characteristic of the lubricant comprises measuring pressure, temperature, viscosity, oxidation, water content, or flow rate. 
     
     
         12 . The method according to  claim 1 , wherein the consumers are components of a wind turbine power transmission system. 
     
     
         13 . A lubrication system having different consumers to be monitored via their lubricant, the lubrication system comprising:
 a tank;   drain lines configured to receive lubricant from the different consumers, the drain lines being connected to the tank;   extraction lines connected to the drain lines or the consumers;   a multiplexer connected to the extraction lines, the multiplexer having an output line and being configured to selectively direct flow from the extraction lines to the output line; and   a measurement device connected to the output line, the measurement device being configured to measure a characteristic of the lubricant in the output line.   
     
     
         14 . The lubrication system according to  claim 13 , further comprising a pump connected to the output line, the pump being configured to draw lubricant through the multiplexer. 
     
     
         15 . The lubrication system according to  claim 13 , wherein the measurement device comprises a particle counter configured to detect particles in the lubricant received from the multiplexer. 
     
     
         16 . The lubrication system according to  claim 15 , further comprising:
 a particle collector connected to the particle counter and configured to gather particles greater than a predetermined minimum size detected by the particle collector.   
     
     
         17 . The lubrication system according to  claims 13 , wherein the multiplexer comprises a valve arrangement in which respective valves are associated with the extraction lines and controller for selectively opening the valves. 
     
     
         18 . The lubrication system according to  claim 17 , wherein the drain lines converge before the tank and at least one of the extraction lines is connected downstream from where the drain lines converge so as to be associated with a combined flow from the consumers. 
     
     
         19 . A power transmission system having different consumers of lubrication, the power transmission system including a lubrication system according to  claim 13 . 
     
     
         20 . The power transmission system according to  claim 19 , wherein the different consumers of lubrication system comprise one or more main bearings supporting a main shaft, a gearbox driven by the main shaft, and a generator driven by an output of the gearbox.