Prediction of engine failure by examination of particle size distribution of metal particles in lubricant

• US 3,981,584 A
• Filed: 12/23/1974
• Issued: 09/21/1976
• Est. Priority Date: 06/13/1974
• Status: Expired due to Term

• Current Assignee: Mobil Oil Corporation (Exxon Mobil Corporation)
• Original Assignee: Mobil Oil Corporation (Exxon Mobil Corporation)
• Inventors: Guymer, Jon Anthony
• Primary Examiner(s): McGraw, Vincent P.
• Application Number:
  US05/535,762
• Time in Patent Office: 638 Days
• Field of Search: 356/70, 356/86, 356/102
• US Class Current: 356/70
• CPC Class Codes: F01M 11/10 Indicating devices; Other safety devices
• CPC Class Codes: F16N 2200/04 Detecting debris, chips, swarfs
• CPC Class Codes: F16N 29/00 Special means in lubricating arrangements or systems providing for the indication or detection of undesired conditions; Use of devices responsive to conditions in lubricating arrangements or systems
• CPC Class Codes: G01N 15/0272 with screening; with classification by filtering B01D takes precedence
• CPC Class Codes: G01N 15/0625 Optical scan of the deposits
• CPC Class Codes: G01N 33/2858 Metal particles

Abstract

Method for predicting incipient failure of a lubricated engine by removing a sample of the liquid lubricant employed after the same has been in contact with the moving metal surfaces of the engine. The metal wear particles contained in the lubricant are then separated into at least three predetermined size ranges by passage through membranes having pore openings corresponding in size to such predetermined size. Each of the fractions so separated is analyzed for a selected metal contaminant, such as iron, and the content of such metal contaminant is plotted against the particle size thereof. The likelihood of mechanical failure is determined from the shape of the resulting graph, with a preponderance of large metal contaminant particles being indicative of incipient engine failure.

Claims

1. A method for predicting incipient failure of an apparatus having moving metal surfaces, which surfaces are wetted with a liquid lubricant which comprises separating the metal wear particles contained in a sample of said lubricant into at least three predetermined size ranges by passage through membranes having pore openings corresponding in size to said predetermined size, analyzing each of the fractions so separated for a selected metal contaminant, plotting the content of said metal contaminant for each of said fractions against the particle size thereof and determining the likelihood of mechanical failure in said apparatus from the shape of the resulting graph.

2. The method of claim 1 wherein said apparatus is an engine.

3. The method of claim 1 wherein said apparatus is a jet engine.

4. The method of claim 1 wherein said metal contaminant is iron.

5. The method of claim 1 wherein said predetermined size ranges include a lower size range of between 0.1 and 0.8 micron, an upper size range between 1 and 5 mircons and an intermediate size range between the selected lower size and upper size range.

6. The method of claim 1 wherein said predetermined size ranges include particles below 0.3 micron, between 0.3 and 1.2 micron and greater than 1.2 micron.