Continuous on-board diagnostic lubricant monitoring system and method

Abstract

A continuous on-board diagnostic lubricant monitoring system and method evaluates lubricant quality and detects incipient lubricant failure due to contamination by measuring physical characteristics of the lubricant itself. The lubrication system (1) employs a diagnostic cell (27) which samples engine lubricant (EL) from an engine (2), and exposes the samples to sensors (28) which measure its physical characteristics. The senors (28) preferably include a permittivity sensor, a viscosity sensor, and a temperature sensor. Diagnostic testing based on the measurements can be carried out on-board via a controller (30) running selected algorithms or processes. A time to condemning limit for the lubricant, i.e., the time until the lubricant has degraded to given quality level, is calculated based on permittivity data received by the controller (30) from the sensors (28). Likewise, a time to condemning limit is calculated based on viscosity data. Based on the permittivity and temperature data, the controller (30) is able to detect incipient failure of the lubricant due to water or coolant contamination. Additionally, based on the monitored lubricant viscosity, the controller (30) is able to detect fuel contamination. In this manner, a superior lubricant monitoring system and method is achieved which is particularly applicable to railroad locomotives, mining machinery, and other off-highway vehicles.

Dependencies are inferred from the claim text.