| 摘要 |
<p>A method and apparatus for monitoring the degradation of oil, particularly crankcase oil. A first sensor includes creep material positioned under constant stress in thermal contact with the oil to act as an analogue computer as it changes its length in response to temperature and the time at that temperature to register the degradation of oil due to the oil's oxidation. In addition, a second sensor registers the contamination of the oil by adding the number of times the oil is heated but not heated to a high enough predetermined temperature to disperse the water, acids and sludge which contaminate the oil. When the combination of these outputs reach a predetermined limit, a signal is provided. This is accomplished by an apparatus including a generally U-shaped bracket with a platform movably supported on the bracket for upward movement against a spring. A rod extends through the platform and is connected to a diaphragm which, in turn, is subjected to oil pressure to move downwardly, thereby moving the rod downwardly. A creep material is supported on the platform and extends upwardly in the direction of the rod to a distal end and is placed under a constant stress by a spring reacting between the distal end and the platform. The creep material changes in length exponentially when subjected to temperature and time, the operand of the exponent being the base of the natural system of logarithms. Associated with the platform is a metal member having a pair of gripping tangs engaging the rod so that when the rod moves downwardly and returns after the oil pressure is released it will move the platform upwardly relative to the bracket unless the oil reaches a predetermined temperature at which time the tangs will move away from the rod allowing the rod to freely return upwardly without moving the platform. When the combination of movement or elongation of the creep material and platform movement upwardly is sufficient that the distal end of the creep material contacts the upper portion of the bracket an electrical signal is provided indicating that the oil is sufficiently degraded to be replaced.</p> |
