Method of diagnosing a lubrication system of an engine

Patent metadata

Field	Value
Publication number	US-2019040775-A1
Application number	US-201715668756-A
Country	US
Kind code	A1
Filing date	Aug 4, 2017
Priority date	Aug 4, 2017
Publication date	Feb 7, 2019
Grant date	—

Abstract

A method of diagnosing a lubrication system of an engine includes controlling an oil pump with a control signal. The control signal is a command having a value for a desired lubrication fluid pressure from the oil pump for a current operating state of the engine. A processing unit compares the value of the control signal for the current operating state of the engine to a threshold control value for the current operating state of the engine. When the processing unit determines that the value of the control signal for the current operating state of the engine deviates from the threshold control value for the current operating state of the engine, the processing unit analyzes the value of the control signal to identify a fault in the lubrication system.

First claim

What is claimed is:

1 . A method of diagnosing a lubrication system of an engine, the method comprising:
controlling an oil pump with a control signal, wherein the control signal is a command having a value for a desired lubrication fluid pressure from the oil pump for a current operating state of the engine; comparing the value of the control signal for the current operating state of the engine to a threshold control value for the current operating state of the engine, with a processing unit, to determine if the value of the control signal for the current operating state of the engine is substantially equal to the threshold control value for the current operating state of the engine, or if the value of the control signal for the current operating state of the engine deviates from the threshold control value for the current operating state of the engine; and analyzing the value of the control signal, with the processing unit, to identify a fault in the lubrication system, when the value of the control signal for the current operating state of the engine deviates from the threshold control value for the current operating state of the engine.

2 . The method set forth in claim 1 , wherein analyzing the value of the control signal to identify a fault in the lubrication system includes tracking at least one operating condition of the engine relative to the value of the control signal.

3 . The method set forth in claim 2 , wherein the at least one operating condition of the engine includes at least one of a rotational speed of the engine, the desired lubrication fluid pressure from the oil pump, an actual lubrication fluid pressure from the oil pump, and a lubrication fluid temperature.

4 . The method set forth in claim 1 , further comprising normalizing the value of the control signal for the current operating state of the engine based on a current lubrication fluid temperature.

5 . The method set forth in claim 1 , wherein the value of the control signal for the current operating state of the engine is substantially equal to the threshold control value for the current operating state of the engine when the value of the control signal is within +/−15% of the threshold control value.

6 . The method set forth in claim 1 , wherein analyzing the value of the control signal to identify a fault in the lubrication system includes determining, with the processing unit, if the value of the control signal is greater than the threshold control value with the engine operating in a low lubrication fluid pressure regime and if the value of the control signal is less than the threshold control value with the engine operating in a high lubrication fluid pressure regime.

7 . The method set forth in claim 6 , wherein analyzing the value of the control signal to identify a fault in the lubrication system includes calculating a fault severity, with the processing unit, when the value of the control signal is greater than the threshold control value with the engine operating in the low lubrication fluid pressure regime and when the value of the control signal is less than the threshold control value with the engine operating in the high lubrication fluid pressure regime.

8 . The method set forth in claim 7 , wherein analyzing the value of the control signal to identify a fault in the lubrication system includes issuing a notification, with the processing unit, indicating excessive control chamber clearance in the oil pump, when the fault severity is greater than a severity threshold.

9 . The method set forth in claim 6 , wherein analyzing the value of the control signal to identify a fault in the lubrication system includes determining, with the processing unit, if the value of the control signal deviates from the threshold control value only at low rotational speeds of the engine with the engine operating in the high lubrication fluid pressure regime, when the value of the control signal is not greater than the threshold control value with the engine operating in the low lubrication fluid pressure regime or the value of the control signal is not less than the threshold control value with the engine operating in the high lubrication fluid pressure regime.

10 . The method set forth in claim 9 , wherein analyzing the value of the control signal to identify a fault in the lubrication system includes issuing a notification, with the processing unit, indicating an un-identified fault with the lubrication system when the value of the control signal does not deviate from the threshold control value only at low rotational speeds of the engine with the engine operating in the high lubrication fluid pressure regime.

11 . The method set forth in claim 9 , wherein analyzing the value of the control signal to identify a fault in the lubrication system includes comparing a remaining oil life percentage to an oil life threshold, with the processing unit, to determine if the remaining oil life percentage is greater than the oil life threshold, or if the remaining oil life percentage is not greater than the oil life threshold, when the value of the control signal deviates from the threshold control value only at low rotational speeds of the engine with the engine operating in the high lubrication fluid pressure regime.

12 . The method set forth in claim 11 , wherein analyzing the value of the control signal to identify a fault in the lubrication system includes issuing a notification, with the processing unit, indicating an advised oil change when the remaining oil life percentage is not greater than the oil life threshold.

13 . The method set forth in claim 11 , wherein analyzing the value of the control signal to identify a fault in the lubrication system includes calculating a fault severity, with the processing unit, when the remaining oil life percentage is greater than the oil life threshold.

14 . The method set forth in claim 13 , wherein analyzing the value of the control signal to identify a fault in the lubrication system includes determining, with the processing unit, if the value of the control signal is less than the threshold control value at low rotational speeds of the engine, when the remaining oil life percentage is greater than the oil life threshold.

15 . The method set forth in claim 14 , wherein analyzing the value of the control signal to identify a fault in the lubrication system includes issuing a notification, with the processing unit, indicating an obstruction in an oil gallery of the engine, when the value of the control signal is not less than the threshold control value at low rotational speeds of the engine, and when the fault severity is greater than a severity threshold.

16 . The method set forth in claim 14 , wherein analyzing the value of the control signal to identify a fault in the lubrication system includes issuing a notification, with the processing unit, indicating excessive clearance in an oil gallery of the engine or in pump vanes of the oil pump, when the value of the control signal is less than the threshold control value at low rotational speeds of the engine, and when the fault severity is greater than a severity threshold.

17 . A vehicle comprising:
an engine having an oil gallery; a lubrication system having an oil pump operable in response to a control signal to circulate a lubrication fluid through the oil gallery of the engine; a processing unit connected to the oil pump, wherein the processing unit includes a processor and a memory having a lubrication system diagnostic algorithm stored therein, wherein the processor is operable to execute the lubrica

Assignees

• Gm Global Tech Operations Llc

Inventors

• Sarwar Azeem
• Mehdi Syed B
• Lu Xiangxing
• Pryor Bryan K
• Peer Shanshan L

Classifications

• F01M11/10 Primary

  Indicating devices; Other safety devices · CPC title

• F01M1/16

  Controlling lubricant pressure or quantity (rendering machines or engines inoperative or idling on lubricant pressure failure F01M1/22) · CPC title

• F01M1/02

  using lubricating pumps (pumps in general F04; lubricating pumps per se F16N) · CPC title

• F01M2011/1446

  by considering pressure · CPC title

• F01M2011/142

  by considering speed, e.g. revolutions per minute [RPM] · CPC title