System and method for determining oil quality

• US 6,675,635 B2
• Filed: 04/17/2002
• Issued: 01/13/2004
• Est. Priority Date: 04/17/2002
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: McCluskey, Philip H., Kasen, Jon E., Lee, Michelle A.
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): GARBER, CHARLES D
• Application Number:
  US10/124,555
• Publication Number:
  US 20030196479A1
• Time in Patent Office: 636 Days
• Field of Search: 73/530.5, 73/540.2, 73/540.1, 73/544.2, 73/544.3
• US Class Current: 73/53.05
• CPC Class Codes: G01N 33/2888 Lubricating oil characteristics, e.g. deterioration lubricating properties G01N33/30

Abstract

The oil quality used in a machine, vehicle or system can be determined in response to determining a temperature and pressure within an oil supply. Once the oil quality is determined, an oil quality warning light can be activated, indicating the need to change the oil.

Claims

1. A method for determining an oil quality comprising:

measuring a temperature in an oil supply;

measuring a pressure in said oil supply;

measuring a duration of an event drawing oil from said oil supply;

determining an oil grade for said oil supply;

determining an estimated pressure drop for said oil supply as a function of said event duration and said oil grade; and

determining said oil quality in response to said measuring temperature step, said measuring pressure step, and said estimated pressure drop.

2. The method of claim 1 further including:

determining a pressure drop in said oil supply.

3. The method of claim 1 further including:

measuring a second pressure in said oil supply;

comparing said pressure to said second pressure; and

determining a pressure drop in said oil supply.

4. The method of claim 3 further including:

measuring the time between measuring said pressure and measuring said second pressure.

5. The method of claim 1 wherein determining said oil grade includes:

inputting said oil grade.

6. The method of claim 1 further including:

determining a pressure drop in said oil supply;

comparing said pressure drop to said estimated pressure drop; and

determining said oil quality in response to said comparing step.

7. The method of claim 6 further including:

measuring a second pressure in said oil supply;

comparing said pressure to said second pressure; and

determining a pressure drop in said oil supply in response to said comparing step.

8. The method of claim 6 further including:

activating an oil quality warning light in response to said determining oil quality step.

9. A method of determining an oil quality of a oil supply comprising:

determining an oil grade of said oil supply;

measuring a temperature of said oil supply;

measuring a first pressure of said oil supply;

measuring a duration of an event drawing oil from said oil supply;

measuring a second pressure of said oil supply;

estimating a pressure drop of said oil supply;

determining an actual pressure drop of said oil supply in response to measuring said first pressure and measuring said second pressure;

comparing said actual pressure drop to said estimated pressure drop; and

determining said oil quality in response to said comparing step.

10. The method of claim 9 including:

measuring said first pressure before said event.

11. The method of claim 10 further including:

activating an oil quality warning light in response to determining said oil quality.

12. The method of claim 10 further including:

averaging said actual pressure drop over time;

comparing said averaged pressure drop to said estimated pressure drop; and

determining said oil quality in response to said comparing said averaged pressure drop to said estimated pressure drop.

13. The method of claim 9 including:

measuring said first pressure proximate in time to a start of said event.

14. The method of claim 9 including:

measuring said second pressure at an end of said event.

15. The method of claim 9 including:

measuring said second pressure proximate in time to an end of said event.

16. A method for determining an oil quality comprising the steps of:

determining a temperature of an oil supply and generating a responsive temperature signal;

determining a pressure of said oil supply and generating a responsive pressure signal;

delivering said temperature and pressure signals to an electronic control module;

determining an oil grade for said oil supply;

determining a duration of an event drawing oil from said oil supply;

determining an estimated pressure drop as a function of said event duration and said oil grade; and

determining said oil quality as a function of said temperature, said pressure, and said estimated pressure drop.

17. A method, as set forth in claim 16, wherein determining a pressure of said oil supply includes the steps of:

determining a first pressure at a first predetermined time;

determining a second pressure at a second predetermined time;

comparing said first and second pressures; and

determining a pressure drop from said first predetermined time to said second predetermined time.

18. A method, as set forth in claim 17, further including the steps of:

comparing said determined pressure drop with said estimated pressure drop; and

responsively determining said oil quality.