Method for determinating of an oil condition

• US 7,266,472 B2
• Filed: 12/16/2005
• Issued: 09/04/2007
• Est. Priority Date: 01/13/2005
• Status: Expired due to Fees

• Current Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Schwemer, Christian, Wagner, Jens, Neumann, Dieter, Grundler, Rainer
• Primary Examiner(s): Ramos-Feliciano; Eliseo
• Assistant Examiner(s): Barbee; Manuel L
• Application Number:
  US11/305,412
• Publication Number:
  US 20060155502A1
• Time in Patent Office: 627 Days
• Field of Search: 702/30, 702 45- 49, 702/130, 702/132, 702/136, 702176-178, 702/22, 702/23, 702/25, 702/32, 702/50, 702/81, 340/500, 340/584, 340/588, 340/450.3, 340/457.4, 701/30, 701/31, 73/530.5, 73/530.6, 73/530.7, 73/617.6
• US Class Current: 702/177
• CPC Class Codes: G01N 33/2888 Lubricating oil characteristics, e.g. deterioration lubricating properties G01N33/30

Abstract

A method for determining an oil condition, namely, an oil condition corresponding to the oil age or oil damage, with the following steps: a) measuring a temperature of the oil or of the part through which the oil flows, coordinating each temperature measured with one temperature range defined by an upper limit and/or a lower limit; b) as soon as the measured temperature exceeds or falls below a limit of a temperature range, measuring the period of time during which the measured temperature dwells in this range; c) in addition, integrating an oil flow running during this time over the time period measured in step b); d) from the time period measured in step b) and the integral of the oil flow determined in step c), determining an oil age or oil damage characteristic for the current temperature range.

Claims

1. A method for determining a condition of lubricating oil corresponding to an oil age or an oil damage value of the oil, the method comprising the steps of:

measuring a temperature of one or more of the oil and a part through which the oil flows and coordinating each measured temperature with a temperature range defined by at least one of an upper limit and a lower limit;

measuring, as soon as the measured temperature exceeds or falls below a limit of the temperature range, a first period of time during which the measured temperature dwells in the temperature range which exceeds the upper limit or falls below the lower limit;

integrating a flow of oil running during the time period over the first period;

determining the oil age or the oil damage value representing at least one of the oil age and oil damage for a current temperature range from the first period time and the integral of the flow of oil; and

providing an output representing the condition of the oil based upon the determined oil age or the oil damage value; and

producing an oil change signal when the oil age or the oil damage valued exceeds a preset limit value is exceeded indicating that an oil change is required.

2. The method according to claim 1, further comprising the step of starting a time meter when the measured temperature one of exceeds or falls below the temperature limit, and measuring the time period during which the measured temperature dwells in the temperature range, and resetting the time meter when the measured temperature falls outside the temperature range.

3. The method according to claim 1, further comprising the step of determining a current oil age or a current oil damage value by multiplying an integral of the oil flow by the time period and divided dividing by a total oil volume of the oil.

4. The method according to claim 3, further comprising the step of determining the oil age or the oil damage value representing an accumulated oil age or accumulated oil damage value for the current temperature range by adding the current oil age or the current oil damage value to a previously determined oil age or a previously determined oil damage value determined by multiplying an integral of a previous oil flow by a previous time period divided by the total oil volume value optionally previously determined in the same manner for the same temperature range and thus a characteristic accumulated oil age or oil damage value is determined for the current temperature range.

5. The method according to claim 4, further comprising the step of checking each temperature range to determine whether the oil age or the oil damage value exceeds a preset limit value for the current temperature range.

6. The method according to claim 4, further comprising the step of determining a mean oil age value or a mean oil damage value from at least one of the oil age and or the oil damage value of an individual temperature range, which preferably comprises all temperature ranges, and checking whether an averaged oil aging or averaged oil damage value exceeds a preset limit value.

7. The method according to claim 6, further comprising the step of in evaluating at least one of the mean oil age or the mean oil damage value for the individual temperature ranges with different strictness.

8. The method according to claim 1, further comprising the step of calculating at least one of the oil age value and the oil damage value of the individual temperature ranges from the following equation:

$\mathrm{sum}<br><br>\left[i\right]={\mathrm{sum}}_{\mathrm{alt}}<br><br>\left[i\right]+\frac{\int <br><br>\stackrel{.}{V}<br><br>\left[i\right]*d<br><br>t}{V_{\mathrm{ges}}}*T<br><br>\left[i\right]$

where;

{dot over (V)} [i]=oil flow in the temperature range I,

V_ges=total volume of oil,

T[i]=time period for which the temperature dwells in the temperature range I,

sum[i]=accumulated, characteristic oil aging or oil damage value to be determined for the temperature range I, and

sum_alt[i]=previously determined characteristic oil aging or oil damage value for the temperature range I.

9. A method for determining a condition of lubricating oil, flowing within a transmission, corresponding to an oil age or an oil damage value of the oil, the method comprising the steps of:

measuring a temperature of at least one of the oil and a part through which the oil flows and coordinating each measured temperature with a temperature range defined by at least one of an upper limit and a lower limit;

measuring, as soon as the measured temperature exceeds the upper limit of the temperature range or falls below the lower limit of the temperature range, a period of time during which the measured temperature exceeds the upper limit of the temperature range or falls below the lower limit of the temperature range;

integrating a flow of oil flowing during the period of time;

determining, from the period of time and the integral of the flow of oil, at least one of the oil age and the oil damage for a current temperature range;

providing an output representing the condition of the oil based upon the determined oil age or the oil damage value; and

when the oil age or the oil damage valued exceeds a preset limit value, generating an oil change signal indicating a need for changing the oil of the transmission.

10. The method according to claim 9, further comprising the step of calculating at least one of the oil age value and the oil damage value of the individual temperature ranges from the following equation:

$\mathrm{sum}<br><br>\left[i\right]={\mathrm{sum}}_{\mathrm{alt}}<br><br>\left[i\right]+\frac{\int <br><br>\stackrel{.}{V}<br><br>\left[i\right]*d<br><br>t}{V_{\mathrm{ges}}}*T<br><br>\left[i\right]$

where;

{dot over (V)} [i]=oil flow in the temperature range I,

V_ges=total volume of oil,

T[i]=time period for which the temperature dwells in the temperature range I,

sum[i]=accumulated, characteristic oil aging or oil damage value to be determined for the temperature range I, and

sum_alt[i]=previously determined oil aging or oil damage value characteristic for the temperature range I.

11. A method for determining a condition of lubricating oil, flowing within a transmission, corresponding to an oil age or an oil damage value of the oil, the method comprising the steps of:

a) measuring a temperature of at least one of the oil and a part through which the oil flows and coordinating each measured temperature with a temperature range defined by at least one of an upper limit and a lower limit;

b) measuring a period of time during which the measured temperature exceeds the upper limit or falls below the lower limit by starting a time meter, as soon as the measured temperature exceeds the upper limit of the temperature range or the lower limit of the temperature range, and stopping the time meter as soon as the measured temperature falls within the temperature range, and resetting the time meter;

c) integrating a flow of oil flowing during the period of time;

d) determining, from the period of time end the integral of the flow of oil, at least one of the oil age and the oil damage for a current temperature range;

e) providing an output representing the condition of the oil based upon the determined oil age or the oil damage value;

f) repeating steps b through e each time the measured temperature exceeds the upper limit or falls below the lower limit; and

when the output, representing the condition of the oil based upon the determined oil age or the oil damage value, exceeds a preset limit value, generating an oil change signal indicating a need for changing the oil of the transmission.

12. The method according to claim 11, further comprising the step of calculating at least one of the oil age value and the oil damage value of the individual temperature ranges from the following equation:

$\mathrm{sum}<br><br>\left[i\right]={\mathrm{sum}}_{\mathrm{alt}}<br><br>\left[i\right]+\frac{\int <br><br>\stackrel{.}{V}<br><br>\left[i\right]*d<br><br>t}{V_{\mathrm{ges}}}*T<br><br>\left[i\right]$

where;

{dot over (V)} [i]=oil flow in the temperature range I,

V_ges=total volume of oil,

T[i]=time period for which the temperature dwells in the temperature range I,

sum[i]=accumulated, characteristic oil aging or oil damage value to be determined for the temperature range I, and

sum_alt[i]=previously determined oil aging or oil damage value characteristic for the temperature range I.