Method for monitoring a drive belt of a continuously variable transmission and method for preventing damage to the drive belt

1. A method for monitoring a drive belt of a continuously variable transmission (CVT) provided in a vehicle having a motor driving the CVT, the method comprising:

sensing a rotational speed of the motor;

sensing a power level of the motor; and

setting an abuse indicator for the drive belt when, concurrently, the rotational speed of the motor increases at a rate that exceeds a change threshold, and the power level of the motor exceeds a power threshold.

2. The method of claim 1 , further comprising:

sensing a speed of the vehicle;

wherein the abuse indicator is set when, concurrently, the rotational speed of the motor increases at a rate that exceeds the change threshold, the speed of the vehicle is lower than a speed threshold and the power level of the motor exceeds the power threshold.

3. The method of claim 2 , further comprising:

if the abuse indicator is not set, setting an adjusted abuse indicator equal to a null value; and

if the abuse indicator is set:

determining a severity factor based on the speed of the vehicle, and

setting the adjusted abuse indicator equal to the severity factor.

4. The method of claim 3 , wherein:

the speed threshold is a first speed threshold;

the severity factor has a minimum value when the speed of the vehicle exceeds the first speed threshold; and

the severity factor has a maximum value when the speed of the vehicle is less than or equal to a second speed threshold lower than the first speed threshold.

5. The method of claim 3 , further comprising:

sensing a temperature of the drive belt using a sensor adapted for sensing a surface temperature of the drive belt or using a sensor adapted for sensing an ambient temperature within a housing of the CVT;

determining a wear factor of the drive belt based on the temperature of the drive belt; and

calculating a level of abuse for the drive belt by multiplying the adjusted abuse indicator by the wear factor of the drive belt.

6. The method of claim 5 , wherein:

the wear factor has a minimum value when the temperature of the drive belt is less than or equal to a temperature threshold; and

when the temperature of the drive belt exceeds the temperature threshold, the wear factor increases as a function of the temperature of the belt up to a maximum value.

7. The method of claim 6 , further comprising providing a visible or audible high drive belt temperature indication when the temperature of the drive belt exceeds the temperature threshold.

8. The method of claim 6 , further comprising recording every instance of the drive belt exceeding the temperature threshold.

9. The method of claim 5 , further comprising:

detecting a new abuse event for the drive belt;

recording information about the new abuse event for the drive belt; and

calculating a short-term accumulated level of abuse by summing values for the level of abuse for new abuse events detected over a first predetermined period ending when a most recent abuse event is detected.

10. The method of claim 9 , further comprising providing a visible or audible drive belt abuse indication when the short-term accumulated level exceeds a short-term abuse threshold.

11. The method of claim 9 , further comprising calculating a long-term accumulated level of abuse by summing values for the level of abuse for new abuse events detected over a second predetermined period ending when the most recent abuse event is detected, the second predetermined period being longer than the first period.

12. A method of preventing damage to a drive belt of a continuously variable transmission (CVT) provided in a vehicle having a motor driving the CVT, the method comprising:

monitoring the drive belt using the method of claim 11 ; and

limiting a power output of the motor when the long-term accumulated level of abuse exceeds a long-term abuse threshold.

13. The method of claim 12 , further comprising providing a visible or audible power limiting indication when limiting the power output of the motor.

14. The method of claim 12 , wherein:

the motor is an internal combustion engine; and

limiting the power output of the motor comprises performing at least one action selected from closing at least in part an exhaust valve of the engine, reducing a fuel supply to the engine, cutting at least in part ignition to the engine, reducing at least in part an opening of an engine throttle, and a combination thereof.

15. The method of claim 12 , further comprising recording each instance when limiting the power output of the motor.

16. A method of preventing damage to a drive belt of a continuously variable transmission (CVT) provided in a vehicle having a motor driving the CVT, the method comprising:

monitoring the drive belt using the method of claim 9 ; and

limiting a power output of the motor when the short-term accumulated level of abuse exceeds a short-term abuse threshold.

17. The method of claim 1 , wherein:

the motor is an internal combustion engine; and

sensing the power level of the motor comprises sensing a position of an exhaust valve of the engine.

18. The method of claim 1 , wherein:

the motor is an internal combustion engine; and

sensing the power level of the motor comprises sensing a pressure at an air intake of the engine.

19. The method of claim 1 , wherein:

the motor is an internal combustion engine; and

sensing the power level of the engine comprises:

sensing a position of an engine throttle, and

calculating the power level as a function of the position of the engine throttle and of the rotational speed of the engine.