A motor drive apparatus equipped with a machine learning device comprises a fan motor and an alarm output unit which provides an indication that it is time to replace the fan motor, wherein the machine learning device comprises a state observing unit which observes the number of revolutions of the fan motor, a reward calculating unit which calculates a reward based on the time that the alarm output unit output an alarm and the time that the fan motor actually failed, an artificial intelligence which judges action value based on an observation result supplied from the state observing unit and on the reward calculated by the reward calculating unit, and a decision making unit which, based on the result of the judgment made by the artificial intelligence, determines whether or not to output an alarm from the alarm output unit.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. A motor drive apparatus equipped with a machine learning device, comprising: a fan motor; and an alarm output unit for providing an indication that it is time to replace the fan motor, and wherein: the machine learning device comprises: a state observing unit for observing the number of revolutions of the fan motor; a reward calculating unit for calculating a reward based on the time that the alarm output unit output an alarm and the time that the fan motor actually failed; an artificial intelligence for judging action value based on an observation result supplied from the state observing unit and on the reward calculated by the reward calculating unit; and a decision making unit for determining whether or not to output an alarm from the alarm output unit based on a result of the judgment made by the artificial intelligence. 2. The motor drive apparatus according to claim 1, wherein the state observing unit also observes ambient temperature of the motor drive apparatus, and the artificial intelligence judges the action value by also considering the ambient temperature. 3. The motor drive apparatus according to claim 1, wherein the state observing unit also observes current consumption of the fan motor, and the artificial intelligence judges the action value by also considering the current consumption. 4. The motor drive apparatus according to claim 1, wherein the state observing unit also observes a variation in the number of revolutions of the fan motor at power on and at power off, and the artificial intelligence judges the action value by also considering the variation in the number of revolutions. 5. The motor drive apparatus according to claim 1, wherein the reward calculating unit calculates a higher reward as the time elapsed from the output of the alarm until the fan motor actually failed is shorter, calculates a higher reward when the alarm was not output and the fan motor continued to rotate without failing, and calculates a lower reward when the fan motor failed before the alarm was output. 6. The motor drive apparatus according to claim 1, wherein the artificial intelligence judges the action value by also including a variation in the number of revolutions of the fan motor changing over time. 7. The motor drive apparatus according to claim 1, wherein the decision making unit outputs the time to failure of the fan motor. 8. The motor drive apparatus according to claim 1, further comprising a data exchange unit for exchanging data between a plurality of motor drive apparatuses, and wherein the machine learning device performs learning by also utilizing data obtained by learning performed by a machine learning device provided in another motor drive apparatus.