Predictive Maintenance Method
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Accused Products
Abstract
The predictive apparatus and method for preventive maintenance of rotating CNC machinery for application to a multi motor machine tooling operating under computer numerical control with provisions for a program control using the computer (22) and a multiplexing device (24) with steps for measuring the constant load momentum of inertia while running each motor and load alone from start to f speed and to the inertia idled stop while recording the performance factors and calculating a plurality of relationships with steps for setting the allowed limits to the recorded relationships and displaying the details of any relationship which falls outside the allowed limits and predicating the timely required preventative maintained schedule for the equipment (10).
18 Citations
27 Claims
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1-12. -12. (canceled)
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13. A method for producing predictive maintenance data of a motorized machine, the machine having a motor connected to a constant load, the method comprising the steps of:
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a) providing the motor with a mechanism which measures rotational speed of a motor axis within the motor; b) accelerating said motor with the constant load from zero speed to a maximum speed and decelerating the motor with the constant load from said maximum speed to zero speed; c) during said accelerating and said decelerating, sampling in time the rotational speed of the motor with the constant load, thereby determining absolutely or proportionally based on differentiating said sampling, at least one characteristic of the motor, said at least one characteristic selected from the group consisting of;
dynamic torque-speed, dynamic torque-time, static torque-time, static torque-speed, friction torque-speed, friction torque-time, and friction torque spectrum; and
d) comparing said at least one characteristic to at least one allowed limit.
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20. A data acquisition system for predictive maintenance data of a machine tool, the machine tool having a plurality of motors, the system comprising:
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a) for each motor, wherein a measurement mechanism which measures rotational speed is operatively connected to the motor shaft of each motor, said measurement mechanism providing an indication of rotational speed of the motor shaft; b) a multiplexing device (MUX) which electrically connects said measurement mechanism to a computer; c) a switching means for successively accelerating each motor from zero speed to maximum speed and for decelerating from maximum speed to zero speed; d) a sampling means for sampling in time the rotational speed of the motors during said accelerating and said decelerating; e) a calculating means for calculating absolutely or proportionally for each motor at least one characteristic based on differentiating said sampling, said at least one characteristic selected from the group consisting of;
dynamic torque-speed, dynamic torque-time, static torque-time, static torque-speed, friction torque-speed, friction torque-time, and friction torque spectrum;f) a recording means for recording said at least one characteristic;
g) setting means for setting at least one allowed limit for said at least one characteristic. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27)
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Specification