Method and system for lubricating one or more rotary bearings

A method for monitoring and lubricating at least one rotary bearing of a machine, by incrementally supplying a lubricant to the bearing in one or several consecutive supply steps in a lubrication sequence, comprising:

• determining a prescribed lubricant amount,
• measuring an ultrasound signal before a first lubricant supply step using a transducer mounted in connection with the bearing, and obtaining an initial value of a scalar indicator extracted from the signal that is representative of the lubrication condition of the bearing, and said measurement and value extraction is repeated after each subsequent lubricant supply step,
• wherein each measurement is performed after a stabilization period following the lubricant supply, wherein the duration of the stabilization period being such that it allows the supplied lubricant to be fully operational,
• the amounts of lubricant supplied in the consecutive steps are smaller than the prescribed lubricant amount,
• starting with a second extracted value, each value of the scalar indicator is evaluated, with respect to the initial value, and, starting from a third measurement, with respect to one or more of the previously extracted values,
• based on each of the evaluations, a decision is made about stopping or continuing the lubrication sequence.