Method and device for monitoring an elevator system

Monitoring device (20, 22) configured for monitoring movement of at least one linearly moving component (6, 12) of an elevator system (2), wherein the monitoring device (20, 22) includes:

• an acceleration sensor (24) configured for detecting accelerations (g, g′) of the at least one component (6, 12) and providing a corresponding acceleration signal (28, 30);
• and
• a controller (26) configured for:
• determining peaks (28a, 28b, 30a, 30b) having positive or negative signs in the detected acceleration signal (28, 30);
• determining the signs of the detected peaks (28a, 28b, 30a, 30b);
• determining that the moving direction of the at least one component (6, 12) has changed when two subsequent peaks (28a, 28b, 30a, 30b) having the same sign are detected;
• counting a number of changes of direction of the component;
• predicting necessary maintenance of the elevator system (2) based on the number of changes of direction of the component.