A weighted or spring-loaded lower pulley that maintains constant tension in the overspeed governor rope, ensuring reliable governor operation.
Full Definition
The governor tension sheave is located at the bottom of the hoistway and is connected to the overspeed governor rope that runs between the governor at the top of the shaft and the safety gear linkage on the car. The sheave maintains rope tension through dead weight or a spring mechanism, ensuring the governor rope does not go slack and that the rope velocity faithfully represents the car velocity. Loss of rope tension or sheave binding can cause false tripping or failure to trip the safety gear. EN 81-20 requires the tension sheave to be accessible for inspection and its condition — rope groove wear, bearing condition, and clearance — to be checked during periodic maintenance.
