COLLAR SHAFT 75mm.

Function and technical context

The 75 mm shaft collar is a component of the shaft line transmission system in boats with internal or semi-diesel propulsion, whose main function is to axially fix the tail shaft and prevent unwanted longitudinal displacements during turning. It works in close relationship with the thrust bearing, the stuffing box and the coupling, forming part of the assembly that transmits the propulsion effort from the engine to the propeller. Its correct installation guarantees that the axial loads generated by the propeller are absorbed effectively, avoiding vibrations, misalignments and premature wear of adjacent components of the shaft line. If the collar works in poor conditions or has excessive play, the shaft can move axially, which compromises the tightness of the stuffing box and can lead to water entering the boat.

When to replace this part?

The most common symptoms that indicate that the shaft collar needs to be checked or replaced are: noticeable axial play in the shaft, abnormal vibration transmitted to the hull at low or high revolutions, and excessive dripping or loss of tightness in the stuffing box as a result of longitudinal movement of the shaft. It is recommended to visually inspect the collar at each seasonal maintenance, checking for cracks, corrosion or wear on the fitting surfaces. Replacing it preventively at the slightest sign of deterioration prevents serious damage to the axle line that can be costly and dangerous in navigation.

Compatibility table