Helical gears

2. Can a damaged parallel helical gear be easily replaced with another?

A parallel helical gear with the teeth inclined to the right will mesh with a parallel helical gear with the teeth inclined to the left if both gears have the same angle of inclination (HA -helical angle). The latter is not standardised, and can vary from one manufacturer to another. HPC offers standard gears with an HA of 17°45'. The HA has an effect on the pitch diameter (PCD), a parallel helical gear is not interchangeable with just any other old helical gear.

3. What use are helical crossed axis gears?

This type of gearing permits a change of direction of the rotational forces. There is a progressive meshing, due to the angle of the teeth. The number of teeth engaged at any one time is high, which assures a smooth mesh. The change of direction obtained is therefore smoother and quieter than can be obtained from bevel gearing.

4. How is a helical crossed axis gear used?

A Right Hand helical crossed gear meshes with another Right Hand gear. The relatively weak yield, due to the axial forces, can cause the transmission to overheat, which can be easily reduced by good lubrication.

5. How to find the angle of the teeth of an helical gear?

You can visually check the angle of the teeth. Place the gear lying flat on a table, if the teeth go up to the right direction, the angle of the teeth is a Right Hand one, if the teeth go up to the left direction, the angle of the teeth is a Left Hand one.

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