5. When does a helical gear need an oil expansion tank?

An oil expansion tank should be used for geared motors that are used in gearbox size M57 and above with low gear ratios (i<20) in the M4 installation position.

Likewise, with an increased input speed (greater than 1800 rpm), an oil expansion tank may be necessary in the M4 installation position, regardless of the gearbox size.

The reason for this measure is that due to the high oil level, oil foam forms, which could escape from the vent screw.