Winch Gear Trains - Gear Systems

There are three common gearing systems, planetary gear, worm gear, and spur gear. 

The job of the gear system on all three types is to gear down the high speed motor to a low speed, high torque output to turn the winch drum. 

The gear reduction ratio is how much the motor's output revolutions are reduced for the spindle.

The greater the reduction, the more revolutions the motor has to turn for one spindle revolution and the less the motor has to work for that revolution. 

The difference in the gearing  systems is mainly in their transfer efficiency.


Planetary Gears - Planetary gears are the most common and provide both strength and smooth operation with good resistance to torque loads.  The planetary gear systems have efficiency 65% and have a tendency to free spool when loaded, therefore a braking mechanism is needed.

Worm Gear - The worm gear has a transfer efficiency of 35-40%.  This causes the winch to be self-braking even under heavy loads, but this means the unit will need a clutch mechanism for free spooling.  Worm gears offer the most reduction, very high reliability, built-in braking mechanism, and generally a slower winching speed.   Worm drives are generally stronger and simpler than other gear systems such as the planetary due to the lack of the need for a braking system as well as the extreme gear reductions possible.  The primary drawback of a worm gear system is the noticeable reduction in overall line speed, especially in a 'no load' cable reel-up situation.  Here, the planetary has an advantage.


Spur Gear - The spur gear systems have efficiency of 75% and like the planetary gear system, they have a tendency to free spool when loaded, therefore a braking mechanism is needed.   Only the WARN M8274 has a spur gear due to its different design  characteristics.