Planetary Gearbox

Planetary gearboxes are widely used in a number of industries for their efficiency and torque capacity. These gearboxes are so named because of their resemblance to a solar system. Before we go on to describe what is a planetary gear box it would be essential to learn about the planetary gears. Any planetary gear set is composed of three components :

• Sun gear
• Planet gears and the planet gears' carrier
• Ring gear

Either of the three components can be the input, the output or held in a stationary position.

Working of a Planetary Gearbox
The gearbox is driven with the help of a center shaft, connected to a carrier plate carrying three smaller gear wheels. These gear wheels run inside a toothed outer ring and drive the central gear cut around the central output shaft. This leads to the load being divided among many contact points around each gear, thus ensuring less friction and finally an increased efficiency.

The planet wheels in these gearboxes are generally set 120 degrees apart, leading to 'load equilibrium' and thus resulting in a balanced or 'zero force' within the geared components. This further results in very low wear and high shock loading capacity.

This gearbox system is used in precision instruments and water processing systems due to high reliability and accuracy.

Advantages of a Planetary Gearbox
This gearbox offers many advantages as compared to other types of gearbox. Some of them are :

• Higher torque to weight ratio
• Low backlash
• Compact size
• Less weight
• High cyclic and radial load carrying capacity
• Improved efficiency
• Modular construction allowing assembly in several stages
• Greater resistance to shock
• Improved lubrication

Uses of Planetary Gearbox
This special type of gearbox is commonly used in a number of industries including :

• Wind turbines
• Power industry
• Sugar industry
• Automotive industry
• Material handling equipment
• Medical equipment
• Robotics machinery
• Aviation equipment
• Packaging equipment