Glossary

Deutsch: Getriebe / Español: Caja de Engranajes / Português: Caixa de Velocidades / Français: Boîte de Vitesses / Italiano: Scatola del Cambio

Gearbox, also known as a gear case or gearhead pertains to a gear or a hydraulic system responsible for transmitting mechanical power from a prime mover (an engine or electric motor), into some form of useful output. It is referred to the metal casing in which a number of gears are sealed.

Gearbox functions as a housing or container for gear oil, a metal casing for protecting gears and lubricant from water, dust, and other contaminants. It is precisely bored to control gear and shaft alignment.

General Description

In the industrial context, the gearbox serves three primary functions: speed alteration, torque multiplication, and direction change. By using a precise arrangement of different-sized gears (the gear train), it converts the high speed and low torque output of a motor into the low speed and high torque required by heavy machinery, or vice versa. The robust metal casing itself functions as a housing or container for gear oil, providing lubrication and heat dissipation, and crucially, protecting the gears and lubricant from water, dust, and other contaminants. The casing is precisely bored and manufactured to ensure accurate gear and shaft alignment, which is vital for long-term efficiency and minimizing wear.

Key Aspects

The application and selection of a gearbox in industry depend on several critical engineering aspects:

• Torque Capacity and Ratio: The primary consideration is the gear ratio, which determines the output torque and speed. Industrial gearboxes must be rated for the high torque capacities required by heavy machinery, often necessitating rugged, multi-stage designs.

• Efficiency and Heat Management: Efficiency is crucial to prevent energy loss. Friction between gear teeth generates heat, which must be effectively managed by the casing design and the quality of the lubricant (gear oil) to prevent thermal failure and material degradation.

• Maintenance and Reliability: Due to their critical role in continuous operations (24/7), industrial gearboxes must be highly reliable. Design choices often favor low-maintenance types, such as worm gearboxes for high ratio reduction or helical gearboxes for high-speed, smooth operation.

• Environmental Protection (IP Rating): The casing must protect internal components against harsh environmental factors (dust, moisture, chemicals) prevalent in industries like mining and food processing, often requiring specific IP (Ingress Protection) ratings.

Examples

Gearboxes are critical components across diverse industrial sectors:

By application, gearbox plays a very important role, among the industries that use a gearbox are:

1. Aerospace - gearbox plays a critical role in distributing engine power to the rotors and is responsible for other power outputs in an airplane. Specialty gearbox is used in aircrafts and space shuttles etc. for high performance and torque capacity. It is used to transfer power from the main shaft of the engine to an oil-cooled generator for producing electrical power;

2. Agriculture - gearbox is used in many processes including tilling, seeding, ploughing, irrigation, pest and insect control etc. . It make use of a variety of specialized gears, pumps and engines for better farming technique. Agriculture vehicles like tractor also use different gearboxes;

3. Automotive - different types of gearboxes are being used for cars, bus, trucks, motorcycles, scooters. These gearboxes are used to convert the mechanical energy smoothly and noiselessly;

4. Cement industry - requires rugged and high-torque gearbox for multiplying an engine's torque to produce the required output. Gearbox is being used in cement manufacturing and processing machines and equipments for continuous and smooth functioning;

5. Fertilizer manufacturing - required power-driven heavy and light industrial machines of high capacity. The machinery incorporates premium quality gearboxes along with other components for smooth and efficient working of machines;

6. Food processing - use of quality gearboxes and other components in compact design help to cut down lot of cost involved in maintenance and repair of the machine parts. The gearboxes are specifically designed to ensure low maintenance and wear & tear.

7. Marine industry - uses high performance marine gears and gearboxes in a variety of vessels including fast ferry boat s, luxury yatchs, frigates and work boats etc. These gear boxes are generally much more powerful and complicated than the non-marine counterparts;

8. Power industry is making use of high quality and high precision gears and gearboxes for use in the power generation equipment and machines. These gearboxes are available in variety of sizes and shapes with high torque capacity and powerful performance for use in powerful machines.

Other industries that utilized gearboxes are: mining, pulp and paper, steel plant, sugar plant, waste recycling and management plant, and wind turbines.

There are wide varieties of gearbox and some of the main types are: Sequential Gearbox, Helical Gearbox, Shaft mounted Gearbox, Planetary Gearbox, Worm Gearbox

Worm Reduction Gearbox, and Bevel Gearbox

Similar Terms

• Reducer (Speed Reducer): A common synonym for a gearbox, explicitly highlighting its function of reducing rotational speed while increasing torque.

• Gear Train: Refers to the arrangement or network of gears within the casing; the core mechanism of the gearbox.

• Drivetrain: The entire system that connects the engine to the final drive, encompassing the gearbox, drive shafts, axles, and differential.

• Power Transmission: The general engineering field and process of conveying energy from the source (motor) to the point of use (driven component).

• Differential: A specific type of gear system (often using bevel gears) used primarily in automotive and heavy machinery to allow wheels on the same axle to rotate at different speeds when cornering.

Articles with 'Gearbox' in the title

• Accessory gearbox: Accessory gearbox has something to do with a gearbox, usually attached to the back of an aero engine to power the engine accessories and to transmit the drive of the engine to accessories such as instruments, electric generators, de-icing . . .

Weblinks

• wind-lexikon.de: 'Getriebe' in the wind-lexikon.de (German)

Summary

The Gearbox is a fundamental mechanical component in the industrial sector, serving as an enclosed system for transmitting, reducing, or multiplying torque and speed between a motor and a driven machine. Its function is crucial for efficiency, power application, and longevity across all heavy industries. Key aspects include selecting the correct gear ratio and torque capacity for the application, ensuring high thermal efficiency via proper lubrication, and providing a robust, sealed casing (often with a high IP rating) to protect the internal gear train from contaminants. Common types include Helical, Planetary, and Worm gearboxes, each chosen for their specific performance characteristics in demanding environments.