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The Basics of Speed Reducers

A speed reducer is simply a gear train that is located between the machinery and the motor. It is  used to reduce the speed that power is transmitted. They are also called  gear reducers.

These devices reduce the output speed of the motor with a proportional increase in output torque using two or more gears configured to obtain the correct rotational or translational direction, speed or torque to the output device. There are several gear sets used in speed reducers, dependent upon the application. 

The least expensive is a worm gear reducer. These are also the most compact. Worm gear reducers can deliver large reductions of input rotational speed and large increases in output torque. They are less efficient than some alternatives because the gears slide rather than roll during contact. This causes friction and higher operating temperatures and can result in the need for special lubrication.

Helical gear reducers are similar to spur gear reducers except that their teeth are cut at an angle to the hole (axis) rather than straight and parallel to the hole like the teeth of a spur gear. The line of contact between two teeth is not parallel to the teeth but inclined. Contact starts at one end of the gear tooth and increases as the gears rotate until the input and output teeth are fully engaged.

Helical gear reducers have greater load-carrying capacity, since more of the gear teeth share the load. Lower stress, reduced wear on the gears, and quieter operation are advantages to these types of gear reducers.  A major disadvantage of helical gear reducers is they have high maintenance costs. Also, the transmission is likely to misalign with these.

Bevel gear reducers have the axes of the two shafts intersect and the tooth-bearing faces of the gears themselves are conically shaped. These are most often mounted on shafts that are 90 degrees or less apart.  Bevel gears are usually cone-shaped, but depending on the application, they can be configured to any arbitrary angle.   bevel gear reducers

This type is called external because the gear teeth point outward. The pitch surfaces of meshed external bevel gears are coaxial with the gear shafts. The apexes of the two surfaces are at the point of intersection of the shaft axes.

Tight tolerances are required as they are ideally matched to precise orientations. Bevel gear reducers may be manufactured with spur gears or helical gears.   Spur gears are the less expensive option but as only one gear is in contact at any given time, it results in higher gear stresses and noisier operation. 

Planetary gear reducers are often used when space and weight are an issue, but a large amount of speed reduction and torque are needed.  

Planetary gear reducers contain a sun gear that drives two or more planet gears, which in turn drive an internal ring gear. Most planetary gears require that the motor and driven equipment be in-line with one another.

They are capable of significant gear reductions in a compact space and are ideally suited for applications requiring significant torque or impact loading since several gear teeth are engaged at once. Tractors and construction equipment are common applications.

Low backlash gear reducers are ideal for applications that require frequent starting and stopping or load reversals while maintaining precise position. 

From pumping, to lifting, crushing, harvesting, processing, general manufacturing, or distribution, IER Services has a full line of shaft mount reducers, worm gear reducers, helical inline gear reducers, and helical-bevel gear reducers from WorldWide Electric. They feature reliable industrial-grade designs and drop-in compatibility with most major brands. Give us a call at 614-298-1600 to learn more

Topics: speed reducers

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Written by IER Services