When an electric motor needs the output speed reduced and/or torque increased, gears are often used to do this. A speed reducer, also known as gear drives, gearboxes and transmission reducers, slow electrical currents in power transmission to protect against surges, and to make dangerous levels usable for normal applications.
By putting a gear reducer coupled with an electric motor, the input speed can be reduced and the torque can be high. With this combination, the output torque obtained from the motor is multiplied and the input speed is reduced by the same amount to keep a constant ratio.
While in many applications gear reduction reduces speed and increases torque, in some applications the gear reduction is used to increase speed and reduce torque. An example of this would be generators used in wind turbines.
These use gear reduction to convert a relatively slow turbine blade speed to a high speed capable of generating electricity. These applications use gearboxes that are assembled opposite of those in applications that reduce speed and increase torque.
There are many different kinds of gear reducers, and the most common ones are worm, helical, or bevel gears. There are two main configurations: in-line and right angle. Each can be achieved using different types of gearing.
In-line models are made of helical or spur gears, planetary gears, cycloidal mechanisms, or harmonic wave generators. Planetary designs generally provide the highest torque in the smallest package. Cycloidal and harmonic drives offer compact designs in higher ratios, while helical and spur reducers are generally the most economical. Most in-line reducers are fairly efficient.
Right angle models are usually made with worm gearing or bevel gearing. Hybrid drives are also an option. Your application will determine which design is best for you.
Worm gears tend to be the most cost effective reduction solution, but have a minimum 5:1 ratio and can lose considerable efficiency as ratios go higher. Bevel reducers are very efficient but have an effective speed reduction upper limit of 6:1.
Before choosing any reducer, specifications must be collected to properly size and install the unit: torque, speed, horsepower, reducer efficiency, service factor, mounting position, connection variables, and life required. In some applications the amount of backlash, transmission error, torsional rigidity, and moment of inertia are important factors to consider.
Gear reducers ensure that rotating machinery runs at the correct torque and speed. All speed reducer types come in a variety of quality levels and prices. If you need help choosing which gear reducer to use, give us a call. We'll be happy to help you make the right decision for your application and your budget.
ER Services is a leader in rotating machinery repairs. We offer many electromechanical repair services that our customers have requested such as diagnostic services, thermal-imaging, laser alignment, and advanced winding analysis. These tools help us to determine quickly where the problem is, and often we can fix it on site!
As a Baldor dealer, we carry a variety of reducers including the Baldor Speed Reducer, S-918-10-G.
It features a heavy duty cast iron housing, precision ground hardened worm, ball bearing on the input shaft, and tapered roller bearings on the output shaft. This model is typically used in applications requiring slow speed and high torque, ideal for conveyors, material handling, textile machines, packaging machinery, etc.