Speed reducers are a combination of sets of gears as found in gearboxes and gear-heads, having shafts and bearings, assembled in an enclosed metal housing. The purpose of application of speed reducers is to convert input to a known output speed, there-by reducing the RPM at the output with increased torque.
In its present form of new invention, the multiple speed gear reducer has an input shaft and a power output shaft, with a series of train of load sharing gears interconnecting the shafts at the output and input. The gear trains also interconnect two or more reaction gears of different sizes. These reaction gears are of different sizes, which are connected to the input shaft coaxially, producing relative rotational motion between the gears and the input shaft. These are then operatively connected to the gear trains. Each of the reaction gears has a clutch, which selectively restricts the gear trains to attain a predetermined gear reduction ratio between the input and output shafts. There are separate coaxially arranged sleeves put around the input shaft, which is used to mount these reaction gears. The clutches on the sleeves control the reaction gears in order to maintain the specific gear ratio.
Speed reducers are used in machine tools to set the different speed that is required for different kinds of machining. The common types of reducers that are used are the pulley pairs of different diameter, gearboxes, and stepped electric motors. Gear boxes which are termed as speed reducers are generally found in different machine tools, automobiles, transmission products, cranes and hoists, etc. The most common type of speed reducers are:
Gearboxes or speed reducers are constructed out of high performance hardened and toughened shaved gears, which have been designed to operate smoothly with loss of little power. The gears and the shafts are assembled in a metallic housing using shafts and bearings. The input to the speed reducer comes from an electric motor shaft. The gears are of different sizes, having variety of numbers of teeth and coming in different diameter. The gear combination that is required to be meshed into each other is selected by the set of levers and clutches, and this combination enables the speed reducer to run in varied fixed steps. The output of this speed reducer came from the output shaft. The speed reducer needs to be thoroughly lubricated for the system to run smoothly.
In designing a speed reducer, the number of teeth of that of the larger gear is divided with that of the smaller gear. This ratio will provide you with the one you want in a helical and bevel gear set. For example, with the large gear having 28 teeth, if the smaller one has 14, the speed reducer ratio between the input and output would give you a ratio of 2:1. However, in worm gears the ratio is designed in a different way, where the number of teeth in the gear, is selected with respect to the number of that of the worm threads. If the worm has 2 threads with the gear having 60, then the speed reducer ratio would be 30:1.