What is a reduction gearbox?
Reduction gearbox is a device that enables the input speed to be reduced when outputting under the same or higher output torque. The reduction gear device is composed of a set of rotating gears connected to the rotating device. The high-speed movement from the rotating device is transmitted to the rotating gear, and the movement or torque is thus changed. The number of gears used in the reduction gear unit depends on the output speed requirements of the application equipment. The reduction gear unit is generally regarded as a reduction gear box.
Why are reduction gearboxes used?
In order to understand why the reduction gearbox is used on a specific machine, we will take a ship using a high-speed turbine as an example. In order to achieve a high efficiency, the steam turbine should run in a high speed range, which is a basic requirement for ships. However, lower than the propeller, it requires a low speed. In order to achieve this goal, a reduction gear was invented, through which the high-speed motion of the turbine will be reduced to the low speed required by the propeller.
Types of reduction gearboxes:
Unipolar reduction gear:
This kind of device consists of only a pair of gears. The reduction gearbox is usually composed of holes through which the propeller shaft and the engine shaft enter the assembly. It is called the pinion when it is driven by the shaft of the engine. The small gear directly drives the large gear mounted on the propeller shaft. The speed is adjusted by making the reduction ratio proportional to the radius of the pinion gear and the large gear. Generally speaking, a single gear unit has a large gear that is twice the size of a small gear.
Bipolar reduction gear:
Bipolar reduction gears are usually used in high-speed applications. In this case, the pinion gear is connected to the input shaft using flexible coupling. The pinion gear connected to the intermediate gear is called the first-stage reduction gear. Then, with the help of one or more shafts, the first-stage reduction gear is connected to the low-speed gear. This pinion is connected to a secondary reduction gear mounted directly on the propeller shaft. This arrangement helps the reduction ratio to reach 20:1.
Actual types of reduction gearboxes:
1, power transmission gear box
2, worm reduction gearbox
3, mining plant gear box