Bevel gears are used to drive the dam gates.
A bevel gear is a gear designed to connect to a gear mounted on a shaft that can be positioned at any number of angles. Classically, bevel gears are used at 90 degree angles to each other, although other types of angles can also be used. This is unlike other types of gears, which generally must be used parallel to each other or at right angles, in some specialized cases. Bevel gears are used in a variety of applications, including an automobile differential gear.
Bevel gears are also used in other types of doors and gates, such as flood gates.
As the term “bevel” suggests, the face of a bevel gear has an angle. Typically, a bevel gear is tapered in shape, with the teeth running along the side of the cone, and the angle of the sides can vary depending on the application of the gear. The bevel design allows the gear to mate with another bevel gear at many different angles depending on how it was machined.
In a straight bevel gear, the teeth are straight and run vertically along the cone. The problem with spur gears is that all the impact falls on a single tooth, which makes the gear quite rough and eventually chipping the gear teeth. For this reason, some people prefer spiral gears, in which the teeth are set at an angle, allowing pressure to be distributed so the gears mesh evenly and smoothly. Spiral bevel gears are available for a variety of tasks.
Hypoid bevel gears are specialized bevel gears with non-intersecting shafts. These gears use a large toothed wheel with a smaller toothed gear and are used in applications such as car differentials where the gears may need to rotate at different speeds in some situations. Hypoid gears require custom lubricants because they are often subjected to a significant amount of stress.
An example of a bevel gear can be found in the operation of many garage doors. The gears used to turn the door are often set at right angles to each other, as can be seen on closer inspection. Bevel gears are also used in other types of doors and gates, such as dam gates, which are often operated by a user manipulating a screw that turns a bevel gear to open or close the gate.