Bevel gears are used to move gates in dams.
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 different from 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 the differential gear of a car.
Bevel gears are also used in other types of doors and gates, such as floodgates.
As the term “bevel” suggests, the face of a bevel gear is angled. 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 be varied depending on the gear application. The beveled 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, running vertically along the cone. The problem with spur gears is that the entire impact goes down on a single tooth, making the gear quite rough and causing chipping along the gear teeth over time. For this reason, some people prefer spiral gears, in which the teeth are placed at an angle, allowing the pressure to be distributed so that the gears mesh evenly and evenly. Spiral bevel gears are readily available for a variety of tasks.
Hypoid bevel gears are specialized bevel gears with shafts that do not intersect. These gears utilize a large sprocket with a smaller cog gear and are used in applications such as car differentials where it may be necessary for the gears to rotate at different rates of speed 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 upon closer examination. 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.