A crown wheel is a type of circular gear wheel with teeth that extend perpendicular to the base. While a traditional gear features teeth that sit parallel to the edges of the base, a crown wheel's teeth sit on the surface of the wheel, forming a crown-like shape. Crown wheels are considered a type of beveled gear, which is the general term for all gears with teeth located on the surface of the wheel rather than the edges. The teeth on a beveled wheel may be placed at any angle to the surface, while the crown wheel teeth are distinguished by the fact that they are positioned at a 90-degree angle to the gear.
These gears are often used along with a pinion to rotate a mechanical device. They are used in many automotive applications, as well as in industrial and manufacturing equipment. Many vehicles rely on crown wheel and pinion systems to create the vehicle's forward motion, or to rotate the axles. A crown wheel gear is also used with a pinion to operate a traditional mechanical clock.
While standard gears line up edge to edge, crown wheels mesh at an angle with pinions or other gears. Rather than being located in the same plane, the two gears are positioned at an angle, or perpendicular to one another. This allows the teeth in the gears to fit together and transfer motion or force between various operating components.
There are three basic types of crown wheel for buyers to choose from. Standard models have squared-off teeth that sit parallel to the top of the gear. This design results in a high level of vibration and noise when these gears are used. Spiral gears use teeth with angled edges, resulting in quieter performance, but also in faster wear and more maintenance. Hypoid crown wheels are similar to spiral models, but work with an offset pinion to create better strength and performance.
Users should select crown wheel gears carefully to match the needs of the application. The size and pattern of the teeth on the wheel must fit exactly with all adjacent gears or pinions. It is also helpful to choose higher quality gears, because are more precisely made to minimize noise and vibration. The material used to manufacture these gears is also a critical factor. If one gear is harder than the adjacent one, it will rapidly wear away the edges of the softer gear, shortening the life of the installation.