Bevel Gears
Overview
Bevel gears are a special type of gear that has teeth which are cut at an angle that is non-parallel to one another. This type of gear is most commonly used in drive systems that require angular changes in the direction of a rotating member, such as an axle or shaft, as they can be used to alter the speed, torque, and direction of rotation. Bevel gears come in a variety of shapes and sizes and can accommodate different amounts of torque. In addition to the more commonly used straight cut bevel gear, there are also hypoid, ratchet, and spiral bevel gears, each with its own advantages for particular applications.
Bevel Gear Design
Bevel gears are typically designed using a combination of mathematics and CAD/CAM software. First, the desired parameters of the gear must be determined, such as the outer diameter, number of teeth, face width, and backlash. Once these parameters are decided upon, the motion and size of the gear is modeled in the software, which then produces a 3-D visual image of the gear. The designer then works to refine the design until all parameters are satisfied, either virtual simulations or physical prototype testing can then be used to evaluate the gear’s performance.
Bevel Gear Manufacturing
Bevel gears are typically manufactured using high-precision methods such as hobbing, blanking, shaping, and grinding, which offer superior accuracy and repeatability. The most common method is hobbing, which uses a cylindrical tool called a hob that is pushed against the gear blank to cut the bevel teeth into the gear material. This method is usually followed by f heaping or grinding to achieve a smooth, burr-free finish that meets the required tolerance. Blanking and shaping are also used for softer materials or if a lower precision is needed.
Quality Control
Once the bevel gears have been manufactured, they must be inspected to ensure that they meet the desired precision and specifications. This is done by running the bevel gears through a series of tests and inspections that measure the gears performance and assess its quality. These tests may include metal hardness tests, gear mesh tests, gear tooth contact tests, and gear runout measurements. The results of these tests are then compared to the designers specifications to ensure the gears meet the desired quality standard.
Conclusion
Bevel gears are a special type of gears that are used in drive systems that require angular changes in the rotation of its members. They are typically designed using a combination of mathematics and CAD/CAM software, and are manufactured using methods such a hobbing, grinding and blanking. As with any precision gear, quality control is essential to ensure the bevel gears meet the desired specifications and performance standards.
