Spiral Bevel Gears: Types and Applications In general, there are three main types of gears. These include parallel shaft gears, intersecting shaft gears and non-intersecting and non-parallel shaft gears. Spiral bevel gears fall into theintersecting shaft category. Within this category, there is the crown gear, bevel gear, coniflex bevel gear, zerol bevel gear, angular gear and miter gear. The primary function of spiral bevel gears is the transfer of power between two or more intersecting shafts. Intersecting shafts have a 90-degree orientation. Just like hypoid gears of the non-intersecting and non-parallel gear category, spiral bevels also have curved and oblique teeth. A conical surface forms the base of the gears teeth.
The teeth of standard bevel gears have a straight formation. As such,the teeth are parallel to the cones apex. While some spiral bevels have a unique teeth formation, others have a formation that resembles an arc. It is important to note that the replacement of these gears is always in pairs. This is because manufacturers set and lap the right hand and left hand gears in pairs. Right hand spiral bevels have an outer half tooth inclination that has a clockwise direction with respectto the axial plane. Left hand spiral bevel gears, on the other hand, have an outer half tooth inclination that has a counter clockwise direction with respect to the axial plane. It is important to note that spiral bevel gears and pinions have opposite orientations even if the spiral bevel is internal.
Spiral bevel gears help overcome the rapid or fast impact of gear teeth as they engage with each other. This is a common problem among straight bevel gears. With spiral bevels, their curved gear teeth make contact gradually, which significantly reduces wear and tear. The engagement of spiral teeth is just like that of helical teeth. That is, contact starts at one end before spreading progressively to the rest of the tooth. Most spiral gears require that their shafts be perpendicular to each other in addition to being on the same plane for successful engagement. Hypoid gears are a type of spiral bevel gears that have the capacity to engage while their axes are indifferent planes. They have a revolved hyperboloid shape- their pitch surface is hyperbolic. This is in contrast to the conical shape of the normal spiral bevel gear.
The pinion of the hypoid gear is off-axis to the ring gear or crown wheel.This effectively increases the contact area of the pinion. When subjected to loads, hypoid gears convey the same through multiple teeth. On the other hand, bevel gears load one tooth at a time. This feature makes them ideal for use in car differentials and other power transmissionapplications. Their multiple contacts when lubricated well are extremely silent. Other applications of the spiral bevel gears include root designs, tooth fillet, and tooth surface geometry in rotorcrafts. However, theseapplications of the spiral bevel gear still involve the transfer of power and motion. Tail-rotor and main-rotor gearboxes are the main application points of these helicopter spiral bevel gear. Please visit our website for more information on our spiral bevel gears manufacturing and other products and services we offer.