Bevel gears are used to transmit motion between two intersecting shafts. They can have straight or spiral teeth and are usually used at a 90 degree shaft angle but can be made for any angle. Bevel gear design considers the clearance, total depth, working depth, tooth thickness, and tooth space. Common types include straight, spiral, zerol, and hypoid gears which are used in differentials, drills, and other applications requiring power transfer between non-parallel shafts. Material selection depends on operating conditions and environment.
Double Revolving field theory-how the rotor develops torque
Design of bevel gear
1. DESIGN OF BEVEL GEAR
Name - Sarthak Muttha
Roll No. - 351041
G.R. No. - 21820140
2. Introduction
1. Bevel gears are used to transmit motion between two intersecting axes shafts.
2. The teeth of the bevel gears may be straight or spiral.
3. Although the bevel gears are usually made for a shaft angle of 90 degree, they can be produced
for almost any shaft angle.
3. Terminology of bevel gears
1. Clearance. It is the radial distance from the top of the tooth to the bottom of the tooth, in a
meshing gear. A circle passing through the top of the meshing gear is known as clearance circle.
2. Total depth. It is the radial distance between the addendum and the dedendum circle of a gear. It is
equal to the sum of the addendum and dedendum.
3. Working depth. It is radial distance from the addendum circle to the clearance circle. It is equal to
the sum of the addendum of the two meshing gears.
4. Tooth thickness. It is the width of the tooth measured along the pitch circle.
5. Tooth space. It is the width of space between the two adjacent teeth measured along the pitch
circle.
4. Types of Bevel Gears
1. Straight bevel gears have conical pitch surface and teeth are straight and tapering towards
apex.
2. Spiral bevel gears have curved teeth at an angle allowing tooth contact tpo be gradual and
smooth.
3. Zerol bevel gears are very similar to a bevel gear only exception is the teeth are curved: the
ends of each tooth are coplanar with the axis, but the middle of each tooth is swept
circumferentially around the gear.
4. Hypoid bevel gears are similar to spiral bevel but the pitch surfaces are hyperbolic and not
conical. Pinion can be offset above, or below, the gear center, thus allowing larger pinion
diameter, and longer life and smoother mesh, with additional ratios e.g., 6:1, 8:1, 10:1. In a
limiting case of making the "bevel" surface parallel with the axis of rotation, this configuration
resembles a worm drive. Hypoid gears were widely used in automobile rear axles.
5. Selection of Gear Material
The material for any gear is selected based on,
1. The working condition ie, power, speed and torque to be transmitted
2. Working environment, i.e., temperature, vibration, chemical etc.
3. Ease of manufacture
4. Overall cost of material and manufacture
6. Applications
1. Bevel gears are used in differential drives, which can transmit power to two axles spinning at
different speeds, such as those on a cornering automobile.
2. Bevel gears are used as the main mechanism for a hand drill.
3. The gears in a bevel gear planer permit minor adjustment during assembly and allow for some
displacement due to deflection under operating loads without concentrating the load on the end
of the tooth.
