Page 71 - Robotics and AI class 10
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Here are some key details about bevel gears:
• Tooth Profile: Bevel gears have teeth that are cut on a conical surface. The teeth are shaped to form an involute
profile, similar to spur gears. The tooth shape allows for smooth engagement and efficient power transmission.
• Shaft Orientation: Bevel gears are used when the shafts they connect are not parallel or perpendicular but
intersect at an angle. The angle between the shafts can vary, allowing for versatile applications where motion
needs to be transmitted at different angles.
• Types of Bevel Gears: There are two primary types of bevel gears:
o Straight Bevel Gears: Straight bevel gears have teeth that are straight and taper towards the apex of
the gear cone. They are used when the intersecting shafts need to change the direction of rotation by 90
degrees.
o Spiral Bevel Gears: Spiral bevel gears have curved teeth that are angled in a spiral pattern around the gear
cone. The spiral tooth arrangement allows for smoother engagement and quieter operation compared to
straight bevel gears. Spiral bevel gears are commonly used when high torque transmission and reduced noise
are required.
• Gear Meshing: Bevel gears mesh with each other in a similar manner to spur gears. The conical teeth of one gear
engage with the teeth of the mating gear. The meshing action transmits rotational motion and torque between
the shafts.
• Power Transmission: Bevel gears are effective in transmitting power between intersecting shafts. When one
bevel gear rotates, it drives the other bevel gear, resulting in rotational motion in the second shaft. The gear
ratio, speed, and torque can be adjusted by using bevel gears with different numbers of teeth.
Example: Let’s consider an example of a robotic arm that requires a change in the direction of motion between
two intersecting shafts. The first shaft is connected to a motor, and the second shaft needs to rotate at a
90-degree angle to the first shaft. Bevel gears can be used to achieve this motion transmission.
A set of straight bevel gears is chosen, with one gear attached to the first shaft and another gear connected to
the second shaft. The gears have the same number of teeth to maintain a 1:1 gear ratio. As the motor-driven gear
rotates, the teeth of the first gear mesh with the teeth of the second gear, resulting in the rotation of the second
shaft at a 90-degree angle to the first shaft.
Bevel gears are also commonly used in differential systems, vehicle drivetrains, and steering mechanisms, among
other applications where rotational motion needs to be transmitted between intersecting shafts. Their ability
to change the direction of rotation at various angles makes them versatile components in mechanical systems,
including robotics.
Components of Robots as a System 69

