Introduction to basics of bevel gears, its geometry and design calculation.

1. Subject: Machine Design
Topic: Bevel Gears

2. Bevel Gears
• Bevel gears are used to transmit motion between two
intersecting axes shafts.
• The teeth of the bevel gears may be straight or spiral.
• Although the bevel gears are usually made for a shaft angle of
90 degree, they can be produced for almost any shaft angle.

4. DESIGN PROCEDURE FOR BEVEL
GEARS
• From the requirements choose suitable materials for
pinion and gear, tooth profile and pressure angle are
selected.
• Minimum cone distance,R can be determined by
using equation,

5. • Average module mav can be calculated
based on the beam strength using the
equation,
DESIGN PROCEDURE FOR BEVEL
GEARS

6. Diameter of pinion,
Diameter of the wheel,
Recalculate cone distance,
Calculate the face width,
DESIGN PROCEDURE FOR BEVEL
GEARS

7. Checking conditions:
Check for surface compressive stress using the equation,
Check for bending stress using the equation,
Tabulate the results.
DESIGN PROCEDURE FOR BEVEL
GEARS

8. APPLICATIONS OF BEVEL GEARS
• 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.
• Bevel gears are used as the main mechanism for a hand
drill. As the handle of the drill is turned in a vertical
direction, the bevel gears change the rotation of the
chuck to a horizontal rotation. The bevel gears in a
hand drill have the added advantage of increasing the
speed of rotation of the chuck and this makes it possible
to drill a range of materials.

9. Bevel Gears
Advantages
• This gear makes it possible
to change the operating
angle.
• Differing of the number of
teeth (effectively diameter)
on each wheel
allows mechanical
advantage to be changed.
Disadvantages
• One wheel of such gear is
designed to work with its
complementary wheel and
no other.
• Must be precisely mounted.
• The shafts bearings must be
capable of supporting
significant forces.

10. THANK YOU…