stresses in straight tooth bevel gears

1. STRESSES IN STRAIGHT
TOOTH BEVEL GEAR

2. Introduction
Gears: A gear is a rotating machine part having cut teeth which mesh with
another toothed part to transmit torque. Geared devices can change the
speed, torque, and direction of a power source.
Types of gears:
1. Spur Gear 1. 2.
2. Helical Gear 1. 2. 3.
3. Herringbone Gear
4. Bevel Gear
5. Worm Gear
6. Rack and Pinion 4. 5. 6.
7. Internal and External Gear
8. Face Gear
9. Sprcokets
7. 8. 9.

3. Bevel gears
SPIRAL BEVEL GEARS
• A Spiral Bevel Gear are used to
transmit power between shafts
that are at a 90-degree
orientation to each other.
• Since spiral bevel gears are not
offset, less sliding occurs within
gear teeth. This results in a low
temperature operation with
more efficient functionality than
hypoid gear types.
• since there is a large amount of
tooth surface this allows for
greater interlocking during the
rotation process.

4. STRAIGHT BEVEL GEARS
Straight Bevel Gears have a straight tooth
geometry, which if extended, would pass
through the point of intersection of their axes.
Teeth are produced from forged alloy steel for
maximum strength and case hardened for
increased durability.

5. Stresses in straight bevel gear tooth
BENDING STRESS :
The equation for bevel gear bending
stress is the same as for spur gears as
shown below:
σ = (Ft/bmJ)*Km*Kv*Ko
Where,
Ft =Tangential load in N
m = module at the large end
of the tooth in mm
b = Face width in mm
J = Geometry form factor
based on virtual number of teeth
Kv = Velocity factor
Ko = Overload factor
Km= Mounting factor,
depending on whether gears are
straddle mounted