Straight Bevel Gears

Straight
Bevel Gears are also known by the name of plain bevel. They have got this
name for the simple reason that in these gears, tooth is cut straight across
the face. Operating conditions wise they are similar to
spur gears. Likespur Gears they also do not have any helix angle. Straight tooth bevels though efficient but can be noisy.
The sides of these Bevel Gears are tapered to facilitate the intersection
of the axis at a common point known as pitch cone.
Today in most of the straight bevel gears, the face cone elements are now
increasingly made parallel to root cone elements of the corresponding mating
gear. This is done for obtaining an uniform clearance through the length of
the point, inside a pitch cone. These gears are most simple to calculate
while being economical also.
Manufacturing Straight Bevel Gears
Straight bevel gears are manufactured on precision generating machines by
indexing method ensuring teeth of tapered depth and thickness. Preferably
case hardened material is used for production of these gears. Further it is
carburized for achieving the corresponding case depth. These gears are all
the time manufactured in pairs. This ensures proper mounting distance. It is
then properly lapped in pairs for a perfect wearing in and also for
accommodating optimum contact ratio.
Features of Straight Bevel Gears
- Simplicity and Economy of operation - This is made possible
by two reasons: a) Compared to Spiral Bevel Gears, the axial and radial
thrust components originating from the torque and acting at the teeth
are low. b) Also, the axial and radial thrust components are always in
the same direction (out-of-mesh) irrespective of which member is the one
that is driving or the rotational direction. This is able to simplify
the requirements of bearing, saves space and also cuts costs.
- Hassle free manufacturing
- Reduction ratio easily up to 1:5
- Perfect for a Differential Gear unit
Application of Straight Bevel Gears
There are a variety of industrial application in such industries are shown
below:
- Chemical Plants(Agitators/Mixer/Separators & Dryers)
- Pharmaceutical Industries
- Steel plant
- Pulp and paper industry
- Cement plants
- Food processing units
- Textile processing units
- General Machinery & Machine Tool
- Material handling systems (Crane/Conveyors/Earth moving equipments.)
- Rubber plants
- Sugar mills
- Printing machines
- Mining equipments
Recommended use of Straight Bevel
Gears
- A these gear is recommended as a prefect instrument for peripheral
speeds that can be up to 1000 feet/minute (ft/min). It is ideal in cased
where quietness and maximum smoothness are not that vital. However, it
is not unlikely to see ground straight bevels being successfully used
for generating speeds up to even 15,000 ft/min. To conclude, as
straight-bevel gears are very easy to calculate, set up, and develop,
they are used best for small lots.
- These Gears works best when loads are comparatively lighter, can be
recommended for high static loads only if surface wear is not that
critical.
- These Gears are also the perfect choice when space, mountings and
gear weight is at premium. This also includes planetary gear systems,
where constricted space does not allow any inclusion of rolling-element
bearings.