Gears are used for changing the direction of rotary motion or to increase the torque. Industrial machines typically use a bevel gearbox for these purposes. Let us see the inner construction of a simple bevel gearbox and understand its mechanism.
A Peep Inside a Bevel Gearbox
On opening the housing of a bevel gearbox one comes to know that the construction is really simple. It consists of an input gear coupled with another gear called the output gear at right angles to each other. The gears can be either of spur or helical type. Helical gears are preferred as they are less noisy due to gradual engagement and have a longer life.
In case a reduction in speed is required, the diameter of the output gear is kept larger than that of the pinion. If only change in direction is required the diameters of both the gears are equal.
Materials commonly used are plastic or metal and depend on the load. Three gears are used in case the axis of rotation the same as that of input. The point of contact is well lubricated with gear oil.
Mechanism of a Bevel Gearbox
The electric motor or engine causes the input gear to spin which in turn rotates the output gear. Thus the rotary motion is passed on from the input arm to the output arm.
In case the diameter the output gear is larger than that of the input gear, the torque of the system increases at the expense of speed. Such a system is known as a reducer. The gears are at right angles to each other and hence the direction of the rotary motion is changed.
Applications of a Bevel Gearbox
The property of change of axis and speed of the bevel gearbox is used in a variety of industrial and automotive machines. It is used in turbines, pumps, grinders, etc. In vehicles the gearbox is used in the limited slip differential. One can clearly understand the working of the bevel gearbox by opening a simple hand drill.