GEARS

Similar to spiral bevel gears except they transmit motion between non-intersecting shafts.The teeth on a hypoid gear are helical

Advantages

Provides quiet operation and additional durability.

Less sliding and high efficiency result in smaller capacity motors.

Compared to worm, the offset between pinion and gear is small with resultant space savings.

Increases the flexibility of a machine design because the axis can be extended to both directions and the height of axis can be set freely in some degree.

Disadvantages

Requires special EP (extreme pressure) gear oil in order to maintain effective lubrication.

It requires high technology in design and manufacturing.

The material requires special care when meshing.

Some gears may warp or become brittle in the face of extreme temperatures.

Examples

Truck drive differentials, where high torque and an offset pinion are valued.

Sumitomo hyponic drive.

The teeth are parallel to the axix of the gear

Examples

Auomobile Gear Boxe

Advantage:

They are compact and are easy to install

They do not have slip

They are highly reliable

Disadvantages

They produce a lot of noise

They experience a large amout of stress

They are usually low speed gears

Diameter of the wheel infinite

Advantages

They are cheap

They are compact

Robust

Easiest way to convert rotation motion into linear motion

Rack and pinion gives easier and more compact control over the vehicle

Disadvantages

The wheel is also the most convenient and somewhat more extensive in terms of energy too.

They can only work with certain levels of friction

Due to the friction, it is under a constant wear, possibly needing replacement after a certain time.

Applications

Steering Wheel

Stairlifts

Railways

A worm and worm gear system consists of a worm and worm wheel. The worm resembles a screw, which meets with a worm wheel. It works when rotational power is applied to the worm so it rotates against the wheel and transfers power to the worm wheel.

Applications

Advantages

The system provide high-ratio speed reduction.
They are used to increase torque or reduce speed.
They are the smoothest and quietest of the gear systems.

Disavantages

Gears should be assembled with respective shaft precisely.
The mechanism might produce an annoying sound at a high speed.

There are two types of helical gears

Crossed

Parallel

They are similiar to the spur gears, but they have a hélix angle between every teeth

Examples

Railway industry

Advantages

They are more silent than spur gears

They can be used for high load applicatons

They can transmit more power between either parallel of right angle shafts

Disadvantages

They tend to have more friction

They are more expensive than spur gears

The efficency is less than a spur gear

They are gears where the xes of the two shafts intersect and the tooth bearing faces of the gears themselves are conically shaped.

Advantages

- It lets you 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.

Aplications

The bevel gear has many diverse applications such as locomotives, marine applications, automobiles, printing presses, cooling towers, power plants, steel plants, railway track inspection machines, etc.

(Also known as double helical) is a gear designed to transmit power through parallel or perpendicular axes. It works like a helical gear, but, because of its tooth structure, it nullifies the axial thrust.

Advantages

Quiet and pulse free flow

Great strength

Minimum hydraulic shock

Improved load carrying ability

Disadvabtages

Manufacturing cost is too high

Difficult aligning during assembly

Applications

External gear pumps