The compound gear train allows you to multiply gear ratios together . Consequently, it is possible to create very large gear ratios and hence generate very large torque and low speeds from high-speed, low-torque motors, for example. The overall gear ratio is found by multiplying all the individual gear ratios together.
Where are compound spur gears used?
Spur gears can be used to increase or decrease the torque, or power, of a given object. Spur gears are used to this effect in washing machines, blenders, clothes dryers, construction equipment, fuel pumps and mills .
How are compound gear trains used in watches?
The gear train allows the watch to run for many hours by multiplying the output rotation . The gear train is also responsible for dividing time into useful segments – hours, minutes, and seconds. Beyond its usefulness, a gear train is visually compelling because of its constant movement.
Why are compound gears better than two gears?
A compound gear train connects gears that may share axles or shafts. Two gears on the same shaft share the same torque and speed although they are different sizes. This allows more efficient manipulation of speed and torque throughout the system .
What is a gear train used for?
The main purpose of a gear train is to increase torque or speed . The arrangement of the driver and driven gears determine if the gear train will increase torque or speed. To increase output torque using a gear train, a power source should be directly connected to a smaller gear and used to drive a larger gear.
What is an example of a compound gear train in real life?
The gear train below has an arrangement of gear wheels including two compound gears. Gear trains like this are often found inside machines such as centre lathes and milling machines . On a smaller scale, plastic gear trains are found inside DVD recorders.
When would you use a compound gear train?
Compound gear trains involve several pairs of meshing gears. They are used where large speed changes are required or to get different outputs moving at different speeds .
Why are spur gears used?
Spur gears are used in mechanical applications to increase or decrease the speed of a device or multiply torque by transmitting motion and power from one shaft to another through a series of mated gears.
Why indexing is used in gear cutting?
Indexing is an operation of dividing a periphery of a cylindrical workpiece into equal number of divisions by the help of index crank and index plate. ... Because the operator of the machine may want to rotate the part to an arbitrary angle indexing plates are used to ensure the part is accurately positioned.
What are the 4 types of gears?
- Spur Gear. Spur gears transmit power through shafts that are parallel. ...
- Helical Gear. Helical gears have teeth that are oriented at an angle to the shaft, unlike spur gears which are parallel. ...
- Double Helical Gear. ...
- Herringbone Gear. ...
- Bevel Gear. ...
- Worm Gear. ...
- Hypoid Gear.
Do idler gears affect torque?
An idler gear does not affect the gear ratio between the input and output shafts . ... The intermediate gears, regardless of their size, do not alter the overall gear ratio of the chain, except to change the direction of rotation of the final gear.
How is gear ratio calculated?
To calculate the gear ratio:
Divide the number of driven gear teeth by the number of drive gear teeth . In our example, it’s 28/21 or 4 : 3. This gear ratio shows that the smaller driver gear must turn 1,3 times to get the larger driven gear to make one complete turn.
Where are gear trains used in real life?
Planetary gear train (PGT) has been widely used in the transmissions of helicopters, automobiles, wind turbine, aircraft engines, etc . The main advantages of this transmission are its high efficiency, its compactness, its large transmission ratio and its large power-to-weight ratio, etc.
Do train engines have gears?
The traction motors provide propulsion power to the wheels. ... Each motor drives a small gear , which meshes with a larger gear on the axle shaft. This provides the gear reduction that allows the motor to drive the train at speeds of up to 110 mph.
Which gear ratio is faster?
A lower (taller) gear ratio provides a higher top speed, and a higher (shorter) gear ratio provides faster acceleration. . Besides the gears in the transmission, there is also a gear in the rear differential.
What is an example of a gear train?
For example, a pair of spur gears fixed to parallel shafts will form a simple gear train.
