General Design Information > Gear Mechanisms

FIXED centerS:

•One Gear-Pair

•Two or more Gear-Pairs, including

oSimple Gear-Train

oCompound Gear-Trains

oReverted Gear-Trains

One Gear-Pair

Fixed Gear centers
External Gear 1 < Gear 2	External Gear 1 > Gear 2

Internal Gear 1 < Gear 2	Internal Gear 1 > Gear 2

Simple Gear-Trains

Schematic of Simple Gear Train

A Simple Gear-Train is a number of Simple Gear-Pairs in series. Each rotating shaft has only one gear.

Simple Gear-Trains are used to:

•Increase the distance between the input and output shafts, so it is possible to use a number of smaller gears than when you use one gear-pair

•Reverse the direction of the output shaft of a Simple Gear-Pair

The image to the left shows a schematic of a 'Simple Gear Train'.

Notes for Simple:

•Gears that are not on the input and output shafts do not change the speed ratio. They only change the direction of rotation.

•The gears between the input and output shafts are 'idle gears' or 'idlers'.

Monobloc-scematic

'Monobloc Machines'

This is a schematic of the gears you frequently find on a 'Monobloc' machine. Monobloc are often use for Filling, Capping, Labelling, Coding, Orientating and many other high-speed packaging applications.

Monobloc machines use Simple Gear-Trains to transmit the motion from one 'wheel', or 'head' to the next.

See Also: the YouTube Video: http://youtu.be/fvRp2lC1aXw

Compound Gear-Trains

Schematic of Compound, Three-Stage, Gear Train

A 'Compound Gear Train' has at least:

•two Gear-Pairs

•one shaft with more than one gear

Compound Gears are used to:

•Increase the distance between the input and output shafts and still use small gears

•Dramatically reduce the speed between the input and output shafts

•Give 'difficult' gear ratios

The image to the left shows a Compound Gear Train. There is more than one gear-pair and two shafts have two gears.

Therefore, it agrees the definition of the Compound Gear Train.

Reverted Gear-Pairs

Schematic of Compound, Three-Stage, Gear Train

A 'Reverted Gear Train' has:

•two Gear-Pairs

•two shafts

•the input and output shafts are co-axial

•the two shafts are usually co-axial

It is a Compound Gear with, two Gears-Pairs, and a special condition that makes the total number of teeth of the first gear-pair equals the number of teeth of the second-gear-pair, when the module is the same.

The image to the left shows a Reverted Gear Train. There is more than one gear-pair, two shafts, and the input and output shafts are collinear.