Getting Started Tutorials - MechDesigner > Tutorial 14: Gear-Pairs / Rack-Pinions > A: Fixed Gear Centers

Simple Gear Trains

Schematic of Simple Gear Train

A Simple Gear-Train has two or more Gear-Pairs that you connect in series. The Driven-Gear of one Gear-Pair becomes the Driving-Gear of the next Gear-Pair in the series, and so on in the series.

Use a Simple Gear-Train to:

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

•reverse the direction of the output shaft on a Simple Gear-Pair

•increase or decrease the Torque and Speed at the output-shaft.

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

Note:

1.The Driving-Gear on the first Gear-Pair and the Driven-Gear or the last Gear-Pair in the series of gears control the gear and speed ratio.

2.All other gears are idle gears or idlers - they do not affect the overall Gear-Ratio.

Schematic of a Monobloc machine.

Application of Simple Gear-Train - a Monobloc Machine

Monobloc machines include Filling, Capping, Labeling, Coding, Orientating and many other high-speed applications.

The Monobloc uses a simple gear-train to transmit the motion from shaft to shaft.

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

Gear-Pair 1

Gear-Pair with Fixed Centers

Add a Gear-Pair

1.Do Add a Gear-Pair with Fixed-centers

2.Edit the Gear-Pair.

Open the Gear-Pair dialog:

3.Edit the Gear 1 and Gear 2:

number-of-teeth, Z1=20

number-of-teeth, Z2=40

4.Edit the Module:

Module = 2

Gear Ratio is Z1/Z2 = 2 ; Distance between Gear Axes = 60mm

Gear-Pair 2 : PREPARATION

Line-1(5) in Part-1(4)

Line 1 in Part 1 :

The Driven-Gear of Gear-Pair 1 will be the Driving-Gear of the Gear-Pair 2.

Line in Part - see Gear-Pair 1, above

Line 2 in Part-2 Before you do Merge-Points

Line 2 in Part 2 (the Base-Part)

1.Edit the Base-Part

2.Geometry toolbar > Add Line

IMPORTANT Rule for a Gear-Train: You must MERGE Point and Point.

To merge the Points:

Either

a)Drag to add Line - hover above Point to merge Point and Point automatically.

a)Drag to add the Line (near to Point)

Geometry toolbar > Merge-Points

a)Click the end-Point of the Line-of-Centers of Gear-Pair 1

b)Click the start-Point of Line

c)Click the graphics-area

3.Geometry toolbar > Add Dimension

a)Add a Dimension to Line (the length is not important)

4.Close the Part-Editor.

Line 3 in Part 3 (new Part)

Line 3 in Part 3 :

A new Part - it will be the Driven-Gear.

1.Click Kinematics-toolbar > Add Part: Drag to add Part

2.Click Kinematics-toolbar > Add Pin-Joint :

a)Click the start-Point of CAD-Line in Part

b)Click the end-Point of Line in the Base-Part.

The length the CAD-Line in Part is not important.

Gear-Pair 2 : ADD GEAR-PAIR

GST-14.A2-05

You can now add Gear-Pair 2

1.Click Machine-elements toolbar > Add Gear-Pair

2.Click the elements, from top to bottom - refer to Preparation images, above

3.Click at the bottom of the Command-Manager.

GST-14.A2-06

You can see the Gear-Pair 2

There are two new gears.

However, a Simple Gear Train has three gears.

You must edit Gear-Pair 2 so that its Gear-1 has an equal number-of-teeth to the Gear-2 of the Gear-Pair 1.

GST-14.A2-07

Use the Gear-Pair dialog to edit:

1.Module = 3

2.Number-of-teeth Gear 1 = 40 : the same as Gear 2 of Gear-Pair 1

3.Number-of-teeth Gear 2 = 20

The image is Gear-Pair and Gear-Pair

The position of Gear 2 of Gear-Pair is identical to Gear 1 of Gear-Pair .

Simple Gear-Trains

Simple Gear-Trains

Simple Gear Trains

Gear-Pair 1

Gear-Pair 2 : PREPARATION

Gear-Pair 2 : ADD GEAR-PAIR