Fixed Pulley centers - Belt Driven by Driving-Pulley

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Fixed Pulley centers - Belt Driven by Driving-Pulley

Fixed Pulley Centers: Belt driven by a Driving-Pulley

This design arrangement is very common : there is one Driving-Pulley.

The Driving-Pulley drives the Belt and all other Pulleys along the Belt. The other Pulleys are termed Driven-Pulleys.

Preparation: Sketch-Loop and Pulley Parts


STEP 1: Add a sketch-loop to represent the path of the belt.

a)Edit the Base-Part : Add a sketch-loop to represent the path of the Belt

In this example, the sketch-loop has two Arcs and two Lines.

b)Part-Editor: Add a LineRed-14-1b and merge its start-Point with center-point of the Arc.

c)Part-Editor: You MUST dimension each Arc Red-14-2.

d)Part-Editor (Optionally, but a good idea:): Dimension the distance between the Arcs and the length of the lineRed-14-1b - see b)

The radius of each Arc is not important.

The Pulley's number-of-teeth and the Belt's tooth-pitch will define the radius of the Pulley and Arc

e)Exit the Part-Editor

STEP 2: Add a Motion-Path FB

a)Mechanism-Editor: Kinematic FB toolbar > Add Motion-Path FBRed-14-3

b)Mechanism-Editor: Click the sketch-loop that represents the path of the belt.

c)Click OK-tiny-15-18 in the Command-Manager

The Motion-PointRed-14-4 shows at the start-Point of the sketch-element you select in the sketch-loop.



STEP 3: Add the Parts for the Pulley's

a)Mechanism-Editor: Add one PartRed-14-5 for each Pulley. The length of each Part is not important.

b)Mechanism-Editor: Add Pin-JointRed-14-6 between the start-Point of each Part and the center-Point of an Arc.

c)Mechanism-Editor: Kinematic-FB toolbar > Add Motion-Dimension FBRed-14-7 to the Part that will be a Driving-Pulley.

In this case, the Driving-Pulley is a Rocker. A Driving-Pulley can be any kinematically-defined Part

Use Add Pulley


STEP 1: Add the Pulleys  

a)Mechanism-Editor: Machine elements toolbar > Add Pulley


Add Pulley opens in the Command-Manager.

Click, in the graphic-area, the four(4) elements from top to bottom - see images Red-14-6Red-14-3Red-14-2Red-14-5 above

Red-14-6 The Pin-Joint

Red-14-3 The Motion-Path FB

The Part-Editor opens to show the sketch-loop to which you added the Motion-Path FB.

Red-14-2 The Radius Dimension of the Arc sketch-element with the Green rotating-Part

The Part-Editor closes.

Red-14-5 The Part joined with a Pin-Joint at the center of the Arc.

b)Click OK-tiny-11-15 to complete the command and to close the Command-Manager.



This is called a Driving-Pulley.

A Driving-PulleyRed-14-8 is driven by the kinematically-driven Part (the Rocker, in this case).

Belt Speed = Radius of Driving-Pulley * Angular-Velocity of the Driving-Pulley



Do a) and b) again to add a Driven-Pulley.

A Driven-PulleyRed-14-9 is added to the free-Part

Its default color is different to that of a Driven-Pulley.

STEP 1: Add the Pulleys  

Edit each Pulley : Number-of-Teeth in the Pulley dialog.

tog_minusKinematics Tree Rocker and Pulley-Rocker