Pulleys Driven By Belt

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Pulleys Driven By Belt

Fixed Pulleys centers: Pulleys become driven by a Belt

This design arrangement is a little more unusual than the Belt driven by a Pulley.

Physically, the Belt is wrapped around freely rotating Pulleys. The Belt is driven by motion-values at the input-connector to the Motion-Path FB.

Free Running Pulleys that are driven by a Belt

Preparation:

	STEP 1: Edit the Base-Part STEP 2: Add a sketch-loop - with lines and arcs only - to represent the Path for the Belt Hover+Drag to merge the Points at the end of each Line and Arc to give a sketch-loop. STEP 3: Add a dimension to each Arc The radius of the Arc is not important. MechDesigner adds a Pulley with an integer number-of-teeth with a Pulley that has a radius that is near to the starting dimension. STEP 4: Close the Part-Editor
	STEP 5: Click Kinematic-FB toolbar > Add Motion-Path FB The Command-Manager has one selection-box: Click a sketch-element in the sketch-loop. Click in the Command-Manager.
	A Motion-Point shows at the start-Point of the sketch-element you select in the sketch-loop. It is a small triangle inside the Point-Symbol. STEP 6: Add a Linear-Motion FB Connect the Linear-Motion FB to the Motion-Path FB with a wire. Motion-values of 0 - 360 (at the output of the Linear-Motion FB) move the Motion-Point the total length of the sketch-loop. You can use motion-values from any Function-Block,of course. E.g.: Motion FB .
	STEP 7: Add Parts : one part for each Pulley / Arc The length of each Part is not important for the Pulley or belt. STEP 8: Add a Pin-Joint between the start-Point of each Part and the center-Point of each Arc The Pin-Joint will be at the center of the Pulley.

Add Pulley command

	Do Kinematic-elements > Add Pulley to add each Pulley. Click Add Pulley in the: •Mechanism menu - or - •Kinematic-elements toolbar Add Pulley opens in the Command-Manager. Select the four element in the graphic-area. Note: See Preparation, above, to identify the four elements.

	Click the Pin-Joint Click the Motion-Path FB (not the Motion-Point) The Part-Editor opens to show the sketch-loop Click the radius Dimension of one of the Arc sketch-element The Part-Editor closes. Click the Part, with a Pin-Joint at the center-Point of the Arc. Click to close the Command-Manager Do Add Pulley again, to add a Pulley at the other Arc.
Two Pulleys Driven by the Belt'	Notes: The Pulleys are Driven Pulleys. The angular-velocity of each Pulley is defined by the linear-speed of the Motion-Point along the sketch-loop (Belt) and the radius of each Pulley. •When you add a Pulley, the radius of the Arc will change a little to give an integer number-of-teeth •The Parts are horizontal when the MMA is zero. •Driven Pulleys are Purple •Edit the number-of-teeth with the Edit Pulley dialog. •Edit the Tooth-Pitch in the Motion-Path FB.
	Kinematics Tree of the Pulley-Rocker element.