Add Pulley makes a motion relationships between a Rocker, a Motion-Point on a sketch-loop and the radius of a Pulley. There are two Pulley types:
The linear speed of the Motion-Point along a sketch-loop is equal to the product of the angular velocity of the Pulley and the Pitch-Centre-Radius of the Pulley. VelocityMOTION-POINT = RadiusPULLEY * ωPULLEY You can add one Drive Pulley and one or more Driven Pulley to each sketch-loop. For the Drive-Pulley Specify a Drive Pulley at an Arc in a sketch-loop with a Rocker joined to its centre. VMP = Velocity of the Motion-Point - calculated by MechDesigner RP = Radius of the Drive Pulley - specified by the Pulley dia Example Kinematic-Chains log-box ωP = Angular Velocity of a Rocker - specified by Kinematic FBs For each Driven-Pulley Specify a Driven Pulley at an Arc with a Free-Rotating-Part joined at its centre. VMP = Velocity of the Motion-Point - specified by the Drive-Pulley RP = Radius of the Driven Pulley - specified by the Pulley dialog-box ωP = Angular Velocity of the Free-Rotating-Part becomes a Pulley-Rocker - calculated by MechDesigner The Pulley-Rocker is a kinematically-defined Part. |
A Pulley-Rocker is constructed with a: |
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Command: |
Add Pulley |
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What for: |
To add a Drive Pulley or a Driven Pulley.
You can also add all Driven-Pulleys. The Motion-Path FB gives the speed of the Belt.
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The Belt can be a complex element to add to the model. Before you can use Add Pulley, other elements must be added to the model in particular ways |
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Before you can start this command: |
Part-Editor Edit the Base-Part, or an Added-Part, to add a sketch-loop to represent the path of the Belt. Add these Elements:
When the Arc is intended for a Drive Pulley Drive-Pulley with sketch-loop in Base-Part
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Drive-Pulley with sketch-loop in Added-Part
When the Arc is intended for a Driven Pulley Driven-Pulley:
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Mechanism-Editor
Note: The default direction for a Motion-Point is counter-clockwise along the sketch-loop. The initial position of the Motion-Point is at the most clockwise point of the sketch-element you select. When the Arc is intended for a Drive Pulley The Drive Pulley gives the peripheral velocity to the Motion-Point(s) along the sketch-loop.
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When the Arc is intended for a Driven Pulley Driven Pulleys rotate with the peripheral velocity of the Belt. Elements in the Mechanism-Editor
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What to do: |
Typically add a Drive Pulley first, followed by Driven-Pulleys at other arcs in the sketch-loop. Click Add Pulley in the Kinematic-elements toolbar. Click the Pin-Joint Click the Motion-Path FB Click the dimension Click the Rotating-Part* Click OK in the Command-Manager * Rocker for a Drive Pulley, Free-Part for Driven Pulleys, or Base-Part if the Pulley is fixed to the Frame. |
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Result: |
When you Click OK in the Command-Manager, MechDesigner:
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Video: |
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Notes: |
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Result: |
MechDesigner adds a Drive Pulley or a Driven Pulley |
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Kinematics-Tree: |
The Kinematics-Tree adds a Pulley-Rocker for each Driven Pulley you add to the model. A Drive Pulley is a Rocker. The Red Belt identifies that the Belt drives the Pulley. |
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See Also: |
Pulley dialog-box |
Use two Belts to:
The image to the left shows a Simple Belt with the three Pulleys and two Belts |
Step 1: Add first Motion-Path and two Pulleys
Use Add Pulley
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Step 1: Add second Motion-Path and two Pulleys
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