Dynamics of Cam Mechanical Systems

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Dynamics of Cam Mechanical Systems

Packaging Machine with Cams. Courtesy of Lareka NL

Example Cams in an enclosure with forced oil feed.

Dynamics of Cam Mechanical Systems

The Cam Mechanical System includes all of the mechanical components from the 'Power Source' (usually the Servo or AC Motor) to the 'Payload'.

MechDesigner calculates the exact force or torque that a motor must provide to move your mechanisms with the motion you have designed in MotionDesigner. It also calculates the active and reactive forces to overcome the inertia, gravity and spring forces in each joint as they move.

These forces and torques are called 'kinetostatic-forces'. It is important to know that kinetostatic-forces do not consider the parasitic effects of rigidity, vibration, backlash, friction, stiction, speed variation at the drive motor..and more.

These parasitic effects will mean the motion of the payload is not the same motion as designed. The worse the design, the larger the difference will be between your motion design and the motion at the output.

This section reviews the 'parasitic effects' on the performance of Cam Mechanical Systems. We also suggest how to improve your designs.

There is an emphasis on the Traditional Motion-Laws that are applied to mechanisms with Dwell-Rise-Dwell type motions. This is because their causes and effects on the mechanical system are easier to understand, which provides us with valuable design insights. You should be able to apply these insights even when you need to design a complex motion and a complex mechanism.

Dynamics of Cam Mechanical Systems

Transmission Design Considerations: Rigidity

Dynamic Response: Period-Ratio, Damping, Backlash

Example 1: Indexing Table with Backlash

Example 2: Torque to Drive an External Load

Payload Types, Normalized Loads, Input Torque

Torque, Overrun, Power

Example 3: Power Calculation