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The book takes the subject from an introductory level through advanced topics needed to properly design, model, analyze, specify, and manufacture cam-follower systems.
Cam Design and Manufacturing Handbook
(Controlling Cam Speed - Motors)

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   by Robert L. Norton
Published By:
Industrial Press Inc.
Up-to-date cam design technology, correct design and manufacturing procedures, and recent cam research. SALE! Use Promotion Code TNET11 on book link to save 25% and shipping.
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9.7 CONTROLLING CAM SPEED—MOTORS

 

Some type of driver device is needed to provide the input torque to the camshaft. A motor or engine* is the logical choice. Motors come in a wide variety of types. The most common energy source for a motor is electricity, but compressed air and pressurized hydraulic fluid are also used to power air and hydraulic motors. Gasoline or diesel engines are another possibility.

 

A conventionally driven industrial machine will use open-loop electric motors, often 3-phase AC, shunt-wound DC, or permanent magnetDC motors that allow some degree of speed control via circuitry that converts the readily available AC power from the line to DC and controls current to the motor for speed control. The torque-speed characteristic of these motors varies depending on the type of windings and field-armature connections.

 

Machine designers are increasingly using servomotors to power automated assembly equipment. Though the expense is high compared to other types of motors, the added cost is sometimes justified on the basis of the superior control and programming flexibility that results. The design of servo systems is well beyond the scope of this book and requires specialized knowledge not typically possessed by the machine designer. Servo engineers usually work as a team with machine design engineers to accomplish this task. We will limit our discussion to an overview of some of the differences, advantages, and disadvantages of using servomotors in lieu of conventional power sources. First, some definitions, terminology, and descriptions.

 

* The terms motor and engine are often used interchangeably, but they do not mean the same thing. Their difference is largely semantic, but the “purist” reserves the term motor for electrical, hydraulic, and pneumatic motors and the term engine for thermodynamic devices such as steam engines and internal combustion engines. Thus, your automobile is powered by an engine, but its windshield wipers and window lifts are run by motors.

 

† Other battery types have different cell voltages. Carbon-zinc batteries are 1.5 V/cell, alkaline batteries are 1.3 or 1.55V cell, and nickel-cadmium batteries are 1.2 V/cell.

 

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