ISBN: 978-0976511618
Printed: 162 pages, 8.5″ x 11″, perfect binding
Publisher: Copperhill Media Corporation
Copyright: © 2007 by Copperhill Technologies Corporation
Language: English
Country: United States
Edition: First Edition

Ordering Information

About this book

The Importance of servo motor sizing should not be underestimated. Proper motor sizing will not only result in significant cost savings by saving energy, reducing purchasing and operating costs, reducing downtime, etc.; it also helps the engineer to design better motion control systems. However, the knowledge of mechanical systems and their influence on motor speed, inertia and torque requirements seems to decline in a world where modern technology aspects, such as tuning and programming, seem to be the main focus. The motor sizing process involves a number of mathematical equations, which are most certainly documented, but not necessarily with the motor sizing process in mind. This book focuses primarily on servo motor sizing and it documents in detail the inertia and torque calculations of standard mechanical components and the motor selection process.

About the author

Wilfried Voss is the President of Copperhill Technologies Corporation, a company specializing in motor sizing software development for various motor manufacturers all over the world. In addition, Copperhill Technologies sells user licenses of its generic motor sizing program, VisualSizer-Professional.

Mr. Voss has been involved with motion control applications since 1985 as a specialist in the paper industry. He has a master’s degree in electrical engineering from the University of Wuppertal in Germany. Mr. Voss has traveled the world extensively, settling in New England in 1989. He presently lives in an old farmhouse in Greenfield, Massachusetts with his Irish-American wife and their son Patrick.

Table of Content

1. Overview

2. The Importance of Servo Motor Sizing

2.1 Why Motor Sizing?
2.2 Technical Aspects
2.3 The Objective of Motor Sizing

3. The Motor Sizing and Selection Process

3.1 Selection of mechanical components
3.2 Definition of a load cycle
3.2.1 Triangular motion profile
3.2.2 Trapezoidal motion profile
3.2.3 Motion profile processing
3.2.4 Motion profile calculation
3.2.5 Motion profile equations
3.2.6 Jerk Limitation
3.2.6.1 S-Curve Calculation
3.3 Load calculation
3.3.1 Load maximum speed
3.3.2 Load inertia and maximum torque
3.3.3 Load RMS torque
3.4 Motor Selection
3.4.1 Matching Motor Technologies to Applications
3.4.1.1 Stepper Motors
3.4.1.2 DC Brush Motors
3.4.1.3 DC Brushless Motors
3.4.1.4 AC Induction Motors
3.4.2 Selection Criteria
3.4.2.1 Inertia Matching
3.4.2.2 Interpretation of Torque/Speed Curves
3.4.2.3 Servo Motor Performance Curves
3.4.2.4 Stepper Motor Performance Curves
3.4.2.5 Servos vs. Steppers
3.5 Special Design Considerations
3.5.1 Gearing
3.5.2 Holding Brake and Motor Torque Requirements
3.5.3 Vertical Applications
3.5.4 Thrust Forces
3.5.5 Load Variations
3.5.6 Multi-Dimensional (X-Y-Z) Applications
3.5.7 Thermal Considerations
3.6 Sample application – comprised

4. Load Inertia and Torque Calculation

4.1 Basic Calculations
4.1.1 Fundamental Equations
4.1.2 Solid Cylinder
4.1.3 Hollow Cylinder
4.1.4 Rectangular Block
4.2 Calculation of Mechanical Components
4.2.1 Disk
4.2.2 Chain Drive
4.2.3 Coupling
4.2.4 Gears
4.2.5 Gearbox / Servo Reducer
4.2.6 Belt-Pulley
4.2.7 Conveyor
4.2.8 Leadscrew
4.2.9 Linear Actuator
4.2.10 Nip Roll
4.2.11 Rack Pinion
4.2.12 Rotary Table
4.2.13 Center Driven Winder
4.2.14 Surface Driven Winder

5. Motor Sizing Programs

5.1 Motor Sizing Programs for Windows
5.1.1 Axis Design
5.1.2 Velocity Profile
5.1.3 Motor Selection
5.1.4 Report Generator
5.1.5 Performance Curves

Appendix A – References
Appendix B – Web Site References
Appendix C – Symbols & Definitions
Appendix D – Material Densities
Appendix E – Mechanism Efficiencies

Articles on Servo Motor Sizing

Why is Servo Motor Sizing so important?
The importance of servo motor sizing should not be underestimated. Proper motor sizing will not only result in significant cost savings by saving energy, reducing purchasing and operating costs, reducing downtime, etc.; it also helps the engineer to design better motion control systems. Click here to read more…

Motion Mechanisms’ Inertia & Torque Calculations
This page provides all equations necessary to calculate the inertia and torque of mechanisms like gears, reducers, timing belts, rack & pinions, conveyors, and leadscrews. Click here to read more…

Calculation of Motion Parameters
This page provides all equations necessary to determine the parameters of a triangular or trapezoidal motion profile. The equation address velocity, acceleration, distance and time based on what parameters are known and which need to be determined. Click here to read more…

Holding Brake and Motor Torque Requirements
The effect of a holding brake on motor torque requirements is usually minimal in a regular rotary or linear horizontal motion application and is therefore not necessarily recommended. However, the torque and power reduction can be quite dramatic in case of vertical linear applications. Click here to read more…

Servo Motor Selection Criteria
The motor data needed to select a motor are rated speed, rated torque, intermittent torque, and rotor inertia. However, the best servo motor selection criteria is to use the motor’s performance curve (torque over speed) and to verify it with the application requirements. Not all motor data sheets do provide such detailed information, since some manufacturers prefer to define the rated/intermittent torque and the rated speed of their motors in a more conservatively manner. Under certain conditions it is, however, possible to operate motors beyond their rated data. Click here to read more…

Optimizing motion-control-system design
Choosing the right PC-based motion-control system requires evaluating motion controllers, software, amplifiers, motors, and positioning hardware.
Vision Systems Design – July 2005 - Click here to read more…

When to Choose a Linear Motor
For rotary or linear motors, motion is produced the same way and the same basic physics and electromagnetic forces apply. The theory that produces “torque” in a rotary motor produces “force” in a linear motor. But a closer look reveals that linear motors provide unique advantages for motion applications. Click here to find out how linear motors work and what the advantages are for motion applications.