Introduction to Gear Design
Charles D. Schultz, P.E.
Beyta Gear Service
Winfield, IL
Contents
Dedication
Introduction
About the 2nd Edition
1 How to Use This Book
2 What Kind of Gears Should I Use?
2.1 Parallel-Shaft Gears
2.2 Intersecting-Shaft Gears
2.3 Non-Intersecting-Shaft Gears
3 What Should They Be Made Of?
3.1 Rating Calculations
3.2 Gear Materials and Heat Treatment
3.3 The Gear-Design Process
4 What Should They Look Like?
4.1 Mounting Characteristics
4.2 Backlash
4.3 Blank Tolerancing
4.4 Quality Classes
4.5 Surface Finish
4.6 Blank Design
4.7 Tooth-Form Selection
5 How Should They Be Made?
5.1 Milling
5.2 Hobbing
5.3 Shaping
5.4 Broaching
5.5 Lapping
5.6 Shaving
5.7 Honing
5.8 Gear Grinding
Form Grinders
Generating Grinders
5.9 Bevel Gears
5.10 Worm Gears
6 How Should They Be Inspected?
7 Where Do I Look For Help?
8 Acknowledgments
9 About the Author
List of Figures
2.1 Parallel-Shaft Gear Types
2.2 Intersecting-Shaft Gear Types
2.3 Non-Intersecting-Shaft Gear Types
3.1 Critical Sections in Typical Parts
3.2 Mid-Band Jominy Hardness vs. Alloy
3.3 Approximate Min. Core Hardness vs. Alloy
3.4 Jominy Position vs. Critical Section
3.5 AISI Numbering System for Steel
4.1 Anti-Backlash Methods
5.1 Hob Nomenclature — 1
5.2 Hob Nomenclature — 2
5.3 Hobbing-Clearance Diagram
5.4 Double-Helical Gap-Width Diagram
5.5 Shaper-Cutter Nomenclature
5.6 Shaper-Cutter Clearance Diagram
5.7 Shaving-Cutter Nomenclature
5.8 Hob-Dipping Diagram
5.9 Tooth Modifications
5.10 Gear Grinder Types
5.11 Grinding-Wheel Interference on Cluster Gears
5.12 Bevel-Cutter Interference with Front Shaft
5.13 Worm-Gear Throat Diameter
6.1 Bearing Pattern Checks
List of Tables
2.1 Relative Characteristics of Gear Types
3.1 Popular Gear Materials
3.2 Approximate Minimum Hardenability of 1045, 4140, 4150, & 4340
4.1 Typical Gear-Blank Tolerances
4.2 Outside-Diameter Tolerances
4.3 Gear-Blank Standards
4.4 Minimum-Suggested Quality Level vs. Pitch-Line Velocity
4.5 Achievable AGMA 2000 Quality Levels by Manufacturing Method
4.6 Achievable Tooth-Surface Finishes by Manufacturing Method
4.7 Surface-Finish Description
4.8 Surface Finish vs. Tolerance
4.9 Popular Tooth Forms
5.1 Normally-Available Milling Cutters
5.2 Normally-Available Gear Hobs
5.3 Normally-Available Spline Hobs
5.4 Minimum Number of Teeth to Avoid Undercutting
5.5 Shaper-Cutter Teeth vs. Minimum Internal Gear Teeth to Avoid Interference
6.1 Sampling Plans
For information, contact:
Beyta Gear Service
Charles D. Schultz, p.e.
0N230 County Farm Road
Winfield, IL 60190
chuck@BeytaGear.com
(630) 209-1652
Visit Beyta Gear Service on the web:
http://BeytaGear.com
©1987, 2004 Charles D. Schultz
All rights reserved.
Self-published by Charles D. Schultz, Beyta Gear Service .
Document typesetting and diagram conversions by BD Tech Concepts LLC — 2015.
Statement of Non-Liability Due to today’s legal climate, it is necessary to state that this book has been written for general education purposes
only. Nothing written in these pages should be considered to be definitive advice about any specific situation.