Direct Gear Design – Alexander L. Kapelevich – 1st Edition

1 Historical Overview
1.1 Direct Gear Design® Origin
1.2 Gear Design Based on Rack Generating Technology
1.3 Gear Design without Rack Generation
1.4 Gears with Asymmetric Teeth

2 Macrogeometry of Involute Gears
2.1 Involute Tooth Parameters
2.1.1 Symmetric Gear Teeth
2.1.2 Asymmetric Gear Teeth
2.2 Gear Mesh Characteristics
2.2.1 Symmetric Gearing
2.2.2 Asymmetric Gearing
2.2.3 Contact Ratio for Helical Gears
2.3 Pitch Factor Analysis
2.4 Application of Direct Gear Design for Different Types of Involute Gears

3 Area of Existence of Involute Gears
3.1 Area of Existence of Symmetric Gears
3.1.1 Pressure Angle Isograms
3.1.2 Transverse Contact Ratio Isograms
3.1.3 Interference Isograms
3.1.4 Pitch Point Location Isograms
3.1.5 Performance Parameters’ Isograms
3.1.6 Area of Existence and Gear Tooth Profiles
3.1.7 Areas of Existence for Gear Pairs with Different Relative Tooth Tip Thicknesses
3.1.8 Areas of Existence for Gear Pairs with Different Numbers of Teeth
3.2 Area of Existence of Asymmetric Gears
3.2.1 Area of Existence and Gear Tooth Profiles
3.2.2 Areas of Existence for Gear Pairs with Different Asymmetry Factors
3.3 Area of Existence and Pitch Factors
3.4 Application of Area of Existence

4 Involute Gearing Limits
4.1 Number of Teeth
4.1.1 Symmetric Gearing
4.1.2 Asymmetric Gearing
4.2 Pressure Angle
4.3 Contact Ratio
4.4 Practical Range of Involute Gear Parameters

5 Tooth Geometry Optimization
5.1 Involute Profile Optimization
5.1.1 Gear Pair Size Reduction
5.1.2 Asymmetry Factor Selection
5.1.3 Mesh Efficiency Maximization
5.2 Tooth Modeling and Bending Stress Calculation
5.3 Root Fillet Optimization
5.3.1 Root Fillet Optimization Method
5.3.2 Fillet Optimization Analysis
5.3.3 Benefits of Fillet Optimization
5.4 Bending Strength Balance
5.5 Final Stress Definition

6 Gear Design Details
6.1 Gear Transmission Density Maximization
6.1.1 Introduction of Volume Function
6.1.2 Volume Functions for Two-Stage Gear Drives
6.1.3 Internal Gear Ratio Optimization
6.2 High Gear Ratio Planetary Drives
6.2.1 One-Stage Arrangements
6.2.2 Two-Stage Arrangements
6.3 Self-Locking Gears
6.3.1 Self-Locking Conditions
6.3.2 Self-Locking Gear Design
6.4 Plastic Gear Design Specifics
6.4.1 Polymer Benefits and Limitations
6.4.2 Direct Gear Design of Polymer Gears
6.4.3 Metal-to-Plastic Conversion
6.5 Gear Tooth Profile Modeling

7 Tolerancing and Tolerance Analysis
7.1 Gear Specification
7.2 Accuracy Selection
7.3 Tolerance Analysis

8 Gear Fabrication Technologies and Tooling
8.1 Gear Machining
8.1.1 Form Machining
8.1.2 Generating Machining
8.1.3 Contour Machining
8.2 Gear Forming

9 Gear Measurement
9.1 Measurement over (between) Balls or Pins
9.1.1 Spur Gears
9.1.2 Helical Gears
9.2 Span Measurement
9.3 Composite Gear Inspection
9.4 Elemental Gear Inspection

10 Comparison of Traditional and Direct Gear Design
10.1 Comparable Geometry and Stress Analysis
10.2 Gear Testing Results Comparison
10.2.1 Test Specimen Design and Analysis
10.2.2 Test Specimen Manufacturing
10.2.3 Test Arrangement and Procedure
10.2.4 Test Results
10.2.5 Results Analysis
10.2.6 Testing Results Conclusion
10.3 Design Method Selection

11 Implementation Examples
11.1 Speed Boat Gearbox
11.1.1 Gear Design
11.1.2 Gear Fabrication
11.1.3 Gearbox Performance Testing
11.2 Turboprop Engine Gearbox
11.3 Seed Planter Gearboxes
References