Screw extractor

Contents

TABLE OF CONTENTS

Introduction

1 Screw transmission design and verification calculations

1.1 Selection of thread type and materials

1.2 Screw Design

1.2.1 Calculated average thread diameter:

1.2.2 Self-braking test

1.2.3 Check of nut turns number:

1.2.4 Friction moment in thread

1.3 Nut Design

1.3.1 Nut check calculation

1.4 Heel Design

1.4.1 Friction moment on solid heel

1.5 Screw stability check

1.5.1 Screw Flexibility

1.6 Screw strength check

1.6.1 Geometric characteristics of sections

1.6.2 Compression and torsion stresses

1.6.3 Equivalent voltages

1.7 Drive Design

1.8 Calculation of transmission parameters

2 Design and verification calculations of screw extractor housing

2.1 Design of pickup

2.1.1 Grip Sketch

2.1.2 Cross section selection

2.2 Traverse Design

2.2.1 Cross-arm sketch

2.2.2 Cross section selection

List of sources used