Course design: design of three-stage cylindrical reduction gear box

Contents

Table of contents

Introduction

1. Energy-kinematic calculation of the drive

2. Calculation of gears

2.1 Calculation of high-speed stage

2.1.1 Definition of allowable stresses

2.1.2 Design calculation of high-speed stage

2.1.3 Determination of module value based on bending stress strength

2.1.4 Calculation of load dynamics factors

2.1.5 Check of strength condition by contact stresses

2.1.6 Checking compliance with the bending stress strength condition

2.1.7. Geometrical dimensions of gear train

2.1.8 Engagement forces

2.2 Calculation of intermediate stage

2.2.1 Definition of permissible stresses

2.2.2 Design calculation of intermediate stage

2.2.3 Determination of module value based on bending stress strength

2.2.4 Calculation of load dynamics factors

2.2.5 Check of strength condition by contact stresses

2.2.6 Check of compliance with the condition of strength by bending stresses

2.2.7. Geometrical dimensions of gear train

2.2.8 Engagement forces

2.3 Calculation of slow-moving stage

2.3.1 Definition of allowable stresses

2.3.2 Design calculation of intermediate stage

2.3.3 Determination of module value based on bending stress strength

2.3.4 Calculation of load dynamics factors

2.3.5 Check of strength condition by contact stresses

2.3.6 Checking compliance with the bending stress strength condition

2.3.7. Geometrical dimensions of gear train

2.3.8 Engagement forces

3. Shaft Design

3.1 Determination of shaft diameters

3.2 Determination of shaft section lengths

Figure 5 - sketch of low-speed gear box shaft

5. Shaft Design Calculation

5.1 High speed shaft

5.2 Intermediate shaft of high-speed stage

5.3 Intermediate shaft of slow-moving stage

5.4 Slow-moving shaft

6. Selection of rolling bearings

6.1 High-speed shaft bearings

6.2 High-speed intermediate shaft bearings

6.3 Low-speed intermediate shaft bearings

6.4 Low-speed shaft bearings

7. Selection and inspection of key connections

7.1 High speed shaft

7.2 Intermediate shaft of high-speed stage

7.3 Intermediate shaft of slow-moving stage

7.4 Slow-moving shaft

8. Gear Design

8.1 High speed stage

8.2 Intermediate stage

8.3 Slow-moving stage

9. Selecting Bearing Covers

10. Lubrication, lubricants and seals

10.1 Lubrication of gears

10.2 Lubrication of bearings

10.3 Lubricants

10.4 Sealing devices

11. Shell Part Design

12. Gearbox assembly

13. Frame Design

Conclusion

List of sources used

Introduction

The goal of course design is to systematize, consolidate, expand theoretical knowledge, as well as develop the calculation and graphic skills of students. The main requirements for the machine are high performance, reliability, processability, minimum dimensions and weight, ease of use and cost-effectiveness. Gears are used in the designed gear box.

A reducer is a mechanism consisting of gear or worm gears, made in the form of a separate unit and serving to transfer power from the engine to the working machine.

The purpose of the reduction gear is to reduce the angular speed and increase the torque of the driven shaft compared to the driving shaft.

In our work, we need to design a reduction gear for the belt conveyor, as well as select couplings, engine. The reduction gear consists of cast iron housing, in which there are gear elements - gears, wheels, bearings, shafts, etc. Input shaft is connected by means of clutch to motor, output shaft is also connected by means of clutch to conveyor.

Conclusion

In this course design, a two-stage cylindrical reduction gearbox with a bifurcated slow-moving stage was designed. Calculations of the main units and parts of the mechanical drive were made:

selection and check of electric motor;

design and check calculations of gear train, with preliminary selection of wheel materials;

calculation of reduction gear shaft load;

calculation of bending and torque moments of gear box shafts;

design, and then verification (refined) calculations of shafts;

pre-selection of rolling bearings, and then checking their suitability.

All calculations were satisfactory. According to the design data, the assembly drawing of the reduction gear and drive is made on a scale of 1:2, the drawings of the shaft and wheel are made on a scale of 1:1.