Design of chain conveyor drive with reduction motor

Contents

CONTENTS

CONTENTS

INTRODUCTION

1. Electric motor selection

1.1. Calculation of required capacity

1.2. Total gear ratio and step ratios

1.3. Shafts RPM

1.4. Capacity on shafts

1.5. Torques

2. Calculation of cylindrical gears

2.1 Slow-moving stage (spur gear)

2.1.1 Allowable contact stresses

2.1.2 Allowable bending stress

2.1.3 Geometric transmission parameters

2.1.4 Transmission check calculations

2.1.5 Forces in engagement

2.2. High speed stage (helical gear)

2.2.1 Allowable contact stresses

2.2.2 Allowable bending stress

2.2.3 Geometric transmission parameters

2.2.4 Transmission check calculations

2.2.5 Forces in engagement

3. Calculation of chain transmission

4. Shaft Design and Rolling Bearing Calculation

4.1 Slow-moving shaft

4.1.1 Low-speed shaft sketch and definition of support reactions

4.1.2 Geometric characteristics of section A

4.1.3 Stress Determination

4.1.4 Endurance Limits

4.1.5 Coefficients

4.1.6 Geometric characteristics of section B

4.1.7 Stress Determination

4.1.8 Endurance Limits

4.1.9 Coefficients

4.1.10. Calculation of low-speed shaft rolling bearings

4.2 Intermediate shaft

4.2.1 Intermediate shaft sketch and definition of support reactions

4.2.2 Geometric characteristics of the section

4.2.3 Stress Determination

4.2.4 Endurance Limits

4.2.5 Coefficients

4.2.6 Geometric characteristics of the section

4.2.7 Stress Determination

4.2.8 Endurance Limits

4.2.9 Coefficients

4.2.10 Calculation of intermediate shaft rolling bearings

5. Calculation of connections

6. Calculation of gearbox housing components

7. Lubricant

7.1.Transmission of gears, oil grade selection, quantity, oil level control

7.2.Bonding of bearings

8. Gearbox Assembly Order

Conclusion

Bibliographic list

Introduction

The object of the calculation and design study is a process equipment drive consisting of an engine, a chain transmission and a two-stage cylindrical reduction gear. Gear gears of this type are widely used in the drive of various machines (conveyors, metal cutting machines, etc.). The drive in question serves to transfer torque to the conveyor actuator.

For gearbox design design and check calculations of gears are made.

Based on the sketched design, the obtained data for strength calculations of shafts and rolling bearings. Calculations were made on the basis of modern approaches to the design of gears using the criterion of operability - strength by contact stresses. Based on calculation procedure as per GOST 2135487. The obtained dimensions are accepted as standard according to GOST 2.30768 * and GOST 21.10579.

The design part of the project was made using the Compass computer-aided design system.

Gearbox Assembly Order

Prior to assembly, inner cavity of reducer is thoroughly cleaned and covered with oil-resistant paint.

Assembly is performed in accordance with gearbox assembly drawing, starting from shaft assemblies.

The bushing is fitted on the engine shaft, then the key is laid and the helical gear is pressed until it rests against the bushing. Then round splined nut is screwed onto shaft, thus fixing gear.

In advance, a key is laid in a slow-moving shaft. Gear spur-shaped cylindrical wheel is pressed on it until stop against shaft collar. Bushing and ball radial bearing are fitted. Then bushing and second bearing are fitted. They are pressed by screwing round splined nut.

Gearbox cover and sleeve are assembled. Assembled slow-moving shaft is inserted into them. Before installation of through cover into sleeve, cuff is put into grooves.

Impeller is fitted in intermediate shaft, keys are laid and gear wheel and gear are pressed until stop. Bushings, oil reflecting ring and ball radial bearings pre-heated in oil to 80100 ° С are fitted on the shaft.

The assembled intermediate shaft is laid in the base of the reduction gear case and the cover of the case is installed, covering the surfaces of the joint of the cover and the case with alcohol varnish. For alignment, the cover is installed in the housing with the help of two cylindrical pins.

Check a provorachivaniye of shafts lack of jamming of bearings (shafts have to turn by hand). Before attachment of covers with bolts, gaskets are placed between body and covers.

Then, trigger oil plug with gasket is screwed in and iron oil indicator is installed. Oil is poured into the housing and the inspection hole is closed with a cover with a gasket; cover is bolted. The assembled gearbox is rolled and tested on the bench according to the program set by the specifications.

Conclusion

Having completed the project and made calculations, I received the following results:

Durability of bearings on low-speed shaft is 118948 h.

Durability of bearings on intermediate shaft is 382558.4 h.

For geared gear bearings, the durability of LE 10000 h. Consequently, the durability of the bearings on the shafts is sufficient for the long-term operation of the geared gear.

The safety factors on the shafts exceed the recommended value, which ensures sufficient strength and rigidity of the structure.

Bending stresses in wheel teeth:

At slow-moving stage - 54.48 MPa

At the high-speed stage - 13.07 MPa,

which is less than permissible bending stresses of 198.68 MPa and 216.18 MPa.

The safety factors on the shafts exceed the recommended value, which ensures sufficient strength and rigidity of the structure.

When designing the gearbox, the optimal parameters of the product were chosen, satisfying often contradictory requirements, such as: the smallest weight and dimensions of the product, low cost, the greatest efficiency, the required rigidity and reliability.