Design of Belt Conveyor Mechanical Drive

Contents

1. Kinematic calculation

1.1. Selection of electric motor and determination of total gear ratio of the drive

1.2. Breakdown of total gear ratio of the drive by stages

1.3. Gear materials

2. Calculation of belt transmission

2.1. Parameters and kinematics of V-belts

2.2. Geometric calculation of V-belt transmission

2.3. Complex calculation of belt transmission for endurance and traction capacity

2.4. Forces acting on shafts in belt transmission

2.5. Belt gear pulleys

3. Calculation of bevel gear train

3.1. Design calculation of bevel gears

3.1.1. Design Transmission Load

3.1.2. Definition of durability factors

3.1.3. Determining the approximate value of allowable contact stresses

3.1.4. Calculation of approximate value of gear initial circumference diameter

3.1.5. Determining the number of teeth and displacement factors

3.1.6. Calculation of geometric parameters of orthogonal conical transmission with straight teeth at standard initial contour

3.2. Taper Gear Strength Check

3.2.1. Definition of allowable contact stresses

3.2.2. Determination of contact stresses in engagement of conical wheels

3.2.3. Determination of bending stresses in dangerous sections of bevel gear teeth

3.2.4. Determining Forces in Bevel Gear

4. Design calculation of cylindrical gear train

4.1. Design Transmission Load

4.2. Definition of durability factors

4.3. Select the inclination angle of the tooth line and the precision of the gears

4.4. Determining the approximate value of allowable contact stresses

4.5. Calculation of approximate value of gear initial circumference diameter

4.6. Define allowable bending stresses on the tooth surface

4.7. Calculation of the maximum number of gear teeth

4.8. Check calculation of cylindrical gear train

4.8.1. Calculation of updated values of dimensions of cylindrical gear train

4.8.2. Calculating the Geometry of a Cylindrical Gear Train

4.8.3. Calculation of refined allowable contact stresses

4.8.4. Definition of refined values of load coefficients

4.8.5. Determination of design values of contact and bending stresses in teeth of cylindrical gears

4.8.6. Forces in engagement of cylindrical gears

6.1. Gearbox High Speed Shaft Calculation

6.1.1. Calculation of gearbox high-speed shaft for complex resistance

6.1.2. Calculation of speed shaft of gearbox for endurance

6.2. Calculation of gearbox intermediate shaft

6.2.1. Calculation of gearbox intermediate shaft for complex resistance

6.3.1. Calculation of low-speed gear shaft for complex resistance

6.3.2. Calculation of low-speed gear shaft for endurance

7. Defining Key Connection Parameters

8. Calculation of rolling bearings

8.1. Calculation of high-speed shaft bearings

8.2. Calculation of intermediate shaft bearings

8.3. Calculation of low-speed shaft bearings

9. Calculation of gearbox housing parameters

10. Reduction gear box lubrication

11. Gearbox assembly

List of literature

Introduction

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

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

In this course design, the power mechanical drive of the belt conveyor is calculated and designed. Drive consists of conical-cylindrical two-stage reduction gear and V-belt transmission. Selection of electric motor, calculation of connections, coupling and main parts of reduction gear box, as well as values of efficiency factor are performed.

The design of machines, mechanisms and their assemblies consists in the constructive development of a common location and the choice of the shape of individual parts. The main requirements for design objects are: strength, durability, economic feasibility and safety in maintenance.

This type of reduction gear is used for intersecting axes of drive and driven shafts. The disadvantages of conical gears include a smaller, compared to cylindrical gears of the same size, transmitted load; at the same load large weight and dimensions; the relatively high cost of producing conical wheels; considerable non-uniformity of load distribution over wheel rim width.

Gearbox assembly

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

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

drive shaft and bearings, pre-heated in oil to 80-100 ° C, are assembled into a cup .

a key is inserted into the intermediate shaft and the bevel gear wheel is pressed to rest against a cylindrical gear made integral with the shaft; Then spacer bushing is put on and bearings preheated in oil are installed.

a key is put into the driven shaft and the cylindrical gear wheel is pressed to rest against the shaft collar; Then spacer bushing is put on and bearings preheated in oil are installed.

The assembled shafts are laid in the base of the reduction gear case and the cover of the case is put on, previously covering the surfaces of the cover and the case with alcohol varnish. For alignment, a cover is installed on the body using two conical pins; bolts that attach the cover to the housing are tightened. Bearing covers are placed on bearing chambers.

Before installation of through covers, sealing cuffs are inserted into them. By turning the shafts there is no jamming of bearings (the shafts must be rotated by hand) and the covers are fixed with screws.

Keys are laid on ends of driving and driven shafts in key grooves; driven pulley of belt gear is installed on drive shaft, elastic sleeve-and-flange clutch is installed on driven shaft and fixed with end washers on screws.

Then plug of oil discharge hole with gasket and oil indicator from organostecle are screwed in.

Oil is poured into housing and inspection hole is closed with cover with gasket made of technical cardboard; cover is bolted.

The assembled gearbox is rolled and tested on the bench according to the program set by the specifications.