Coursework on belt conveyor drive

Contents

Contents

Introduction

1Description of Operation and Drive Device

2 Motor selection and kinematic calculation of the drive

3 Calculation of open drive gears

3.1 Calculation of open belt transmission

3.2 Calculation of open chain transmission

4 Calculation of gearbox closed gear train

5 Selection of structures of housing parts and their calculation

6 Selection of structures and approximate calculation of shafts

7 Bearing selection and gearbox design

8 Check calculations of shafts, bearings, key joints

8.1 Determination of forces acting on shafts and supports

8.2 Final Bearing Selection

8.3 Selection and check calculation of keys

8.4 Calculation of shafts for fatigue strength by safety factor

9 Selection of lubrication, control and lubricants method

gears and bearings

10 Selection of fits and precision quotas for all drive couplings

11 Selection of deviations of dimensions, shape, mutual arrangement,

roughness parameters

12 Gearbox assembly and adjustment

13 Safety precautions

14 Frame Design. Assembly and adjustment of the drive

List of sources used

Appendix A. Specification

Project Description

Explanatory note - 45 s., 16 Fig., 3 Table, 6 sources.

ENGINE, BELT DRIVE, TRANSFER CHAIN, GEAR TRANSMISSION, GEAR WHEEL, WHEEL, MODULE, SHAFT, SPLINE, LUBRICANT.

The purpose of the course design is to design the drive.

Kinematic and power calculations of the drive were made. According to modern methods, design and verification calculations of open belt and chain gears, closed gear train, calculation of shafts, bearings and gearbox housing were carried out. The calculation should ensure the necessary operability of individual units, as well as the economic feasibility of their manufacture.

As a result, a conical reducer of optimal sizes and durability of units of at least 10 tons was designed. hours.

The graphic part includes:

- the sbotochny drawing of a reducer - 1 sheet A1;

- detail drawings - 4 A3 sheets;

- a general view of the drive - 1 sheet A1;

- a frame - 1 sheet A1.

Introduction

1 The role of mechanical engineering in the development of the domestic national economy.

Mechanical engineering is the basis of mechanical re-equipment of all public production. The scale and pace of the introduction of modern progressive equipment, the level of mechanization and authorization of production in all sectors of industry, agriculture, transport depend on the development of mechanical engineering.

In the national economy, mechanical engineering replaces the leading position. This can be judged by the ever-increasing specific gravity of the industry.

The emergence of mechanical engineering as an independent industry and its sectoral differentiation are directly related to the social division of labor. Under the influence of the frequent division of labor in mechanical engineering, new industries are constantly being revived.

Modern trends in the development of mechanical engineering. Mechanical Engineering Challenges

Modern mechanical engineering represents many interconnected industries and industries. A particular production becomes a separate industry of mechanical engineering with certain technical and economic prerequisites.

Currently, the engineering industries are combined into a single engineering complex, which includes nineteen large industries and about a hundred specialized industries, sub-sectors and industries.

The engineering complex has the main role in the implementation of the scientific and technical revolution. The mass production of new generations of machinery, capable of giving a multiple increase in labor productivity, to open the way to automotisation of all stages of production, requires significant structural types.

In the period until 2000, it was planned to primarily carry out a radical reconstruction of the machine-building complex, primarily machine-tool engineering, computer engineering, instrument engineering, electrical and electronic industry. This period is characterized by progressive structural shifts not only between engineering industries, but also within each industry.

The pace of development of industries and changes in intersectoral relations of mechanical engineering is determined primarily by those tasks that are set in the field of mechanization and automation of production, the development of energy economy, electrification and chemization. Currently, the share of workers engaged in manual labor in industry, construction, and agriculture is still large. It is planned to accelerate the pace of integrated mechanization of production, especially the mechanization of auxiliary, transport and warehouse operations, production processes in agriculture.

Thus, the main direction of structural changes in the national economy, including in the machine-building complex, is associated with accelerating scientific and technological progress and improving the efficiency of public production on this basis.

The role of a mechanical specialist in solving the problems facing mechanical engineering in scientific and technical progress

Workers are the most important element of productive forces, determine the growth rate of production and labor productivity, the number of products and the success of the industry.

An important role in mechanical engineering is played by engineering workers or mechanical specialists. These include persons who conduct research, as well as perform functions of office management, supply, maintenance.

A characteristic feature of changing the structure of workers in industry is a decrease in the share of workers and an increase in the share of engineering and technical workers. Such changes are a consequence of scientific and technological progress.

This structure is the result of an increase in the level of technical equipment of the main production and an increase in labor costs for the maintenance and repair of complex automatic equipment, automatic process control systems.

Design Objectives and Objectives

The purpose of the course design in the discipline "Machine Parts" is to systematize, consolidate, expand theoretical knowledge, train students in the practical calculation and design of parts and assembly units of mechanical drives, develop calculation and graphic skills, and also prepare for the performance of diploma design and subsequent production work. The main requirements for the machine are high performance, reliability, processability, minimum dimensions and weight, ease of use and cost-effectiveness.

The main objectives of the course project are:

familiarization with scientific and technical literature on the topic of the course project;

study of known designs of similar machines and mechanisms with analysis of their advantages and disadvantages;

selection of the simplest design option taking into account the requirements of the technical specification for the project;

performing the necessary calculations in order to ensure the specified technical characteristics of the designed device;

selection of materials and required accuracy of manufacturing of parts and assemblies of the designed device, surface roughness, required tolerances and fits, feature and location tolerances;

execution of the graphic part of the course project in accordance with the ESKD standards;

preparation of necessary descriptions and explanations for the course project.

Gearbox Overview

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.

Reduction gear consists of housing accommodating transmission elements

- gears, shafts, bearings, etc.

Gearboxes are classified according to the following main characteristics:

- transmission type (toothed, worm)

- number of stages (single-stage, two-stage, etc.)

-type of gears (cylindrical, conical, etc.)

- relative location of gear box shafts in space

(horizontal, vertical).

- peculiarities of kinematic scheme.

Selection of lubrication method, control and lubricants of gears and bearings

To lubricate the gear train, we use continuous lubrication with liquid oil in a crankcase by a non-accurate method (dipping).

The choice of oil grade depends on the value of the calculated contact stress in the teeth αH = 512MPa and the actual circumferential speed of the wheels ο= 2.9m/s.

We choose industrial oil I-G-A-46 GOST17479.487.

For single-stage reduction gears, when dipping, the volume of the oil bath is determined based on (0.5... 0.8) dm3 per 1 kW of the transmitted power of the reduction gear box. At power P = 6.77 kW, accept volume of oil chamber V = 3.8 dm3.

Check the level of oil in the gearbox housing by the oil rod indicator.

Lubricate bearings with plastic lubricant. Lubricant is packed into bearing manually at removal of bearing assembly cover for several years. Lubricating plastic material is changed during repair.

Choose plastic lubricant of solidol fat type (as per GOST 103379).

Select variances of dimensions, shape, mutual arrangement,

roughness parameters

Shaft roughness in places of gear wheel, pulleys and sprockets fit

Ra1,6

Shaft roughness at bearing seats, conical holes for pins Ra0,8

Surfaces of wheel teeth projections, chamfers, non-working ends of gear wheels surfaces, pulleys, sprockets Ra 6,3

According to GOST 332589, the tolerance of end run-out of shaft shoulders is not more than 25 μm.

Errors in the shape and arrangement of surfaces arise during processing of parts due to deformations of equipment, tools and parts, inhomogeneity of the workpiece material and other reasons.

Surface feature control tolerances are indicated on the drawings by legend in accordance with GOST 2.308

Deviation from roundness and profile of longitudinal section 4 mcm, mounting surfaces for bearings.

Deviation from parallelism of wheel key slots is not more than 20 mcm and deviation from symmetry 160 mcm.

Journals of shafts for bearings are made with shaft deflection along k6.

Internal surfaces of reduction gear box for external rings of bearings as per H7.

Gearbox assembly and adjustment

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.

On the drive shaft we install a retaining ring and roller bearings, pre-heated in oil to 80100 ° С. Bearings refrain from axial movement on the one hand by a shaft fillet, with other washer and a nut of M36x1.5.

We put the key 14 × 9 × 50 mm into the driven shaft and press the gear wheel until we rest against the collar of the shaft, then put on the holding rings and install roller bearings preheated in oil.

The assembled shaft units are laid in the base of the lower part of the body and put on the cover of the body, covering the surfaces of the joint of the cover and the body with alcohol varnish. For alignment, install the cover on the housing using two conical pins and tighten the bolts that attach the cover to the housing.

We put plastic grease in the bearing chambers, put bearing covers with a set of metal gaskets for adjustment.

Before installation of through covers, install sealing cuffs in grooves. By turning the shafts make sure that there is no jamming of bearings and attach the covers with bolts.

Then screw in the plug of oil outlet with gasket and iron oil indicator.

Pour oil into the housing and close the inspection hole with a cover with a gasket made of technical cardboard, attach the cover with screws.

The assembled reduction gear is rolled and tested on the bench according to the program established by the technical conditions.

Frame design. Assembly and adjustment of the drive

Assembly is performed in accordance with assembly drawing of drive.

According to the assembly drawing, using manual arc welding, we produce a drive frame. The frame is made of an angle of steel hot-rolled equal-wing No. 5 and a channel of steel hot-rolled No. 10.

Install 4AM132S4Y3 motor and reduction gear on the frame. Attach the electric motor to the frame using four M12 bolts with a nut. To attach the reduction gear, use four M20 bolts with a nut and a washer.

Drive pulley of V-belt transmission is pressed on motor shaft. Attach the pulley on the shaft with M12 bolt with washer.

Press the driven pulley of V-belt transmission onto the input shaft of the reduction gear box. Attach the pulley on the shaft with M12 bolt with washer.

We put on six wedge GOST 1284.280 A1120 belts on pulleys. Tension of belts of open V-belt transmission is provided by movement of electric motor along slots in frame plate. Once the belts have reached the required tension, the bolted thrust bar keeps the motor from moving.

Drive sprocket of chain transmission is installed on output shaft of reduction gear.

For safety, we close all rotating drive units with a guard (casing).

The assembled drive is rolled and tested according to the program established by the technical conditions.

When working with the conveyor, observe safety rules.

When servicing the drive, it is necessary to monitor the integrity of the belts.

In case of straps stretching and sag, move the electric motor along the slots by means of a stop plate with bolts, providing the necessary tension of the straps.

Periodically replenish, and if necessary change the lubricant of the reduction gear box and electric motor.