Robot Arm Extension Mechanism

Contents

INTRODUCTION

1 ENGINE SELECTION

2 CALCULATION OF THE ACTUATOR

3 Calculation of belt gear

4 DETERMINATION OF MOMENTS, POWERS AND SPEEDS OF ROTATION OVER ALL SHAFTS

5 DETERMINATION OF TOTAL GEAR RATIO AND ITS DISTRIBUTION BY STAGES

6 MECHANISM DESIGN

7 Shaft strength calculation

7.1 Verification calculation

8 Calculation of bearings

8.1 Determination of normal force component in engagement

8.1.1 Input shaft

8.1.2 Intermediate shaft

8.1.3 Output shaft

8.2 Calculation of equivalent load

8.3 Definition of Bearing Life

8.4 Determination of dynamic bearing lifting capacity

8.5 Check of service life of structurally selected bearings

9 Check calculation of key

10 SELECTION OF COUPLINGS

11 Calculation of bolts that attach the engine to the housing

12 LUBRICATION OF MECHANISMS

CONCLUSIONS

BIBLIOGRAPHIC LIST

Introduction

Robotics is a new fast-growing area of ​ ​ science and technology associated with the creation and use of robots and robotic systems. The robot, which is one of the main objects of study in this science, is a universal machine for reproducing human motor and intellectual functions. There are different classes of robots. Among them, manipulation works are an important class. Their private type is industrial robots.

The practical part of creating robots is to transfer to them those activities that are labor-intensive, heavy, monotonous, harmful to health and life for humans. These are first of all auxiliary and production operations (loading and unloading of installations, machines, automatic machines), the main production operations (welding, coloring, cutting, assembly, etc.) and also work in so-called extreme conditions (under water, in space, in radioactive and poisonous environments).

Robots designed to perform motor and control functions in the production process are called industrial robots. With the help of industrial robots, it is possible to solve the problems of integrated mechanics and automation of production, growth of the labor industry, and improvement of product quality. Industrial robots differ from traditional automation tools in versatility, the ability to quickly readjust them, which allows you to create robotic systems on the basis of universal equipment. The scope of robots is constantly expanding. They begin to be used in transport, agriculture, health care, and services.

As a result of the development of human robotics, it will be possible to solve fundamentally new scientific and production tasks, for example, the creation of artificial intelligence and fundamentally new technologies on earth and in space.

In this course project, one of the modules of an industrial robot is being calculated, namely, the mechanism for lifting and lowering the hands of an industrial robot. Displacement upwards and downwards along two guides which are fixed in upper and lower support plates. DC electric motor drives ball-screw transmission through clutch and two-stage cylindrical coaxial reduction gear, which provides translational movement of robot arm. The screw is protected from dust and dirt by a corrugated shell. Rubber shock absorbers soften impacts at the end of hand stroke in upper and lower positions. Track switches are used to control the movement, or if necessary, can be connected to a processor control system where the position will be monitored by sound or optical position sensors.

In general, the following basic requirements apply to industrial robot modules:

Ensuring constructive and functional independence;

Provision of design static and dynamic characteristics;

Possibility of layout in different positions and combinations with other modules;

Unification of connecting elements, communications and components;

The possibility of unifying assembly units, both within individual and adjacent sizes, as well as between different types of units and assemblies.

Lubrication of mechanisms

Lubrication of bearing assemblies, toothed and splined joints and joints is necessary to reduce contact stresses, reduce friction and wear forces of parts, remove heat (generated during friction), protect against corrosion and glue, to remove solid particles from the friction surface. The lubrication system shall provide the required quantity of lubricants to the parts. The type of lubricants used is determined by the operating conditions of the mechanisms, the required viscosity, the type of bearings, etc. Lubricants are both liquid oils and plastic lubricants. Depending on the viscosity, oils are usually divided into light, medium and heavy (high viscosity). Lubricants by purpose are divided into universal, industrial, motor vehicles. This division has been preserved since the middle of the last century and, in general, determines the field of application of lubricants.

Lubrication shall prevent welding and adhesion (adhesion) of working surfaces, especially at high contact loads.

There are two types of lubrication: forced - with the help of a pump, spraying - the mechanism washes itself.

The mechanism described and calculated above uses a spray method. Lubrication in bearings and gears is the same, gears are washed with transmission oil (Nigral) GOST 52450, radial thrust bearing is lubricated with plastic lubricant LITOL GOST 2115087, immediately before assembly, screw-nut transmission before installation is lubricated with plastic lubricant (SOLIDOL) GOST 103379.

Lubrication level: in the plane of the gearbox bottom, the gear wheel must be not more than 5 mm in lubrication.

Conclusions

As a result of design calculations, specific parameters of the mechanism parts were obtained, and standard fastener parts were selected.

Gear belt gear was calculated. All parameters were calculated and selected in accordance with GOST, which will undoubtedly facilitate the assembly of this module in production and ensure its quality work.

The belt gear allows for high positioning accuracy, slow motion and relatively small power losses.

Standard bearings were selected, followed by dynamic load testing.

Materials were selected for all parts of the gearbox.