Mechanical drive design

Introduction

Designing any machine is a complex design task, the solution of which can be found not only with achieving the required technical level, but also giving the design certain properties that characterize the possibility of reducing the cost of materials, energy and labor for the development and manufacture, repair and maintenance.

The task of the designer is that, guided by the considerations of the technical feasibility of the designed machine, you can use engineering calculation methods that allow you to achieve the task while rationally using the resources allocated for its creation and use.

The course project on "Machine Parts" completes the general technical cycle of engineering training of a specialist. He is an important independent work of the student, covering the issues of calculating machine parts according to the criteria of operability, rational choice of materials for contacting steam and lubrication systems in order to ensure the maximum possible efficiency and based on knowledge of a number of subjects: mechanics, machine theory and mechanisms, material resistance, interchangeability and standardization, the basis of machine design, engineering production processes, etc .

When performing a course project, the student widely uses GOST, educational and reference literature. The experience acquired by the student is the basis for his course projects in special disciplines and for graduate design.

The project consists of an explanatory note, a specification and a graphic part. The volume of these documents depends on the volume of the entire project established by the training programs for the relevant specialties.

The scope of course design is limited to various types of mechanical drives. The task includes objects studied in the course of machine parts: gears, couplings, bearings, connections, etc.

In this course design worm gear with axes crossing at right angle is considered, with Archimedean worm having in axial section rectilinear profile with angle αd = 20 °.

Worm gears are used in drives of machines operating with short-term or medium-term mode.

The advantages of worm gears and gearboxes include the possibility of obtaining large gear ratios from one stage of gears, silent operation and high resistance to impact loads and a minimum number of moving parts. The disadvantages of worm gear include low efficiency, increased heating during long-term operation and the need to use bronze in the manufacture of worm wheels.

Description of Process Measures to Restore Quickly Worn Mechanical Drive Parts

For restoration of working surfaces of quickly worn out details of cars a number of the ways based on methods of welding, building up, dusting, etc. finds application.

With the help of various types of welding, it is possible to brew cracks in the body parts, weld straps, inserts, and weld wear-resistant materials.

The build-up allows to obtain on the surface of the parts a layer of small thickness and the necessary composition, providing high hardness and wear resistance.

Spraying is a high-performance process with a number of advantages: a slight influence on the substrate, the possibility of coating large parts. It is used to restore working surfaces such as "bodies of revolution" and "flat surface" with a wear value from a fraction of a millimeter to a dozen millimeters, to apply wear-resistant and protective coatings with special properties. Most often, spraying is used to restore trunnions and other mounting surfaces of shafts.