General Purpose Drive Design Course Project

Contents

Contents

Introduction

1. TERMS OF REFERENCE

2. SKETCHED DESIGN

2.1 Engine selection. Kinematic and power calculation of the drive

2.2 Gearing Calculation

2.3 Load of gear box shafts

2.4 Design calculation of shafts. Sketched Layout

2.5 Determination of low-speed shaft support reactions. Creates moment symbols. Check calculation of bearings

3. TECHNICAL DESIGN

3.1 Structural arrangement of the drive

3.2 Lubrication

3.3 Coupling Selection

3.4 Calculation of key connections

3.5 Refined Shaft Calculation

3.6 Gearbox assembly

4. WORKING DOCUMENTATION

4.1 Development of gearbox assembly drawing

4.2 Developing a General View Drawing

4.3 Development of detail working drawings

4.4 Specifications

5. LIST OF LITERATURE

Introduction

Mechanical engineering has a leading role among other sectors of the economy, since machines perform the main production processes. Therefore, the technical level of many industries largely determines the level of development of engineering.

Improving operational and quality indicators, reducing the time of development and implementation of new machines, improving their reliability and durability are the main tasks of machine builders. One of the areas of solving these problems is improving the design training of engineers of higher technical educational institutions.

A large opportunity for improving the work of designers is provided by the use of computers, which allows you to optimize designs, automate various parts of the design process.

The objects of course design are drives of various machines and mechanisms, using most parts and assemblies of general machine-building applications.

An important goal of the project is to develop engineering thinking, including the ability to use previous experience, find new ideas, model using analogues. The course project on the details of machines is characterized by the multivariability of decisions with the same task, which develops the students' thinking activity and initiative.

The most important task of course design is to develop the ability to develop technical documentation. Based on the initial prerequisites from the course of graphics and machine-building, in the process of independent work on the course project, students master free reading and execution of drawings of unlimited complexity.

Gearbox assembly

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.

On high-speed shaft-gear there installed are retaining rings, radial bearings of light series, previously heated in oil up to.

Key is laid in slow-moving shaft and gear wheel is pressed. Then spacer ring, oil retaining rings are installed and radial ball bearings of light series are installed, previously heated in oil to.

The assembled shafts are laid in the base of the reduction gear box housing and put on the cover of the housing. Butt surfaces of the cover and base of the housing shall be covered with alcohol varnish. Cover is centered by means of two conical pins and bolts are tightened, which attach cover to body.

After that bearing covers with set of metal gaskets for adjustment are installed on shafts.

Prior to installation of through covers, cuffs impregnated with hot oil are put into grooves. By turning the shafts there is no jamming of bearings (the shafts must be rotated by hand) and the covers are fixed with screws.

Then key is laid in keyway on end of drive shaft and clutch is installed. Then plug of oil discharge hole with gasket and iron oil indicator are screwed in.

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

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

Working documentation

4.1 Development of gearbox assembly drawing

The gearbox assembly drawing is made in two projections based on the designed design layout.

The following dimensions are specified in the assembly drawing:

- overall (by limit external outlines);

- connection (diameter and length of end section of high-speed and slow-speed shafts);

- installation (distances between centers of foundation bolts, height of landing centers);

- landing (dimensions of mating surfaces with indication of fits);

- main parameter of reduction gear (axial distance of gears, external dividing diameter of wheels);

In accordance with the specification, the position numbers of all assemblies and parts of the reduction gear box are set. The numbers are placed on polkahvynosks parallel to the title block, on one horizontal or vertical line and one distance from the outline of the drawing (at least 300 mm).

The technical characteristics of the gearbox are indicated above the title block of the drawing, for example:

Gear ratio

Speed of high-speed shaft.

Speed of low-speed shaft rotation.

Technical requirements:

Shafts of the assembled reduction gear must turn without jamming and jamming;

Easy rotation with gaskets;

Crankcase lubricant, aviation oil MS22 (as per GOST 2079975). Volume of poured oil V = 3 l.

4.2 Development of the general view drawing of the drive

The general view drawing of the drive contains the front projection of the drive and the projections of the frame, giving a complete understanding of its design. The zoom of the frame may differ from the zoom of the drive. The drive elements (electric motor, gearbox, etc.) are drawn without small details, but so that their image is clear and clear, with the necessary dimensions.

The following data are indicated in the general view of the drive:

- positions of units, parts, articles;

- overall, connecting, installation dimensions;

- technical requirements concerning adjustment of gear and engine shafts, e.g.:

1. Axial displacement is not more than 3 mm;

2. Misalignment of shafts axes is not more than

3. Provide radial displacement of shafts not more than 0.3 mm due to gaskets.

On a sheet of paper of A1 format, we draw a general view of the drive, which consists of a two-stage cylindrical reduction gear box, an electric motor and an elastic bushing-flange coupling connecting them to each other. Then we draw a welded frame consisting of elements of high-grade rolled stock and channels. We place all the necessary dimensions.

4.3 Development of detail working drawings

Detail drawings must contain a minimum number of projections, views, sections sufficient to understand part shape and dimension.

Parts such as revolutions (shafts, wheels) are placed in the drawing so that their axis is parallel to the title block of the drawing, regardless of their working position .

On the working drawing of the part we specify the data necessary for its manufacture and control:

- dimensions;

- limit deviation (tolerances) for landing and chain dimensions;

- limit deviations of shape and mutual arrangement of surfaces;

- permissible values of surface roughness;

- material grade;

- technical requirements (hardness of material, moulding and stamping slopes, radii);

- table of basic geometric parameters for parts of gears.

4.4 Specifications

The gearbox assembly drawing and the general view drawing are scheduled in the standard form. The BOM sections are arranged in the following order:

Documentation;

Assembly units;

Parts;

Standard products.