Drive with cylindrical gearbox

Contents

INTRODUCTION

1 KINEMATIC AND POWER CALCULATION OF DRIVE

2. CALCULATION OF GEARS

2.1 CALCULATION OF CYLINDRICAL TRANSMISSION

2.2. BELT TRANSMISSION CALCULATION

3. SHAFT CALCULATION AND DESIGN

4. CALCULATION OF KEY CONNECTIONS

5. CALCULATION AND DESIGN OF BEARING ASSEMBLIES

6. DESIGN OF BODY PARTS, MACHINES AND COVERS

7. LUBRICATION OF ENGAGEMENT

8. SELECTION OF COUPLINGS

9. SELECTION OF FITS

10. GEARBOX ASSEMBLY AND ADJUSTMENT

11.SAFE TECHNICS

LIST OF LITERATURE USED

Introduction

A reduction gear is a mechanism consisting of geared or worm gears (wheels) 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 rotational torque of the driven shaft compared to the driving one.

The reduction gear consists of a body (cast iron or welded steel), in which the transmission elements are placed - gears, shafts, bearings, etc. In some cases, other auxiliary devices are also placed in the housing.

Gearboxes are classified according to the following main features: gear type (toothed, worm or gear-worm);

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

to type of cogwheels (cylindrical, conic, konicheskotsilindrichesky, etc.);

relative location of gear box shafts in space (horizontal, vertical);

peculiarities of kinematic scheme (unfolded, coaxial, with bifurcated stage, etc.).

Two-stage cylindrical reduction gears.

The most common are two-stage horizontal gearboxes made according to an expanded scheme. These gearboxes are simple, but due to the asymmetric arrangement of the wheels on the shafts, the concentration of load along the length of the tooth increases. Therefore, rigid shafts should be used in these gearboxes.

Designed machines should have the highest performance (productivity, efficiency), low energy consumption and operational materials at the lowest weight and dimensions: high reliability: be economical both during production and during operation, be convenient and safe to maintain: allow automation of the machine, standardization of parts and assemblies. Mechanical engineering is of great importance in the economy, since all other industries and agriculture are developing on the basis of mechanical engineering.

Mounting frames and slabs, attachment to floor

When installing drives, certain requirements of accuracy of position of one assembly unit relative to another, for example, electric motor and reduction gear box, must be observed.

To meet this requirement, drive mechanisms are installed on welded frames or cast plates.

Frames are welded from sheet steel and shaped rolled stock (angles, channels).

When making welded frames from channels, it is taken into account that for the convenience of bolting, these channels must be installed with shelves outside. Oblique washers are applied to the inner surface of the shelf or oblique patches are welded, which align the support surface under the bolt heads.

Support surfaces - plates, on which reduction gears and electric motors are installed, are created by welding narrow strips of steel with a height of 5... 6 mm.

Since the frame is warped during welding, all the base (support) surfaces on which the drive mechanisms are installed are processed after welding.

Cast slabs are more expensive than welded frames, because they are less common.

Assembly units are bolted to the plate.

The configuration and dimensions of the frame depend on the type and dimensions of the gearbox and the e.

The distance between them depends on the selected coupling.

Frame is fixed to floor of shop by foundation bolts.

Gearbox assembly

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

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

Oil retaining rings and ball bearings pre-heated in oil to 80... 100 0C are put on the driving shaft.

Keys are laid on driven shaft and gear wheel is pressed until stop against shaft collar, then spacer bushing, retaining rings are put on and ball bearings, previously heated 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, having previously covered the surface of the joint of the cover and the case with alcohol varnish. For alignment, the cover is installed on the housing with the help of two conical pins, bolts are tightened, which attach the cover to the housing. After that, spacer rings are put on the driven shaft, solidol is put into bearing chambers of the cover, bearing covers with a set of metal gaskets for adjustment are placed.

Then the shafts turn, there is no clamping of bearings (the shafts must be rotated by hand) and attach the covers with screws. Then plug is screwed in oil of drain hole with gasket and oil indicator is installed.

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

The assembled gearbox is rolled and tested on the bench according to the program established by the operating specification.

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