Design of Test Unit Main Gearbox

Contents

CONTENTS

Introduction

1 Kinematic calculation of the drive

1.1 Selection of electric motor

1.2 Determination of transmission ratio

2 Gearing Calculation

2.1 Selection of gear material

2.2 Determination of stress contacts

2.3 Determination of allowable bending stresses

2.4 Permissible voltages at short-term load

3 Design dimensions and parameters

4 Verification calculation

4.1 Test calculation by contact voltages

4.2 Check calculation for bending stresses

4.3 Check calculation for G-load

5 Design calculation of shafts and selection of bearings

5.1 Design calculation of high-speed shaft

5.1.1 Design diagram of high-speed shaft

5.2 Design calculation of low-speed shaft

5.2.1 Design diagram of low-speed shaft

5.3 Bearing Selection

6 Gear Design

7 Calculation of key connections

8 Selection and calculation of couplings

9 Check calculation of low-speed shaft

10 Calculation of output shaft statistical strength

11 Input shaft calculation for stiffness

12 Design of gearbox housing and bearing covers

13 Reduction gear box lubrication

14 Frame Design

15 Gearbox assembly and selection of fits

Bibliographic list

Summary

Vyshegorodtseva Yu.V .

Drive Design

of the test unit

Trekhgorny: TTI NIYAU MEPhI, PTM, 2015, 41 liters.

Bibliography of literature - 5

names.

In the course design, the drive for the test plant was calculated.

The course design includes the selection of an electric motor, the selection of material for gears and gears, as well as the calculation of permissible contact and bending stresses, the determination of rotation frequencies and torque on the shafts of the reduction gear. Design and check calculation of cylindrical spur gear, design and check calculation of gearbox shafts and selection of bearings were also carried out.

In the course design, gear wheels were designed, key joints were calculated, the gearbox housing and bearing covers were designed. A choice of lubricants and gearbox lubrication systems, selection and calculation of couplings was made. The gearbox assembly procedure and fit assignment were described.

Introduction

Testing is critical in the creation, production and operation of equipment. Tests cannot be replaced by calculations and expert assessments. It is the correct tests that determine the quality of the products being developed and manufactured.

In this work, the design of the test plant drive with a single-stage spur gear gearbox was carried out.

Frame Design

Frames are used for installation of drive units (engine, reduction gear box, etc.). and ensuring that they are properly positioned throughout their life cycle. Length and width are determined in accordance with dimensions of units installed on it.

Frame parts are welded along the fillet contour. No reinforcement in the form of slashes and straps is required.

During welding, the plates are deformed. This causes the need to make platters to accommodate the legs of the nodes. We set them on the same level.

Attachment to the foundation is carried out by studs, which are poured into the foundation. After installation of the frame, twist with nuts. The diameter of studs is taken equal to the diameter of bolts that attach the reduction gear box to the frame M12 .

We weld non-standard washers. 8 pieces for attachment to the foundation and 8 pieces for attachment of the engine and reduction gear box.

Since the height difference is large, an add-in is additionally made, cut to the desired height.

Gearbox assembly and selection of fits

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

Assembly is started with shaft assemblies: an oil protection washer is put on the driving shaft, ball bearings are fitted, previously heated in oil up to 80- 100˚S, then an O-ring and an embedded cover are put on the shaft.; a key 16 × 10 × 55 is put into the drive shaft and the gear wheel is pressed until it rests against the booth of the shaft; Then remote spacer ring is put on and ball bearings pre-heated in oil are installed, then sealing ring and embedded cover are put on shaft .

Assembled shafts are installed in base of reducer housing, sealing rings are inserted into bearing bosses. After that cover of body is put on, covering preliminary surfaces of cover and body joint with alcohol lacquer. For alignment, a cover is installed on the body using two prismatic pins; bolts that attach the cover to the housing are tightened.

Then plug of oil discharge hole with gasket and iron oil indicator are screwed in. Oil is poured into the housing and the inspection hole is closed with a cover with a gasket; cover is bolted.

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

We make a choice of planting according to the recommendations.

Landing for cogwheels to shafts and H7/r6 half-couplings.

We carry out necks of shafts under bearings with a deviation of a wave of k6, a deviation of openings in the case under external rings on H7.

Fits for bearing covers as per H8, h8.

Unspecified limit deviations of shafts and holes as per H14, h14.