Handout Box Development Project

Contents

1. Introduction

2. Analysis of existing car analogues

3. Analyzing Existing Constructs

4. Handout Box Calculation

4.1. Determination of gear ratios of transfer gearbox

4.2. Definition of design loads

4.2.1. Load modes

4.2.2. Determination of gear ratios

4.2.3. Determination of torque on shafts

4.2.4. Determination of forces in the handout box engagement

4.2.5. Determination of forces in the gear box differential engagement

4.3. Select Gear Options

4.4. Calculation of inter-axial differential

4.4.1. Calculation of axle differential gears for static

durability

4.5. Calculation of teeth for contact strength

4.6. Calculation of teeth for bending strength

4.7. Calculation of the highest transmission

4.8. Lower transmission calculation

4.9. Calculation of transmission shafts

4.9.1. Gearbox Input Shaft Calculation

4.9.2. Calculation of the input shaft of the transfer gearbox for strength

4.9.3. Calculation of intermediate shaft of transfer gearbox

4.9.4. Calculation of intermediate shaft of transfer gearbox for strength

4.9.5. Gearbox Output Shaft Calculation

4.9.6. Calculation of the output shaft of the transmission for strength

4.10. Calculation of gearbox bearings

5. Justification for selection of lubricating and cooling liquids

6. Conclusion

7. List of used literature

Introduction

Currently, the network of road freight and passenger transport is expanding, both within the unified transport system of the country and within the regional, departmental and production transport structures. The most rational solution to the problem of improving the efficiency of road transport is the improvement of road transport structures and the creation of specialized rolling stock. In both the first and second cases, the aim is to ensure the maximum compliance of vehicle designs with the operating conditions and requirements arising from their specific purpose.

Along with the creation of incomplete buses, which are mainly used on paved roads (categories I - III, GOST2162481), four-wheel drive buses are needed in our country to deliver passengers on all categories of roads to hard-to-reach, rural areas. To increase cross-country ability, transfer transmissions are additionally installed in cars after the gearbox. The transfer box transmits torque to the front and rear driving axles. In the transfer box there is a device for switching on and off the front axle and an additional reduction gear, which allows to significantly increase the torque on the wheels of the car. This is necessary when driving in difficult road conditions. If the car operates without loads and moves mainly on roads with improved coating, it is undesirable to turn on the front axle, since the fuel consumption increases and the wear of the transmission units increases. The above-mentioned negative phenomena can be eliminated by using an inter-axial differential in the transfer box. To increase the cross-country capacity of the car, inter-axle differentials are sometimes made with forced locking or differential of increased friction.

Handout Box Calculation

4.4. Calculation of inter-axial differential

The inter-axial differential is symmetrical, since the bus is biaxial and it is necessary to divide the torque into two parts. The calculation of differential gears has some features. Most of the car's run, differential gears are stationary relative to the body or have only small movements caused by different values ​ ​ of wheel radii. Since there is no obvious cyclic nature of the voltage change in the differential gears under the action of long-term working loads, they are calculated only for static strength.

4.9. Calculation of transmission shafts

Shafts of automobile transfer gearboxes are made of steels of the same grades as gears and are calculated for strength and rigidity.

The strength of the transmission shafts is checked under the joint action of bending and torsion. Components of support reactions and their corresponding bending moments in vertical Mv and horizontal Mg planes are determined. When calculating, the shaft is considered as a beam lying on hinge supports.

Conclusion

During the course design, handout work was developed for a small-class off-road bus with a 4x4 wheel formula.

During the work, a patent search and review of analogues was carried out. gear ratios of higher and lower gear are calculated. To increase the cross-country capacity of the bus, the axle differential is made with forced locking. Gears are made spur-toothed, therefore, there are no axial forces in engagement, i.e. simpler structurally radial bearings can be used.

Gear materials - alloyed structural steels with heat treatment to ensure the necessary strength. Gears were tested for contact endurance and bending strength. The transfer box shafts are designed for strength and rigidity. The bearings were also selected and calculated.

These calculations showed the feasibility of using transfer boxes of this design.

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