Worm gearbox drive Uob.=15,4

NTUU "KPI" named after I. Sikorsky, Department of Biotechnology and Biotechnology

Coursework on the discipline "Machine parts"

On the topic: "Calculation and drawing of the worm gearbox"

Kyiv 2019

Output data: Output shaft power P = 3.8 kW, Output shaft speed n = 30 min^-1, gear ratio = 96 min^-1, drive efficiency nred = 0.8, overall dimensions (lxbxh) = 576x35

This paper describes the purpose and scope of the worm drive, the technical characteristics, the description and justification of the selected design, the calculation of the operability and the possibility of operation of the electric drive.

Technical characteristics of the drive:

1. Power on the slow-moving shaft P = 3.8 kW;

2. Torque on the slow-moving shaft T = 1210 Nm;

3. Rotational speed of the low-speed shaft n = 30 min;

4. Drive gear ratio 15.39. and 30 gearboxes

Content

Chapter 1. Purpose and scope of the drive 3

Chapter 2. Specification 4

Section 3. Description and justification of the selected design 6

Section 4. Calculation of operability and reliability of the electric drive 7

4.1. General calculation of the drive 7

4.1.1. Baseline 7

4.1.2. Determination of the design power and selection of the drive electric motor 7

4.1.3. Determination of the gear ratio of the drive and the gear ratio of each stage 8

4.1.4. Determination of energy force parameters 8

4.1.5. Determination of minimum shaft diameters and cross-sectional dimensions of keyholes 9

4.1.6. Calculation of V-belt transmission 10

4.1.7. Choosing the cross-section of the wedge belt 10

4.1.8. Determine the diameter of the drive pulley 10

4.1.9. Determine the circular speed (m/s) and compare it with the belt 11 allowed for this type

4.1.10. Approximately determine the diameter of the driven pulley d2 11

4.1.11. Specify the gear ratio 11

4.1.12. Determine the relative error of the gear ratio 11

4.1.13. Find the actual rotational speed of the driven pulley 11

4.1.14. Determine approximately the center spacing 11

4.1.15. Determine the calculated length of the belt 12

4.1.16. Determine the number of belt runs 12

4.1.17. Specify the center spacing in accordance with the accepted belt length 12

4.1.18. Determine the girth angle of the drive pulley 12

4.1.19. Determine the required number of belts 13

4.1.20. Determine the main structural elements of pulleys 13

4.2. Determination of stress forces and design durability 15

4.2.1. Wheel power 15

4.2.2. Initial tension force of one pass 15

4.2.3. Find the forces acting on the shaft and bearings 15

4.2.4. Voltage in the leading branch of the belt 15

4.2.5. Bending tension in the belt on the arc of the girth of the drive pulley 15

4.2.6. The voltage arising in the belt from the action of the central forces 15

4.2.7. Maximum voltages 16

4.2.7. Estimated durability 16

4.3. Worm Transfer Calculation 16

4.3.1. Design scheme 16

4.3.2. Take the number of measures of the worm 16

4.3.3. calculate the torque on shaft 16

4.3.4. Approximate sliding speed 16

4.3.5. Select the required degree of accuracy 17

4.3.6. Determine the allowable contact voltage 17

4.3.7. Allowable contact voltage when calculating the maximum load 17

4.3.8. Allowable bending voltage at baseline voltage change for non-reversible load 17

4.3.9. Total number of load cycles 17

4.3.10. Finding a durability coefficient of 17

4.3.11. Permissible bending voltage 17

4.3.12. Permissible bending stress when calculated on the action of the maximum load 17

4.3.13. Determine the number of teeth of the worm wheel 17

4.3.14. Worm Diameter Coefficient 17

4.3.15. Coefficient taking into account the distribution of the load along the width of the crown 18

4.3.16. Coefficient taking into account dynamic load 18

4.3.17. Determine the center-to-axis transmission distance from the contact endurance condition 18

4.3.18. Finding the engagement module 18

4.3.19. With a standard module, the center spacing 18

4.3.20. Dividing worm lifting angle 18