Course Design for Machine Parts

The course project includes:

Introduction.................................................................................................................. 6

1 Kinematic calculation............................................................................................ 7

1.1 Development of kinematic diagram.................................................................. 7

1.2 Selection of typical electric motor................................................................................................................. 7

1.2.1 Power on drive shaft................................................................................................................................................................................................................................. 7

1.2.2 Calculate the efficiency of the drive (efficiency).............. 7

1.2.3 Calculate design power of electric motor.............................. 7

1.2.4 Output shaft RPM............................................................. 8

1.2.5 Select motor 8 by catalog [1, Table 17.7.1 and Table 17.7.2]

1.3 Determination of total gear ratio and its breakdown by stages..... 8

1.3.1 Calculate the actual gear ratio of the drive..................... 8

1.3.1 Accept and calculate the actual numbers of drive gears............. 8

1.4 Determination of power and torque speeds on all shafts............................................................................................................................................................................................................................................................. 8

1.4.1 Calculate power and kinematic parameters of drive shafts........ 8

2 Calculation of open transmission with determination of all geometric dimensions and forces acting in transmission......................................................................................................................................................................................................................................................... 10

2.1 Calculate V-belt transmission..................................................................................................................................................................................................................... 10

2.1.1 Calculate the main parameters of V-belt transmission................ 10

2.2 Calculate pulley geometry.......................................................................................... 13

3 Gearbox transmission calculation, determination of all geometrical dimensions and forces..................................................................................................................................................................................................................................................................................................................................... 15

3.1 Calculate cylindrical worm closed gear................... 15

3.1.1 Select materials for permissible stresses................................. 15

3.1.2 Calculate the axial distance and select the main transmission parameters........................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 17

3.1.3 Check design bending stresses..................................................................................................................................... 20

3.1.4 Determine stiffness and heat treatment of worm.............................. 20

3.1.5 Perform thermal calculation of transmission................................................................................................................................................. 22

3.1.6 Select transmission lubrication............................................................................................................................. 23

3.1.7 Calculate forces in engagement of worm gear............................................................................................................................................................................................................................................................................................................................................................................. 23

3.1.8 Calculate the geometry of the worm wheel..................................................................................................................................................................................................................................................................................................................................................... 23

4 Calculation diagrams of shafts with determination of total reactions of their supports, selection and calculation of bearings..................................................................................................................................................................................................................... 25

4.1 Calculate diameters of drive shafts ends based on torsion only at reduced permissible stresses............................................................................................................................................................................................................................................................................................................................................................. 25

4.2 Select diameters of shafts in the place where shafts fit for bearings............ 25

4.3 Select the shafts diameters at the hub landing place............................................................................................................................................................................................................................................................................................................................................. 25

4.4 Design calculation of shaft 1..................................................................................................................................................................................................................................................................... 26

4.4.1 Initial data...................................................................................... 26

4.4.2 Define the paragraphs of the annex, directions and values of forces loading the shaft in the XOZ plane (Figure 4.1a)........................................................................................................................................................................................................................................................................................................................................................................................ 26

4.4.3 Calculate the reactions Rax and Rbx in the shaft supports A and B of the plane XOZ (Figure 4.1a)..................................................................................................................................................................................................................................................................................... 26

4.4.4 Calculate bending moments at the characteristic points of the shaft with construction of the index of bending moments Mich (Figure 4.1b)......................................... 26

4.4.5 Determine the points of application, directions and values of forces loading the shaft in YOZ plane (Figure 4.1c)............................................................................................................................................................................................................................................................................................................................................................................................ 27

4.4.6 Calculate Ray and Rby reactions in supports A and B of YOZ plane shaft (Figure 4.1c)................................................................................................................................................................................................................................................................................. 27

4.4.7 Calculate bending moments at the characteristic points of the shaft with construction of the period of bending moments Miu (Figure 4.1d)......................................... 27

4.4.8 Calculate full cross reactions Ra and Rb in shaft supports........... 27

4.4.9 Calculate the total bending moments Mi in the characteristic sections of the shaft with the construction of the index of bending moments (Figure 4.1e)................ 28

4.4.10 Representation of the torques T transmitted by the shaft (Figure 4.1e)..................................................................................................................................................................................................................................................................................................................................................... 28

4.5 Check of shaft 1 for fatigue strength......................................................................................................................................................................................................................................................................................... 29

4.5.1 Calculate the safety factor of the shaft by normal stresses..................................................................................................................................................................................................................... 29

4.5.2 Calculate the safety factor by tangent voltages for non-reversible transmission............................................................................................................................................................................................................................................................................................................................................. 30

4.5.3 Calculate the total fatigue resistance margin.............................. 31

4.6 Design calculation of shaft 2..................................................................................................................................................................................................................................................................... 32

4.6.1 Initial data...................................................................................... 32

4.6.2 Let's define paragraphs of the application, the direction and size of forces loading a shaft in the XOZ planes (figure 4.2a)............................................................... 32

4.6.3 Calculate the reactions Rax and Rbx in the shaft supports A and B of the plane XOZ (Figure 4.2a)............................................................................................................................................................................................................................................................................. 32

4.6.4 Calculate bending moments at the characteristic points of the shaft with construction of the index of bending moments Mich (Figure 4.2b)......................................... 33

4.6.5 Determine the points of application, directions and values of forces loading the shaft in YOZ plane (Figure 4.2c)......................................................................................................................................................................................................................................................................................... 33

4.6.6 Calculate Ray and Rby reactions in supports A and B of YOZ plane shaft (Figure 4.2c)................................................................................................................................................................................................................................................................................. 33

4.6.7 Calculate bending moments at the characteristic points of the shaft with construction of the period of bending moments Miu (Figure 4.2g)......................................... 33

4.6.8 Calculate the full cross reactions Ra and Rb in the shaft supports........... 34

4.6.9 Calculate the total bending moments Mi in the characteristic sections of the shaft with the construction of the index of bending moments (Figure 4.2e)................ 34

4.6.10 Representation of the torques T transmitted by the shaft (Figure 4.2e)..................................................................................................................................................................................................................................... 34

4.7 Check of shaft 2 for fatigue strength..................................................................................................................... 35

4.7.1 Calculate the safety factor of the shaft by normal stresses..................................................................................................................................................................................................................................................................................................................................................................... 35

4.7.2 Calculate the safety factor by tangent voltages for non-reversible transmission............................................................................................................................................................................................................................................................................. 36

4.7.3 Calculate total fatigue resistance margin.............................. 37

4.8 Calculation and selection of bearings................................................................................. 38

4.8.1 Select bearing for 1 shaft......................................................................................................................................................................................................................... 38

4.8.1.1 Select bearing parameters and calculate the ratio....... 38

4.8.1.2 Calculate axial components from radial loads in supports A and B............................................................................................................................................................................................................................................................................................................................................................................. 38

4.8.1.3 Determine the magnitude and direction of the resulting force.......... 38

4.8.1.4 ΑFoc is directed from support A in support B, then it is perceived [1, Table 8.5.1]:.................................................................................................................................................................................................................................................................................................................................................................................... 38

4.8.1.5 Determine for each support:..................................................................................................................................................................................................................................................................................................................................................................................... 38

4.8.1.6 Equivalent dynamic radial load............................ 39

4.8.1.7 Design life of bearing operation................................... 40

4.8.2 Select bearing for shaft 2......................................................................................................................................................................................................................................................................... 40

4.8.2.1 Select bearing parameters and calculate the ratio...... 40

4.8.2.2 Calculate axial components from radial loads in supports A and B..................................................................................................................................................................................................................................................... 40

4.8.2.3 Determine the value and direction of the resulting force......... 40

4.8.2.4 ΑFoc is directed from support A in support B, then it is perceived [1, Table 8.5.1]:................................................................................................................................................................................................................................................................................. 40

4.8.2.5 Determine for each support:..................................................................................................................................................................................................................................................................................................................... 41

4.8.2.6 Equivalent dynamic radial load........................... 41

4.8.2.7 Design life of bearing operation.............................. 42

5 Selection of keys and their check for crushing......................................................................................................................................................................................................................................................................................................................................................................................................... 43

5.1 Select key for 1 shaft.................................................................................. 43

5.1.1 Check key size by permissible stresses....................... 43

5.2 Selection of key for shaft 2......................................................................................................................................................................................................................................................................................................................................................................................... 43

5.2.1 Check the key size by permissible stresses................... 43

5.2.2 Check key size by permissible stresses................... 44

6 Gearbox housing calculation and design......................................................................................................................................................................................................................................................................... 45

6.1 Calculate gearbox wall thickness......................................................................................................................................................................................................................................................................................................................................................................................................... 45

6.2 Calculate the distance from the inner surface of the gearbox wall...... 45

6.3 Calculate the distance between rotating parts............................. 45

6.4 Calculate radial clearance between gear wheel of one stage and shaft of the other stage..................................................................................................................................................................................................................................................................................................................................................... 45

6.5 Calculate radial clearance from tooth vertices surface....................... 45

6.6 Select distance from side surfaces of elements rotating together with shaft to fixed external parts of reduction gear box..................................................................................................................................................................................................................................................................... 46

6.7 Calculate flange width connected by bolt................................................................................................................................................................. 46

6.8 Select the flange thickness of the side cover [1, Fig. 12.1.2, Table 12.1.1].... 46

6.9 Calculate recommended diameters of bolts connecting:................... 46

6.10 Calculate the thickness of the gear box flanges...................................................... 46

7 Calculation and selection of coupling. 48

7.1 Calculate elastic bushing-finger coupling............................................................................................................................................. 48

7.1.1 Calculate the condition of finger bending strength.................................. 48

7.1.2 Calculate the condition of bushing crushing strength.................................... 49

8 Calculation and design of foundation frame............................................................................................................. 50

8.1 Select channels [1, Table 15.2.3]..................................................................................................................................................................................................................................................... 50

8.2 Transverse size of channel installation..................................................... 50

8.3 Level difference of motor and reduction gear box support surfaces. 50

8.4 Motor, gearbox and foundation bolt supports 50

9 Design of protective and other devices................................................. 52

10 Description of the process of assembly and operation of the drive principle of operation and assembly of the drive......................................................................................................................................................................................................................................................................... 53

Conclusion............................................................................................................ 54

List of sources used