Design for calculation of machine 6P82G

Contents

Summary

Contents

1 Selection of drive motor based on cutting modes

1.1Selection of drive motor

2 Kinematic calculation of the speed box. Theoretical

calculation description. Description of calculation on SIRIUS program

2.1.1 Determination of the overall drive control range

2.1.2 Determination of the total number of speed stages

Selection of drive design options

2.1.3 Determination of the number of possible kinematic variants

2.1.4 Determination of maximum gear ratios by group of gears

2.1.5 Selection of structural formula variants

2.1.5.1 Selection of the first option

2.1.5.2 Selection of the second option

2.1.5.3 Selection of the third option

2.1.5.4 Select the fourth option

2.1.6 Structural Grid Construction

2.1.7 Plotting of rotation speeds

2.1.8 Determination of gear teeth numbers

2.1.9 Determination of torques on the shafts of the gearbox

2.2 Kinematic calculation. Description of operation with SIRIUS program

2.2.1 Kinematic calculation

3 Calculation of spur-toothed involute gears for each of the variants. Calculation Description

3.1 Description of program and calculation

3.1.1 Description of the program

3.1.2.3 Calculation procedure

3.3 Check of calculation correctness condition

4.1.1 Mass criterion

4.1.2 Gearbox noise criterion

5.2 Determination of forces P and Q

6 Calculation and selection of bearings

6.1.1 Initial data

6.1.2 Calculation results

6.1.3 Calculation procedure

6.2 Calculation of bearings

6.3 Selection of standard bearings

7 Calculation of shafts. Selection of key and spline connections

7.1.1 Initial data

7.1.2 Calculation results

7.1.3 Calculation procedure

7.1.3.1 Calculation of static strength margin

7.1.3.2 Calculation of fatigue strength (endurance)

7.2 Calculation of shafts

8 Spindle Design

8.1 Calculation of spindle for stiffness

8.2 Thermal calculation of spindle assembly

9 Calculation of friction losses in shaft rolling bearings

10 Calculation of thermal balance of supports

11 Selection and justification of fits

11.1 Selection of rolling bearing fits

11.2. Selection of splined joint fits

11.3. Selection of key joint fits

APPENDIX A

APPENDIX B

APPENDIX B

APPENDIX D

APPENDIX D

EXHIBIT E

APPENDIX G

APPENDIX Z

APPENDIX G

Kinematic calculation. Description of operation with SIRIUS program

2.2.1 Kinematic calculation

For kinematic calculation of the speed box, we use the SIRIUS 2 computer program developed by the Department of Moscow State University (OSU) for calculating the main motion drives and feed drives.

We start the program, select "kinematic calculation," enter the initial data:

highest output shaft speed - 1605 rpm, lowest output shaft speed - 126 rpm

drive motor shaft speed - 2800 rpm;

drive motor power - 11 kW;

row denominator = 1.26 [see input to course design];

The gearbox type code is 4 [gearbox].

After pressing "Enter" key select "kinematics calculation." In the "there are design options" window, select the row "choose the best option." The program recommends taking the best - constructive option: (3.0000, 2.0000, 2.0000). After pressing the OK key, the window "there are kinematic options" appeared on the screen - we select "choose the optimal option," after which a red window "recommended kinematic option" will appear on the screen, and the values: (1.0000, 3.0000, 6.0000). Press "Enter." The window "results of distribution of characteristics of the whole circuit into groups of gears" with values of total characteristics of the whole circuit and characteristics 0.1,2,3 appeared. In this case, to the question of the program: "Do you want to continue your distribution option?" we answer "No." The message "Calculation is finished" was displayed, press "OK." Then we will look at the calculation results in the "calculation result" menu. After performing this calculation, it is necessary, by analogy, to perform the calculation for the design version: (2.0000, 3.0000, 2.0000). To do this, with the same source data, in the window "there are design options" select a row with the value: (2.0000, 3.0000, 2.0000). All other actions are as in the first calculation version. The third calculation must be made by analogy with the first, but in the window "there are kinematic options" it is necessary to select the option: (2,000, 1.0000, 6.0000). After viewing the calculations, the last option is made by analogy with the second, only when the window "results of the distribution of the characteristic of the entire circuit into groups of gears" appears, it is necessary to change the characteristics 1, 2 and 3 so that the value of the characteristic of the entire circuit does not change. Let's choose Yes. Set the values ​ ​ of the characteristics: first: 3, second: 4 and third: 6; then Enter. The characteristic of the entire circuit has remained the same, so we press No. In the calculation results there is a clause "gear ratio matrix" with values, each of which should be in the range where i gear ratio (values ​ ​ of 0.2499 are allowed).

Construction of speed box convolution

The convolution of the speed box is necessary to clarify the kinematic scheme of the drive and the selection of bearings for the shafts. Convolution - section along kinematic chain.

The positions of the centers of the drive shafts are applied, while the axial distances are determined from the calculation of gear wheels, and the position of the imaginary line connecting the centers of the shafts is determined by: structural features of the drive (ensuring functionality); convenience of switching mechanisms.

Gearbox convolution rules:

- connect shaft centers with straight lines;

- orthogonal lines shall be drawn at the point of engagement;

- specify rotation of shafts;

- apply direction of equal forces through the engagement point from

involute engagement volume (20 °).

Spindle Design

The calculation and design of the spindle is carried out on the basis of the basic spindle assembly given in the technical certificate of the horizontal milling machine 6P82.

8.1 Calculation of spindle for stiffness

The finite element method is used for calculation. The spindle assembly is represented by rod end elements, each rod is described by three parameters: length, inner diameter and outer diameter. When splitting the spindle assembly into end elements, the number of spindle supports is taken into account; type of supports and their installation diagram. The type of supports and their installation scheme are modeled depending on a number of conditions:

bearing stiffness;

configurations of the inner and outer surfaces of the spindle;

arrangement of gears;

availability of other drive elements.

In general, the splitting of the spindle into finite elements is carried out on the basis of uniqueness conditions: physical, initial and boundary.

In accordance with the specified conditions, a calculation diagram of the spindle is compiled, used for subsequent calculation on the computer. This calculation was made using the TEMOS calculation and graphic software package developed at the Machine Tools and Aircraft Department.

The calculation results are contained in Appendix D.

8.2 Thermal calculation of spindle assembly

The thermal calculation of the spindle assembly is carried out based on the solution of the axisymmetric problem by the finite element method. As a typical finite element in this case, a triangle is taken. To simplify the formation of the calculation scheme, a procedure is used to triangulate quadrangular elements, which are figures obtained during the splitting of the axial section of the spindle. The spindle and all elements installed on it fall under the split, with the exception of heat sources, which in this case are rolling supports .

The calculation is performed in the following order:

1) The number of quadrangular regions is assigned, not necessarily of the correct shape, in accordance with the conditions of uniqueness.

2) Boundary conditions (convective heat exchange and heat generation capacity) are assigned.

3) Initial data are assigned for calculation of heat emission power and heat transfer coefficients on heat-removing surfaces.

4) Conditions for thermal calculation (time and node numbers) are entered.

The TEMOS package was used to heat calculate the spindle assembly. The calculation results are contained in annex E.

Selection and justification of fits

11.1 Selection of rolling bearing fits

When assigning tolerance fields for shaft fits for the inner ring and casing holes for the outer ring of rolling bearings, it is necessary to take into account :

a) the shaft (inner ring) or housing rotates;

b) type of load;

c) operation mode;

d) type and dimensions of bearings ;

e) bearing accuracy class;

f) speed of the rotating ring;

g) installation and operation conditions, etc.

In accordance with the specified conditions, for mounting on the shaft of ball radial bearings of accuracy class P6, circulation loading

(rotating shaft) and normal operation mode, tolerance field k6 is selected. H7 tolerance field is selected to fit bearings in the housing. JS 7 tolerance field is used to fit radial and thrust bearings into spindle sleeve.

11.2. Selection of splined joint fits

For fixed straight splined joints: H7/JS 7 fit is selected as the diameter fit when centering on the outer diameter; F8/f8 fit is selected as fit along width of spline.

For movable straight splined joints: the fit is selected as a diameter fit when centering on the outer diameter

H7/f 7; F8/f 8 fit is selected as fit along width of spline.

11.3. Selection of key joint fits

For fixed key connections H7/p6 transition fit is selected.