DEVELOPING CNC PROGRAM FOR THE MANUFACTURING OF GUIDE BLADE GOOVES

ON STEAM TURBINE CASINGBy

P.Kranthi KumarR.Aditya

Contents Introduction to steam turbine Steam Turbine Elements Introduction to CNC Computer Numerical Control Introduction to CNC programming CNC Programming

Introduction To Steam Turbine A Steam turbine can be defined as a form of heat engine in which the energy

of the steam is transformed into kinetic energy by the means of expansion through nozzles and kinetic energy of the resulting jet is in turn converted into force during work on rings of blading mounted on a rotating part.

Fundamental Parts of Steam

Turbine

FrameNozzleStatorRotor

Steam Turbine Elements Turbine casing and guide blade carrier:

Inner Casing:

Turbine Rotor and Blading

Introduction to CNC ProgrammingNumerical

control

Type of machine

Storage Media

Programming

methods

Type of control

Point –to –Point NC

Continuous NC

Open Loop

Closed Loop

Incremental

Absolute

Magnetic Disc

Punched Paper

Magnetic Tape

Computer Numerical Control

Tape reader for

initial program

entry

Minicomputer or microcomputer

(software functions and NC part program

storage)

Computer

hardware

interface and servo

system

Motion Feedback

Introduction To CNC ProgrammingPart

programming structure

Character

Digit Letter Symbol

Word BlockProgra

m

FUNCTIONAL CODES: There are two main codes used to perform the operation on the machine.

CODES

M-CODESG-

CODES

CNC PROGRAMMain program HP side.Subroutine Programs. 

1) Diameter Roughing

2) Groove Roughing

3) Calculation Subroutine

4) Groove Width Roughing / Depth Finishing

5) Diameter Finishing

6) Groove Width Finishing / 0.3 Recess

7) Step Diameter Finishing

8) Top Suspension

9) Bottom Suspension

10) Packing Groove

11) Chamfering Upper Lower

12) Fin Grooves

GROOVE DIAGRAM

AF LHT

1X 45

BF BHLN BHMN

LHL

LHM

MAIN PROGRAM(I.P SIDE) 

G00 G90 X850 D1; Z = 2; R10 = 9; (Diameter Roughing)

=10; (Groove Roughing) =11; (Groove width Roughing/ depth finishing) =12; (Diameter finishing) =13; (Groove width Roughing/0.3 recess) =14; (Step Diameter Finishing) =15; (Top suspension)

=16; (Bottom suspension) =17; (Packing Groove) =18; (Upper chamfering) =19; (lower chamfering) = 20; (Fin Grooves)

NO10 (POS 20) R1=1357 R2=1318 R3=143 R4=137.7 R5=18 R6=10

R7=21 R8=14 R9=25.8 R11=25 R12=80.9 R13=17

L=R10;

L10 .Groove Roughing (Using grooveing tool)

D15

D25

R1

R20

R4

R22

L9.Diameter Roughing (Using boring tool) D1 R3 R1 R2

L11 Groove Width Roughing / Depth Finishing (Using grooving tool)

R1 R20 R4 R2 R22

L12 Diameter Finishing (Using grooving tool) R3 R1 R2

L14 Step dia finishing (Using grooving tool)

R24 R1

R3 R23

L13 Top suspension (Using top suspension tool)

D10 D20

R20

R29

r3

R27 R22

L17 Packing groove (Using radius tool of 3mm diameter) D21 R1 R22 R35 R4 R2

L20 Fin grooves (Using a special grooving tool of 1.5 mm width) D5 R1 R12 R13

L100. Calculation Subroutine

  

R20 = R4-R5; R21 = 2*R7; R22 = R1+6+R21; R23 = R3-0.3; R24 = R23-R11; R25 = R7-R6; R26 = 2*R25; R27 = (R9-R5)/2; R29 = R20-R28; R30 = R4+R28; R31 = 2*R8; R32 = 2*R6; R33 = R31 + R32 + 6; R34 = R1 + R33; R35 = R5/2; 

THANK YOU