Helical-Gear-Group-1fdssdddss-ME-2C.pptx

Helical gear with problems

1. GROUP 1 | ME2C SUBMITTED TO: ENGR. DIEGO AGUADO HELICAL GEAR

2. OUR TEAMS 04 03 WHAT IS HELICAL GEAR AND IT’S CUTTING PRAMETERS SAMPLE PROBLEM LEARNING OBJECTIVES 02 01 TABLE OF CONTENTS

3. OUR TEAMS ABONYAWAN, COLEEN FRANCES ESPENDE, KYRTH FERRER, MICHAEL GUEVARRA, GABRIEL JOHN NIEPES, KYLENE TONACAO, OSCAR

4. – Marcel Pagnol “One has to look out for engineers - they begin with sewing machines and end up with the atomic bomb.”

5. TO BE ABLE TO UNDERSTAND WHAT IS HELICAL GEAR , IT’S FUNCTIONS , AND CUTTING PARAMETERS. TO BE ABLE TO ANALYZE AND SOLVE PROBLEMS RELATED TO HELICAL GEAR GOALS AND OBJECTIVES OBJECTIVE NUMBER 1 OBJECTIVE NUMBER 2

6. WHAT IS A HELICAL GEAR? 1

7. Helical gears are  one type of cylindrical gears with slanted tooth trace . Compared to spur gears, they have the larger contact ratio and excel in quietness and less vibration and able to transmit large force. A pair of helical gears has the same helix angle but the helix hand is opposite.

8. HELICAL GEAR TERMINOLOGIES LEAD/LEAD OF WORK HELIX ANGLE OUTSIDE DIAMETER CENTER DISTANCE INDEXING REQUIREMENT PITCH DIAMETER GEAR COMBINATION MODULE DIAMETRAL PITCH LEAD OF MACHINE

9. LEAD/ LEAD OF WORK L (Lead) - The lead is the axial advance of a helix gear tooth during one complete 360° turn. It is the length along the axle for one single complete helical revolution about the pitch diameter of the gear.

10. CENTER DISTANCE Z (Center Distance) - The center distance is the distance between the center shafts of two gears

11. OUTSIDE DIAMETER OD (Outside Diameter) - The outside diameter is the major diameter of the gear produced by connecting the tooth tips.

12. INDEXING REQUIREMENT IR (Indexing Requirement) - The indexing requirement is the value for dividing a periphery of a workpiece into equal number of divisions by the help of index crank and index plate. It is a division used to cut gear teeth accurately and equal spacing of the teeth of the gear.

13. PITCH DIAMETER (Pitch Diameter) - The pitch diameter is the imaginary diameter for which the widths of the threads and the grooves are equal. They can be determined directly from the center distance and the number of teeth.

14. HELIX ANGLE β (Helix Angle) - The helix angle is the angle between the axis (bore) of a helical gear and an imaginary line tangent to the tooth.

15. GEAR COMBINATION Gear Combination - A gear combination is the ratio of the number of rotations of a driver gear to the number of rotations of a driven gear. At minimum, two gears must be engaged with each other — this is called a "gear train." Usually, the first gear is a "drive gear" attached to the motor shaft and the second is a "driven gear" attached to the load shaft.

16. MODULE Module - The module (m) is a unit of gear tooth size defined by ISO (International Organization for Standardization). It is the ratio of pitch circle diameter to the total number of teeth on a gear or pinion. Gears will only mesh with each other if they have teeth of the same module.

17. DIAMETRAL PITCH Diametral Pitch - The diametral pitch is the number of teeth to each inch of the pitch diameter. It is used to specify the pitch of the cutter profiles.

18. TYPES OF HELICAL GEAR

19. TWO TEETH CONFIGURATIONS If the thumb of our left hand is following the inclination of tooth of gear, that helical will be termed as left hand helical gear. If the thumb of our right hand is following the inclination of tooth of gear, that helical will be termed as right hand helical gear.

20. TWO AXIAL CONFIGURATIONS Gears involving two axis, which are parallel to each other, are called Parallel Axis Gears.

21. TWO AXIAL CONFIGURATIONS Gears involving two axis that intersect perpendicularly.

22. SAMPLE PROBLEM

23. QUESTION : 2 HELICAL GEARS WILL BE MESHED GIVEN THE MODULE (m) WHICH IS 2.5. THE NUMBER OF TEETH (N) OF 1 ST and 2 ND GEAR ARE 15T AND 17T RESPECTIVELY. ALSO, THE ANGLE IS β =25 ˚ . SOLVE FOR THE CUTTING PARAMETERS BEING DISCUSSED IN THE PREVIOUS SLIDE.

24. LEGENDS: β- HELIX ANGLE N-NUMBER OF TEETH m-MODULE L-LEAD OF WORK z-CENTER DISTANCE OD- OUTSIDE DIAMETER IR-INDEXING REQUIREMENT PD-PITCH DIAMETER CG-GEAR COMIBINATION

25. GIVEN: β =25 ˚ N 1=15T N2=17T M=2.5 REQUIRED: L 1 , L2, Z , OD, IR, PD,CG CALCULATIONS SOLVING: L1:= L2:= Mn= = = 2.76mm Solve for the normal module first using the given module, this will going to be substituted to the formula of lead of work . To solve for the lead of work, substitute the value of teeth of the 1st gear then multiply it by the value of pi over sin beta, enclosed them in an open and close parenthesis then multiply into the normal module.Same process on Lead 2, use the 2nd gear Number of teeth.

26. GIVEN: β =25 ˚ N 1=15T N2=17T M=2.5 REQUIRED: L 1 , L2, Z , OD, IR, PD,CG CALCULATIONS SOLVING: OD1:=( =42.5 mm OD2:=( =47.5 mm IR1:=( =2 2\3 IR2:=( =2 6\17 To solve for the Outside Diameter, substitute the value of teeth of the 1st gear then add 2 , divide it to the division of 1 over module, now solve .Same process applies on OD2, only the number of teeth varies. To solve for the Indexing Requirement, just divide the number of teeth of both gears to 40 and you will get the answer!

27. GIVEN: β =25 ˚ N 1=15T N2=17T M=2.5 REQUIRED: L 1 , L2, Z , OD, IR, PD,CG CALCULATIONS SOLVING: Z= =48.69 mm CG1:= =6.99 CG2:= =7.92 To solve for the Center Distance, substitute the value of teeth of the 1st gear then add it to the 2nd gear number of teeth enclosed them and multiply to the normal module , afterwards divide it to 2cos beta(angle) . To solve for the Gear Combination, substitute the value of Lead Number 1 and divide it to 40 as Indexing Head + lead of machine .Same process goes with Gear Combination #2. (Lead of work varies)

28. GIVEN: β =25 ˚ N 1=15T N2=17T M=2.5 REQUIRED: L 1 , L2, Z , OD, IR, PD,CG CALCULATIONS PD1=N1( m )=15(2.5)=37.5 mm PD2=N2( m )=17(2.5)=42.5 mm To solve for the Pitch Diameter, just multiply the number of teeth of the first gear to the given module.For Pitch Diameter #2, multiply the 2nd gear Number of Teeth to the given module as well. Watch out for correct/proper units to be used.

29. CARPE DIEM!