ContentsABSTRACT3CHAPTER 141.0INTRODUCTION41.1Advantages of Gear Drives:41.2DISADVANTAGES OF GEAR DRIVES:51.3 General Classification of gears:51.3.1 According to the position of axes of the shafts:51.3.2 According to the peripheral velocity of the gears:51.3.3 According to type of gearing:51.3.4 According to the position of the teeth on the gear surface:51.3.5 According to the position of axes of the shafts:5CHAPTER 292.0 HELICAL GEARS SPECIFICATIONS92.1 Helical gear nomenclature92.2 Helical Gear geometrical proportions102.3 Mounting Specifications of Helical Gears122.4 Helical Gear Materials12CHAPTER 3143.0 INTRODUCTION TO CATIAV5R16143.1 Definition of Software: Feature based parametric bidirectional associative software.143.1.0 Sketcher (To know about 2d tools only)143.1.1 Part modeling (To create any solid models)143.1.2 Assembly (In this just we insert the components already created in part)143.1.3 Drafting (To generate the views with projections, dimensions, BOM, etc.)143.1.4 Wireframe and surface designing (To create the surfaces without thickness)143.1.5 Generative Sheet metal Design (Total design follows the fixed thickness)143.2 Designing of a helical gear with involute profile using CATIAV5R1615CHAPTER 4324.0 Introduction to ANSYS:324.1 MODAL ANSYS:324.2 Static Analysis324.3 STRUCTURAL ANALYSIS FOR ALUMINUM384.4 RESULTS:51CHAPTER 552CONCLUSION52FUTURE SCOPE OF THE WORK53REFERENCES54

ABSTRACT

This project mainly deals with the design and analysis of Helical gear with involutes profile. Theinvolutes gearprofile is the most commonly used system forgearingtoday. In an involutes gear, the profiles of the teeth are involutesof a circle. In involutes gear design contact between a pair of gear teeth occurs at a single instantaneous point. Rotation of the gears causes the location of this contact point to move across the respective tooth surfaces. The teeth onhelical gearsare cut at an angle to the face of the gear. When two teeth on a helical gear system engage, the contact starts at one end of the tooth and gradually spreads as the gears rotate, until the two teeth are in full engagement .This gradual engagement makes helical gears operate much more smoothly and quietly than spur gears. For this reason, helical gears are used in almost all power transmissions. One interesting thing about helical gears is that if the angles of the gear teeth are correct, they can be mounted on perpendicular shafts, adjusting the rotation angle by 90 degrees. Under this project the Helical gear with involutes profile is designed with the help of CATIA V5R16 software , modal and static structural analysis is carried by the Ansys software .

CHAPTER 11.0 INTRODUCTION

Gears are most commonly used for power transmission in all the modern devices. These toothed wheels are used to change the speed or power between input and output. They have gained wide range of acceptance in all kinds of applications and have been used extensively in the high-speed marine engines. In the present era of sophisticated technology, gear design has evolved to a high degree of perfection. The design and manufacture of precision cut gears, made from materials of high strength, have made it possible to produce gears which are capable of transmitting extremely large loads at extremely high circumferential speeds with very little noise, vibration and other undesirable aspects of gear drives. A gear is a toothed wheel having a special tooth space of profile enabling it to mesh smoothly with other gears and power transmission takes place from one shaft to other by means of successive engagement of teeth. Gears operate in pairs, the smallest of the pair being called pinion and the larger one gear. Usually the pinion drives the gear and the system acts as a speed reducer and torque converter. 1.1 Advantages of Gear Drives: The following are the advantages of the gear drives compared to other drives. Gear drives are more compact in construction due to relatively small centre distance. Gears are used where the constant velocity ratio is desired. Gears can be operated at higher speeds. It has higher efficiency. Reliability in service. It has wide transmitted power range due to gear shifting facility. Gear offers lighter loads on the shafts and bearings. Gear can change the direction of axis of rotation.1.2 DISADVANTAGES OF GEAR DRIVES:

Not suitable for the shafts which are at longer center distance. Manufacturing is complex. It needs special tools and equipment. Require perfect alignment of shafts. Requires more attention to lubrication. The error in cutting teeth may cause vibration and noise during operation.

1.3 General Classification of gears: Although the types and the modalities of gear design vary widely for mechanical power transmission, gears are generally categorized into the following types.1.3.1 According to the position of axes of the shafts: The axes of the two shafts between which the motion is to be transmitted, may be ( a) Parallel, (b) Intersecting, and (c) Non-Intersecting and Non-parallel1.3.2 According to the peripheral velocity of the gears: The gears, according to the peripheral velocity of the gears, may be classified as: (a) Low Velocity, (b) Medium Velocity and (c) High Velocity.

1.3.3 According to type of gearing: The gears, according to the type of gearing may be classified as (a) External Gearing, (b) Internal Gearing, (c) Rack and Pinion.1.3.4 According to the position of the teeth on the gear surface: The teeth on the gear surface may be (a) Straight (b) Inclined (c) Curved. 1.3.5 According to the position of axes of the shafts: Spur Gears: Spur gears are the simplest and most common type of gear. Their general form is a cylinder or disk. The teeth project radially, and with these "straight-cut gears", the leading edges of the teeth are aligned parallel to the axis of rotation. These gears can only mesh correctly if they are fitted to parallel axles. Spur gears on non-parallel shafts can mesh, but only point contact will be achieved, not line contact across the full width of the tooth; also the length of the path of contact may be too short. This causes impact stress and noise. Spur gears make a characteristic whine at high speeds and cannot take as much torque as helical gears because their teeth are receiving impact blows. Fig: 1.1 Figure showing different lines of contact Helical Gears: Helical gears offer a refinement over spur gears. The leading edges of the teeth are not parallel to the axis of rotation, but are set at an angle. Since the gear is curved, this angling causes the tooth shape to be a segment of a helix. The angled teeth engage more gradually than do spur gear teeth. This causes helical gears to run more smoothly and quietly than spur gears. Helical gears also offer the possibility of using non-parallel shafts. With parallel helical gears, each pair of teeth first makes contact at a single point at one side of the gear wheel; a moving curve of contact then grows gradually across the tooth face. It may span the entire width of the tooth for a time. Finally, it recedes until the teeth break contact at a single point on the opposite side of the wheel. Thus force is taken up and released gradually. . Fig: 1.2 Pitch pointDouble Helical Gears: Double helical gears, also known as herringbone gears, overcome the problem of axial thrust presented by 'single' helical gears by having teeth that set in a 'V' shape. Each gear in a double helical gear can be thought of as two standards, but mirror image, helical gears stacked. This cancels out the thrust since each half of the gear thrusts in the opposite direction. They can be directly interchanged with spur gears without any need for different bearings.Bevel Gears: Bevel gears are essentially conically shaped, although the actual gear does not extend all the way to the vertex (tip) of the cone that bound it. With two bevel gears in mesh, the vertices of their two cones lie on a single point, and the shaft axes also intersect at that point. The angle between the shafts can be anything except zero or 180 degrees. Bevel gears with equal numbers of teeth and shaft axes at 90 degrees are called miter gears. Fig: 1.3 Bevel GearsWorm Gears: Worm gear is a special case of a spiral gear in which the larger wheel usually has hollowed or concave shape such that a portion of the pitch diameter of the other gear is enveloped on it. The smaller of the two wheels called the worm which also has a large spiral angle. The shafts may have any angle between them, but normally it is 90.The system can be non-throated, single throated, double throated types. Hypoid Gears: These are similar to spiral bevel gears, but have non-intersecting axes i.e. the axes of pinion is offset relative to the gear axis. However the plane containing the two axes is usually at right angles to each other.

CHAPTER 22.0 HELICAL GEARS SPECIFICATIONSHelical gears offer a refinement over spur gears. The leading edges of the teeth are not parallel to the axis of rotation, but are set at an angle. Since the gear is curved, this angling causes the tooth shape to be a segment of a helix. Helical gears can be meshed in a parallel or crossed orientations. The former refers to when the shafts are parallel to each other; this is the most common orientation. In the latter, the shafts are non-parallel.The angled teeth engage more gradually than do spur gear teeth causing them to run more smoothly and quietly. With parallel helical gears, each pair of teeth first make contact at a single point at one side of the gear wheel; a moving curve of contact then grows gradually across the tooth face to a maximum then recedes until the teeth break contact at a single point on the opposite side. In spur gears teeth suddenly meet at a line contact across their entire width causing stress and noise. Spur gears make a characteristic whine at high speeds and cannot take as much torque as helical gears. Whereas spur gears are used for low speed applications and those situations where noise control is not a problem, the use of helical gears is indicated when the application involves high speeds, large power transmission, or where noise abatement is important. The speed is considered to be high when the pitch line velocity exceeds 25m/sQuite commonly helical gears are used with the helix angle of one having the negative of the helix angle of the other; such a pair might also be referred to as having a right-handed helix and a left-handed helix of equal angles. The two equal but opposite angles add to zero: the angle between shafts is zero that is, the shafts are parallel. Where the sum or the difference (as described in the equations above) is not zero the shafts are crossed. For shafts crossed at right angles the helix angles are of the same hand because they must add to 90 degrees.2.1 Helical gear nomenclatureHelix angle, Angle between a tangent to the helix and the gear axis. Is zero in the limiting case of a spur gear.Normal circular pitch, pnCircular pitch in the plane normal to the teeth.Transverse circular pitch, pCircular pitch in the plane of rotation of the gear. Sometimes just called "circular pitch". pn = pcos()

2.2 Helical Gear geometrical proportions p = Circular pitch = d g. p / z g = d p. p / z p p n = Normal circular pitch = p .cos P n =Normal diametrical pitch = P /cos p x = Axial pitch = p c /tan m n =Normal module = m / cos n = Normal pressure angle = tan -1 ( tan.cos ) =Helix angle d g = Pitch diameter gear = z g. m d p = Pitch diameter pinion = z p. m a =Center distance = ( z p + z g )* m n /2 cos a a = Addendum = m a f =Dedendum = 1.25*m

2.3 Mounting Specifications of Helical Gears Consider the gear center, bore diameter and shaft diameter. The gear center can be abored holeor an integral shaft. The bore diameter is the diameter of the center hole. The shaft diameter is the diameter of the shaft for gears with an integral shaft.Helical gears can be mounted on a hub or shaft. A hub is a cylindrical projection on one or both sidesof ahelical gear, often for the provision of a screw or other shaft attachment mechanism. Hubless gears are typically attached via press fit, adhesive or internal keyway.2.4 Helical Gear Materials2 Gear composition is determined by application, including the gear's service, rotation speed, accuracy and more.3 Cast ironprovides durability and ease of manufacture.4 Alloy steelprovides superior durability and corrosion resistance. Minerals may be added to the alloy to further harden the gear.5 Cast steelprovides easier fabrication, strong working loads and vibration resistance.6 Carbon steelsare inexpensive and strong, but are susceptible to corrosion.7 Aluminumis used when low gear inertia with some resiliency is required.8 Brassis inexpensive, easy to mold and corrosion resistant.9 Copperis easily shaped, conductive and corrosion resistant. The gear's strength would increase if bronzed.10 Plasticis inexpensive, corrosion resistant, quiet operationally and can overcome missing teeth or misalignment. Plastic is less robust than metal and is vulnerable to temperature changes and chemical corrosion. Acetal, delrin, nylon, and polycarbonate plastics are common.11 Othermaterial types like wood may be suitable for individual applications

CHAPTER 33.0 INTRODUCTION TO CATIAV5R16

CATIA: Computer Aided Three Dimensional Interactive ApplicationIt was developed by Dassault Systmes in 1981 and it is located in French.Versions of CATIA are V1,V2,V3,V4,V5 and V6 more companies are using from V4 only. Now in the market many companies are using V5R16 and in V5 we have many versions from V5R1 to V5R21It is a tool based software these tools we call as features, so it is a feature based software .It is a parametric software, parametric mean while designing or after completing the design we can change the parameters of the component.3.1 Definition of Software: Feature based parametric bidirectional associative software.It is a advanced designing software compared to Autocad, and in Autocad we can complete all the tasks in single window, but in this we have different windows those windows we call as modules, the main modules in designing are 3.1.0 Sketcher (To know about 2d tools only)3.1.1 Part modeling (To create any solid models)3.1.2 Assembly (In this just we insert the components already created in part)3.1.3 Drafting (To generate the views with projections, dimensions, BOM, etc.) 3.1.4 Wireframe and surface designing (To create the surfaces without thickness)3.1.5 Generative Sheet metal Design (Total design follows the fixed thickness)

3.2 Designing of a helical gear with involute profile using CATIAV5R16

Before creating helical gear we should know the specifications of helical gear based on the data and formulas we can design the helical gear.Specifications of helical gear: rb - base cylinder radiusr - pitch circle radiusrk - outside circle radiusrf - root radiusa - pressure angle (20deg)m modulo (in our example 20) m=p/3.14159 where p is circular pitch 2r=m*zz - Number of teeth (in our example 30)Now open the catia software set some settings go to TOOLS->OPTIONS->infrastructure->part infrastructure and in Display select Paramteres and Relationsas shown below.

Then in Options->General in Parameters and Measures select with value and With formula in Parameters Tree View.

Now go to Start Generative Shape design

Fog and f(x) are two most important tools on the knowledge tool bar to create the gear design, now we have to enter some basic parameters that define gear.Now select the f(x) icon from the knowledge tool bar it opens the below window and then we see dialog box: Formulas: Part1 fist select Parameter type (real, length or angle) click new parameter of type and then edit value. You can do this until all parameters are entered.

When you enter parameters it is time to enter some formulas. For, r, rb, rk and rf we enter formulas by naming them and by clicking Add Formula. Formula editor will appear:

After typing all formulas and expanding specification tree you will see something like this

It is time to add laws that will define our involute. Click on fog icon, name law x add parameters, t and x select their types and add law: x=rb*(sin(t*PI*1rad))-rb*t*PI*cos(t*PI*1rad)

Same should be done for y (y=(rb*cos(t*PI*1rad))+((rb*t*PI)*sin(t*PI*1rad)) . This law will help us to create points that define spline for our involute. Involute is line that is trajectory of point belonging to line that is always tangent to base gear cylinder. It is used for tooth profile.If gears had profiles formed by straight lines they wouldn't work.

After expanding specification tree you should be able to see something like this:

Now it is time to start creating our points for involute spline. Click on point icon, select xy plane for support and when asked to enter H and V cordinates right button click should bring menu where you should chose edit formula:

You will be prompet by edit formula dialog. Type in: Relations\x .Evaluate(0)

You should do same for V except you should use Relations\y .Evaluate (0). You will get starting point for involute:

After repeating this step for .Evaluate(0.1)-.Evaluate(0.5) you will get this:

Click on spline icon and chose all 6 points

Your involute is created. This is how it looks in sketcher

From this point everything is more or less simple. Create base cirle by clicking on circle icon.Right click on radius and chose rb from formula editor:

Now it is time to extrapolate our involute. For length also right click and chose formula (rb-rf)*1.5

You can use View-> zoom and pan to see what actually you are doing. Create plane. Use formula: inv(360/z)/4. You will get -4.5deg angle offset from ZY plane.

After this create rf circle and from inser menu use corner to create corner. Corner dialog will apear:

This is what you should get

Now use trim and result should be

It is time for simetry. Tooth starts to get shape

Create rk circle and use trims to get tooth shape

Crete a plane above top plane then select sketch select new plane then project the involute profile and circles then trim the unnecessary portion as shown below finally it looks as below.

Translate the profile with 100mm parallel to top plane and tehn rotate 20 degrees hide the original now profiles looks as below

Use multi sections surface tool to create the surface as below.

Now go to part modeling select close surface tool and select the surface this surface will be converted into solid then hide the surface it looks as below.

Use circular pattern and create 30 parts with 12 degrees with each as shown below.

Now create two circles as shown below exit workbench.

Use the pad tool to add the material with hole as below now the gear is completed.

To see the gear clearly use shade option it looks as below. This is our final output of helical gear.

CHAPTER 44.0 Introduction to ANSYS:

The ANSYS Workbench platform is the framework upon which the industrys broadest and deepest suite of advanced engineering simulation technology is built. An innovative project schematic view ties together the entire simulation process, guiding the user through even complex multi physics analyses with drag-and-drop simplicity. With bi-directional CAD connectivity, powerful highly-automated meshing, a project-level update mechanism, pervasive parameter management and integrated optimization tools, the ANSYS Workbench platform delivers unprecedented productivity, enabling Simulation Driven Product Development. Source: http://www.ansys.com/Products/Workflow+Technology/ANSYS+Workbench+PlatformANSYS works on three principles; those are Penalty method, Lagrange method and augmented Lagrange method. These principles used in the process of contact analysis and non linear analysis. Source: http://www.cadfamily.comIn this project ANSYS 13.0 played a major role, all the analysis was done with the implementation of ansys. Mainly Modal ANSYS and Static Structural ANALYSIS was done in this Project. Modal and Stress Analysis was done on master rod and thermal analysis was done on piston.4.1 MODAL ANSYS:In this Modal ANSYS, only the deformation of the component was calculated with applying forces and boundary conditions. The deformation will be calculated at different natural frequencies and it was mentioned as different modes. Applying of the boundary conditions will give you the specified directional deformation along with the total deformation.4.2 Static Analysis

After the preprocessing, the solution has to be done. From solution phase, choose the new analysis as static. Then solve the current load step option. The solution will be done, the following table given the Von Mises stress at various loads.

IMPORTED GEOMETRY

MESH

FIXED SUPPORT

MODAL TREE

TD1

TD2

TD3

TD4

TD5

TD6

4.3 STRUCTURAL ANALYSIS FOR ALUMINUMAT 100:

FIXED SUPPORT

ROTATIONAL VELOCITY

EQUIVALENT STRESS

TOTAL DEFORMATION

AT 200:

ROTATIONAL VELOCITY

EQUIVALENT STRESS

TOTAL DEFORMATIONAT 300

ROTATIONAL VELOCITY

EQUIVALENT STRESS

TOTAL DEFORMATION

AT 400

ROTATIONAL VELOCITY

EQUISTRESS

TOTAL DEFORMATION

AT 500

ROTATIONAL VELOCITY

EQUISTRESS

TOTAL DEFORMATION

STRUCTURAL STEEL:AT 100

EQUIVALENT STRESS

TOTAL DEFORMATIONAT 200

EQUIVALENT STRESS

TOTAL DEFORMATION

AT 300

EQUIVALENT STRESS

TOTAL DEFORMATION

AT 400

EQUIVALENT STRESS

TOTAL DEFORMATION

AT 500

EQUIVALENT STRESS

TOTAL DEFORMATION

4.4 RESULTS:MODAL ANALYSIS:S.NoTOTAL DEFORMATIONEQUIVALENT STRESS

17.04873609.7

210.3344346.2

310.3384346.7

47.18344668.9

511.195243.8

611.1895244

STRUCTURAL ANALYSIS: ALUMINUMS. NOLOADEQUIVALENT STRESSTOTAL DEFORMATION

11000.814450.00055919

22003.25780.0022368

33007.33010.0050327

440013.0310.008947

550020.3610.01398

STRUCTURAL ANALYSIS: STRUCTURAL STEELS. NOLOADEQUIVALENT STRESSTOTAL DEFORMATION

11002.25720.00055696

22009.02880.0022279

330020.3150.050127

440030.1150.0089114

550056.430.013924

CHAPTER 5CONCLUSION

1. Bending and compressive stresses were obtained theoretically & by using Ansys software for both ceramic& steel.2. From the tables, it is observed that bending and compressive stresses of ceramics are less than that of the steel.3. Weight reduction is a very important criterion in the helical gears.4. Hence aluminum material is preferred.

FUTURE SCOPE OF THE WORK 5. In the present investigation of static analysis, a high speed helical gear, is analyzed by FEM package ANSYS.6. As a future work, modal analysis and harmonic analysis of the gear can be performed to find out the mode shapes and natural frequencies of the gear.

REFERENCES

7. Thirupathi R. Chandrupatla & Ashok D.Belegundu ., INTRODUCTION TO FINITE ELEEMENT IN ENGINEERING, Pearson ,20038. Joseph Shigley, Charles Mischike ., MECHANICAL ENGINEERING DESIGN, TMH,20039. Maithra ., HANDBOOK OF GEAR DESIGN,200010. V.B.BHANDARI., DESIGN OF MACHINE ELEMENTS,TMH,200311. R.S.KHURMI ., MACHINE DESIGN, SCHAND,200512. DARLE W DUDLEY.,HAND BOOK OF PRACTICAL GEAR DESIGN,195413. ALEC STROKES., HIGH PERFORMANCE GEAR DESIGN,197014. www.matweb.com