Capital University of Science and TechnologyIslamabad CAD-CAM PROJECT REPORT Manual Gearbox Design Using PTC Creo and Analysis Using Ansys By: Rana M Jahanzaib ME-123079 Usama Bilal ME-123097 Khalid Munir Hashmi ME-123078 Submitted To: Dated: Sir Abdul Wahab Jan 08,2016 Copyright 2016 by CUST Student All rights reserved. Reproduction in whole or in part in any form requires the prior written permission of Rana M Jahanzaib, Usama Bilal, Khalid Munir hashmi or designated representative. A Project Report submitted to the DEPARTMENT OF MECHANICAL ENGINEERING in partial fulfillment of the requirements for the Lab project of CAD/CAM Faculty of Engineering Capital University of Science and Technology Islamabad Jan 08, 2016 connected to a stick shift. manual transmissions are still produced and are seen commonly in sports cars. and analyze an efficient four speed manual transmission. using concepts and ideas researched beforehand about transmissions. moves between gears to select different gear combinations. turns at the desired speed. and at the end the designed model will be analyzed on ansys for the total deformation of gears. The design will be followed by the calculations of gear ratios and gear specifications. The lay-shaft has many gears which mesh with the gears on the outgoing shaft. Depending on which gear is meshed with the shifting gear. Design Goal: . Although less common. Applying this transmission towards general automotive use will make the gearing lean more towards speed rather than torque. Manual Transmissions have been around since the invention of the car and were the most common transmission until the introduction of the automatic transmission in 1938. Gear ratios will be calculated to determine the most efficient transmission. the output shaft. The gear on the incoming shaft is connected to the lay-shaft. Efficiency will be based on speed and torque. The transmission will be designed to optimize efficiency in terms of speed and power (torque). A manual transmission is a transmission commonly used in motor vehicle applications. A shifting gear. The transmission has an ingoing shaft connected directly to the motor. equivalent stresses on the shaft and the elastic strain on the shaft.Problem Overview: The objective of this project is to design. which is connected to the differentiable. The CAD program Creo will then be used to make a computer model of the gearbox. since a large amount of low-end torque is not necessary for automobiles. This means that the gearing will be created to favor higher gear ratios and thus sacrifice power and torque for general speed and more efficient use of the engine’s RPM. and fourth gear will serve as an overdrive with an approximate 0. Gear ratios in first gear will start around 3:1 (Engine : Drive shaft).8:1 ratio. A four speed transmission has been decided on that will be used for general automobile purposes. 1:1 in third gear.The purpose of designing and creating a two or four speed transmission is to find the most efficient way to optimize power and speed using the input of the transmission. . This will make both third and fourth gear very efficient in converting the engine’s RPM’s into speed at the drive shaft. around 2:1 in second gear. It consists of its own set of gear ratios that the gears have on each shaft.Top View DESIGN SPECIFICATIONS: Motor: 5 hp.8:1 . They have straight teeth. Spur gears are the most common type of gears. with 1800 rpm Spur Gear: The simplest mean of transferring rotary motion from one shaft to another shaft is by using a gear train. and are mounted on parallel shafts. In our design of the gear box the gear ratio was: Gear ratio in first gear: 3:1 (engine: drive shaft) Gear ratio in second gear: 2:1 Gear ratio in third gear: 1:1 Gear ratio in fourth(overdrive gear): 0. 5" .Pitch Diameter (dp) = N Pd = 48/32 = 1.1875" .125" * cos(14.5) = 1.Outside Diameter (Do) = Pd + 2*a = 1.03125" 1.5625" .0362" Pd .5" .Dedendum (b) = 1 Pd = 1/32 = 0.157 = 0.125" .03125" 1.5" * cos(14.2*0.125" + 2*0.Gear Tooth Spacing (GT) = 360 N = 360/48 = 7.5 Diametral pitch (Pd): 32 Light Blue (48 teeth): .03125" = 1.Root Diameter (DR) = Pd .157 = 0.Base Circle Diameter (db) = dp * cos(ɸ) = 1.0362" = 1.2*d = 1.452" .03125" = 1.Base Circle Diameter (db) = dp * cos(ɸ) = 1.Pitch Diameter (dp) = N Pd = 40/32 = 1.5) = 1.5" + 2*0.0891" .Outside Diameter (Do) = Pd + 2*a = 1.0362" Pd .Dedendum (b) = 1 Pd = 1/32 = 0.Addendum (a) = .Engine RPM: ω2 = 1800 rpm Pressure Angle (ɸ): 14.5 degrees Purple: (40 teeth) .Addendum (a) = .4276" . 9681" .03125" = 1.125" .157 = 0..Pitch Diameter (dp) = N Pd = 40/32 = 0.0362" = 0.Dedendum (b) = 1 Pd = 1/32 = 0.Base Circle Diameter (db) = dp * cos(ɸ) = 0.2*b = 0.157 = 0.Outside Diameter (Do) = Pd + 2*a = 1" + 2*0.5) = 0.5" * cos(14.Gear Tooth Spacing (GT) = 360 N = 360/40 = 9 degrees Green: (16 teeth) .5" .03125" 1.Pitch Diameter (dp) = N Pd = 40/32 = 1" .0362" Pd .03125" 1.Gear Tooth Spacing (GT) = 360 N = 360/16 = 22.2*b = 1.Dedendum (b) = 1 Pd = 1/32 = 0.0362" = 1.4840" .Root Diameter (DR) = dp .4276" .5) = .5" + 2*0.0362" Pd .5" .Outside Diameter (Do) = Pd + 2*a = 0.Addendum (a) = .5625" .Root Diameter (DR) = dp .0526" .5 degrees Red: (32 teeth) .03125" = 0.Base Circle Diameter (db) = dp * cos(ɸ) = 1" * cos(14.2*0.0625" .Addendum (a) = .2*0. 03125" = 0.Outside Diameter (Do) = Pd + 2*a = 0. a rectangular frame and a shaft.03125" 1.Addendum (a) = .7261" .25 degrees Dark Blue: (24 teeth) . select type “Part”.Gear Tooth Spacing (GT) = 360 N = 360/24 = 15 degrees Modeling of our Project: It involves five involute profile spur gears.75" + 2*0.0362" = 0.Root Diameter (DR) = dp . Involute Spur Gears: To make gears.2*0.0362" = 0..0362" Pd .75" . all the gears have same following steps: Steps: Open New file.75" .8125" .157 = 0. check “use default template” and click “ok” .6776" .5) = 0.Base Circle Diameter (db) = dp * cos(ɸ) = 0.Pitch Diameter (dp) = N Pd = 40/32 = 0.2*0.75" * cos(14.Dedendum (b) = 1 Pd = 1/32 = 0.Root Diameter (DR) = dp .9276" . name the file “spur_gear”.2*b = 1" .2*b = 0..Gear Tooth Spacing (GT) = 360 N = 360/32 = 11. rd (root circle diameter) and bd (base circle diameter) and click ok of sketch Go to “Model” bar. click datum points and make points on origin and on pitch circle where involute curve is touching the circle and join them with DatumCurveCurve through points. It will create the involute curve at angle k to the original curve. On “Model” bar. . Click Copy then Paste SpecialApply move/rotate transformations to copies then click ok then click rotate then select edge to z-axis and set angle to be 360/2xno. click DatumCurvesCurve from equation Add the Equations o r=bd/2 o ang=t*90 o s=(3. of teeth(N) = k and click ok. od (outer diameter).1416*r*t)/2 o xc=r*cos(ang) o yc=r*sin(ang) o x=xc+(s*sin(ang)) o y=yc-(s*cos(ang)) o z=0 Click ok and select your reference to Default Coordinate System that will make the involute curve and click ok. Sketch four circles and set their diameter values to be d (pitch circle diameter). Make datum Point on the new curve on pitch circle where involute curve is touching the pitch circle and join it with origin through DatumCurveCurve through points. Create axis alongside with z-axis on origin and create plane choose that new axis and the curve through points of second involute curve. select mirror then select our new made plane and click ok Extrude your pitch circle up to your desired thickness Select Sketch then select front plane then select project and select the curves which make the gear teeth and delete all other . Click involute curve. unnecessary segments then click ok then extrude it to required thickness Click Pattern and switch the first option to axis and choose z-axis then put no. of teeth in next box and select angle to be 360˚and click ok it will make the required teeth on your gear . 452" od=1.5" bd=1.5˚ .5625" rd=1. Gear 1: N= 48 d=1.4276" tooth angle = 7. Make a hole in a center of gear for the shaft. Gear 2: N= 40 d=1.0526" tooth angle = 9˚ .125" bd=1.1875" rd=1.0891" od=1. Gear 3: N= 16 d=0.4276" tooth angle = 22.5625" rd=0.5˚ .5" bd=0.4840" od=0. 25˚ .Gear 4: N= 32 d=1" bd=0.9681" od=1.9276" tooth angle = 11.0625" rd=0. 8125" rd=0.6776" tooth angle = 15˚ .Gear 5: N= 24 d=0.75" bd=0.7261" od=0. Make three circle on it. first one will be on origin. .19".Rectangular Frame: Steps: Sketch a rectangle on Front Plane having Area = 4"x3. Second one is on left of first and have center to center distance of 0.8".95" Diameter of Each circle is 0. Extrude it to 0.19".97" Second one is on right of first and have center to center distance of 0. Shaft: Steps: Sketch a circle of diameter 0. Extrude it to the length of 3.19" on front plane. Assembly: .785". The procedure is as follow: We defined the walls of the gear box as a fixed support . equivalent stress on shaft and the elastic strain on the shaft. we applied static structural analysis on our model on ansys for the total deformation of gear. we assembled them in a single file as shown: ANALYSIS ON ANSYS At the end.After generating all the parts of gearbox separately. Then we applied the pressure on gear And analyzed the gears for the total deformation . Applied equivalent (von-Mises) stress analysis on the shaft And then the Equivalent elastic strain analysis of the shaft . CONCLUSION In conclusion. PTC Creo Parametric provides a significant level of capability to support engineers/designers to design and document frameworks and deliver productivity boost over using standard modeling techniques. In this project we applied the knowledge and skills we learned in this course and made improvement by the practical implementation of our intuitions. we can compare the analytical solution with the analyzed values to strengthen our results and findings. . PTC Creo provides a patient platform to design a model and using ansys we can analyze the model. In this way we can reduce the production cost by analyzing model before production.