圈上海夫通大华 西+口 LECTURE 12-1 ME371/ME337 DESIGN AND MANUFACTURING Gears Introduction Covered: 漏 Ch9 in Design of Machinery SHAN 圈上泽夫通大学 Lectures Power/Energy Conversion (Electrical Motors) Power/Energy Transmission (Gears,Cam,Linkage, Belt Drives, Power Screws Transmission Joints (Fasteners, Support Connectors) (Bearings) Structural Support (Frames) Tools Statics,Dynamics, Stress Analysis,etc. 1
1 Gears Introduction LECTURE 12-I ME371/ME337 DESIGN AND MANUFACTURING Covered: Ch9 in Design of Machinery Lectures Power/Energy Conversion (Electrical Motors) Transmission Support (Bearings) Joints (Fasteners, Connectors) Structural Support (Frames) Tools Statics, Dynamics, Stress Analysis, etc. Power/Energy Transmission (Gears, Cam, Linkage, Belt Drives, Power Screws)
圆上清支大学 Outline Common Types of Gears Fundamental Law of Gearing Gear tooth nomenclature How to manufacture a gear? Interference and undercutting 圆上海文大学 Where can we find gears? 上方肉 2
2 Outline Common Types of Gears Fundamental Law of Gearing Gear tooth nomenclature How to manufacture a gear? Interference and undercutting Where can we find gears?
圈上海文通大华 Why Use Gears? 1.Reduce/lncrease speed 2.Increase torque 3.Move power from one point to another 4.Change direction of power 5.Split power Generally this functionality is accomplished by many gears mounted in a gear box! 圈上泽充大学 Common Types of Gears 3
3 1. Reduce/Increase speed 2. Increase torque 3. Move power from one point to another 4. Change direction of power 5. Split power Generally this functionality is accomplished by many gears mounted in a gear box! Why Use Gears? Common Types of Gears
圈上泽文通大华 Common Types of Gears 圈上泽夫道大学 Spur Gear(直齿轮) These gears have teeth parallel to the axis of rotation and are used to transmit motion and power from one shaft to another parallel shaft. low cost for transmitting motion and power between parallel shafts. 口 Low cost to manufacture. 4
4 Common Types of Gears Spur Gear（直齿轮） These gears have teeth parallel to the axis of rotation and are used to transmit motion and power from one shaft to another parallel shaft. low cost for transmitting motion and power between parallel shafts. Low cost to manufacture
圆上清支美大学 Helical Gears(斜齿轮) Helical gears are similar to spur gears but have teeth inclined to the axis of rotation. ▣ Helix angle can be a few degrees or as much as 450 ▣ Can perform essentially same function as spur gears, connecting parallel shafts for speed reduction/increase and torque increase/reduction. o 周 上海充廷大学 Helical Gears(斜齿轮) 口 Helix is either right or left-handed (左旋、右旋) ▣ Opposite-hand helical gears with the same helix angle mesh(啮合) with their axes parallel. Same-hand helical gears mesh with their (non-intersecting)axes skewed or crossed >Have theoretical point contact between the teeth. >Limits their load-carrying capacity compared to parallel-axis helicals. which mate with a roll-slide motion (a)Opposite-hand pair (b)Same-hand pair similar to spur gears,but engage meshed on parallel meshed on crossed their teeth in a smooth,wiping axes axes action across the face width 5
5 Helical gears are similar to spur gears but have teeth inclined to the axis of rotation. Helical Gears（斜齿轮） Helix angle can be a few degrees or as much as 450 Can perform essentially same function as spur gears, connecting parallel shafts for speed reduction/increase and torque increase/reduction. Helix is either right or left-handed (左旋、右旋) Opposite-hand helical gears with the same helix angle mesh (啮合) with their axes parallel. Same-hand helical gears mesh with their (non-intersecting) axes skewed or crossed Have theoretical point contact between the teeth. Limits their load-carrying capacity compared to parallel-axis helicals, which mate with a roll-slide motion similar to spur gears, but engage their teeth in a smooth, wiping action across the face width Helical Gears（斜齿轮）