图 上酒短大峰 色h人A口 LECTURE 15 ME371/ME337 DESIGN AND MANUFACTURING Bearings Covered in Cha11 Mechanical Engineering Design SHAN 国上清通大学 Lectures Power/Energy Conversion (Electrical Motors) Power/Energy Transmission (Gears,Cam,Linkage Belt Drives, Power Screws) Joints Transmission (Fasteners, Support Connectors) (Bearings) Structural Support (Frames) Tools Statics,Dynamics, Stress Analysis,etc. 1
1 Bearings LECTURE 15 ME371/ME337 DESIGN AND MANUFACTURING Covered in Cha11 Mechanical Engineering Design 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)
上酒短大峰 Outline ▣Introduction ▣Rolling bearing Types ▣Bearing Life ▣Bearing Design 国 上酒文通大学 Why Bearings Bearing is defined by Webster's to be"a support or supporting part'” In machine design,a bearing is a component that allows for relative motion between two bodies ▣Bearings are for:: reduce friction >carry load >guide of moving parts Rotary Encoder ☒I AC Brushless Motor Flexible Coupling Rearing Housing Ballscrew Ballnut Support Bearings 2
2 Introduction Rolling bearing Types Bearing Life Bearing Design Outline Why Bearings Bearing is defined by Webster’s to be “a support or supporting part” In machine design, a bearing is a component that allows for relative motion between two bodies Bearings are for: reduce friction carry load guide of moving parts
图 上海久通大学 Bearings Applications Bearing Bearing 图 上泽充道大学 Principles of Operation 口Rolling Friction(Rolling Contact Bearing滚动轴承) Roller/ball (滚子球) Outer Ring(外圆) Lubrication (润滑剂) ~Inner Ring(内圜) 3
3 Bearings Applications Bearing Bearing Principles of Operation Rolling Friction (Rolling Contact Bearing 滚动轴承) Roller/ball （滚子/球） Lubrication （润滑剂） Outer Ring（外圈） Inner Ring（内圈）
公 上海久通大学 Principles of Operation 口Sliding Friction(Sleeve Bearing滑动轴承) Hydrodynamic lift is Sleeve(轴承座) generated by fluid being dragged into gap by viscous shear Lubrication Circumferential pressure profile Bushing(轴瓦) 圈上充通大学 History 4
4 Principles of Operation Sliding Friction (Sleeve Bearing 滑动轴承) Sleeve（轴承座） Lubrication Circumferential pressure profile Hydrodynamic lift is generated by fluid being dragged into gap by viscous shear Bushing（轴瓦） History
图 上海久通大学 Development of the Bearing 3500B.C. 1794A.D. 1869 700B.C 40A.D. CARB 1995 图上涤夫廷大学 Outline ▣Introduction 口Rolling Bearing Types ▣Bearing Life ▣Bearing Design 5
5 Development of the Bearing 700 B.C. 3500 B.C. 40 A.D. 1794 A.D. 1869 1995 Introduction Rolling Bearing Types Bearing Life Bearing Design Outline
图 上海通大学 Types of Loads 口 Radial loads(径向载荷：act toward the center of the bearing along a radius,created by spur gears(直齿轮)，V-belt drives, and chain drives. ▣ Thrust loads(轴向载荷)：act parallel to the axis of the shaft. The axial components of the forces on helical gears(斜齿轮 ),bevel gears(圆锥齿轮)，or supporting shafts with vertical axes. ▣Misalignment(轴线偏斜)：refers to the angular deviation of the axis of the shaft at the bearing from the true axis of the bearing itself. 图 上泽充道大学 Types of Antifriction Bearings 口 Ball Bearings Width→ Corner radius Outer ring 外圆 Shoulders Inner 内 Corner radius 罢 農 Inner ring ball race 染 Separator 保持架 (retainer) 端面 -Outer ring 外圈 Face ball race 6
6 Radial loads(径向载荷): act toward the center of the bearing along a radius, created by spur gears(直齿轮), V-belt drives, and chain drives. Thrust loads(轴向载荷): act parallel to the axis of the shaft. The axial components of the forces on helical gears(斜齿轮 ), bevel gears(圆锥齿轮) , or supporting shafts with vertical axes. Misalignment(轴线偏斜): refers to the angular deviation of the axis of the shaft at the bearing from the true axis of the bearing itself. Types of Loads R A Types of Antifriction Bearings Ball Bearings外径 内径 端面 外圈 滚道 内圈 滚道 保持架 内圈 外圈
图 上海文通大学 Bearings Components Seal Rolling elements Inner ring Outer ring Cage Seal 图上涤夫廷大学 Types of Antifriction Bearings Bearing width Tapered Roller Bearings Cun back face radius r Cup back face Cup front face ▣Components: 保特架Cae -Cone back face rib >Cone =Inner ring C Cone back face >Cup -Cone length 8- =Outer ring >Tapered rollers >Cage Space retainer Cone front- face radius Cone front face- Cone Standout F 7
7 Bearings Components Seal Rolling elements Inner ring Outer ring Cage Seal Types of Antifriction Bearings Tapered Roller Bearings 保持架 Components: Cone = Inner ring Cup = Outer ring Tapered rollers Cage =Space retainer
图 上海文通大学 Types of Antifriction Bearings 圆上泽支大学 Rolling Elements Ball Spherical Asymmetrical Cylindrical Taper Needle 8
8 Types of Antifriction Bearings Rolling Elements Cylindrical Needle Taper Ball Spherical Asymmetrical
图 上海通大学 Types of Roller Bearings A)Cylindrical(圆柱滚子) B)Spherical(球面滚子) C)Tapered Roller,Thrust (推力圆锥滚子) D)Needle(滚针) E)Tapered Roller (h) (圆锥滚子) F)Steep-angle Tapered Roller(大锥角圆锥滚子) (f) 国上清通大学 Types of Ball Bearings ( id) Filling notch Shielded Sealed 深沟球 有装球缺口 Λ角接触 带防尘盖 带密封圈 Ig 1 } External Double row Self-aligning Thrust Self-aligning thrust 带球面外衬圈 双列球 双列自动调心 单向推力 单向推力带 球面座圈 9
9 Types of Roller Bearings A) Cylindrical（圆柱滚子） B) Spherical（球面滚子） C) Tapered Roller, Thrust （推力圆锥滚子） D) Needle（滚针） E) Tapered Roller (圆锥滚子) F) Steep-angle Tapered Roller（大锥角圆锥滚子） Types of Ball Bearings 深沟球 有装球缺口 角接触 带防尘盖 带密封圈 带球面外衬圈 双列球 双列自动调心 单向推力 单向推力带 球面座圈
图 上海久通大学 Concept of Contact Angle n A (a) (b) (c) 国 上酒充通大学 Types of Ball Bearings 口Single Row Deep Groove BB(单列深沟球轴承) >Spherical balls roll in deep groove in both races >Space maintained by separators(retainers/cages) >Ball radius smaller than groove radius >Mostly take radial loads,some thrust load(轴向载荷) >Theoretical point contact(actually a small circular area),so high local contact stress >Some permissible misalignment 深沟球轴承 10
10 Concept of Contact Angle Types of Ball Bearings Single Row Deep Groove BB（单列深沟球轴承） Spherical balls roll in deep groove in both races Space maintained by separators (retainers/cages) Ball radius smaller than groove radius Mostly take radial loads, some thrust load(轴向载荷) Theoretical point contact (actually a small circular area), so high local contact stress Some permissible misalignment