上海交通大学：《Design & Manufacturing II and Project》课程教学资源（讲义）Lecture 5 Bearings（1/2）

上海充通大学 Shanghai Jiao Tong University Mechanical Design and Manufacturing ll Transmission Support Bearings(轴承)

1 1 Mechanical Design and Manufacturing II Transmission Support Bearings（轴承）

上潘充通大学 Shanghai Jiao Tong University Lectures Power/Energy Conversion (Electrical Motors) Power/Energy Transmission (Gears, Belt Drives, Power Screws) Transmission Joints (Fasteners, Support Structural Connectors) (Bearings) Support (Frames Shafts Axles Spindles) Tools Stress Analysis, Failure Theories Dynamics,Statics,Etc.... 2

2 Lectures Power/Energy Conversion (Electrical Motors) Power/Energy Conversion (Electrical Motors) Power/Energy Transmission (Gears, Belt Drives, Power Screws) Transmission Transmission Support Support (Bearings) (Bearings) Joints (Fasteners, Connectors) Structural Support (Frames Shafts Axles Spindles) Tools Stress Analysis, Failure Theories Dynamics, Statics, Etc…

上潘充通大学 Shanghai Jiao Tong University Principles of Operation Rolling Friction (Rolling Contact Bearing滚动轴承) Roller/ball (滚子/球) Outer Ring(外圈) Lubrication (润滑剂) Inner Ring(内圈) Sliding Friction(Sleeve Bearing滑动轴承) Hydrodynamic lift is Sleeve(轴套) generated by fluid being dragged into gap by viscous shear Lubrication Circumferential pressure profile 3

3 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） Sliding Friction (Sleeve Bearing 滑动轴承) Sleeve（轴套） Lubrication Circumferential pressure profile Hydrodynamic lift is generated by fluid being dragged into gap by viscous shear

上淄克通大学 Shanghai Jiao Tong University 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 Carriage Rotary Encoder ☒ AC Brushless Motor Flexible Coupling Rearing Housing Ballscrew Ballnut Support Bearings

4 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

上潘充通大学 Shanghai Jiao Tong University Bearings Applications 大

5 Bearings Applications

图 上浒充通大学 Shanghai Jiao Tong University History

6 History

上浒充通大学 Shanghai Jiao Tong University Reconstruction of Old Bearing 840 44-45 11-16 110-115 700 +Di 7

7 Reconstruction of Old Bearing

上浒充通大学 Shanghai Jiao Tong University Development of the Bearing 3500B.C. 1794A.D. 官 1869 0 700B.C. 40A.D. CARB 1995 8

8 Development of the Bearing 700 B.C. 3500 B.C. 40 A.D. 1794 A.D. 1869 1995

上海充通大学 Shanghai Jiao Tong University Sliding or Rolling Bearings Sliding bearings: sliding friction u Rolling bearings: u rolling friction 9

9 Sliding or Rolling Bearings Sliding bearings: sliding friction µ Rolling bearings: rolling friction µ

上游充通大率 Shanghai Jiao Tong University Objectives of the Lecture Identify the types of rolling contact bearings,select the appropriate type for a given application. ■ Use the relationship between forces on bearings and the life expectancy for the bearings to determine critical bearing selection factors. Compute the equivalent load on a bearing corresponding to combinations of radial and axial loads applied to it. Specify suitable ball bearings for a given application. Understand certain practical considerations involved in the application of bearings. 10

10 Objectives of the Lecture  Identify the types of rolling contact bearings, select the appropriate type for a given application.  Use the relationship between forces on bearings and the life expectancy for the bearings to determine critical bearing selection factors.  Compute the equivalent load on a bearing corresponding to combinations of radial and axial loads applied to it.  Specify suitable ball bearings for a given application.  Understand certain practical considerations involved in the application of bearings