2.1Basic Concepts of Mechanisms(4) Lower pairs(低副) joints with surface contact Prismatic joint Revolute joint Cylindric joint Spherical joint Helical joint Planar joint ype joint R joint C joint S ioint f joint DOF
Lower pairs（低副）:joints with surface contact Prismatic joint Revolute joint Cylindric joint Spherical joint Helical joint Planar joint Type P joint R joint C joint S joint H joint F joint DOF 1 1 2 3 1 3 2.1Basic Concepts of Mechanisms(4)
2.1 Basic Concepts of mechanisms( (5) Higher pairs(高副): joints with point or line contact DOF 5
Higher pairs（高副）:joints with point or line contact 2.1Basic Concepts of Mechanisms(5) DOF 5 2
2.1 Basic Concepts of Mechanisms(6) Examples of higher pairs 烈Z Form -closed Force-closed closed by its geometry need external force
Examples of higher pairs Force –closed need external force Form –closed closed by its geometry 2.1Basic Concepts of Mechanisms(6)
2.1 Basic Concepts of Mechanisms(7) iagram of Kinematic pairs(运动副简图) Prismatic joint Revolute joint Cylindric joint Spherical joint Helical joint Diagram Joint R joint Joint S ioint H ioint DOF
Diagram of Kinematic pairs（运动副简图） Prismatic joint Revolute joint Cylindric joint Spherical joint Helical joint Type P joint R joint C joint S joint H joint DOF 1 1 2 3 1 Diagram 2.1Basic Concepts of Mechanisms(7)
2.1 Basic Concepts of Mechanisms(8) Machine element(机械零件): minimum unit during manufacturing This link has several machine elements B Inar link
Machine Element（机械零件）: minimum unit during manufacturing 2.1Basic Concepts of Mechanisms(8) Binary link This link has several machine elements