清华大学：《机械原理》课程PPT教学课件（双语版）Chap 4 Cam Mechanism

Chap 4 Cam Mechanism 4.1 Introduction 4.2 Classification of cam mechanisms 4,3 Cam Nomenclature 4. 4 Motion events 4.5 Graphical Synthesis of Cam Contour 4.6 Analysis Synthesis of Cam Contour 4.7 Considerations of cam mechanisms Synthesis

Chap.4 Cam Mechanism 4.1 Introduction 4.2 Classification of Cam Mechanisms 4.3 Cam Nomenclature 4.4 Motion events 4.5 Graphical Synthesis of Cam Contour 4.6 Analysis Synthesis of Cam Contour 4.7 Considerations of Cam Mechanisms Synthesis

4 1 Introduction ■1 What is a can? 2 Cam mechanisms a 3 Application

4.1 Introduction ◼ 1 What is a Cam? ◼ 2 Cam Mechanisms ◼ 3 Application

i What is a cam? Simple Cam experiment encil Table Book

1 What is a Cam? Simple Cam experiment

Cam and follower aa cam may be defined as a machine element having a curved outline or a curved groove, which by its oscillation or rotation motion, gives a predetermined specified motion to another element called the follower

Cam and Follower ◼ A cam may be defined as a machine element having a curved outline or a curved groove, which, by its oscillation or rotation motion, gives a predetermined specified motion to another element called the follower

张

2 Cam Mechanisms a cam mechanism usually consists of two moving elements the cam and the follower mounted on a fixed frame Cam mechanism is a mechanism which is conveniently used to transform one of the simple motions, such as rotation into any other motions, such as translation oscillation

2 Cam Mechanisms ◼ A cam mechanism usually consists of two moving elements, the cam and the follower, mounted on a fixed frame. ◼ Cam Mechanism is a mechanism which is conveniently used to transform one of the simple motions, such as rotation, into any other motions, such as translation, oscillation

3 Application The cam has a very important function in the operation of many classes of machines especially those of the automatic type such as printing presses, shoe machinery, textile machinery, gear-cutting machines and screw machines. In any class of machinery in which automatic control and accurate timing are paramount the cam is an indispensable part of mechanism The possible applications of cams are unlimited and their shapes occur in great variety. Example(video)

3 Application ◼ The cam has a very important function in the operation of many classes of machines, especially those of the automatic type, such as printing presses, shoe machinery, textile machinery, gear-cutting machines, and screw machines. In any class of machinery in which automatic control and accurate timing are paramount, the cam is an indispensable part of mechanism. The possible applications of cams are unlimited, and their shapes occur in great variety. ◼ Example (video)

张

42 Classification of cam mechanisms a By Modes of Input/Output Motion By the configuration of the follower ■ By shape of the can a By force and form closure a By arrangement of the follower a By type of motion constrain a By type of motion program

4.2 Classification of Cam Mechanisms ◼ By Modes of Input/Output Motion ◼ By the configuration of the follower ◼ By shape of the cam ◼ By Force and form closure ◼ By arrangement of the follower ◼ By type of motion constrain ◼ By type of motion program

Modes of Input/Output Motion 1. Rotating cam-translating follower 2. Rotating cam-Rotating follower The follower arm swings or( Ar/(A oscillates in a circular arc with respect to the follower pivot 3. Translating cam-translating follower A/(分

Modes of Input/Output Motion 1. Rotating cam-translating follower 2. Rotating cam-Rotating follower The follower arm swings or oscillates in a circular arc with respect to the follower pivot. 3. Translating cam-translating follower