1. 1 Pertemuan 23 CAM Matakuliah: D0164 / PERANCANGAN ELEMEN MESIN Tahun: 2006

2. 2 LEARNING OUTCOMES Pada akhir pertemuan ini, diharapkan mahasiswa akan dapat menggunakan metode yang tepat untuk merancang ulir gerak

3. 3 OUTLINE MATERI Definisi Cam Cam and Follower Tipe Cam Cam Eksentrik

4. 4 CAMS and FOLLOWERS V. Ryan © 2002 Have you ever looked closely at a simple mechanical toy ? If you have the opportunity to study one closely you will see that it is made up of mechanisms, usually including CAMS. Can you name any mechanical devices that use cams as part of its movement? A CAM changes the input motion, which is usually rotary motion (a rotating motion), to a reciprocating motion of the follower. They are found in many machines and toys CAMS AND FOLLOWERS

5. 5 CAM AND FOLLOWER A CAM changes the input motion, which is usually rotary motion (a rotating motion), to a reciprocating motion of the follower. They are found in many machines and toys A CAM has two parts, the FOLLOWER and the CAM PROFILE. Diagrams one to six show a rotating cam pushing a follower up and then allowing it to slowly fall back down. There are different types of follower but they all slide or roll on the edge of the cam. Various types are shown below.

6. 6 TYPICAL USE OF CAM Below is a typical use of a cam. A simple toy based on a cartoon character (Ed the Handyman) is controlled by a cam and follower. As the cam rotates in an anticlockwise direction, the follower falls and so does the arm of the toy. As the cam continues to rotate the arm begins to rise as seen in diagram 4. The cam shown is a pear shaped cam (named after its shape).

7. 7 ECCENTRIC CAM PRACTICAL EXAMPLE - ECCENTRIC CAM V. Ryan © 2006 An eccentric cam is a disc with its centre of rotation positioned ‘off centre’. This means as the cam rotates the flat follower rises and falls at a constant rate. This type of cam is the easiest to make and yet it is one of the most useful. The diagrams (1 to 7) seen below show the cam rotating in an anticlockwise direction. As it rotates it pushes the flat follower upwards and then allows it to drop downwards. The movement is smooth and at a constant speed.

8. 8 CAM - EXAMPLES CAM - EXAMPLES AND QUESTIONS POSSIBLE ANSWERS V. Ryan © 2002-2006 As you have seen in the previous examples, cams can be used to change rotary motion into linear motion. Examine the cams on this page and explain how the various cam profiles control the movement of the followers. 1. What is the name of this cam profile? Explain how it controls the movement of the follower. PEAR SHAPED CAM. As the cam rotates, the follower stays level for ½ a revolution, then it rises and falls following the cam profile.

9. 9 CAM - EXERCISE 3. What is the name of this cam profile? Explain how it controls the movement of the follower. ECCENTRIC CAM. The follower moves up and down in a vertical direction. Its movement is very smooth. 4. What is the name of this cam profile? Explain how it controls the movement of the follower. SWASH CAM. This cam is like a ‘spinning top’. As the angled disc rotates the follower rises and falls, following the movement of the disc.

10. 10 CAM - EXERCISE 5. What is the name of this cam profile? Explain how it controls the movement of the follower. BOX CAM. As the disc (cam) rotates, the follower - follows a groove cut into the disc. 6. What is the name of this cam profile? Explain how it controls the movement of the follower. FLAT PLATE CAM. The follower rises and falls according the movement of the cam profile, as it travels from left to right.