Matching Cam Parts to Descriptions

Understanding the different parts of a cam mechanism is fundamental in mechanical engineering. This question asks us to match common cam terminology with their precise definitions or functions.

Let's look at each term in Column I and find its corresponding description in Column II:

Let's explain why each match is correct:

• 1. Pitch curve: The pitch curve is defined as the path traced by the pitch point (a reference point on the follower, e.g., the center of the roller) relative to the cam when the cam is stationary and the follower rotates around the cam axis. This matches description B.
• 2. Pitch circle: The pitch circle is a circle drawn from the cam center through the pitch point. The pitch point's location on the pitch circle influences the pressure angle, which is a critical factor in cam design, especially for determining the minimum cam size without excessive wear or jamming. Therefore, it is E.
• 3. Working curve: Also known as the cam profile, this is the actual physical contour or surface of the cam that makes contact with the follower. This directly corresponds to description D.
• 4. Prime circle: The prime circle is the smallest circle that can be drawn from the cam center tangential to the pitch curve. This aligns with description C.
• 5. Working circle: The working circle, often called the base circle, is the smallest circle drawn from the cam center tangential to the actual working surface (cam profile) of the cam. This matches description A.

Based on these definitions, the correct matching is:

• 1 - B
• 2 - E
• 3 - D
• 4 - C
• 5 - A

This corresponds to the option 1 - B, 2 - E, 3 - D, 4 - C, 5 - A.