The cam angle, the rise and fall, and the output motion of a disk cam with a reciprocating roller follower are given in Table P6.34. The diameter of the base circle of the cam is 75 mm, the diameter of the roller follower is 25 mm, and the follower eccentricity is 20 mm.

Table P6.34 Displacement information for disk cam and the reciprocating roller follower.

Cam Angle

Θ (degrees)

Lift L

(mm) Output motion y 0◦−60◦ 0 Dwell 60◦−180◦ 90 Full-rise cycloidal motion 180◦−240◦ 0 Dwell 240◦−360◦ 90 Full-return cycloidal motion Sketch the displacement diagram and its first two derivatives. At the cam angle Θ = 300◦, determine:

(a) the first- and second-order kinematic coefficients of the displacement diagram;

(b) the coordinates of the point of contact between the cam and the roller follower. Express your answers in the moving Cartesian coordinate system attached to the cam;

(c) the radius of the curvature of the cam surface; and

(d) the pressure angle of the cam.