Mechanisms

Linkage and Cam Kinematics

Kinematics of the common planar mechanisms. Four-bar linkage: Grashof class, the closed-form position of both assemblies, angular velocities and accelerations of the coupler and the output link, a coupler point with its path, velocity and acceleration, the transmission angle and its extremes, the limit positions of the output link with the swing angle and the time ratio, the mechanical advantage, the crank torque that holds an output torque and a force on the coupler point (virtual work), a table over the rotation and charts. Slider-crank with offset: position, velocity and acceleration of the slider and of the rod, the first-order (two-term) form beside the exact one, stroke, dead centres, time ratio, peak speed and acceleration, the inertia force of the reciprocating mass and the crank torque. Cam and follower: a program of rise, dwell and return segments with constant velocity, parabolic, simple harmonic, cycloidal, 3-4-5 and 4-5-6-7 polynomial, modified trapezoid and modified sine motion; displacement, velocity, acceleration and jerk per degree and per second with the peak factors of every segment; pressure angle and radius of curvature for a translating roller follower with offset or a flat-faced follower; the smallest base circle for a pressure-angle limit; pitch-curve and surface coordinates with CSV export. Geneva wheel: geometry, indexing and dwell times, peak speed and acceleration of the wheel.

1 worked example reproduced, listed on the tool page.

Other Mechanical Design sections

Shafts · Gears · Bearings · Springs · Fasteners and Power Screws · Pressure Vessels · Tolerances · Mass Properties · Vibration · Acoustics · Brakes, Clutches and Belts · Machining and Manufacturing · Lubrication and Wear