Geneva Mechanism

grabcad

The Geneva mechanism is designed to provide accurate and controlled intermittent motion, typically converting continuous rotational motion into intermittent rotational motion. It consists of a drive wheel, often referred to as the "star wheel," and a driven wheel, known as the "geneva wheel" or "maltese cross."The star wheel typically has four or more equally spaced radial slots or teeth. The geneva wheel features a corresponding number of radial slots or notches, often rectangular in shape, equally spaced along its circumference. The slots in the star wheel and the geneva wheel are offset by half the distance between them.The mechanism operates as follows: When the drive wheel rotates, one of its slots engages with a pin or driver located on the geneva wheel. This connection causes the geneva wheel to rotate by a fixed angle, typically 90 degrees, resulting in intermittent motion. The motion stops when the slot on the star wheel releases the pin on the geneva wheel, and another slot comes into position to engage the pin again.The Geneva mechanism is widely used in various applications requiring intermittent motion, such as indexing tables, film projectors, and rotary packaging machines. Its design offers precise control over positioning and motion, making it suitable for applications where accurate alignment and synchronization are necessary.The mechanism's design considerations include the number of slots on the star wheel and the geneva wheel, the shape and dimensions of the slots, and the overall dimensions and materials used for construction. These factors are determined based on the specific application requirements, such as the desired intermittent motion angle, torque requirements, and load capacity.