Application of compliant mechanisms in mechanical watches is a cutting edge technique in the world of horology. Flexous Mechanisms BV is leading the charge with the development of the silicon escapement, a monolithic design capable of oscillating at 40 Hertz (10 times faster than
...
Application of compliant mechanisms in mechanical watches is a cutting edge technique in the world of horology. Flexous Mechanisms BV is leading the charge with the development of the silicon escapement, a monolithic design capable of oscillating at 40 Hertz (10 times faster than traditional escapements). Integration of this technology into a mechanical chronograph is a goal for Flexous, however silicon escapements are more susceptible than traditional escapements to disruption from both internal and external factors. A major internal factor to overcome is the drop in torque delivered to the escapement while the stopwatch of the chronograph is in use. This drop in torque results in significant accuracy loss and potential failure in chronographs featuring a silicon escapement. Addressing this phenomenon is critical for improving torque control and enabling the use of silicon escapements in mechanical chronographs. This thesis explores mechanical methods for constant torque delivery to the escapement, leading to the development of a compliant iris mechanism capable of modulating the effective diameter of a watch barrel to control torque output. Two diameter-torque relationship experiments were conducted: one with a large scale model and inserts for accessible testing, and a second at real scale with inserts designed for an actual watch barrel to confirm findings at large scale. Results showed that the large scale and real scale systems exhibited the same quadratic diameter-torque trends, though of opposite sign attributed to different working mechanisms in friction force creation between the mainsprings. The scaled-up model was further used to evaluate the effect that the number of flexures has on consistency of torque delivery. Flexure count and geometry were found to affect torque smoothness, suggesting a topic for future optimization. While scaled-up fabrication of the complaint iris was limited to 3D prints and adhesive, future designs may employ dual-side Deep Reactive Ion Etching (DRIE) on silicon wafers for monolithic construction. These findings contribute to the design of mechanically integrated torque management systems for chronographs, enabling more versatility in the application of silicon escapements.