The movement structure of a mechanical alarm clock includes two major systems: running time and alarm time.

① Travel time system. The primary system uses spring as the energy storage element, which generally stores energy for 1 day and 8 days. Alarm clocks that store energy for one day often adopt a structure without a spring box; The gears in the transmission system often use modified cycloidal pin meshing, with the small gears (pinions) made of cylindrical steel wire as the teeth; The escapement mechanism often adopts a pin type (commonly known as a coarse horse), which uses cylindrical steel wire as the fork pin, which has lower cost but also lower travel accuracy; The vibration system adopts a cycloidal hairspring type. Due to the high rotational speed of the pendulum, with a vibration period of 0.6 seconds, the pendulum shaft and the pendulum bearing rotate and rub back and forth 288000 times in 24 hours. Therefore, the selection of the structure and material of the pendulum support directly affects the lifespan of the clock. To improve the lifespan, the pendulum shaft and bearing of alarm clocks produced in China adopt a cylindrical mating structure. The top of the pendulum shaft is a spherical surface with a larger curvature radius, and the pendulum bearing is made of cheap glass drills. This type of surface or line contact extends the maintenance cycle and travel time of the clock exponentially. The hairspring is often made of phosphorus bronze or nickel based alloy.

② Alarm system: usually includes four parts: alarm mechanism, transmission mechanism, escape mechanism, and alarm mechanism. The alarm timing mechanism can also share a spring with the travel timing mechanism, but a limited position mechanism is added to the spring axis to control the length of the spring released during the alarm; The timing escapement mechanism does not have high requirements for the isochronity of the vibration period, so escapement governors without inherent vibration periods are often used instead of the pendulum and hairspring, and the hammer is installed on the fork shaft. The mechanical music alarm clock also comes with a scroll wheel with a dial driven by an alarm spring. The dial is arranged according to the music score, and the sound spring is moved to play music.