The clock movement structure of mechanical alarm clock includes the travel time system and the alarm system.
For the travel time system, its prime mover is to spring as an energy storage element, of which the stored energy generally is 1 day and the 8 days. The alarm clock of 1 day’s energy storage is often used with clockwork spring box structure; gear in power transmission often uses the pin shaped gear of modified cycloid, of which the small gear (two wheels) is with cylindrical steel for gear tooth; escapement uses pin type (commonly known as coarse MA), with its cylindrical steel wire as a fork pin. The cost is lower, but the accuracy of the clock is low. The vibration system is adopted with balance wheel hairspring. Because the wheel speed is higher, the vibration period is 0.6 seconds, balance wheel and swings bearing in 24 hours are in reciprocating friction up to 288000 times, so choosing on the pendulum support structure and selection of materials directly affects the service life of the clock. In order to improve the service life, the clock pendulum swing axle and bearing produced by China is used with cylindrical structure. The top of pendulum shaft is a larger radius of curvature of the sphere, and then spherical pendulum bearing is with cheap glass drilling. The surface contact or line contact twice extended Clock Repair Cycle and walking life. Hairspring is often used in phosphor bronze or nickel base alloy.
The alarm system includes usually driving mechanism, driving mechanism, escapement and the alarm mechanism with 4 parts. The alarm driving mechanism can also be associated with walking motive mechanism sharing clockwork, but in the spring shaft it is added to control the spacing mechanism, and release spring length. The request for alarm escapement mechanism on the vibration cycle isochronous is not high, it is often used the escapement speed regulator of non-natural vibration period without balance and balance spring, and the hammer is mounted on the fork shaft. Mechanical music alarm clock is also provided with a roller of a clockwork drive with a shifting needle, and the needle is arranged according to music to prod the Gong, and play music.
Mechanical alarm clock stores energy with spring, which is a kind of high manganese steel material; after many level gear to increase angular velocity profile, we can find that it is cycloid, not involute. In order to reduce friction, it is suitable for small torque efficiency drive; after the reciprocating swinging escapement, a kind of structure of natural vibration period realizes the timing requirements. That is the constant angular velocity. The gossamer, like clockwork spring, used in escapement, is constant elastic alloy, which is an elastic element. Its mechanical properties would be not much affected by temperature relatively.
