Principle of clock
Clock application range is very wide, breed is very much, may be classified according to the vibration principle, structure characteristics and purposes. According to the principle can be divided into the use of low frequency vibration of mechanical vibration of clocks and watches, such as a pendulum clock, torsion pendulum clock, etc; Use of high frequency electromagnetic oscillation and quartz clocks and watches of oscillation, such as synchronous clock, quartz watches and clocks, etc; According to the structure characteristics can be divided into mechanical, such as machinery, automatic alarm clock, calendar, double calendar, a spring and other mechanical watches, Pendulum clock electric mechanical, such as electricity, electricity torsion pendulum clocks, etc; Electronic, such as balance wheel electronic clock, electronic watches and clocks, a tuning fork pointer and digital display type quartz electronic watches and clocks, etc.
Mechanical clocks and watches have a variety of structures, but its working principle, is the original system, transmission system, escapement speed governor, Pointers and article on the dial needle and other parts.
Mechanical clock using spring as power of the original system, through a set of gear transmission system to push the escapement speed; Again by escapement regulator, in turn, control the turning speed of the drive train; Transmission system in promoting the escapement speed governor also drive the pointer mechanism, the transmission speed is controlled by escapement speed, so the pointer can according to certain rules on the dial indicator moment; Article on the dial needle is wind or moving the parts of the pointer.
In addition, there are some additional institutions, can increase the function of the clocks and watches, such as automatic article on the institutions, calendar (double calendar), when the alarm device, the moon instructions and measuring time, etc.
The original dynamic system is to store and transfer energy agency work, usually article by article box wheel, lifted the lid, shaft, spring and spring hook. Spring in the state of freedom is a spiral or s-shaped springs, its inner side has a small hole, set on the shaft of the hook. Its outer end through the spring hook, hook in the article on the inner wall of the box of wheel. Article, through the article on the dial needle wearing make spring roll tightly on the article shaft axis rotation. Article spring elasticity effect makes the box of wheel rotation, and thus drive transmission system.
Drive train is to the original department of energy to escapement speed governor of a set of drive gear, it is made of two round (center), three rounds (round), round (second round) and the escapement of gear shaft, the round piece is driving gear, gear shaft is driven gear. Clock drive train most of the tooth profile according to the principle of the theory of cycloid, revised and modified cycloid tooth profile.
Escapement regulator is made up of escapement and vibration system of two parts, it relies on vibration system of periodic vibration, keep the escapement precision and regularity of intermittent movement, to achieve speed control function. Mega fork tile type longitudinal mechanism is the most widely used an escapement. It consists of the escapement wheel, escapement fork, double disc and banking pin, etc. Its role is to put the original system of energy transfer to vibration system, in order to maintain continuous vibration vibration system, and the number of the vibration of the vibration system is passed to the indicating device, achieve the goal of measuring time.
Vibration system is mainly composed of torsion pendulum, pendulum shaft, balance spring, activities outside piles, (, etc. The inside and outside the end of the balance spring respectively fixed on pendulum shaft and pendulum splint; Escapements deviate from its equilibrium position by external forces began to swing, balance spring then who can be reversed, called the restoring moment. Escapement completed the course of the two movements, vibration system under the effect of balance spring potential energy, the swing in the opposite direction and complete the other half of the vibration period, this is the mechanical clock escapement speed when running continuously and working principle of the repetitive cycle.
Article on the dial needle's role is to fasten and dial needle. It by handle, arbor, head set, clutch, clutch, clutch spring, gears, compression spring, dial needle wheel, wheel, wheel, wheel, when big steel wheel, small steel wheel, ratchet and pawl springs, etc.
On the bar and dial needle is achieved through the handle head piece. Whenever the article on the wheel and the wheel clutch in the meshing state, when turning the grip, clutch wheel drive wheel, wheel and the small steel wheel and steel wheel, make the shaft roll tightly wound. Stop the pawl is great steel wheel to turn back. Dial needle, pull handle, pull the gear in gear shaft rotate and push on clutch, clutch wheel and the wheel off, and the pin gear meshing. When turning the handle head then dial needle wheel through the wheel turns round and round, when reach the purpose of correction the hour and minute hand.
Walking clock requires accurate, stable and reliable. But some internal factors and external environment condition will affect the precision clock's travel time. Internal factors include the composition system structure design, working performance, choosing materials, processing technology and assembly quality, etc. Spring torque, for example, the stability of transmission system working stability, escapement walking speed and so on can affect the accuracy of precision.
The external environment conditions including temperature, magnetic field, humidity, air pressure, vibration, impact, use location, etc. For example, the temperature change can cause clocks in lubricating oil and the watch-balance enhances the performance of balance spring change, causing the change of the performance when the; Environment of the magnetic field strength greater than 60 oster, can cause parts magnetization and go slow; Humidity assembly parts caused by oxidation, corrosion and so on.
[editor this paragraph] eight major factors affecting mechanical clock timing accuracy
Mechanical watches as precision affected by many factors, in general, mainly the following eight factors:
Is affected by the various from external clock, depends on the working environment of the clock. Often adopt the measures are: shockproof, waterproof design, antimagnetic design, additional protection shell, etc. Precision navigation watch universal joint, is often used to make the navigation watch can remain in the turbulence level.
The frictional force
Friction usually have both positive and negative influence, it has a positive on the other hand, such as friction wheel, automatic watch spring and a box of the friction between, screw locking, etc; Friction, on the other hand, can reduce the transmission efficiency of the parts and the friction losses, and thus affect the timing. Common solutions: to improve the lubrication conditions, according to different requirements, choose different lubricating oil; The jewel bearing or gasket; Improve the gear tooth surface conditions, including the science of conjugate tooth profile and improve the surface finish, etc., but the general tooth surface without lubrication (in this case, the lubricating oil viscosity resistance may be higher than produced by friction force).
(is a convenience of the school when the economic structure, but the theory and practice has been confirmed that it will affect the system isochronous, also may produce a bad, the timing error randomness is bigger, can compensate or offset. Solution: minimize the internal and external (spacing; But the best thing to do is not