SEIKO Spring Drive : One second a day accuracy in a watch powered by a mainspring
SEIKO Spring Drive and the environment
It was the ultimate watchmaker’s dream: An automatic watch with one- second-a-day accuracy. And now it is reality. Spring Drive: No battery, extended service intervals and absolutely no environmental impact.
Spring Drive is the only watch movement in the world that is powered by a main spring and has a regulator without an escapement. Others have tried to make such a watch, but only SEIKO has achieved it.
Spring Drive’s hands move in perfect, continuous and precise glide motion. Like the solar system itself, the movement reflects the natural and eternal flow of time. After all, planets don’t tick!
All the motion of the components in Spring Drive is in one direction; therefore, friction is greatly reduced. By eliminating the need for the very rapid back and forth motion of a balance wheel, Spring Drive has eliminated a problem that has taxed watchmakers for 200 years: the vulnerability of the escapement to wear, tear, shock and temperature change. The result? A prestige, hand built watch that is more accurate, more reliable and more durable than any other luxury watch in the world.
While most mechanical watches have a power reserve of 40 to 50 hours, Spring Drive delivers 72 hours. This is achieved by the use of a new main spring, made from SEIKO’s unique alloy, Spron 510, and by a super-efficient gear train.
As in all automatic watches, an oscillating weight winds the Spring Drive mainspring and drives the hands. Uniquely, however, a tiny part of this mechanical energy is used to drive a magnetic rotor, which generates electrical energy. This electricity activates an integrated circuit and a crystal oscillator. This tri-synchro regulator regulates the speed of the hands via a glide wheel that rotates at exactly 8 times a second and delivers one-second-a-day accuracy.
In 1977, a young watch engineer, Yoshikazu Akahane, dreamed of a “perfect watch” that would combine the beauty of the mechanical watch with the precision of electronic timekeeping. Over 600 prototypes and 230 patents later, Akahane’s dream was realized in Spring Drive.
Spring Drive provides the perfect platform for a luxury chronograph, because elapsed time is measured precisely and not to the nearest fraction. With one-second-a-day accuracy, with its 12 hour duration, with its vertical clutch and column wheel for precise button operation, this is one of the world’s great chronographs. Assembled by hand, with 416 parts, 50 jewels, 140 oil points and 5 different lubricants, the Spring Drive chronograph has a power reserve of 72 hours, even when the chronograph is in use.
In October 2008, the Spring Drive revolution went into space. At the request of the space adventurer, Richard Garriott, SEIKO designed and built a watch that he could wear throughout his mission to the International Space Station. The use of a battery-powered movement was ruled out on safety grounds, and no conventional mechanical watch can maintain its accuracy under the extreme temperature swings experienced in space (from - 20 °C to + 70 °C). Thus, Spring Drive was the natural choice as its performance under extreme conditions is both stable and reliable. Richard wore the watch on his 12-day mission, and two months later, the watch was actually worn during a space walk, or EVA. It performed perfectly throughout.
The genius of Spring Drive lies in its incredibly efficient use of energy. To activate the electronic regulator with just the power of the mainspring required the creation of an IC with extraordinarily low power consumption. Only 25 nano watts are required to operate its IC. Twenty-five nano-watts? Imagine that all six billion inhabitants on the Earth wore Spring Drive watches. Their total power consumption would be as little as that required to power just one 150 watt light bulb.