Which country holds the patent for the AT transmission?
2 Answers
AT transmission is patented in Japan. Below is relevant information about transmissions: 1. Main functions: Changing the transmission ratio to expand the range of torque and speed variations of the driving wheels, adapting to frequently changing driving conditions while allowing the engine to operate under favorable conditions. With the engine's rotation direction unchanged, the vehicle can only move in reverse; utilizing neutral gear to interrupt power transmission enables engine starting, speed variation, and facilitates gear shifting or power output. 2. Working principle: Manual transmissions mainly consist of gears and shafts, achieving speed and torque variation through different gear combinations; whereas automatic transmissions (AT) are composed of torque converters, planetary gears, and hydraulic control systems, achieving speed and torque variation through hydraulic transmission and gear combinations.
I understand that the patent origins of AT transmissions primarily involve Canada and the United States. Tracing back the history, the first significant patent was filed in 1921 by Canadian engineer Alfred Horner Munro, which implemented automatic gear shifting based on a hydraulic system, but this concept never entered mass production. The true commercialization came in 1939 with General Motors' Hydra-Matic transmission in the U.S., first applied in Oldsmobile vehicles, marking the beginning of the automatic transmission era. Later, Japanese companies like Toyota improved the technology and introduced their own patented versions. Today, patents are distributed globally, but the origins lie in North America. It's fascinating to discuss this—automatic transmissions make driving easier by eliminating the hassle of manual gear shifting. For maintenance, it's important to regularly change the transmission fluid to prevent wear and tear.
