What improvements did Watt make to the steam engine?

178 1 year, watt adopted planetary gear mechanism to change the reciprocating motion of steam engine into rotary motion. 1782, Watt built a more perfect combined steam engine, and its efficiency increased by four times. 1784, he invented the parallel linkage mechanism, which made the steam engine more widely used. A year later, the first spinning machine driven by a steam engine appeared in Britain. 1788 watt invented the centrifugal governor and throttle valve. 1790, made a cylinder actuator, and finally completed the whole invention process of the steam engine. Since then, the Watt steam engine with superior performance has completely replaced the old button door engine.