A mechanized tool that uses a motor or an electromagnet to drive the working head through a transmission mechanism is called a power tool. It is a tool that is held and operated by hand, driven by a low-power motor or electromagnet, and driven by a transmission mechanism.
In 1895, Germany made the world's first DC drill. The housing is made of cast iron and can drill 4mm holes in the steel plate. Then a three-phase power frequency (50Hz) electric drill appeared, but the motor speed failed to exceed 3000r/min.
In 1914, electric tools driven by single-phase series motors appeared, and the motor speed reached more than 10000r/min.
In 1927, an intermediate frequency power tool with a power supply frequency of 150-200Hz appeared. It not only has the advantages of high speed of a single-phase series motor, but also has the advantages of a simple and reliable structure of a three-phase power frequency motor, but it needs to be powered by an intermediate frequency current. , use is restricted. Common power tools are electric drills, electric grinders, electric wrenches and electric screwdrivers, electric hammers and electric impact drills, concrete vibrators, electric planers.
