Grinding machine is one of the most important milling equipment, and it has nearly 200 years of development history. The old grinding mill’s structure is simple. It only has a pair of roller with the length of about 20mm, and no feeding roller. Large and medium-sized milling machine is equipped with 4 root rollers and 4 feeding roller. It began to popularize application in early twentieth Century. After 100 years of development, the basic structure has not changed. With the progress of science and technology, detailed design constantly updated, compared with the grinding machine in 100 years ago, the new mill already is quite different in appearance, structure and performance.
The grinding mill is the most important component, and its performance directly affects the effect of grinding equipment. The early grinding machine used porcelain roller and ordinary cast iron roller. In 1874, it began to use the high hardness and good wear resistance of chilled cast iron roll. Afterwards, the grinding roller changed alloy chilled cast iron containing nickel, chromium and other elements. In 1953, the grinding roller started to cast in centrifugal way. Later, it changed to double varieties cast iron, and gradually promoted the advanced technology with the use of electric furnace smelting, improving the formula, automatic pouring, rapid detection and blank heat treatment. The quality of the products was becoming more and more perfect.
Feeding system and the grinding mechanism, are the two most important parts of grinding machine. Grinding machine, in the late twentieth century, most were equipped with automatic feeding control system. It can automatically adjust the feed quantity to achieve balanced and grinding, according to the accumulation of the materials in the barrel. The new mill most used the high sensitivity electric automatic feeding system. The commonly used material position sensor had two types: capacitance and infrared.
The design of the grinding shell is also developing and update continuously. The material part of old mill shell was the wood on the top, and the lower half part is cast iron. The bearing and a belt wheel transmission device were exposed outside. In the middle of the 20th century, it gradually changed to steel plate welding production. The transmission device was enclosed in a protective cover, and the appearance is more beautiful. Recently, the high quality grinding shell uses a variety of materials. Using a variety of materials gives full play to the characteristics of the different materials. It not only to enhance the performance of the machine, but also reduce the labor cost. The appearance is more beautiful.