History Of Bulldozer Development

The track-type tractor (also known as crawler dozer) was successfully developed by American Benjamin Holt in 1904. It was formed by installing a manual bulldozer device in front of a crawler tractor. The power at that time was a steam engine. Later, crawler bulldozers driven by natural gas and gasoline engines were successfully developed. The bulldozer blade also developed from manual lifting to wire rope lifting. Benjamin Holt was also one of the founders of Caterpillar Inc. in the United States. In 1925, Holt Manufacturing Company and C.L. Best Bulldozer Company merged to form Caterpillar Bulldozer Company, becoming the world's first bulldozer equipment manufacturer. In 1931, the first batch of 60 bulldozers using diesel engines were successfully launched. With the continuous advancement of technology, bulldozers are all powered by diesel engines, and bulldozer blades and ripper are all lifted by hydraulic cylinders. In addition to crawler bulldozers, there are also wheel bulldozers, which appeared about ten years later than crawler bulldozers. Because crawler bulldozers have better adhesion performance and can exert greater traction, the variety and quantity of crawler bulldozers far exceed those of wheel bulldozers at home and abroad. Caterpillar is the world's largest construction machinery manufacturer. Its crawler bulldozers include 9 series, D3-D11, large, medium and small. The largest one is D11 RCD, with a diesel engine flywheel power of 634kw. Komatsu of Japan ranks second. It started to introduce and produce D50 crawler bulldozers in 1947. There are 13 series of crawler bulldozers, from D21 to D575. The smallest one is D21, with a diesel engine flywheel power of 29.5kw, and the largest one is D575A-3SD, with a diesel engine flywheel power of 858kw. It is also the largest bulldozer in the world. Another unique bulldozer manufacturer is Liebheer of Germany. All its bulldozers are driven by hydrostatics. After more than ten years of research and development, the prototype was launched in 1972, and mass production of PR721-PR731 and PR741 began in 1974. The maximum power of the hydrostatically driven crawler bulldozer is currently only 295Kw due to the limitation of hydraulic components. The model is PR751 for mining.