According to the search results, the Roots pump. This pump is used in combination with a robust oscillating piston-type oil rotary vacuum pump and is most widely applied in the metal and automotive industries, with extensive use also in the chemical, pharmaceutical, and food industries. Since it does not use lubricating oil, it remains stable even when handling vapors such as water vapor and solvents. The exhaust direction can be selected, increasing the flexibility of equipment design and allowing for more compact equipment.。