W, WY type reciprocating piston vacuum pump is one of the main equipment for obtaining rough vacuum. It is used to extract air or other gases from sealed containers or reaction kettles. It is not suitable for pumping corrosive gases or gases containing hard particle ash. Its structure consists of two main parts: the mechanical transmission part and the gas flow part.
1. Mechanical Transmission Section:
The mechanical transmission is housed within a sealed casing, with the vacuum pump crankshaft supported by cone roller bearings on either side of the casing. One end of the crankshaft is fitted with a large belt wheel to drive the transmission. The connecting rod links the crankshaft's journals to the crosshead. The piston rod has one end fitted with a large belt wheel to drive the transmission, and the other end is mounted in the piston's conical bore, secured with a nut. The motor and a small belt wheel mounted on the shaft are driven by a V-belt to rotate the crankshaft, allowing the piston to reciprocate within the cylinder due to the action of the connecting rod and crosshead. Shanghai Wanjing Pump Valve
The connecting rod crank mechanism moves within the housing, causing the lubricating oil in the oil pan to splash and lubricate surfaces such as the bearings, crankshaft journals, crosshead, and sliding surfaces. For easy inspection and maintenance of the transmission mechanism, removable door covers are installed on both sides and the rear of the housing. An oil window is fitted on the rear cover to indicate the oil level height in the oil pan inside the housing. Shanghai Wanjing Pumps and Valves
2. Gas Flow Section:
The gas chamber and cylinder are cast as a single unit. The intake valve is installed on the top of the gas chamber, serving as the intake port, while the exhaust valve is fitted on the bottom, functioning as the exhaust port. A check valve is composed of a valve plate and a spiral spring in the valve groove to control the intake and exhaust and automatically complete the gas distribution function.
A piston is within the cylinder, equipped with piston rings to ensure airtightness at both ends of the cylinder separated by the piston. As the piston moves back and forth within the cylinder, it continuously changes the volume at both ends; one end expands to吸入(gas) while the other contracts to排出(gas). The combined action of the piston and the valve cyclically completes the vacuum pump's suction and exhaust functions.
The cooling water flowing through the cylinder water jacket removes the heat generated from the compression of gases within the cylinder and from the friction of the metal surfaces, preventing the cylinder from overheating. The cooling water enters from beneath the cylinder head and flows through the jacket, exiting at the outlet above the cylinder neck to the vacuum pump.
The cylinder wall and piston ring friction surface are lubricated with oil injected from a cup mounted on the cylinder.
The W and WY type vacuum pumps have been widely applied in various industrial sectors. For example, in chemical or food industries for vacuum distillation, evaporation, crystallization, drying, and filtration; in vacuum metallurgy for degassing; and in electrical industries for impregnation.
