Abstract: An oil-injected vacuum pump element, where two mating helical rotors are rotatably provided in a housing, where this housing includes an inlet port and an outlet end face with an outlet port, where compression chambers are formed between the helical rotors and the housing. The vacuum pump element is provided with a connection that extends from a first compression chamber to a second smaller compression chamber at the outlet end face, where this first compression chamber is at a lower pressure than the second compression chamber and where this second compression chamber can make connection with the outlet port upon rotation of the helical rotors, where the connection is such that a flow from the second compression chamber to the first compression chamber is possible, where the connection is not directly connected to the outlet port.

Abstract: An oil-injected vacuum pump element, whereby two mating helical rotors are rotatably provided in a housing, whereby this housing comprises an inlet port and an outlet end face with an outlet port, whereby compression chambers are formed between the helical rotors and the housing, wherein the vacuum pump element is provided with a connection that extends from a first compression chamber to a second smaller compression chamber at the outlet end face, whereby this first compression chamber is at a lower pressure than the second compression chamber and whereby this second compression chamber can make connection with the outlet port upon rotation of the helical rotors, whereby the connection is such that a flow from the second compression chamber to the first compression chamber is possible, whereby the connection is not directly connected to the outlet port.