The elastic rotor (Fig.1), composed of elastic spring (6) with one end firmly connected to shaft (13) and with the other end to carrying shell (5) via bearing (4), and of pressure shell (3) connected to sliding plate (8) by holders (9) which are strained by elastic spring (7), is in permanent contact with stator (1) in order to achieve the sealing which enables a controlled streaming of the medium in the machine working process. In the case of the system overloading, spring declines and the pressure on the projected quantity decreases, what ensures the security in the work.