Inventia se refera la industria constructoare de masini, si anume la instalatiile destinate pentru transformarea energiei potentiale a lichidului sau a mediilor fluide comprimabile in energie mecanica si viceversa, si poate fi aplicata in actionari hidraulice si pneumatice, in motoare cu ardere interna cu formare exterioara sau interioara a amestecului, precum si in motoare cu ardere externa, in masini cu vid, in contoare volumetrice pentru lichid si medii fluide comprimabile. Masina volumica rotativa, conform primei variante, contine un corp cilindric, in interiorul caruia, coaxial cu el, este instalat un arbore motor 6, un rotor 5, care contine un cilindru interior 7 si unul exterior 8, ambii amplasati coaxial si legati rigid intre ei, precum si rotor-despartitor 19 ce contine cilindru despartitor 20 echipat cu discuri frontale 21, amplasat excentric fata de rotor intre cilindrii lui, care formeaza impreuna cu el si cu discurile frontale, cavitati de lucru de volum variabil. Noutatea consta in aceea ca corpul este confectionat compus, cu despartire inelara in partea de mijloc a peretelui lateral, in care este executat un orificiu 18 pentru aportul sau refularea fluidului de lucru. Arborele motor 6 este instalat in bucse excentrice 4, totodata fusul de la un capat al arborelui este executat monolit, iar in fusul capatului opus este executat un canal axial 17 ce comunica cu orificiul din capacul distribuitor 15 destinat pentru circulatia fluidului de lucru si cu cavitatea cilindrului interior. Pe fus este montata o supapa flotanta 13, care desparte cavitatea cilindrului interior 7 si cavitatea inelara, formata de suprafata exterioara a cilindrului exterior 8 si suprafata interioara a corpului. Cilindrii rotorului sunt fixati rigid pe arborele motor 6, sunt legati intre ei cu perete despartitor inelar transversal 9, instalat in partea lor mijlocie si sunt legati adaugator cu bariera longitudinala, care se afla in fisura longitudinala executata in peretele cilindrului despartitor, iar in bariera longitudinala sunt executate canale, care comunica cavitatile de lucru de volum variabil cu cavitatea cilindrului interior si cavitatea inelara formata de suprafata exterioara a cilindrului exterior si suprafata interioara a corpului. Masina volimica rotativa poate contine adaugator a doua bariera longitudinala, montata sub un unghi de 180° fata de prima.The invention relates to the machine building industry, namely to installations intended for transforming the potential energy of the liquid or compressible fluid media into mechanical energy and vice versa, and can be applied in hydraulic and pneumatic actuators, in internal combustion engines with external formation or interior of the mixture, as well as in external combustion engines, in vacuum machines, in volumetric meters for liquid and compressible fluid media. The rotary volumetric machine, according to the first variant, contains a cylindrical body, inside which, coaxially with it, is installed a motor shaft 6, a rotor 5, which contains an inner cylinder 7 and an external one 8, both located coaxially and rigidly connected between they, as well as the separator rotor 19 containing the separator cylinder 20 equipped with front discs 21, located eccentrically relative to the rotor between its cylinders, which together with it and the front discs, work cavities of variable volume. The novelty consists in the fact that the body is made of compound, with an annular partition in the middle part of the side wall, in which an orifice 18 is executed for the contribution or the discharge of the working fluid. The motor shaft 6 is installed in eccentric bushes 4, at the same time the spindle at one end of the shaft is executed monolithically, and in the spindle at the opposite end is executed an axial channel 17 which communicates with the hole in the distributor cover 15 intended for the circulation of the working fluid and with the cavity. inner cylinder. On the spindle is mounted a floating valve 13, which separates the inner cylinder cavity 7 and the annular cavity, formed by the outer surface of the outer cylinder 8 and the inner surface of the body. The rotor cylinders are rigidly fixed to the motor shaft 6, they are connected to each other by the transverse annular partition 9, installed in their middle part and they are connected with the longitudinal barrier, which is in the longitudinal crack executed in the wall of the separating cylinder, and in the longitudinal barrier. channels are executed, which communicate variable working cavities with the inner cylinder cavity and the annular cavity formed by the outer surface of the outer cylinder and the inner surface of the body. The rotary volume machine may contain the addition of two longitudinal barriers, mounted at an angle of 180 ° to the first.