Rotary, positive displacement mono- or Moineau pump, for e.g. oil industry wastes, is constructed with metal liner inside elastomer and casing, in positive contact with rotor to assure required pressure increase

The stator (2) comprises two parts. The first (2a) is made of a relatively inelastic material (e.g. metal). The second (2b) is located between the internal wall (1a) of the casing and the first part. The second part (2b) applies and/or maintains a mechanical pressure between the first (2a) and the rotor (3), to obtain the required pressure increase in the liquid pumped. An Independent claim is included for the method of making the pump described. A mandrel with external shape corresponding to the internal shape of the first, metal part, is located inside it. This assembly is then located within the outer casing, which includes opening(s). Pressure is applied to shape the first component onto the mandrel, which is then extracted. The second part is adapted (e.g. in terms of its resilience and pre-stressing) to exert mechanical pressure against the rotor as described. Preferred Features: The first part is made of a material allowing the properties of the second part to be preserved (i.e. it especially provides a barrier against the pumped medium). The first part is made of metal, the second of an elastomer. The first part is a metallic network (11) impregnated in an elastomer matrix. The second part includes a liquid under sufficient pressure to apply the required mechanical pressure against the rotor. The liquid under pressure is part of the liquid pumped. In the corresponding method of construction, the following further features are noted. Liquid pressure forms the metal onto the mandrel. A material is injected into the interspace and polymerized, forming the second part of the stator (clearly, this can also be the liquid cited). Adhesive material is injected before the polymer. A heat-dissipating entity is located between the casing and the metal section (e.g. mesh) before injecting the polymer and/or before centering it in the casing. La présente invention concerne une pompe à cavités progressantes destinée à communiquer de l'énergie à un fluide, la pompe comportant au moins un carter (1), un stator (2) et un rotor (3) disposé à l'intérieur du stator.Selon l'invention le carter est constitué d'au moins deux parties, une première partie (2a) constituée en un matériau peu élastique et une deuxième partie (2b) disposée entre la paroi interne (la) du carter et la première partie (2a), la deuxième partie étant adaptée pour appliquer et/ ou conserver une contrainte sigma de la première partie (2a) sur le rotor (3) afin d'obtenir le gain en pression requis pou