Crinkle diaphragm pump

1. An undulating diaphragm pump having a propulsion chamber for receiving a diaphragm, wherein the diaphragm has mechanical characteristics that vary from an inlet of the propulsion chamber towards an outlet of the propulsion chamber in such a manner that when said pump is operated, the diaphragm is actuated to deform with a traveling wave that propagates from the inlet towards the outlet of the propulsion chamber in order to propel the fluid and the propagation speed of the wave in the diaphragm in any cross-section relative to the movement of the fluid inside the propulsion chamber is equal to or greater than the mean travel speed of the fluid in said section, and wherein the diaphragm is made out of at least one material so as to have a modulus of elasticity (E) in the material of the diaphragm that increases going from the inlet towards the outlet of the propulsion chamber.

2. The pump according to claim 1 , wherein the product of the modulus of elasticity (E) of the material of the diaphragm multiplied by the thickness (h) of the diaphragm increases going from the inlet towards the outlet of the propulsion chamber.

3. An undulating diaphragm pump having a propulsion chamber for receiving a diaphragm, wherein the diaphragm has mechanical characteristics that vary from an inlet of the propulsion chamber towards an outlet of the propulsion chamber in such a manner that when said pump is operated, the diaphragm is actuated to deform with a traveling wave that propagates from the inlet towards the outlet of the propulsion chamber in order to propel the fluid and the propagation speed of the wave in the diaphragm in any cross-section relative to the movement of the fluid inside the propulsion chamber is equal to or greater than the mean travel speed of the fluid in said section, and wherein the diaphragm includes a core of material having a large modulus of elasticity (E 1 ) and having a thickness (h 1 ), and a covering that covers the core and that is made on at least one side of the core out of a material having a small modulus of elasticity (E 2 ) and has a thickness (h 2 ) in such a manner that the sum of the product of the modulus of elasticity (E 1 ) multiplied by the thickness (h 1 ) of the core plus the product of the modulus of elasticity (E 2 ) multiplied by the thickness (h 2 ) of the covering increases going from the inlet towards the outlet of the propulsion chamber.

4. An undulating diaphragm pump having a propulsion chamber for receiving a diaphragm, wherein the diaphragm has mechanical characteristics that vary from an inlet of the propulsion chamber towards an outlet of the propulsion chamber in such a manner that when said pump is operated, the diaphragm is actuated to deform with a traveling wave that propagates from the inlet towards the outlet of the propulsion chamber in order to propel the fluid and the propagation speed of the wave in the diaphragm in any cross-section relative to the movement of the fluid inside the propulsion chamber is equal to or greater than the mean travel speed of the fluid in said section, and wherein the diaphragm has a star-shaped stiffener made of a material having a large modulus of elasticity and comprising a central ring with branches extending therefrom; the stiffener being integrated in a web made of a material having a modulus of elasticity smaller than said large modulus of elasticity.

5. An undulating diaphragm pump having a propulsion chamber for receiving a diaphragm, wherein the diaphragm has mechanical characteristics that vary from an inlet of the propulsion chamber towards an outlet of the propulsion chamber, the diaphragm having a stiffness that varies and that increases going from the inlet towards the outlet of the propulsion chamber.

6. The pump according to claim 5 , wherein the diaphragm is constituted by a disk of thickness that decreases from an inlet towards the outlet of the propulsion chamber, with annular grooves formed therein in order to leave a core remaining in said grooves.

7. The pump according to claim 5 , wherein the diaphragm extends as a body of revolution and presents a neck at its center that extends around a central axis (Z) of the diaphragm.

8. The pump according to claim 5 , wherein the diaphragm includes in the vicinity of its edge beside the inlet of the propulsion chamber a portion that is made flexible, presenting a profile of wavelets or crenellations.

9. The pump according to claim 5 , wherein the diaphragm includes in the vicinity of its edge, beside the outlet from the propulsion chamber, a portion that is stiffened by radial ribs of height that increases going towards said edge.