US 12,215,689 B2
Eccentric screw pump with a pressure chamber between an elastomeric stator portion and a casing
Niels Erik Linnemann Nielsen, Bjerringbro (DK)
Assigned to GRUNDFOS HOLDING A/S, Bjerringbro (DK)
Appl. No. 17/778,262
Filed by GRUNDFOS HOLDING A/S, Bjerringbro (DK)
PCT Filed Nov. 19, 2020, PCT No. PCT/EP2020/082750
§ 371(c)(1), (2) Date May 19, 2022,
PCT Pub. No. WO2021/099502, PCT Pub. Date May 27, 2021.
Claims priority of application No. 19210909 (EP), filed on Nov. 22, 2019.
Prior Publication US 2022/0389926 A1, Dec. 8, 2022
Int. Cl. F04C 2/107 (2006.01); F04C 14/06 (2006.01); F04C 15/00 (2006.01)
CPC F04C 2/1075 (2013.01) [F04C 14/06 (2013.01); F04C 15/0046 (2013.01); F04C 2240/10 (2013.01); F04C 2240/802 (2013.01); F05C 2251/02 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An eccentric screw pump comprising:
a rotor; and
a stator surrounding the rotor, the stator comprising at least one elastomeric stator portion in contact with the rotor and a pressure chamber formed on a radial outer side of said elastomeric stator portion, the radial outer side facing away from said rotor, wherein said pressure chamber is connected to a pressure region of the eccentric screw pump such that the at least one elastomeric stator portion is subjected to a pressure produced by the eccentric screw pump, the pressure chamber being connected to a pressure region of a delivery end of the pump via at least one pressure channel, the at least one pressure channel being arranged inside a casing of the stator, wherein the pressure in the pressure chamber is greater than the pressure on a radial inner side of the at least one elastomeric stator portion, the at least one elastomeric stator portion comprising elastomeric material, the pressure channel being formed inside the elastomeric material of the elastomeric stator portion, wherein the pressure channel has a cross section that is less than a cross section of the pressure chamber.
 
19. An eccentric screw pump comprising:
a rotor; and
a stator surrounding the rotor, the stator comprising at least one elastomeric stator portion and a pressure chamber formed on a radial outer side of said elastomeric stator portion, the radial outer side facing away from said rotor, wherein said pressure chamber is connected to a pressure region of the eccentric screw pump such that the at least one elastomeric stator portion is subjected to a pressure produced by the eccentric screw pump, wherein the elastomeric stator portion of the stator has a varying thickness over an axial extension thereof, wherein a flexibility of the elastomeric stator portion at a delivery end of the eccentric screw pump is greater than a flexibility of the elastomeric stator portion at a suction end of the eccentric screw pump, the pressure in the pressure chamber being greater than the pressure on a radial inner side of the at least one elastomeric stator portion, the at least one elastomeric stator portion comprising elastomeric material, the pressure channel being formed in the elastomeric material of the elastomeric stator portion, wherein the pressure channel has a cross section that is less than a cross section of the pressure chamber.