Centrifugal pump having axially moveable impeller wheel for conveying different flow paths

Patent metadata

Field	Value
Publication number	US-10539143-B2
Application number	US-201414392325-A
Country	US
Kind code	B2
Filing date	Jun 25, 2014
Priority date	Jun 27, 2013
Publication date	Jan 21, 2020
Grant date	Jan 21, 2020

Abstract

A pump assembly (2) includes an electric drive motor (14) and with at least one impeller (18) which is driven by the motor. The impeller is movable in an axial direction (X) between at least one first and one second position. The impeller in the first axial position is situated in a first flow path through the pump assembly and delivers a fluid through this first flow path. The impeller in the second position is situated in a second flow path through the pump assembly and delivers a fluid through this second flow path. The pump assembly (2) is configured such that a movement of the impeller (18), between the first and the second position at least in one direction, is effected by a hydraulic force which acts on the impeller (18) and is produced by the delivered fluid. A heating installation is provided with such a pump assembly.

First claim

The invention claimed is:

1. A pump assembly comprising:
an electric drive motor;
at least one impeller driven by the electric drive motor, wherein:
the at least one impeller is movable in an axial direction between at least one first axial position and a second axial position;
the at least one impeller in the first axial position is situated in a first flow path through the pump assembly and delivers fluid through the first flow path;
the at least one impeller in the second axial position is situated in a second flow path through the pump assembly and delivers a fluid through the second flow path;
the pump assembly is configured such that a movement of the at least one impeller between the first axial position and the second axial position at least in one direction is effected by a hydraulic force which acts on the at least one impeller and is produced by the delivered fluid;
the pump assembly is configured such that the hydraulic force can be produced by differently accelerations of the electric drive motor;
the at least one impeller is maintained in the at least one first axial position via a first acceleration;
the at least one impeller is moved to the second axial position via a second acceleration.

2. A pump assembly according to claim 1 , wherein the pump assembly is configured such that the at least one impeller on operation is held in at least one of the positions by at least one hydraulic force produced by the delivered fluid.

3. A pump assembly according to claim 1 , wherein the pump assembly is configured such that the at least one impeller on operation is held in at least one of the positions by way of an interaction of at least one hydraulic force produced by the delivered fluid, of a spring force or an axially acting magnetic force or any combination of the at least one hydraulic force, the spring force and the axially acting magnetic force, wherein the magnetic force acts on a rotor of the drive motor which is connected to the at least one impeller.

4. A pump assembly according to claim 1 , wherein the at least one impeller is connected to a rotor of the electrical drive motor, and at least one magnetic force acting on the at least one impeller in the axial direction results from a magnetic interaction between the rotor and a surrounding stator from an axial shift between the rotor and the stator, the at least one impeller being maintained in the first position via the at least one magnetic force and the hydraulic force.

5. A pump assembly according to claim 1 , wherein the at least one impeller in the first axial position is arranged such that the at least one impeller delivers into a first exit channel, and the at least one impeller in the second axial position is arranged such that the at least one impeller delivers into a second exit channel.

6. A pump assembly according to claim 1 , wherein the at least one impeller in the first axial position is arranged such that the at least one impeller is connected at a suction side to a first inlet channel, and the at least one impeller in the second axial position is arranged such that at the suction side the at least one impeller is connected to a second inlet channel.

7. A pump assembly according to claim 1 , wherein the pump assembly is configured such that the hydraulic force can be produced by the electric drive motor by way of a speed change.

8. A pump assembly according to claim 1 , wherein the pump assembly is configured as a bistable system, in which the at least one impeller on operation is held in the first axial position or the second axial position by way of the acting hydraulic or magnetic forces or both the hydraulic and magnetic forces.

9. A pump assembly according to claim 1 , wherein the at least one impeller in the first axial position is situated axially closer to the stator of the electric drive motor than in the second axial position.

10. A pump assembly according to claim 1 , wherein the pump assembly is configured such that in the first axial position of the at least one impeller, a hydraulic force acting in a direction of the first axial position acts on a suction-side, axial face side of the at least one impeller or of a pressure element which is coupled to the at least one impeller in a force-transmitting manner.

11. A pump assembly according to claim 1 , wherein the pump assembly is configured such that in the first position of the at least one impeller, a magnetic force acting in the direction of the first position acts on the at least one impeller.

12. A pump assembly according to claim 1 , wherein the pump assembly is configured such that at least in the second position of the at least one impeller, a hydraulic force acting in the direction of the second axial position acts on a pressure-side, axial face side of the at least one impeller.

13. A pump assembly according to claim 12 , wherein the pump assembly is configured such that in the second axial position of the at least one impeller, a suction-side axial face side of the at least one impeller or of a pressure element coupled to the at least one impeller is pressure-relieved.

14. A pump assembly according to claim 1 , further comprising:
at least one connection channel which connects a pressure region situated downstream of the at least one impeller to a side of the at least one impeller or of a pressure element coupled to the at least one impeller for transmitting a hydraulic pressure, said side being away from the pressure region; and
a control element configured to control the flow through the connection channel and arranged in the connection channel.

15. A pump assembly according to claim 1 , further comprising a structure defining a receiving space into which a closed, suction-side axial face side of the at least one impeller or a pressure element coupled to the at least one impeller enters in at least one position of the at least one impeller and which is configured such that, via a throttle location, the receiving space is subjected to a hydraulic pressure produced by the at least one impeller, for producing a hydraulic force, wherein an annular gap is defined between a peripheral edge of the structure and the closed, suction-side axial face side of the at least one impeller or the pressure element and the closed, suction-side axial face side of the at least one impeller or the pressure element is located at a position outside of the receiving space when the at least one impeller is in the first axial position, at least a portion of a control disc being located in the receiving space when the at least one impeller is in the second axial position, wherein the receiving space is in fluid communication with an inlet channel of the pump assembly when the at least one impeller is in the second axial position and when the at least one impeller is in the first axial position.

16. A pump assembly according to claim 1 , wherein the at least one impeller comprises at least one exit opening and at least one entry opening, wherein the entry opening is situated in a peripheral section of the at least one impeller.

17. A pump assembly according to claim 16 , wherein the entry opening is configured as an annular opening extending over a whole periphery of the at least one impeller.

18. A pump assembly according to claim 16 , wherein the at least one impeller at a suction side comprises an extended cylindrical section which has an outer area which is 50 to 150% of an inner cross section in the inside of this section.

19. A heating installation comprising:
a pump assembly comprising:
an electric drive m

Assignees

• Grundfos Holding As

Inventors

• Blad Thomas

Classifications

• F04D15/0027

  Varying behaviour or the very pump (F04D15/0055 and F04D29/46 take precedence) · CPC title

• F04D13/064

  Details of the magnetic circuit · CPC title

• F04D1/00

  Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps (adapted for pumping specific fluids F04D7/00; priming or boosting F04D9/00) · CPC title

• F04D29/0416

  balancing pistons · CPC title

• F24D2220/0207

  Pumps · CPC title