Device for providing a flow and a method of varying a flow rate

1. A device for providing a flow, comprising:

a gear pump comprising a casing,

a main shaft, wherein a first end of the main shaft is configured to be drivingly connected to a rotating component, and,

the casing housing a toothed wheel and at least one other toothed element intermeshed with the toothed wheel,

wherein a second end of the main shaft is connected to the toothed wheel and the casing,

wherein the main shaft is configured to be rotated with respect to the rotating component around an axis defined by the main shaft for rotating the toothed wheel and the at least one other toothed element relative to the casing for generating a flow, wherein

wherein the casing is configured to be rotated with respect to the rotating component around the axis defined by the main shaft for varying a flow rate of the generated flow,

wherein a first end of a further shaft is connected to the casing and a further toothed wheel, and

wherein the further shaft is aligned with the main shaft and extends opposite to the main shaft.

2. The device according to claim 1 , wherein the toothed wheel is mounted on the second end of the main shaft, wherein the

further toothed wheel mounted on the first end of the further shaft has outwardly extending teeth;

wherein the further shaft extends parallel to the main shaft, and

wherein an outer surface of the casing comprises outward extending teeth intermeshed with the teeth of the further toothed wheel.

3. The device according to claim 1 , further comprising a controller and an energy recuperation component, wherein the energy recuperation component is connected to a second end of the further shaft for recuperating energy from a rotation of the casing and the toothed wheel or from the at least one other toothed element, respectively, and wherein the controller is configured to control an amount of energy recuperated by the energy recuperation component for varying the flow rate.

4. The device according to claim 3 , further comprising

an outer casing housing the casing;

wherein the casing can be rotated with respect to the outer casing.

5. The device according to claim 4 , wherein the second end of the further shaft extends out of the outer casing.

6. The device according to claim 5 , further comprising:

an inlet and an outlet provided in the outer casing;

two parallel circumferential notches in a circular cylindrical surface of the casing,

two radially extending tubular channels in the casing, wherein the radially extending channels extend in opposite directions and are connected to the two parallel circumferential notches;

a circumferential sealing between the notches, and

a pair of further circumferential sealings enclosing the notches,

wherein the notches, together with the outer casing, the sealing and the further sealings, form tubular channels and one of the notches is in fluid connection with the inlet and the other of the notches is in fluid connection with outlet.

7. A method for using a device for providing a flow, comprising:

providing a main shaft having a first end connected to a rotating component and a second end connected to a toothed wheel, a casing housing the toothed wheel and at least one other toothed element, a further shaft connected to the casing, and a controller and an energy recuperation component, wherein the energy recuperation component is connected to the further shaft for recuperating energy from a rotation of the casing and the toothed wheel or from the at least one other toothed element, respectively, and wherein the controller is configured to control an amount of energy recuperated by the energy recuperation component for varying the flow rate,

rotating the main shaft relative to the rotating component for rotating the toothed wheel and the at least one other toothed element with respect to the rotating component around an axis defined by the main shaft to the casing for generating a flow, and

rotating the casing and a further toothed wheel not connected to the main shaft with respect to the rotating component around the axis defined by the main shaft for varying a flow rate of the generated flow,

using the controller for controlling the amount of energy recuperated by the energy recuperation component for varying the flow rate.