The present invention refers to an automotive fluid flow pump for pumping a fluid, preferably a liquid, to a fluid target, preferably the cooling system of an internal combustion engine.

The automotive fluid flow pump according to the present invention can be a mechanical pump which is mechanically driven by an internal combustion engine, or alternatively can be an electric pump which is directly driven by an electric motor. An example of a typical flow pump is disclosed in WO 2015/131948.

Flow pumps generally generate a complex noise spectrum which is caused by numerous effects, for example pressure peaks caused by the rotating rotor blades passing by a static wall or edge, the energy transfer from the pump rotor to the fluid etc. As a result, fluid flow pumps generate considerable vibrations and mechanical noise.

It is an object of the present invention to provide an automotive fluid flow pump with an improved vibration and noise characteristics.

This object is solved with an automotive fluid flow pump with the features of main claim 1.

The automotive fluid flow pump according to the invention is provided with a pump housing with a fluldlc pump inlet opening and a fiuidic pump outlet opening through which fluid flows in and out of the pump housing.

A rota table pump rotor is provided inside the pump housing. The pump rotor comprises a driven rotor body rotating around a rotation axis with at least five blades, which define at least five rotating open rotor sectors with different sector angles. The sector angle Is the opening angle of a rotor sector and is defined by the rotor blades separating the rotor sector in circumferential direction. The sector angle of the rotating pump sectors is not identical for all rotor sectors but follows a particular pattern. Exactly three different sensor angles are present, namely an intermediate sensor angle (a), a small sensor angle (b) of a-x , wherein x Is a constant value of, for example, 0,5° to 5°, and a large sector angle (c) of a+y, wherein y is a constant valve of, for example, between 0,5° and 5,0°.

The total number of small rotor sectors can be Identical with the total number of large rotor sensors. All large rotor sectors are neighbored and adjacent with each other, as well as all small rotor sectors are neighbored with each other in a clean row. In other words, all large rotor sectors define a single clean sequence as well as all small rotor sectors define a single sequence. These two sensor sequences are separated from each other by one single or two intermediate rotor sector(s).

The vibration energy is not only directed to maximum orders, but is also directed and split to next orders. Experiments have surprisingly shown that the claimed rotor sectors angle sequence causes a significant reduction of vibration and noise.

Preferably, only one single average rotor sectors is provided which is located between all large rotor sectors and all small rotor sectors. As a result, the total number of rotor sectors is uneven.

According to a preferred embodiment of the invention, the total number of rotor sectors is at least seven.

Preferably, the fluidic inlet opening is orientated axially and the fluidlc outlet opening is orientated tangentially. The pump rotor is provided as an impeller which accelerates the fluid from the center radially outwardly into a volute.

According to a preferred embodiment of the invention, the rotor blades protrude substantially axially from the rotor base disk lying In a transversa! plane. The distal side of the rotor blades can be covered by a ring wall defining circular wheel Inlet opening. Two embodiments of the invention are described with reference to the enclosed drawings, wherein :

figure 1 shows an automotive fluid flow pump,

figure 2 shows a cross section of an automotive fluid flow pump with an uneven number of seven rotor sectors, and figure 3 shows a cross section of an automotive fluid flow pump with an even number of eight rotor sectors.

The figures show an automotive fluid flow pump 10; 10' for pumping a fluid. In particular, the present figures 1, 2 and 3 show a coolant or lubricant flow pump for pumping a liquid, for example oil or water, to the coolant or the lubrication system of an internal combustion engine (not shown).

The present embodiments both show a pump which could be driven mechanically by the engine or could be driven by an electric motor.

The flow pump 10; 10' comprises a pump housing 20 comprising an inlet opening 24 and an outlet opening 26. The pump fluid enters the pump housing 20 through the Inlet opening 24 and leaves the pump housing through the outlet opening 26.

The pump 10; 10 ^* is provided with a rotatable pump rotor 30 which comprises a driven rotor body 32 defining a rotor base disk 34 and several rotor blades 36. In the present embodiments, the rotor blades 36 are orientated radially and are provided separately, seen in circumferential direction. The rotor body of the first embodiment defines seven rotor sectors 21 A, 21B, 21C, or eight rotor sectors 21 A, 21B, 21C in the second embodiment.

The rotor sectors 21A, 21B, 21C of the first embodiment shown in figure 2 do not all have the same sector angle, but have three different sensor angles a,b,c. One rotor sector 21A has exactly an average sector angle a of 51°. The three large rotor sectors 21C have an increased sector angle c=a+x, wherein x Is, for example, 2,0° so that the large sector angle c in the present embodiment is 53°. The three small rotor sectors 21B have a decreased sector angle b=a-y wherein y=2° so that the small sector angle b in the present embodiment is 49°. The circumferential sequence of the sector angles of all seven rotor sectors 21 A, 21B, 21C therefore is; b-b-b- a-c-c-c.

The in total eight rotor sectors 21A, 21B, 21C of the second embodiment shown in figure 3 do have an intermediate sector angle a=45,0°, a small sector angle b of the small rotor sectors 21B of b=a-y, namely with y=2° of b=43,0° and an increased sector angle c of the large rotor sectors 21C of c=a+x, namely with x=2° of 47,0°. The circumferential sequence of the sector angles of all eight rotor sensors 21 A, 21 B, 21C of the second embodiment therefore is: b-b-b-a-c-c-c-a.

Generally, the angles x and y can be any value which makes sense, but will generally be in the range of 0,5° to 5,0°. However, the angles x, y should not result in sensor angles a,b,c with a divider in common.