WATER PUMP

Abstract

A water pump with a stator, a chamber defined inside the stator, a ring arranged inside said chamber having a radially outer surface in contact with a radially inner surface of the stator, and a rotor arranged inside the ring and rotatable around a rotation axis. The rotor has a plurality of vanes movable along respective radial directions and having respective radially outer ends in contact with a radially inner surface of the ring. The ring is made of a material having a friction coefficient lower than friction coefficient of metal materials.

Claims

1. A water pump comprising a stator, a chamber defined inside the stator, a rotor rotatable inside said chamber around a rotation axis and provided with a plurality of vanes movable along respective radial directions, and a ring arranged inside said chamber in a radially outer position with respect to said rotor, wherein said ring has a radially outer surface in contact with a radially inner surface of said stator and a radially inner surface in contact with radially outer ends of said vanes, and said ring is made of a material having a friction coefficient lower than friction coefficient of metal materials.

2. The water pump according to claim 1, wherein said ring is made of carbon graphite.

3. The water pump according to claim 1, wherein said ring is rotatable with respect to said stator.

4. The water pump according to claim 1, wherein said ring is integral with said stator.

5. The water pump according to claim 1, wherein said stator is made of a metal material.

6. The water pump according to claim 1, wherein said stator is made of a plastic material.

7. The water pump according to claim 1, wherein said vanes and said rotor are made of carbon graphite.

8. A cooling circuit of an internal combustion engine, comprising the water pump according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Additional features and advantages of the present disclosure will appear more clearly from the following detailed description of a preferred embodiment thereof, made with reference to the accompanying FIG. 1 and given for indicative and non-limiting purposes.

[0033] FIG. 1 schematically shows a cross section of a preferred embodiment of the water pump of the present disclosure.

DETAILED DESCRIPTION

[0034] With reference to FIG. 1, it shows a first embodiment of a water pump in accordance with the present disclosure. The water pump is indicated with 10.

[0035] The water pump 10 has a fixed displacement (or flow).

[0036] The water pump 10 is configured to be used in a cooling circuit of an internal combustion engine for motor vehicles, preferably a gasoline or diesel internal combustion engine,

[0037] The pump 10 comprises a stator 12, inside which a chamber 13 is defined.

[0038] A rotor 14 is provided inside the chamber 13. The rotor 14 is rotatable around a rotation axis O and is provided with a plurality of radial cavities that slidingly house respective vanes 18. For the sake of clarity of illustration, the numerical reference 18 is associated with only two of the vanes illustrated.

[0039] The vanes 18 contact, in a hydraulically sealed manner, two surfaces (not illustrated) perpendicular to the rotation axis O of the rotor 14.

[0040] A ring 23 is radially interposed between the stator 12 and the rotor 14. The ring 23 has a radially outer surface 23b in contact with the radially inner surface 12a of the stator 12.

[0041] The ring 23 can be integral with the stator 12 or rotatable with respect to the stator 12.

[0042] The radially outer ends 18a of the vanes 18 contact, in a hydraulically sealed manner, the radially inner surface 23a of the ring 23. A pressurisation chamber 24 is thus defined between each pair of vanes 18, the ring 23, the rotor 14 and said surfaces perpendicular to the rotation axis O of the rotor 14. For the sake of clarity of illustration, the numerical reference 24 is associated with only one of the pressurisation chambers illustrated.

[0043] The stator 12 has a water inlet (or intake) opening 13a which leads into a pressurisation chamber 24 from a suction conduit (not illustrated) and a water outlet (or delivery) opening 13b leading from the pressurisation chamber 24 towards the internal combustion engine and possible heat exchangers provided downstream of the water pump 10.

[0044] During the rotation of the rotor 14, the volume inside the pressurisation chambers 24 into which water has been fed through the inlet opening 13a is reduced, thus achieving the desired pressure for feeding the water to the engine cooling circuit through the outlet opening 13b.

[0045] The ring 23 is made of a material having a friction coefficient lower than the friction coefficient of metal materials.

[0046] Preferably, the ring 23 is made of carbon graphite.

[0047] Alternatively, the ring 23 is made of plastic, thermoplastic or thermosetting, materials, with or without fillers or additives.

[0048] The ring 23 can be integral with (for example planted on) the stator 12 or rotatable with respect to the latter by virtue of the thrust exerted by the vanes 18 as a result of the rotation of the rotor 14.

[0049] The stator 12 can be made of a non-metal material, such as, for example, carbon graphite or a plastic, thermoplastic or thermosetting, material, with or without fillers or additives.

[0050] Preferably, the stator 12 is made of a metal material, such as, for example, aluminium or alloys thereof, or steel or alloys thereof.

[0051] The vanes 18 and the rotor 14 are made of non-metal materials, preferably carbon graphite or, alternatively, plastic, thermoplastic or thermosetting, materials, with or without fillers or additives.

[0052] For the purpose of satisfying specific and contingent needs, a person skilled in the art can make numerous modifications and variants to the water pump 10 described above, all of which being within the scope of protection defined by the following claims.