Pump assembly

Abstract

The invention is a pump assembly (1) for a cooling system of an operating assembly of a vehicle, which extends with respect to an axis (X-X) and comprises: i) a container group (2), which comprises a container body (21) and an auxiliary body (22) delimiting a dry chamber (201) and a wet chamber (202); ii) an electric motor assembly (4) comprising a stator (41), housed in the dry chamber (201) and a rotor (42), housed in the wet chamber (202); iii) an impeller group (3), housed in the wet chamber (202), comprising a blade body (30) and a control body (35) in which the rotor (42) is at least partially housed; iv) a shaft group (5), mainly housed in the wet chamber (202), about which the impeller group (3) rotates, comprising : a shaft (50), which extends along the axis (X-X) comprising a fixed end (500) engaged with the container group (2) and a free end (501); a head (51) positioned at the free end (501), radially protruding from the shaft (50) to provide an axial abutment against the axial movement of the impeller group (3). Shaft (50) and head (51) are in a single body. The shaft (50) extends in a cantilevered manner from the container group (2) to the head (51) along the axis (X-X) over a shaft segment (L), and the head (51) has a head height (1) along the axis (X-X); the ratio of shaft segment (L) to head height (1) is between 10 and 25, preferably between 15 and 20.

Description

PUMP ASSEMBLYDESCRIPTION

[0001] The present invention relates to a pump assembly of a cooling system of a vehicle.

[0002] In this disclosure, the term "vehicle" means any transport means, without any limitation related to type or size, i.e., a motor vehicle or an articulated lorry .

[0003] In other words, the present invention relates to the automotive field, and in detail, to the heat management system of an operating assembly of a vehicle or a plurality of operating systems.

[0004] In particular, in the present disclosure, "operating assembly" means a component or group of specific components for carrying out a certain operation necessary for the motion of the vehicle. In a preferred embodiment, the "operating assembly" comprises the motor assembly, e.g., of endothermic, electric, or hybrid type. In further constructional variants, the "operating assembly" comprises other vehicle components, of both mechanical, such as a transmission assembly, and electrical, such as a "battery assembly" or "electric motor group", included in the vehicle.

[0005] In the prior art, multiple embodiments of pump assemblies for a cooling system of an operating assemblyof a vehicle are known, which are distinguished by their actuation types.

[0006] Specifically, the pump assembly of the present invention fits into such a context, having an electric type actuation. In other words, the pump assembly of the present invention comprises at least one electric motor which controls the rotary movement of the impeller group included therein, thus controlling the movement of the cooling liquid which flows in the cooling system to which the pump assembly is fluidly connectable.

[0007] In particular, the "cooling liquid" is a waterbased liquid, e.g., a solution comprising water and glycol .

[0008] A multiplicity of technical solutions of pump assemblies comprising an electric drive with an electric motor are known, in which the rotor is "wet," i.e., is housed in the hydraulic part of the pump assembly so that it is cooled precisely by the cooling liquid moved by the impeller group.

[0009] In particular, embodiments of pump assemblies are known, in which impeller group and rotor are rotationally free with respect to a fixed shaft, where said fixed shaft is cantilevered in a wet chamber.

[0010] A typical problem of such embodiments is related to the presence of vibration of the componentsand to the production of noise upon the pump assembly actuation .

[0011] Therefore, it is the object of the present invention to provide a pump assembly for a cooling system of an operating assembly of a vehicle which solves such a typical problem of the prior art.

[0012] Such an object is achieved by a pump assembly according to claim 1. The claims dependent thereon relate to preferred constructional variants having further advantageous aspects.

[0013] The object of the present invention will now be described in detail, with the aid of the accompanying drawings, in which:

[0014] - figure 1 is a side view of a pump assembly according to the present invention;

[0015] - figures 2' and 2" show the same section view of the pump assembly as in claim 1;

[0016] - figure 2a is an enlarged view of a region of figure 2;

[0017] - figure 3 is a sectional perspective view of some components, i.e., impeller group, rotor and cylindrical bushing, assembled by co-molding;

[0018] - figure 3a is a perspective view with separate parts of the components in figures 3;

[0019] - figure 4 is a perspective view with separateparts of some components of the pump assembly in figure1.

[0020] In the aforesaid drawings, reference numberl indicates, as a whole, a pump assembly for a cooling system of an operating assembly of a vehicle.

[0021] The pump assembly 1 of the present invention extends mainly lengthwise with respect to an axis X-X.

[0022] According to the invention, the pump assembly 1 comprises a container group 2.

[0023] Preferably, the container group 2 is suitable for containing at least the majority of components of the pump assembly 1 of the present invention, described below .

[0024] Preferably, the container group 2 is fluidly connectable to the pipes of the cooling system, in which the cooling liquid moved by the pump assembly 1 flows.

[0025] The container group 2 comprises a container body 21 and an auxiliary body 22.

[0026] The container group 2 delimits a dry chamber 201 and a wet chamber 202 in the coupling between container body 21 and auxiliary body 22. In other words, the cooling liquid has unrestricted access into the wet chamber 202, while the cooling liquid is prevented from entering into the dry chamber 201, which is sealed off from said wet chamber 202.

[0027] The wet chamber 202 comprises a central portion202' along the axis X-X and the dry chamber 201 comprises an annular portion 201' surrounding said central portion 202 ' .

[0028] In other words, according to a preferred embodiment, container body 21 and auxiliary body 22 are mutually sealingly engaged. Preferably, appropriate gaskets are provided on the container body 21 or the auxiliary body 22.

[0029] According to a preferred embodiment, the container group 2 is assemblable with appropriate components of the vehicle in which system fluid pipes are created, e.g., appropriate systems in which operating assemblies and / or valve groups are housed. For example, said components comprise specific volute portions in which the pump assembly 1 operates.

[0030] According to a preferred embodiment, the container group 2 comprises a bottom wall.

[0031] Preferably, said bottom wall 220 is included in the auxiliary body 22.

[0032] Preferably, said bottom wall is included in the container body 21.

[0033] According to a preferred embodiment, the bottom wall 220 comprises a bottom disc made of a metallic material .

[0034] Preferably, the bottom wall comprises a supporting collar 225, protruding along the axis X-X, in the central portion 202' .

[0035] According to a preferred embodiment, the container body 21 is made of a metallic material, e.g., is made of an aluminum alloy.

[0036] According to a preferred embodiment, the container body 21 is made of a plastic material, e.g., is made of PPS .

[0037] According to a preferred embodiment, the auxiliary body 22 is made of a plastic material, e.g., is made of PPS.

[0038] According to a preferred embodiment, the bottom wall 220 comprises a disc portion made of a metallic material .

[0039] Preferably, the supporting collar 225 is made of a metallic material, e.g., is made of aluminum.

[0040] According to a further preferred embodiment, the container group 2 comprises a volute body fluidly connected to the pipes of the cooling system.

[0041] Preferably, the volute body is suitable for engaging the container body 21 and / or the auxiliary body 22. Preferably, the container group 2, in the coupling between volute body and container body 21 and / or auxiliary body 22, delimits an impeller portion 202" atthe top in the wet chamber 202, in which the impeller 3(described below) is housed. Specifically, the wet chamber 202, in which the cooling liquid flows, is defined as a whole in the coupling between volute body and container body 21 and / or auxiliary body 22.

[0042] According to a preferred embodiment, the volute body is made of a plastic material, e.g., is made of PPS .

[0043] As mentioned, the pump assembly 1 comprises an impeller group 3 housed in the wet chamber 202.

[0044] The impeller group 3 comprises a blade body 30 housed in the impeller portion 202".

[0045] According to a preferred embodiment, such as that shown in the accompanying drawings, the pump assembly 1 further comprises a blade cover 300 assemblable on the blade body 30 of the impeller group 3. As a function of the shape of the blade body 3, said blade cover 300 is in one piece, i.e., is embedded in the impeller group 3, or is a separate component engaged with the blade body 3.

[0046] Preferably, the impeller group 3 is made of a plastic material, preferably is made of PPS.

[0047] Moreover, the pump assembly 1 comprises an electric motor assembly 4 comprising a stator 41, housed in the dry chamber 201, and a rotor 42, housed in the wet chamber 202.

[0048] The stator 41 is housed in the annular portion201' and the rotor 42 is housed in the central portion 202 ’ .

[0049] Preferably, the rotor 42 comprises a rotor body 420.

[0050] Preferably, the rotor body 420 comprises a plurality of packed laminar elements.

[0051] Preferably, the rotor 42 comprises rotor poles 421, e.g., comprising specific magnetic elements.

[0052] According to a preferred embodiment, the laminar elements define appropriate housings in the pack thereof, in which the rotor poles 421 are positioned.

[0053] According to the present invention, the pump assembly 1 comprises a shaft group 5 housed mainly in the wet chamber 202, comprising:- a shaft 50, which extends along the axis X-X in the central portion 202' comprising a fixed end 500 engaged with the container group 2 and a free end 501;- a head 51 positioned at the fixed end 501, radially protruding from the shaft 50 to provide an axial abutment against the axial movement of the impeller group 3.

[0054] According to present invention, shaft 50 and head 51 are made in one piece.

[0055] According to a preferred embodiment, the pump assembly 1 comprises a cylindrical bushing 7 extendingalong the axis X-X, which is rotationally free and externally engaged with rotor 42 and impeller group 3.

[0056] According to a preferred embodiment, the pump assembly 1 has a geometry such that the rotation of the rotor 42 corresponds to the rotation of cylindrical bushing 7 and impeller group 3 on the shaft 5.

[0057] Preferably, the cylindrical bushing 7 is made of a metallic material, e.g., sintered steel with graphite .

[0058] Preferably, the cylindrical bushing 7 is made of pressed graphite.

[0059] Preferably, the cylindrical bushing 7 is made of graphite-filled resin.

[0060] Preferably, the rotor 42 is fitted onto the cylindrical bushing 7. And the impeller group 3 is then molded over said components.

[0061] Preferably, rotor 42 and cylindrical bushing 7 are mutually joined by geometric interference. Preferably, rotor 42 and cylindrical bushing 7 are integrally interconnected.

[0062] According to the present invention, the impeller group 3 comprises a control body 35 extending lengthwise along the axis X-X from the blade body 30.

[0063] Preferably, the control body 35 is engaged with the cylindrical bushing 7 and the rotor 42, furtherfixing them.

[0064] In other words, the impeller group 3 is comolded onto the cylindrical bushing 7 and the rotor 42 so as to form a single "complex component", whose respective components are mutually integral.

[0065] According to a preferred embodiment, the rotor 42 is positioned on the cylindrical bushing 7, and once placed in an appropriate mold, the impeller group 3 is molded, thus obtaining said "complex component". Said "complex component" is then fitted onto the rotationally free shaft 50.

[0066] According to a preferred embodiment, the control body 35 extends radially from the cylindrical bushing 7 and at least partially contains the rotor 42.

[0067] According to a preferred embodiment, the cylindrical bushing 7 has outer surfaces 71 suitable for promoting the engagement with the impeller group 3, e.g., at the two sides of the rotor 42. For example, said outer surface 71 has slots and / or roughness.

[0068] According to a preferred embodiment, the pump assembly 1 comprises at least one cooling pipe 6 suitable for the recirculation of the cooling liquid. Preferably, the cooling liquid flows in the cooling pipe 6 towards the blade element 30.

[0069] Preferably, the cooling pipe 6 extendssubstantially parallel to axis X-X.

[0070] Preferably, said cooling pipe 6 comprises a rotor segment 64 which crosses the rotor 42.

[0071] Preferably, the rotor segment 64 of the cooling pipe 6 extends into the rotor body 420. In other words, the laminar elements are shaped exhibiting specific openings so that they define said rotor segment 64 in the pack .

[0072] According to a preferred embodiment, the cooling pipe 6 comprises at least one impeller segment 635', 635", which crosses the impeller 3 aligned with the rotor segment 64.

[0073] Preferably, the cooling pipe 6 comprises a first impeller segment 635' and a second impeller segment 635" on opposite sides with respect to the rotor segment 64.

[0074] According to a preferred embodiment, the impeller segment 635', 635" has a greater passage section than the passage section of the rotor segment 64.

[0075] According to a preferred embodiment, the pump assembly 1 comprises a plurality of angularly equidistant cooling pipes 6.

[0076] Preferably, each cooling pipe 6 is positioned in a region radially proximal to the cylindrical bushing 7.

[0077] Preferably, each cooling pipe 6 is positioned radially between the cylindrical bushing 7 and a rotor pole 421.

[0078] According to a preferred embodiment, the pump assembly 1 further comprises a washer 9 axially positioned between cylindrical bushing 7 and head 51.

[0079] Preferably, said washer 9 is suitable for minimizing the friction between cylindrical bushing 7 and head 51.

[0080] According to a preferred embodiment, said washer 9 is made of a material selected from ceramic materials .

[0081] Preferably, the washer 9 is made of alumina.

[0082] According to a preferred embodiment, the washer 9 comprises radial slots 91, through which cooling liquid flows up to the shaft 50.

[0083] Preferably, the washer 9 comprises radial slots 91 on the upper surface facing the head 51.

[0084] Preferably, the washer 9 comprises radial slots 91 on the lower surface facing the cylindrical bushing 7.

[0085] Preferably, at the free end 501 close to the head 51, the shaft 50 has an annular groove 591 in which cooling liquid flows.

[0086] According to the present invention, the shaft50 extends in a cantilevered manner from the containergroup 2 to the head 51 along the axis X-X over a shaft segment L.

[0087] Preferably, the shaft 50 has a shaft diameter D.

[0088] According to the present invention, the head 51 has a head height I along the axis X-X.

[0089] Preferably, the head 51 has a head diameter d.

[0090] According to the present invention, the ratio of shaft segment L to head height 1 is between 10 and 25.

[0091] Preferably, the ratio of shaft diameter D to head diameter d is between 0.4 and 0.8.

[0092] Preferably, the ratio of shaft length L to head height 1 is between 15 and 20.

[0093] Preferably, the ratio of shaft diameter D to head diameter d is between 0.5 and 0.7.

[0094] Preferably, the shaft segment L is between 25 and 30 millimeters I in size.

[0095] Preferably, the shaft diameter D is between 4 and 6 millimeters in size.

[0096] According to a preferred embodiment, the shaft segment L extends from said support collar 225 to the head 51.

[0097] Preferably, the disc portion is made of a metallic material and the shaft 50 is also made of a metallic material. Preferably, shaft 50 and disc portionare connected by force coupling.

[0098] According to a preferred embodiment, the pump assembly 1 having the aforesaid features is subjected to a particular manufacturing method.

[0099] Specifically, said manufacturing method comprises the step of co-molding the impeller group 3 with the rotor 42 and the cylindrical bushing 7.[000100] According to a preferred embodiment, the present invention also relates to a step in which the rotor 42 is positioned on the cylindrical bushing 7 and, together, they are housed in an appropriate mold in which the impeller group 3 is molded on said "complex component" .[000101] Preferably, said appropriate mold comprises specific rod-like elements adapted to create the segments of the cooling pipe.[000102] Innovatively, the pump assembly largely fulfills the intended purpose by overcoming the typical problems of the prior art.[000103] Advantageously, indeed, the pump assembly has impeller group and rotor housed in the same chamber, both wetted by the cooling liquid.[000104] Advantageously, cylindrical bushing and washer avoid the presence of friction and wear situations on the shaft .[000105] Advantageously, the washer also serves the purpose of avoiding the presence of friction and wear situations between bushing and head.[000106] Advantageously, the washer is effectively lubricated by the cooling liquid. Advantageously, the shaft is effectively lubricated by the cooling liquid.[000107] Advantageously, the pump assembly has a simple and certain positioning of the impeller group, from the shaft of the shaft group fixed in an unambiguous position .[000108] Advantageously, the cylindrical bushing is easy to make, and is structurally solid, having no slots, voids and / or openings.[000109] Advantageously, the pump assembly has the cantilevered impeller group, not requiring additional axial support in addition to the single fixed end of the shaft .[000110] Advantageously, the pump assembly is usable in both configurations with volute body and configurations in which the volute is obtained on other vehicle components .[000111] Advantageously, the pump assembly is quiet, having a solution that solves the problem of noise, e.g., caused by an incorrect positioning of the blade element or by undesired rubbing.[000112] Advantageously, the pump assembly is quite having a specific shaft geometry.[000113] Advantageously, the pump assembly and in particular the shaft, has its own frequency such as to ensure a reduction in vibration and noise upon the rotation of the impeller group.[000114] Advantageously, the pump assembly has a simple construction .[000115] Advantageously, the pump assembly is easy to assemble.[000116] It is apparent that, in order to meet contingent needs, those skilled in the art could make changes to the above-described invention, all contained within the scope of protection as defined by the following claims.

Claims

CLAIMS1. A pump assembly (1) for a cooling system of an operating assembly of a vehicle, which extends with respect to an axis (X-X) and comprises: i) a container group (2) , which comprises a container body (21) and an auxiliary body (22) , wherein the container group (2) delimits a dry chamber (201) and a wet chamber (202) in the coupling between the container body (21) and the auxiliary body (22) , wherein said wet chamber (202) comprises a central portion (202' ) along the axis (X-X) and the dry chamber (201) comprises an annular portion (201' ) , which surrounds said central portion (202' ) ; ii) an electric motor group (4) comprising a stator (41) , housed in an annular portion (201' ) and a rotor (42) , housed in the central portion (202' ) ; iii) an impeller group (3) , housed in the wet chamber (202) , comprising a blade body (30) and a control body (35) in which the rotor (42) is at least partially housed; iv) a shaft group (5) , mainly housed in the wet chamber (202) , about which the impeller group (3) rotates, comprising :- a shaft (50) extending along the axis (X-X) in the central portion (202' ) comprising a fixed end (500)engaged with the container group (2) and a free end (501) ;- a head (51) positioned at the free end (501) , radially protruding from the shaft (50) to provide an axial abutment against the axial movement of the impeller group (3) ; wherein shaft (50) and head (51) are in a single body; wherein the shaft (50) extends in a cantilevered manner from the container group (2) to the head (51) along the axis (X-X) over a shaft segment (L) , wherein the head (51) has a head height (1) along the axis (X-X) , wherein the ratio of shaft segment (L) to head height (1) is between 10 and 25, preferably between 15 and 20.

2. Pump assembly (1) according to claim 1, wherein the shaft (50) has a shaft diameter (D) and the head has a head diameter (d) , wherein the ratio of shaft diameter (D) to head diameter (d) is between 0.4 and 0.8, preferably between 0.5 and 0.7.

3. Pump assembly (1) according to any one of the preceding claims, wherein the container group (2) comprises a bottom wall and a supporting collar in which the fixed end (500) is housed, wherein the shaft segment (L) extends from said supporting collar (225) to the head (51) .

4. Pump assembly (1) according to any one of thepreceding claims, wherein the bottom wall comprises a disc portion made of a metallic material, and the shaft (50) is made also of a metalic material, wherein shaft (50) and disc portion are connected by force coupling.

5. Pump assembly (1) according to any one of the preceding claims, comprising a cylindrical bushing (7) extending along the axis (X-X) , which is rotationally free and externally engaged with rotor (42) and impeller group (3) .

6. Pump assembly (1) according to claim 5, wherein the cylindrical bushing (7) has an axial dimension along the axis (X-X) substantially equal to the shaft segment (L) .

7. Pump assembly (1) according to claim 5, comprising a washer (9) positioned axially between the cylindrical bushing (7) and the head (51) , wherein said washer (9) is made of a material chosen from ceramic materials.

8. Pump assembly (1) according to claim 7, wherein the cylindrical bushing (7) and the washer (9) have an axial dimension along the axis (X-X) substantially equal to the shaft segment (L) .

9. Pump assembly (1) according to any one of claims 5 to 8, wherein the rotor (42) is engaged with the cylindrical bushing (7) , for example by force coupling.

10. Pump assembly (1) according to claim 9, wherein the control body (35) extends radially from the cylindricalbushing (7) and at least partially contains the rotor

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