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: 1) 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 group (4) comprising a stator (41), housed in the dry chamber (201), and a rotor ( 42 ), housed in the wet chamber (202); ill) 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), 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); v) a cylindrical bushing (7) extending along the axis (X-X), which is rotationally free and externally engaged with rotor (42) and impeller group (3); vi) 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.

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 assembly of a vehicle are known, which are distinguished among theactuation types .

[0006] Speci fically, 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 water-based 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 components and to the production of noise upon the pump assembly actuation .

[0011] Therefore , it is the obj ect of the present inventionto 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 obj ect 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 obj ect 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 separate parts of some components of the pump assembly in figure 1 .

[0020] In the aforesaid drawings , reference numeral 1 indicates , as a whole , a pump assembly for a coolingsystem 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 maj ority of components of the pump assembly 1 of the present invention, described below .

[0024] Preferably, the container group 2 is fluidly connectable to the conduits 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 of f from said wet chamber 202 .

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

[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 conduits are created, e . g . , appropriate systems in which operating assemblies and / or valve groups are housed . For example , said components comprise speci fic 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 support collar 225 , protruding along the axis X-X, in the central portion 202 ' .

[0035] According to a preferred embodiment , the containerbody 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., of PPS .

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

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

[0039] Preferably, the support 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 conduits 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" at the 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 group 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 portion 201' 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 laminarelements 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 a preferred embodiment , shaft 50 and head 51 are made in one piece .

[0055] According to an alternative embodiment , shaft 50 and head 51 are in two separate components engageable to each other .

[0056] Moreover, the pump assembly 1 comprises a cylindrical bushing 7 extending along axis X-X, which is rotationally free and externally engaged with rotor 42 and impeller group 3 .

[0057] According to the present invention, the pump assembly 1 has a geometry such that the rotation of the rotor 42 corresponds to the rotation of the cylindrical bushing 7 and the impeller group 3 on shaft 5.

[0058] Preferably, the cylindrical bushing 7 is made of ametallic material , e . g . , is made of sintered steel with graphite .

[0059] Preferably, the cylindrical bushing 7 is made of pressed graphite .

[0060] Preferably, the cylindrical bushing 7 is made of graphite- filled resin .

[0061] Preferably, the rotor 42 is fitted onto the cylindrical bushing 7 . And the impeller group 3 is then molded over said components .

[0062] Preferably, rotor 42 and cylindrical bushing 7 are mutually j oined by geometric interference . Preferably, rotor 42 and cylindrical bushing 7 are integrally interconnected .

[0063] 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 .

[0064] Preferably, the control body 35 is engaged with the cylindrical bushing 7 and the rotor 42 , further fixing them .

[0065] In other words , the impeller group 3 is co-molded onto the cylindrical bushing 7 and the rotor 42 so as to form a single " complex component" , the respective components of which are mutually integral .

[0066] According to a preferred embodiment , the rotor 42 is positioned on the cylindrical bushing 7 , and once placedin 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 .

[0067] According to a preferred embodiment , the control body 35 extends radially from the cylindrical bushing 7 and at least partially contains the rotor 42 .

[0068] According to a preferred embodiment , the cylindrical bushing 7 has outer surfaces 71 adapted to promote 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 .

[0069] According to a preferred embodiment , the pump assembly 1 comprises at least one cooling conduit 6 adapted to allow the recirculation of the cooling liquid . Preferably, the cooling liquid flows in the cooling conduit 6 towards the blade element 30 .

[0070] Preferably, the cooling conduit 6 extends substantially parallel to axis X-X .

[0071] Preferably, said cooling conduit 6 comprises a rotor segment 64 which crosses the rotor 42 .

[0072] Preferably, the rotor segment 64 of the cooling conduit 6 extends into the rotor body 420 . In other words , the laminar elements are shaped exhibiting speci fic openings so that they define said rotor segment64 in the pack .

[0073] According to a preferred embodiment , the cooling conduit 6 comprises at least one impeller segment 635 ' , 635" , which crosses the impeller 3 aligned with the rotor segment 64 .

[0074] Preferably, the cooling conduit 6 comprises a first impeller segment 635 ' and a second impeller segment 635" on opposite sides with respect to the rotor segment 64 .

[0075] According to a preferred embodiment , the impeller segment 635 ' , 635" has a greater passage section than the passage section of the rotor segment 64 .

[0076] According to a preferred embodiment , the pump assembly 1 comprises a plurality of angularly equidistant cooling conduits 6 .

[0077] Preferably, each cooling conduit 6 is positioned in a region radially proximal to the cyl indrical bushing 7 .

[0078] Preferably, each cooling conduit 6 is positioned radially between the cylindrical bushing 7 and a rotor pole 421 .

[0079] According to the present invention, the pump assembly 1 further comprises a washer 9 axially positioned between cylindrical bushing 7 and head 51 .

[0080] Preferably, said washer 9 is suitable for minimi zing the friction between cylindrical bushing 7 and head 51 .

[0081] According to the present invention, said washer 9 ismade of a material selected from ceramic materials.

[0082] Preferably, the washer 9 is made of alumina.

[0083] According to a preferred embodiment, washer 9 comprises radial slots 91 through which the cooling liquid flows up to shaft 50.

[0084] Preferably, the washer 9 comprises radial slots 91 on the upper surface facing the head 51.

[0085] Preferably, the washer 9 comprises radial slots 91 on the lower surface facing the cylindrical bushing 7.

[0086] Preferably, at the free end 501 close to the head 51, the shaft 50 has an annular groove 591 in which cooling liquid flows.

[0087] According to a preferred embodiment, washer 9 is positioned so as to keep its angular position fixed.

[0088] According to a preferred embodiment, washer 9 engages shaft 50 so as to keep its angular position fixed .

[0089] Preferably, shaft 50, close to head 51, i.e., in the region proximal to the free end 501, is shaped to achieve a positive coupling with washer 9 so as to keep it in a fixed angular position.

[0090] Preferably, shaft 50, in a region proximal to head 51, has grooves (or concavities) , and bushing 9 has a shaped hole, e.g., a slot-shaped hole, so as to geometrically couple to the shaft section with thegrooves ( or concavities ) .

[0091] Preferably, shaft 50 , in a proximal region, has protruding radial portions , while bushing 9 has radial slots in which said protruding radial portions are housed .

[0092] According to such embodiments , washer 9 is coupled to shaft 50 , in said region, and then head 51 is mounted to shaft 50 so as to block washer 9 in place .

[0093] According to a further preferred embodiment , washer 9 engages head 51 so as to keep its angular position fixed .

[0094] According to a preferred embodiment , shaft 50 extends in a cantilevered manner from the container group 2 to head 51 along axis X-X over a shaft segment L .

[0095] According to a preferred embodiment , shaft 50 has a shaft diameter D .

[0096] According to a preferred embodiment , head 51 has a head height I along axis X-X .

[0097] According to a preferred embodiment , head 51 has a head diameter d .

[0098] Preferably, the ratio of shaft length L to head height I is between 10 and 25 .

[0099] Preferably, the ratio of shaft diameter D to head diameter d is between 0 . 4 and 0 . 8 .

[0100] Preferably, the ratio of shaft length L to headheight 1 is between 15 and 20 .

[0101] Preferably, the ratio of shaft diameter D to head diameter d is between 0 . 5 and 0 . 7 .

[0102] Preferably, the shaft segment L is between 25 and 30 millimeters I in si ze .

[0103] Preferably, the shaft diameter D is between 4 and 6 millimeters in si ze .

[0104] According to a preferred embodiment , the shaft segment L extends from said support collar 225 to the head 51 .

[0105] Preferably, the disc portion is made of a metallic material and the shaft 50 , in turn, is made of a metallic material . Preferably, shaft 50 and disc portion are connected by force coupling .

[0106] According to a preferred embodiment , the pump assembly 1 having the aforesaid features is subj ected to a particular manufacturing method .

[0107] Speci fically, said manufacturing method comprises the step of co-molding the impeller group 3 with the rotor 42 and the cylindrical bushing 7 .

[0108] 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 " complexcomponent" .

[0109] Preferably, said appropriate mold comprises speci fic rod-like elements adapted to create the segments of the cooling conduit .

[0110] Innovatively, the pump assembly largely ful fills the intended purpose by overcoming the typical problems of the prior art .

[0111] Advantageously, indeed, the pump assembly has impeller group and rotor housed in the same chamber, both wetted by the cooling liquid .

[0112] Advantageously, cylindrical bushing and washer avoid the presence of friction and wear situations on the shaft .

[0113] Advantageously, the washer also serves the purpose of avoiding the presence of friction and wear situations between bushing and head .

[0114] Advantageously, the washer is ef fectively lubricated by the cooling liquid . Advantageously, the shaft is ef fectively lubricated by the cooling liquid .

[0115] 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 .

[0116] Advantageously, the cylindrical bushing is easy to make , and is structurally solid, having no slots ,conduits and / or openings .

[0117] Advantageously, the pump assembly has the cantilevered impeller group, not requiring additional axial support in addition to the single fixed end of the shaft .

[0118] Advantageously, the pump assembly is usable in both configurations with volute body and configurations in which the volute is obtained on other vehicle components .

[0119] 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 .

[0120] Advantageously, the pump assembly is quite having a speci fic shaft geometry .

[0121] 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 .

[0122] Advantageously, the pump assembly has a simple construction .

[0123] Advantageously, the pump assembly is easy to assemble .

[0124] It is apparent that , in order to meet contingent needs , those ski lled in the art could makechanges 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) , 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) ; v) a cylindrical bushing (7) extending along the axis (X- X) , which is rotationally free and externally engaged with rotor (42) and impeller group (3) ; vi) 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 .

2. Pump assembly (1) according to claim 1, wherein the shaft (50) and the head (51) are made in one piece.

3. Pump assembly (1) according to any one of the preceding claims, wherein the washer (9) comprises radial slots (91) through which a coolant flows up to the shaft (50) .

4. Pump assembly (1) according to any one of the preceding claims, wherein the shaft (50) close to the head (51) is shaped to be fitted by positive coupling with the washer (9) so as to hold it in a fixed angular position .

5. Pump assembly (1) according to any one of the preceding claims, wherein the shaft (50) close to thehead (51) at the washer (9) has an annular groove (591) .

6. Pump assembly (1) according to any one of the preceding claims, wherein the cylindrical bushing (7) extends along the axis (X-X) from the auxiliary body (22) to the washer (9) .

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

8. Pump assembly (1) according to any one of the preceding claims, wherein the control body (35) extends radially from the cylindrical bushing (7) and at least partially contains the rotor (42) .

9. Pump assembly (1) according to any one of the preceding claims, wherein the impeller group (3) is comolded with the cylindrical bushing (7) and the rotor (42) .

10. Pump assembly (1) according to any one of the preceding claims, wherein the container group (2) comprises a bottom wall in which the fixed end (500) is engaged, wherein the bottom wall is comprised in the container body (21) or in the auxiliary body (22) .

11. Pump assembly (1) according to any one of the preceding claims, wherein the container group (2) comprises a volute body, adapted to engage the containerbody (21) and / or the auxiliary body (22) , wherein the container group (2) , in the coupling between volute body and container body (21) and / or auxiliary body (22) , delimits an impeller portion at the top of the wet chamber (202) in which the impeller (3) is housed.

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