pump group

Abstract

The invention is a pump group for a cooling system of an operating group of a vehicle, preferably an engine group. The pump group extends with respect to an axis and comprises: an impeller; a shaft on which the impeller is integrally mounted; and an electric motor comprising a rotor integrally mounted on the shaft and a stator axially and circumferentially surrounding the rotor. The pump group comprises a pump body comprising along the axis: - an impeller casing in which the impeller is housed; - a separation and support element comprising a neck engaging and rotatably supporting the shaft; - a motor casing in which the electric motor is housed. Said impeller chamber and said motor chamber are hermetically separated from each other and the motor chamber contains an amount of oil adapted to cool the rotor and the stator by convection, the rotation of the rotor in the motor chamber pushing the oil.

Description

TECHNICAL FIELD

[0001] The present invention relates to a pump group for a cooling system of a vehicle. BACKGROUND

[0002] In the present description, the term "vehicle" refers to any mobile means comprising an internal combustion engine and to hybrid vehicles, without any limitation related to the type or size, i.e. cars or articulated vehicles.

[0003] In other words, the present invention relates to the automotive sector and, in particular, to the thermal management system of a vehicle.

[0004] In particular, the cooling system is dedicated to the cooling of an "operating group" of the vehicle.

[0005] In particular, in the present description, an "operating group" refers to a specific component or group of components for performing a specific operation required for the movement of the vehicle. In a preferred embodiment, the "operating group" comprises an engine group, for example an internal combustion engine or an electric motor.

[0006] In other embodiment variants, the "operating group" comprises other components of the vehicle, i.e. both mechanical type components (for example a transmission assembly) and electrical type components (for example a "battery assembly" comprised in the vehicle).

[0007] In the prior art, there are several embodiments of pump groups for operating group cooling systems that differ from each other in terms of size and type of drive.

[0008] In particular, the pump group of the present invention is one in which there is an electric drive. In other words, the pump group of the present invention comprises at least one electric motor that drives the rotation of the impeller comprised therein, thus pushing the cooling liquid flowing in the cooling system that can be fluidically connected to the pump group.

[0009] Several technical solutions are known of pump assemblies comprising an electric drive, in which pump groups of this type have an unavoidable main problem, i.e. the need to effectively cool the electric motor and the components related thereto.

[0010] In particular, several embodiments of pump assemblies are known in which the cooling liquid present in the chamber that houses the impeller is also used to cool the electric motor and the components related thereto. Even more specifically, in the prior art, the cooling liquid is used to cool the rotor of the electric motor.

[0011] However, these embodiments have a complex geometry, in particular due to the need to develop a particularly complex hydraulic portion, i.e. the portion in which the cooling liquid flows. Furthermore, some pump assemblies have a particularly large size, which makes it difficult to meet the needs of the automotive sector, which requires compact pump assemblies in terms of size and overall size so that they occupy as little space as possible. SUMMARY

[0012] It is therefore the object of the present application to provide a pump group for a cooling system of an operating group of a vehicle, which effectively cools all the control-type electronic components, thus solving the problems as described above.

[0013] This object is achieved by a pump group.

[0014] The pump group is for a cooling system of an operating group of a vehicle, preferably an engine assembly, the pump group being positioned with respect to an axis and comprising:

[0015] i) an impeller, rotatable about the axis;

[0016] ii) a shaft, positioned along the axis and comprising an impeller end, on which the impeller is integrally mounted;

[0017] iii) an electric motor comprising a rotor integrally mounted on the shaft and a stator axially and circumferentially surrounding the rotor;

[0018] vi) a pump body comprising, along the axis:

[0019] - an impeller casing in which the impeller is housed in an impeller chamber in which a cooling fluid circulates;

[0020] - a motor casing in which the electric motor is housed inside a motor chamber;

[0021] - a separation and support element comprising a neck engaging and rotatably supporting the shaft;

[0022] - a motor casing in which the electric motor is housed inside a motor chamber;

[0023] wherein the impeller chamber and the motor chamber are fluidically separated from each other; wherein the motor chamber contains an amount of oil suitable for cooling the rotor and the stator by convection, the rotation of the rotor in the motor chamber pushing the oil;

[0024] wherein the neck is positioned along an axial section parallel to the axis, the neck comprising an axial channel which houses the shaft and along which the shaft extends. BRIEF DESCRIPTION OF DRAWINGS

[0025] The subject matter of the present application is described in detail below with reference to the attached drawings, in which:

[0026] - Figure 1a and Figure 1b a longitudinal sectional view of a pump group according to the present application, shown in a vertical operating position, according to a possible embodiment, along different planes of section;

[0027] - Figure 2 a longitudinal sectional view of a pump group according to the present application, shown in a horizontal operating position, according to a possible embodiment.

[0028] - Figure 3 A longitudinal sectional view of a pump group according to the present application is shown in an inclined operating position, according to a possible embodiment. DETAILED DESCRIPTION

[0029] In the above figures, reference 1 refers to the overall of a pump group for a cooling system of a vehicle operating group, preferably for a cooling operating group, such as an internal combustion operating group.

[0030] The pump group 1 of the present application is mainly longitudinally positioned with respect to an axis X-X.

[0031] The pump group 1 of the present application comprises an impeller 2 that can rotate about said axis X-X. In other words, said impeller 2 has a rotation center lying on said axis X-X.

[0032] Preferably, the impeller 2 is a radial type impeller specifically designed to perform a suction action on a cooling liquid, preferably in an axial direction, and to perform a push action on the cooling liquid, preferably in a radial direction. In particular, the “cooling liquid” is a water-based liquid, such as a solution comprising water and glycol, which circulates in a cooling system of a vehicle to which the pump group 1 of the present application can be fluidically connected.

[0033] Furthermore, according to the present application, the pump group 1 comprises a shaft 3 longitudinally positioned along the axis X-X. Preferably, said shaft 3 comprises a rotation end 32 on which the impeller 2 is integrally mounted.

[0034] According to the present application, the pump group 1 comprises an electric motor 4 adapted to rotate the shaft 3.

[0035] The electric motor 4 comprises a rotor 41 and a stator 42. According to a preferred embodiment, the rotor 41 and the stator 42 are concentrically arranged with respect to the axis X-X.

[0036] According to the present application, the rotor 41 is integrally mounted (for example with a key connection) on said shaft 3: the rotation of the shaft 3 and, in turn, of the impeller 2 corresponds to the electronically controlled rotation of the rotor 41. The stator 42 axially and circumferentially surrounds the rotor 41. In particular, the stator 42 comprises a plurality of stator coils forming stator poles.

[0037] According to a preferred embodiment, the pump group 1 comprises an electronic control board operatively connected to the motor shaft 3 and adapted to control the rotation of the motor shaft about the axis X-X. In other words, the electronic board controls the operation of the electric motor 4, thus controlling the rotation of the shaft 3 and, in turn, the rotation of the impeller 2.

[0038] According to the application, the pump group 1 comprises a pump body 5 positioned parallel to and mainly around the axis X-X. The pump body 5 is suitable to comprise the various operating components of the pump group 1 and to be fluidically connectable to the vehicle cooling system.

[0039] According to the application, the pump body 5 comprises, along the axis X-X:

[0040] - a first impeller casing 6 in which the impeller 2 is housed in an impeller chamber 60 through which the cooling liquid flows;

[0041] - a separation and support element 7 comprising a neck 70 which engages and rotatably supports the shaft 3;

[0042] - a motor casing 8 in which the electric motor 4 is housed inside a motor chamber 80.

[0043] In particular, the impeller chamber 60 and the motor chamber 80 are sealed with respect to each other. In other words, thanks to the presence of the separation and support element 7, only the "hydraulic portion" in which the cooling liquid flows, present only in the impeller casing 6, is separated from the "electrical portion" comprised in the motor casing 8.

[0044] According to a preferred embodiment, said separation and support element 7 substantially has the shape of a flange and is sealingly engaged on one side by the impeller casing 6 and on the other side by the motor casing 8.

[0045] Preferably, the shaft 3 crosses the separation and support element 7, which is defined on one side as an impeller end 32 and on the opposite side as a motor end 34 on which the electric motor 4 is engaged.

[0046] According to a preferred embodiment, the neck 70 extends through an axial section parallel to the axis X-X, comprising an axial channel 700 along which the shaft 3 is housed and extends.

[0047] According to a preferred embodiment, the neck 70 has a tapered section comprising a top end 70' close to the rotor 41, preferably housed in the stator 42.

[0048] In other words, the neck 70 has a flanged end 70" close to the impeller 2, the cross section of which is greater than that of the top end 70'. Therefore, the flanged end 70" is suitable to support greater loads and forces.

[0049] According to a preferred embodiment, the separation and support element 7 comprises a sealing member 9 for providing a hydraulic seal between the impeller casing 6 and the motor casing 7.

[0050] Preferably, the sealing member 9 is housed in the neck 70, in particular in the axial channel 700.

[0051] Preferably, the sealing member 9 is proximally axially positioned with respect to the impeller chamber 60.

[0052] According to a preferred embodiment, the sealing member 9 is of the type comprising a first sealing member 91 and a second sealing member 92 adapted to jointly axially define a gas-tight chamber 95.

[0053] Preferably, the first sealing member 91 is of the water-tight type.

[0054] Preferably, the second sealing member 92 is of the oil-tight type. Preferably, the second sealing member 92 is an oil retainer.

[0055] According to a preferred embodiment, the separation and support element 7 comprises at least one venting passage 79 for fluidly connecting the gas-tight chamber 95 to the external environment.

[0056] According to the present application, the pump group 1 comprises a quantity of oil adapted to cool the electric machine 41 and the stator 42 by convection.

[0057] This quantity of oil is stored in the electric machine chamber 80 and then moved by the rotation of the rotor 41.

[0058] The oil is thus adapted to facilitate cooling by thermal convection both in static conditions and in dynamic conditions.

[0059] According to the present application, the oil and the coolant circulate in separate parts of the pump group 1 without mixing. This mixing is indeed prevented by the presence of the sealing member 9 and the rotating member 35.

[0060] Preferably, the oil is of the dielectric type.

[0061] According to a preferred embodiment, the viscosity of the oil is such that the rotor 41 can easily move. In other words, the presence of the oil does not in any way hinder the movement of the rotor 41.

[0062] According to a preferred embodiment, as previously mentioned, the shaft 3 comprises a rotating member 35 operatively connected to the neck 70.

[0063] Preferably, the rotating member 35 is housed in the axial channel 700.

[0064] According to a preferred embodiment, the rotating member 35 radially engages the shaft 3 and the neck 70, in particular the wall that defines the axial channel 700.

[0065] According to a preferred embodiment, the rotating member 35 is a bearing, preferably a double-row ball bearing. In other words, the rotating member 35 has two ball bearing rings 351, 352 axially spaced apart along the axis X-X.

[0066] This means that the first ball bearing ring 351 is close to the electric motor 4 and the second ball bearing ring 352 is close to the impeller 2.

[0067] According to the application, the rotating member 35 does not have an oil-tight function.

[0068] According to a preferred embodiment, the neck 70 comprises lubrication ducts 75 through which the oil flows freely in order to keep the rotating member 35 lubricated.

[0069] According to a preferred embodiment, the neck 70 comprises a plurality of lubrication ducts 75, which are preferably angularly uniformly spaced.

[0070] Preferably, the neck 70 comprises at least three lubrication ducts 75. Thereby, each side comprises at least one lubrication duct 75 with respect to the apparent plane in which the axis X-X lies.

[0071] According to a preferred embodiment, in which the oil has a specific viscosity and the diameter of the lubrication ducts 75 allows the oil to flow according to its viscosity.

[0072] Preferably, the lubrication ducts 75 comprise an inlet 750 adapted to receive the oil and to facilitate the flow of the oil through the lubrication ducts 75 to the rotating member 35.

[0073] According to a preferred embodiment, the inlet 750 has a larger size than the diameter of the lubrication ducts 75.

[0074] According to a preferred embodiment, the inlet 750 also acts as an oil tank or reservoir in order to collect a predetermined amount of oil and to allow the oil to flow into the corresponding lubrication duct 75. Preferably, the inlet 750 is adapted to act as a funnel for the oil flow to the lubrication ducts 75. According to a preferred embodiment, the oil contained in the inlet 750 is adapted to lubricate the rotating member 35.

[0075] According to a preferred embodiment, the lubrication ducts 75 are positioned axially in order to allow the oil to flow to the second ball bearing ring 352.

[0076] Preferably, the lubrication ducts 75 lubricate both the first ball bearing ring 351 and the second ball bearing ring 352.

[0077] According to a preferred embodiment, the first ball bearing ring 351 is lubricated directly by the oil in the motor chamber 80.

[0078] Preferably, the second ball bearing ring is also lubricated by the oil in the motor chamber 80 which lubricates the first ball bearing ring 351.

[0079] According to a preferred embodiment, the amount of oil is such that the oil establishes a free surface higher than the lubrication ducts 75 with respect to the axis X-X in order to ensure the flow of oil to the rotating member 35.

[0080] Preferably, the amount of oil is such that it establishes a free surface higher than the lubrication duct 75 with respect to the axis X-X in any spatial position of the pump group 1.

[0081] In other words, according to a preferred embodiment, the pump group 1 can be positioned in the vehicle in a vertical position, in a horizontal position or in an inclined position and still have the same cooling performance, thus ensuring a higher level of cooling of the electrical components. Preferably, the rotating member 35 is still lubricated so as to operate effectively, thus ensuring a higher rotation speed of the impeller 2.

[0082] Innovatively, the pump group fully achieves the intended purpose by solving the typical problems of the prior art.

[0083] In fact, the pump group advantageously comprises oil suitable for promoting the convective cooling of the "electrical part" of the pump group.

[0084] Advantageously, the pump group effectively cools both the stator and the rotor by exploiting the fact that the rotor drives the oil and promotes forced convection.

[0085] Advantageously, the oil effectively lubricates the rotating member, which operates in optimal conditions.

[0086] Advantageously, the heat generated by the electronic components is effectively carried and transferred to the cooling liquid by the oil and the neck.

[0087] Advantageously, the presence of the oil makes the temperature uniform inside the motor chamber.

[0088] Advantageously, the number of components of the pump group is very limited.

[0089] Advantageously, the assembly steps of the pump group are extremely simple.

[0090] Advantageously, the amount of oil and the number and / or position of the lubrication ducts are able to ensure the lubrication of the rotating member in any position of the pump group. Advantageously, the pump group can be positioned in any position inside the vehicle.

[0091] Advantageously, the lubrication ducts are designed to ensure the uniform inflow of lubricating oil at the start of the vehicle. In other words, the lubrication ducts advantageously store a certain amount of oil that can be used during the start of the vehicle.

[0092] It is clear that a person skilled in the art can make changes to the content of the invention as described above to meet contingent needs, all of which fall within the scope of protection defined by the following claims.

Claims

1. A pump assembly (1) for a cooling system of a vehicle's operating assembly, the pump assembly being positioned relative to an axis (XX) and comprising: i) Impeller (2), which can rotate around the axis (XX); ii) Shaft (3), the shaft being positioned along the axis (XX) and including an impeller end (32), the impeller (2) being integrally mounted on the impeller end; iii) An electric motor (4) comprising a rotor (41) integrally mounted on the shaft (3) and a stator (42) axially and circumferentially surrounding the rotor (41). vi) Pump body (5), the pump body comprising along the axis (XX): - Impeller housing (6), in which the impeller (2) is housed in an impeller chamber (60) in which coolant circulates; - Separating and supporting elements (7), including a neck (70) that engages and rotatably supports the shaft (3); - Motor housing (8), in which the motor (4) is housed inside the motor chamber (80); The impeller chamber (60) and the motor chamber (80) are fluid-tightly separated from each other; The motor chamber (80) contains a certain amount of oil suitable for cooling the rotor (41) and the stator (42) by convection, and the rotation of the rotor (41) in the motor chamber drives the oil. The neck (70) is positioned along an axial segment parallel to the axis (XX), the neck includes an axial channel (700) that accommodates the shaft (3) and the shaft (3) extends along the axial channel; The shaft (3) includes a rotating member (35) operatively connected to the neck (70) and housed in the axial channel (700), wherein the neck (70) has a tapering section including a tip (70') near the rotor (41), and the neck includes a lubrication conduit (75) through which oil flows to lubricate the rotating member (35). The conduit (75) includes an inlet (750) which is larger than the diameter of the lubrication conduit (75) and is adapted to contain oil and facilitate the flow of oil out of the lubrication conduit (75) and toward the rotating member (35). The amount of oil is such that the oil defines a free surface higher than the lubrication conduit (75) relative to the axis (XX) at any spatial location of the pump assembly (1), to ensure that the oil flows into the rotating member (35).

2. The pump set (1) according to claim 1, wherein, The operating group is the engine assembly.

3. The pump set (1) according to claim 1, wherein, The oil is dielectric.

4. The pump assembly (1) according to any one of the preceding claims, wherein, The neck (70) includes multiple lubrication conduits (75).

5. The pump assembly (1) according to claim 4, wherein, The multiple lubrication conduits are spaced at equal angles.

6. The pump assembly (1) according to any one of claims 1-3, wherein, The oil has a specific viscosity and the diameter of the lubrication conduit (75) allows the oil to flow according to its viscosity.

7. The pump assembly (1) according to any one of claims 1-3, wherein, The inlet (750) is an oil tank or reservoir for collecting a predetermined amount of oil and allowing the oil to flow into the corresponding lubrication conduit (75).

8. The pump assembly (1) according to any one of claims 1-3, wherein, The rotating component (35) is a bearing.

9. The pump assembly (1) according to claim 8, wherein, The rotating component (35) is a double-row ball bearing.

10. The pump assembly (1) according to any one of claims 1-3, wherein, The separation and support element (7) includes a sealing member (9) which is received in the neck (70) in the axial channel (700) and located proximal to the impeller chamber (60), wherein the sealing member (9) is adapted to ensure a hydraulic seal between the impeller housing (6) and the motor housing (7).

11. The pump assembly (1) according to claim 10, wherein, The sealing member (9) includes a watertight first sealing element (91) and an oiltight second sealing element (92), with an airtight chamber (95) between the first sealing element and the second sealing element.

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