EP3426926A1

EP3426926A1 - Pump group with electric drive and mechanical drive comprising a joint group

Info

Publication number: EP3426926A1
Application number: EP17709175.8A
Authority: EP
Inventors: Alfonso SURACE; Marco Pedersoli
Original assignee: Industrie Saleri Italo SpA
Current assignee: Industrie Saleri Italo SpA
Priority date: 2016-03-08
Filing date: 2017-01-20
Publication date: 2019-01-16
Anticipated expiration: 2037-01-20
Also published as: EP3426926B1; HUE048795T2

Abstract

A pump group (1) for a cooling circuit of a motor of a vehicle, comprising: - an impeller (2) rotatable around an axis (X-X) moved by an impeller shaft (200); - a mechanical drive (3) and a mechanical shaft (300) rotatable by the mechanical drive (3) and operatively connected to the impeller shaft (200); - an electric drive (4) and an electric shaft (400) rotatable by the electric drive (4) and operatively connected to the impeller shaft (200); - a joint group (5) comprising respectively an impeller shaft joint end (205), a mechanical shaft joint end (305) and an electric shaft joint end (405), in which the respective ends are operatively connected to each other by means of a first one-way coupling (51) and a second one-way coupling (52).

Description

DESCRIPTION

"PUMP GROUP WITH ELECTRIC DRIVE AND MECHANICAL DRIVE

COMPRISING A JOINT GROUP"

[0001] The present invention relates to a pump group for a cooling circuit of a vehicle, preferably for cooling a motor, such as an internal combustion engine.

[0002] As is known, during normal use of a motor, it is appropriate to vary the intensity of the cooling action.

[0003] For example, an intense cooling is appropriate when the motor is working at full capacity or in towing conditions or on an uphill road or with high ambient temperatures .

[0004] In other conditions of use instead, it is appropriate for the cooling not to be accentuated, for example when starting the motor or after use.

[0005] The prior art discloses cooling pumps in which this need has been addressed.

[0006] Cooling pumps are in fact known of for electrically operated vehicles, in which the speed of rotation of the impeller is regulated by means of an electric drive and thus the amount of coolant liquid moved by it in circulation in the cooling circuit.

[0007] Unfortunately, such pumps, although extremely versatile in their application and in the possibilities of rotation management thanks to the dedicated electronic control, typically have low delivery power, limited by the electric power provided by the vehicle's electrical system .

[0008] Furthermore, these pumps do not have the "fail-safe" feature in case of failure, i.e. the possibility to function in an emergency configuration when the electric motor has suffered a breakage.

[0009] Mechanically operated pumps are also known of where the rotation of the impeller is related to the number of revolutions of the internal combustion engine; in these solutions, the adjustment of the quantity of coolant liquid is entrusted to special adjustment elements, placed upstream or downstream of the impeller, suitable to change the through cross-section of the circuit thus varying the flow of coolant liquid.

[0010] Unfortunately, such solutions although suitable for delivering high power and proving conspicuously reliable, have less versatile cooling management, related to the motor speed and the characteristics of the adjustment element, and are typically too large. Also, in a "post- run" configuration, i.e. with the motor off, no cooling is performed .

[0011] Lastly, dual driven pumps are also known of, i.e. comprising both an electric drive and a mechanical drive.

[0012] Unfortunately, these pumps have particularly complex management of the two drives, as well as an articulated and bulky structure.

[0013] The purpose of the present invention is to provide a pump group for a cooling circuit of a vehicle, for example for an internal combustion engine, which meets the requirements mentioned, overcoming the drawbacks spoken of. In other words, the aim is to provide a dual action pump group, with simplified management of the two drives, and with a simple and compact structure.

[0014] Such purpose is achieved by a pump group made according to claim 1. The dependent claims refer to preferred embodiment variants having further advantageous aspects .

[0015] The object of the present invention will be described in detail below, with the help of the appended drawings, wherein :

[0016] - figure 1 shows a perspective view of the pump group according to the present invention, according to a first possible embodiment;

[0017] - figure 2 shows a cross-section view of the pump group in figure 1;

[0018] -figure 2a shows an enlarged cross-section view of a detail of the pump group shown in figure 2.

[0019] With reference to the aforementioned drawings, reference numeral 1 globally denotes a pump group for a cooling circuit of a motor, preferably an internal combustion engine, according to an embodiment variant of the invention.

[0020] The pump group 1 of the present invention comprises an impeller 2 rotatable around an axis X-X so that the rotation of the impeller 2 corresponds to the movement of a predetermined quantity of coolant liquid in the circuit.

[0021] Preferably, the impeller 2 is of the radial type, i.e. provides that the incoming flow of liquid has an overall substantially axial direction and the flow of liquid in output has a radial direction.

[0022] The pump group 1 comprises an impeller shaft 200 which extends along said axis X-X, and comprises an impeller end 202 on which the impeller 2 is mounted integral in rotation. In other words, the rotation action of the impeller shaft 200 corresponds to a rotation of the impeller 2.

[0023] The pump group 1 provides a dual drive, i.e. it is operable both mechanically and electrically. To such purpose, the pump group 1 comprises a mechanical drive 3 and an electric drive 4.

[0024] In particular, the pump group 1 comprises a mechanical shaft 300 rotatable by the mechanical drive 3 and operationally connected to the impeller shaft 200. In other words, the movement of the mechanical shaft 300 induces the movement of the impeller shaft 200.

[0025] In a preferred embodiment, the mechanical drive 3 comprises a pulley for a drive belt connected, for example by using a kinematic chain, to the drive shaft.

[0026] Preferably, the pulley is an electromagnetic pulley 33.

[0027] In the embodiment with the electromagnetic pulley 33, this is normally engaged and only when it is actuated (i.e. the coil in it is electrically excited) does the release mechanism disengage the pulley from the mechanical shaft 300.

[0028] In fact, preferably, the electromagnetic pulley 33 comprises an outer ring on which the drive belt is mounted, an inner ring and an intermediate release mechanism which comprises an intermediate coil. The inner ring is, in this embodiment, the drive ring operationally connected to the mechanical shaft 300, which by means of a first one-way coupling 51 (described below) is operatively connected to the impeller shaft 200.

[0029] Normally, when the electromagnetic pulley 33 is not electrically energized, the outer ring is integral in rotation with the inner ring. In this configuration of electromagnetic pulley 33 disabled, if the inner ring has a rotation speed greater than the driven ring, the mechanical shaft 300 is dragged in rotation mechanically. Instead, when the electromagnetic pulley 33 is activated (i.e. the coil is electrically energised), the release mechanism releases the outer ring from the inner ring, so that the outer ring, while driven in rotation by the belt, does not transmit any rotation to the inner ring and thus to the mechanical shaft 300.

[0030] In addition, the pump group 1 comprises an electric shaft 400 rotatable by the electric drive 4 and operationally connected to the impeller shaft 200.

[0031] Preferably, the electric drive 4 comprises an electric motor 40 comprising an impeller 41 mounted on a motor end 401 of the electric shaft 400 and a stator 42 fixed coaxial to the rotor 41.

[0032] The pump group 1 further comprises an electronic control device for controlling the electric drive 4 and/or electromagnetic pulley 33; preferably, said control device is placed on board the pump group 1.

[0033] According to a preferred embodiment, the pump group 1 of the present invention further comprises a joint group 5 suitable to place in connection the impeller shaft 200 with the mechanical shaft 300 and electric shaft 400. Preferably, the joint group 5, as described below, is also suitable to place in motion the impeller shaft 200 as a function of the action of the mechanical shaft 300 and/or of the electric shaft 400. [0034] Preferably, in fact, the joint group 5 comprises respectively an impeller shaft joint end 205, a mechanical shaft joint end 305 and an electric shaft joint end 405.

[0035] According to a preferred embodiment, the impeller shaft joint end 205 is operatively connected with the mechanical shaft joint end 305 by means of a first one-way coupling 51; while the impeller shaft joint end 205 is operatively connected with the electric shaft joint end 405 by means of a second one-way coupling 52.

[0036] Preferably, the first one-way coupling 51 comprises a rolling bearing for the support in rotation of the mechanical shaft joint end 305 to the impeller shaft joint end 205. For example, the rolling bearing is of the type with rollers or needle rollers, having rolling elements placed between the driven ring and the drive ring.

[0037] Preferably, the second one-way coupling 52 comprises a rolling bearing for the support in rotation of the electric shaft joint end 405 to the impeller shaft joint end 205. For example, the rolling bearing is of the type with rollers or needle rollers, having rolling elements placed between the driven ring and the drive ring.

[0038] According to a preferred embodiment, the mechanical shaft 305 and the electric shaft 405 extend along said rotation shaft X-X.

[0039] Preferably, the impeller 2, mechanical drive 3 and electric drive 4 are aligned along the rotation shaft X- X. In other words, the mechanical drive 3 is placed between the impeller and the electric drive 4.

[0040] According to a preferred embodiment, the joint group 5 is positioned along the axis X-X between the impeller 2 and the mechanical drive 3.

[0041] The one-way couplings 51, 52 comprised in the joint group 5 are suitable to operate in conditions of lubrication; preferably, the joint group 5 comprises sealing elements 55 suitable to operate radially with the respective shafts to sealingly contain the lubrication lubricant of the first one-way coupling 51 and the second one-way coupling 52.

[0042] In a preferred embodiment, the impeller shaft joint end 205 is hollow and defines therein an impeller shaft housing 205' suitable to house the second one-way coupling 52 and the electrical shaft joint end 405. While the impeller shaft joint end 205, outside, supports the first one-way coupling 51 and the mechanical shaft joint end 305, the latter defining a mechanical shaft housing 305' . Preferably, in fact, the mechanical shaft housing 305' extends in length to contain the electric shaft joint end 405, the first one-way coupling 51, the impeller shaft joint end 205 and the second one-way coupling 52.

[0043] Embodiments are also provided for in which the joint ends have different shapes from those described above, but are structured to house and support the reciprocal portions and the one-way couplings so as to be operatively connected with the impeller shaft 200, in particular with the impeller shaft joint end 205.

[0044] For example, in a further embodiment (not shown in the appended drawings) the impeller shaft joint end 205 is hollow and defines therein an impeller shaft housing 205' suitable to house the first one-way coupling 51 and the mechanical shaft joint end 305. While the impeller shaft joint end 205, outside, supports the second one-way coupling 52 and the electric shaft joint end 405, the latter defining an electric shaft housing 305'. Preferably, in fact, the electric shaft housing 405' extends in length to contain the mechanical shaft joint end 305, the second one-way coupling 52, the impeller shaft joint end 205 and the first one-way coupling 51.

[0045] Preferably, the pump unit 1 comprises a pump body 10 housing the impeller 2 in a specially shaped, impeller chamber 120.

[0046] The pump body 10, in particular, is designed to be suitable to rotatably support the impeller shaft 200 and the joint element 5.

[0047] The pump group 1 in fact comprises rotation means 60 suitable to rotatably support the impeller shaft 200 and joint group 5 to the pump body 10. Preferably, the rotation means 60 comprise at least a first rolling element 61 operatively connected to the impeller shaft 200; in addition, preferably, the rotation means 60 comprise at least a second rolling element 62 operationally connected to the joint group 5.

[0048] According to a preferred embodiment, moreover, the rotation means 60 further comprise at least one dynamic seal 65 engaging the pump body 10 and impeller shaft 200 to sealingly close the impeller chamber 120.

[0049] Moreover, in a preferred embodiment the pump group 1 comprises a throttle valve (not shown) , fitted in the pump body so as to be placed along the outlet duct from the impeller chamber 120. The valve is controllable using an actuator (not shown) , for example electric, hydraulic or vacuum, preferably controllable by the control device. The characteristics of such valve are disclosed in the documents EP2534381, EP13188771, EP13801735, W02015 / 059586 and BS2014A000171 on behalf of the Applicant.

[0050] In addition, according to a further embodiment, the pump group 1 comprises, upstream of the impeller 2, an adjustment cartridge (not shown) suitable to adjust the amount of coolant liquid towards the impeller. The characteristics of said obturator cartridge are illustrated for example in the document WO2015/004548 on behalf of the Applicant.

[0051] According to the embodiments described above, the electric drive 4 and/or any electromagnetic pulley 33 are controlled electronically depending on the occurrence of certain conditions during use of the vehicle.

[0052] In a normal configuration, the electromagnetic pulley 33 is not energised and the electric drive 4 is off, so that the impeller shaft 200 is moved only by the electromagnetic pulley 33, i.e. by the rotation of the mechanical shaft 300.

[0053] For example, when starting the vehicle, if the engine is still cold (so-called "warm-up" configuration), the electromagnetic pulley 33 is activated, in order to disengage the action on the mechanical shaft 300 while the electric drive 4 is left off. As a result the impeller 2 remains stationary, the liquid does not circulate in the circuit and the motor warms up faster.

[0054] According to another example, under heavy load conditions, such as when the vehicle is towing a trailer or going uphill struggle, typically at low speed (and therefore with low engine revs), the electric drive 4 is activated in order to place the impeller shaft 200 in rotation at a speed greater than that induced by the mechanical drive 3.

[0055] Advantageously, in this configuration, the first one- way coupling 51 disengages in rotation the impeller 200 from the mechanical shaft 300 reducing the masses dragged in rotation by the electric drive 4.

[0056] According to a further example, after use of the vehicle, if the coolant liquid is still very hot, the electric drive 4 is activated so as to rotate the impeller shaft 2 (this stage is therefore called "post run") .

[0057] This way, the impeller 2 rotates at a predetermined rotation speed, while the mechanical drive 3 is completely inactive, since the vehicle engine is off. Specifically, for example, the electromagnetic pulley 33 is not energized, it not being necessary for the movement of the rotation shaft. In this case too, the first one-way coupling 51 disengages in rotation the impeller shaft 200 from the mechanical shaft 300 reducing the masses dragged in rotation by the electric drive 4.

[0058] In general, therefore, the electric drive 4 is activated whenever it is necessary to increase the cooling capacity, regardless of the mechanical drive 3, related to the engine speed.

[0059] For example, in an embodiment in which the pump group 1 comprises a mechanical drive 3 which has a "classic pulley", of the mechanical type, therefore not controlled electronically, and the above described throttle valve, in the above-described "warm-up phase in which the engine is still cold and heating as fast as possible is desired, the quantity of coolant in circulation is regulated by controlling the positioning of the throttle valve.

[0060] Innovatively, the pump group according to the present invention satisfies the cooling requirements of the engine and overcomes the drawbacks referred to above.

[0061] In the first place, advantageously, the pump group according to the invention is very flexible, as it responds to the cooling needs of the vehicle depending on the actual demand and not on the engine speed or availability of electric power of the system. That is to say that, advantageously, the pump group proves particularly suitable for entirely managing the quantity of cooling liquid in the cooling system, for example by managing the cooling of further vehicle components besides the engine, such as the turbo group, obviating the need to have specific electrical pumps to move the predetermined quantities of coolant liquid in such components, permitting extra space to be gained in the engine compartment .

[0062] Moreover, advantageously, the pump group is particularly compact and small in dimensions, making it particularly suitable to be housed in the engine compartment of a motor vehicle.

[0063] For example, advantageously, the impeller (and the impeller chamber with the volute) is more compact and not oversized, and always operating under optimum performance conditions compared to the known pump groups, where the impeller is often oversized to compensate for the poor flexibility of the mechanical pumps and limited power of the electric pumps.

[0064] A further advantageous aspect lies in the fact that the joint group simplifies the structure of the pump group, which is more compact in size compared to solutions of the prior art .

[0065] Yet a further advantageous aspect is due to the fact that the hydraulic and mechanical loads are distributed on the impeller shaft in an optimised manner. For example the impeller shaft is of a particularly compact size compared to the solutions of the prior art.

[0066] In addition, yet a further advantageous aspect consists of the fact that the pump group requires a limited number of dynamic seals.

[0067] Advantageously, the design of the electric drive is simplified and is optimizable by the designer.

[0068] Moreover, advantageously, the transition from the electric drive to the mechanical drive and vice versa is operated mechanically by the one-way couplings. Therefore, advantageously, the electronic management of the pump group is very simple. [0069] In addition, advantageously, the pump group is able to avoid the cooling action, even though the engine is in gear, when, for example, in conditions of "warm-up", it is appropriate to heat the motor.

[0070] In a further advantageous aspect, the pump group has the "fail-safe" features; in fact, in the event of a failure of the electric drive the pump group, thanks to the mechanical drive and the second one-way coupling, continues to ensure the movement of the impeller.

[0071] According to a further advantageous aspect, the pump group is operative in "after-run" conditions, i.e. with the engine off. Advantageously, in conditions of "post- run", it is possible to avoid electrically powering the electromagnetic pulley saving electricity.

[0072] A further advantageous aspect consists in the fact that the pump group has a more limited power absorption compared to standard mechanical pumps.

[0073] In addition, advantageously, the second one-way coupling allows, in a configuration in which the impeller is made to rotate by the mechanical drive, the rotor not to be rotated by the shaft; magnetic friction is thus not produced (or nor does the rotor-stator group work as an electric generator) .

[0074] It is clear that a person skilled in the art may make modifications to the pump group described above so as to satisfy contingent requirements, all contained within the scope of protection as defined by the following claims.

[0075] In addition, each variant described as belonging to a possible embodiment may be realised independently of the other embodiments described.

Claims

1. Pump group (1) for a cooling circuit of the motor of a vehicle, comprising:

- an impeller (2) rotatable around an axis (X-X) and an impeller shaft (200), which extends along said axis (X-X) and comprises an impeller end (202) on which the impeller (2) is mounted integral in rotation;

- a mechanical drive (3) and a mechanical shaft (300) rotatable by the mechanical drive (3) and operatively connected to the impeller shaft (200) ;

- an electric drive (4) and an electric shaft (400) rotatable by the electric drive (4) and operatively connected to the impeller shaft (200) wherein the electric drive (4) comprises an electric motor (40);

- a joint group (5) comprising respectively an impeller shaft joint end (205), a mechanical shaft joint end (305) and an electric shaft joint end (405), in which the impeller shaft joint end (205) is operatively connected with the mechanical shaft joint end (305) by means of a first one-way coupling (51) and the impeller shaft joint end (205) is operatively connected with the electric shaft joint end (405) by means of a second one-way coupling (52) .

2. Pump group (1) according to any of the preceding claims, wherein the mechanical shaft (305) and the electric shaft (405) extend along said rotation axis (X-X) .

3. Pump group (1) according to claim 2, wherein the impeller (2), mechanical drive (3) and (4) electric drive are arranged aligned along the rotation axis (X-X) .

4. Pump group (1) according to claim 3, wherein the joint group (5) is positioned along the axis (X-X) between the impeller (2) and the mechanical drive (3) .

5. Pump group according to any of the preceding claims, wherein the joint group (5) comprises sealing elements (55) suitable to operate radially with their respective shafts to sealingly contain lubrication lubricant (51) of the first one-way coupling and of the second one-way coupling (52) .

6. Pump group according to any of the preceding claims, wherein the impeller shaft joint end (205) is hollow and defines therein an impeller shaft housing (205') suitable to house the second one-way coupling (52) and electric shaft joint end (405), wherein the impeller shaft joint end (205) supports on the outside the first one-way coupling (51) and the mechanical shaft joint end (305), the latter defining a mechanical shaft housing (305') .

7. Pump group according to claim 6, wherein the mechanical shaft housing (30') extends in length and houses therein the electric shaft joint end (405) .

8. Pump group according to any of the preceding claims, wherein the impeller shaft joint end (205) is hollow and defines therein an impeller shaft housing (205') suitable to house the first one-way coupling (51) and the mechanical shaft joint end (305), wherein the impeller shaft joint end (205) supports on the outside the second one-way coupling (52) and the electric shaft joint end (405), the latter defining an electric shaft housing.

9. Pump group according to any of the preceding claims, wherein the first one-way coupling (51) comprises a rolling bearing for the support in rotation of the mechanical shaft joint end (305) .

10. Pump group according to any of the preceding claims, wherein the second one-way coupling (52) comprises a rolling bearing for the support in rotation of the electric shaft joint end (405) .

11. Pump group (1) according to any of the preceding claims, further comprising a pump body (10) housing the impeller (2) in an impeller chamber (120), in which the pump body (10) rotationally supports the impeller shaft (200) and the joint element (5) .

12. A pump group (1) according to claim 11, comprises means of rotation (60) suitable to rotationally support the impeller shaft (200) and the joint group (5) to the pump body (10), wherein said rotation means (60) comprise at least a first rolling element (61) operatively connected to the impeller shaft (200) and a least a second rolling element (62) operatively connected to the joint group (5) .

13. Pump group (1) according to claim 12, wherein the rotation means (60) further comprise at least one dynamic seal (65) engaging the pump body (10) and impeller shaft (200) to sealingly close the impeller chamber (120) .

14. Pump group (1) according to any of the preceding claims, wherein the mechanical drive (3) comprises an electromagnetic pulley (33) mounted at a pulley end (303) of the mechanical shaft (300) wherein the electromagnetic pulley is normally engaged, excitable electrically to disengage the mechanical drive from the shaft.

15. Pump group (1) according to any of the preceding claims, wherein the electric drive (4) comprises a rotor (41) mounted on a motor end (401) of the electrical shaft (400), opposite the electric shaft joint end (405), and a fixed stator (42) coaxial to the rotor (41) .

16. Pump group (1) according to any of the preceding claims, comprising an electronic control device for controlling the electric drive (4) and/or electromagnetic pulley (33), said control device being placed on board the pump group (1) .