Pump for engine cooling circuits with magnetic-actuated flow regulator

Abstract

 A pump (10, 10') for the circulation of a cooling fluid into a device such as an internal combustion engine or a fuel cell and provided with a magnetic-actuated flow regulator, said pump comprising an impeller (12) keyed to the end of a rotation shaft (14) connected to a means suitable for transmitting the rotary motion to the shaft itself and turnably arranged, by means of one or more bearings or brasses (20), relative to a container body (18) suitable for allowing the steady and safe fixing of the pump relative to the internal combustion engine or to the fuel cell, with said pump further comprising means for enabling/disabling the cooling fluid circulation with said magnetically-actuated means.

Description

[0001] This invention relates to a pump for cooling circuits provided with a magnetic-actuated flow regulator.

[0002] More in particular, this invention relates to a pump especially usable for allowing the circulation of a cooling fluid in internal combustion engines or fuel cells.

[0003] It is known that in the particular but non-exclusive case of internal combustion engines, some components, during the engine operation, reach very high temperature values and as such potentially harmful for the life and for the correct and safe operation of the components, besides the engine. For this reason it is important to provide for the cooling of the engine components ensuring the dissipation of excess heat.

[0004] The dissipation of excess heat is usually obtained fitting the engine or the fuel cell with a cooling fluid circulation system.

[0005] The circulation of the aforesaid cooling fluids into the engine is obtained, in a preferred but non-limiting manner, using mechanical, electro-mechanical or magnetic drive pumps that circulate the fluid and keep the component temperature at such a value as to ensure correct and safe operation thereof.

[0006] The mechanical pumps used for achieving the aforesaid purpose are characterised by an impeller keyed onto a shaft placed in rotation by a belt drive, pulley or the like connected to the engine.

[0007] In magnetic drive pumps, on the contrary, the impeller is placed in rotation by means of the magnetic field induced through a series of permanent magnets arranged in coaxial direction relative to the internal body.

[0008] In both types of pumps, the cooling fluid circulates continuously with a flow rate that is function of the number of revolutions per minute of the engine and as a consequence, the pump continues to operate even when this is not strictly necessary; for example, when the external temperature is quite low or very low, engine cooling is even counter-productive as regards optimal operation in steady conditions, control of consumptions and control of the emissions of burnt gases.

[0009] The object of this invention is to obviate the drawback mentioned hereinabove.

[0010] More in particular, the object of this invention is to provide a pump for cooling circuits with magnetic-actuated flow regulator which allows actuating the cooling fluid circulation only when this is required by the temperature conditions reached by the engine components.

[0011] A further object of this invention is to provide a pump as defined above of the "fail-safe" type, that is, such as to ensure correct operation of the pump itself even in the case of malfunction or fault.

[0012] A further object of this invention is to provide the users with a magnetic drive pump for cooling circuits suitable for ensuring high level of resistance and reliability over time, which allows to be quickly and easily to assembled and also such as to be easily and inexpensively constructed.

[0013] These and other objects are achieved by the pump according to claim 1. Further advantageous features are stated in the dependent claims.

[0014] The construction and functional features of the pump for cooling circuits with magnetic-actuated flow regulator of this invention can be better understood from the following detailed description, wherein reference is made to the annexed drawings showing a preferred and non-limiting embodiment thereof, and wherein:

figure 1 shows a schematic and axonometric view of a longitudinal section of the pump for cooling circuits with magnetic-actuated flow regulator of the invention according to a first operating configuration;

figure 2 shows a schematic and axonometric view of a longitudinal section of the pump of the invention according to a second operating configuration;

figure 3 shows a schematic enlarged detail of a portion of the pump of the invention;

figure 4 shows a schematic and axonometric view of a longitudinal section of the pump of the invention according to an alternative embodiment and in a first operating configuration;

figure 5 shows a schematic view of a longitudinal section of the pump of the invention of figure 4 according to a second operating configuration;

figure 6 shows a schematic enlarged detail of the pump of the invention according to the alternative embodiment.

[0015] With reference to the aforesaid figures, the pump for engine cooling circuits with magnetic-actuated flow regulator of the invention, globally indicated with 10, is composed of an impeller 12 known per se and keyed, by means of a bush 13 or in other known manner, to the bottom end of a rotation shaft 14, preferably with differentiated diameters.

[0016] Said shaft is connected, through a hub 16 fixed at the top end of the rotation shaft itself and on the opposite side relative to that of fixing of the impeller 12, to a pulley (not shown in the figure) or to an equivalent means suitable for transmitting the rotary motion to the shaft.

[0017] The rotation shaft 14 is turnably arranged relative to a container body 18, advantageously made by fusion of aluminium alloy or other suitable material and suitable for allowing the steady and safe fixing of the pump relative to the internal combustion engine or to the fuel cell. The container body 18, moreover, externally and concentrically to the central part suitable for receiving the rotation shaft 14, defines two concentric chambers 17 and 19, of the annular type, extending in axial direction and open at the bottom front of the container body 18 facing the direction of the impeller 12 (said chambers are well visible in the detailed view at figure 3).

[0018] The rotation shaft 14 is supported in the movement thereof into the container body 18 by one or more bearings or brasses 20 arranged inside the container body 18 and coaxially to the rotation shaft 14.

[0019] A mechanical seal 22 keyed on the rotation shaft 14, at the impeller 12 and stabilised in a known manner to the container body 18, ensures the absence of any fluid leaks.

[0020] A shaped element 24 is arranged in the region comprised between the impeller 12 and the bottom front, facing the direction of the impeller itself, of the container body 18.

[0021] Said shaped element 24, made of sheet metal or moulded plastic or other suitable material, comprises:

a bottom portion 24' with hollow discoid shape so as to fit onto the outer surface of the impeller 12 of the pump according to the methods described hereinafter;

a top portion 24" defined by one or more appendices that, starting from the top front of the bottom portion 24', partly develop in a direction opposite that of the impeller 12.

[0022] The appendices of the top portion 24" of the shaped element 24 insert into the chamber 19 of the container body and preferably have an "S" shaped profile; said appendices are sliding in axial direction into the chamber 19 according to the methods described hereinafter.

[0023] A sleeve 26 is fixed to the container body 18 at the central portion thereof and is inserted into the chamber 19 of the container body 18; said sleeve 26 has a flange or edge 26' suitable for defining a stop to the sliding, into the chamber 17, of the appendices of the top portion 24" of the shaped element 24.

[0024] A first magnetic ring 28 made in a single piece preferably of plastic neodymium, neodymium-iron-boron (NdFeB) or other equivalent and known material is fixed, by means of a joint, by gluing or other known manner, at the top end of the shaped appendices of the top portion 24" of the shaped element 24. In an alternative embodiment, the first magnetic ring 28 may be defined by a plurality of magnetic blocks preferably inserted in a metal beam and fixed in a known manner to the top side of the appendices of the top portion 24".

[0025] The chamber 17 is closed underside, at the bottom of the container body 18 facing the direction of the impeller 12 of the pump, by means of an annular cap 30 partly inserted into the chamber 17. Two or more seals 32 that define static seals, ensure the seal of the annular cap 30 and prevent the infiltration of fluid into the chamber 17 of the container body 18.

[0026] An elastic means, for example a helical spring 34, whose function will be explained hereinafter, is inserted into the chamber 17.

[0027] The helical spring supports an annular element 36, made of metal or plastic or other known material, from whose top front facing the direction opposite the annular cap 30 at least one optional lip 38 develops in vertical direction, extending in a continuous or partial manner, along the entire circumference of the annular element 36.

[0028] The aforesaid annular element 36 has a section basically shaped as an "H" with two grooves into each whereof one or more rings 37 are received, preferably made of Teflon, which ensure the seal and help the movement of the annular element itself into the chamber 17.

[0029] The annular element 36 together with the lip 38 defines the support for a second magnetic ring 40 made, like the first magnetic ring 28, in a single piece and of plastic neodymium, neodymium-iron-boron (NdFeB) or other equivalent and known material.

[0030] As with the first magnetic ring 28, also the second magnetic ring 40 may be defined by a plurality of magnetic blocks, preferably inserted in a metal beam , relative to the annular element 36 and the at least one optional lip 38.

[0031] Figures 4, 5 and 6 schematically show the pump for engine cooling circuits with magnetic-actuated flow regulator of the invention according to an embodiment alternative to the preferred one said alternative embodiment is indicated by reference numeral 10'.

[0032] For simplicity, the parts in common with the preferred embodiment whereof at figures 1, 2 and 3 will be indicated with the same reference numeral.

[0033] With reference to said alternative embodiment whereof at figures 4, 5 and 6, the container body 18, externally and concentrically to the central part suitable for receiving the rotation shaft 14, defines two concentric chambers 17' and 19', of the annular type, extending in axial direction and open at the bottom front of the container body 18 facing the direction of the impeller 12.

[0034] A hollow cylindrical body 50 and made of sheet metal or moulded plastic or other suitable material, is arranged in the region comprised between the impeller 12 and the bottom front, facing the direction of the impeller itself.

[0035] Said cylindrical body 50 is partly inserted into the chamber 17' and slidingly arranged in axial direction relative to the same according to the methods described hereinafter.

[0036] At least a first magnetic ring 52 made, like those described before with reference to the preferred embodiment, of plastic neodymium, neodymium-iron-boron (NdFeB) or other equivalent and known material, is fixed in a known manner on the inner side surface of said cylindrical body 50 and at the top portion thereof, facing the direction of the bottom of the chamber 17'; said first magnetic ring is made in a single piece or is defined by a plurality of magnetic blocks, preferably inserted in a metal frame, fixed to the side surface of the cylindrical body 50.

[0037] The chamber 19' is closed underside, at the bottom of the container body 18 facing the direction of the impeller 12, by means of an annular cap 30" partly inserted into the chamber itself. Two or more seals 54, defining seals, ensure the seal of the annular cap 30' and prevent the infiltration of cooling fluid into the chamber 19' of the container body 18.

[0038] As in the preferred embodiment, an elastic means, for example at least one helical spring 56, whose function shall be explained hereinafter, is inserted into the chamber 19'.

[0039] The helical spring supports an annular element 58, made of metal or plastic or other known material, from whose top front facing the direction opposite the annular cap 30' at least one optional lip 60 develops in vertical direction, extending in a continuous or partial manner, along the entire circumference of the annular element 58. The aforesaid annular element 58 has the same structural features as the annular element 36 of the preferred embodiment and for this reason it is not subject of a detailed description; one or more rings 62, similar to rings 37, which ensure the seal and help the movement of the annular element itself into the chamber 19', are inserted into each of the grooves of the annular element 58.

[0040] The annular element 58 together with the optional lip 62 defines the support for at least a second magnetic ring 64 made, like the first magnetic ring 52, in a single piece and of plastic neodymium, neodymium-iron-boron (NdFeB) or other equivalent and known material.

[0041] Likewise the first magnetic ring 52, also the second magnetic ring 64 may be defined by a plurality of magnetic blocks, preferably inserted in a metal frame, relative to the annular element 58 and the at least one optional lip 60.

[0042] The pump for engine cooling circuits of the invention is preferably connected to a pneumatic supply circuit (not shown in the figure) suitable for actuating, by drawing air into the chamber 17 or 19' of the container body 18, the movement according to the methods discussed hereinafter; as an alternative, the movement may also be actuated by hydraulic, mechanical or electromagnetic drives, or other known type.

[0043] In both embodiments axial movement means is provided, such as for example a pneumatic supply circuit for the axial movement of the shaped element 24, or respectively of the cylindrical body 50, which by drawing air into the chamber 17 or 19' of the container body 18, actuates the axial movement of said elements, or hydraulic, mechanical, electromagnetic drives or other known type.

[0044] The operation of the pump for engine cooling circuits of the invention, described in detail hereinabove as regards the structural components thereof, is described hereinafter with reference first to the preferred embodiment and then to the alternative one.

[0045] Figure 2 shows the final "on" condition of the pump, that is, the condition wherein, with the impeller 12 in rotation, the cooling fluid circulates into the circuit.

[0046] In such operating condition, the bottom portion 24' of the shaped element 24 is not in contact with the volute (the body that surrounds the impeller 12 of the pump and not shown in the figure) of the pump basement; as schematised in figure 2, the top front of the bottom element 24' is in contact with the bottom front of the annular cap 30; starting from the configuration whereof at figure 2, the pneumatic supply circuit draws air from the chamber 17 (by means of the pneumatic supply circuit) of the container body 18 and then, the helical spring 34 is in the condition of maximum compression into the chamber 17 itself (see figure 1).

[0047] As said above, in such operating condition the impeller 12 is actuated by means of the pulley or another motion driving means and allows the circulation of the cooling fluid.

[0048] When air is drawn from the chamber 17 of the container body 18, by the effect of the pressure exerted by the air (the pump of the invention operates in pressure), the annular element 36, which acts as a piston, is drawn downwards in the direction of the annular cap 30; such translatory movement inside the chamber 17 causes the compression of the helical spring 34.

[0049] When the second magnetic ring 40 (constrained relative to the annular element 36) slides into the chamber 17, also the first magnetic ring 28, by the effect of the magnetic attraction of the second magnetic ring 40, is induced to slide inside the chamber 19 of the container body 18. Considering that the second magnetic ring 28 is constrained relative to the appendix of the top portion 24" of the shaped element 24, the shaped element itself undergoes a translatory movement lowering in the direction of the impeller 12.

[0050] The downwards movement of the shaped element 24 interrupts when it contacts the volute of the pump basement.

[0051] The bottom portion 24' of the shaped element 24 is thereby fitted onto the impeller 12 and in contact with the top front of the same.

[0052] IN this way, the cooling fluid circulation into the pump is interrupted; in such configuration defined as "off" and schematised at figure 1, the impeller 12 continues to rotate without circulation of the cooling fluid into the circuit.

[0053] Figure 5 shows the "on" condition of the pump of the invention according to the alternative embodiment; the impeller 12 is already in rotation and the cooling fluid circulates into the circuit as already mentioned before.

[0054] The suction of air from the chamber 19' determines a vacuum into the chamber itself as a consequence whereof the annular element 58 is pushed downwards and in the direction of the annular cap 30'. Such translatory movement of the annular element 58 into the chamber 19', due to the presence of the first magnetic ring 64, determines the descent of the cylindrical body 50 according to the methods already described with reference to the preferred embodiments whereof at figures 1, 2 and 3.

[0055] The pump then moves to the "off" configuration schematised in figure 4 wherein the cylindrical body 50 closes the volute of the pump base thus preventing the fluid circulation.

[0056] As can be noticed from the above, the advantages achieved by the pump of the invention are clear.

[0057] The pump for engine cooling circuits of the invention by the effect of the alternating up/down movement of the shaped element 24 enables/disables the supply of cooling fluid keeping the impeller itself always in rotation.

[0058] A further advantage is represented by the fact that varying the position of the annular element 36 and 58 into the chamber 17 and 19' it is possible to "choke" the cooling fluid supply according to the specific needs.

[0059] A further advantage of the pump of the invention is represented by the fact that it defines a "fail- safe" device suitable for ensuring the pump operation even in conditions of malfunction or failure; in fact, with particular reference to the preferred embodiment, if the pneumatic supply fails, the helical spring 34 moves to rest condition, that is, fully extended into the chamber 17 of the container body 18 and the pump is in the "off" configuration described above and schematised at figure 2.

[0060] A further advantage of the pump of the invention is represented by the fact that it allows eliminating the dynamic mechanical seals that in the long term may cause breakage and malfunctions.

[0061] A further advantage is the fact that the pump of the invention is simple and inexpensive to construct, and its components are quick and easy to replace in the case of maintenance.

[0062] Even if the invention has been described hereinbefore with particular reference to an embodiment thereof made by way of a non-limiting example only, several changes and variations will appear clearly to a man skilled in the art in the light of the above description. This invention therefore is intended to include any changes and variations thereof falling within the spirit and the scope of the following claims.

Claims

1. A pump (10, 10') for the circulation of cooling fluid into a device provided with a magnetic-actuated flow regulator, comprising:

- a container body (18) suitable for allowing the steady and safe fixing of the pump relative to the device to be cooled;

- an impeller (12) keyed to the end of a rotation shaft (14) turnably arranged in said container body (18) and connected to means for transmitting the rotary motion to the shaft itself; said pump being characterised in that it comprises a regulation component (24, 50) axially moving under the action of axial movement means for enabling/disabling the cooling fluid circulation with said magnetically-actuated means.

2. The pump for engine cooling circuits according to claim 1, characterised in that said regulation component suitable for enabling/disabling the cooling fluid circulation comprises a shaped element (24) of moulded plastic or metal, comprising a bottom portion (24') with hollow discoid shape such as to fit onto the outer surface of the impeller (12) and a top portion (24") defined by one or more appendices that, starting from the top front of the bottom portion (24'), partly develop in a direction opposite that of the impeller (12), an annular element (36), supported by an elastic means with said shaped element (24) and annular element (36) respectively sliding in axial direction into a chamber (19) and chamber (17), externally and concentrically made in the central part of the container body (18) suitable for receiving the rotation shaft (14), by magnetic means. (Figs. 1, 2)

3. The pump for engine cooling circuits according to claim 2, characterised in that the magnetic means are defined by a first magnetic ring (28) fixed at the top end of the appendices of the top portion (24") of the shaped element (24) and by a second magnetic ring fixed to the annular element (36).

4. The pump for engine cooling circuits according to claim 1, characterised in that said regulation component suitable for enabling/disabling the cooling fluid circulation comprises a hollow cylindrical body (50), made of sheet metal or moulded plastic, arranged in the region comprised between the impeller (12) and the bottom front of the container body (18) facing the direction of the impeller itself and by an annular element (58) supported by an elastic means, with said cylindrical body (50) and annular element (58) slidingly arranged respectively at concentric chamber (17') and (19'), of annular type extended in axial direction and open at the bottom front of the container body (18) facing the direction of the impeller (12) and moved by magnetic means. (Figs. 4, 5)

5. The pump for engine cooling circuits according to claim 4, characterised in that the magnetic means are defined by a first magnetic ring (52) fixed at the inner side surface of the cylindrical body (50) in the proximity of the top portion thereof, facing the direction of the bottom of the chamber (17') and by a second magnetic ring (64) fixed to the annular element (58).

6. The pump for engine cooling circuits according to one or more of the previous claims, characterised in that the first magnetic ring (28, 52) and the second magnetic ring (40, 64) are made of plastic neodymium.

7. The pump for engine cooling circuits according to one or more of the previous claims, characterised in that the first magnetic ring (28, 52) and the second magnetic ring (40, 64) are made of neodymium-iron-boron (NdFeB).

8. The pump for engine cooling circuits according to one or more of the previous claims, characterised in that the first ring (28, 52) and the second magnetic ring (40, 64) are made in a single piece.

9. The pump for engine cooling circuits according to claim 1, characterised in that the first magnetic ring (28, 52) and the second magnetic ring (40, 64) are defined by a plurality of magnetic blocks inserted in a metal frame and fixed relative to the annular element (36).

10. The pump for engine cooling circuits according to one or more of the previous claims, characterised in that the appendices of the top portion (24") of the shaped element (24) have an "S" shaped profile.

11. The pump for engine cooling circuits according to one or more of the previous claims, characterised in that the annular element (36, 58) starting from the top front thereof facing the direction of the bottom of the chamber (17, 19') develops in vertical direction at least one optional lip (38, 60) extending, in a continuous or partial manner, along the entire circumference of the annular element (36, 58).

12. The pump for engine cooling circuits according to one or more of the previous claims, characterised in that the annular element (36, 58) has a section basically shaped as an "H" with two grooves into each whereof one or more rings (37, 62) are received, which ensure the seal and help the movement of the annular element itself into the chamber (17, 19') of the container body (18).

13. The pump for engine cooling circuits according to one or more of the previous claims, characterised in that the elastic means supporting the annular element (36, 58) is defined by at least one helical spring (34, 56) arranged between the annular element (36, 58) and an annular cap (30, 30') placed for closing the chamber (17, 19') of the container body (18).

14. The pump for engine cooling circuits according to one or more of the previous claims, characterised in that it comprises a sleeve (26) fixed to the container body (18) at the central portion thereof, inserted into the chamber (19) of the container body itself and having a flange or edge (26') suitable for defining a stop to the sliding, into the chamber (17), of the appendices of the top portion (24") of the shaped element (24).

15. The pump for engine cooling circuits according to one or more of the previous claims, characterised in that the movement of the annular element (36, 58) into the chamber (17, 19') is actuated in a pneumatic, hydraulic, mechanical or electromagnetic manner.

Drawing