WO2018207043A1

WO2018207043A1 - Pump assembly with mechanical drive comprising a command assembly

Info

Publication number: WO2018207043A1
Application number: PCT/IB2018/052718
Authority: WO
Inventors: Alfonso SURACE; Marco Pedersoli
Original assignee: Industrie Saleri Italo SpA
Current assignee: Industrie Saleri Italo SpA
Priority date: 2017-05-09
Filing date: 2018-04-19
Publication date: 2018-11-15
Anticipated expiration: 2019-11-09
Also published as: IT201700050034A1; EP3622180A1; HUE054513T2; EP3622180B1

Abstract

The invention is a pump group (1) for a vehicle cooling system of a vehicle, for example for an engine group of the vehicle. Said pump group (1) comprises an impeller (2) and a mechanical drive (3) operatively connectable with mechanical movement means comprised in the vehicle, preferably operatively connected to the engine drive shaft of the vehicle, wherein the mechanical drive (3) is operatively connected to the impeller (2) to command it in rotation; The pump group (1) comprises a command gearbox group (5), located between the impeller (2) and the mechanical drive (3). The command gearbox group (5) comprises a plurality of gear pairs (50) each commandable in reciprocating gearing to vary the transmission ratio and to vary the rotation speed of the impeller (2) on command from the mechanical drive (3).

Description

DESCRIPTION

"PUMP ASSEMBLY WITH MECHANICAL DRIVE COMPRISING A COMMAND

ASSEMBLY"

[0001] The present invention concerns a pump group for a cooling system of a vehicle, preferably for the cooling of an engine group, e.g. with internal combustion, or for the cooling of other vehicle components, e.g. the transmission group, or the turbo group, or the exhaust gas recirculation group.

[0002] In the state of the art, pump groups are known that are adapted to vary their cooling action in such a way as to vary the cooling modes of the component connected to the cooling system according to the needs thereof, for example, according to the needs of the engine group.

[0003] First of all, the known pump groups with mechanical drive may be operatively connected to the mechanical movement means comprised in the vehicle, typically commanded in rotation with special kinematic systems connected to the drive shaft of the engine. Obviously, such pump groups with mechanical drive vary their action according to the engine RPM.

[0004] In other words, mechanically driven pump groups do not have flexible operative and driving modes, but rather have operative modes directly dependent on the behavior of the vehicle; through pump groups with mechanical drive at low engine speeds there is low-intensity operation of the pump group, thus low-level cooling, while at high engine speeds there is high-intensity operation of the pump group and thus high-level cooling; for example, all this happens regardless of the environmental conditions in which the vehicle finds itself.

[0005] In order to remedy such a problem, in the state of the art there has been a proliferation of electrically driven pump group solutions or dual-drive pump group solutions with both electrical and mechanical drive, which have replaced solutions of pump groups with mechanical drive.

[0006] The pump group object of the present invention is placed in the aforementioned context, providing a pump group with mechanical drive that solves the aforesaid problems, thus resulting in a valid alternative to a pump group with electric drive or a dual-drive pump group. In other words, the purpose of the present invention is to provide a pump group with mechanical drive for a vehicle cooling system wherein the cooling action is controllable and is not solely a function of the aforesaid mechanical drive, i.e. not solely a function of the engine speed.

[0007] This object is achieved by a pump group made according to claim 1. The claims dependent on this claim refer to preferred variant embodiments, having further advantageous aspects.

[0008] The object of the present invention is hereinafter described in detail with the aid of the accompanying figures, wherein:

[0009] - figure la and lb illustrate a perspective view of the pump group object of the present invention, according to a possible embodiment;

[0010] - figures 2a and 2b show two perspective views in separate parts of the pump group object of the present invention shown in figures la and lb;

[0011] - figure 3 represents one view from above in separate parts of the pump group shown in figures 2a and 2b;

[0012] - figure 4a and 4b represent two sectional views of the pump group respectively along the sectional planes V- V and VI-VI, as shown in figure 3.

[0013] With reference to the aforesaid figures, a pump group for a cooling system of a vehicle is indicated collectively at reference number 1. Specifically, such pump group 1 is suitable to circulate a predefined amount of coolant in the cooling system. Preferably, said cooling system is fluidically connected to the engine group of the vehicle, the engine preferably being of the internal combustion type, and/or to the transmission group, or to the turbo group, or to the exhaust gas recirculation group for the purpose of regulating the temperature thereof.

[0014] The pump group 1 in accordance with the present invention comprises an impeller 2 rotatable around an X-X impeller axis. The induced rotation of the radiant corresponds to the circulating action of the coolant in the system.

[0015] Preferably, the impeller 2 is of the radial type, i.e., it provides that the inlet flow of coolant has an overall substantially axial direction and the outlet flow of coolant has a radial direction.

[0016] In addition, the pump group 1 comprises also an impeller shaft 20, which extends along said impeller axis X-X and is integrally connected to the impeller 2 to move it in rotation; i.e., one rotation of the impeller shaft 20 corresponds to one induced rotation of the same impeller 2.

[0017] The pump group 1 object of the present invention also comprises a mechanical drive 3 operatively connected to the impeller to command it in rotation.

[0018] Preferably, the mechanical drive 3 includes a mechanical shaft 30. Preferably, in some preferred embodiments, the mechanical shaft 30 is commandable in rotation, while in other embodiments, the mechanical shaft 30 is fixed and supports a plurality of components suitable to be placed in rotation thereon.

[0019] In accordance with a preferred embodiment, the mechanical drive 3 is operatively connectable with mechanical movement means comprised in the vehicle, preferably connected to the drive shaft of the engine. Preferably, such mechanical movement means comprise a gear or a cascade of gears, a joint or a cascade of joints, or flexible elements, for example, comprising a belt or a chain. Therefore, the form of the mechanical drive 3 depends on the type of mechanical movement means: for example the mechanical drive 3 may be a joint (as shown in the accompanying figures, located at the end of the mechanical shaft 30) or a gear or a pulley (not shown, but in turn positionable at the end of the mechanical shaft 30) .

[0020] According to a preferred embodiment, the mechanical shaft 30 extends along a second axis Y-Y. Preferably, the impeller axis X-X and the second axis Y-Y are respectively arranged in such a way that they lie on a same plane. Preferably, the second axis Y-Y extends parallel to the impeller axis X-X.

[0021] According to the present invention, the pump group 1 comprises a command gearbox group 5, located between the impeller 2 and the mechanical drive 3, suitable to vary the drive modes with which the mechanical drive 3 commands the impeller 2 in rotation.

[0022] In other words, the gearbox group 5 is suitable to command the rotation speed of the impeller 2 by varying the rotation action induced by the mechanical drive 3.

[0023] The command gearbox group 5 comprises in effect a plurality of gear pairs 50 each commandable in reciprocating gearing to vary the transmission ratio and to vary the rotation speed of the impeller 2 on command from the mechanical drive 3.

[0024] According to a preferred embodiment, the plurality of gear pairs 50 comprise at least two gear pairs; preferably, the plurality of gear pairs 50 comprise three gear pairs; for example, the accompanying figures show, by way of example, an embodiment of the pump group 1 wherein the command gearbox group 5 comprises three gear pairs 510, 520, 530.

[0025] According to the present invention, each gear pair comprises a first gear 511, 521, 531 commanded in rotation by the mechanical drive 3. Preferably, the first gear is also identifiable as the motor or driving gear.

[0026] According to a preferred embodiment, the mechanical shaft 30 is commandable in rotation, and each first gear 511, 521, 531 is mounted integrally on said mechanical shaft 30; in other words, the rotation of the mechanical shaft 30 corresponds to the rotation of each first gear 511, 521, 531 mounted thereon.

[0027] Moreover, according to the present invention, each gear pair comprises a second gear 512, 522, 532, commanded in rotation by the respective first gear 511, 521, 531 and commanding in rotation the impeller 2. Preferably, the second gear is identifiable as the driven gear .

[0028] According to a preferred embodiment, said second gears 512, 522, 532 are housed on the impeller shaft 20. According to a preferred embodiment, said second gears

512, 522, 532 are inserted axially onto the impeller shaft 2, positioned concentrically relative to the impeller axis X-X.

[0029] Each gear pair has a transmission ratio according to which the speed at which the rotary motion of the mechanical drive 3 is transmitted to the impeller 2 varies .

[0030] Preferably, said transmission ratios allow a rotation speed of the impeller 2 within an indicative range between 0.5 and 2 times the speed of the mechanical drive 3.

[0031] According to a preferred embodiment of the present invention, the command gearbox group 5 comprises a command device 55 suitable to command which gear pair must be in reciprocating gearing to transmit the motion from the mechanical drive 3 to the impeller 2.

[0032] According to a preferred embodiment, the command device 55 comprises an axially movable engagement element 550, wherein, according to the axial position of the engagement element 550, a respective gear pair 50 is commanded in transmission.

[0033] Preferably, the command device 55 moves the engagement element 550 parallel to the impeller axis X-X.

[0034] According to a preferred embodiment, the engagement element 550 is a cross element.

[0035] In addition, according to a preferred embodiment, the command device 55 comprises a stop element 552 housed on the impeller shaft 20 and suitable to engage the engagement element 550 to maintain it in a preferred axial position corresponding to a gear pair 50.

[0036] In other words, by means of the reciprocating action between the engagement element 550 and the stop element 552, a second gear and the impeller shaft 20 are reciprocally engaged with each other: the action between the respective first gear and the second gear induces thus the impeller shaft 20 and thus the impeller 2 to rotate. The other second gears will rotate idly on the impeller shaft 2.

[0037] According to a preferred embodiment, the engagement element 550 comprises at least one engagement member 550' suitable to engage directly the respective second gear. Similarly, each second gear 512, 522, 532 has at least one engagement recess 512', 522', 532' that accommodates the engagement element 550' once positioned in a predefined axial position. Preferably, a plurality of (preferably four) engagement members 550' are included, arranged angularly equidistant from each other (with reference to the axis X-X) . Similarly, preferably, each second gear 512, 522, 532 has a number of engagement recesses 512', 522', 532' at least equal to the number of engagement members 550' .

[0038] According to a preferred embodiment, the engagement element 550 has a plurality of slots 550" in which the stop element 552 operates to maintain the axial position of the engagement element 550 relative the impeller shaft 20 and thus relative to each second gear 512, 522, 532. Typically, each second gear 512, 522, 532 corresponds to at least one slot 550".

[0039] In accordance with a preferred embodiment of the present invention, the command device 55 comprises an electric actuator 555 suitable to move the engagement element 550 in the axial direction. In other words, through the command of the electric actuator 555, the engagement element 550 (position maintained by the stop element 552) is moved into a preferred axial position, thus commanding the meshing of a preferred gear pair 510, 520, 530.

[0040] In addition, according to a further preferred embodiment, the electric actuator 555 is suitable to move the impeller shaft 2 in rotation.

[0041] In other words, the impeller shaft 2 and the command device 55 are reciprocally coupled together in such a way that, in certain preferred embodiments of the electric actuator 555, the latter is also able to command the impeller shaft 20 in rotation via the engagement element 550.

[0042] For example, the electric actuator 555 moves the engagement element 550 into an axial gearbox disengagement position (or "idle" position) , wherein the engagement element 550 is not in an engagement position with a respective gear. Preferably, with the engagement element 550 arranged in the gearbox disengagement position, the actuator 555 is suitable to command the impeller shaft 20 in rotation or, if necessary, to keep the impeller still.

[0043] In accordance with a preferred embodiment, the engagement element 550 has an additional slot (in addition to the above-described slots 550" and not shown in the accompanying figures) wherein in turn the stop element 552 operates. In other words, in the gearbox disengagement position, the stop element 552 is housed in said additional slot.

[0044] As described above, the actuator 555 in a preferred embodiment comprises an electric motor and a set of transmission and conversion means suitable to transform and convert the rotary motion of said electric motor into translatory and/or rotary motion at the impeller shaft 20.

[0045] According to a preferred embodiment, said electric motor is distinguished from electric motors in electric drive pumps or dual-drive pumps. Specifically, the electric motor of the actuator 555 is characterized by low power and does not require sophisticated control boards, as it is not designed to operate continuously or over long periods of time, unlike the electric motors of pumps which require sophisticated control boards that must operate continuously and over long periods of the life of the pump.

[0046] According to a preferred embodiment, the transmission and conversion means comprise, for the transmission of the axial motion, a rotating body and a worm screw suitable to transmit and command the axial motion of the engagement element; whereas they comprise, for the transmission of rotary motion, said rotary body and a dummy gear in turn geared to the engagement element .

[0047] According to a preferred embodiment, the pump group 1 comprises a pump body 10 delimiting an impeller chamber 12 housing the impeller 2 and containing the coolant in transit. Preferably, the impeller chamber 12 has an inlet mouth 121 through which the coolant, sucked in, enters, and an outlet port 122 through which the coolant, pressed out, exits.

[0048] According to a preferred embodiment, the pump body 10 also comprises a command chamber 15 housing the plurality of gear pairs 50 of the command gearbox group 5.

[0049] Preferably, such command chamber 15 is insulated from the coolant.

[0050] Preferably, in this command chamber 15, together with the gear pairs 50, at least the respective portions of the shafts are also housed, whereon the gears are inserted, for example, the impeller shaft 20 and/or the mechanical shaft 30.

[0051] According to a preferred embodiment, the command chamber 15 is fluidically connected to a lubrication system of the vehicle, for example, a lubrication system of an engine group or gearbox group comprised in the vehicle .

[0052] Preferably, moreover, the pump body 10 is suitable to provide a support for the command device 55, which is adapted to extend cantilevered therefrom.

[0053] Preferably, in addition, the pump body 10 is suitable to provide a support for the mechanical movement means comprised in the vehicle engaging the mechanical drive 3.

[0054] It should be noted that in the present discussion, the term "gear" is intended in a general sense to refer to "toothed wheels".

[0055] In accordance with the embodiments shown in the accompanying figures, the gears comprised in the pump group are operatively connected directly to each other, meshing with the respective teeth.

[0056] However, embodiments are also envisaged wherein the gears comprised in the pump group are operatively connected to each other indirectly by means of flexible transmission elements comprising belts or chains, which in turn are comprised in the kinematic transmission group .

[0057] Preferably, the gears (i.e. the toothed wheels) have respective forms according to the arrangement of the various axes on which the described shafts lie, and according to the described modes of reciprocating connection (direct or indirect) .

[0058] Innovatively, the pump group object of the present invention satisfies the engine cooling requirements and overcomes the drawbacks typical in the state-of-the-art solutions mentioned above.

[0059] Advantageously, the pump gruop comprises a mechanical drive, but, due to the command gearbox group, the pump group is remarkably flexible, being suitable to meet the cooling needs of the vehicle according to actual demand and not according to the engine speed. This means that, due to the command gearbox group, the speed of the impeller is commandable according to the actual needs.

[0060] Advantageously, the pump group is suitable to regulate in an unobtrusive way the rotation speed of the impeller, according to the cooling needs. Advantageously, the pump group, object of the present invention, differs from pump groups with mechanical drive known in the state of the art in that it is suitable to regulate the speed of the impeller by acting thereon; unlike known pump groups with mechanical drive in which there are adjustments of the coolant which are designed to regulate the pressure drops of the cooling circuit, the pump group object of the present invention operates directly on the regulation of the speed of the impeller.

[0061] In addition, advantageously, the pump group provides no power conversion from the engine force to the pump force. In other words, the pump group does not need any power conversion to transform mechanical power into hydraulic power. Advantageously, the pump group uses the required hydraulic power for cooling, thus avoiding excess hydraulic power, as is typically the case with pumps with mechanical drive, which are part of the state of the art.

[0062] Moreover, advantageously, also the impeller (and the impeller chamber with the volute) is more compact and not oversized and thus operates always in conditions of optimal efficiency with respect to the known pump groups, where the impeller is often oversized to compensate for the poor flexibility of mechanical pumps.

[0063] Moreover, the pump group has much lower loads on the impeller shaft than the loads typically found on the impeller shaft in state-of-the-art embodiments; advantageously, in effect, due to the command gearbox group, the radial loads on the impeller shaft are reduced to zero, and the impeller shaft may thus be designed to be compact in size. Advantageously, moreover, the pump group are designable and producible with lighter materials, such as plastic materials: advantageously, the pump group object of this invention is thus lighter in weight than the state-of-the-art solutions.

[0064] In a further advantageous aspect, the pump group has a "fail-safe" feature; in effect, in the event of a failure of the electric actuator, the command device is suitable to keep at least one gear pair engaged while continuing to ensure the movement of the impeller.

[0065] According to a further advantageous aspect, the pump group is operative in "post-run" conditions, i.e. with the engine off. Preferably, in effect, the electric actuator is suitable to command the impeller 2 in rotation even in a configuration wherein the mechanical drive does not put the respective gears in motion.

[0066] According to a further advantageous aspect, the pump group is also operative in warm-up conditions, i.e. at the start-up of the engine. Advantageously, in warm-up conditions in which rapid warming of the engine is desired, in some preferred embodiments, the command gearbox group commands the meshing of a specific gear pair with the lowest transmission ratio so as to have the minimum possible rotation of the impeller. Similarly, according to further preferred embodiments, the command gearbox group is also suitable for commanding an "idle" configuration wherein the impeller is not placed in rotation: preferably, in such "idle" configuration, no gear is engaged and the actuator does not command the impeller in rotation.

[0067] Moreover, advantageously, the command gearbox group is designble according to the hydraulic needs of the pump, for example by providing specific transmission ratios .

[0068] Advantageously, the command gearbox group is greseable directly with the lubricant already in circulation in the vehicle, for example with the oil in circulation in the engine group, or with the oil in circulation in the gearbox group.

[0069] Advantageously, the pump group is particularly suitable to manage the entire amount of coolant in the cooling system, for example, managing the cooling of other vehicle components in addition to the engine, such as, for example, the turbo group. This saves additional space in the engine compartment .

[0070] Moreover, advantageously, the pump group is particularly compact and of small size, being particularly suitable to be housed in the engine compartment of a motor vehicle.

[0071] It is clear that a person skilled in the art, in order to meet contingent needs, may make changes to the pump group, all contained within the scope of protection defined by the following claims.

[0072] Furthermore, each variant described as belonging to a possible embodiment may be achieved independently of the other described variants.

Claims

1. Pump group (1) for a vehicle cooling system, for example for a vehicle engine group, comprising:

- an impeller (2) rotatable around a rotating axis (X-X) ; - a mechanical drive (3) operatively connectable with mechanical movement means comprised in the vehicle, preferably operatively connected with the engine drive shaft of the vehicle, in which the mechanical drive (3) is operatively connected to the impeller (2) to command it in rotation;

a command gearbox group (5) interposed between the impeller (2) and the mechanical drive (3), comprising a plurality of gear pairs (50) each commandable in reciprocating gearing to vary the transmission ratio and to vary the rotation speed of the impeller (2) on command from the mechanical drive (3) .

2. Pump group (1) according to claim 1, wherein the command gearbox group (5) comprises a command device (55) comprising an engagement element (550) movable axially, wherein, depending on the axial position of the engagement element (550), a respective pair of gears (50) is commanded in transmission.

3. Pump group (1) according to claim 2, wherein the command device (55) comprises an electric actuator (555) adapted to move the engagement element (550) in an axial direction .

4. Pump group (1) according to claims 2 or 3, comprising an impeller shaft (20) extending along the impeller axis (X-X) , wherein some gears are housed on the impeller shaft (20) .

5. Pump group (1) according to claim 4, wherein the command device (55) operates in the direction of the impeller axis (X-X) .

6. Pump group (1) according to claim 5, wherein the command device (55) comprises a stop element (552) housed on the impeller shaft (20) and suitable for engaging the engagement element (550) to maintain it in a preferred axial position corresponding to a gear pair (50) .

7. Pump group (1) according to any of the claims 5 through 6 in combination with claim 3, wherein the electric actuator (555) is suitable to move the impeller shaft (2) in rotation.

8. Pump group (1) in accordance with claim 7, wherein the electric actuator (555) moves the engagement element (550) to a shift disengagement axial position in which the engagement element (550) is not in a position of engagement with a respective gear, wherein the actuator (555) is suitable to command in rotation the impeller shaft (20) with the engagement element (550) in the shift disengagement axial position.

9. Pump group (1) according to any one of the preceding claims, wherein the plurality of gear pairs (50) comprises at least two, preferably three, gear pairs (510, 520, 530), wherein each pair of gears comprises a first gear (511, 521, 531) commanded in rotation by the mechanical drive (3) and a second gear (512, 522, 532) commanded in rotation by the respective first gear (511, 521, 531) and commanding the impeller (2) in rotation.

10. Pump group (1) according to claim 9, wherein the mechanical drive (3) comprises a mechanical shaft (30) commandable in rotation, wherein each first gear (511, 521, 531) is mounted solidly on said mechanical shaft (30) .

11. Pump group (1) according to any one of the preceding claims, comprising a pump body (10) defining an impeller chamber (12) wherein the impeller (2) is housed and a separate command chamber (15) sealed from the impeller chamber (12) and housing the plurality of gear pairs (50) of the command gearbox group (5) .