Pumping unit

Description

[0001] The present invention relates to a pumping unit.

[0002] The invention falls within the sector of fluid dynamic machines and has an application in particular in the sector of agricultural machinery.

[0003] It is known to use a pump in various fluid dynamic applications, where the operating concept is to draw a quantity of liquid from a tank and convey it to delivery nozzles or, more generally, to delivery openings in order to favour spraying of liquid from the tank.

[0004] For this purpose, fluid dynamic machines using a volumetric pump, generally of the membrane type, are known, said machines having the functions described above. A particular example of these machines are agricultural machines intended for the spraying of agricultural ground and towed by tractors which generally comprise a tank for containing a liquid, for example an aqueous solution of a chemical component, a plurality of spraying nozzles arranged in a position facing the ground and communicating with the tank in order to spray a given quantity of liquid onto the ground, and a volumetric pump which is powered by a power take-off of the tractor and active between the tank and the spraying nozzles in order to generate in the liquid a head sufficient to disperse it through the spraying nozzles.

[0005] Spraying of the liquid through the nozzles results in gradual emptying of the tank of said agricultural machines.

[0006] Replenishing of the tank with liquid, drawn from a liquid source, is performed by the same volumetric pump.

[0007] This fact results in the need to design said pump with larger dimensions so that it is also able to perform the liquid replenishing functions, therefore resulting in high installation costs.

[0008] Moreover, owing to the low throughputs which are typical of volumetric pumps, replenishing of the tanks requires a fairly long time-scale.

[0009] It is also noted that the liquid in the tank requires frequent mechanical stirring in order to ensure the homogeneity of the solution to be sprayed.

[0010] In this case also, the function of stirring the liquid is performed by the volumetric pump via partial recirculation of the product.

[0011] The use of these pumps in the agricultural machines described above results in the disadvantage of long down times for replenishing the tank with liquid and moreover a reduction in spraying efficiency due to the partial recirculation of the liquid in order to ensure uniformity thereof. A way of solving the problem is to adopt a second pump, generally of the centrifugal type, in order to perform the functions of replenishing and mechanical stirring of the liquid in the tank.

[0012] However, it must be considered that the two pumps perform different functions, i.e. in the specific case the first pump performs the function of delivery of the liquid at a high pressure, while the second pump performs a filling function, in which therefore a high throughput of liquid is required. This has a negative effect on the connection of the pumps to the motor means, owing to the fact that the latter must be powered with different operating parameters.

[0013] Consequently it is envisaged installing the usual volumetric pump, powered by the power take-off of the tractor, and the additional installation of the centrifugal pump powered by a combustion engine or a hydraulic motor.

[0014] This configuration results in various disadvantages such as high installation and maintenance costs owing to the presence of two pumps and a dedicated motor for powering one of them, large dimensions due to the use of an additional pump and associated power supply motor, and problems of reliability due to the management of two pumps and an additional motor.

[0015] To overcome drawbacks mentioned above, in DE 101 04 635 A1 (closest prior art) it is disclosed a multistage feed device having a constant overall displaced volume and comprising a first oil pump driven by a combustion engine and a second oil pump connected to the first one by a continuously controllable speed variator. If the displaced volume of the first oil pump varies because of a speed variation of the combustion engine, the speed variator will vary the number of rotations of the second oil pump with respect to the number of rotation of the first pump in order to keep constant the overall displaced volume.

[0016] Nevertheless, this solution shows the important drawback that it cannot allow the two pumps to perform their specific different functions because it is not able to keep the two pumps at their optimum speed of rotation. In fact, the speed variator varies the number of rotations of the second oil pump with respect to the number of rotation of the first pump and so it cannot link two pumps speeds with a stated ratio.

[0017] In this situation, the technical task forming the basis of the present invention is to propose a pumping unit which does not possess the abovementioned drawbacks.

[0018] The main object of the present invention is to provide a pumping unit which simplifies the connections of the pumps to the motor means intended for operation of the said pumps.

[0019] A further object of the invention is to provide a pumping unit which reduces the dimensions of components necessary for connecting the pumps to the respective motor means.

[0020] Another object of the invention is to provide a pumping unit which can be easily maintained in view of the fact that said unit operates in agricultural fields and therefore in conditions which are often critical.

[0021] These objects, together with others, which will appear more clearly from the following description, are achieved according to the present invention by a pumping unit in accordance with the contents of Claim 1 and/or one or more of the claims dependent thereon.

[0022] Further characteristic features and advantages of the invention will appear more clearly from the description of a preferred, but not exclusive embodiment of a pumping unit, in accordance with that explained in detail in the following description and with the aid of the accompanying drawings in which:

• Figure 1 shows a fluid dynamic diagram of an installation comprising a pumping unit according to the present invention;
• Figure 2 shows a front view of a pumping unit according to the present invention;
• Figure 3a shows a cross-sectional view of a first portion of the pumping unit according to Figure 2 in a first operating condition;
• Figure 3b shows a cross-sectional view of the portion according to Figure 2a in a second operating condition;
• Figure 4a shows a perspective view of a second portion of the pumping unit according to Figure 2 in the first operating condition;
• Figure 4a shows a perspective view of the portion according to Figure 4a in the second operating condition. In accordance with the accompanying figures, 1 denotes overall a pumping unit according to the present invention.

[0023] The pumping unit 1 can be used in particular in an installation of the type shown in the fluid dynamic diagram according to Figure 1. According to this diagram, the installation comprises a tank 2 for containing a liquid, and one or more delivery openings 4, for example spraying nozzles of an agricultural machine. The pumping unit 1 is active between the tank 2 and the delivery openings 4 and between the tank 2 and one or more sources "S" of liquid, according to an operating sequence which will be illustrated in detail below.

[0024] In accordance with the front view of Figure 2 and with the cross-sectional views of Figures 3a and 3b, the pumping unit 1 comprises a first pump 6 having a respective first drive shaft 6a and active at least between the tank 2 and the delivery openings 4 for producing a head in the liquid to be delivered. The first pump 6 is preferably of the volumetric type, for example a membrane pump, since it has to produce a high head in order to deliver the liquid through the delivery openings 4.

[0025] The pumping unit also comprises a second pump 7, having a respective second drive shaft 7a and acting on the tank 2 at least so as to ensure a supply of the liquid to the tank 2 itself. Preferably, the second pump 7 is of the continuous-flow type, in particular of the centrifugal type comprising an impeller 7b and a bell 7c, the second pump 7 having the function of supplying the liquid to the tank 2. It must be remembered in fact that volumetric pumps differ from centrifugal pumps, or more generally from continuous-flow pumps, in that volumetric pumps have operating heads which are higher than centrifugal pumps, but, on the other hand, they are able to cope with a smaller throughput of liquid. It is clear, therefore, that a volumetric pump is better suited than a centrifugal pump for providing the liquid with an optimum head for suction thereof through the delivery nozzles. A delivery pump is, moreover, clearly better for supplying a liquid throughput - even if high - to the inlet of the tank 2.

[0026] One of the two drive shafts 6a, 7a, preferably that of the first volumetric pump 6, is directly connected to motor means defined, in the example of agricultural applications, by the power take-off of a tractor not shown in the accompanying figures.

[0027] In the case where the pumping unit 1 is housed on an agricultural spraying machine, during operating conditions, the engine of the tractor is always running and therefore the first volumetric pump 6 is always in operation, unless the power take-off of the tractor is disengaged. In order to be able to interrupt the flow of liquid delivered through the delivery openings 4, the first volumetric pump 6 may act on the tank 2 even during recirculation. In detail, in this condition the first pump 6 is active between the tank 2 and the tank 2 itself in order to recirculate a quantity of liquid, drawn from the tank 2, inside it so that it is not necessary to deactivate the first pump 6 in order to interrupt the delivery of the liquid during operation of the tractor, or more generally of the motor means. The recirculation condition is ensured by a first three-way valve "V1" situated downstream of the first pump 6 and communicating selectively with a recirculation pipe "R" leading into the tank 2 or, alternatively with at least one delivery pipe "E" for conveying the liquid to the delivery openings 4, in accordance with the fluid dynamic diagram shown in Figure 1.

[0028] Advantageously the pumping unit 1 comprises transmission means 8 which are active between the first drive shaft 6a and the second drive shaft 7a so as to transmit, preferably in a regulated manner, a driving power from the first pump 6 to the second pump 7. The transmission means 8 are rendered necessary by the fact that, as mentioned above, the two pumps 6, 7 have different operating parameters associated with the different design characteristics. In particular, among the characteristic operating parameters of the two pumps 6, 7, most important is the number of revolutions at which each pump 6, 7 is operated. In particular, the first centrifugal pump 6 has an optimum speed of rotation higher than the optimum speed of rotation of the second volumetric pump 7. As a result, the transmission means must ensure at least a suitable reduction - or multiplication - ratio for the number of revolutions of the first drive shaft 6a and the number of revolutions of the second drive shaft 7a.

[0029] In the preferred embodiment illustrated in Figures 4a and 4b, the transmission means 8 comprise an epicyclic gearing 9 which comprises a central hub 9a, a ring gear 9b and a plurality of planet gears 9c, preferably three in number, which mesh with an outer portion of the central hub 9a and an inner portion of the ring gear 9b by means of meshing teeth.

[0030] Advantageously, the second drive shaft 7a has a first end defining the said central hub 9a, while the first drive shaft 6a is operationally active on the planet gears 9c in the manner which will be described below. From the above it can be seen that, since the planet gears 9c have a revolving movement coaxial with the central hub 9a, the two drive shafts 6a, 7a rotate coaxially with each other about a same main axis of rotation "X".

[0031] Therefore, the first volumetric pump 6 is of the membrane type and, in the embodiment shown, comprises six valve bodies 10, only two of which are visible in Figure 2, being arranged in an angularly equidistant manner about the main axis of rotation "X". A free space is created inside a volume of the six valve bodies 10 and therefore in the vicinity of the said main axis of rotation "X" and may be advantageously occupied by at least one portion of the epicyclic gearing 9 so as to reduce an overall volume of the assembly formed by the pumps 6, 7 and by the epicyclic gearing 9.

[0032] Figures 3a, 3b show a preferred embodiment of the transmission means 8 in accordance with the present invention. In particular, the left-hand side of Figures 3a, 3b shows the first drive shaft 6a, which is supported by respective first bearings 11, only one of which is visible in these figures. The right-hand side of Figures 3a, 3b shows instead the second drive shaft 7a, which is supported directly by a respective second bearing 12 and, indirectly, by a third bearing 13 arranged between the first bearings 11 and the second bearing 12.

[0033] The transmission means 8 comprise a containing body 14 which is divided into a first portion 14a and a second portion 14b which can be stably joined together by means of first threaded connections 14c.

[0034] The first portion 14a and the second portion 14b of the containing body 14 define internally an operating chamber 15 which can be occupied stably by the epicyclic gearing 9. The latter has the ring gear 9b fixed, in particular rigidly joined to the two portions 14a, 14b of the containing body.

[0035] The planet gears 9c are rigidly joined together by means of a connecting part 16 which is rotatable about the main axis of rotation "X" and rotatably supports the planet gears 9c by means of respective pins 17 of the connecting part 16. The latter extends from the epicyclic gearing 9 towards the first shaft 6a and is also supported by the third bearing 13. The third bearing 13, therefore, acts as an indirect support for the second drive shaft 7a by means of the connecting part 16 which is connected to the epicyclic gearing 9 to which in turn the second drive shaft 7a is stably connected. The second bearing 12 is housed stably inside a respective seat of the second portion 14b of the containing body 14.

[0036] The first portion 14a of the containing body 14 has a terminal portion 18 in the form of a flange which can be stably joined to a respective portion of the first volumetric pump 6, for example by means of second threaded connections 19. The first portion 14a of the containing body 14 and the respective portion of the first pump 6 joined together define internally an operating chamber 20. Reversible engaging means 21 are housed inside this operating chamber 20, active between the epicyclic gearing 9 and the first drive shaft 6a so as to connect the latter together and disengage them from each other in order to interrupt in a controlled manner a flow of power towards the second centrifugal pump 7.

[0037] This is useful when the tank 2 has reached a predetermined filling level and it is required to interrupt the supply of other liquid to the tank 2.

[0038] In detail, the reversible engaging means comprise an engaging member 22, having a first terminal portion 23 slidably inserted inside the connecting part 16 and rotationally integral with the connecting part 16 itself. This is achieved by coupling the first terminal portion 23 of the engaging member 22 with the connecting part 16 by means of a splined connection, preferably of the telescopic type.

[0039] The engaging member 22 has moreover a second terminal portion 24 which is opposite the first terminal portion 23 and can be stably coupled with the first drive shaft 6a in order to form a mechanical connection between the first drive shaft 6a and the second drive shaft 7a, via the connecting part 16 and the epicyclic gearing 9.

[0040] In the preferred embodiment shown, the first drive shaft 6a, at its end directed towards the transmission means 8, is integral with a sleeve 25 which defines a hole 26 arranged along the main axis of rotation "X" and able to be engaged by a respective coupling part 27. The latter has a first terminal portion 27a which can be stably inserted inside the sleeve 25 in a stable manner at least with a relative rotational movement of the sleeve 25 and the coupling part 27. This is obtained by providing, inside the sleeve 25, a longitudinal seat 28 which can be engaged by a projection of the coupling part 27, preferably a tongue 29.

[0041] Preferably the coupling part 27 is connected to the sleeve 25 so as not to have any freedom of movement relative thereto. This is obtained, for example, by means of a screw which can be inserted in an axial opening 30 of the coupling part 27 and can be stably engaged with a bottom portion 31 of the sleeve 25.

[0042] In an alternative embodiment, the sleeve 25 is defined by the said end of the first drive shaft 6a directed towards the transmission means 8.

[0043] The coupling part 27 also has a second terminal portion 27b, opposite to the first portion 27a and shaped so as to match substantially the second terminal portion 24 of the engaging member 22, for stably engaging therewith. In particular, the second terminal portion 27b of the coupling part 27 comprises a protuberance 32 which can be engaged inside a respective engaging seat 33 formed in the second terminal portion 24 of the engaging member 22. In particular, the engaging member 22 is movable, along the main axis of rotation "X", between an active position shown in Figure 3b, where the engaging seat 33 engages with the said protuberance 32, producing a stable rotational coupling, and an inactive position shown in Figure 3a, where the engaging seat 33 is distant from the protuberance 32 so as to render the second drive shaft 7a idle with respect to the first drive shaft 6a.

[0044] Advantageously, the transmission means 8 and the second pump 7 may be removed from the pumping unit 1, and the coupling part 27 extracted from the sleeve 25 so that the latter may be connected to a generic motor for separate operation of the first pump 6. In this condition, the first pump 6 may be operated independently of the second pump 7.

[0045] Therefore, the form of the sleeve 25, which has a longitudinal seat 28 for the tongue, makes it suitable for coupling in a simple and practical manner with any type of motor since it is known that most of the commercially distributed motors have a shaft with a tongue as the member for transmission of the output movement.

[0046] The engaging member 22 has a peripheral seat 34 which extends around the main axis of rotation "X", as shown in Figures 3a, 3b, 4a, 4b. This peripheral seat 34 has an inset form, namely it is delimited laterally by two parallel flanges 35 with an annular shape.

[0047] The two flanges 35 allow the engagement of the peripheral seat 34 by a projection 36 of a lever "L". The lever "L" can be operated manually by an operator and is rotatably mounted on the first portion 14a of the containing body 14. The projection 36 is eccentric with respect to an axis of rotation "Y" of the lever "L" and therefore movable about this axis of rotation "Y" with a revolving movement having a component parallel to the main axis of rotation "X" and a component perpendicular to the main axis of rotation "X". The said parallel component of the revolving movement causes a displacement of the engaging member 22 along the main axis of rotation "X" and therefore between the respective active and inactive positions, since the projection 36 is engaged inside the peripheral seat 34 and therefore conveys with it the engaging member 22 with a translatory movement along the main axis of rotation "X".

[0048] The perpendicular component of the said revolving movement of the projection 36 does not produce any action on the engaging member 22, the projection 36 being free to move along the peripheral seat 34.

[0049] With regard to the second centrifugal pump 7, Figures 3a, 3b show that the second drive shaft 7a supports, at an opposite end to that connected to the epicyclic gearing 9, the impeller 7b of the second centrifugal pump 7. The second portion 14b of the containing body 14 is moreover stably coupled, by means of threaded connections, to the bell 7c of the second pump 7. Sealing means 37, for examples seals of the dynamic type, are also provided between the bell 7c and the second drive shaft 7a.

[0050] In accordance with the diagram shown in Figure 1, the pumps 6, 7 of the pumping unit 1 according to the invention have auxiliary functions which will be described hereinbelow.

[0051] The first volumetric pump 6 is connected to a respective filling pipe "P1" which departs downstream of the first pump 6 and upstream of the first three-way valve "V1" by means of a second three-way valve "V2" and leads into the tank 2. The second three-way valve "V2" therefore establishes fluid communication selectively between the first pump 6 and the first three-way valve "V1" or, alternatively, the filling pipe "P1" of the first pump 6. The first pump 6 is also connected, upstream thereof, to a respective supply line "A1" which can be associated with a source "S" of liquid, preferably water. In the case where the pumping unit 1 is mounted on an agricultural spraying machine, the source "S" could be a tank, a ditch or a water basin. A third three-way valve "V3" is therefore provided upstream of the first pump 6 and selectively supplies to the first pump 6 the liquid from the tank 2 or alternatively the water drawn via the supply pipe "A1" of the first pump 6. As a result thereof, in operating conditions, the first pump 6 is able to ensure autonomously a supply of the liquid to the tank 2, drawing it via the respective supply pipe "A1" and conveying it to the tank 2 via the respective filling pipe "P1", even though this means that, during this step, it is not possible to deliver the liquid through the delivery openings 4.

[0052] The second pump 7 is connected on its intake side to a respective supply pipe "A2" which can be associated with the said source "S" of liquid. The second pump 7 is also connected, on the delivery side, to a respective filling pipe "P2" leading into the tank 2. The second pump 7 is also advantageously connected to a stirring pipe "G" emerging in a bottom portion of the tank 2 or, more generally, in a portion thereof occupied by the liquid, in order to produce swirling movements in the said liquid, favouring the mixing of any components added to the said liquid.

[0053] A fourth three-way valve "V4" is therefore provided downstream of the second pump 7 and selectively establishes fluid communication between the second pump 7 and the respective filling pipe "P2" or, alternatively, the stirring pipe "G".

[0054] In certain applications, for example in agricultural machines for spraying liquid fertilizers or weedkillers or more generally for spraying chemical products mixed with water, the first pump 6 delivers a first liquid to the delivery openings 4 which is different from a second liquid supplied to the tank 2 by the second pump 7. Generally, the second liquid supplied to the tank 2 is water. Solid tablets containing chemical components are added, for example, to the water inside the tank 2 and, following the abovementioned stirring movement, dissolve in the water. The first pump 6, therefore, conveys to the delivery openings 4 a respective first liquid which may have properties different from those of the second liquid. This first liquid, in the circumstances described above, is an aqueous solution or a suspension, in water, of one or more given chemical substances.

[0055] If other components are not added to the liquid contained inside the tank 2, the first liquid would be entirely identical to the second liquid.

[0056] The present invention achieves the proposed objects, overcoming the drawbacks of the prior art.

[0057] The presence of means for transmission of the movement between the two pumps in the form of an epicyclic gearing achieves a considerable reduction in the dimensions of the said transmission means. In fact, the epicyclic gearing does not require the presence of transmission shafts which are typical of reducers of the known type and allows alignment of the drive shafts of the two pumps coaxially with each other.

[0058] In such a situation it is therefore possible to embed at least partially the transmission means inside a volume of the volumetric pump, achieving a reduction in the overall dimensions of the assembly formed by the pumps and the transmission means. Therefore, unlike the reducers of the known type which must be constrained to a fixed structure owing to their considerable mass, the epicyclic gearing according to the invention may advantageously be connected to one of the two pumps, for example the volumetric pump.

[0059] In fact, the direct connection between the two pumps, via the said transmission means, has an extreme constructional simplicity, complex members not being envisaged for distributing the movement from the Cardan joint to the two pumps.

[0060] The present invention achieves moreover the important advantage of rendering the operation of the two pumps independent of each other, since the reversible engaging means allow deactivation of the centrifugal pump while keeping the volumetric pump in operation, for example in conditions where the tank is full.

[0061] Moreover, it is also possible to supply the tank with the volumetric pump alone, the usefulness of which is particularly obvious in the case of malfunctioning of the centrifugal pump.

Claims

1. Pumping unit, comprising:

- a first pump (6) having a respective first drive shaft (6a) and able to be associated with a tank (2) containing a first liquid and with at least one delivery pipe (E) having delivery openings (4) for conveying a quantity of said first liquid from the tank (2) to said delivery pipe (E) ;

- a second pump (7), having a respective second drive shaft (7a) and able to be associated with the tank (2) and with a source (S) of a second liquid for supplying a quantity of said second liquid to the tank (2), one of said pumps (6, 7) being connected to motor means in order to receive a driving power;

- means (8) for transmission of the movement, which are active between said first drive shaft (6a) and second drive shaft (7a) so as to transmit a driving power between the two pumps (6, 7);
characterized in that:

- said first pump (6) is of the volumetric type, for supplying said first liquid to said delivery openings (4), said second pump (7) being of the continuous-flow and preferably centrifugal type for supplying said second liquid to said tank (2);

- said first shaft (6a) and second shaft (7a) are coaxial and rotatable about a same main axis of rotation (X); said first drive shaft (6a) rotating at an optimum speed for a volumetric pump and said second drive shaft (7a) rotating at an optimum speed for a continuous-flow pump;

- said transmission means (8) comprising an epicyclic gearing (9) which is connected to both the drive shafts (6a, 7a) so as to cause rotation of said drive shafts (6a, 7a) at different speeds relative to each other; said speeds being linked by a stated ratio between the optimum speed for the volumetric pump and the optimum speed for the continuous-flow pump.

2. Pumping unit according Claim 1, characterized in that said transmission means (8) are at least partly embedded inside a volumetric space of at least one of said pumps (6, 7).

3. Pumping unit according to any one of the preceding claims, characterized in that it comprises reversible engaging means (21), which are active between the said epicyclic gearing (9) and one of said drive shafts (6a, 7a), so as to connect stably the latter and disengage them from each other, interrupting in a controlled manner a power flow towards the pump (6, 7) not connected to the motor means.

4. Pumping unit according to Claim 3, characterized in that said reversible engaging means (21) comprise an engaging member (22), slidable with respect to the epicyclic gearing (9) along the main axis of rotation (X) and movable between an active position, where it is stably coupled with one of said drive shafts (6a, 7a) in order to connect rotationally the drive shafts (6a, 7a) of the two pumps (6, 7), and an inactive position, where it is separated from said drive shaft (6a, 7a) in order to interrupt the power flow between the two pumps (6, 7).

5. Pumping unit according to Claim 4, characterized in that said engaging member (22) is supported by the epicyclic gearing (9), said engaging member (22) in the active position, being coupled with the first drive shaft (6a) of the first volumetric pump (6) and, in the inactive position, being separated from said first drive shaft (6a), said second drive shaft (7a) being stably connected to the epicyclic gearing (9).

6. Pumping unit according to Claim 5, characterized in that said engaging member (22) is stably associated with planet gears (9c) of the epicyclic gearing (9) via a connecting part (16) with which in particular it is slidably coupled, the latter supporting rotatably said planet gears (9c) in order to receive a rotational movement from the engaging member (22) and transmit said movement to said planet gears (9c).

7. Pumping unit according to any one of the preceding claims, characterized in that said second drive shaft (7a) has an end defining a central hub (9a) of said epicyclic gearing (9).

8. Pumping unit according to any one of Claims 4 to 6, characterized in that it comprises a coupling part (27) able to be at least rotationally associated in a stable manner with one end of the first shaft (6a), said coupling part (27) comprising a first terminal portion (27a) shaped so as to match substantially a corresponding portion of the engaging member (22) so as to be stably coupled therewith when the latter is in the active position.

9. Pumping unit according to Claim 8, characterized in that the coupling part (27) comprises a second terminal portion (27b) opposite to the first portion (27a) and having a protuberance (32) which can be engaged stably inside an internal seat (28) of a sleeve (25) integral with said end of the first drive shaft (6a).

10. Pumping unit according to Claim 4, characterized in that it comprises a lever (L) which can be operated manually by an operator and acting on the engaging member (22) so as to move it between the active position and the inactive position.

Ansprüche

1. Pumpeinheit, umfassend:

- eine erste Pumpe (6), die eine dazugehörige erste Antriebswelle (6a) aufweist und mit einem Behälter (2), der eine erste Flüssigkeit enthält, und mit mindestens einer Verteilleitung (E), die Verteilöffnungen (4) aufweist, verbunden werden kann, um eine Fördermenge dieser ersten Flüssigkeit vom Behälter (2) zu dieser Verteilleitung (E) schicken;

- eine zweite Pumpe (7), die eine dazugehörige zweite Antriebswelle (7a) aufweist und mit dem Behälter (2) und einer Quelle (S) einer zweiten Flüssigkeit verbunden werden kann, um den Behälter (2) mit einer Fördermenge dieser zweiten Flüssigkeit zu versorgen, wobei eine dieser Pumpen (6, 7) mit Antriebsmittel verbunden ist, um eine Antriebsleistung zu empfangen;

- Mittel für die Bewegungsübertragung (8), die zwischen der ersten (6a) und der zweiten (7a) Antriebswelle wirken, um eine Antriebsleistung zwischen den zwei Pumpen (6, 7) zu übertragen;
dadurch gekennzeichnet, dass:

- die erste Pumpe (6) eine Verdrängerpumpe ist, um die Verteilöffnungen (4) mit der ersten Flüssigkeit zu versorgen, wobei die zweite Pumpe (7) eine Strömungspumpe, vorzugsweise eine Kreiselpumpe, ist, um den Behälter (2) mit der zweiten Flüssigkeit zu versorgen;

- die erste (6a) und die zweite (7a) Welle koaxial und um eine selbe Hauptdrehachse (X) drehbar sind; wobei sich die erste Antriebswelle (6a) mit einer für eine Verdrängerpumpe optimalen Drehzahl dreht und sich die zweite Antriebswelle (7a) mit einer für eine Strömungspumpe optimalen Drehzahl dreht;

- wobei die Übertragungsmittel (8) ein Planetengetriebe (9) umfassen, das an beide Antriebswellen (6a, 7a) angeschlossen ist, um die Antriebswellen (6a, 7a) mit voneinander verschiedenen Drehzahlen drehen zu lassen; wobei diese Drehzahlen an ein festes Verhältnis zwischen der optimalen Drehzahl für die Verdrängerpumpe und der optimalen Drehzahl für die Strömungspumpe gebunden sind.

2. Pumpeinheit nach Anspruch 1, dadurch gekennzeichnet, dass die Übertragungsmittel (8) zumindest teilweise in ein Volumen von mindestens einer der Pumpen (6, 7) eingelassen sind.

3. Pumpeinheit, nach einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass sie reversible Kupplungsmittel (21) umfasst, die zwischen dem Planetengetriebe (9) und einer der Antriebswellen (6a, 7a) wirken, um diese letzteren stabil zu verbinden und um sie voneinander zu lösen und so einen Leistungsfluss zur nicht an die Antriebsmittel angeschlossenen Pumpe (6, 7) in gesteuerter Weise zu unterbrechen.

4. Pumpeinheit nach Anspruch 3, dadurch gekennzeichnet, dass die reversible Kupplungsmittel (21) ein Kupplungsglied (22) umfassen, das gegenüber dem Planetengetriebe (9) längs der Hauptdrehachse (X) verschiebbar und zwischen einer aktiven Stellung, in der es sich stabil an eine der Antriebswellen (6a, 7a) ankuppelt, um die Antriebswellen (6a, 7a) der zwei Pumpen (6, 7) in Drehung zu verbinden, und einer inaktiven Stellung beweglich ist, in der es von der Antriebswelle (6a, 7a) entfernt ist, um den Leistungsfluss zwischen den zwei Pumpen (6, 7) zu unterbrechen.

5. Pumpeinheit nach Anspruch 4, dadurch gekennzeichnet, dass das Kupplungsglied (22) vom Planetengetriebe (9) getragen wird, wobei dieses Kupplungsglied (22) in der aktiven Stellung an die erste Antriebswelle (6a) der ersten Verdrängerpumpe (6) angekuppelt ist, und in der inaktiven Stellung von dieser ersten Antriebswelle (6a) entfernt ist, wobei die zweite Antriebswelle (7a) stabil mit dem Planetengetriebe (9) verbunden ist.

6. Pumpeinheit nach Anspruch 5, dadurch gekennzeichnet, dass des Kupplungsglied (22) mit Planetenrädern (9c) des Planetengetriebes (9) durch ein Verbindungselement (16) stabil verbunden ist, mit dem es insbesondere verschiebbar gekoppelt ist; wobei dieses letztere die Planetenräder (9c) drehbar trägt, um eine Drehbewegung vom Kupplungsglied (22) zu empfangen und diese Bewegung auf die Planetenräder (9c) zu übertragen.

7. Pumpeinheit nach einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass die zweite Antriebswelle (7a) ein Ende aufweist, das einen Mittelzapfen (9a) des Planetengetriebes (9) definiert.

8. Pumpeinheit nach einem der Ansprüche 4 bis 6, dadurch gekennzeichnet, dass sie ein Kupplungselement (27) umfasst, dass zumindest drehend stabil mit einem Ende der ersten Welle (6a) verbunden werden kann; wobei dieses Kupplungselement (27) einen ersten Endabschnitt (27a) umfasst, der im Wesentlichen zu einem entsprechenden Anschnitt des Kupplungsglieds (22) gegengleich geformt ist, um sich mit diesem stabil zu verbinden, wenn sich dieses letztere in der aktiven Stellung befindet.

9. Pumpeinheit nach Anspruch 8, dadurch gekennzeichnet, dass das Kupplungselement (27) einen zweiten Endabschnitt (27b) umfasst, der dem ersten (27a) entgegengesetzt ist und einen Vorsprung (32) aufweist, der in einem Sitz (28) innerhalb einer fest mit dem besagten Ende der ersten Antriebswelle (6a) verbundenen Muffe (25) stabil in Eingriff gebracht werden kann.

10. Pumpeinheit nach Anspruch 4, dadurch gekennzeichnet, dass sie einen Hebel (L) umfasst, der von einer Bedienperson von Hand betätigt werden kann und auf das Kupplungsglied (22) wirkt, um dieses zwischen der aktiven Stellung und der inaktiven Stellung zu bewegen.

Revendications

1. Unité de pompage, comprenant :

- une première pompe (6), ayant un premier arbre d'entraînement respectif (6a) et associable à un réservoir (2) contenant un premier liquide et à au moins un conduit de distribution (E) comportant des ouvertures de distribution (4) pour envoyer un débit dudit premier liquide à partir du réservoir (2) vers ledit conduit de distribution (E) ;

- une deuxième pompe (7), ayant un deuxième arbre d'entraînement respectif (7a) et associable au réservoir (2) et à une source (S) d'un deuxième liquide pour alimenter un débit dudit deuxième liquide au réservoir (2), une desdites pompes (6, 7) étant reliée à des moyens moteurs pour recevoir une puissance motrice ;

- des moyens de transmission (8) du mouvement, actifs entre lesdits premier (6a) et deuxième (7a) arbres d'entraînement pour transmettre une puissance motrice entre les deux pompes (6, 7) ; caractérisée en ce que :

- ladite première pompe (6) est de type volumétrique, pour alimenter ledit premier liquide auxdites ouvertures de distribution (4), ladite deuxième pompe (7) étant du type à flux continu, de préférence centrifuge, pour alimenter ledit deuxième liquide dans ledit réservoir (2) ;

- lesdits premier (6a) et deuxième (7a) arbres sont coaxiaux et rotatifs autour d'un même axe de rotation principal (X); ledit premier arbre d'entraînement (6a) tournant à un régime optimal pour une pompe volumétrique et ledit deuxième arbre d'entraînement (7a) tournant à un régime optimal pour une pompe à flux continu ;

- lesdites moyens de transmission (8) comprenant un train d'engrenages épicycloïdaux (9), relié aux deux arbres d'entraînement (6a, 7a) pour faire tourner lesdits arbres d'entraînement (6a, 7a) à des vitesses différentes l'une de l'autre ; lesdites vitesses étant liées à un rapport fixe entre le régime optimal pour la pompe volumétrique et le régime optimal pour la pompe à flux continu.

2. Unité de pompage selon la revendication 1, caractérisée en ce que lesdits moyens de transmission (8) sont au moins partiellement noyés dans l'encombrement volumétrique d'au moins une desdites pompes (6, 7).

3. Unité de pompage selon l'une quelconque des revendications précédentes, caractérisée en ce qu'elle comprend des moyens d'embrayage (21) réversibles, actifs entre ledit train d'engrenages épicycloïdaux (9) et un desdits arbres d'entraînement (6a, 7a), pour relier ces derniers de manière stable et les désengager entre eux, en interrompant de manière contrôlés un flux de puissance vers la pompe (6, 7) non reliée aux moyens moteurs.

4. Unité de pompage selon la revendication 3, caractérisée en ce que lesdits moyens d'embrayage (21) réversibles comprennent un organe d'embrayage (22), coulissant par rapport au train d'engrenages épicycloïdaux (9) suivant l'axe de rotation principal (X) et mobile entre une position active, dans laquelle il s'accouple de manière stable avec un desdits arbres d'entraînement (6a, 7a) pour relier en rotation les arbres d'entraînement (6a, 7a) des deux pompes (6, 7), et une position inactive, dans laquelle il est éloigné dudit arbre d'entraînement (6a, 7a) pour interrompre le flux de puissance entre les deux pompes (6, 7).

5. Unité de pompage selon la revendication 4, caractérisée en ce que ledit organe d'embrayage (22) est supporté par le train d'engrenages épicycloïdaux (9), ledit organe d'embrayage (22), dans la position active, étant accouplé au premier arbre d'entraînement (6a) de la première pompe (6) volumétrique et, dans la position inactive, étant éloigné dudit premier arbre d'entraînement (6a), ledit deuxième arbre d'entraînement (7a) étant relié de manière stable audit train d'engrenages épicycloïdaux (9).

6. Unité de pompage selon la revendication 5, caractérisée en ce que ledit organe d'embrayage (22) est associé de manière stable avec des satellites (9c) du train d'engrenages épicycloïdaux (9) par l'intermédiaire d'un élément de liaison (16) auquel il est accouplé en particulier de manière coulissante ; ce dernier supportant de manière rotative lesdits satellites (9c) pour recevoir un mouvement de rotation de l'organe d'embrayage (22) et pour transmettre ledit mouvement auxdits satellites (9c).

7. Unité de pompage selon l'une quelconque des revendications précédentes, caractérisée en ce que ledit deuxième arbre d'entraînement (7a) présente une extrémité définissent un axe central (9a) dudit train d'engrenages épicycloïdaux (9).

8. Unité de pompage selon l'une quelconque des revendications 4 à 6, caractérisée en ce qu'elle comprend un élément d'accouplement (27) associable au moins de manière rotative de manière stable avec une extrémité du premier arbre (6a); ledit élément d'accouplement (27) comprenant une première portion terminale (27a) avec un profil sensiblement correspondant à une portion correspondante de l'organe d'embrayage (22) pour s'accoupler de manière stable avec celui-ci quand ce dernier se trouve dans la position active.

9. Unité de pompage selon la revendication 8, caractérisée en ce que l'élément d'accouplement (27) comprend une deuxième portion terminale (27b), opposée à la première (27a) et ayant une protubérance (32) pouvant être engagée de manière stable dans un siège (28) interne d'un manchon (25) solidaire d'une dite extrémité du premier arbre d'entraînement (6a).

10. Unité de pompage selon la revendication 4, caractérisée en ce qu'elle comprend un levier (L) actionnable manuellement par un opérateur et actif sur l'organe d'embrayage (22) pour le déplacer entre la position active et la position inactive.

Drawing