ES2335890T3 - HYBRID PUMP. - Google Patents

Abstract

The invention relates to a hybrid pump for delivering a pump medium, which comprises a housing (2), said housing (2) having an inlet (3), an outlet (4) and a pump room (5). In the pump operation, the pump medium in the pump room (5) is delivered and in the idle state, the pump room (5) is substantially void of pump medium. The pump room (5) has a substantially round or roundish running surface (6) for a rotor (7) having rotor blades (8). The rotor (7) is mounted off-center in the pump room (5) and the rotor blades (8) are each mobile in relation to the rotor (7). A nominal pump operation is provided for a defined nominal speed range of the rotor (7). When the pump is operated in the idle state and the rotor (7) is operated in the nominal speed range, the rotor blades (8) contact the running surface (6) with their blade tips (11). The arrangement of the rotor (7) in the pump room (5) and the design of the rotor (7) and the running surface (t) are adapted to the nominal speed range and the viscosity of the pump medium in such a manner that a lubricating film from the pump medium is produced between the blade tips (11) of the rotor (7) and the running surface (6) at nominal pump operation in a hydrodynamic slide-bearing type of manner so that there is only fluid friction between the blade tips (11) and the running surface (6) at nominal pump operation.

Description

Hybrid pump.

The present invention concerns a pump hybrid to transport a pumping means according to the preamble of claim 1

Hybrid pump is understood herein. context a pump that in a working class works as positive displacement machine and in a second class of operation works as a continuous flow machine to be able to combine the respective advantages of these two kinds of bombs

A widespread continuous flow machine is the centrifugal pump. This is characterized by a construction class robust and a simple constitution and makes operation possible poor in noise and wear to control large flow rates of transport. Frequent fields of use of centrifugal pumps are the rapid filling and emptying of containers, the transfer of liquids, etc.

In the use of centrifugal pumps is disadvantageous the fact that operation is not possible self-sucking Therefore, for the start-up of the pump centrifuges have been provided in the past additionally aids of suction in the form of a stage of aspiration by piston or Similar.

A widespread positive displacement machine It is a cell vane pump. This certainly makes possible a self-priming operation, but, due to the power of friction that occurs immanently to the system, is linked to a relatively high operating noise and a high wear Document DE 36 14 349 A1 shows an approach to reduce friction power. It is a bomb here paddle cell with a rotor whose sides, as usual, rotate ahead of associated side surfaces of an enclosure of pumping. The sides of the rotor each have a bevel of such that the formation of a lubricating film is encouraged hydrodynamic between the sides of the rotor and the side walls partners of the pumping enclosure. Despite this measure, the Remaining friction power is considerable.

Another known vane cell pump (document DE 195 45 045 A1) is equipped with a rotor whose paddles are also pivotally articulated in the rotor. Rotor vanes are maintained during operation pumping in constant contact with a sliding surface Associated pumping enclosure. Also here is considerable the friction power produced.

In the hybrid pump that is being discussed is provided that the pump has in principle the characteristic of a centrifugal pump and can only work during commissioning march like a cell vane pump self-sucking

The known pump (document DE 101 58 146 A1) from which the present invention shows the behavior previously described of a hybrid pump. The hybrid pump is equipped with a housing equipped with an input and an output and that It presents a pumping enclosure. During pumping operation the pumping medium is transported in the pumping enclosure, being the pumping enclosure substantially free of pumping medium during idle operation. The pumping enclosure it has a sliding surface of cross section round for a rotor with vanes that is eccentrically arranged in the pumping enclosure.

The hybrid pump works primarily with high number of revolutions in the manner of a cell vane pump in self-suction operation - suction operation. Due to the entry of the sucked pumping medium into the enclosure of pumping reduces the number of revolutions of the rotor to a number of revolutions that are in the range of revolutions pump ratings. Due to the inherent reduction of strength centrifugal and due to a properly selected elasticity of the rotor vanes, these vanes partially lose in in any case the contact with the sliding surface, seen along this sliding surface. During the pumping operation that is thus set in the interval of nominal speed numbers - nominal pump operation - the pump then shows the characteristic of a pump centrifuge

Therefore, the "switching" of the pump centrifuge from operation as a vane cell pump until the operation as a centrifugal pump materializes here by means of a reduction in the rotor speed. Without reducing the speed, the hybrid pump will would keep in the operating mode as a cellular pump of pallets In some cases of application this is not desirable speed variation.

Regarding the start-up behavior, the pump described above also shows a singularity which in itself has nothing to do with pumping operation. The rotor vanes are constructed of a material elastically deformable and, during running operation in empty and while running the rotor with low number of revolutions, do not make contact with the sliding surface of the pumping enclosure or only temporarily. In this way, the resistance to the start-up of the pump is especially small and it quickly reaches its high speed of idle gear

The present invention is based on the problem of configure and refine the known hybrid pump with respect to suction and pump operation in such a way that the transition of the hybrid pump from the operation as a pump vane cell to function as a centrifugal pump is not necessarily linked to a reduction in the number of Revolutions

The aforementioned problem is solved in a hybrid pump with the characteristics of the preamble of the claim 1 by means of the characteristics of the part characterizing said claim 1.

The fact that during the Nominal pumping operation forms a lubricating film of  pumping means in the manner of a sliding bearing hydraulic between the tips of the rotor vanes and the sliding surface. It is guaranteed that during the Nominal pumping operation reine exclusively friction of liquid between the tips of the vanes and the surface of glide.

In case of a special configuration of a slit between two surfaces, filled with a liquid medium of uniform viscosity, and corresponding relative motion between these surfaces is formed in principle in this slit a lubricating film that is suitable for the transmission of large forces. This effect is used for the bearing design of hydrodynamic slip and also forms the operating mechanism on which the present invention is based.

The above operating mechanism is used here to ensure the above-described transition from operation as a vane cell pump to operation as a centrifugal pump. The design of the rotor and the sliding surface is thus adjusted to the range of nominal revolutions and viscosity so that the rotor vanes, which in idle operation and with the rotor operating in the range of numbers of nominal revolutions would touch the sliding surface with their tips, somehow separate from the surface
slippage during nominal pumping operation due to the formation of the lubricating film.

Due to the previous separation of the pallets of the rotor, the hybrid pump goes into operation as a pump centrifuge The existing solid body friction during the operation as a cell vane pump between the tips of the vanes and the sliding surface of the pumping enclosure It has then become a friction of liquid.

In order to ensure the establishment of the lubricating film of pumping medium in the manner of a bearing of hydrodynamic slippage a series of marginal conditions. To this end, we must refer to the relevant technical bibliography ("Dubbel - Taschenbuch für den Maschinenbau ", 19th edition, Springer Verlag, 1997, Chapter G-5).

One of the previous marginal conditions resides in the design of the eccentricity of the rotor within the pumping enclosure, which determines the movement of the vanes of the rotor during a revolution of this rotor. It is also from importance the weight of the rotor vanes with respect to the force produced centrifuge. The surface of the tips of the vanes and the sliding surface, especially the depth of roughness there, are important influencing factors for the formation of the previous lubricating film. Finally, a Special conformation of the tips of the pallets can encourage Obtaining the lubricating film. It is advantageous, for example, a corresponding beveling of the tips of the vanes.

It can be summarized that the establishment of the lubricating film of pumping medium in the manner of a bearing hydrodynamic slippage is by itself the cause of the rotor vanes separate from the sliding surface; no a variation in the number of revolutions is necessary to achieve the rotor vane spacing.

For the rest, the mobility of the pallets of the rotor in relation to the latter is advantageously the result of a flexible or elastic rotor configuration. However, it can also provide that, to ensure mobility, the rotor present hinges between the different components thereof. This is advantageous especially when the rotor material is not sufficiently flexible and / or elastic, as can happen in If the rotor is designed for chemically pumping means aggressive.

In the following the invention is explained with more detail using the drawing and referring to examples of preferred embodiment. In the course of these explanations, will also clarify other executions and improvements and other characteristics, properties, aspects and advantages of the invention. In the drawing they show:

Figure 1, a hybrid pump in a view in section in a direction parallel to the axis of rotation of the rotor during suction operation,

Figure 2, the hybrid pump of Figure 1 in the view in section A-A,

Figure 3, the hybrid pump of Figure 1 during nominal pumping operation and

Figure 4, a hybrid pump according to another execution in a view according to figure 1, being represented only one rotor vane.

Figure 1 shows a hybrid pump 1 for transport a pumping means with a housing 2, where the housing 2 has an input 3 and an output 4. Both input 3 as the outlet 4 flows into a pumping enclosure 5 of the housing 2 in which the pumping medium is transported during pumping operation. During running operation in vacuum the pumping enclosure 5 is substantially free of  pumping. In this idle operation, the suction of the pumping medium through inlet 3. This is explain still in detail in the following.

The pumping enclosure 5 has a surface slide 6 substantially round in cross section for a rotor 7 with vanes 8. The sliding surface 6 is configured in the present case in the form of a ring with a extension perpendicular to the drawing plane and with a central axis 9. However, depending on the case of application, it can be advantageous also deviate from the round shape in cross section until rounded or other shapes of the sliding surface 6.

As shown in Figure 1, the vanes 8 of the rotor can also move all of them in relation to the rotor 7. Due to the eccentricity, the vanes 8 of the rotor are elongated in the lower zone of said rotor 7 and are highlighted in the zone top of this rotor 7.

Figures 1 and 2 now show the pump hybrid during suction operation pending explain, in which the means of Pumping to be transported. Once the aspiration is carried out of the pumping medium, follow the nominal pumping operation in a predetermined range of nominal revolutions of the rotor 7.

It is essential during the operation of aspiration the fact that the rotor vanes 8 make contact with the sliding surface 6 by means of its tips 11, of so that about rotor rotor vanes 8 can be formed compression enclosures in the manner of a vane cell pump and self-priming operation is guaranteed. The contactee necessary for self-aspirating operation can be guaranteed  by different measures. A measure to explain consists in in which, in addition, the rotor vanes 8 are prestressed with with respect to the rotor 7 in the direction of the sliding surface 6, so that even in a stationary state there is a contact correspondent. Now, it can be expected that only force centrifuge during operation of rotor 7 is the cause of the contacted The last cited variant is especially advantageous because it can be kept especially under the solid body friction during start-up.

It is also essential that pallets 8 of the rotor, which would make contact with the sliding surface  6 by means of its tips 11 during running operation in empty and while rotor 7 operates in the range of numbers of nominal revolutions, then separate from the surface of sliding 6 (figure 3), once the aspiration is carried out, during nominal pumping operation, as described  previously.

The arrangement of the rotor 7 in the enclosure of pumping-eccentricity- and the configuration of rotor 7 and the sliding surface 6 in the manner described above are adjusted for this at the speed range nominal and the viscosity of the pumping medium such that during nominal pumping operation it is formed between the tips 11 of the rotor vanes 7 and the surface of sliding 6 the lubricant film also described of means of pumping in the manner of a hydrodynamic sliding bearing. It is thus guaranteed that during nominal pumping operation only a friction of liquid between the tips 11 of the vanes and the sliding surface 6.

The special design described above of the hybrid pump can be derived from the general design rules for hydrodynamic sliding bearings, mentioned in the part general description, or it can be obtained through essays. Below are still specific values for the materialization of a hybrid pump of this class.

It can be summarized that the hybrid pump 1 according to the invention works during idle operation, and while the tips 11 of the vanes make contact with the sliding surface 6, substantially in the manner of a positive displacement machine, especially a pump paddle cell, in self-priming mode of operation - suction operation. The number of revolutions of the hybrid pump 1 during suction operation may be in the range of nominal revs or you can deviate from it up or down. During the Nominal pumping operation subsequent hybrid pump 1 then rotates in the range of nominal revolutions substantially in the manner of a continuous flow machine, especially of a centrifugal pump.

According to an especially preferred embodiment the tips 11 of the pallets have a conformation that encourages obtaining the lubricating film during the operation of Nominal pumping This conformation can be a bevel correspondingly provided that, seen in the direction of rotation, be located on the front side of the tip 11 of each pallet. In another preferred embodiment, the tips 11 of the vanes have each of them a rounded conformation, seen in its section transverse, which in turn encourages separation above described between the rotor vanes 8 and the surface of slip 6.

Otherwise, as depicted in Figure 1, the mobility of the vanes 8 in relation to the rotor 7, which is necessary for the operation described above of the pump Hybrid 1, can be guaranteed by flexible configuration and / or elastic rotor 7. It may also be sufficient that the vanes 8 of rotor 7 are configured flexibly and / or elastic However, it can also be foreseen that, in addition, rotor vanes 8, if necessary additionally, are connected to the rotor 7 in flexible and / or elastic form.

Especially cheap manufacturing is achieved of the rotor 7 by configuring this rotor 7 in one piece. It's possible then, for example, fabricate the rotor 7 by the process of cast iron injected in only a single operation.

However, it can be advantageous too. set the rotor 7 in several pieces, especially when the rotor 7 must be composed of different materials. This is for For example, the case when the rotor blades 8 are elastic construction and, otherwise, rotor 7 is of construction rigid In the case of the rotor 7 formed by several pieces, the different rotor components are connected to each other by shape complementarity coupling, preferably glued between them, riveted between them, screwed between them and / or plugged into each other.

You get a configuration especially preferred by making the different rotor components joined together by hinges. For the rest, according to a simple execution, the rotor vanes 8 are connected to the 7 rotor through two hinges. As already explained in the general part of the description, the configuration of the rotor 7 with hinges is advantageous especially for the use of the pump Hybrid 1 in the chemical sector.

In the embodiment shown in Figure 4 and preferred in this aspect, the rotor vanes 8 are configured all of them in several pieces, being again joined the components 12, 13 of the rotor vanes between them through hinges 14.

In particular, rotor vanes 8 have each of them a first partial palette 12 and a second partial vane 13, the two partial vanes 12, 13 being joined with each other through a double articulation hinge 14. This realization is especially advantageous because, being Fully extended rotor vanes 8, the two vanes partials 12, 13 are applied to each other in such a way that it prevents a buckling of the rotor vane 8 to the left in the figure Four.

It follows from the operating mode described above of the hybrid pump 1 according to the invention which,  otherwise, a prestressing of the vanes 8 with respect to the rotor 7. However, it is prestressed it can be advantageous in any case to be able to insure in everything moment a defined operating state.

The prestressing can be provided here in a direction towards the sliding surface 6. The tips 11 of the rotor vanes 7 then contact the sliding surface 6 even in stationary state. Without However, it can also be provided that, in addition, vanes 8 of the rotor are prestressed with respect to rotor 7 in one direction that moves away from the sliding surface 6. Rotation of the rotor 7 during the suction operation then originates from moment, due to the effect of centrifugal force, the contact of the sliding surface 6 by the tips 11 of the pallets The nominal pumping operation then runs again as described above.

The above-described establishment of a lubricating film of pumping medium in the manner of a bearing Hydrodynamic slip can be used advantageously also in an entirely different place. The surface of sliding 6 of the pumping enclosure 5 is followed by two opposite side surfaces 15, 16 that extend each of they perpendicular to the axis of rotation 10 of the rotor 7 and ahead of which the sides 17, 18 of the rotor 7 pass (figure 2). According configuration of side surfaces 15, 16 and sides 17, 18 of the rotor, a body friction can be formed here unwanted solid.

In an especially preferred embodiment the rotor 7 with its vanes 8 and the lateral surfaces 15, 16 of the pumping enclosure 5 are then adjusted to the range of numbers of nominal revolutions and the viscosity of the pumping medium of such that it is formed during nominal pumping operation a lubricating film of pumping medium between the sides 17, 18 of the rotor and the respective lateral surface 15, 16 of the enclosure of pumping 5 in the manner of a hydrodynamic sliding bearing. It is thus guaranteed that during nominal pumping operation Only a friction of liquid between the sides 17, 18 of the rotor and lateral surfaces 15, 16.

It is especially advantageous in this regard that the rotor bearing 7 has a clearance in the axial direction that is made by the lubricating film produced on the sides 17, 18 of the rotor an automatic centering of the rotor 7 in the direction axial.

To encourage film formation lubricant described above between the sides 17, 18 of the rotor and the lateral surfaces 15, 16, the sides 17, 18 of the rotor are preferably equipped with a corresponding bezel. Seen in the direction of rotation, the bezel is on the front side of the respective rotor blade 8.

Numerous possibilities are imaginable for Parameterize the hybrid pump 1 according to the invention. It should go to the design rules above commented.

In the following a parameterization is presented preferred which is especially suitable for the pumping medium Water. In this case, pump operation is planned. Hybrid 1 under normal conditions (room temperature, etc.). By of course, hybrid pump 1 can also be applied to others pumping means. It is necessary then eventually a adaptation of the parameterization to the material properties of the respective pumping medium.

According to the preferred parameterization, the interval The number of nominal revolutions includes in any case a speed of approximately 8,000 rpm, presenting the rotor diameter 7 when the tips 11 of the vanes make contact with the sliding surface 6 a diameter value medium of approximately 50 mm. It is then a speed of sliding of the tips 11 of the vanes on the surface of 6 sliding of approximately 21 m / s.

The rotor material has with this Preferred parameterization a Shore A hardness of approximately 75, measured in the rotor 7.

The parameterization preferred above described should not be understood as limiting. They are possible and are also planned deviations. In particular, the speed of sliding of the tips 11 of the vanes on the surface of slip 6 is in the range of numbers of nominal revolutions, preferably in a range of about 14 m / s at about 28 m / s and more preferably in a range of about 18 m / s at approximately 24 m / s. With the anterior mean diameter of rotor 7 of approximately 50 mm then a range of number of nominal revolutions comprising revolutions numbers between approximately 5,300 rpm and approximately 10,700 rpm or between approximately 6,900 rpm and approximately 9,200 rpm.

The rotor 7 is preferably made of a elastomer, for example NBR, FKM, PERBUNAN, VITON, EPDM, PEEK or PP Particularly when the rotor 7 is designed for media chemically aggressive pumping, can be finally advantageous build the rotor 7 at least partially based on PTFE.

Claims (20)

1. Hybrid pump for transporting a pumping means with a housing (2), where the housing (2) has an inlet (3), an outlet (4) and a pumping enclosure (5), where the pumping means in the pumping enclosure (5) during pumping operation, where the pumping chamber (5) is substantially free of pumping medium during idling operation, where the pumping chamber (5) it has a sliding surface (6) substantially round or rounded in cross section for a rotor (7) with vanes (8), wherein the rotor (7) is eccentrically arranged in the pumping enclosure (5), where, in addition , the rotor vanes (8) can all be moved relative to the rotor (7) and where a nominal pumping operation is provided in a predetermined range of nominal rotor revs (7), characterized in that the vanes ( 8) of the rotor make contact with the surface of desli by means of its tips (11) during idle operation and while the rotor (7) operates within the range of nominal revolutions, and because the arrangement of the rotor (7) in the pumping enclosure (5) and the configuration of the rotor (7) and the sliding surface (6) are adjusted to the range of nominal revolutions and the viscosity of the pumping medium such that during the nominal pumping operation it is formed between the tips (11) of the rotor vanes (7) and the sliding surface (6) a lubricating film of the pumping medium in the manner of a hydrodynamic sliding bearing, whereby a friction reigns exclusively during the nominal pumping operation of liquid between the tips (11) of the vanes and the sliding surface (6). 2. Hybrid pump according to claim 1, characterized in that, during idling operation and while the tips (11) of the vanes make contact with the sliding surface (6), the hybrid pump (1) works in the mode of self-aspirating operation - suction operation - substantially in the manner of a positive displacement machine, especially of a vane cell pump, and because during the nominal pumping operation the hybrid pump (1) works substantially in the manner of a machine continuous flow, especially of a centrifugal pump. 3. Hybrid pump according to any of the preceding claims, characterized in that the tips (11) of the vanes have a conformation that promotes the obtaining of the lubricating film during the nominal pumping operation, preferably because each of said tips is correspondingly beveled and more preferably because the tips (11) of the vanes each have a rounded shape, seen in its cross section. 4. Hybrid pump according to any of the preceding claims, characterized in that the rotor (7) is configured at least partially flexible and / or elastic, preferably because the vanes (8) of the rotor are flexible and / or elastic and / or more preferably because the vanes (8) of the rotor are, in addition, joined in a flexible and / or elastic manner with the rotor (7). 5. Hybrid pump according to any of the preceding claims, characterized in that the rotor (7) is configured in one piece. 6. Hybrid pump according to any of claims 1 to 4, characterized in that the rotor (7) is configured in several pieces. 7. Hybrid pump according to claim 6, characterized in that the different rotor components are connected to each other by complementary shape coupling, preferably being glued together, riveted together, screwed together and / or plugged into each other. 8. Hybrid pump according to claim 6 or 7, characterized in that the different components of the rotor are connected to each other through hinges and preferably because the vanes (8) of the rotor are also joined together with the rotor ( 7) through a hinge. 9. Hybrid pump according to any of claims 6 to 8, characterized in that the vanes (8) of the rotor are each made in several pieces and preferably because the components (12, 13) of the rotor vanes are joined together with another through hinges (14). 10. Hybrid pump according to claim 9, characterized in that the rotor vanes each have a first partial vane (12) and a second partial vane (13) and because the two partial vanes (12, 13) are joined together with another through a hinge (14) of double articulation. 11. Hybrid pump according to any of the preceding claims, characterized in that the vanes (8) of the rotor are also prestressed with respect to the rotor (7) in a direction towards the sliding surface (6). 12. Hybrid pump according to any one of claims 1 to 10, characterized in that the vanes (8) of the rotor are also prestressed with respect to the rotor (7) in a direction away from the sliding surface (6) and can be tilted by the rotation of the rotor (7), by means of centrifugal force, in the direction of the sliding surface (6). 13. Hybrid pump according to any of the preceding claims, characterized in that the rolling surface (6) of the pumping enclosure (5) is followed by two opposite lateral surfaces (15, 16) which extend each of them perpendicular to the axis of rotation (10) of the rotor (7) and in front of which the sides (17, 18) of the rotor (7) pass. 14. Hybrid pump according to claim 13, characterized in that the rotor (7) with its vanes (8) and the lateral surfaces (15, 16) of the pumping enclosure (5) are adjusted to the range of nominal revolutions and viscosity of the pumping means such that during the nominal pumping operation a lubricating film of the pumping medium is formed between the sides (17, 18) of the rotor and the respective lateral surface (15, 16) of the pumping enclosure (5) in the manner of a hydrodynamic sliding bearing, whereby a friction of liquid reigns exclusively between the sides (17, 18) of the rotor and the lateral surfaces (15, 16) during the nominal pumping operation. 15. Hybrid pump according to claim 14, characterized in that the sides (17, 18) of the rotor have a conformation that promotes the obtaining of the lubricating film and preferably because said sides are conveniently beveled. 16. Hybrid pump according to any of the preceding claims, characterized in that the range of nominal revolutions in any case comprises a speed of approximately 8,000 rpm. 17. Hybrid pump according to any of the preceding claims, characterized in that the diameter of the rotor (7), when the tips (11) of the vanes make contact with the sliding surface (6), has an average diameter value of approximately 50 mm 18. Hybrid pump according to any of the preceding claims, characterized in that within the range of nominal revolutions the sliding speed of the tips (11) of the vanes on the sliding surface (6) is within a range of approximately 14 m / s to about 28 m / s, preferably because the sliding speed is within a range of about 18 m / s to about 24 m / s and more preferably because the sliding speed is about 21 m / s. 19. Hybrid pump according to any of the preceding claims, characterized in that the rotor material has a Shore A hardness of approximately 75, measured in the rotor (7). 20. Hybrid pump according to any of the preceding claims, characterized in that the rotor (7) is made at least partially of an elastomer, preferably of NBR, FKM, PERBUNAN, VITON, EPDM, PEEK or PP, and / or because the rotor ( 7) It is made at least partially of PTFE.