DE202004021643U1 - 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

The The present invention relates to a hybrid pump for conveying a pumping medium according to the preamble of the claim 1.

Under a hybrid pump is understood in the present case a pump which in a first mode as positive displacement machine and in a second mode operates as a turbomachine, to the respective advantages of these two types of pumps with each other to be able to combine.

A widespread turbomachine is the centrifugal pump. she is characterized by a robust design and a simple structure and allows a low-noise and low-wear Operation for coping with large flow rates. Frequent applications of centrifugal pumps are the rapid Filling and emptying of containers, pumping of liquids etc ..

adversely when using centrifugal pumps is the fact that a Self-priming operation is not possible. For Starting the centrifugal pump were therefore in the past additional priming aids in the form of a piston suction stage o. The like. Provided.

A popular displacement machine is the vane pump. Although it allows a self-priming operation, but is connected by the system inherent friction performance with a relatively high operating noise and high wear. One approach to reduce the friction performance shows the DE 36 14 349 A1 , This is a vane pump with a rotor whose rotor sides as usual pass by associated side surfaces of a pump chamber. The rotor sides each have a chamfer such that the formation of a hydrodynamic lubricant film between the rotor sides and the associated side walls of the pump chamber is promoted. Despite this measure, the remaining friction performance is considerable.

Another known vane pump ( DE 195 45 045 A1 ) Is equipped with a rotor, the rotor blades are pivotally on the rotor in the rest is deflected. The rotor blades are kept in pumping operation in constant contact with an associated running surface of the pump chamber. Again, the resulting friction performance is considerable.

at the hybrid pump in question, it is provided that the Pump basically the characteristic of a centrifugal pump and only at start-up in the manner of a self-priming vane pump can work.

The known pump ( DE 101 58 146 A1 ), from which the present invention proceeds, shows the above-described behavior of a hybrid pump. The hybrid pump is provided with a housing having an inlet and an outlet having a pumping space. In pumping operation, the pumping medium is conveyed in the pumping space, wherein in idle operation, the pumping space is substantially free of pumping medium. The pump chamber has a cross-sectionally round running surface for a rotor with rotor blades, which is arranged eccentrically in the pump chamber.

The Hybrid pump works at high speed first by type a vane pump in self-priming operation - suction -. By the inflow of the sucked pumping medium in the Pump space reduces the speed of the rotor to a speed, which is within the rated speed range of the pump. By the associated Reduction of centrifugal force and through a suitably chosen Elasticity of the rotor blades lose the rotor blades at least partially along the tread Contact to the tread. At the thus beginning pumping operation in rated speed range - nominal pumping operation - shows the pump then the characteristic of a centrifugal pump.

The "switching" of Hybrid pump from vane pump operation in the centrifugal pump operation So here is accomplished by reducing the speed of the rotor. Without the speed reduction, the hybrid pump would be in vane pump operation remain. Such a speed change is at some Applications not desired.

Regarding the startup behavior shows the previously described pump otherwise a special feature that has nothing to do with the pumping operation itself Has. The rotor blades are made of an elastically deformable Material designed and contact in idle mode with with low speed rotor operated the tread of the Pump room not or only temporarily. This is the starting resistance The pump is particularly low and it quickly reaches its high idle speed.

Of the The present invention is based on the problem known Hybrid pump so in terms of the suction and pumping to design and further that transition of the hybrid pump from vane pump operation to centrifugal pump operation not necessarily associated with a speed reduction.

The above problem is in a hybrid pump with the features of the preamble of claim 1 by the features of the characterizing one Part of claim 1 solved.

Essential is the fact that in nominal pumping operation between the wing tips of the rotor and the tread a lubricating film of pumping medium in the manner of a hydrodynamic sliding bearing forms. This ensures that the nominal pumping operation between the wing tips and the tread only liquid friction prevails.

at special training one with a liquid medium of certain viscosity filled gap between two surfaces and a corresponding relative movement between These surfaces are basically formed in this gap a lubricating film that transmits high forces suitable. This effect is used in the design of hydrodynamic plain bearings exploited and also forms the basis of the present invention Mechanism of action.

Of the The above mechanism of action is used here for the above described transition from vane pump operation to ensure the centrifugal pump operation. The design of rotor and tread are so on the rated speed range and the Viscosity matched that the rotor blades, operated in idle mode and at rated speed range Rotor with its wing tips contact the tread in nominal pumping mode by the formation of the lubricating film lift off from the tread, so to speak.

By the above lifting of the rotor blades goes the hybrid pump in the centrifugal pump operation over. The in vane pump operation existing solid friction between the wing tips and the tread of the pump chamber is then transferred to fluid friction.

In order to ensure the structure of the lubricating film of pumping medium in the manner of a hydrodynamic plain bearing, a number of boundary conditions must be observed. For this, reference may be made to the relevant specialist literature ( "Dubbel - Paperback for Mechanical Engineering", 19th Edition, Springer Verlag, 1997, Chapter G-5 ).

A the above boundary conditions lies in the design of the eccentricity the rotor in the pump room, which controls the movement of the rotor blades determined at one rotor revolution. Furthermore, the weight of the rotor blades in terms of the resulting centrifugal force of importance. Also the surface of the wing tips and the tread, in particular the local roughness, are important influencing factors for the formation of the above lubricating film. Finally, one can special shape of the wing tips the formation of the Promote lubricating film. For example, it is advantageous appropriate chamfering of the wing tips.

It can be summarized that the structure the lubricating film of pumping medium in the manner of a hydrodynamic Slide bearing alone is the cause of the lift-off the rotor blade is off the tread, a speed change is not necessary for lifting the rotor blades.

The Mobility of the rotor blades relative to the rotor in the rest preferably results from a resilient or elastic Design of the rotor. But it can also be provided that the rotor for ensuring mobility hinges between having the individual rotor components. This is especially true advantageous if the material of the rotor is not sufficiently yielding and / or is elastic, as in the design of the rotor for chemically aggressive pumping media may be the case.

in the The following is the invention with reference to the drawing with reference explained in detail on preferred embodiments. In the course of this explanation will be further embodiments and further education and other features, characteristics, aspects and advantages of the invention with explained. In the drawing shows

1 a hybrid pump in a sectional view in a direction parallel to the rotational axis of the rotor in the intake operation,

2 the hybrid pump off 1 in the sectional view AA,

3 the hybrid pump off 1 in nominal pump mode,

4 a hybrid pump according to a further embodiment in a view according to 1 , wherein only one rotor blade is shown.

1 shows a hybrid pump 1 for conveying a pumping medium with a housing 2 , where the case 2 an inlet 3 and an outlet 4 having. Both the inlet 3 as well as the outlet 4 lead into a pump room 5 of the housing 2 , in which the pumping medium is pumped in pumping operation. In idle mode is the pump room 5 essentially free of pumping medium. In this idle mode, the suction of the pumping medium through the inlet 3 required. This will be explained in detail below.

The pump room 5 has a cross-section substantially round tread 6 for a rotor 7 with rotor blades 8th on. The tread 6 is present annularly with an extension perpendicular to the plane and with a central axis 9 designed. Depending on the application, however, it may also be advantageous to have the cross-sectionally round shape roundish or other forms of tread 6 dodge.

As it turned out 1 results are the rotor blades 8th relative to the rotor 7 otherwise movable in each case. Due to the eccentricity are the rotor blades 8th in the lower part of the rotor 7 stretched and in the upper part of the rotor 7 compressed.

The 1 . 2 now show the hybrid pump in the still to be explained suction, in which the pumping medium to be pumped through the inlet 3 is sucked. After suction of the pumping medium follows the nominal pumping operation in a predetermined nominal speed range of the rotor 7 ,

It is essential in Ansaugbetrieb the fact that the rotor blades 8th with their wing tips 11 the tread 6 Contact so that between the rotor blades 8th Forming compression chambers in the manner of a vane pump and the self-priming operation is guaranteed. The necessary for the self-priming operation contacting can be ensured by various measures. One measure to be explained is the rotor blades 8th opposite the rotor 7 otherwise in the direction of the tread 6 pretension, so that a corresponding contact is given even at a standstill. But it can also be provided that only the centrifugal force during operation of the rotor 7 is the cause of the contact. The last-mentioned variant is particularly advantageous insofar as the solid-state friction during start-up can be kept particularly low.

It is essential that the rotor blades 8th , in idle mode and in the rated speed range operated rotor 7 with their wing tips 11 the tread 6 would contact, after priming in nominal pumping now from the tread 6 , as described above, take off ( 3 ).

This is the arrangement of the rotor 7 in the pump room - eccentricity - and the design of the rotor 7 and the tread 6 tuned in the manner described above to the rated speed range and the viscosity of the pumping medium that in the nominal pumping operation between the wing tips 11 of the rotor 7 and the tread 6 also forms the described lubricating film of pumping medium in the manner of a hydrodynamic sliding bearing. This ensures that in the nominal pumping operation between the wing tips 11 and the tread 6 only liquid friction prevails.

The described above, special design of the hybrid pump leaves from the general part of the description, general Derive design rules for hydrodynamic plain bearings, or by testing. Below are still concrete Values for the realization of such a hybrid pump called.

It can be summarized that the hybrid pump according to the invention 1 in idle mode and at the tread 6 contacting wing tips 11 essentially in the manner of a positive displacement machine, in particular a Flügelzel lenpumpe, works in self-priming operation - intake -. The speed of the hybrid pump 1 In intake mode may be in the rated speed range, or deviate up or down from it. In the subsequent nominal pumping operation, the hybrid pump runs 1 then in the rated speed range substantially in the manner of a turbomachine, in particular a centrifugal pump.

According to a particularly preferred embodiment, the wing tips 11 a shaping promoting the formation of the lubricating film in the nominal pumping mode. This may be a correspondingly arranged chamfer, seen in the direction of the front of the wing tip 11 is arranged. In a further preferred embodiment, the wing tips 11 each one seen in its cross-section round shape, which in turn the lifting of the rotor blades described above 8th from the tread 6 promotes.

The for the above described operation of the hybrid pump 1 required mobility of the rotor blades 8th relative to the rotor 7 Otherwise, as in 1 represented by the resilient and / or elastic configuration of the rotor 7 to be guaranteed. It may also be enough that the rotor blades 8th of the rotor 7 are designed resilient and / or elastic. But it can also be provided that the rotor blades 8th , optionally in addition, yielding and / or elastic with the rotor 7 otherwise connected.

A particularly cost-effective production of the rotor 7 is achieved by the fact that the rotor 7 is designed in one piece. Then it is possible, for example, the rotor 7 In the injection molding process in just a single operation.

But it can also be advantageous to the rotor 7 to design multi-piece, especially if the rotor 7 should be composed of different materials. This is the case, for example, when the rotor blades 8th elastic and the rotor 7 are designed otherwise rigid. In the case of the multi-piece rotor 7 the individual rotor components are positively connected to each other, preferably glued together, riveted, screwed and / or inserted into each other.

A particularly preferred embodiment results from the fact that the individual rotor components are connected by hinges. After a one-time configuration, the rotor blades 8th each with a hinge to the rotor 7 otherwise connected. As already explained in the general part of the description, the design of the rotor 7 with hinges especially for the use of a hybrid pump 1 advantageous in the chemical field.

At the in 4 illustrated and so far preferred embodiment are the rotor blades 8th each designed in several pieces, wherein the rotor blade components 12 . 13 again via hinges 14 connected to each other.

In detail, the rotor blades 8th each a first sub-wing 12 and a second wing 13 on, with the two sub-wings 12 . 13 via a double-articulated hinge 14 connected to each other. This embodiment is particularly advantageous insofar as the two sub-wings 12 . 13 with completely outstretched rotor blades 8th lie against each other such that a folding of the rotor blade 8th in 4 is prevented to the left.

From the above-described operation of the hybrid pump according to the invention 1 shows that a bias of the rotor blades 8th opposite the rotor 7 otherwise not absolutely necessary. However, such a bias voltage can in any case be advantageous in order to be able to ensure a defined operating state at any time.

In this case, the bias in one direction to the tread 6 be provided. Then contact the wing tips 11 of the rotor 7 the tread 6 even at a standstill. But it can also be provided that the rotor blades 8th opposite the rotor 7 otherwise in one direction from the tread 6 are biased away. Then the rotation of the rotor causes 7 in the intake operation via the centrifugal force first contacting the tread 6 through the wing tips 11 , The nominal pumping operation then proceeds again as described above.

The structure described above of a lubricating film of pumping medium in the manner of a hydrodynamic plain bearing can be used advantageously at a completely different location. To the tread 6 the pump room 5 close two opposite side surfaces 15 . 16 on, each perpendicular to the axis of rotation 10 of the rotor 7 extend and where the rotor sides 17 . 18 of the rotor 7 pass by 2 ). Depending on the design of the side surfaces 15 . 16 and the rotor sides 17 . 18 can form unwanted solid friction here.

In a particularly preferred embodiment, the rotor is now 7 with its rotor blades 8th and the side surfaces 15 . 16 the pump room 5 tuned to the rated speed range and the viscosity of the pumping medium, that in the nominal pumping operation, a lubricating film of pumping medium between the rotor sides 17 . 18 and the respective side surface 15 . 16 the pump room 5 forms in the manner of a hydrodynamic sliding bearing. This ensures that in the nominal pumping operation between the rotor sides 17 . 18 and the side surfaces 15 . 16 only liquid friction prevails.

It is particularly advantageous if the storage of the rotor 7 in the axial direction has a bearing clearance such that by the resulting lubricant film on the rotor sides 17 . 18 an automatic centering of the rotor 7 takes place in the axial direction.

To promote the formation of the above-described lubricating film between the rotor sides 17 . 18 and the side surfaces 15 . 16 are the rotor sides 17 . 18 preferably equipped with a corresponding chamfer. Seen in the direction of rotation, the chamfer is located on the front side of the respective rotor blade 8th ,

There are numerous possibilities for parameterization of the hybrid pump according to the invention 1 conceivable. For this, reference may be made to the above-mentioned design rules.

In the following, a preferred parameterization is presented, which is particularly suitable for the pumping medium water. This is an operation of the hybrid pump 1 provided under normal conditions (room temperature, etc.). Of course, the hybrid pump 1 also applicable for other pumping media. Then it may be necessary to adapt the parameterization to the material properties of the respective pumping medium.

After the preferred parameterization of the rated speed range in any case comprises a speed of about 8,000 U / min, wherein the diameter of the rotor 7 at the tread 6 contacting wing tips 11 has an average diameter of about 50 mm. This results in a running speed of the wing tips 11 on the tread 6 from about 21 m / s.

The rotor material has a rotor on this preferred parameterization 7 measured Shore A hardness of approx. 75.

The preferred parameterization described above is not intended to be restrictive. There are also deviations possible and provided. In particular, the running speed of the wing tips 11 on the tread 6 at rated speed Range preferably in a range of about 14 m / s to about 28 m / s, more preferably in a range of about 18 m / s to about 24 m / s. With the above average diameter of the rotor 7 of about 50 mm then results in a rated speed range, the speeds between about 5,300 rev / min to about 10,700 rev / min or between about 6,900 rev / min to about 9,200 rev / min includes.

The rotor 7 is preferably made of an elastomer, for example NBR, FKM, PERBUNAN, VITON, EPDM, PEEK or PP. Especially in the design of the rotor 7 Finally, for chemically aggressive pumping media, it may be beneficial to use the rotor 7 at least partially made of PTFE.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 3614349 A1 [0005]
• - DE 19545045 A1 [0006]
• - DE 10158146 A1 [0008]

Cited non-patent literature

• - "Dubbel - Paperback for Mechanical Engineering", 19th Edition, Springer Verlag, 1997, Chapter G-5 [0018]

Claims (20)

Hybrid pump for conveying a pumping medium with a housing ( 2 ), the housing ( 2 ) an inlet ( 3 ), an outlet ( 4 ) and a pump room ( 5 ), wherein in pumping operation, the pumping medium in the pump chamber ( 5 ), wherein in idling mode the pump space ( 5 ) is substantially free of pumping medium, the pumping space ( 5 ) a cross-section substantially round or round tread ( 6 ) for a rotor ( 7 ) with rotor blades ( 8th ), wherein the rotor ( 7 ) eccentric in the pump room ( 5 ), wherein the rotor blades ( 8th ) relative to the rotor ( 7 ) are otherwise movable and wherein a nominal pumping operation in a predetermined nominal speed range of the rotor ( 7 ) is provided, characterized in that in idle mode and operated in the rated speed range rotor ( 7 ) the rotor blades ( 8th ) with their wing tips ( 11 ) the tread ( 6 ) and that the arrangement of the rotor ( 7 ) in the pump room ( 5 ) and the design of the rotor ( 7 ) and the tread ( 6 ) are tuned to the rated speed range and the viscosity of the pumping medium such that in the nominal pumping operation between the wing tips ( 11 ) of the rotor ( 7 ) and the tread ( 6 ) forms a lubricating film of pumping medium in the manner of a hydrodynamic sliding bearing, so that in the nominal pumping operation between the wing tips ( 11 ) and the tread ( 6 ) only fluid friction prevails. Hybrid pump according to claim 1, characterized in that the hybrid pump ( 1 ) in idle mode and at the tread ( 6 ) contacting wing tips ( 11 ) operates essentially in the manner of a displacement machine, in particular a vane pump, in the self-priming operation - suction operation - and that the hybrid pump ( 1 ) operates in the nominal pumping operation substantially in the manner of a turbomachine, in particular a centrifugal pump. Hybrid pump according to one of the preceding claims, characterized in that the wing tips ( 11 ) have a shape promoting the formation of the lubricating film in the nominal pumping mode, preferably that they are each chamfered accordingly, more preferably, that the wing tips ( 11 ) each have a round shape viewed in their cross-section. Hybrid pump according to one of the preceding claims, characterized in that the rotor ( 7 ) is designed at least partially compliant and / or elastic, preferably, that the rotor blades ( 8th ) are designed yielding and / or elastic and / or, more preferably, that the rotor blades ( 8th ) yielding and / or elastic with the rotor ( 7 ) are otherwise connected. Hybrid pump according to one of the preceding claims, characterized in that the rotor ( 7 ) is designed in one piece. Hybrid pump according to one of claims 1 to 4, characterized in that the rotor ( 7 ) is configured in several pieces. Hybrid pump according to claim 6, characterized that the individual rotor components form fit interconnected, preferably glued together, riveted, screwed and / or inserted into each other. Hybrid pump according to claim 6 or 7, characterized in that the individual rotor components are connected to one another via hinges, preferably that the rotor blades ( 8th ) in each case via a hinge with the rotor ( 7 ) are otherwise connected. Hybrid pump according to one of claims 6 to 8, characterized in that the rotor blades ( 8th ) are each designed in several pieces and, preferably, that the rotor blade components ( 12 . 13 ) via hinges ( 14 ) are interconnected. Hybrid pump according to claim 9, characterized in that the rotor blades each have a first part wing ( 12 ) and a second wing ( 13 ) and that the two wings ( 12 . 13 ) via a double hinge ( 14 ) are interconnected. Hybrid pump according to one of the preceding claims, characterized in that the rotor blades ( 8th ) opposite the rotor ( 7 ) otherwise in a direction to the tread ( 6 ) are biased towards. Hybrid pump according to one of claims 1 to 10, characterized in that the rotor blades ( 8th ) opposite the rotor ( 7 ) otherwise in a direction away from the tread ( 6 ) biased away and by rotation of the rotor ( 7 ) by means of centrifugal force in the direction of the tread ( 6 ) are pivotable. Hybrid pump according to one of the preceding claims, characterized in that the tread ( 6 ) of the pump room ( 5 ) two opposite side surfaces ( 15 . 16 ), each perpendicular to the axis of rotation ( 10 ) of the rotor ( 7 ) and on which the rotor sides ( 17 . 18 ) of the rotor ( 7 ) pass by. Hybrid pump according to claim 13, characterized in that the rotor ( 7 ) with its rotor blades ( 8th ) and the side surfaces ( 15 . 16 ) of the pump room ( 5 ) to the rated speed range and the viscosity of the pumping medium are adjusted so that in nominal pumping operation, a lubricating film of pumping medium between the rotor sides ( 17 . 18 ) and the respective side surface ( 15 . 16 ) of the pump room ( 5 ) forms in the manner of a hydrodynamic sliding bearing, so that in the nominal pumping operation between the rotor sides ( 17 . 18 ) and the side surfaces ( 15 . 16 ) only fluid friction prevails. Hybrid pump according to claim 14, characterized in that the rotor sides ( 17 . 18 ) have a shape promoting the formation of the lubricating film, preferably that they are chamfered accordingly. Hybrid pump according to one of the preceding claims, characterized in that the rated speed range in any case a speed of about 8,000 rev / min includes. Hybrid pump according to one of the preceding claims, characterized in that the diameter of the rotor ( 7 ) at the tread ( 6 ) contacting wing tips ( 11 ) has an average diameter of about 50 mm. Hybrid pump according to one of the preceding claims, characterized in that in the rated speed range the running speed of the wing tips ( 11 ) on the tread ( 6 ) is in a range of about 14 m / s to about 28 m / s, preferably, that the running speed in a range of about 18 m / s to about 24 m / s, more preferably that the running speed at about 21 m / s. Hybrid pump according to one of the preceding claims, characterized in that the rotor material is one on the rotor ( 7 ) measured Shore A hardness of about 75 has. Hybrid pump according to one of the preceding claims, characterized in that the rotor ( 7 ) is at least partially made of an elastomer, preferably of NBR, FKM, PERBUNAN, VITON, EPDM, PEEK or PP, and / or that the rotor ( 7 ) is at least partially made of PTFE.