DE102008038625A1 - Spur gear pump - Google Patents

Abstract

It is a spur gear pump proposed in the pump housing (2) a driven shaft rotor (6) and a driven by this counter rotor (9) are mounted, wherein the rotors (6, 9) are formed in sections outwardly and mutually spherical and wherein the Halbkugelausnehmung (10) for receiving the rotors (6, 9) in the pump housing (2) by a centering cover (12) is closed and bearing pin (21, 24) for pivotally mounting the rotors (6, 9).

Description

State of the art

The Invention is based on a spur gear pump with a driven mounted in a pump housing shaft rotor and a from this when moving over the teeth taken Counter rotor, the rotors at least partially outward and are formed spherical to each other, the spherical bearing walls as well as the teeth of the gear pump the working spaces limit which in the pump housing an access and a Have outlet for the medium to be conveyed and wherein the axis of rotation of the shaft rotor, the axis of rotation of the counter-rotor intersecting at a certain angle.

such Spur gear pumps have been in different design for a long time known and wise depending on the development and the corresponding objectives different benefits and effects with other pumps Design are unreachable. This is usually the case with such Spur gear pumps also sought, except a promotion of gaseous or liquid media, such Machines also use as motors by the conveyed Media about the pump work spaces a corresponding Achieve output on the shaft rotor.

In a known rotary engine of the generic type ( DE 42 41 320 C2 ) there is the advantage that the comb of the teeth of the rotor cooperating in each case with the other rotor has a radius which can be freely designed. It is only on closer examination of the advantage of this invention that it can be seen that this free-formable rounding of the teeth results in a sealing positive connection between the toothed ridges and the drainage surfaces associated therewith at the cycloidal part without, therefore, leaving the basic cycloidal function. It was previously known only use sealing strips to take advantage of a Trochoide.

In another generic spur gear pump ( U.S. Patent 3,865,440 ) claim wave rotor and counter rotor with their almost complete ball design a correspondingly large pump housing, shaft shaft and counter rotor have approximately the same volume, without therefore an improvement or enlargement of the working spaces arises.

In yet another known generic spur gear pump ( U.S. Patent 3,236,186 ), the drive of the shaft rotor via a driving ring, which is mounted spherically but is pressed with the full delivery pressure on the ball level.

The invention is based task

Of the Invention, the object is based on a spur gear pump generic type to develop further, wherein mainly because of the construction the outer ones Dimensions are reduced and reduces the pivot bearing friction so, due to the principle of the spur gear pump with trochoidal teeth a pump with high efficiency is achieved.

The invention and its advantages

The Spur gear pump according to the invention of the generic type Type in which the toothing is a trochoid toothing in which both shaft rotor and counter rotor with their outer spherical design in a hemispherical recess of the pump housing are arranged, whose axis falls in the axis of rotation of the counter-rotor, in which the Halbkugelausnehmung for receiving the rotors in the pump housing closed by a centering cover which is the same axis as the counter rotor is where the counter rotor turns away with the teeth Side supports and the bearing journal for pivotal mounting the rotors opposite the pump housing and centering cover are present, has the advantage that a Pump with very small outside dimensions constructable but with an exceptionally high efficiency, bearing in mind that such pumps are extraordinary are in demand. Already the constructive difference to the above mentioned state The technique shows how difficult such developments are and that above all a bias of the professional world overcome had to be, since, as a part of the state of the art removable is, constructions of the type given there are long ago, whereas the problem has remained unchanged.

To an advantageous embodiment of the invention have both centering lid as well as end portion of the hemispherical recess a mating cylindrical section on. This makes it possible in a simple way the Zentrierdeckel in the end portion of the Halbkugelausnehmung, namely their open side, insert and fasten. at the known devices is such a cylindrical section not provided, so that a second having a Halbkugelausnehmung Part must be connected to the first part.

According to an additional advantageous embodiment of the invention, the drive of the shaft rotor via an electric motor, preferably external rotor motor, the axis of the pump housing takes place is fastened equal and has a rotary coupling to the shaft rotor. Although it is known a pump in which the promotion of the medium via vane cells and the drive is given by an electric motor ( DE 32 21 389 A1 ), but this is a pump of a completely different genus, and the underlying problem is a completely different.

To an additional advantageous embodiment of the invention also serve for the axial bearing of shaft rotor or counter rotor rolling bearings, arranged on the journal of shaft rotor or centering cover are. By such bearings is natural on the one hand promoted the rotation of the rotors, but it will be In addition, cone forces in the axial direction of the bearing absorbed, so that the friction load on the ball walls within the housing or even the counter rotor to the shaft rotor can be reduced. This mainly contributes to one favorable efficiency, as he usually does not expect becomes.

To an additional advantageous embodiment of the invention is the journal of the shaft rotor on the teeth arranged on the opposite side and serves as a rotary joint, where he in a corresponding bore of the pump housing projects the side facing away from the teeth. Also this is one complete relief of the shaft rotor in the axial direction given to the electric motor, without therefore the driving torque suffers.

To an additional advantageous embodiment of the invention The bearing pin protrudes on the centering cover of the pump housing as a guide means in a bore of the counter rotor and Although on the side facing away from the teeth of the counter-rotor. This has only the second look recognizable the advantage that the Centering cover and thus the external dimensions of the pump can be kept flat and that as well the mass volume of the counter-rotor with its only pump workspace limiting function is greatly reduced. This too is coming Efficiency of the pump benefits.

To an additional advantageous embodiment of the invention the inlet and outlet of the pump are in the form of pipe sockets, which are parallel to each other and largely perpendicular to the axis of the shaft rotor, wherein within the pump housing appropriate connections to the working spaces of the pump available. Also this feature is the cheap Possible uses of the pump, whereby usually the supply of and outlets from pumps are on different sides and redirected in case of a desired parallelization Need to become.

additional Embodiments of the invention relate to improving the efficiency Design of the teeth, but for example their cross-section also in their longitudinal extent, the curved one brings particularly good effect. So is the case with the chosen one Design the spur gear pump according to the invention especially in the field of gaseous media, for example Air, advantageous.

drawing

One Embodiment of the subject of the invention shown in the drawing and explained in more detail below.

It demonstrate:

1 , a longitudinal section through the entire inventive pump unit;

2 a view of the unit from the pump side;

3 the shaft rotor in longitudinal section and the

4 - 7 Volume flow curves of the inventive pump with a capacity up to 200 liters per minute.

As in 1 shown is a spur gear pump 1 with her case 2 with a very simplified illustrated electric motor 3 connected. This electric motor 3 is not shown in detail, but will preferably be designed as an external rotor motor. Anyway, it's about a wave 4 of the engine and a rotary joint 5 a wave rotor 6 the pump driven, which front teeth 7 which is in teeth 8th a counter-rotor 9 grab, so when passing through the electric motor 3 driven rotating the shaft rotor 6 this the counter rotor 9 rotatably mitverdreht. The axes of rotation of the two rotors 6 and 9 include a certain angle, so that one between the teeth 7 and 8th Rotary pumping space is reduced or increased, thereby causing the suction or pressure effect of the pump.

Both rotors, namely shaft rotor and counter rotor, are in a hemispherical recess 10 of the housing 2 arranged so that they are from the opening side 11 in the case 2 can be used. Since it is a Halbkugelausnehmung it is possible unhindered from the opening side 11 to use both rotors. To be able to generate the necessary pumping action between the rotors this Halbkugelausnehmung 10 through a centering lid 12 closed, the counter rotor 9 facing a cylindrical section 13 having, in a corresponding gestal teten cylindrical end portion 14 the Halbkugelausnehmung is plugged.

How special 2 is removable, the centering lid 12 on the pump housing 2 about screws 15 attached. Both the case 2 as well as the area around the screws 15 is reduced as much as possible in terms of material accumulation, thereby obtaining as light aggregate as possible. Of course, this also applies to the connection between the pump housing 2 and electric motor 3 , for which noses 16 are provided - but shown in the drawing without connecting screws.

From the pump housing 2 branches, as in 2 shown, two connections 17 starting to connect to the medium to be conveyed to the between the teeth 7 and 8th formed working spaces and for practical reasons are largely parallel, the more so than a spur gear pump suction and pressure side almost on the same housing half.

The counter rotor 9 has to the wave rotor 6 towards a spherical elevation 18 in a corresponding spherical depression 19 of the shaft rotor 6 protrudes. As a result, the due to a certain angle enclosing axes of rotation of the shaft rotor and counter-rotor to each other resulting position change is achieved, but usually with the disadvantage of the strong accumulation of material through this spherical survey. Around this volume of the spherical elevation 18 to decrease is in the spherical elevation 18 from the side of the centering cover 12 fro a central hole 20 provided, in which a centering pin 21 of the centering lid 12 protrudes. About one between the centering pin 21 and the central hole 20 arranged rolling bearing 22 on the one hand, the smoothness of the counter-rotor is promoted, but on the other hand also frictional forces between the counter-rotor 9 and centering lid 12 reduced or completely degraded, since such a rolling bearing 22 can also absorb corresponding axial forces that occur at the counter rotor by the pressure forces in the pump work spaces between the teeth 7 and 8th , To accommodate the axial forces of course corresponding shoulders are provided by Abrehungen in the storage area.

This effect improving the friction reduction effect is particularly remarkable when considering 3 combined with 1 recognizable. The in 3 enlarged wave rotor shown 6 has, in contrast to the counter rotor 9 , a difference from a tooth to achieve the desired pumping action. The rolling bearing 23 is here on a cone 24 of the shaft rotor 6 arranged, with axially this rolling bearing 23 on a cross shoulder 25 of the shaft rotor 6 supported and on the other hand on a support ring 26 of the housing 2 , which may be, for example, a Segerring. Decisive is that through the bearings 22 and 23 the radial forces are reduced to the spherical wall with its conical clamping action or even canceled. The rotary joint 5 between rotary shaft 4 and wave rotor 6 may be a simple axial clutch allowing a toothed coupling with a spline 27 or the like.

Out The diagrams of the advantage of the invention can be derived, with a fundamental improvement over known ones Pumps of at least 20% is achieved.

In 4 the volume flow is plotted against the speed, in 5 the volumetric efficiency over the volume flow, in 6 the pressure build-up above the volume flow and in 7 the compressor efficiency over the volume flow. As can be clearly seen, similar results have been obtained in all of the fundamental investigations, with the efficiency according to 7 meaningful.

All in the description, the following claims and the Drawing illustrated features can both individually as well as in any combination essential to the invention essential to the invention be.

1

Spur gear pump

2

Housing of 1

3

electric motor

4

Wave of 3

5

rotary joint

6

wave rotor

7

teeth

8th

teeth

9

against rotor

10

Halbkugelausnehmung

11

opening side

12

centering

13

cylindrical section of 12

14

cylindrical section of 10

15

screw

16

nose

17

connections

18

spherical survey of 9

19

spherical depression in 6

20

central drilling

21

spigot

22

roller bearing

23

roller bearing

24

Cones of 6

25

transverse shoulder

26

support ring

27

spline

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 4241320 C2 [0003]
• - US 3865440 [0004]
• - US 3236186 [0005]
• - DE 3221389 A1 [0009]

Claims (9)

Spur gear pump - with a driven from the outside in a pump housing shaft rotor and a taken from this when rotating on the teeth counter rotor, - the rotors are at least partially outwardly and mutually spherical, the spherical walls and the teeth limit the working space of the pump which have an access and an outlet in the pump housing and - wherein the axis of rotation of the shaft rotor intersects the axis of rotation of the counter-rotor enclosing a certain angle, characterized in that - the toothing is a trochoid toothing, - that both shaft rotor ( 6 ) as well as counter rotor ( 9 ) with its outer spherical shape in a hemispherical recess ( 10 ) of the pump housing ( 2 ) are arranged whose axis in the axis of rotation of the counter-rotor ( 9 ) - that the hemisphere recess ( 10 ) for receiving the rotors ( 6 . 9 ) in the pump housing ( 2 ) by one with the counter rotor ( 9 ) same centering cover ( 12 ) is closed, at which the counter rotor ( 9 ) with the teeth ( 7 . 8th ) facing away from side and - with bearing pin ( 21 . 24 ) for the rotary bearing of the rotors ( 6 . 9 ) opposite pump housing ( 2 ) and centering cover ( 12 ). Spur gear pump according to claim 1, characterized in that both centering covers ( 12 ) as well as end portion of the hemisphere recess ( 10 ) a mating cylindrical portion ( 13 . 14 ) and are joined together. Spur gear pump according to claim 1 or 2, characterized in that the drive of the shaft rotor ( 6 ) via an electric motor ( 3 ) carried on the pump housing ( 2 ) and to the wave rotor ( 6 ) a rotary coupling ( 5 ) having. Spur gear pump according to claim 1 to 3, characterized in that also for the axial bearing of wave rotor ( 6 ) or counter rotor ( 9 ) Roller bearing ( 22 . 23 ), which on the journal ( 21 . 24 ) of wave rotor ( 6 ) or centering cover ( 12 ) are arranged. Spur gear pump according to one of the preceding claims, characterized in that the bearing journal ( 21 . 24 ) of the shaft rotor ( 6 ) on the teeth ( 7 . 8th ) facing away from side, as a rotary joint ( 5 ) and in a corresponding bore of the pump housing ( 2 ) protrudes on the teeth ( 7 . 8th ) facing away. Spur gear pump according to one of the preceding claims, characterized in that the bearing journal ( 21 . 24 ) on the centering cover ( 12 ) of the pump housing ( 2 ) as a guide means in a bore of the counter-rotor ( 9 ) protrudes on the teeth ( 7 . 8th ) facing away from the counter rotor ( 9 ). Spur gear pump according to one of the preceding claims, characterized in that at least one of the pivot bearing as a rolling bearing ( 22 . 23 ) is trained. Spur gear pump according to one of the preceding claims, characterized in that inlet and outlet of the pump in the form of pipe sockets are formed, which are mutually parallel and substantially perpendicular to the axis of the shaft rotor ( 6 ), wherein within the pump housing ( 2 ) corresponding connections to the working spaces of the pump are present. Spur gear pump according to one of the preceding claims, characterized in that the toothing as a helical toothing is trained.