DE102010052487B4 - Pump with stabilized by stationary magnets in the pump housing and oscillating piston in a driven rotor - Google Patents

Abstract

Pump (1) for conveying a fluid from a suction area (2) into a discharge area (3), which comprises a housing (4), the housing (4) having a receiving space for a rotor (5) and the end face of the rotor (5) has arranged end regions (6, 7), the rotor (5) being rotatable about an axis of rotation (8) and driven in rotation by a drive element (9, 10), characterized in that the rotor (5) has a number of radially running bores ( 11), the bores (11) extending from a radially outer region (12) of the rotor (5) to a radially inner region (13) of the rotor (5), the bores (11) before reaching the axis of rotation (8) end and the bores (11) in the radially inner region (13) are connected via a fluidic connection (14) to an end region (6) on the end face, in each case a piston element (15) being arranged in the bores (11) , which can move in the longitudinal axis of the bore (L), that in the housing (4) a number of magnets (16, 16 ', 16' ', ...) or a ring magnet is fixed, the magnets or the ring magnet exerting or exerting a magnetic attraction force on the piston element (15) and the magnets (16 , 16 ', 16' ', ...) are arranged along a closed cam track (21) in the housing (4), the magnets (16, 16', 16 '', ...) or the ring magnet in the housing (4) are placed or is that when the rotor (5) rotates about the axis of rotation (8), the piston element (15) performs an oscillating movement (O) due to the magnetic attraction force in the bore (11), one in the end End area (6) in the radial height of the fluidic connections (14) two pressure spaces (17, 18) are arranged offset over the circumference of the end area (6), which temporarily with the bores (11) in the rotation of the rotor (5) The rotor (5) is in fluid communication, the one pressure chamber (17) running over one in the end region (6) The fluid line (19) is connected to the suction area (2) and the other pressure chamber (18) is connected to the discharge area (3) via a fluid line (20) running in the end area (6).

Description

The invention relates to a pump for conveying a fluid from a suction region into a delivery region, which comprises a housing, wherein the housing has a receiving space for a rotor and end regions of the rotor arranged end portions, wherein the rotor rotatably disposed about a rotation axis and rotationally driven by a drive element is.

Pumps of this type are well known in the art. They are used for example in heating systems to pump water through the heating circuit. In most cases, centrifugal pumps are used in particular for the mentioned application.

A generic pump is in the GB 143 688 A described. A piston in a rotor bore is here operated to oscillate, with the possibility of providing an electromagnetic actuation using gravity. Similar solutions show the DE 640 936 A , the GB 147 471 A , the DE 1 218 882 B and the US 1 307 210 A ,

However, these pumps have proven to be disadvantageous in terms of energy efficiency. At typical speed and flow rate, the hydraulic efficiency is usually not more than 35%. The reason for this is the recirculation with which centrifugal pumps work to achieve the necessary pressure build-up. The resulting losses have a disproportionate effect with a small pump size, as is typical for applications in the heating industry.

From an economic point of view, it is still necessary to be able to produce the pump cost, since it is needed in very large quantities.

The invention is therefore the object of a pump of the type mentioned in such a way that the hydraulic efficiency can be increased, with a cost-effective manufacturing capability should exist. Thus, the pump should be used advantageously, but not exclusively, in the field of heating construction. Furthermore, the aim is to provide an efficient pump, in particular for the field of vehicle cooling or in the field of air conditioning technology.

The solution of this object by the invention is characterized in that the rotor has a number of radially extending bores, wherein the bores extend from a radially outer region of the rotor (preferably from a cylindrical peripheral surface) to a radially inner region of the rotor, wherein the Holes end before reaching the axis of rotation and wherein the holes are connected in the radially inner region via a fluidic connection with one of the end-side termination areas, that in each of the bores a piston element is arranged, which can move in bore longitudinal axis that stationary in the housing a number is arranged by magnets or a ring magnet, wherein the magnet or the ring magnet on the piston member exerting a magnetic attraction and the magnets are arranged along a closed curved path in the housing, wherein the magnets or the ring magnet are placed in the housing or is that upon rotation of the rotor about the axis of rotation, the piston member due to the magnetic attraction force in the bore performs an oscillating movement, wherein in the end-side termination region adjacent to the fluidic connections, in the radial height of the fluidic connections two offset over the circumference of the end region arranged pressure chambers are arranged, which come into fluid communication with the holes in the rotor during the rotation of the rotor, wherein the one pressure chamber via a running in the end region fluid line is connected to the suction and wherein the other pressure chamber connected via a running in the end region fluid line with the delivery area is.

The pressure chamber preferably has an elongated shape, in particular a kidney shape, in its region adjoining the rotor, viewed in the direction of the axis of rotation.

The provided with the fluid lines termination region of the housing is preferably designed as a detachable lid.

The two pressure chambers are preferably arranged offset in an end-side termination area by 180 ° around the circumference of the termination area. It can be provided in particular that extends each of the two pressure chambers by a circumferential angle between 130 ° and 170 °.

Preferably, the bores in the rotor extend from the outer periphery to a radially inner region, wherein the bore terminates at a distance from the axis of rotation, which amounts to at least 5% of the radius of the rotor.

The rotor preferably has at least 4, preferably at least 6 and particularly preferably 8 bores, in each of which a piston element is arranged.

The piston element is preferably a cylindrical body or a ball.

Between the housing and the rotor a seal is preferably arranged or formed at two opposite points of the rotor. The seal is preferably formed by a constriction between the rotor and the housing. Between the sealing points and the intake region, a flow channel for fluid to be sucked can be formed. Accordingly, a flow channel for fluid to be dispensed can be formed between the sealing points and the delivery area.

The magnets which control the movement of the piston element in the bore are preferably arranged along a closed circular path in the housing. As an alternative to a number of discrete magnets, a ring magnet can also be used. The magnets or the ring magnet are or is preferably designed as permanent magnets.

Accordingly, the magnets move the piston element during rotation of the rotor in the direction of the longitudinal axis of the bore; this oscillating movement is used to convey the fluid and pressurize it.

The piston element can also be designed as a magnet or it can have a magnet.

The piston element (that is to say preferably the ball) is preferably tolerated in the bore in such a way that during the translational displacement of the piston element in the bore fluid located in the bore is displaced out of the bore or sucked into the bore.

The bore extends advantageously in the rotor perpendicular to the axis of rotation of the rotor.

The diameter of the bore in the piston is preferably an amount between 0.01 mm and 0.1 mm, preferably between 0.03 mm and 0.08 mm, greater than the diameter of the piston member, in particular of the cylinder.

The inner surface of the bore is particularly preferably provided with a hard material layer in order to increase the wear resistance of the bore surface.

The proposed design of the pump has the consequence that a much higher hydraulic efficiency can be achieved than is the case with centrifugal pumps. By the proposed displacement principle, an efficiency can be achieved, which is a two-digit percentage higher than in centrifugal pumps same power range.

In addition, the positive displacement pump described, in contrast to centrifugal pumps mentioned also in oil-based media used.

A particular advantage is further that by providing a plurality of bores in connection with the fluid delivery via the radially inner regions and the fluidic connections to the pressure chambers and the further promotion via the fluid lines to the intake or discharge area a plurality of individual strokes of the piston per Rotation of the rotor takes place. This results in a very uniform fluid delivery result.

The relatively simple structure also allows cost-effective production, so that even large lots of pumps can be produced economically.

In the drawing, an embodiment of the invention is shown. Show it:

1 an exploded view of an embodiment of the pump according to the invention,

2 in the illustration according to 1 the pump, though seen from another direction,

3 the radial section through the complete pump in the assembled state,

4 the pump housing having a front-side end portion, in the front view, as seen in the direction of the axis of rotation of the pump rotor,

5 the section II according to 4 through the case,

6 the section GG according to 4 through the case,

7 the section HH according to 4 through the case,

8th the rotor of the pump in the front view, seen in the direction of its axis of rotation,

9 according to the rotor in the view 8th , but shown cut at the axial height of its holes,

10 the cut KK according to 8th through the rotor,

11 the other end-side end portion of the housing, designed as a lid, in the front view, as seen in the direction of the axis of rotation of the pump rotor,

12 the cut JJ according to 11 through the lid,

13 the section DD according to 11 through the lid,

14 the section EE according to 11 through the lid,

15 in a perspective view of the course of the fluid conveying paths through the rotor and the cover of the pump,

16 the same representation as in 15 but from the other side,

17a and 17b 2 shows a perspective view of two parts of the rotor of the pump according to an alternative embodiment,

18 the rotor according to 17a and 17b in the mounted state in the front view, seen in the direction of its axis of rotation,

19 the section AA according to 18 through the rotor,

20 in perspective view guide elements for the pistons, in the rotor according to 17 to 19 are mounted, and

21 according to the guide elements 20 , seen from a different direction.

In the 1 to 3 is a pump 1 shown, with only the relevant essential components are outlined here. The pump 1 works according to the displacement principle. She has a housing 4 , which extends in a conveying direction F, in which a fluid, for. As water is promoted. In this case, the housing extends 4 essentially from a suction area 2 up to a delivery area 3 , In the intake area 2 will fluid into the pump 1 sucked and pressurized, the fluid then in the delivery area 3 is discharged under increased pressure.

The housing 4 takes a rotor 5 on, around a rotation axis 8th is rotationally driven. The drive of the rotor 5 is done by an electric motor, which consists of the two drive elements 9 and 10 consists of, namely a stator 9 in the case 4 is fixed in place, and a magnetic ring 10 that in the rotor 5 is arranged and that of the stator 9 is driven.

Front side, the housing 4 two graduation areas 6 and 7 on. The one graduation area 7 is in the case 4 formed. The other graduation area 6 is designed as a cover, which is attached to the housing - after assembly of the rotor 5 - is screwed on.

In the case 4 is stationary a number of permanent magnets 16 . 16 ' . 16 '' ... arranged. The magnets are formed in the embodiment as a single magnet along a circular curved path 21 are arranged. This is especially good 4 forth; the 5 to 7 show different cuts through the housing 4 , It can be seen here that a number of magnets are fixed in a circle in the housing, wherein the circle center of the magnets to the axis of rotation 8th is offset. It can also be seen that present - which is not mandatory, but is preferred - two rows of magnets 16 . 16 ' . 16 '' ... are arranged in two concentric circles.

The one in the pump 1 used rotor 5 is in the 8th to 10 shown. The rotor 5 here has eight holes 11 on, which extend radially and on the outer circumference of the rotor 5 start with a cylindrical outer contour; the holes 11 So start in a radially outer area 12 , The bores extend radially inwardly from the outer circumference to a distance a (s. 10 ) to end; the holes 11 thus extend into a radially inner region 13 , The distance a is the distance to the axis of rotation 8th and is at least 5% of the radius r of the rotor 5 (S. 9 ).

In the radially inner area 13 sets in an axial direction from the front side of the rotor 5 from extending bore (s. 10 ), which is a fluidic connection 14 forms over which the bore 11 with the front of the rotor 5 is fluidly connected in the radially inner region.

In each of the holes 11 is ever a piston element 15 arranged. This can be a ball or - as in the embodiment - a short cylindrical element.

During the rotation of the rotor 5 in the case 4 is due to the magnets 16 . 16 ' . 16 '' ... an attraction on the piston elements 15 so these in the holes 11 an oscillating motion O (s. 9 ), ie, they move along the bore longitudinal axis L back and forth. This is due to the fact that the next magnet 16 . 16 ' . 16 '' ... on the piston element 15 the dominant attraction.

In the 11 to 14 is the final area 6 represented in the form of a lid, the frontally into the housing 4 used and fixed by means of screws.

It is essential that in the lid 6 two pressure chambers 17 and 18 are incorporated, as can be seen from the synopsis of 11 to 14 results. The pressure chambers 17 . 18 pointing - in the direction of the axis of rotation 8th seen - a kidney-shaped shape. The two kidneys are arranged offset over the circumference by 180 °. They extend, you put at their peripheral ends radial lines to an angle α (s. 11 ), which is at about 150 °.

From the pressure chambers 17 . 18 out of fluid lines extend 19 . 20 radially outward, which - especially in conjunction with 3 becomes clear - with the intake area 2 or with the delivery area 3 are fluidically connected. For this serve short bore sections 22 and 23 (S. 13 and 14 ), which are incorporated in the lid.

Looking at the fluidic paths of the fluid to be pumped, which is in the 15 and 16 determine recognizable structure. Here is the rotor 5 schematically indicated in the holes 11 are introduced. The holes 11 are in the radially inner region fluidly with the pressure chambers 17 . 18 in turn, which in turn fluidly via the fluid lines 19 . 20 with the intake area 2 or the delivery area 3 are connected.

If the piston element moves 15 translatory in the hole 11 back and forth, that is, it performs the oscillating movement O, it is due to the relatively close (play) fit between the piston diameter and bore diameter to a conveying of the fluid from the bore 11 out. The outer diameter of the piston element 15 is preferably about 0.1 to 0.2 mm smaller than the diameter of the bore 11 ,

The principle of magnetic actuation of the piston elements 15 in a generic pump and the conveying effect achieved thereby is in the DE 10 2010 006 929 A1 of the applicant, to which express reference is made.

In the present embodiment of a pump, it follows that per revolution of the rotor 5 the piston element 15 once moved back and forth.

Due to the sealing of the pump, no appreciable fluid flow can take place outside of said fluid conveying paths. As a result, a significant increase in pressure in the described pumping operation can be achieved. The pressure build-up can easily reach up to 0.5 bar, but for the purpose of application in the heating industry hardly more than a pressure build-up of 0.2 to 0.3 bar is needed. With correspondingly more powerful stationary magnets also pressures up to 7 bar can be achieved, as they are to be found, for example, in oil circulation pumps in the automotive sector.

In normal operation, maximum oscillation speeds of the piston element 15 in the hole 11 between 0.5 and 2 m / s achieved.

As the piston element 15 So in the hole 11 oscillates at a relatively high frequency, a low-friction and low-wear running of the piston member in the bore is important. Accordingly, the cylindrical inner surface of the bore 11 provided with a hard material layer, so that a high abrasion or wear resistance exists.

At the same time can be achieved by appropriate choice of the coating and also the piston member, a low coefficient of friction between the piston element and bore surface.

In the piston element 15 a magnet of rare earth can be arranged. In the embodiment are discrete magnets 16 ' . 16 '' , ... intended. Likewise, of course, a ring magnet can be used. The use of a ring magnet may prove more favorable and in particular make the guiding properties of the piston element more uniform.

The housing 4 , the lid-like completion area 6 and the rotor 5 may all be provided with sliding surfaces which are coated with a wear and friction-reducing hard material, for example with modified polytetrafluoroethylene (PTFE). The same applies to the holes 11 in the rotor 5 , The components are preferably made of fiber-reinforced polyphenylene sulfide (PPS).

The piston element may be cylindrical or spherical. It can be provided with a dense, corrosion-inhibiting coating, for example with a 2-component epoxy resin bonded coating.

If - as in the embodiment - find cylindrical piston elements use, they may have chamfered edges to prevent tilting.

The rotor 5 with his holes 11 may have segmental cavities between the holes 11 in order to produce in the case of production by injection molding the plastic part (for example, from PPS with 40% glass fiber content) injection technology with respect to homogeneous walls better can. In this case, the rotating mass and the associated inertia losses can be minimized. These cavities can be welded, for example via segment lid with ultrasound.

The rotor 5 has, s. in particular 10 , an axially extending region (left in FIG 10 ), in which there is a correspondingly dimensioned multi-polar permanent magnet (for example, encapsulated by the plastic material). This axial region is rounded to the running, sliding u. Centering properties of the rotor 5 to optimize. Also at the right axial end (s. 10 In this case, a (short) axially extending section is provided.

If necessary, in the housing 4 or the lid 6 let in, circular encircling, resiliently mounted seals are provided (for example, silicon carbide) to a leakage above or below the rotor 5 away from the intake area 2 to the delivery area 3 to prevent.

The kidney-like pressure chambers 17 . 18 (Abgreifnuten) act as a permanent suction or pressure side and are on the supply and discharge channels 19 . 20 placed in the pump housing 4 open, each with the outer pressure or suction channels (intake 2 or delivery area 3 ). They ensure that a majority of holes 11 in the piston 5 , which are open towards the inside in the axial rotor direction, can be tapped and thus both sucked in and displaced in each stroke direction without Kavitationsgefahr.

They are provided with circumferential sealing surfaces so that they seal against the axial openings of the rotor to the outside.

The housing 4 is like that with an annular groove 24 provided (see 7 ) that the drive element 9 can be installed or used in the form of the stator as a rotating copper coils with correspondingly shaped teeth, separated over an approximately 1 mm thick wall to the magnetic ring 10 in the rotor 5 , Thus, a permanent-magnet, variable-speed electric motor is realized.

It can also be envisaged that soft metallic pole shoes are integrated into the rotor area in the bore area, which form a north-south bore lining, as it were. This can be achieved that the air gap can be reduced to the piston elements. For this purpose, reference is made to a specific embodiment of the rotor 5 pointed out, as in the 17 to 21 is illustrated.

The rotor 5 is here formed in two parts, ie he has a first part 5 ' and a second part 5 '' , Each of the parts 5 ' . 5 '' is doing with a number (in the present case: eight) recesses 25 respectively. 26 provided, each having a rectangular shape. The recesses 25 . 26 are in the range of rotor parts 5 ' . 5 '' introduced, on which the two parts are in the mounted state together. Therefore, results in the mounted state of the rotor 5 a rectangular receiving space.

In these recording rooms are guiding elements 27 arranged (pushed), as in the 20 and 21 are shown in the arrangement as they come to rest in the rotor relative to each other; This results in a star-shaped configuration.

The guide elements 27 each have a hole 11 for the piston element 15 on. The guide elements 27 consist of soft magnetic material (eg of iron). This creates a close magnetic flux to the surrounding orbital magnets 16 guaranteed. The side walls of the guide elements 27 is in the region of the thinnest point preferably between 0.3 and 1.5 mm, more preferably between 0.5 and 1.0 mm.

This results in an advantageous magnetic flux line looping.

LIST OF REFERENCE NUMBERS

1

pump

2

suction

3

delivery area

4

casing

5

rotor

5 '

Part of the rotor

5 ''

Part of the rotor

6

termination region

7

termination region

8th

axis of rotation

9

Drive element (stator)

10

Drive element (magnetic ring)

11

drilling

12

radially outboard area

13

radially inner area

14

fluidic connection

15

Piston element (cylinder, ball)

16

Magnet (ring magnet)

16 '

Magnet (ring magnet)

16 ''

Magnet (ring magnet)

17

pressure chamber

18

pressure chamber

19

fluid line

20

fluid line

21

cam track

22

bore section

23

bore section

24

ring groove

25

recess

26

recess

27

guide element

L

bore longitudinal axis

O

oscillating motion

α

circumferential angle

a

distance

r

Radius of the rotor

F

conveying direction

Claims (11)

Pump ( 1 ) for conveying a fluid from a suction area ( 2 ) into a delivery area ( 3 ), which is a housing ( 4 ), wherein the housing ( 4 ) a receiving space for a rotor ( 5 ) and the front side of the rotor ( 5 ) ( 6 . 7 ), wherein the rotor ( 5 ) about a rotation axis ( 8th ) and rotatable by a drive element ( 9 . 10 ) is rotationally driven, characterized in that the rotor ( 5 ) a number of radially extending bores ( 11 ), wherein the holes ( 11 ) from a radially outer area ( 12 ) of the rotor ( 5 ) to a radially inner region ( 13 ) of the rotor ( 5 ), the bores ( 11 ) before reaching the axis of rotation ( 8th ) and where the holes ( 11 ) in the radially inner region ( 13 ) via a fluidic connection ( 14 ) with a frontal end region ( 6 ), that in the holes ( 11 ) one piston element each ( 15 ), which can move in bore longitudinal axis (L), that in the housing ( 4 ) fixed a number of magnets ( 16 . 16 ' . 16 '' , ...) or a ring magnet is arranged, wherein the magnet or the ring magnet on the piston element ( 15 ) exerts a magnetic attraction and wherein the magnets ( 16 . 16 ' . 16 '' , ...) along a closed curved path ( 21 ) in the housing ( 4 ) are arranged, wherein the magnets ( 16 . 16 ' . 16 '' , ...) or the ring magnet in the housing ( 4 ) are or is that upon rotation of the rotor ( 5 ) about the axis of rotation ( 8th ) the piston element ( 15 ) due to the magnetic attraction force in the bore ( 11 ) exerts an oscillating movement (O), wherein in a front end region ( 6 ) in the radial height of the fluidic connections ( 14 ) two beyond the scope of the completion area ( 6 ) offset pressure chambers ( 17 . 18 ) are arranged, which during the rotation of the rotor ( 5 ) temporarily with the holes ( 11 ) in the rotor ( 5 ) enter fluidic connection, wherein the one pressure chamber ( 17 ) in the final area ( 6 ) extending fluid line ( 19 ) with the intake area ( 2 ) and wherein the other pressure chamber ( 18 ) in the final area ( 6 ) extending fluid line ( 20 ) with the delivery area ( 3 ) connected is. Pump according to claim 1, characterized in that the pressure chamber ( 17 . 18 ) in his to the rotor ( 5 ) adjacent area in the direction of the axis of rotation ( 8th ) seen an elongated shape, in particular a kidney shape, has. Pump according to claim 1 or 2, characterized in that the with the fluid lines ( 19 . 20 ) ( 6 ) of the housing ( 4 ) is designed as a detachable lid. Pump according to one of claims 1 to 3, characterized in that the two pressure chambers ( 17 . 18 ) in a front-end area ( 6 ) by 180 ° around the circumference of the closure area ( 6 ) are arranged offset. Pump according to one of claims 1 to 4, characterized in that each of the two pressure chambers ( 17 . 18 ) extends through a circumferential angle (α) between 130 ° and 170 °. Pump according to one of claims 1 to 5, characterized in that the bores ( 11 ) in the rotor ( 5 ) from the outer periphery to a radially inner region ( 13 ), wherein the bore ( 11 ) at a distance (a) from the axis of rotation ( 8th ) ending at least 5% of the radius (r) of the rotor ( 6 ) is. Pump according to one of claims 1 to 6, characterized in that the rotor ( 5 ) at least 4, preferably at least 6, more preferably 8 holes ( 11 ), in each of which a piston element ( 15 ) is arranged. Pump according to one of claims 1 to 7, characterized in that the piston element ( 15 ) has a cylindrical shape. Pump according to one of claims 1 to 8, characterized in that between two sealing points and the intake area ( 2 ) is formed a flow channel for fluid to be sucked and that between the sealing points and the delivery area ( 3 ) is formed a flow channel for the fluid to be dispensed. Pump according to one of claims 1 to 9, characterized in that the magnets ( 16 . 16 ' . 16 '' , ...) along a circular path in the housing ( 4 ) are arranged. Pump according to one of claims 1 to 10, characterized in that the magnets ( 16 . 16 ' . 16 '' , ...) are permanent magnets or that the ring magnet is a permanent magnet.

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