EP1914381B1 - Pumping device, in particular for pumping fuel to a vehicle heating device - Google Patents

Description

The present invention relates to a conveyor, in particular for conveying fuel to a vehicle heater, according to the preamble of claim 1.

From the EP 0 617 753 B1 ( EP-A-0617753 ), a rotary piston pump is known in which a rotary piston is arranged in a housing with a cylindrical and coaxial with an axis of rotation inner peripheral surface. The rotary piston has in the circumferential direction successively a plurality of elongated in the direction of the rotation axis elevation areas, which extend up to the inner peripheral surface of the housing, so that between each circumferentially immediately consecutive survey areas a delivery volume range is formed. The rotary piston is carried on a drive shaft extending into the housing which is to be driven for rotation by a drive arranged outside the housing or axially following the housing.

A conveyor according to the ob-term of claim 1 is known from WO 93/13296 (= EP-A-0 617 753 ) known. In this known conveyor, the rotatable about an axis of rotation piston is rotatably supported on a drive shaft driving them for rotation and stored on this. This drive shaft is arranged coaxially to the inner peripheral surface of a Gehäuseaußenwandung.

The GB-A-2 379 482 discloses a hydraulic motor with a rotary piston disposed in a housing. This is formed like a ring and is mounted at its radially inner region via two axially spaced bearing on the housing for rotation about an axis of rotation.

The BE 414,448 discloses a conveyor with a driven in a housing for rotation while fluid conveying piston. This is rotatably held on a shaft rotatably supported on the housing and driven by this for rotation.

The DE 87 08 465 U1 discloses a conveyor formed with a rotary piston. The rotary piston is rotatably supported in a housing on a drive shaft, which in turn is mounted in frontal housing walls.

The JP 62 067 286 A discloses a pump with a rotary piston with basically circular outer periphery. In the radially outer region of the piston, radially displaceable blades are provided with respect to a rotational axis, which can produce a substantially fluid-tight seal with respect to an inner circumferential surface of a housing outer wall. In the inner peripheral region of the ring-shaped piston, a coil arrangement of a drive motor is provided.

The JP 10 184 568 A discloses a pump having a rotary piston rotatably supported by a bearing on a shaft concentric with a rotation axis and fixedly supported on the housing.

The DE 25 03 575 A1 discloses a multiway valve with a pump integrated therein. This pump comprises an eccentrically arranged to an annular wall designed inner circumferential wall annular piston with also kreisartigem outer circumference. In the radially outer region of this annular piston radially displaceable blades are arranged, which produce a fluid-tight closure with respect to the Gehäuseausßenumfangswandung.

The GB 191209282 discloses a pressurized fluid motor having a rotor disposed in a generally annular housing. On the housing biased radially inward leaves are arranged, which are biased against an outer peripheral surface of the rotor. The rotor is supported by two axially spaced bearings relative to the housing.

It is the object of the present invention to provide a trained with a rotating piston conveyor, in particular for conveying fuel to a vehicle heater, which has a small size with a simple structure.

According to the invention, this object is achieved by a conveying device, in particular for conveying fuel to a vehicle heater according to claim 1. This comprises a housing with a housing outer wall substantially concentric with a rotation axis and a housing inner wall substantially concentric with the axis of rotation, wherein between the housing outer wall and the housing inner wall an annular space is formed, one in the annular space about the rotation axis rotatably angeord-Neten Annular piston, which lies with its radially inner region in the region of an outer peripheral surface of the housing inner wall and in its radially outer region has a plurality of circumferentially successive and elongated in the direction of the rotation axis elevation areas which end in the region of an inner peripheral surface of the housing outer wall, wherein between each two in the circumferential direction successive elevation areas a delivery volume range is formed, and an electric drive arrangement having a substantially arranged in a space surrounded by the housing inner space region and a stator arrangement rotatable with the annular piston and can be brought into magnetic interaction with the stator assembly rotor assembly.

In the conveyor according to the invention, therefore, the annular piston which rotates in the conveying operation about the axis of rotation, not supported on a festgekoppelten with this and driven for rotation shaft, but is enclosed in the annular space formed between the housing outer wall and the Gehäuseinnenwandung and without any fixed coupling to a Drive shaft rotatable. The drive is effected by the magnetic interaction between the likewise within the housing, namely in the space enclosed by the Gehäuseinnenwandung space arranged stator assembly with the annular piston provided on the rotor assembly. In this way, on the one hand, it is not necessary to provide a fluid-tight passage for a drive shaft in the housing, and on the other hand can be dispensed with the axial attachment of a drive for a shaft.

It is further provided that the annular piston is mounted with its elevation regions on the inner peripheral surface of the housing outer wall for rotation about the axis of rotation. By this storage on the inner peripheral surface of the housing outer wall, a substantially fluid-tight completion of the delivery volume ranges is generated at the same time. At the radially inner region of the annular piston can then have a small, gap-like gap to the outer surface of the housing inner wall, which avoids over-determination and thus constraints, while ensuring a sufficiently strong magnetic interaction between the stator and the rotor assembly.

The stator assembly may comprise a plurality of armature / coil regions providing a star-like configuration, which armature / coil regions may be oriented such that when excited in a radially outer end region thereof, depending on polarity, a north magnetic pole or a south magnetic pole arises.

In order to keep the structure as simple and insensitive as possible, it is proposed that the rotor arrangement comprises a plurality of provided on the annular piston near the outer peripheral surface of the housing inner wall and in the circumferential direction successive permanent magnet. Upon excitation of the stator arrangement or the armature / coil regions thereof, therefore, a magnetic interaction between these armature / coil regions and the permanent magnet rotating with the annular piston is generated, as a result of which a driving force can be generated.

In order to be able to fill in the rotation of the annular piston moving around the axis of rotation conveyor volume ranges with the medium to be conveyed or to deduct this again, it is proposed that at least one inlet channel is open through the housing outer wall to the annular space and at least one outlet channel is open through the housing outer wall to the annular space.

In order to ensure that the medium enclosed in the delivery volume range is forcibly conveyed into the at least one outlet channel, in particular when pumping, it is proposed that a radially movable slide following in the circumferential direction on the at least one outlet channel is prestressed against an outer surface of the annular piston.

Further, it is possible that the circumferential distance of the region in which the at least one inlet channel is open to the annulus, to the region in which the at least one outlet channel is open to the annulus, is greater than the circumferential distance of the apex regions of two in the circumferential direction immediately following survey areas. In this case, it is ensured that the at least one inlet channel and the at least one outlet channel can not come into direct contact in any rotational positioning of the annular piston over a delivery volume range.

If the housing comprises two housing elements which follow one another in the direction of the axis of rotation and are firmly connected to one another, the structure can be kept very simple on the one hand, but it is ensured that only in a single area, namely where the two housing elements rest against one another a tight conclusion must be taken care of.

Fig. 1

eine Querschnittansicht einer erfindungsgemäß aufgebauten Fördereinrichtung, geschnitten quer zu einer Rotationsachse;

Fig. 2

die in Fig. 1 dargestellte Fördereinrichtung in einer anderen Drehpositionierung eines Ringkolbens;

Fig. 3

eine Schnittansicht der in Fig. 1 gezeigten Fördereinrichtung, geschnitten längs einer Linie III - III in Fig. 1;

Fig. 4 bis 8

in prinzipartiger Darstellung die erfindungsgemäße Fördereinrichtung in verschiedenen Betriebsphasen;

Fig. 9

eine der Fig. 1 entsprechende Ansicht einer alternativ ausgestalteten Fördereinrichtung.

The present invention will be described below in detail with reference to the accompanying drawings. Show it:

Fig. 1

a cross-sectional view of a conveyor constructed according to the invention, cut transversely to a rotation axis;

Fig. 2

in the Fig. 1 illustrated conveyor in a different rotational positioning of an annular piston;

Fig. 3

a sectional view of in Fig. 1 shown conveyor, taken along a line III - III in Fig. 1 ;

Fig. 4 to 8

in a principled representation, the conveyor according to the invention in different operating phases;

Fig. 9

one of the Fig. 1 corresponding view of an alternative designed conveyor.

The Fig. 1 to 3 show a conveyor 10 constructed according to the invention, with which, for example, liquid fuel from a fuel reservoir to a burner of a fuel-powered vehicle heater can be passed.

The conveyor 10 includes a housing, generally designated 12, which, as in FIG Fig. 3 recognizable, composed of two housing elements 14 and 16 are. These two housing elements 14 and 16 are attached to one another to a rotation axis R, for example, perpendicular separating plane E together and connected to each other, for example, by gluing, soldering, welding or other fluid-tight manner. In particular, with such a construction, the two housing parts 14, 16 can be provided with a construction which is essentially identical to one another but mirror-symmetrical with respect to the parting plane E.

The housing 12 constructed with the two housing elements 14 and 16 has a housing outer wall 18 substantially concentric to the axis of rotation R and a housing inner wall 20, which is also concentric with the axis of rotation R. Between these two housing walls 18, 20, an annular space 22 is thus formed, in which an annular piston 24 is received. Each of the housing elements 14, 16 further has an end wall 15, 17, wherein these end walls 15, 17 on the one hand close off the annular space 22 in the axial direction, and on the other hand complete a space region 52 formed radially inside the housing inner wall 20.

The annular piston 24 is arranged with its radially inner region of an outer peripheral surface 26 of the housing inner wall 20 opposite. In its radially outer region, the annular piston 22 has a plurality of circumferentially spaced apart and in the direction of the rotation axis R over the length of the annular piston 24 extending elevation regions 28. These raised areas 28 form in the circumferential direction between them depressions 30, which together with an inner peripheral surface 32 of the housing outer wall 18 limit delivery volume regions 34.

It is possible to provide radially outwardly open, gap-like depressions 38 in the elevation regions 28, as in FIG Fig. 1 left recognizable, in which a blade-like sealing element 40 is added. In rotary operation of the annular piston 34, this is urged by centrifugal force radially outward and is thus on the inner peripheral surface 32 sealingly. Even the smallest manufacturing tolerances can be compensated due to the radial mobility of the sealing element 40. The medium to be pumped, for example diesel fuel, in particular in contact of the elevation regions 28 or the sealing elements 40 to the inner peripheral surface 32, but also to the outer peripheral surface 20 before a lubricating effect.

An inlet channel 42 is open via an opening 44 to the annular space 22. An inlet channel 46 immediately adjacent to the outlet channel 46 is open via a in the direction of movement or rotation of the annular piston 22 of the opening 44 immediately preceding opening 48 to the annulus. Between the outlet channel 46 and the inlet channel 42, a slider 50 is provided, which is pressed by the action of a biasing spring 52 radially inward and against the outer surface 54 of the annular piston 24. This slider 50 is at the in Fig. 1 a recognizable arrangement in which the two openings 44 and 48 of the inlet channel 42 and the outlet channel 46 in the rotational direction immediately following, a reliable separation of the inlet channel 42 and the outlet channel 46 from each other safe, even if a delivery volume range 34 both to the inlet channel 42 and to the outlet channel 46 is open. This condition is in Fig. 2 shown. In this operating phase, fluid to be delivered is thus taken up or drawn in via the opening 44 in the delivery volume area 34 located up here, while fluid is conveyed through the opening 48 into the outlet channel 46 from the area of this delivery volume area facing the opening 48. In this case, the slider 50 also has the function that with progressive movement of the annular piston 24 by the system of the slider 50 on the outer surface 54, the available volume of the delivery volume range is getting smaller and thus the fluid contained therein must forcibly enter the outlet channel 46. For this purpose, it is advantageous that the slider 50 has an extension length in the direction of the rotation axis R, which approximately corresponds to the extension length of the annular piston 24 and the delivery volume regions 34. In order then when a sealing element 40, as in Fig. 1 can be seen on the left, is provided on the elevation regions 28, to prevent entanglement of this seal member 40 with the slider 50, at the peripheral ends of the annular piston 24th the inner peripheral surface 32 in the circumferential direction be completely closed continuously, so that there is forcibly ensured that the sealing element 40 is held in its as far as possible inserted into the recess 38 positioning.

To drive the ring piston 24 for rotation about the axis of rotation R, an electric drive assembly, generally designated 50, is provided. In the example illustrated, the stator arrangement 54 has four armature / coil areas 56, 58, 60, 62 arranged at an angular distance of 90 ° from one another. Each of these armature / coil areas 56, 58, 60, 62 can be energized by energization so that either a magnetic north pole or a magnetic south pole is generated in its radially outer and the Gehäuseinnenwandung 20 immediately adjacent area. With this star-like configuration, as explained below, an alternating distribution of magnetic north poles and magnetic south poles of the stator arrangement 54 can also be generated, for which it is advantageous if the number of armature / coil areas corresponds to an even number.

A rotor assembly 64 provided on the annular piston 24 includes four permanent magnets 66, 68, 70, 72. These may be embedded in the building material of the annular piston 24 and, for example, may also provide a portion of the inner circumferential surface thereof due to their curved configuration. One recognizes in Fig. 1 in that the number of permanent magnets corresponds to the number of armature / coil areas and that the circumferential extent of the permanent magnets also corresponds approximately to the circumferential extent of the radially outer areas of the armature / coil areas.

The electric drive assembly 50 for moving the ring piston 24 about the rotation axis R will be described below with reference to FIGS Fig. 4 to 8 explained.

These Fig. 4 to 8 show in a schematic manner, the radially outer portions of the armature / coil portions 56, 58, 60, 62 and provided on the annular piston permanent magnets 66, 68, 70, 72. Here, in Fig. 4 the relative positioning of the Fig. 1 shown, in which therefore, for example, the permanent magnet 66 is the armature / coil portion 56 radially outwardly opposite and approximately centered in the circumferential direction to this. Due to the in Fig. 1 Also identifiable symmetrical configuration is therefore each of the armature / coil areas 56, 58, 60, 62 in the circumferential direction approximately centrally each one of the permanent magnets 66, 68, 70, 72 opposite. It is further assumed that the polarity of the permanent magnets as in Fig. 4 is shown. The magnetic poles of the permanent magnets 66, 68, 70, 72 are thus consecutive in the circumferential direction, wherein in each case at the circumferential ends of two immediately successive permanent magnets each of the same magnetic pole is present.

If now the conveyor device 10 starting from the in Fig. 4 Positioning shown are put into operation, in such a way that the annular piston 24, starting from the in Fig. 1 Also rotates recognizable positioning in a clockwise direction, so the stator assembly 54 and its armature / coil portions 56, 58, 60, 62 is energized such that at the armature / coil portion 56 radially outside a magnetic south pole is generated, as in the armature / coil region 60 which is directly opposite the armature / coil region 56. The two other armature / coil areas 58, 62 are excited so that radially outward in each case a magnetic north pole is generated. Between each armature / coil region and the permanent magnet associated with it or positioned directly radially outside of it, a magnetic interaction is generated which generates a propelling force in the clockwise direction. For example, the magnetic North pole of the permanent magnet 66 from the armature / coil portion 56 is attracted while the magnetic south pole of this permanent magnet 66 is repelled. A corresponding interaction is also generated in the other pairings. The annular piston 24 is set in motion, so that the circumferential centering of the paired permanent magnets and armature / coil areas is canceled. In this case, for example, the magnetic south pole of the permanent magnet 66 now moves closer to the magnetic north pole of the armature / coil region 58 and is attracted by this stronger. Similarly, the magnetic north pole of the permanent magnet 58 is attracted by the magnetic south pole of the armature / coil region 60, etc.

In the course of this circumferential movement of the annular piston 24 is then in Fig. 6 recognizable relative positioning achieved in which, for example, the permanent magnet 66 overlaps with the armature / coil portion 56 and the armature / coil portion 58 to the same extent. Would in this positioning or movement phase in the 4 and 5 detectable excitation and thus polarity of the stator 54 are maintained, the further movement of the annular piston 24 would actually be slowed down, for example, the magnetic north pole of the permanent magnet 66 would be repelled from the magnetic north pole of the armature / coil portion 58, but from the magnetic south pole of Anchor / coil area 56 would be tightened.

It is therefore advantageous at or shortly before reaching the in Fig. 6 recognizable positioning to end the excitation of the stator assembly 54, so that in the in Fig. 6 discernible movement phase temporarily no magnetic interaction between the stator assembly 54 and the rotor assembly 64 exists. The rotor assembly 64 will continue to move briefly due to inertia, in a direction in which, for example, the permanent magnet 66 will overlap more strongly with the armature / coil portion 58 than with the armature / coil portion 56th

Is at or shortly after going through the in Fig. 6 As shown, the polarity of the stator assembly 54 reversed, so that now form the armature / coil portions 56 and 60 radially outside a magnetic north pole, while the armature / coil portions 58 and 62 form a magnetic south pole radially outward, so for example, the magnetic South pole of the permanent magnet 66 from the magnetic south pole of the armature / coil portion 58 in the circumferential direction repelled while the magnetic north pole of the permanent magnet 66 is attracted by the magnetic south pole of the armature / coil portion 58. The same applies, of course, also in the other armature / coil areas and permanent magnets. So there is a transition to the in Fig. 7 recognizable positioning instead, in which now again, for example, the permanent magnet 66 overlaps more strongly with the armature / coil portion 58. Upon further rotation, a relative positioning is again obtained, as they are already in Fig. 4 was present, namely with circumferential alignment of each armature / coil area with a permanent magnet, now compared to Fig. 4 however, reverse polarity.

It can be seen from the preceding explanation that by alternately changing the polarity of the armature / coil regions, a magnetic field pattern rotating about the rotation axis R and advancing the ring piston 24 can be obtained. It can be provided that in each case diametrically opposite armature / coil areas or all those armature / coil areas, which are each to form the same magnetic pole radially outward, are applied in-phase or with the same voltage and all anchor / Coil regions that are to form another magnetic pole, are excited with a voltage opposite polarity. For example, these two groups of armature / coil regions could be excited with sinusoidal oscillating voltages, which have a phase relationship of 180 ° to one another. Due to the frequency of these alternating voltages, this can also influence the rotational speed the magnetic field equally the rotation speed of the annular piston can be specified. Of course, it is not absolutely necessary to use sinusoidal voltage curves here. For example, sawtooth or rectangular voltage curves could also be selected.

It is apparent from the foregoing description that it is of course also possible to equip the stator assembly and in a corresponding manner, the rotor assembly with a different number of stator / coil areas or permanent magnets, but preferably the number of permanent magnets and the number of anchors / Coil areas corresponds. The larger this number, the smoother the drive can be. Of course, a configuration with only two armature / coil areas and correspondingly two permanent magnets is possible, which then have to provide the star-like configuration an angular distance of 180 °.

A modified embodiment of a conveyor 10 according to the invention is shown in FIG Fig. 9 shown. In this case, components or assemblies designated by the same reference numerals correspond to those already explained above. The essential difference in this embodiment is that the annular piston 24 has a larger number of elevation regions 28 and consequently also a larger number of delivery volume regions 34 formed in the circumferential direction therebetween. In particular, a configuration with six elevation regions 28 following one another in the circumferential direction and correspondingly also six depressions 30 or delivery volume regions 34 formed between them can be seen here. This leads to a homogenization of the delivered volume flow. It will be appreciated, however, that the stator assembly 54 and the rotor assembly 64 are constructed in the same manner as described above. It can be seen that the number of land areas 28 is completely independent of the number of permanent magnets of the rotor assembly 64 and, correspondingly, the number of armature / coil areas of the stator assembly 54.

The annular piston 24 is mounted on the inner peripheral surface 32 of the housing outer wall 18. In this case, the embodiment is such that the elevation regions 28 abut with their apices on this inner circumferential surface 32 and move in a sliding manner along this inner circumferential surface 32. The medium to be delivered will provide a very beneficial lubricating effect here. Radially inside the annular piston 24 then has a small distance to the outer peripheral surface 26 of the housing inner wall 20 in order to avoid constraints.

It is of course also possible to provide a plurality of inlet channels 42 or openings 44 or / and a plurality of outlet channels 56 or openings 48. These could then lie consecutively in the direction of the longitudinal axis, so that over a plurality of openings 44 distributed in the direction of the longitudinal axis or possibly a gap-like opening over the length of the annular piston 24 distributed more uniformly, the medium to be conveyed can enter into the delivery volume regions 34 and with appropriate design the outlet side can escape there. It is of course also possible to provide several pairings of an inlet channel and an outlet channel distributed over the circumference, so that a plurality of conveyor sections, each comprising a pair of at least one inlet channel and at least one outlet channel, can be provided in association with a single annular piston 24 and thus can work at the same time. With suitable positioning in the circumferential direction, also in coordination with the number or the circumferential positioning of the elevation regions 28, it is then possible to obtain a phase-shifted ejection from these multiple conveyor regions, so that when merging the ejected volume flows then a further gleichmäßter Total volume flow can be obtained. In a further modification, it is possible to arrange the openings 44 and 48 or the associated channels 42 and 46 so that their circumferential distance is greater than the distance between two vertices of elevation areas 28 which follow one another directly in the circumferential direction.

Claims (8)

1. A conveying arrangement, in particular for conveying fuel to a vehicle heating device, comprising:

   - a housing (12) with an outside wall of the housing (18) being substantially concentric to an axis of rotation (R),

   - a piston (24) being arranged rotatably inside the housing and comprising in its radially outer region a plurality of projection regions (28) succeeding each other in the circumferential direction and elongated in the direction of the axis of rotation (R), ending in the region of an inner circumferential surface (32) of the outside wall of the housing (18), a conveying volume space (34) being formed between two consecutive projection regions (28) in the circumferential direction,

   - an electric drive arrangement (50) with a stator arrangement (54) and a rotor arrangement (64) rotating with the piston which can be brought in magnetic interaction with the stator arrangement (54),

   characterized by
   the housing further comprising an inside wall of the housing (20) substantially concentric to the axis of rotation (R), a ring space (22) being formed between the outside wall of the housing (18) and the inside wall of the housing (20) and the piston adapted as ring piston (24) being arranged rotatably inside the ring space (22) and being located with its radially inner region in the region of an outer circumferential space (26) of the inside wall of the housing (20),
   the stator arrangement (54) being arranged substantially in a space (52) defined by the inside wall of the housing (20), and
   the ring piston (24) with its projection regions (28) being carried at the inner circumferential surface (32) of the outside wall of the housing (18) for rotation around the axis of rotation (R).
2. The conveying arrangement according to claim 1,
   characterized by the stator arrangement (54) comprising a plurality of armature/coil regions (56, 58, 60, 62) providing a star-like configuration.
3. The conveying arrangement according to claim 2,
   characterized by these armature/coil regions (56, 58, 60, 62) being directed so that after excitation in their radially outer end region, depending on the polarity, a magnetic north pole (N) or a magnetic south pole (S) develops.
4. The conveying arrangement according to one of claims 1 to 3,
   characterized by the rotor arrangement (34) comprising a plurality of permanent magnets (56, 58, 60, 62) provided at the ring piston (24) near the outer circumferential surface (26) of the inside wall of the housing (20) and consecutive in the circumferential direction.
5. The conveying arrangement according to one of claims 1 to 4,
   characterized by at least one inlet channel (42) being open through the outside wall of the housing (18) towards the ring space (22) and by at least one outlet channel (46) being open through the outside wall of the housing (18) towards the ring space (22).
6. The conveying arrangement according to claim 5,
   characterized by a radially displaceable slider (50) succeeding the at least one outlet channel (46) in the circumferential direction being biased against an outer surface (55) of the ring piston (24).
7. The conveying arrangement according to claim 5 or 6,
   characterized by the circumferential distance between the region where the at least one inlet channel (42) is open towards the ring space (22) and the region where the at least one outlet channel (46) is open towards the ring space (22) being larger than the circumferential distance between the apex areas of two projection regions (28) succeeding each other directly in the circumferential direction.
8. The conveying arrangement according to one of claims 1 to 7,
   characterized by the housing (12) comprising two fixedly connected housing elements (14, 16) succeeding each other in the direction of the axis of rotation (R).

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