DE3311745A1 - DEVICE FOR PROMOTING, IN PARTICULAR, FUEL FROM A STORAGE TANK TO THE INTERNAL COMBUSTION ENGINE OF A MOTOR VEHICLE - Google Patents

Description

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16.3.1983 oa / Kc '- & -

ROBERT BOSCH GMBH, JOOO Stuttgart 1

Device for conveying, in particular, fuel from a storage tank to the internal combustion engine of a motor vehicle

State of the art

The invention is based on a conveyor device according to the preamble of the main claim. It's a funding agency known, in the case of the chamber walls adjacent to the end faces of the impeller, a conveying channel is arranged. In such a conveyor are those between the adjacent wings Delivery chambers open to both end faces of the impeller. Such feed pumps work without axial thrust, but are only able to build up a relatively low delivery pressure.

In another known conveying device, the conveying chambers of the impeller are only one end face of the impeller open minded. This results in a significant increase in the delivery pressure. Due to the unilateral application of the impeller by the delivery pressure - the

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rises steadily in the one-sided conveyor channel, only act Difficult to control forces on the impeller, which either lead to premature wear of the feed pump lead or require additional expenses to absorb these forces.

Advantages of the invention

The conveyor according to the invention with the characterizing features of the main claim has the opposite The advantage that it is completely balanced with regard to the forces mentioned, but on the other hand with this conveyor unit a delivery pressure can be achieved which is in the order of magnitude of the delivery pumps with only one wing face open delivery chambers.

Another advantage is that by the invention circular cross-sectional design of the annular chamber, flow losses in the pump can be reduced.

Through the measures listed in the subclaims are advantageous developments and improvements of the In the main claim specified conveyor possible.

drawing

Embodiments of the invention are shown in the drawing and in the following description in more detail explained. FIG. 1 shows a schematic representation of an arrangement with a fuel storage tank, a Fuel delivery unit and an internal combustion engine, FIG. 2 shows a partial section in the area of the feed pump through a first embodiment of the feed unit according to FIG Figure 1, Figure 3 is a view of a feed pump used

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Dimension Figure 2 belonging housing plate seen in the direction of arrow III, with dash-dotted impeller indicated, Figure k is a partial section according to Figure 2 through another embodiment of the delivery unit and Figure 5 is a further embodiment of the feed pump belonging to the delivery unit in section.

Description of the exemplary embodiments

FIG. 1 shows a fuel storage tank 10 which is connected via a suction line 12 to the suction side of a fuel delivery unit 1 k . A pressure line 16, which leads to an internal combustion engine 18, is connected to the pressure side of the fuel delivery unit 1U. During operation of the internal combustion engine, the fuel delivery unit 1 U delivers fuel from the storage tank 10 to the internal combustion engine 18.

The fuel delivery unit 1U is equipped with an electric drive motor 20 (FIG. 2), the armature shaft 22 of which is connected non-rotatably to an impeller 2k. The impeller 2k is arranged in a housing cavity 26 which forms the pumping chamber of a feed pump 28. This pump chamber 26 is formed in two housing plates 30 and 32, which together represent the pump housing. An annular chamber 3k, in which the impeller 2k rotates, is recessed in the housing plate 32. In the housing plate 30 there is an approximately annular conveying channel 36 (FIGS. 2 and 3) which is interrupted by a separating web 38 has an inlet opening through which the medium to be conveyed is sucked into the pump chamber 26 when the conveying device is in operation

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the electric motor 20 housed in a unit housing ^ 2. The housing plate 32 also has an outlet opening kk which opens into the pump chamber 26 and through which the medium to be conveyed leaves the feed pump 28. An extension of the shaft 22 passes through the plate 32 and the impeller 2k and is received and guided by a bearing point k6 in the other housing plate 30. The blades kQ of the impeller 2k , which extend radially in relation to the axis of rotation of the armature shaft 22, are arranged at a distance from one another (FIG. 3). Conveying chambers 50 are formed between the wings kQ which are arranged adjacent to one another. The separating web 38 is in the direction of rotation of the impeller arrow 52, which also indicates the conveying direction of the medium to be conveyed - wider than the distance between the adjacent blades kQ , so that a proper separation between the suction side and the pressure side is guaranteed. It can also be seen from FIGS. 2 and 3 that the radial length 52 of the blades kQ is greater than the width 5 ^ of the conveying channel 36. These two figures also show that the inlet opening ko is closer to the axis of rotation of the impeller 2k than the conveying channel 36. The distance between the axis of rotation of the armature shaft 22 and the inlet opening ko is denoted by 56, while the distance between the conveying channel 36 and the axis of rotation of the armature shaft 22 is denoted by 58.

For a better understanding of Figures 2 and 3, it should be noted that the course of the section through the Figure 2 goes through two planes standing at a certain angle to one another. As can be seen from the in Figure 3

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shown housing plate 30 can be determined is located the inlet opening Uo is close to a suction area 39 of the conveying channel 36. The outlet opening UU arranged in the other housing plate 32 - the only is shown in Figure 2 - is located near the end of the conveying channel 36, seen in the conveying direction 52 from the inlet opening Uo and also as Pressure range Ui of the conveying channel 36 can be designated.

What has been said about the course of the section naturally also applies to the sectional representations according to FIGS

The delivery chambers 50 present between the adjacent vanes U8 are open, as seen in the axial direction of the axis of rotation of the armature shaft 22. According to the embodiment shown in FIG. 2, the end face 6o facing away from the conveying channel 36 toward the free wing end is provided with a rounding 62, to which the course of the wall 6U of the annular chamber 3U - taking into account the required gap 66 between the wall 6U and the end face 6o - is adapted. The peripheral area of the annular chamber 3U is also rounded. The conveying channel 36 formed in the other housing plate 30 is semicircular when viewed in cross section. The course of the wall 68 of the conveying channel 36 joins the curve of the wall 6U of the annular chamber 3U in a seamless manner. In order to keep the flow losses in the pump as low as possible, the radius of the rounding of the wall 6U corresponds to the radius which defines the course of the wall 68 of the delivery channel 36. The above explanations also determine that the conveying channel 36 is arranged in the area of the flight circle of the blades U8 of the impeller 2U.

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During operation, the feed pump 28 sucks in the medium to be conveyed via the inlet opening Uo (see flow arrows 70), the medium initially accelerated in the radial direction and then set into a circular movement, with an increase in pressure occurring during the conveyance in the direction of arrow 52, until the medium leaves the feed pump 28 via the outlet opening kk (arrow T1). It enters a space in which the 'electric motor is housed and which forms part of the pressure line.

The arrangement according to FIG. H differs from the embodiment of the invention just discussed in that the inlet opening 1U0 of the feed pump opens directly into the feed channel 136. Accordingly, the radial length of the wings 1U8 is adapted to the radial width 15 ^ · of the conveyor channel I36. In this embodiment, the non-rotatable entrainment of the impeller 12U by the armature shaft 122 of the electric motor is provided by entrainment surfaces 121, 123 on the extension of the armature shaft 122, which fit into a central opening 125 of the impeller 12U.

In the embodiment of Figure 5, the wings of the impeller 22 ^, as well as the cross section of the annular chamber 23U is essentially semicircular. The ring chamber is arranged in the G-ehäus eplatxe 230, which has the inlet port 2 ^ 0, which opens directly into the annular chamber 23 ^ ·. The one in the other Housing plate 232 located conveyor channel 236 also has a substantially semicircular cross-section, so that the annular chamber 23 ^ together with a middle section of the conveyor channel 236 forms a full circle. This full circle can be applied to the middle

Section of the conveying channel 236 remain restricted, because both the one end (suction area) of the conveying channel 236 located near the inlet opening and its end (pressure area) of the conveying channel 236 near the outlet opening 2UU can have a cross-section that rejects the semicircular shape. In this embodiment it can be seen that the wings 2U8, which have an outer rounding 262, are also provided with an inner rounding 263, so that the said semicircular shape results. The wall of the annular chamber 23U is adapted to this shape of the wings 2k 8, taking into account the gap 266.

All the exemplary embodiments have in common that the wings kB, 1U8, 2U8 are rounded on their end face facing away from the conveying channel 36, 136, 236 towards the free wing end, and that the wall 6k, 16U, 26k of the annular chamber, taking into account the required gap 66 , 266 is adapted to the rounding 62, 2Ö2, 263 of the wings kB, 1U8, 2U8.

When considering the impeller separately, the delivery chambers 50 present between the adjacent blades are open to the end faces 60, 61 of the impeller. Because the wall 6k or 26k of the annular chamber moves in its shape and in its distance from the end face 60 of the impeller to close to this end face 60 , it is also possible to speak of conveying chambers closed on one side. The wall 6k thus forms, so to speak, a fixed end wall for the revolving conveyor chambers 50, but nevertheless builds up

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in the gap 66 or 26o a pressure which in its size and also with regard to its increase in the direction of the arrow 52 corresponds completely to the pressure in the feed channel 36 or 236, so that the impeller 2U, or 12U or 22U is pressure-compensated is. The disadvantages of the thrust or tilting moments, as they occur in the case of a conveying device with conveying chambers closed on one side, are thus avoided in the conveying device according to the invention.

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Claims (1)

7 O March 16, 1983 Sa / Kc ROBERT BOSCH GMBH, 7OOO Stuttgart 1 Expectations Device for conveying, in particular fuel, "from a storage tank to the internal combustion engine of a motor vehicle, with a feed pump, preferably driven by an electric motor, the conveying element of which is an impeller rotating in a housing cavity, which has preferably radially extending vanes arranged at a distance from one another on the circumference Conveying chambers being formed between adjacent blades, which are open to both end faces of the disc-shaped impeller, the housing cavity being formed by at least two assembled housing plates, of which one housing plate is an annular chamber for the impeller and the other housing plate is an almost annular, have conveying channel interrupted by a separating web, characterized in that the wings (U8 or 1U8 or 2U8) are rounded on their end face (6θ) facing away from the conveying channel (36 or 136 or 236) towards the free wing end and that the Wan d (61+ or 16H or 26U) of the annular chamber (3 ^ or 13 ^ or 23 ^) taking into account the required gap {66 or 266) to the rounding (62 or 262, 263) of the wing ( U8 or 1U3 or 2 ^ 8) is adapted. 8470 2. Device for conveying fuel, in particular, from a storage tank to the internal combustion engine of a motor vehicle with a preferably electric motor drivable Feed pump, the feed member of which is an impeller rotating in a housing cavity, which is on the Has circumferentially spaced apart, preferably radially extending wings are formed between adjacent wings conveyor chambers to the one end face of the disc-shaped impeller are open, the housing cavity is formed by at least two assembled housing plates, one of which is a housing plate an annular chamber for the impeller and the other housing plate a near-ring-shaped through have a separating web interrupted conveying channel, characterized in that to delimit the conveying chambers 50 to the other end face 6o of the impeller 2U or 12U or 22U) a fixed, up to close to the other end face (βθ) approaching wall (6U or 26U) is arranged, which forms the end wall for the rotating conveyor chambers (50). 3. Device according to claim 2, characterized in that the wings (U8 or 1 U8) are rounded radially on the outside and that the wall adjacent to this end face (6 ^ or 16U or 26U) of the annular chamber (3U, 13U or 23U ) is adapted to the rounding (62 or 262, 263) of the sash (U3 or 1U8 or 2U8) taking into account the required gap (66 or 266). 1847 « H. Device according to claim 3, characterized in that the blades (2U8) are provided radially on the inside with an inner rounding (2Ö3) preferably adjoining the outer rounding (262) and that this inner rounding (263) has the wall (26U) adjacent to it. the annular chamber (23 ¹ +) is adapted taking into account the required gap (266). 5. Device according to one of claims 1 "to h, characterized in that the cross section of the conveying channel (36 or 136 or 236) is arranged essentially semicircular and in the region of the flow circle of the wings (U8 or 1U8 or 2U8) and that the conveying channel (36 or 136 or 236) merges into the rounding of the annular chamber (3U or I3U or 23 * 0. 6. Device according to claim 5, characterized in that the annular chamber (23U) seen in cross section is substantially semicircular and that this together with at least the central portion of the conveyor channel (236) forms a full circle. 7. Device according to claim 5, characterized in that that the rounding of the wall (6U or I6U) of the annular chamber (3U or 13U) and the rounding of the wall (68) of the conveying .channel (36 or 136) loop around at least approximately 270. 8. Device according to claim 7> characterized in that the rounding of the wall (6U or I6U or 26U) of the annular chamber (3U or 13U or 23 ¹ O and the rounding of the wall (68) of the conveyor channel (36 or '136 or 236) have the same radius, -U- 9. Device according to claim 8, characterized in that the inlet opening (iUo) in the conveying channel (136) flows out. 10. Device according to claim 9, characterized in that the inlet opening (Uo) of the axis of rotation of the impeller (2U) is closer than the conveyor channel (36). 11. Device according to claim 10, characterized in that that the radial length (52) of the wing (U8) is greater than the width (5U) of the conveyor channel. 12. The device according to claim 6, characterized in that the inlet opening (2U0) in the annular chamber (23 ¹ O opens