DE3313950A1 - Electrically driven pump - Google Patents

Abstract

An electrically driven pump for the delivery of a liquid is proposed which has a housing, a cover, with a liquid outlet aperture, fixed at one end to the housing, an armature arranged in the housing and having a rotating shaft supported in the cover, a pump area fixed to the other side of the housing and a connecting piece for connecting the armature to the pump area. The pump area comprises a first plate on the intake side with an inlet aperture, a second plate on the outlet side with an outlet aperture and a distance piece arranged between the first and second plate, between which the pump chamber is formed in which an impeller is accommodated which rotates with the connecting piece. A plurality of lugs are arranged on the outer circumference of the impeller and a first recess is formed by the lugs. A second recess is provided in the first and second plate in the area surrounding the lugs, forming the passage for the liquid. A first and a second cut-out duct are provided on the inner peripheral surface of the distance piece, which act in concert with the inlet aperture of the first plate and with the outlet aperture of the second plate respectively. A separation area is formed between the first and second duct in order to divide the pump chamber. <IMAGE>

Description

Henkel, Pfenning, Feiler, Hänzel & Meinig

Patent Attorneys Kurfürstendamm 170, D-1000 Berlin 15

T58-59

3313950 patent attorneys

European Patent Attorneys Admitted to the European Patent Office

Dr. phil. G. Henkel, Munich Dipl.-Ing. J. Pfenning, Berlin Dr. rer. nat L Feiler, Munich Dipl.-Ing. W Hänzel, Munich Dipl.-Phys. K. H. Meinig, Berlin Dr.-Ing. A Butenschön, Berlin

Kurfürstendamm 170 D-1000 Berlin 15

Tel .: 030 / 8812008-09 Telex: 0529802 hnkld Telegrams: rope defense patent

April 18, 1983 Me / bschu

133213, (VGN)

AISAN KOGYO KABUSHIKI KAISHA 1-1, Kyowa-cho 1-chome, Obu-shi, Aichi-ken, Japan

Electrically driven pump

Electrically driven pump

The invention relates to an electrically driven pump which is driven by a motor, and particularly relates to an electrically driven pump for conveying a liquid in the embodiment with a cascade pump.

A cascade pump is useful in the art as a pump for raising water to a point higher stroke and lower flow velocity known and generally the diameter its impeller, the stroke and the flow rate 100 mm, 30-5Om and 100 l / min. Such cascade pumps are usually used for electrically driven fuel pumps in of the low pressure embodiment used in an automobile. However, one requires another embodiment of a fuel pump for use in a fuel injection system a higher pressure, for example no less

2
than 4 kg / cm as the cut-off pressure and therefore the

Cascade pump cannot be used for fuel injection systems. Instead of the cascade pump positive displacement pumps, such as vane or roller pumps, are therefore used in motor vehicles. Such a positive displacement pump is, however, disadvantageously expensive and complicated Structure and therefore the object of the invention is an electrically driven pump of the higher pressure type that is an inexpensive and compact cascade pump which is capable of handling liquids at higher pressures and lower flow rates to promote.

An electrically driven pump according to the present invention comprises a housing and a cover attached to one end of the housing and having a liquid outflow opening. Furthermore, an armature arranged in the housing is provided, the one rotating around the armature Includes shaft mounted in the cover. A pumping area is provided at the other end of the housing, a connector connecting the armature to the pumping area. The pumping area includes

a first plate on the suction side with an inlet opening, a second plate on the outflow side with an outlet opening and a spacer arranged between them, which together form the pump chamber in the an impeller is added, which rotates with the connecting piece. A variety of Tabs are arranged on the outer circumference of the impeller, which are designed in such a way that that they form a first cavity. A second cavity is in the first and second

- to-

provided in the vicinity of the flaps in order to form a liquid passage. First and second cut-out channels are located in the inner circumferential surface of the spacer and work with the inlet opening of the first plate and the outlet, respectively. opening the second plate together. A separation area for separating the pump chamber is formed between the first and second channels. In this arrangement the impeller has an outer diameter D of 25 = D ^ 55 mm, the width a of the first cavity of each lobe is 1.2 = a * 2.5 mm, the thickness b of each lobe becomes b = 0, 7 mm, the distance c between the outer circumferential surface of the pump chamber and the tip of the lobes in the separation area is c = 0.1 mm, the cross-sectional area S of the liquid passage except in the separation area is 5 ^ S = 15 mm ² , the height d of the liquid passage in the cross-section is set to 2.8 = d ^ 4.5 mm, the ratio d / e of the height d to the distance e between the side surface of the liquid passage and the outer edge of the flap opposite the side surface is 0.5 = d / e = 2 and the sum f ₁ + f _{2 of} the distances f, and f ₂ between the impeller and

each side wall of the first and second plate ₂

is f ^ + f ₂ = 0.07 mm.

The invention is shown in the drawing and - is explained in more detail in the following description. Show it:

Fig. 1 is a vertical cross section

a first embodiment of the electrically driven pump;

FIG. 2 shows a section along the line H-II according to FIG. 1;

3 shows a partial section along the line IH-III according to FIG. 2;

Fig. 4 is an enlarged view of the

area labeled A

Fig. 3; and

5 shows a characteristic curve of the cut-off pressure

P (kg / cm) and the outflow velocity Q (liters / hour), by a certain definition of each dimension of the essential

union elements of the pumping area is obtained.

Fig. 1 shows schematically an electrically driven Pump, the reference numerals 1 and 2 having a cylindrical housing and one with the upper End of the cylindrical housing 1 connected by crimping covers. The lid comes with a Provided fuel outflow opening 3. A resin plate 4 is connected to the inner surface of the Cover 2 connected. The reference number 5 denotes a pumping area forming a cascade pump, which is provided in the lower end of the housing 1. A plate 6 is on the outflow side by flanging the lower end of the housing

-Λ

tied together. Reference numerals 7 and 7a denote an armature with a rotating shaft. The wave 7a is rotatably mounted at its upper area in a bearing 9, which via a bearing holder 8 is attached to the cover 2 and is also stored in its lower area in a bearing 11, which is connected to the plate 6 on the outflow side via a bearing holder. Reference numeral 12 denotes a connector pin,

to which the connection of an external electrical conductor (not shown) via a washer 14 and nuts 13 can be attached. The pin 12 is through the cover 2 and the plate 4 out and includes a collar 12a,

which is supported against the plate 4. A synthetic resin bushing 15 and a Rubber O-ring seals 16 are placed between the connecting pin 12 and the cover 2. One Brush 18 is provided on the plate 4 to the electrical current through a commutator 17 to feed the armature 7.

The structure of the pump area 5 will then be described. Numeral 19 denotes a plate

on the suction side with an inlet opening The plate 19 on the suction side is with the Plate 6 attached to the outflow side by a plurality of screws 21, between them a spacer 22 is interposed. In Fig.

only one screw 21 is shown for the sake of clarity. The plate 6 at the The outflow side is provided with an outlet opening 23. The plate 19 on the suction side, the Spacer 22 and the plate 6 on the outflow side form the casing of the pump through which

the pump chamber is defined. The top end the plate 19 on the suction side and the lower end of the plate 6 on the outflow side the side walls Wa, and Wa- the pump chamber and the inner circumferential surface of the spacer forms the peripheral boundary wall Wb of the pump chamber. Numeral 24 denotes a Impeller, which is connected via a bearing 26 to a plate 19 on the suction side Shaft is arranged. The impeller 24 is on its outer peripheral portion with a plurality provided by tabs 27. The plate 19 on the suction side and the plate 6 on the outflow side are provided with annular recesses in the area surrounding the tabs 27, except for a separate portion forming a liquid passage 28, as will be described later Reference numeral 29 denotes a connector which is connected to the lower end of the shaft 7a of the armature 7 is attached. The connecting piece 29 is provided with pawl parts 29a, which are inserted into recesses 24a passing through the impeller 24.

Referring to Figs. 2 to 5, the outer diameter D of the impeller 24 is set at 25 "^ D = 55 mm. The tip goes at = to the left. The width of the cavities 27a formed along the lobes 27 is 1.2 = a - 2.5 _# mm and the thickness b of each tab 27 is b - 0.7 mm The suction side and cooperate with the outlet opening 23 of the plate 6 on the outflow side.

-. R- A fluid passageway 28a is formed between the cut channels 22a and 22 b in the circumferential direction of the spacer 22 is formed, which shown a circumferential distance corresponding to the circular arc L., as shown in Figure 2, and having a separating region for separating the inlet opening into and the outlet opening from the pump chamber, the gap c between the peripheral wall Wb at the liquid passage 28a and the tip of the lobes 27 being c * 0.1 mm. On the other hand, a liquid passage 28b is formed in the circular arc area L ₂ as shown in FIG. 2, and the cross-sectional area S of the liquid passage 28b is set to 5 = S = 15 mm.

- ^ ⁵ As shown in Fig. 4, the height of the liquid passage 28b is 2.8 - d - 4.5 mm in section. The designation e.shows the distance between the side wall Wc. of the liquid passage 28b and the lower, the side wall Wc, opposite edge 27b of the flap 27, or between the side wall Wc _{2 of} the liquid passage 28b and the lower, the side wall Wc ₂ opposite edge 27b of the flap 27. The ratio of the height d to the distance ed / e is 0.5 = d / e =

set. Furthermore, the symbols f _{1 and f 2 show} the distance between the impeller 24 and the side wall Wa, the pump chamber and another distance between the impeller 24 and the side wall Wa- the pump chamber. The sum of f, and f_ is ^ ₁ ⁺ f ₂ ~ ° ^{'07 1} ^ ¹ *

Such fixed dimensions of the elements required for the construction described are like

summarized as follows:
35

- .KT-

(1) D = 25 - 55 mm, a = 1.2 - 2.5 mm, b ^ 0.7 mm

(2) c = 0.1 mm

(3) S = 5-15mm ²

(4) d = 2.8 - 4.5 mm, d / e = 0.5-2 (5) f _x + f ₂ = 0.07 mm

The above dimensions have been identified by the invention as a result of extensive experimentation which was found to be essential to the construction of a compact cascade pump

ο with high pressure (not less than 4 kg / cm of the cut-off pressure) and low flow rate (approx. 2 l / min) for the pump area 5).

For operation, if electrical current is fed to the armature 7 via the connecting pin 12, the rotation of the armature is communicated to the impeller 24 via the connecting piece 29. Fuel will

through the inlet opening 20 into the pump housing 20

of the pumping area is sucked in by the rotation of the impeller and then flows through the discharge opening 23 into the housing 1. The fuel flow in the housing 1 is via the environment

of the armature of the fuel outflow opening 3 closed

leads and the fuel then flows through the opening 3 at higher pressure and lower Flow rate therethrough to be fed to a motor (not shown).

If the respective dimensions of the essential elements are defined as described above as D = 35 mm, a = 1.7 mm, b = 0.3 mm, c = 0.05 mm, S = 8 mm ² , d = 3.7 mm, d / e = 1.8 and ΐ _χ + f ₂ = 0.02 mm, the result is a characteristic curve for the cut-off pressure P (kg / cm) and the outflow velocity

- Zi -

Q (liter / hour) according to Fig. 5 and the maximum cut-off pressure of 6 kg / cm is obtained, when the rotation speed of the armature is 4400 revolutions / min.

Although the invention has been described with respect to a particular embodiment, the Description is illustrative only and is not to be regarded as limiting the concept of the invention. A variety of modifications and changes can be made by those of ordinary skill in the art without leaving the scope of protection defined in the claims.

ι Ή ·· Blank page

Claims (3)

Claims Electrically driven pump for pumping a liquid with a housing and a lid attached to one end of the housing and having a discharge opening therethrough characterized in that an armature (7) is provided in the housing (1), which has a circumferential rotatable in the cover (2) bearing shaft (7a) comprises that one with the other end of the housing (1) connected Pump area and a connecting piece (29) for connecting the armature (7) to the pump area (5) are provided, the pump region (5) having a first one provided on the suction side Plate (19) with an inlet opening (20) and a second one provided on the outflow side Has plate (6) with an outlet opening (23) and that between the first and second Plate (6,19) a spacer (22) is arranged, which together with the plates (6,19) the The pump chamber is formed by an impeller (24) rotating with the connecting piece (29) includes, 2. Electrically driven pump according to claim 1, characterized in that the impeller (24) on its outer circumference has a plurality of tabs (27) that through the tabs (27) a first cavity (27a) and in the first. and second plate (6,19) in the surrounding area the flap (27) a second cavity is formed, which the liquid passage (28) define that in the inner peripheral surface of the spacer (22) a first channel (22a) is cut out, which cooperates with the inlet opening (20) of the first plate (19), that in the inner peripheral surface of the spacer (22) a second channel (22b) is cut out, which is connected to the outlet opening (23) of the second plate (6) cooperates, and that between the first and second channel (22a, 22b) a separation area (28a) is provided for separating the pump chamber. 3. Electrically driven pump according to claim 2, characterized in that the impeller (24) has an outer diameter (D) of 25 = D = 55 mm, that the width (a) of the first Cavity (27a) of the tabs (27) 1.2 = a 2.5 mm, so that the tabs (27) have a thickness (b) of b = 0.7 mm have that the distance (c) between the outer circumferential surface of the pump chamber and the tip of the tabs (27) in the separation area (28a) is c ^ 0.1 mm, that the cross-sectional area (S) of the liquid passage (28) except in the separation area (28a) is set to 5 = S ^ 15 mm that the height (d) of the liquid passage (28) is 2.8 = d = 4.5 mm in section, that the ratio £ / e) of the height (d) to the distance (e) between the side surface of the liquid passage (28) and the outer surface opposite the side surface Edge of the flaps is set to 0.5 = d / e = 2 and that the sum f + f_ of the distances f ^ and ± ₂ between the impeller (24) and the respective side wall of the first and second plate f ^ + f ₂ = 0.07 mm.