EP2677178A2 - Pump - Google Patents

Abstract

An impeller radial pump has a pump chamber (14) with a central suction (15) and with a pump chamber outlet (16), wherein an impeller (18) is located in the pump chamber. Radially outwardly of the impeller, an annular and circumferential pump chamber annulus portion (28) is provided as part of the pump chamber, the pump chamber annulus portion having a substantial extent along the axial direction of the pump from the impeller opposite to the suction direction. The pump chamber ring portion has varying width and is narrower in the circumferential direction in a compression region.

Description

The invention relates to a pump, as it can be used well in particular for household appliances such as dishwashers or washing machines, wherein the pump is designed as a radial pump.

Such radial pumps are for example from the EP 2150165 A known. They include a pumping chamber having a central aspiration and a pumping chamber outlet, wherein an impeller rotates in the pumping chamber to move fluid from the aspiration in the radial direction out of the impeller into the pumping chamber and after several recirculations in the pumping chamber out of the latter via the pumping chamber outlet , Outside the impeller or in the fluid path downstream of the impeller, so to speak, a substantially annular pump chamber ring section is provided in the pump chamber, extending in the axial direction of the pump, away from the impeller, counter to the suction direction into the pump, ie towards the pump chamber outlet extends.

In particular, when starting a pumping operation after a long time can accumulate in the pump chamber air, especially at a pump chamber bottom near the impeller. At the start of the pumping process, this air impedes the efficiency of the pump. To bring out the air faster has been proposed, vanes with blades or the like. to arrange in the pump chamber, in particular close to the impeller. This shows, for example, the aforementioned EP 2150165 B. These guide elements, however, mean additional structural or component costs.

Task and solution

The invention has for its object to provide an aforementioned pump, can be solved with the problems of the prior art and in particular a pump can be created, which works efficiently and above all in the pump chamber existing air can promote at the start of the pumping operation.

This object is achieved by a pump having the features of claim 1. Advantageous and preferred embodiments of the invention are contained in the further claims and are described in more detail below. The wording of the claims is incorporated herein by express reference.

The pump has a pumping chamber with a central suction and with a pumping chamber outlet, wherein in the pumping chamber, an impeller rotates for conveying fluid or for discharging the fluid from the suction in the radial direction from the impeller into the pumping chamber. The discharged fluid is moved to circulate in the pump chamber towards the pump chamber outlet, and it also flows in the axial direction of the pump from the impeller against the suction direction to the outlet or Pumpenkammerauslass. Radially outside the impeller, an annular and circumferential pump chamber ring portion is provided as part of the pump chamber, wherein the pump chamber ring portion has an extension substantially along the axial direction of the pump. In the invention, it is provided that the axial length of the pump chamber ring portion is the multiple or four times to ten times the width of the pump chamber ring portion, advantageously the maximum width of the pump chamber ring portion. It is preferably about five times to seven times, and that is the maximum width of the pump chamber ring section.

In such a pump, the invention provides that the pump chamber ring section has varying width in the circumferential direction and is narrower in a compression area. In this case, a narrow width, in particular in the radial direction, amount to at least 20% or 30% of the greatest width. In particular, it is less than 70%. In the invention, it is also provided that the pump chamber or the entire pump is formed without a guide or no guide elements in the manner of a ladder wheel or the like. having. Such guide elements are those elements or components which protrude from the other walls in the pump chamber and extend into the fluid path for the particular conduction or diversion of the pumped fluid. This can simplify the construction of the pump. Due to the above-described effect of the narrower pump chamber ring portion could be shown in experiments that the efficiency of the pump can be improved without vanes.

By the aforementioned narrow formation of the pump chamber ring portion, the pressure in the conveyed fluid can be changed or increased and the circulation speed of the fluid can be increased for improved delivery. In particular, accumulated air in the pump chamber is better removed or transported away by this pressure increase. In addition, this reduces the maximum volume of air in the pump chamber, since less space is available, which also helps here.

In one embodiment of the invention, it is provided that the pump chamber ring section gradually becomes narrower in the direction of circulation of the conveyed fluid toward the compression region, so that then a narrow width along the circumferential direction substantially over a certain length of the compression region is constant. This may be at least 20% to 30% of the circumference, preferably up to 40% or 50%. Advantageously, the width in the direction of rotation thereafter again, this being slower and over a even greater length than can be done to the compression area.

In an advantageous embodiment of the invention, it is provided that along the axial direction of the pump, the radial width of the pump chamber ring portion remains substantially the same over at least half the axial length of the pump chamber ring section or the pump chamber itself, preferably slightly more than two thirds thereof. Preferably, this area is close to the Pumpenkammerauslass or he extends to this point. In the direction of the impeller to the pump chamber ring portion may also be slightly widened, in particular as a transition to the rest of the pump chamber in the region of the impeller itself.

In a further embodiment of the invention can be provided that the pump chamber in terms of their width in the radial direction, so quasi with respect to their cross-sectional area outside the impeller monotonically tapers in the axial direction away from the pump chamber floor. This rejuvenation is advantageously strictly monotonic. Only at the outlet is a widening, but then in the circumferential direction. Through this tapering of the cross section of the pump chamber or of the pump chamber ring section, the pressure conditions can be advantageously designed for a good delivery and thereby good heating of the fluid or water conveyed. Furthermore, here the conveying speed of the fluid can be increased for an adaptation with respect to the heat absorption of the heating device, since the fluid is indeed becoming increasingly warmer in the passage through the pump chamber.

In yet another embodiment of the invention, a heater may be integrated into the pump to heat the pumped fluid with the pump. Advantageously, it can be provided that an outer pump chamber wall is heated as the outer wall of the pump chamber ring section, partially also of the other pump chamber or part of a heater or is formed by this. Particularly advantageously, this pump chamber wall then occupies at least 75%, advantageously at least 90% or even substantially the entire, axial length of the pump chamber ring section or the pump chamber. Such a heating device can then be substantially round-cylindrical or formed as a pipe section, that is also continuous in the circumferential direction and advantageously seamless.

In particular, in the case of a heated pump or a pump with integrated heating device, a higher heating power can be introduced into the fluid or the heat absorption by the heating device can be increased by the narrower pump chamber ring section and the resulting increase in the speed of the fluid delivered.

In a further embodiment of the invention, it is advantageously provided, such a curved shape form a lower cover plate of the impeller that it is curved radially inwardly toward an aforementioned intake manifold, which forms the suction towards, so to speak in the axial direction away from a pump chamber floor. Advantageously, the lower cover plate of the impeller is curved radially outward in the same axial direction. This curvature may be weaker than that radially inward, but it may still be distinct. Above the said pump chamber bottom in the pump chamber, the impeller rotates, wherein advantageously the pump chamber bottom radially outwardly of the impeller is also curved with continuation of the curvature of the lower cover plate of the impeller in the radially outer region. In particular, the curvature seen in the side section of the impeller is continuous and uniform and continues substantially continuously and uniformly in the pump chamber bottom. For this purpose, the impeller or its lower cover disk can be inserted somewhat into the pump chamber floor. The pump chamber bottom then reaches with a certain curvature close to the pump chamber ring section or even up to this and thus directs the impeller discharged from the fluid at an oblique angle to the heated pump chamber ring section for heating.

Said area of the minimum width or cross-sectional area of the pump chamber annular section is advantageously located in a region of the pump chamber or the pump shortly after the point where the outlet leaves the pump housing. Namely, the outlet from the pump chamber is advantageously in the range of the largest width or largest cross-sectional area, that is, that the molded-out outlet in this area moves out of the otherwise existing shape of the pump chamber and molded out.

These and other features will become apparent from the claims but also from the description and drawings, wherein the individual features each alone or more in the form of sub-combination in one embodiment of the invention and in other areas be realized and advantageous and protectable Represent embodiments for which protection is claimed here. The subdivision of the application into individual sections as well as intermediate headings does not restrict the general validity of the statements made thereunder.

Brief description of the drawings

Fig. 1

eine geschnittene Längsansicht einer erfindungsgemäßen Pumpe,

Fig. 2

eine um etwa 70° verdrehte geschnittene Längsansicht der Pumpe aus Fig. 1,

Fig. 3

eine Draufsicht auf die Pumpe von oben und

Fig. 4

eine geschnittene Queransicht der Pumpe mit Verlauf der Breite eines Pumpenkammerringabschnitts in Umlaufrichtung.

Embodiments of the invention are shown schematically in the drawings and are explained in more detail below. In the drawings show:

Fig. 1

a longitudinal sectional view of a pump according to the invention,

Fig. 2

a cut by about 70 ° longitudinal cutaway view of the pump Fig. 1 .

Fig. 3

a plan view of the pump from above and

Fig. 4

a cross-sectional view of the pump with the width of a pump chamber ring portion in the circumferential direction.

Detailed description of the drawings:

In Fig. 1 a pump 11 is shown with a pump housing 12, as is apparent from the above-mentioned prior art in principle. The pump housing 12 has a pump chamber 14 into which a central, axial intake 15 leads, and from which an outlet 16 leads out in the tangential direction. The suction 15 leads exactly to a centrally arranged impeller 18 with a lower cover plate 18a and an upper cover plate 18b. The impeller 18 is driven by a pump motor 19 and passes over a pump chamber bottom 21 with a step-like central recess adapted to the lower cover plate 18a.

The radially outer wall of the pump chamber 14 is formed by a tubular heater 23, as for example from the EP 2150165 B is known, namely as a metallic tube of constant diameter with straight cut ends. On the outside of the tube heating elements 23 not shown here are provided for the heater, advantageously thick-film heating elements.

The heater 23 is held in the lower portion in a V-seal 26 a to the seal, wherein the V-seal 26 a rotates radially outside of the pump chamber bottom 21 and close thereto. At the upper end of the pump chamber 14, ie axially away from the impeller 18, a sealing ring 26 b is provided with a round cross-section on the outside of the heater 23. Thus, the heater 23 is sealed to the outside against the pump housing 12 and forms the inside of the outer wall of the pump chamber 14. As out Fig. 4 can be seen, the heater 23 is circular or has circular cross-section.

The pump chamber 14 has radially outside the impeller 18 at approximately the same axial height on a transition region, which merges into a pump chamber ring portion 28. The pump chamber ring portion 28 defines substantially in the region where the pump chamber 14 in the radial direction has approximately the same width 29, which does not change in the axial direction or can decrease. Thus, while the outer wall of the pump chamber ring portion 28 is formed by the heater 23, the inner wall is formed by an inner wall 30 of the pump housing 12. It can be seen that on both sides in the axial direction slightly above the fluid outlet from the impeller 18, this inner wall 30 and the heater 23 are approximately at a constant distance from each other, the pump chamber ring portion 28 thus approximately constant width or even decreasing width in the axial Direction.

The pump chamber ring portion 28 now has in the axial direction in each case approximately constant width or same cross-section or even decreasing width, wherein the width 29, however, varies in the direction of rotation, as shown in the sectional view in FIG Fig. 4 can be seen. In the Fig. 1 is a section through the pump 11 is shown, in the above a width 29a of the pump chamber ring portion 28 is approximately the largest, while right below a width 29c is approximately minimal. The sectional view according to CC of Fig. 4 shows this, where there just cut longitudinal view of Fig. 1 is shown as section AA.

To the Fig. 2 is to say that in the sectional plan view of the Fig. 4 according to section BB shows a region in which on the right-hand side again the minimum width 29c is present at the pump chamber ring section 28. On the left hand side, there is a mean width 29b, which in Fig. 4 is also marked.

The Fig. 3 shows a plan view of the pump 11 with the pump housing 12 together with intake 15 and outlet 16, which merges into an outlet 17. More interesting, however, is the one directly below Fig. 4 according to the section CC of Fig. 1 , wherein here outlet 16 and outlet 17 are still shown in dashed lines. It can be seen that, coaxially with the suction 15, the heating device 23 extends as the outer wall of the pump chamber 14. However, the width 29 of the pump chamber ring portion 28 is determined by the differently extending inner wall 30. The width 29a, which is approximately the maximum, the average width 29b and the smallest or narrow width 29c are shown approximately. This narrow width 29 c extends over an arc angle of about 120 ° to just before an electrical connector 24, which is arranged on the outside of the heater 23. From here on, the width 29 of the pump chamber ring section 28 widens again continuously over the central width 29b until just at the maximum width 29a. This maximum width 29a is approximately where the outlet 16 is separated with the tube-like outlet 17 relative to the pump chamber 14 and the pump chamber ring portion 28 itself, which is approximately at the marked section AA. From this area, the width 29 tapers again with a taper 32 up to the taper end 32 ', where then again the smallest or narrow width 29c begins. The taper 32 extends over a range of about 70 °.

It can be clearly seen that the width 29 of the pump chamber ring section 28 is determined externally by the annular heating device 23 and inwardly by the inner wall 30.

From the top view in Fig. 4 It can also be seen that actually the area of the pump chamber ring portion 28 having the smallest width 29c is the only one of constant width. In the area adjacent thereto in the direction of rotation in the clockwise direction, the width widened substantially uniformly, and then in the region of the taper 32 just to lose weight again. It can also be seen that approximately the factor 3 lies between the maximum width 29a and the smallest width 29c.

At the same time, however, it is also conceivable that the inner wall 30 of the pump chamber 14 or of the pump chamber ring section 28 is circular and concentric to the axis of rotation of the impeller 18 or to the longitudinal central axis of the suction 15. Then, the outside surrounding outer wall, in particular in the form of a heater, non-concentric so that it is so to speak offset to this or just out of round is formed. As a further alternative, both walls could be non-concentric to each other or to the longitudinal center axis of the pump.

Due to the narrowed flow cross-section of the in Fig. 4 in the clockwise circulating fluid in the region of the smallest width 29c of the pump chamber ring portion 28, the fluid velocity is greatly increased. This is good, inter alia, for a venting of the pump 11, so if in the region of the pump chamber bottom 21 air bubbles are present, for whatever reason. By increasing the width 29 from the narrow region 29c over the central width 29b to the largest width 29a, the velocity of the fluid is reduced. Both by the change in the velocity of the circulating fluid, which circulates for example from the outlet of the impeller 18 in the pump chamber 14 to the outlet of the outlet 16 and outlet 17 about three times to eight times, as well as in the narrower range significantly higher speed trapped air or an air / fluid mixture better out of the pump 11. For this purpose, otherwise guide wheels or similar guide devices were provided and necessary, as for example from the aforementioned EP 2150165 B are known. However, their manufacture and installation are relatively complex and can lead to problems and failure and thus errors in the pump. Furthermore, the heat transfer increases from the Heating device to the fluid or water due to the increased flow rate of the fluid.

It has been found to be advantageous, but not absolutely necessary, for the mentioned effects of improving the ventilation as well as the improvement of the heating, if, as in the Fig. 1 and 2 can be seen, the pump chamber ring portion 28 over a certain axial length has the same width or decreasing width. At the same time, however, it should be noted that the enlarged width of the pump chamber ring portion 28 is also in the region radially outside of the impeller 18 and at its axial height. Precisely because of this, the improved ventilation can probably be achieved.

Claims (10)

Pump, in particular for household appliances such as dishwashers or washing machines, which is designed as a radial pump, with a pump chamber with a central suction and a Pumpenkammerauslass, wherein in the pump chamber, an impeller rotates to convey fluid and for discharging the fluid from the suction in the radial Direction from the impeller into the pump chamber, wherein the discharged fluid is moved to circulate in the pump chamber to the Pumpenkammerauslass, wherein radially outside the impeller an annular and circumferential Pumpenkammerringabschnitt is provided as part of the pump chamber and wherein the pump chamber ring portion substantially an extension along the axial direction of the pump from the impeller opposite to the suction direction up to the pump chamber outlet, wherein the axial length of the pump chamber ring portion is four times to ten times the width, characterized in that the pump chamber ring abs Chnitt has varying width and is narrower in the circumferential direction in a compression region, wherein the pump chamber is formed without a vane and has no guide elements in the manner of a stator. A pump according to claim 1, characterized in that the pump chamber ring portion is gradually narrower in the direction of rotation toward the compression region, in particular in a constant small width of the compression region along the direction of rotation over a certain length, and preferably in The direction of circulation then continues again. Pump according to claim 1 or 2, characterized in that the width in the compression region is at least 20% of the maximum width of the pump chamber ring portion, preferably at least 30%, and in particular less than 70%. Pump according to one of the preceding claims, characterized in that the pump chamber ring portion over at least 20% of its length or one revolution has the same small width, preferably less than 50%. Pump according to one of the preceding claims, characterized in that the increase in the width of the pump chamber ring portion in the circumferential direction away from the compression region is less strong or slower than the decrease in the width in the circumferential direction towards the compression region. Pump according to one of the preceding claims, characterized in that in the axial direction of the pump, the width or the cross section of the pump chamber ring portion remains largely the same, in particular in the axial direction of the impeller remote area of the pump chamber ring portion, preferably close to the Pumpenkammerauslass. Pump according to one of the preceding claims, characterized in that the pump chamber tapers monotonically in the radial direction outside the impeller, preferably tapers in a strictly monotonous manner. Pump according to one of the preceding claims, characterized in that it comprises an integrated heating device for heating the pumped fluid. Pump according to claim 8, characterized in that an outer pump chamber wall is heated as the outer wall of the pump chamber ring portion or part of the heater and in particular this pump chamber wall occupies the entire axial length of the pump chamber ring portion, preferably the entire pump chamber. Pump according to one of the preceding claims, characterized in that a lower cover plate of the impeller is curved such that it is curved radially inwardly toward an intake port as the suction and preferably radially outwardly in the same axial direction, wherein the pump chamber a pump chamber bottom over which the impeller rotates, wherein the pump chamber bottom is curved radially outside the impeller with continuation approximately corresponding to the curvature of the lower cover plate and thereby merges into an outer wall of the pump chamber and the then following pump chamber ring portion.

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