Orbital pump device comprising crowning for delivering liquid medium as well as method and use

Abstract

In many pump types, in particular in orbital pumps, there is an optimization need with regard to the running characteristics, in particular with regard to parameters which relate to the delivery flow. What is provided is an orbital pump device for delivering liquid medium by a rotational movement including a hydraulic housing surrounding a hydraulic chamber in a fluid-tight manner at least one membrane unit which is arranged inside the hydraulic chamber in flat contact with an inner jacket surface of the hydraulic housing; and an inlet and an outlet provided in the hydraulic housing. At least one crowning is provided at the inner jacket surface and/or at the membrane unit such that a radial gap between the membrane unit and the inner jacket surface is defined by the crowning in a circumferential section of less than 360°, and in particular less than 180°.

Claims

1. An orbital pump device set up to deliver liquid medium by a rotational movement of an actuating eccentric, the orbital pump comprising: a hydraulic housing surrounding a hydraulic chamber in a fluid-tight manner; at least one membrane unit, which can be actuated to effect pumping and which is arranged inside the hydraulic chamber in flat contact with an inner jacket surface of the hydraulic housing; an inlet, which is provided in the hydraulic housing and which provides a hydraulic connection to the hydraulic chamber in order to introduce the liquid medium; an outlet, which is provided in the hydraulic housing and via which the liquid medium can be discharged from the hydraulic chamber; wherein at least one crowning is provided at the inner jacket surface and/or at the membrane unit in such a way that a radial gap between the membrane unit and the inner jacket surface is defined by means of the at least one crowning in a circumferential section of less than 180°, further wherein the radial gap defined by the at least one crowning is sickle-shaped, shrinking tangentially and tapering tangentially; wherein a compensation geometry that increases a volume of the hydraulic chamber is provided in circumferential sections by means of the at least one crowning; wherein the at least one crowning has, halfway along the circumferential extension thereof, the largest radial depth; wherein the at least one crowning is symmetrical in the circumferential direction; and wherein a size of the radial gap has a maximum value at a circumferential position on the inner jacket surface, and a ratio of the maximum value of the radial gap size to a nominal diameter of the membrane unit is in the range of 0.001-0.003.

2. The orbital pump device according to claim 1, wherein a curvature radius of the at least one crowning varies as a function of a circumferential position at a respective transition to the inner jacket surface.

3. The orbital pump device according to claim 1, wherein the at least one crowning is formed along an entire longitudinal extension of the membrane unit.

4. The orbital pump device according to claim 1, wherein the at least one crowning is arranged in an arrangement in hydraulic communication with the inlet and/or with the outlet; and wherein the at least one crowning extends, in the circumferential direction, starting at the inlet or extends to the outlet with a circumferential overlap of maximally 25% of an absolute circumferential extension of the crowning.

5. The orbital pump device according to claim 1, wherein the at least one crowning extends at a circumferential angle in a range from 5 to 120°; wherein an interface between the membrane unit and the inner jacket surface is divided into four circumferential sections of equal size, wherein the at least one crowning extends in only one circumferential section or in/over maximally two adjacent circumferential sections; and wherein the crowning extends at least over 90° circumferential angle to at most 100° and thereby overlaps either the inlet or the outlet by 5 to 20° circumferential angle.

6. The orbital pump device according to claim 1, wherein the membrane unit is ring-shaped and is supported by means of a membrane support located inside the membrane unit, which surrounds the eccentric of the orbital pump device; and wherein the inner jacket surface is cylindrical.

7. The orbital pump device according to claim 1, wherein the ratio of radial gap extent to the nominal radius of the membrane unit or of the hydraulic chamber lies in the range of from 0.9 to 1.1.

8. The orbital pump device according claim 1, wherein the at least one crowning is provided exclusively at the inner jacket surface; or wherein the crowning is provided exclusively at the membrane unit.

9. The orbital pump device according to claim 1, wherein the at least one crowning is provided exclusively in an arrangement in hydraulic communication with the inlet; or wherein the at least one crowning is provided exclusively in an arrangement in hydraulic communication with the outlet.

10. A method for operating an orbital pump device for delivering liquid medium by a rotational movement, by actuation of a membrane unit by an eccentric, the method comprising: providing an orbital pump device comprising: a hydraulic housing surrounding a hydraulic chamber in a fluid-tight manner; at least one membrane unit, which can be actuated to effect pumping and which is arranged inside the hydraulic chamber in flat contact with an inner jacket surface of the hydraulic housing; an inlet, which is provided in the hydraulic housing and which provides a hydraulic connection to the hydraulic chamber in order to introduce the liquid medium; an outlet, which is provided in the hydraulic housing and via which the liquid medium can be discharged from the hydraulic chamber; wherein at least one crowning is provided at the inner jacket surface and/or at the membrane unit in such a way that a radial gap between the membrane unit and the inner jacket surface is defined by means of the at least one crowning in a circumferential section of less than 180°; further wherein the radial gap defined by the at least one crowning is sickle-shaped, shrinking tangentially and tapering tangentially; wherein a compensation geometry that increases a volume of the hydraulic chamber is provided in circumferential sections by means of the at least one crowning; wherein the at least one crowning has, halfway along the circumferential extension thereof, the largest radial depth; wherein the at least one crowning is symmetrical in the circumferential direction; wherein a size of the radial gap has a maximum value at a circumferential position on the inner jacket surface, and a ratio of the maximum value of the radial gap size to a nominal diameter of the membrane unit is in the range of 0.001-0.003; wherein a relative movement of the membrane unit of the orbital pump device relative to the inner jacket surface of the hydraulic housing of the orbital pump device is controlled or regulated to deliver the liquid medium, wherein the membrane unit contacts the inner jacket surface; and wherein the membrane unit is moved relative to at least one crowning which is arranged at an interface between the membrane unit and the inner jacket surface and which is in hydraulic communication with the inlet and/or with the outlet.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The disclosed embodiments will be described in more detail in the following figures, whereby, for reference numerals, which are not explicitly described in a respective drawing figure, reference is made to the other drawing figures. In particular, individual alternatives for the arrangement and design of a crowning of orbital pump are illustrated, in which:

(2) FIG. 1 shows an orbital pump device comprising a crowning according to an exemplary embodiment in a cut side view;

(3) FIG. 2 and FIG. 5 show special geometric features of a crowning at a hydraulic housing of an orbital pump device according to exemplary embodiments, each in a cut side view;

(4) FIG. 3 shows exemplary diameter ratios of a crowning of an orbital pump device according to one of the exemplary embodiments in a cut side view;

(5) FIG. 4 shows an exemplary arrangement of a crowning at a hydraulic housing of an orbital pump device according to exemplary embodiments in a perspective side view;

(6) FIG. 5 shows an exemplary arrangement of a crowning at a hydraulic housing of an orbital pump device according to exemplary embodiments in a perspective side view;

(7) FIG. 6, FIG. 7, FIG. 8, and FIG. 9 show exemplary arrangements and designs of a crowning at a hydraulic housing or at the membrane unit in the case of an orbital pump device according to exemplary embodiments, each in schematic illustration.

DETAILED DESCRIPTION OF EMBODIMENTS

(8) The figures are initially described jointly with reference to all reference numerals. Individual aspects are emphasized by reference to each of the figures.

(9) An orbital pump device 10 comprises a hydraulic chamber 11 (nominal diameter D11), a hydraulic housing 12 comprising an inner jacket surface 13, and a membrane unit 14 (nominal diameter D14). A membrane support 1 is supported on a bearing 3, in particular needle bearing, and is actuated by an eccentric 5. The liquid to be pumped is delivered via an inlet 7 into the chamber 11 and is further pumped via an outlet 9.

(10) A radial gap 16 between the membrane unit 14 and the inner jacket surface 13 is created by means of a crowning 15 (fictitious or mathematical diameter D15, respectively), in a circumferentially specific position. The crowning starts at a circumferential point A, and the crowning ends at a circumferential point C. The circumferential center point B of the crowning region is in particular the location with the deepest radial gap (gap size R15).

(11) The crowning can be characterized in more detail, based on the following geometric characteristic numbers:

(12) α circumferential angular position inlet or outlet, in particular with regard to the vertical (0°);

(13) β circumferential angular position of the beginning of the crowning;

(14) β0 transition region to the crowning;

(15) β1 tapering region of the crowning or of the buffer sickle, respectively;

(16) γ circumferential section of the crowning (buffer sickle);

(17) δ standard region or default region, respectively (no crowning);

(18) S1 ratio diameter crowning to nominal diameter hydraulic chamber or nominal diameter membrane unit; and

(19) S2 ratio nominal diameter hydraulic chamber to gap size or radial extension of the crowning, respectively.

(20) The transition regions β0 or tapering region β1, respectively, of the crowning can be described as that region, in which a hydraulic effect already occurs due to the crowning, in particular with regard to the pressure. The transition region can in particular lie within the single-digit range, depending on the geometric design of the crowning, and depending on whether a circumferential overlap of the crowning with the inlet/outlet is at hand. The ratios S1, S2 can in each case characterize the crowning, but are not the only parameters, by means of which the crowning can be interpreted.

(21) An orbital pump device 10 is shown in cross section in FIG. 1, with a viewing direction parallel to the axis of the eccentric. A crowning, which overlaps the inlet 7, is provided in an angular range of approx. 10° to approx. 125° (quadrant top right). Apart from this, the membrane unit 14 abuts on the inner jacket surface of the housing 12.

(22) A standard region δ (without radial gap) compared to a crowning 15 is shown in FIG. 2. The crowning 15 cannot be easily seen here, in particular because the membrane unit is not illustrated. The crowning 15 extends over a circumferential section of, e.g., 40 to 80°, and the respective transition region β0 and β1 in each case extends over approx. 10°.

(23) The diameters D15 and D11 are described in more detail in FIG. 3. The crowning diameter D15 is the sum from the nominal diameter D11 of the chamber 11 and the radial depth R15 of the gap. A diameter ratio D15 to D11 (ratio S1) lies, for example, in the range of 1.002 (corresponding to approx. 2 per thousand crowning depth). Depending on the admissible tolerance, the gap size R15, however, can also be significantly larger, in particular up to 10% of the standard diameter of the chamber. A further ratio S2 can also be formed from the nominal diameter D11 of the hydraulic chamber and the gap size R15 (D11:R15).

(24) An exemplary position of a crowning 15 provided at the inner jacket surface is identified in FIG. 4 in perspective view, namely in an overlapping arrangement with the inlet 7.

(25) A comparatively long crowning 15 (extension ≥120°) is shown in FIG. 5, wherein the radial gap R15 is illustrated in a relatively excessively large manner. The crowning has a sickle-shaped geometry and overlaps the inlet region.

(26) One of the exemplary embodiments is described in more detail in FIG. 6. The crowning 15 is provided at the inner jacket surface 13 and starts in the region of the inlet (β≤α). The local gap increase is thereby ensured by a stronger (concave) curvature of the inner jacket surface (smaller curvature radius than standard diameter). The circumferential section γ of the crowning is approx. 70°. In the case of this and also in the case of the further exemplary embodiments, the circumferential position of the inlet 7 and the inner diameter of the housing can be selected or adapted individually, respectively.

(27) A comparatively long and deep crowning 15 is illustrated in FIG. 7. The crowning is provided at the inner jacket surface and starts in the region of the inlet, but with comparatively large overlap region (β−α≈20°). The circumferential section γ of the crowning is approx. 120°.

(28) A comparatively weak crowning 15 is illustrated in FIG. 8. The crowning is provided at the membrane unit. The local gap increase is thereby ensured by means of a weaker (concave) curvature of the membrane unit (larger curvature radius than the standard sections of the outer jacket surface of the membrane unit). The circumferential section γ of the crowning is approx. 70°.

(29) A crowning 15 is shown in FIG. 9, which is comparable to the crowning in FIG. 6, but which, in contrast, is arranged on the side of the outlet. The crowning can optionally be provided at the inner jacket surface or at the membrane unit (negative). The circumferential section γ of the crowning is approx. 70°.

(30) In the case of the exemplary embodiments of FIGS. 6 to 9, the circumferential section can optionally also be varied in the range of from 5 to 120°. The crowning in each case overlaps the circumferential position of the inlet (β<α) or outlet, respectively (FIG. 9).

LIST OF REFERENCE NUMERALS

(31) 1 membrane support 3 bearing, in particular needle bearing 5 eccentric 7 inlet 9 outlet 10 orbital pump device 11 hydraulic chamber 12 hydraulic housing 13 inner jacket surface of the hydraulic housing 14 membrane unit 15 crowning 16 radial gap A circumferential point beginning of the crowning B center point of the crowning region, in particular largest gap C circumferential point end of the crowning D11 nominal diameter hydraulic chamber or inner jacket surface, respectively D14 nominal diameter membrane unit (outer diameter) D15 diameter crowning R15 gap size α circumferential angular position inlet or outlet, in particular with regard to the vertical (0°) β circumferential angular position beginning of the crowning or circumferential section, respectively β0 transition region to the crowning or to the circumferential section, respectively β1 tapering region of the crowning or of the buffer sickle, respectively γ circumferential section crowning or buffer region, respectively, or buffer sickle, respectively δ standard region or default region, respectively S1 ratio diameter crowning to nominal diameter hydraulic chamber or nominal diameter membrane unit S2 ratio nominal diameter hydraulic chamber to gap size or radial extension of the crowning, respectively