Abstract
An apparatus (1) for damping pressure pulsations, includes: a working chamber (5) to which a working pressure (p.sub.1) is or can be applied; and a compensation chamber (6) which is separated from the working chamber (5) by an at least partially elastic separating diaphragm (4). The apparatus (1) is distinguished in that working chamber (5) and compensation chamber (6) are connected to one another in a fluid-conducting manner via at least one line device (7).
Claims
1. An apparatus (1) for damping pressure pulsations (Δp.sub.1), the apparatus comprising: a working chamber (5) to which a working pressure (p.sub.1) is applicable; a compensation chamber (6) which is separated from the working chamber (5) by an at least partially elastic separating diaphragm (4); and a line device (7) which fluidically connects the working chamber (5) and the compensation chamber (6) to one another.
2. The apparatus (1) as claimed in claim 1, wherein the line device (7) acts as a damping throttle.
3. The apparatus (1) as claimed in claim 1, wherein, due to the connection of the working chamber (5) and the compensation chamber (6), a dynamic pressure profile (p.sub.2(t)) in the compensation chamber (6) is at least one of delayed or damped in relation to a dynamic working pressure profile (p.sub.1(t)) in the working chamber (5), resulting in a pressure difference, Δp, between the compensation chamber (6) and the working chamber (5).
4. The apparatus (1) as claimed in claim 3, wherein the pressure difference (Δp) is settable between a minimum value zero and a maximum value Pmax by a geometrical design of the line device (7).
5. The apparatus (1) as claimed in claim 1, wherein the separating diaphragm (4) is relieved of load from a quasi-static proportion of the working pressure (p.sub.1) due to an approximately same quasi-stationary absolute pressure prevailing in the working chamber (5) and the compensation chamber (6) based on the line device (7).
6. The apparatus (1) as claimed in claim 1, further comprising a housing (2) which receives the separating diaphragm (4) and defines the compensation chamber (6).
7. The apparatus (1) as claimed in claim 6, wherein the housing (2) is dimensioned in relation to a maximum absolute working pressure.
8. The apparatus (1) as claimed in claim 3, wherein the separating diaphragm (4) is dimensioned in relation to the pressure difference, Δp, between the compensation chamber (6) and the working chamber (5).
9. The apparatus (1) as claimed in claim 6, wherein the line device (7) comprises an exchangeable element formed as a separate component with respect to the housing (2).
10. The apparatus (1) as claimed in claim 1, wherein the line device (7) is at least one of adaptable or adjustable by a variable aperture or a variable length.
11. The apparatus (1) as claimed in claim 1, further comprising at least one of a closed-loop or open-loop control unit (12) in signal-transmitting operative connection with at least one of a measuring or sensor device (13, 14), said at least one of a measuring or sensor device (13, 14) is configured to detect at least one of a varying load or media states in at least one of the working chamber (5) or the compensation chamber (6), said control unit (12) is configured to perform at least one of open-loop or closed-loop control actions on at least one property of the line device (7).
12. The apparatus (1) as claimed in claim 6, wherein the separating diaphragm (4) is connected to the housing (2), or to a connecting piece (3) for connecting the housing (2) to a further article, in a pressure-resistant manner.
13. The apparatus (1) as claimed in claim 1, wherein the separating diaphragm (4) comprises a bellows which is closed on one side.
14. The apparatus (1) as claimed in claim 13, further comprising a housing (2) which receives the separating diaphragm (4) and defines the compensation chamber (6), and a spring (8) arranged between a housing wall (2a) of the housing (2) and the separating diaphragm (4).
15. The apparatus (1) as claimed in claim 14, wherein a spring constant (C.sub.2) of the spring (8) corresponds approximately to a spring constant (C.sub.1) of the bellows (4).
16. The apparatus (1) as claimed in claim 15, wherein the spring (8) comprises a helical spring, a gas bladder (9), a diaphragm cell (10) or a gel cushion.
17. The apparatus (1) as claimed in claim 1, wherein the line device (7) is arranged in the separating diaphragm (4).
18. The apparatus (1) as claimed in claim 12, wherein the line device (7) is arranged in the connecting piece (3).
19. The apparatus (1) as claimed in claim 1, wherein a delimited volume is formed in the compensation chamber (6), and said volume is filled with a compressible medium.
20. The apparatus (1) as claimed in claim 1, further comprising a valve (7b), and the line device (7) is configured to be at least partially closable at least in one direction by the valve (7b).
21. The apparatus (1) as claimed in claim 6, wherein the line device (7) comprises a bore in a housing wall of the housing (2) or in a connecting piece (3) for connecting the housing (2) to a further article.
22. The apparatus (1) as claimed in claim 6, further comprising a sensor (15) for travel detection or closed-loop control, and the sensor (15) is arranged between the separating diaphragm (4) and a housing wall (2a) of the housing (2).
23. The apparatus (1) as claimed in claim 13, further comprising a housing (2) which receives the separating diaphragm (4) and defines the compensation chamber (6), a connecting piece (3) for connecting the housing (2) to a further article projects at least in certain portions into the bellows (4), the compensation chamber (6) is at least partially in the form of a cut-out (3b) in the connecting piece (3), and the cut-out (3b) is connected to the working chamber (5) in a fluid-conducting manner via the line device (7).
24. The apparatus (1) as claimed in claim 23, wherein the connecting piece (3) has a free end (3c), said free end being located within the bellows (4), and a housing wall (2a) of the housing (2), said housing wall lying opposite to the free end (3c), functions as stop surfaces for limiting a working stroke of the separating diaphragm (4).
25. The apparatus (1) as claimed in claim 24, further comprising a throttle element (7b′) movably arranged within the cut-out (3b), an outer wall (7d) of the throttle element (7b′), which is mechanically connected to the separating diaphragm (4), and a delimiting surface of the cut-out (3b) form a fluid gap, at least one of a cross-sectional area or a length of the fluid gap varies depending on a differential pressure-dependent position of the separating diaphragm (4), such that a throttling action which is defined over a working range of the separating diaphragm (4) is produced.
26. The apparatus (1) as claimed in claim 25, wherein the throttle element (7b′) is tubular, the fluid gap remains between an outer wall (7d) of the throttle element (7b′) and a delimiting surface of the cut-out (3b), and the throttle element (7b′) is located, in a first state, with the outer wall (7d) in a region of an opening of the line device (7), and, in a second state, due to deformation of the separating diaphragm (4), with the outer wall outside an opening of the line device (7).
27. The apparatus (1) as claimed in claim 26, wherein the throttle element (7b′) comprises a rectilinear pipe portion and is arranged with a longitudinal axis thereof aligned with a longitudinal axis of the cut-out (3b).
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0060] Further properties and advantages of the invention emerge from the following description of exemplary embodiments on the basis of the drawing.
[0061] FIG. 1 shows a first configuration of the apparatus according to the invention together with illustrative graphs;
[0062] FIG. 2 shows a second configuration of the apparatus according to the invention;
[0063] FIG. 3A shows a third configuration of the apparatus according to the invention;
[0064] FIG. 3B shows a modification of the third configuration of the apparatus according to the invention;
[0065] FIG. 4 shows a fourth configuration of the apparatus according to the invention;
[0066] FIG. 5 shows a fifth configuration of the apparatus according to the invention;
[0067] FIG. 6 shows a sixth configuration of the apparatus according to the invention;
[0068] FIG. 7A shows a seventh configuration of the apparatus according to the invention;
[0069] FIG. 7B shows a modification of the seventh configuration of the apparatus according to the invention;
[0070] FIG. 8 shows the configuration from FIG. 7A with an additional, movable throttle element;
[0071] FIG. 9A shows another configuration of the apparatus according to the invention; and
[0072] FIG. 9B shows a modification of the configuration from FIG. 9A.
DETAILED DESCRIPTION
[0073] FIG. 1 illustrates an apparatus 1 according to the invention in a longitudinal section. An elastic separating diaphragm in the form of a (metal) bellows 4, which bellows 4 is of closed configuration on one side, is arranged within a housing 2, which housing 2 has, on its one side, a connecting or connection piece 3 for connecting to a further component (not shown). At its other, open end, the bellows 4 is attached, at reference sign 4a, all the way around peripherally in a cohesive and fluid-tight manner in the region of an orifice 3A of the connecting piece 3. The connecting piece 3 is, for its part, connected to the housing 2 in a fluid-tight and cohesive manner, as illustrated.
[0074] In this way, a working chamber 5 is configured within the bellows 4, while a compensation chamber 6 is formed within the housing 2, around the bellows 4, which compensation chamber 6 is separated from the working chamber 5 by the elastic separating diaphragm, i.e. the bellows 4. Working chamber 5 and compensation chamber 6 are, however, connected to one another in a fluid-conducting manner via a line device or throttle 7, as illustrated. In the shown configuration of the apparatus 1, the line device or throttle 7 is in the form of an (oblique) bore through the connecting piece 3.
[0075] A spring 8 is arranged between the closed end of the bellows 4 (at reference sign 4b) and a housing wall 2a of the housing 2, said housing wall lying opposite to this end 4b, which spring 8 in the case of corresponding expansion of the bellows 4 cooperates with the bellows 4 so as to generate a restoring force. Advantageously, a spring constant C.sub.1 of the bellows 4 corresponds approximately to a spring constant C.sub.2 of the spring 8, i.e. C.sub.1≈C.sub.2. The spring 8 constitutes merely an optional feature of the shown configuration and can in principle be dispensed with.
[0076] FIG. 1 also illustrates that a working pressure p.sub.1 prevails within the working chamber 5, while a (compensation) pressure p.sub.2 prevails in the compensation chamber 6. However, the separating diaphragm, i.e. the bellows 4, “sees” only a differential pressure or pressure difference Δp between these two pressures, which pressure difference is accompanied by a change in volume ΔV of the bellows 4, as shown, which change in volume leads to the already mentioned expansion of the bellows 4. Said pressure difference and the damping of pressure pulsations is influenced by properties of the line device or throttle 7, in particular the length and/or diameter thereof, and by properties of a medium (fluid) present in the working chamber 5 or compensation chamber 6, in particular the temperature-dependent density and/or viscosity thereof.
[0077] The damping action of the shown apparatus 1 for pressure pulsations is illustrated in two graphs in FIG. 1: the time-dependent pressure in the region of the working chamber 5 is illustrated on the left. The corresponding curve shows clearly identifiable pressure oscillations or pressure pulsations Δp.sub.1. The corresponding time-dependent pressure profile in the region of the compensation chamber is shown on the right. Here, the pressure oscillations or pressure pulsations have essentially disappeared, Δp.sub.2≈0.
[0078] The Figures which are described below show further configurations of the apparatus 1 according to the invention. In this case, identical reference signs denote identical or at least identically acting elements. For the purposes of a readable illustration, all the individual apparatus elements are not discussed in a detailed manner again, but rather reference is essentially made only to the respective particular features.
[0079] According to the configuration in FIG. 2, instead of the spring 8 (cf. FIG. 1), a gas bladder or a gel cushion 9, which can be filled with a particular medium, which medium has specific compression properties in order to influence the damping action of the apparatus 1 overall, is arranged in the compensation chamber 6 between the bellows end 4b and the housing wall 2a.
[0080] According to the configuration in FIG. 3A, the connecting piece 3 (cf. FIG. 1) can be dispensed with. Here, the bellows 4 is or can be connected directly (in a cohesive manner) to the housing 2 in the region of a housing opening 2b. The line device or throttle 7 is configured in the bellows 4 itself, specifically in the form of a tubular insert 7a in the closed bellows end 4b, through which fluid can flow according to the double arrow shown in FIG. 3A. In particular, but not only in this configuration, the line device 7 may be of exchangeable configuration in order to adapt a damping characteristic curve to certain conditions, for example by corresponding exchange of the tubular insert 7a.
[0081] According to the configuration in FIG. 3B, the throttle is in the form of a simple orifice 7a′ in the closed bellows end 4b; the tubular insert (cf. FIG. 3A) is omitted.
[0082] The configuration according to FIG. 4 corresponds substantially to the configuration in FIG. 2. Here, the gas bladder or the gel cushion 9 has been replaced by a diaphragm cell 10, which diaphragm cell 10 is filled with a compressible medium.
[0083] In the configuration according to FIG. 5, the diaphragm cell 10 (cf. FIG. 4) has in turn been replaced by an elastomer bladder 11, which elastomer bladder 11 is likewise filled with a compressible medium.
[0084] The apparatus 1 according to the configuration in FIG. 6 initially corresponds substantially to the configuration according to FIG. 1, without the optional spring 8 shown therein. In addition, the configuration in FIG. 6 has a closed-loop and/or open-loop control unit 12 which is in signal-transmitting operative connection with two measuring and/or sensor device 13, 14 and which is configured to detect varying load or media states, for example variable viscosities as a result of temperature changes, in the working chamber 5 and/or in the compensation chamber 6. To this end, the one measuring/sensor device 13 is arranged in the working chamber 5 and the other measuring/sensor device 14 is arranged in the compensation chamber 6. The closed-loop and/or open-loop control unit 12 is configured to perform, in accordance with the stipulations of the measuring/sensor device 13, 14 (for example in the form of pressure and/or temperature sensors), open-loop or closed-loop control actions on at least one property of the line device, in the present case on a valve 7b arranged on or in the line device 7, in order to (partially) open and/or close the line device 7.
[0085] FIG. 7A shows a fundamentally differently constructed configuration of the apparatus 1 according to the invention, in which the connecting or connection piece 3 (cf. FIG. 1) extends relatively far into the housing 2 and also into the bellows 4. The compensation chamber 6 is partially formed by a central bore or cut-out 3b in the connecting piece 3, which bore or cut-out 3b extends along a longitudinal axis L of the connecting piece 3, which longitudinal axis L is aligned with a longitudinal axis of the bellows 4. The housing wall at reference sign 2a, which has already been mentioned several times, and an end-side end 3c of the connecting piece 3, said end being located in the bellows 4, function as stops (stop surfaces) for a stroke movement of the bellows 4. The bellows 4 is laterally peripherally fastened to the connecting piece 3 in a cohesive manner. A fluidic connection between the surroundings and the working chamber 5 is formed by an (obliquely running) bore 3d through the connecting piece 3. A further bore, which functions as the line device or throttle 7, leads from the interior space of the housing 2 through the connecting piece 3 into the region of said cut-out 3b. In FIG. 7A, working chamber 5 and compensation chamber 6 have thus been interchanged to some extent in relation to the previously shown configurations (cf. the corresponding indications p.sub.1 and p.sub.2).
[0086] FIG. 7B shows a combination of the configuration according to FIG. 7A with parts of the apparatus according to FIG. 6. Thus, the configuration in FIG. 7B also has a closed-loop and/or open-loop control unit 12 which is in signal-transmitting operative connection with two measuring and/or sensor device 13, 14 and which is configured to detect varying load or media states, for example variable viscosities as a result of temperature changes, in the working chamber 5 and/or in the compensation chamber 6. To this end, the one measuring/sensor device 13 is arranged in the working chamber 5 and the other measuring/sensor device 14 is arranged in the compensation chamber 6. The closed-loop and/or open-loop control unit 12 is configured to perform, in accordance with the stipulations of the measuring/sensor device 13, 14 (for example in the form of pressure and/or temperature sensors), open-loop or closed-loop control actions on at least one property of the line device, in the present case on a valve device 7b arranged on or in the line device 7, in order to (partially) open and/or close the line device 7.
[0087] FIG. 8 shows a refinement of the configuration according to FIG. 7A (or 7B; control unit etc. are not illustrated), in which a throttle element (or valve element) 7b′ is arranged within the bore or cut-out 3b, which throttle element is in the form of a rectilinear pipe portion. A longitudinal axis of said pipe portion is aligned with the already mentioned longitudinal axis L of the connecting piece 3 or with the longitudinal axis of the bellows 4. The throttle element 7b′ is fixedly connected to the end 4b of the bellows 4 by a (mechanical) connecting element 7c, with the result that the throttle element 7b′ moves within the bore 3b when the bellows 4 is deformed by pressure actions (cf. the double arrow P in FIG. 8).
[0088] In a first, unloaded state of the apparatus 1 or of the bellows 4, the throttle element 7b′ is arranged (cf. FIG. 8) in such a way that it is located with its outer wall 7d in front of a mouth of said further bore or line device 7 into the cut-out 3b and thus largely closes the line device 7 (except for a relatively small ring gap between a wall of the cut-out 3b and said outer wall 7d). If the bellows 4 is now deflected toward the right, the throttle element 7b′ moves in the same direction and successively frees up said mouth. A liquid located within the cut-out 3b can then also flow inward through the pipe portion, such that a damping characteristic curve of the apparatus 1 changes accordingly.
[0089] Furthermore, FIG. 9A shows a configuration which corresponds substantially to FIG. 1 (without the spring 8 therein). A generic sensor 15—here illustrated symbolically in the form of a simple mechanical switch with connected circuit—is arranged in the region of the housing wall 2a which has already been mentioned several times, which sensor 15 can be used to detect and display a determined degree of deflection of the bellows 4 and to trigger suitable open-loop or closed-loop control operations, for example for a change of properties of the line device 7.
[0090] This is finally schematically illustrated again in FIG. 9B. The sensor 15 is used to detect and display a determined degree of deflection of the bellows 4 and to trigger suitable open-loop or closed-loop control operations, for example for a change of properties of the line device 7. According to FIG. 9B, provision is made for open-loop or closed-loop control actions to be performed on at least one property of the line device, in the present case again on a valve 7b arranged on or in the line device 7, in order to (partially) open and/or close the line device 7.
