Damping device

0001The invention relates to a damping device for damping or avoiding pressure surges, such as pulsations, in hydraulic supply circuits, preferably in the form of a silencer, with the features in the preamble of claim 1.

0002Damping devices of this type are known in the art. Such hydrostatic damper, also called muffler or silencer, serve to reduce vibrations that are generated by pressure pulsations that are imposed periodically on a particular hydrosystem, in particular by the operation of hydraulic pumps. As in the document<patcit id="pcit0001" dnum="DE10217080C1"><text>DE 102 17 080 C1</text></patcit> is shown, the known damping devices of this type on a damping housing in the form of a circular cylinder which is rounded spherical at both axial end portions, wherein the fluid inlet and fluid outlet are coaxial with the cylinder axis at one end. As a damping chamber, which traverses the fluid flow from fluid inlet to fluid outlet, a damping tube is provided in these damping devices, which extends coaxially between the fluid inlet and fluid outlet and has openings in the pipe wall to the fluid space surrounding the tube. Corresponding to the cylinder diameter, the fluid space is widened radially relative to the axial throughflow direction predetermined by the damping tube.

0003The <patcit id="pcit0002" dnum="DE60017902T2"><text>DE 600 17 902 T2</text></patcit> describes a generic damping device for damping or avoiding pressure surges, such as pulsations in hydraulic supply circuits, preferably in the form of a silencer, having a damper housing surrounding a damper housing, the at least one fluid inlet and at least one fluid outlet and a fluid inlet between the fluid inlet and fluid outlet extending fluid receiving space, wherein during operation of the device, a fluid flow in a flow direction from the fluid inlet in the direction of the fluid outlet traverses the damping chamber, at least parts of the fluid receiving space extending in at least one direction of expansion transverse to the flow direction and wherein the fluid receiving space forms a disc-like cavity within the damping housing.

0004The <patcit id="pcit0003" dnum="DE202014006687U1"><text>DE 20 2014 006 687 U1</text></patcit>, the <patcit id="pcit0004" dnum="DE69512934T2"><text>DE 695 12 934 T2</text></patcit>, the <patcit id="pcit0005" dnum="DE102007003631A1"><text>DE 10 2007 003 631 A1</text></patcit>, the <patcit id="pcit0006" dnum="US20060124186A1"><text>US 2006/0124186 A1</text></patcit> and the <patcit id="pcit0007" dnum="US5016730A"><text>US 5 016 730</text></patcit> disclose further damping devices.

0005Based on this prior art, the invention has the object to provide a damping device of the type considered available, which is characterized by a favorable performance in a simple design.

0006According to the invention this object is achieved by a damping device having the features of claim 1 in its entirety.

0007According to the characterizing part of claim 1, an essential feature of the invention is that more than one fluid receiving space is arranged in the flow direction one behind the other, that the upstream first and the downstream last fluid receiving space immediately adjacent to the fluid inlet and the fluid outlet and that each fluid receiving space is a disk-like formed cavity formed within the damping housing. Due to the direct connection of the fluid receiving chambers to the fluid inlet or fluid outlet and the consequent elimination of a damping tube, the device according to the invention is characterized on the one hand by a simplified construction. In addition, the presence of more than one fluid receiving space offers the opportunity to better tune the damping device to different pulsation frequencies. This is particularly advantageous in variable-speed drives, for example in the form of screw compressors, which produce a large frequency range as an excitation spectrum.

0008The disc-like cavities may be cylindrical or polygon formed, however, come for a specific frequency tuning and other shapes, such as oval outline shapes, into consideration.

0009The respective cavities may have the same volumes and the same outline shapes or be differently shaped in terms of volumes and / or outline shape.

0010In particularly advantageous embodiments, the cavities may be completed by mutually parallel boundary walls of the damping housing, wherein parts of the fluid inlet and the fluid outlet run in alignment with these boundary walls in the damping housing and wherein the diameter of formed as a damper housing bores fluid inlet and fluid outlet can be the same size and can correspond to the distance between the boundary walls.

0011With particular advantage, the arrangement can be made such that the damping housing is designed in several parts and that the following components are provided:<ul id="ul0001" list-style="dash"><li>a bottom portion receiving cup-shaped center recesses with the one boundary walls and the fluid inlet and outlet, and</li><li>flange-like cover parts, which engage flush with the other boundary walls, which are part of engagement, fixed in the bottom part fixed lid parts in the Mittenausnehmungen the bottom part.</li></ul>

0012For the sealing of the cavities with respect to the surroundings, a sealing device, in particular in the form of a sealing ring inserted in a circumferential groove, can be arranged on the engagement socket of the cover parts, which seals the respective cavity as part of the central recesses relative to the surroundings.

0013For a pressure-tight construction of the damping housing, the cover parts, diametrically opposite to their vertical axis, have a plurality of through holes defined by fixing screws set the cover parts on the bottom part, the arrangement can be made with advantage so that the fixing screws, leaving the range of fluid inlet and Fluid outlet are arranged evenly along an outer periphery of the cover parts on the damping housing, comprising the disc-like fluid receiving spaces.

0014In advantageous embodiments, two cavities are provided in succession in the flow direction, which are interconnected by a fluid passage which, in alignment with the fluid inlet and fluid outlet of the damper housing, is located in a wall portion of the bottom part and has the same diameter as the fluid inlet and outlet.

0015For connection to a respective hydraulic system, a receptacle for a sealing ring may be provided at the fluid inlet and / or at the fluid outlet on the damping housing, which housing comprises the fluid inlet and / or fluid outlet. On third components, the damping housing can be defined in the manner of a Festlegeblocks by means of several fixing bolts surrounding the region of the fluid inlet and / or fluid outlet.

0016The invention with reference to an embodiment shown in the drawing is explained in detail. Show it:<dl id="dl0001"><dt>Fig. 1</dt><dd>a comparison with a practical embodiment, approximately scaled down on a scale of 1: 3 perspective oblique view of an embodiment of the damping device according to the invention;</dd><dt>Fig. 2</dt><dd>a double in size <figref idref="f0001">Fig. 1</figref> drawn plan view of the embodiment;</dd><dt>Fig. 3</dt><dd>a longitudinal section of the embodiment according to the section line III-III of <figref idref="f0002">Fig. 2</figref>;</dd><dt>Fig. 4</dt><dd>a partial view of only the fluid outlet having terminal portion of the damping housing of the embodiment; and</dd><dt>Fig. 5</dt><dd>one of the <figref idref="f0001">Fig. 4</figref> corresponding partial view of the fluid inlet having connection area.</dd></dl>

0017With reference to the drawing, the invention is explained with reference to the embodiment of a so-called. Silencers, which is intended to reduce the vibrations generated by pulsations in under high pressure, such as in the range of 200 bar, standing hydraulic fluids. In this case, the basic mechanical structure corresponds to a silencer provided for such an application, as it is post-published in the prior art in the patent application<patcit id="pcit0008" dnum="DE102014005822"><text>DE 10 2014 005 822.0</text></patcit> is described. In the present figures, the embodiment of the damping device is shown in the assembled state. The damping housing 1 shown in these figures, as best of<figref idref="f0003">Fig. 3</figref> it can be seen from three main parts, namely a bottom part 3 and cover parts 5 and 7, which are formed as equal parts. As the<figref idref="f0001">Fig. 1</figref> and <figref idref="f0002">2</figref> show, the bottom part 3 has the outline of a rounded corners 9 having rectangle with a longitudinal axis 11, the course of which corresponds to the flow direction of the fluid flowing from the left side in the figures located on the left end side 13 into the device and leaves it on the opposite end side 15. The bottom part 3 has to form fluid receiving spaces 17 and 19 two center recesses 21 and 23 (s.<figref idref="f0002">Fig. 2</figref>), which are formed by circular, pot-like depressions, which through unverted, surrounding wall parts 25 (FIG.<figref idref="f0003">Fig. 3</figref>) of the bottom part 3 are bounded. The Mittenausnehmungen 21, 23 are closed on the bottom side by running in a common plane boundary walls 27 and 29 of the bottom part 3. To limit the fluid receiving spaces 17 and 19 in disc-like form the cover parts 5 and 7 with its flat bottom upper boundary walls 31 and 33, which extend at the bottom part 3 mounted cover parts 5 and 7 in a plane parallel to the boundary walls 27 and 29. At the left end side 13 of the bottom part 3 in the drawing, there is the fluid inlet 35, which is aligned with the boundary walls 27 and 31, so that the diameter of the fluid inlet 35 corresponds to the thickness of the circular disk-shaped fluid receiving space 17.

0018The circular disk-shaped cavity forming the second fluid accommodating space 19 formed in the center recess 23 of the bottom part 3 is connected to the upstream first fluid accommodating space 17 via a fluid passage 37 located in the wall portion 39 of the bottom part 3 located centrally between the end faces 13 and 15 located. The fluid passage 37 is coaxial with the axis 11 and has the same diameter as the fluid inlet 35. In the embodiment shown, both fluid receiving chambers 17 and 19 are formed by similar circular Mittenausnehmungen 21 and 23 and therefore have equal volumes. In the left end of the drawing 15 in the drawing located in the wall portion 25 of the bottom part 3 of the fluid outlet 41, which as well as fluid inlet 35 and fluid passage 37 to the axis 11 and thus to the flow direction is coaxial and has the same diameter as fluid inlet 35 and fluid passage 37.

0019Again <figref idref="f0003">Fig. 3</figref> can be removed, the cover parts 5 and 7 designed as a flange-like identical parts. Starting from an upper side, which engage in the mounted on the bottom part 3 state of its wall parts 25 and the wall portion 39, the cover parts 5 and 7 each have a projecting engagement stub 43 which is formed kreiszylindrisch and mounted on the bottom part 3 position fitting in the Mittenausnehmungen 21 or 23 engages. In this case, each engagement nozzle 43 has a circumferential annular groove 45, in which a sealing ring 47 is seated, which seals the engagement nozzle 43 against the wall parts 25 and the wall portion 39 of the bottom part 3 and thus the fluid receiving chambers 17 and 19 seals against the environment.

0020For the screw connection of the cover parts 5, 7 with the bottom part 3 are formed in this threaded holes, which are not visible in the drawing. These are arranged for each eight fixing screws 51 of each cover part 5, 7 on partial arcs surrounding the Mittenausnehmungen 21 and 23 and with which the cover parts 5, 7 are fixed to the bottom part 3 that they with their flat side 53 at the central wall portion 39 of the bottom part 3 adjacent to each other. In the region opposite the flat side 53, the cover parts 5, 7 are shaped so that they are adapted to the outer contour of the bottom part 3 in attached condition, with flat sides 55 of the cover parts 5, 7 respectively connected to the end side 13 and 13 at fluid inlet 35 and fluid outlet 41 the end face 15 of the bottom part 3 are flush and also in the rounded corner regions 9 a paragraph-free outer shape is formed.

0021For the attachment of the damping housing 1 to respective third components 15 threaded bolt 57 are arranged symmetrically to the fluid outlet 41 in the embodiment shown at the right side in the drawing end side 15. Further, a receiving groove 59 is formed on the opposite end side 13 at the fluid inlet 35 for a sealing ring. For connection connections 13 mounting holes 61 are arranged in a symmetrical arrangement to fluid inlet 35 at the end side.

0022It is understood that a sealing arrangement can be provided in a corresponding manner on the end face 15 assigned to the fluid outlet 41. Due to the symmetrical housing design, the inlet side and outlet side can also be exchanged with one another with changed sealing geometries. Due to the disc-shaped damping chambers with a transverse to the actual flow direction extended cavity a silencer is achieved with high efficiency, which has a low weight based on its specifiable liquid volume. Furthermore, if at all, only a small gain occurs between the silencer and a hydraulic pump which can be connected to it.

0023In a non-illustrated embodiment of the damping device according to the invention, it is possible to design the individual, successively arranged damping chambers 17, 19 in terms of volume differently, so as to create differently sized damping chambers, so that individual frequency bands can be effectively damped with different frequencies, wherein a damping space 17 can be assigned to the one frequency band and the other damping space 19 to the other hand, different frequency band.

0024Furthermore, in a further series arrangement, which is also not shown, still a third damping chamber and possibly further damping chambers connect to the first two damping chambers 17, 19 optionally with changed volumes, so starting from a damping chamber with the smallest volume to one with the media leading connected largest damping chamber within the chain a relaxation occurs in the pressure curve of the media flow, so that also in this respect effective damping effects can be generated. This has no equivalent in the prior art.