The invention relates to a filter assembly for a liquid medium such as described in the preamble of claim 1.
Such a filter assembly is known from US 2012/0012517 A.
In this known filter assembly the second and the third layer of filter material are constituted by the opposite walls of a flat rectangular sac of filter material of which the folding edge lies, together with one end of the spacer, at a distance from the neighbouring housing wall. Thus the second and the third filtering layer consist of the same material while the dimension of this sac perpendicular to the folding edge is, together with same of the spacer, smaller than the dimension of the housing in this direction.
The invention aims to improve this known filter assembly and more particularly to provide a filter assembly in which the dimensions of the filter housing are used optimally and a structure is obtained which is not only highly shock-resistant and which can operate with relatively high pressures but in which the designer has complete freedom in the choice of the material of the respective layers. Furthermore it is aimed to provide a filter assembly in which an optimal filtering is obtained with only a limited pressure drop across the layers of filter material and in which various layers with mutually different filter density can be used so that this filter is very flexible as to its practical use and can be adapted in a simple way to any specific use.
To this end the invention proposes a filter assembly such as defined in the main claim.
Preferred embodiments of this filter assembly are described in the sub-claims.
The invention is elucidated on the hand of the drawing. Therein show:
In
The first housing part 4 carries a schematically indicated filter inlet 20 which ends in the end wall 8 and the second housing part 6 carries a filter outlet 22—details of these parts will be given below.
Within the filter assembly there is a spacer 24 which is in more detail shown in
Each of the ribs 32a . . . 32g is provided with a range of cut-outs 38. It is clear that the chambers 35a . . . 35g defined between the ribs 32a . . . 32g are mutually interconnected via these cut-outs 38.
In each of the short end sides 30a, 30b there is an opening 40a, 40b respectively and via these openings the chamber 35a . . . 35g between the ribs are interconnected with the surroundings of the spacer 24.
The lower edges 40a . . . 40g of the ribs 32a . . . 32g lie in one plane and the upper edges 42a . . . 42g lie also in one plane; both these planes define abutment planes for a respective layer of filter material—vide
Two retaining rings 35a, 35b, each one having an L-shaped cross-section, fit closely on the respective ends of the ring 34; they each enclose with their end edge the filter material 46 and 48 respectively. From the upper ring 35b extends a number of radial thin arms 37 which each carry a spacer 39 supporting the third layer of filter material 50.
As particularly
The user is fully free in his choice of the filter material for the first, second and third layer respectively; it is for instance possible that one uses for the first filter layer 46 a material with a high filter density and for the second and third layers 48 and 50 respectively a material with a lower filter density, thus a more coarse filter material.
The circumferential edges of the three layers of filter material 46, 48 and 50 are sealed with respect to each other so that the medium to be filtered (generally oil) which enters via the inlet 20 and then reaches the space 49 beneath the first layer of filter material 46 can choose between the following paths:
a. from the space 49 through the filter material 46 directly to the chambers 35 between the ribs 32a . . . 32g and from there via the outlet passage 40b to the outlet 22;
b. via the central passage 36 to the space 5a between the filter layer 48a on the one hand and the filter layer 50 on the other end and from there:
either via the filter layer 48 to the above-mentioned chambers 35 and from there to the outlet 22 or
via the filter layer 50 to the chambers 54 and from there to the outlet 22.
As there are four different current paths in combination with the possibility to influence the choice there between by the choice of the three used filter materials properties, to be chosen at will, in combination with the configuration of the spacer the user can realize various filter properties so that for each use an optimal filter can be designed.
Number | Date | Country | Kind |
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1040244 | Jun 2013 | NL | national |
Filing Document | Filing Date | Country | Kind |
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PCT/IB2014/001016 | 6/10/2014 | WO | 00 |