DE1977428U - FILTER UNIT. - Google Patents

Description

Utility model registration-W 33 090/12 d Gbm Winslow Engineering and Manufacturing Qo, ...

ffilter unit

The furnace is based on I-filter units for cleaning and conditioning of fluids, and more particularly relates to an improved dual filter element ! Filter unit for removing sludge, solid particles and other harmful substances from lubricating oil, the used in an oil circulation system of an internal combustion engine will.

Among the aggregates for lubricating oil in which the ! Let inflation be used particularly advantageously include those Types which comprise a housing to which the oil to be filtered is continuously fed via a line and from which the filtered oil can be continuously withdrawn via a further line, a suitable one Filter material in the housing in the flow path of the flowing through Oil is arranged to remove the filterable material from the oil. In the case of such units, this includes filter material usually a mixture of fibrous and porous Materials in the form of an annular pack of

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is held in considerable length and either by a flexible hollow envelope made of a porous knitted fabric or knitted fabric or- is enclosed by a perforated wall part made of metal. Examples of suitable filter materials are spun cotton, natural and synthetic fibers, Wood fibers and other natural lasers such as sisal or hemp are called. You can also use different ones for conditioning chemicals used in the oil that are insoluble in the oil and not compatible with those contained in the cleaning oils Chemical compounds react to be mixed with the fibrous materials in such a way that they become permanent form a homogeneous part of the filter element. Other types of filter material can also be used, e.g. pleated Paper, and although the ring shape is the most widely used, the filter elements can be used in a variety of ways Forming them into housings of the most varied types accommodate.

Filter units of the type mentioned are switched on in most lallen in the oil circulation system, either in a secondary flow or in the main flow of the filter system. With a weaving separation system, only part of the total amount of oil circulated through the filter unit, so that an interruption or obstruction of this flow through the filter in no way obstructs the flow of unfiltered oil to the surfaces to be lubricated. The main stream— Filter system offers a better effect, because every time you

The entire amount of circulating oil is filtered during the course of the run. However ■ causes any interruption or restriction in such a system the flow rate of the filter unit has a corresponding Decrease in the speed at which the oil is delivered to the surfaces to be lubricated. A maximum efficiency the filtration is "of course achieved when that Filter element composed of relatively fine materials, so that the filter element has a high percentage of the sludge, which can hold back solid particles and other harmful substances. However, the filter material must be sufficiently porous so that the amount of oil that is required to lubricate the surfaces to be lubricated with oil can flow through the filter to supply,

Come during normal operation of an internal combustion engine Often there are cases in which the oil can only flow with difficulty through a fine filter element and the required Flow velocity can reach; this applies, for example, to a cold start as well as to cases in which the filter element is partially is clogged. In the case of filters arranged in the main flow, it has been customary for a long time to provide a bypass valve, which allows the oil to be routed completely around the filter element when there is sufficient oil flow through the Filter element can no longer be maintained. However, this bypassing of the unfiltered oil is undesirable, since in this case there is no more filtration, so that all harmful substances in the oil go straight to the engine's oil sump can flow back.

ν / - 4 -

There are filter units known in which an immediate Avoiding all of the oil bypassing the Filter element consists of two parts "and a Y-valve is arranged between them, so that only when clogging begins Another filter part with the same I-filter material switched on and thus a delay occurs before the entire amount of oil is diverted. This is a fundamental remedy not created because there is only a delay until the other part of the filter is no longer permeable enough.

In an earlier property right of the applicant, a filter with two filter elements is described, one of which is Filter elements composed of a relatively fine filter material, while the other element consists of a relatively coarse one Filter material consists, - The two filter materials are enclosed in a single housing and arranged in such a way that the Oil when there is a higher oil pressure and the oil can only pass the fine filter material with difficulty, the other Filter material with the larger pores can pass without difficulty. With this arrangement there is complete rerouting of the oil around the filter under extreme pressure conditions.

With this filter arrangement, however, there is a difficulty and / or a disadvantage in the fact that even under normal pressure conditions a significant part of the oil to be filtered

re
the filter material with the larger pores passes. Thus becomes

the entire filtration efficiency of the unit does not show up

held to the highest possible value. Furthermore, if a clogging ^ of the fine filter material, so that a stronger resistance is opposed to the oil flow, the oil flows due to the more porous and therefore less effective! filter element.

To avoid these disadvantages, inflation is the task basically, an improved filter unit with two filter elements to create "in which the entire amount of oil is passed through a relatively fine filter material under normal pressure conditions is, and "in which the oil entering the filter unit is only passed through a more porous filter material, when the pressure drop across the fine-pored filter element exceeds a predetermined value.

The solution to this is the rise in prices for a filter unit of the type previously described that between the filter element with the coarse filter material and the filter element A valve is interposed with the fine filter material, which allows the material to be filtered to flow through the coarse filter element normally prevents and allows the coarse filter element to flow through before the bypass valve is opened, if the fine filter element to the flowing through, to be filtered opposes an increased resistance.

The inventive arrangement makes it possible to reduce pressure peaks in the filter system, especially with thick oil in the Cold start by switching on a coarser filter element

to start without that-during normal operation oil through the coarse Filter element flows. With an additional filter element with the same fine filter material, "when clogging pressure peaks of the first filter element cannot really be absorbed, since the effect of the connection remains low and only means a delay for a complete unwanted diversion of the oil.

Further details and advantages of the inflation result from the following description of several exemplary embodiments with reference to the drawings.

Fig. 1 is a longitudinal section through one embodiment a filter unit according to the innovation;

Fig. 2 shows in plan a part of the annular resilient Disc for the return valve of the filter unit according to FIG. 1;

3 is a longitudinal section through a further embodiment a filter unit after the control;

Fig. 4 is a partial section along line 4-4Sad Fig. 3 and shows the inlet connection of the filter unit.

In Fig. 1, an oil filter unit TO is shown for switching on in a main stream; this filter unit after the ! Inflation is particularly suitable for use in lubricating oil systems of engines which require a relatively small but constant flow of oil to various of the

η

. To ensure wear and tear of exposed surfaces. According to I ¹ Ig * 1, the filter unit 10 is designed as a completely closed, screwable unit on the outside, which can be thrown away and harvested if the efficiency of the filtration has become too low after a long period of use. The unit is detachable connected to a combined inlet and outlet connection 11 for the lubrication system of an engine; the connection piece comprises a central channel 12 for receiving the filtered oil emerging from the unit 10 as well as an outer line part 13, which forms an annular channel 14- by means of which the contaminated , the oil to be filtered can be fed to the filter unit 10. The filter unit 10 can be connected to the connection piece 11; also differently designed inlet and outlet closures as well as other means of fastening Use n of the filter unit 10.

According to FIG. 1, the filter unit 10 comprises a relative thick-walled base part 16 with a centrally arranged, upwardly projecting, internally threaded tubular section 17, which can be screwed onto the G-thread connector 15 of the motor connection piece 11. The base part 16 is in Area of the tubular connecting piece 17 formed somewhat deepened, and circumferentially spaced inlet openings 18 are on Outer edge of the recess is provided in such a way that they are generally aligned with the annular inlet channel 14. Above

of the base part 16 and around this extends a cylindrical metal housing 19> which has an integral top wall 20 at its upper end. On his At the lower end, the housing is connected to an annular retaining plate 22 by crimping at 21. The holding plate 22 supports the base part 16 within the housing 19 and has two ribs 23 separated by a distance, opposite the Beaded edge 21 are offset inward and delimit an annular groove which receives a flexible seal 24, by means of which the unit 10 can be connected to the inlet and outlet connection 11 with a sealing effect. Within the sealed housing 19 is a cylindrical filter cartridge 25 is arranged, which will be described in more detail below.

According to! Ig. 1, the filter cartridge 25 has a smaller diameter than the housing 19, and it is fixedly arranged in the housing so that the unfiltered oil can enter via the lower inlet openings 18, flow past a check valve element 26 and to the annular space 27 on the outside of the Cartridge 25 can reach, According to the! Price increase, the cartridge 25 comprises two ring-shaped filter elements 28 and 29> which are filled with filter materials of different porosity. The first element 28 contains a fine filter material of any suitable and known type, for example wood, cotton fiber or folded paper, and it is suitable for fine particles up to a size of, for example. To hold back 0.010 mm. The first element 28 effects the complete filtration process of the unit under normal operating conditions, namely until it ¹

is saturated and clogged with residue and debris, so that its flow resistance increases and a higher pressure builds up in the annular space 27. The second element 29 contains a coarser filter material, the larger only Particles "down to e.g. 0.050 mm. However, the oil does not flow through the second element 29 until the predetermined Pressure drop has been reached across the first member 28; as soon as this is the pail, the second element 29 comes automatically take effect.

In the unit 10 according to FIG. 1, the two annular filter elements 28 and 29 are coaxial and end to end one behind the other within an outer cylindrical wall 30 arranged. The wall 30 can be made of metal, plastic or a other suitable material and is perforated so that the oil can pass through the wall. With the top of the wall 30 is a circular end wall 32 made of sheet metal is connected by beading at 31 with a sealing effect. A central circular The recess 33 in the end wall 32 serves to support a helical spring 34, the other end of which is on the inner surface the upper wall 20 of the housing 19 engages in order to hold the filter cartridge securely in its position in the housing. On theirs At the lower end, the cartridge 25 has an annular base 35 on, the one at 36 also by flanging with the lower edge the wall 30 is connected. The annular bottom 35 carries on its inner edge an upwardly projecting flange 37. Am lower end of the cartridge 25 engages on the bottom 35 a surrounding

hungsventilaggregat, which axially supports the cartridge 25 and zieaatriert the cartridge with respect to the housing 19; the Yentilaggregat is offset upwards in the assembled unit 10 with respect to the base plate 16.

The first filter element 28 filled with a relatively fine filter material is different from that with a coarser filter material filled second element 29 separated by an annular plate 39. An inner one extends above the plate 39 tubular perforated wall 40 upward; this wall has an inwardly projecting flange 41 at its lower end the plate 39 rests and together with the wall 40 a cylindrical Chamber 42 delimits. Under the plate 39 a similar perforated tubular wall part 43 is arranged, the inside the cartridge 25 delimits a somewhat larger cylindrical chamber 44. The lower wall 43 is at its lower end with the inner flange 37 of the bottom 35 of the cartridge near the bypass valve 38 connected. The annular plate 39 has a central opening 45, on the edge of which is a circular, after flange 46 inclined at the top and inside. On the bottom the annular plate 39 is attached to an inverted groove-shaped component 47, which opposite the plate 39 downwards in the chamber 44 protrudes and at its lower end carries a flange 48 which delimits an opening and at the same time a Forms seat for a valve spring 49 designed as a helical spring. At the upper end of the coil spring 49 is a movable one arched Tentilorgan 50 attached, which by the spring 49 normally pushed upwards and in sealing contact with

the inner circular flange 46 of the annular plate 39 is held; The Yentilorgan 50 can move down when the pressure difference between the upper chamber 42 within the element 29 and the lower chamber 44 within the element 28 enlarged. When this pressure difference the valve member is enlarged in that the oil can no longer flow unhindered through the first element 28 50 pressed down, so that the oil flows through the second filter element 29 made of coarser material and into the chamber 42 can reach, from where the oil can flow through the opened Y-valve 50 and the lower chamber 44 to the outlet 12 to to supply the surfaces to be lubricated.

Within the lower end of the housing 19, the bypass valve, designated as a whole by 38, serves to direct the oil divert from the annular inlet channel I4 to the outlet channel when the oil is neither through the lower element 28 nor can flow through the upper element 29 of the filter cartridge 25. According to FIG. 1, the bypass valve assembly 38 comprises an annular one Plate 51 with an inner tubular flange 52, the encloses the upper end of the tubular section of the base part 16 with a close fit. With the annular component 51 is connected to the outer edge of the lower end of the flange 55 of a hat-shaped component 56, which is a circular Has a cross-section and comprises a conical upper portion 57 which extends above the annular plate 51 into the chamber 44 of the filter element 28 extends into it. Multiple openings

are formed in your stationary annular component 51 and distributed in volume. These openings 58 are normally held closed by a "movable annular closure organ 59, which preferably consists of a resilient Material is made and carries an upwardly projecting flange 60 on its inner edge. In the upper side of the occlusion organ 59 is embedded a reinforcement ring 61 made of metal with an upwardly protruding inner flange. A compression spring 62 is supported with its lower end on the metal ring 61 and with its upper end on an inwardly protruding flange 63 at the upper end of the cave-shaped component 56. Thus the presses Spring 62 keeps the Yersohlussorgan 59 down against the annular plate 51 »around the timing openings 58 during the to keep the filter closed during normal operation. However, if the pressure within the filter housing 19 to a predetermined increases high value, since the cartridge 25 is completely clogged, the ring-shaped closure member 59 is ent ~ pressed upwards against the force of the spring 62, so that the oil flows through the openings 58 directly to the outlet 12 can.

In combination with the bypass valve 38 is the filter unit 10 further equipped with a check valve 26, which prevents the reverse flow of oil through the inlet channels 14 prevents when the filter 10 is not supplied with oil under pressure. G-emäss Fig. 1, the valve 26 on the circumference of the tubular outlet connector 17 on the base plate 16 through the inner flange 52 of the annular component 51 is retained

th. The flange 52 engages a washer 64 which is arranged near the inner edge of an annular resilient holding part 65. The disk-shaped retaining part 65, which consists of thin, flexible sheet metal, extends around the tubular outlet nozzle 17 and covers a lower annular seal 66 made of a flexible or flexible material. Another disk 67 is a short distance below the inner edge of the component 66 so that it is separated from the base plate 16 near its inner part by a small distance 16. The retaining disk 65 exerts a downwardly directed compressive force which tends to hold the annular component 66 in place in order to close the openings 18; The tongues 68 extend from their foot end inward and upward, and their free ends can engage the plate 51 in order to cause the retaining washer 65 to press the annular sealing member 66 against the base part 16. The tongues 68, of course, apply only a small amount of force so that they can yield slightly to allow the oil to flow into the filter through the openings during normal operation of the filter,

According to FIG. 2, the tongues 68 have a straight shape and they

extend radially inward towards the center of the retaining washer 65 'However, the tongues could also be curved and extend, for example, along a helical line or the like inwardly refreshed. Wear on their inner ends the tongues have a bent or upset section 69, so that they can firmly grip the annular component 51.

The operation of the filter unit 10 according to the innovation is described below; the contaminated oil gets first pushed through the openings 18 of the base part 16 and reaches the annular space 27 via the check valve 26 the outside of the two filter elements enclosing Wall 30. When elements 28 and 29 are new and the oil has normal viscosity, the domed valve member 50 will be normally held in firm and sealing contact with the inner flange 45 of the partition wall 39 by the spring 49. Consequently the oil entering the unit 10 flows only through the first filter element 28 filled with the fine filter material. After a long period of use, i.e. when the first filter element is 28 gradually clogged with the dirt particles separated from the oil, or when the oil is cold and is viscous, the oil pressure in the housing 19 increases. When the pressure drop across the first member 28 increases, i.e. when the Oil pressure in the chamber 42 above the annular partition wall 39 has a predetermined value, e.g., about 0.35 to about 0.4 Atu reached, the valve member 50 moves downward against the force of the spring 49 and lifts off the flange 46

at the edge of the opening 45 of the partition wall 39 al), so that the second FiIterelement 29 is brought into action and the oil from the Annular channel 27 can flow through this element.

The increase in price can be applied not only to the lost filter unit 10 described soeToen, but also to "filters" in which only the filter cartridge has been replaced
as it is preferred in some use cases. Such a filter unit 10a is shown in FIGS. 3 and 4. In this embodiment, the housing 19a comprises a lower housing part 70 which is connected to an upper housing part 71 by a “Marmon” clamp 72, with between the “two
Housing parts a sealing ring 73 is. Mowing the upper end of the lower housing part 70 is with this housing part
Inlet connection 74 connected, via which the supplied oil is introduced tangentially into the filter unit 10a, as it is from
4 is apparent. The outlet for the filtered or cleaned oil is through a connection 75 at the lower end
of the lower housing part 70 is formed.

In the interconnected housing parts 70 and 71
two filter elements 28a and 29a are arranged. The bigger one
Filter element 28a contains a relatively fine filter material,
For example, the various known fibrous materials, and this filter material is in a hose-like covering 76 made of a permeable knitted fabric or knitted fabric of ring-shaped
Felt included. The smaller filter element 29a is
generally of a similar construction to the larger filter

element, apart from the fact that the knitted or knitted hose-like covering 77 with a coarser filter material is filled. The elements 28a and 29a are through a impermeable transverse annular plate 39a separated, the diameter of which is equal to the diameter of the "two filter elements or is greater than the latter; the plate 39a has in the middle a hat-shaped cut 47a which is open at the end with an inwardly protruding harness 48a. on. With the plate 39a, an annular Yentilsitzteil 78 is connected to the circumference of the opening 45A by spot welds, the one after inwardly inclined flange 41a, which has a central opening 45a delimits. A coil spring 49a is supported with a End on the annular flange 48a al) and is firmly connected at its other end to a curved Yentilorgan 50a, which has a larger diameter than the opening 45a. The spring normally presses the valve member into the opening 45a into it, so that a seal is effected along the flange 41a, but the valve element can move downwards move so that the oil can flow through the opening 45a when the pressure above the Yentilorgans within the second Element 29a the pressure below the Yentilorgans within the larger first element 28a by a predetermined amount exceeds. This operating state occurs when the first element 28a is blocked. The bigger element 28a comprises a perforated inner tube 43a extending along the axis of this element and below the annular plate 39a delimits a cylindrical chamber 44a. A similar perforated tube 40a is in the smaller element

29a built in to a chamber 42a above the plate 39a to delimit »

Near the lower end of the larger first element 28a a plate 80 is provided to support the element 28a; The plate 80 has a central opening 81 which is delimited by a flange 82 which is bent or inclined inwards will. The diameter of the opening 81 is somewhat larger than the diameter of a tubular component 83 »das is fixedly connected to the outlet connection 75 and axially into the Chamber 44a of the first element 28a protrudes. In the annular recess formed by the flange 82 is a resilient sealing ring 84 arranged. This sealing ring is held in place by a washer 85, which by a coil spring 86 is urged against the face plate 80; the coil spring 86 is supported on an inwardly facing Outlet port 75 shoulder. The end wall 80 is shaped to have a perforated annular flange 87 carries, the outer edge of which is bent downwards in the direction of the wall of the housing 19a. The end wall 80 has a set of circumferentially spaced openings 88 near the outer edge of flange 87; these openings lead to a collecting space 89 at the lower end of the housing 19a, in which sludge and the heavier solids that are separated from the oil can collect, so that a constant renewed circulation of the separated substances by the oil in the housing is prevented. The outer edge

of the flange on the end wall 80 is basically a gate in one arranged a small distance from the jacket 19a of the filter unit 10a.

The upper end of the smaller second filter element 29a is held in place by a cylindrical member 90 having a cup-shaped end portion; A bypass valve assembly 38a is arranged centrally on this component. The component 90 has a central opening 91 »which is surrounded by a flange 92 angled upwards. A hat-shaped holding part 93 is connected to the component 90 on the circumference of the central opening 91 by spot welds, which axially protrudes into the chamber 42a and carries an inwardly protruding flange 94 as a seat for one end of a valve spring 95. The upper end of the spring 95 is firmly connected to the inner wall of an arched valve member 96 which is normally pressed against the flange 92 with a sealing effect. If the pressure in the space 97 above the second element 29a exceeds a predetermined value, the oil contained in the unit 10a can flow around both filter elements, pass through the openings 91 and 45a and leave the unit 10a via the outlet 75.

The terminating part 90 comprises a short cylindrical vertical wall section 98 with which a jacket 99 made of magmesium is connected, which extends almost to the lower end of the first filter element 28a downward and approximately in the middle between the housing 19a and the outer surface of elements 28a and 29a is arranged. This coat 99

generally has the task of bringing about a circular flow of the supplied oil in such a way that through! healing powers all air is separated from the oil, which can escape before the oil reaches the element 28a or the element 29a flows through «Furthermore, the jacket 99 serves to ,, the To reduce turbulence, which is due to the fact that the oil Liinwegström'ström directly over the filter elements. Mow his At the lower end in the region of the lower end of the element 98a, the jacket 99 carries a section which is widened downwards 100, which extends in the direction of the housing wall 70. As a result, there is a narrowed annular channel 101, so that the flow of the upwardly moving oil is increased along the lower edge of the shell 99; this carries also helps to separate the oil from any larger solid particles that move down through openings 88 in can move the filter sump 89,

At the lower end of its vertical wall section 98 the terminating part 90 carries a set of radially outwardly projecting rectangular projections 102, the shape of which is in plan Fig. 4 is evident. These extensions 102 are shaped so that they fit into somewhat larger openings 103 that are circumferentially spaced are distributed over the edge of a component 104 provided with a flange, which on the inner surface of the lower housing part 70 is attached and inwardly protruding, carries projections 105 distributed at intervals so that a bayonet lock is available for the filter elements, The combined filter elements 28a and 29a with the

Td es ohr i level valve units can be easily installed, by inserting them axially into the lower housing part 70, whereupon the end part is rotated slightly around the filter elements to lock against axial movements. The leather serves to support the cooperating port sets 102 and 105 to press against each other and so secure the combined elements 28a and 29a in their position in the housing 19a. If the Elements are secured in their position, enable the openings lying between the cooperating extensions 103 the oil or the air, up into room 97 to flow in

At the upper end of the upper housing part 71 is a connection 106 seen with a throttle opening by means of which the filter can be vented, and at the lower end of the Unit 10a is provided with a screw connection 107 for draining liquid. The vent 106 is in particular of importance when the filter unit 10a is used to filter oil that is heavily mixed with air, such as it is necessary e.g. for engines with a dry sump. Before such oil can be properly filtered, the Air can be removed. As a means of intercepting and removing the air from the filter unit 10a is in the upper housing part 71 a plate 110 is arranged near its upper end. This plate is with the housing wall in the indicated at 111 Way, preferably connected by spot welds, and near the edge of the plate there are a large number of small openings 112 spaced apart; the diameter of this

Opening is e.g. about 0.8 mm. At the normal operating pressure The openings 112 allow air to flow through the plate 110 but prevent the openings from flowing through their small diameter that oil passes through; For this the difference in viscosity between the oil and the air also contributes. The air collects in a chamber 113 above of the plate 110, until it is finally pressed outwards via the throttled vent port 106; the above The amount of oil escaping through the vent port remains limited when an unusually high pressure builds up in the filter unit 10a.

The filter unit 10a works essentially in the same way as the unit 10 described. The oil to be filtered through the unit 10a enters the inlet 74 in a tangential direction and flows into the Casing 99 made of magnesium surrounding king space 108. While the oil is swirling along the inner surface of the housing 19a executes centrifugal forces through which air bubbles and larger solid particles carried along by the oil are separated will. The separated air passes through the small openings 112 of the plate 110 and is via the vent port 106 discharged at the upper end of the housing. Any solid particles in the feed oil will be in the sump 89 at the bottom of the aggregate, the de-aerated oil that is around the flows around the lower edge of the jacket 99, then enters the filter element 28a. When this first filter element 28a, the contains relatively fine filter material, is clogged, reached

the pressure in the chamber 42a has a predetermined value, so that the valve element 50a is lifted downward from its seat and the oil can flow through the second element 29a, which is filled with coarser filter material. If the second filter element 29a also clogs, the oil pressure in the housing 19a and in the spaces 97 and 108 on the outside of the filter elements reaches such a value that the complete diversion of the oil around the filter elements is initiated. The oil can flow upwards from the space 108 via the openings 103 (I ¹ Ig. 4-) to the space 97; when the pressure becomes high enough to overcome the force of the spring 95, the bypass valve 38a is actuated so that the oil can flow through the chambers 42a and 44a directly to the outlet port 75.

Each of the described innovation according to the filter units 10 and 10a provides a greater filtering effect over a longer period of time, because it flows through during normal operation the oil in its total amount only the lilterelement that is filled with the fine filter material. The flow of oil through the second one filled with the coarser filter material Filter element only starts after the first element is clogged, or when the oil is too cold and viscous to to be able to pass the filter element 28a. If both filter elements should clog and the oil pressure drop increases reaches a predetermined value of, for example, about 0.55 "to 0.65 atm in the filter housing 19 the bypass valve 38 or 38a, so that the supplied

Oil can flow directly to the outlet port.

There is a "special advantage" in the way it works of the renewal filter in that oil can only get through the second filter element with the coarser filter material flows when along the first element with the fine filter material a precisely predetermined pressure drop occurs. If one observes the oil pressure gauge, which the pressure within of the filter, you can determine exactly when the first element is clogged with the fine filter material and no longer acts as a filter; thus it can be seen at the same time that the second filter element has been put into operation is. When this has been done, there is still sufficient time available so that the entire filter unit can be replaced can be, a long time before the point in time at which the east stream is completely at the filter elements would be passed by.

It should be noted that various modifications can be made to the exemplary embodiments described above and can provide modifications without departing from the scope of innovation.

S chuiz requests:

Claims (6)

P.A.67032WMU7 - 24 claims 1. Filter unit for a motor to be supplied with lubricant with an inlet and an outlet opening for the material to be filtered on the same side of the I ¹ IIt he housing and ring-shaped and coaxially arranged next to each other in the housing, one of the filter elements from a relatively coarse filter material and the other filter element consists of a relatively fine filter material, as well as a bypass valve between the inlet opening and the outlet opening, which can be opened when the pressure in the 6-ehäuse exceeds a predetermined value, characterized in that between the filter element and the coarse filter material (29) and the filter element with the fine filter material (28) a Yentil is interposed, which allows the material to be filtered to flow through the coarse Filter element normally prevents flow through the coarse filter element before the bypass valve is opened if the fine filter element opposes the material to be filtered flowing through an increased resistance. 2. Filter unit according to claim 1, characterized in that the filter element with the coarser filter material (29) arranged in a manner known per se at the end of the filter unit furthest away from the inlet opening (14) is. 3. Filter unit according to claim 1 or 2, characterized characterized in that the closing part (50) of the valve, which works against the pressure of a spring (49), is coaxial between the in a tandem arrangement with an intermediate separating plate (39) arranged filter elements (28, 29) on the Separating plate (39) is arranged. 4. Filter unit according to one of the preceding claims, characterized in that the filter elements (28a, 29a) are enclosed in a known manner in a filter cartridge, each with a cylindrical, perforated one outer (76) and inner (44a) wall, with the valve between the coarse and fine filter element on the partition plate (39a) and the bypass valve are arranged in the end cap (90) of the cartridge. 5. Filter unit according to claim 4, characterized gekennzeichnei that when the inlet opening (74) is arranged in the middle part of the filter housing (19a), on the end cap (90) extending axially downward in the G-housing (19a) until after the lower end of the fine filter element (28a) reaching jacket (99) is attached. 6. Filter unit according to claim 5, characterized by a vent connection (106) on the known per se upper end of the housing (19a) as well as a plate extending transversely in the housing over the ventilation connection (106) (110) that with a set of small ones, as we chokes kenden openings is provided. Of the ntanwalt