EP2545260A1

EP2545260A1 - Oil mist separator and internal combustion engine comprising an oil mist separator

Info

Publication number: EP2545260A1
Application number: EP11713200A
Authority: EP
Inventors: Dirk Hornung; André TEMMINGHOFF
Original assignee: Ing Walter Hengst GmbH and Co KG
Current assignee: Hengst SE and Co KG
Priority date: 2010-03-11
Filing date: 2011-03-10
Publication date: 2013-01-16
Anticipated expiration: 2031-03-10
Also published as: EP2545260B1; WO2011110628A1; DE102010002784A1

Abstract

The invention relates to an oil mist separator (1) for separating oil from the crankcase ventilation gas of an internal combustion engine, comprising a rotor (2) that is disposed on a rotatably mounted shaft (3) and separates oil from the gas by means of centrifugal forces, wherein in a region of the shaft (3) that is axially spaced from the rotor (2) a rotary drive (4) having at least one blowback nozzle (43) is disposed on said shaft. The rotor (4) is disposed in a gas cleaning chamber (11) of the separator, (1) and the rotary drive (4) is disposed in a drive chamber (12) of the separator (1). The shaft (3) is mounted between the rotor (2) and rotary drive (4) in two bearings (33.1, 33.2) which are axially spaced from one another in a carrier part (5) which separates the gas cleaning chamber (11) and the drive chamber (12) from one another, and a pressure oil channel (73) which can be supplied with pressurized lubricating oil is provided in the carrier part (5) and opens into a hollow channel (34) in the shaft (3) which leads to the at least one blowback nozzle (43) of the rotary drive (4). An untreated gas channel (71) feeding a crankcase ventilation gas opens into an inlet region of the gas cleaning chamber (11), and a treated gas channel (72) leads out of the outlet region of the gas cleaning chamber (11), and an oil drain channel (75) for lubricating oil exiting the blowback nozzle (43) leads out of the drive chamber (12). The oil mist separator (1) according to the invention is characterized in that both bearings (33.1 and 33.2) of the shaft (3) are sliding bearings and, in the carrier part (5), an annular channel (55.1, 55.2) surrounding the shaft (3) leads to each sliding bearing (33.1, 33.2) from the pressure oil channel (73).

Description

Description:

Oil mist separator and internal combustion engine with an oil mist separator

The present invention relates to a Ölnebelabscheider for separating oil from the crankcase ventilation gas of an internal combustion engine, arranged on a rotatably mounted shaft, oil from the gas by centrifugal forces separating rotor, wherein in a rotor axially spaced portion of the shaft at this a rotary drive with at least a thruster is arranged, wherein the rotor is arranged in a gas cleaning space of the separator and the rotary drive in a drive space of the separator, wherein the shaft is mounted between rotor and rotary drive in two axially spaced bearings in a gas cleaning space and the drive space from each other separating carrier part wherein in the support part is provided with a pressurized lubricating oil feedable pressure oil passage, which opens into a leading to the at least one return nozzle of the rotary drive hollow channel in the shaft, wherein a crankcase ventilation gas Zuf a raw gas duct discharges into an inlet region of the gas cleaning chamber, a clean gas duct discharging from an outlet region of the gas cleaning chamber, with an oil return channel emerging from an oil collecting region of the gas cleaning chamber and an oil drain channel for lubricating oil emerging from the recoil nozzle emerging from the drive chamber. In addition, the invention relates to an internal combustion engine with such a Ölnebelabscheider.

An oil mist separator of the aforementioned type is known from WO 2009/010248 A1. In this Ölnebelabscheider only the rotor remote, located near the rotary drive bearing is a plain bearing, while the rotor near bearing is a rolling bearing. The plain bearing is sufficiently lubricated by leaking from the recoil nozzle as spray oil lubricating oil. However, the lube oil exiting the recoil nozzle does not reach the upper bearing, which is also undesirable for preventing oil from passing from the drive space into the gas cleaning space. For this reason, here the upper bearing is designed as a rolling bearing. On the one hand, the rolling bearing is a purchased part, which represents a considerable cost factor which is notable in the overall costs of the separator. On the other hand, the rolling bearing must be installed separately and secured by means of a snap ring or a spring and in many cases also covered with at least one cover. Thus, even relatively high installation costs arise.

For the present invention, therefore, the object is to provide a Ölnebelabschei- of the type mentioned above and an internal combustion engine with such a Ölnebelabscheider which avoid the disadvantages mentioned and in which in particular the number of required components and the cost of assembly are reduced without causing a deterioration of the Abscheidefunktion occurs.

The solution of this object is achieved according to the invention with an oil mist separator of the type mentioned above, which is characterized in that both bearings of the shaft slide bearings and that in the carrier part of the pressure oil passage each one surrounding the shaft annular channel leads to each slide bearing.

With the invention, the rotornahe consuming rolling bearing is advantageously replaced by a simpler and cheaper sliding bearing. At the same time, a targeted and reliable supply of lubricating oil to the two slide bearings, including the rotor-near slide bearing, is ensured by the two annular channels. The lubricating oil emerging from the recoil nozzle or the recoil nozzles of the rotary drive is no longer needed for the lubrication of the plain bearings. At the same time, the slide bearings serve as gap seals which allow at most a small leakage oil flow to pass through, so that the effectiveness and the performance of the rotary drive with the at least one recoil nozzle are not impaired.

In a further embodiment of the oil mist separator is preferably provided that the pressure oil passage opens between the plain bearings in the hollow channel of the shaft. This allows a structurally simple and geometrically favorable design of the support member with the annular channels and the shaft. The confluence with the hollow channel of the shaft can be formed here simply by one or more transverse bores. An elaborate rotary feedthrough is not necessary here, because the form two sliding bearings simultaneously gap seals and thus act as end seals of the ring channels.

A particularly low processing and cost requires the oil mist separator, if, which is preferably provided, the shaft on the one hand and the support part on the other hand directly form the two plain bearings and consist of a pair of bearing material forming materials. To form the plain bearings, only the shaft and the carrier part have to be machined into the surface regions forming the slide bearings. The manufacturing and mounting of other bearing parts is not required here. A practical suitable material pairing is, for example, aluminum for the carrier part and steel for the shaft.

If it should be necessary for technical or other reasons, then alternatively, at least one of the two bearings can be performed with a plain bearing bushing. The plain bearing bush is then preferably pressed into the carrier part and takes up the shaft with the necessary bearing clearance.

In order to ensure a low-friction rotation of the shaft in the two plain bearings, a sufficiently large bearing gap between the mutually rotating parts of the plain bearings is required. Since the oil for the lubrication of the sliding bearing is supplied under pressure, a certain, albeit small amount of lubricating oil passes through the plain bearings, which is quite desirable for their lubrication and for the formation of a stable oil pad. In the region of the rotor-near plain bearing, however, this can lead to oil, which has flowed through this plain bearing, undesirably enters the gas cleaning space above the carrier part. To prevent this, the invention proposes that from the side of the rotor-side slide bearing facing the rotor, an oil return channel leads away from the rotor into the drive space, through which lubricating oil flowing through the rotor-side slide bearing can be returned to the drive space. Thus, the oil, which flows through the rotor near sliding bearing, safely kept away from the gas cleaning space and reliably returned to the drive chamber, from where it can flow together with the exiting from the recoil nozzle or the recoil nozzle lubricating oil.

In order to accommodate the oil return passage functionally cheap and space-saving, it is provided that the oil return passage is annular gap-shaped and radially inward is limited by a leading to the rotor-side sleeve bearing ring channel radially outwardly bounding inner annular wall of the support member.

In a further embodiment, it is preferably provided that the oil return passage is bounded radially on the outside by a hollow cylinder forming part of the rotor and extending from the latter in the direction of the rotary drive, concentric with the inner annular wall. In addition to guiding the lubricating oil passing through the rotor-near sliding bearing, the hollow cylinder has the further function of keeping a gas stream possibly flowing out of the drive space into the gas-cleaning space separated from the oil flow so that this oil can not get into the gas stream flowing to the gas-cleaning space.

Another measure to favor the above-described function of the hollow cylinder is that preferably the hollow cylinder is designed at its free end with a circumferential acute-angled and / or radially outwardly bent or angled Abschleuderkante. The Abschleuderkante ensures that in the operation of the separator, the recirculated oil is thrown radially outward in the form of larger drops without it could be taken by a possibly flowing from the drive chamber into the gas cleaning space gas stream.

Further, the invention proposes that the crankcase ventilation gas supplying raw gas channel passes through the support member and under the rotor open to this open and closed at its opposite side by a bottom Rohgasringkanal and that the hollow cylinder with the Abschleuderkante seen from the rotor beyond the ground extends. With this design, a uniform loading of the rotor is achieved with the raw gas to be cleaned on the one hand. On the other hand, the stated design of the hollow cylinder with the Abschuder edge ensures that the Abschleuderkante is located at a sufficient distance from a portion of the drive space in which gas flow rates could occur that would be able to take oil drops.

In practice, it is sufficient to achieve the effect described above, if the Abschleuderkante from the bottom has a distance s of at least 3 mm, preferably at least 10 mm. In order to achieve a maximum rotational speed of the rotor and thus a good separation effect at a drive power given on the rotary drive, braking effects on the rotor and the shaft must be avoided. This means, in particular, that a rubbing seal between the drive space and the gas cleaning space is undesirable. In order nevertheless to ensure a sufficient mutual seal between the drive chamber and the gas cleaning space, it is proposed that the hollow cylinder and the Rohgasringkanal radially inner limiting central annular wall of the support member form a non-contact gap or labyrinth seal between the drive chamber and gas cleaning space.

A further embodiment of the oil mist separator provides that the recoil nozzle is arranged at the free end of an outwardly and obliquely pointing in the direction of the rotor nozzle arm and that the rotor side of the rotary drive on the support part a circumferential, pointing to the rotary drive axially projecting splash guard ring is formed or mounted. The specified orientation of the nozzle arm in combination with the splash guard ensures that leaking from the recoil nozzle lubricating oil can not or at least only to a very limited extent in the gap or labyrinth seal, so that the risk of unwanted passage of oil from the drive compartment is further reduced in the gas cleaning room.

An even further reduction of a transfer of oil from the drive space into the gas cleaning space can be achieved, that according to a further embodiment, a conical splash guard is inserted with its larger end in the splash guard and with its smaller, at least one passage opening end in the direction of Rotary drive extends out. The splash guard shields the area of the drive space within the splash guard ring further, but at the same time allows a passage of oil, which is returned from the rotor near sliding bearing in the drive chamber.

The oil mist separator according to the invention can be functionally coupled or be in different ways to an associated internal combustion engine. In a first related embodiment, it is provided that the oil mist separator has a housing lower part, which is connected to a component of the internal combustion engine to produce flow connections. is flangeable and comprises the support member and the drive space, and that it has an upper housing part, which is formed by a lower part attached to the housing, removable cover and containing the gas cleaning space. For flanging expediently flanges are provided on the side of the Olnebelabscheiders and on the side of the component of the internal combustion engine, which are clamped against each other under sealing by axial seals. In the sense of the simplest possible assembly, as many flow connections or, in the best case, all flow connections are integrated into the flange connection.

A second, alternative embodiment proposes an oil mist separator and an internal combustion engine with such an oil mist separator, in which it is provided that the drive space is designed as an outwardly open recess in a component of the internal combustion engine that sealingly insertable into the recess, the support member to produce flow connections is and that on the support member or on the component a lying outside the recess, removable cover is attached or attachable, which contains the gas cleaning space. In this embodiment, in particular a compact design is achieved because the Olnebelabscheider to a part, in practice about half its height, within the component of the internal combustion engine, so that only the other part of the component of the internal combustion engine protrudes.

A third, alternative embodiment proposes a Olnebelabscheider and an internal combustion engine with such a Olnebelabscheider before, in which it is provided ,, that the support part is designed with at least the pressure oil passage as an integral part of a component of the internal combustion engine, that the drive space is located in an interior of the component and that on the outside of the component a removable lid containing the gas cleaning space is sealingly attached or attachable. It is characteristic of this embodiment that the carrier part is embodied integrally with the component of the internal combustion engine, that is, does not have to be manufactured as a separate component. The oil mist separator also does not have its own drive space here, but an interior which is present in any case in the component is also used here as the drive space of the rotary drive. Thus, a particularly high degree of integration is achieved with reduced manufacturing and assembly costs. The mentioned component of the internal combustion engine may in practice for example be the engine block of the internal combustion engine or its cylinder head cover or a functional module connected to the internal combustion engine, such as oil module with oil filter and / or oil cooler.

In the following, embodiments of the invention will be explained with reference to a drawing. The figures of the drawing show:

1 shows a oil mist separator in a first embodiment, in longitudinal section,

FIG. 2 shows an enlarged detail from FIG. 1, in longitudinal section,

3 shows the oil mist separator in a second embodiment, in longitudinal section,

FIG. 4 shows an enlarged detail from FIG. 3, in longitudinal section,

5 shows the oil mist separator in a third embodiment, in longitudinal section,

Figure 6 shows the Olnebelabscheider in a fourth embodiment, in longitudinal section, and

Figure 7 shows a Olnebelabscheider in a stepped cross-section.

Figure 1 of the drawing shows a first embodiment of an oil mist separator 1, which can be flanged by means of a flange 70 to an associated internal combustion engine or a component of the associated internal combustion engine. The separator 1 has an upper part in the form of a lid 6, in which a gas cleaning space 1 1 is located, and a lower part in the form of a trough 13, in which a drive chamber 12 is located. The gas cleaning chamber 1 1 and the drive chamber 12 are spatially separated from each other by a support member 5. The cover 6 is releasably connected by means of a cover flange 60 with the support member 5 from above, while the tub 13 is sealed from below connected to the support member 5. In the gas cleaning chamber 1 1, a rotor 2 is arranged, which is secured against rotation on a shaft 3 and for the separation of oil mist from the crankcase Seentlüftungsgas an associated internal combustion engine is used. For this purpose, the rotor 2 is designed in a known manner, for example as a stack of plates.

The shaft 3 is rotatably mounted about its central axis 30 in the support member 5, namely in an upper bearing 33.1 and in an axially spaced therefrom lower bearing 33.2. Both bearings 33.1 and 33.2 are designed as plain bearings, here each with a plain bearing bush 56.1 or 56.2. For receiving or forming the two plain bearings 33.1 and 33.2, the support part 5 has an inner annular wall 58 ', which is arranged concentrically to the shaft 3. Below the upper slide bearing 33.1, a first annular channel 55.1 is arranged between the inner annular wall 58 'and the shaft 3. Above the lower sliding bearing 33.2, a second, lower annular channel 55.2 extends between the shaft 3 and the inner annular wall 58 '. From the side, in Figure 1 from the left, through the support member 5, a pressure oil passage 73 to the shaft 3. At the level of the pressure oil passage 73, the shaft 3 has a transverse bore 35. From the transverse bore 35, a hollow channel 34 extends through the Interior of the shaft 3 down. Widely, the pressure oil passage 73 is connected at the level of the transverse bore 35 both with the upper annular channel 55.1 and with the lower annular channel 55.2.

Connected to the lower end of the shaft 3 is a rotary drive 4, which is embodied here by a single nozzle arm 41 with a nozzle channel 42 connected to the hollow channel 30 and a recoil nozzle 43 arranged at the outer end of the nozzle arm 41. Seen in the circumferential direction of the shaft 30 is opposite the nozzle arm 41, a counterweight 44, which serves to avoid an imbalance. The rotary drive 4 is here attached rotationally fixed to the lower end of the shaft 3 and by means of a cap nut 45, which simultaneously closes the hollow channel 30 at its lower end secured.

During operation of the associated internal combustion engine and the oil mist separator 1, lubricating oil under pressure from an oil pump of the internal combustion engine is guided into the carrier part 5 by the oil pressure passage 73. At the radially inner end of the pressure oil passage 73, the oil flow branches into three branch streams.

A first, most volumenstrommäßig largest branch stream flows through the transverse bore 35 into the hollow channel 30 and from there through the nozzle channel 42 in the nozzle arm 41 to the recoil nozzle 43. The exiting from the recoil nozzle 43 oil jet ensures a Rotation of the rotary drive 4 and the thus rotationally connected shaft 3 with the thus rotationally connected rotor 2. The exiting from the recoil nozzle 43 lubricating oil flows under pressure by gravity through an oil drain passage 75 which is provided in a flange 70, which with a matching counter flange of the associated internal combustion engine or a component of the internal combustion engine is connectable.

A second branch stream flows through the upper annular channel 55.1 to the upper sliding bearing 33.1 and supplies it with lubricating oil. A third branch stream flows through the lower annular channel 55.2 to the lower sliding bearing 33.2 and supplies it with lubricating oil. The plain bearings 33.1 and 33.2 also serve as gap seals, which do not allow a significant passage of lubricating oil through their bearing gap.

Via a crude gas channel not visible in FIG. 1, the crankcase ventilation gas to be deoiled passes into a raw gas annular channel 52, which runs radially inward in the carrier part 5 below the rotor 2. From there, the gas flows axially upwards into the rotor 2 and leaves it radially outward, with separation of the entrained oil particles, which precipitate on the inner circumference of the cover 6. The de-oiled gas leaves the gas cleaning chamber 1 1 by a not visible in Figure 1 clean gas duct. The precipitated oil flows downwardly on the inner circumference of the cover 6 under gravity, thus entering an oil collecting channel 54 formed in the carrier part 5. The oil collecting channel 54 communicates with an oil return channel 74, which in turn is connected to the oil discharge channel 75 Bore 74 ".

Figure 2 shows an enlarged view of a detail of Figure 1, wherein the detail shows the mounting of the shaft 3 in the support member 5. In the center of FIG. 2, the shaft 3, which is rotatable about its longitudinal axis 30, has the hollow channel 34 in its lower part. In its upper part above the transverse bore 35, the shaft 3 is massive here.

The support member 5 surrounds with its inner annular wall 58 ', the shaft 3 above and below the transverse bore 35. Each at the upper end and at the lower end of the inner annular wall 58' is one of the two sliding bearings 33.1 and 33.2, here with the plain bearing bushes 56.1 and 56.2 arranged. The plain bearing bushes 56.1 and 56.2 are each pressed into the carrier part 5 from above or below. The shaft 3 extends with a sufficiently large bearing gap through the plain bearing bushes 56.1 and 56.2. Above the upper bearing bush 56.1, the shaft 3 has an outwardly projecting step 31, which serves as a stop and determines a defined height position of the shaft 3.

In the area between the two bearings 33.1 and 33.2, the shaft 3 with the inner annular wall 58 'forms the upper annular channel 55.1 and the lower annular channel 55.2, both, as well as the hollow channel 34 in the shaft 3, with the pressure oil passage extending in the support member 5 73 are in fluid communication. Radially outward from the inner annular wall 58 'extends the Rohgasringkanal 52 which is bounded at the bottom by the right in Figure 2 visible bottom 53 and separated from the drive chamber 12.

At the top in Figure 2, a small part of the shaft 3 rotationally connected to the rotor 2 can be seen. At the bottom of FIG. 2, the rotary drive 4 can be seen to a small extent, here with a section of the nozzle arm 41 with the nozzle channel 42 and diametrically opposite the counterweight 44.

A second embodiment of an oil mist separator 1 is also shown in Figure 3 in a longitudinal section. Here, too, the oil mist separator 1 has a gas cleaning space 1 1 with a rotor 2 arranged therein and a drive space 12 with a rotary drive 4 arranged therein. Again, the gas cleaning space 11 and the drive space 12 are spatially separated from each other by the carrier part 5. Externally, the gas cleaning space 1 1 is closed again by a cover 6, which is releasably connected to a cover flange 60 with the support member 5 from above. The drive space 12 is closed to the environment by a lower part in the form of a trough 13.

Both the rotor 2 and the rotary drive 4 are here again rotationally mounted on a shaft 3 which is rotatably mounted about its longitudinal axis 30 in the support member 5. For this rotatable mounting two sliding bearings 33.1 and 33.2 are again provided here, which are here between the shaft 3 and the support member 5 directly, so without interposition of plain bearing bushes formed. To form the plain bearings 33.1 and 33.2, the support part 5 is here again formed with an inner annular wall 58 ', which at its upper end with the shaft 3, the upper sliding bearing 33.1 and forms at its lower end with the shaft 3, the lower sliding bearing 33.2. In the area between the two sliding bearings 33.1 and 33.2, the inner annular wall 58 'with the shaft 3 again forms an upper annular channel 55.1 and a lower annular channel 55.2. The shaft 3 is here again provided in its lower portion with a hollow channel 34 and with a transverse bore 35. On the lower end of the shaft 3, the rotary drive 4 is placed in the manner already described. Reference is made in this regard to the preceding description of FIG.

The rotor 2 has in the embodiment shown in Figure 3, a hollow cylinder 28 which is integral or connected to the rest of the rotor 2 and concentric with the inner ring wall 58 'extends from the bottom of the rotor 2, wherein formed between the two an annular gap as the oil return passage 58 is. The lower end of the hollow cylinder 28 is formed with a pointed Abschleuderkante 29.

Radially outwardly of the hollow cylinder 28 extends concentrically to this a middle annular wall 52.2, which is part of the support member 5. Radially outward from the middle annular wall 52.2 extends an outer annular wall 52.1, also as part of the carrier part 5, wherein a Rohgasringkanal 52 is formed between the two said annular walls 52.1 and 52.2. The Rohgasringkanal 52 is open at the top to the bottom of the rotor 2 and down the Rohgasringkanal 52 is limited by a bottom 53.

In operation of the oil mist separator 1 according to FIG. 3 and the associated internal combustion engine, pressurized lubricating oil is conducted through the pressure oil channel 73 within the carrier part 5 to the shaft 3. There, the oil flow branches back into the three already described with reference to Figure 1 oil flows to the recoil nozzle 43 of the rotary drive 4 and to the two plain bearings 33.1 and 33.2.

To ensure particularly safe that no lubricating oil can pass through the upper slide bearing 33.1 in the gas cleaning chamber 1 1 and into the clean gas duct 72 for the clean gas, the aforementioned oil return passage 58 is provided. By this lubricating oil, which has passed through the upper sliding bearing 33.1, radially outwardly from the inner annular wall 58 'down and thus returned to the drive chamber 12. The Abschleuderkante 29 at the lower end of the hollow cylinder 28 ensures that relatively large drops from the hollow body 28 in the Drive space 12 are thrown, which are not subject to the risk of being taken from a gas flow from the drive chamber 12 in the gas cleaning space 1 1. For this purpose, the Abschleuderkante 29 is significantly lower than the bottom 53 of the Rohgasringkanals 52, whereby the centrifuging of the oil drops takes place in a range of low gas flow velocity. A gas flow from the drive chamber 12 into the gas cleaning chamber 1 1 can occur at corresponding pressure conditions in the oil mist separator 1, wherein the gas stream could flow through a gap space between the outer periphery of the hollow cylinder 28 and the inner circumference of the middle annular wall 52.2. In order to avoid or minimize such a gas flow, here form the outer circumference of the hollow cylinder 28 and the inner circumference of the middle ring wall 52.2 together a gap or labyrinth seal 57. Since this works without contact, it does not brake the shaft 3 and the rotor 2.

The separated in the gas cleaning chamber 1 1 from the crankcase ventilation gas oil flows over the inner surface of the cover 6 under gravity down into an oil collecting channel 54 and from this into an oil return channel 74, both of which are formed in the support member 5. At the bottom, the drive space 12 is closed by the bottom of a trough 13, wherein the trough 13 is sealingly connected to the support member 5. In the area of the oil return channel 74, the trough 13 with the oil return channel 74 forms a siphon 74 '. Through the siphon 74 ', the oil separated from the crankcase ventilation gas also passes through the drive chamber 12 into the oil drain channel 75.

A further feature of the oil mist separator 1 according to FIG. 3 is that the oil mist separator 1 can be flanged to a suitably designed counter flange 80 of the associated internal combustion engine or a component of the internal combustion engine by means of a flange 70 pointing to the left in FIG. In the example shown via the flange connection, the supply of raw gas into the raw gas channel 71, the supply of pressure oil in the pressure oil passage 73 and the pressureless removal of lubricating oil from the drive chamber 12 through the oil drain passage 75th

Figure 4 shows a section of Figure 3 with the mounting of the shaft 3 in an enlarged view, also in longitudinal section. In the middle of Figure 4, the shaft 3, which rotates about its central axis 30 in the two plain bearings 33.1 and 33.2 is stored. The two sliding bearings 33.1 and 33.2 are formed directly between the shaft 3 on the one hand and the support member 5 with the inner annular wall 58 'on the other. Between the upper region of the inner annular wall 58 'and the local part of the shaft 3, the first, upper annular channel 55.1 is visible; between the lower, the hollow channel 34 having portion of the shaft 3 and the lower part of the inner annular wall 58 'is the second, lower annular channel 55.2 recognizable. From the left, the pressure oil channel 73 leads through the carrier part 5 to the shaft 3, which at the level of the pressure oil channel 73 has the transverse bore 35, which connects the pressure oil channel 73 with the hollow channel 34 in the shaft 3.

As already explained above, a partial flow of the lubricating oil supplied through the pressure oil channel 73 flows during operation of the oil mist separator to the non-visible in Figure 4 recoil nozzle of the rotary drive 4. Two other, smaller partial flows reach the two plain bearings 33.1 and 33.2. In the region of the upper plain bearing 33.1, which is located directly below the rotor 2, there is a risk that oil, which passes through the bearing gap of the sliding bearing 33.1, from there into the gas cleaning chamber 1 1 and there in an undesirable manner in the clean gas flow can. To avoid this undesirable effect, extending from the rotor 2 of the hollow cylinder 28 concentric with the upper part of the inner annular wall 58 'of the support member 5 down and forms with the inner annular wall 58' the oil return passage 58. Lubricating oil, which through the bearing gap of the Upper slide bearing 33.1 passes, enters the upper region of the oil return passage 58 and flows through this under gravity down. Oil, which thereby reaches the inner circumferential surface of the hollow cylinder 28, flows thereon also under the action of gravity downwards and is finally thrown off the Abschleuderkante 29 in the drive chamber 12. As Figure 4 clearly shows, the Abschleuderkante 29 is significantly spaced, namely at a distance s, below the bottom 53, which limits the Rohgasringkanal 52 down. Thus, the centrifuging of the oil drops from the hollow cylinder 28 takes place in a region of the drive chamber 12 in which only small gas velocities can occur in the direction of the gas cleaning chamber 11. Higher gas velocities in the corresponding direction can occur at most in an annular gap space between the outer circumference of the hollow cylinder 28 and the inner circumference of the middle annular wall 52.2, but offset significantly upwards relative to the abrading edge 29. In its region facing the oil return channel 28, the rotor 2 is tightly closed, so that no gas flow from the drive chamber 12 through the oil return channel 58 into the gas cleaning chamber can result even under unfavorable circumstances. Such a gas flow is at most possible by a gap between the outer circumference of the hollow cylinder 28 and the inner circumference of the middle annular wall 52.2. In order to prevent a passage of gas from the drive space 12 into the rotor 2 and in this way into the gas cleaning space, a gap or labyrinth seal 57 is provided between the upper area of the outer circumference of the hollow cylinder 28 and the upper area of the inner circumference of the middle ring wall 52.2. Radially outward from the middle annular wall 52.2, the outer annular wall 52.1, which are both parts of the carrier part 5 and between which the Rohgasringkanal 52 is located.

At the bottom of FIG. 4, a small part of the rotary drive 4 is visible, as in FIG. 2.

FIG. 5 shows a further embodiment of the oil mist separator 1, for which it is characteristic that the drive space 12 is designed as a recess 81 in a component 8 of the associated internal combustion engine and that the carrier part 5, together with the rotary drive 4, seals in the recess 81 from above is plugged in. In the assembled state of the oil mist separator 1 shown in FIG. 5, simultaneous flow connections are made to the component 8, namely to supply crankcase vent gas to be purged with the raw gas passage 71 for supplying pressurized gas

Lubricating oil in the pressure oil passage 73 and for unpressurized discharge from the recoil nozzle 43 of the rotary drive 4 leaking lubricating oil in the oil drain passage 75th

Furthermore, different from the oil mist separator 1 previously described in FIG. 3, in the oil mist separator 1 according to FIG. 5, the carrier part 5 has on its underside concentric with its inner annular wall 58 'and thus concentric with the shaft 3 a splash guard ring 59.1. In addition, a downwardly tapered splash cap 59.2 is used from below in the splash guard 59.1, which is locked with its lower end radially outward into the inner annular wall 58 '. The splash guard 59.2 is formed in its lower part with at least one passage opening to let the oil flowing down through the oil return passage 58 into the drive space 12. In reverse Direction shield the splash guard 59.1 and the splash guard 59.2 together the the inner ring wall 58 'immediately surrounding area against a squirting from the recoil nozzle 43 leaking lubricating oil.

The gas cleaning chamber 1 1 with the rotor 2 is located in this oil mist separator 1 above the component 8 of the internal combustion engine within a detachably attached to the support member 5 lid. 6

The support member 5 is sealed by a total of three superposed, not specifically numbered radial seals against the component 8 of the engine. The part of the support member 5 forming oil return channel 74 is immersed as a dip tube in a recess formed in the component 8, whereby there a siphon 74 'is formed. In the gas cleaning chamber 1 1 separated from the crankcase ventilation gas oil passes through the oil collecting groove 54 in the oil return passage 74 and through the siphon 74 'via the drive chamber 12 in the oil drain passage 75 to pass through this together with the exiting from the recoil nozzle 43 oil, for example in the oil pan associated internal combustion engine to flow.

In its other parts, the oil mist separator 1 corresponds to the example according to FIG. 3, and reference is therefore made to the description of FIG. 3 with regard to the further reference numbers in FIG.

FIG. 6 likewise shows a longitudinal section of a further oil mist separator 1, for which a further integration into a component 8 of the internal combustion engine, for example a cylinder head cover, is typical.

The component 8 of the internal combustion engine contains both the raw gas channel 71 and the pressure oil channel 73 and the carrier part 5 as integral components. Above the two said channels 71 and 73, a recess 81 is formed in the component 8, in which the lid 6 is sealed and releasably inserted with its cover flange 60. At the top of the lid 6 of the clean gas duct 72 is arranged as a hose connection piece.

In the lower part of Figure 6 is an interior 82 of the component 8 of the internal combustion engine, said interior 82 at the same time the drive space 12th of the oil mist separator 1 forms. In this interior 82 or drive chamber 12 is the rotary drive 4 of the oil mist separator 1, which is identical to the previous examples.

The two bearings 33.1 and 33.2 of the shaft 3 in the support part 5 are again both designed as plain bearings, which are supplied by the Druckolkanal 73 and the two annular channels 55.1 and 55.2 with lubricating oil. Likewise, the recoil nozzle 43 of the rotary drive 4 is supplied from the Druckolkanal 73 through the transverse bore 35, the hollow channel 34 and the nozzle channel 42 with lubricating oil.

For the return of lubricating oil flowing through the upper bearing 33.1, the oil return channel 58 also serves radially inward from the hollow cylinder 28 connected to the rotor 2 or integrally extending downwards. Here, too, the hollow cylinder 28 has a lower, acute-angled Abschleuderkante 29th

With regard to the further reference numerals in Figure 6, reference is made to the preceding description.

Finally, FIG. 7 shows an oil mist separator 1, in this case its carrier part 5, in a stepped cross section, to the left of the dot-dash line L the sectional plane at the level of the raw gas channel 71 and to the right of the dot-dash line L the cutting plane at the level of the pressure oil channel 73, ie slightly downstream offset below, runs. In the center, the shaft 3 with the here cut hollow channel 34 and the transverse bore 35 can be seen. Radially outward therefrom lies the second, lower annular channel 55.2 in the background. Radially outward, the inner ring wall 58 'connects to it. Even further radially outward is the outer ring wall 52.1. Between the annular wall 58 'and the annular wall 52.1 is the Rohgasringkanal 52. Radially outermost lies over part of the circumference of the support member 5, the oil collecting channel 54th

The hollow channel 34 in the shaft 3 and the annular channel 55.2 are in fluid communication with the pressure oil channel 73 running radially inwardly from above in FIG. The Rohgasringkanal 52 is in flow communication with the Druckolkanal 73 parallel, but to this sideways and elevationally slightly upwardly offset Rohgaskanal 71st The other parts of the Olnebelabscheiders 1 are not visible in Figure 7 or not shown for clarity.

LIST OF REFERENCE NUMBERS

Sign label

1 oil mist separator

1 1 gas cleaning room

12 drive room

13 tub

2 rotor

28 hollow cylinders

29 Abschleuderkante

3 wave

30 axis of rotation

31 level

33.1 first camp

33.2 second camp

34 hollow channel

35 transverse bore

4 rotary drive

41 Nozzle arm

42 nozzle channel

43 recoil nozzle

44 counterweight

45 mother

5 carrier part

52 raw gas ring channel

52.1 outer ring wall .2 middle ring wall

Bottom of 52

Oil collection trough

.1, 55.2 Ring channels in 5

.1, 56.2 plain bearing bushes

Gap or labyrinth seal Oil return channel

'inner ring wall

.1 splash guard ring

.2 splash cap cover

Lid flange

raw gas

Clean gas channel

Oil return passage

Siphon

" Drilling

Oil drain channel Component of the internal combustion engine Counter flange

Recess in 8 interior of 8

Claims

claims:

1 . An oil mist separator (1) for separating oil from the crankcase ventilation gas of an internal combustion engine, having a rotor (2) disposed on a rotatably mounted shaft (3) and separating gas from the gas by centrifugal forces, wherein in an area axially spaced from the rotor (2) Shaft (3) at this a rotary drive (4) with at least one recoil nozzle (43) is arranged, wherein the rotor (4) in a gas cleaning space (1 1) of the separator (1) and the rotary drive (4) in a drive space (12 ) of the separator (1) is arranged, wherein the shaft (3) between the rotor (2) and rotary drive (4) in two axially spaced bearings (33.1, 33.2) in a gas cleaning space (1 1) and the drive space (12) is supported in the carrier part (5) provided with a pressurized lubricating oil pressure oil passage (73) which lead into a to the at least one recoil nozzle (43) of the rotary drive (4) the hollow channel (34) in the shaft (3) opens, wherein a crankcase vent gas supplying Rohgaskanal (71) opens into an inlet region of the gas cleaning chamber (1 1), wherein a clean gas duct (72) from an outlet region of the gas cleaning chamber (1 1) goes off, an oil return passage (74) leaves an oil collecting area of the gas cleaning space (11) and an oil discharge passage (75) for lubricating oil emerging from the recoil nozzle (43) leaves the drive space (12),

characterized ,

that both bearings (33.1 and 33.2) of the shaft (3) are slide bearings and that in the carrier part (5) of the pressure oil passage (73) each one the shaft (3) surrounding annular channel (55.1, 55.2) to each sliding bearing (33.1, 33.2) leads.

2. oil mist separator according to claim 1, characterized in that the pressure oil passage (73) between the plain bearings (33.1, 33.2) in the hollow channel (34) of the shaft (3) opens.

3. oil mist separator according to claim 1 or 2, characterized in that the shaft (3) on the one hand and the support part (5) on the other hand, the two plain bearings (33.1, 33.2) form directly and consist of a pair of bearing material forming materials.

4. oil mist separator according to claim 1 or 2, characterized in that at least one of the two plain bearings (33.1, 33.2) with a plain bearing bush (56.1, 56.2) is executed.

5. oil mist separator according to one of claims 1 to 4, characterized in that from the rotor (2) facing side of the rotor-side slide bearing (33.1) from the rotor (2) away in the drive chamber (12) leading oil return passage (58) emanates, by the lubricating oil flowing through the rotor-side sliding bearing (33.1) can be returned to the drive space (12).

6. Ölnebelabscheider according to claim 5, characterized in that the oil return passage (58) is annular gap-shaped and radially inwardly of a to the rotor-side sliding bearing (33.1) leading annular channel (55.1) radially outwardly bounding inner annular wall (58 ') of the support part (5) limited is.

7. Ölnebelabscheider according to claim 6, characterized in that the oil return passage (58) radially outwardly from a part of the rotor (2) forming, from this in the direction of the rotary drive (4) extending towards the inner annular wall (58 ') concentric Hollow cylinder (28) is limited.

8. Ölnebelabscheider according to claim 7, characterized in that the hollow cylinder (28) at its free end with a circumferential acute-angled and / or radially outwardly bent or angled Abschleuderkante (29) is executed.

9. Ölnebelabscheider according to claim 8, characterized in that the crankcase ventilation gas supplying Rohgaskanal (71) through the support member (5) and below the rotor (2) open to this and on its opposite side by a bottom (53) closed Rohgasringkanal (51) forms and that the hollow cylinder (28) with the Ab- As seen from the rotor (2), the centrifugal edge (29) extends beyond the bottom (53).

10. Olnebelabscheider according to claim 9, characterized in that the Abschleuderkante (29) of the bottom (53) has a distance (s) of at least 3 mm, preferably at least 10 mm.

1 1. Olnebelabscheider according to claim 9 or 10, characterized in that the hollow cylinder (28) and the Rohgasringkanal (51) radially inner bounding central annular wall (52.2) of the support member (5) a non-contact gap or labyrinth seal (57) between drive space (12) and gas cleaning space (1 1) form.

12. Olnebelabscheider according to claim 1 1, characterized in that the recoil nozzle (43) at the free end of an outwardly and obliquely in the direction of the rotor (2) pointing nozzle arm (41) is arranged and that on the rotor side of the rotary drive (4) Carrier part (5) a circumferential, the rotary drive (4) facing axially projecting splash guard ring (59.1) is integrally formed or mounted.

13. Olnebelabscheider according to claim 12, characterized in that a conical splash guard (59.2) is inserted with its larger end in the splash guard ring (59.1) and extends with its smaller, at least one passage opening end in the direction of the rotary drive (4) out.

14. Olnebelabscheider according to one of claims 1 to 13, characterized in that it comprises a lower housing part which is flangeable to a component (8) of the internal combustion engine to produce flow connections and the carrier part (5) and the drive space (12), and in that it has an upper housing part which is formed by a removable cover (6) attached to the lower housing part and contains the gas cleaning space (11).

15. Olnebelabscheider according to one of claims 1 to 13 and internal combustion engine with such a Olnebelabscheider (1), characterized in that the drive space (12) is designed as a recess (81) which is open to the outside in a component (8) of the internal combustion engine such that the carrier part (5) can be plugged sealingly into the recess (81) to produce flow connections and in that the carrier part (5 ) or on the component (8) outside the recess (81) lying, removable cover (6) is attached or attachable, which contains the gas cleaning space (1 1).

16. Oil mist separator according to one of claims 1 to 13 and internal combustion engine with such a Ölnebelabscheider (1), characterized in that the carrier part (5) with at least the pressure oil passage (73) is designed as an integral part of a component (8) of the internal combustion engine, that the drive space (12) lies in an interior space (82) of the component (8) and that on the outside of the component (8) a removable cover (6) containing the gas cleaning space (11) is sealingly attached or attachable.