EP3259459A1

EP3259459A1 - Pump device for driving blow-by gas

Info

Publication number: EP3259459A1
Application number: EP16703942.9A
Authority: EP
Inventors: Alfred ELSÄSSER; Volker Kirschner; Thomas Riemay; Stefan Ruppel
Original assignee: Mahle International GmbH
Current assignee: Mahle International GmbH
Priority date: 2015-02-18
Filing date: 2016-02-03
Publication date: 2017-12-27
Also published as: CN108026805A; US20180030868A1; US10253662B2; JP6297760B2; DE102015202946A1; WO2016131654A1; CN108026805B; JP2018505988A

Abstract

The invention relates to a pump device for driving blow-by gas (32) in a crankcase ventilation apparatus (10) comprising a side channel compressor (20) having a housing (44) which has a conveying chamber (46), a liquid inlet (48), and a liquid outlet (50), having an impeller (52) which has blades (56) on the radial outside and which is rotatably mounted in the housing (44), wherein the blades (56) are in the conveying chamber (46), having a shaft (58), which is rotatably mounted about a rotation axis (60) and to which the impeller (52) is held to the shaft (58) in a rotationally fixed manner, wherein the conveying chamber (46) has at least one side channel (62, 64, 66) which extends axially adjacent to the blades (56) and connects the liquid inlet (48) and the liquid outlet (50) to each other.

Description

Pumping device for driving blow-by gas

The invention relates to a pump device for driving blow-by gas in a crankcase ventilation device, comprising a side channel compressor having a housing which has a delivery chamber, a fluid inlet and a fluid outlet, with an impeller having radially outer blades, and which is rotatably mounted in the housing, wherein the blades lie in the delivery chamber, and with a shaft which is rotatably mounted about a rotation axis and to which the impeller is attached, wherein the delivery chamber has at least one side channel which in the region of the blades runs and connects the fluid inlet and the fluid outlet with each other. Furthermore, the invention relates to an oil separation device with such a pump device and a crankcase ventilation device with such a Ölabscheideeinrichtung.

Most motor vehicles are equipped with an internal combustion engine, which usually provides for the drive of the vehicle. Such an internal combustion engine, preferably when it is equipped as a piston engine, has a crankcase. In the crankcase is a crankshaft, which is connected via connecting rods with pistons of the individual cylinders of the internal combustion engine. Leakages between the pistons and the associated cylinder walls result in a blow-by-gas flow through which blow-by gas passes from the combustion chambers into the crankcase. To avoid undue overpressure in the crankcase modern engines are equipped with a crankcase ventilation device to dissipate the blow-by gases from the crankcase. To reduce pollutant emissions, the blow-by gas with the help of the crankcase ventilation device is not supplied to an environment, but usually a fresh air system of the internal combustion engine, which supplies the combustion chambers of the internal combustion engine with fresh air.

In the crankcase there is an oil mist, so that the blow-by-gas carries oil with it. This oil, as an oil droplet, can damage elements in the intake tract, such as a turbocharger. To protect these elements and to reduce oil consumption, the crankcase breather usually has an oil separator and preferably an oil return which returns the separated oil to the crankcase.

In the case of crankcase ventilation systems, it is basically possible to distinguish passive systems from active systems. Passive systems use the pressure difference between the crankcase and the negative pressure of the fresh air system to drive the blow-by gas. Active systems additionally generate a negative pressure for the extraction of the blow-by gas from the crankcase. As a result, a higher pressure difference can be used in the oil separation, so that the deposition is improved. The achievable in this way pressure differences are still limited, since the maximum negative pressure can be generated is limited.

The present invention has for its object to provide for a pumping device of the type mentioned an improved or at least other embodiment, which is characterized in particular by an increased efficiency in terms of oil separation. This object is achieved by the subjects of the independent claims. Advantageous embodiments are the subject of the dependent claims.

The invention is based on the general idea to use a side channel compressor for driving the blow-by gas and to optimize this for use for driving blow-by gases. Side channel blowers can produce high pressure differences even in a compact design, so that thereby a particularly compact crankcase ventilation device can be achieved.

A favorable possibility provides that the pumping device has at least one oil drain through which oil can drain from the pumping chamber. In this way can be pumped with the pumping device gas containing oil mist, such as blow-by gas. Thus, the pumping device can be fluidly used between a crankcase and an oil separator. In this case, the pumping device can also already function or be used in particular as an oil separator, for example as a first stage.

A particularly favorable variant provides that the oil drains are respectively arranged at the lowest point of the delivery chamber in the direction of gravity. The

Direction of gravity refers to the later installation position. As a result, the oil, which possibly collects in the delivery chamber and the side channels, run through the oil drains.

An advantageous variant provides that the oil drain in the side channel compressor directs separated oil into an oil return, which returns the oil to an oil circuit. This can reduce oil consumption as the oil continues to be used. A favorable solution for the efficiency of the side channel compressor provides that in the side channel at least one rib is arranged, which extends at least partially obliquely to a circumferential direction. The arranged in the side channel at least one rib disturbs the flow of gases to be pumped in the circumferential direction within the side channel, so that the gases in the side channel can flow largely without pressure loss radially inward, where they can in turn be driven by the impeller again to a To experience pressure gain.

Another favorable possibility provides that the at least one rib in the side channel separates at least two open chambers from one another to the impeller. The formation of the chambers in the side channel supports the circulation of the blow-by gas in the side channel, so that the efficiency of the side channel compressor is improved in certain operating states.

Another favorable variant provides that the pumping device has in at least one side channel for each chamber an oil drain through which oil can drain from the respective chamber. Thus, oil can not accumulate in any chamber, which would hinder the operation of the pumping device. The oil drains are only necessary if the side channel is arranged at the bottom in the installed state, since the oil in the direction of the impeller can emerge from the chambers of a side channel arranged at the top in the installed state from the chambers open to the impeller.

Another favorable possibility provides that the housing has an insert which is inserted into the delivery chamber and has at least one rib. In this way, stable and precise ribs or contours for the delivery chamber can be formed in a very simple manner. A particularly favorable possibility provides that the insert forms at least part of the side channel. The insert can be made with high precision and, for example, be made of a material with high strength, so that the side channel can be made very precise and stable.

Another particularly favorable possibility provides that the housing and the at least one insert have different materials. As a result, materials which are more favorable for the housing and which can be processed more favorably, in particular in mass production, can be used. While in the insert materials can be used which have the necessary stability and precision, which is necessary in the formation of the side channel.

An advantageous solution provides that the housing consists of over 50% plastic or composite plastic, such as fiber-reinforced plastic.

Plastic or composite plastic is a favorable material, which is particularly suitable for mass production. As a result, the production of the side channel compressor can be carried out particularly cost-effectively.

A further advantageous solution provides that at least one rib is formed from the same material as the housing. As a result, the ribs can also be produced inexpensively. It when the rib is molded onto the insert is particularly advantageous.

A particularly advantageous solution provides that the pumping device has two opposing side channels and wherein it can be provided in particular that at least one rib is attached in each of the two side channels. is arranged, which extends at least partially obliquely to the circumferential direction. Preferably, the ribs each separate at least two chambers open to the impeller from each other. Thus, the efficiency-increasing effect of the chambers or ribs in both side channels can be exploited. Thus, the efficiency of the side channel compressor is further increased.

Preferably, the mounting position of the pumping device is such that the axis of rotation of the impeller is substantially vertical. The side channels are then above and / or below the blades of the impeller. The term "essentially vertical" encompasses deviations from the vertical direction of a maximum of 15 ° or a maximum of 10 ° or a maximum of 5 °.

An advantageous possibility provides that the pumping device has a drive unit which is coupled to the shaft. In this way, a particularly compact design of the pumping device can be achieved. For example, the drive unit may be formed by a hydraulic motor, an electric motor, a pneumatic motor or by a drive coupling with the internal combustion engine.

A particularly advantageous possibility provides that the drive unit has a turbine wheel, in particular a Pelton turbine wheel, which is held against rotation and on the shaft. Such a Pelton turbine is particularly suitable if high pressures but only low volume flows are available in the respective drive medium.

Another particularly advantageous possibility provides that the pumping device has a bearing device which is arranged between the impeller and the drive unit is arranged. By this arrangement of the storage device, a particularly compact design can be achieved.

Another particularly advantageous possibility provides that the shaft is axially and radially supported by the bearing device. If both the turbine wheel and the impeller are each held against rotation on the shaft, this is sufficient for a bearing device to support both the impeller and the drive unit, so that a particularly compact design can be achieved.

A favorable solution provides that the bearing device has needle roller bearings, sliding bearings and / or ball bearings.

Another favorable solution provides that the storage facility has exactly one bearing. As a result, an even more compact design of the pumping device can be achieved.

A particularly favorable solution provides that the impeller between a shaft connection and the blades has a ring portion which extends between the shaft connection and the blades and which in particular connects the shaft connection with the blades, the ring portion in the axial direction opposite to a wall, in particular extends between the impeller and the drive unit, wherein an axial distance between this wall and the ring portion varies from the rotation axis in the radial direction.

Thereby, the axial distance between the wall and the ring portion can vary radially and be increased, for example towards the shaft connection, so that the friction due to shear flows between the wall and the ring portion is reduced. A favorable solution provides that the wall runs in a longitudinal section parallel to the axis of rotation obliquely to the ring portion and / or bent and / or stepped. In this way, the varying axial distance can be easily achieved.

An advantageous variant provides that the wall has a recess, based on the direction of gravity in the installed position. The depression increases the axial distance between the wall and the ring section.

A further advantageous variant provides that the axial distance between the ring section and the wall opposite the ring section is at least partially greater than an axial distance between the ring section and the wall opposite the ring section in the region of a sealing device. Such a clearance sufficiently reduces the frictional losses due to the shear flows between the ring portion and the wall.

Furthermore, the above object is achieved by a crankcase ventilation device with such a pumping device and with a inertia-based oil separator. Such a crankcase ventilation device can particularly benefit from the advantages of the pumping device, to the above description of which reference is made.

A favorable possibility provides that the inertia-based oil mist separator is arranged downstream of the pumping device. By arranging the inertia-based oil mist separator downstream of the pumping device, the pumping device acts as a first oil separation stage, so that a two-stage oil separation can be achieved which can particularly effectively separate oil mist from the gas flow, for example the blow-by gas flow. In addition, at the Olnebelabscheider abut an increased pressure difference, which allows a more effective oil mist separation.

Another favorable possibility provides that the load-bearing oil mist separator is an impactor. An impactor is a inertia-based oil separator that achieves an improved separation rate with an increased pressure difference between inlet and outlet. Thus, the effects of the pumping device can be optimally utilized.

A particularly favorable possibility provides that the impactor has nozzles which are at least partially permanently open and through which the gas flow flows, the impactor has at least one baffle plate arranged opposite the nozzles, which deflects the gas flow and at which liquid droplets are deposited the impactor on a flow-parallel to the nozzles arranged spring-loaded poppet valve which opens with increasing pressure difference between the valve inlet and valve outlet and forms a flow gap through which flows a portion of the gas flow, and opposite a baffle plate is arranged, which deflects the gas flow and at which Liquid drops precipitate.

An advantageous variant provides that the load-based oil mist separator has an oil drain, which conducts oil separated in the oil mist separator to an oil return. This reduces oil consumption as the separated oil is not lost.

A further advantageous variant provides that the oil drain directs the oil into a drive housing part of the crankcase ventilation device. The drive housing part thus acts as an oil collection point, from which the oil can be returned via the oil return to the oil circuit. This reduces the required number of oil lines, so that a cost-effective and compact design is possible.

A particularly advantageous variant provides that the oil return oil from the drive housing part returns to an oil circuit. This reduces the required number of oil lines, so that a cost-effective and compact design is possible.

A further particularly advantageous variant provides that the oil drain of the side channel compressor passes oil into the drive housing part. Thus, the oil separated in the side channel compressor can also be recirculated centrally via the drive housing part to the oil circuit.

Other important features and advantages of the invention will become apparent from the dependent claims, from the drawings and from the associated figure description with reference to the drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Preferred embodiments of the invention are illustrated in the drawings and will be described in more detail in the following description, wherein like reference numerals refer to the same or similar or functionally identical components.

Show, in each case schematically, a schematic diagram of a crankcase ventilation device, a sectional view through the crankcase ventilation device, an exploded view of the Kurbelgehäuseentlüftungseinrichtung, a schematic diagram illustrating the function of a side tenkanalverdichters, a sectional view through a side channel compressor along the sectional plane AA of Fig. 4, a sectional view through the side channel compressor along the sectional plane BB 4, a perspective view of a housing upper part of the side channel compressor, a perspective view of a housing lower part of the side channel compressor with an impeller arranged therein, an enlarged view of the region C from FIG. 6, an enlarged view of the region D from FIG. 6, a schematic diagram of a plan view of a housing part of the side channel compressor, 12 is an illustration of an insert,

13 is a schematic plan view of another insert,

14a-g is a schematic representation of the course of ribs in the side channels,

15 is a sectional view through a side channel compressor along the sectional plane AA of FIG. 4 to illustrate the ribs,

16 is a sectional view through a side channel compressor according to another variant, along the sectional plane AA of Fig. 4, and

17 is a sectional view through a side channel compressor according to another variant along the sectional plane AA of Fig. 4th

A crankcase ventilation device 10 shown in Fig. 1 is used to vent a crankcase 12 of an internal combustion engine 14. In this case, blow-by gas 32 is removed from the crankcase 12 and freed from an oil mist and fed to an intake tract 16 of the internal combustion engine 14. The crankcase ventilation device has a pump device 18, which comprises a side channel compressor 20 which is driven by a drive unit 22, and an oil mist separator 24, which has a inertia-based oil mist separator 26, for example an impactor 28. Furthermore, the crankcase ventilation device 10, a pressure control valve 30, which prevents the pressure in the crankcase 12 drops too much or even oil is sucked. The crankcase ventilation device 10 is arranged such that blow-by gas 32 is first led from the crankcase 12 to the pressure control valve 30 and then flows through the pumping device 18 and is through the

Pumping device 18 is driven, then the compressed blow-by gas 32 is passed through the oil mist separator 26, in which the blow-by gas 32 is released from oil mist. From the oil mist separator 26, the purified blow-by gas 32 is supplied to the intake tract 16 of the internal combustion engine 14.

In particular, the cleaned blow-by gas 32 is supplied to the intake tract 16 downstream of a filter device 15 of the intake tract 16. Because the oil mist from the blow-by gas 32 is largely removed, the elements arranged downstream of the filter device 15, for example a compressor 17 of a charging device 19, are protected. For example, FIG. 1 shows an internal combustion engine 14 with a charging device 19 with a compressor 17 and a turbine 21 driven by an exhaust gas flow, that is, with an exhaust gas turbocharger. However, the crankcase ventilation device 10 according to the invention can also be used in otherwise supercharged or uncharged internal combustion engines 14.

As shown, for example, in FIGS. 2 and 3, the crankcase ventilation device 10 has a housing 34, which is formed in several parts, for example in four parts. The housing 34 has a cover 36 in which the oil mist separator 26 is arranged. Furthermore, the housing 34 has an upper part 38 of the side channel compressor 20, a lower part 40 of the side channel compressor 20 and a drive housing part 42, in which the drive unit 22 is arranged. Preferably, the individual housing parts are arranged in this order in the direction of gravity from top to bottom together. be- see the individual housing parts seals 25 are provided which seal an interior of the housing 34 against the environment.

Alternatively or additionally, it may be provided that the cover is formed integrally with the upper part 38 of the side channel compressor 20, thereby necessary seals and screw connections could be saved.

As shown for example in FIGS. 3 to 6, the side channel compressor 20 has a housing 44 which is formed by the upper part 38 and the lower part 40. The housing 44 encloses a delivery chamber 46 and has a fluid inlet 48 and a fluid outlet 50, which each have a fluidic connection to the delivery chamber 46. Further, in the housing 44 of the side channel compressor 20, an impeller 52 is arranged, which has a shaft connection 54 and radially outer blades 56. A ring portion 96 of the impeller 52 connects the shaft connection 54 with the blades 56. The impeller 52 is arranged such that the blades 56 are located in the delivery chamber 46. Furthermore, the impeller is rotatably held on a shaft 58, which in turn is rotatably mounted about a rotation axis 60. Consequently, the impeller 52 is also rotatable about the rotation axis 60.

The delivery chamber 46 has at least one side channel 62, for example an upper side channel 64 and a lower side channel 66. The side channels 62 extend in the region of the vanes 56 of the impeller 52. In particular, the side channels 62 extend adjacent to the vanes 52. As seen in the circumferential direction, the side channels 62 extend between the fluid inlet 48 and the fluid outlet 50.

The fluid inlet 48 and the fluid outlet 50 are arranged such that at an angle of less than 90 °, particularly preferably less than 60 °, of- are spaced apart. The angle information relates to the axis of rotation 60. Consequently, there is a short connection possibility in the circumferential direction and a long connection possibility between the fluid inlet and the fluid outlet 50.

The side channels 62 connect the fluid inlet 48 and the fluid outlet 50 over the long path. In an intermediate region 68, which lies on the short path between the fluid inlet 48 and the fluid outlet 50, none of the side channels 62 extends. In particular, in the intermediate region 68, the distance between the blades in the axial direction to the next wall is very small, so that in This area no or little fluid flows occur.

In operation, the impeller 52 is rotated about the axis of rotation 60 so that the blades transport the medium to be pumped, such as blow-by gas 32, from the fluid inlet 48 over the long path to the fluid outlet 50. By the rotation of the impeller 52, the blow-by gas 32 is compressed radially outward due to the centrifugal force. Since the blades of the impeller 52 are open to the outside, the blow-by gas 32 there may flow into the side channels 62 from spaces between the blades 56. In the side channels 62, the blow-by gas 32 is braked in the circumferential direction and thus can flow radially inwards without losing pressure. Radially inside, the blow-by gas 32 again flows into areas between the blades 56 of the impeller 52 and is again taken in the circumferential direction, so that it can be compressed again. Through this cycle, a pressure difference between the fluid outlet 50 and the fluid inlet 48 may build up.

The compression of the blow-by gas 32 in the side channel compressor 20 takes place without that sealing surfaces must slide on each other, thus the friction of a side channel compressor 20 is extremely low, so that both the efficiency Enz particularly high and the life is particularly high and a particle load of the blow-by gas 32 through the side channel blower 20 is particularly low. Thus, a side channel compressor 20 is particularly well suited to drive the blow-by gas in the crankcase ventilation device.

For mass production, it is desirable to manufacture a majority of the crankcase ventilation device 10, in particular the housing 34, made of plastic or fiber-reinforced plastic. However, with plastic or fiber-reinforced plastic, the required tolerances, in particular in the intermediate region 68, in which the distance between the impeller 52 and the wall of the housing 44 is low, can not be sufficiently maintained. In addition, the required stability can not be maintained with the help of plastics or fiber-reinforced plastics.

For this reason, at least one insert 70 is provided, as shown for example in Figs. 7 to 10. The insert 70 may be made of a different material than the housing 44 of the side channel compressor 20 and the housing 34 of the crankcase ventilation device 10. Consequently, a higher quality material can be selected which has a higher stability and allows smaller manufacturing tolerances. At the same time thereby reduces the required amount of high-quality material, since not the entire housing 44 of the side channel compressor 20 must be made of the high quality material.

For example, the insert 70 is made of metal, so that results for the crankcase ventilation device 10 is a hybrid construction of plastic and metal. The insert 70 may be made, for example, by stamping and / or bending and / or deep-drawing and / or turning process. In this case, the at least one insert 70 forms a wall 72 of the delivery chamber 46, in particular in the intermediate region 68. Accordingly, the insert 70 is of annular design, the rotational symmetry being broken by the intermediate region 68.

Preferably, the side channel compressor 20 has two inserts 70, namely a first insert 73 and a second insert 74. The first insert 73, for example, in the upper part 38 of the housing 44 of the side channel compressor 20 inserted. In particular, it forms an upper wall of the delivery chamber 46 in the intermediate region 68.

The second insert 74 is inserted, for example, in the lower part 40 of the housing 44 of the side channel compressor 20. In the radially outer region, it forms the lower side channel 66 and the intermediate region 68. In a radially inner region, the second insert 74 forms a radial bearing surface 76, on which a bearing device 78 is arranged.

The bearing device 78 preferably supports the shaft 58 of the impeller 52.

As a result, the alignment of the impeller 52 with the high precision of the second insert 74 is also accurate, so that the tolerance in the positioning of the impeller 52 to the wall in the intermediate region 68 can be further reduced.

In order to further improve the efficiency of the side channel compressor 20, at least one rib 80, preferably at least two ribs 80, are provided, which are arranged in the side channels 62 and extend at least in sections obliquely to the circumferential direction. As a result, the ribs 80 brake the movement of the blow-by gas to be pumped 32 in the circumferential direction, so that the rotation of the blow-by gas 32 is additionally supported in the side channels 62 and thereby the pressure increase through the side channel 62nd is improved. The ribs 80 improve the efficiency in certain load ranges.

Various courses and arrangements of the ribs 80 are conceivable. In a variant shown by way of example in FIG. 14 a, the side channels have eight ribs 80, which run essentially perpendicular to the ribs 80. Alternatively, the ribs may also be tilted, as shown for example in Fig. 14 b.

Moreover, it is also possible that the ribs 80 are not straight but curved. For example, the rib may be S-shaped, as shown for example in Fig. 14c. Furthermore, the ribs 80 may have a kink. Alternatively or additionally, it can also be provided that the ribs 80 have interruptions, as shown for example in FIGS. 14e and 14f.

By the differently shaped ribs 80, the dependence of the efficiency can be improved from the operating point. This means that the efficiency is less dependent on the respective operating point and thus a high efficiency can be achieved over a wider range.

Furthermore, it can be provided that more or fewer ribs 81 are arranged in the upper side channel 64 than ribs 83 are arranged in the lower side channel 66.

Finally, it can also be provided that ribs 81 are arranged offset in the upper side channel 64 and ribs 83 in the lower side channel 66 in the circumferential direction by an angle. In addition, it may also be provided that the ribs 81 in the upper side channel 64 differently shaped or larger or smaller are as the ribs 83 in the lower side channel 66, as shown by way of example in Fig. 15.

By the ribs 80 chambers 82 are formed in the side channels 62, which are open to the impeller 52. In the chambers 82, the flow vortices of the blow-by gas 32 can form particularly effectively.

The ribs 80 may be formed, for example, by the at least one insert 70. The insert 70 may be stamped accordingly so that a tab in the insert may be bent upwardly to form a rib 80. Furthermore, the ribs 80 may also be formed by parts of the housing 44, in particular by the upper part 38 or lower part 40. For example, the injection mold can be adjusted accordingly.

Furthermore, plastic surfaces can be injection-molded onto the inserts 70, 73, 74, on which the ribs 80 are formed from plastic.

Due to its mode of action, a side channel compressor 20 acts as an oil mist separator according to the principle of inertia. For this reason, oil from the blow-by gas 32 accumulates in the delivery chamber 46 of the side channel compressor 20. For this reason, at least one oil drain 84 is provided, through which oil can drain from the delivery chamber 46 from the side channel compressor 20 and in particular in an oil return 85 is fed, which returns the separated oil to an oil circuit. For example, the oil drain 84 directs the oil into the drive housing part 42, from which the oil return 85 returns the oil to the oil circuit.

Preferably, the lower side channel 66, the oil drain 84, since due to gravity, the deposited in the side channel compressor 20 oil in the lower side channel 66 will run. More preferably, the lower side channel 66 for each chamber 82 has its own oil drain 84 so that the separated oil from each of the chambers 82 can drain. In particular, the oil drains 84 are arranged at locations of the respective chamber which are located at the lowest point in the direction of gravity so that no or at least only very little oil can remain in the side channel compressor 20.

Due to this configuration of the side channel compressor 20, the side channel compressor 20 can be used as a first stage in the oil mist separation, so that the crankcase ventilation device 10 offers a two-stage oil mist separation. In particular, it is only possible by means of the at least one oil drain 84 that the pump device 18 and thus the side channel compressor 20 are arranged between the crankcase 12 and the oil mist separator 26. Thus, in this way by the pumping device 18, a relative to the ambient pressure increased pressure can be generated, which can be exploited in the inertia-based oil mist separator 26 to separate oil from the blow-by gas 32. Compared to the generation of negative pressure, the generation of overpressure is advantageous, since in this way higher pressure differences can be made available to the oil mist separator 26.

Furthermore, the bearing device 78, as shown for example in FIGS. 5 or 10, disposed between the impeller 52 and the drive unit 22, so that there is a particularly compact design of the crankcase ventilation device 10. The bearing device 78 has an oil feed 86, which is fed in particular from, for example, an oil drain 84 or the oil return of the oil mist separator 26. Furthermore, the bearing device 78 has an oil drain 88, so that an oil circulation in the bearing device 78 can be achieved. The bearing device 78 is designed in particular as an axial and radial bearing, so that a single bearing device 78 is sufficient. Alternatively, as shown for example in FIG. 6, the bearing device can also have a thrust bearing and a separate radial bearing, which however are both arranged between the impeller 52 and the drive unit 22.

The bearing device 78 supports the shaft 58, on which the impeller 52 and, for example, the drive unit 22 are held in a rotationally fixed manner, so that the oil mist separator 24 manages with a single bearing device 78.

In particular, the bearing device 78 may comprise a ball bearing, a plain bearing, a rolling bearing or a needle bearing.

For example, as shown in FIG. 5, a seal device 90 is provided which seals the delivery space of the side channel compressor 20 from an inside portion of the side channel compressor 20 so that unnecessary gas flow does not occur in the interior section 92. The sealing device 90 is preferably designed as a labyrinth seal, so that it generates only a small amount of friction.

In a further variant, as shown for example in FIGS. 16 or 17, the side channel compressor 20 has a recess 94 in a wall 93 of the housing 44. In particular, the depression 94 is arranged in the inner region 92. The recess 94 is in this case a ring portion 96 of the impeller 52 opposite, which extends between the shaft connection 54 and the blades 56. Through the recess 94, an axial distance 95 between the impeller 52 and the wall 93 of the housing 44 is increased, so that the frictional forces generated due to shear flows can be reduced and thus the friction losses can be reduced. The recess 94 may be formed in that the wall 93 extends obliquely to the annular portion 96 of the impeller 52, as shown for example in Fig. 17. This allows oil, which collects on the wall 93, to be guided to the bearing device 78, whereby the bearing device can be lubricated.

Furthermore, the depression 94 may be formed by the wall 93 being curved and thus forming a depression or, as shown for example in FIG. 16, being staged.

The inertia-based oil mist separator 26 of the oil mist separator 24 is formed as an impactor 28 and may also deposit other liquids. In an impactor 28, the gas flow to be cleaned, for example, the blow-by gas 32, passed through at least one nozzle, which is arranged opposite a baffle plate, so that the gas flow is deflected immediately after the nozzle. Through the nozzle, the gas flow is given a high speed, so that the liquid droplets, referred to below as oil droplets, the deflection by the baffle plate can not follow and hit the baffle plate and hang there and thus be separated from the gas flow.

Furthermore, the impactor 28 has a poppet valve which is spring-loaded closed, wherein the poppet valve opens when a pressure difference between the valve inlet and valve outlet is exceeded. In this case, the poppet valve forms an annular flow gap, which also acts like a nozzle, and the gas flow flowing through the impactor 28, for example the blow-by gas 32, accelerated. The annular flow gap is surrounded by a cylindrical baffle plate, which deflects the gas flow, which has flowed through the annular flow gap, and thus there is a deposit of oil droplets from the gas flow allows. Due to the fact that the poppet valve opens when the pressure difference increases, a flow cross-section of the imprpactor is increased and thus the flow cross-section of the oil mist separator 24 is increased. The flow cross section is composed of the cross section of all nozzles and the flow area of the annular flow gap.

The Ölnebelabscheideeinrichtung 24 has an oil drain 97 which connects the lid 36 fluidly with the drive housing part 42. The oil separated by the oil mist separator 26, here the impactor 28, is fed to the oil outlet 97. Through the oil outlet 97, the oil can drain into the drive housing part 42 and be returned from there via the oil return 85 to the oil circuit.

The drive unit 22 has, for example, a turbine wheel 98, which is held against rotation on the shaft 58. Thus, the turbine 98 may drive the impeller 52 of the side channel compressor 20. Furthermore, the turbine wheel 98 is thus also supported by the bearing device 78, with which the shaft 58 is mounted, so that a compact design is achieved.

For example, the turbine 98 is driven by oil, which is directed via a nozzle 100 onto the turbine 98. A hydraulic system is usually already present in internal combustion engines 14, so that the drive unit 22 can be realized cost-effectively. In particular, the turbine wheel is designed as a Pelton turbine wheel.

Since oil that drives the turbine wheel 98 accumulates in the drive housing part 42, the oil can be returned to the oil circuit via the oil return 85. As a result, the oil mist separation device 24 into the drive housing part 42 and the side channel compressor 20 in the drive housing part 42 associated oil with the oil used to drive the turbine wheel 98, are recirculated through the oil return 85 to the oil circuit. As a result, oil lines can be saved, resulting in a cost-effective and compact design.

Claims

claims

1 . A pump device for driving blow-by gas (32) in a crankcase ventilation device (10) comprising a side channel compressor (20),

- With a housing (44) having a delivery chamber (46), a fluid inlet (48) and a fluid outlet (50),

- With an impeller (52) having radially outer blades (56) and which is rotatably mounted in the housing (44), wherein the blades (56) lie in the delivery chamber (46),

- With a shaft (58) which is rotatably mounted about a rotation axis (60) and on which the impeller (52) is fixed,

- wherein the delivery chamber (46) at least one side channel (62, 64, 66), which extends in the region of the blades (56) and the fluid inlet (48) and the fluid outlet (50) interconnected.

2. Pumping device according to claim 1,

characterized,

in that the pump device (18) has at least one oil outlet (84) through which oil can drain out of the delivery chamber (46).

3. Pumping device according to claim 2,

characterized,

in that the at least one oil drain (84) is arranged in each case at a point of the delivery chamber (46) which is the lowest point in the direction of gravity.

4. Pumping device according to claim 2 or 3,

characterized,

in that the oil drain (84) in the side channel compressor (20) directs separated oil into an oil return (85) which returns the oil to an oil circuit.

5. Pumping device according to one of claims 1 to 4,

characterized,

in that the pump device (18) has at least one rib (80) in the side channel (62, 64, 66) which separates at least two chambers (82) which are open towards the impeller (52).

6. Pumping device according to claim 5,

characterized,

in that the pump device (18) has, in at least one side channel (62, 64, 66) for each chamber (82), an oil drain (84) through which oil can drain from the respective chamber (82).

7. Pumping device according to one of claims 1 to 6,

characterized,

in that the housing (44) has an insert part (70, 73, 74) which is inserted into the delivery chamber (46).

8. Pumping device according to claim 7,

characterized,

in that the housing (44) has the at least one insert part (70, 73, 74) different materials.

9. Pumping device according to one of claims 1 to 8,

characterized, - That the pumping device (18) has two opposite side channels (62, 64, 66), and in particular

- That in each side channel (62, 64, 66) at least one rib (80) is arranged, which extends at least partially obliquely to a circumferential direction and / or

- That in each of the two side channels (62, 64, 66) at least two to the impeller (52) open chambers (82) are arranged.

10. Pumping device according to one of claims 1 to 9,

characterized,

in that the pump device (18) has a drive unit (22) which is coupled to the shaft (58).

1 1. Pumping device according to claim 10,

characterized,

in that the drive unit (22) has a turbine wheel (98), in particular a Pelton turbine wheel, which is held rotationally fixed to and on the shaft (58).

12. crankcase ventilation device with a pump device (18) according to any one of claims 1 to 1 1 and with a inertia-based Ölnebelabschei- (26).

13. crankcase ventilation device according to claim 12,

characterized in that the inertia-based oil mist separator (26) is disposed downstream of the pumping device (18).

14 crankcase ventilation device according to claim 12 or 13, that the inertia-based oil mist separator (26) is an impactor (28).

15. Kurbelgehäuseentlüftungseinrichtung according to any one of claims 13 to 14, characterized in that the inertia-based oil mist separator (26) has a

Olablauf (97) which directs oil separated in the oil mist separator to an oil return (85).

16. crankcase ventilation device according to claim 15,

characterized,

the oil outlet (97) directs the oil into a drive housing part (42) of the crankcase ventilation device (10).

17. crankcase ventilation device according to claim 16,

characterized,

the oil return (85) returns oil from the drive housing part (42) to an oil circuit.

18. crankcase ventilation device according to claim 15 or 16,

characterized,

the oil drain (84) of the side channel compressor (20) conducts oil into the drive housing part (42).

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