Oil separator

Abstract

Oil separator (1) for separating oil droplets and / or oil mist from gases to be cleaned, with a housing (2), a rotor comprising an oil separator element (3) arranged in the housing (2) and spaced apart from the housing (2) and a shaft (4) for rotatably mounting the oil separator element (3), a first gas inlet (5) for supplying the gases to be cleaned to the oil separator element (3) along the shaft (4) and a first gas outlet (6) in the wall of the housing (2) surrounding the rotor, characterized in that that a second gas inlet (10) for supplying the gases to be cleaned is arranged in the wall of the housing (2) surrounding the rotor.

Description

[0001] The present invention relates to an oil separator for separating oil droplets and / or oil mist from gases, in particular from blow-by gases of an internal combustion engine.

[0002] Such oil separators are designed, for example, as centrifugal separators with a disc separator, in which a gas is rotated within a chamber of a stationary housing by means of a rotor. The resulting centrifugal force propels the oil droplets and oil mist outwards and separates them on impact walls. To set the gas in rotation, an oil separation element is used, for example, which can be designed as a stack of identically designed truncated cone-shaped discs. The gas to be cleaned is then guided centrally or from the periphery into the spaces between the individual discs of the stack and is entrained there by a rotating movement of the stack and the discs at up to 15,000 rpm. This separates the oil droplets and oil mist from the discs and the housing wall of the oil separator.The oil separation element is usually rotated by a drive element via a shaft, which in turn is driven by the oil pressure of the combustion engine or electrically.

[0003] Such oil separators are used in particular to separate oil mist and oil droplets from blow-by gases of combustion engines.

[0004] However, the gas flows that such an active oil separator can handle with a limited pressure drop across the oil separator are limited. In particular, the gas flows to be conducted through such an oil separator, particularly through the spaces between the individual plates of the disc separator, cannot be increased arbitrarily. Therefore, if high gas flows requiring purification occur, especially high blow-by gas flows, these can no longer be adequately diverted or cleaned of oil mist and / or oil droplets.

[0005] DE 20 2007 009 913 U1 discloses a separator for separating oil mist from the crankcase ventilation gas of an internal combustion engine. The separator has a gas cleaning chamber in which a rotatably mounted centrifugal rotor is arranged. The gas cleaning chamber has a raw gas inlet, a clean gas outlet, and an oil outlet. The crankcase ventilation gas can be introduced into a radially inner region of the centrifugal rotor through the raw gas inlet. Clean gas freed of oil mist can be discharged from the gas cleaning chamber through the clean gas outlet. Oil separated from the gas can be discharged from the gas cleaning chamber through the oil outlet.Furthermore, the device has a rotary drive for the centrifugal rotor, wherein the rotary drive is arranged in a drive chamber of the separator separate from the gas cleaning chamber and is operable with pressurized lubricating oil of the internal combustion engine and is connected to the centrifugal rotor via a shaft running from the drive chamber into the gas cleaning chamber.

[0006] The document DE 195 20 553 A1 describes a device for separating oil and / or soot and / or foreign substances from an air, gas, and / or vapor stream. The device comprises at least one drum arranged in a closed chamber and rotatably driven by a drive about a longitudinal or drum axis. The drum forms an interior space and, at least on a portion of its casing surrounding the drum axis and delimiting the interior space, is provided with a plurality of sieve-like openings through which the sub-spaces formed by the interior of the drum and the part of the chamber surrounding the drum communicate. Furthermore, the device comprises at least one first connection opening into one of the sub-spaces for supplying the air, gas, and / or vapor stream, and a second connection opening into the other sub-space for discharging a purified air, gas, and / or vapor stream free of oil, soot, and / or other foreign substances.

[0007] It is therefore an object of the present invention to provide an oil separator, for example of the above design, which has a high operational reliability and good separation behavior even at high gas flows.

[0008] This object is achieved by the oil separator according to claim 1.

[0009] Advantageous further developments of the oil separator according to the invention are given in the respective dependent claims.

[0010] The oil separator according to the invention serves to separate oil droplets and / or oil mist from gases, in particular from blow-by gases of an internal combustion engine.

[0011] The oil separator has a housing in which a rotor is arranged. The rotor, in turn, has a shaft and an oil separation element arranged on the shaft and rotatable with the shaft. The oil separation element can be a stack of discs as described above, to which the gas to be cleaned is fed largely centrally via a bore in the shaft or in another way parallel to the shaft. If the oil separation element, in particular a stack of discs, is set in rotation, the gases to be cleaned are set in tangential and radial movement, for example by the gases to be cleaned flowing through the spaces between the individual discs of the stack of discs. This ultimately results in the separation of the oil droplets and oil mist on the discs and on the walls of the housing surrounding the rotor.

[0012] The gas to be purified is supplied to the oil separation element, for example, via a first gas inlet along the shaft, i.e., in particular, through grooves or bores in the shaft, which essentially run, at least in sections, in the axial direction of the shaft. It is also possible to supply the gas to be purified outside the shaft along the shaft to the spaces between the disks of the disk stack. For this purpose, the disks of the disk stack typically have openings adjacent to or near the shaft, which allow a flow parallel to the axial direction of the shaft.

[0013] The housing wall surrounding the rotor and the oil separation element has a first gas outlet through which the gas purified of oil mist and / or oil droplets can exit the housing. Typically, the purified gases, in the case of blow-by gases, are redirected into the intake tract of the combustion engine.

[0014] The first gas inlet, the through-opening in the oil separation element and the shaft, in particular the spaces between disc stacks of disc separators, and the first gas outlet limit the gas flow to be cleaned by the oil separator and define the pressure difference between the first inlet and the first outlet.

[0015] According to the invention, it is therefore now provided that a second gas inlet is arranged in the wall of the housing surrounding the rotor, through which gases to be cleaned can additionally be introduced into the space between the rotor and the housing.

[0016] In contrast to conventional bypass solutions for oil separators, additional gas to be cleaned is introduced into the separation chamber in addition to the gas to be cleaned flowing through the rotor. Although this gas does not flow through the oil separation element itself and is therefore not subject to oil droplet or oil mist separation by this oil separation element, it is also set in rotation by the rotation of the rotor and the rotation of the gas stream leaving the rotor, so that this gas introduced into the rotor housing through the second gas inlet is also subjected to oil droplet and / or oil mist separation on the housing wall. The mixed, cleaned gas is then discharged from the housing via the first gas outlet.

[0017] Advantageously, the oil separator according to the invention can also have a second gas outlet arranged in the housing. This makes it possible to reliably divert very high volume flows from the separation chamber within the housing.

[0018] It is particularly advantageous if one or both additional flow options, namely the second gas inlet and / or the second gas outlet, are each closed with a valve that has a specific opening characteristic. The respective valve can be set so that it only opens when a predetermined inlet flow rate is exceeded (for the second gas inlet) or when a predetermined outlet flow rate is exceeded (for the second gas outlet), or when a predetermined pressure difference between the gas on the pressure side of the respective valve and the suction side of the respective valve is exceeded.

[0019] Such an opening characteristic can be achieved by controlling the first valve and / or the second valve by means of the motor control or an actuator, for example a servo motor, an actuator or a pressure cell.

[0020] The first and second gas inlets, as well as the first and second gas outlets, can each be connected outside the housing to a common gas supply line or gas discharge line. For example, a common vent line can lead to both the first gas inlet and the second gas inlet. Furthermore, a common line can lead from the first gas outlet and the second gas outlet to the intake tract of an internal combustion engine.

[0021] The first and / or second valve can be designed as a mushroom valve, the valve plate of which advantageously consists of or contains an elastomeric material. To open the valve, the outer edge of the valve plate can then bend away from the valve seat, thereby creating a gap between the valve plate and the valve seat.

[0022] It is also possible to design the first valve and / or the second valve as a valve closure with a movable spring tongue or a movable spring plate.

[0023] For this purpose, a movable spring tongue or a movable spring plate can be arranged adjacent to the valve opening and, when the valve is closed, completely cover the valve opening. With a spring tongue, the lifting advantageously occurs laterally, whereas with a spring plate, a centrally arranged area preferably exposes the cross-section. While with spring tongues, connections are provided in particular via one or two retaining arms, for example, two parallel retaining arms, with centrally lifting spring plates, two, three, or even more retaining arms are preferably provided.

[0024] In an embodiment that is particularly easy to manufacture, the spring tongue or spring plate can consist of an elastic metal sheet, in particular of spring steel.

[0025] For such valve reeds or plates, it is advantageous if the side facing the valve opening is coated with a closed-pore elastomer material, at least in sections on the peripheral edge of the valve opening. This is particularly effective if the valve opening has an edge that protrudes beyond its surroundings, upon which the valve reed can rest. In the latter case, further efficient oil separation occurs on the spring reed as the gases pass through the valve opening. Oil separation is also particularly effective if the spring reed is coated with a closed-pore elastomer material in the area where it rests on the valve opening.

[0026] The spring tongue or the spring plate can, in turn, be mounted differently or can have predetermined shapes, so that a predetermined manner results in how the spring tongue or the spring plate closes or opens the valve opening.

[0027] In particular, such spring tongues or plates can each have at least one holding arm which is resiliently attached to the valve body in such a way that the spring tongue or the spring plate is movable between a first position in which it closes the gas passage opening covered by it and a second position in which it releases the gas passage opening covered by it.

[0028] The spring tongue or spring plate can further be pre-tensioned in such a way that it closes the covered gas passage opening below a predetermined positive pressure difference.

[0029] Furthermore, it is possible for the spring tongue or spring plate to be movably mounted via at least one retaining arm in such a way that it successively opens or closes the valve opening. This allows the pressure difference and the volume flow between the intake and discharge sides of the valve to be precisely adjusted. This makes it possible to operate the oil separator at an operating point with the optimal size of the total openings of the first and second gas inlets or the first and second gas outlets, depending on the volume flow of the gases to be purified.

[0030] For the spring tongue, the at least one retaining arm can also be attached in such a way that the associated spring tongue gradually moves away from or closes one or more valve openings of one or more first valves (and similarly for one or more second valves) in a tilting movement. This allows the pressure difference and the volume flow between the suction side and the pressure side of the first valves or the second valves to be adjusted more precisely. The present invention thus allows the oil separator to be operated at an operating point with an optimal number of open / released first valves (or second valves) depending on the volume flow of the gases to be purified.

[0031] As an alternative to mushroom valves and spring tongues or plates, valve designs with spiral springs can also be used, although mushroom valves, spring tongues and spring plates are usually simpler in design and therefore more cost-effective.

[0032] According to the invention, further gas inlets and / or gas outlets can also be provided, wherein the procedure described above for each two gas inlets and / or two gas outlets can then be implemented for each further gas inlet and / or gas outlet or for all of the gas inlets and / or gas outlets.

[0033] It is further advantageous if, when a second inlet and a second outlet are provided, these are arranged in the housing wall essentially on opposite sides of the oil separation element. In this case, the gases to be purified introduced via the second inlet travel a maximum distance and are thereby set in rotation and also purified along this path.

[0034] However, the second inlet and the second outlet can also be arranged immediately adjacent to each other with respect to the direction of rotation of the rotor, resulting in a bypass with lower pressure losses and greater efficiency, but the separation of the gas conducted in the bypass is very limited.

[0035] With respect to the axial direction of the shaft, the second inlet and the second outlet can be arranged at the same height or offset from each other. It is particularly advantageous with regard to pressure loss if the second outlet is arranged close to the first outlet.

[0036] The rotor of the oil separator is driven, in particular, by the shaft. The drive element can be a hydraulically driven drive element, in particular a Heron turbine or a Pelton turbine, or an electrically driven drive element.

[0037] The oil separator according to the invention is particularly suitable for cleaning blow-by gases in combustion engines, but can also be used in other areas for removing oil from gases.

[0038] The following are some examples of oil separators according to the invention. These examples illustrate a variety of inventive features and advantageous features, each in combination. However, it is also possible to combine and implement each of the advantageous features presented therein individually with the inventive features of the present invention. This is also possible for any combination of the advantageous features in the attached examples.

[0039] In the examples, the same and similar reference symbols are used for the same and similar elements, so that their explanation is not repeated where necessary.

[0040] It shows Fig. 1 an oil separator according to the state of the art and Fig. 2-6 Oil separators according to the present invention; Fig. 7 shows the pressure loss across the blow-by channels of an internal combustion engine as a function of the volume flow in comparison between a conventional oil separator and an oil separator according to the present invention.

[0041] Fig. Figure 1 shows a prior art oil separator 1. This oil separator 1 has a housing 2 enclosing an oil separation chamber 7. A rotor 3 is arranged in the oil separation chamber 7. The rotor 3 comprises a stack of discs arranged one above the other. There are gaps between the individual discs. The disc stack 3 is mounted on a shaft 4 and can be rotated by this shaft 4.

[0042] The housing 2 is surrounded by a further outer housing / wall 8, wherein both the gas supply and the forwarding of the purified gas are arranged between the housing 2 and the outer housing 8.

[0043] Via a supply line 5 serving as a gas inlet, which runs between the housing 2 and an outer wall 8, the gas to be cleaned of oil mist and / or oil droplets is fed largely centrally to the disk stack along the shaft 4. The gas then flows between the individual disks of the disk stack 3 and exits them along their peripheral edge into the outer region of the oil separation chamber 7 in the area between the disk stack 3 and the wall of the housing 2. The rotation of the disk stack 3 causes the gas flowing through the disk stack 3 to rotate and accelerate, so that oil mist and oil droplets are separated both on the surfaces of the disks and on the wall of the housing 2. These are then collected in the lower region of the oil separation chamber 7 and removed from the oil separation chamber 7 in a manner not shown. The cleaned gas then leaves the oil separation chamber 7 via the gas outlet 6.

[0044] In the case of internal combustion engines, such an oil separator 1 introduces, in particular, blow-by gas from the crankcase via the gas inlet 5 into the oil separator 1 and then supplies it as purified blow-by gas to the intake tract of the internal combustion engine via the gas outlet 6.

[0045] In the case of very high blow-by gas volume flows, the blow-by gas cannot be properly passed through the oil separator 1, as its capacity is limited by the cross-sections of the inlet 5, the clearances between the discs of the disc stack 3, the geometry of the housing 2, and the cross-section and geometry of the outlet 6 at a given available pressure difference across the oil separator. As a result, the pressure difference across the oil separator becomes unacceptably large.

[0046] Conventionally, additional bypass lines are therefore provided around the oil separator 1, in which no or only insignificant oil separation and purification of the blow-by gas takes place before it enters the intake tract of the internal combustion engine.

[0047] According to the invention, the oil separator according to Fig. 2, a second gas inlet 10 is arranged in the housing 2 into the oil separation chamber 7. This second gas inlet 10 has a mushroom valve 11 with a valve seat 12, a valve opening 13, and a mushroom-shaped valve plate 14. Fig. Figure 2A shows the valve in a cutaway view.

[0048] When a predetermined volume flow or a predetermined pressure difference between the pressure side and the suction side (oil separation chamber 7) of the valve 11 is exceeded, the valve disk of the mushroom valve lifts off the valve seat 12 and opens a passage between the supply line and the oil separation chamber 7. This allows additional gas to flow into the oil separation chamber 7. Although this gas no longer flows through the spaces between the discs of the disc stack 3, it is entrained in a rotary motion along the inside of the wall 2 by the rotation of the disc stack and the gas surrounding it, and is thus also cleaned of oil droplets and oil mist. The mushroom valve also serves as a check valve to prevent gas from escaping from the oil separation chamber 7 via the second gas inlet 10.

[0049] Consequently, the gas flows mix in the oil separation chamber 7 between the rotor 3 and the wall of the housing 2, namely the gas flow that has flowed through the disk stack 3 and the gas flow that has entered the oil separation chamber 7 via the mushroom valve 11, and then leave the oil separation chamber 7 via a sufficiently large gas outlet 6.

[0050] Fig. 2A shows one of the oil separators 1 with only a low volume flow of the gas to be cleaned, ie with the mushroom valve 11 closed.

[0051] Fig. Figure 2B shows a section through the oil separator 1 in the same state, with the mushroom valve 14 also shown in section. Here, as in the following Fig. In Figures 2C to 5B, the disc stack 3 is only indicated schematically as a block.

[0052] Fig. 2C shows the oil separator 1 with the valve 11 open at a high volume flow of the gas to be cleaned.

[0053] Fig. 3 shows another oil separator 1, which is designed in the same way as the one shown in Fig. 2 is shown.

[0054] In addition, however, the housing 2 has a second gas outlet 20, which is designed as a mushroom valve 21. The mushroom valve 21 has a valve seat 22, a valve opening 23, and a valve plate 24 made of elastomeric material.

[0055] The flow direction of valve 11 leads from the inlet 5 into the oil separation chamber 7, while the flow direction of valve 21 is directed from the oil separation chamber 7 into the gas line following the gas outlet 6. Both mushroom valves also function as check valves, so that valve 11 always prevents the flow of gas from the oil separation chamber 7 toward the gas inlet, and mushroom valve 21 prevents the flow of purified gas into the oil separation chamber 7.

[0056] In Fig. 3A both valves are closed at low flow rate.

[0057] In Fig. 3B, both valves are open, i.e., at an operating point where the volume flow of the gases to be purified is very high. The opening characteristics of valves 11 and 21 can be designed identically, so that both valves open and close simultaneously. Depending on requirements, however, it is also possible to equip both valves 11 and 21 with different opening characteristics. The same applies to the closing characteristics of valves 11 and 21.

[0058] For example, in Fig. 3C shows a state in which the second exhaust valve 21 is closed while the second intake valve 11 is opened via the valve opening.

[0059] In Fig. 3D shows a state in which the second exhaust valve 21 is open, while the second intake valve 11 is now closed. Such different opening and closing characteristics of the valves 11 and 21 can be adjusted by suitable material selection and valve design.

[0060] The Fig. 3C and Fig. The conditions shown in 3D can arise, for example, if the flow into the first gas inlet via the supply line 5 is limited or blocked ( Fig. 3C) or if the outflow through the first gas outlet is restricted or blocked ( Fig. 3D), for example when local icing occurs.

[0061] Fig. 3D has been improved compared to the Fig. 3A to 3C are supplemented by two collars 25, 26 surrounding the second gas outlet 20 on the inside of the housing 2, which act as a kind of labyrinth seal to help prevent oil from being entrained as the gas passes through the gas outlet 20 from the surroundings of the gas outlet 20. Similar collars can also be attached to the outside of the housing 2 around the second gas inlet opening 10 to prevent oil separated upon impact with the housing 2 from being entrained there. However, a separate illustration has been omitted here.

[0062] Fig. 4 shows in two Fig. 4A and Fig. 4B shows another oil separator according to the invention, which, like the oil separator in Fig. 2. In contrast to Fig. 2, however, the second gas inlet 10 is now provided with a different valve construction 11. The valve 11 is provided here as a valve opening 13 within a valve seat 12, which can be closed or opened via an elastic spring tongue 14. The spring tongue is attached to a support 15 as a fastening point on the valve seat 12, for example, screwed or riveted. The opening characteristic of the spring tongue 14 can be adjusted by selecting the material thickness, the material, the geometric design of the transition between the fastening point 15 and the free end of the spring tongue 14, and other parameters. It can be advantageous if the side of the spring tongue 14 facing the valve opening 13 is coated with a closed-pore elastomer material 16, as in Fig. 4B. In this case, this spring tongue 14 achieves a particularly high oil separation performance when gas flows through the opening gap between the valve seat 12 and the spring tongue 14. Instead of the partial coating shown, a full-surface coating is also possible, or the spring tongue 14 can be manufactured from a spring-hardened sheet metal with a full-surface elastomer coating, at least on the side facing the valve seat 12.

[0063] Fig. 5 shows in two Fig. 5A and Fig. 5B shows another example of an oil separator 1 according to the invention, which, like the oil separator in Fig. 4. According to Fig. 3, however, the housing 2 has a second outlet 20 in its wall, which is designed as a valve in the same way as the gas inlet 10. Only the opening direction is as in Fig. 3, ie the first valve 11 opens in the direction of the oil separation chamber 7, while the second valve 21 opens in the direction of the gas outlet 6 or the gas line downstream of the gas outlet 6.

[0064] In Fig. Figure 5B shows the oil separator 1 at a high volume flow of the gas to be purified. Both valves 11 and 21 are open, allowing flow through the oil separation chamber without the corresponding volume flow being completely directed through the disc stack 3.

[0065] Instead of the Fig. 4 and Fig. 5 inserted spring tongues 14, which are fastened by a single holding arm, a spring plate can also be used, which is fastened by two holding arms, as is the case in DE 20 2014 006 149 U1, for example in the Fig. 1 and Fig. 2. It is also possible to use a centrally lifted valve plate, as is disclosed in EP 1 743 110 A1 (published as WO 2005 / 108 835 A1) in the Fig. 1, further geometric designs for this can be found in figure group 15 of DE 20 2015 103 420 U1.

[0066] In Fig. 3 and Fig. 5, the first valve 11 and the second valve 21 are arranged opposite each other in the wall of the housing 2. The valves are slightly offset from each other in the axial direction of the shaft 4. However, a non-offset or non-opposite arrangement is also possible.

[0067] Fig. 6 shows another oil separator 1 corresponding to the one in Fig. 2. This illustration clearly shows that the gas flowing through the second gas inlet flows into the oil separation chamber 7 essentially tangentially along the wall of the housing 2 and is thus directly entrained by the disk stack 3 or its surrounding gas flow. The tangential inflow amplifies the rotational movement of the gas flowing in via the second gas inlet 10, resulting in further improved oil separation from this portion of the gas flow as well. In the preceding embodiments, the gas inlets of the oil separators also have at least one tangential inlet portion with respect to the rotation of the housing 2.

[0068] Fig. Figure 7 now shows a comparison of the pressure loss as a function of the volume flow between the gas inlet and the gas outlet. The line marked with black dots shows the pressure loss of a conventional oil separator. As the volume flow increases, the pressure loss continues to rise. In other words, this means that at a predetermined available pressure difference between the outlet and inlet sides of the oil separator, the gas flow through the oil separator is limited.

[0069] The curve shown without closed points shows the pressure loss as a function of the volume flow for an oil separator according to the invention according to Fig.2. The arrangement of the additional second gas inlet, which is exposed as a bypass around the oil separation element, ensures that the pressure loss remains limited even with ever-increasing volume flow of the gas to be purified. In other words, with an available pressure difference between the outlet and inlet of the oil separator 1, even a high volume flow can be passed through the oil separator and at least thoroughly purified. In the present oil separator according to the present invention, a portion of the gas to be purified is always passed through the oil separation element 3 and is thereby largely completely purified of oil mist and oil droplets.However, the gas to be cleaned which is not passed through the oil separation element 3 is also accelerated in the oil separation chamber 7 and thus largely cleaned of oil mist and oil droplets, so that the gas flowing out of the oil separator 1 is largely cleaned as a whole, even in the case of high volume flows and / or a limited pressure difference available across the oil separator.

Claims

[1] Oil separator (1) for separating oil droplets and / or oil mist from gases to be cleaned, comprising a housing (2), a rotor having an oil separation element (3) arranged in the housing (2) and spaced from the housing (2) and a shaft (4) for rotatably supporting the oil separation element (3), a first gas inlet (5) for supplying the gases to be cleaned to the oil separation element (3) along the shaft (4) and a first gas outlet (6) in the wall of the housing (2) surrounding the rotor, characterized by , that a second gas inlet (10) for supplying the gases to be cleaned is arranged in the wall of the housing (2) surrounding the rotor. [2] Oil separator (1) according to the preceding claim, characterized byin that the second gas inlet (10) is closed by a first valve (11) which is prestressed for a predetermined opening characteristic or is actively controllable, in particular by means of a motor control or an actuator, for example a servomotor, an actuator or a pressure cell. [3] Oil separator (1) according to the preceding claim, characterized by that the first valve (11) opens the second gas inlet (10) when a predetermined volume flow through the first gas inlet (5) is exceeded and / or when a predetermined pressure difference between the gas on the pressure side of the first valve (11) and the suction side of the first valve (11) in the interior of the housing (2) is exceeded. [4] Oil separator (1) according to one of the preceding claims, characterized by that the first gas inlet (5) and the second gas inlet (10) are connected to a common gas supply line (5) outside or inside the housing (2). [5] Oil separator (1) according to one of the preceding claims, characterized by that the second gas inlet (10) is designed such that the gas flowing through flows into the housing (2) largely tangentially along the wall of the housing (2). [6] Oil separator (1) according to one of the preceding claims, characterized by a second gas outlet (20) in the wall of the housing (2) surrounding the rotor. [7] Oil separator (1) according to the preceding claim, characterized by in that the second gas outlet (20) is closed with a second valve (21) which is prestressed for a predetermined opening characteristic or is actively controllable, in particular by means of a motor control or an actuator, for example a servomotor, an actuator or a pressure cell. [8] Oil separator (1) according to one of the preceding claims, characterized byin that the first valve (11) and / or the second valve (21) each have a valve opening (13, 23), a valve seat (12, 22) and a valve closure (14, 24), wherein either the valve closure (14, 24) is designed as a movable spring tongue which covers the valve opening (13, 23) and is advantageously coated, at least in sections, with an elastomer (16), advantageously with a closed-pore elastomer, on the side facing the valve opening (13, 23), or the valve (11, 21) is designed as a mushroom valve with a valve shield made of elastomer material as the valve closure (14, 24). [9] Oil separator (1) according to one of claims 6 to 8, characterized by that the second inlet (10) and the second outlet (20) are arranged substantially on opposite sides of the oil separation element (3). [10] Oil separator (1) according to one of claims 6 to 8, characterized bythat the second inlet (10) and the second outlet (20) are arranged adjacent to one another or directly adjacent to one another substantially in the direction of rotation of the rotor and / or that the second inlet (10) and the second outlet (20) are arranged adjacent to one another or directly adjacent to one another substantially perpendicular to the direction of rotation of the rotor. [11] Oil separator (1) according to one of claims 6 to 10, characterized by that the second inlet (10) and the second outlet (20) are arranged at the same height or offset from one another when viewed parallel to the axis of the shaft (4). [12] Oil separator (1) according to one of the preceding claims, characterized by a drive element for driving the oil separation element of the rotor by means of the shaft (4). [13] Oil separator (1) according to the preceding claim, characterized by that the drive element is a hydraulically driven drive element, in particular a Heron turbine or a Pelton turbine. [14] Oil separator (1) according to claim 12, characterized by that the drive element is an electrically driven drive element.

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