CN108506066B

CN108506066B - Crankcase gas suction and decantation apparatus and associated device

Info

Publication number: CN108506066B
Application number: CN201810166004.5A
Authority: CN
Inventors: 帕斯卡·盖里; 阿德里安·厄斯塔什; 卢多维克·塞吕里耶
Original assignee: Axwell
Current assignee: Axwell
Priority date: 2017-02-28
Filing date: 2018-02-28
Publication date: 2021-06-04
Anticipated expiration: 2038-02-28
Also published as: CN108506066A; JP7128631B2; FR3063304B1; FR3063304A1; JP2018173077A

Abstract

The present invention discloses a crankcase gas suction and decantation plant and associated installation, the object of the invention being a crankcase gas suction and decantation plant (1) comprising at least combustion gases and motor oil, said suction and decantation plant (1) comprising: -a collecting cylinder (2) of crankcase gases comprising a cylinder inlet (2a) and a cylinder outlet (2b) shaped to convey crankcase gases, said cylinder inlet (2a) being arranged tangentially to said cylinder (2), -a first conical portion (3) comprising a first end (3a) and a second end (3b), said first end (3a) being arranged at the cylinder outlet (2b), said first conical portion (3) converging from its first end (3a) towards its second end (3b), characterized in that the suction and decantation apparatus (1) further comprises a second conical portion (6), the second conical portion (6) comprising a first end (6a) and a second end (6b), the first end (6a) of the second conical portion (6) being positioned opposite the second end (3b) of the first conical portion (3), the second conical portion (6) diverges from its first end (6a) to its second end (6 b).

Description

Crankcase gas suction and decantation apparatus and associated device

Technical Field

The present invention relates to the field of motor crankcase gas recovery and treatment systems having air introduction into the motor crankcase, also known as "positive crankcase ventilation" and which is also referred to by the acronym PCV. The invention is preferably applied to a vehicle equipped with such a crankcase gas recovery system having air introduced into the motor crankcase.

Background

In this application, the term "crankcase gas" refers to motor combustion gases that are mixed with small amounts of motor oil particles released from the motor pistons and cylinders. In operation, the combustion gases mix with the oil particles in the hermetically sealed lower motor. When too much crankcase gas is formed, the pressure of the lower motor will rise, which may cause operational problems, leakage, etc. of the motor, which may lead to motor failure. The term "lower motor" refers to the lower portion of the motor, typically including the crankshaft, connecting rods, pistons, oil crankcase. To avoid these dysfunctions, crankcase gas must be evacuated from the lower motor.

Since crankcase gas cannot be evacuated directly to the atmosphere due to its polluting nature and oil must be kept within the motor, the crankcase gas recovery system allows for suction (intake) of reinjection into the combustion chamber of the gas and recovery of the maximum amount of unused oil through the oil separator.

In some configurations of the gas recovery and treatment apparatus, external air is introduced into the lower motor to limit the presence of water that may mix with nitrogen oxides contained in the combustion gases and form droplets of nitric acid that may damage the motor oil to be recovered.

In order to introduce outside air into the lower motor, the lower motor must be depressurized to draw the crankcase gas mixture and bring it into the upper motor at the combustion chamber for processing. Conventionally, vacuum is performed using an air conduit connected downstream of the motor throttle body and by closing the throttle body. The suction created by the vacuum allows the crankcase gas to pass through a gravity operated oil separator to recover oil particles contained in the crankcase gas and carry the remaining crankcase gas into the combustion chamber.

However, in idle mode, the throttle body is nearly closed and the vacuum downstream of the throttle body is too high, thus requiring the positioning of one or more "PCV" valves to regulate this vacuum. In full power mode, the throttle body is open and there is not enough vacuum to draw air from the lower motor. Accordingly, some manufacturers use suction systems that include venturi effect devices. However, these devices are added within the gas recovery and treatment apparatus, and therefore they are somewhat bulky for the lower and upper motors.

Disclosure of Invention

The present invention aims to remedy all or part of the above-mentioned drawbacks and more particularly to allow an efficient treatment of crankcase gas without cluttering the lower or upper motor.

The object of the invention is a suction and decantation installation of crankcase gases comprising at least combustion gases and motor oil, comprising:

a first conical portion comprising a first end and a second end, said first end being arranged at the cylinder outlet, said first conical portion converging from its first end to its second end,

-a central duct shaped to guide air through the suction and decantation apparatus, the central duct being at least partially arranged inside the cylinder, the cylinder comprising an inner circumferential wall forming a passage with an outer circumferential wall of the central duct, said passage being configured to recover motor oil contained in the crankcase gas by centrifugation,

characterized in that the suction and decantation apparatus also includes a second conical portion including a first end and a second end, the first end of the second conical portion being positioned opposite the second end of the first conical portion, the second conical portion diverging from its first end to its second end, one end of the central conduit being positioned opposite the first end of the second conical portion.

Thanks to the suction and decantation apparatus of the invention, the suction through the venturi effect (which is through the combination of the first conical portion and the second conical portion) and the separation/decantation performed through the first conical portion of the apparatus are gathered in the same structural apparatus, which allows efficiency gains and space savings in the lower motor and/or the upper motor.

The suction and decantation apparatus according to the invention therefore allows, on the one hand, to separate the motor oil droplets present in the crankcase gas (such as a cyclone separator) thanks to the first conical portion and the cylinder, and on the other hand, to create, thanks to the combination of the first conical portion and the second conical portion, a venturi system which allows to introduce air into the lower motor of a device by creating a vacuum, and to improve the discharge capacity of the oil trapped in the channel, exploiting the suction force created by the venturi effect. This type of oil pumping is advantageous over conventional cyclones that use only gravity and the pressure drop of the fluid to create suction through holes located on the perimeter of the cyclone to pump oil upward.

According to one feature of the invention, the suction and decantation apparatus is configured to perform the suction of the decant oil from the crankcase gas by means of the combination of the first and second conical portions of said suction and decantation apparatus, without using the action of gravity. Indeed, thanks to the suction and decantation apparatus according to the invention, we no longer rely on gravity for the decantation but on the suction associated with the creation of the venturi effect by the first and second conical portions of the suction and decantation apparatus.

According to one characteristic of the invention, the suction and decantation apparatus includes a motor oil evacuation member cooperating directly or indirectly with said channel.

According to a feature of the invention, the evacuation member is depressurized by a venturi system formed by the first and second conical portions of the suction and decantation apparatus.

According to one feature of the invention, the motor oil evacuation member is a siphon.

According to one feature of the invention, the suction and decantation apparatus includes a first chamber connected to the motor oil evacuation member, said first chamber including at least one slot that opens into the passage. Advantageously, the first chamber allows the recovery of oil separated from the combustion gases within the channel.

According to one feature of the invention, the suction and decantation apparatus comprises a second chamber arranged between the second conical portion and the first chamber, said second chamber being provided with a slot substantially open at the first end of the second conical portion. Advantageously, this second chamber allows the vacuum within the first chamber to be maintained to allow oil to be drawn into the first chamber. More specifically, the second cavity is disposed adjacent to the second conical portion.

According to one feature of the invention, the central conduit includes an inlet, a converging conical section including an inlet end and an outlet end.

According to one characteristic of the invention, the conical portion of the conduit opens into the second conical portion of the suction and decantation apparatus.

According to a feature of the invention, the outlet end of the conical portion of the central duct is located opposite the first end of the second conical portion of the suction and decantation apparatus.

According to a feature of the invention, the second end of the first conical portion is coaxial with the outlet end 4c of the conical portion of the central duct.

According to a feature of the invention, the second end of the first conical portion opens into the second conical portion of the suction and decantation apparatus and/or the second end of the first conical portion is located opposite the second conical portion of the suction and decantation apparatus.

According to a feature of the invention, the parts constituting the suction and decantation apparatus can be assembled by welding and clamping.

The object of the invention is also a gas recovery and treatment device comprising at least:

-a combustion motor comprising a lower motor, an upper motor, at least one chimney configured to direct crankcase gas from the lower motor to the upper motor,

-a compressor for compressing the refrigerant,

characterized in that the apparatus further comprises a crankcase gas suction and decantation device according to the invention, said device being arranged in the upper motor downstream of the compressor.

According to one feature of the invention, the apparatus is arranged horizontally with respect to the motor.

According to one feature of the invention, the central duct is configured to bring air from downstream of the compressor into the suction and decantation apparatus.

According to one feature of the invention, the second end of the second conical portion of the suction and decantation apparatus is connected to a first conduit configured to direct the treated gas coming from the suction and decantation apparatus towards the upstream of the compressor.

According to one feature of the invention, the device comprises a second external air duct connecting the upstream of the compressor to the lower motor.

Advantageously, the second conduit may be equipped with a check valve which allows to prevent crankcase gas from being transferred through the suction line without being decanted during some motor operating phases when the motor generates a large amount of crankcase gas at low compressor rotational speeds.

Alternatively, the second external gas conduit connects upstream of the compressor to the upper motor.

Alternatively, the second external air conduit connects upstream of the compressor to the suction and decantation installation of crankcase gases according to the invention, which opens into the suction and decantation installation through an air inlet tangential to the cylinder of the latter. Preferably, the air inlet of the external air conduit is positioned opposite the cylinder inlet of the suction and decantation apparatus through which the crankcase gas enters the suction and decantation apparatus. Alternatively, the air inlet from the external air conduit is positioned offset with respect to the cylinder inlet of the suction and decantation apparatus through which the crankcase gas enters the suction and decantation apparatus.

Drawings

The invention will be better understood in view of the following description, which relates to an embodiment according to the invention, given as a non-limiting example and explained with reference to the schematic drawing in which:

figure 1 is a perspective view of the suction and decantation apparatus according to the invention and according to the first embodiment, without the oil emptying member of said suction and decantation apparatus,

figure 2 is another perspective view from the side of the suction and decant apparatus shown in figure 1, showing the oil evacuation members of said suction and decant apparatus,

figure 3 is a longitudinal cross-section of the suction and decantation apparatus shown in figure 1,

figure 4 shows the different flows of air, oil and crankcase gas through the suction and decantation apparatus according to the invention,

figure 5 is a detailed view of figure 4,

figure 6 shows the different pressures at the suction and decantation equipment,

figure 7 is an exploded view of the suction and decantation apparatus according to the invention and a variant, without the oil emptying member of said suction and decantation apparatus,

figure 8 is a perspective view of the suction and decantation apparatus according to the invention according to the variant shown in figure 7,

figure 9 is a cross-sectional view of the suction and decantation apparatus according to the invention according to the variant shown in figure 7,

figure 10 is a diagram according to a first configuration of a gas recovery and treatment plant according to the invention, equipped with a suction and decantation apparatus according to a first or second embodiment of the invention,

figure 11 is an illustration of a second configuration of a gas recovery and treatment plant according to the invention, equipped with a suction and decantation apparatus according to the first embodiment or the variant shown in figures 7 to 10,

figure 12 is a diagram of a third configuration of a gas recovery and treatment plant according to the invention, equipped with a suction and decantation apparatus according to a second embodiment,

figure 13 is a perspective view of the suction and decantation apparatus according to the invention according to the second embodiment.

Detailed Description

The following description is given of the common elements attached to all the embodiments of the suction and decantation apparatus 1 according to the invention.

As illustrated in fig. 1 to 9 and 13, the crankcase gas pumping and decanting apparatus 1 according to the invention comprises a collecting cylinder 2 of crankcase gas, which collecting cylinder 2 has a cylinder inlet 2a and a cylinder outlet 2b, said cylinder inlet 2a being shaped to tangentially convey crankcase gas, said cylinder inlet 2a being arranged tangentially to said cylinder 2.

Furthermore, the suction and decant apparatus 1 comprises a first conical portion 3, this first conical portion 3 comprising a first end 3a and a second end 3b arranged at the cylinder outlet 2 b. As clearly shown in fig. 3 and 9, the first conical portion 3 converges from its first end 3a towards its second end 3 b.

As shown in figures 3 and 9 and in figures 1, 2, 4 to 8 and 13, the suction and decantation apparatus 1 comprises a central duct 4, this central duct 4 being shaped so as to direct the air through the suction and decantation apparatus 1. As shown in fig. 3 and 9, the central conduit 4 is at least partially arranged within the cylinder 2. The cylinder 2 comprises an inner circumferential wall 2c, which inner circumferential wall 2c forms with the outer circumferential wall of the central duct 4a channel 5, which channel 5 is configured to recover motor oil contained in the crankcase gas by centrifugation. The central duct 4 comprises an inlet 4a and a converging conical portion comprising an inlet end 4b and an outlet end 4 c. Advantageously, the conical portion of the conduit 4 leads to a second conical portion 6 of the suction and decantation apparatus 1. More specifically, the outlet end 4c of the conical portion of the central conduit 4 is located opposite the first end 6a of the second conical portion 6 of the suction and decant apparatus 1. The second end 3b of the first conical portion 3 is coaxial with the outlet end 4c of the conical portion of the central duct 4. Furthermore, the second end 3b of the first conical portion 3 opens into the second conical portion 6 of the suction and decantation apparatus 1 and/or the second end 3b of the first conical portion 3 is located opposite the second conical portion 6 of the suction and decantation apparatus 1.

As illustrated in figures 1 to 9, 13, the suction and decantation apparatus 1 also comprises a second conical portion 6, this second conical portion 6 comprising a first end 6a and a second end 6b, said first end 6a being positioned opposite the second end 3b of the first conical portion 3. The second conical portion 6 diverges from its first end 6a towards its second end 6 b.

In figures 3 and 9, the suction and decant apparatus 1 is shown to comprise a first chamber 7, this first chamber 7 comprising at least one slot 7a leading to the passage 5. Furthermore, the suction and decantation apparatus 1 comprises a second chamber 8, this second chamber 8 being arranged between the second conical portion 6 and the first chamber 7, said second chamber 8 being equipped with a slot 8a substantially guided at the first end 6a of the second conical portion 6.

As illustrated in fig. 2 and 13, the suction and decant apparatus 1 comprises a motor oil evacuation member 9, the motor oil evacuation member 9 being fluidly connected to at least the first chamber 7.

Thus, according to the invention, crankcase gas enters through the cylinder inlet 2a, this gas is centrifuged and oil droplets are smeared on the inner circumferential wall 2c of the cylinder 2. An oil film is formed on the inner circumferential wall 2c and sucked into the first chamber 7 via the slit 7 a. Oil is recovered from the first chamber 7 and emptied through the emptying member 9. According to the embodiment shown in the figures, the oil is drawn directly into the cylinder 2 and all around its periphery.

Figures 1 to 3 show a first embodiment of the suction and decant apparatus 1. Figures 7 to 9 show a variant of the suction and decant apparatus 1. This variant differs from the first embodiment in the number of parts constituting the suction and decantation apparatus 1. In fact, as shown in figure 7, the suction and decantation apparatus 1 according to this variant consists of only four parts and one emptying member, not shown. The first part corresponds substantially to the second conical portion 6 of the suction and decant apparatus 1, the second part corresponds substantially to the first conical portion 3, the third part corresponds substantially to the cylinder 2 and the fourth part corresponds substantially to the central duct 4. However, the suction and decant apparatus 1 according to the first embodiment has more parts, fulfilling the same function as the four parts of the variant of the first embodiment. For example, the cylinder 2 is formed of at least two parts, one part forming a part of the passage 5 and the inlet of the cylinder 2a, and the other protruding part extending the passage 5 to the first conical portion 3. Of course, the suction and decantation apparatus according to the present invention can be realized in less than four assembled parts.

Regardless of the embodiment, the parts constituting the suction and decant apparatus 1 can be assembled by welding or clamping. Advantageously, the second and third parts corresponding to the first conical portion 3 and the cylinder 2, respectively, may be integrated into a part of the cylinder head cover according to the architecture of the vehicle.

Fig. 4 and 5 illustrate the flow through the device in detail. More specifically, a crankcase gas flow, indicated by arrows G/H containing oil particles, enters the apparatus 1 through the inlet 2a and is then treated in the cylinder 2 of the apparatus, so that the crankcase gas G/H is separated from the oil H by centrifugal action and thereby becomes treated gas G. The oil H of the crankcase gas is placed over the wall of the passage 5 in a fine stream of oil and is sucked into the first chamber 7 via the slot 7a, as illustrated in fig. 5. The treated gas G is mixed with the air flow F downstream from the compressor 101 through the conduit 4 at the venturi of the apparatus, which corresponds to the second conical portion 6 of the apparatus 1. The mixture of treated gas and air flow, represented by the double arrow F/G, leaves the apparatus through its outlet 6a to be directed upstream of the compressor 101 through the conduit 103.

Fig. 6 shows in detail the different pressure levels inside the device, which allows for an explanation: the separation of oil H and gas G inside the cyclone part of suction and decantation apparatus 1 and the suction of the treated gas G inside the second conical part 6 of suction and decantation apparatus 1 and the suction of oil H inside the oil recovery chamber 7 by venturi effect. Therefore, the oil film smeared on the peripheral wall 2c of the cylinder 2 is driven into the slot 7a due to the pressure difference between the pressure P9 of the

chambers

7 and 8 and the pressure P8 of the passage 5 of the cylinder 2, the pressure P9 being lower than the pressure P8. Furthermore, the tangential inlet 2a of the cylinder 2 has a pressure P2 and has a pressure P4 at the outlet 3b of the first conical portion 3 and at the inlet 6a of the second conical portion 6. By comparing the different pressures inside the suction and decant apparatus 1, we obtain P2> P8> P9> P4.

The invention also relates to a device 100 of a gas recovery and treatment device, shown in detail in fig. 10 to 12.

Regardless of the configuration of the apparatus 100 illustrated in fig. 10-12, the apparatus 100 includes at least one combustion motor 102 and a compressor 101, the combustion motor 102 having a lower motor 102a, an upper motor 102b, at least one chimney 102c, the at least one chimney 102c configured to direct crankcase gases from the lower motor 102a to the upper motor 102 b. Furthermore, according to the invention, the apparatus 100 comprises a suction and decantation installation 1 of crankcase gas in the upper motor arranged downstream of the compressor. More specifically, and as shown in the figures, the suction and decant apparatus 1 is positioned horizontally with respect to the motor 102. Furthermore, central conduit 4 is configured to convey air from downstream of compressor 101 into suction and decant apparatus 1, as shown in figures 10 to 12. Furthermore, second end 6b of second conical portion 6 of suction and decant apparatus 1 is connected to a first conduit 103, this first conduit 103 being configured to direct the treated gas coming from suction and decant apparatus 1 towards the upstream of compressor 101.

Fig. 10 illustrates an apparatus according to the invention in a first configuration. In this first configuration, suction and decant apparatus 1 is supplied by an air flow F coming from downstream of compressor 101 through conduit 4 and returning to upstream of compressor 101 via conduit 103. Crankcase gas G/H contained in the lower motor 102a is generated by leakage from the combustion chamber 102d of the motor and is charged with oil droplets H to form an aerosol. The crankcase gas G/H is evacuated to the upper motor 102b through a stack 102 c. The crankcase gas G/H enters the apparatus 1 through the cylinder inlet 2a of the suction and decant apparatus 1. The oil flows out of suction and decantation apparatus 1 through an emptying member 9, here a siphon. In the first configuration, apparatus 100 comprises a second external air F 'conduit 104 connecting upstream of compressor 101 to lower motor 102a, this second external air F' conduit 104 allowing the operation of suction and venturi suction of decant apparatus 1. Advantageously, the second conduit 104 may be equipped with a check valve 105. In the apparatus of the first configuration, the pressure upstream of compressor 101 is pressure P1, the pressure downstream of compressor 101 is pressure P3, the pressure inside upper motor 102a is pressure P2, the pressure at lower motor 102b is pressure P6, and the pressure downstream of suction and decant apparatus 1 at conduit 103 is pressure P5. By comparing the different pressures in the apparatus according to the first configuration with the different pressures in the suction and decantation apparatus 1, we have P3> P1> P6> P2 ≈ P5> P4.

Fig. 11 illustrates an apparatus according to the invention in a second configuration. This second configuration differs from the first configuration in that a second external air F' conduit 104 connects the upstream of the compressor 101 to the upper motor 102 b. Thus, by bringing outside air to the top of the motor 102b, we are closer to the intake of air from upstream of the second conical section 6. The pressure drop between these two zones is generated only by the cyclones of the suction and decantation apparatus 1, whereas in the first configuration (figure 10) of the air arriving at the lower motor 102a, the air suction and the pressure drop between the venturi tubes formed by the two conical parts of the suction and decantation apparatus 1 comprise the pressure drops of the cyclones and of the gas-lifting apparatuses of the suction and decantation apparatus 1. Advantageously, second conduit 104 may be equipped with a check valve 105, or, as illustrated in fig. 11, may be devoid of a check valve by reducing the pressure drop by no longer passing through the chimney and by dimensioning the cyclones of suction and decantation apparatus 1 so that their pressure drop is always lower than the vacuum created by the venturi of suction and decantation apparatus 1. In the apparatus in the second configuration, the pressure upstream of compressor 101 is pressure P1, the pressure downstream of compressor 101 is pressure P3, the pressure inside upper motor 102a is pressure P2, and the pressure downstream of suction and decant apparatus 1 at conduit 103 is pressure P5. By comparing the different pressures in the apparatus according to the first configuration with the different pressures in the suction and decantation apparatus 1, we obtain P3> P1> P2 ≈ P5> P4.

Fig. 12 illustrates an apparatus according to the invention according to a third configuration. This third configuration differs from the first configuration in that a second external air conduit 104 connects the upstream of the compressor 101 to the suction and decantation apparatus 1, the second conduit 104 leading to the suction and decantation apparatus 1 through an air inlet 104a tangential to the cylinder 2 of the suction and decantation apparatus 1, as illustrated in figure 13. Preferably, the air inlet 104a of the second external air conduit 104a is positioned opposite the cylinder inlet 2a of the suction and decant apparatus 1, through which cylinder inlet 2a crankcase gas enters the suction and decant apparatus 1. In the apparatus according to the third configuration, the pressure upstream of compressor 101 is pressure P1, the pressure downstream of compressor 101 is pressure P3, the pressure inside upper motor 102a is pressure P2, the pressure at the external air inlet F' in suction and decantation apparatus 1 is pressure P7 and the pressure downstream of suction and decantation apparatus 1 at conduit 1031 is pressure P5. By comparing the different pressures in the apparatus according to the first configuration with the different pressures in the suction and decantation apparatus 1, we have P3> P1> P7 ≈ P2 ≈ P5> P4.

Of course, the invention is not limited to the embodiments described and shown in the drawings. Modifications are still possible, in particular from the point of view of the construction of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims

1. A suction and decantation installation (1) of crankcase gases comprising at least combustion gases and motor oil, said suction and decantation installation (1) comprising:

-a collecting cylinder (2) of crankcase gas comprising a cylinder inlet (2a) and a cylinder outlet (2b) shaped to convey crankcase gas, the cylinder inlet (2a) being arranged tangentially to the cylinder (2),

-a first conical portion (3) comprising a first end (3a) and a second end (3b), said first end (3a) being arranged at the cylinder outlet (2b), said first conical portion (3) converging from its first end (3a) to its second end (3b),

-a central duct (4) shaped to guide air through the suction and decantation apparatus (1), the central duct (4) being at least partially arranged inside the cylinder (2), the cylinder (2) comprising an inner circumferential wall (2c), the inner circumferential wall (2c) forming a channel (5) with an outer circumferential wall (4a) of the central duct (4), said channel (5) being configured to recover, by centrifugation, motor oil contained in the crankcase gas,

characterized in that the suction and decantation apparatus (1) also comprises a second conical portion (6), the second conical portion (6) comprising a first end (6a) and a second end (6b), the first end (6a) of the second conical portion (6) being positioned opposite the second end (3b) of the first conical portion (3), the second conical portion (6) diverging from its first end (6a) to its second end (6b), the end (4 c) of the central duct (4) being positioned opposite the first end (6a) of the second conical portion (6).

2. The suction and decantation apparatus according to claim 1, comprising a motor oil evacuation member (9) cooperating with said channel (5).

3. A suction and decantation apparatus according to claim 2, comprising a first chamber (7) connected to the motor oil evacuation member (9), said first chamber (7) having at least one slot (7a) opening into the channel (5).

4. A suction and decantation apparatus according to claim 3, comprising a second chamber (8) arranged between the second conical portion (6) and the first chamber (7), said second chamber (8) being provided with a slot (8a) substantially open at the first end (6a) of the second conical portion (6).

5. The suction and decantation apparatus according to any of claims 1 to 4, configured to perform the suction of the decant oil from the crankcase gas by means of the combination of the first conical portion (3) and the second conical portion (6) of the suction and decantation apparatus (1), without the aid of the action of gravity.

6. A gas recovery and treatment apparatus (100) comprising at least:

-a combustion motor (102) having a lower motor (102a), an upper motor (102b), at least one chimney (102c) configured to conduct crankcase gas from the lower motor (102a) to the upper motor (102b),

-a compressor (101),

characterized in that the apparatus (100) further comprises a suction and decantation installation (1) of crankcase gas according to any of the previous claims, said suction and decantation installation (1) being arranged inside the upper motor (102b) downstream of the compressor (101).

7. Apparatus according to claim 6, wherein the suction and decantation device (1) is arranged horizontally with respect to the motor (102).

8. The apparatus according to any of claims 6 or 7, wherein the second end (6b) of the second conical portion (6) of the suction and decantation device (1) is connected to a first conduit (103), the first conduit (103) being configured to direct the treated gas coming from the suction and decantation device (1) upstream of the compressor (101).

9. The device according to any one of claims 6 to 8, comprising a second external air duct (104) connecting the compressor (101) upstream to the lower motor (102 a).

10. The device according to any one of claims 6 to 8, comprising a second external air duct (104) connecting the upstream of the compressor (101) to the upper motor (102 b).

11. Apparatus according to any one of claims 6 to 8, comprising a second external air duct (104) connecting the compressor (101) upstream to the suction and decantation device (1), the second external air duct (104) opening into the suction and decantation device (1) through an air inlet (104a) tangential to the air cylinder (2) of the suction and decantation device (1).