WO2012069357A1

WO2012069357A1 - Rotary internal combustion engine

Info

Publication number: WO2012069357A1
Application number: PCT/EP2011/070362
Authority: WO
Inventors: Michael Steinbauer; Andreas Krobath; Johannes Rieger; Christof Knollmayr; Roland Santner; Kurt Salzgeber
Original assignee: Avl List Gmbh
Priority date: 2010-11-25
Filing date: 2011-11-17
Publication date: 2012-05-31
Also published as: AT510166A4; AT510166B1

Abstract

The invention relates to a rotary internal combustion engine (1) comprising at least one rotor (4) which rotates inside the chamber (3) of a housing (2), said chamber (3) being defined by a trochoidal running surface (5) in a central housing part (2a) and by interspaced lateral running surfaces (6, 7) that are arranged at a right angle to an eccentric shaft (10). An inner housing chamber (15) formed in the region of the eccentric shaft (10) is in fluid connection with a vent channel (18) and a vent chamber (17) is arranged between the inner housing chamber (15) and the vent channel (18) and preferably forms a preliminary oil separator. The vent chamber (17) is arranged in a lateral first housing part (2b) that is directly or indirectly contiguous to the central housing part (2a) in the direction of the axis (10a) of the eccentric shaft (10). The aim of the invention is to devise a compact rotary internal combustion engine which allows an efficient discharge of blow by gases and high oil separation rates. To this end, the vent chamber (17) has at least one separation wall (20) and/or at least one separation wall (33) that is preferably arranged at a right angle to a main direction of flow (S) in the vent chamber (17).

Description

Rotary piston engine

The invention relates to a rotary piston internal combustion engine having at least one circulating in a chamber of a housing rotary piston, wherein the chamber is formed by a trochoidenförmigen running surface in a central housing part and spaced from each other, arranged normal to an eccentric shaft side treads, and wherein a trained in the eccentric shaft inner housing space is fluidly connected to a vent channel, wherein between the inner housing space and the venting channel preferably a pre-separator forming deaerating space is arranged, wherein the vent space is arranged in an adjacent to the central housing part in the direction of the axis of the eccentric shaft directly or indirectly subsequent lateral first housing part.

Due to the gas pressures in the working chambers, blow-by gases pass via lateral sealing strips of the rotary piston into the piston interspaces defined by the lateral running surfaces and the rotary piston and via oil separation rings into an inner housing space surrounding the eccentric shaft. From the publications DE 2 333 613 A, DE 1 451 809 A, DE 1 299 645 B it is known to connect this inner housing space via a check valve, an air duct and an air filter with the atmosphere. The check valve is dimensioned such that it establishes a connection between the inner housing space and the atmosphere when the pressure in the inner housing space is above a certain level.

JP 62-197615 A describes a rotary piston internal combustion engine with a first and a second blow-by line, wherein the first blow-by line opens upstream of the compressor part and the second blow-by line downstream of the compressor part of an exhaust gas turbocharger in the inlet line. This should make it possible to reduce the blow-by quantities.

Another blow-by gas arrangement for rotary piston internal combustion engines is known from JP 2-056808 Ul.

Known devices have the disadvantage that blow-by gas lines and oil pre-separation devices are arranged at least predominantly outside the housing of the internal combustion engine, whereby the space of the internal combustion engine is increased.

DE 23 44 198 AI discloses a rotary piston internal combustion engine with a circulating in a chamber of a housing rotary piston, wherein the Kam- mer of a trochoidenförmigen running surface in a central housing part and spaced apart, arranged normal to an eccentric shaft side treads is formed. An inner housing space formed in a region of the eccentric shaft is flow-connected to a venting channel. Between the inner housing space and the vent channel a vent space is arranged, wherein the vent space is arranged in a subsequent to the central housing part in the direction of the axis of the eccentric shaft side housing part.

The object of the invention is to achieve in a rotary piston internal combustion engine of the type mentioned a ventilation of the inner housing space at high oil separation rates and extremely compact design.

According to the invention, this is achieved in that the venting space has at least one partition wall and / or at least one separation wall, preferably arranged transversely to a main flow direction in the venting space.

In a particularly advantageous embodiment, it is provided that the vent space is divided by at least two successively between the inner housing space and the vent passage labyrinth or meander-like flowed through vent chambers, wherein in the flow path between the two vent chambers, a calming chamber may be formed, preferably the calming chamber is disposed at the lowest operating point of the venting space. It can emanate from the lowest point of the venting chamber, preferably from the settling chamber an oil return passage. The two labyrinth-like bleeding chambers and the settling chamber act as pre-separator for the oil entrained by the blow-by flow. The vent space is preferably arranged in the region of a bearing of the eccentric shaft intersecting normal plane of the eccentric shaft. This makes it possible to carry out the oil pre-separation already within the housing without adversely affecting the axial length of the rotary piston internal combustion engine.

As viewed around the axis of the eccentric shaft, rotary piston internal combustion engines have a cold angular segment region of the housing in the inlet region and a hot angular segment region of the housing in the combustion and exhaust region. Preferably, the venting chamber is arranged in a cold angular segment region of the rotary piston internal combustion engine, it being particularly advantageous if the venting chamber - viewed in a section transverse to the axis of the eccentric shaft - has substantially the shape of a circular segment, which preferably extends over an angular range between about 120 ° and 210 °, preferably between 130 ° and 180 °, about the axis of the eccentric shaft extends.

The quantities of oil transported with the blow-by gases can be kept very low if the venting channel starts from the highest point of the venting area in operation, wherein preferably the venting chamber is flow-connected to the inner housing space via at least one overflow channel. The venting space is advantageously flow-connected to the inner housing space via at least one first overflow channel of the housing, the first overflow channel preferably being arranged in the region of a bearing of the eccentric shaft. It can be provided that the first overflow channel and the vent channel are arranged in a preferably vertical plane parallel to the axis of the eccentric shaft.

In order to achieve as complete as possible an oil separation from the blow-by gases, it may further be provided that an oil separator adjoins the ventilation channel, whereby preferably an oil return channel discharges into the deaeration chamber, particularly preferably into the settling chamber, from the oil separator , The separated oil can either be fed via channels cast with the housing via the settling chamber and the oil return channel of the oil sump or via a separate oil channel directly to the oil sump.

In a further embodiment of the invention it can be provided that the vent space is connected via a second overflow channel with at least one limited by the rotary piston and at least one lateral tread piston gap, wherein the second overflow between the piston gap and the vent space can be formed increasing. It is particularly advantageous if the second overflow channel has a defined flow cross section which is preferably formed by a throttle or diaphragm. Due to the defined smallest flow cross-section in the second overflow channel, the pressure gradient between the working space, the piston gap and the inner housing space can be preset exactly. In this way, oil consumption and blow-by gas quantities can be kept at extremely low levels.

To the length of the rotary piston internal combustion engine can be kept as small as possible, if only on one side of the rotary piston integrated a vent space in the housing. In order to quickly derive blow-by gases from the piston gap on the side facing away from the vent space of the rotary piston, it is particularly advantageous if the rotary piston at least one having two end faces of the piston flow connecting connection opening.

With regard to the smallest possible amount of blow-by gas and oil consumption, it is advantageous if the second overflow channel starts from a region of the lateral first tread, which by the largest diameter of a surface swept by a Olabstreifring and the smallest diameter of one of a frontal sealing strip the circular piston swept area is limited. For weight, cost and skill reasons, it may be advantageous to use side plates made of material different from the other housing parts between the central and the lateral housing parts. The side plate which adjoins the lateral first housing part can form a section of the second overflow channel which extends from the piston gap.

The - preferably protruding from a housing wall of the housing - partition walls can be arranged radially to the eccentric shaft. In order to allow easy drainage of the accumulating at the separation walls oil, it is advantageous if the separation walls are arranged inclined to a horizontal plane. The separation walls can also be formed by reinforcing ribs in the housing or by Schraubenbutzen. The separation walls can be arranged offset on both sides of the main flow, as seen in the direction of the main flow in the venting space, so that a meandering flow profile is achieved.

In a particularly preferred embodiment of the invention it is provided that the vent space is fluidly connected to an oil pan space, wherein preferably the vent space is designed to be open to the oil pan space. Due to the construction open to the oil sump space, the sump chamber can be used as a calming and oil separation space.

The invention will be explained in more detail below with reference to FIGS. Show it :

1 shows a rotary piston internal combustion engine according to the invention in a first embodiment in a section along the line I - I in Fig. 2.

Fig. 2, this rotary piston internal combustion engine in a cut according to the

Line II - II in Fig. 1;

3 shows a rotary piston internal combustion engine according to the invention in a second embodiment in a longitudinal section. and 4 shows a rotary piston internal combustion engine according to the invention in a third embodiment in a cross section through a lateral first housing part with a view in the direction of the central housing part.

The rotary piston internal combustion engine 1 shown in FIGS. 1 to 4 each have a housing 2 with a chamber 3, in which a rotary piston 4 is arranged circumferentially along a trochoidal running surface 5 of the housing 2. The chamber 3 is formed by the trochoidenförmige career 5 and by lateral treads 6, 7. The housing 2 has a trochoidal tread 5 forming the central housing part 2a, a lateral first housing part 2b and a lateral second housing part 2c. Furthermore, the housing 2 between the central housing part 2a and the lateral first housing part 2b and / or the lateral second housing part 2c may have a lateral side plate 8, 9 forming the lateral tread 6, 7, respectively.

In the first and second housing part 2b, 2c, an eccentric shaft 10, which is arranged in an inner housing space 15 and is driven by the rotary piston 4, is rotatably supported by bearings 11, 12, which are designed, for example, as roller bearings. Shaft equal to the eccentric shaft 10 of the rotor 13 is arranged in the same housing 2, for example, permanent magnet excited electric machine 14 is arranged.

The first housing part 2 b has a ventilation space 17 connected to the inner housing space 15 via a first overflow channel 16 and functioning as an oil pre-separator, which is flow-connected via a venting channel 18 to an oil separator 19 and further to the inlet system of the rotary piston internal combustion engine 1. As shown in Fig. 2, the venting chamber 17 has a substantially kreisringsegment- shaped shape, wherein the circular ring segment extends in the exemplary embodiment over an angular range α of about 140 ° to 170 ° about the axis 10a of the eccentric shaft 10. From the operationally lowest point of the venting chamber 17 is a to an oil sump not shown leading oil return channel 32 goes out. The relatively large volume venting space 17 causes a reduction in the flow velocity and thus favors the oil pre-separation.

The first overflow channel 16 opens into a region adjoining the bearing 11 between the bearing 11 and the venting channel 18 arranged at the highest point of the venting chamber 17. In the embodiment shown in FIGS. 1 and 2, the venting space 17 is divided by a partition wall 20 into a first venting chamber 21 and a second venting chamber 22, between the first and second venting chambers 21, 22 a calming chamber 23 at the lowest Location of the venting chamber 17 is arranged. The partition wall 20 may be cast with the first lateral housing part 2b or formed by a separate, for example, screwed-in plate. The blow-by gases entering through the first overflow channel 16 from the inner housing space 15 into the venting space 17 are deflected by the partition wall 20 and flow from the first venting chamber 21 into the settling chamber 23 and from there via the second venting chamber 22 via the venting channel 18 the oil separator 19.

In the embodiment shown in FIG. 3, a second overflow channel 30 is provided for the entry of the blow-by gases into the venting chamber 17 in addition to the first overflow channel 16, wherein the second overflow channel 30 of a through the rotary piston 4 and the first lateral tread. 6 limited first piston gap 24 goes out. In the exemplary embodiment, the second overflow channel 30 is partially provided in the first lateral housing part 2b and partially in the first side plate 8 arranged between the first lateral housing part 2b and the central housing part 2a. The second overflow channel 30 starts from a region of the first lateral raceway 6 which is delimited by the outer diameter of the surface covered by the outer oil scraper ring 25 and an inner diameter of a surface swept by the frontal sealing strips 26. By precise definition of the narrowest cross section in the second overflow channel 17, for example by a throttle or orifice, the pressure gradient between the working chamber 29 - which is bounded by the central housing part 2a and the rotary piston 4 and the side treads 6, 7 - and the piston gap 24th on the one hand, as well as the pressure gradient between the piston clearance 24 and the inner housing space 15 on the other hand can be preset exactly. The second overflow channel 30 is further formed rising at least between the first side plate 8 and the entry into the venting chamber 17, so that the second overflow opens at an acute angle into the venting space 17. As a result, the outflow of blow-by gases from the piston clearance 24 can be improved.

Characterized in that only one side of the rotary piston 4 in the housing 2, a venting chamber 17 is arranged, the axial length of the rotary piston internal combustion engine 1 can be kept very short. To blow-by gases also from the limited by the rotary piston 4 and the second side plate 9 second Kol Beween space 27 to carry away quickly with the least possible design effort, the two piston spaces 24, 27 are fluidly connected to each other through a connection opening 28 in the rotary piston 4.

The blow-by gas flows according to the arrows in Fig. 3 from the working chamber 29 to the side sealing strips 26 over into the piston interspaces 24, 27. A portion of the blow-by gas passes through the second overflow 30 into the venting space 17. Das remaining blow-by gas flows between the oil control rings 25 and the side plates 8, 9 over into the inner housing space 15 and passes through the first overflow 16 into the vent space 17. From the vent space 17, the blow-by gas flows into the oil separator 19 and is guided via further lines 31 to the inlet system not shown.

FIG. 4 shows a further embodiment variant of a rotary piston internal combustion engine 1. In the lateral first housing part 2b of the rotary piston internal combustion engine 1, a venting space 17 is also formed here, wherein at least one overflow duct 16 opens into the venting space 17. Furthermore, the venting space communicates with passages 36 with the storage space 37 of bearings, not further apparent in FIG. 4, for the eccentric shaft. The venting chamber 17 extends over an angular range α of about 180 ° about the axis 10a of the eccentric shaft, which can not be further seen. As in the embodiment variants already described, the venting space 17 is connected at its highest point via a venting channel 18 to an oil separator 19, from which an oil return line 34 leads to the oil pan space 35. The venting chamber 17 is designed to be open downwards to the oil pan space 35 so that blow-by gases entering from the overflow channel 16 and oil flowing out of the storage space 37 can flow unhindered into the oil pan space 35. Thus, the oil sump space 35 - together with the calming chamber 23 at the lowest point of the venting space 17 - can also be used as a calming room for calming the blow-by gas flow. The venting space 17 has a number of separation walls 33, which may be formed by screw or housing ribs. In particular, in the subsequent to the settling chamber 23 vertical part of the venting chamber 17 of the housing walls 2 'projecting Abscheidewände 33 are inclined to a horizontal plane ε arranged to facilitate unimpeded flow of separated oil. The separation walls 33 arranged on both sides of the main flow S are arranged offset relative to one another. The resulting turbulences have a beneficial effect on the separation of oil.

The described venting arrangement allows a very compact construction of the rotary internal combustion engine 1, wherein high oil separation rates can be achieved with the lowest possible blow-by gas quantities.

Claims

PATENT APPLICATIONS

1. A rotary piston internal combustion engine (1) with at least one in a chamber (3) of a housing (2) circulating rotary piston (4), wherein the chamber (3) of a trochoidenförmigen running surface (5) in a central housing part (2a) and from each other , an inner housing space (15) formed in the region of the eccentric shaft (10) is flow-connected to a venting channel (18), wherein between the inner housing space ( 15) and the venting channel (18), preferably a Ölvorabscheider ausbildender, venting chamber (17) is arranged, wherein the venting space (17) in a to the central housing part (2a) in the direction of the axis (10a) of the eccentric shaft (10) directly or indirectly adjoining lateral first housing part (2b), characterized in that the venting space (17) has at least one partition (20) and / or at least one - before Preferably, transverse to a main flow direction (S) in the vent space (17) arranged - Abscheide- wall (33).

2. rotary piston internal combustion engine (1) according to claim 1, characterized in that the vent space (17) through at least one partition (20) in at least two successively between the inner housing space (15) and the vent channel (18) labyrinth or meander-like flowed through vent chambers ( 21, 22), wherein preferably in the flow path between the two venting chambers (21, 22) a settling chamber (23) is formed, and wherein particularly preferably the settling chamber (23) is arranged in a operationally deepest region of the venting space (17).

3. rotary piston internal combustion engine (1) according to claim 1 or 2, characterized in that from a lowest point of the venting chamber (17), preferably from the settling chamber (23), at least one oil return passage (32) goes out.

4. rotary piston internal combustion engine (1) according to one of claims 1 to 3, characterized in that the vent space (17) - viewed in a section transverse to the axis (10 a) of the eccentric shaft (10) - has substantially the shape of a circular segment, which is preferably over an angular range (a) between about 120 ° and 210 °, more preferably between 130 ° and 180 °, about the axis (10a) of the eccentric shaft (10).

5. rotary piston internal combustion engine (1) according to one of claims 1 to 4, characterized in that the venting chamber (17) is arranged in a cool angular segment region of the housing (2).

6. rotary piston internal combustion engine (1) according to one of claims 1 to 4, characterized in that the venting channel (18) emanates from the operationally highest point of the venting space (17).

7. rotary piston internal combustion engine (1) according to one of claims 1 to 6, characterized in that the venting space (17) in the region of a through a bearing (11) of the eccentric shaft (10) extending normal plane (ε) on the eccentric shaft (10) is arranged ,

8. rotary piston internal combustion engine (1) according to one of claims 1 to 7, characterized in that the vent space (17) via at least a first overflow channel (16) of the housing (2) with the inner housing space (15) is fluidly connected, wherein preferably the first Overflow channel (16) in the region of a bearing (11) of the eccentric shaft (10) is arranged.

9. rotary piston internal combustion engine (1) according to one of claims 1 to 8, characterized in that the vent channel (18) an oil separator (19) connects, preferably by the oil separator (19) into the vent space (17), particularly preferably in the settling chamber (23), or in an oil sump emptying oil return channel emanates.

10. rotary piston internal combustion engine (1) according to one of claims 1 to 9, characterized in that the venting space (17) via at least one second overflow channel (30) with at least one by the rotary piston (4) and at least one lateral tread (8) limited piston gap (24, 27) is fluidly connected, wherein preferably the second overflow channel (30) between the piston space (24) and the vent space is formed rising.

11. rotary piston internal combustion engine (1) according to claim 10, characterized in that the second overflow channel (30) has a preferably formed by a throttle or aperture defined smallest flow cross-section.

12. A rotary piston internal combustion engine (1) according to claim 10 or 11, characterized in that the second overflow (30) from a region of the lateral first tread (6) emanates, which by the largest diameter of a Ölabstreifring (25) swept area and the smallest diameter of one of a lateral sealing strip (26) of the rotary piston (4) swept area is limited.

13. Rotary piston internal combustion engine (1) according to one of claims 1 to 12, characterized in that the rotary piston (4) has at least one the two piston intermediate spaces (24, 27) at different end faces of the rotary piston (4) flow connecting connection opening (28).

14, rotary piston internal combustion engine (1) according to one of claims 10 to 13, characterized in that between the central housing part (2a) and at least one lateral housing part (2b, 2c) a side tread (6, 7) forming side plate (8, 9) is arranged, wherein preferably the side plate (8) forms a piston from the space (2) outgoing portion of the second overflow channel (30).

15. rotary piston internal combustion engine (1) according to one of claims 1 to 14, characterized in that - preferably by a housing wall (2 ') of the housing (2) projecting - Abscheidewand (33) radially to the eccentric shaft (10) and / or inclined to a horizontal plane (ε) is arranged.

16, rotary piston internal combustion engine (1) according to one of claims 1 to 15, characterized in that the venting space (17) with a Ölwan- nenraum (35) is fluidly connected, wherein preferably the venting space (17) to the oil pan space (35) is made open ,