US3832104A

US3832104A - Rotary piston internal combustion engine

Info

Publication number: US3832104A
Application number: US00035177A
Authority: US
Inventors: H Lamm
Original assignee: Daimler Benz AG
Current assignee: Daimler Benz AG
Priority date: 1969-05-07
Filing date: 1970-05-06
Publication date: 1974-08-27
Anticipated expiration: 1991-08-27
Also published as: GB1297848A; FR2042457A1; DE1923231A1

Abstract

A rotary piston internal combustion engine, particularly of trochoidal construction, which includes a rotating piston equipped at its corners with sealing bars which are constructed relatively wide for reducing wear and which are provided with slots and/or apertures for increasing their elasticity.

Description

o United States Patent 1191 1111 3,832,104 Lamm Aug. 27, 1974 1 ROTARY PISTON INTERNAL 3,180,564 4/1965 Fuhrmann et a1. 418/122 3,182,641 5/1965 Lamm 418/124 COMBUSTIOF ENGINE 3,185,387 5/1965 Paschke.... 418/124 Inventor: Heinz Lamm, g 3,207,426 9/1965 Gassmann et a1 418/124 Bernhardt, Germany 3,245,387 4/1966 Froede 418/120 1. 3,263,913 8/1966- Fuhrmann et a1. 418/113 [73] Asslgnee: namler'Benl Aklengfieuschafi, 3,270,954 9/1966 Yamamoto 418/113 stuttgart-umemerkhelm, Germany 3,301,231 1/1967 Tadd 418/122 3,323,498 6/1967 Kraic et a]. 418/122 PP N05 35,177 Primary Examiner-William L. Freeh Assistant Examiner-John .1. Vrablik [30] Foreign Application Priority Data Attorney, Agent, or Firm-Craig and Antonelli ay Gerrnany 192 31 [57] ABS CT [52] US. Cl. 418/113 A o y piston internal combustion g p [51] Int. CL... F01c 19/02, F04c 15/00, F0412 27/00 larly of trochoidal construction, which includes a ro- [58] Field of Search; .418/61, 1 13-124 tating piston equipped at its comers with sealing bars which are constructed relatively wide for reducing [56] References Cit d wear and which are provided with slots and/or aper- UNITED STATES PATENTS tures for increasing their elasticity.

3,113,526 12/1963 Paschke 418/122 13 Claims, 6 Drawing Figures ROTARY PISTON INTERNAL COMBUSTION ENGINE The present invention relates to a rotary piston internal combustion engine of especially trochoidal-type of construction with a piston that is provided at its corners with sealing bars.

The present invention is concerned with the task to construct the sealing bars more wear-resistant than known heretofore without sacrifice in elasticity.

The underlying problems are solved by the present invention in that the sealing bars of solid material are constructed relatively wide for the purpose of reducing wear and are provided with slots and/or apertures for increasing their elasticity.

Sealing bars are constructed for the most part from a homogeneous material, for example, from piston ring material, either integral or multi-partite. Experience, however, has demonstrated that with increasing'sealing bar thickness, the lubricating and wear conditions become more favorable. On the other hand, a thin sealing bar is more elastic. The materials used at present have a high modulus of elasticity so that one is relegated to a thin construction. These thin sealing bars adapt themselves considerably better to the shape of the trochoidal cam or running surface. The engine becomes more gas-tight and therewith achieves a higher power or output.

During idling and at small loads, a gas-tight engine is also necessary in order to obtain an uninterrupted running, i.e., an operation free from misfirings. For the purpose of decreasing'the carbon monoxide value and the hydrocarbon emission, a radially gas-tight piston, i.e.., a well-sealing sealing bar is absolutely desirable. A good adaptability of the sealing bar to the trochoidal cam or running surface exists only with a thin sealing bar (about 2 mm. However, the wear of the top of the sealing bar is not satisfactory in the cases of limitlubrication, i.e., at the point of transition of dry friction to floating friction.

Accordingly, one aims at utilizing thicker sealing bars (about 3-6 mm.) which are equipped with a larger head radius and thus reduce the wear as a result of a larger utilizable surface. Additionally, a larger oil wedge forms on the leading side between the head portion and the running surface, which is of great significance for the lubrication and radial gas sealing of the piston. This lubricant wedge serves in connection with the metered lubrication also as oil reservoir over several working cycles until the next small oil drop is again metered to the lubrication.

Furthermore, it is also worthy of mention that thicker sealing bars also produce a more favorable heat removal.

in order to utilize completely the advantages of the thicker sealing bars, such a sealing bar has to be constructed elastically for reasons pointed out above.

in one preferred type of construction according to the present invention, the radius of the head portion of the sealing bar is constructed at least equal to. half the thickness of the sealing bar.

For the purpose of increasing the elasticity, a slot may be provided extending from the bottom side of the sealing bar, preferably in the center of the sealing bar, whose depth corresponds approximately to threequarters of the height of the sealing bar.

In order that the gas force becomes rapidly effective underneath the sealing bar and is not blocked off by a tilting of the sealing bar in the piston groove, bores may be arranged in thelower portion of the sealing bar or small milled-in cuts may be provided in the lower portion of the sealing bar whose cross section preferably decreases from the outside toward the slot. An arrangement thereof may be realized both on the leading as also on the trailing sealing bar flank.

Another possibility to increase the elasticity of the sealing bar resides in that two slots, whose depth corresponds approximately to a quarter of the width of the sealing bar, are arranged in proximity to the head portion or in the head portion of the sealing bar perpendicularly to the flanks thereof or at an angle to one-another which is not smaller than the pivot angle of the sealing bar. The head portion thus becomes elastic with respect to the lower portion of the sealing bar and the latter continues to remain a guide body in the piston groove. For reasons of permitting as large as possible a vertical wear of the sealing bars, the lateral slots may also be arranged somewhat lower.

Moreover, the lower portion of the sealing bar can be constructed more elastically in that additionally a slot is provided extending from the bottom side of the sealing bar whose depth corresponds approximately to half the height of the sealing bar.

For the purpose of increasing the elasticity of the sealing bar, the present invention further proposes that a recess or aperture, preferably triangularly shaped in cross section, is provided extending from the bottom side of the sealing bar whose depth corresponds approximately to three quarters of the height of the sealing bar. 7

According to a further feature of the present invention, an approximately V-shaped recess or aperture may be arranged in a diagonal direction of the cross section of the sealing bar, which extends from a lower edge of the sealing bar.

Another possibility to increase the elasticity of th sealing bar resides in that in addition to the aforementioned preferably triangularly shaped recess, a slot is provided in proximity to the head portion of the sealing bar extending from one of its flanks whose depth corresponds approximately to two-thirds the width of the sealing bar.

Accordingly, it is an object of the present invention to provide a rotary piston internal combustion engine equipped with sealing bars in the comers of the piston which avoids by simple means the aforementioned shortcomings and drawbacks encountered in the prior art.

Another object of the present invention resides in a sealing bar for the corner of a piston of a rotary piston internal combustion engine which is more wearresistant without sacrifice in elasticity thereof.

A further object of the present invention resides in a sealing bar for the piston corners of rotary piston internal combustion engines which improves the wear and lubricating conditions.

A still further object of the present invention resides in a sealing bar for the piston corners of a piston used in rotary piston internal combustion engines which is simple in construction, improves the gas tightness of the engine and reduces the wear of the sealing bar.

These and other objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, several embodiments in accordance with the present invention, and wherein:

FIG. 1 is a transverse cross-sectional view through a first embodiment of a sealing bar for the piston of a rotary piston internal combustion engine in accordance with the present invention;

FIGS. 2 through are cross-sectional views, similar to FIG. 1, through four further embodiments of a sealing bar in accordance with the present invention, and

FIG. 6 is a schematic cross-sectional view illustrating a rotary piston internal combustion engine of trochoidal construction.

Referring now to the drawing wherein like reference numerals are used throughout the various views to designate like parts, and more particularly to FIG. 1, this figure illustrates in cross section a sealing bar 1 provided with a slot 2 that extends from the bottom side 3 in the center of the sealing bar and whose depth corresponds approximately to three-quarters of the height of the sealing bar 1; the further possibility exists with the sealing bar 1 of this embodiment to provide in the lower portion of the sealing bar 1 in the leading as well as in the trailing surfaces, bores 4 leading from the outside to the slot 2 and/or to provide small milled-in cuts 5 whose cross section decreases essentially in the shape of a triangle from the outside in the direction toward the slot 2. The head radius 6 of the sealing bar 1 corresponds to half its thickness. Furthermore, the possibility is indicated in dash and dot lines to utilize a head radius 6a which is larger than half the thickness of the sealing bar 1.

FIG. 2 illustrates in cross section a sealing bar 1 in a different type of construction with two oppositely disposed slots 7 and 8 which are provided in the sealing bar 1 in proximity to its head portion 9 perpendicularly to the flanks 10 and 11 thereof and whose depth corresponds to about one-fourth the width of the sealing bar 1, with the possibility to provide an additional slot 12 extending from the bottom side 3 of the sealing bar 1 whose depth corresponds approximately to half the height of the sealing bar 1. The head radius 6 of the sealing bar 1 corresponds to half of its thickness. Furthermore, as in FIG. 1, the possibility is indicated in dash and dot lines to utilize a head raduis 6a that is larger than half of the thickness of the sealing bar 1.

FIG. 3 illustrates in cross section a further embodiment of a sealing bar 1 with two oppositely disposed

slots

13 and 14 which are mutually arranged in the head portion 9 of the sealing bar I at an angle 15 that is larger than the pivot angle 16 of the sealing bar 1, and whose depth corresponds approximately to a quarter of the width of the sealing bar 1, with the possibility to provide an additional slot 17 extending from the bottom side of the sealing bar 1 whose depth corresponds.

to approximately two-thirds of the height of the sealing bar 1. The head radius 6 of the sealing bar 1 is larger than half of its thickness.

FIG. 4 illustrates in cross section a fourth embodiment of a sealing bar 1 with an approximately V-shaped slot-like aperture vl8 which starts from a lower edge 19 of the sealing bar 1 in a diagonal direction of the cross section of the sealing bar 1 and extends approximately over two-thirds the width of the sealing bar 1. The slotlike aperture 18, if it is accommodated on the leading side of the sealing bar 1, serves simultaneously as gas inlet groove. The head radius 6 of the sealing bar 1 is larger than half of its thickness. 1

FIG. 5 illustrates in cross section a fifth embodiment of a sealing bar 1 with an approximately triangularly shaped slot-like aperture 20 whose one side 21 is arranged parallel to a flank of the sealing bar 1 whereby almost the entire bottom side 3 of the sealing bar 1 is open. The height (depth) of the slot-like aperture 20 corresponds approximately to three-quarters the height of the sealing bar 1. The possibility is additionally indicated to provide a slot 23 in proximity to the head portion 9 of the sealing bar 1 cut-in from the flank 22 of the sealing bar 1 disposed opposite the side 21 of the slot-like aperture 20; the depth of the slot 23 is about two-thirds the width of the sealing bar 1. The head radius 6 of the sealing bar 1 is larger than half of its thickness.

FIG. 6 illustrates in schematic cross-section a rotary piston internal combustion engine of trochoidal construction which includes a casing 31 provided with an internal running or contact surface 36, along which the piston 33 slides with the sealing bars 1 accommodated in grooves 34 at the corners of the piston. Arrow 32 thereby indicates the normal direction of rotation of the piston 33. The casting 31 is closed off on both sides by lateral housing parts (not shown) of convention construction.

While I have shown and described several embodiments in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to those skilled in the art. Thus, for example, the features described hereinabove and/or shown in the drawing as well as those of the claims may be utilized individually as well as in any desired combination with one another for the realization of the present invention in its most varied types of construction. Consequently, I do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

I claim:

1. A rotary piston internal combustion engine with a polygonal piston provided at its corners with grooves accommodating sealing bars, characterized in that a sealing bar includes a solid body and is operable as the only sealing bar in a respective piston groove and to that end, is constructed relativey wide for reducing the wear at the top surface thereof and is provided with at least one continuous slot-like means extending into the solid body of the bar for increasing the elasticity thereof, said continuous slot-like means being closed at the inner end thereof by the solid body of the bar, extending uninterruptedly over its entire length in the longitudinal direction of the sealing bar and being open over its entire length in the area thereof at'least partially facing the bottom of a respective groove, and

characterized in that said slot-like means are constituted by at least one slot and one slot-like aperture in each sealing bar completely closed off with respect to one another by the body of the sealing bar.

2. A rotary piston internal combustion engine with a polygonal piston provided at its corners with grooves accommodating sealing bars, characterized in that a sealing bar includes a solid body and is operable as the only sealing bar in a respective piston groove and to that end, is constructed relatively wide for reducing the wear at the top surface thereof and is provided with at least one continuous slot-like means extending into the solid body of the bar for increasing the elasticity thereof, said continuous slot-like means being closed at the inner end thereof by the solid body of the bar, extending uninterruptedly over its entire length in the longitudinal direction of the sealing bar and being open over its entire length in the area thereof at least partially facing the bottom of a respective groove,

characterized in that the radius of the head portion of the sealing bar is at least equal to half the thickness of the sealing bar,

characterized in that said slot-like means includes a slot extending uninterruptedly into the sealing bar from the bottom side thereof whose depth corresponds approximately to three-quarters the height of the sealing bar, and

characterized in that bores are provided in the lower part of the sealing bar which extend substantially transversely to the longitudinal direction of the slot.

3. A rotary piston internal combustion engine with a polygonal piston provided at its corners with grooves accommodating sealing bars, characterized in that a sealing bar includes a solid body and is operable as the only sealing bar in a respective piston groove and to that end, is constructed relatively wide for reducing the wear at the top surface thereof and is provided with at least one continuous slot-like means extending into the solid body of the bar for increasing the elasticity thereof, said continuous slot-like means beingclosed at the inner end thereof by the solid body of the bar, extending uninterruptedly over its entire length in the longitudinal direction of the sealing bar and being open over its entire length in the area thereof at least partially facing the bottom of a respective groove,

characterized in that the raduis of the headportion of the sealing bar is at least equal to half the thickness of the sealing bar,

characterized in that small milled-in cuts are provided in the lower portion of the sealing bar.

4. A rotary piston internal combustion engine according to claim 3, characterized in that said milled-in cuts have a cross section which decreases from the outside in the direction toward the slots.

5. A rotary piston internal combustion engine with a polygonal piston provided at its corners with grooves accommodating sealing bars, characterized in that a sealing bar includes a solid body and is operable as the only sealing bar in a respective piston groove and to that end, is constructed relatively wide for reducing the wear at the top surface thereof and is provided with at least one continuous slot-like means extending into the solid body of the bar for increasing the elasticity thereof, said continuous slot-like means being closed at the inner end thereof by the solid body of the bar, extending uninterruptedly over its entire length in the longitudinal direction of the sealing bar and being open over its entire length in the area thereof at least partially facing the bottom of a respective groove,

characterized in that the radius of the head portion of the sealing bar is at least equal to half the thickness of the sealing bar, I

characterized in that said means includes a continuous slot-like aperture extending from the bottom side of the sealing bar into the same, whose depth corresponds approximately to three-quarters of the height of the sealing bar, and

characterized in that said slot-like aperture is of approximately triangularly shaped configuration.

6. A rotary piston internal combustion engine with a polygonal piston provided at its comers with grooves accommodating sealing bars, characterized in that a sealing bar includes a solid body and is operable'as the only sealing bar in a respective piston groove and to that end, is constructed relatively wide for reducing the wear at the top surface thereof and is provided with at least one continuous slot-like means extending into the solid body of the bar for increasing the elasticity thereof, said continuous slot-like means being closed at the inner end thereof by the solid body of the bar, extending uninterruptedly over its entire length in the longitudinal direction of the sealing bar andbeing open over its entire length in the area thereof at least partially facing the bottom of a respective groove,

characterized in that the radius of the head portion of the sealing bar is at least equal to half the thickness of the sealing bar, and

characterized in that said means includes an approximately V-shaped, continuous slot-like aperture which extends from a lower edge of the sealing bar in a diagonal direction of the cross section of the sealing bar. I

7. A rotary piston internal combustion engine with a polygonal piston provided at its corners with grooves accommodating sealing bars, characterized in that a sealing bar includes a solid body and is operable as the only sealing bar in a respective piston groove and to that end, is constructed relatively wide for reducing the wear at the top surface thereof and is provided with at.

least one continuous slot-like means extending into the solid body of the bar for increasing the elasticity thereof, said continuous slot-like means being closed at the inner end thereof by the solid body of the bar, extendinguninterruptedly over its entire length in the longitudinal direction of the sealing bar and being open over its entire length in the area thereof at least partially facing the bottom of a respective groove,

characterized in that the raduis of the head portion of the sealing bar is at least equal to half the thicknes of the sealing bar, characterized in that said means includes a continuous slot-like aperture extending from the bottom side of the sealing bar into the same, whose depth corresponds approximately to three-quarters of the height of the sealing bar, and

characterized in that additionally a slot is provided in proximity to the head portion of the sealing bar which extends into the same from a flank thereof, the depth of said last-mentioned slot being about two-thirds the width of the sealing bar.

8. A rotary piston internal combustion engine with a polygonal piston provided at its corners with grooves accommodating sealing bars, characterized in that a sealing bar includes a solid body and is operable as only bar in a respective piston groove filled out in its width by the bar, and to that end, is constructed relatively wide for reducing the wear and includes a head portion having a radius at least equal to half thethickness of the sealing bar, the sealing bar being provided with continuous slot-like means for increasing the elasticity thereof in the form of two uninterrupted slots provided in each sealing bar whose depth corresponds approxi mately to a quarter of the width of the sealing bar and which extend uninterruptedly over the entire length thereof in the longitudinal direction of the sealing bar, the two slots extending from an outer surface of the sealing bar into the solid body thereof so that the two slots are open over the entire length thereof at said surfaces, and said two slots being closed with respect to one another by the solid body of the sealing bar.

9. A rotary piston internal combustion engine according to claim 8, characterized in that said two slots are provided in proximity of the head portion of the sealing bar.

10. A rotary piston internal combustion engine according to claim 8, characterized in that said two slots are provided in the head portion of the sealing bar.

11. A rotary piston internal combustion engine according to claim 8, characterized in that said two slots are disposed substantially perpendicularly to the flanks of a respective sealing bar.

12. A rotary piston internal combustion engine according to claim 8, characterized in that said two slots are arranged to one another at an angle that is at least equal to the pivot angle of the sealing bar.

13. A rotary piston internal combustion engine according to claim 8, characterized in that an additional uninterrupted slot is provided which extends into the sealing bar from the bottom side thereof, the depth of said additional slot being about half the height of the sealing bar, and said additional slot being in noncommunication relationship with said two slots by being separated therefrom by the body of the sealing

Claims

1. A rotary piston internal combustion engine with a polygonal piston provided at its corners with grooves accommodating sealing bars, characterized in that a sealing bar includes a solid body and is operable as the only sealing bar in a respective piston groove and to that end, is constructed relativey wide for reducing the wear at the top surface thereof and is provided with at least one continuous slot-like means extending into the solid body of the bar for increasing the elasticity thereof, said continuous slot-like means being closed at the inner end thereof by the solid body of the bar, extending uninterruptedly over its entire length in the longitudinal direction of the sealing bar and being open over its entire length in the area thereof at least partially facing the bottom of a respective groove, and characterized in that said slot-like means are constituted by at least one slot and one slot-like aperture in each sealing bar completely closed off with respect to one another by the body of the sealing bar.

2. A rotary piston internal combustion engine with a polygonal piston provided at its corners with grooves accommodating sealing bars, characterized in that a sealing bar includes a solid body and is operable as the only sealing bar in a respective piston groove and to that end, is constructed relatively wide for reducing the wear at the top surface thereof and is provided with at least one continuous slot-like means extending into the solid body of the bar for increasing the elasticity thereof, said continuous slot-like means being closed at the inner end thereof by the solid body of the bar, extending uninterruptedly over its entire length in the longitudinal direction of the sealing bar and being open over its entire length in the area thereof at least partially facing the bottom of a respective groove, characterized in that the radius of the head portion of the sealing bar is at least equal to half the thickness of the sealing bar, characterized in that said slot-like means includes a slot extending uninterruptedly into the sealing bar from the bottom side thereof whose depth corresponds approximately to three-quarters the height of the sealing bar, and characterized in that bores are provided in the lower part of the sealing bar which extend substantially transversely to the longitudinal direction of the slot.

3. A rotary piston internal combustion engine with a polygonal piston provided at its corners with grooves accommodating sealing bars, characterized in that a sealing bar includes a solid body and is operable as the only sealing bar in a respective piston groove and to that end, is constructed relatively wide for reducing the wear at the top surface thereof and is provided with at least one continuous slot-like means extending into the solid body of the bar for increasing the elasticity thereof, said continuous slot-like means being closed at the inner end thereof by the solid body of the bar, extending uninterruptedly over its entire length in the longitudinal direction of the sealing bar and being open over its entire length in the area thereof at least partially facing the bottom of a respective groove, characterized in that the raduis of the head portion of the sealing bar is at least equal to half the thickness of the sealing bar, characterized in that said slot-like means includes a slot extending uninterruptedly into the sealing bar from the bottom side thereof whose depth corresponds approximately to three-quarters the height of the sealing bar, and characterized in that small milled-in cuts are provided in the lower portion of the sealing bar.

5. A rotary piston internal combustion engine with a polygonal piston provided at its corners with grooves accommodating sealing bars, characterized in that a sealing bar includes a solid body and is operable as the only sealing bar in a respective piston groove and to that end, is constructed relatively wide for reducing the wear at the top surface thereof and is provided with at least one continuous slot-like means extending into the solid body of the bar for increasing the elasticity thereof, said continuous slot-like means being closed at the inner end thereof by the solid body of the bar, extending uninterruptedly over its entire length in the longitudinal direction of the sealing bar and being open over its entire length in the area thereof at least partially facing the bottom of a respective groove, characterized in that the radius of the head portion of the sealing bar is at least equal to half the thickness of the sealing bar, characterized in that said means includes a continuous slot-like aperture extending from the bottom side of the sealing bar into the same, whose depth corresponds approximately to three-quarters of the height of the sealing bar, and characterized in that said slot-like aperture is of approximately triangularly shaped configuration.

6. A rotary piston internal combustion engine with a polygonal piston provided at its corners with grooves accommodating sealing bars, characterized in that a sealing bar includes a solid body and is operable as the only sealing bar in a respective piston groove and to that end, is constructed relatively wide for reducing the wear at the top surface thereof and is provided with at least one continuous slot-like means extending into the solid body of the bar for increasing the elasticity thereof, said continuous slot-like means being closed at the inner end thereof by the solid body of the bar, extending uninterruptedly over its entire length in the longitudinal direction of the sealing bar and being open over its entire length in the area thereof at least partially facing the bottom of a respective groove, characterized in that the radius of the head portion of the sealing bar is at least equal to half the thickness of the sealing bar, and characterized in that said means includes an approximately V-shaped, continuous slot-like aperture which extends from a lower edge of the sealing bar in a diagonal direction of the cross section of the sealing bar.

7. A rotary piston internal combustion engine with a polygonal piston provided at its corners with grooves accommodating sealing bars, characterized in that a sealing bar includes a solid body and is operable as the only sealing bar in a respective piston groove and to thaT end, is constructed relatively wide for reducing the wear at the top surface thereof and is provided with at least one continuous slot-like means extending into the solid body of the bar for increasing the elasticity thereof, said continuous slot-like means being closed at the inner end thereof by the solid body of the bar, extending uninterruptedly over its entire length in the longitudinal direction of the sealing bar and being open over its entire length in the area thereof at least partially facing the bottom of a respective groove, characterized in that the raduis of the head portion of the sealing bar is at least equal to half the thicknes of the sealing bar, characterized in that said means includes a continuous slot-like aperture extending from the bottom side of the sealing bar into the same, whose depth corresponds approximately to three-quarters of the height of the sealing bar, and characterized in that additionally a slot is provided in proximity to the head portion of the sealing bar which extends into the same from a flank thereof, the depth of said last-mentioned slot being about two-thirds the width of the sealing bar.

8. A rotary piston internal combustion engine with a polygonal piston provided at its corners with grooves accommodating sealing bars, characterized in that a sealing bar includes a solid body and is operable as only bar in a respective piston groove filled out in its width by the bar, and to that end, is constructed relatively wide for reducing the wear and includes a head portion having a radius at least equal to half the thickness of the sealing bar, the sealing bar being provided with continuous slot-like means for increasing the elasticity thereof in the form of two uninterrupted slots provided in each sealing bar whose depth corresponds approximately to a quarter of the width of the sealing bar and which extend uninterruptedly over the entire length thereof in the longitudinal direction of the sealing bar, the two slots extending from an outer surface of the sealing bar into the solid body thereof so that the two slots are open over the entire length thereof at said surfaces, and said two slots being closed with respect to one another by the solid body of the sealing bar.

13. A rotary piston internal combustion engine according to claim 8, characterized in that an additional uninterrupted slot is provided which extends into the sealing bar from the bottom side thereof, the depth of said additional slot being about half the height of the sealing bar, and said additional slot being in non-communication relationship with said two slots by being separated therefrom by the body of the sealing bar.