EP1144806A1

EP1144806A1 - Oscillating piston engine

Info

Publication number: EP1144806A1
Application number: EP00901093A
Authority: EP
Inventors: Herbert Hüttlin
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-01-14
Filing date: 2000-01-12
Publication date: 2001-10-17
Anticipated expiration: 2020-01-12
Also published as: DE19901110A1; ATE226275T1; EP1144806B1; US20020029756A1; JP2002535529A; US6431139B1; WO2000042290A1; AU2108000A; DE19901110C2; DE50000646D1

Abstract

An oscillating-piston engine, comprising a housing, in which several pistons configured as two-armed levers are arranged pivotably, respectively, around a pivot axis being parallel to a central housing axis and moving commonly in a revolution direction. The pistons comprise running surfaces on a side facing away from said housing inner wall, which are guided alongside at least one control cam, when the pistons revolve in the housing, of a centrally housing-fixed cam piece, in order to control pivot movements of the pistons in the revolution. The control cam is configured as an inner contour on the cam piece, alongside of which the pistons are guided supported to a side of a centrifugal force via the running surfaces, The cam piece comprises another inner contour configured as a control cam alongside of which the pistons are guided supported to a direction of the central housing axis via the running surfaces.

Description

Swing piston machine

The invention relates to a oscillating piston machine with a housing in which a plurality of pistons designed as two-armed levers are arranged so as to be pivotable about a respective pivot axis parallel to a central housing axis and are movable together in one direction of rotation, the pistons having running surfaces on their side facing away from an inner wall of the housing Circulation of the pistons in the housing are guided along at least one control curve of a central curve piece fixed to the housing in order to control the pivoting movements of the pistons during the rotation.

CONFIRMATION COPY Such a oscillating piston machine is known from WO 98/13583, the disclosure of which is hereby expressly incorporated into the present application.

Swing piston machines belong to a genus of internal combustion engines, in which the individual work cycles of intake, compression, ignition (expansion) and ejection of the combustion mixture are mediated by rocker-like swiveling movements of the individual pistons between two end positions.

The known oscillating-piston machine has, in the center of the housing, a curve piece which is fixed to the housing and which has an outer contour designed as a control curve. The pistons point on their side facing away from the inner wall of the housing, i.e. the center of the curve facing sides on treads that are guided while rotating the piston in the housing along the outer contour of the curve piece with constant contact with the same. The pivoting movements of the pistons are controlled when the pistons rotate in the housing by guiding the running surfaces of the pistons along the outer contour of the cam piece in cooperation with a rolling engagement of adjacent pistons.

Although the known oscillating piston machine has proven to be particularly favorable with regard to its running properties, it can still be improved with regard to its wear resistance and functional reliability, particularly in long-term and high-performance operation.

Calculations on the kinematics of the known swinging piston machine have shown that the centrifugal forces of the swinging piston Over a full revolution, depending on the current rotational position, assume different values between a minimum and a maximum, which can be explained by the asymmetrical mass position of the swivel pistons in relation to the center of the swivel axes of the individual pistons. The difference between the centrifugal force minimum and the centrifugal force maximum can be in the range of more than 1000 N at high speeds.

The maximum centrifugal force occurs with each piston when it is in the so-called top dead center (TDC) position (12 o'clock position) or in the bottom dead center (UT) position (6 o'clock position). This maximum centrifugal force acting on the leading lever arm of the piston in the TDC position, which pushes this lever arm outwards in the direction of the housing inner wall, brings about an equally large force acting on the cam piece and acting on the trailing lever arm of the same piston. Since this trailing lever arm is in rolling engagement with the leading lever arm of the next trailing piston, the trailing lever arm of the leading piston presses the leading lever arm and thus the running surface of the trailing piston arranged thereon with increased force against the cam piece. Because on the leading lever arm of the trailing piston, which is currently in the retracted 9 o'clock position or 3 o'clock position, only a centrifugal force minimum acts, so that this minimal centrifugal force is the compressive force caused by the centrifugal force in the TDC position not compensated. The result is that the tread of the trailing piston in the 9 o'clock position or the piston in the 3 o'clock position is pressed against the curve piece with very high force, whereby both the tread and the curve piece are excessively loaded. In long-term operation, especially at high speeds at which the centrifugal forces are high, this can lead to increased wear or even damage to these parts.

From the above it follows that the toothing of the rolling engagement, which must absorb counteracting forces, is even more strongly loaded.

Furthermore, from DE-OS-15 51 101 a centrifugal piston internal combustion engine is known, which has six spaced pistons of approximately triangular shape, which are pivotally mounted on a circular drive wheel in such a way that they rotate when rotating in the housing of the engine Centrifugal forces are pressed against the inner wall of the housing. The control of the pivoting movement of the individual pistons is effected by a special trochoidal design of the inner wall of the housing. In the housing there are also two fixed guide cams with an outer contour, which are intended to ensure at low engine speeds, at which the centrifugal forces are low, that the pistons are pressed against the inner wall of the housing in order to maintain the functionality of the engine at low speeds receive. However, this centrifugal piston engine is already disadvantageous because of the required special non-circular contouring of the inner wall of the housing.

From DE-OS-15 26 408 an internal combustion engine with rotating pistons forming a closed chain is also known. The pistons, together with the non-round, oval cylinder jacket, form closed rotating working chambers. volume. The polygon formed by the pistons is a pentagon or polygon, with a regular pentagon being considered the most advantageous. To control the piston movement, two secondary rotors are provided, which consist of five segments, these segments being articulated by means of bolts. Rollers are mounted on the bolts, which control the movement of the rotors while rolling over the raceway, and by means of further bolts also the movement of the pistons. This embodiment of a swing piston machine is comparatively complex. Further disadvantages of this configuration are the non-circular configuration of the inner wall of the housing and the articulated connection of the segments forming the two secondary rotors for controlling the pivoting movement of the pistons.

Another swinging piston machine is known from US Pat. No. 3,642,391, in which the pistons are connected to one another in an articulated manner. The inside wall of this oscillating piston machine is not round, but rather elliptically shaped. The piston swiveling movements are controlled by cam pieces on which the pistons run with rollers. The non-circular contouring of the inner wall of the housing is also disadvantageous on this oscillating piston machine.

The invention is therefore based on the object of developing a swing piston machine of the type mentioned in such a way that the disadvantages mentioned above are avoided. The swing piston machine is to be further improved in terms of its wear properties and functional reliability. According to the invention, this object is achieved in a oscillating piston machine of the type mentioned at the outset in that the control cam is designed as an inner contour on the cam piece, along which the pistons are guided on the centrifugal force side via the running surfaces.

The oscillating piston machine according to the invention therefore continues to assume that the pivoting movements of the individual pistons are controlled during rotation by a central curve piece fixed to the housing, which has proven to be advantageous in the known oscillating piston machine compared to the known centrifugal piston internal combustion engine. In the oscillating piston machine according to the invention, however, in the form of the control curve designed as an inner contour, along which the running surfaces of the pistons are guided, a measure is taken to absorb the centrifugal forces of the piston halves or lever arms of the pistons. Characterized in that the control curve designed as an inner contour absorbs the centrifugal forces, it is avoided that the centrifugal forces, in particular the maximum centrifugal forces that occur in the TDC position, via the rolling engagement on the tread or running surfaces of the respective preceding and following piston and be transferred to the curve piece. In this way, overloading of the treads and the curve piece are avoided. Another advantage that arises from the configuration of the curve piece according to the invention is that the forces in the area of a rolling engagement between adjacent pistons, if there is one, are also advantageously reduced.

The object underlying the invention is thus completely achieved. In a particularly preferred embodiment, the curve piece has a further outer contour designed as a control curve, along which the same running surfaces or further running surfaces of the pistons, which are likewise arranged on the piston on the side facing away from the housing inner wall, are guided to the housing axis in a supported manner.

With this measure, each piston advantageously experiences both an “outer guidance” along the known outer contour and additionally an “inner guidance” along the inner contour of the curve piece. Such a combination of inner and outer guidance enables a kinematically exact and at the same time dynamically favorable control of the pivoting movements of the pistons when rotating in the housing, the considerable advantage being achieved that the running surfaces guided on the outer contour in the position 9 a.m. and 3 a.m. Difference to the known swing piston machine are depressurized. Another advantage of the combination of inner and outer guidance is that when a piston engages adjacent pistons, the latter essentially has no control function, but that the roller engagement only assumes the function of a seal. This opens up the possibility of designing the rolling engagement instead of in the form of a toothing in the form of a smooth rolling surface, or even completely dispensing with rolling engagement, as is provided in a preferred embodiment.

In a further preferred embodiment, the outer contour and the inner contour run parallel to one another.

In this embodiment, the inner contour and the outer contour have curves which are essentially complementary to one another on. Each piston is thus guided both centrifugally and centripetal as on a rail. The design of the inner contour parallel to the curve of the outer contour has the advantage that it is possible with simple means to modify the swing piston machine known and proven from WO 98/13583 in accordance with the present application. For example, the piston geometry and the geometry of the outer contour of the curve piece can be adopted essentially unchanged, in which case an inner guide surface for the pistons then only has to be provided on the curve piece.

In a further preferred embodiment, the inner contour is continuous in the circumferential direction.

It is advantageous here that each piston over a full revolution on the centrifugal side, i.e. is supported centrifugally, so that centrifugal forces are absorbed in each rotational position of the piston and pressure loads are thereby reduced in each rotational position.

Alternatively, however, in the case of a configuration with an inner and outer contour, it is also preferred if the inner contour extends in the circumferential direction only over one or more peripheral partial areas.

This enables a simpler construction of the oscillating piston machine to be achieved, in which case it is advantageous if the inner contour extends at least in the area of the top dead center and bottom dead center, for example from 10 a.m. to 2 a.m. and from 4 a.m. to 8 a.m. In a further preferred embodiment, the curve piece has the outer contour and the at least one inner contour in one-piece design.

In this embodiment, the curve piece can be made in one piece overall, whereby the manufacturing effort and the number of parts involved in the construction can be reduced. Starting from the curve piece of the known oscillating piston machine, the inner contour provided according to the invention can be formed during the production of the curve piece. Another advantage of a one-piece design of the outer contour and inner contour is that a permanent orientation of the two is guaranteed in the long run during operation of the oscillating piston machine.

As an alternative to this, however, it is also preferred if the curve piece is constructed in several parts, at least a first part having the control curve designed as an outer contour and at least a second part having at least one control curve designed as an inner contour and the parts being firmly connected to one another.

This configuration proves to be advantageous because of easier assembly when bringing together the running surfaces of the pistons with the cam piece. The inner contour can be formed on an annular flange which is flanged to the rest of the curve piece, which has the outer contour, after insertion of the pistons. In a further preferred embodiment, the inner contour is formed on an inside of pocket-like flanges of the curve piece.

This measure is particularly advantageous both in terms of production technology and assembly technology. If the curve piece has both the inner contour and the outer contour, the flange or the flanges can be formed in one piece with the remaining part of the curve piece which has the outer contour, or as separate ring flanges which then with the remaining part of the curve piece which forms the outer contour has, positively connected, for example mortised. The pocket-like flanges form an approximately reverse L-shaped overlap of those running surfaces which are provided for guidance on the inner contour.

In a further preferred embodiment, the curve piece has axially delimited the inner contour in the region of both axial ends of the pistons.

In this embodiment, each piston is therefore guided with its two axial ends on the centrifugal force side. The axially central region of each piston can, if this is provided, have the running surfaces which are guided in a radially inwardly supported manner on the outer contour.

If the curve piece has both the inner contour and the outer contour, it is further preferred if each piston has at least two running surfaces, at least one of which is guided on the inner contour, while the at least one further running surface is guided on the outer contour. This embodiment advantageously opens up the possibility of realizing the running surfaces by means of rollers, in which case the at least one roller guided along the inner contour can roll freely thereon and the at least one roller guided on the outer contour can also roll freely on the latter.

In a further preferred embodiment, the running surfaces are surfaces of rollers rotatably attached to the piston.

Rollers have the advantage that they can be guided along the inner contour or along the outer contour of the curve piece with a substantially lower friction. The requirements for the lubrication of the treads can be significantly reduced in contrast to piston-resistant sliding shoes.

In a further preferred embodiment, the pistons are in rolling engagement with one another in pairs.

This measure is advantageous if the pistons are only guided along the inner contour, but not along the outer contour, so that the rolling engagement can then take on an additional control function for the reciprocating pivoting movement of the pistons.

In a further preferred embodiment, the pistons are in rolling engagement with one another in pairs via an unserrated curved rolling surface. As already mentioned above, the forces in the area of the rolling engagement of adjacent pistons are reduced by the inventive guiding of the pistons along the inner contour and even more with an additional guiding of the pistons along the outer contour, so that the rolling engagement mainly has a sealing function. Accordingly, the rolling engagement can also be represented by a smooth rolling surface that is easier to manufacture than a toothing.

As an alternative to a rolling engagement of adjacent pistons, it is also preferred if the pistons, viewed in the circumferential direction, are each spaced in pairs by a separating element, the separating elements rotating together with the pistons in the housing.

This configuration is particularly advantageously possible if the pivoting movement of the individual pistons is carried out both via the inner outer guide and on the outer inner guide of the curve piece. The individual pistons are then completely independent of one another because of the rolling engagement no longer present, with the advantage that seals of a conventional type can be used in a structurally simple manner on the system between the piston and the separating element.

It is further preferred if each separating element has two sliding surfaces on which piston fist surfaces of the two corresponding pistons in contact with the respective separating element slide back and forth during their pivoting movement.

The separating elements are therefore preferably stationary with regard to the pivoting movement of the pistons, and only run with them the piston in the housing in the circumferential direction. The separating elements can be firmly clamped between two ring bodies moving with the pistons at the respective end of the swinging piston machine.

It is further preferred if the piston fist surfaces of the pistons and the sliding surfaces of the separating elements are complementary to one another in a curved manner.

The piston fist surfaces of the pistons can be convex, for example, and the sliding surfaces of the separating elements can be concave, or vice versa. Such a curved shape of the piston fist surfaces and sliding surfaces sliding against one another is optimally adapted to the reciprocating pivoting movement of the individual pistons. The complementary shape of the piston fist surfaces and the sliding surfaces also enables an optimal sealing of the working chambers against the oil space of the oscillating piston machine over the entire swivel stroke of the pistons if the separating elements extend in the axial direction over the length of the interior of the housing of the oscillating piston machine.

For this purpose, it is preferably provided to arrange at least one seal in each sliding surface of the separating elements.

Such seals can be provided in the form of sealing lips which are arranged at the same point where the corresponding sealing lips are arranged in the front annular surfaces of the piston cage closest to the longitudinal center axis of the oscillating piston machine. However, the arrangement of the seals in the separating elements is not mandatory, and the seals can also be arranged in the piston fist surfaces of the pistons instead of in the separating elements.

In a further preferred embodiment, a fire seal closer to the housing inner wall and an oil seal closer to the curve piece are arranged in each sliding surface of the separating elements.

The fire seal seals the working chambers in which the combustion process takes place in a gas-tight manner, while the oil space arranged centrally in the oscillating piston machine is additionally sealed against the working chambers via the oil seal.

In a further preferred embodiment, the oscillating piston machine has a plurality of chambers in the axial direction, a set of pistons being arranged in each chamber, and the sets of pistons being arranged offset from one another in the circumferential direction from chamber to chamber.

While the known oscillating piston machine is designed in the axial direction as a single-chamber system, the advantage of the multi-chamber configuration is that the torques introduced by the pistons onto the cam piece can be halved, divided into three or divided even further, depending on the number of chambers, because the Torque effective surface of the piston can be made correspondingly smaller in the axial direction. Due to the offset of the piston sets from one chamber to the next chamber, the introduction of torque to the central curve piece is distributed more evenly in the circumferential direction. As a result, the smooth running of the oscillating-piston machine can advantageously be increased and the load on the cam piece, which can be made in one piece or even in several parts through all the chambers, can be reduced even further.

Further advantages result from the following description and the attached drawing.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in their respectively specified combination but also in other combinations or on their own without departing from the scope of the present invention.

An embodiment of the invention is shown in the drawing and is described below with reference to this. Show it:

1 shows a longitudinal section through an oscillating piston machine according to the invention according to a first embodiment.

FIG. 2 shows a cross section through the oscillating piston machine along the line II-II in FIG. 1;

3 shows a cross section through the oscillating piston machine along the line III-III in Fig. 1. 4 shows a longitudinal section through an oscillating piston machine according to the invention in accordance with a second exemplary embodiment, which is slightly modified compared to the first exemplary embodiment;

5 shows a cross section through the oscillating piston machine along the line V-V in Fig. 4.

5a shows a detail from FIG. 5 on an enlarged scale; and

6 shows a cross section through the oscillating piston machine along the line VI-VI in FIG. 4.

1 to 3 show a swing piston machine provided with the general reference number 10. The oscillating piston machine 10 is used, for example, in a motor vehicle as an internal combustion engine.

The oscillating piston machine 10 has a circumference on a housing 12 which seals the oscillating piston machine 10 to the outside. The housing 12 is substantially cylindrical, i.e. Round in cross-section, designed and extends over the axial length of the oscillating piston machine 10. A housing inner wall 14 is axially round in cross-section.

The housing 12 is, as can be seen from FIG. 1, constructed from individual housing segments, namely from cylindrical housing segments 16 and 18 and from housing end segments 20 and 22, which are each suitably tightly connected to one another, for example mortised and / or screwed. Due to the construction of the housing 12 in individual housing segments the assembly of the oscillating piston machine 10 is considerably simplified and enables a modular construction in the case of a multi-chamber system.

In the axial direction, the oscillating piston machine 10 is divided into two chambers 24 and 26.

A set of pistons is arranged in each of the chambers 24 and 26, FIG. 2, which is a cross section through the chamber 24, showing the pistons 28a to 28d of the chamber 24. Four pistons 28a to 28d are thus arranged in each of the two chambers 24 and 26. The pistons are identical to the pistons of the chamber 26, which are not shown in detail, so that only the chamber 24 with the pistons 28a to 28d arranged therein is described in more detail below.

The pistons of the chamber 26 are identical to the pistons 28a to 28d of the chamber 24, but the pistons of the chamber 26 are offset with respect to the pistons 28a to 28d of the chamber 24 by approximately 45 °, viewed in the circumferential direction.

The pistons 28a to 28d are each designed as two-armed levers, i.e. each of the pistons 28a to 28d has a first lever arm 30 and a second lever arm 32 with respect to a pivot axis 34, which are designated by way of example for the piston 28a in FIG. 2. A pivot axis 34 is thus assigned to each of the pistons 28a to 28d. The pivot axes 34 lie on a circle and are equidistant from each other.

Each of the four pivot axes 34 extends in the axial direction parallel to a central housing axis 36. The pistons 28a 28d to 28d can be pivoted back and forth about their respective pivot axis 34 between two end positions, the respective lever arm 30 with its outside on the housing inner wall 14 in the first end position and the respective lever arm 32 with its outside on the housing inner wall 14 in the second end position is present.

For this purpose, each of the pistons 28a to 28d is pivotally mounted about an axially extending axis rod 38, which is itself not pivotable. Each axis rod 38 forms the respective pivot axis 34 of the individual pistons 28a to 28d.

The pistons 28a to 28d continue to engage each other in pairs. For this purpose, the pistons 28a to 28d each have toothings 40 on both ends in the circumferential direction, which mesh with one another. The piston 28a, for example, is in rolling engagement with both the piston 28b and the piston 28d. The rolling engagement formed by the toothing 40 is tight, so that between the housing inner wall 14 and the outer sides of the pistons 28a to 28d opposite the housing inner wall 14, the working chambers 42 are hermetically sealed by the rolling engagement.

Instead of via the toothing 40, the individual pistons 28a to 28d can also be in meshing engagement with one another via a convexly curved rolling surface 44, which is shown with broken lines in FIG. 2, with adjacent ones of the rolling surfaces 44 then in each pivoting position of the pistons 28a to 28d lie sealingly against one another, in order in turn to ensure the hermetic tightness of the working chambers 42. The pistons 28a to 28d also run together in the housing 12 in a circumferential direction 46 around the central housing axis 36. The axially rotating axis rods 38 are sealed against the inner wall 14 of the housing, specifically by means of centrifugal seals 47, as described in detail in WO 98/13583, to which reference is made for a more detailed description.

Accordingly, one of the working chambers 42 is formed between each two adjacent ones of the axle rods 38, the corresponding section of the housing inner wall and two adjacent lever arms 32 and 30 ', in the exemplary embodiment shown with four pistons 28a to 28d, accordingly four working chambers 42 in the circumferential direction 46, which face each other are sealed. The volume of the working chambers 42 changes during the rotation of the pistons 28a to 28d in accordance with the reciprocating pivoting movements of the pistons 28a to 28d in order to enable the different work cycles of suction, compression, ignition (expansion) and ejection.

A cam piece 48 is arranged in the center of the housing 12 and extends through the chamber 24 and the chamber 26. In contrast to the pistons 28a to 28d, the curve piece 48 is designed to be fixed to the housing.

The curve piece 48 has at least one inner contour 50 designed as a control curve (see FIG. 3).

The pistons 28a to 28d in turn have running surfaces 52 on their side facing away from the inner wall 14 of the housing or facing the curve piece 48, which, when the pistons 28a to 28d rotate in the housing 12, along the control curve formed inner contour 50 are guided. As a result, the pistons 28a to 28d are guided, supported on the centrifugal force, along the cam piece 48.

The inner contour 50 is arranged on the cam piece 48 in the region of an axial end of the pistons 28a to 28d.

A second inner contour 52, which is identical to the inner contour 50 with respect to the curve shape and is designed as a control curve, is arranged on the curve piece 48 in the region of the opposite axial end of the pistons 28a to 28d. At this end, the pistons 28a to 28d each have a further running surface 54, which is guided along the inner contour 52 of the cam piece 48 when the respective piston 28a to 28d rotates.

In the chamber 26, the curve piece 48 has the inner contours 50 and 52 corresponding inner contours 56 and 58, also designed as control cams, which serve to guide corresponding, unspecified running surfaces of the pistons arranged in the chamber 26 supported on the centrifugal force side.

In the area between the inner contours 50 and 52 or between the inner contours 56 and 58, the curve piece 48 also has an outer contour designed as a control curve. The outer contour 62 extends axially into the area of the inner contours 50, 54, 58, 60 or already ends axially in the middle between the inner contours 50 and 54 or 58 and 60.

The pistons 28a to 28d each have at least one further running surface 64 which, when the pistons 28a to 28d rotate in the housing 12, along the outer contour 62 of the curve piece 48 are guided, whereby the pistons 28a to 28d are also supported radially inwards towards the central housing axis 36.

In the exemplary embodiment, each piston 28a to 28d has three running surfaces 64 which are axially spaced apart and which are guided together along the outer contour 62 of the curve piece 48.

The inner contours 50, 54, 58 and 60 of the curve piece 48 are each formed on an inside of a flange 66, 68, 70 and 72 forming a pocket.

The flanges 68 and 70, which form the inner contours 54 and 58 on their radial inside, are formed in one piece with the rest of the body of the curve piece 48. The flanges 66 and 72, on the other hand, are formed on ring flanges 74 and 76, which are positively connected to the rest of the body of the cam piece 48 and are firmly mortised with it. The ring flanges 74 and 76 are also positively connected to the housing end segment 22 and the housing end segment 20 on their respective axial outer sides, so that the ring flanges 74 and 76 form a housing-fixed arrangement with the rest of the body of the curve piece 48.

The running surfaces 64, which are guided along the outer contour 62, and the running surfaces 52 and 56, which are guided along the inner contours 50 and 54, are surfaces of rotatable rollers 78 and 80, respectively, which are mounted on the pistons 28a to 28d. The rollers 78, each of which pistons 28a to 28d have two, rest exclusively on the inner contour 50 and 54, while the rollers 80, each of which pistons 28a to 28d has three, rest only on the outer contour 62.

The running surfaces 64 are in constant contact with the outer contour 62 when the pistons 28a to 28d rotate. The running surfaces 52 and 56 are in constant contact with the inner contour 50 and 54 when the pistons 28a to 28d rotate.

With reference to Fig. 3 it should be mentioned that the treads 52 of the rollers 78 do not touch the outer contour 62 of the cam piece 48, but are spaced from this with a slight clearance, so that the rollers 78 freely rotating on the pistons 28a to 28d Inner roll 50 of the curve piece 48 can roll.

For this purpose, the rollers 78 and 80 are preferably mounted on a common bolt which passes axially through the rollers 78 and 80, respectively. The treads 54 and 52 of the rollers 78 are in constant contact with the inner contour 50 while the pistons 28a to 28d are running along the inner contour 50, while the treads 64 of the rollers 80 are in constant contact with the pistons 28a to 28d while rotating the outer contour 62 of the curve piece 48 are guided along the same.

As can be seen from FIG. 3, the inner contour 50 extends completely around the curve piece 48 in the circumferential direction.

Together with the ring flanges 74 and 76, the cam piece 48 is formed in several parts, whereby the assembly of the oscillating piston machine 10, more precisely the insertion of the Pistons 28a to 28d and assembly with the curve piece 48 is facilitated.

In FIGS. 2 and 3, the oscillating-piston machine 10 is shown in an operating position in which the piston 28a, more precisely, its lever arm 30, which runs in the direction of rotation 46, is at top dead center (TDC). The piston 28d trailing the piston 28a, i.e. more precisely, its leading lever arm 30 ', on the other hand, is in its maximally radially inwardly retracted position. In this position, a maximum centrifugal force acts on the forward lever arm 30 of the forward piston 28a when rotating, in particular at high speeds. However, this maximum centrifugal force is absorbed by the inner contour 50 via the running surfaces 52 and 56, which are guided on the inner contour 50 of the curve piece 48. As a result, this high centrifugal force is not transmitted via the trailing lever arm 32 of the leading piston 28a to the leading lever arm 30 'of the trailing piston 28d, which is in the 9 o'clock position, so that the running surface 64' or the running surfaces 64 'of the Piston 28d are not excessively pressed against the curve piece 48. Likewise, this centrifugal force is not transmitted to the subsequent lever arm 32 'of the leading piston 28b and therefore not as a compressive force to the leading lever arm 30' ', which is in the 3 o'clock position, so that its tread 64' 'is also relieved of pressure is.

The curve piece 48 also has axially extending bores 82, 84 and 86, which are used for oil mist cooling or oil lubrication of the running surfaces 50, 54 or 64 of the pistons 28a to 28d or the lubrication of the rollers 78, 80. As already mentioned at the beginning of the description, the oscillating piston machine 10 is designed in the axial direction as a multi-chamber system, more precisely as a two-chamber system in the exemplary embodiment shown.

The pistons arranged in the chamber 26, which are not identified in the drawing, have the same design as the pistons 28a to 28d of the chamber 24 with regard to their guidance along the curve piece 48.

The pistons of the chamber 26 are also pivotally mounted on axle rods, of which two axle rods 88 and 90 opposite pistons can be seen in FIG. 1. The axle rods 88, 90 and the two further axle rods, which cannot be seen in the drawing, are arranged offset by approximately 45 ° with respect to the axis rods 38, on which the pistons 28a to 28d of the chamber 24 are pivotably mounted.

The axis rods 38 of the chamber 24 and the axis rods 88, 90 and the other two axis rods of the chamber 26 together with three ring bodies 92, 94 and 96 form a rigid cylindrical piston cage, which together with the pistons 28a to 28d of the chamber 24 and the piston of the Chamber 26 rotates together. The axis rods 38 of the chamber 24 are fixedly connected to the ring bodies 92 and 94, while all axis rods 88, 90 of the chamber 26 are fixedly connected to the ring bodies 94 and 96. The first ring body 92 is rotatably and tightly mounted on the ring flange 74 of the cam piece 48. Correspondingly, the third ring body 96 is rotatably and tightly mounted on the ring flange 76 of the cam piece 48. The middle ring body 94 is rotatably mounted on the outer sides of the flanges 68 and 70 of the curve piece 48. The third ring body 96 carries on its axially outer side a ring gear 98 which has an external toothing 100 which meshes with a corresponding toothing of a changer wheel 102, which in turn meshes with a corresponding toothing 104 of a ring gear 106 which rotatably with an output shaft 108 of the oscillating piston machine 10 is connected. The rotation of the third ring body 96 about the central housing axis 36 thus causes a rotational movement of the output shaft 108, which can then be transmitted via a clutch disc 110 into a drive train of the motor vehicle, in which the oscillating piston machine 10 is installed.

Furthermore, the oscillating-piston machine has spark plugs 112 and 114 for each chamber 24, 26, as well as an inlet cross section 116 and an outlet cross section for each chamber 24 and 26.

Because of the functioning of the oscillating piston machine, reference is made here to WO 98/13583, in which the individual work cycles of the oscillating piston machine 10 are shown in FIG. 5.

4 to 6 show an embodiment of a swing piston machine 10 'which is slightly modified compared to the swing piston machine 10 according to FIGS. 1 to 3, of which only the differences from the swing piston machine 10 according to FIGS. 1 to 3 are described below. The same or comparable features as in the oscillating piston machine 10 have been provided with the same reference number followed by an apostrophe. Features and functions of the oscillating piston machine 10 ', to which no express reference is made hereinafter, are identical to those of the oscillating piston machine 10.

1 to 3, the pistons 28a to 28d are in rolling engagement with one another in pairs, the pistons 28a 'to 28d' of the oscillating piston machine 10 'are seen in pairs in the circumferential direction, each by a separating element 140, 142, 144, 146 spaced apart, the separating elements 140, 142, 144, 146 rotating with the pistons 28a 'to 28d' in the housing 12 '.

The four separating elements 140 to 146 extend according to FIG. 4 over the axial length of the chamber 24 ', and corresponding separating elements between the pistons in the chamber 26' also extend over the axial length of this chamber 26 '.

The separating elements 140 to 146 are clamped between the ring bodies 94 'and 92' or 96 'and 94' and are immovable relative to these ring bodies.

Because the pistons 28a 'to 28d' are spaced apart from one another by the separating elements 140 to 146, the pistons 28a 'to 28d' are kinematically independent of one another. This means that the reciprocating pivoting movements of the individual pistons 28a 'to 28d "are conveyed solely by guiding the pistons 28a' to 28d 'along the curve section 48'.

The separating elements 140 to 146 have, as is shown by way of example on the separating element 140, two sliding surfaces 148 and 150, on which piston fist surfaces 152 (pistons 28a ') and 154 (Pistons 28b ') of the two corresponding pistons 28a''and28b' respectively resting on the separating element 140 slide back and forth during their pivoting movement.

5a, the separating element 140 is shown in detail on an enlarged scale. In the sliding surfaces 148 and 150, seals are embedded in the separating element 140, specifically fire seals 156 and 158, which are arranged closer to the housing inner wall 14 ', and two old seals 160 and 162, which are arranged closer to the curve piece 48'.

The fire seals 156 and 158 seal the working chambers 42 'in a gas-tight manner towards the longitudinal center axis of the oscillating piston machine 10', while the old seals 160 and 162 provide a seal for the oil chamber in the middle of the housing against the working chambers 42 '.

The seals 156 to 162 also extend over the entire axial length of the separating elements 140 to 146.

The design of the oscillating piston machine 10 'with the separating elements 140 to 146 makes it possible to provide almost classic piston seals, the sealing effects of which can be predetermined with a high degree of certainty.

6, the fire seals 156 and 158 and the old seals 160 and 162 in the separating elements 140 to 146 are at the same height, where the fire and old seals are located in the ring bodies 92 'and 94' and 96 ', respectively is indicated in FIG. 6 with the reference number 164. While the seals in the exemplary embodiment shown in FIGS. 4 to 6 are arranged in the separating elements 140 to 146 themselves, the seals can, however, also be arranged conversely in the piston fist surfaces 152 and 154 of the pistons 28a 'to 28d'.

5 and 6, the sliding surfaces 148 and 150 of the separating elements 140 to 146 are concavely curved, while the piston fist surfaces 152 and 154 of the pistons 28a 'to 28d' are complementarily curved and convex. As a result, the piston fist surfaces 152 and 154 of the pistons 28a 'to 28d' are always guided past the sliding surfaces 148 and 150 of the separating elements 140 to 146 at their minimum distance during their reciprocating pivoting movement.

Claims

claims

Swing piston machine, with a housing (12; 12 '), in which a plurality of pistons (28a-28d; 28a' -28d ') designed as two-armed levers are arranged so as to be pivotable about a pivot axis (34) parallel to a central housing axis (36) and together are movable in a circumferential direction (46), the pistons (28a-28d; 28a'-28d ') having on their side facing away from an inner wall of the housing (14; 14') running surfaces (52, 56) which, when the pistons (28a -28d) are guided in the housing (12) along at least one control curve of a central curve piece (48; 48 ') fixed to the housing in order to control the pivoting movements of the pistons (28a-28d; 28a'-28d') during the rotation, characterized in that that the control cam is designed as an inner contour (50, 54) on the cam piece (48; 48 '), along which the pistons (28a-28d; 28a'-28d') are guided on the centrifugal force side via the running surfaces (52, 56).

Swing piston machine according to claim 1, characterized in that the cam piece (48; 48 ') has a further outer contour (62) designed as a control curve, along which the same running surfaces (52, 56) or further running surfaces (64) of the pistons (28a-28d ; 28a'-28d '), which are also arranged on the side facing away from the housing inner wall (14; 14') on the pistons (28a-28d; 28a'-28d '), are guided so as to be supported towards the housing axis (36).

3. Swing piston machine according to claim 2, characterized in that the outer contour (62) and the inner contour (50, 54, 58, 60) run parallel to each other.

4. Swing piston machine according to one of claims 1 to 3, characterized in that the inner contour (50, 54) in the circumferential direction (46) is continuous.

5. Swing piston machine according to claim 2 or 3, insofar as this is related to claim 2, characterized in that the inner contour (50, 54) extends in the circumferential direction (46) only over one or more peripheral partial areas.

6. Swinging piston machine according to claim 2 or according to one of claims 3 to 5, insofar as these are related to claim 2, characterized in that the curve piece (48; 48 '), the outer contour (62) and the at least one inner contour (54) in one piece Training.

7. Swing piston machine according to claim 2 or according to one of claims 1 to 5, insofar as they are related to claim 2, characterized in that the curve piece (48; 48 ') is formed in several parts, at least a first part of the outer contour (62) and at least one second part which has at least one inner contour (50) and the parts are firmly connected to one another.

8. Swinging piston machine according to one of claims 1 to 7, characterized in that the inner contour (50, 54) is formed on an inside of a pocket-forming flange (66, 68) of the curve piece (48).

9. Swing piston machine according to one of claims 1 to 8, characterized in that the cam piece (48; 48 ') in the region of both axial ends of the pistons (28a-28d; 28a'- 28d') each axially limits the inner contour (50, 54th ) having.

10. Swing piston machine according to claim 2 or one of claims 3 to 9, insofar as these are related to claim 2, characterized in that each piston (28a-28d; 28a'-28d ') has at least two running surfaces (52, 56, 64) , of which at least one is guided on the inner contour (50, 54), while the at least one further running surface (64) is guided on the outer contour.

11. Swing piston machine according to one of claims 1 to 10, characterized in that the running surfaces (52, 56, 64) surfaces of rotatably on the pistons (28a-28d; 28a'-28d ") are rollers (78, 80).

12. Swing piston machine according to one of claims 1 to 11, characterized in that the pistons (28a-28d) are in pairs with each other in rolling engagement.

13. Swing piston machine according to claim 12, characterized in that the pistons (28a-28d) are in pairs with each other via an unserrated curved rolling surface (44) in rolling engagement.

14. Swing piston machine according to one of claims 1 to 11, characterized in that the pistons (28a'-28d 'seen in the circumferential direction each in pairs by one Separating element (140-146) are spaced apart, the separating elements (140-146) rotating together with the pistons (28a '- 28d') in the housing (12 *).

15. Swinging piston machine according to claim 14, characterized in that each separating element (140-146) has two sliding surfaces (148, 150), on which piston fist surfaces (152, 154) of the two corresponding pistons in contact with the respective separating element (140-146) (28a'-28d ') slide back and forth during their pivoting movement.

16. Swinging piston machine according to claim 15, characterized in that the piston fist surfaces (152, 154) of the pistons (28a'-28d ') and the sliding surfaces (148, 150) of the separating elements (140-146) are curved complementary to one another.

17. Swing piston machine according to claim 15 or 16, characterized in that in each sliding surface (148, 150) of the separating elements (140-146) in each case at least one seal is arranged.

18. Swing piston machine according to claim 17, characterized in that in each sliding surface (148, 150) one of the housing inner wall (14 ') closer fire seal (156, 158) and one of the curve piece (48') closer oil seal (160, 162) is arranged .

9. Swing piston machine according to one of claims 1 to 12, characterized in that it has a plurality of chambers (24, 26; 24 ', 26') in the axial direction, wherein in each chamber (24, 26; 24 ', 26') a set of pistons (28a-28d; 28a'-28d ") is arranged, and wherein the sets of pistons (28a-28d; 28a'-28d ') from chamber (24; 24') to chamber (26; 26 ') in Circulation direction (46) are arranged offset to one another.