WO2013120526A1

WO2013120526A1 - Screw assembly and internal combustion engine having a screw assembly

Info

Publication number: WO2013120526A1
Application number: PCT/EP2012/052683
Authority: WO
Inventors: Oliver Heid
Original assignee: Siemens Aktiengesellschaft
Priority date: 2012-02-16
Filing date: 2012-02-16
Publication date: 2013-08-22

Abstract

The invention relates to a screw assembly (100) comprising three screws (110), each screw (110) having a convex cross-section (120) perpendicular to the longitudinal axis (130) thereof. Each screw (110) is twisted in the longitudinal direction about the longitudinal axis (130) thereof. The longitudinal axes (130) of the screws (110) are arranged parallel to one another. Each screw (110) can be rotated about the longitudinal axis (130) thereof.

Description

description

Screw arrangement and internal combustion engine with Schraubenanord ^¬ tion

The present invention relates to a screw assembly according to claim 1, and an internal combustion engine with egg ^¬ ner such a screw assembly according to claim 15.

From the prior art, various new constructions ^¬ nen of internal combustion engines are known. Known Brennkraftma ^¬ machines can be divided into continuously flowed gas turbines and intermittent piston engines. In gas turbines, a fuel is combusted at a constant pressure, which limits the efficiency of such gas turbines. Piston engines, however, allow a pressure increase, but this requires closed combustion chambers with variable volume.

Rotary and rotary piston engines represent known variants of piston engines. Such rotary and

Rotary piston engines traditionally use planar mechanisms to achieve compression and expansion of gas volumes required for thermodynamic engines. The Wankel engine is a well-known example of a rotation ^¬ piston engine.

A disadvantage of known rotary piston machines lies in the unfavorable ratio between the surface and the volume of the combustion chamber. This unfavorable ratio ^{results in} high heat losses.

Therefore, an object of the present invention is to provide an arrangement which has a more favorable ratio between surface area and volume of a combustion chamber on ^¬. This object is achieved by a screw arrangement with the features of claim 1. Another object of the present invention is to provide an internal combustion engine To provide machines whose combustion chamber has a favorable ratio between surface and volume. In this ^¬ handover is solved by an internal combustion engine having the features of claim 15. Preferred developments are specified in the dependent claims.

A coil assembly according to the invention comprises three Schrau ^¬ ben, each bolt having its longitudinal axis perpendicular to a convex cross section. Each screw is twisted longitudinally about its longitudinal axis. In addition, the longitudinal axes of the screws are arranged parallel to each other. Furthermore, each screw is rotatable about its longitudinal axis. ^¬ advantageous way is enough, in this screw assembly including a volume between the screw, which is transported upon rotation of the screw in the longitudinal direction.

In a preferred embodiment of the screw arrangement, each screw perpendicular to its longitudinal axis on a cross ^{¬ section} in the form of a Reuleaux triangle. Advantageously ^¬ example, the cross section of the screws is then formed as a uniform thickness. This advantageously ensures that the three screws touch each other under each angular position and along its entire longitudinal direction. This advantageously leads to a reliable concluded Volu ^¬ men, which is sandwiched between the screws.

It is expedient that the longitudinal axes of the screws are arranged on the corners of an equilateral triangle. ^¬ advantageous way legally is also ensured that the Schrau ^¬ ben can touch under any angular position and over its entire length to each other or have a constant distance from each other.

It is particularly useful when the screws touch each other. This advantageously provides a reliable seal ^¬ From one enclosed by the screw channel is achieved against an environment of screw arrangement. Preferably, the screws are formed substantially identical. Advantageously, thereby reduce the Her ^¬ cost of the screw assembly, since only one type of screws is needed.

In a preferred embodiment of the screw arrangement, each screw is rotated in the longitudinal direction by a total of 360 °. Advantageously, a rotation of the screws of the screw assembly by 360 ° then promotes three mutually completed partial volumes in the longitudinal direction of the screws of the screw assembly.

In a particularly preferred embodiment of the screw arrangement, the rotation of the screws per length is in

Longitudinal direction not constant. In other words, this means that the screws have differently steep twists, ie twists with different values of twist angle per length, in different regions along their longitudinal axis. As a result legally advantageous ^¬ that the size of the area enclosed by the screws use screw ^¬ benanordnung partial volumes change during a caused by the rotation of the screws of the screw arrangement transport of the partial volumes in the longitudinal direction of the screw. As a result, it is advantageously possible to achieve compression and / or expansion of a gas enclosed in the partial volumes.

In a simple embodiment of the screw arrangement, each screw has in the longitudinal direction a first section with a first twist per length and a second section with a second twist per length. ^¬ advantageous way legally then obtained during rotation of the

Screwing the screw assembly at the transition between the first portions of the screws and the second portions of the screws, a volume change of a partial volume of the enclosed by the screws of the screw assembly channel. This can advantageously a compression or relaxation of a gas enclosed in the sub-volume can be achieved.

In a further development of this screw arrangement, each screw in the longitudinal direction also has a third section with a third rotation per length. Vorteilhafterwei ^¬ se can then in the longitudinal direction of the coil arrangement, two volume changes of a partial volume of the area enclosed by the screws of the screw arrangement the channel reaches the advertising.

In a preferred embodiment of this screw arrangement, the second section is arranged longitudinally between the first section and the third section. In this case, the second portion is shorter in the longitudinal direction than the first portion and formed as the third portion. Before ^¬ geous enough, then results in a rotation of the

Screwing this screw assembly at the transition between the first section and the second section, a reduction of a partial volume of a trapped by the screws of the screw assembly channel and at the transition between the second section and the third section, an enlargement of the partial volume of the enclosed by the screws of Schraubenanord ^¬ tion channel , Advantageously, a trapped in the enclosed sub-volume gas then transported in the longitudinal direction through the screw assembly and thereby first compressed and then relaxed.

It is expedient that the rotation in this screw arrangement is 120 ° in each section. Advantage ^¬ way legally can then emerge a completed partial volume in each section of the screw assembly.

In a preferred disclosed embodiment, the coil arrangement, all the screws are simultaneously rotatable in the same direction of rotation Rich ^¬ tung same rotation speed. Advantageously, it is then ensured that the screws are arranged at each time under identical angles. This advantageously ensures that the screws have a constant distance from each other under each angular position and along their entire length.

In a further development of the screw arrangement, a fuel can be fed to a cavity arranged between the screws at one longitudinal end of the screws. Advantageously, the fuel can then be transported along the longitudinal direction of the screws through the screw arrangement during rotation of the screws of the screw arrangement and thereby subjected to a compression and / or relaxation.

In an additional development of the screw arrangement, this has a fourth screw. Advantageously, it ^¬ enables the addition of the fourth screw an inclusion of a further transport channel serving as the cavity, which presents all the advantageous properties and applications referred to above. In additional developments of the screw arrangement further screws can be added, each additional screw allows the formation of a wei ^¬ direct transport channel.

An internal combustion engine according to the invention has a Schrau ^¬ benanordnung of the type described above. Advantageously, the screw arrangement of this internal combustion engine can be used for transport, compression and expansion of a fuel. Another advantage of this internal combustion engine is that no external housing is required. This advantageously results in a favorable ratio between the power of the internal combustion engine and the mass of the internal combustion engine. Advantage ^¬ way legally can be this ratio even further improved by adding more screws to screw arrangement. A further advantage of the internal combustion engine is that the screw arrangement consists exclusively of components rotating about their center of gravity axes, whereby a complete torque compensation is made possible. In addition, by the screws of the screw assembly of the Internal combustion engine enclosed combustion chamber of the internal combustion ^¬ machine a favorable ratio between surface and Vo ^¬ lumen, whereby the internal combustion engine advantageously suffers only low heat loss.

The above-described characteristics, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understood in connection with the following description of embodiments, which will be described in connection with the drawings. Hereby show:

Figure 1 is a Reuleaux triangle;

FIG. 2 shows a section through a screw arrangement perpendicular to a longitudinal axis of the screw arrangement;

FIG. 3 shows an angle-dependent cross-sectional ^{surface course of a} channel enclosed by the screw arrangement;

Figure 4 is a schematic view of a screw of the screw ^¬ benanordnung in the longitudinal direction; and

Figure 5 is a perspective view of the Schraubenanord ^¬ tion.

Figure 1 shows a Reuleaux Triangle 10. The Reuleaux Triangle

10 is a constant diameter, which means that the distance rule Zvi ^¬ a corner of the Reuleaux triangle 10 and each point on the respective opposite side of the Reuleaux triangle 10 is the same.

The Reuleaux Triangle 10 can be made from an equilateral triangle

11 are constructed by a circular arc 13 is pulled around each corner 12 of the gleichseiti ^¬ gen triangle 11, which runs between the other two other corners 12 of the equilateral triangle 11. The three circular arc 13 form together quantitative ^¬ sets the Reuleaux triangle 10. The radius of the Reuleaux- Triangle 10 corresponds to the edge length of the equilateral triangle 11. The Reuleaux triangle 10 has a center 14 corresponding to the center of the equilateral triangle 11.

FIG. 2 shows, in a slightly schematized representation, a section through a screw arrangement 100. The screw arrangement 100 comprises three screws 110, in detail a first screw 111, a second screw 112 and a third screw 113. The three screws 110 are identical to one another.

The three screws 110 extend in a longitudinal direction, which is oriented perpendicular to the paper plane of Figure 2. The section of FIG. 2 therefore runs perpendicular to the longitudinal direction of the screws 110 and thus also perpendicular to the longitudinal direction of the entire screw arrangement 100.

Each screw 110 has a cross-sectional area 120 in the form of a Reuleaux triangle. Each screw 110 has a

Longitudinal axis 130 which extends in the sectional view of Figure 2 through the center of the formed as a Reuleaux triangle cross-sectional area 120 of the respective screw 110. The longitudinal axes 130 of the screws 110 are, in the sectional view of Figure 2, arranged on the corners of an equilateral triangle. All the screws 110 are under the moving ^¬ chen angle of rotation 165 about their respective longitudinal axis 130 angeord ^¬ net.

Each screw 110 of the screw assembly 100 is rotatable in a rotational direction 160 about its respective longitudinal axis 130. The direction of rotation 160 is the same for all screws 110 of the screw assembly 100. In the example of Figure 2, the direction of rotation 160 is selected counterclockwise. The

However, the direction of rotation 160 could also be oriented according to the Time ^¬ gersinns. The bolts 110 are each ^¬ weils same rotational speed in the rotational direction 160 to IH- re longitudinal axes 130 rotated. As a result, the screws 110 are always oriented at a common angle of rotation 165.

The screws 110 of the screw assembly 100 touch each other. In the sectional view of Figure 2, there are between two respective screws 110 of the screw assembly 100 exactly one contact point 140. Thus, there is between the first Schrau ^¬ be 111 and the second screw 112 in the section of Figure 2 shows a contact point 140 between the first screw 111 and the third screw 113 a contact point 140 and between the second screw 112 and the third screw 113 also has a contact point 140th

Because of the formed as Reuleaux triangles cross-sectional areas 120 of the screws 110 of the screw assembly 100 is exactly one touch point 140 between two screws 110 of the screw assembly 100 for any rotation angle 165 of the screws 110 about their longitudinal axes 130, if only all screws 110th the screw assembly 100 are oriented at the same rotational angle 165, which is ensured because of the uniform rotational speed. This ^¬ be indicated that the screws 110 in the section of Figure 2, be ^¬ stir at each time point in each case exactly one point of contact 140th

Between the three screws 110 of the screw assembly 100, a cavity or a channel 150 is included, which has a channel cross-sectional area 155 in the sectional view of FIG. The channel cross-sectional area 155 has the shape of a concave arch triangle. The size of the channel ^¬ cross-sectional area 155 is dependent on the angle of rotation 165 of the screws 110 of the screw assembly and can be calculated to:

Α (φ) = R ² - 3 (l - cos ^) - \ φ - sin ^ | Here, φe is the rotation angle 165, R is the radius of the

Cross-sectional area A 120 and the size of the channel cross-section area ^¬ 155th

In Figure 3, the rotation angle-dependent cross-sectional surface profile 200 of the channel cross-sectional area 155 is graphically Darge ^¬ represents. On the horizontal axis, the angle of rotation 165 of the screws 110 is applied around the respective longitudinal axis 130 of each screw 110 in the range between 0 ° and 360 °. On the vertical axis of the channel cross-sectional area 155 is shown of the LAT ^¬ rule screws 110 enclosed channel 150th The channel cross-sectional area 155 is normalized to a radius of the cross-sectional area 120 of the screws 110 of the value 1. As can be seen, the channel cross-sectional area 155 oscillates approximately sin ² -shaped with a period of 120 °.

The three screws 110 of the screw assembly 100 extend along their longitudinal axes 130 perpendicular to the paper plane of Figure 2. In this case, the screws 110 each have over their entire length a cross section in the form of Querschnittsflä ^¬ surface 120, ie in the form of a Reuleaux triangle. However, the screws 110 are not merely cylindrical, but are twisted or twisted about their longitudinal axes 130 along their longitudinal axes 130. Each screw 110 is rotated over its entire length by a total of 360 °.

Are the screws 110, each with the same rotational speed in the same direction of rotation 160 to their

Rotated longitudinal axes 130, the channel cross-sectional area 155 changes at each point in the longitudinal direction of

The rotation of the screws 110 leads to a phase shift of the variation of the channel cross-sectional area 155 along the longitudinal axis 130, so that between two adjacent zeros of the cross-sectional area profile 200 of Figure 3 in each case a closed partial volume of the channel 150th which forms upon rotation of the Screws 110 of the screw assembly 100 in the longitudinal direction by the screw assembly 100 moves.

Since each screw 110 is rotated along its longitudinal axis 130 by a total of 360 °, the channel 150 between the

Screw 110 over the entire length of the screw assembly 100 three mutually closed partial volumes. Each of these partial volumes extends between two adjacent zeros of the cross-sectional surface profile 200 of FIG. 3. Each of these partial volumes is spindle-shaped, thus tapering in the direction of its longitudinal ends. If the screws 110 of the screw arrangement 100 are rotated in the direction of rotation 160 by a total of 360 °, then three partial volumes of the channel 150 once travel completely through the entire length of the screw arrangement 100.

The size of the partial volumes of the channel 150 enclosed in the screw arrangement 100 depends on the pitch of the rotation of the screws 110 along their longitudinal axes 130, that is to say on the rotation of the screws 110 per unit length. If the rotation per unit length is large, the result is a smaller volume of the channel 150 enclosed between two zeros of the cross-sectional area profile 200. If the rotation per unit length is small, a large volume of the channel 150 enclosed between two zeros of the cross-sectional area profile 200 results.

The rotation per unit length, ie the slope of the Ver ^¬ rotation of the screws 110 along their longitudinal axes 130, in the screw 110 of the screw assembly 100 on the

Length of the screws 110 along their longitudinal axes 130 is not constant. This has the sizes of the partial volumes ^¬ of the channel 150 to change during the movement of the partial volumes in the longitudinal direction of the screw assembly 100 result. A rotation of the screws 110 about their longitudinal axes 130 thus causes both an axial transport of the partial volumes of the Ka ^¬ nals 150 along the longitudinal axis 130, as well as a volume ^¬ change of the sub-volumes of the channel 150th Figure 4 shows a schematic side view of a Schrau be ^¬ 110 of a screw assembly 100. The longitudinal axis 130 of the screw 110 defines a longitudinal direction 131. The screw 110 has a first longitudinal end 301 and a second longitudinal end 302.

When the screws 110 of the screw arrangement 100 are rotated about the longitudinal axes 130, the partial volumes of the channel 150 in the longitudinal direction 131 travel through the screw arrangement

100. the twist per unit length Increases use screw ^¬ be 110 from the first longitudinal end 301 to the center of the screw 110 back, then the volume is reduced each partial volume of the Ka ^¬ Nals 150, while in the longitudinal direction 131 from the first longitudinal end 301 toward the Center of the screw assembly 100 moves. If the twist per unit length of the screw 110 between the center of the screw 110 and the second longitudinal end 302 of the screw 110 decreases again, the volume of the partial volume of the channel 150 increases on the way between the center of the screw arrangement 100 and the second longitudinal end 302 of the screw 110 again. In this way, a moving through the screw assembly 100 sub-volume of the channel 150 is first compressed and then re-expanded ^¬ who.

The change in the twist per unit length of the screw 110 can be carried out continuously in the longitudinal direction 131 of the screw 110. In a simple embodiment, however, the screw 110 can also be subdivided in the longitudinal direction 131 into different sections of a respective constant rotation per unit length. This is shown schematically in FIG. The

Screw 110 has a first portion 310, a second portion 320, and a third portion 330. The first section 310 is arranged on ^¬ side of the first longitudinal end of three hundred and first The third section 330 is disposed on the side of the second longitudinal end 302. The second section 320 is between see the first section 310 and the third section 330. In each section 310, 320, 330, the screw is rotated by a total of 120 ° about its longitudinal axis 130. However, the second portion 320 is formed shorter off in the longitudinal direction 131 than the first portion 310 and as the third From ^¬ section 330. Thereby, the screw 110 in the second Ab ^¬ section 320 has a higher rotation per unit length than in the first portion 310 and in the third section 330. A partial volume of the passage 150 traveling through the screw arrangement 100 by rotation of the screws 110 of the screw arrangement 100 about their longitudinal axes 130 in the longitudinal direction 131 undergoes a volume reduction at the transition between the first section 310 and the second section 320 the second section 320 and the third

Section 330 is an increase in volume. If a gas is included in the partial volume of the channel 150, it is compressed at the transition between the first section 310 and the second section 320 and expanded at the transition between the second section 320 and the third section 330.

Figure 5 shows a perspective view of the screw assembly 100. It can be seen that all the screws 110 of the screw assembly 100 are identical. each

Screw 110 has a first portion 310, a second portion 320, and a third portion 330.

The bolt assembly 100 may find use in an internal combustion engine 400. Then, the channel 150 between the screws 110 of the screw assembly 100 at the first longitudinal end 301, a gaseous fuel can be supplied. By rotating the screws 110 about their longitudinal axes 130, the fuel supplied at the first longitudinal end 301 is transported in the longitudinal direction 131 through the screw arrangement 100. At the transition between the first section 310 and the second section 320, the fuel is compressed. In the second section from ^¬ 320 can cause an ignition of the compressed fuel. Subsequently, the fuel or the Combustion products at the transition between the second section 320 and the third section 330 relaxes. The relaxing gas drives the rotation of the screws 110.

The sealing gaps between the screws 110 of the screw assembly 100 of the internal combustion engine 400 can be adjusted to a first approximation by varying the distances between the longitudinal axes 130 of the screws 110 to each other.

Advantageously, the internal combustion engine 400 does not require an outer housing. Thereby a favorable ratio between the power of the internal combustion engine 400 and the mass of the internal combustion engine 400 arises in of the internal combustion machine ^¬ 400th

The screw assembly 100 may also include more than three screws 110. By adding a fourth screw 110, a second channel can be created which is oriented parallel to the first channel 150. The addition of a fifth screw 110 allows the provision of a third channel. Each additional screw 110 allows the provision of a white ^¬ ter channel. By providing further channels, the power of the internal combustion engine 400 having the screw arrangement 100 can be increased. In this case, the Ver ^¬ ratio of power to mass with increasing number of the channels 150 towards even lower values will change.

If the screws 110 of the screw arrangement 100 have a radius of 10 cm, the maximum channel cross- ^{sectional area} 155 of the channel 150 is approximately 48 cm ² . Have the coil 110 of the coil assembly 100 in the longitudinal direction 131 has a length of 30 cm, so are about 12 cm to Kompressi ^¬ on disposal. This corresponds to a size of a partial volume of the channel of 288 cm ³ . Since the channel promotes 150 per vollständi ^¬ ger rotation of the screw 110 has three part volumes by the coil arrangement 100, results in a displacement of 864 cm ³ per one complete rotation of the screw 110 of the Screw Assembly 100. In order to achieve a compression ratio of 1: 8, the ratio of rotations per unit length in the first section 310 and in the second section 320 must also have a ratio of 1: 8. As a result, the second portion 320 must be one eighth the length of the first portion 310 and the third portion 330. An average working pressure of 0.8 MPa results in a Mo ^¬ torleistung of 115 kW at a speed of 10,000 min ^-1.

Although the invention has been illustrated and described in detail by the preferred embodiment, the invention is not limited by the disclosed examples ^¬ limits. Other variations can be deduced therefrom by those skilled in the art without departing from the scope of the invention.

Claims

Screw arrangement (100)

with three screws (110),

wherein each screw (110) perpendicular to its longitudinal ^¬ axis (130) has a convex cross-section (120),

wherein each screw (110) is twisted in the longitudinal direction (131) about its longitudinal axis (130),

wherein the longitudinal axes (130) of the screws (110) are arranged parallel to one another,

wherein each screw (110) is rotatable about its longitudinal axis (130).

Screw arrangement (100) according to claim 1,

wherein each screw (110) perpendicular to its longitudinal ^¬ axis (130) has a cross section (120) in the form of a Reuleaux triangle (10).

A screw arrangement (100) according to one of the preceding claims.

wherein the longitudinal axes (130) of the screws (110) are arranged on the corners of an equilateral triangle.

A screw arrangement (100) according to one of the preceding claims.

the screws (110) touching each other.

A screw arrangement (100) according to one of the preceding claims.

wherein the screws (110) are formed substantially identical.

A screw arrangement (100) according to one of the preceding claims.

wherein each screw (110) in the longitudinal direction (131) is rotated by a total of 360 °.

7. Screw arrangement (100) according to one of the preceding claims,

wherein the rotation of the screws (110) per length in the longitudinal direction (131) is not constant.

8. screw arrangement (100) according to claim 7,

wherein each screw (110) in the longitudinal direction (131) has a first portion (310) with a first twist per length and a second portion (320) with a second twist per length.

9. screw arrangement (100) according to claim 8,

wherein each screw (110) in the longitudinal direction (131) has a third portion (330) with a third twist per length.

10. screw arrangement (100) according to claim 9,

wherein the second portion (320) is disposed longitudinally (131) between the first portion (310) and the third portion (330),

wherein the second portion (320) is shorter in the longitudinal direction (131) than the first portion (310) and as the third portion (330).

11. Screw arrangement (100) according to one of claims 8 to 10,

wherein the twist in each section (310, 320, 330) is 120 °.

12. Screw arrangement (100) according to one of the preceding claims,

wherein the screws (110) are rotatable in the same direction of rotation (160) at the same rotational speed.

13. Screw arrangement (100) according to one of the preceding claims, wherein a fuel is provided to a cavity (150) disposed between the screws (110) at a longitudinal end (301) of the screws (110).

Screw arrangement (100) according to one of the preceding claims,

wherein the screw assembly (100) is a fourth

Screw (110).

Internal combustion engine (400) with a screw arrangement (100) according to one of claims 1 to 14.