AXIAL PISTON MOTOR AND METHOD FOR OPERATION OF AN AXIAL PISTON MOTOR

Abstract

An axial piston motor with inner continuous combustion burns a compressed combustion medium with fuel in a continuously operating combustion chamber to form a working medium, the working medium is supplied to cyclical working cylinders in order to extract mechanical energy, and the mechanical energy extracted in the working cylinders is also used for the compression of the combustion medium. The compression is carried out in two steps or at a compression end temperature of less than 300 C. with a compression ratio of more than 10 and/or a rotating distributor includes at least two distributor openings which cyclically open and close the firing connections and/or are cyclically guided past or through firing channels.

Claims

1. An axial piston motor (10) with internal continuous combustion, having a continuously operating combustion chamber (20), having at least two working cylinders (30), and having at least two compressor cylinders (41, 42) driven by the working cylinders (30), wherein firing connections (25) between the continuously working combustion chamber (20) and the working cylinders (30) can be cyclically closed and opened, and wherein a combustion medium feed line (21) for supplying compressed combustion medium to the continuously working combustion chamber (20) is provided between the compressor cylinders (41, 42) and the combustion chamber (20), wherein an outlet (72) of a first compressor cylinder (41) of the two compressor cylinders (41, 42) is connected with an inlet (73) of a second compressor cylinder (42) of the two compressor cylinders (41, 42).

2. The axial piston motor (10) according to claim 1, wherein an inlet (71) of the first compressor cylinder (41) is connected with a combustion medium inlet (75), and an outlet (74) of the second compressor cylinder (42) is connected with the combustion medium feed line (21).

3. The axial piston motor (10) according to claim 1, wherein the second compressor cylinder (42) has a cylinder surface area or the second compressor cylinders (42) in total have a cylinder surface area that corresponds to the root of the compression ratio multiplied by a surface area of the first compressor cylinder (41) or of the first compressor cylinders (41).

4. The axial piston motor (10) according to claim 1, wherein the diameter of the first compressor cylinder (41) is less than 90%, preferably less than 85%, in particular less than 83% of the diameter of one of the working cylinders (30).

5. The axial piston motor (10) according to claim 1, wherein the first compressor cylinder (41) is dimensioned or the first compressor cylinders (41) are dimensioned in such a manner that sufficiently compressed combustion medium for idling of the axial piston motor (10) is made available by the first compressor cylinder(s) (41).

6. The axial piston motor (10) according to claim 1, wherein the rotating distributor (27) is a combustion chamber bottom (28).

7. The axial piston motor (10) according to claim 1, wherein a rotating distributor (27) has at least two distributor openings (29), which cyclically open and close the firing connections (25) and/or are cyclically moved past firing channels (26) or passed through firing channels (26).

8. The axial piston motor (10) according to claim 1, wherein working pistons (35) run in the working cylinders (30), which pistons act on a cam disk (62) of a power take-off (60), which disk forces two strokes to occur per revolution.

9. The axial piston motor (10) according to claim 1, wherein multiple first compressor cylinders (41), each having an outlet (72), and/or multiple second compressor cylinders (42), each having an inlet (73), are provided, wherein each of the outlets (72) is connected with precisely one of the inlets (73) or wherein an outlet (72) is connected with multiple inlets (73) and/or one inlet (73) is connected with multiple outlets (72).

10. The axial piston motor (10) according to claim 1, wherein an intermediate storage unit (48) and/or an intermediate cooler (49) is provided between the outlet (72) of the first compressor cylinder (41) and the inlet (73) of the second compressor cylinder (42).

11. A method for operation of an axial piston motor (10) with internal continuous combustion, in which compressed combustion medium is combusted in a continuously working combustion chamber (20) together with fuel to produce working medium, the working medium is cyclically supplied to working cylinders (30) so as to obtain mechanical energy, and the mechanical energy obtained in the working cylinders (30) is also used for a compression of the combustion medium, wherein compression takes place in two stages and/or wherein compression takes place at final compression temperatures below 300 C.

12. The operating method according to claim 11, wherein the combustion chamber (20) simultaneously has at least two open firing connections (25) to a working cylinder (30), in each instance.

13. The operating method according to claim 11, wherein intermediate cooling takes place between the two stages.

14. The operating method according to claim 11, wherein compression takes place at final compression temperatures below 280 C., preferably below 270C.

15. The operating method according to claim 11, wherein sufficiently compressed combustion medium for idling of the axial piston motor (10) is made available in the first stage.

Description

[0034] Further advantages, goals, and properties of the present invention will be explained using the following description of exemplary embodiments, which are particularly also shown in the attached drawing. The drawing shows:

[0035] FIG. 1 a schematic sectional view of a first axial piston motor;

[0036] FIG. 2 a schematic cross-section through the combustion chamber bottom of the axial piston motor according to FIG. 2;

[0037] FIG. 3 a schematic cross-section through the compressor cylinders of the axial piston motor according to FIGS. 1 and 2;

[0038] FIG. 4 a schematic cross-section through the compressor cylinders of a second axial piston motor;

[0039] FIG. 5 a schematic sectional view of a third axial piston motor in a representation similar to FIG. 1; and

[0040] FIG. 6 a diagram of the principle of the axial piston motors according to FIGS. 1 to 5.

[0041] The axial piston motors 10 shown in the drawing each have a combustion chamber 20, to which combustion medium is supplied by way of combustion medium feed lines 21, which medium is continuously combusted together with fuel, which is applied to the combustion chamber 20 by way of one or more fuel feed lines 22 of the combustion chamber 20, to produce working medium.

[0042] The working medium is passed to working cylinders 30 by way of firing connections 25, which are configured as firing channels 26 in these exemplary embodiments, in which cylinders working pistons 35 run back and forth, which pistons obtain mechanical energy from the working medium and pass this energy, in turn, to a power take-off 60, which in turn comprises a cam disk 62 and a power take-off shaft 61.

[0043] In this regard, the working pistons 35 are provided with connecting rods 50, which run back and forth on the cam disk 62.

[0044] Furthermore, the mechanical energy obtained by means of the working pistons 35 or in the working cylinders 30 is passed to compressor pistons 46, 47, which run back and forth in compressor cylinders 41, 42, so that compression of the combustion medium is carried out there.

[0045] The compressed combustion medium then gets back to the combustion chamber 20 by way of the combustion medium feed line 21, wherein it also runs through heat exchangers 55 for this purpose, in which the thermal residual energy of the working medium can then be passed to the combustion medium supplied to the continuously working combustion chamber 20. The working medium leaves the heat exchangers 55 as exhaust gas 56.

[0046] It is understood that in deviating embodiments, only one heat exchanger 55 and only one combustion medium feed line 21 can be provided. Likewiseunder some circumstancesa combustion medium feed line 21 that does not run through a heat exchanger can be provided in special embodiments. Also, there are embodiments in which multiple heat exchangers 55 are provided, through which multiple combustion agent feed lines 21 or combustion agent feed lines 21 from multiple compressor cylinders 41, 42 and/or multiple working medium lines or working medium lines from multiple working cylinders pass.

[0047] The combustion chamber 20 can be configured in one stage, two stages or multiple stages, but ultimately, this is unimportant for an explanation of the present invention. As is evident from FIG. 6, as much energy as possible can be recovered from the working medium after it leaves the working cylinders 30, the lower the temperature of the compressed combustion agent upon entry into the heat exchanger.

[0048] In all the exemplary embodiments, the axial piston motor 10 has a rotating distributor 27, in each instance, which distributes working medium to the working cylinders 30 successively, in each instance.

[0049] In this regard, the rotating distributor 27 is configured as a combustion chamber bottom 28 in these exemplary embodiments, wherein purely theoretically, other embodiments, such as a separate rotating distributor ring that rotates in the firing channels 26 and separates them, for example, or also a different rotating device that is able to distribute working medium successively to the working cylinders 30 can be provided.

[0050] The rotating distributor 27 has distributor openings 29 that run past the firing channels 26 during rotation, in each instance, so that in this manner, the firing connections 25 can be speedily opened and closed.

[0051] In the present exemplary embodiment, the rotating distributor 27 is connected with the drive shaft 61 or the cam disk 62, so that it rotates along with the latter. If necessary, the synchronization between the rotation of the distributor 27 and the rotation of the cam disk 62 or of the power take-off shaft 61 can be adapted to the given operating conditions, such as short-term power demand or different speeds of rotation, by means of a displacement of the angle of rotation of the rotating distributor 27 with regard to the cam disk 62 or with regard to the power take-off shaft 61.

[0052] In the case of the present exemplary embodiments, compression takes place in two stages, in each instance, so that structurally separable first compressor cylinders 41 and second compressor cylinders 42 are defined. It is understood that if necessary, it is possible to eliminate two-stage compression and therefore a differentiation between first compressor cylinders 41 and second compressor cylinders 42 if the advantages of the rotating distributor and the related characteristics are to be utilized individually. Likewise, it is possible to eliminate the rotating distributor 27 if the firing connections 25 are utilized in conventional manner and two-stage compression is to be provided.

[0053] Each of the compressor cylinders 41, 42 has an inlet 71, 73 and an outlet 72, 74, in each instance.

[0054] In this regard, the inlets 71 of the first compressor cylinders 41 are connected with a combustion medium inlet 75, in each instance, wherein in deviating embodiments, multiple inlets 71 of the first compressor cylinders 41 can also be connected with a common combustion medium inlet 75.

[0055] Also, the outlets 72 of the first compressor cylinders 41 are connected with the inlets of the second compressor cylinders 42, in each instance; this is done, in the present exemplary embodiments, by way of a manifold 78, in each instance, which is also utilized as an intermediate cooler 49. It is understood that in place of the manifold 78, a direct connection between an outlet 72 of the first compressor cylinder 41 and an inlet 73 of the second compressor cylinder 42 can be provided, in each instance, so that a first compressor cylinder 51 communicates with precisely one second compressor cylinder 42, in each instance.

[0056] In order for the manifold to be able to be active as an intermediate cooler 49, it is provided, in the exemplary embodiment according to FIGS. 1 to 4, with cooling plates 49a, while it has cooling coils 49b in the exemplary embodiment according to FIG. 5, in which cooling medium flows.

[0057] In this manner, the final compression temperature can be restricted to 250 C. at a compression ratio of 16 over both stages, due to the two-stage nature and the intermediate cooling. This makes it possible for the compression to approach isothermal compression with its correspondingly good degree of effectiveness.

[0058] In the exemplary embodiment according to FIG. 5, an intermediate storage unit 48 is furthermore provided, which is connected with the manifold 78 by way of a line, not numbered in any detail, in which a valve, not shown in any detail, is provided, so that here, compressed combustion medium can be temporarily stored in the first stage. In this exemplary embodiment, the intermediate storage unit 48 also serves as an intermediate cooler 49, and is also provided with cooling plates 49a for this purpose. Since the combustion medium is frequently supposed to be temporarily stored in the intermediate storage unit 48 over an extended period of time, it is easily possible to eliminate an embodiment of the intermediate storage unit 48 as an intermediate cooler 49 if, for example, short-term intermediate storage remains the exception in a corresponding operating method.

[0059] Furthermore, the outlets 74 of the second compressor cylinder 42 are provided with a manifold 79, in each instance, from which the combustion medium feed lines 21 proceed.

[0060] As is directly evident, the combustion medium therefore reaches the heat exchangers 55 at a temperature that is as low as possible; this actually appears counterproductive in terms of thermodynamics, since the important thing ultimately appears to be bringing the combustion medium to the combustion chamber 20 at a temperature that is as high as possible. On the other hand, isothermal compression proves to be so effective, in terms of energy, that the effort for intermediate cooling or two-stage compression appears to be justified.

[0061] In the present exemplary embodiments, the first compressor cylinders 41 have a clearly greater diameter than the second compressor cylinders 42. The diameter of the first compressor cylinders 41 is 1.8 times the diameter of the second compressor cylinders 42.

[0062] Furthermore, in these exemplary embodiments the diameters of the first compressor cylinders 41 are approximately as great as the diameters of the working cylinders 30. In concrete terms, the diameter of the first compressor cylinders 41 is smaller than the diameter of the working cylinders 30, but not less than 96% of the diameter of the working cylinders 30.

[0063] In the exemplary embodiment according to FIGS. 1 to 4, precisely one compressor cylinder 41, 42 or compressor piston 46, 47 is provided for each working piston 35 or working cylinder 30, wherein in the exemplary embodiment according to FIGS. 1 to 3, three first compressor cylinders 41 and three second compressor cylinders 42 are provided, in each instance, which are disposed with rotation symmetry with regard to the power take-off shaft 61 or the cam disk 62 and the combustion chamber 20, so that the axial piston motor 10 runs as balanced as possible, wherein possible imbalances can be further minimized by means of configurations of the connecting rods and of the pistons.

[0064] Fundamentally, the arrangement in the case of the axial piston motor 10 according to FIG. 4 is similar, so that precisely one working cylinder 30 is also provided for each compressor cylinder 41, 42, which cylinders are arranged coaxially, in each instance. However, only two second compressor cylinders 42 and three first compressor cylinders 41 are provided, which are accordingly arranged around the power take-off shaft 41, the cam disk 62 or the combustion chamber 20 as symmetrically as possible. Here, too, the cam disk 62 can be configured in such a manner that it forces two strokes to occur per revolution, wherein then the distributor openings 29 should be structured in suitable manner and have the firing channels 26 on different levels, if applicable, and interact with different distributor openings 29. Likewise, of course, here a conventional opening of the firing connections 25 can be provided. Also, it is conceivable to provide merely one distributor opening 29, and to configure the cam disk 62 in such a manner that it only forces one stroke to occur per revolution.

[0065] In the exemplary embodiment shown in FIG. 5, two compressor cylinders 41 interact with one working piston 35. For this purpose, the related compressor pistons 46, 47 sit on top of one another, wherein it is advantageous to set the compressor piston 47 of the second compressor cylinder 42, which preferably should have a smaller diameter, onto the compressor piston 46 of the first compressor cylinder 41.

REFERENCE SYMBOL LIST

[0066] 10 axial piston motor [0067] 20 combustion chamber [0068] 21 combustion medium feed line [0069] 22 fuel feed line [0070] 25 firing connections [0071] 26 firing channel [0072] 27 rotating distributor [0073] 28 combustion chamber bottom [0074] 29 distributor opening [0075] 30 working cylinder [0076] 35 working piston [0077] 41 first compressor cylinder [0078] 42 second compressor cylinder [0079] 46 compressor piston [0080] 47 compressor piston [0081] 48 intermediate storage unit [0082] 49 intermediate cooler [0083] 49a cooling plate [0084] 49b cooling coil [0085] 50 connecting rod [0086] 55 heat exchanger [0087] 56 exhaust gas [0088] 60 power take-off [0089] 61 power take-off shaft [0090] 62 cam disk [0091] 71 inlet of the first compressor cylinder 41 [0092] 72 outlet of the first compressor cylinder 41 [0093] 73 inlet of the second compressor cylinder 42 [0094] 74 outlet of the second compressor cylinder 42 [0095] 75 combustion medium inlet [0096] 78 manifold [0097] 79 manifold