Engine

Abstract

An engine having at least one displacer cylinder in which a liquid, in particular an ionic liquid, is arranged and which can be connected to a feed passage and a discharge passage for a medium, is disclosed. The liquid is operatively connected to a displacer device. The displacer cylinder is arranged in a cylindrical drum, rotatably mounted about an axis of rotation, at an angle to the axis of rotation of the cylindrical drum. In an embodiment, the displacer cylinder is arranged perpendicularly to the axis of rotation of the cylindrical drum, and the displacer cylinder is designed as a radial bore arranged in the cylindrical drum.

Description

BACKGROUND AND SUMMARY OF THE INVENTION

This application claims the priority of International Application No. PCT/EP2006/007332, filed Jul. 25, 2006, and German Patent Document No. 10 2005 036 308.3, filed Aug. 2, 2005, the disclosures of which are expressly incorporated by reference herein.

The invention relates to an engine having at least one displacer cylinder in which a liquid, in particular an ionic liquid, is arranged and which can be connected to a feed passage and a discharge passage for medium, wherein the liquid is operatively connected to a displacer device.

These types of engines are used for example as compressors for compressing gaseous media. The medium in this case is displaced by means of the liquid in the displacer cylinder, whereby these types of engines are designated as non-positive compressors. An ionic liquid can be used as the liquid. However, it is also possible to use liquids with a low vapor pressure or liquids with low gas solubility. What these types of liquids have in common is that they do not dissolve in the medium and can be separated from the medium without leaving a residue so that the compressed medium exhibits a high level of purity.

A generic engine embodied as a compressor for gaseous media is known from U.S. Pat. No. 6,652,243 B2. In the case of this non-positive compressor, the liquid in the displacer cylinders is connected to a pump, whereby a control valve is provided to control the supply and discharge of the liquid, and this valve is controlled as a function of the liquid level in the displacer cylinders, which is detected by means of electronic displacement measuring systems. The displacer cylinders are preferably arranged vertically in order to support the discharge of liquid from the displacer cylinder via gravity. In the case of this type of compressor, the liquid column cannot be accelerated beyond the gravitational acceleration so that the cycle speed of the compressor is limited by the gravitational acceleration. These types of compressors require a lot of construction space and have limited displacer output. In addition, the electronic displacement measuring systems result in higher construction expenditures.

The present invention is based on the objective of making available an engine of the species cited at the outset, which does not require a lot of construction space and has high displacer output.

This objective is attained in accordance with the invention in that the displacer cylinder is arranged in a cylindrical drum, rotatably mounted about an axis of rotation, at an angle to the axis of rotation of the cylindrical drum. According to the invention, the displacer cylinder is thereby embodied in a cylindrical drum rotating around the axis of rotation, whereby the displacer cylinder and thus the longitudinal axis of the displacer cylinder are at an angle to the axis of rotation of the cylindrical drum. Due to the rotation of the cylindrical drum and thus the displacer cylinder, a centrifugal force that is a function of the speed of the cylindrical drum acts on the liquid located in the displacer cylinder thereby accelerating the liquid. The accelerations of the liquid that can be achieved hereby are greater than the gravitational accelerations so that the liquid column in the case of the inventive engine can be moved at a higher speed as compared with a prior art engine, therefore making it possible to achieve a high cycle speed. This makes it possible to provide high displacer output with a low requirement for construction space for the engine. In addition, the inventive engine requires only a low quantity of liquid, in particular ionic liquid, thereby resulting in low manufacturing costs for the inventive engine.

Special advantages are yielded, if, according to a preferred embodiment of the invention, the displacer cylinder is arranged perpendicularly to the axis of rotation of the cylindrical drum. This results in a high centrifugal force, whereby high displacer output can be made available with a low requirement for construction space for the engine.

Simple manufacturing of the displacer cylinder can be achieved, if the displacer cylinder according to a preferred embodiment of the invention is designed as a radial bore in the cylindrical drum.

A valve plate is advantageously provided for controlling the connection of the displacer cylinder to the feed passage as well as to the discharge passage. A valve plate can be used in a simple manner to control the connection of the displacer cylinder arranged in the rotating cylindrical drum to the feed passage and the discharge passage.

In this case, the cylindrical drum is expediently supported in the axial direction on the valve plate, which is arranged on a housing. This design allows axial sealing gaps between the displacer cylinders and the feed passage as well as the discharge passage to be achieved, which can be sealed in a simple manner allowing the engine to be operated at high operating pressures with low leakage losses.

The cylindrical drum is advantageously operatively connected to a drive shaft, whereby a drive or an output of the engine can be formed in a simple manner.

If according to a development of the invention, the displacer cylinder is provided with a cooling device, in particular internal cooling, isothermal compression can be realized with an engine operating as a compressor or isothermal expansion with an engine operating as a drive motor. This allows low thermal stress and strain on the engine to be achieved as well as a high degree of efficiency of the engine. Cooling fins for example can be arranged in the displacer cylinder as the cooling device.

According to a preferred embodiment of the invention, the displacer device is embodied as an axial piston machine, whereby each displacer cylinder is connected to a cylinder space of the axial piston machine. An axial piston machine that has a rotating cylinder block, in which the cylinder spaces are embodied, allows, in connection with the cylindrical drum featuring the displacer cylinder, a simple structure and a low requirement for construction space for the engine to be realized.

A development of the invention provides that the axial piston machine be embodied as a diagonal plate machine with a diagonal plate, in particular an adjustable diagonal plate. A diagonal plate machine, whose conveyance volume and/or absorption capacity can be adjusted, allows the displacer output of the engine and the speed of the cylindrical drum that is provided with the displacer cylinders to be modified in a simple manner by pivoting the diagonal plate. As a result, it is possible to guarantee in a simple manner that the acceleration of the liquid column, which is caused by the rotation of the displacer cylinder and thus by the centrifugal forces, is greater than the sinusoidal acceleration of the liquid column generated by the axial piston machine, and therefore that the engine is in equilibrium.

According to a preferred embodiment of the invention, in which the axial piston machine has a cylinder block equipped with the cylinder spaces, the cylinder block of the axial piston machine is coupled in a rotationally synchronous manner to the cylindrical drum accommodating the displacer cylinder. This permits a secure and rotationally synchronous connection to be achieved in a simple manner between the cylinder spaces arranged in the cylinder block of the axial piston machine and the displacer cylinders of the cylindrical drum.

If, according to another embodiment of the invention, the cylinder block of the axial piston machine and the cylindrical drum accommodating the displacer cylinder are embodied as a common cylindrical drum, the displacer cylinder can be integrated into the cylinder block of the axial piston machine, thereby making an engine available that has a lower number of parts, does not require a lot of construction space and therefore has low manufacturing expenditures.

With respect to a simple structure and a low requirement for construction space, it is favorable, if, according to a development of the invention, the cylindrical drum and the displacer device are arranged in a common housing.

According to an advantageous embodiment, the inventive engine can be embodied as a compressor for compressing a gaseous medium, in particular hydrogen. With an inventive non-positive compressor, in which the medium is compressed by the axial piston machine operated as a pump through the liquid conveyed by the axial piston machine, high compressor output can be achieved with a low requirement for construction space as well as low manufacturing expenditures and a high level of purity of the compressed medium.

The inventive engine can also be embodied as a drive motor for tapping torque. Propulsion takes place in this case via the medium, whereby torque is generated by means of the axial piston machine operated as a motor and driven by the liquid, which can be tapped via the cylindrical drum and the drive shaft. Due to the inventive radial arrangement of the displacer cylinders, high displacer output can be generated in this case with a low requirement for construction space.

Additional advantages and details of the invention are explained in greater detail on the basis of the exemplary embodiment depicted schematically in the FIGURE.

BRIEF DESCRIPTION OF THE DRAWING

The FIGURE provides a longitudinal section view of an embodiment of an engine in accordance with the principles of the present invention.

DETAILED DESCRIPTION OF THE DRAWING

The FIGURE depicts a longitudinal section of an inventive engine 1. A drive shaft 3 is rotatably mounted within a housing 2 around an axis of rotation 4. A cylindrical drum 5, in which several displacer cylinders 6 are embodied, is coupled to the drive shaft 3 in a rotationally synchronous manner. The displacer cylinders 6 in this case are embodied as radial bores 14 arranged in the cylindrical drum 5 and are arranged in a star-shape around the axis of rotation 4, whereby the longitudinal axis 7 of the displacer cylinders 6 is arranged perpendicularly to the axis of rotation 4 of the drive shaft 3 and thus of the cylindrical drum 5.

In the radial inner region, the displacer cylinders 6 are each connected to a connecting passage 8, which is operatively connected to a plate-shaped valve plate 9, whereby the connection of the displacer cylinders 6 to a feed passage 10 as well as to a discharge passage 11 can be controlled by means of the valve plate 9. The cylindrical drum 5 in this case is supported in the axial direction on the valve plate 9, which is arranged on a housing cover 12 fastened to the housing 2.

A liquid 15, in particular an ionic liquid, is arranged in the displacer cylinders 6.

Each displacer cylinder 6 is connected by means of a connecting passage 13 to a cylinder space 16 of a hydraulic displacer device 17 embodied as an axial piston machine having a diagonal plate design. In this case, the displacer device 17 embodied as an axial piston machine has a cylinder block 18, which is arranged coaxially to the cylindrical drum 5 and is connected to the cylindrical drum 5 and/or the drive shaft 3 in a rotationally fixed manner. It is also possible to embody the cylinder block 18 and the cylindrical drum 5 as a common and therefore one-piece cylindrical drum.

The cylinder spaces 16 of the axial piston machine are formed by the longitudinal bores 20 arranged concentrically in the cylinder block 18, in which bores pistons 21 are respectively arranged in a longitudinally displaceable manner. The pistons 21 are each supported on a diagonal plate 23 by means of a sliding block 22. A spherical sliding block articulation is embodied between the piston 21 and sliding block 22.

The axial piston machine is embodied as an axial piston machine whose displacer volume can be adjusted, whereby the diagonal plate 23 is swivel-mounted on the housing 2 and can be inclined with respect the axis of rotation 4 by means of a regulating device (not shown). However, it is also possible to embody the axial piston machine with a fixed displacer volume, whereby the diagonal plate can be embodied directly on the housing 2.

In this case, the cylindrical drum 5 and the displacer device 17 are arranged in the common housing.

In the case of an embodiment of the inventive engine 1 as a compressor, the cylindrical drum 5 and the cylinder block 18 are driven via the drive shaft 3. In this case, the axial piston machine functions as a pump and conveys liquid 15 from the cylinder spaces 16 to the displacer cylinder 6, whereby the medium flowing into the displacer cylinder 6 via the feed passage 10 is compressed by the liquid 15 and conveyed to the discharge passage 11. When the engine 1 is in operation, centrifugal force acts on the liquid 15 due to the radial arrangement of the displacer cylinders 6 through the rotation of the cylindrical drum 5, and this centrifugal force accelerates the liquid, allowing the liquid column to be moved at a great speed and thus the engine 1 can be operated at a great speed and therefore at a high cycle speed.

Therefore, the construction space of the inventive engine can be reduced as compared to generic compressors having the same conveying capacity, whereby a high conveying capacity with high efficiency can be achieved with a low requirement for construction space.

Direct control of the conveying capacity is possible due to the adjustable diagonal plate 23 of the axial piston pump. Controlling the connection of the rotating displacer cylinder 6 to the feed passage 10 as well as to the discharge passage 11 via the valve plate 9 makes it possible to dispense with an electric displacement measuring system, which results in lower manufacturing costs for the inventive engine 1.

In the case of an embodiment of the inventive engine 1 as a drive motor, pressurized medium is supplied to the displacer cylinders 6 via the feed passage 10. The liquid 15 acts on the pistons 21, whereby the axial piston machine is operated as a motor and a rotational movement of the cylindrical drum 5 and of the cylinder block 18 is generated, whereby torque can be tapped on the drive shaft 3.

Claims

1-14. (canceled)

15. An engine having a displacer cylinder in which a liquid, in particular an ionic liquid, is arranged and which is connectable to a feed passage and a discharge passage for a medium, wherein the liquid is operatively connected to a displacer device, wherein the displacer cylinder is arranged in a cylindrical drum that is rotatably mounted about an axis of rotation, and wherein the displacer cylinder is arranged in the cylindrical drum at an angle to the axis of rotation of the cylindrical drum.

16. The engine according to claim 15, wherein the displacer cylinder is arranged perpendicularly to the axis of rotation of the cylindrical drum.

17. The engine according to claim 15, wherein the displacer cylinder is designed as a radial bore arranged in the cylindrical drum.

18. The engine according to claim 15, wherein a valve plate is provided to control a connection of the displacer cylinder to the feed passage and the discharge passage.

19. The engine according to claim 18, wherein the cylindrical drum is supported in an axial direction on the valve plate, which is arranged on a housing.

20. The engine according to claim 15, wherein the cylindrical drum is operatively connected to a drive shaft.

21. The engine according to claim 15, wherein the displacer cylinder is provided with a cooling device.

22. The engine according to claim 15, wherein the displacer device is embodied as an axial piston machine, wherein the displacer cylinder is connected to a cylinder space of the axial piston machine.

23. The engine according to claim 22, wherein the axial piston machine is embodied as a diagonal plate machine with an adjustable diagonal plate.

24. The engine according to claim 22, wherein the axial piston machine has a cylinder block equipped with the cylinder space, wherein the cylinder block of the axial piston machine is coupled in a rotationally synchronous manner to the cylindrical drum accommodating the displacer cylinder.

25. The engine according to claim 22, wherein a cylinder block of the axial piston machine and the cylindrical drum accommodating the displacer cylinder are embodied as a common cylindrical drum.

26. The engine according to claim 15, wherein the cylindrical drum and the displacer device are arranged in a common housing.

27. The engine according to claim 15, wherein the engine is embodied as a compressor for compressing a gaseous medium

28. The engine according to claim 27, wherein the gaseous medium is hydrogen.

29. The engine according to claim 15, wherein the engine is embodied as a drive motor for tapping torque.

30. An engine, comprising:

a displacer device; and

a rotatable drum coupled to the displacer device;

wherein the rotatable drum defines a displacer cylinder and wherein the displacer cylinder is arranged in the cylindrical drum at an angle to an axis of rotation of the cylindrical drum.

31. The engine according to claim 30, wherein a longitudinal axis of the displacer cylinder is perpendicular to the axis of rotation of the cylindrical drum.

32. The engine according to claim 30, wherein an ionic liquid is disposed within the displacer cylinder and wherein a pressure of the ionic liquid is increased by a centrifugal force imparted to the ionic liquid by a rotation of the cylindrical drum.

33. The engine according to claim 32, wherein the ionic liquid with an increased pressure compresses a medium supplied to the displacer cylinder.

34. The engine according to claim 30, wherein the cylindrical drum is coupled to a drive shaft.