FLUID ENERGY MACHINE, METHOD FOR GENERATING A FLUID VOLUME FLOW AND/OR FOR COMPRESSING A FLUID AND METHOD FOR REFUELLING A VEHICLE

Abstract

The invention relates to a fluid energy machine and a method for generating a fluid-volume flow and for compressing a fluid by means of the fluid energy machine according to the invention. The invention also relates to a method for refuelling a vehicle with a fluid using the method according to the invention for generating a fluid-volume flow and for compressing a fluid, and to the use of a fluid energy machine according to the invention for refuelling a motor vehicle. The fluid energy machine comprises a crank drive (20) and a drive device (10) that is mechanically connected to the crank drive (20), by means of which drive device a torque can be introduced into the crank drive (20), as well as a piston-cylinder unit (30), the piston (32) of which is mechanically connected to the crank drive (20). The drive device (10) comprises two electric motors (50, 60), the respective output members (51, 61) of which are mechanically connected to the crank drive (20).

Claims

1. A fluid energy machine, comprising a crank drive and a drive device which is mechanically connected to the crank drive, with which a torque can be introduced into the crank drive, and also comprising a piston-cylinder assembly, the piston of which is mechanically connected to the crank drive, characterized in that the drive device comprises two electric motors, the respective output members of which are mechanically connected to the crank drive and that the piston-cylinder unit comprises only one piston and only one cylinder.

2. The fluid energy machine according to claim 1, characterized in that the fluid energy machine is a low-temperature pump, for generating a fluid volume flow and for compressing a fluid.

3. The fluid energy machine according to claim 1, characterized in that the fluid energy machine is set up such that the fluid can be compressed up to a pressure of 50 to 1000 bar.

4. The fluid energy machine according claim 1, characterized in that the mechanical coupling of the electric motors to the crank drive on the crank of the crank drive is implemented such that the motor torque is introduced into the crank.

5. The fluid energy machine according to claim 4, characterized in that an output member of at least one electric motor is directly coupled to the crank of the crank drive by means of a shaft.

6. The fluid energy machine according to claim 4, characterized in that between an output member of at least one electric motor and the crank of the crank drive a transmission is arranged for transforming the torque generated by the electric motor up or down.

7. The fluid energy machine according to claim 1, characterized in that the crank drive comprises a connecting rod, and the piston is mechanically connected to the connecting rod.

8. The fluid energy machine according to claim 1, characterized in that the shaft is mounted on a ball bearing.

9. A method for using a fluid energy machine comprising a crank drive and a drive device which is mechanically connected to the crank drive, with which a torque can be introduced into the crank drive, and also comprising a piston-cylinder assembly, the piston of which is mechanically connected to the crank drive, characterized in that the drive device comprises two electric motors, the respective output members of which are mechanically connected to the crank drive and that the piston-cylinder unit comprises only one piston and only one cylinder for generating a hydrogen volume flow and for compressing hydrogen, said hydrogen to be transported and compressed being provided in a liquid state, characterized in that the hydrogen is fed to the piston cylinder assembly and the electric motors of the fluid energy machine are operated such that the piston of the piston cylinder assembly is displaced and a hydrogen volume flow is thereby generated and the hydrogen is compressed.

10. The method according to claim 9, characterized in that the compressed hydrogen is used for refuelling a vehicle with liquid or gaseous hydrogen.

11. The method according to claim 9, characterized in that the fluid energy machine is designed as a two-stage piston machine and in the first stage a pre-compression of the hydrogen takes place and in the second stage the compression up to the system pressure takes place.

12. The method according to claim 11, characterized in that during the pre-compression the pressure is increased by from 4 to 12 bar.

13. The method according to claim 11, characterized in that the system pressure is 50 to 1000 bar.

14. The method according to claim 9, characterized in that the pumping quantity of hydrogen of the fluid energy machine is adjusted via the frequency of the electric motors and this is between 0 and 250 kg/h.

15. The method as claimed in claim 13 characterized in that the system pressure is 350 to 700 bar.

16. The method as claimed in claim 13 characterized in that the system pressure is 350 to 500 bar.

17. The method as claimed in claim 14 characterized in that the pumping quantity of hydrogen is between 30 to 200 kg/h.

Description

[0029] Shown are

[0030] FIG. 1: a fluid energy machine according to the invention in a first embodiment,

[0031] FIG. 2: a fluid energy machine according to the invention in a second embodiment.

[0032] The embodiments shown in FIGS. 1 and 2 differ in that in the version shown in FIG. 1, the motors are directly connected to the crank drive and in variant 2 shown in FIG. 2, transmissions are provided between the motors and the crank drive.

[0033] To describe the features present in both embodiments, reference will be first made to both figures.

[0034] Both versions comprise a drive device 10, which in the exemplary embodiments shown is implemented by a first motor 50 and a second motor 60. Both motors are implemented as electric motors. Both motors 50, 60 are each connected to a rotation rate sensor 53, 63 for setting the motor rotation speed. In both embodiments of the fluid energy machine a crank drive 20 is provided, which comprises a crank 21, shown here with two eccentric disks, and a connecting rod 22 or coupling, which is connected to the crank 21 or to the two eccentric disks thereof via a first joint 23. Furthermore, in both embodiments a piston-cylinder assembly 30 is provided, which comprises a piston 32 that can be displaced in a cylinder 31. The connecting rod 22 or coupling of the crank drive 20 is connected via a second joint 24 to the piston 32 of the piston-cylinder assembly 30. During rotation of the crank 21, a typical combined motion of rotation and translation of the connecting rod 22 takes place, which absorb the shear forces from the piston 32, the piston rod of which is mounted on both sides by bearings, not shown here, which each form a sliding joint, and cause the forced operation of the piston 32 in the cylinder 31 in the form of a piston stroke action.

[0035] On the cylinder 31 of the piston-cylinder assembly 30 an inlet device 33 is provided for feeding a fluid 40 into the cylinder 31, and an outlet device 34 for discharging the fluid 40 located in the cylinder 31, which may be compressed. The first motor 50 comprises a first output member 51 and the second motor 60 comprises a second output member 61. These output members 51, 61 are, for example, the shaft journals of the motors 50, 60. The respective output member 50, 60 is connected to a shaft, so that the first output member 51 is connected to a first shaft 52 and the second output member 61 is connected to a second shaft 62.

[0036] In the embodiment shown in FIG. 1 both the first shaft 52 and the second shaft 62 are connected directly to the crank 21 of the crank drive 20, so that a torque generated by the respective motor 50, 60 is applied via the output member 51, 61 to the shaft 32, 62 arranged thereon and by this shaft 52, 62 is applied to the crank 21 of the crank drive 20, so that the stroke motion of the piston 32 can be implemented by the crank drive 20.

[0037] In the embodiment shown in FIG. 2 the first shaft 52 is connected to a first transmission 70, which comprises a first driving spur gear 71 on the first shaft 52, which gear meshes with a first driven spur gear 72 that is seated on a first output shaft 73, which is rigidly connected to the crank 21 of the crank drive 20.

[0038] In a similar manner, a second driving spur gear 81 sits on the second shaft 62, which gear meshes with a second driven spur gear 82, which in turn is seated on a second output shaft 33 that is rigidly connected to the crank 21 of the crank drive 20. This mechanism allows the torque and the rotation speed of the motors 50, 60 to be transformed up or down, to increase the torque to be generated by the crank drive 20 or else to increase the frequency of the motion of the piston 32.

[0039] The invention is not limited to an embodiment shown in FIG. 2 with a symmetrical arrangement of transmission members, rather it can also be provided to arrange different transmissions between the motors 50, 60 and the crank drive 20 and possibly also couplings between the respective motor 50, 60 and the crank drive 20, in order to engage or disengage a drive train as appropriate and thereby provide a torque on demand.

LIST OF REFERENCE NUMERALS

[0040] Drive device 10 [0041] Crank drive 20 [0042] Crank 21 [0043] Connecting rod 22 [0044] First joint 23 [0045] Second joint 24 [0046] Piston-cylinder unit 30 [0047] Cylinder 31 [0048] Piston 32 [0049] Inlet device 33 [0050] Outlet device 34 [0051] Fluid 40 [0052] First motor 50 [0053] First output member 51 [0054] First shaft 52 [0055] First rotation rate sensor 53 [0056] Second motor 60 [0057] Second output member 61 [0058] Second shaft 62 [0059] Second rotation rate sensor 63 [0060] First transmission 70 [0061] First driving spur gear 71 [0062] First driven spur gear 72 [0063] First output shaft 73 [0064] Second transmission 80 [0065] Second driving spur gear 81 [0066] Second driven spur gear 82 [0067] Second output shaft 83