DRIVE AND METHOD FOR OPERATING A DRIVE

Abstract

A drive includes an electric motor and a first gearbox that can be driven by the electric motor. An output shaft of the first gearbox is connected rotation-fast to a first shaft by a coupling, e.g., a rigid shaft coupling, and the first shaft is mounted by an axial bearing, e.g., a single axial bearing, that can be subjected to a force by at least one controllable first linear actuator.

Claims

1-16. (canceled)

17. A drive, comprising: a first gearbox; and an electric motor adapted to drive the first gearbox, the first gearbox including an output shaft of the first gearbox is connected rotatably-fixed to a first shaft by a coupling, the first shaft being mounted by an axial bearing adapted to be subjected to a force by at least one controllable first linear actuator.

18. The drive according to claim 17, wherein the coupling is arranged as a rigid coupling, and the axial bearing is arranged as a single axial bearing.

19. The drive according to claim 17, wherein the first shaft is connected and/or rotationally-fixedly connected to a generator unit via a cardan shaft and/or by cardan joints.

20. The drive according to claim 19, wherein the generator unit includes a generator adapted to be driven by a second gearbox.

21. The drive according to claim 17, wherein the first shaft is connected and/or rotationally-fixedly connected at an end region facing away from the first gearbox, via a coupling and/or a rigid coupling, to a first cardan joint that at a side facing way from the first shaft is connected and/or rotationally-fixedly connected to a cardan shaft, the cardan shaft being connected and/or rotationally-fixedly connected at a side facing away from the first shaft to a second cardan joint, so that at a side facing away from the cardan shaft is rotatably-fixedly connected by a coupling and/or a rigid coupling to a drive shaft of a generator unit and/or of a second gearbox of the generator unit.

22. The drive according to claim 17, wherein the first gearbox is connected to an expansion tank, an inner space of the first gearbox being filled and/or completely filed with oil, thermally caused expansions of the oil in the inner space being receivable in the expansion tank.

23. The drive according to claim 22, wherein the expansion tank includes an inner space formed from two subregions separated from one another by a membrane, a first one of the subregions being connected to the inner space of the first gearbox with an oil line, a second one of the subregions being connected to the environment.

24. The drive according to claim 23, wherein the first subregion and the inner space of the first gearbox is completely filled with oil, and the inner space of the expansion tank and/or the membrane is arranged higher in a direction of gravity than the inner space of the first gearbox.

25. The drive according to claim 17, wherein a further axial bearing and/or a thrust bearing is arranged in a housing of the first gearbox, and the output shaft of the first gearbox is rotationally mounted by the further axial bearing and/or the thrust bearing, a rotational axis of the output shaft being oriented horizontally and/or perpendicular to a direction of gravity.

26. The drive according to claim 25, wherein the output shaft of the first gearbox is rotationally mounted by two additional bearings arranged in the housing of the first gearbox.

27. The drive according to claim 26, wherein each of the two additional bearings is arranged as a twin row bearing.

28. The drive according to claim 17, wherein the drive is arranged on a flat base surface of an industrial plant, and a rotational axis of the output shaft is oriented perpendicular to a normal of a plane of the base surface.

29. The drive according to claim 17, the axial bearing is adapted to be subjected to a force by at least one controllable second linear actuator.

30. The drive according to claim 29, wherein the force by the second linear actuator is oriented perpendicular to the force by the first linear actuator.

31. The drive according to claim 29, wherein the axial bearing is adapted to be subjected to an axially oriented force by at least one controllable third linear actuator and/or the axial bearing is adapted to be subjected to a force oriented perpendicular to the force by the first linear actuator, perpendicular to the force by the second linear actuator, and in an axial direction, by at least one controllable third linear actuator.

32. The drive according to claim 29, wherein the first linear actuator is adapted to be controlled by a control device with a time-variable first control signal, and/or a periodically variable first control signal, the second linear actuator is adapted to be controlled by the control device with a time-variable second control signal and/or a periodically variable second control signal.

33. The drive according to claim 32, wherein the first and second control signals have a same frequency and have a 90° phase offset relative to one another.

34. A method for operating the drive recited in claim 17, the axial bearing adapted to be subjected to a further force by at least one controllable second linear actuator, comprising: controlling the first linear actuator by a control device with a time-variable first control signal and/or a periodically variable first control signal; and controlling the second linear actuator by the control device with a second time-variable second control signal and/or a periodically variable second control signal.

35. The method according to claim 34, wherein the first and second control signals have a same frequency.

36. The method according to claim 35, wherein the first control signal has a phase offset and/or a 90° phase offset relative to the second control signal and/or a rotational speed of the output shaft equals the frequency.

37. The method according to claim 34, wherein the first and second control signals have a same frequency, a rotational speed of the output shaft differs from the frequency.

38. The method according to claim 37, wherein the rotational speed of the output shaft differs from the frequency by less than 40%.

39. The method according to claim 37, wherein the first control signal has a phase offset and/or a 90° phase offset relative to the second control signal.

40. The method according to claim 34, further comprising, after the controllings: removing the first gearbox of the drive, connecting the first gearbox to a further electric motor, and (a) orienting a direction of a rotational axis of the output shaft perpendicular to a direction of the rotational axis of the output shaft during the controllings and/or (b) rotating the output shaft of the first gearbox 90°, in a vertical direction, and/or parallel to a direction of gravity.

41. The method according to claim 34, wherein, during the controllings, an inner space of the first gearbox is completely filled with oil, and, during the removing, the connecting, and the (a) orienting and/or (b) rotating, the inner space of the first gearbox is only partially filled with oil and/or is not completely filled with oil and/or a further axial bearing and the two additional bearings arranged in a housing of the first gearbox are arranged at least in part below an oil level.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0028] FIG. 1 schematically illustrates a test stand for introducing transverse force into the output shaft of a gearbox.

DETAILED DESCRIPTION

[0029] An electric motor 1 of the test stand drives a test specimen 2, e.g., a gearbox. To this end, the rotor shaft of the electric motor 1 is connected to the drive shaft of the test specimen 2 arranged as a gearbox.

[0030] The housing of the test specimen 1 and the housing of the electric motor 1 are connected to the base 14 of the industrial plant in which the test stand is arranged.

[0031] Toothed parts having rotationally mounted shafts are arranged in the inner space surrounded by the housing of the test specimen 1 and are surrounded by oil, e.g., lubricating oil. Since the gearbox used as test specimen 1 is provided for applications in which the output shaft is oriented vertically, for example, is provided for as mixer gearbox, and in the application at least partial filling of the inner space with oil is provided, the gearbox is completely filled with oil for the testing on the test stand. This ensures that all regions to be wetted with oil in the application are also wetted with oil on the test stand during the testing. An expansion tank 3 is connected to the gearbox so that, in the event of thermal expansion of the oil, the oil can flow into and/or out of a volume, e.g., limited by a diaphragm. To this end, the inner space of the gearbox is connected to the inner space of the expansion tank 3, and the part of the inner space of the expansion tank 3 not filled with oil is connected to the surroundings. The expansion tank 3 is arranged higher than the gearbox, at least in part.

[0032] The output shaft of the gearbox is connected by a first coupling 5, e.g., a rigid shaft coupling, to a first shaft 4 arranged rotationally mounted via at least one axial bearing 6.

[0033] The axial bearing 6 has an inner ring, rolling elements, and an outer ring. The inner ring is placed over the first shaft 4. The inner ring is, for example, connected to the first shaft 4 in a non-positive fit, e.g., by a snug fit.

[0034] The outer ring is movable by a first linear actuator 15, e.g., by a hydraulic actuator, transverse to the rotational axis of the first shaft 4, that is, also transverse to the rotational axis of the output shaft of the gearbox. The first linear actuator 15 is supported on the base 14.

[0035] Thus, by the first linear actuator 15, the first shaft 4 and therefore also the output shaft of the gearbox can be subjected to a transverse force that is oriented perpendicular to the direction of the rotational axis of the first shaft 4 and of the output shaft of the gearbox.

[0036] By modulated operation of the linear actuator 15, a corresponding time-dependent transverse force can be generated. In this manner, a periodic load can, for example, be introduced during the rotational movement of the output shaft.

[0037] A second coupling 7, e.g., a rigid shaft coupling, is arranged at the end region of the first shaft 4 facing away from the gearbox, to which coupling a cardan joint 8 is connected, so that the torque supplied by the output shaft of the gearbox 2 is fed to a cardan shaft 9, which is connected to a generator 13 connected to a gearbox 12 via a further cardan joint 10 arranged on its side facing away from the gearbox, with a further coupling 11, e.g., with a further rigid shaft coupling.

[0038] Thus, transverse deflections of the first shaft 4 can also be compensated by the cardan joints 8, 10.

[0039] According to exemplary embodiments, a second linear actuator 15 is arranged supported on the base and also presses on the outer ring of the axial bearing, the direction of the transverse force being applied, e.g., perpendicular or at least at an angle of more than 50° to the effective direction of the first linear actuator 15.

[0040] Thus, with suitable modulation, e.g., 90° phase-shifted periodic modulation, of the two linear actuators 14, circularly circumferential transverse forces can also be generated.

[0041] Thus, the first linear actuator is, for example, subjected to a sinusoidal time-dependent control signal, and the second linear actuator to a cosinusoidal time-dependent control signal.

[0042] Such a periodically circulating load is suitable for simulating a load during stirring operation of a mixer.

[0043] According to exemplary embodiments, alternatively or in addition, a third linear actuator is provided that loads the outer ring in the axial direction, that is, parallel to the direction of the rotational axis of the output shaft. Thus, an axial force, e.g., a modulated axial force, can also be simulated.

LIST OF REFERENCE NUMERALS

[0044] 1 Electric motor [0045] 2 Test specimen, e.g., gearbox [0046] 3 Expansion tank, e.g., for oil [0047] 4 First shaft [0048] 5 First coupling [0049] 6 Axial bearing [0050] 7 Second coupling [0051] 8 Cardan joint [0052] 9 Second shaft, e.g., cardan shaft [0053] 10 Cardan joint [0054] 11 Third coupling [0055] 12 Gearbox [0056] 13 Generator [0057] 14 Base [0058] 15 Linear actuator, e.g., hydraulic actuator