CRANE AND METHOD FOR OPERATING A CRANE USING RECOVERY OF ENERGY FROM CRANE OPERATIONS AS A SECONDARY ENERGY SOURCE

• US 20120160796A1
• Filed: 12/22/2010
• Published: 06/28/2012
• Est. Priority Date: 12/22/2010
• Status: Active Grant

• Current Assignee: Tadano Demag GmbH (Tadano Limited)
• Original Assignee: Terex Demag GmbH (Tadano Limited)
• Inventors: Schnittker, Frank, WECKBECKER, Alfons, Krebs, Marc, Beckmann, Axel, Helfrich, Steffen
• Granted Patent: US 8,857,635 B2
• Time in Patent Office: Days
• US Class Current: 212/284
• CPC Class Codes: B66C 13/28 utilising regenerative braking for controlling descent of heavy loads and having means for preventing rotation of motor in the hoisting direction when load is released
• CPC Class Codes: B66C 23/76 and movable to take account of variations of load or of variations of length of jib
• CPC Class Codes: B66D 1/12 incorporating electric motors
• CPC Class Codes: B66D 1/22 Planetary or differential gearings for actuating grab buckets B66D1/70 , i.e. with planet gears having movable axes of rotation

Abstract

A crane, in particular a large crane, including a power consumer system for providing energy, a primary energy source for feeding primary energy into the power consumer system, at least one secondary energy source, independent of the primary energy source, for feeding secondary energy into the power consumer system, at least one energy storage unit arranged locally on the crane and is, in particular, associated with the at least one crane component and connected to the power consumer system for storing primary energy and/or secondary energy, at least one drive motor connected to the power consumer system for operating at least one crane component and a secondary energy source configured such that energy returned from the crane operation is at least partially fed as secondary energy into the power consumer system. The at least one crane component is configured as a secondary energy source for energy recovery.

Claims

1. A crane comprising:

a power consumer system for providing energy;

a primary energy source for feeding primary energy into the power consumer system;

at least one secondary energy source, controllable independent from the primary energy source, for feeding secondary energy into the power consumer system, wherein the secondary energy source is connected to the power consumer system, and configured such that energy returned from operation of the at least one secondary energy source is at least partially fed as secondary energy into the power consumer system, said secondary energy source comprising at least one crane component;

at least one energy storage unit arranged locally on the crane associated with the at least one crane component and connected to the power consumer system for storing primary energy and/or secondary energy; and

at least one drive motor connected to the power consumer system for operating the at least one crane component in response to energy fed into the power consumer system.

2. The crane according to claim 1, further comprising a control unit, which is in signal connection with the power consumer system, the primary energy source and the at least one secondary source to control energy supply to the at least one crane component.

3. The crane according to claim 2, further comprising a data bus enabling bidirectional data transfer, said data bus is connected to the control unit and further to the power consumer unit to provide electrical input and output variables to the control unit.

4. The crane according to claim 1, wherein the primary energy source is configured to be activated when a start condition is fulfilled and is configured to be deactivated when a stop condition is fulfilled.

5. The crane according to claim 1, wherein the stop condition is fulfilled when at least one of the following conditions is met:

a) no demand for hydraulic power is detected;

b) a battery voltage within predetermined limits is detected;

c) a cooling water temperature of the primary energy source is detected to be within limit values;

d) temperature of pressure oil is detected to be within limit values;

e) when only auxiliary components connected to receive energy solely from the secondary energy source are turned on; and

f) other predetermined stop conditions set by a user.

6. The crane according to claim 5, wherein the stop condition is disabled if a current load moment which is monitored by a load moment indicator exceeds a load moment threshold value of 30% of a maximum available load moment of the crane.

7. The crane according to claim 1, wherein the primary energy source comprises an internal combustion engine, a gear connected by a clutch to the internal combustion engine, and a generator.

8. The crane according to claim 1, wherein the primary energy source comprises a diesel engine.

9. The crane according to claim 1, wherein the secondary energy source comprises an engine.

10. The crane according to claim 1, further comprising auxiliary crane components connected to the power consumer system to receive energy solely from the secondary energy source.

11. The crane according to claim 1, further comprising at least one fuel cell connected to said primary energy source to supplement the energy output from the primary energy source.

12. The crane according to claim 1, wherein the at least one crane component comprises a rotary mechanism or a hydraulic or electric linear drive, an energy converter, and an electric motor.

13. The crane according to claim 11, wherein the energy converter comprise a consumer gear or a hydraulic pump.

14. The crane according to claim 1, further comprising at least one power consumer connected to the power consumer system, which system supplies energy to the at least one power consumer from the primary energy source.

15. The crane according to claim 1, further comprising at least one power consumer connected to the power consumer system, which system supplies energy to the at least one power consumer from the at least one secondary energy source.

16. The crane according to claim 1, wherein the at least one secondary source comprises an internal combustion engine.

17. The crane according to claim 1, further comprising:

a primary energy source radiator for cooling the primary energy source; and

a secondary energy source radiator in cooling connection with the primary energy source radiator for cooling at least one of the primary energy source and the secondary energy source.

18. The crane according to claim 2, wherein in an emergency operation, the control unit is configured to cause energy to be supplied to the crane from the secondary power source.

19. The crane according to claim 1, wherein the primary energy source comprises:

a diesel engine;

at least two primary source generators to convert mechanical energy from the diesel engine to electric energy to be fed via rectifiers into the power consumer system; and

a clutch and gear connected together and between the diesel engine and the at least two primary source generators to transmit the mechanical energy from the diesel engine to the at least two primary energy source generators.

20. The crane according to claim 18, further comprising a cooling water supply connected to the rectifiers and the primary energy source generators.

21. The crane according to claim 1, further comprising:

an undercarriage;

a superstructure rotatably arranged on the undercarriage;

a hydraulic pump;

a plurality of hydraulic cylinders connected to support the undercarriage;

a converter;

an electric motor connected to the hydraulic pump, the converter and the power consumer system to convert power supplied from the power consumer system to hydraulic energy to be supplied to the hydraulic pump to control positioning of the undercarriage.

22. The crane according to claim 20, further comprising:

a superlift mast on the superstructure;

a pressure transmitter connected to the superlift mast to detect and transmit an angular position of the superlift mast to the control unit.

23. The crane according to claim 1, wherein the at least one crane component comprises:

at least one rotary device;

a corresponding rotary gear connected to the at least one rotary device;

corresponding at least one electric motor connected to the at least one rotary gear for converting rotary movement from the at least one rotary gear into electric energy; and

a converted connected to the at least one corresponding electric motor to feed the electric energy to the power consumer system.

24. The crane according to claim 1, further comprising an external energy supply configured to supply mains power to the power consumer system.

25. The crane according to claim 1, wherein the at least one crane component comprises at least one rotary device, and the crane further comprises a central switch-over unit connected to each of the at least one rotary devices and the power consumer system for converting the rotary movement of the at least one rotary devices to electric energy to be supplied as secondary energy to the power consumer system.

26. The crane according to claim 1, wherein the power consumer system comprises two power lines.

27. The crane according to claim 1, comprising a cable winch, the cable winch comprising:

a cable drum having a central cavity;

an electric motor having a drive shaft extending along a central longitudinal axis of the central cavity;

a first winch holder to connect the winch to the electric motor;

a gear housing connected near a distal end of the drive shaft;

a fixed planetary gear connected to the gear housing and the drive shaft;

a second winch holder connected to the fixed planetary gear at a side opposite from the gear housing; and

a brake connected to an end of the drive shaft and at an opposite side of the winch holder from the planetary gear;

wherein the electric motor and gear are capable of driving the winch to wind a cable on the cable drum to lift a load, and

wherein the electric motor operates as a generator for generating electric power when the cable is driven by the gear and drive shaft to lower the load.

28. The crane according to claim 2, further comprising an angle transmitter connected to the superstructure to detect and transmit an angular position of the superstructure to the control unit.

29. The crane according to claim 1, further comprising a second energy storage unit, arranged centrally on the crane for storing excess energy from at least one of the primary energy source and the secondary energy source.

30. The crane according to claim 28, wherein the second energy storage unit comprises a battery arrangement arranged as a stackable counter-weight on the crane.

31. The crane according to claim 28, wherein the second energy storage unit comprises a battery arrangement arranged as a superlift counter-weight on a counter-weight carriage separated from the crane.

32. The crane according to claim 1, wherein the secondary energy source has a maximally available secondary output P_S,max that is smaller than a maximally available primary output P_P,max of the primary energy source (12), and wherein P_S,max≦

0.5·

P_P,max.

33. The crane of claim 1, wherein the control unit comprises a non-transitory computer readable medium storing software that performs the following steps:

providing a total energy amount comprising at least one of primary energy generated by means of the primary energy source and secondary energy generated by means of the at least one secondary energy source;

determining an energy usage fraction demanded by the at least one crane component; and

storing an energy storage fraction in the at least one energy storage unit,

wherein the total energy amount comprises the energy usage fraction and the energy storage fraction, and wherein the secondary energy is energy returned from operations performed by the at least one crane components.

34. The crane according to claim 32, wherein the software performs the following step of causing energy to be supplied to meet the energy usage fraction from the energy storage unit in preference over energy supplied from the primary energy source.

35. The crane according to claim 32, wherein the software comprises the step of controlling the supply of energy to predetermined crane components in preference over other predetermined crane components.

36. The crane of claim 32, wherein the software performs the following steps:

activating, in a working operation of the crane, at least one crane component;

deactivating in a no-load operation of the crane, the at least one crane component; and

controlling operation of the crane such that in an intermittent operation, a ratio of operating period in the working operation to operating period in the no-load operation is at most 0.3.

37. The crane according to claim 32, wherein the software performs the step of providing the energy usage fraction to the at least one crane component by causing energy to be fed into the power consumer system.

38. The crane according to claim 32, further comprising at least one energy converter connected to the at least one crane component to convert energy from the at least one crane component into power, and wherein said software performs the step of providing the energy usage fraction to the at least one crane component using the power from the at least one energy converter.

39. The crane according to claim 38, wherein the control unit controls a ratio of the energy usage fraction to the energy storage fraction.

40. The crane according to claim 38, wherein the control unit determines an excess energy fraction such that a sum of the energy usage fraction and a maximum energy storage fraction is equal to a sum of the excess energy fraction and the total energy amount.

41. The crane according to claim 40, wherein the control unit controls reduction of the excess energy fraction by converting energy obtained from additional brake resistances into thermal energy, a return of the thermal energy to the crane being used to heat a crane cabin.

42. The crane according to claim 41, wherein the software performs the following step of causing energy to be supplied to meet the energy usage fraction from the energy storage unit in preference over energy supplied from the primary energy source.

43. The crane according to claim 42, wherein the software comprises the step of controlling the supply of energy to predetermined crane components in preference over other predetermined crane components.

58. The crane according to claim 2, wherein the control unit is capable of selectively controlling operation of the crane in four modes, the four modes being a standby mode, a semi-hybrid mode, a full-hybrid mode, and a full electric mode.

59. The crane according to claim 58, wherein in the standby mode, at least one auxiliary functions can be activated by the secondary energy source during a stop function when the primary energy source is deactivated.

60. The crane according to claim 58, wherein in the semi-hybrid mode, both the primary energy source and electric drives for the at least one crane component are used to generate energy to be used to run the crane.

61. The crane according to claim 60, wherein in the full-hybrid mode, energy reserves stored in the energy storage unit or electric energy from the secondary energy sources are used preferentially over energy supplied from the primary energy source to run the crane.

62. The crane according to claim 58, wherein in the full electric mode, only electric energy sources are used to run the crane.

63. The crane according to claim 58, further comprising an operator interface to allow a crane operator to switch between the four modes.

64. The crane according to claim 58, wherein the control unit comprises a module to automatically determine which of the four modes should be used and to cause the control unit to switch to the predetermined mode.

44. A method for operating a crane, the method comprising:

activating, in a working operation of the crane, at least one crane component;

deactivating, in a no-load operation of the crane, the at least one crane component;

controlling operation of the crane such that in an intermittent operation, a ratio of operating period in the working operation to operating period in the no-load operation is at most 0.3;

providing a total energy amount comprising at least one of primary energy generated by means of a primary energy source and secondary energy generated by means of at least one secondary energy source;

determining an energy usage fraction demanded by the at least one crane component, wherein the at least one crane component is configured as a secondary energy source for energy recovery; and

storing an energy storage fraction in the at least one energy storage unit,

wherein the total energy amount comprises the energy usage fraction and the energy storage fraction, and wherein the secondary energy is energy returned from operations performed by the at least one crane components.

45. The method according to claim 44, further comprising providing the energy usage fraction to the at least one crane component by feeding energy into the power consumer system.

46. The method of claim 44, further comprising providing the energy usage fraction to the at least one crane component using at least one energy converter connected to the at least one crane component to convert energy from operation of the at least one crane component into power.

47. The method according to claim 45, further comprising controlling a ratio of the energy usage fraction to the energy storage fraction by means of a control unit.

48. The method according to claim 46, further comprising determining an excess energy fraction by means of the control unit such, that a sum of the energy usage fraction and a maximum energy storage fraction is equal to a sum of the excess energy fraction and the total energy amount.

49. The method according to claim 48, further comprising controlling reduction of the excess energy fraction by converting energy obtained from additional brake resistances into thermal energy, a return of the thermal energy to the crane being used to heat a crane cabin.

50. A method of operating a crane comprising:

providing energy to at least one crane component using a power consumer system;

feeding primary energy into the power consumer system using a primary energy source;

operating the at least one crane component using at least one drive motor connected to the power consumer system;

feeding secondary energy into the power consumer system by recovering the secondary energy from operation of the at least one crane component as a secondary energy source, controllable independent from the primary energy source; and

storing at least one of primary energy and secondary energy using at least one energy storage unit arranged locally on the crane and connected to the power consumer system.

51. A method of operating a crane, the crane comprising at least one crane component, a primary energy source, at least one secondary energy source, and a power consumer system connected to the at least one crane component the primary energy source and the at least one secondary energy source for supplying energy from at least one of the primary energy source and the at least one secondary energy source to the at least one crane component, the method comprising the following steps:

providing a total energy amount comprising at least one of primary energy generated by means of a primary energy source and secondary energy generated by means of at least one secondary energy source;

determining an energy usage fraction demanded by the at least one crane component; and

storing an energy storage fraction in at least one energy storage unit,

wherein the total energy amount comprises the energy usage fraction and the energy storage fraction, and wherein the secondary energy is energy returned from operations performed by the at least one crane components.

52. The method of claim 51, further comprising the following steps:

activating, in a working operation of the crane, at least one crane component;

deactivating in a no-load operation of the crane, the at least one crane component; and

controlling operation of the crane such that in an intermittent operation, a ratio of operating period in the working operation to operating period in the no-load operation is at most 0.3.

53. The method according to claim 51, further comprising the step of providing the energy usage fraction to the at least one crane component by causing energy to be fed into the power consumer system.

54. The method according to claim 51, further comprising the steps of:

converting energy from operation of the at least one crane component into power using at least one energy converter connected to the at least one crane component, and

providing the energy usage fraction to the at least one crane component using the power from the at least one energy converter.

55. The method according to claim 51, further comprising the step of controlling the supply of energy to the at least one crane component by controlling a ratio of the energy usage fraction to the energy storage fraction.

56. The method according to claim 54, further comprising the step of determining an excess energy fraction such that a sum of the energy usage fraction and a maximum energy storage fraction is equal to a sum of the excess energy fraction and the total energy amount.

57. The method according to claim 56, further comprising the step of reducing the excess energy fraction by converting energy obtained from additional brake resistances into thermal energy, a return of the thermal energy to the crane being used to heat a crane cabin.

65. A cable winch comprising:

a cable drum having a central cavity;

an electric motor having a drive shaft extending along a central longitudinal axis of the central cavity;

a first winch holder to connect the winch to the electric motor;

a gear housing connected near a distal end of the drive shaft;

a fixed planetary gear connected to the gear housing and the drive shaft;

a second winch holder connected to the fixed planetary gear at a side opposite from the gear housing; and

a brake connected to an end of the drive shaft and at an opposite side of the winch holder from the planetary gear;

wherein the electric motor and gear are capable of driving the winch to wind a cable on the cable drum to lift a load, and

wherein the electric motor operates as a generator for generating electric power when the cable is driven by the gear and drive shaft to lower the load.