HYBRID POWER TRAIN WITH A LOW-VOLTAGE MOTOR-GENERATOR

Abstract

Hybrid power train (1) with a low-voltage motor-generator (2), in particular with a 48V motor-generator (2), comprising: an internal combustion engine (3); a clutch (4) operatively connected to the internal combustion engine (3); a drive shaft (5) which at a first end portion is operatively connected to the clutch (4), and which at a second end portion is operatively connected to a gearbox; a low-voltage motor-generator (2) operatively connected to the drive shaft (5); an inverter unit (7) operatively connected to the low-voltage motor-generator (2); an electronic control unit (8); an electric power source (9) operatively connected to the inverter unit (7); wherein the low-voltage motor-generator (2) is arranged in a concentric manner around the drive shaft (5) in such a way as to form a driving connection between a rotor of the low-voltage motor-generator (2) and the drive shaft (5); wherein the low-voltage motor-generator (2), the inverter unit (7) the electric power source (9), and the gearbox are arranged entirely inside a bell housing (10) of the gearbox, and wherein the electronic control unit (8) comprises a) at least one controller arranged in the bellhousing (10) and no controller arranged out of the bellhousing (10); b) two or more controllers, wherein at least one controller is arranged in the bellhousing (10) and at least one controller is arranged out of the bellhousing (10); or c) at least one controller arranged out of the bellhousing (10) and no controller arranged in the bellhousing (10).

Claims

1.-15. (canceled)

16. A hybrid power train comprising: an internal combustion engine; a clutch operatively connected to the internal combustion engine; a drive shaft which at a first end portion is operatively connected to the clutch, and which at a second end portion is operatively connected to a gearbox; a low-voltage motor-generator operatively connected to the drive shaft; an inverter unit operatively connected to the low-voltage motor-generator; an electronic control unit; an electric power source operatively connected to the inverter unit; wherein the low-voltage motor-generator is arranged in a concentric manner around the drive shaft in such a way as to form a driving connection between a rotor of the low-voltage motor-generator and the drive shaft; and wherein the low-voltage motor-generator, the inverter unit, the electric power source, and the gearbox are arranged entirely inside a bell housing of the gearbox.

17. The hybrid power train according to claim 16, wherein the electronic control unit comprises at least one controller arranged in the bellhousing and no controller arranged out of the bellhousing.

18. The hybrid power train according to claim 16, wherein the electronic control unit comprises two or more controllers, wherein at least one controller is arranged in the bellhousing and at least one controller is arranged out of the bellhousing,

19. The hybrid power train according to claim 18, wherein the at least one controller arranged out of the bellhousing is arranged at an outer sidewall of the bellhousing.

20. The hybrid power train according to claim 16, wherein the electronic control unit comprises at least one controller arranged out of the bellhousing and no controller arranged in the bellhousing.

21. The hybrid power train according to claim 20, wherein the at least one controller arranged out of the bellhousing is arranged at an outer sidewall of the bellhousing.

22. The hybrid power train according to claim 16, wherein the electronic control unit comprises at least one controller capable of controlling the high power switching between phases of the motor to allow the basic control of speed and torque.

23. The hybrid power train according to claim 16, wherein the electronic control unit comprises at least one controller capable of operating torque and speed based on a variety of inputs such as driver demand, engine operation, temperature, environmental and/or application inputs.

24. The hybrid power train according to claim 16, wherein the electrical power source is positioned no farther than 1000 mm distant from the inverter unit.

25. The hybrid power train according to claim 24, wherein the electrical power source is positioned no farther than 500 mm distant from the inverter unit.

26. The hybrid power train according to claim 16, wherein the inverter unit is positioned no farther than 1000 mm distant from the low-voltage motor-generator.

27. The hybrid power train according to claim 26, wherein the inverter unit is positioned no farther than 1.00 mm distant from the low-voltage motor-generator.

28. The hybrid power train according to claim 16, wherein the low-voltage motor-generator comprises axial single-pole conductors, which are configured being able to conduct at least 300 Ampere each, and wherein the inverter unit is configured such that it provides at least two solid state switches for each axial single-pole conductor of the low-voltage motor-generator, and wherein the solid state switches are directly arranged at the respective single-pole conductor.

29. The hybrid power train according to claim 16, wherein the low-voltage motor-generator is configured in such a way as to provide an operating power of at least 30 kW.

30. The hybrid power train according to claim 29, wherein the low-voltage motor-generator is configured in such a way as to provide an operating power of at least 45 kW.

31. The hybrid power train according to claim 29, wherein the low-voltage motor-generator is configured in such a way as to provide an operating power of at least 75 kW

32. The hybrid power train according to claim 29, wherein the low-voltage motor-generator is configured in such a way as to provide an operating power of at least 105 kW.

33. The hybrid power train according to claim 16, wherein the low-voltage motor-generator operates with an operating voltage below a threshold voltage that is safe for human contact.

34. The hybrid power train according to claim 16 wherein the low-voltage motor-generator operates with an operating voltage that is less than or equal to 60 Volts.

35. The hybrid power train according to claim 34, wherein the low-voltage motor-generator operates with an operating voltage that is less than or equal to 48 Volts

36. The hybrid power train according to claim 16 wherein the electric power source comprises capacitors.

37. The hybrid power train according to claim 16, wherein the electric power source consists only of capacitors

38. The hybrid power train according to claim 16, wherein a hollow shaft is arranged between the low-voltage motor-generator and the drive shaft, and wherein the hollow shaft comprises: an outer spline at a first end portion, connected to the rotor of the low-voltage motor-generator; and an inner spline at a second end portion, connected to the drive shaft; and wherein both the connection of the outer spline to the rotor of the low-voltage motor-generator and the connection of the inner spline to the drive shaft is formed as a crowned spline connection in such a way as to being able to accommodate for a horizontal and/or vertical angular misalignment and/or a horizontal and/or vertical displacement between the drive shaft and the rotor of the low-voltage motor-generator.

39. The hybrid power train according to claim 38, further comprising: a first damping element arranged in between the drive shaft and the hollow shaft at the first end portion of the hollow shaft; and a second damping element arranged in between the drive shaft and the hollow shaft at the second end portion of the hollow shaft; wherein the at least first damping element and second damping element are configured in such a way as to dampen the transmission of horizontal and/or vertical angular movements of the drive shaft via the hollow shaft to the rotor of the low-voltage motor-generator.

40. The hybrid power train according to claim 38, wherein the length of the hollow shaft in between the outer spline at the first end portion of the hollow shaft and the inner spline at the second end portion of the hollow shaft is in a range between 20% and 200% of the length of the low-voltage motor-generator, and preferably in a range between 50% and 100% of the length of the low-voltage motor-generator.

41. The hybrid power train according to claim 38, further comprising: a first pair of ring elements arranged in between the drive shaft and the hollow shaft at the first end portion of the hollow shaft, wherein the first pair of ring elements is capable of lubricant retention to retain a lubricant between the first pair of ring elements; and a second pair of ring elements arranged in between the drive shaft and the hollow shaft at the second end portion of the hollow shaft, wherein the second pair of ring elements is capable of lubricant retention to retain a lubricant between the second pair of ring elements.

Description

[0043] The advantages of the invention are described in the following in connection to the drawings. In the following:

[0044] FIG. 1 shows the low-voltage motor-generator, the inverter unit, the electronic control unit, the electric power source, and the gearbox arranged entirely inside a bell housing of the gearbox;

[0045] FIG. 2 shows the hollow shaft arranged at the drive shaft.

[0046] FIG. 1 shows the low-voltage motor-generator 2 for a hybrid powertrain 1 having an internal combustion engine 3 and a clutch 4 operatively connected thereto. The inverter unit 7, the electronic control unit 8 and the electric power source 9 are arranged entirely inside a bell housing 10 of the gearbox (dotted lines). This is enabled partly be the low-voltage motor-generator 2 being arranged in a concentric manner around the drive shaft 5 in such a way as to form a driving connection between a rotor (not shown) of the low-voltage motor-generator 2 and the drive shaft 5.

[0047] In that the low-voltage motor-generator 2, the inverter unit 7, the electronic control unit 8, the electric power source 9 are arranged entirely inside a bell housing 10 of the gearbox, the current-carrying components, i.e., the low-voltage motor-generator 2, the inverter unit 7, the electronic control unit 8 and the electric power source 9, are not directly exposed to access from outside the bell housing 10 of the gearbox.

[0048] In FIG. 1 also depicts the aspect of an additional controller 81 of the electronic control unit 8 arranged out of the bellhousing and in this example on the outer side wall of the bell housing. Preferably, the additional controller is a low current-carrying controller capable of operating torque and speed based on a variety of inputs such as driver demand, engine operation, temperature, environmental and/or application inputs.

[0049] The electronic control unit 8 comprises one controller in the bell housing capable of controlling the high power switching between phases of the motor to allow the basic control of speed and torque.

[0050] The third case of (c) at least one controller arranged out of the bellhousing and no controller arranged in the bellhousing can be derived from the illustration in FIG. 1 as well, wherein advantageously any high current-carrying controller can be covered from human contact either by separate means (not shown) or by an covered arrangement (not shown).

[0051] The low-voltage motor-generator 2, the inverter unit 7, the electronic control unit 8, the electric power source 9, and the gearbox have a size and shape as to fit entirely inside a bell housing 10 of the gearbox.

[0052] The low-voltage motor-generator 2 comprises axial single-pole conductors, which are configured being able to conduct at least 300 Ampere each. This allows for operating the low-voltage motor-generator 2 with more than 30 kW operating power and/or more than 45 kW operating power and/or more than 75 kW operating power and/or more than 105 kW operating power, in each case at operating voltages that are safe for human contact, and in particular at operating voltages below 60V.

[0053] The inverter unit 7 is configured such that it provides at least two solid state switches for each axial single-pole conductor of the low-voltage motor-generator 2. The solid state switches are directly arranged at the respective single-pole conductor.

[0054] The electric power source 9 comprises capacitors only. Such capacitors can be designed as ultracapacitors. In that the electric power source 9 comprises capacitors only is beneficial for providing higher electrical power within a shorter period of time compared to batteries. This allows for a higher acceleration of the vehicle or other equipment.

[0055] FIG. 2 shows the hollow shaft 12 arranged at the drive shaft 5. The hollow shaft 12 comprises an outer spline 121 at a first end portion 122, connected to the rotor 21 of the low-voltage motor-generator 2 and an inner spline 123 at a second end portion 124, connected to the drive shaft 5.

[0056] Both the connection of the outer spline 121 to the rotor (not shown) of the low-voltage motor-generator (not shown) and the connection of the inner spline 123 to the drive shaft 5 is formed as a crowned spline connection in such a way as to being able to accommodate for a horizontal and/or vertical angular misalignment; and/or a horizontal and/or vertical displacement between the drive shaft 5 and the rotor (not shown) of the low-voltage motor-generator (not shown).

[0057] To being able to accommodate for a horizontal and/or vertical angular misalignment; and/or a horizontal and/or vertical displacement between the drive shaft 5 and the rotor (not shown) of the low-voltage motor-generator (not shown) the length of the hollow shaft 12 in between the outer spline 121 at the first end portion 122 of the hollow shaft 12 and the inner spline 123 at the second end portion 124 of the hollow shaft 12 is 100% the length of the low-voltage motor-generator (not shown).

[0058] Moreover first damping elements 131a, 131b are arranged in between the drive shaft 5 and the hollow shaft 12 at the first end portion 122 of the hollow shaft 12; and second damping elements 132a, 132b are arranged in between the drive shaft 5 and the hollow shaft 12 at the second end portion 124 of the hollow shaft 12.

[0059] The damping elements 131a, 131b, 132a, 132b are configured in such a way as to dampen the transmission of horizontal and/or vertical angular movements of the drive shaft 5 via the hollow shaft 12 to the rotor (not shown) of the low-voltage motor-generator (not shown). The damping elements 131a, 131b, 132a, 132b in FIG. 2 are designed as ring elements positioned around the driving shaft 5 or the hollow shaft 12 and are made of a rubber material.

[0060] In this way, the transmission of vibrations from the drive shaft 5, which are generated by the combustion engine (not shown), to the low-voltage motor-generator (not shown) and in particular to the inverter unit (not shown), which is operatively connected to the low-voltage motor-generator (not shown), can be reduced by the use of the hollow shaft 12. In this way, the low-voltage motor-generator (not shown) and the inverter unit (not shown) are protected from harmful mechanical impact that would be caused by the vibrations.

[0061] According to at least one advantageous aspect, damping elements 131a, 131b, 132a, 132b in FIG. 2 are designed as ring elements and may serve as lubricant retention elements such that a lubricant (not shown) may be retained between damping elements 131a, 131b and/or between damping elements 132a, 132b.