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EP-4313730-B1 - STEERING DRIVE SYSTEM FOR A VEHICLE WITH WHEEL-BASED STEERING, VEHICLE WITH WHEEL-BASED STEERING AND METHOD FOR THE OPERATION THEREOF

EP4313730B1EP 4313730 B1EP4313730 B1EP 4313730B1EP-4313730-B1

Inventors

  • Müller, Nikolaus
  • PFÄNDER, Marcel
  • HARSCHER, MARIO

Dates

Publication Date
20260513
Application Date
20220323

Claims (15)

  1. A steering drive system (11) for a wheel-steered vehicle, comprising a coupling element (20), which can be coupled to the vehicle's output shafts (14, 15), so that, when the magnitude of the superimposed rotational speed of the coupling element (20) is greater than zero, which are driven by a drive system (10) of the vehicle at a base speed, to provide a superimposed speed to be superimposed on the base speed for steering the vehicle, using at least a first electric machine (29) whose speed is variably adjustable or controllable, with a power summing and/or power splitting unit (25), wherein a first connection (25a) of the power summing and/or power splitting unit (25) is coupled to a shaft (26), which, in particular via a defined transmission ratio, can be coupled to a shaft (16) of the drive system (10), wherein a second connection (25b) of the power summing and/or power splitting unit (25) is coupled to the at least one first electric machine (29), wherein a third connection (25c) of the power summing and/or power splitting unit (25) is coupled to the coupling element (20), in particular via at least one defined transmission ratio, wherein a reversing gearbox (37) is provided after superposition of the power from the shaft (26), to which the first connection (25a) of the power summing and/or power splitting unit (25) is coupled, in particular from the first connection (25a), with the power provided by the at least one first electric machine (29), in particular from the second connection (25b).
  2. The steering drive system according to claim 1, wherein the steering drive system (11) comprises a power unit (35) connected in parallel with the power summing and/or power splitting unit (25), which is configured to drive the shaft (26), to which the first connection (25a) of the power summing and/or power splitting unit (25) is also coupled, to the coupling element (20) in parallel with the power summing and/or power splitting unit (25), in particular with slippage.
  3. The steering drive system according to claim 1, wherein the second connection of the power summing and/or power splitting unit is coupled at the same rotational speed to the at least one first electric machine, or wherein the second connection of the power summing and/or power splitting unit is coupled to the at least one first electric machine via a defined transmission ratio.
  4. The steering drive system according to one of the preceding claims, wherein at least one first electrical machine (29) interacts with the, in each case with at least one first power electronics unit (31) configured to control the rotational speed of the respective first electrical machine (29), and/or wherein the respective first electrical machine (29) is designed with electrically isolated phases ; and/or with at least one second electric machine (33) coupled to the shaft (26) to which the first connection (25a) of the power summing and/or power splitting unit (25) is also coupled and/or with at least one second electric machine (33) coupled to the coupling element (20).
  5. The steering drive system according to the preceding claims, wherein at least one second electric machine (33) cooperates with at least one second power electronics unit (34) ( ), which is configured to control the rotational speed of the respective second electric machine (33), and/or wherein the respective second electric machine (33) is designed with electrically isolated phases; and/or with at least one electric machine (33; 39) that is configured to supply the at least one first electric machine (29) with electrical energy, in particular directly, in generator mode, and/or is configured to be supplied with electrical energy, in particular directly, by the at least one first electric machine (29) in motor mode; and/or wherein the power unit (35) is configured such that the shaft to which the first connection of the power summing and/or power splitting unit is also coupled to the coupling element in parallel with the power summing and/or power splitting unit, in one operating state of the power unit with a rotational direction and in another operating state of the power unit with a rotational direction opposite thereto, in particular, a direction-of-rotation reversal device is provided, comprising at least one gear track coupled to the coupling element, which is configured to be driven by the shaft in one operating state of the power unit and to rotate the coupling element in one direction of rotation, and in the other operating state of the power unit to be driven by the shaft and to rotate the coupling element in a direction opposite to this direction of rotation, or comprises at least two wheel tracks coupled to the coupling element, one of which is configured, in one operating state of the power unit, to couple the shaft to which the first connection of the power summing and/or power splitting unit is also coupled to the coupling element in a rotational direction, and of which the other track is configured to couple the shaft to which the first connection of the power summing and/or power splitting unit is also coupled to the coupling element in the other operating state of the power unit with a rotational direction opposite to the former.
  6. The steering drive system according to one of the preceding claims, comprising a power unit (35) arranged, in particular, between the first electric machine and the second connection of the power summing and/or power splitting unit, which power unit is configured to couple the shaft, to which the first connection of the power summing and/or power splitting unit is also coupled, in parallel with the first electric machine, in particular with slippage, to the power summing and/or power splitting unit, in particular to its second connection; and/or wherein the power unit (35) comprises a switchable friction clutch or a hydrodynamic clutch, in particular .
  7. The steering drive system according to one of the preceding claims, wherein the reversing gearbox (20) comprises at least two gear tracks coupled to the coupling element, one of which is configured such that, in one operating state of the reversing gearbox, the coupling element is driven by the power summing and/or power splitting unit in one direction of rotation, and the other gear train is configured to drive the coupling element, in another operating state of the reversing gearbox, via the power summing and/or power splitting unit in a direction of rotation opposite to said direction of rotation.
  8. The steering drive system according to any one of the preceding claims, wherein the power summing and/or power splitting unit (25) is configured to couple the first terminal (25a) and the second terminal (25b) to the third terminal (25c), in particular to couple, in a second operating state, the first connection (25a) and/or the second connection (25b) to the third connection (25c), in particular to couple the first port, in particular at least when the second port is unloaded, to the third port at a fixed gear ratio, in particular wherein the power summing and/or power splitting unit (25) is configured to provide, in a third operating state, a mixed mode between the first and second operating states; and/or wherein the power summing and/or power splitting unit (25) comprises one or more planetary gear sets and/or one or more switching elements, in particular wherein at least two planetary gear sets and at least two switching elements form the reversing gearbox (37) integrated into the power summing and/or power splitting unit (25), and/or wherein at least two gear tracks, each of which is coupled to at least one shifting element, in particular a clutch, form the reversing gearbox connected between the power summing and/or power splitting unit and the coupling element, /or wherein at least two planetary gear sets and/or at least one shifting element are involved in providing the different operating states of the power summing and/or power splitting unit (25) depending on the shifting position of the shifting elements.
  9. The steering drive system according to one of the preceding claims, wherein the power summing and/or power splitting unit (25) comprises at least one planetary gear set and/or, in particular, at most six planetary gear sets, specifically exactly four, five, or six planetary gear sets, and/or wherein the power summing and/or power splitting unit (25) comprises at least one shifting element, or at most five switching elements, in particular exactly two, three, four, or five switching elements, wherein at least one switching element or several are designed as brakes, and/or wherein at least one switching element or several are designed as clutches, or wherein all switching elements are designed as brakes or as clutches.
  10. A wheel-steered vehicle, comprising a drive system (10) that includes at least a drive unit (12), a transmission (13), and a main power splitting unit (17), with a steering drive system (11) according to one of the preceding claims, wherein the shaft (26) of the steering drive system (11), to which the first connection (25a) of the power summing and/or power splitting unit (25) is also coupled, is coupled to the main power splitting unit (17), and/or the coupling element (20) is coupled to output shafts (14, 15) of the vehicle.
  11. The wheel-steered vehicle according to the preceding claim, wherein the drive system (10) comprises a switchable clutch (38) configured to couple the at least one drive unit (12) to the main power splitting unit (17) and to decouple it from the main power splitting unit (17); and/or wherein the drive system (10) comprises at least one further electric machine (39), wherein the at least one further electric machine (39) is configured such that, when the at least one second electric machine (33) is coupled to the shaft (26) to which the first connection (25a) of the power summing and/or power splitting unit (25a) is coupled, to support functions of the steering drive system (11) provided by the at least one second electric machine (33) of the steering drive system (11).
  12. A method for operating a wheel-steered vehicle according to any one of claims 10 to 11, wherein the at least one first electric machine (29) of the steering drive system (11) is operated as a motor, wherein the at least one second electric machine (33) of the steering drive system (11) is operated as a generator, wherein the electrical energy provided by the at least one second electric machine (33) of the steering drive system (11) is used to drive the at least one first electric machine (29) of the steering drive system (11), wherein the power supplied by the at least one first electric machine (29) of the steering drive system (11) to the second connection (25b) of the power summing and/or power splitting unit (25) is combined with a second portion of the drive power of the vehicle drive system (10), which is supplied by the main power splitting unit (17) to the steering drive system (11) and which is applied to the first terminal (25a) of the power summing and/or power splitting unit (25), is superimposed and supplied to the third terminal (25c) of the power summing and/or power splitting unit (25), preferably wherein when the at least one second electric machine (33) is coupled to the shaft (26) to which the first connection (25a) of the power summing and/or power splitting unit (25) is coupled, wherein at least one second electric machine (33) of the steering drive system (11) operated as a generator provides a first portion of the drive power of the vehicle drive system (10), which the main power splitting unit (17) provides to the steering drive system (11), into electrical energy t .
  13. The method for operating a wheel-steered vehicle according to any one of claims 10 to 11, in particular the method according to the preceding claim, wherein, in particular in an alternative operating state to an operating state in which the at least one first electric machine is operated as a generator and the at least one second electric machine is operated as a motor, the at least one first electric machine (29) of the steering drive system (11) is operated as a generator, the at least one second electric machine (33) of the steering drive system (11) is operated as a motor, the power summing and/or power splitting unit (25) branches the drive power of the drive system (10), which is provided by the main power splitting unit (17) to the steering drive system (11) and which is applied to the first connection (25a) of the power summing and/or power splitting unit (25) and supplies it partly to the second terminal (25b) of the power summing and/or power splitting unit (25) and partly to the third terminal (25c) of the power summing and/or power splitting unit (25), the at least one first electric machine (29) operated as a generator converts the portion of the drive power present at the second connection (25b) into electrical energy, and the electrical energy provided by the at least one first electric machine (29) is used to drive the at least one second electric machine (33) of the steering drive system (11).
  14. The method for operating a wheel-steered vehicle according to claim 10 or 11, in particular a method according to any of claims 12 to 13, wherein, when the at least one drive unit (12) of the drive system (10) is stopped or has failed, the clutch (38) of the drive system is opened and the at least one drive unit (12) is decoupled from the main power splitting unit (17), wherein the vehicle's kinetic energy is used to steer the vehicle, preferably, wherein, when the at least one second electric machine (33) is coupled to the shaft (26) to which the first connection (25a) of the power summing and/or power splitting unit (25), the kinetic energy of the vehicle is converted into electrical energy via the at least one second electric machine (33) of the steering drive system (11) operating as a generator, and/or wherein the kinetic energy of the vehicle is converted into electrical energy via the at least one further electric machine (39).
  15. The method for operating a wheel-steered vehicle according to claim 10 or 11, in particular a method according to one of claims 12 to 13, wherein, when the at least one drive unit (12) of the drive system (10) is stopped or has failed, the clutch (38) of the drive system is opened and the at least one drive unit (12) is decoupled from the main power splitting unit (17), wherein the first electric motor (29) of the steering drive system (11) and, if applicable, the additional electric motor (39) of the drive system (10) and/or the second electric motor (33) of the steering drive system (11) are used to drive and/or steer the vehicle.

Description

The invention relates to a steering drive system for a wheel-steered vehicle, in particular a wheel-steered vehicle. Furthermore, the invention relates to a wheel-steered vehicle and a method for operating the same. A wheel-steered vehicle, such as a tracked vehicle, has a drive system as well as a steering drive system. The drive system of a wheel-steered vehicle has at least one drive unit and a drive transmission to provide drive power and a basic speed to outputs of the wheel-steered vehicle, which are positioned on both sides of the vehicle, particularly for straight-ahead driving of the wheel-steered vehicle. In dynamic, side-steered vehicles, a superimposed steering system is typically used, in which each wheel of the side-steered vehicle is driven crosswise at a superimposed rotational speed to effect a steering movement via a differential torque. Preferably, the superimposed rotations are connected crosswise via a coupling element or link to recover steering energy from the translational movement of the vehicle. This coupling element or link can be designed as a so-called zero shaft, which is stationary when driving straight ahead and alternately superimposes both wheel sides during steering movements. To steer a wheel-steered vehicle with a zero-axis drive shaft, the zero-axis drive shaft must rotate. A superimposed rotational speed can then be applied to the output shafts, increasing the base rotational speed on one side of the wheel-steered vehicle and decreasing it on the opposite side. This enables the wheel-steered vehicle to be steered. From the DE 10 2009 016 639 A1 A steering drive system for a wheel-steered vehicle and a wheel-steered vehicle equipped with the steering drive system are known. Drives are shown that drive into a summing gearbox. The summing gearbox is operatively connected to a zero shaft via a spur gear stage. The zero shaft provides the respective superimposed rotational speed for the two sides of the wheel-steered vehicle, which is superimposed on a base rotational speed provided by a drive motor for steering purposes. From the DE 102 746 870 B3 Another wheel-steered vehicle with a steering drive system is known. The neutral shaft of the steering drive system can be driven by a combination of a power component derived from a drive system and a power component from at least one electric motor, wherein the electric motor is designed with several independent circuits. A hydrodynamic steering clutch or a mechanically controlled, load-shiftable clutch serves to transmit the power component derived from the drive system. Other wheel-steering vehicles are from the DE 10 2005 035 824 A1 and from the DE 103 14 956 B4 known. The document EP 1 650 109 A1 reveals a hybrid drive system for vehicles with wheeled or tracked chassis and slip control. There is a need for a steering drive system for a wheel-steered vehicle that has a simple design and/or enables reliable operation of the wheel-steered vehicle. Furthermore, there is a need for a wheel-steered vehicle with such a steering drive system and for a method for operating the wheel-steered vehicle. Starting from this, the present invention is based on the objective of creating a novel steering drive system for a wheel-steered vehicle or a wheel-steered vehicle, a wheel-steered vehicle with such a steering drive system and a method for operating the same. This problem is solved in particular by a steering drive system according to claim 1 or a wheel-side-steered vehicle according to claim 10 or methods according to claims 12 to 15. The steering drive system according to the invention comprises a coupling element or member which can be coupled to the vehicle's outputs, or in one embodiment is coupled, in order to provide, when the magnitude of a superimposed speed of the coupling element is greater than zero, a superimposed speed to the outputs driven by the vehicle's drive system at a base speed, for steering the vehicle. The coupling element and coupling member are preferably synonymous. The steering drive system according to the invention further comprises at least one first electric machine whose speed is variably adjustable or controllable, and a power summation and/or power splitting unit. A first, in particular single- or multi-segment, in one version single- or multi-strand, connection of the power summation and/or power branching unit, In one embodiment, the input of the power summation and/or power splitting unit is coupled to a shaft which, in one embodiment, can be coupled to a shaft of the drive system via a defined transmission ratio, or is coupled in another embodiment. In one embodiment, the defined transmission ratio is provided by a main power splitting unit; in a further development, by a main power splitting unit configured to direct drive power, in particular at least temporarily wholly or partially, to the drive transmission and/or, in particular at least temporarily wholly or partially, to the steering drive