OPTIMISING THE DISTRIBUTION OF TORQUES ON VEHICLE WHEELS

or how precise mechanical tracking of traction forces ensures maximally high levels of: drive energy efficiency; traffic stability and safety; technical expediency; cheapening and large-scale decarbonisation in the automotive industry

In its essence, the distribution?of?torques on the wheels of vehicles means equalizing in real time?the driving or braking forces applied to the wheels and the road with the force of traction between them. This implies that the equalization is carried out accurately and independently of the speed of changes and amplitudes of the adhesion force parameter, in its capacity as the only argument of the distribution and a measure of useful work done.

The commonly accepted delayed and inaccurate sensor determination?of the traction force in existing distribution systems makes equalizing of the described kind unattainable. The discrepancies?between the torques formed by the systems on the wheel(s) and the road with the???traction??forces between them are conceptually predetermined.

These inconsistencies in the systems' generated stabilization/distributive responses, even with slight complications in the road conditions, produce cumulative energy losses from wheel slips and deterioration of driving stability.

The calculation and?making?of stabilizing reactions with acceptable efficiency in the conditions of delayed and inaccurate reporting of changes in traction forces requires the introduction of a large volume of corrective electronic and other high-tech equipment to improve the adequacy of reactions in various risky situations on the road.

Despite the achieved results in traffic stabilization, the existing systems are too far from the physically possible levels of energy efficiency and the corresponding levels of traffic stability and safety. The imprecise sensor method?for determining the adhesion force?parameter?imposed in practice is an insurmountable obstacle to achieving the high levels of these characteristics. The solved?problem is of undeniable relevance?in the situation of "electrification"?and "decarbonization"?of transport.

A solution?to the technical task of energy-efficient countermeasures to changes in road conditions by applying precisely defined driving or braking torques to the wheels and the road is provided by the invention "SYSTEM FOR CONTROLLING TORQUE DISTRIBUTION".

Patented technology

?? USA - US Patent 9,751,401 ? China - CN Patent 101449085 ? Russia – RU Patent 2424130(C2)

TECHNICAL ESSENCE OF THE DECISION

In the system presented by the invention, the drive torque applied to the wheels and the road is formed by means of couplings?which connect drive shafts of individual wheels or axles to a common drive shaft of the vehicle.

The control pressure on the clutch discs?is produced by kinematically simple mechanical devices that are integrated into the drive shafts of wheels and axles.

The integrated devices convert the torsional forces in the shafts (which are equivalent to the traction forces) into a control pressure on the clutch discs. In the description, the devices are presented with the name "torsion unit",?and here we refer to them as "torsion devices"?or abbreviated TD. The type of distribution carried out by the presented system is called "torsion distribution".

The integration of the TDs?into the drive shafts is done after transverse shearing of the shafts and connection of the resulting two shafts by means of the TD?components. The connection??provides limited angular displacements between the two shafts depending on the values of the torsional forces (adhesion forces).

The kinematics of the TD?transforms angular displacements into axial pressure on the clutch discs. The counteraction of the discs balances and limits the values of the angular displacements between the shafts.

TD?works with removed clearances between the discs and minimum pre-set pressure . There is a wide range of changes in the pressure on the discs, respectively - a wide range of torques formed on the wheels, which in practice are associated with negligible and well-balanced аngular and linear displacements in the system.?

Fig. 1

Fig. 1,?presents a schematic view of a specific embodiment of the patented system. TD?includes frontally engaged cam surfaces 7?and 8, which are formed on discs 6?and 9. The discs are connected to shafts 1A?and 1B?obtained after shearing a drive shaft. The shaft 1A?is connected to the disc 9 of the device through a splined joint 10?and to the source of driving power (not shown in the figure a common driving shaft). The other shaft – 1B?is a wheel or axle drive shaft (also not shown in the figure).

The transmission of torque from the TD?and the shafts is carried out through the frontally engaged cam surfaces 7?and 8. The cams engagement and the spline joint 10?provide the possibility of radial relative displacement (for example, lag) of the shaft 1B,?relative to the rotation of the shaft 1A.

Radial displacements are carried out simultaneously and in proportion to the changes in the adhesion force, i.e. at any disturbance of the balance between driving force and traction force. Simultaneously, the following actions are also performed: sliding between the cam surfaces 7?and 8; axial relative displacement?of the disc 9?on the spline joint 10; a change in the tension?of the clutch 16, respectively a change in the torque applied to the wheel/s.

The radial relative displacements and the enumerated concurrent changes cease whenever the driving force equalizes the traction force. Thus, the system maintains a precise and automatic balance of these forces, which ensures high sensitivity?to changes in road conditions.

The system excludes any possibility of applying to the road a greater driving force than it can bear without skidding.?Thus, the volume of energy losses eliminated is greater in worse road conditions.

The direct impact of the changing traction forces on the couplings provided by the TD?and the precise balance between the traction forces and the driving forces continuously maintained by the system ensures the sought-after extreme accuracy and speed?of the formed stabilizing reactions, which guarantees maximum energy efficiency of the drives and stability of the movement.

This means preventing significant energy losses from slips and skids , as well as their harmful consequences, and at the same time ensures full utilization of the road's opportunities for energy-efficient, stable and safe movement.

Thus preventing the harmful consequences of the loss of traction, the technical solution eliminates the need for technical means to overcome them.

Fig. 2

Fig. 2?represents a constructive implementation of the diagram from fig. 1. The device here is called a Torsion Module (TM).

The presented construction can serve as an automatic inter-axle clutch that precisely distributes the applied driving torque on two axles, i.e. performs automatic torque vectoring. It can immediately be seen that this simplest application of the system will perform its function flawlessly, additionally providing the elimination of the need for the participation of a significant number of sensors, control electronics and a separate actuator for the clutch.

The figure represents a case in which the TD?and the connector 16?serve a separate object that is both an object of tracking and control, and the stabilizing reaction of the system is an equalizing type.?The cases where this object is a separate wheel, the description characterizes with the expression "systems that distribute torque to each wheel independently". When the TD?and clutch 16?are on different drive shafts, the object served by the shaft with the clutch compensates for changes in the traction of the object connected to the TD?and the system response is compensatory type.

Fig. 3

Fig. 3?presents an axle drive with TMs. The precise balance of forces?automatically maintained by the TDs?and the high sensitivity?to changes in road conditions, manifested by all applications of the presented system, exclude the need for the application of differential mechanisms for axle and inter-axle differentiation of wheel rotation.

A drive axle with TMs?for each wheel ensures precise vector distribution?of torque between the wheels?with all the resulting benefits for energy efficiency and motion stabilization.

The figure shows that the patented design?is composed of well-known components known for their reliable?and complete predictability in operation.

In addition, it is clear that the introduction of the torsion system can?be done by redesigning the differential cassette on a standard drive axle.

Fig. 4

Fig. 4 presents a hybrid drive of a vehicle with any number of drive axles equipped with TMs.

The figure further illustrates beneficial effects resulting from the extended application of torsional distribution, including major structural simplifications of the propulsion, stabilization and braking systems:

- Elimination of the need to use differentials, due to the extremely high adaptability of TMs?to all kinds of road conditions. The increased weight, volume occupied, higher prices and complications interfering with the vector distribution and caused by the presence of differentials and the equalization of the torques of the differential shafts are also eliminated.

-Technical possibility of concentrating in one common shaft?1 the functions?of drive, braking and electric recovery of the kinetic energy of the vehicle, which greatly simplifies the management of these functions. This possibility is also a consequence of the high adaptability of TMs.

- Elimination of the need to use actuators to control?both the technical means of distribution and operations related to traction force data. The significant technical complications associated with their application are also eliminated. These simplifications are due to the fact that the torsional distribution is carried out with the drive energy.

??-Technical possibility of using only one electric machine?in electric drives with more than one drive axis. This is the most rational solution in terms of energy efficiency, management of work modes, weight, occupied volume, price and service.

- Highly simplified software.?The use of electric motors for individual wheels or axles controlled by?software that has to distribute the torques, is not able to ensure the precision, the energy efficiency respectively, achieved by the torsional distribution. The software is inevitably based on the sensor data from the known stabilization systems, as a result of which the delays and inaccuracies in this data, as well as the problems they cause, are transferred to the control of operating modes of the electric motors.

- Technical capability of the system to provide braking of any number of driving wheels using only one braking device B, i.e. without using individual wheel braking devices and without involving the ABS?system.

This option derives from the ability of TMs/TDs?to transmit driving or braking torques applied to the common shaft and to distribute them precisely and without any delay on the wheels, depending on the values of traction with the road of each of them. These capabilities ensure maximum braking and regenerative efficiency under any road/ terrain conditions.

- Elimination of the need to apply individual braking devices?not only reduces the weight of the vehicle, but also greatly simplifies the entire braking system, and leads to an improvement of the driving comfort?due to the reduction of unsprung?masses.

- The vehicle kinetic energy recovery mode, as a variant of the braking mode, utilizes the same advantages of the torsional torque distribution. The recuperation will be maximally efficient even under difficult road conditions, due to the possibility provided by TMs for maximum utilization of the traction of all driving wheels with the road.

The lightning-fast and precise distribution?of driving and braking torques on the wheels, in addition to a significant amount of saved driving energy, technical simplification, weight reduction and cheaper automotive products will additionally provide: improvements in dynamic indicators acceleration, braking; increased average speed in complex road conditions; increased patency; reduced wear on all transmission parts and tires.

The advantages that the torsional stabilization of the movement of wheeled vehicles provides and the level of problem solving that this technology brings with it in terms of environmental friendliness, decarbonization and safety standards are unattainable by known technologies.?This makes it suitable for all cases related to the distribution of torques on wheels.

The crucial importance of energy efficiency?for the operation of electric, autonomous and hybrid vehicles?predetermines the importance of torsional?stabilization?of motion for these types of vehicles.

The invention is offered for sale.

Please note my contact details:

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