Recovery of kinetic energy lost during the braking stage, its subsequent reuse and pneumatic rotary engine

Abstract

A device and method to recover and reuse kinetic energy during vehicle braking and subsequent restart. During braking, a piston air compressor A is driven by vehicle wheels 2 via a crankshaft 10 and t

Description

This invention relates to a device and method for recovering kinetic energy lost during the braking phase and for its use during the starting stage of a vehicle. This invention, unlike similar solutions, relates mainly to towed, towed or non-self-propelled vehicles, but may also be applied to motor vehicles whose platform permits the adaptation of such a device. It is intended to be used mainly in the rail transport industry, TIR transport or lorries consisting of trailers, but also other types of vehicles whose mass and gauge exceed the usual values. The device used for this purpose consists of three main interconnected components, each having different roles, as follows: - a kinetic energy recuperator, represented by an air compressor with compressor cylinders, interleaved by means of an engine block, a sectioned axle, inside which is installed a crankshaft solidary at its ends with a pair of wheels of the vehicle, wheels from which it directly takes over their rotational motion and transmitted torque, to drive the cylinder pistons of the air compressor in this way to produce a quantity of compressed air directly proportional to the value of the kinetic energy lost during the braking process; - a torque generator and rotational motion represented by a pneumatic rotary engine of a special construction which will be described in the contents of this invention, interspersed in turn to another sectioned axle and which is supplied during the start-up stage with the quantity of compressed air produced during the braking phase by the air compressor, designed to transmit directly and fully the rotational motion and torque produced to the wheels to which its engine crankshaft is connected; - compressed air tank storing the amount of compressed air produced by the air compressor as elastic potential energy, for later use by the pneumatic rotary engine. Interlacing the air compressor and rotary penumatic engine into different axles of the same vehicle is strategic in order to achieve maximum possible efficiency by minimizing the length of the kinematic chain that makes it possible to take over and transmit forces without loss. By means of this device, all kinetic energy specific to a vehicle in motion shall be transmitted through the wheels and wholly taken over directly at the commencement of braking by a crankshaft permanently coupled to the wheels on which that vehicle is moving. This crankshaft is part of an air compressor with compressor cylinders, which converts the kinetic energy transmitted to the crankshaft into elastic potential energy in the form of compressed air produced by this compressor and stored in a dedicated tank. This invention also describes how elastic potential energy stored in the form of compressed air is used after the braking stage or during the start-up stage to drive a pneumatic rotary engine of a special design type, integrated into another sectioned axle of the vehicle and whose crankshaft is permanently coupled to the wheels of that axle, in order to produce an equivalent torque necessary to restore that vehicle to the state of motion corresponding to the starting point of the braking phase. This invention also refers to a method whereby, by means of the air compressor integrated into an axle of a vehicle in motion, during the period corresponding to the usual journey, it supplies compressed air necessary for supercharging the combustion engine, either of the locomotive in the case of a trainset or of the tractor unit in the case of a lorry or motor vehicles towing trailers, for example. Current state of the art contains many different solutions for recovering kinetic energy produced during the braking process. Most of the solutions used for this purpose present us with hybrid solutions that basically use two types of engines in the same vehicle, one thermal with a main role, another reversible electric engine with the role of producing electricity and taking over propulsion for determined periods of operation, depending on certain parameters. There are also solutions that propose the recovery of heat released by the flue gases of a combustion engine in order to convert this thermal energy into steam by means of heat exchangers, which in turn drive a turbine to provide additional engine torque. All these solutions involve complicated technologies, numerous and difficult to manage components. The integration of all components on the same platform leads to a considerable increase in the weight of the machine, which practically negates the benefits of efficient energy recovery, thus a low efficiency. Also, the reliability of such recovery systems is relatively low. Through these similar solutions that use the kinetic energy of a vehicle to convert it into electrical energy, the efficiency obtained is extremely low, existing technologies do not allow the efficient transformation of a huge amount of kinetic energy into a directly proportional amount of electrical energy obtained during the braking process, which is a very short one. The present invention solves these problems much more simply and efficiently by means of the device used, the amount of kinetic energy proper to a moving mass being converted into a directly proportional quantity of elastic potential energy, this transformation being effected concretely and efficiently only during the braking process, that is, only during that stage when the kinetic energy accumulated by printing on that vehicle a travel speed, diminishes due to decreasing travel speed. For this reason, this invention also aims to correct a phrase often used in the literature, namely "kinetic energy produced during the braking process". During the braking process, kinetic energy is not produced, but lost or diminished. It goes without saying that it is not possible to recover what you produce, but what is lost. A particularly important and common problem of existing technical solutions is the quantitative limitation of efficient recovery of kinetic energy lost during the braking process. These solutions basically refer to low-mass vehicles whose kinetic energy during travel does not reach values comparable to those of large masses characteristic of e.g. trainsets primarily, heavy trucks with or without trailers, oversized trailers with multiple axles, etc. This invention offers a solution to this problem primarily due to the possibility of sizing the device used according to the inertial mass of the vehicle, respectively its own kinetic energy. Thus, in the case of a trainset consisting of multiple wagons, the recovery of kinetic energy lost during braking will be done individually, each wagon being equipped with at least one such device for recovery and reuse of kinetic energy. Similarly, this device is adaptable to any type of trailer or multi-axle platforms. The solution offered by this invention can be regarded as a practical application to a consequence of the first principle of mechanics. We know the statement of this principle that tells us that a body retains its state of motion as long as no other forces act on it to modify this state. In the case of a vehicle travelling on wheels on a road, the air resistance force acts on it in the opposite direction of travel, which is overcome by the powertrain of that vehicle. At the same time, the powertrain consumes an amount of energy to give this body a certain speed of travel, this energy being directly proportional to its own speed and mass. Thus, that body or vehicle in our case, is charged in this way with an amount of kinetic energy that, in the absence of other factors, will tend to keep it that acquired state of motion. This equilibrium is maintained by the action of the corresponding inertial force acting on that body in that sense and direction of its movement. The forces opposing this inertial force are the air drag force and the braking force triggered by the braking process. The air drag force shall be negligible quantitatively in relation to the braking force acting on the vehicle when the braking process is initiated. This means that the change in the inertial mass of that body (vehicle) is mostly due to the action of the braking force. Consequently, if kinetic energy lost during braking were to be recovered, this should, in one form or another, to return that body (vehicle) to that state of motion it had before the braking process was triggered. Based on these considerations, the following reformulation or corollary of the first principle of mechanics or inertia can be stated: " The amount of energy used to modify the state of motion or rest of a material body must be equal or directly proportional to the amount of energy required to return that material body to its initial state of motion." In the patent literature, as a relevant state of the art, we found invention number GB2591859 and RO135169B1 in which is presented a solution for efficient recovery of kinetic energy produced during the braking process and its reuse during the starting process. It is also revealed a method of supplying compressed air to a combustion engine in order to supercharge it. In this invention, an air compressor driven by means of a crankshaft in the extension of the crankshaft of a thermal or electric engine is used to drive simultaneously with the combustion cylinders of the combustion engine some cylinders of the air compressor, thus producing a quantity of compressed air that is directed and stored in a compressed air tank in the form of elastic potential energy by means of selectively controlled solenoid valves by a controller, this potential energy will then be used to drive a turbine in solidarity with the crankshaft during the start-up process. The main disadvantages of this solution are: - diminished efficiency due to the length of the kinematic chain: crankshaft, clutch, gearbox, transmission system, wheels; - significant changes to the engine or its attachments; - constructive limitation of the amount of kinetic energy recovered during the braking process; - non-delimitation by state parameters of the stages of braking, starting and usual movement; - the compressed air turbine produces small torques. The present invention removes these disadvantages by using a much more efficient device consisting of 3 main components, namely an air compressor with compressor cylinders driven by a crankshaft permanently solidary with a pair of wheels on which the vehicle moves, the crankshaft being located coaxially inside a sectioned axle fixed at the extremities by the wheels on which the vehicle moves, a compressed air tank and a pneumatic rotary engine of a special construction, the engine crankshaft of which is similarly located inside another sectioned axle and which is permanently coupled to another pair of wheels of the same vehicle. Each component is intended to be used differently depending on the 3 distinct stages of operation of a vehicle, namely braking, starting and usual driving. For the right delimitation of these stages of operation, we will specify the characteristic physical quantities for which we will use the following notations: 1. The braking phase is triggered by actuation of the brake pedal or lever and lasts until its application is interrupted. It is manifested by lowering the speed of the vehicle from the initial travel speed at the moment of commencement of braking Vi, to a final travel value from the moment of completion of the braking process Vf. Thus, the value of the vehicle's own kinetic energy corresponding to the moment of commencement of braking is: _ . mxVi2 . E CI =------, where m = mass of the vehicle; 2 The value of the kinetic energy of the vehicle corresponding to the moment of completion of the braking phase is: mxVf2 _ 2 ' It follows that the kinetic energy lost during the braking process will be: Ecp = Eci — Ecf = m x —; This relationship shows us that the amount of kinetic energy lost will be greater as the greater will be the difference between vehicle speed when the braking stage is triggered and the vehicle speed when the braking stage is completed. 2. The start-up phase shall be triggered by actuation of the accelerator pedal or lever and shall last for the period of time necessary to return the vehicle to its state of motion from the moment the braking stage is triggered, i.e. for the period of time corresponding to the increase in speed Vf of the vehicle from the moment of completion of the braking phase to a maximum of the running speed Vi corresponding to the speed of movement of the vehicle at the moment of initiation of the braking phase. 3. The normal travel stage is that stage of operation of a vehicle which excludes the other two stages, namely braking and starting. The solution offered by this invention shows how the main components of the device are each used with a well-defined role depending on the stages of braking, starting and habitual movement described above, as follows: - during the braking stage only the compressor will actively operate being coupled to a pair of wheels by means of a crankshaft using as driving force of the cylinders pistons the vehicle's own inertia force acting on it during the entire braking phase, thereby producing a quantity of compressed air directed and stored in the dedicated compressed air tank. Thus take place the transformation of that quantity of kinetic energy lost during the braking phase into a directly proportional amount of elastic potential energy; - during the start-up phase, only the pneumatic rotary engine of a special design will operate actively, being supplied with compressed air produced and stored in the dedicated tank, its engine crankshaft being permanently coupled to another pair of wheels of the same vehicle, with the role of driving and transmitting thus to the wheels to which it is coupled, an engine torque necessary to return the vehicle to the state of motion appropriate to the initiation of the braking process; - during the usual driving phase, both the compressor and the pneumatic rotary engine operate passively or inertially, being self-supplied with atmospheric air via air intakes, the air compressor optionally supplying compressed air to the vehicle's combustion engine to ensure its supercharging via another dedicated air intake, while the compressed air tank is locked by closing the EV2 and EV3 solenoid valves. From the brief description of these components and their role results the advantages that this invention offers compared to the disadvantages of the solution described in the GB2591859 and RO135169B1 patent. Firstly, the amount of kinetic energy recovered is no longer dependent on the mass of the vehicle, the device which is the subject of this invention allowing the recovery of a virtually unlimited amount of kinetic energy lost during the braking phase through the use of multiple devices depending on the number of axles of the vehicle, trailers, wagons or towed platforms. This is a particularly important application because vehicles with a very high gross weight, lose a huge amount of kinetic energy through braking, the classic friction braking process in this situation being a very difficult one and with very high operating costs due to wear of the components of this braking system. Another objective technical problem that this invention solves is the maximum efficiency generated due to minimizing the length of the kinematic chain transmission of forces and moments generated or taken. Furthermore, this solution presented does not involve structural modifications to the engine of a vehicle, the only fully adaptable modifications relating to the axles or axles of that vehicle, whether self-propelled, towed or towed. Another advantage of the presented solution consists in the use of precise and measurable physical quantities (Vi, Vf, Vd and Vr) that are used as algorithms by a microcontroller to efficiently manage through the solenoid valves it drives all the components of the device used according to the different stages of operation: braking, starting and usual driving. In conclusion, the main advantages of this invention in relation to the state of the art are: - recovery of virtually unlimited kinetic energy lost during the braking phase; - maximum efficiency due to taking over and reusing or transmitting directly and proportionately the forces and moments of the forces generated and used during both braking and starting; - constructive and functional simplicity; - efficient and selective management of all device components through the use by a microcontroller of quantities characteristic of each process; - by using a pneumatic rotary motor of a special design powered by compressed air, very high torques are obtained and transmitted directly to the wheels of the vehicle. The following is presented according to fig.l the constructive diagram of the principle of the device used for the recovery and reuse of kinetic energy: Vd Fig-1 R = Towed, towed, oversized, self-propelled vehicle, etc. A = Air compressor with compressor cylinders; B = Dedicated pneumatic rotary engine driven by cylinders supplied with compressed air stored in tank C ; C = Compressed air tank; MC = Microcontroller; EVI, EV2, EV3 and EV4 = Solenoid valves driven by MC microcontroller; Vd = Vehicle speed; Vr = Tangential speed of the wheels at the point of contact with the road; Vi = Running speed of the vehicle when the braking phase is triggered by application of the brake pedal or lever; Pi = Air pressure in air tank C at the moment of initiation of the braking phase; Vf = Running speed of the vehicle at the moment of completion of the braking phase by interrupting the application of the brake pedal or lever; Pf = Air pressure in air tank C at completion of the braking phase; 1. Driveway; 2. Wheels corresponding to sectioned axle 3; 3. Sectioned axle corresponding to engine block 15 of compressor A; 4. Wheels corresponding to sectioned axle 5; 5. Sectioned axle corresponding to engine block 16 of pneumatic rotary motor B; 6. Air ducts; 7. Atmospheric air intake sockets; 8. Air outlet; 9. Compressed air supply socket to the combustion engine to ensure its supercharging; 15. Engine block of compressed air compressor A; 16. Dedicated pneumatic rotary motor engine block B; According to Fig. 1 and the notations, it is observed that air compressor A, which is in solidarity with crankshaft 3, takes directly from wheels 2 via its own crankshaft 10 all the kinetic energy of vehicle R moving at speed Vd on driveway 1, in order to produce through the component compressor cylinders, a quantity of compressed air directly proportional to the kinetic energy transmitted, and direct it through connecting pipes 6 and solenoid valves EVI and EV2 to be stored as elastic potential energy in compressed air tank C. This process of compression and storage of the air drawn through the air intake 7 shall be carried out only during the braking stage corresponding to the decrease of travel speed Vi to the final value Vf. Following this braking process, i.e. during the start-up stage corresponding to the increase in travel speed from the Vf value close to the initial value Vi, the compressed air stored in the compressed air reservoir C feeds through connecting pipes 6 and solenoid valves EV3, EV4 driven by the MC microcontroller, the pneumatic rotary engine B, which, In turn, it transmits the rotational motion and torque produced directly to the wheels 4 attached to sectioned axle 5 via the crankshaft 11. Next, in Fig.2, a longitudinal section overview of the device that is the subject of this invention is presented, for a better representation and understanding of the role and arrangement of the component elements. Fig.2 This figure shows the coaxial arrangement inside the sectioned axles 3 and 5 of crankshafts 10 and 11, of the air compressor A and the corresponding rotary pneumatic engine B, respectively the sliding supports 12 of the engine blocks 15 and 16 on which the 2 crankshafts rest. The integration of the two main components, compressor A and B, into engine blocks 15 and 16 has the following roles: - to secure the fasteners with the vehicle platform; - to protect their mechanisms from potentially destructive mechanical actions during movement of vehicle R on road 1; - to ensure the necessary rigidity of these components with the axles and thus the wheels of the vehicle. The following drawing, Fig.3, shows in detail the component parts of air compressor A as well as its connections with the other components of the device for recovering and reusing kinetic energy lost during the braking phase. Afr compressor driven by piston cylinders Fig-3 In this case too, for simplicity, the same symbols of the component parts and numbering used in Fig.l and Fig.2 were kept, adding where necessary the new elements represented in Fig.3, as follows: 13. Compressor cylinder; 14. Piston cylinder compressor A; 15. Compressor engine block A; 17. Rod-Crank mechanism; 18. Intake and exhaust valves of air compressor A; Active operation of air compressor A shall occur only during the braking stage corresponding to the stage of loss of cynetic energy to be recovered and converted into elastic potential energy by producing an equivalent amount of compressed air. Pistons 14 of compressor cylinders 13 are driven by means of a rod-crank mechanism 17 of the crankshaft 10 which takes directly from the wheels 2 of vehicle R all its kinetic energy transmitted to them when the braking stage is triggered. The inlet-exhaust valves 18 are thus operated, which alternately allow atmospheric air to be drawn in through air intake 7, directing the compressed air produced through connecting ducts 6 and solenoid valves EVI and EV2 to air tank C, where it is stored as elastic potential energy, to be used later during the start-up stage by the pneumatic rotary engine B. The pressure of compressed air accumulated in tank C increases from Pi up to the value of Pf, while the moving speed of vehicle R decreases from the Vi value to the Vf value. In the following figure Fig.4 is shown the construction diagram of the pneumatic rotary engine B. Fig.4 In this case too, for simplicity, the same symbols of the component parts and numbering used in Fig.l, Fig.2 and Fig.3 were kept, adding where necessary the new elements represented in Fig.4, as follows: 16. Pneumatic rotary engine block B; 19. Pneumatic cylinder; 20. Pneumatic cylinder piston; 21. Timing belt; 22. Inlet-exhaust valves of pneumatic engine B; 23. Camshaft. The pneumatic motor used in this invention to produce and transmit the rotational motion, but especially the torque directly to the wheels on which the vehicle R moves, is an engine of a special construction, different from other similar engines. This pneumatic engine is similar in principle of operation to a two-stroke combustion engine, both types of engines the operating cycle is made over a single revolution of the crankshaft. The difference is that in the case of this rotary penumatic engine, the pressure in the engine cylinders necessary to drive its pistons is obtained due to their supply of compressed air from an external source, namely from the compressed air reservoir C. In the case of combustion engines, this increase in pressure inside the cylinders is achieved exclusively by ignition of a fuel mixture. In this type of pneumatic rotary engine, compressed air stored in tank C enters the interior of cylinders 19 by alternately opening the inlet-exhaust valves 22 driven by camshaft 23, pushing piston 20 from external PME dead centre to PMI inner dead centre during intake, thereby achieving the intake-compression cycle. During this cycle, the piston performs the useful stroke by acting through the rod-crank mechanism 17 crankshaft 11, imprinting on it a rotational motion and engine torque which are transmitted directly, without loss, to the wheels 4 on which the vehicle R is moving. As shown in the drawing, the crankshaft 11 is coupled to camshaft 23 by means of timing belt 21, their simultaneous drive being designed to achieve in this way the alternating closing and opening of the intake-exhaust valves 22. This is necessary to remove pistons 20 of pneumatic cylinders 19 from PME and PME dead centres. After achieving the work-generating useful stroke of a piston from the PME to the PMI, the intake valve is closed and the air exhaust valve in that cylinder is opened, which is freely discharged through the air outlet 8. This reverse piston course from PMI inner dead centre to PME outer dead centre coincides with the expansion-exhaust cycle. The alternative actuation of the compressed air intake and exhaust valves is made by camshaft 23 which, depending on the number of cylinders in the penumatic engine or the number of rod-crank mechanisms, thus performs the distribution phases. Active operation of this rotary pneumatic motor occurs by actuating solenoid valves EV3 and EV4. The need to use such a pneumatic motor arose due to the need to transmit a sufficiently powerful generated torque to the wheels of the vehicle, knowing that pneumatically driven rotary engines generally do not generate a high torque. Due to the quantity and high pressure of compressed air accumulated in the C tank supplying this dedicated pneumatic engine, this one can generate very high torques sufficient for removal from standstill, for example that vehicles with very high kerb masses, which is very difficult to achieve with known types of rotary pneumatic engine. Next, the description of the components being made, we will refer to their selective operation during the 3 stages of operation of a vehicle. As we have already shown in this invention, each stage corresponds to a certain operating phase of either air compressor A or rotary pneumatic engine B. Their active or passive(inertial) operation is conditioned by actuation of solenoid valves EVI, EV2, EV3 and EV4 by the MC microcontroller according to parameters Vd, Vr, Vi with corresponding Pi and Vf with corresponding Pf. During the braking phase, the MC microcontroller allows active operation of air compressor A only by actuating the EVI and EV3 solenoid valves in the closed position, while the EV2 and EV4 solenoid valves are operated in the open position. The pneumatic rotary engine B operates only passively or inertia I ly, feeding itself by free suction with atmospheric air through air intake 7. At this braking stage, the travel speed Vi of vehicle R decreases until Vf is reached, while the pressure of compressed air accumulated in reservoir C increases from Pi to the final value Pf. These state parameter values are used as reference points by the MC microcontroller for selective actuation of EVI, EV2, EV3 and EV4 solenoid valves depending on the vehicle operating stages. For example, if during the braking stage, due to excessive braking, one of the wheels of the vehicle R has locked, it means that Vr = 0, Vt * 0 and therefore these must be unlocked by actuating the solenoid valves EVI and EV4 in the open position and the solenoid valves EV2 and EV3 in the closed position. The start-up phase shall be delimited by the MC microcontroller over a period of time corresponding to the increase of Vf speed of vehicle R to a maximum of the travel value Vi, corresponding to the decrease of the pressure of compressed air in air tank C from the Pf value to a maximum of Pi value. During this process, the MC microcontroller allows active operation of only the pneumatic rotary engine B by actuating the EVI and EV3 solenoid valves in the open position, while the EV2 and EV4 solenoid valves are operated in the closed position. Compressor A operates passively or inertially, supplying itself with atmospheric air through air intake 7. During usual driving, the MC microcontroller allows only passive or inertial operation of air compressor A and pneumatic motor B by actuating solenoid valves EVI and EV4 in the open position and EV2 and EV3 solenoid valves in the closed position. Optionally, during this stage of travel, compressed air supply 9 can ensure the supply of compressed air to the combustion engine in order to ensure its supercharging. All these actuation sequences are shown in the block diagram in Fig.5.: Microcontroller - MC Solenoidal VaivesEj^ EVi EV2 EV3 EV4 Opejaliog Stages Braking Vi —-i.V« Pi .—Pf Closed Open Closed Open Starting vf_—v; W Pi Open Closed Open Closed UsuaJ Driving Open Closed Closed Open Vr=O Vd / O Open Closed Closed Open Fig.5 Component parts and notations: R = Towed, oversized, self-propelled vehicle, etc.; A = Air compressor with compressor cylinders; B = Dedicated pneumatic rotary engine driven by cylinders supplied with compressed air stored in tank C; C = Compressed air tank; MC = Microcontroller; EVI, EV2, EV3 and EV4 = Solenoid valves driven by MC microcontroller; Vd = speed of movement of the vehicle; Vr = tangential speed of the wheels at the point of contact with the railway or roadway; Vi = speed of the vehicle when the braking phase is triggered by application of the brake pedal or lever; Pi = air pressure in air tank C at the moment of initiation of the braking stage; Vf = speed of the vehicle at the moment of completion of the braking phase by interrupting the application of the brake pedal or lever; Pf = Air pressure in air tank C at completion of the braking phase; Kinetic energy of vehicle R corresponding to the initiation of the braking phase: _ . mxVi2 . E CI =-----, where m = mass of the vehicle; 2 Kinetic energy of vehicle R corresponding to completion of the braking phase: mxVf2 2 ' Kinetic energy lost during the braking process: Ecp = Eci — Ecf = mx —; 1. Railway, roadway,etc. 2. Wheels corresponding to sectioned axle 3; 3. Sectioned axle corresponding to engine block 15 of compressor A; 4. Wheels corresponding to sectioned axle 5; 5. Sectioned axle corresponding to engine block 16 of pneumatic rotary engine B; 6. Airducts; 7. Atmospheric air intake sockets; 8. Air outlet socket; 9. Compressed air supply socket to the combustion engine to ensure its supercharging; 10. Crankshaft of air compressor A; 11. Crankshaft of dedicated pneumatic rotary motor B; 12. Sliding supports of crankshafts 10 and 11; 13. Compressor cylinder A; 14. Piston cylinder compressor A; 15. Motor block compressor A; 16. Motor block of pneumatic rotary engine B; 17. Rod-crank mechanism; 18. Inlet-outlet valves of air compressor A; 19. Pneumatic cylinder; 20. Pneumatic cylinder piston; 21. Timing belt; 22. Inlet-outlet valves of pneumatic rotary engine B; 23. Camshaft.

Claims

1. Device for recovering kinetic energy lost during the braking stage, for its reuse during the start-up stage and pneumatic rotary engine, characterised by the fact that this consist into an assembly of three main components A, B and C interconnected by means of air ducts 6 fitted with solenoid valves EVI, EV2, EV3, EV4 selectively operated by the MC microcontroller in accordance to certain state parameters Vd, Vr, Vi, Pi, Vf, Pf, each of these components having a well-determined functional role, as follows:- air compressor A consisting of one or more compressor cylinders 13 piston 14 and inlet-exhaust valves 18, integrated into an engine block 15, driven by crankshaft 10 coupled directly to wheels 2 of vehicle R and positioned coaxially inside a sectioned axle 3 supported on sliding supports 12 by means of a connecting rod-crank mechanism 17, intended to compress atmospheric air drawn in through an air intake 7 and to selectively direct it, depending on stages of movement of the vehicle by solenoid valves EVI, EV2, EV3 and EV4 operetad by microcontroller MC, to air tank C through air ducts 6 where it is accumulated as elastic potential energy for subsequent use, either to combustion engine in order to supercharge it with compressed air via the supply socket 9, or directly into the atmosphere via exhaust outlet 8;- pneumatic rotary engine B supplied with compressed air from compressed air tank C only during the braking stage through connecting ducts 6 and solenoid valves EV3, EV4 operated by the MC microcontroller, engine consisting of one or more pneumatic cylinders 19 piston 20 fitted with valves 22 driven by camshaft 23 which is driven in turn through the timing belt 21 by crankshaft 11 positioned coaxially in the interior of another sectioned axle 5 supported on the sliding supports 12 of engine block 16, crankshaft which, by means of a connecting rod-crank 17 mechanism, directly transmits the rotational motion and torque produced to the wheels 4 of vehicle R moving on railway or roadway 1;- compressed air tank C intended to store the quantity of compressed air produced by air compressor A during the braking stage as elastic potential energy and to supply this accumulated compressed air to pneumatic rotary engine B only during the start-up phase.

2. Method of recovering kinetic energy lost during braking by means of air compressor A according to claim 1, characterised by the fact that this take place by conversion of kinetic energy ECp lost during braking stage into elastic potential energy represented by the amount of compressed air produced by compressor A and accumulated in the air tank C over a period of time corresponding to the decrease of travel speed value Vi of vehicle R to the value Vf, respectively of pressure increase of compressed air accumulated in tank C from the initial value Pi according with Vi, to final value Pf according with Vf.

3. Method of reusing the value of lost kinetic energy during the start-up process by means of a pneumatic rotary engine B according with claims 1 and 2, characterised by the fact that this take place by transforming elastic potential energy accumulated in air tank C during braking stage, into useful mechanical work transmitted directly to wheels 4 via crankshaft 11 of engine B, over a period of time corresponding to the increase of vehicle speed from Vf value to not more than Vi value, in sametime by decrease of pressure of compressed air from air tank C from Pf value, to Pi value.

4. Method for recovering kinetic energy lost during braking stage and reusing it during the start-up stage in accordance with claims 1, 2 and 3, characterised by the fact that during normal travel excepting braking stage and starting stage, air compressor A and pneumatic rotary engine B it only works inertially by usual moving of vehicle R on railway or roadway 1, both components being supplied exclusively with atmospheric air drawn through air intake 7 and then evacuated freely through air intake 8, optionally during this stage compressor A can supply through air intake 9 and selective actuation of solenoid valves EVI and EV2, compressed air necessary to supercharge the combustion engine, while tank C is isolated from the rest of the assembly by closing the solenoid valves EV2 and EV3 by the MC microcontroller.

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