The present invention relates to a brake kinetic energy recovery system for any type of vehicle that can be fitted in the brake system thereof, thus recovered energy being used to accelerate the vehicle.

In order to recover braking energy, hydraulic systems are known acting on the universal joints of the vehicle.

The disadvantage of these systems is that they can be installed only on vehicles with universal axles and have a complex construction.

To the same purpose of recovery of the braking energy, hydraulic systems are known directly coupled with the engine.

The disadvantage of these systems is related to the investment due to the modification of the engine in order of their adaptation.

Also known are electrical hybrid systems that store the energy in batteries.

The disadvantage of these systems is due to the fact that the recovery of braking energy requires a power generator, electrical batteries and an electric motor.

The technical problem solved by this invention is to provide a kinetic energy recovery system during braking that brings fuel savings by converting the total kinetic energy during braking the car in a pressure that can be reused to accelerate the vehicle.

The brake kinetic energy recovery system according to the present invention eliminates the above disadvantages in that it is made up of motor hydraulic pumps, which are mounted on the wheels of the vehicle, a distributor, hydraulic tanks connected to air tanks, a pneumohydraulic cylinder and an oil tank connected to an air tank, whose control is performed by means of distributors equipped with double circuit solenoid valves and solenoid valves, sub-assemblies which are connected by means of pipes. The motor hydraulic pumps are formed by rotors, stators, and distributors, these being connected to each other, the hydraulic connection between the distributors and the stators being achieved by pipe lines. The stator and the flange are provided with circular channels connected to radial channels that are coupled to a transversal channel, whereas the possible oil leakage between the stator and the rotor can be evacuated exit channel. The distributor comprises a tubular element which is provided with threaded holes and another threaded hole, whereas a metal housing is mounted on the tubular element. Inside the tubular element slides a piston which is provided with circular channels and the piston is pushed by a helical spring which is supported on the tubular element, and an electromagnet is attached to the distributor and the metal rod of the electromagnet is designed to block the piston. The pneumohydraulic cylinder is made from tubular elements with a piston sliding axially within them and an electromagnet which in turn may drive the piston, the tubular elements being provided with threaded holes.

Following benefits can be obtained applying this invention:

• Eliminate the braking system of the vehicles partially or totally;

• It can be installed on any type of vehicle;

• In case of heavy vehicles, the intarder can be eliminated;

• The kinetic energy during braking is entirely recovered and is used to accelerate the vehicle, the urban fuel consumption decreases reaching the value of the extra-urban consumption;

• The production costs are reduced due to simple construction;

• As the environmental factor, reducing the fuel consumption the harming emissions decrease too.

In the following, two embodiments of the invention are described, in connection also with figures 1-7, in which:

- fig. 1 - electrohydraulic schematic of the brake energy recovery system according to the invention;

- fig. 2 - cross section through the motor hydraulic pump, pos. A and Ai;

- fig. 3 - axial section through the motor hydraulic pump which allows, in the first alternative, pos. Γ, mounting thereof in place of the brake disc;

- fig. 4 - axial section through the distributor, pos. B;

- fig. 5 - axial section through the pneumohydraulic cylinder, pos. E;

- fig. 6 - axial section through the motor hydraulic pump which allows, in the second alternative, pos. G, mounting thereof in the wheel drums, replacing the braking shoes.

The brake kinetic energy recovery system, in a first embodiment, according to the invention, consists of the motor hydraulic pumps A and Ai that are identical and are mounted in place of the brake discs for the vehicles equipped with disc brakes. The motor hydraulic pump A is mounted on one of the driving wheels and the motor hydraulic pump Ai is mounted on the other driving wheel of the vehicle. Also, these motor hydraulic pumps A and Ai may be installed on any wheel or on all wheels of a car.

Since motor hydraulic pump Ai is identical by design to motor hydraulic pump A, it will not be described in the presentation.

Motor hydraulic pump A consists of a rotor 1, a stator 2 and a distributor 3, the latter being connected with a distributor 3'.

The rotor 1 is provided with a cylindrical element a mounted with screws 4 to a hub 5 of the motor vehicle wheel.

The cylindrical element a is connected to a drum b having the radial channels c communicating with other longitudinal channels d belonging to the cylindrical element a.

The radial channels c communicate with the radial recesses e within which the blades 7 are sliding, each equipped with a metal disc pressed by the helical springs 8, which are based on the metallic elements 9. The latter close by pressing the radial recesses e. Also, both the metallic elements 9 and the blades 7 are equipped with seals 10.

On the cylindrical element a is also mounted a pressure chamber 11, respectively 11', for the cylindrical element a of the motor hydraulic pump Ai, which is supported by the ball bearings 12, the pressure chambers 11 and 11' have each a radial channel f communicating with the longitudinal channels d.

Inside the stator 2 of the motor hydraulic pump A, the rotor 1 is mounted, the latter being closed by a flange 13 which presses on the stator 2 becoming supportive of that one and being assured by a security component 14. Both the stator 2 and the flange 13 rest on the ball bearings 15 mounted on the cylindrical element of the rotor 1. The flange 13 is fitted with teeth, not numbered, necessary for the ABS system.

Also, the stator 2 and the flange 13 have recesses in which the sealing rings 15' are fitted, which are designed to block the flow of oil that could leak between the body of the stator 2 and the rotor 1.

The stator 2 and the flange 13 have also the circular channels g, the radial channels h, a cross channel i and an exit channel j, to drain the oil leaking between the stator 2 and the rotor 1. At the same time, the stator 2 has the inlet recesses k and the exit recesses I that communicate with the inlet lines 16 and the exit lines 17, through which the oil is circulating towards the distributor 3, which is composed of the double circuit solenoid valves 18 and 19. The stator 2 is fixed with the screws 20 to a support 21 on which the brake system calipers were fixed.

The lines 22 and 23 are connected to the distributors 3 and 3'. The line 22 is connected to an oil tank 24 through a metal beaker m. The tank 24 is also equipped with an air valve n, to which a line 25 is connected, which in turn is connected to an air tank 26.

Also to the line 22, a line 27 is connected which makes the connection to the exit channel j of the motor hydraulic pump A.

In this first version, the coupling of the motor hydraulic pumps A and Ai in place of the brake disc is accomplished according to the assembly F in figure 3.

The line 23 is connecting to the distributor 3 and the solenoid valves 28 and 29. To the line 23 is connected also a line 30 having the branches o, p and q, which are connected to a distributor B.

The distributor B is made of a tubular element 31 which has the threaded holes ri, n and re to pass the oil under pressure, and another threaded hole s. On the tubular element 31, a metal housing 32 is screwed in which an electrical contactor with a hydraulic piston is fitted, not numbered.

Inside the tubular element 31, a piston 33 is sliding that has the circular channels ti, ti and t3 through which the oil passes to the threaded holes ri, n and re, and other circular channels u in which seals are fitted, not numbered.

The piston 33 is pressed by a helical spring 34 which is supported on the tubular element 31. To the distributor B an electromagnet 35 is attached whose metal rod serves to lock the piston 33.

To the threaded hole ri, a line 36 is connected which communicates with the solenoid valve 28. To the line 36 another line 37 is connected which is connected to a hydraulic valve 38 of a hydraulic tank C, which is provided with an air valve v, to which a line 39 is connected, which in turn connects to an air tank 40.

To the threaded hole r ₂ a line 41 is connected that connects to the solenoid valve 29. To the line 41, another line 42 is connected, which makes the connection to a hydraulic valve 43 of a hydraulic tank D, similar in construction to the hydraulic tank C. On the hydraulic tank D, an air valve 44 is fitted, which in turn is connected to a pipe 45 which connects to an air tank 46. Also on the hydraulic tank D, a hydraulic valve 47 is fitted, that communicates with a line 37 by means of a line 48, and a hydraulic valve 49 that is connected to a line 50 connected to the oil tank 24.

To the threaded hole ro, a line 51 is connected that makes the connection to the oil tank 24.

The brake kinetic energy recovery system, according to the invention, is equipped also with a pneumohydraulic cylinder E, which is composed of tubular elements wi and w ₂ , having different diameters within which a piston x is sliding axially. The pneumohydraulic cylinder E is fitted also with an electromagnet W3 which in turn can drive the piston x.

The tubular element wi has a smaller diameter then the tubular element W2. The tubular element wi has a threaded hole zi to which a line 52 is connected, which is connected to the braking circuit of the vehicle, circuit composed of various hydraulic systems, based on brake fluid, pneumohydraulic systems or compressed air systems. The tubular element W2 has a threaded hole in which a cross connection Z3 is mounted.

The lines 53, 54 and 55 are connected to the cross connection Z3. The line 53 is communicating with the pressure chamber 11', the line 54 is communicating with the pressure chamber 11 and the line 55 is connected to the threaded hole s of the distributor B. Likewise, inside the tubular member w ₂ there is a volume of oil required for the hydraulic system.

The brake kinetic energy recovery system, according to the invention, is equipped also with an electrical switchboard 56 powered from the electric battery existing on the vehicle. The contactor in the metal housing 32 of the distributor B is powered from the switchboard 56, and from this contactor to the double circuit solenoid valves 18 and 19 of the distributors 3 and 3'. Also from the switchboard 56 are powered from an electric circuit 57, coming from an electrical contact actuated by the gas pedal, the solenoid valves 28 and 29, but also the double circuit solenoid valves 18 and 19.

The brake kinetic energy recovery system, in the second embodiment, according to the invention, allows the mounting of the motor hydraulic pumps A and Ai in place of the brake shoes for the vehicles that have drum braking systems. The motor hydraulic pumps A and Ai are the same as those in the first embodiment, the difference consisting in the mounting of the rotor 1, the cylindrical element a of which is fastened with the screws 4 to the brake drum 6 of the vehicle wheel, and the mounting of the stator 2 that is fixed with the screws 20 to the support 21 to which the brake shoes of the drum vehicle braking system were fixed, according to assembly G in figure 6.

The operation of the brake kinetic energy recovery system, according to the invention, will be presented in the following, taking a generic vehicle as an example.

When the car is equipped with the brake kinetic energy recovery system, according to the invention, is moving, the rotors 1 of the motor hydraulic pumps A and Ai describe a rotation movement, as blades 7 are not activated, being withdrawn into the drums b. When the driver operates the brake pedal, the brake fluid or the pressurized air passes through line 52 and presses the piston x in the pneumohydraulic cylinder E that forces the oil under pressure through pipes 53 and 54 to the pressure chambers 11 and 1 , and from here, through the channels f, d and c, the oil reaches under the blades 7 pressing them onto the stators 2. At the same time the oil is pushed by the piston x, through the line 55, towards the distributor B where it acts on the piston 33, which moves axially through the tubular element 31. Also during this time the pressured oil from the tubular element 31 is acting also on the hydraulic piston in the metal housing 32 that operates the electric contactor, sending power to the double circuit solenoid valves 18 and 19; those open and allow the oil from the oil tank 24 to penetrate through line 22 and reaches the inlet lines 16 and hence the intake recesses k. The blades 7, being activated, aspire the oil and press it toward the oil exit recesses 1, then the oil is sent through the discharge lines 17, gets in line 23, and from here it passes through the line 30 reaching ramifications o, p and q.

When the driver brakes the vehicle, holding the brake pedal depressed in a short stroke, the piston 33 of the distributor B allows the oil to pass through the branch o towards the threaded hole ri, from here via the lines 36 and 37 and the hydraulic valve 38 it reaches the hydraulic tank C, that has air under pressure. The air pressure in the hydraulic tank C is the result of calculation of the mass and the velocity of the vehicle.

When the oil enters the hydraulic tank C, the air is compressed and passes through the air valve v and line 39 into the compressed air tank 40. Because of this, an air cushion is building up in the hydraulic tank C that opposes to the movement of the oil and consequently to the rotors 1 being in a rotating motion. When the driver brakes the vehicle, holding the brake pedal depressed in a long stroke, the piston 33 is moving axially, so the oil circuit between the branch o and the threaded hole rl is obstructed and the oil circuit between the branch p and the threaded hole r2 is opening partially, enabling the oil to pass through the lines 41 and 42 and the hydraulic valve 43 into the hydraulic tank D, which has an air pressure higher than that in the hydraulic tank C, compressing the air in it and forcing it through the air valve 44 and the line 45 into the compressed air tank 46. In this case, the air cushion built up in the hydraulic tank D opposes a greater resistance to the rotors 1, so the braking distance of the vehicle is reduced.

When the hydraulic tank C is filled with oil, the air valve v closes and the oil pressure causes the hydraulic valve 47 to open and the oil in the line 37 passes into the line 48 reaching the hydraulic tank D. The hydraulic tanks C and D are calculated also in relationship to the braking space and the mass of the vehicle. When the hydraulic tanks C and D are filled with oil at maximum, the hydraulic valve 49 allows the oil to pass through the line 50 in the oil tank 24. The oil tank 24 is larger than the combined volume of the hydraulic tanks C and D.

If the driver is forced to emergency brake the vehicle by pressing the brake pedal fully, the piston 33 of the distributor B is closing the oil circuit between the branch o and the threaded hole ri and the oil circuit between the branch p and the threaded hole rz and opens the oil circuit between the branch q and the threaded hole rc through which the oil enters the line 51 and reaches the oil tank 24. The size of the circular channel t3 on the piston 33 is calculated to allow the passage of oil at a high pressure opposing resistance to the rotors 1 of the motor hydraulic pumps A and Ai which helps the braking process in a short space and effectively.

When the driver no longer operates the brake pedal, the piston x withdraws because of the helical spring 34, so the hydraulic piston in the metal housing 32 is released and the double circuit solenoid valves 18 and 19 close, and the oil pressure in the chambers 11 and 11' decreases, and due to the helical springs 8 the blades 7 retract into the radial recesses e causing the release of the drums b of the rotors 1, so the wheels of the vehicle are released from the braking process.

Pressing the gas pedal, the contactor that is coupled therewith, but at a less stroke of the gas pedal, sends an electrical current through the circuit 57 into the switchboard 56 and there from to the solenoid valves 28 and 29 and also to the electromagnet 35 and to the electromagnet W3. The electromagnet W3 is acting on the piston x sending oil pressure into the pressure chambers 11 and 11' and hence the oil gets under the blades 7 driving themselves. The electromagnet 35 is acting on the piston 33 blocking it. At the same time, the electric circuit 57 sends power also to the double circuit solenoid valves 18 and 19, these solenoid valves reverse the oil, and after this the oil under pressure in the hydraulic tank D changes its direction that it had at charging, being pressed by the air from the air tank 46, it exits through the hydraulic valve 43, passes through line 42, and then through line 41 reaching the solenoid valves 28 and 29 from where it is going toward the 3 and 3' through line 23. From the distributors 3 and 3', the oil passes through the inlet lines 16 and inlet recesses k and reaches behind the blades 7 driving themselves, causing rotation of the rotors 1 and by default of the vehicle wheels and thus putting it in motion. From here the oil exits through the exit recesses 1, it passes through the discharge lines 17 and then through the distributors 3 and 3' and reaches through the line 22 the oil tank 24 via the metal beaker m.

After discharging of the energy stored in the hydraulic tank D, the driver can accelerate the vehicle, thus leading to the discharge of the energy from the hydraulic tank C on the wheels and the hydraulic valves 38, 43, 47 and 49 are closed automatically.