EP3374614A1

EP3374614A1 - Drive system and associated motor vehicle

Info

Publication number: EP3374614A1
Application number: EP16794326.5A
Authority: EP
Inventors: Anthony PELLETIER; Philippe CHINA
Original assignee: Total Marketing Services SA
Current assignee: TotalEnergies Marketing Services SA
Priority date: 2015-11-13
Filing date: 2016-11-10
Publication date: 2018-09-19
Also published as: US10513953B2; KR20180081553A; JP2018535349A; US20180328241A1; WO2017081142A1; CN108307644A; FR3043717B1; FR3043717A1

Abstract

This drive system (1) for a motor vehicle comprises a top end (5) and a bottom end (7) that are coupled together, a kinematic drive chain, a compressor (35), a main lubrication system, that comprises a main circuit (105) and a main pump (103), which supplies at least the bottom end with a main lubricant via the main circuit, and a secondary lubrication system, that comprises at least one secondary circuit (115) separated from the main circuit and at least one secondary pump (113) separate from the main pump, the secondary pump supplying the top end and/or the compressor with a secondary lubricant via the secondary circuit (115). The secondary lubrication system comprises at least one secondary actuator (119) mechanically separate from the kinematic drive chain and that drives the secondary pump (113) to supply the top end (5) and/or the compressor (35) with the secondary lubricant.

Description

Motorization system and associated motor vehicle

The present invention relates to a motorization system for a motor vehicle and a motor vehicle comprising such a motorization system.

The majority of current motor vehicles are equipped with a motorization system including a two-part internal combustion engine:

A so-called "low-motor" part, comprising a movable coupling (connecting rods, pistons and crankshaft) within an "engine block", containing the cylinders, and a housing containing the engine lubricant.

- A part called "high-engine" consisting of the or, breech (s) which are assembled on the low-motor. The cylinder head is the seat of the distribution of the intake gases in the combustion chamber, through the intake duct and intake valves, and the discharge of the combustion gases, via a exhaust duct and exhaust valves.

The limitation between the "low-engine" and the, or "top (s) -engine (s)" is materialized by the, or the bolt joint (s).

The combustion chamber, seat of the combustion of an air-fuel mixture, is the volume between the top of the piston when it is in the high position, named "top dead center" and the cylinder head.

FR-A-2 605 677 discloses a lubrication system for an internal combustion engine which comprises a main lubrication circuit of the lower engine incorporating an oil pump mounted at the end of the crankshaft, and a secondary circuit for lubricating the engine. high-motor that is independent of the main circuit and incorporates itself a pump mounted at the end of the engine camshaft. The lubrication system is thus separated into two separate circuits, so that the oil to lubricate the high-engine is not polluted by the oil used to lubricate the lower-engine, which improves the life of the engine .

Nevertheless, the lubrication of the built-in engine is only performed when the engine is running, so that the starting and stopping phases of the motor cause significant wear of the components of the built-in engine.

The motorization system of certain motor vehicles further comprises a compressor designed to compress the air to form the air-fuel mixture before admission to the combustion chambers to improve the power of the engine. Such a compressor is traditionally operated either by the crankshaft of the engine, or using the kinetic energy contained in the exhaust gas emitted by the engine. In the second case, the compressor is equipped with a drive turbine, which is placed in the path of the exhaust gas, so as to form a turbocharger.

In the case of engines equipped with a turbocharger, the lubrication of the latter is also stopped when the engine is stopped, since the operation of the lubricant pump depends on that of the crankshaft. When stopped, lubricant residues still present in the lubrication system of the turbocharger are found in contact with hot metal surfaces in the body of the latter. Indeed, the proximity of the hot exhaust gas side of the turbine generates an increase in temperature of the metal parts of the body of the turbocharger by conduction. This phenomenon is sometimes referred to as "coking" of the lubricant.

On the other hand, the economic, legislative and environmental constraints push the designers and users of internal combustion engines to reduce the fuel consumption of these engines. For example, European standards provide for a CO2 emission level of 95g / km or less from 2021.

It is these problems that the invention intends to meet by proposing a new engine system with improved lifetime and reduced fuel consumption.

For this purpose, the invention relates to a motorization system according to claim 1.

Thanks to the invention, the lubrication of the compressor and / or the high-engine is performed independently of the operation of the engine and in particular of its drive kinematic chain. The secondary lubrication system can for example be actuated before starting the engine so as to pre-lubricate the compressor and / or the high-engine and thus prevent wear of the latter when starting the engine. Also, the lubrication of these elements can be extended after stopping the engine, especially for cooling purposes.

The use of a lubricant suitable for the compressor, that is to say, resistant to temperature and with good friction characteristics, makes it possible to limit losses by pumping the motor by facilitating admission of the intake fluid. while limiting the back pressure to the exhaust. This results in an increase in power, at the same fuel consumption, or in a decrease in consumption at identical power. The reactivity of the compressor in the transient phases, such as accelerations, is also improved with the use of this suitable lubricant, which allows to optimize the fuel consumption during these transient phases.

Moreover, the circulation of this lubricant after stopping the engine makes it possible to evacuate the calories and limit the stagnation of the lubricant on the hot parts, correcting the problems of coking.

The configuration of the lubrication system of the invention then makes it possible to optimize the supply of lubricant as a function of the contact to be lubricated by the drive system. For each of the circuits, the pressure can be adjusted to the maximum value of the minimums required for the lubrication of each of the lubricated contacts via the circuit in question. This results in a lower drive force of the pumps than in the case of a motorization system in which a single global lubrication circuit would be provided, so that an overall energy saving is achieved.

Finally, the secondary lubricant can be chosen to be particularly adapted to the lubrication of the compressor and / or the high-engine, and in particular to the physical, mechanical and thermal stresses of these parts of the engine system, while the main lubricant is particularly suitable for the lubrication of the low-engine and its own mechanical and thermal physical constraints. The choice of a lubricant specifically adapted to the low-engine allows, at equal power, to obtain a reduced fuel consumption.

Other advantageous features of the invention are defined in claims 2 to 1 1.

The invention also relates to a motor vehicle defined in claim 12.

The invention will be better understood on reading the description which will follow, given solely by way of nonlimiting and non-exhaustive example and with reference to the drawings in which:

FIG. 1 is a schematic view of a motorization system according to a first embodiment according to the invention, and

- Figure 2 is a schematic view of a motorization system according to a second embodiment according to the invention.

The drive system 1 of Figure 1 is designed to equip a motor vehicle, for example land, such as a car.

In what follows, the terms "top", "top" and their equivalents, are used to designate a direction oriented vertically towards the top of the vehicle when it is in a position of use, in which it rests for example on the ground. The expressions "low" and "lower" and their equivalents designate an opposite direction.

The drive system 1 of Figure 1 comprises an internal combustion engine 3, equipped with a compressor 35. The internal combustion engine 3 forms a mechanical assembly which is intended to rotate a crankshaft and a feed system in air comprising the compressor 35, which forms for example a turbocharger.

In a manner known per se, the internal combustion engine 3 comprises a high-engine 5 and a low-engine 7 coupled.

The lower engine 7 includes a crankshaft 9 which is rotatable relative to a housing 11 of the lower engine 7, includes a motor block 17 or "cylinder block" in which the crankshaft 9 is mounted.

The lower engine 7 also includes connecting rods 13 and pistons 15, each connecting rod 13 being rotatably mounted on one of the pistons 15 and on the crankshaft 9. The engine block 17, belonging to the lower engine 7, defines cylinders 19 in which slide the pistons 15. The engine block 17 is closed, downwards, by the housing 1 1, and upwards, by the upper motor 7. The housing 1 1 forms a pocket closed by the bottom , and is assembled from above with the engine block 17. The pistons 15 are driven in an alternating translational movement within the cylinders 19 in order to drive the crankshaft 9 via the connecting rods 13. In the example of Figure 1, four pistons 15 and four connecting rods 13 are shown. However, in a variant, the lower engine 7 comprises a single piston 15, a single connecting rod 13 and a single associated cylinder 19, or a greater number of pistons 15, connecting rods 13 and associated cylinders 19.

The high-engine 5 includes a cylinder head 21, equipped with a distribution system including air and fuel distribution members to the cylinders 19. The cylinder head 21 caps the engine block 17 via a cylinder head gasket 23 3. The cylinder head gasket 23 constitutes the boundary between the high-engine 5 and the low-engine 7.

The space between the top of each piston 15 in its cylinder 19, at top dead center, and the cylinder head 21, represents a combustion chamber 24. Each combustion chamber 24 comprises one, and preferably several, orifice (s) intake, through which the intake of air and fuel is carried out. Depending on the type of the combustion engine 3, air and fuel are admitted separately or already mixed in the combustion chambers, and are therefore generally designated in the following by "intake fluid". Each combustion chamber 24 includes also at least one product exhaust port of the combustion of this intake fluid. Each combustion chamber 24 is the seat of combustion reactions of the intake fluid, this reaction being carried out above the piston 15 concerned, in order to generate the reciprocating translation movement of the piston 15 to drive the crankshaft 9.

The dispensing system of the high-engine 5 includes in particular valves 25 which each evolve between an open position or closure of one of the inlet or exhaust ports of the combustion chambers 24. The distribution system includes also a shaft 27, of the camshaft type, for controlling the valves 25. The control shaft 27 is parallel to the crankshaft 9 and is driven by the latter through a timing belt 29 of the engine 3. In FIG. Alternatively, in place of the timing belt, the drive system 1 comprises a timing chain or a gear. Alternatively, the high-engine 5 is provided with several control shafts, preferably driven by the crankshaft 9. Alternatively, the valves 25 may be controlled by actuators, for example electromagnetic, or electropneumatic, or electrohydraulic.

The crankshaft 9, the rods 13, the pistons 15, the valves 25, the control shaft 27 and the timing belt 29, or its mechanical variants defined above, belong to a driving kinematic chain of the engine 3. The chain driving kinematics of the engine 3 may comprise additional movable elements belonging to the engine 3, such as for example a second control shaft, a lower or upper number of valves, a lower or upper number of pistons of the two connecting rods. Finally, the driving kinematic chain of the engine 3 includes all the moving components of the engine which are driven mechanically, directly or via transmission means, under the action of the combustion reaction of the intake fluid. Any mobile component of the engine 3 not mentioned in the present description, and which would be moved by means distinct from this combustion reaction of the intake fluid, such as pneumatic, hydraulic or electrical means do not belong to the drive kinematic chain of the engine system 1.

An intake manifold 31 of the engine system 1 is connected to the cylinder head 21 so as to distribute the intake fluid into the combustion chambers 24 of the lower engine 7 via valves 25, called "valves". admission ". In general, the intake fluid is admitted into the low-engine 7 through the high-engine 5. An exhaust manifold 33 of the engine system 1 is also connected to the built-in engine 5 to collect combustion chambers 24 the products of the combustion reaction of the intake fluid, through valves 25 called "exhaust valves". These products form, for example, exhaust gases. The path of the intake fluid in the intake manifold 31 is symbolized by the arrow A and the path of the products of combustion within the exhaust manifold 33 is symbolized by the arrow E.

The motorization system 1 comprises a compressor 35, which is designed to compress the intake fluid before it enters the combustion chamber 24, for example upstream of the intake manifold 31. Preferably, the compressor compresses the air for entering the intake fluid composition, fuel being itself added to that air after the air has been compressed by the compressor before or during its admission into the intake fluid composition. Combustion chambers 24. The compressor 35 is thus designed to compress, at least in part, the intake fluid for supplying the high-engine 5.

Several configurations for admission of the intake fluid are therefore possible. For example, in the case of a drive system 1 operating with a gasoline-type fuel, this fuel can be injected either upstream in intake ducts or directly into the combustion chambers 24. In the second case, we speak of motorization with "Direct Injection Essence". In the case of a diesel engine system 1, the fuel is either injected directly into the combustion chambers 24, or admitted into a pre-chamber of the engine system 1, upstream of the combustion chamber 24 and connected to it. last, where the combustion is initiated.

The compressor 35 comprises a compression member 36, of the centrifugal pump type, for compressing the intake fluid, and in particular for compressing all or part of the air entering into the composition of this intake fluid. The compressor 35 preferably forms a turbocharger. In this case, the compressor 35 comprises a turbine 37 driving the compression member 36. The turbine 37 is disposed downstream of the exhaust manifold 33, or at least in the path of the products of the combustion E, so as to capture a portion of the enthalpy and / or kinetic energy of these products E to drive the member 36 and thus compress the intake fluid. As a variant, the compressor 35 may be driven by the driving kinematic chain of the engine 3, and for example by the crankshaft 9.

The engine system 1 further comprises a main lubrication system for lubricating the low-engine 7. In this case, this main lubrication system comprises a main circuit 105 and a main pump 103, which are shown schematically in FIG. The main pump 103 has for example a displacement of between about 5 cc / revolution (cubic centimeters per revolution) and 20 cc / revolution, preferably between about 7 cc / revolution and 12 cc / revolution, more preferably of the order of 10 , 7 cc / turn. The main pump 103 circulates a main lubricant, of the oil type, within the main circuit 105, to feed the lower engine 7 with this main lubricant and lubricate various bodies of the lower engine 7, belonging in particular to the drive kinematic chain . The main circuit 105 extends partly within the lower motor 7 in order to lubricate in particular the connections in rotation between the crankshaft 9 and the connecting rods 13. The main circuit 105 includes a main lubricant reserve 107 and possibly an oil filter not shown. The main circuit 105 is designed to lubricate, with the main lubricant, in particular a segment-piston-liner zone of the lower engine 7, which designates the parts in sliding contact of each piston 15 against its respective cylinder 19. For this, the main circuit 105 comprises for example means for emitting a main lubricant mist, not shown, at the segment-piston-liner zone, which main lubricant mist is emitted by means of bearings The main lubricant supply is preferably by bearings of the crankshaft 9, which are directly connected to a feed ramp belonging to the main circuit 105. Optionally, the main circuit 105 comprises lubricant bottles. main, not shown, which spit oil under the pistons 15 for the purpose of cooling them.

Preferably, the main pump 103 is actuated by the drive kinematic chain of the engine 3, and in particular by the crankshaft 9. Thus, when the engine 3 is running, the crankshaft 9 rotates and drives the main pump 103 so that systematic. The main pump 103 is preferably variable flow and controlled pressure, so that its energy consumption is particularly low for pumping the main lubricant.

The motorization system 1 also comprises a secondary lubrication system, which comprises a secondary circuit 1 15 which is separate and distinct from the main circuit 105. The secondary circuit 1 15 supplies both the compressor 35 and the high-engine 5 with a secondary lubricant, which is different from the main lubricant in its nature and / or composition and / or characteristics.

Preferably, the main lubricant is a lubricating composition having a grade, according to the classification SAEJ300, defined by the formula (X) W- (Y) in which X represents 0 or 5 and Y represents 4, 8, 12, 16 or 20. The main lubricant is for example the Quartz 9000 Future OW-20 or Quartz V-drive OW-20 lubricant, marketed by TOTAL SA. Other lubricants can be implemented for the main lubricant in place of those defined above.

For example, the secondary lubricant is the lubricant Quartz Ineo MC3 5W-30, or Quartz 9000 5W-40 marketed by TOTAL SA. Other lubricants may be used for the secondary lubricant in place of those defined above, as long as the main lubricant is of different composition than the secondary lubricant, these compositions being adapted respectively to the lubricating stresses of the lubricant. lower-motor 7, and of the assembly including the high-engine 5 and the compressor 35.

Alternatively, the main lubricant and the secondary lubricant are of identical composition.

The secondary lubrication system also comprises a secondary pump 1 13, of the hydraulic pump type, for circulating the secondary lubricant in the secondary circuit 1 15. In the example of Figure 1, the secondary circuit feeds both the top -motor 5 and the compressor 35 with the secondary lubricant.

The secondary circuit 1 15 preferably includes a reserve of secondary lubricant 1 17 which is distinct from the main lubricant reserve 107. The secondary circuit 1 15 extends partly within the upper motor 5 in order to lubricate the connections in particular. rotation between the control shaft 27 and the cylinder head 23 and the valves 25. The secondary circuit 1 15 extends partly within the compressor 35 in order to lubricate in particular the rotational links of the member 36, and if necessary , of the turbine 37.

In this document, the term "separate circuits" means that a first lubricant circulating in a first circuit separated from a second circuit, does not come into contact with a second lubricant flowing in the second circuit, the two circuits being separated by sealed separation means such as seals or walls.

The secondary lubrication system comprises an electric motor 1 19, or at least one actuator supplied with electrical energy, driving the secondary pump 1 13, to supply the high-motor 5 and the compressor 35 with the secondary lubricant. . The pump 1 13 is thus an electrically driven pump. The electric power supply of the electric motor 1 19 is for example provided by an electric battery of the motorization system 1. The electric motor 1 19 thus constitutes a secondary actuator of the secondary pump 1 13, which is mechanically independent of the drive kinematic chain. Indeed, the electric motor 1 19 can be operated independently of the movement of the crankshaft 9, rods 13, pistons 15, valves 25, the control shaft 27 or the timing belt 29.

Under these conditions, the secondary pump 1 13 is controlled by means of the electric motor 1 19 to lubricate, with the secondary lubricant, the high-engine 5 and the compressor 35 when the engine 3 is stopped. If necessary, it is possible to control and vary the flow rate of the secondary pump 1 13 by controlling the speed of the actuator 1 19. Preferably, whatever the power supply of the actuator 1 19, it is expected that the secondary pump 1 13 is variable flow by choosing an actuator 1 19 whose speed can be controlled. The secondary pump 1 13 is preferably actuated with the secondary actuator 1 19 to lubricate the high-engine 5 and the compressor 35 with the secondary lubricant just before starting the engine 3, which corresponds to the setting in motion of its kinematic chain. driving. The secondary pump 1 13 is preferably controlled with the secondary actuator 1 19 to lubricate the high-engine 5 and the compressor 35 with the secondary lubricant for a predetermined time starting after a shutdown of the engine 3, which corresponds to immobilization of his driving kinematic chain. In any event, the secondary pump 1 13 is actuated with the secondary actuator 1 19 to lubricate the high-engine 5 and the compressor 35 with the secondary lubricant during the operation of the engine 3, that is to say when the drive kinematic chain is moving. The wear of the high-engine 5 and the compressor 35 is thus particularly reduced, especially in the case where it is a turbocharger, as well as coking.

In the case of a vehicle which comprises a source of hydraulic energy, such as a hydraulic circuit with a pump, or a source of pneumatic energy, such as an air circuit with a compressor, provision may be made for a secondary actuator operating with pneumatic or hydraulic energy in place of the aforementioned electric motor, as long as the operation of the secondary actuator is independent of the operation of the driving kinematic chain. This secondary actuator would then for example be a cylinder, a pneumatic motor or a hydraulic motor.

The secondary pump 1 13 has a smaller capacity than the main pump 103, which, while meeting the lubrication needs of the compressor 35 and the high-engine 5, optimize the amount of energy consumed by the system lubrication. This has the effect of reducing the fuel consumption of the engine system 1. In operation, the low-engine 7 undergoes heavy loads, caused in particular by the action of the pistons 15 on the crankshaft 9. The loads experienced by the compressor 35 are lower, and are caused in particular by the action of the organ compression 36 on the intake fluid, and by the combustion products E on the turbine 37. The loads undergone by the high-engine 5 are even lower, and are caused by the particular action of the tree 27 on the valves 25.

Since the lower engine 7 is subjected to higher loads than the high engine 5 and the compressor 35, it is desirable, for effective lubrication of the engine 7, that the lubricant pressure is higher in the circuit. main 105 that in the secondary circuit 1 15. The main pump 103 having a larger displacement than the secondary pump 1 13, it is easy to obtain a higher pumping pressure in the main circuit 105 than in the secondary circuit 1 15 , so that the lubrication of the system 1 is optimized.

FIG. 2 illustrates a second embodiment of a motorization system 100 according to the invention. Similar elements between the system 1 of Figure 1 and the system 100 of Figure 2 have been assigned the same reference numbers.

In essence, the engine system 100 comprises an internal combustion engine 3, with a built-in engine 5 and a low-engine 7. The low-engine 7 includes a crankshaft 9, a housing 1 1, connecting rods 13, pistons 15, a motor unit 17 with cylinders 19 and combustion chambers 24 defined between the top of the pistons 15 and the bottom of the cylinder head 21. The high-engine 5 is separated from the low-engine 7 by a cylinder head gasket 23 of the engine 3, and includes a cylinder head 21, including, in particular, valves 25, and a control shaft 27. The engine 3 also comprises a belt of distribution 29, or its variants defined above, and a driving kinematic chain corresponding to the same definition as that of the embodiment of FIG. 1.

The system 100 comprises an intake manifold 31 and an exhaust manifold 33, a compressor 35 with a compression member 36 and a turbine 37.

The system 100 includes a main lubrication system with a main circuit 105, a main pump 103 and a main lubricant reservoir 107 for supplying a main lubricant to the lower engine 7 when the drive kinematic chain is in motion.

The system 100 of Figure 2 differs from the system 1 of Figure 1 in that it comprises two separate secondary circuits, including a first secondary circuit 125 and a second secondary circuit 135 separated. The system 100 also includes two separate secondary pumps 123 and 133, including a first secondary pump 123, which supplies the high-engine 5 with a first secondary lubricant through the first secondary circuit 125, and a second secondary pump 133, which is distinct from the first secondary pump 123 and which supplies the compressor 35 with a second secondary lubricant through the second secondary circuit 135. The first secondary lubricant and the second secondary lubricant are of different composition, that is to say are of different nature and different characteristics. The first secondary lubricant and the second secondary lubricant are also of different composition from that of the main lubricant.

For example, the first secondary lubricant is Quartz Ineo MC3 5W-30 lubricant, the second secondary lubricant being the Quartz 9000 5W-40 lubricant marketed by TOTAL SA. In general, the first secondary lubricant is chosen to be particularly adapted to the lubrication constraints of the high-engine 7, the second secondary lubricant being chosen to be particularly adapted to the lubrication constraints of the compressor 35.

Alternatively, of the main lubricant, the first secondary lubricant and the second secondary lubricant, two lubricants are of identical composition, the third being of different composition from the other two. In another variant, the three lubricants are of identical composition.

The secondary circuit 125 preferably includes a first supply of the first secondary lubricant 127 which is distinct from the main lubricant supply 107. The second secondary circuit 135 preferably includes a second supply of the second secondary lubricant 137 which is distinct from the lubricant supply. 107 and Reserve 127.

In the example of FIG. 2, a first secondary actuator 129, mechanically independent of the driving kinematic chain, drives the first secondary pump 123 to supply the high-engine 5 with the first secondary lubricant. A second secondary actuator 139 separate from the first secondary actuator 129, and mechanically independent of the driving kinematic chain, drives the second secondary pump 133 to supply the compressor 35 with the second secondary lubricant.

Preferably, the operation of the two secondary actuators 129 and 139 is independent of each other, so that: the secondary pump 123 supplies the high-engine 5 with the first secondary lubricant for a predetermined duration before starting the engine 3 and / or during the operation of the engine 3;

the secondary pump 133 supplies the compressor 35 with the second secondary lubricant during operation of the engine 3 and / or for a predetermined duration after the engine 3 has been stopped.

Alternatively, the secondary pump 133 feeds the compressor 35 with the second secondary lubricant for a predetermined time before starting the engine 3, to facilitate the starting of the compressor 35 and thus limit its wear.

The first secondary circuit 125 extends in part within the built-in motor 5 in order to lubricate in particular the rotational connections between the control shaft 27 and the cylinder head 23 and the valves 25. The second secondary circuit 135 extends in part within the compressor 35 to lubricate in particular the rotational connections of the member 36, and if necessary, the turbine 37.

The lubrication, as well as the lubricant composition of the low-motor 5 and the compressor 35, can thus be optimized according to the lubrication requirements specific to each of these two members of the motorization system 100.

The secondary actuators 129 and 139 operate either with the same energy, for example electrical, or with two separate energies, for example one being powered by electrical energy and the other with the pneumatic energy.

Preferably, the first secondary pump 123 has a cylinder capacity lower than that of the second secondary pump 133, so that the secondary pumps 123 and 133 provide a quantity of lubricants suitable on the one hand for the high-engine 5 and on the other hand The energy required to operate the secondary pumps 123 and 133 is thus optimized.

Preferably, the first secondary pump 123 has a displacement of between 3 and 15 cc / revolution and the second secondary pump 133 has a displacement of between 1 and 10 cc / revolution.

As a variant, especially in the case where different displacements are provided for the pump 123 and the pump 133, a common actuator, independent of the driving kinematic chain, is provided for driving both the pump 123 and the pump 133, rather than two separate actuators 129 and 139, as is the case in Figure 2. In this variant, the two pumps 123 and 133 are preferably combined to form a two-stage pump. The fuel consumption of the system 100 is thus reduced, insofar as the number of actuators is reduced. In a variant, the invention also applies to engines whose spatial configuration is different from that of the examples of motorization systems described above, in particular so-called "flat" engines. It is understood that in the case of these particular engines, the built-in motor is not necessarily placed above the lower motor. Thus, in the case of these particular engines, the term "built-in motor" defined above designates the cylinder head equipped in particular with, or control shaft (s) and the distribution system, the term "low-engine" designating the crankcase and the engine block, including pistons, rods, crankshaft, cylinders and combustion chambers.

The invention has been tested on a diesel engine of 2L displacement, namely the DW10 engine of the company PSA Peugeot Citroën. It has resulted in a fuel economy gain of at least 3% on stabilized operating points under load conditions, representing the NEDC ("New European Driving Cycle") standardized cycle.

The embodiments and variants described above may be combined to generate new embodiments.

Claims

1. - Motorization system (1) for a motor vehicle, the system comprising:

- an internal combustion engine (3), which comprises a coupled high-engine (5) and a low-engine (7), and a driving kinematic chain including at least one piston (15) and a crankshaft (9) ,

- a compressor (35), which equips the internal combustion engine, and which is designed to compress, at least in part, an intake fluid (A) for filling cylinders of the lower engine,

a main lubrication system, which comprises a main circuit (105) and a main pump (103), which supplies at least the lower motor with a main lubricant via the main circuit, and

- a secondary lubrication system, which comprises at least one secondary circuit (1 15; 125, 135) separate from the main circuit and at least one secondary pump (1 13; 123, 133) separate from the main pump, the secondary pump supplying the high-engine and / or the compressor with a secondary lubricant via the secondary circuit (115, 125, 135),

the system being characterized in that the secondary lubrication system comprises at least one secondary actuator (1 19; 129,139) mechanically independent of the driving kinematic chain and driving the secondary pump (113; 123,133) to supply the high-motor (5) and / or the compressor (35) with the secondary lubricant and in that the main pump (103) has a displacement greater than the displacement of each secondary pump (123, 133).

2. - Motorization system (1) according to the preceding claim, characterized in that the secondary actuator (1 19; 129, 139) operates with electrical energy.

3.- motorization system (1) according to any one of claims 1 or 2, characterized in that two separate secondary circuits are provided, including a first secondary circuit (125) and a second secondary circuit (135) separated, and in that two secondary pumps are provided, of which: a first secondary pump (123), which supplies the high-motor (5) with a first secondary lubricant via the first secondary circuit, and

- A second secondary pump (133), which is distinct from the first secondary pump and which feeds the compressor (35) with a second secondary lubricant through the second secondary circuit.

4. - Motorization system (1) according to claim 3, characterized in that the first secondary pump (123) has a cylinder capacity lower than that of the second secondary pump (133).

5. - Motorization system (1) according to any one of claims 3 or 4, characterized in that the composition of the first secondary lubricant is different from that of the second secondary lubricant.

6. - Motorization system (1) according to any one of the preceding claims, characterized in that the main pump (103) has a displacement of between about 5 cc / turn and 20 cc / turn, preferably between about 7cc / turn turn and 12 cc / revolution, more preferably of the order of 10.7 cc / revolution.

7. - Motorization system (1) according to any one of the preceding claims, characterized in that the main pump (103) is actuated by the drive kinematic chain.

8. Motorization system (1) according to any one of the preceding claims, characterized in that the secondary pump (1 13; 123, 133) is a variable flow pump.

9. A motorization system (1) according to any one of the preceding claims, characterized in that the main lubricant is a lubricant composition having a grade, according to classification SAEJ300, defined by the formula (X) W- (Y) wherein X is 0 or 5 and Y is 4, 8, 12, 16 or 20.

10. - Motorization system (1) according to any one of the preceding claims, characterized in that the composition of the main lubricant is different from that of the secondary lubricant.

1 1. - Motorization system (1) according to any one of the preceding claims, characterized in that the compressor (35) is a turbocharger.

12. - Motor vehicle comprising a drive system (1) according to any one of the preceding claims.