METHOD FOR SEPARATE LUBRICATION OF A DRIVE SYSTEM FOR A MOTOR VEHICLE

Abstract

The present application concerns a method for separate lubrication of a drive system for a motor vehicle, the system including a compressor and an internal combustion engine including a top end and a bottom end that are coupled together, the method including: lubricating the bottom end with a lubricating composition CL1 having an SAE J300 grade defined by the formula (X)W(Y) in which X represents 0 or 5 and Y represents 4, 8, 12, 16 or 20; lubricating the top end with a lubricating composition CL2 different from the lubricating composition CL1; and lubricating the compressor with a lubricating composition CL2 or with a lubricating composition CL3 different from the lubricating compositions CL1 and CL2.

Claims

1-6. (canceled)

7. A lubrication method for separate lubrication of a drive system for a motor vehicle, the said system comprising a compressor, and an internal combustion engine that comprises an engine top part (or top end) and an engine bottom part (or bottom end) that are coupled together, the said method comprising: the lubrication of the engine bottom part with a lubricating composition CL1 having an SAE J300 grade, defined by the formula (X)W(Y) in which X represents 0 or 5 and Y represents 4, 8, 12, 16 or 20; the lubrication of the engine top part with a lubricating composition CL2 that is different from the lubricating composition; and the lubrication of the compressor with a lubricating composition CL2 or with a lubricating composition CL3 that is different from the lubricating compositions CL1 and CL2.

8. A method according to claim 7, wherein the composition CL1, has an SAE J300 grade, selected from 0W-4, 0W-8, 0W-12, 0W-16, 0W-20, 5W-4, 5W-8, 5W-12, 5W-16 or 5W-20.

9. A method according to claim 7, wherein the CL1 composition has a high temperature high-shear viscosity measurement (HTHS) at 150 C. that is at most equal to 2.9 mPa.Math.s.

10. A method according to claim 7, wherein the lubricating composition CL1 does not include any anti-wear additives.

11. A lubrication method, according to claim 7, for lubricating a drive system (1, 100) for a motor vehicle comprising: an internal combustion engine (3), which comprises an engine top part (5) and an engine bottom part (7) that are coupled together, as well as a driving power train including at least one piston (15) and a crankshaft (9); a compressor (35), which is fitted to the internal combustion engine, and which is designed for compressing, at least in part, an inlet fluid (A) intended for filling cylinders of the engine bottom part, the said method comprising: the lubrication of the engine bottom part with a lubricating composition CL1, by making use of a main lubrication system comprising a main circuit (105) and a main pump (103); the lubrication of the engine top part with a lubricating composition CL2 and/or of the compressor with a lubricating composition CL2, by making use of a secondary lubrication system comprising at least one secondary circuit (115, 125, 135) which is separate from the main circuit, at least one secondary actuator (119, 129, 139) that drives a secondary pump (113, 123, 133).

12. A lubrication method, according to claim 7, for lubricating a drive system (1, 100) for a motor vehicle comprising: an internal combustion engine (3), which comprises an engine top part (5) and an engine bottom part (7) that are coupled together, as well as a driving power train including at least one piston (15) and a crankshaft (9); a compressor (35), which is fitted to the internal combustion engine, and which is designed for compressing, at least in part, an inlet fluid (A) intended for filling cylinders of the engine bottom part, the said method comprising: the lubrication of the engine bottom part with a lubricating composition CL1, by making use of a main lubrication system comprising a main circuit (105) and a main pump (103); the lubrication of the engine top part with a lubricating composition CL2 by making use of a first secondary lubrication system (125) which is separate from the main circuit, comprising a first secondary pump (123); and the lubrication of the compressor with a lubricating composition CL3, by making use of a second secondary lubrication system (135) which is separate from the first secondary circuit, comprising a second secondary pump (133), which is distinct and separate from the first secondary pump.

Description

[0069] FIG. 1 is a schematic view of a drive system which is capable of enabling the implementation of the method according to the invention.

[0070] FIG. 2 is a schematic view of a drive system which is capable of enabling the implementation of the method according to the invention.

[0071] The drive system 1 shown in FIG. 1 is designed so as to equip a motor vehicle, for example a land-based motor vehicle, such as a car.

[0072] The present invention also relates to a lubrication method for separate lubrication of a drive system 1, 100 for a motor vehicle comprising: [0073] an internal combustion engine 3, which comprises an engine top part 5 and an engine bottom part 7 that are coupled together, as well as a driving power train including at least one piston 15 and a crankshaft 9; [0074] a compressor 35, which is fitted to the internal combustion engine, and which is designed for compressing, at least in part, an inlet fluid A intended for filling cylinders of the engine bottom part,
the said method comprising: [0075] the lubrication of the engine bottom part with a lubricating composition (CL1), by making use of a main lubrication system comprising a main circuit 105 and a main pump 103; [0076] the lubrication of the engine top part with a lubricating composition (CL2) and/or of the compressor with a lubricating composition (CL2), by making use of a secondary lubrication system comprising at least one secondary circuit 115, 125, 135 which is separate from the main circuit, at least one secondary actuator 119, 129, 139 that drives a secondary pump 113, 123, 133.

[0077] In an advantageous fashion, the secondary actuator is mechanically independent from the driving power train.

[0078] The present invention also relates to a lubrication method for separate lubrication of a drive system 1, 100 for a motor vehicle comprising: [0079] an internal combustion engine 3, which comprises an engine top part 5 and an engine bottom part 7 that are coupled together, as well as a driving power train including at least one piston 15 and a crankshaft 9; [0080] a compressor 35, which is fitted to the internal combustion engine, and which is designed for compressing, at least in part, an inlet fluid A intended for filling cylinders of the engine bottom part,
the said method comprising: [0081] the lubrication of the engine bottom part with a lubricating composition (CL1), by making use of a main lubrication system comprising a main circuit 105 and a main pump 103; [0082] the lubrication of the engine top part with a lubricating composition (CL2) by making use of a first secondary lubrication system 125 which is separate from the main circuit, comprising a first secondary pump 123; and [0083] the lubrication of the compressor with a lubricating composition (CL3), by making use of a second secondary lubrication system 135 which is separate from the first secondary circuit, comprising a second secondary pump 133, which is distinct and separate from the first secondary pump.

[0084] The compressor may be in particular a turbocharger compressor.

[0085] The present patent application will now be illustrated by making use of non-limiting examples presented here below.

[0086] The lubrication method according to the present invention has been operationally implemented in the drive system represented in FIG. 2, the engine used being a DW10 engine from the automaker PSA Peugeot Citroen. Two tests were carried out with the compositions (CL1) and (CL2) that are distinct from one another.

[0087] In these tests: [0088] the engine bottom part 7 is lubricated with a lubricating composition (CL1), by making use of a main lubrication system comprising a main circuit 105 and a main pump 103; [0089] the engine top part 5 corresponding to the cylinder head is lubricated with a lubricating composition (CL2) by making use of a first secondary lubrication system 125 which is separate from the main circuit, comprising a first secondary pump 123; and [0090] the compressor 35 corresponding to a turbocharger compressor is lubricated with the lubricating composition (CL2), by making use of a second secondary lubrication system 135 which is separate from the first secondary circuit, comprising a second secondary pump 133, which is distinct and separate from the first secondary pump.

[0091] The lubricating compositions used in operation are described in Table I here below:

TABLE-US-00002 TABLE I Test 1 Test 2 CL1 Group III Base Oil 85 82.8 (KV100 measured according to the standard ASTMD445 = 4.1 mPa .Math. s) Additives (friction 11.2 11.2 modifier, type: molybdenum dithiocarbamate; PPD, type: polymethacrylate; dispersant, type: succinimide; detergents, type: phenate, sulfonate and carboxylate) Polymer 1 3.8 (hydrogenated styrene/isoprene copolymer) Polymer 2 6 (polymethacrylate) CL2 Base Oil 1 (group III 37.4 37.4 base oil with a KV100 measured according to the standard ASTMD445 = 4.1 mPa .Math. s) Base Oil 2 (Group 15 15 III base oil with a KV100 measured according to the standard ASTMD445 = 5.1 mPa .Math. s) Base Oil 3 (Group 30 30 IV base oil with a KV100 measured according to the standard ASTMD445 = 4 mPa .Math. s) Additives (friction 11.5 11.5 modifier, type: molybdenum dithiocarbamate; dispersant, type: borated ester; anti- wear, type: zinc dithiophosphate; detergent, type: salicylate; antioxidants, type: phenol and amine) Polymers 6.1 6.1 (hydrogenated styrene/isoprene copolymer and polymethacrylate)

[0092] For the Test 1, the composition CL1 is defined by an SAE 0W 16 grade rated according to the SAEJ300 classification.

[0093] For the Test 2, the CL1 composition is defined by an SAE 0W-20 grade rated according to the SAEJ300 classification.

[0094] The average gain in fuel consumption for the Tests 1 and 2 was determined by effectively implementing the method here below comprising the following three steps: [0095] Measurement of the consumption in non-separated configuration: this step consists in the measuring of consumption over stabilised points representative of the standard cycle NEDC (New European Driving Cycle) (or NCEC Nouveau Cycle Europen de Conduite) with a 0W30 grade reference oil corresponding to the composition CL2; [0096] Measurement of the consumption in separated configuration: this step consists in repeating the same measurements of consumption over the same points of operation as those of the first step, but this time with an engine whereof the lubrication system circuit has been separated into three sub-circuits as shown in FIG. 2 dedicated respectively to the turbocharger compressor, to the cylinder head and to the engine bottom part. The turbocharger compressor circuit as well as the cylinder head circuit contain the same 0W30 grade reference oil as that of the first step corresponding to the composition CL2. As for the engine bottom part circuit it contains a candidate oil CL1. [0097] Calculation of the relative gains in consumption over points of operation that are comparable between the candidate oil CL1 in the engine in separate lubrication configuration and the reference oil in the engine in unseparated lubrication configuration.

[0098] By means of this method, it is possible to compare, over each point of operation, the gain in fuel consumption by using a separate lubrication engine system with the candidate oil CL1 specifically formulated for the engine bottom part.

[0099] The results of the gain in fuel consumption for the Tests 1 and 2 are presented in Table II here below:

TABLE-US-00003 TABLE II Test 1 Test 2 Average gain in fuel 3.94% 4.85% consumption (%)

[0100] The above results show that the operational implementation of a lubrication method according to the invention makes it possible to obtain significant gains in motor fuel consumption, in particular greater than 3%.