MX2008010373A - Improvement of energy efficiency in hydraulic systems - Google Patents

Abstract

The present invention describes use of a fluid having a VI of at least 130 to improve the en- ergy efficiency of a hydraulic system. Furthermore, the present invention relates to a hy- draulic system comprising a hydraulic fluid having a VI of at least 130, a unit for creating mechanical power, a unit that converts mechanical power into hydraulic energy, and a unit that converts hydraulic energy into mechanical work. Preferentially, engine speed can be reduced to decrease load and stress while delivering the same amount of hydraulic power.

Description

IMPROVEMENTS IN ENERGY EFFICIENCY IN HYDRAULIC SYSTEMS Description The present invention relates to improvements in the efficiency of energy in hydraulic systems. The hydraulic systems are designed to transmit energy and apply great forces with a high degree of flexibility and control. It is convenient to build systems that efficiently convert the input energy from a motor, electric motor, or other source into useful work. The hydraulic power can be used to create rotary or linear motion, or to store energy for future use in an actuator. Hydraulic systems provide a significantly more accurate and adjustable means of transmitting energy than electrical or mechanical systems. In general, hydraulic systems are reliable, efficient, and cost-effective, which results in their widespread use in the industrial world. The fluid power industry is constantly improving the cost effectiveness of hydraulic systems through the use of new mechanical components and construction materials. Water and many other liquids can be used to make practical use of Pascal's Law, which states that a fluid compressed in a closed container will transmit the resulting pressure through the unimpaired and similar system in all directions. Although several innovations in hardware and hydraulic system controls have been marketed in the last 50 years, very little change has occurred in the functionality of hydraulic fluids. There are advances in the composition of base oils and additives that have improved the life of fluids and the compatibility of metals, however, it is not known if fluids offer any advantage for labor productivity or fuel economy. The most widely specified and purchased fluid grades (ISO VG 46 and 68, HM performance grade) are based on Group I mineral oils and are very similar to those recommended for 50 years. Hydraulic fluid is not a critical design element in most hydraulic systems, it is usually the last element of the selected system, and it is assumed that a standard monograde oil will offer sufficient performance. In general, the "HM" Standard mono oil is selected as it is the lowest cost option and has a long history of reliable performance without maintenance problems. Outdoor applications of fluid power that experience wide variations in temperature will use fluids with a lower degree of viscosity in winter and fluids with a higher viscosity grade in summer. Some hydraulic fluids are formulated with PAMA additives as viscosity index improvers, in order to achieve good low temperature flow properties under cold start conditions ("HV" grade oils). It is not known if PAMA additives offer any other performance benefit. For example, WO 2005108531 describes the use of hydraulic fluids containing PAMA additives in order to reduce the temperature increase of a hydraulic fluid under a workload. However, no improvement is indicated with respect to energy efficiency nor is it suggested in that document either. In addition, WO2005014762 presents a functional fluid having an improved fire resistance. The fluid can be used in hydraulic systems. However, the document does not indicate anything regarding the energy efficiency of the fluid. The improvement of energy efficiency is a common goal in all fields of technology. In general, these objectives are achieved through improvements in the construction of the unit that provides the mechanical energy of the hydraulic system, for example, a combustion engine or an electric motor. However, it is still necessary to make further improvements regarding this issue. A further common objective of the present invention is the improvement of the operation of a hydraulic system. As usual, the operation of a hydraulic system improves by using a combustion engine or an electric motor with greater power. However, this approach is usually related to a higher energy consumption. Taking into consideration the prior art, an object of the present invention is to offer hydraulic systems having improved energy efficiency and improved system operation. Additionally, an object of the present invention is to improve the life time of the unit that provides the mechanical power to the hydraulic system. These goals, as well as other tasks not explicitly mentioned, which, however, can be derived or easily developed from the introductory part, are achieved by the use of a fluid according to claim 1 hereof. Suitable modifications of the use according to the invention are described in the appended claims. The use of a fluid having a viscosity index of at least 130 provides an unexpected improvement in the energy efficiency of a hydraulic system. In addition, the operation of the system of a hydraulic system can be improved in an unpredictable manner. At the same time, many other advantages can be achieved through the hydraulic fluids according to the invention. Among these are: the hydraulic fluid of the present invention shows improved performance at low temperature and an operating window of wider temperatures. The hydraulic fluid of the present invention can be sold at a favorable cost and with a fast payback time. The hydraulic fluid of the present invention shows a good resistance to oxidation and is very chemically stable, compared to a standard HM fluid. The viscosity of the hydraulic fluid of the present invention can be adjusted over a wide range. In addition, the hydraulic fluids of the present invention are suitable for high pressure applications. The hydraulic fluids of the present invention show a minimal change in viscosity due to their good shear stability. Additionally, improvements in system operation and energy efficiency can be achieved without changes in the construction of the hydraulic system. Consequently, also the operation and the efficiency in the power of old hydraulic systems can be improved with very low costs.

The hydraulic fluid used in accordance with the present invention has a viscosity index of at least 130, preferably at least 150, more preferably at least 180, and more preferably at least 200. According to the Preferred embodiment of the present invention, the viscosity index is in the range of 150 to 400, more preferably 200 to 300. The viscosity index can be determined according to the method of ASTM D 2270. The use in accordance with the present invention provides an improvement in the energy efficiency of a hydraulic system. The expression energy efficiency means a better effectiveness of the energy provided to the hydraulic system in order to achieve a defined result. In particular, the energy consumption of the system can be decreased by at least 5%, preferably by at least 10% and more preferably by at least 20%, based on the energy consumption of a system using a hydraulic fluid monograde with a viscosity index of approximately 100 and that provides the same work or system result. The type of energy usually depends on the unit that provides the mechanical energy to the hydraulic system. In addition, energy consumption can be improved based on a defined period of time. In addition, the operation of the hydraulic system can be improved. The expression "operation of the system" means the work productivity carried out by the hydraulic system within a defined period of time. In particular, the operation of the system can be improved by at least 5%, preferably by at least 10% and by more preferred by at least 20%. The type of work depends on the hydraulic system. In preferred systems, work cycles per hour are improved. The improvement in energy consumption and the operation of the system can be observed at all operating speeds of a typical motor or electric motor. Preferably, the improvement in energy consumption and the operation of the system can be determined in approximately 90% of the maximum operation of the unit that provides the mechanical energy to the hydraulic system, for example 90% of the regulator, if a combustion engine. Preferably, the motor speed can be reduced to decrease the load and voltage while delivering the same amount of hydraulic power. Fluids having a viscosity index of at least 130 are well known in the art. In general, these fluids are used, for example, in combustion engines and gears as lubricating oil. According to the needs of the consumer, the viscosity of the hydraulic fluid of the present invention can be adapted in a wide range. For example, ISO VG fluid grades 15, 22, 32, 46, 68, 100, 150 can be achieved.

Preferably, the kinematic viscosity of 40 ° C according to ASTM D 445 is the range from 15 mm2 / s to 150 mm2 / s, preferably 28 mm2 / s to 110 mm2 / s. For use in accordance with the present invention, the preferred hydraulic fluids are NFPA multigrade fluids (for example: National Fluid Power Association: National Fluid Power Association), for example double, triple, tetra and / or penta fluids. according to that defined in NFPA T2, 13, 13 - 2002. Preferred fluids include at least one mineral oil and / or a synthetic oil. Mineral oils are substantially known and commercially available. They are usually obtained from petroleum or crude oil by distillation and / or refining and optionally additional purification and processing methods, especially the higher boiling fractions of crude oil or petroleum that fall under the concept of mineral oil. In general, the boiling point of the mineral oil is higher than 200 ° C, preferably higher than 300 ° C, to 5000 Pa. It is also possible the preparation by distillation at low temperature of shale oil, coking of anthracite, distillation of lignite under exclusion of air, as well as the hydrogenation of anthracite or lignite. To a lesser degree, mineral oils are also produced from raw materials of vegetable origin (for example jojoba, rapeseed (canola), sunflower and soybean oil) or animal origin (eg tallow or leg oil). of cow). According to this, the mineral oils show different quantities of aromatic, cyclic, branched and linear hydrocarbons, in each case according to the origin. In general, paraffin, naphthenic and aromatic base fractions are distinguished in crude oil or mineral oil, where the term paraffin-based fraction means longer chain or highly branched isoalkanes and naphthemic fraction means cycloalkanes. In addition, the mineral oils, in each case according to their origin and processing, show different fractions of N-alkanes, isoalkanes with a low degree of branching, called branched monomethyl paraffins, and compounds with heteroatoms, especially or, N and / or S, to which polar properties are attributed. However, attribution is difficult, since the individual alkane molecules can have both branched long-chain and cycloalkane residues and aromatic components. For purposes of this invention, the classification can be made according to DIN 51 378. The polar components can also be determined in accordance with ASTM D 2007. The fraction of n-alkanes in the preferred mineral oils is less than 3% by weight, and the fraction of compounds containing O, N and / or S is less than 6% by weight. The fraction of aromatic compounds and branched monomethyl paraffins is generally in each case within the range of 0-40% by weight. According to an interesting aspect, the mineral oil includes mainly naphthenic and paraffin-based alkanes, which generally have more than 13, preferably more than 18 and especially preferably more than 20 carbon atoms. The fraction of these compounds is generally at least 60% by weight, preferably at least 80% by weight, without the purpose of limiting them thereto. A preferred mineral oil contains 0.5-30% by weight of aromatic components, 15-40% by weight of naphthenic components, 35-80% by weight of paraffin-based components, up to 3% by weight of n-alkanes and 0.05% by weight of polar components, in each case with respect to the total weight of the mineral oil. An analysis of the preferred mineral oils in particular, which was carried out with traditional methods such as urea dewaxing and liquid chromatography on silica gel, shows, for example, the following components, where the percentages refer to the total weight of the oil Relevant mineral: n - alkanes with approximately 18 - 31 carbon atoms: 0.7 - 1.0%, low branched alkanes with 18 - 31 carbon atoms: 1.0 - 8.0 %, aromatic compounds with 14 - 32 carbon atoms: 0.4 - 10.7%, iso - and cycloalkanes with 20 - 32 carbon atoms: 60.7 - 82.4%, polar compounds: 0.1 - 0.8%, loss: 6.9 - 19.4%. Valuable advice can be found regarding the analysis of mineral oils, as well as a list of mineral oils that have other compositions, for example in Ullmann's Encyclopedia of Industrial Chemistry, 5th Edition on CD-ROM, 1997, under the heading "Lubricants and related products ". Preferably, the hydraulic fluid is based on API Group I, II or III mineral oil. According to a preferred embodiment of the present invention, a mineral oil containing at least 90% by weight of saturates and at most approximately 0.03% of sulfur measured by elemental analysis is used. In particular, Group II API oils are preferred.

Synthetic oils are, among other substances, organic esters such as carboxylic esters and phosphate esters; organic ethers such as silicone oils and polyalkylene glycol; and synthetic hydrocarbons, especially polyolefins. They are in some way more expensive than mineral oils, but they have advantages with respect to their performance. For an explanation, reference is made to the 5 API classes of base oil type (API: American Petroleum Institute - American Petroleum Institute). Oil Classifications Base of the North American Petroleum Institute (API) Synthetic hydrocarbons, special polyolefins are well known in the art. In particular, polyalphaolefins (PAO) are preferred. These compounds can be obtained by the polymerization of alkenes, especially alkenes having from 3 to 12 carbon atoms, such as propene, hexene-1, octet-1 and dodexeno-1. Preferred PAOs have an average molecular weight in the range from 200 to 10000 g / mol, more preferably from 500 to 5000 g / mol. According to a preferred aspect of the present invention, the hydraulic fluid may include an oxygen-containing compound selected from the group of carboxylic acid esters, polyether polyols and / or organophosphorus compounds. Preferably, the oxygen-containing compound is a carboxylic ester containing at least two ester groups, a diester of carboxylic acids contains from 4 to 12 carbon atoms and / or an ester of a polyol. By using an oxygen-containing compound as a base stock, the fire resistance of the hydraulic fluid can be improved. The phosphorous ester fluids can be used as a component of the hydraulic fluid such as for example the alkyl aryl phosphate ester; trialkyl phosphates such as, for example, tributyl phosphate or tri-2-ethylexyl phosphate; triaryl phosphates such as mixed isopropylphenyl phosphates, mixed t-butylphenyl phosphates, trixylenyl phosphate, or tricresyl phosphate. The additional classes of organophosphorus compounds are the phosphonates and the phosphinates, which may contain substituents of the alkyl and / or aryl. Dialkylphosphonates such as di-2-ethylhexylphosphonate; alkyl phosphinates such as di-2-elylyhexylphosphinate. Like the alkyl group herein, straight or branched chain alkyls having from 1 to 10 carbon atoms are preferred. Like the aryl group herein, aryls that include from 6 to 10 carbon atoms that can be substituted by alkyls are preferred. In particular, hydraulic fluids may contain from 0 to 60% by weight preferably from 5 to 50% by weight of organophosphorus compounds. As with carboxylic acid esters, products of the reaction of alcohols such as, for example, polyhydric alcohol, monohydric alcohol, and the like, and fatty acids such as, for example, monocarboxylic acid, polycarboxylic acid and the like can be used. Of course, these carboxylic acid esters can be a partial ester.

The carboxylic acid esters may have a carboxylic ester group with the formula R-COO-R, where R is independently a group including from 1 to 40 carbon atoms. Preferred ester compounds include at least two ester groups. These compounds can be based on polycarboxylic acids having at least two acid groups and / or polyols having two hydroxyl groups. The polycarboxylic acid residue generally has from 2 to 40, preferably from 4 to 24, in particular from 4 to 12, carbon atoms. Useful polycarboxylic acid esters are, for example, esters of adipic, acetic, sebacic, phthalate and / or dodecanoic acids. The alcohol component of the polycarboxylic acid compound preferably includes from 1 to 20, in particular from 2 to 10, carbon atoms. Examples of useful alcohols are methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol and octanol. In addition, oxoalcohols such as, for example, diethylene glycol, triethylene glycol, tetraethylene glycol, up to decamethylene glycol can be used. Especially preferred compounds are esters of polycarboxylic acids with alcohols including a hydroxyl group. Examples of these compounds are described in Ullmanns Encyclopaedia der Technischen Chemie, third edition, vol. 15, page 287-292, Urban & Schwarzenber (1964). Useful polyols for obtaining ester compounds including at least 2 ester groups generally contain from 2 to 40, preferably from 4 to 22, carbon atoms. Examples are neopentyl glycol, diethylene glycol, dipropylene glycol, 2,2-dimethyl-3-hydroxypropyl-2 ', 2'-dimethyl-3'-hydroxy propionate, glycerol. trimethylol ethane, trimetanol propane, trimethylol nonane, ditrimethylol propane, pentaerythritol, sorbitol, mannitol and dipentaerythritol. The carboxylic acid component of the polyester can contain from 1 to 40, preferably from 2 to 24, carbon atoms. Examples are straight or branched saturated fatty acids such as for example formic acid, acetic acid, propionic acid, octanoic acid, capric acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecanic acid, lauric acid, tridecanic acid, acid myristic, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, nonadecanoic acid, aracaric acid, behenic acid, isomiristic acid, isopalmitic acid, isostearic acid, 2, 2-dimethylbutanoic acid, 2,2-dimethylpentanoic acid, 2, 2 acid - dimethyloctanoic, 2-ethyl-2, 3, 3-trimethylbutanoic acid, 2, 2, 3, 4-tetramethylpentanoic acid, 2, 5, 5-trimethyl-2-1-butylhexanoic acid, 2, 3, 3-trimethyl - 2 - ethylbutanoic acid, 2,3-dimethyl-2-isopropylbutanoic acid, 2-ethylhexanoic acid, 3,5,5,5-trimethylhexanoic acid; unsaturated linear or branched fatty acids such as linoleic acid, linolenic acid, octadeceneic acid 9, undeceneic acid, elaidic acid, ketorolac acid, erucic acid, bradydic acid, and commercial grades of oleic acid from a variety of sources vegetable oil or animal fat. It is also possible to use mixtures of fatty acids, such as, for example, liquid resin fatty acids. Especially useful compounds which include at least two ester groups are, for example, neopentyl glycol talate, neopentyl glycol dioleate, propylene glycol talate, propylene glycol dioleate, diethylene glycol talate, and diethylene glycol dioleate. Several of these compounds are commercially available from Inolex Chemical Co. under the trademark Lexolube 2G-214, at Cognis Corp. under the trademark ProEco 2965, at Uniquema Corp. under the trademarks Priolube 1430, and Priolube 1446 and under Georgia Pacific under the trademarks Xtolube 1301 t Xtolube 1320. In addition, the ethers are useful as a component of the hydraulic fluid.

Preferably, polyether polyols are used as a component of the hydraulic fluid of the present invention. These compounds are well known. As examples we have the polyalkylene glycols as, for example, polyethylene glycols, polypropylene glycols and polybutylene glycols. The polyalkylene glycols can be based on mixtures of alkylene oxides. These compounds preferably include from 1 to 40 units of alkylene oxide, more preferably from 5 to 30 units of alkylene oxide. Polybutylene glycols are the preferred compounds for anhydrous fluids. The polyether polyols may include other groups, such as, for example, alkylene or arylene groups including from 1 to 40, in particular from 2 to 22, carbon atoms. According to another aspect of the present invention, the hydraulic fluid is based on a synthetic base existence including polyalphaolefin (PAO), carboxylic esters (diester, or polyol ester), a vegetable ester, phosphate ester (trialkyl, triaryl) , or alkyl aryl phosphates), and / or polyalkylene glycol (PAG). Preferred synthetic base stocks are oils of Group IV and / or Group V API. Preferably, the hydraulic fluid can be obtained by mixing at least two components. At least one of the components shall be a base oil with a kinematic viscosity at 40 ° C in accordance with ASTM D 445 of 35 mm2 / s or less. Preferably, the hydraulic fluid includes at least 60% by weight of at least one component having a kinematic viscosity at 40 ° C according to ASTM D 445 of 35 mm2 / s or less. Preferably, at least one of the components can have a viscosity index of 120 or less. According to a preferred embodiment, the hydraulic fluid can include at least 60% by weight of at least one component with a viscosity index of 120 or less. In particular, a polymeric viscosity index improver can be used as a component of the hydraulic fluid. Viscosity index improvers are well known and, for example, are presented in the Ullmann Encyclopedia of Industrial Chemistry, 5th Edition on CD-ROM, 1997. Preferred polymers which are used as viscosity index improvers include units derived from alkyl esters with at least one ethylenically unsaturated group. These polymers are well known in the art. Preferred polymers can be obtained by polymerization in particular, (meth) acrylates, maleates and fumarates. The term (meth) acrylates includes methacrylates and acrylates as well as mixtures of the two. These monomers are well known in the art. The alkyl residue may be linear, cyclic or branched. Mixtures to obtain preferred polymers including units derived from alkyl esters contain 0 to 100% by weight, preferably 0.5 to 90% by weight, especially 1 to 80% by weight, more preferably 1 at 30% by weight, and more preferably from 2 to 20% by weight based on the total weight of the monomer mixture of one or more ethylenically unsaturated ester compounds of the formula (I) (I) wherein R is hydrogen or methyl, R1 means a linear or branched alkyl residue with 1-6, especially 1 to 5 and preferably 1 to 3 carbon atoms, R2 and R3 are independently hydrogen or a group of the formula -COOR1, where R 'means hydrogen or an alkyl group with 1-6 carbon atoms. Examples of component (a) are, among others, (meth) acrylates, fumarates and maleates, which are derived from saturated alcohols such as methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, tere-butyl (meth) acrylate, pentyl (meth) acrylate and hexyl (meth) acrylate; cycloalkyl (meth) acrylates, such as for example cyclopentyl (meth) acrylate. In addition, the monomer compositions for obtaining the units including polymers derived from alkyl esters contain 0-100% by weight, preferably 10-99% by weight, especially 20-95% by weight and more preferably 30% by weight. to 85% by weight based on the total weight of the monomer mixture of 1 or more ethylenically unsaturated ester compounds of the formula (II) where R is hydrogen or methyl, R4 means a linear or branched alkyl residue with 7-40, especially 10 to 30 and preferably 12 to 24 carbon atoms, R5 and R6 are independently hydrogen or a group of the formula -COOR1 wherein R "means hydrogen or an alkyl group with 7 to 40, in particular 10 to 30 and preferably 12 to 24 carbon atoms, among which are the (meth) acrylates, fumarates and maleates that are derived from saturated alcohols, such as 2-ethylhexyl (meth) acrylate, heptyl (meth) acrylate, 2-tere-butylheptyl (meth) acrylate, octyl (meth) acrylate, 3-isopropylheptyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth ) acrylate, undecyl (meth) acrylate, 5-methylundecyl (meth) acrylate, dodecyl (meth) acrylate, 2-methyldodecyl (meth) acrylate, tridecyl (meth) acrylate, 5-methyltridecyl (meth) acrylate, tetradecyl (meth) acrylate , pentadecyl (meth) acrylate, 2-methylhexadecyl (meth) acrylate, heptadecyl (meth) acrylate, 5-isopropylheptadecyl (meth) acrylate, 4-tere - butyloctadecyl (meth) acrylate, 5-ethylloctadecyl (meth) acrylate, 3-isopropyloctadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate, cetyleicosyl (meth) acrylate, stearylearyl (met ) acrylate, docosyl (meth) acrylate, and / or eicosyltetratriacontyl (meth) acrylate; cycloalkyl (meth) acrylates such as 3-vinylcyclohexyl (meth) acrylate, cyclohexyl (meth) acrylate, bornyl (meth) acrylate, 2,4,5-tri-1-butyl-3-vinylcyclohexyl (meth) acrylate, , 3, 4, 5-tetra-1-butylcyclohexyl (meth) acrylate; and the corresponding fumarates and maleates. The ester compounds with a long-chain alcohol residue, in particular component (b), can be obtained, for example, by reacting (meth) acrylates, fumarates, maleates and / or the corresponding acids with long-chain fatty alcohols. , where in general there is a mixture of esters such as (meth) acrylates with different long chain alcohol residues. These fatty alcohols include, among others, Oxo Alcohol® 7911 and Oxo Alcohol® 7900, Oxo Alcohol® 100 (Monsanto); Alphanol® 79 (ICI); Nafol® 1620, Alfol® 610 and Alfol® 810 (Sasol); Epal® 610 and Epal® 810 (Etil Corporation); Linevol® 79, Linevol® 911 and Dobanol® 25L (Shell AG); Lial 125 (Sasol); Dehydad® and Dehydad® and Lorol® (Cognis). Of the ethylenically unsaturated ester compounds, (meth) acrylates are particularly preferred over the maleates and fumarates, ie R2, R3, R5, R6 of the formulas (I) and (II) represent hydrogen in embodiments preferred in particular. In a particular aspect of the present invention, preference is given to the use of mixtures of ethylenically unsaturated ester compounds of the formula (II), and the mixtures have at least one (meth) acrylate having from 7 to 15 carbon atoms. carbon in the alcohol radical and at least one (meth) acrylate having 16 to 30 carbon atoms in the alcohol radical. The fraction of the (meth) acrylates having 7 to 15 carbon atoms in the alcohol radical is preferably in the range of 20 to 95% by weight, based on the weight of the monomer composition for the preparation of the polymers. The fraction of the (meth) acrylates having 16 to 30 carbon atoms in the alcohol radical is preferably in the range of 0.5 to 60% by weight based on the weight of the monomer composition for the preparation of the polymers which include the units derived from alkyl esters. The ratio of the weight of the (meth) acrylate having from 7 to 15 carbon atoms in the alcohol radical and the (meth) acrylate having from 16 to 30 carbon atoms in the alcohol radical is preferably in the range of 10: 1 to 1:10, more preferably in the range of 5: 1 to 1.5: 1. Component (c) includes, in particular, ethylenically unsaturated monomers which can be copolymerized with the ethylenically unsaturated ester compounds of the formula (I) and / or (II). The comonomers corresponding to the following formula are suitable in particular for the polymerization according to the invention: where R1 * and R2 * independently are selected from the group consisting of hydrogen, halogens, CN, linear or branched alkyl groups with 1-20, preferably 1-6 and especially preferably 1-4 carbon atoms, which can be substituted with 1 a (2n + 1) halogen atoms, where n is the number of carbon atoms of the alkyl (for example CF3), a, ß-linear or branched unsaturated alkenyl group or alkynyl groups with 2-10, preferably 2-6 and especially preferably 2-4 carbon atoms, which can be substituted with 1 to (2n-1) halogen atoms, preferably chlorine, where n is the number of carbon atoms of the alkyl group, example CH2 = CCI-, cycloalkyl groups with 3-8 carbon atoms, which can be substituted with 1 to (2n-1) halogen atoms, preferably chlorine, where n is the number of carbon atoms of the cycloalkyl group; C (= Y *) R5 *, C (= Y *) NR6 * R7 *, Y * C (= Y *) R5 *, SOR5 *, SO2R5 *, OSO2R5 *, NR8 * SO2R5 *, PR5 * 2, P (= Y *) R5 * 2, Y * PR5 * 2) and * P (= Y *) R5 * 2, NR8 * 2) which can be quaternized with an additional R8 *, aryl, or heterocyclic group, where Y * it can be NR8 *, S or O of preference O; R5 * is an alkyl group with 1-20 carbon atoms, an alkylthio group with 1-20 carbon atoms, or R15 (R15 is hydrogen or an alkali m), alkoxy with 1-20 carbon atoms, aryloxy or heterocyclyloxy; R6 *, and R7 * independently are hydrogen or an alkyl group with 1 to 20 carbon atoms, or R6 * and R7 * together can form an alkylene group with 2-7, preferably 2-5 carbon atoms, where they form a 3-8 membered ring, preferably 3-6 membered, and R8 * is straight or branched alkyl or aryl groups with 1-20 carbon atoms; R3 * and R4 * independently are selected from the group consisting of hydrogen, halogen (preferably fluorine or chlorine), alkyl groups with 1-6 carbon atoms and COO R9 *, where R9 *, is hydrogen, an alkali m or a alkyl group, with 1-40 carbon atoms, or R1 * and R3 * can together form a group of the formula (CH2) n, which can be substituted with 1-2 n 'halogen atoms or Ci-C4 alkyl groups, or it can form a group of the formula C (= 0) - Y * - C (= 0), where n 'is from 2 - 6, preferably 3 or 4, and Y * is defined as above; and wherein at least 2 of the residues R1 *, R2 *, R3 * and R4 * are hydrogen or halogen. Comonomers include, among others, hydroxyalkyl (meth) acrylates such as 3-hydroxypropyl (meth) acrylate, 3,4-dihydroxybutyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2- (meth) acrylate. hydroxypropyl, 2,5-dimethyl-1,6-hexanediol (meth) acrylate, 1,1-decanediol (meth) acrylate; aminoalkyl (meth) acrylates and aminoalkyl (meth) acrylamides such as n- (3-dimethylaminopropyl) (meth) acrylamide, 3-diethylaminopentyl (meth) acrylate, 3-dibutylaminohexadecyl (meth) acrylate; nitriles of (meth) acrylic acid and other nitrogen-containing (meth) acrylates such as n- (methacryloyloxyethyl) diisobutyl-ketimine, N-methacryloyloxyethyl) dihexadecylcetimine, (meth) acryloylamidoacetonitrile, 2-methacryloyloxyethylmethylcyanamide, cyanomethyl (meth) acrylate; aryl (meth) acrylates such as benzyl (meth) acrylate or phenyl (meth) acrylate, wherein the acrylic residue in each case can not be replaced or replaced up to 4 times; (meth) acrylates containing carbonyl such as 2-carboxyethyl (meth) acrylate, carboxymethyl (meth) acrylate, oxazolidinylethyl (meth) acrylate, n-methylacryloyloxy) formamide, acetonyl (meth) acrylate, N-methacryloylmorpholine, N-methacryloyl-2- pyrrolidinone, N - (2-methylacryloxyethyl) -2-pyrrolidinone, N - (3-methacryloyloxypropyl) -2-pyrrolidinone, N - (2-methacryloyloxypentadecyl (2-pyrrolidinone, N - (3-methacryloyloxyheptadecyl-2-pyrrolidinone; meth) acrylates of ether alcohols such as tetra hydrofluoride I (meth) acrylate, vinyloxyethoxyethyl (meth) acrylate, methoxyethoxyethyl (meth) acrylate, 1-butoxypropyl (meth) acrylate, 1-methyl- (2-vinyloxy) ethyl (meth) acrylate, cycloxyloxymethyl (meth) acrylate, methoxymethoxyethyl (meth) acrylate, benzyloxymethyl (meth) acrylate, furfuryl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 2-ethoxyethoxymethyl (meth) acrylate, 2-ethoxyethyl ( met) acrylate, ethoxylated (meth) acrylates, allyloxymethyl (meth) acrylate, 1-ethoxybutyl (meth) acrylate, methoxy ethyl (meth) acrylate, 1-ethoxyethyl (meth) acrylate, ethoxymethyl (meth) acrylate; (meth) acrylates of halogenated alcohols such as 2, 3-dibromopropyl (meth) acrylate, 4-bromophenyl (meth) acrylate, 1,3-dichloro-2-propyl (meth) acrylate, 2-bromoethyl (meth) acrylate, 2 - iodoethyl (meth) acrylate, chloromethyl (meth) acrylate; (meth) oxiranyl acrylate such as 2,3-epoxybutyl (meth) acrylate, 3,4-epoxybutyl (meth) acrylate, 10,11 epoxyundecyl (meth) acrylate, 2,3-epoxycyclohexyl (meth) acrylate, (met) oxiranyl acrylates such as 10,11-epoxyhexadecyl (meth) acrylate, glycidyl (meth) acrylate; (met) acrylates containing phosphorus, boron and / or silicon such as 2- (dimethylphosphonate) propyl (meth) acrylate, 2- (ethylphosphite) propyl (meth) acrylate, 2-dimethylphosphinomethyl (meth) acrylate, dimethyl phosphonoethyl (met) acrylate, diethylmethacryloyl phosphonate, dipropylmethacryloyl phosphate, 2- (dibutylphosphono) ethyl (meth) acrylate, 2,3-butylene-methacryloyloyl-borate, methyldiethoxymethacryloyloxytoxy, diethylphosphathatethyl (meth) acrylate; sulfur-containing (meth) acrylates such as ethylsulfinylhexyl (meth) acrylate, 4-thiocyanatobutyl (meth) acrylate, ethylsulfonylethyl (meth) acrylate, thiocyantomethyl (meth) acrylate, methylsulfinylmethyl (meth) acrylate, bis (methacryloyloxyethyl) sulfide; heterocyclic (meth) acrylates such as 2- (1-imidazolyl) ethyl (meth) acrylate, 2- (4-morpholinyl) ethyl (meth) acrylate and 1- (2-methacryloyloxyethyl) -2-pyrrolidone; vinyl halides such as, for example, vinyl chloride, vinyl fluoride, vinylidene chloride and vinylidene fluoride; vinyl esters such as vinyl acetate; vinyl monomers containing aromatic groups such as styrene, styrenes substituted with an alkyl substituent on the side chain, such as for example a-methylstyrene and a-ethylstyrene, styrenes substituted with an alkyl substituent on the ring such as, for example, vinyl toluene and p-methylstyrene , make us halogenated, such as, for example, monochlorostyrenes, dichlorostyrenes, tribromostyrenes and tetrabromostyrenes; Heterocyclic vinyl compounds such as 2-vinylpyridine, 3-vinylpyridine, 2-methyl-5-vinylpyridine, 3-ethyl-4-vinylpyridine, 2,3-dimethyl-5-vinylpyridine, vinylpyrimidine, vinylpiperidine, 9-vinylcarbazole, 3-vinylcarbazole , 4-vinylcarbazole, 1-vinylimidazole, 2-methyl-1-vinylimidazole, N-vinylpyrrolidone, 2-vinylpyrrolidone, N -vinylpyrrolidine, 3-vinylpyrrolidine, N-vinylcaprolactam, N-vinylbutyrolactam, vinyloxolane, vinylfuran, vinylthiophene, vinylthiolane, vinylthiazoles , and hydrogenated vinyl thiazoles, vinyl oxazoles and hydrogenated vinyl oxazoles;what.

Vinyl ethers Soprenyl; maleic acid derivatives such as, for example, maleic anhydride, methylmalic anhydride, maleinimide, methylmaleimide; fumaric acid and fumaric acid derivatives such as, for example, mono and diesters of fumaric acid. Monomers that have a dispersion functionality can also be used as comonomers. These monomers are well known in the art and usually contain heteroatoms such as oxygen and / or nitrogen. For example, the aforementioned hydroxyalkyl (meth) acrylates, aminoalkyl (meth) acrylates and aminoalkyl (meth) acrylamides, (meth) acrylates of ether alcohols, heterocyclic (meth) acrylates and heterocyclic vinyl compounds which are considered as dispersion comonomers. Preferred mixtures in particular contain methyl methacrylate, lauryl methacrylate and / or stearyl methacrylate. The components can be used individually or as mixtures. The hydraulic fluid of the present invention preferably includes polyalkyl methacrylate polymers. These polymers obtainable by polymerization compositions and including alkyl methacrylate monomers are well known in the art. Preferably, these polyalkyl methacrylate polymers include at least 40% by weight, especially at least 50% by weight, more preferably at least 60% by weight and even more preferably at least 80% by weight units repeaters of methacrylate. Preferably, these polyalkyl methacrylate polymers include Cg-C2 methacrylate repeating units and Ci-c- methacrylate repeating units. The molecular weight of the alkyl ester derived polymers is not important. In general, the polymers derived from the alkyl esters have a molecular weight in the range of 300 to 1,000,000 g / mol, preferably in the range of 10,000 to 200,000 g / mol and more preferably in the range of 25,000 to 100,000 g / mol, without limiting it in any way for this. These values refer to the average molecular weight of the polymers. Without the purpose of limiting the above, the alkyl (meth) acrylic polymers show a polydispersity, provided by the ratio of the average molecular weight to the number average molecular weight Mw / Mn, in the range of 1 to 15, preferably 1.1 to 10, especially preferably 1.2 to 5. Polydispersity can be determined by gel permeation chromatography (GPC: gel permeation chromatography). The monomer mixtures described above can be polymerized by any known method. Conventional radical initiators can be used to carry out a classical radical polymerization. These initiators are well known in the art. Examples of these radical initiators are azo initiators such as 2,2'-azodiisobutyronitrile (AIBN), 2,2'-azobis (2-methylbutyronitrile) and 1,1-azobiscyclohexanecarbonitrile; peroxide compounds, for example methyl ethyl ketone peroxide, acetylacetone peroxide, dilauryl peroxide, tere-butyl per-2-ethyl hexanoate, ketone peroxide, methyl isobutyl ketone peroxide, cyclohexanone peroxide, dibenzoyl peroxide, tere perbenzoate butyl, tert-butyl peroxy isopropyl carbonate, 2,5-bis (2-ethylhexanoyl-peroxy) -2,5-dimethylhexane, tere-butyl peroxy 2-ethyl hexanoate, tere-butyl peroxy-3-hexanoate , 5-trimethyl, dicumary peroxide, 1, 1 bis (tere butyl peroxy) cyclohexane, 1, 1 bis (terebutyl peroxy) 3, 3, 3, 5-trimethylcyclohexane, eumeno hydroperoxide and tere-butyl hydroperoxide. Low molecular weight poly (meth) acrylates can be obtained using chain transfer agents. This technology is known ubiquitously and is practiced in the polymer industry, and is described in Odian, Principles of Polymerization, 1991. Examples of chain transfer agents are sulfur-containing compounds such as, for example, thiols., for example n- and t-dodecanetiol, 2-mercaptoethanol, and mercaptocarboxylic acid esters, for example methyl-3-mercaptopropionate. Preferred chain transfer agents contain up to 20, especially up to 15 and more preferably up to 12 carbon atoms. In addition, the chain transfer agents may include at least one, especially at least 2, oxygen atoms. In addition, low molecular weight poly (meth) acrylates can be obtained using transition metal complexes, such as low turnover cobalt complexes. These technologies are well known and are described, for example, in the patent of USSR 940,487-A and by Heuts, et al., Macromolecules 1999, pp 2511-2519 and 3907-3912. In addition, new polymerization techniques can be applied, for example ATRP (Atom Transfer Radical Polymerization: Radical Polymerization of Atom Transfer) and / or the RAFT (Reversible Addition Fragmentation Chain Transfer: Reversible Addition Fragmentation Chain Transfer) to obtain useful polymers derived from alkyl esters. These methods are well known. For example, the reaction method of ATRP is described by J-S. Wang, et al., American Chemical Bulletin Soc, Vol. 1 17, p. 5614, - 5615 (1995), and by Matyjaszewski, Macromolecules, Volume 28, pp. 7901-7910 (1995). In addition, patent applications WO 96/30421, W097 / 47661, W097 / 18247, W098 / 40415 and WO 99/10387 present variations of the ATRP explained above which is expressly referred to for purposes of the presentation. The RAFT method is presented extensively in WO 98/01478, for example, to which reference is expressly made for purposes of presentation. The polymerization can be carried out under normal pressure, reduced pressure or high pressure. The temperature of the polymerization is not important either. However, in general it is within the range of -20 -200 ° C, preferably, 0 - 130 ° C and especially preferably 60-120 ° C, without the purpose of limiting it with this. The polymerization can be carried out with or without solvents. The term solvent must be understood broadly here. According to a preferred embodiment, the polymer can be obtained by means of a polymerization in the mineral oil of Group II or Group III of the API. These solvents were presented above. In addition, polymers obtainable by polymerization in a polyalphaolefin (PAO) are preferred. More preferably, the PAO has a number average molecular weight in the range of 200 to 10,000, more preferably 500 to 5,000. This solvent was presented above.

The hydraulic fluid may include 0.5 to 50% by weight, especially 1 to 30% by weight, and preferably 5 to 20% by weight, based on the total weight of the fluid, of one or more of the derived polymers of the alkyl esters. According to a preferred embodiment of the present invention, the hydraulic fluid includes at least 10% by weight of one or more polymers derived from alkyl esters. According to a preferred aspect of the present invention, the fluid can include at least two polymers with a different monomer composition. Preferably, at least one of the polymers is a polyolefin. Preferably, the polyolefin is useful as a viscosity index improver. These polyolefins include in particular polyolefin copolymers (OCP) and hydrogenated styrene / diene copolymers (HSD). The polyolefin copolymers (OCP) which can be used according to the invention are known per se. These are primary polymers synthesized from ethylene, propylene, isoprene, butylene and / or additional olefins with 5 to 20 carbon atoms. Systems that have been grafted with small amounts of monomers containing oxygen or nitrogen (for example from 0.05 to 5% by weight of maleic anhydride) can also be used. The copolymers containing diene components are generally hydrogenated in order to reduce the oxidation sensitivity and the cross-linking tendency of the viscosity index improvers. The molecular weight Mw is generally from 10,000 to 300,000, preferably from 50,000 to 150,000. These aforementioned olefin copolymers are described, for example, in German Open Applications DE-A 16 44 941, DE-A 17 69 834, DE-A 19 39 037. DE-A 19 63 039 and DE-A 20 59 981. Ethylene / propylene copolymers are particularly useful and terpolymers having the known ternary components, such as ethylidene norbornene (see Macromolecular Reviews, Vol. 10 (1995)) are also possible, but their tendency to cross-link should be taken in consideration in the aging process. The distribution can be substantially random, but sequential polymers including ethylene blocks can also be beneficially used. The ratio of the ethylene / propylene monomers is variable within certain limits, which may be set at approximately 75% for ethylene and approximately 80% for propylene as an upper limit. Due to its reduced tendency to dissolve in oil, polypropylene is less suitable than ethylene / propylene copolymers. In addition to polymers having a predominantly atactic propylene incorporation, those having a more pronounced isotactic or syndiotactic propylene incorporation can also be used. These products are available commercially, for example under the trade names Dutral® CO 034, Dutral® CO 038, Dutral® 043, Dutral® CO 058, Buna® EPG 2050 or Buna® EPG 5050. Hydrogenated styrene / diene copolymers (HSD) are also known, these polymers are described for example in DE 21 56 122. They are generally hydrogenated isoprene / styrene or butadiene / styrene copolymers. The ratio of the diene to the styrene is preferably in the range of 2: 1 to 1: 2, particularly preferably to about 55:45. The molecular weight Mw is generally from 10,000 to 300,000, preferably from 50,000 to 150,000. According to a particular aspect of the present invention, the ratio of double bonds after hydrogenation is not greater than 15%, particularly preferably not greater than 5%, based on the number of double bonds before hydrogenation.

The hydrogenated styrene / diene copolymers can be obtained commercially under the trademark of SHELLVIS® 50, 150, 200, 250 or 260.

Preferably, at least one of the polymers in the mixture includes units derived from the monomers selected from acrylate monomers, methacrylate monomers, fumarate monomers and / or maleate monomers. These polymers are described above. The weight ratio of the polyolefin to the polymer includes units derived from the monomers selected from acrylate monomers, methacrylate monomers, fumarate monomers and / or maleate monomers and may be in the range of 1: 10 to 10: 1, especially from 1: 5 to 5: 1. The hydraulic fluid may include usual additives. These additives include for example antioxidants, anti-wear agents, corrosion inhibitors and / or defoamers, often purchased as a commercial additive package. Preferably, the hydraulic fluid has a viscosity in accordance with ASTM D 445 at 40 ° C in the range of 10 to 120 mm2 / s, more preferably 22 to 100 mm2 / s. Preferably, the hydraulic system includes the following components: 1. A unit that creates mechanical energy, for example a combustion engine or an electric motor. 2. A force or fluid flow generating unit that converts mechanical energy into hydraulic energy, such as a pump. 3. Pipe to transmit the fluid under pressure. 4. A unit that converts the hydraulic energy of the fluid into mechanical work, such as an actuator or a fluid motor. There are two types of engines, cylindrical and rotary. 5. A control circuit with valves that regulate the flow, pressure, direction of movement and applied forces. 6. A fluid reservoir that allows the separation of water, foam, entrained air, or debris before the clean fluid returns to the system through a filter. 7. A liquid with low compressibility able to operate without degradation under the conditions of the application (temperature, pressure, radiation). The more complex systems will use several pumps, rotary motors, cylinders, electronically controlled with valves and regulators. The system can be operated at high pressures. The improvement of the present invention can be achieved with pressures in the range of 50 to 500 bar, preferably 100 to 350 bar. Preferably, the fluid is used in military hydraulic systems, in hydraulic launch assistance systems, in hydraulic systems for industrial, maritime, mining and / or mobile equipment. In addition, the present invention offers a hydraulic system that includes a hydraulic fluid with a viscosity index of at least 130, a unit to create mechanical power, a unit that converts mechanical power into hydraulic energy, and a unit that converts energy hydraulic in mechanical work. Preferably, the motor speed can be reduced to decrease the load and voltage while delivering the same amount of hydraulic power. Preferably, the mechanical output power of the motor or electric motor can be operated at less than 98% of its total power capacity to deliver the same amount of hydraulic power as the hydraulic system using a HM grade fluid with a viscosity index less than 120. The invention is illustrated in more detail below by means of examples and comparison examples, without the purpose of limiting the invention to these examples. Examples and comparative examples. A field test was carried out to compare the fuel consumption speeds in a Caterpillar model 318CL 2001 hydraulic excavator. The hydraulic flow is generated by a double piston pump that feeds 2 rotary motors to drive the belts, a rotary motor to activate the pivot, and 3 linear actuators to activate the arm, the pivot and the bucket. A standardized work protocol was developed that involved moving a 100-foot pile of loose soil. The excavator takes a full pallet of earth, the cab rotates 180 degrees, and travels in full speed in a straight line to empty the bucket. After emptying the load, the cab rotates 180 degrees and returns in the same band to the starting point. This completes a work cycle. Diesel fuel consumption was measured during a working day, which was progressing according to the following program: Field Test Procedures: 15 minutes of heating 15 minutes of waiting to fill the fuel tank to the top of the neck filling time 1 - 55 working minutes after the standard cycle protocol 5 minutes of operator rest Time 2 - 55 working minutes after the standard cycle protocol 5 minutes of operator rest Time 3 - 55 working minutes after the protocol of the standard cycle 5 minutes of rest of the operator Rest - 1 Hour Fill the fuel tank to the top of the filler neck, record the weight of the fuel addition to + 0.1 grams Time 4 - 55 minutes of work after the standard cycle protocol 5 minutes of rest of the operator Time 5 - 55 minutes of work after the protocol of the standard cycle 5 minutes of rest of the operator Time 6 - 55 minutes of work after the standard cycle protocol 5 minutes of operator's rest Fill the fuel tank to the top of the filler neck, record the weight of the fuel, add to ± 0.1 grams The measurements of the line operational base were made with the excavator using the Caterpillar brand monograde oil recommended and sold by Caterpillar for its hydraulic excavators (Caterpillar HYDO 10W, viscosity grade L46 - 46 of NFPA). The total number of work cycles and the total fuel consumption were recorded. These performance tests were considered as comparative examples. Comparative example 1 was carried out with full regulation (2200 rpm) and comparative example 2 was carried out at 90% of the regulation (2200 rpm). The results are shown in Table 1. For the examples, the monograde oil was subsequently exchanged for multigrade oil "HV" after a triple wash procedure. The multigrade oil was an NFPA grade L32 - 100, which is a suitable substitute for this monograde oil according to the practice recommended by NFPA T2, 13.13 - 2002. Subsequently the same working protocol was followed both in complete regulation and regulation at the 90%, measuring the total number of work cycles and the total fuel consumption. Example 1 was carried out with complete regulation and example 2 was carried out with a 90% regulation. The results are shown in Table 1. The tetrafluidic fluid of NFPA used in this test was formulated from a mixture of mineral oil Group I and Group II, together with the Dynavis® additive system (from Degusta - RohMax Oil Additives ). The Dynavis * 1 additive system consists of a viscosity index improver of stable polyalkylmethacrylate in the cut (VISCOPLEX® 8-219) manufactured and diluted in Group II mineral oil. The formulation contained a PAMA Group II additive with 16 percent by weight, and a zinc-based anti-wear package of 0.08 percent by weight, which allows the fluid to meet the main global operating standards. This extremely high percentage of PAMA treatment is unusual and is not found in any commercial hydraulic fluid. To conclude the test, the NFPA multigrade oil was exchanged for the Caterpillar mono-grade oil L46-46, and the baseline tests were re-measured both in full regulation and at 90%. The second tests of the baseline had a good concordance with the first baseline tests.

Table 1 The data collected in the field test show that multigrade oil "HV" formulated with PAMA Group II was responsible for both increased productivity (+ 5.8 to 24.3%) and reduced daily fuel consumption (- 8.6 to - 13.8%) . When taking into consideration the fuel consumption per work cycle, the multigrade fluid "HV" produced a reduction of 18.4% to 26.3% in the total amount of fuel required to achieve an equivalent amount of work. In particular, the improvement based on the same amount of work is very surprising. This improvement is also achieved with a 90% regulation. Furthermore, it was not predicted that productivity with a 90% regulation could be improved in the manner shown by the examples.

Claims (47)

1. Claims 1. A use of a fluid having a viscosity index of at least 130 to improve the energy efficiency of a hydraulic system.
2. 2. The use according to claim 1, wherein the energy consumption is reduced by at least 5%.
3. 3. The use according to claim 1 or 2, wherein the performance of the system of the hydraulic system is improved.
4. 4. The use according to claim 3, wherein the performance of the system is improved by at least 5%.
5. The use according to at least one of the preceding claims, wherein the lifetime of a unit that provides mechanical power to the hydraulic system is improved.
6. 6. The use according to claim 5, wherein the speed of the motor is reduced to decrease the load and voltage while delivering the same amount of hydraulic power.
7. The use according to at least one of the preceding claims, wherein the fluid has a viscosity index of at least 150.
8. 8. The use according to claim 7, wherein the fluid has a viscosity index of at least 180.
9. 9. The use according to at least one of the preceding claims, wherein the fluid is a hydraulic fluid with double viscosity grade, triple viscosity grade, tetra viscosity grade or viscosity grade penta of the NFPA.
10. 10. The use according to at least one of the preceding claims, wherein the fluid can be obtained by mixing a base fluid and a polymer viscosity index improver. eleven .
11. The use according to claim 10, wherein the base fluid has a kinematic viscosity at 40 ° C according to ASTM D 445 of 35 mm2 / s or less.
12. The use according to claim 1, wherein the fluid includes at least 60% by weight of at least one base fluid having a kinematic viscosity at 40 ° C in accordance with ASTM D 445 of 35 mm2 / or less 13.
13. The use according to at least one of claims 10 to 12, wherein the base fluid has a viscosity index of 120 or less.
14. The use according to claim 13, wherein the fluid includes at least 60% by weight of at least one base fluid having a viscosity index of 120 or less.
15. 15. The use according to at least one of the preceding claims, wherein the fluid includes a mineral oil and / or a synthetic oil.
16. The use according to claim 15, wherein the fluid includes an API Group I, Group II API, Group III API, Group IV API or Group V API oil.
17. 17. The use according to at least one of the preceding claims, wherein the fluid includes a polyalphaolefin (PAO), a carboxylic ester, a vegetable ester, a phosphate ester and / or a polyalkylene glycol (PAG).
18. 18. The use according to at least one of the preceding claims, wherein the fluid includes at least one polymer.
19. 19. The use according to claim 16, wherein the polymer includes units derived from the monomers selected from acrylate monomers, methacrylate monomers, fumarate monomers and / or maleate monomers.
20. 20. The use according to claim 19, wherein the fluid includes a polyalkyl methacrylate polymer.
21. 21. The use according to at least one of claims 18 to 20, wherein the fluid includes a polymer that can be obtained by polymerizing a mixture of olefinically unsaturated monomers, consisting of a) 0 - 100% by weight based on the total weight of the ethylenically unsaturated monomers of one or more ethylenically unsaturated ester compounds of the formula (I) where R is hydrogen or methyl, R1 signifies a linear or branched alkyl residue with 1-6 carbon atoms, R2 and R3 independently represent hydrogen or a group of the formula -COOR ', where R' signifies hydrogen or an alkyl group with 1-6 carbon atoms, b) 0-100% by weight based on the total weight of the ethylenically unsaturated monomers of one or more ethylenically unsaturated ester compounds of the formula (II) wherein R is hydrogen or methyl, R4 means a linear or branched alkyl residue with 7-40 carbon atoms, R5 and R6 independently are hydrogen or a group of the formula -COOR ", where R" signifies hydrogen or an alkyl group with 7-40 carbon atoms , c) 0-50% by weight based on the total weight of the comonomers of the ethylenically unsaturated monomers.
22. 22. The use according to at least one of claims 18 to 21, wherein the polymer can be obtained by means of a polymerization in a mineral oil of Group II or Group III of the API.
23. 23. The use according to at least one of claims 18 to 22, wherein the polymer can be obtained by means of a polymerization in a polyalphaolefin (PAO).
24. 24. The use according to claim 23, wherein the PAO has a molecular weight in the range of 200 to 10,000 g / mol.
25. 25. The use according to one of claims 18 to 24, wherein the polymers can be obtained by polymerizing a mixture including dispersing monomers.
26. 26. The use according to one of claims 18 to 25, wherein the polymers can be obtained by polymerizing a mixture including vinyl monomers containing aromatic groups.
27. 27. The use according to at least one of claims 18 to 26, wherein the polymer has a molecular weight in the range of 10,000 to 200,000 g / mol specifically from 25,000 g / mol to 100,000 g / mol.
28. 28. The use according to at least one of claims 18 to 27, wherein the fluid includes from 0.5 to 40% by weight of the polymer.
29. 29. The use according to claim 28, wherein the fluid includes from 10 to 30% by weight of the polymer.
30. 30. The use according to at least one of claims 18 to 29, wherein the fluid includes at least two polymers having a composition different from the monomer.
31. 31. The use according to claim 30, wherein at least one of the polymers is a polyolefin.
32. 32. The use according to claim 31, wherein at least one of the polymers includes units derived from alkyl ester monomers.
33. 33. The use according to claim 32, wherein the weight ratio of the polyolefin and the polymer includes units derived from alkyl ester monomers and is in the range of 1: 10 to 10: 1.
34. 34. The use according to at least one of the preceding claims, wherein the fluid includes an oxygen-containing compound selected from the group of carboxylic acid esters, polyether polyols and / or organophosphorus compounds.
35. 35. The use according to claim 34, wherein the oxygen-containing compound is a carboxylic ester containing at least two ester groups.
36. 36. The use according to claim 34 or 35, wherein the oxygen-containing compound is a diester of carboxylic acids containing from 4 to 12 carbon atoms.
37. 37. The use according to claim 36, wherein the oxygen-containing compound is an ester of a polyol.
38. 38. The use according to at least one of the preceding claims, wherein the fluid has an ISO viscosity grade in the range of 15 to 150.
39. 39. The use according to at least one of the preceding claims, wherein The fluid is used at a temperature in the range of -40 ° C to 120 ° C.
40. 40. The use according to at least one of the preceding claims, wherein the fluid includes antioxidants, anti-wear agents, corrosion inhibitors and / or defoamers.
41. 41. The use according to at least one of the preceding claims, wherein the fluid is used in military hydraulic systems, in hydraulic launch assistance systems, in hydraulic systems of industrial, maritime, mining and / or mobile equipment.
42. 42. The use according to at least one of the preceding claims, wherein the hydraulic system includes at least one unit that provides mechanical energy, at least one unit that converts mechanical energy to hydraulic energy, at least one pipeline to transmit the fluid under pressure and at least one unit that converts the hydraulic energy of the fluid into mechanical work.
43. 43. The use according to claim 42, wherein the unit that provides mechanical energy includes a combustion engine.
44. 44. The use according to at least one of the preceding claims, wherein the speed or power output of the unit can be controlled and adjusted.
45. 45. A hydraulic system that includes a hydraulic fluid with a viscosity index of at least 130, a unit to create mechanical power, a unit that converts mechanical power into hydraulic energy, and a unit that converts hydraulic energy into mechanical work.
46. 46. The hydraulic system according to claim 45, wherein the speed of the motor can be reduced to decrease the load and voltage while delivering the same amount of hydraulic power.
47. 47. The hydraulic system according to claim 45 or 46, or the use according to claims 42 to 44, wherein the mechanical output power of the motor or the electric motor can be operated at less than 98% of its capacity. Total power to deliver the same amount of hydraulic power as the hydraulic system using a HM grade fluid with a viscosity index of less than 120.