Gear oil composition usable in wind turbine gearbox

Abstract

The present invention relates to the field of lubricating oil technology, and in particular to a gear oil composition that can be used in a gearbox of a wind turbine generator set. The gear oil composition comprises: a low-viscosity poly-α-olefin and a high-viscosity synthetic ester; the weight ratio of the low-viscosity poly-α-olefin to the high-viscosity synthetic ester is 1:2 to 4.5; the kinematic viscosity of the low-viscosity poly-α-olefin at 100°C is 2 to 4.5 mm 2 / s; the high viscosity synthetic ester has a kinematic viscosity of 500 to 1500 mm at 40°C 2 The gear oil composition of the present invention has good biodegradability and sealing material compatibility, excellent hydrolysis resistance, low-temperature fluidity, extreme pressure and anti-wear properties, good oxidation stability, corrosion and rust resistance, and demulsification properties, can meet the performance requirements of wind power gearboxes, and is environmentally friendly.

Description

Technical Field

[0001] The present invention relates to the technical field of lubricating oils, and in particular to a gear oil composition that can be used in a gearbox of a wind turbine generator set. Background Art

[0002] Wind turbines operate in harsh outdoor environments for a long time, which places stringent requirements on the gear oil used in the gearbox. Once a wind turbine gearbox fails, the maintenance cost is very high. Good lubrication can reduce friction and wear, lower oil temperature, and improve transmission efficiency. It is an important condition to ensure the service life of the gearbox and bearings.

[0003] The constantly fluctuating wind loads and the frequent start-up and shutdown of wind turbines impose significant shock loads on transmissions, creating low-speed, high-torque operating conditions that require gear oils with excellent wear resistance, high load-carrying capacity, and excellent resistance to micropitting. Wind turbine gearboxes operating outdoors require excellent low-temperature and viscosity-temperature properties to facilitate low-temperature starts and energy conservation. The difficulty of maintaining wind turbine gear oils requires long life, placing high demands on thermal oxidation stability and hydrolysis resistance. Wind turbine gear oils are also required to exhibit excellent foaming properties, rust and corrosion resistance, filterability, demulsification properties, and compatibility with non-metallic materials.

[0004] Wind turbine main gearboxes typically use lubricants with an ISO 320 viscosity. Polyalphaolefin (PAO) synthetic lubricants surpass mineral oils in many performance areas, including load-carrying capacity, micropitting resistance, oxidation resistance, low-temperature start-up performance, and carbon deposition tendency, making them widely used in the wind power industry. However, existing PAO synthetic wind turbine gear oils have poor biodegradability, and leaks can cause serious environmental pollution. Summary of the Invention

[0005] The purpose of the present invention is to provide an environmentally friendly wind turbine gearbox gear oil composition, which has good biodegradability and sealing material compatibility, excellent hydrolysis resistance, extreme pressure and anti-wear properties, and good oxidation stability and corrosion resistance, and can meet the lubrication requirements of wind turbine gearboxes.

[0006] First, the present invention provides a gear oil composition, comprising: a low-viscosity poly-α-olefin and a high-viscosity synthetic ester;

[0007] The weight ratio of the low-viscosity poly-α-olefin to the high-viscosity synthetic ester is 1:2 to 4.5;

[0008] The low-viscosity poly-α-olefin has a kinematic viscosity of 2 to 4.5 mm at 100°C. 2 / s;

[0009] The kinematic viscosity of the high-viscosity synthetic ester at 40°C is 500 to 1500 mm 2 / s.

[0010] The present invention has discovered that a base oil formulated with the aforementioned low-viscosity polyα-olefin (PAO) and a high-viscosity synthetic ester in a weight ratio of 1:2 to 4.5 exhibits excellent viscosity-temperature performance, low-temperature performance, and biodegradability. The inclusion of an appropriate proportion of the low-viscosity PAO imparts both excellent rubber compatibility and load-bearing capacity. Furthermore, the aforementioned base oil exhibits a synergistic effect with other additives in the lubricant composition, resulting in a gear oil composition with excellent overall performance, making it more suitable for use in wind turbines.

[0011] As a preferred embodiment of the present invention, the low-viscosity poly-α-olefin is PAO4; preferably Durasyn 162 or Durasyn 164.

[0012] The biodegradability of the low-viscosity poly-α-olefin is tested using CEC L-33-T-93, a biodegradability assessment method commonly used in the lubricant industry, and the biodegradability is at least 60%.

[0013] As a preferred embodiment of the present invention, the high-viscosity synthetic ester is Priolube 1847 or UNIESTER 4415.

[0014] Preferably, the low-viscosity poly-α-olefin is prepared by oligomerization of alkane-substituted 1-olefins having 8 to 12 carbon atoms, followed by hydrogenation and distillation.

[0015] Preferably, the high viscosity synthetic ester is obtained by esterification of polyols with saturated aliphatic monocarboxylic acids and dicarboxylic acids to obtain a kinematic viscosity of 500 mm at 40°C. 2 / s~1500mm 2 / s high viscosity complex ester.

[0016] More preferably, the polyol is selected from at least one of pentaerythritol and trimethylolpropane;

[0017] and / or, the monocarboxylic acid is at least one of a linear or branched carboxylic acid having 5 to 20 carbon atoms;

[0018] And / or, the dicarboxylic acid is at least one of succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid having 4 to 10 carbon atoms.

[0019] As a preferred embodiment of the present invention, the gear oil composition further comprises: an alkylamine; preferably at least one of a secondary alkylamine or a tertiary alkylamine;

[0020] The weight ratio of the low-viscosity polyalphaolefin, the high-viscosity synthetic ester and the alkylamine is 75-100:220-250:1.

[0021] The present invention further discovered that, under the above ratio, the base oil formed by low-viscosity poly-α-olefin and high-viscosity synthetic ester can promote the alkylamine to exert the effect of inhibiting ester hydrolysis, so that the gear oil composition has excellent hydrolysis stability.

[0022] As a preferred embodiment of the present invention, the gear oil composition further comprises: an extreme pressure anti-wear agent, an antioxidant, a demulsifier, a metal deactivator, a rust inhibitor and an anti-foaming agent.

[0023] As a preferred embodiment of the present invention, the extreme pressure anti-wear agent is a compound containing sulfur and / or phosphorus; preferably at least one of sulfided olefins, sulfurized oils and fats, polysulfides, alkyl phosphate amine salts, thiocarbamates, and dialkyl dithiophosphates; more preferably sulfurized oils and fats and / or thiocarbamates;

[0024] The antioxidant is an amine antioxidant; preferably, the amine antioxidant is bis-octyl diphenylamine, butyl octyl diphenylamine, or dinonyl diphenylamine; the phenolic antioxidant is at least one of 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-cresol, 4,4-methylenebis(2,6-di-tert-butylphenol), high molecular weight phenol, and thioether phenol; more preferably, dinonyl diphenylamine and / or 2,6-di-tert-butyl-p-cresol;

[0025] The demulsifier is at least one of a polyoxyethylene-polyoxypropylene block copolymer, a propylene oxide diamine condensation polymer, and an ethylene glycol ester, preferably a propylene oxide diamine condensation polymer;

[0026] The metal deactivator is at least one of a benzotriazole derivative and a thiadiazole derivative, preferably at least one of benzotriazole, methylbenzotriazole, N,N-dialkylaminomethylenebenzotriazole, 2,5-dimercapto-1,3,4-thiadiazole, 2,5-di(alkylthio)-1,3,4-thiadiazole, and 2-mercaptobenzothiazole, more preferably a benzotriazole derivative;

[0027] The rust inhibitor is at least one of calcium sulfonate, alkenyl succinic acid half ester, and acyl sarcosine, preferably alkenyl succinic acid half ester;

[0028] The anti-foaming agent is at least one of dimethyl silicone oil, polyether, and polyacrylate, preferably polyacrylate.

[0029] As a preferred embodiment of the present invention, the gear oil composition comprises the following components in parts by weight:

[0030]

[0031] As a preferred embodiment of the present invention, the gear oil composition comprises the following components in parts by weight:

[0032]

[0033]

[0034] In the above system, the base oil can produce a good synergistic effect with a variety of additives, so that the gear oil composition has excellent hydrolytic stability, viscosity-temperature performance, low-temperature performance, rubber compatibility and biodegradability.

[0035] More preferably, the gear oil composition consists of the following components in percentage by weight:

[0036]

[0037] The percentages of the above components add up to 100%.

[0038] As a preferred embodiment of the present invention, the weight ratio of the alkylamine to the gear oil composition is 0.1 to 1.0%;

[0039] The weight ratio of the extreme pressure anti-wear agent to the gear oil composition is 0.2 to 2.0%;

[0040] The weight ratio of the antioxidant to the gear oil composition is 0.1 to 1.0%;

[0041] The weight ratio of the demulsifier to the gear oil composition is 0.01 to 0.1%;

[0042] The weight ratio of the metal deactivator to the gear oil composition is 0.05 to 0.1%;

[0043] The weight ratio of the rust inhibitor to the gear oil composition is 0.05 to 0.5%;

[0044] The weight ratio of the antifoaming agent to the gear oil composition is 0.001 to 0.1%.

[0045] Furthermore, the present invention also provides a method for preparing the gear oil composition in any of the above embodiments, comprising: mixing the low-viscosity polyα-olefin and the high-viscosity synthetic ester, stirring at 40-60°C, and then mixing with other components and stirring at 40-60°C.

[0046] Preferably, the preparation method comprises: mixing the low-viscosity poly-α-olefin and the high-viscosity synthetic ester, stirring at 40-60° C. for 1-2 hours, and then mixing with other components and stirring at 40-60° C. for 2-4 hours.

[0047] Furthermore, the present invention also provides the use of the gear oil composition and the preparation method thereof in a wind turbine generator set, preferably in a gearbox gear of a wind turbine generator set.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] The gear oil composition of the present invention has good biodegradability and sealing material compatibility, excellent hydrolysis resistance, low-temperature fluidity, extreme pressure and anti-wear properties, good oxidation stability, corrosion and rust resistance, and demulsification properties, and can meet the performance requirements of wind power gearboxes. At the same time, the gear oil composition has low toxicity and good environmental protection characteristics, and meets the environmental protection requirements of lubricants for equipment in field and offshore conditions. DETAILED DESCRIPTION

[0050] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0051] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0052] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0053] In the following examples, the kinematic viscosity of Priolube 1847 at 40°C is 1040 mm 2 / s;

[0054] In the following examples, the kinematic viscosity of Durasyn 164 at 100°C is 4.1 mm 2 / s.

[0055] Example 1

[0056] This embodiment provides a gear oil composition, which is composed of the following components in percentage by weight:

[0057]

[0058]

[0059] Example 2

[0060] This embodiment provides a gear oil composition, which is composed of the following components in percentage by weight:

[0061] Example 3

[0062] This embodiment provides a gear oil composition, which is composed of the following components in percentage by weight:

[0063]

[0064]

[0065] Example 4

[0066] This embodiment provides a gear oil composition, which is composed of the following components in percentage by weight:

[0067]

[0068] Comparative Example 1

[0069] This comparative example provides a gear oil composition, which differs from Example 1 only in that: Comparative Example 1 does not contain Durasyn 164, and the base oil is replaced by 75.5% Priolube 1847 and 21.8% Priolube 3970. The base oil obtained by mixing the two has a similar kinematic viscosity at 40°C to the base oil obtained by mixing Priolube 1847 and Durasyn 164 in Example 1, which is 325 mm. 2 / s.

[0070] Comparative Example 2

[0071] This comparative example provides a gear oil composition, which differs from Example 1 only in that it does not contain tertiary alkylamine.

[0072] Comparative Example 3

[0073] This comparative example provides a gear oil composition, which differs from Example 1 only in that: PAO (100°C kinematic viscosity> 6mm 2 / s) as the base oil and does not contain complex esters.

[0074] Test example

[0075] The performance of the gear oil compositions prepared in the examples and comparative examples was tested, and the results are shown in Table 1.

[0076] Table 1

[0077]

[0078]

[0079] Test evaluation results show that the environmentally friendly wind turbine gearbox gear oils obtained in Examples 1-4 exhibit good biodegradability and low aquatic toxicity, making them environmentally friendly lubricants. Comparative Example 1, which utilizes an ester base oil alone, exhibits excellent environmental performance, but its antioxidant and rubber compatibility are inferior to those of the Examples. Examples 1-4 maintain an acid value of 2.0 mgKOH / g for more than 10,000 hours in the GB / T 12581 test, passing the static seal test. Comparative Example 1, however, exhibits an antioxidant GB / T 12581 test duration of less than 5,000 hours and fails the static seal test. Comparative Example 3, which utilizes PAO, exhibits poor biodegradability. Comparative Example 2, which does not contain a tertiary alkylamine, exhibits inferior antioxidant properties compared to the Examples, indicating that the introduction of a tertiary alkylamine can inhibit the hydrolysis of the complex ester, thereby improving the antioxidant properties of the formulation. The environmentally friendly wind turbine gearbox gear oil obtained in Examples 1 to 4 has an anti-micropitting ability verification test (FZG) greater than level 10, an anti-scratch load capacity (FZG) greater than level 13, a viscosity index greater than 150, and a pour point lower than -30°C, indicating that the developed environmentally friendly gear oil has excellent viscosity-temperature performance, low-temperature performance, extreme pressure anti-wear performance, and anti-micropitting performance, and can meet the lubrication protection requirements of wind power gearboxes.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A gear oil composition, characterized in that: The gear oil composition is composed of the following components in percentage by weight:

2. The method for preparing the gear oil composition according to claim 1, wherein: include: Mix Priolube 1847 and Durasyn 164, stir at 40-60°C, then mix with other components and stir at 40-60°C.

3. Use of the gear oil composition according to claim 1 or the preparation method according to claim 2 in a wind turbine generator set.

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