KR-20260064695-A - Grease composition for constant velocity joints and constant velocity joint containing the same

KR20260064695AKR 20260064695 AKR20260064695 AKR 20260064695AKR-20260064695-A

Abstract

(a) Giyu, (b) Diurea-based thickeners, (c) Molybdenum dialkyldithiocarbamate, which is solid at 25°C, (d) Molybdenum dialkyldithiocarbamate, which is liquid at 25°C, (e) perbasic calcium sulfonate, and (f) zinc dialkyldithiocarbamate A grease composition for constant velocity joints comprising, wherein the content of component (f) is 0.3 mass% to 3.5 mass% based on the total mass of the composition.

Inventors

쓰노다 준페이
오우 위셍

Assignees

교도유시 가부시끼가이샤

Dates

Publication Date: 20260507
Application Date: 20240829
Priority Date: 20230905

Claims (9)

(a) base oil, (b) Diurea-based thickeners, (c) Molybdenum dialkyldithiocarbamate, which is solid at 25°C, (d) Molybdenum dialkyldithiocarbamate, which is liquid at 25°C, (e) perbasic calcium sulfonate, and (f) zinc dialkyldithiocarbamate Includes, The content of component (f) is 0.3 mass% to 3.5 mass% based on the total mass of the composition, Grease composition for constant velocity joints.
In paragraph 1, A grease composition for constant velocity joints, wherein the content of component (e) is 0.5 mass% to 8.5 mass% based on the total mass of the composition.
In paragraph 1, A grease composition for constant velocity joints, wherein the content of component (d) is 0.3 mass% to 7.0 mass% based on the total mass of the composition.
In paragraph 1, A grease composition for constant velocity joints, wherein the content of component (c) is 0.2 mass% to 4.0 mass% based on the total mass of the composition.
In paragraph 1, A grease composition for constant velocity joints, further containing a sulfur-based extreme pressure agent (g).
In paragraph 1, A grease composition for constant velocity joints, wherein component (b) is at least one selected from the group consisting of a diurea compound represented by the following formulas (1-1), (1-2), or (1-3): [Chemical Formula 1] (In the formula, R1 is a cycloalkyl group having 6 to 12 carbon atoms, and R2 is an alkyl group having 6 to 30 carbon atoms).
In paragraph 1, A grease composition for constant velocity joints, wherein component (a) comprises a large proportion of mineral oil.
In any one of paragraphs 1 through 7. Grease for sliding constant velocity joints, for constant velocity joints.
A grease composition for constant velocity joints containing the grease composition described in any one of claims 1 to 7, Tripod-type sliding constant velocity joint.

Description

Grease composition for constant velocity joints and constant velocity joint containing the same The present invention relates to a grease composition for a constant velocity joint and a constant velocity joint containing the same. In the automotive industry, front-engine, front-drive (FF) vehicles are widely adopted for the purpose of vehicle environmental measures ( CO2 reduction) and securing living space, and constant velocity joints (CVJ), which are indispensable for power transmission in FF vehicles, are being used. Since a CVJ is a device that transmits rotation between two axes rotating at an angle, it performs complex rolling and sliding movements between parts within the joint. Among CVJs, flanged CVJs also possess an axial sliding mechanism, so friction between internal parts generates axial sliding resistance, and if this sliding resistance is large, it can cause vibration or noise. Furthermore, vehicle characteristics regarding these vibrations and sounds are generally referred to as NV characteristics (N stands for noise, V stands for vibration). Recent automobiles are undergoing electrification of power sources with the aim of achieving carbon neutrality and low fuel consumption, and interior quietness has been significantly improved. Accordingly, performance requirements regarding abnormal noise and vibration for conventional internal combustion engine vehicles are increasing, and the requirements regarding NV characteristics for flanged constant velocity joints are also becoming more stringent. Furthermore, with the distribution of HEVs, PHEVs, and BEVs into the general market, an environment has emerged where low-torque driving conditions resulting from the generalization of energy-saving driving coexist with high-torque driving conditions during acceleration due to the installation of motors. As discussed above, compared to vehicles equipped with internal combustion engines, the surface pressure environment surrounding the flanged constant velocity joint ranges from low surface pressure conditions caused by energy-saving driving inputs to high surface pressure conditions caused by motor acceleration inputs. Consequently, a decrease in NV characteristics may become a challenge due to increased internal friction resulting from changes in the lubrication environment of the sliding parts. Since the increase in slide resistance, a major factor in the degradation of NV characteristics, is attributed to increased internal friction, reducing friction under a wide range of surface pressure conditions serves as a countermeasure. In order to solve these problems, structural improvements have been made to the CVJ itself, but there are significant cost challenges, and a grease with excellent low friction under a wide range of surface pressure conditions is required. As a grease with excellent vibration suppression of CVJ, a grease for constant velocity joints (see Patent Document 1) formed by combining base oil and urea grease with additives of molybdenum dithiocarbamate and molybdenum dithiophosphate, or by mixing zinc dithiophosphate with these organic molybdenum compounds, and a composition for constant velocity joints containing a base oil, a diurea-based thickener, molybdenum dialkyldithiocarbamate sulfide, zinc sulfonate, a sulfur-phosphorus-based extreme pressure agent, and vegetable oil have also been proposed. In addition, as a grease that considers wear of the lubricated part in addition to vibration suppression performance, a grease composition for constant velocity joints that does not contain a trinuclear molybdenum compound consisting of a base oil, a thickener, montan wax, zinc sulfonate, and molybdenum dialkyldithiocarbamate (see Patent Document 3) has been proposed. (a) Giyu In the present invention, the type of base oil is considered to affect the grease ingress properties or oil film formation characteristics of the lubricating part, but has little effect on the low-friction characteristics of the present invention. Therefore, the type of base oil that can be used in the present invention is not particularly limited, and mineral oil, synthetic oil, or a mixture thereof may be used. Examples of mineral oil include paraffinic mineral oil and naphthenic mineral oil. Examples of synthetic oil include hydrocarbon-based synthetic oils such as polyα-olefins and ether-based synthetic oils represented by alkyl diphenyl ethers. Furthermore, the synthetic oil may be so-called biomass oil manufactured using biological resources generated from plants and animals as raw materials. For example, biomass ester oil synthesized from various fatty acids and alcohols using vegetable oil as a raw material, or biomass hydrocarbon oil using vegetable oils such as palm oil, corn oil, and soybean oil may be used. For the base oil of the present invention, it is preferable to use mineral oil from the perspective of cost. It is desirable for the base oil to contain a large proportion of mineral oil, and for exa