JP3508801B2 - Water pump bearings - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing incorporated in a water pump attached to a radiator of various vehicles. 2. Description of the Related Art For example, a water pump for circulating cooling water is attached to a radiator of an automobile. As shown in FIG. 1, the water pump 1 circulates cooling water by rotation of an impeller 2, and the impeller 2 rotates a shaft 4 by rotation of a pulley 3 connected to an engine (not shown) by a belt. Is driven through. A water pump bearing 7 including a roller row 5 and a ball row 6 is fitted on the shaft 4. Further, the water passage 8 side where the impeller 2 is arranged and the water pump bearing 7 side are partitioned by a mechanical seal 9 with a waterproof structure. Furthermore,
A drain hole 10 is formed on the water pump bearing 7 side in case water leaks from the water channel 8 side. [0003] The water pump bearing 7 is generally lubricated with grease, but water cannot enter the inside of the bearing due to long-term use, and as a result, the grease softens and flows out, and the lubricating performance is reduced. It can also lead. Therefore, the grease sealed in the water pump bearing 7 is required to have water resistance, and lithium soap-mineral oil based grease is generally used. Further, in order to further improve the water resistance, for example, in JP-A-4-46997, addition of a copolymer of a polyoxyalkylene derivative and maleic anhydride, or a hydrolyzate or a salt of a hydrolyzate thereof to grease is disclosed. It is proposed to include an agent. [0004] However, as a recent trend, there is a high demand for a larger cabin space, which necessitates integration and miniaturization of components in an engine room. This causes the temperature inside the room to rise. In addition, the rotating parts tend to rotate at a higher speed, which increases the temperature in the engine room and exposes the used bearings to high temperatures. [0005] The water pump bearing 7 also tends to be used at a higher temperature and at a higher rotational speed, like other rotating parts. Further, the belt is strengthened to cope with high-speed rotation, and accordingly, a high load is applied to the water pump bearing 7.
In some cases, peeling or seizure of the raceway surface may occur. Therefore, the grease sealed in the water pump bearing 7 is required to have not only water resistance but also performance that can sufficiently withstand use at high temperature and high speed rotation. JP-A-4-46
The grease containing a specific additive described in Japanese Patent Application Publication No. 997 cannot sufficiently meet those requirements. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a water pump bearing that can withstand use at high temperatures and high speed rotation in addition to water resistance. Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, have found that a particular base oil
A double- row type water pump bearing filled with grease containing a certain diurea compound and a thickener has been found to have excellent water resistance and lubrication performance at high temperatures and high speed rotation, leading to the completion of the present invention. Was. That is, the above purpose is
The shaft of the water pump of the present invention, which is attached to a radiator of an automobile and rotates a pulley connected to the engine by a belt by the driving force of the engine and rotates an impeller through the shaft to circulate cooling water, is supported. A back row including a roller row and a ball row , which is a bearing for a water pump.
Type and at least 40% by weight of synthetic hydrocarbon oil
Kinematic viscosity at 40 ° C. is 150 to 25
0 mm ² / s base oil at both ends as thickener
Diure having at least one of an aliphatic group and an alicyclic group
A) Distribute the compound at a rate of 13 to 15% by weight of the total amount of grease.
It is achieved by a bearing for a water pump, wherein the combined grease is sealed. Hereinafter, a bearing for a water pump according to the present invention will be described in detail. The bearing for a water pump of the present invention,
As shown in FIG. 1, a return row including a row of rollers 5 and a row of balls 6.
Grease, which will be described later. [0009] Grease thickeners have aliphatic terminals at both ends.
Compound having at least one of a group and an alicyclic group
Things. As desirable diurea compounds include those with cyclohexyl and octadecyl groups at both terminal groups of the diurea are mixed, the molar ratio occupied number actually cyclohexyl and octadecyl groups at both end groups 6: Most of about 4 desirable. Percentage of grease total amount of di-urea compounds, Ru 1:13 5 wt% der. On the other hand, the base oil which is the other main component of grease contains a synthetic hydrocarbon oil in an amount of 40% by weight or more based on the total amount of the base oil.
Combination lubrication oils, for example mineral oils, et ether oil, ester oil, silicone oil, fluorinated oils and the like. The kinematic viscosity at 40 ° C. is 150 to 250 mm ² / sec.
It is . Also, when using a mixture of said lubricating oil is adjusted so as to satisfy the kinematic viscosity. Mineral oil is subjected to distillation under reduced pressure, solvent removal, solvent extraction, hydrocracking, solvent dewaxing, sulfuric acid washing, clay refining,
It is preferable to use those obtained by appropriately combining hydrorefining and the like. Examples of the synthetic hydrocarbon oil include lubricating oils composed of poly-α-olefins such as normal paraffin, isoparaffin, polybutene, polyisobutylene, 1-decene oligomer, co-oligomer of 1-decene and ethylene, or hydrides thereof. Can be. As the synthetic hydrocarbon oil, an aromatic synthetic hydrocarbon oil can also be used. For example, alkylbenzene such as monoalkylbenzene, dialkylbenzene, and polyalkylbenzene, or alkylnaphthalene such as monoalkylnaphthalene, dialkylnaphthalene, and polyalkylnaphthalene can be used. And the like. [0012] Grease used in the present invention is the above-di c <br/> rare compound and a base oil essential components, adding further antioxidants and rust inhibitors, extreme pressure agents, and oiliness agents such as By doing so, the durability of the lubricant film can be improved. Although any of these additives may be known, particularly preferred compounds are shown below. The amount of these additives is
The total amount of grease is preferably 20 wt% or less. The antioxidant is preferably a mixture of a nitrogen-containing compound antioxidant and a phenolic antioxidant. Examples of the nitrogen-containing compound antioxidant include phenyl α-naphthylamine, diphenylamine, phenylenediamine, oleylamideamine, phenothiazine and the like.
Examples of the phenolic antioxidant include p-tert-butyl-phenyl salicylate, 2,6-di-tert-butyl-p-phenylphenol, 2,2′-methylenebis (4-methyl-6-tert-butylphenol),
2,2'-methylenebis (4-methyl-6-tert-
Octylphenol), 4,4'-butylidenebis-6
-Tert-butyl-m-cresol), tetrakis [methylene-3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2,4 , 6-Tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, n-octadecyl-β- (4′-hydroxy-3 ′, 5′-di-tert-butylphenyl)
Propionate, 2-n-octylthio-4,6-di (4'-hydroxy-3 ', 5'-di-tert-butyl) phenoxy-1,3,5-triazine, 4,4'-
There are hindered phenols such as thiobis- [6-tert-butyl-m-cresol] and 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole. As the rust inhibitor, organic metal sulfonic acid salts or esters are preferable, and these can be used alone or in combination. As the organic sulfonic acid salt, for example, dinonylnaphthalene sulfonic acid and heavy alkylbenzene sulfonic acid are used, and as the metal salts thereof, there are calcium sulfonate, barium sulfonate, sodium sulfonate and the like. Sorbitan derivatives as esters include sorbitan monolaurate, sorbitan trilaurate, sorbitan monostearate, sorbitan tristearate, sorbitan monooleate and sorbitan trioleate as partial esters of polybasic carboxylic acids and polyhydric alcohols. Examples of the alkyl ester type include polyoxyethylene laurate, polyoxyethylene oleate, and polyoxyethylene stearate. The extreme pressure agent is preferably a solid lubricant such as MoS ₂ , a sulfur-based, phosphorus-based, sulfur-phosphorus-based organic compound, molybdenum dialkyldithiocarbamate, molybdenum dialkyldithiophosphate, zinc dialkyldithiophosphate, and the like. They can be used alone or as a mixture. The oily agent is preferably a higher fatty acid such as oleic acid or stearic acid, the higher alcohol is preferably lauryl alcohol or oleyl alcohol, the amine is preferably stearylamine or cetylamine, and the phosphate ester is preferably tricresyl phosphate or the like. Can be used alone or as a mixture. In addition to the above, a viscosity index improver, an anti-wear agent and the like may be contained. These may be any of known ones. The grease for use in the present invention, the di-c <br/> rare compound and various additives, obtained by mixing the above base oil. At this time, considering that the grease is used for a water pump bearing, the penetration of grease is set to N
It is desirable to adjust from o2 to No4. EXAMPLES The water pump bearing of the present invention can be further clarified by the following examples and comparative examples. (Examples 1 to 4 , Comparative Examples 1 to 7) Greases of Examples and Comparative Examples were prepared by changing the base oil and the thickener as shown in Table 1. In addition, for each grease,
An antioxidant and a rust preventive are blended so as to be 3% by weight of the total amount of grease. As Comparative Example 7, a commercially available lithium-mineral oil grease “Albania No.
3 "was used. [Table 1] Each grease was sealed in a water pump bearing shown in FIG. 1, and subjected to the following high-temperature life test and cooling water mixing durability test. The test results are also shown in the table. [High-Temperature Life Test] The grease-sealed water pump bearing was rotated under the following conditions, and the time required for the rotation to become unrotatable due to seizure or the occurrence of peeling on the raceway surface and the occurrence of abnormal vibration was measured.・ Ambient temperature: 120 ° C. ・ Rotation speed: 10000 rpm ・ Load: 100 kgf of Asial load at a portion 15 mm from the end face of the thick shaft [Cooling water mixing endurance test] Rotate a water pump bearing filled with grease under the following conditions. The time until rotation became impossible due to seizure or peeling occurred on the raceway surface and abnormal vibration occurred was measured.・ Ambient temperature: 90 ° C. ・ Rotation speed: 8000 rpm ・ Load: 120 kgf of asial load at a portion 15 mm from the end face of the thick shaft ・ Cooling water: A commercially available coolant twice diluted ・ Mixing amount of cooling water: Initially 0.3 ml, then 20 0.15 ml is injected with a syringe every hour. The water pump bearing in which the grease of the present invention shown in Examples is filled is superior in both tests to the water pump bearing shown in Comparative Examples. I understand. As described above, the water pump bearing of the present invention is not only excellent in water resistance, but can withstand use at high temperature and high speed rotation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic sectional view showing a water pump bearing of the present invention. [Description of Signs] 1 Water pump 2 Impeller 3 Pulley 4 Shaft 5 Roller row 6 Ball row 7 Water pump bearing 8 Water path 9 Mechanical seal 10 Drain hole

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F01P 5/10 C10M 115/08 F16C 19/00 C10N 40:02

Claims (1)

(57) [Claims 1] A pulley which is attached to a radiator of an automobile and which is connected to the engine by a belt by a driving force of an engine is rotated, and an impeller is rotated via a shaft to rotate the cooling water. met bearing water pump for supporting the shaft of the water pump for circulating, and a roller rows and ball row
It is a back row type and 40% by weight of synthetic hydrocarbon oil
Containing at the above ratio, the kinematic viscosity at 40 ° C. is 150 to
250mm ² / s base oil, both ends as thickener
Di- or di-cyclic groups having at least one of an aliphatic group and an alicyclic group
Urea compound in a proportion of 13 to 15% by weight of the total amount of grease
A bearing for a water pump characterized by being filled with grease blended in the above .