JP2008081558A - Grease composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grease composition capable of reducing the abrasion of a lubricated part even by using a small amount and realizing the long life and cleaning of a processing machine. <P>SOLUTION: This grease composition used in the lubricating part of the processing machine is provided by blending ≥8 and ≤16 wt.% triazine triurea as a thickening agent with a base oil having ≥150 and ≤200 mm<SP>2</SP>/s viscosity at 40°C, and capable of maintaining the lubricated state even after working by 200,000 times by an initial application to the lubricating part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a grease composition used for a lubrication part of a processing machine, and more particularly to a grease composition used for a lubrication part of an injection molding machine operated at high load and high speed.

  Grease is used for each lubricating part of the processing machine. This will be described using an injection molding machine as an example. The injection molding machine has a mold clamping ball screw that converts the rotation of the motor into a linear motion, a toggle mechanism that amplifies the thrust of the ball screw to a larger thrust, and clamps the mold, and the reaction of the thrust A mold clamping mechanism with a tie bar that receives force, a molded product ejecting mechanism with a projecting ball screw that converts the rotation of the motor into a linear motion, and a pellet that is the raw material of the molded product, rotating the screw into the heating cylinder A mechanism for melting, and an injection mechanism having an injection ball screw for converting the rotation of the motor into a linear motion in order to fill the cavity of the mold with the heated and melted resin so that the molten resin is injected by the screw. With.

  FIG. 1 is a side view of an injection molding machine. In the injection molding machine 1, lubricating parts such as the clamping ball screw 4a, the protruding ball screw 4b, the injection ball screw 4c, the tie bar 14, the linear guide 5 and the toggle mechanism 2 are connected from the grease pump 31 to the pipe 33. The grease is supplied from the metering valve 32 connected thereto.

  2 is a partially cutaway cross-sectional view of the toggle mechanism of the injection molding machine as viewed from above, and FIG. 3 is a side view of the lubricating portion of the toggle mechanism of FIG. The lubrication part of the toggle mechanism 2 has a structure in which a toggle bush 22 serving as a bearing is fitted into a hole formed in the link 24 and a toggle pin 21 serving as a swing shaft is fitted into and supported by the toggle bush 22. Yes. More specifically, the lubrication portion of the toggle mechanism includes a sliding surface 211 of the toggle pin 21 and an inner surface 221 of the toggle bush 22 which is a bearing surface facing the sliding surface 211 via the bearing gap 23. During mold clamping, each link 24 of the toggle mechanism 2 swings, and friction is generated between the sliding surface 211 of the toggle pin 21 and the inner surface 221 of the toggle bush 22. In order to reduce this friction, a grease composition is supplied to the bearing gap 23.

In the toggle bush 22, a high surface pressure of 500 to 1000 kgf / cm ² is usually applied, and partial reciprocating sliding is repeated at a peripheral speed of ^{2 to 5} m / min. The toggle pin 21 that is the counterpart of the toggle bush 22 uses hardened steel and is made of a hard material that has undergone surface treatment such as hard chrome plating. In high cycle molding of compact discs, etc., one cycle takes 3 seconds. In many cases, grease is periodically replenished by an automatic supply device to prevent the wear of the bush and pins from being accelerated.

  FIG. 4 is a cross-sectional view of the ball screw. In the ball screw 4, a nut 42 that is a bearing having a circulation function of the ball 6 supports a ball screw shaft 41 that is a rolling shaft, and the ball screw shaft 41 is rotated, so that the nut 42 extends in the longitudinal direction of the ball screw shaft 41. It has a structure that allows linear motion. The lubrication part of the ball screw 4 includes a rolling surface 411 of the ball screw shaft 41 and an inner surface 421 of a nut 42 which is a bearing surface facing the rolling surface 411 with a bearing gap 43 therebetween. In order to reduce the friction generated on the rolling surface 411 of the ball screw shaft 41 and the inner surface 421 of the nut 42, a grease composition is supplied to the bearing gap 43.

The state at the time of operation | movement of a ball screw is demonstrated using the ball screw 4c for injection | emission. The injection ball screw 4c that repeats rolling motion is used in a harsh state in order to fill the mold cavity with the resin melted by heating. In particular, in the molding of a thin molded product having a thickness of 0.5 mm or less, the resin pressure needs to be a high filling pressure of 2000 to 3000 kgf / cm ² and an injection speed of 300 to 500 mm / s. There is. For this reason, the ball screw for injection is used at a high speed and with a high load, and grease must be periodically replenished by an automatic supply device.

  FIG. 5 is a cross-sectional view of the linear guide. The linear guide 5 has a structure in which a block 52 serving as a bearing having a circulation function of the ball 6 supports a rail 51 serving as a rolling shaft, and the block 52 can linearly move in the longitudinal direction of the rail 51. The lubrication part of the linear guide 5 includes a rolling surface 511 of the rail 51 and an inner surface 521 of the block 52 which is a bearing surface facing the rolling surface 511 with a bearing gap 53 therebetween. In order to reduce the friction generated on the rolling surface 511 of the rail 51 and the inner surface 521 of the block 52, a grease composition is supplied to the bearing gap 53. Similarly to the toggle mechanism and the ball screw described above, the linear guide must be periodically replenished with an automatic supply device.

As described above, the lubrication part of a processing machine such as an injection molding machine is operated at a high load and at a high speed, and therefore, grease having excellent heat resistance and containing an anti-seizing agent is often used. Patent Document 1 proposes an additive for an organic molybdenum compound and an organic tellurium compound. Patent Document 2 proposes a combination of a urea compound, an organic nickel compound, and an organic molybdenum compound. Patent Document 3 proposes a combination of a urea compound and a base oil viscosity at 40 ° C. of 300 mm ² / s or more and a consistency of 300 or more. Patent Document 4 proposes a combination of molybdenum disulfide, an organic molybdenum compound, and a sulfur compound. In addition, Patent Documents 5 and 6 propose similar high-load grease.

JP 2000-230616 A JP 2000-303089 A JP 2001-49274 A JP 2001-49278 A JP 2001-304371 A JP 2003-269562 A

  However, even if the techniques proposed in the above-mentioned Patent Documents 1 to 6 are used, the amount of grease used in the lubrication part of the processing machine cannot be reduced and cannot be made maintenance-free. Large amount of grease must be replenished. This is because the oil film breakage of the lubrication part occurs early. That is, since the fixability (adhesive force) of grease is poor, the grease is likely to leak by driving. If the grease leaks, the lubrication part becomes a boundary lubrication region and metal contact occurs and abnormal wear occurs. To compensate for this, an organometallic additive is added. The organometallic additive is sludged by heat generation and causes an increase in torque. Further grease is supplied for the purpose of discharging the sludge. Therefore, it is necessary to continue supplying excessive grease. That is, since the grease is discharged, the wear resistance of the processing machine lubrication part and the cleanliness of the apparatus are not realized, and a lubrication technique using a small amount of grease for realizing this has been desired.

  The present invention has been made in view of the above-mentioned problems, and provides a grease composition that reduces the wear of the lubrication part even when the amount of use is small, and realizes a long life and cleanliness of the processing machine. The purpose is to do.

The grease composition according to claim 1 is a grease composition used for a lubrication part of a processing machine, and as a thickener for a base oil having a viscosity at 40 ° C. of 150 mm ² / s or more and 200 mm ² / s or less. 8% by weight or more and 16% by weight or less of triazine triurea is blended, and the lubricating state can be maintained after operation 200,000 times in the initial application to the lubricating part.

  The grease composition according to claim 2 is the grease composition according to claim 1, wherein the base oil is a mineral oil, a synthetic hydrocarbon oil, a mixture containing mineral oil as a main component, or a mixture containing a synthetic hydrocarbon oil as a main component. It includes at least any one of them.

  The grease composition according to claim 3 is the grease composition according to claim 1 or 2, wherein the ratio of the synthetic hydrocarbon-based oil and the mineral oil to be contained is (0: 100) or more and (30:70) or less by weight. It is characterized by.

  The grease composition according to claim 4 is characterized in that, in claim 3, the synthetic hydrocarbon-based oil is a poly-α-olefin, and the mineral oil is a paraffin-based mineral oil.

  The grease composition according to claim 5 is characterized in that, in any one of claims 1 to 4, the penetration is 220 or more and 295 or less.

  The grease composition according to claim 6 is characterized in that, in any one of claims 1 to 5, the surface roughness of at least one surface of the lubrication part is 0.15 μm or more and 0.50 μm or less. And

  A grease composition according to a seventh aspect is characterized in that, in any one of the first to sixth aspects, at least one surface of the lubrication portion is subjected to a hard chrome plating treatment.

  The grease composition according to claim 8 is the grease composition according to any one of claims 1 to 7, wherein the grease is supplied to the lubrication part by an automatic supply device, and 0.5 cc of grease is supplied every 100,000 operations. A lubrication state can be maintained if lubrication is performed.

  A grease composition according to a ninth aspect is characterized in that, in any one of the first to eighth aspects, the grease composition is used in common for all the lubricating parts of the processing machine.

  A grease composition according to a tenth aspect of the present invention is the grease composition according to any one of the first to eighth aspects, wherein the lubrication part of the processing machine has a sliding surface of the swing shaft, and a clearance gap between the sliding surface and the bearing. It is characterized by comprising bearing surfaces that face each other and support the rocking shaft.

  The grease composition according to claim 11 is the grease composition according to any one of claims 1 to 8, wherein the lubricating part of the processing machine is opposed to the rolling surface of the rolling shaft and the rolling surface through a bearing gap. And a bearing surface for supporting the rolling shaft.

  ADVANTAGE OF THE INVENTION According to this invention, even if there is little usage-amount, while reducing the abrasion of a lubrication part, the grease composition which implement | achieves the lifetime improvement and the cleanliness of a processing machine can be provided.

  An embodiment of the present invention will be described. Since the processing machine is substantially the same as that described in the background art, the description of the same part is omitted in this embodiment, and the different part will be described below. The following example is only one specific example of the present invention, and the present invention is not limited to the following embodiment.

  Base oils used in the present invention include synthetic hydrocarbon oils such as poly-alpha olefins, polybutenes and synthetic squalanes, ester base oils such as dibasic acid diesters and neopentyl polyol esters, alkyl phosphate esters, and allyl phosphate esters. Phosphoric ester oils such as polyethylene glycol, polypropylene glycol, polyethylene glycol ester, polyethylene glycol ether, etc., and mineral base oils such as naphthenic mineral oil, paraffin mineral oil, aromatic mineral oil, highly refined mineral oil, etc. 1 type or a mixture of 2 or more types of base oils such as poly-olefins and paraffinic mineral oils that can suppress heat generation due to a low pressure viscosity coefficient A base oil as a component is preferred.

Here, the poly alpha olefin and mineral oil will be described in detail. The polyalphaolefin used in the present invention has an average molecular weight of 200.
˜2000, preferably 400 ˜1400, and those obtained by polymerizing decene-1, isobutene or the like with a Lewis acid complex or an aluminum oxide catalyst are suitable. The hydride of polyalphaolefin is obtained by hydrogenating polyalphaolefin in the presence of a hydrogenation catalyst. By using poly-α-olefin or a hydride thereof as a component of the base oil of lubricating oil or lubricating grease, heat resistance can be improved and the amount of sludge generated from the oil can be extremely suppressed.

  Further, the mineral oil used in the present invention includes paraffinic, naphthenic and aroma-based, but the preferred mineral oil is paraffinic mineral oil. Paraffinic mineral oil has a high viscosity index and is compatible with other parts, so it is used as a base oil for many lubricants. Among them, refined paraffinic mineral oil has a low wax content and is environmentally friendly because it has few impurities such as sulfur and nitrogen. Therefore, by using paraffinic mineral oil as the main component and using poly-α-olefin as the auxiliary agent, the performance of the grease can be sufficiently exhibited.

  When the synthetic hydrocarbon oil and mineral oil are mixed and used, the blend ratio is (0: 100) or more and (30:70) or less by weight ratio. When the blending ratio of the synthetic hydrocarbon oil increases, the grease softens, so the above ratio needs to be kept.

The viscosity of the base oil may be 250 mm ² / s or less at 40 ° C., but is preferably in the range of 150 to ²⁰⁰ mm ² / s. If a base oil of 250 mm ² / s or more is used, the supply to the lubrication part will be poor, leading to oil starvation (depletion of lubricating oil), and an exothermic chain will be generated. Therefore, the base oil used is preferably 250 mm ² / s or less.

  The triazine triurea used as a thickener in the present invention is preferably a compound represented by the following general formula 1.

In the above general formula 1, R ₁ is an alkyl group having 12 to 24 carbon atoms, R ₂ is a divalent triazine derivative group, R ₃ is a divalent aromatic hydrocarbon group having 6 to 15 carbon atoms, R ₄ represents an alkyl group or an aryl group.

  Examples of the triazine derivative group include those in which one carbon of the triazine ring is substituted with an alkyl group, a phenyl group, an amino group, an alkylamino group, or an amide group. This triazine triurea can be produced, for example, by the method described in JP-A No. 63-15896.

  The grease of the present invention preferably has a consistency of 220 to 295. When the consistency is 300 or more, softening leakage is caused, and when the consistency is 220 or less, supply of base oil from grease is caused. In order to obtain grease in the above consistency range, it is necessary to adjust the blending amount of triazine triurea to 8 to 16% by weight.

  In the present invention, surface treatment can be performed on at least one surface of the metal surfaces that are in contact with each other. However, the life of the molding machine cannot be extended by polishing to reduce the surface roughness. When surface treatment is performed, the surface roughness is preferably in the range of Ra 0.15 to 0.50 μm. When the surface roughness is less than 0.15 μm, there is no grease reservoir (oil pot), so that grease is quickly cut out. Further, when the surface roughness exceeds 0.50 μm, the metal contact is promoted and the amount of wear increases. Therefore, the surface roughness needs to be in the range of Ra 0.15 to 0.50 μm.

  For the surface treatment used in the present invention, single plating, alloy plating, chemical plating, shot blasting, thermal spraying, PVD (physical vapor deposition), CVD (chemical vapor deposition), DLC coating, or the like can be used. Among them, hard chrome plating is preferable because the surface roughness after construction matches the above optimum value.

  In an ordinary processing machine, if the operation is performed about 200,000 times, the wear amount exceeds the initial wear region and the wear amount is saturated. Therefore, if the lubrication state can be maintained after 200,000 operations, the lubrication state can be maintained thereafter.

  The grease for a processing machine of the present invention can be supplied to the lubrication part by an automatic supply device. The amount of grease supplied to the lubrication part can maintain the state of lubrication 200,000 times with only the initial application when the inventive grease is used. In view of the above, the lubrication state can be maintained by applying grease of about 0.5 cc at least every 100,000 times.

The grease used in the present invention can contain a metal deactivator. Typical examples of the metal deactivator include benzotriazole and derivatives thereof, but imidazoline and pyridine derivatives may also be used. Many of these compounds are effective among compounds having at least an N—C—N bond, and have an action of forming an inactive film on a metal surface and an antioxidant action. Other than this, there are compounds having an N—C—S bond, but benzotriazole derivatives and the like are effective from the viewpoint of volatility and the like. The blending ratio of the metal deactivator is preferably in the range of 0.05 to 5% by weight with respect to the lubricating oil or the base oil of the lubricating grease.

  Furthermore, an antioxidant can be blended in the grease used in the present invention. As the antioxidant, one or more antioxidants selected from phenolic, amine-based, sulfur-based antioxidants acting as free radical chain terminators, and peroxide-decomposing agents, or zinc dialkyldithiophosphates. The agents can be used alone or in combination, but it is preferable to use a mixture of amine and phenol.

  Examples of phenolic antioxidants include 2,6-di-t-butylphenol, 4,4′-methylenebis (2,6-di-t-butylphenol), and 2,6-di-t-butyl-4-ethyl. Examples include phenol and 2,6-di-t-4-n-butylphenol. From the viewpoint of evaporation characteristics, 4,4′-methylenebis (2,6-di-t-butylphenol) is preferable. Examples of amine-based antioxidants include dioctyl diphenylamine and phenyl-α-naphthylamine.

  In view of evaporation characteristics, dioctyl diphenylamine is preferred. The blending amount is preferably 0.1 to 10% by weight of amine-based antioxidant and 0.1 to 10% by weight of phenol-based antioxidant with respect to the grease.

  When used alone, 0.1 to 10% by weight of an amine-based antioxidant is suitable. A phenolic antioxidant is effective when used in combination with an amine. In addition, when adding dialkyl dithiophosphate zinc as antioxidant, 0.5 weight% or less is preferable. Addition of 1% by weight or more generates hard sludge.

  Furthermore, the grease used in the present invention includes a rust inhibitor, a pour point depressant, an ashless dispersant, a metal detergent, an interface, as necessary, as long as the purpose and effect of the present invention are not impaired. An activator, a friction modifier and the like can be blended.

  Examples and Comparative Examples of the present invention are shown below. Using the base oil shown in Table 1, the grease shown in Table 2 was obtained. For the greases of Examples 1 to 3 and Comparative Examples 1 to 4, a wear evaluation test of the toggle bush and toggle pin of the toggle mechanism was performed using an injection molding machine having a mold clamping force of 50 ton. In Table 2, the blending amount is% by weight, and “balance” indicates the remainder when the entire grease composition is 100% by weight.

Here, the grease is applied only at the initial stage, the PV value is 6370 N / cm ² · m / min, the wear depth of the toggle bush and the toggle pin is measured by disassembling 200,000 times, and Ra 0.25 μm is formed on the surface of the toggle pin. Evaluation was performed under conditions of hard chrome plating.

  In the pass / fail judgment, the life passed when the number of operations reached 200,000 times, and the wear passed when the wear amount was 20 μm or less. It is determined that the lubrication state was maintained after 200,000 operations by passing both the life and wear. The thickener is a triazine obtained by reacting 2-octadecylureido-4,6-diamino-1,3,5-triazine, octadecylamine, p-anisidine and diphenylmethane-4,4'-diisocyanate. Triurea was used. In the comparative example, a mineral oil lithium soap grease containing an extreme pressure additive (equal amounts of MoDTC and ZnDTP) was used. In addition, 4,4'methylenebis which is a phenolic antioxidant was used as the antioxidant, and Irgamet (registered trademark) 30 was used as the metal deactivator.

  Table 3 shows the relationship between the surface roughness of the hard chrome plating evaluated using Examples 4 to 5 and Comparative Examples 6 to 7 and the amount of wear when the molding machine test reaches 10,000 times. The initial conformability was simulated, and the wear amount was 10 μm or less, and judged to be “good” or more.

  It can be seen from Table 2 that the amount of wear increases when the base oil viscosity is high. This is because of the high viscosity oil, it is difficult for the grease to intervene in the gap between the toggle pin and the toggle bush, and the rotational resistance increases due to the high base oil viscosity. That is, the grease is insufficient at the lubrication interface, and even less grease causes the oil film to become thin due to heat generation and metal contact, resulting in increased wear. Further, in Example 1 and Comparative Example 1 in which the weight ratio between the base oil amount and the thickener amount was the same, the wear amount of Comparative Example 1, which is a hard grease, was large. This is because the amount of oil contributing to lubrication is reduced due to the influence of the thickener which is a solid content.

  In addition, Comparative Example 4 in which an extreme pressure additive is blended with a lithium soap grease that is excellent in oil separation and pressure in the presence of pressure cannot reach 200,000 operations, and the amount of wear is also low. The biggest result. This is because the shear stability of lithium soap is inferior to that of triazine triurea, and even though it seems to function on the lubrication surface, the soap fibers are actually broken by pressure and shear, and the thickening property is lost. This is because the grease shortage occurred early (discharged from the lubricated surface together with the base oil).

  Grease that easily intervenes in the gap and has excellent oil supply to the interface is easily discharged from the lubrication interface. Also, the extreme pressure additive is simultaneously discharged from the lubrication interface. Therefore, if grease is not continuously supplied, the frictional environment of the lubrication part becomes severer than the effectiveness of the extreme pressure additive, and wear progresses. Therefore, when using the grease as in the comparative example in which the environment of the lubrication part is severe, continuous excessive supply of grease is essential.

  On the other hand, in the examples, the strong fiber structure unique to triazine triurea and the synergistic effect of the oil retained at the lubrication interface by the oil retention force of the thickener, the amount of wear can be significantly reduced if the optimum blend is selected. it can.

In Example 2 and Example 3, the relationship between the type of base oil and the amount of thickener was confirmed. As a result, it was found that when the base oil viscosity was 200 mm ² / s or less and the consistency was in the range of 220 to 295, excellent abrasion resistance was obtained as in Example 1. As for the type of thickener, triazine triurea was superior to lithium soap from Example 1 and Comparative Example 4. Therefore, triazine triurea is indispensable as a grease thickener for reducing wear of the lubrication part and extending the life and cleaning of the processing machine even if the amount used is small.

  Further, it has been found that if the present invention is used, excellent wear resistance can be obtained without depending on the efficacy of the extreme pressure additive, and the problem can be solved by a technique not belonging to any of Patent Documents 1 to 6.

  Table 3 shows the relationship between the surface roughness and wear of the hard chrome plating. From the results shown in Table 3, it was discovered that initial wear can be suppressed by having a certain degree of roughness and having a grease reservoir rather than reducing the surface roughness. Suppression of initial wear means that the life reaching time is extended. It was found that the effects of the examples can be obtained stably over a long period of time by applying an appropriate surface roughness.

  Based on these results, the conventional toggle bushing was greased with about 0.5 cc every 10,000 operations, but the lubrication state can be maintained after 200,000 operations with only initial application. A lubrication state can be maintained if grease of about 0.5 cc is supplied for each operation. However, grease may deteriorate due to the retention of grease for a long period of time, so at least 1/10 of the supply frequency compared to the conventional case, that is, about 0.5 cc of grease should be supplied every 100,000 operations. If this is the case, the lubricating state can be sufficiently maintained. Moreover, in the injection molding machine, the durability test was conducted with the ball screw for injection with the highest load. However, good results were obtained even with a conventional greasing frequency of 1/10.

  The grease of the present invention can be applied to various bearings and other lubricating parts in addition to the processing machine.

＊ポリαオレフィンＡ：DURASYN168（55.7%）とDURASYN180（44.3%）の混合物
＊ポリαオレフィンＢ：DURASYN174（DURASYNは登録商標でINNOVENE製品）
＊ポリオールエステル：ハトコール５１５０（ハトコ製）
＊精製鉱油Ａ：ダイアナプロセスオイルＰＷ−１５０とＰＷ３８０を混合して２００mm²/sに調整した（ダイアナプロセスオイルは出光興産製）
＊精製鉱油Ｂ：ダイアナプロセスオイルＰＷ−３８０（出光興産製）

* Poly alpha olefin A: A mixture of DURASYN168 (55.7%) and DURASYN 180 (44.3%) * Poly alpha olefin B: DURASYN174 (DURASYN is a registered trademark INNOVENE product)
* Polyol ester: Hatcoal 5150 (manufactured by Hatco)
* Refined mineral oil A: Diana process oil PW-150 and PW380 were mixed and adjusted to 200 mm ² / s (Diana process oil manufactured by Idemitsu Kosan Co., Ltd.)
* Refined mineral oil B: Diana Process Oil PW-380 (manufactured by Idemitsu Kosan)

極圧添加剤：サクラルーブ（登録商標）165（1.5%）とキクルーブ（登録商標）Z112（1.5%）を添加
酸化防止剤：エチル７０２（オロナイトジャパン製）
金属不活性剤：イルガメット３０（チバスペシャリティケミカルズ製）

Extreme pressure additive: SakuraLube (registered trademark) 165 (1.5%) and Kiclub (registered trademark) Z112 (1.5%) added Antioxidant: Ethyl 702 (made by Oronite Japan)
Metal deactivator: Irgamet 30 (manufactured by Ciba Specialty Chemicals)

It is a side view of an injection molding machine. It is the partially cutaway sectional view which looked at the toggle mechanism of an injection molding machine from the upper part. It is a side view of the lubrication part of a toggle mechanism. It is sectional drawing of a ball screw. It is sectional drawing of a linear guide.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Injection molding machine 14 Tie bar 2 Toggle mechanism 21 Toggle pin 211 Toggle pin sliding surface 22 Toggle bush 221 Toggle bush inner surface 23 Bearing clearance 24 Link 31 Grease pump 32 Metering valve 33 Pipe 4 Ball screw 4a Clamping ball screw 4b Ball screw 4c Ball screw for injection 41 Ball screw shaft 411 Rolling surface of ball screw shaft 42 Nut 421 Inner surface of nut 43 Bearing clearance 5 Linear guide 51 Rail 511 Rolling surface of rail 52 Block 521 Inner surface of block 53 Bearing clearance 6 Ball

Claims (11)

A grease composition for use in a lubrication part of a processing machine, having a viscosity at 40 ° C. of 150 mm ² / s or more and 200 mm ² / s or less as a thickener, 8% by weight or more and 16% by weight or less of triazine A grease composition comprising triurea and capable of maintaining a lubrication state after operation 200,000 times by initial application to the lubrication part.   The base oil includes at least one of mineral oil, synthetic hydrocarbon oil, a mixture mainly composed of mineral oil, and a mixture mainly composed of synthetic hydrocarbon oil. The grease composition according to 1.   3. The grease composition according to claim 1, wherein the weight ratio of the synthetic hydrocarbon-based oil to the mineral oil is (0: 100) or more and (30:70) or less.   The grease composition according to claim 3, wherein the synthetic hydrocarbon oil is a poly-α-olefin, and the mineral oil is a paraffin mineral oil.   The grease composition according to any one of claims 1 to 4, wherein the penetration is 220 or more and 295 or less.   The grease composition according to any one of claims 1 to 5, wherein a surface roughness of at least one surface of the lubrication part is 0.15 µm or more and 0.50 µm or less.   The grease composition according to any one of claims 1 to 6, wherein at least one surface of the lubrication part is subjected to hard chrome plating.   The grease supply to the lubrication part is performed by an automatic supply device, and the lubrication state can be maintained if 0.5 cc of grease is supplied every 100,000 operations. The grease composition according to item.   The grease composition according to any one of claims 1 to 8, wherein the grease composition is used in common for all lubrication parts of the processing machine.   The lubrication part of the said processing machine consists of a bearing surface which supports the said rocking | fluctuation shaft facing the sliding surface of this rocking | fluctuation shaft, and this sliding surface through a bearing clearance gap. The grease composition according to any one of the above.   9. The lubrication part of the processing machine includes a rolling surface of a rolling shaft and a bearing surface that faces the rolling surface through a bearing gap and supports the rolling shaft. The grease composition according to claim 1.

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