JP2016147991A - chain - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chain, where a lubricant composition adjusted to desired use condition is impregnated into a bush and the lubricant composition favorably flows from pores of the bush during operation, suppressing generation of oil film cut at a sliding part, good in oil film strength and having good abrasion elongation life.PROBLEM TO BE SOLVED: To provide a chain 1 manufactured by connecting a pair of outer plates 4 connected by two pins 5 and a pair of inner plates 2 connected by 2 bushes 3 alternatively at a status that the pins 5 is free fitted to the bushes 3 and a lubricant composition containing a lubricant (A) having kinetic viscosity of 12 to 52 mm/s at 40°C and a viscosity modifier (B) having kinetic viscosity of 320 to 40000 mm/s at 40°C with (A)/(B) of 20/80 to 90/10 by mass ratio.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a chain in which a bush made of a sintered metal is impregnated with a lubricating oil composition.

  Conventionally, chains such as bush chains and roller chains have been used as power transmission mechanisms and transport mechanisms. The bush chain is formed by alternately connecting a pair of outer plates connected by two pins and a pair of inner plates connected by two bushes with the pins loosely fitted to the bushes. In the case of the roller chain, the roller chain further includes a roller fitted on the bush.

  An oil-impregnated bush made of a sintered member impregnated with a lubricating oil (composition) is used as the chain bushing of the above-described structure, and the lubricating oil impregnated in the oil-impregnated bush is exuded without additional oil supply. There is known an oil-free chain configured such that an oil-impregnated bush and a pin are in sliding contact with each other.

  Patent Document 1 discloses an invention of a sintered oil-impregnated bearing oil composition obtained by blending 0.01 to 3.0% by mass of a carboxylic acid ester and / or an organic sulfonic acid zinc salt as a rust inhibitor with a base oil. ing. In Patent Document 1, when poly-α-olefin (PAO) or a hydride thereof is used as a base oil, the average molecular weight of PAO is 200 to 1600, preferably 400 to 800.

  Patent Document 2 includes a base oil containing a polyolefin and a polyol ester, and the ratio of the polyolefin to the polyol ester in the base oil is 20/80 to 80/20 in mass ratio. The invention is disclosed.

Patent Document 3 includes one or two or more base oils selected from the group consisting of mineral oil, poly-α-olefin, and alkyl diphenyl ether, or a base oil and an additive. Among the elution components obtained by GPC (gel permeation chromatography), the kinematic viscosity is 230.8 mm ² / s or more and 419 mm ² / s or less. Lubricating oil for oil-impregnated bushings having an average molecular weight (Mn) of 800 to 2300 and Mw (mass average molecular weight) / Mn of 1.0 to 1.3, and a kinematic viscosity at 40 ° C. of 45.8 mm ² / s or higher 287.7mm and at ² / s or less, among the elution ingredients, most mass% of high content component is less than 95 wt%, Mn is 800 or more and 2300 or less, Invention of the lubricating oil is disclosed w / Mn is 1.0 or more and 2.0 or less.

JP-A-11-140478 Japanese Laid-Open Patent Publication No. 9-1225086 Japanese Patent No. 4480748

The sintered oil-impregnated bearing of Patent Document 1 is applied to a capstan bearing such as a portable radio cassette player and a motor bearing. The sintered oil-impregnated bearing of Patent Document 2 is applied to bearings of various motors such as automobile electrical parts (fan motors and the like).
Chain bearings (bushings), unlike shaft bearings that rotate at high speed, such as motors, are generally low in sliding with the pin (shaft) and have high surface pressure, and the pin performs rocking motion. To do. In the oil-free chain, the lubricating oil is easily sucked out from the pores of the bush by the sliding movement (pump action) of the pin fitted in the oil-impregnated bush, or the lubricating oil oozes out due to expansion due to frictional heat. Moreover, after oozing out on the surface of the bush, it is difficult to scatter from between the pins / bushings, and it is required to have good wear resistance.

  The lubricating oil of Patent Document 3 is a lubricating oil for bushes of an oil-free chain, but has a wider range of applications than the lubricating oil, that is, has a wide range of characteristics such as kinematic viscosity, and is used at operating temperature and load load. It is desirable to develop a lubricating oil that can be impregnated into the bushings of chains for various uses under different conditions, and can be certified to the H1 grade of NSF (National Sanitation Foundation) International, for example, and can also be applied to food machinery chains. Yes.

  The present invention has been made in view of such circumstances, and the bushing is impregnated with a lubricating oil composition capable of having wear resistance and elongation suitable for the desired use conditions. An object of the present invention is to provide a chain in which the lubricating oil composition flows out well from the pores, the occurrence of oil film breakage at the sliding portion is suppressed, the oil film strength is good, and the wear resistance is good. .

The chain according to the present invention connects a plurality of pairs of outer plates connected by two pins and a pair of inner plates connected by two bushes alternately with the pins loosely fitted to the bushes. The bush is made of a metal sintered body, and in the chain impregnated with the lubricating oil composition, the lubricating oil composition has a kinematic viscosity at 40 ° C. of 12 mm ² / s or more and 52 mm ² / s or less. there lubricating oil (a), and a kinematic viscosity at 40 ° C. containing 320 mm ² / s or more 40000 mm ² / s or less is a viscosity modifier (B), the (a) / (B), at a mass ratio of 20 / It is 80 or more and 90/10 or less.

The chain according to the present invention is characterized in that the lubricating oil composition has a kinematic viscosity at 40 ° C. of 18 mm ² / s or more and 560 mm ² / s or less.

  The chain according to the present invention is characterized in that the lubricating oil composition has a number average molecular weight of 700 or more and 2000 or less.

  In the chain according to the present invention, the lubricating oil is at least one selected from the group consisting of poly-α-olefin, paraffinic mineral oil, ester oil, fluorine oil, and polyglycol, and has a number average molecular weight. It is 550 or more and 1000 or less.

  In the chain according to the present invention, the viscosity modifier is at least one selected from the group consisting of an ethylene / propylene copolymer, a poly-α-olefin, and a polymethacrylate, and has a number average molecular weight of 1400 to 5000. It is characterized by being.

According to the chain of the present invention, kinematic viscosity at 40 ° C. is 12 mm ² / s or more 52 mm ² / s or less is a lubricating oil (A), and a kinematic viscosity at 40 ° C. is 320 mm ² / s or more 40000 mm ² / s or less It contains a certain viscosity modifier (B), and (A) / (B) is configured to impregnate the bushing with a lubricating oil composition having a mass ratio of 20/80 to 90/10. Since the numerical range of the viscosity viscosity of the viscosity modifier is wide, select the lubricant (A) and viscosity modifier (B) based on the chemical structure, kinematic viscosity, etc. Lubricating oil compositions that can have performances such as wear elongation resistance suitable for conditions (such as operating temperature and load load) can be designed over a wide range and impregnated into the bush. That is, the chain of the present invention has a lubricating oil composition that flows out well from the pores of the bush during operation according to the conditions of use, and also prevents the oil film from being cut (scattered) at the sliding portion, and the oil film strength Has good wear resistance elongation life.

It is a partially exploded perspective view showing a roller chain type chain of an example of an embodiment of the present invention. It is a graph which shows the relationship between a composition viscosity and abrasion elongation time (h) at the time of using "Lucant HC-40" as a viscosity modifier. It is a graph which shows the relationship between composition viscosity (mm < ² > / s) and abrasion elongation time (h) at the time of using "Lucant HC-100" as a viscosity modifier. It is a graph which shows the relationship between composition viscosity (mm < ² > / s) and abrasion elongation time (h) at the time of using "Lucant HC-600" as a viscosity modifier. It is a graph which shows the relationship between a composition viscosity at the time of using "Lucant HC-2000" as a viscosity modifier, and wear elongation time (h). It is a graph which shows the relationship between Mn of a lubricating oil composition, and wear elongation time (h) at the time of using "Lucant HC-40" as a viscosity modifier. It is a graph which shows the relationship between Mn of lubricating oil composition, and wear elongation time (h) at the time of using "Lucant HC-100" as a viscosity modifier. It is a graph which shows the relationship between Mn of a lubricating oil composition, and wear elongation time (h) at the time of using "Lucant HC-600" as a viscosity modifier. It is a graph which shows the relationship between Mn of a lubricating oil composition, and wear elongation time (h) at the time of using "Lucant HC-2000" as a viscosity modifier.

Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.
The chain of the present invention is made of an iron-based material, a pair of spaced apart inner plates, a bushing that is press-fitted into a bushing press-fitting hole of the inner plate, and inner and rear inner plates that are disposed outside the inner plate. A bushing chain comprising a pair of outer plates for connecting the pins, a pin loosely fitted on the inner surface side of the bushing and press-fitted into a pin press-fitting hole of the outer plate, and a roller on the outer peripheral surface of the coupling pin and bushing It is possible to apply to a chain such as a roller chain that is further loosely fitted.

FIG. 1 is a partially exploded perspective view showing a roller chain type chain 1 as an example of an embodiment of the present invention.
The inner plate 2 and the outer plate 4 of the chain 1 form inward arc-shaped depressions on both side edges of the center part of the oval flat plate member, and the holes 2a and 2a and the holes 4a and 4a are formed at both ends of the oval. The inner plate 2 is larger than the outer plate 4 in terms of the plate width and the diameter of the opened holes. One end of each of the cylindrical oil-impregnated bushings 3 and 3 is fitted into the two holes 2a and 2a of the inner plate 2, and the other end of the oil-impregnated bushings 3 and 3 is connected to the holes 2a and 2a of the other inner plate 2, respectively. The inner plates 2 and 2 are connected to each other by interference fitting. Cylindrical rollers 6 and 6 having an inner diameter larger than the outer diameter of the oil-impregnated bushes 3 and 3 are rotatably fitted to the oil-impregnated bushes 3 and 3. The oil-impregnated bush 3 is made of a metal sintered body and impregnated with a lubricating oil composition described later.

One end of each of the cylindrical pins 5 and 5 is fitted into the two holes 4a and 4a of the outer plate 4 respectively. The pins 5 and 5 have a diameter smaller than the inner diameter of the oil-impregnated bushes 3 and 3 and a length longer than the distance between the inner plates 2 and 2, and the other ends of the pins 5 and 5 are connected to the holes of the other outer plate 4. The outer plates 4 and 4 are configured to be connected by being fitted to the 4a and 4a.
Then, one of the pins 5 and 5 fitted in the outer plate 4 is inserted into one oil-impregnated bush 3 of the inner plates 2 and 2, and as described above, it is tightly fitted into the hole 4a of the other outer plate 4, The outer plates 4 and 4 and the inner plates 2 and 2 are alternately connected to form a chain 1.

The lubricating oil composition is the kinematic viscosity at 40 ° C. is 12 mm ² / s or more 52 mm ² / s or less is a lubricating oil (A), and a kinematic viscosity at 40 ° C. is 320 mm ² / s or more 40000 mm ² / s or less A viscosity modifier (B) is contained, and (A) / (B) is 20/80 or more and 90/10 or less by mass ratio.

The kinematic viscosity at 40 ° C. of the lubricating oil (A) is preferably 18 mm ² / s or more, and more preferably 25 mm ² / s or more. The kinematic viscosity is preferably 50 mm ² / s or less, and more preferably 40 mm ² / s or less.
The kinematic viscosity at 40 ° C. of the viscosity modifier (B) is preferably 400 mm ² / s or more, more preferably 1000 mm ² / s or more, and further preferably 9000 mm ² / s or more. The kinematic viscosity is preferably 30000 mm ² / s or less.

  When the total amount of the lubricating oil (A) and the viscosity modifier (B) is 100% by mass, when the content of the viscosity modifier (B) is 10% by mass or more and 80% by mass or less, good viscosity adjusting effect Is obtained. The content of the viscosity modifier (B) is preferably 20% by mass or more, and more preferably 30% by mass or more. And it is preferable that it is 70 mass% or less, It is more preferable that it is 60 mass% or less, It is further more preferable that it is 50 mass% or less.

  The lubricating oil composition according to the present invention is suspended endlessly on two sprockets (number of teeth: 16), and a load is applied from the center of one sprocket in a direction opposite to the direction toward the other sprocket. In this state, it is preferable that the operation time (wear elongation life) is 120 hours or more when the operation time until the wear elongation amount reaches 0.2% is measured by rotating at 500 revolutions per minute. The abrasion resistant elongation life is more preferably 150 hours or more, and further preferably 200 hours or more.

The kinematic viscosity at 40 ° C. of the lubricating oil composition according to the present invention is preferably 18 mm ² / s to 560 mm ² / s. When the kinematic viscosity is 18 mm ² / s or more, better wear elongation resistance can be obtained. When the kinematic viscosity exceeds 560 mm ² / s, when the bushing is impregnated with the lubricating oil composition, the foam does not run out, so it must be processed while raising or lowering the degree of vacuum, resulting in poor workability. After assembly, the chain has a large amount of oil adhering to the bushing surface, and there is a problem that excessive oil drips from the chain and pollutes the surrounding environment. The kinematic viscosity is preferably 40 mm ² / s or more, more preferably 50 mm ² / s or more, further preferably 60 mm ² / s or more, and particularly preferably 100 mm ² / s or more. Then, but preferably not more than 500 mm ² / s, and more preferably not more than 400 mm ² / s.

  The number average molecular weight of the lubricating oil composition is preferably 700 or more and 2000 or less. When the number average molecular weight is 700 or more and 2000 or less, better wear elongation resistance is obtained. The number average molecular weight is preferably 900 or more, and more preferably 1000 or more.

  The lubricating oil (A) is at least one selected from the group consisting of poly-α-olefin, paraffinic mineral oil, ester oil, fluorine oil, and polyglycol, and has a number average molecular weight of 550 or more and 1000 or less. Is preferred. The number average molecular weight is more preferably 600 or more, and even more preferably 700 or more. And it is more preferable that it is 900 or less.

  The viscosity modifier (B) is at least one selected from the group consisting of an ethylene / propylene copolymer, a poly-α-olefin, and a polymethacrylate, and has a number average molecular weight of 1400 or more and 5000 or less. preferable. The number average molecular weight is more preferably 2000 or more, and still more preferably 3000 or more. The number average molecular weight is more preferably 4000 or less.

  The lubricating oil composition according to the present invention takes into consideration the chemical structure, kinematic viscosity, molecular weight, volume, compatibility, etc., depending on the required use conditions (use temperature and load load, etc.), wear-resistant elongation life, Select the lubricant and viscosity modifier and determine the amount.

  When the chain is a chain used in a food machine, the lubricant (A) and the viscosity modifier (B) select materials that can be certified with NSF (National Sanitation Foundation) International H1 grade. For example, mineral oil containing impurities should not be used.

  In order to impart an additional function to the lubricating oil composition, an oil agent, a rust inhibitor, an antioxidant, an extreme pressure agent, an antifoaming agent, etc. are added to the lubricating oil (A) and the viscosity modifier (B). One or two or more agents may be added in combination. This additive is preferably included in an amount exceeding 0% by mass and not more than 10% by mass with respect to the entire lubricating oil composition.

Examples of the oily agent include long chain fatty acids such as stearic acid and oleic acid, and salts thereof.
Examples of the rust preventive include carboxylic acid, carboxylate, sulfonate, phosphate ester and the like.
Examples of the antioxidant include DBPC (2,6-di-t-butylparacresol), phenyl-α-naphthylamine, zinc diallyldithiophosphate, benzotriazole, and the like.
Examples of the extreme pressure agent include dialkyl polysulfides, alkyl phosphate esters, and zinc alkylthiophosphates.
Examples of the antifoaming agent include dimethylpolysiloxane.

Hereinafter, although an example and a comparative example of the present invention are explained concretely, the present invention is not limited to this example.
Specific examples of lubricating oils and viscosity modifiers that can be used in the lubricating oil composition according to the present invention are shown in Table 1 below.

[Example 1]
The oil-impregnated bush 3 of the chain 1 is made of an iron-based sintered metal and has a large number of holes.
“Synfluid PAO 6” (manufactured by Chevron Phillips Chemical Co., Ltd .: Synthetic PAO, VG32) as the lubricating oil (A) of the lubricating oil composition impregnated in the oil-impregnated bush 3, and “Lucant HC-” as the viscosity modifier (B) 40 ”(manufactured by Mitsui Chemicals, Inc .: ethylene / propylene copolymer) was blended in an amount of 30 wt%, heated at 100 ° C. or lower and mixed.
The bush was immersed in the lubricating oil composition and impregnated under reduced pressure until no bubbles were generated.
The chain 1 of Example 1 was produced using the obtained oil-impregnated bush 3 and other chain parts.

In Table 2 below, the viscosity classification of the lubricating oil, the Mn of the lubricating oil, the blending amount of the lubricating oil (wt%), the brand name of the viscosity modifier, the Mn of the viscosity modifier, the blending amount of the viscosity modifier (wt%) , Mn of the lubricating oil composition, kinematic viscosity (40 ° C., mm ² / s) of the composition, and wear life (wear resistance elongation life: time).

[Examples 2 to 17]
According to the said Table 2, lubricating oil (A) and the viscosity modifier (B) were mix | blended, respectively, and the chain of Examples 2-17 was produced.
“VG15” of the lubricating oil (A) in Table 2 is “Synfluid PAO 4” in Table 1, and “VG46” is “Synfluid PAO 8” in Table 2.
“HC-100”, “HC-600” and “HC-2000” of the viscosity modifier (B) in Table 2 are “Lucanto HC-100”, “Lucanto HC-600” and “Lucanto” in Table 1, respectively. It corresponds to “HC-2000”.

[Comparative Examples 1-6]
According to the said Table 2, lubricating oil (A) and the viscosity modifier (B) were mix | blended, respectively, and the chain of Comparative Examples 1-6 was produced.

In order to evaluate the wear resistance elongation life of the oil-free chains according to Examples 1 to 17 and Comparative Examples 1 to 6, the following performance evaluation tests were performed.
At an ambient temperature of 40 ° C., each oil-free chain 1 (JIS B1801-1895, equivalent to nominal number 50) is suspended endlessly on two sprockets (number of teeth: 16T), and from the center of one sprocket to the other sprocket Rotating at 500 revolutions per minute with a load applied (surface pressure 4.00 kN / cm ² , sliding speed 8.0 m / min) in the opposite direction, the wear elongation of the oil-free chain is 0 The operating time until 2% was measured. The results are shown in Table 2 above.

FIG. 2 is a graph showing the relationship between the composition viscosity (composition kinematic viscosity: mm ² / s) and the wear elongation time (h) when “Lucant HC-40” is used as the viscosity modifier (B). It is. From FIG. 2, when the kinematic viscosity of 50 to 200 mm ² / s, because it has a better abrasion elongation resistance, kinematic viscosity is seen that preferably a 50 to 200 mm ² / s.

FIG. 3 is a graph showing the relationship between the composition viscosity (mm ² / s) and the wear elongation time (h) when “Lucant HC-100” is used as the viscosity modifier (B). Than 3, when the kinematic viscosity is 50~650mm ² / s, because it has a better abrasion elongation resistance, kinematic viscosity is seen that preferably the 50~650mm ² / s. The kinematic viscosity is more preferably 70 mm ² / s or more. From the standpoint that the workability deteriorates and the assembled chain has a large amount of oil adhering to the bushing surface, excessive oil dripping from the chain and contaminating the surrounding environment, the kinematic viscosity is 560 mm ² / s or less. Is more preferably 500 mm ² / s or less.

FIG. 4 is a graph showing the relationship between the composition viscosity (mm ² / s) and the wear elongation time (h) when “Lucant HC-600” is used as the viscosity modifier (B). From FIG. 4, when the kinematic viscosity of 50~2000mm ² / s, because it has a better abrasion elongation resistance, kinematic viscosity is seen that preferably the 50~2000mm ² / s. The kinematic viscosity is more preferably 100 mm ² / s or more, more preferably 560 mm ² / s or less, and further preferably 500 mm ² / s or less.

FIG. 5 is a graph showing the relationship between the composition viscosity (mm ² / s) and the wear elongation time (h) when “Lucant HC-2000” is used as the viscosity modifier (B). From FIG. 5, when the kinematic viscosity is 80 to 120 mm ² / s, because it has a better abrasion elongation resistance, kinematic viscosity is seen that preferably a 80 to 120 mm ² / s.

  FIG. 6 is a graph showing the relationship between the Mn of the lubricating oil composition and the wear elongation time (h) when “Lucant HC-40” is used as the viscosity modifier (B). From FIG. 6, when Mn is 900-1400, since it has the better abrasion elongation property, it turns out that it is preferable that Mn is 900-1400. Mn is preferably 980 or more.

  FIG. 7 is a graph showing the relationship between the Mn of the lubricating oil composition and the wear elongation time (h) when “Lucant HC-100” is used as the viscosity modifier (B). FIG. 7 shows that when Mn is 900-1800, it has better wear elongation resistance, so that Mn is preferably 900-1800. Mn is more preferably 1000 or more, and more preferably 1600 or less.

  FIG. 8 is a graph showing the relationship between the Mn of the lubricating oil composition and the wear elongation time (h) when “Lucant HC-600” is used as the viscosity modifier (B). From FIG. 8, when Mn is 900-2000, since it has favorable abrasion-proof elongation property, it turns out that it is preferable that Mn is 900-2000. Mn is more preferably 1000 or more.

  FIG. 9 is a graph showing the relationship between the Mn of the lubricating oil composition and the wear elongation time (h) when “Lucant HC-2000” is used as the viscosity modifier (B). FIG. 9 shows that when Mn is 1150 to 1400, Mn is preferably 1150 to 1400 because it has better wear resistance.

  From the above, considering the chemical structure, kinematic viscosity, molecular weight, volume, compatibility, etc., the lubricating oil (A) and the viscosity modifier (B) are selected, and the blending amount is determined and prepared. A lubricating oil composition having characteristics such as wear elongation resistance suitable for a desired use condition (use temperature, load load, etc.) can be obtained, and a chain in which the bush is impregnated with the lubricant composition is used under the use condition. Accordingly, during operation, the lubricating oil composition flows out well from the pores of the bush, and the occurrence of oil film breakage at the sliding portion is suppressed, and the oil film strength is good, so it has a good wear elongation life. I understand that.

  In the above embodiment, the case where the chain 1 is a roller chain type has been described. However, the present invention is not limited to this, and a chain such as a bush chain type may be used.

  The embodiment described above is an exemplification of the present invention, and the present invention can be implemented in variously modified forms within the scope defined by the matters described in the claims and the description of the claims. .

1 Chain 2 Inner plate 2a, 4a Hole 3 Oil-impregnated bush 4 Outer plate 5 Pin 6 Roller

Claims (5)

A plurality of pairs of outer plates connected by two pins and a pair of inner plates connected by two bushes are alternately connected in a state in which the pins are loosely fitted to the bushes. In a chain made of a sintered metal and impregnated with a lubricating oil composition,
The lubricating oil composition is
Kinematic viscosity at 40 ℃ is 12 mm ² / s or more 52 mm ² / s or less is a lubricating oil (A), and a kinematic viscosity at 40 ℃ is 320 mm ² / s or more 40000 mm ² / s or less is a viscosity adjusting agent (B) A chain characterized by containing (A) / (B) in a mass ratio of 20/80 to 90/10. The chain according to claim 1, wherein the lubricating oil composition has a kinematic viscosity at 40 ° C. of 18 mm ² / s or more and 560 mm ² / s or less.   The chain according to claim 1 or 2, wherein the lubricating oil composition has a number average molecular weight of 700 or more and 2000 or less.   The lubricating oil is at least one selected from the group consisting of poly-α-olefin, paraffinic mineral oil, ester oil, fluorine oil, and polyglycol, and has a number average molecular weight of 550 or more and 1000 or less. The chain according to any one of claims 1 to 3, characterized by:   The viscosity modifier is at least one selected from the group consisting of an ethylene / propylene copolymer, a poly-α-olefin, and a polymethacrylate, and has a number average molecular weight of 1400 to 5000. The chain according to any one of claims 1 to 4.

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