JP2009036331A - Oil-free chain - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil-free chain drastically reducing chain manufacturing burden while avoiding decline in plate strength and increase in the number of chain components, preventing leakage of lubricating oil and entry of outside dust during chain operation, and enabling long supply of lubricating oil between connecting pins and bushes by excellent sustained release of the lubricating oil by the bushes. <P>SOLUTION: The oil-free chain comprises inner plates 110, the bushes 130, outer plates 150 and the connecting pins 160. Lubricating oil is filled between the bushes 130 and the connecting pins 160. Each bush projecting end part 131 partially protruded from the outer face of the inner plate 110 is surrounded and supported by an annular swelling part 151 for journaling the bush 130 formed by recessing the outer face of the outer plate 150 and swelling it to the inner face in the offset state. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an oil-free chain used for a transmission roller chain, a transport conveyor chain, etc., and in particular, press-fitting both ends of a pair of front and rear bushes into bush press-fit holes of a pair of left and right inner plates. The inner link and the outer link formed by press-fitting and fitting both ends of a pair of front and rear connecting pins penetrating into the bush respectively into the pin press-fitting holes of a pair of left and right outer plates are alternately connected in the longitudinal direction of the chain, The present invention relates to an oil-free chain in which lubricating oil is sealed between an inner peripheral surface of a bush and an outer peripheral surface of a connecting pin.

Conventionally, an outer link in which both ends of two outer link plates are connected by pins and an inner link in which two inner link plates are connected by bushes are alternately connected by loosely fitting the pins to the bushes. In addition, there is known a seal chain provided with sealing means for sealing lubricating oil injected between the pin and the bush. The sealing means of such a seal chain includes an elastic seal that is press-contacted between a ring member disposed so as to contact at least the axial end face of the bush and the ring member and an outer link plate facing the ring member. A ring (see, for example, Patent Document 1).
JP 2004-256262 A (column 4, FIG. 3)

  In the conventional seal chain as described above, a ring member and an elastic seal ring are provided in order to maintain the sealing effect of the lubricating oil injected between the pin and the bush by sealing between the bush and the outer link plate. The bush is arranged in a pressed state between the outer link plate and the pressing force in such a pressed state causes the relative bending resistance between the outer link plate and the inner link plate, that is, the bending resistance of the chain itself. There was a problem of getting bigger.

In addition, in order to prevent a reduction in the sealing effect caused by the sliding contact and wear of the ring member and the elastic seal ring with respect to the outer link plate or the like, the inner side surface and the bush of the outer link plate in contact with the ring member and the elastic seal ring can be prevented. There is a problem that it is necessary to carry out a surface finishing process for reducing the surface roughness of the end face, and the processing burden of the surface finishing process increases.

  Since the ring member and the elastic seal ring as the sealing means are provided between the bush and the outer plate, which are basic chain components, the number of parts and assembly man-hours of the chain increase, and the chain is easy to assemble. There was a problem of getting worse.

  Therefore, the present invention solves the conventional problems, that is, the object of the present invention is to significantly reduce the chain manufacturing burden while avoiding a decrease in plate strength and an increase in the number of chain parts, and a chain. Lubricating oil leakage and external dust intrusion are prevented during operation, and the bush exhibits excellent lubricating oil release characteristics, so that the lubricating oil is between the outer peripheral surface of the connecting pin and the inner peripheral surface of the bushing. It is to provide an oil-free chain that supplies oil over a long period of time.

  The present invention according to claim 1 is characterized in that both ends of a pair of front and rear bushings are inserted into the bush press-fit holes of the pair of left and right inner plates and both ends of the pair of front and rear connection pins penetrating into the bushes. The outer links formed by press-fitting the portions into the pin press-fitting holes of the pair of left and right outer plates are alternately connected in the longitudinal direction of the chain, and lubricating oil is provided between the inner peripheral surface of the bush and the outer peripheral surface of the connecting pin. In a non-lubricated chain that is enclosed, the bushing protruding end partly protruding from the outer surface of the inner plate is recessed in the outer surface of the outer plate and bulges to the inner surface in an offset state. The above-described problems are solved by being supported by the ring bulges.

  The present invention according to claim 2 solves the above-described problems by forming the bush from a sintered oil-impregnated metal material impregnated with the lubricating oil in addition to the configuration according to claim 1. is there.

  According to a third aspect of the present invention, in addition to the configuration according to the first or second aspect, the oil sump groove for supplying lubricating oil between the inner peripheral surface of the bush and the outer peripheral surface of the connecting pin includes: By being engraved on the outer peripheral surface of the connecting pin, the above-described problems are further solved.

  According to a fourth aspect of the present invention, in addition to the structure according to any one of the first to third aspects, the bulging surface of the annular bulge portion for bushing shaft support is an annular bulging portion for bushing shaft support. The above-described problems are further solved by having a larger outer diameter and a smaller inner diameter than the concave surface.

  According to a fifth aspect of the present invention, in addition to the structure according to any one of the first to fourth aspects, the bulging surface of the annular bulging portion for bushing shaft support and the outer surface of the inner plate are close to each other. By providing the facing labyrinth structure forming rough surface, the above-described problems are further solved.

  According to a sixth aspect of the present invention, in addition to the configuration according to the fifth aspect, the bulging amount Dj from the inner surface of the outer plate of the annular bulging portion for bushing shaft support and the outer surface of the inner plate of the bushing protruding end portion. The protrusion amount Db is formed so as to satisfy Dj <Db, thereby further solving the above-described problem.

  According to a seventh aspect of the present invention, in addition to the structure according to any one of the first to sixth aspects, a bulging amount Dj from the inner surface of the outer plate of the annular bulging portion for supporting the bushing shaft, a bushing protrusion The protrusion Db from the outer surface of the inner plate at the end, the inner width Do of the outer link, and the outer width Di of the inner link are formed so as to satisfy Do-Dj <Di + 2Db <Do, respectively. It solves the problem further.

  According to an eighth aspect of the present invention, in addition to the structure according to any one of the first to seventh aspects, the inner diameter Wji of the bulging surface of the annular bulging portion for bushing shaft support, the inner diameter Wbi of the bushing, The outer diameter Wbo and the outer diameter Wp of the connecting pin are formed so as to satisfy Wji-Wbo> Wbi-Wp, respectively, thereby further solving the above-described problems.

The “offset state” as used in the oil-free chain of the present invention means a state in which the annular bulging portion for bushing shaft support and the other plate portions are shifted in the plate thickness direction to form a stepped shape. is doing.
In addition, the term “sintered oil-impregnated metal material” in the oil-free chain of the present invention means that metal powder is compression-molded so as to have countless pores inside and sintered at a temperature below the melting point. It means a metal material obtained by impregnating the obtained porous material with a lubricating oil.
The “labyrinth structure-formed rough surface” in the oil-free chain of the present invention means a rough surface that can form a labyrinth structure for oil sump.
In addition, the “inner width of the outer link” in the oil-free chain of the present invention means an interval at which the inner surfaces of the outer plates arranged in a pair of left and right are separated from each other.
The “outer width of the inner link” in the oil-free chain of the present invention means an interval at which the outer surfaces of the inner plates arranged in a pair of left and right are separated from each other.

  Therefore, the present invention provides a pair of left and right ends of a pair of front and rear connecting pins penetrating into the bushing and the inner link formed by press-fitting both ends of the pair of front and rear bushes into the bush press-fitting holes of the pair of left and right inner plates. The outer links that are press-fitted into the pin press-fitting holes of the outer plate are alternately connected in the longitudinal direction of the chain, and lubricating oil is sealed between the inner peripheral surface of the bush and the outer peripheral surface of the connecting pin. As a result, not only can the chain drive be performed for a long period of time without lubrication from the outside, but also the following specific effects can be achieved.

  According to the oil-free chain of the present invention according to claim 1, the bush protruding end part that partially protrudes from the outer side surface of the inner plate dents the outer side surface of the outer plate and bulges to the inner side surface in an offset state. For oil sump formed between the projecting end of bushing, the annular bulging part for bushing shaft, and the inner surface of the outer plate by being surrounded and supported by the annular bulging part for bushing shaft The labyrinth structure can suppress the leakage of the lubricating oil due to the centrifugal force and the like generated by the circular running during the chain operation, and can suppress the intrusion of the external dust, thereby preventing the chain from being worn and extended for a long time.

  Further, the annular bulging portion for the bushing shaft support is formed in an offset state in which the outer surface of the outer plate is recessed and bulged to the inner surface, so that the section modulus of the annular bulging portion for the bushing shaft support and the Since the section modulus of the plate portion other than the same is approximately the same, it is possible to suppress a decrease in the strength of the outer plate due to the formation of the annular bulging portion for the bushing shaft support, and when the outer plate is subjected to press punching, The punching of the outer plate and the formation of the annular bulging part for the bushing shaft can be performed at the same time simply by using a mold having a shape in which the outer surface of the plate is recessed and bulged to the inner surface. Apart from the punching of the plate, there is no need to perform machining such as grinding or milling to form the annular bulging portion for the bushing shaft support on the outer plate, and the manufacturing burden of the chain can be reduced.

In addition, there is no separate seal member between the inner plate and the outer plate between the bush and the outer link plate as in the conventional seal chain. While bending and traveling around, an increase in the number of chain parts can be avoided.
In addition, in the conventional seal chain, the surface that reduces the surface roughness on the outer surface of the inner link plate and the inner surface of the outer link plate in order to prevent sliding contact wear of the seal member and maintain the sealing performance of the lubricating oil. Although it is necessary to perform finishing, the oil-free chain of the present invention does not require surface finishing as in the prior art, and can reduce the manufacturing burden of the chain.

  According to the oil-free chain of the present invention according to claim 2, in addition to the effect exhibited by the oil-free chain according to claim 1, the bush is formed from a sintered oil-impregnated metal material impregnated with lubricating oil. Even if the lubricating oil is not sufficiently supplied between the outer peripheral surface of the connecting pin and the inner peripheral surface of the bush, the bush exhibits excellent lubricating oil release characteristics, that is, the chain operates. Lubricating oil impregnated in countless pores formed inside the bush due to centrifugal force generated by the orbital running at the time gradually oozes between the outer peripheral surface of the connecting pin and the inner peripheral surface of the bush. The sliding contact wear between the outer peripheral surface of the connecting pin and the inner peripheral surface of the bushing can be reduced to prevent the chain from being stretched over a long period of time. It has the same shape as a normal bush that has not been applied. Since it can be handled like normal bushing can easily achieve degradation assembling work such as the chain cut splicing.

  According to the oil-free chain of the present invention according to claim 3, in addition to the effect exhibited by the oil-free chain according to claim 1 or 2, lubrication is provided between the inner peripheral surface of the bush and the outer peripheral surface of the connecting pin. Since the oil reservoir groove for supplying oil is engraved on the outer peripheral surface of the connecting pin, more lubricating oil can be enclosed and the lubricating oil can be continuously supplied between the connecting pin and the bush. The sliding contact wear between the outer peripheral surface of the pin and the inner peripheral surface of the bush can be reduced over a long period of time, and the wear elongation of the chain can be further prevented.

  According to the oilless chain of the present invention according to claim 4, in addition to the effect produced by the oilless chain according to any one of claims 1 to 3, the bulging surface of the annular bulging portion for supporting the bushing shaft is provided. The outer diameter of the stepped portion formed on the outer plate, that is, the pin hole is centered on the outer diameter by having a larger outer diameter and smaller inner diameter than the concave surface of the annular bulging portion for bushing shaft support The section modulus of the plate portion that is larger than the outer diameter of the bulging surface and the section modulus of the plate portion that is larger than the inner diameter of the bulging surface and smaller than the inner diameter of the recessed surface around the pin hole. Since the section modulus of each of the other plate portions is larger, the strength of the stepped portion of the outer plate that tends to cause fatigue failure during chain operation can be improved.

  According to the oil-free chain of the present invention according to claim 5, in addition to the effect produced by the oil-free chain according to any one of claims 1 to 4, the bulging surface of the annular bulging portion for bushing shaft support The outer surface of the inner plate is provided with a rough surface that forms a labyrinth structure facing each other, so that an oil reservoir labyrinth is provided between the bulging surface of the annular bulging portion for bushing shaft support and the outer surface of the inner plate. Since the structure is formed, the sealing effect of the lubricating oil injected between the connecting pin and the bushing can be further improved, and the external leakage and external dust of the lubricating oil injected between the bushing and the connecting pin can be improved. Can be prevented from entering.

  According to the oilless chain of the present invention according to claim 6, in addition to the effect produced by the oilless chain according to claim 5, the bulging amount Dj from the inner surface of the outer plate of the annular bulging portion for bushing shaft support and Since the protrusion amount Db of the bushing protruding end portion from the outer surface of the inner plate satisfies Dj <Db, the inner link skews and swings with respect to the outer link in the chain width direction during chain operation. Even when moving or unevenly distributed, the end surface of the bushing with low sliding contact resistance and the inner surface of the outer plate come into contact with each other, and the bulging surface and inner plate of the annular bulging portion for bushing shaft support with high sliding contact resistance Since the contact with the outer surface of the chain is completely prevented, the chain can be bent and slid smoothly over a long period of time.

  According to the oilless chain of the present invention according to claim 7, in addition to the effect produced by the oilless chain according to any of claims 1 to 6, the inside of the outer plate of the annular bulging portion for bushing shaft support The bulging amount Dj from the side surface, the protruding amount Db of the bushing protruding end portion from the outer surface of the inner plate, the inner width Do of the outer link, and the outer width Di of the inner link satisfy Do-Dj <Di + 2Db <Do. By forming each, the bushing protruding end portion of the bushing shaft support ring swells even when the inner link skews, swings or deviates in the chain width direction with respect to the outer link during chain operation. Since it does not come off from the protruding part and the lubricating oil does not leak to the outside, the sliding contact wear between the outer peripheral surface of the connecting pin and the inner peripheral surface of the bush can be reduced over a long period of time, and the wear elongation of the chain can be reduced. Further prevent Door can be.

  According to the oil-free chain of the present invention according to claim 8, in addition to the effect of the oil-free chain according to any one of claims 1 to 7, the bulge surface of the annular bulge portion for supporting the bushing shaft is provided. The inner diameter Wji, the inner diameter Wbi of the bush, the outer diameter Wbo of the bushing, and the outer diameter Wp of the connecting pin are formed so as to satisfy Wji-Wbo> Wbi-Wp, respectively, thereby receiving a tensile force in the chain traveling direction. Even when the inner peripheral surface of the bush and the outer peripheral surface of the connecting pin come into contact with each other when the inner link is unevenly distributed in the chain traveling direction with respect to the outer link, the outer peripheral surface of the bush protruding end and the bush Since it completely prevents the inner peripheral surface of the annular bulging part for shaft support from coming into contact with each other, sliding contact between the outer peripheral surface of the bushing projecting end and the inner peripheral surface of the annular bulging part for bushing shaft support Caused by metal wear powder and connecting pins Such metal wear powder is used as an abrasive to prevent abnormal wear damage that tends to occur between the connecting pin and the bush, and greatly prevents chain wear elongation. be able to.

  The present invention provides an inner link formed by press-fitting both ends of a pair of front and rear bushes into bush press-fitting holes of a pair of left and right inner plates, and both ends of a pair of front and rear connecting pins penetrating into the bush. The outer links formed by press-fitting and fitting into the pin press-fitting holes of the outer plate are alternately connected in the longitudinal direction of the chain, and the lubricant is sealed between the inner peripheral surface of the bush and the outer peripheral surface of the connecting pin. In the oil supply chain, a bush protruding end portion that partially protrudes from the outer surface of the inner plate is an annular bulging portion for bushing shaft support that is recessed from the outer surface of the outer plate and bulges to the inner surface in an offset state. Each is supported by a go to significantly reduce the chain manufacturing burden while avoiding a decrease in plate strength and an increase in the number of chain parts, and also prevents leakage of lubricating oil and intrusion of external dust during chain operation. In addition, if the bush exhibits excellent lubricating oil release characteristics and supplies the lubricating oil between the outer peripheral surface of the connecting pin and the inner peripheral surface of the bush over a long period of time, its specific There is no limitation on the embodiment.

  For example, the oil-free chain of the present invention may be either a roller chain or a bush chain. However, in the case of a roller chain, since the meshing with the sprocket becomes smooth, the wear of the chain Is more preferable.

In addition, a specific aspect of the bush incorporated in the oil-free chain of the present invention is obtained by compression molding metal powder so as to have innumerable pores therein and sintering at a temperature below the melting point. As long as it is molded from a sintered oil-impregnated metal material impregnated with a lubricant in a porous material and exhibits toughness and sustained release of the lubricant, the sintered density of the sintered oil-impregnated metal material and its raw materials Any specific type or combination of metal powders may be used. In particular, the sintered oil-impregnated metal material compresses and forms a mixed metal powder containing iron, copper, nickel, chromium molybdenum steel, or the like. together if it is molded by sintering at a sintering density of 6.0g ^/ cm ³ ~7.0g / cm 3, the toughness for receiving the shear and impact force bushing due to chain tension performance And much lubrication The can be sufficiently exerted both oil-bearing performance and sustained performance supplies lubricating oil combines good balance between the impregnated connecting pin and the bushing for a long time.

  Further, the specific type of lubricating oil used in the oil-free chain of the present invention may be any as long as it has lubricity and resistance to deterioration, in particular, poly α olefin, polyol ester, etc. When synthetic oils based on synthetic hydrocarbons are used, they exhibit excellent viscosity, lubricity, and deterioration resistance without causing clogging of the pores formed inside the bush. It oozes out from the air hole of the bush between the connecting pin and the bush over a long period of time and can suppress sliding contact wear.

In addition, the specific shape of the oil sump groove in the oil-free chain of the present invention may be any of a D-cut groove, an annular groove provided around the outer peripheral surface of the connecting pin, etc. In the case of a cut groove, more lubricating oil can be sealed without reducing the strength of the connecting pin, which is more preferable.
In addition, the number of oil retaining grooves in the oil-free chain of the present invention may be any one provided on the outer peripheral surface of the connecting pin, or two provided on the outer peripheral surface of the connecting pin.

  In addition, the specific shape of the bushing protruding end portion in the oil-free chain of the present invention may be any one in which the outer peripheral surface is formed in a circular shape, or the outer peripheral surface is formed in a polygonal shape.

Hereinafter, the oil-free chain 100 which is 1st Example of this invention is demonstrated based on drawing.
Here, FIG. 1 is an overall schematic view in which a part of the oil-free chain according to the first embodiment of the present invention is cut out, and FIG. 2 is a perspective view showing a connected state of the oil-free chain shown in FIG. FIG. 3 is a partially enlarged cross-sectional view of the oil-free chain shown in FIG. 1, and FIG. 4 is a perspective view of the bush incorporated in the oil-free chain shown in FIG. 5 is an assembly dimension diagram of the oil-free chain shown in FIG. 1, FIG. 6 is a dimension diagram showing a state in which the oil-free chain of FIG. 1 is offset in the chain width direction, and FIG. It is a dimension figure which shows the state by which the oil-free chain of this is pulled in the chain advancing direction.

First, as shown in FIGS. 1 and 3, the oil-free chain 100 according to the first embodiment of the present invention includes rollers 120 and 120 in the bush press-fitting holes of the inner plates 110 and 110 that are spaced apart from each other on the left and right sides. A pair of front and rear bushings 130, 130 on which both ends of the inner link 140 are fitted and fixed, and a pair of front and rear connecting pins 160 in the pin press-fitting holes of the outer plates 150, 150 arranged separately on the left and right sides, The outer link 170 having both ends of 160 inserted and fixed thereto is provided, and the inner link 140 and the outer link 170 are connected by loosely fitting the connecting pin 160 to the bush 130.
A lubricating oil is sealed between the bush 130 and the connecting pin 160.

Therefore, specific forms of the bush 130, the outer plate 150, and the inner plate 110, which are the most characteristic features of the oil-free chain 100 of the present embodiment, will be described in detail with reference to FIGS.
First, as shown in FIGS. 2 and 3, the outer plate 150 has an outer surface recessed, that is, an annular bulge for supporting a bushing shaft bulged on the inner surface in an offset state where the outer surface is recessed. A portion 151 is formed, and bushing protruding end portions 131 partially protruding from the outer surface of the inner plate 110 are surrounded and supported by the bushing shaft supporting annular bulging portion 151.
The “offset state” in the oil-free chain 100 of the present invention means a state where the annular bulging portion 151 for bushing shaft support and the other plate portions are displaced and exhibit a step shape. Yes.

As shown in FIG. 4, the bush 130 is obtained by compressing and sintering a sintered oil-impregnated metal material, that is, a metal powder so as to have innumerable pores 132 therein, and sintering it at a temperature below the melting point. The porous material is molded from a metal material impregnated with lubricating oil, and therefore impregnated in the infinite number of pores 132 formed in the bush 130 due to centrifugal force or the like generated by circular travel during chain operation. The lubricated oil gradually oozes between the outer peripheral surface of the connecting pin 160 and the inner peripheral surface of the bush 130.
Incidentally, the sintered density of the sintered oil-impregnated metallic material, iron, copper, ^{nickel, 6.0g / cm 3 ~7.0g / cm} 3 with compressed form the mixed metal powder obtained by blending such as chromium molybdenum steel Therefore, the bushing 130 has a tough performance for receiving a shearing force and an impact force due to chain tension, and is impregnated with a large amount of lubricating oil so that the connecting pin 160 can be impregnated for a long time. Both the oil impregnation performance and the sustained release performance for supplying lubricating oil between the outer peripheral surface of the bushing 130 and the inner peripheral surface of the bush 130 are well balanced and sufficiently exerted.
Further, in the oil-free chain 100 of this embodiment, a synthetic oil based on a synthetic hydrocarbon such as poly-α-olefin or polyol ester is used as the lubricating oil, and has excellent viscosity, lubricity, and deterioration resistance. The outer peripheral surface of the connecting pin 160 and the inner peripheral surface of the bush 130 are stable from the air holes 132 of the bush 130 over a long period of time without causing clogging of the air holes 132 formed inside the bush 130. It oozes out during this time to suppress sliding contact wear.

As shown in FIG. 3, the bulging surface 151 a of the annular bulging portion 151 for bushing shaft support and the outer surface of the inner plate 110 have rough surfaces 152, 111 having a matte-like labyrinth structure, respectively. forming rough surfaces 152,111 is to form an oil reservoir labyrinth structure L ₂ between the outer surface of the bulged surface 151a and the inner plate 110 of the bushing journaling annular swelling portion 151 proximate opposed to each other, The external leakage of the lubricating oil injected between the bush 130 and the connecting pin 160 is suppressed and the entry of external dust is prevented.

As shown in FIG. 5, the outer diameter Wjo of the bulging surface 151 a of the bushing shaft supporting annular bulging portion 151 is set to be larger than the outer diameter Wxo of the recessed surface 151 b of the bushing shaft supporting annular bulging portion 151. The section coefficient of the step portion formed on the outer plate 150, that is, the plate portion having a diameter larger than the outer diameter Wxo of the recessed surface 151b and smaller than the outer diameter Wjo of the bulging surface 151a around the pin hole, The section modulus of the plate portion is larger.
Further, as shown in FIG. 5, the inner diameter Wji of the bulging surface 151a of the bush shaft supporting annular bulging portion 151 is set to be smaller than the inner diameter Wxi of the recessed surface 151b of the bushing shaft supporting bulging portion 151. The step factor formed on the outer plate 150, that is, the section coefficient of the plate portion having a diameter larger than the inner diameter Wji of the bulging surface 151a and smaller than the inner diameter Wxi of the recessed surface 151b with the pin hole as the center, is the other plate portion. It is designed to be larger than the section modulus.

  As shown in FIG. 5, the amount of protrusion Dj from the inner surface of the outer plate 150 of the annular bulging portion 151 for bushing shaft support and the amount of protrusion Db from the outer surface of the inner plate 110 of the bushing protruding end 131 are as shown in FIG. Each is formed so as to satisfy <Db, and as shown in FIG. 6, even when the inner link 140 is skewed, swung, or unevenly distributed in the chain width direction with respect to the outer link 170 when the chain is in operation, The end face of the bushing 130 having a small sliding contact resistance and the inner side surface of the outer plate 150 are in contact with each other, and the bulging surface 151a of the bushing shaft support annular bulging portion 151 having a large sliding contact resistance and the outer surface of the inner plate 110 are brought together. It completely prevents contact.

A bulging amount Dj from the inner surface of the outer plate 150 of the annular bulging portion 151 for bushing shaft support, a protruding amount Db from the outer surface of the inner plate 110 of the bushing protruding end portion 131, an inner width Do and inner of the outer link 170 As shown in FIG. 5, the outer width Di of the link 140 is formed so as to satisfy Do−Dj <Di + 2Db <Do, so that, as shown in FIG. Even when skew, swing, or offset occurs in the chain width direction with respect to the link 170, the bushing protruding end portion 131 does not come off from the bushing shaft support annular bulging portion 151, and the lubricating oil Therefore, the sliding wear between the outer peripheral surface of the connecting pin 160 and the inner peripheral surface of the bush 130 is reduced over a long period of time.
The “inner width Do of the outer link 170” as referred to in the oil-free chain 100 of the present invention means an interval at which the inner surfaces of the outer plates 150 and 150 arranged in a pair of left and right are separated from each other. Yes.
Further, the “outer width Di of the inner link 140” in the oil-free chain 100 of the present invention means an interval at which the outer surfaces of the inner plates 110 and 110 arranged in a pair of left and right are separated from each other. Yes.

  As shown in FIG. 5, the inner diameter Wji of the bulging surface 151a of the annular bulging portion 151 for bushing shaft support, the inner diameter Wbi of the bushing 130, the outer diameter Wbo of the bushing 130, and the outer diameter Wp of the connecting pin 160 are Wji-Wbo> Each is formed so as to satisfy Wbi-Wp, and as shown in FIG. 7, when the chain receives a tensile force in the chain moving direction, that is, the inner link 140 is unevenly distributed in the chain moving direction with respect to the outer link 170. In this case, the inner peripheral surface of the bush 130 and the outer peripheral surface of the connecting pin 160 come into contact with each other, and the outer peripheral surface of the bushing protruding end portion 131 and the inner peripheral surface of the bush shaft support annular bulging portion 151 come into contact with each other. It is designed to completely prevent this.

In the oilless chain 100 of this embodiment obtained in this way, the bushing protruding end portion 131 that partially protrudes from the outer surface of the inner plate 110 dents the outer surface of the outer plate 150 in the offset state. Are respectively supported by the annular bulging portion 151 for supporting the bushing shaft.
Accordingly, the oil reservoir labyrinth structure L _1, which is formed between the inner surface of such a bush projecting end 131 and the bushing shaft journaling annular swelling portion 151 and the outer plate 150, the circumferential travel during operation of the chain It is possible to prevent the lubricating oil from leaking due to the generated centrifugal force and the like, and to suppress the intrusion of external dust, thereby preventing the chain from being worn out for a long time.

An annular bulging portion 151 for bushing shaft support is formed in an offset state in which the outer surface of the outer plate 150 is recessed and bulged to the inner surface.
Therefore, the section modulus of the bush shaft supporting annular bulging portion 151 and the section modulus of the other plate portions are approximately the same, so that the strength of the outer plate 150 by forming the bush shaft supporting annular bulging portion 151 is increased. It is possible to suppress the lowering, and when the outer plate 150 is subjected to press punching, the outer plate 150 can be punched only by using a mold having a shape in which the outer surface of the outer plate 150 is recessed and bulged to the inner surface. Since the forming process of the annular bulging portion 151 for the bushing shaft can be performed at the same time, machining such as grinding or milling for forming the annular bulging portion 151 for the bushing shaft is performed separately from the punching processing of the outer plate 150. Is not required to be applied to the outer plate 150, and the manufacturing burden of the chain can be reduced.

  Between the inner plate 110 and the outer plate 150, a seal member arranged in a pressed state between the bush and the outer link plate like a conventional seal chain is not provided as a separate part, so that the chain can be smoothly operated. While bending and traveling around, an increase in the number of chain parts can be avoided.

  In conventional seal chains, surface finish processing that reduces the surface roughness on the outer surface of the inner link plate and the inner surface of the outer link plate to prevent sliding contact wear of the seal member and maintain the sealing performance of the lubricating oil However, in the oil-free chain 100 of the present invention, it is not necessary to perform the conventional surface finishing process, and the manufacturing burden of the chain can be reduced.

The bush 130 is formed from a sintered oil-impregnated metal material impregnated with a lubricating oil.
Therefore, even when the lubricating oil is not sufficiently supplied between the outer peripheral surface of the connecting pin 160 and the inner peripheral surface of the bush 130, the bush 130 exhibits an excellent gradual release property of the lubricating oil, That is, the lubricating oil impregnated in the countless pores 132 formed inside the bush 130 due to centrifugal force or the like generated by the circular running during the chain operation is applied to the outer peripheral surface of the connecting pin 160 and the inner peripheral surface of the bush 130. Ooze out gradually during this time, so that sliding wear between the outer peripheral surface of the connecting pin 160 and the inner peripheral surface of the bush 130 can be reduced to prevent the chain from being stretched over a long period of time. The bush 130 made of a metal material has the same shape as a normal bush that has not been processed at all, and can be handled in the same way as a normal bush. It can be.

The outer diameter Wjo of the bulging surface 151a of the bushing shaft support annular bulging portion 151 is set to be larger than the outer diameter Wxo of the recessed surface 151b of the bushing shaft support annular bulging portion 151.
Therefore, the section coefficient of the step portion formed in the outer plate 150, that is, the plate portion having a diameter larger than the outer diameter Wxo of the recessed surface 151b and smaller than the outer diameter Wjo of the bulging surface 151a around the pin hole, is Therefore, the strength of the stepped portion of the outer plate 150 that tends to cause fatigue failure during chain operation can be improved.

An inner diameter Wji of the bulging surface 151a of the bush shaft supporting annular bulging portion 151 is set to be smaller than an inner diameter Wxi of the recessed surface 151b of the bushing shaft supporting annular bulging portion 151.
Therefore, the step coefficient formed on the outer plate 150, that is, the section coefficient of the plate portion having a diameter larger than the inner diameter Wji of the bulging surface 151a and smaller than the inner diameter Wxi of the recessed surface 151b around the pin hole, Since it becomes larger than the section modulus of the plate portion, it is possible to improve the strength of the step portion of the outer plate 150 that tends to cause fatigue failure during chain operation.

The bulging surface 151a of the annular bulging portion 151 for bushing shaft support and the outer surface of the inner plate 110 are provided with labyrinth structure forming rough surfaces 152 and 111 that are close to each other.
Thus, between the bushing axis journaling since labyrinth structure L ₂ oil reservoir between the outer surface of the bulged surface 151a and the inner plate 110 of the annular swelling portion 151 is formed, the connecting pin 160 and the bushing 130 Thus, the sealing effect of the lubricating oil injected into the bushing can be further improved, and external leakage of the lubricating oil injected between the bush 130 and the connecting pin 160 and the entry of external dust can be prevented.

The bulge amount Dj from the inner side surface of the outer plate 150 of the annular bulging portion 151 for bushing shaft support and the projection amount Db from the outer surface of the inner plate 110 of the bushing protruding end portion 131 satisfy Dj <Db. Each is formed.
Therefore, even when the inner link 140 is skewed, swung, or unevenly distributed in the chain width direction with respect to the outer link 170 when the chain is in operation, the end surface of the bush 130 having a small sliding resistance and the inner surface of the outer plate 150 are Since the contact with each other and the contact between the bulging surface 151a of the bushing shaft support annular bulging portion 151 having a large sliding contact resistance and the outer surface of the inner plate 110 are completely prevented, the chain can be smoothly bent over a long period of time. Sliding can be realized.

A bulging amount Dj from the inner surface of the outer plate 150 of the annular bulging portion 151 for bushing shaft support, a protruding amount Db from the outer surface of the inner plate 110 of the bushing protruding end portion 131, an inner width Do and inner of the outer link 170 The outer width Di of the link 140 is formed so as to satisfy Do-Dj <Di + 2Db <Do.
Therefore, even when the inner link 140 is skewed, swung, or displaced in the chain width direction with respect to the outer link 170 during the operation of the chain, the bushing protruding end portion 131 has the bushing shaft support annular bulging portion 151. In addition, since the lubricating oil does not leak to the outside, the sliding wear between the outer peripheral surface of the connecting pin 160 and the inner peripheral surface of the bush 130 can be reduced over a long period of time, and the chain wear elongation can be reduced. Further prevention can be achieved.

The inner diameter Wji of the bulging surface 151a of the annular bulging portion 151 for bushing shaft support, the inner diameter Wbi of the bush 130, the outer diameter Wbo of the bush 130, and the outer diameter Wp of the connecting pin 160 satisfy Wji−Wbo> Wbi−Wp. Are formed respectively.
Therefore, when the chain is subjected to a tensile force in the chain traveling direction, that is, when the inner link 140 is unevenly distributed in the chain traveling direction with respect to the outer link 170, the inner peripheral surface of the bush 130 and the outer peripheral surface of the connecting pin 160 are Even if they come into contact with each other, the outer peripheral surface of the bushing protruding end portion 131 and the inner peripheral surface of the bushing shaft support annular bulging portion 151 are completely prevented from contacting each other. Metal wear powder due to sliding contact with the inner peripheral surface of the axially bulging portion 151 for the shaft support enters between the connecting pin 160 and the bush 130, and such metal wear powder becomes an abrasive and is connected. Abnormal wear damage that tends to occur between the pin 160 and the bushing 130 can be prevented, and the wear elongation of the chain can be greatly prevented.

Next, an oil-free chain 200 according to a second embodiment of the present invention will be described with reference to FIGS.
First, as shown in FIGS. 8 and 9, the oil-free chain 200 according to the second embodiment of the present invention includes rollers 220 and 220 in the bush press-fitting holes of the inner plates 210 and 210 that are spaced apart from each other on the left and right sides. A pair of front and rear bushings 230, in which both ends of the bushes 230 are inserted and fixed, and a pair of front and rear connecting pins 260 are inserted into pin press-fit holes of the outer plates 250 and 250 that are spaced apart from each other on the left and right. The outer link 270 is inserted and fixed at both ends of the inner link 260. The inner link 240 and the outer link 270 are connected to each other by fitting the connecting pin 260 to the bush 230.
And between the bush 230 and the connecting pin 260, lubricating oil is enclosed.

Therefore, specific forms of the bush 230, the outer plate 250, the inner plate 210, and the connecting pin 260, which are the most characteristic features of the oil-free chain 200 of this embodiment, will be described in detail with reference to FIGS.
First, as shown in FIGS. 8 and 9, the outer plate 250 has an outer surface recessed, that is, an annular bulge for supporting a bushing shaft bulged on the inner surface in an offset state where the outer surface is recessed. A portion 251 is formed, and a bush protruding end portion 231 that partially protrudes from the outer surface of the inner plate 210 is surrounded and supported by the bush shaft supporting annular bulging portion 251.
In addition, the “offset state” in the oil-free chain 200 of the present invention means a state where the annular bulging portion 251 for bushing shaft support and the other plate portions are shifted and exhibit a stepped shape. Yes.

The bush 230 is made of a sintered oil-impregnated metal material, that is, a lubricating material applied to a porous material obtained by compression-molding a metal powder so as to have countless pores inside and sintering at a temperature below the melting point. It is formed from the impregnated metal material. Therefore, the lubricating oil impregnated in the countless pores formed in the bush 230 due to the centrifugal force or the like generated by the circular traveling during the chain operation is connected to the connecting pin 260. It gradually oozes between the outer peripheral surface and the inner peripheral surface of the bush 230.
Incidentally, the sintered density of the sintered oil-impregnated metallic material, iron, copper, ^{nickel, 6.0g / cm 3 ~7.0g / cm} 3 with compressed form the mixed metal powder obtained by blending such as chromium molybdenum steel Therefore, the bushing 230 has a tough performance for receiving a shearing force and an impact force due to the chain tension, and is impregnated with a large amount of lubricating oil so that the connecting pin 260 can be impregnated for a long time. Both the oil impregnation performance for supplying the lubricating oil and the sustained release performance between the outer peripheral surface of the bushing 230 and the inner peripheral surface of the bush 230 are well balanced and sufficiently exerted.
Further, in the oil-free chain 200 of this embodiment, a synthetic oil based on a synthetic hydrocarbon such as poly-α-olefin or polyol ester is used as the lubricating oil, and has excellent viscosity, lubricity, and deterioration resistance. The air gap between the outer peripheral surface of the connecting pin 260 and the inner peripheral surface of the bushing 230 can be stably extended from the pores of the bushing 230 over a long period of time without causing clogging of the pores formed inside the bushing 230. It oozes out and suppresses sliding contact wear.

  As shown in FIGS. 8 and 9, an oil reservoir groove 261 that supplies lubricating oil is formed between the inner peripheral surface of the bush 230 and the outer peripheral surface of the connection pin 260 on the outer peripheral surface of the connection pin 260. Thus, a larger amount of lubricating oil is enclosed, and the lubricating oil is continuously supplied between the connecting pin 260 and the bushing 230.

As shown in FIG. 9, the bulging surface 251a of the annular bulging portion 251 for bushing shaft support and the outer surface of the inner plate 210 have matte surface labyrinth structure forming rough surfaces 252 and 211, respectively. forming rough surfaces 252,211 is to form an oil reservoir labyrinth structure L ₂ between the outer surface of the bulged surface 251a and the inner plate 210 of the bushing journaling annular swelling portion 251 proximate opposed to each other, The external leakage of the lubricating oil injected between the bushing 230 and the connecting pin 260 is suppressed and the entry of external dust is prevented.

The outer diameter of the bulging surface 251 a of the bush shaft supporting annular bulging portion 251 is set to be larger than the outer diameter of the recessed surface 251 b of the bushing shaft supporting annular bulging portion 251, and the step portion formed on the outer plate 250. That is, the section modulus of the plate portion having a diameter larger than the outer diameter of the recessed surface 251b and smaller than the outer diameter of the bulging surface 251a around the pin hole is larger than the section modulus of the other plate portions. It has become.
In addition, the inner diameter of the bulging surface 251 a of the bush shaft supporting annular bulging portion 251 is set to be smaller than the inner diameter of the recessed surface 251 b of the bushing shaft supporting annular bulging portion 251, and the step portion formed on the outer plate 250. That is, the section modulus of the plate portion that is larger than the inner diameter of the bulging surface 251a and smaller than the inner diameter of the recessed surface 251b around the pin hole is larger than the section modulus of the other plate portions. Yes.

  The protruding amount Dj from the inner surface of the outer plate 250 of the annular bulging portion 251 for bushing shaft support and the protruding amount Db from the outer surface of the inner plate 210 of the bushing projecting end portion 231 satisfy Dj <Db. The inner link 240 is skewed, oscillated, or unevenly distributed in the chain width direction with respect to the outer link 270 when the chain is in operation, and the end face of the bushing 230 having a small sliding resistance and the outer plate 250 The inner side surfaces are in contact with each other, and the bulging surface 251a of the bushing shaft supporting annular bulging portion 251 having a large sliding contact resistance and the outer surface of the inner plate 210 are completely prevented from contacting each other.

A bulging amount Dj from the inner surface of the outer plate 250 of the annular bulging portion 251 for bushing shaft support, a protruding amount Db from the outer surface of the inner plate 210 of the bushing protruding end portion 231, an inner width Do and an inner portion of the outer link 270. Since the outer width Di of the link 240 is formed so as to satisfy Do-Dj <Di + 2Db <Do, the inner link 240 is skewed and swung in the chain width direction with respect to the outer link 270 during chain operation. Alternatively, the bush protruding end portion 231 does not come off from the bushing shaft support annular bulging portion 251 even when the offset occurs, and the lubricating oil does not leak to the outside. The sliding contact wear between the outer peripheral surface and the inner peripheral surface of the bushing 230 is reduced over a long period of time.
The “inner width Do of the outer link 270” referred to in the oil-free chain 200 of the present invention means an interval at which the inner surfaces of the outer plates 250 and 250 arranged in a pair of left and right are separated from each other. Yes.
Further, the “outer width Di of the inner link 240” in the oil-free chain 200 of the present invention means an interval at which the outer surfaces of the inner plates 210 and 210 arranged in a pair of left and right are separated from each other. Yes.

  The inner diameter Wji of the bulging surface 251a of the annular bulging portion for bushing shaft support 251, the inner diameter Wbi of the bushing 230, the outer diameter Wbo of the bushing 230, and the outer diameter Wp of the connecting pin 260 satisfy Wji−Wbo> Wbi−Wp. When the chain is subjected to a tensile force in the chain traveling direction, that is, when the inner link 240 is unevenly distributed in the chain traveling direction with respect to the outer link 270, the inner peripheral surface of the bush 230 and the connecting pin 260 are connected. The outer peripheral surface of the bushing protruding end portion 231 and the inner peripheral surface of the bushing shaft supporting annular bulging portion 251 are completely prevented from contacting each other.

The oil-free chain 200 of this embodiment obtained in this way has the bushing protruding end portion 231 that partially protrudes from the outer surface of the inner plate 210, which causes the outer surface of the outer plate 250 to be recessed and the inner surface in an offset state. Are respectively supported by the annular bulging portions 251 for supporting the bushing shaft.
Accordingly, the oil reservoir labyrinth structure L _1, which is formed between the inner surface of such a bush projecting end 231 and the bushing shaft journaling annular swelling portion 251 and the outer plate 250, the circumferential travel during operation of the chain It is possible to prevent the lubricating oil from leaking due to the generated centrifugal force and the like, and to suppress the intrusion of external dust, thereby preventing the chain from being worn out for a long time.

The bush shaft support annular bulging portion 251 is formed in an offset state in which the outer surface of the outer plate 250 is recessed and bulged to the inner surface.
Therefore, the section modulus of the bush shaft supporting annular bulging portion 251 and the section modulus of the other plate portions are approximately the same, so that the strength of the outer plate 250 by forming the bush shaft supporting annular bulging portion 251 is increased. It is possible to suppress the lowering, and when performing the press punching of the outer plate 250, it is possible to perform the punching of the outer plate 250 only by using a mold having a shape in which the outer surface of the outer plate 250 is recessed and bulged to the inner surface. Since the processing for forming the bush bulge annular bulging portion 251 can be performed at the same time, machining such as grinding or milling for forming the bush bulge annular bulging portion 251 is performed separately from the punching processing of the outer plate 250. Is not required to be applied to the outer plate 250, and the manufacturing burden of the chain can be reduced.

  Between the inner plate 210 and the outer plate 250, there is no separate sealing member disposed in a pressed state between the bush and the outer link plate as in the conventional seal chain, so that the chain can be operated smoothly. While bending and traveling around, an increase in the number of chain parts can be avoided.

  In conventional seal chains, surface finish processing that reduces the surface roughness on the outer surface of the inner link plate and the inner surface of the outer link plate to prevent sliding contact wear of the seal member and maintain the sealing performance of the lubricating oil However, in the oil-free chain 200 of the present invention, it is not necessary to perform the conventional surface finishing process, and the manufacturing burden of the chain can be reduced.

The bush 230 is formed from a sintered oil-impregnated metal material impregnated with a lubricating oil.
Therefore, even when the lubricating oil is not sufficiently supplied between the outer peripheral surface of the connecting pin 260 and the inner peripheral surface of the bushing 230, the bushing 230 exhibits excellent gradual release of the lubricating oil, That is, the lubricating oil impregnated in countless pores formed inside the bushing 230 due to the centrifugal force generated by the circular running during the chain operation is generated between the outer peripheral surface of the connecting pin 260 and the inner peripheral surface of the bushing 230. Since it gradually oozes out in the meantime, the sliding contact wear between the outer peripheral surface of the connecting pin 260 and the inner peripheral surface of the bushing 230 can be reduced, and the wear elongation of the chain can be prevented over a long period of time. The bush 230 made of material has the same shape as a normal bush without any processing, and can be handled in the same way as a normal bush, so that disassembly and assembly work such as chain cut-off can be easily achieved. .

An oil sump groove 261 for supplying lubricating oil between the inner peripheral surface of the bushing 230 and the outer peripheral surface of the connecting pin 260 is formed on the outer peripheral surface of the connecting pin 260.
Therefore, since more lubricating oil can be enclosed and lubricating oil can be continuously supplied between the connecting pin 260 and the bushing 230, sliding wear between the outer peripheral surface of the connecting pin 260 and the inner peripheral surface of the bushing 230 can be prolonged. Thus, the wear elongation of the chain can be further prevented.

The outer diameter of the bulging surface 251a of the bush shaft supporting annular bulging portion 251 is set to be larger than the outer diameter of the recessed surface 251b of the bushing shaft supporting annular bulging portion 251.
Therefore, the step coefficient formed in the outer plate 250, that is, the section coefficient of the plate portion having a diameter larger than the outer diameter of the recessed surface 251b and smaller than the outer diameter of the bulging surface 251a around the pin hole, Since it becomes larger than the section modulus of the plate portion, it is possible to improve the strength of the stepped portion of the outer plate 250 that tends to cause fatigue failure during chain operation.

The inner diameter of the bulging surface 251a of the bush shaft supporting annular bulging portion 251 is set to be smaller than the inner diameter of the recessed surface 251b of the bushing shaft supporting annular bulging portion 251.
Therefore, the step coefficient formed in the outer plate 250, that is, the section coefficient of the plate portion having a diameter larger than the inner diameter of the bulging surface 251a around the pin hole and smaller than the inner diameter of the recessed surface 251b, Therefore, the strength of the stepped portion of the outer plate 250 that tends to cause fatigue failure during chain operation can be improved.

The bulging surface 251a of the annular bulging portion 251 for bushing shaft support and the outer surface of the inner plate 210 include labyrinth structure forming rough surfaces 252 and 211 that are close to each other.
Accordingly, the oil sump labyrinth structure L ₂ is formed between the bulging surface 251 a of the bush shaft supporting annular bulging portion 251 and the outer surface of the inner plate 210. The sealing effect of the lubricating oil injected into the seal can be further improved, and external leakage of the lubricating oil injected between the bushing 230 and the connecting pin 260 and entry of external dust can be prevented.

The protruding amount Dj from the inner surface of the outer plate 250 of the annular bulging portion 251 for bushing shaft support and the protruding amount Db from the outer surface of the inner plate 210 of the bushing projecting end portion 231 satisfy Dj <Db. Each is formed.
Therefore, even when the inner link 240 is skewed, swung, or unevenly distributed in the chain width direction with respect to the outer link 270 when the chain is in operation, the end surface of the bushing 230 having a small sliding resistance and the inner surface of the outer plate 250 are separated. Since the contact with each other and the bulging surface 251a of the annular bulging portion 251 for bushing shaft support having a large sliding contact resistance and the outer surface of the inner plate 210 are completely prevented, the chain can be bent smoothly over a long period of time. Sliding can be realized.

A bulging amount Dj from the inner surface of the outer plate 250 of the annular bulging portion 251 for bushing shaft support, a protruding amount Db from the outer surface of the inner plate 210 of the bushing protruding end portion 231, an inner width Do and an inner portion of the outer link 270 The outer width Di of the link 240 is formed so as to satisfy Do-Dj <Di + 2Db <Do.
Therefore, even when the inner link 240 is skewed, swung, or offset in the chain width direction with respect to the outer link 270 during the chain operation, the bushing protruding end portion 231 is the bushing shaft support annular bulging portion 251. In addition, since the lubricant does not leak to the outside, the sliding wear between the outer peripheral surface of the connecting pin 260 and the inner peripheral surface of the bushing 230 can be reduced over a long period of time, and the wear elongation of the chain can be reduced. Further prevention can be achieved.

The inner diameter Wji of the bulging surface 251a of the annular bulging portion for bushing shaft support 251, the inner diameter Wbi of the bushing 230, the outer diameter Wbo of the bushing 230, and the outer diameter Wp of the connecting pin 260 satisfy Wji−Wbo> Wbi−Wp. Are formed respectively.
Therefore, when the chain is subjected to a tensile force in the chain traveling direction, that is, when the inner link 240 is unevenly distributed in the chain traveling direction with respect to the outer link 270, the inner peripheral surface of the bush 230 and the outer peripheral surface of the connecting pin 260 are Even if they come into contact with each other, the outer peripheral surface of the bushing protruding end 231 and the inner peripheral surface of the bushing shaft support annular bulging portion 251 are completely prevented from contacting each other. Metal wear powder caused by sliding contact with the inner peripheral surface of the axially bulging portion 251 for the shaft support enters between the connecting pin 260 and the bushing 230, and such metal wear powder becomes an abrasive and is connected. Abnormal wear damage that tends to occur between the pin 260 and the bush 230 can be prevented, and the wear elongation of the chain can be largely prevented.

BRIEF DESCRIPTION OF THE DRAWINGS The whole schematic diagram which notched a part of oilless chain which is 1st Example of this invention. The perspective view which shows the connection state of the oil-free chain shown in FIG. FIG. 2 is a cross-sectional view of a part of the oil-free chain shown in FIG. The perspective view which expanded partially the bush integrated in the oil-free chain shown in FIG. The assembly dimension figure of the oil-free chain shown in FIG. The dimension drawing which shows the state which the oil-free chain of FIG. 1 offset in the chain width direction. The dimension drawing which shows the state by which the oil-free chain of FIG. 1 is pulled in the chain advancing direction. The perspective view which shows the connection state of the oil-free chain which is 2nd Example of this invention. FIG. 9 is a cross-sectional view of a part of the oil-free chain shown in FIG.

Explanation of symbols

100, 200 ... Oil-free chain 110, 210 ... Inner plate 111, 211 ... Labyrinth structure forming rough surface 120, 220 ... Roller 130, 230 ... Bush 131, 231 ... Bush protrusion End portions 140, 240 ... inner links 150, 250 ... outer plates 151, 251 ... annular bulging portions 151a, 251a for bushing shaft support ... bulging surfaces 151b, 251b ... recessed surfaces 152, 252 ... Labyrinth structure forming rough surface
160, 260 ... connecting pins 170, 270 ... outer link 261 ... oil sump grooves L ₁ , L ₂ ... oil sump labyrinth structure Dj ... outside the annular bulging portion for bushing shaft support The amount of bulging Db from the inner surface of the plate ... The amount of protrusion Do from the outer surface of the inner plate of the bushing protruding end ... The inner width Di of the outer link ... The outer width Wjo of the inner link ... The outer diameter Wji of the bulging surface of the annular bulging portion for the bush. The inner diameter Wbo of the bulging surface of the annular bulging portion for supporting the bushing shaft. The outer diameter Wbi of the bush. The inner diameter Wp of the bushing. Outer diameter Wxo ... Outer diameter Wxi of the recessed surface of the annular bulge for bushing shaft support ... Inner diameter of recessed surface of the annular bulging portion for bushing shaft

Claims (8)

Pins of a pair of left and right outer plates are connected to inner links formed by press-fitting both ends of a pair of front and rear bushes into bush press-fitting holes of a pair of left and right inner plates and a pair of front and rear connection pins penetrating into the bushes. In an oil-free chain in which outer links formed by press-fitting into press-fitting holes are alternately connected in the longitudinal direction of the chain, and lubricating oil is sealed between the inner peripheral surface of the bush and the outer peripheral surface of the connecting pin,
Bush protruding end portions that partially protrude from the outer surface of the inner plate are respectively surrounded and supported by an annular bulging portion for supporting the bushing shaft that bulges to the inner surface in an offset state by recessing the outer surface of the outer plate. An oil-free chain characterized by   2. The oil-free chain according to claim 1, wherein the bush is formed from a sintered oil-impregnated metal material impregnated with the lubricating oil.   The oil reservoir groove for supplying lubricating oil between the inner peripheral surface of the bush and the outer peripheral surface of the connecting pin is carved on the outer peripheral surface of the connecting pin. Oilless chain as described.   The bulge surface of the annular bulging portion for bushing shaft support has a larger outer diameter and smaller inner diameter than the recessed surface of the annular bulging portion for bushing shaft support. Item 4. The oil-free chain according to any one of items 3.   The bulging surface of the annular bulging portion for supporting the bushing shaft and the outer surface of the inner plate are provided with a rough surface forming a labyrinth structure facing each other in close proximity to each other. Oilless chain as described.   The bulging amount Dj from the inner surface of the outer plate of the annular bulging portion for supporting the bushing shaft and the protruding amount Db from the outer surface of the inner plate of the bushing protruding end are formed so as to satisfy Dj <Db. The oil-free chain according to claim 5.   The bulging amount Dj from the inner surface of the outer plate of the annular bulging portion for supporting the bushing shaft, the protruding amount Db from the outer surface of the inner plate of the bushing protruding end, the inner width Do of the outer link, and the outer width Di of the inner link. The oil-free chain according to any one of claims 1 to 6, wherein each of the oil-free chains is formed so as to satisfy Do-Dj <Di + 2Db <Do.   The inner diameter Wji, the inner diameter Wbi of the bush, the outer diameter Wbo of the bush, and the outer diameter Wp of the connecting pin are respectively formed so as to satisfy Wji-Wbo> Wbi-Wp. The oil-free chain according to any one of claims 1 to 7, wherein the oil-free chain is provided.

Images