JP2020143765A - Seal chain - Google Patents

Abstract

To solve a problem of a seal ring that a clearance between an inner plate and an outer plate becomes large and a length of a pin increases to increase a bending moment.SOLUTION: A recessed part 36 coaxially arranged with a bush hole 35 is formed on an outer surface 26a of an inner plate 26 and a seal ring 31 is housed in the recessed part. An inner surface of the outer plate 22 is formed by a flat surface, and the seal ring 31 is sandwiched between the recessed part and the flat surface. The structure narrows a clearance C between the inner plate 26 and the outer plate 22 to prevent increase of a length of a pin 23.SELECTED DRAWING: Figure 3

Description

The present invention relates to a chain such as a roller chain, and more particularly to a seal chain in which a seal ring for holding lubricating oil is sandwiched between an inner plate and an outer plate on a sliding surface between a pin and a bush.

Conventionally, as shown in FIG. 8, the seal chain 1 has an outer link 5 in which pins 3 are press-fitted into both ends of a pair of outer plates 2 and both ends of the pins are removed and fixed by caulking or the like, and a pair of inner plates. Inner links 10 in which bushes 7 are press-fitted and fixed to both ends of 6 and rollers 9 are loosely fitted into bushes 7 between inner plates 6 and pins 3 are fitted into bushes 7 and connected alternately and endlessly. Based on the roller chain, both ends of the bush 7 are partially projected from the outer surface 6a of the inner plate 6, and the seal ring 11 is sandwiched between the inner plate 6 and the outer plate 2 so as to surround the bush protruding 7a. It is composed of.

In the seal chain 1, the lubricating oil sealed between the pin 3 and the bush 7 is sealed with the seal ring 11, the relative movement between the pin 3 and the bush 7 is smoothed, and the seal chain 1 is bent for a long period of time. Keep smooth over. At this time, the clearance between the inner plate 6 and the outer plate 2 is defined by the bush protruding portion 7a, the crushing allowance of the seal ring 11 sandwiched between the two plates 6 and 2 is regulated, and the seal ring 11 is excessive. It is prevented from being worn early and further damaged by being crushed.

However, since the seal ring 11 is sandwiched between the outer surface 6a of the inner plate 6 made of a flat surface and the inner side surface 2a of the outer plate 2 also made of a flat surface, the seal chain 1 is sandwiched between both plates 2 and 2. The clearance of No. 6 becomes wider, the distance between the pair of outer plates 2 and 2 becomes wider, and the bending moment of the pin 3 fixed to the outer plate becomes larger. As a result, as shown by emphasizing in FIG. 8, the pin 3 is elastically bent and deformed, and the outer plate is elastically flexed and deformed so as to expand outward, thereby reducing the fatigue strength of the chain and reducing the fatigue strength of the chain. The tensile strength of the chain tends to decrease as the pin 3 falls off from the outer plate 2.

Further, as the outer plate 2 expands to the outside, the seal ring 11 is engaged between the bush protrusion 7a and the inner side surface 2a of the outer plate 2 on the outer side in the longitudinal direction of the outer plate 2, and the outer plate 2 is formed in the longitudinal direction. The crushing allowance of the seal ring becomes unstable such that the seal ring 11 is excessively crushed on the inside, and an unnatural force acts on the seal ring, which may hinder the accurate sealing function. This may hinder the smooth operation of the seal chain and shorten the life of the seal chain.

The bush 7 is formed by winding a plate-shaped member, by processing a round bar material, or by cutting a pipe material. Therefore, the accuracy of the bush, particularly its end face, is not high, and the end face of the bush protruding portion 7a may damage the seal ring.

Conventionally, a seal chain (roller chain) has been proposed in which a concave portion concentric with a pin hole is formed on the inner surface side of the outer plate and a convex portion is formed on the outer surface side, and the seal ring is housed together with the bush protrusion in the concave portion. (See Patent Document 1).

JP-A-2018-179121

In the seal chain of Patent Document 1, since the bush protrusion and the seal ring are housed in the recess, the distance (clearance) between the outer plate and the inner plate can be reduced, but in order to secure the rigidity of the outer plate. , A convex portion is formed on the outer surface side of the outer plate in a shape corresponding to the concave portion, and the pin is lengthened by that amount. The outer plate has a concave portion on the inner surface side and a convex portion on the outer surface side to ensure rigidity without increasing the weight, and suppresses elastic bending of the pin and the resulting bending of the outer plate. Even so, the longer the pin, the larger the bending moment of the pin, which may cause bending deformation of the pin and bending of the outer plate in the spreading direction, similar to the conventional seal chain shown in FIG. large.

Further, since a recess is formed in the outer plate and the seal ring and the bush protrusion are housed in the recess, the bush and the pin are integrated with the pin because there is a predetermined gap for relative movement between the bush and the pin due to the bending of the chain. Relative movement due to the above gap occurs between the seal ring housed in the recess of the outer plate and the bush protrusion. As a result, the seal ring may be caught between the tip of the bush protrusion and the outer plate, and the seal ring may be prematurely worn or broken.

Therefore, an object of the present invention is to provide a seal chain that solves the above-mentioned problems by forming a recess for accommodating the seal ring on the outer surface of the inner plate.

In the present invention, a bush (35) is formed in an outer link (25) in which pins (23) are fixed to both ends of a pair of outer plates (22) and bush holes (35) formed in both ends of the pair of inner plates (26). The outer link (30) into which the 27) is press-fitted and the pin (23) are fitted into the bush (27) and connected alternately and in an endless manner, and the lubricating oil interposed between the pin and the bush is applied. In the seal chain (21) (21') sealed with the seal ring (31),
The inner surface (22a) of the outer plate (22) is made of a flat surface.
Recesses (36) (36') are formed on the outer surface (26a) of the inner plate (26) concentrically with the bush hole (35).
The seal ring (31) is housed in the recess, and a predetermined clearance (C) is provided between the inner surface (22a) of the outer plate and the outer surface (26a) of the inner plate. 31) is sandwiched between
It is in a seal chain that is characterized by that.

For example, with reference to FIGS. 1, 3 and 6, the tip thereof is the outer surface (26a) and the surface of the inner plate (26) between the inner diameter side of the recess (36) and the bush hole (35). It is partitioned by a single edge (37).

For example, referring to FIGS. 4 and 5, the recess (36') communicates with the bush hole (35).

It said sealing ring (31 ₁₎ is composed of a cross-section X-shaped.

It said sealing ring (31 ₂₎ consists of a cross-section O-shape.

For example, with reference to FIG. 6, the sealing ring (31 ₁₎ is composed of four lips (a, b, c, d) cross-sectional X-shape having, in one of said four lips The lip (a) has a circular tip and is wider than the other lips (b, c, d), and the tip of the edge (37) and the inner surface (22a) of the outer plate (22). ).

The clearance (C) is 2 to 5% of the diameter of the pin (23) and is set wider than the gap (G) between the pin (23) and the bush (27).

The reference numerals in parentheses are for comparison with the drawings, but do not affect the description of the claims.

The present seal chain according to claim 1 has a simple structure in which a recess is formed on the outer surface of the inner plate and the seal ring is stored in the recess, and the cost can be reduced, but the inside of the outer plate. The side surface is a flat surface, and the seal ring is housed in the recess, and the clearance between the inner plate and the outer plate is sufficient with a relatively narrow gap which is almost the same as that of a normal unsealed chain. As a result, the pin does not become long, the bending moment of the pin is prevented from increasing, the bending deformation of the pin and the expansion and bending deformation of the outer plate are reduced, and the fatigue strength and the tensile strength of the seal chain are improved. it can. In addition, it is possible to reduce the change in the crushing allowance of the seal ring, prevent excessive crushing of the seal ring by the above clearance, and maintain the seal function of the seal ring for a long period of time.

According to the second aspect of the present invention, since the concave portion is partitioned from the bush hole at the edge portion, the accuracy of the inner diameter side surface of the concave portion, particularly the edge portion, is improved, and the contact accuracy with the seal ring is improved to seal the seal. The wear and breakage of the ring can be reduced.

According to the third aspect of the present invention, since the concave portion communicates with the bush hole, the concave portion can be easily formed and the productivity can be improved.

According to the fourth aspect of the present invention, since the seal ring is an X ring having an X-shaped cross section, the sealability can be improved and the frictional resistance due to the seal can be reduced.

According to the fifth aspect of the present invention, since the seal ring is an O-ring having an O-shaped cross section, cost reduction can be achieved.

According to the sixth aspect of the present invention, one lip of the X-shaped seal ring has a circular tip and is wide, and the one lip has two points, the tip of the edge and the inner surface of the outer plate. By contacting, the sealing property of the seal ring can be improved.

According to the seventh aspect of the present invention, the clearance is sufficient with a narrow gap of 2 to 5% of the diameter of the pin, and is wider than the gap between the pin and the bush, so that contact between the inner plate and the outer plate can be prevented.

The plan view which partially cross-sectioned the seal chain by embodiment of this invention. The perspective view which shows the outer plate. A partially enlarged cross-sectional view in which a seal ring having an X-shaped cross section is attached to a recess having an edge portion. A partially enlarged cross-sectional view in which a seal ring having an O-shaped cross section is attached to a recess communicating with the bush hole. An enlarged cross-sectional view showing an embodiment in which the concave portion of the inner plate communicates with the bush hole. An enlarged cross-sectional view showing an embodiment in which a recess of an inner plate is partitioned between a bush hole and an edge. A plan view of a part of a seal chain according to the embodiment of the present invention in which a tensile force is acting. A partial cross-sectional plan view showing a conventional seal chain.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the seal chain 21 has an outer link 25 in which pins 23 are press-fitted into both ends of a pair of outer plates 22 to be connected and both ends of the pins are crimped and removed, and both ends of the pair of inner plates 26. The basic structure is a roller chain in which the bush 27 is press-fitted and fixed to the portion, and the inner link 30 in which the roller 29 is loosely fitted to the bush 27 is alternately and endlessly connected.

The outer surface 26a of the inner plate 26 is made of a flat surface, and the outer surface 26a is formed with an annular recess 36 concentrically with the bush hole 35. The bush 27 is fixed by being press-fitted into the bush hole 35 so that both ends are substantially flush with the outer surface 26a of the inner plate 26. The recess 36 is partitioned from the bush hole 35 by an annular edge portion 37, and the tip surface of the edge portion 37 is flush with the outer surface 26a of the inner plate 26. Therefore, as shown in FIG. 2, the recess 36 is composed of three surfaces, an outer diameter side surface 36a, an inner diameter side surface 36b, and a bottom surface 36c, and is a concave groove independent of the bush 27 and the bush hole 35. As shown in FIG. 3, a seal ring 31 is housed in the recess 36, and the seal ring 31 is sandwiched between the inner plate 26 and the outer plate 22 with a predetermined crushing allowance, and the outer surface 26a of the inner plate 26 And the inner side surface 22a of the outer plate 22 face each other with a relatively narrow clearance C.

The seal ring 31 may be an X-seal ring having an X-shaped cross section as shown in FIG. 3, but is not limited to this, and may have any shape such as an O-seal ring having an O-shaped cross section (see FIG. 4). The clearance C between the inner plate 26 and the outer plate 22 may be a slight clearance for holding a predetermined crushing allowance of the seal ring 31, but the clearance G between the pin 23 and the bush 27 may be the clearance G between the inner plate and the outer plate. The clearance is set to be smaller than the above clearance C in order to avoid contact with the above clearance C. The clearance C is preferably 2 to 5% of the diameter of the pin 23 in order to reduce the bending moment of the pin and maintain the strength of the chain.

In the seal chain 21, a lubricating oil such as grease is injected between the pin 33 and the bush 27, and the lubricating oil is sealed in the seal ring 31. In the seal chain 21, the outer link 25 and the inner link 30 bend as the chain travels, and the pin 23 and the bush 27 move relative to each other during the bending, and the relative movement is sealed by the seal ring 31. It is done smoothly with lubricating oil.

The seal chain 21 has a simple structure in which the recess 36 is formed on the outer surface 26a of the inner plate 26, and the cost can be reduced. Further, in the seal chain 21, since the seal ring 31 is housed in the recess 36 formed in the inner plate 26, the clearance C between the inner plate 26 and the outer plate 22 is a slight distance and is outside. Since the inner side surface 22a of the plate 22 is made of a flat surface, the outer plate 22 has a predetermined rigidity while maintaining the plate shape. Therefore, the axial length of the pin 23 is longer by the slight clearance C than that of a normal roller chain without a seal ring, but the amount is extremely small and is substantially the same length as a normal roller chain. Is enough.

FIG. 7 shows the seal chain 21 of the present embodiment in a state where the same tensile load as that of the conventional seal chain 1 shown in FIG. 8 is applied. In this seal chain 21, since the pin 23 is not long, as shown in FIG. 7, the bending moment acting on the pin 23 via the outer plate 22 is also small, the bending deformation of the pin 23 is small, and the outer plate 22 The deflection deformation in the spreading direction is extremely small, and as a result, it has high resistance to fatigue strength and tensile strength. Further, the outer plate 22 is less flexed and deformed, and the seal ring 31 is housed in the recess 36 and the crushing allowance is regulated by the clearance C, so that the seal ring 31 is appropriately compressed and the deformation is not promoted.

Next, an embodiment partially modified according to FIG. 4 will be described. In the present embodiment, the shape of the recess for accommodating the seal ring 31 is different from that in the previous embodiment, and the other parts are the same. Therefore, the same reference numerals are given and the description thereof will be omitted. The recess 36'of the seal chain 21'communicates to the bush hole 35, and therefore, there is no edge 37 for partitioning the bush hole 35 and the recess 36 as in the previous embodiment. Sealing ring 31, while FIG. 4 in cross-section O-shaped ring (O-ring 31 ₂₎ is shown, cross-sectional X-shaped ring, as shown in FIG. 3 (X-ring 31 ₁₎ may be _used.

In the present embodiment, the inner plate 26 may be concentrically communicated with the bush hole 35 to form a recess 36', which facilitates manufacturing and further reduces costs. it can. In particular, recess 36 ', without the O-ring 31 ₂ from interfering with the bushing 27, compatibility is good, it is possible to achieve a further cost reduction by using the O-ring 31 _2.

The difference between the recess 36 formed of the independent annular recessed groove and the recess 36 ′ communicating with the bush hole 35 will be described with reference to FIGS. 5 and 6 when the X seal ring 31 ₁ is applied. In the natural state, the X-seal ring 31 ₁ has a cross-shaped cross section with the lip a, which is relatively wide and has a nearly circular tip, on the inner diameter side of the center (for details, see Japanese Patent Application Laid-Open No. 64-030946) See Kai 2006-349086). When the cross-shaped ring is mounted and sandwiched between the inner plate 26 and the outer plate 22, the cross-shaped ring rotates around the central lip a and the X-seal ring 31 _{1 having} an X-shaped cross section. It is installed as.

As shown in FIG. 5, in the X seal ring 31 ₁ mounted on the recess 36', a predetermined space e exists between the central lip a and the bush 27, and the central lip a is the inner side surface 22 a of the outer plate 22. The other lips b are in contact with the inner side surface 22a, and the lips c and d are in contact with the bottom surface 36c of the recess 36'. Therefore, the X seal ring 31 ₁ is in a mounted state sandwiched between the inner plate 26 and the outer plate 22 with a predetermined clearance C, and is sealed by a total of four contacts due to a predetermined crushing allowance.

As shown in FIG. 6, when the X seal ring 31 ₁ is attached to the recess 36, the central lip a comes into contact with the tip of the edge portion 37 to rotate the X seal ring 31 ₁ , and the central lip a has an edge. A relatively wide central lip a closely seals the tip portion of the portion 37 and the inner side surface 22a of the outer plate 22, and the clearance C for holding the lubricating oil. The other lip b of the X seal ring 31 ₁ contacts the inner side surface 22a, the lip c contacts the bottom surface 36c of the recess 36, and the lip b contacts the bottom surface 36c of the recess 36 and the corner of the inner diameter side surface 36b on the edge 37 side. Therefore, the X seal ring 31 ₁ is in a mounted state of being sandwiched between the inner plate 26 and the outer plate 22 with a predetermined clearance C, and the central lip b is in close contact with each other so as to seal the lubricating oil, for a total of five locations. Securely seals with high accuracy due to contact with.

Although the above embodiment is applied to a roller chain, it is not limited to this, and can be applied to an outer chain such as a bush chain without a roller. Further, by reducing the deformation of the pin and the outer plate, it is possible to reduce the diameter of the pin and the size and weight of the seal chain.

22 Outer plate 22a Inner side surface 23 Pin 25 Outer link 26 Inner plate 26a Outer side surface 27 Bush 29 Roller 31 Seal ring 31 ₁ X Seal ring 31 ₂ O Seal ring 35 Bush hole 36, 36'Recess 37 Edge

Claims (7)

An outer link in which pins are fixed to both ends of the pair of outer plates and an outer link in which bushes are press-fitted into bush holes formed at both ends of the pair of inner plates are alternately inserted by inserting the pins into the bushes. In a seal chain that is connected in an endless manner and the lubricating oil interposed between the pin and the bush is sealed with a seal ring.
The inner surface of the outer plate is a flat surface.
A recess is formed on the outer surface of the inner plate concentrically with the bush hole.
The seal ring is housed in the recess, and the seal ring is sandwiched between the inner surface of the outer plate and the outer surface of the inner plate with a predetermined clearance.
A seal chain characterized by that. The space between the inner diameter side of the recess and the bush hole is partitioned by an edge portion whose tip is flush with the outer surface of the inner plate.
The seal chain according to claim 1. The recess communicates with the bush hole.
The seal chain according to claim 1. The seal ring has an X-shaped cross section.
The seal chain according to any one of claims 1 to 3. The seal ring has an O-shaped cross section.
The seal chain according to any one of claims 1 to 3. The seal ring has an X-shaped cross section having four lips, and one of the four lips has a circular tip and is wider than the other lips, and the edge thereof. The tip of the portion is in contact with the inner surface of the outer plate.
The seal chain according to claim 2. The clearance is 2-5% of the diameter of the pin and is set wider than the gap between the pin and the bush.
The seal chain according to any one of claims 1 to 6.

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