TWI572793B - Chain - Google Patents

Description

Chain

The present invention relates to a chain in which a lubricant such as Grease is sealed between an inner circumferential surface of a bushing and an outer circumferential surface of a pin, and is disposed between an outer side surface of the inner link and an inner side surface of the outer link. There is a seal. In particular, there is a chain in which the lubricant is prevented from leaking to the outside by the sealing portion, and foreign matter such as water or dust is prevented from entering the inner circumferential surface of the bush and the outer circumferential surface of the pin from the outside.

In the past, as such a chain, a chain in which a sealing structure is provided between the inner link plate and the outer link plate is known (for example, refer to Japanese Laid-Open Patent Publication No. 2000-136848). The seal structure includes an outer peripheral side seal ring, an inner peripheral side seal ring disposed on the inner peripheral side of the outer peripheral side seal ring, and an O-ring disposed between the outer peripheral side seal ring and the inner peripheral side seal ring. Further, an O-ring is disposed between the inner link plate and the outer peripheral side seal ring, and the O-ring has elasticity. A V-ring is disposed between the outer link plate and the inner peripheral side seal ring, and the V-ring has elasticity.

In the chain configured as described above, when the inner link plate and the outer peripheral side seal ring are relatively rotated, the outer peripheral side seal ring and the V-shaped ring are relatively slid relative to the outer link plate. Further, a slit is generally formed in the sliding portion, so that the entry path of the foreign matter from the outside and the leakage path of the lubricant from the inside include the gap between the inner side surface of the outer link plate and the outer peripheral side seal ring, and the outer link plate The gap between the inner side surface and the V-shaped ring is a straight path when viewed along the cross section of the inner side surface of the outer link plate. Therefore, foreign matter and lubricant can be easily advanced on the above-described entry path and leakage path, and there is room for improvement in terms of improving the sealing property of the sealing structure.

The present invention has been made in view of the problems existing in such prior art. It is an object of the invention to provide a chain which can improve the sealing property of a sealing portion.

Hereinafter, means and effects for solving the above problems will be described.

A chain for solving the above problem includes: a pair of inner link plates which are disposed to face each other and are separated from each other; and a cylindrical bush which is inserted into a first through hole provided in each inner link plate, and two of them The end portions respectively protrude toward the outer sides of the pair of inner link plates; the pins are inserted into the bushes; and the outer link plates are disposed to sandwich the pair of inner link plates from the outside, and the two pins are The end portions are respectively inserted into the second through holes provided in the respective outer link plates; and the annular sealing members are disposed on the outer side surfaces of the inner link plates and the inner sides of the outer link plates Each of the seal members is fitted to both end portions of the bushing, and each of the seal members includes an inner circumferential side seal ring that is fitted to the outer circumferential surface of the bush and a peripheral surface that is fitted to the outer circumferential side seal ring. The outer circumferential side seal ring has rigidity, and the inner circumferential side seal ring and the outer circumferential side seal ring have rigidity, and the inner circumferential side seal ring and the outer peripheral side seal ring each have a sliding portion, and the sliding portion and the outer link plate and One of the inner link plates is slidably connected to the inside a seal ring of the side seal ring and the outer peripheral side seal ring, such that a state in which the first elastic ring in a compressed state is interposed between the one seal ring and the inner link plate is slid on the slide portion In the outer link plate, the other one of the inner circumferential side seal ring and the outer circumferential side seal ring is in a state in which the second elastic ring in a compressed state is located between the other seal ring and the outer link plate. The sliding portion is slidably coupled to the inner link plate.

According to this configuration, the sliding portion of the inner circumferential side seal ring and the sliding portion of the outer circumferential side seal ring are opposite to each other. Further, the inner circumference side seal ring and the outer circumference side seal ring are in direct contact with each other in the radial direction of the outer circumference side seal ring and the outer circumference side seal ring. Therefore, the entry path of the foreign matter from the outside and the leakage path of the lubricant from the inside become the side on which the sliding portion is provided on the inner circumferential side seal ring, the side on which the sliding portion is provided on the outer circumferential side seal ring, and A curved path between the inner peripheral side seal ring and the outer peripheral side seal ring. Therefore, foreign matter and lubricant are not easily accessible in the above-mentioned way. Since the diameter and the leakage path advance, the sealing property of the sealing portion can be improved.

11‧‧‧Chain

12‧‧‧Internal link plate

12a‧‧‧Outside

13‧‧‧ Inner link

14‧‧‧Outer link plate

14a‧‧‧ inside

15‧‧‧Outer link

16‧‧‧1st through hole

17‧‧‧ bushing

17a‧‧‧ outer perimeter

17b‧‧‧ end face

18‧‧‧ Roll

19‧‧‧ Sealing members

20‧‧ ‧ sales

21‧‧‧2nd through hole

30‧‧‧ inner circumferential side seal ring

31‧‧‧Outer side seal ring

32‧‧‧Bevel

33‧‧‧1st elastic ring

34‧‧‧1st opposite

35‧‧‧Sliding

36‧‧‧Lubricant Storage Department

41‧‧‧1st slot

42‧‧‧2nd elastic ring

43‧‧‧Sliding

44‧‧‧2nd slot

45‧‧‧3rd elastic ring

51‧‧‧Sliding Department

52‧‧‧4th slot

53‧‧‧4th elastic ring

Y‧‧‧Width direction

Fig. 1 is an exploded perspective view showing a part of a chain of an embodiment.

Figure 2 is a cross-sectional view of a portion of the chain of Figure 1.

Fig. 3 is an enlarged view of the essential part of Fig. 2.

Fig. 4 is an enlarged cross-sectional view showing a main part of a chain according to a first modification.

Fig. 5 is an enlarged cross-sectional view showing a main part of a chain according to a second modification.

Fig. 6 is an enlarged cross-sectional view showing a main part of a chain according to a third modification.

Fig. 7 is an enlarged cross-sectional view showing a main part of a chain according to a fourth modification.

Fig. 8 is an enlarged cross-sectional view showing a main part of a chain according to a fifth modification.

Fig. 9 is an enlarged cross-sectional view showing a main part of a chain according to a sixth modification.

Hereinafter, an embodiment of a chain will be described with reference to the drawings.

As shown in FIGS. 1 and 2, the chain 11 has a plurality of inner links 13 and a plurality of outer links 15. Each of the inner links 13 has a pair of inner link plates 12 which are disposed opposite to each other in the width direction Y and are separated from each other. Each outer link 15 has an outer link plate 14 which is disposed so as to sandwich a pair of inner link plates 12 of the corresponding inner link 13 from the outer side in the width direction Y.

The link plate 12 and the outer link plate 14 outside the inner link 13 are formed so as to extend in the series direction X perpendicular to the width direction Y and have a rounded plate shape. The central portion of the inner link plate 12 and the outer link plate 14 are contracted. The series direction X corresponds to the longitudinal direction of the chain 11 and corresponds to a direction in which the chain 11 is stretched and moved in the longitudinal direction. The inner link plate 12 and the outer link plate 14 which are opposed in the width direction Y are arranged in parallel with each other. The chain 11 of the present embodiment is configured such that the inner link plates 12 on the first end and the second end of the inner link 13 are spaced apart from each other in the series direction X. Equally, the first end of the outer link 15 in the series direction X and the outer link plate 14 on the second end are equal to each other. That is, the chain 11 of the present embodiment is a so-called flat type chain.

In the both end portions of the inner link plates 12 in the series direction X, a circular first through hole 16 for inserting the bushing is formed so as to penetrate the inner link plate 12 in the width direction Y. A pair of cylindrical bushes 17 are attached to the inner link 13 between the pair of inner link plates 12 facing each other so as to maintain the interval between the pair of inner link plates 12.

Both ends of the bushing 17 are fitted to the first through holes 16 of the pair of inner link plates 12, respectively. In other words, both end portions of the bushing 17 are respectively inserted into the first through holes 16 of the pair of inner link plates 12, and protrude toward the outer sides of the pair of inner link plates 12, respectively. The bushing 17 rotatably supports the roller 18 by being inserted through the cylindrical roller 18. That is, the bushing 17 is movably fitted to the roller 18.

The outer circumferential surface of the pair of inner link plates 12 on the outer peripheral surface of the both ends of the bushing 17 constitutes the outer peripheral surface 17a. An annular seal member 19 is fitted to the outer peripheral surface 17a. Therefore, the sealing member 19 is disposed between the outer side surface 12a of each inner link plate 12 and the inner side surface 14a of each outer link plate 14. The thickness of the sealing member 19 is set to be slightly thicker than the protruding length of the bushing 17 from the outer side surface 12a of the inner link plate 12. Therefore, a minute gap is formed between each end surface 17b of the bushing 17 and the inner side surface 14a of each outer link plate 14.

A circular second through hole 21 is formed in each of both end portions of the outer link plate 14 in the series direction X, and the second through hole 21 penetrates the outer link plate 14 in the width direction Y, and the cylindrical pin 20 is inserted into the second through hole 21 . The pin 20 has an outer diameter that is slightly smaller than the inner diameter of the bushing 17. The pin 20 has a diameter-enlarged portion 20a for restricting extraction at the first end portion thereof, and the enlarged diameter portion 20a has a diameter slightly larger than the diameter of the second through hole 21.

The outer link plate 14 of the outer link 15 is rotatably coupled to the pair of inner link plates 12 by the pin 20 from the outer side of the pair of inner link plates 12 of the inner link 13. The inner link 13 is provided with a pair of bushes 17 which are mounted between the pair of inner link plates 12. In this case, each pin 20 is The intermediate portion is inserted into each of the bushings 17, and the both end portions thereof are fitted to the second through holes 21 of the outer link plates 14 of one of the outer links 15 respectively.

Therefore, both end portions of the pin 20 protrude outward through the second through holes 21 of the outer link plate 14, respectively. Further, one of the inner link segments 13 adjacent to the series direction X, the inner link plate 12 and the outer link portion 15, the outer link plate 14, the corresponding end portions in the series direction X are pinned to each other. 20 and the bushing 17 are rotatably coupled.

A portion of the outer peripheral surface of the pin 20 located between the pair of inner link plates 12 is formed with a recess 20b for filling a lubricant such as grease. Further, when the chain 11 is used in a state where the lubricant is filled in the recess 20b, the lubricant in the recess 20b is diffused to the inner peripheral surface of the bushing 17 and the outer peripheral surface of the pin 20 by the relative rotation of the bushing 17 and the pin 20. between. Accordingly, the relative rotation between the bushing 17 and the pin 20 is promoted by the lubricant. The chain 11 of the present embodiment is made of a steel material.

Next, the configuration of the sealing member 19 will be described in detail.

As shown in FIG. 2 and FIG. 3, the sealing member 19 is provided with an annular inner circumferential side seal ring 30 and a rigid outer circumferential side seal ring 31. The inner circumferential side seal ring 30 is fitted to the outer peripheral surface 17a of the bushing 17. The outer peripheral side seal ring 31 is fitted to the outer peripheral surface of the inner peripheral side seal ring 30. In the present embodiment, the inner circumferential side seal ring 30 and the outer circumferential side seal ring 31 are each made of a steel material.

On the inner circumferential surface of the inner circumferential side seal ring 30, near the corner portion of the inner link plate 12, a chamfer 32 is formed by chamfering. In the region surrounded by the inclined surface 32 of the inner circumferential side seal ring 30, the outer side surface 12a of the inner link plate 12, and the outer peripheral surface 17a of the bushing 17, the inclined surface 32, the outer side surface 12a, and the outer peripheral surface 17a are compressed. The elastically deformed state is provided with an annular first elastic ring 33.

That is, the first elastic ring 33 is attached between the inclined surface 32 of the inner circumferential side seal ring 30 and the outer side surface 12a of the inner link plate 12, and the inclined surface 32 and the outer peripheral surface of the bushing 17 in a compressed state. Between 17a. In this case, when the opposing surface of the inner circumferential side seal ring 30 and the outer side surface 12a of the inner link plate 12 is regarded as the first opposing surface 34, the first opposing surface 34 and A slight gap is formed between the outer side faces 12a of the inner link plates 12.

On the sliding side of the inner peripheral side seal ring 30 that is slidably connected to the outer link plate 14, an annular sliding portion 35 that is slidably attached to the inner side surface 14a of the outer link plate 14 is provided, and is slidably connected. The annular lubricant storage portion 36 is adjacent to the portion 35. The lubricant supplied into the sliding portion 35 is stored in the lubricant storage portion 36. On the outer side portion in the radial direction of the inner peripheral side seal ring 30, the sliding portion 35 is provided to protrude toward the outer link plate 14 more than the lubricant retaining portion 36.

The lubricant reservoir portion 36 is formed on the sliding side of the inner circumferential side seal ring 30 that is slidably coupled to the outer link plate. The lubricant storage portion 36 is formed on the inner circumference side of the inner circumferential side seal ring 30 on the inner circumferential side of the inner side of the sliding portion 35, so that a step is formed between the lubricant storage portion 36 and the sliding portion 35. Therefore, a minute slit is formed between the lubricant retaining portion 36 and the inner side surface 14a of the outer link plate 14, and flows between the bush 17 and the pin 20 through between the bush 17 and the outer link plate 14. The lubricant is retained in the gap.

When the surface facing the outer link plate 14 on the outer circumferential side seal ring 31 is the second opposing surface 40, the central portion of the outer circumferential side seal ring 31 in the radial direction of the second opposing surface 40 is provided. The first groove 41 having an annular shape is formed. An annular second elastic ring 42 is fitted into the first groove 41. Since the depth of the first groove 41 is set to be smaller than the thickness of the second elastic ring 42, the second elastic ring 42 is disposed in a state of being elastically deformed by being compressed by the inner side surface 14a of the outer link plate 14 and the first groove 41.

Therefore, the second elastic ring 42 is in close contact with the inner side surface 14a of the outer link plate 14 in accordance with its own elastic restoring force. The second elastic ring 42 is attached between the inner side surface 14a of the outer link plate 14 and the outer peripheral side seal ring 31 in a compressed state. In this case, a minute slit is formed between the second opposing surface 40 of the outer circumferential side seal ring 31 and the inner side surface 14a of the outer link plate 14.

The surface of the outer peripheral side seal ring 31 close to the inner link plate 12 constitutes a sliding portion 43 that is slidably attached to the outer side surface 12a of the inner link plate 12. The outer peripheral side seal ring 31 on the sliding portion 43 An annular second groove 44 is formed in a central portion in the radial direction. The second groove 44 is adjacent to the first groove 41 in the width direction Y. The radial width of the outer circumferential side seal ring 31 of the second groove 44 is set to be the same as that of the first groove 41, and the depth thereof is set to be deeper than the first groove 41.

An annular third elastic ring 45 is fitted into the second groove 44. The third elastic ring 45 has the same structure as the second elastic ring 42. In this case, the depth of the second groove 44 is set to be slightly smaller than the thickness of the third elastic ring 45, and the third elastic ring 45 is slightly elastically deformed by being compressed by the outer side surface 12a and the second groove 44 of the inner link plate 12. Status configuration. Therefore, the third elastic ring 45 is in close contact with the outer side surface 12a of the inner link plate 12 in accordance with its own elastic restoring force. As described above, a pair of annular first grooves 41 and second grooves 44 are formed on both sides of the outer circumferential side seal ring 31, and the first grooves 41 and the second grooves 44 have smaller than the second elastic ring 42 and the third elastic ring. The depth of the thickness of 45. Further, the second elastic ring 42 and the third elastic ring 45 are disposed in the pair of first grooves 41 and second grooves 44, respectively.

Further, in this case, since the depth of the second groove 44 is set deeper than the depth of the first groove 41, the compression ratio of the second elastic ring 42 is larger than the compression ratio of the third elastic ring 45. Therefore, the elastic restoring force of the second elastic ring 42 is greater than the elastic restoring force of the third elastic ring 45. Therefore, the adhesion force of the second elastic ring 42 to the inner side surface 14a of the outer link plate 14 is greater than the adhesion force of the third elastic ring 45 to the outer side surface 12a of the inner link plate 12.

In other words, the second elastic ring 42 and the third elastic ring 45 on both sides of the outer circumferential side seal ring 31 disposed in the width direction Y are disposed in the same manner as the sliding portion 35 of the inner circumferential side seal ring 30. The adhesion force of the second elastic ring 42 on the side is larger than the adhesion force of the third elastic ring 45 disposed on the opposite side of the sliding portion 35.

Each of the first elastic ring 33, the second elastic ring 42, and the third elastic ring 45 is made of an elastic body such as rubber.

Next, the action of the sealing member 19 when the chain 11 is used will be described.

When the chain 11 is used, the inner link plate 12 and the outer link plate 14 are relatively rotated. At this time, the adhesion force of the second elastic ring 42 to the inner side surface 14a of the outer link plate 14 is greater than the third elastic force. The adhesion of the ring 45 to the outer side surface 12a of the inner link plate 12. Therefore, the sliding portion 43 and the third elastic ring 45 of the outer peripheral side seal ring 31 slide with respect to the outer side surface 12a of the inner link plate 12, and the second elastic ring 42 does not slide with respect to the inner side surface 14a of the outer link plate 14. The state of being in close contact with the inner side surface 14a is maintained.

The inner peripheral side seal ring 30 slides on the sliding portion 35 with respect to the inner side surface 14a of the outer link plate 14. Therefore, the inner circumferential side seal ring 30, the first elastic ring 33, and the bushing 17 are integrally rotated with the inner link plate 12. Therefore, the state in which the first elastic ring 33 is in contact with the inclined surface 32 of the inner circumferential side seal ring 30, the outer side surface 12a of the inner link plate 12, and the outer circumferential surface 17a of the bushing 17 is maintained.

As can be seen from the above configuration, when foreign matter such as water or dust existing outside the chain 11 enters the inside of the chain 11, the foreign matter cannot pass between the second elastic ring 42 and the inner side surface 14a of the outer link plate 14. Therefore, the foreign matter enters the chain 11 between the sliding portion 43 of the outer peripheral side seal ring 31 and the outer side surface 12a of the inner link plate 12, and between the third elastic ring 45 and the outer side surface 12a of the inner link plate 12. internal.

At this time, the foreign matter advances through the gap between the first opposing surface 34 of the inner circumferential side seal ring 30 and the outer side surface 12a of the inner link plate 12. However, since the first elastic ring 33 is in close contact with the inclined surface 32 of the inner circumferential side seal ring 30 and the outer side surface 12a of the inner link plate 12, the first elastic ring 33 blocks the entry of foreign matter.

Therefore, the foreign matter that has entered the inside of the chain 11 advances between the outer circumferential surface of the inner circumferential side seal ring 30 and the inner circumferential surface of the outer circumferential side seal ring 31. Thereafter, the foreign matter enters the bushing between the sliding portion 35 of the inner circumferential side seal ring 30 and the inner side surface 14a of the outer link plate 14, and between the end surface 17b of the bushing 17 and the inner side surface 14a of the outer link plate 14 Between the inner circumferential surface of the 17 and the outer circumferential surface of the pin 20.

Therefore, the entry path of the foreign matter from the outside to the inside of the chain 11 is as indicated by the two-dot chain line arrow in Fig. 3, and is cranked when viewed in cross section. That is, the entry path of the foreign matter from the outside to the inside of the chain 11 is to form a so-called labyrinth structure. Therefore, compared with the past, the foreign body is in the seal The internal advancement of the piece 19 becomes difficult. That is, since the sealing property of the sealing member 19 is improved as compared with the past, the foreign matter is effectively prevented from entering the inside from the outside of the chain 11 by the sealing member 19.

When the lubricant between the inner circumferential surface of the bushing 17 and the outer circumferential surface of the pin 20 leaks to the outside of the chain 11, the lubricant flows into the lubrication between the end surface 17b of the bushing 17 and the inner side surface 14a of the outer link plate 14 Agent storage portion 36. This lubricant is stored in the lubricant storage portion 36 and supplied between the sliding portion 35 of the inner circumferential side seal ring 30 and the inner side surface 14a of the outer link plate 14.

The lubricant that is supplied between the sliding portion 35 of the inner circumferential side seal ring 30 and the inner side surface 14a of the outer link plate 14 to lubricate the position cannot pass through the second elastic ring 42 and the outer link plate 14 Between the inner side faces 14a. Therefore, after flowing between the outer peripheral surface of the inner peripheral side seal ring 30 and the inner peripheral surface of the outer peripheral side seal ring 31, the lubricant passes through the sliding portion 43 of the outer peripheral side seal ring 31 and the outer side surface of the inner link plate 12 Between 12a and between the third elastic ring 45 and the outer side surface 12a of the inner link plate 12, it leaks to the outside of the chain 11.

Therefore, the leakage path of the lubricant from the inside to the outside of the chain 11 is as shown by the two-dot chain arrow in Fig. 3, and is cranked in cross-sectional observation. In other words, the leakage path from which the lubricant leaks from the inside of the chain 11 to the outside corresponds to a path in a direction opposite to the direction in which the foreign matter advances on the entry path of the foreign matter, and becomes a so-called labyrinth structure. Therefore, it becomes difficult for the lubricant to advance inside the sealing member 19 as compared with the past. That is, since the sealing property of the sealing member 19 is improved as compared with the past, the lubricant member is effectively prevented from leaking from the inside of the chain 11 to the outside through the sealing member 19.

In this manner, since the distance between the entry path of the foreign matter entering the inside from the outside of the chain 11 and the leakage path of the lubricant leaking from the inside of the chain 11 to the outside by the sealing member 19 are set to be large, the foreign matter can be effectively suppressed. The entry from the outside to the inside of the chain 11 can suppress the leakage of the lubricant from the inside of the chain 11 to the outside. Therefore, the durability of the chain 11 is improved.

According to the above embodiment, the following effects can be obtained.

(1) In the chain 11, the inner circumferential side seal ring 30 is configured such that the first elastic ring 33 in a compressed state is interposed between the inner circumferential side seal ring 30 and the inner link plate 12, The sliding portion 35 is slidably coupled to the outer link plate 14. The outer peripheral side seal ring 31 is configured such that the second elastic ring 42 in a compressed state is interposed between the outer peripheral side seal ring 31 and the outer link plate 14 on the sliding portion 43 and the inner link plate. 12 sliding. In other words, in the chain 11, the sliding portion 35 of the inner peripheral side seal ring 30 and the sliding portion 43 of the outer peripheral side seal ring 31 are located on the opposite side in the width direction Y, and the inner peripheral side seal ring 30 and the outer peripheral side are sealed. The ring 31 is in direct contact in its radial direction. Therefore, the entry path of the foreign matter from the outside into the inside of the chain 11 and the leakage path of the lubricant leaking from the inside of the chain 11 to the outside are passed through the inner side surface 14a of the outer link plate 14 and the inner circumferential side seal ring 30. The sliding portion 35 is formed between the outer side surface 12a of the inner link plate 12 and the sliding portion 43 of the outer circumferential side seal ring 31, and between the inner circumferential side seal ring 30 and the outer peripheral side seal ring 31. The path of the curved crank (maze structure). Therefore, it is difficult for the foreign matter and the lubricant to advance in the entry path of the foreign matter in the chain 11 and the leakage path of the lubricant, so that the sealing property of the sealing member 19 to the foreign matter and the lubricant can be improved. As a result, the durability of the chain 11 can be improved.

(2) In the chain 11, the adhesion force of the second elastic ring 42 disposed on the outer peripheral side seal ring 31 on the inner side surface 14a of the outer link plate 14 on the outer peripheral side seal ring 31 is larger than that on the outer peripheral side seal ring 31. The adhesion of the third elastic ring 45 of the second groove 44 to the outer side surface 12a of the inner link plate 12 is obtained. Therefore, it is possible to effectively suppress the foreign matter existing outside the chain 11 from entering the sliding portion 35 of the inner circumferential side seal ring 30 over the second elastic ring 42, and the sliding portion 35 to the inner circumferential side seal ring 30 can be effectively suppressed. The lubricant that has been lubricated leaks over the second elastic ring 42 and leaks to the outside of the chain 11 .

(3) In the chain 11, the inner peripheral side seal ring 30 is provided with a sliding portion 35 and a lubricant retaining portion 36. The sliding portion 35 is slidably attached to the outer link plate 14, and the lubricant retaining portion 36 is slidably connected. The portions 35 are adjacent to each other and can store the lubricant supplied to the sliding portion 35. Therefore, the lubricant stored in the lubricant storage portion 36 can be smoothly supplied to the sliding portion 35.

(4) In the chain 11, the sliding portion 35 of the inner circumferential side seal ring 30 is disposed at an outer portion in the radial direction of the inner circumferential side seal ring 30. Therefore, since the lubricant retaining portion 36 can be provided on the inner peripheral side of the inner peripheral side seal ring 30 on the inner peripheral side and on the inner circumferential side of the inner peripheral side seal ring 30, the lubricant retaining portion 36 can be provided. The lubricant storage portion 36 is set in the ground.

(5) In the chain 11, since the first elastic ring 33 does not slide, the life is longer than that of the sliding third elastic ring 45. Therefore, when the third elastic ring 45 does not function, the first elastic ring 33 can function as a spare member of the third elastic ring 45.

(Modification)

The above embodiment can also be modified as follows.

. As shown in FIG. 4, the second groove 44 and the third elastic ring 45 on the outer peripheral side seal ring 31 may be omitted.

. As shown in Fig. 5, the inclined surface 32 on the inner circumferential side seal ring 30 may be omitted, and the first opposing surface 34 facing the outer side surface 12a of the inner link plate 12 on the inner circumferential side seal ring 30 may be provided. The third groove 50 of the ring shape. Further, the first elastic ring 33 may be placed in the third groove 50 in a compressed state. In this case, the first elastic ring 33 is sandwiched by the third groove 50 and the outer side surface 12a of the inner link plate 12, so that the first pair of the outer side surface 12a of the inner link plate 12 and the inner circumferential side seal ring 30 A slight gap is formed between the faces 34.

. As shown in Fig. 6, the second groove 44 and the third elastic ring 45 on the outer circumferential side seal ring 31 in the chain 11 of Fig. 5 may be omitted.

. As shown in Fig. 7, the orientation of the inner circumferential side seal ring 30 and the orientation of the outer circumferential side seal ring 31 shown in the chain 11 of Fig. 6 may be set in opposite directions in the width direction Y. In this case, the leakage path of the lubricant leaking from the inside of the chain 11 to the outside and the entry path of the foreign matter entering the inside from the outside of the chain 11 are also shown in the width direction Y as indicated by the two-dotted chain arrow in FIG. The opposite path to the chain 11 of FIG.

. As shown in Fig. 8, the sliding portion 35 and the lubricant retaining portion 36 on the inner circumferential side seal ring 30 in the chain 11 of Fig. 5 are omitted, and the inner peripheral side seal ring 30 is formed close to the outer link. The surface of the inner side surface 14a of the plate 14 serves as a flat sliding portion 51 that is in sliding contact with the inner side surface 14a. Further, a fourth groove 52 may be formed in a central portion in the radial direction of the inner circumferential side seal ring 30 of the sliding portion 51. The fourth groove 52 has the same structure as the second groove 44, and is in the fourth groove. The fourth elastic ring 53 is fitted into the fourth elastic ring 53, and has the same structure as the third elastic ring 45.

. As shown in Fig. 9, the second groove 44 and the third elastic ring 45 on the outer circumferential side seal ring 31 in the chain 11 of Fig. 8 may be omitted.

. In the chain 11, the sliding portion 35 of the inner peripheral side seal ring 30 does not have to be provided in the outer portion in the radial direction of the inner peripheral side seal ring 30.

. In the chain 11, the lubricant storage portion 36 of the inner circumferential side seal ring 30 may be omitted.

. At least one of the inner circumferential side seal ring 30 and the outer circumferential side seal ring 31 may be made of a rigid synthetic resin having rigidity.

. A plurality of second elastic rings 42 may be fitted into the first groove 41, or a plurality of third elastic rings 45 may be fitted into the second groove 44.

. The roller 18 can also be omitted.

. The chain 11 may be rotatably coupled by the bushing 17 and the pin 20 such that the width of one end side in the series direction X of the opposing two link plates is narrower than the width of the other end side. The so-called offset type chain.

11‧‧‧Chain

12‧‧‧Internal link plate

12a‧‧‧Outside

13‧‧‧ Inner link

14‧‧‧Outer link plate

14a‧‧‧ inside

15‧‧‧Outer link

16‧‧‧1st through hole

17‧‧‧ bushing

17a‧‧‧ outer perimeter

17b‧‧‧ end face

18‧‧‧ Roll

19‧‧‧ Sealing members

20‧‧ ‧ sales

21‧‧‧2nd through hole

30‧‧‧ inner circumferential side seal ring

31‧‧‧Outer side seal ring

33‧‧‧1st elastic ring

42‧‧‧2nd elastic ring

45‧‧‧3rd elastic ring

Y‧‧‧Width direction

Claims (6)

A chain comprising: a pair of inner link plates arranged to face each other and separately; a cylindrical bushing inserted through a first through hole provided in each inner link plate, the two ends of which are respectively Projecting toward the outer side of the pair of inner link plates; a pin inserted into the bushing; and an outer link plate disposed to sandwich the pair of inner link plates from the outer side, the two ends of the pin respectively a second through hole provided in each outer link plate; and an annular sealing member disposed between an outer side surface of each of the inner link plates and an inner side surface of each of the outer link plates, and Each of the sealing members includes an inner circumferential side seal ring that is fitted to an outer circumferential surface of the bushing, and a peripheral surface that is fitted to the inner circumferential side seal ring. Each of the inner circumferential side seal ring and the outer circumferential side seal ring has rigidity; the inner circumferential side seal ring and the outer peripheral side seal ring respectively have a sliding portion, the sliding portion and the outer link plate Sliding with one of the aforementioned inner link plates; One of the inner circumferential side seal ring and the outer circumferential side seal ring is such that a first elastic ring in a compressed state is interposed between the one seal ring and the inner link plate, and the sliding portion is The outer peripheral link plate is slidably coupled to the outer outer link plate; and the other inner circumferential side seal ring and the outer peripheral side seal ring are disposed such that the second elastic ring in a compressed state is interposed between the other seal ring and the outer chain The state between the joint plates is slidably coupled to the inner link plate on the aforementioned sliding portion. The chain according to claim 1, wherein the second elastic ring in a compressed state is interposed between the outer circumferential side seal ring and the outer link plate, and the outer circumferential side seal ring and the inner link plate are a third elastic ring in a compressed state is interposed, and the second elastic ring is disposed on the same side as the sliding portion of the inner circumferential side seal ring, and the third elastic ring is disposed on the inner circumferential side. On the opposite side of the sliding portion of the ring, the second elastic ring is configured such that the adhesion force is greater than the adhesion force of the third elastic ring. The chain according to claim 1 or 2, wherein the inner peripheral side seal ring is provided with a lubricant retaining portion adjacent to a sliding portion of the inner peripheral side seal ring, and can be stored and supplied to The lubricant of the aforementioned sliding portion. The chain according to claim 3, wherein the sliding portion of the inner circumferential side seal ring is disposed at an outer portion in the radial direction of the inner circumferential side seal ring. The chain according to claim 2, wherein a pair of annular grooves are provided on both sides of the outer circumferential side seal ring, the pair of annular grooves having a depth smaller than a thickness of the second elastic ring and the third elastic ring The second elastic ring and the third elastic ring are respectively disposed in the pair of grooves. The chain according to claim 5, wherein the groove on the same side as the sliding portion of the inner circumferential side seal ring is the first groove in the pair of grooves of the outer circumferential side seal ring, and is disposed in the first groove. The groove on the opposite side of the sliding portion of the inner circumferential side seal ring is a second groove, and the depth of the first groove is set to be shallower than the depth of the second groove.