Chain seal ring and chain equipped with same

Abstract

To reduce bending resistance of a chain while maintaining necessary sealing performance. [Solution] A first recess 22 is formed between the first lip portion 3 and the main body portion 2. A second recess 23 is formed between the second lip portion 4 and the main body portion 2. The outer surface of the first lip portion 3 is a first inclined surface 31 whose diameter gradually decreases as it moves away from the main body portion 2. The outer surface of the second lip portion 4 is a second inclined surface 41 whose diameter gradually decreases as it moves away from the main body portion 2. When attached to a chain, the inner end of the main body portion 2 is sandwiched between the end of the bushing 8 and the outer plate 5 and abuts against them. The tip of the first lip portion 3 is adapted to abut against the outer plate 5. The second inclined surface 41 is adapted to abut against the inner plate 6.

Description

[Technical Field]

[0001] The present invention relates to a seal ring for a chain and a chain equipped with the seal ring. [Background technology]

[0002] O-rings have traditionally been used between the outer and inner plates to seal in the lubricating oil (grease) that fills the spaces between the pins and bushings that make up the chain. While O-rings provide a strong seal, they also create high sliding resistance when the outer and inner plates rotate relative to one another. This increases the bending resistance of the entire chain, resulting in poor energy transmission efficiency.

[0003] The following Patent Document 1 proposes a seal that enhances sealing by contacting a large contact surface with the inner plate and two small seal portions with the outer plate. However, this document does not focus on the bending resistance of the chain as a whole. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 55-24516 Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors have discovered that by forming a chain seal ring in a specific shape, it is possible to keep the bending resistance of the chain low while maintaining the required sealing performance.

[0006] The present invention was made based on this finding, and its main object is to provide a seal ring for a chain that can keep bending resistance low while maintaining the required sealing performance. [Means for solving the problem]

[0007] The present invention can be expressed as the inventions described in the following items.

[0008] (Item 1) A seal ring for a chain is interposed between an outer plate and an inner plate and fitted to a bushing to seal in lubricating oil filled between the bushing and the pin, a main body portion formed in an annular shape and extending inward; a first lip portion protruding from the main body portion toward one side in a thickness direction of the main body portion; a second lip portion protruding from the main body portion to the other side in the thickness direction of the main body portion, a first recess is formed between the first lip portion and the main body portion; a second recess is formed between the second lip portion and the main body portion; an outer surface of the first lip portion is a first inclined surface that inclines toward the main body portion as it moves away from the main body portion; an outer surface of the second lip portion is a second inclined surface that inclines toward the main body portion as it moves away from the main body portion; When attaching to the chain, an inner end portion of the main body portion is sandwiched between an end portion of the bushing and the outer plate and abuts against them; The tip of the first lip portion is adapted to abut against the outer plate, The second inclined surface is adapted to abut against the inner plate. Chain seal ring.

[0009] (Item 2) The cross-sectional shape is symmetrical about an axis of symmetry extending in the radial direction of the chain seal ring. Item 1. A seal ring for a chain according to item 1.

[0010] (Item 3) The inner end of the main body portion is shaped to bulge outward from the main body portion. Item 2. A seal ring for a chain.

[0011] (Item 4) In the cross-sectional shape, the first inclined surface and the second inclined surface form a mountain-like shape that protrudes radially outward. Item 2. A seal ring for a chain.

[0012] (Item 5) When attaching to the chain, The contact position between the inner end of the main body and the outer plate, the contact position between the tip of the first lip and the outer plate, and the contact position between the second inclined surface and the inner plate are offset from one another in the radial direction of the chain seal ring. Item 2. A seal ring for a chain.

[0013] (Item 6) A chain equipped with the seal ring for a chain according to any one of items 1 to 5.

[0014] (Item 7) A method for manufacturing a chain using the seal ring for a chain according to any one of items 1 to 5, a step of loosely fitting the chain seal ring into the bushing attached to the inner plate; and sandwiching the chain seal ring between the outer plate and the inner plate, and further sandwiching the main body of the chain seal ring between the outer plate and the bushing, thereby deforming the chain seal ring and bringing the tip of the first lip portion into contact with the outer plate and the second inclined surface of the second lip portion into contact with the inner plate. Chain manufacturing method. [Effects of the Invention]

[0015] According to the technology of the present invention, it is possible to provide a seal ring for a chain that can keep bending resistance low while maintaining the required sealing performance. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is an enlarged end view of a main portion of a seal ring for a chain according to one embodiment of the present invention. [Figure 2] 2 is an explanatory view showing a part of the chain in the middle of assembling the chain seal ring of FIG. 1.

[0023] FIG. [Figure 3] FIG. 3 is an enlarged cross-sectional view taken along line AA in FIG. 2. [Figure 4] FIG. 4 is an enlarged cross-sectional view of part B in FIG. [Figure 5] 2 is an explanatory view showing a part of a chain incorporating the chain seal ring of FIG. 1. [Figure 6] FIG. 6 is an enlarged cross-sectional view taken along line CC in FIG. 5. [Figure 7] FIG. 4 is an enlarged cross-sectional view of a portion D in FIG. [Figure 8] 2 is a graph showing the bending load of a chain incorporating the chain seal ring of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A seal ring for a chain (hereinafter sometimes simply referred to as a "seal ring") according to one embodiment of the present invention will be described below with reference to the accompanying drawings.

[0018] (Seal ring configuration) The seal ring 1 of this embodiment is interposed between the outer plate 5 and the inner plate 6, and is fitted into the bushing 8 to seal the lubricating oil filled between the bushing 8 and the pin 7 (see FIG. 7). The structure of the chain will be explained later.

[0019] This seal ring 1 has a main body portion 2 formed in an annular shape and extending inward (toward the right in Figure 1), a first lip portion 3 protruding from the main body portion 2 to one side in the thickness direction of the main body portion 2 (upper side in Figure 1), and a second lip portion 4 protruding from the main body portion 2 to the other side in the thickness direction of the main body portion 2 (lower side in Figure 1).

[0020] A first recess 22 is formed between the first lip portion 3 and the main body portion 2. In addition, a second recess 23 is formed between the second lip portion 4 and the main body portion 2.

[0021] The outer surface of the first lip portion 3 is a first inclined surface 31 that slopes toward the main body portion 2 as it moves away from the main body portion 2. The outer surface of the second lip portion 4 is a second inclined surface 41 that slopes toward the main body portion 2 as it moves away from the main body portion 2.

[0022] The seal ring 1 of this embodiment has a cross-sectional shape (see Figure 1) that is symmetrical about an imaginary axis of symmetry (not shown) extending radially of the seal ring 1 (horizontally in Figure 1).

[0023] The inner end of the main body 2 forms a bulging portion 21 that bulges outward from the main body 2 (in the vertical and rightward directions in FIG. 1).

[0024] In the seal ring 1 of this embodiment, the first inclined surface 31 and the second inclined surface 41 form a mountain-like shape in cross section that protrudes radially outward (see FIG. 1).

[0025] (Structure of a chain using the seal ring of this embodiment) The configuration of a chain incorporating the seal ring of this embodiment will now be described with reference to Figures 2 to 7. This chain has an outer plate 5, an inner plate 6, a pin 7, a bushing 8, and a roller 9. Figures 2 to 4 show the state before the outer plate 5 is brought close to the inner plate 6 (i.e., the state in which the seal ring 1 is being incorporated into the chain), while Figures 5 to 7 show the state after the outer plate 5 has been brought sufficiently close to the inner plate 6 (i.e., the state after the seal ring 1 has been incorporated into the chain).

[0026] The pin 7 is contained within a bushing 8, and lubricating oil (not shown) is filled between the pin 7 and the bushing 8. Two inner plates 6, one above the other, are attached to the bushing 8. A roller 9 is loosely fitted on the outside of the bushing 8 at a position where it abuts against a sprocket (not shown). Two outer plates 5, one above the other, are attached to the pin 7. As shown in Figure 3, the chain of this embodiment uses two seal rings 1, but for ease of explanation, only the upper seal ring 1 in the figure will be described. The lower seal ring 1 is positioned symmetrically to the upper seal ring 1. The pin 7 is crimped, but Figures 5 to 7 show the pin 7 in a state before crimping. The chain configuration itself may be the same as that of a conventional chain, so further detailed explanation will be omitted.

[0027] When the seal ring 1 of this embodiment is assembled into a chain, the inner end of the main body 2 is sandwiched between the end of the bushing 8 and the outer plate 5 and abuts against them. The tip of the first lip 3 abuts against the outer plate 5. Furthermore, the second inclined surface 41 abuts against the inner plate 6.

[0028] Furthermore, in the seal ring 1 of this embodiment, when assembled into a chain, the contact position between the inner end of the main body portion 2 and the outer plate 5, the contact position between the tip of the first lip portion 3 and the outer plate 5, and the contact position between the second inclined surface 41 and the inner plate 6 are offset from each other in the radial direction of the seal ring 1 (left and right direction in Figure 7).

[0029] (Method for manufacturing a chain using the seal ring of this embodiment) Next, a method for incorporating the seal ring 1 of this embodiment into a chain will be described mainly with reference to FIGS.

[0030] First, before the outer plate 5 is attached to the pin 7, the seal ring 1 is loosely fitted into the bushing 8 attached to the inner plate 6 (see FIGS. 3 and 4).

[0031] Next, the outer plate 5 is fitted onto the pin 7, the seal ring 1 is sandwiched between the outer plate 5 and the inner plate 6, and further the main body 2 of the seal ring 1 is sandwiched between the outer plate 5 and the bushing 8, thereby deforming the seal ring 1. Next, once the outer plate 5 is placed in the predetermined position, the pin 7 is crimped to fix the position of the outer plate 5.

[0032] As the outer plate 5 is attached, the bulge 21 of the main body 2 of the seal ring 1 abuts against the end of the bushing 8, and the seal ring 1 receives a pressing force along the axial direction of the bushing 8. As a result, the seal ring 1 rotates counterclockwise in FIG. 4, and the tip of the first lip 3 abuts against the outer plate 5, and the second inclined surface 41 of the second lip 4 abuts against the inner plate 6 (see FIG. 7). In the seal ring 1 of this embodiment, the first recess 22 and the second recess 23 are provided in the main body 2, which makes it easier for the first lip 3 and the second lip 4 to deform (i.e., tilt) relative to the main body 2. This has the advantage that the second inclined surface 41 easily comes into close contact with the inner plate 6, as shown in FIG. 7. This allows the second inclined surface 41 to exert a high sealing effect.

[0033] Furthermore, with the seal ring 1 of this embodiment, the first lip portion 3 and the main body portion 2 each come into contact with the outer plate 5 at two locations, so in this respect too, a high sealing effect can be achieved. Moreover, because the tip of the first lip portion 3 makes linear contact with the outer plate 5, it is possible to keep low the sliding resistance when the outer plate 5 and the inner plate 6 rotate relative to each other, and as a result, it is possible to keep low the bending load of the chain.

[0034] Furthermore, the seal ring 1 of this embodiment is designed so that, when assembled into a chain, the contact position between the inner end of the main body 2 and the outer plate 5, the contact position between the tip of the first lip 3 and the outer plate 5, and the contact position between the second inclined surface 41 and the inner plate 6 are offset from one another in the radial direction of the seal ring 1 (left and right direction in FIG. 7). This allows the compressive stress generated in the seal ring 1 when the seal ring 1 is crushed between the outer plate 5 and the inner plate 6 to be released in the radial direction of the seal ring 1. This reduces the sliding resistance when the outer plate 5 and the inner plate 6 rotate relative to one another, thereby further reducing the bending resistance of the chain.

[0035] Furthermore, the seal ring 1 of this embodiment has a cross-sectional shape that is symmetrical about an axis of symmetry extending in the radial direction of the seal ring 1 (see FIG. 1), which means that there is no need to consider the front and back sides when installing the seal ring, which has the advantage of improving workability. This workability is important not only for mass-produced vehicles, but also when adjusting a chain under extremely short periods of time and under severe conditions, such as in motorcycle racing competitions.

[0036] (Seal characteristics) A bending load test was conducted on a chain using the seal ring 1 of this embodiment. The test conditions involved bending the chain into an M shape, applying a pressure load from above to the center of the bent portion, and gradually increasing this pressure load to deform the chain, and then reading the maximum load at the time of deformation. The results are shown in FIG. 8. The vertical axis in FIG. 8 represents the maximum load (N) at the time of chain deformation in the bending load test. The horizontal axis in FIG. 8 corresponds to examples in which the gap (set height) between the outer plate 5 and the inner plate 6 is changed, with the horizontal axis showing examples of set heights of 1.10 mm, 1.20 mm, and 1.30 mm from the left end to the right end. The maximum value (max), minimum value (min), and average value (ave) for each example were plotted.

[0037] Even when the set height is reduced (i.e., even when the amount of crushing of the seal ring 1 is increased), there is almost no increase in the bending load. By reducing the set height, the chain width (the width of the chain in the axial direction of the pin) can be reduced. Therefore, these results show that the bending load of the chain can be reduced while reducing the chain width. Furthermore, although not shown, preliminary tests using a normal O-ring showed that the bending load of the chain using the O-ring was about twice as high as the results shown in Figure 8. These results show that the seal ring 1 of this embodiment can achieve a lower bending load for the chain compared to an O-ring.

[0038] Therefore, according to the seal ring 1 of this embodiment, the energy transmission efficiency of the chain can be improved.

[0039] It should be noted that the present invention is not limited to the above-described embodiment, and various modifications may be made to the specific configuration of the present invention within the scope of the claims.

[0040] For example, the specific configuration of the chain is not limited to the one described above, and various other configurations can be used. [Explanation of symbols]

[0041] 1 Chain seal ring 2 Main body 21 Bulge 22 First recess 23 Second recess 3 First lip 31 1st slope 4 Second lip 41 Second slope 5 outer plate 6 Inner plate 7-pin 8 bushings 9. Laura

Claims

1. A seal ring for a chain is interposed between an outer plate and an inner plate and fitted to a bushing to seal in lubricating oil filled between the bushing and the pin, a main body portion formed in an annular shape and extending inward; a first lip portion protruding from the main body portion toward one side in a thickness direction of the main body portion; a second lip portion protruding from the main body portion to the other side in the thickness direction of the main body portion, a first recess formed between the first lip portion and the main body portion; a second recess formed between the second lip portion and the main body portion; an outer surface of the first lip portion is a first inclined surface that inclines toward the main body portion as it moves away from the main body portion; an outer surface of the second lip portion is a second inclined surface that inclines toward the main body portion as it moves away from the main body portion; When attaching to the chain, an inner end portion of the main body portion is sandwiched between an end portion of the bushing and the outer plate and abuts against them; a tip end of the first lip portion is adapted to abut against the outer plate, the second inclined surface is adapted to come into contact with the inner plate, Furthermore, there is no other lip portion between the first inclined surface and the second inclined surface that comes into contact with the inner plate when attached to the chain, Furthermore, when the chain is attached, only the second inclined surface is pressed against the inner plate by a pressing force applied from the outer plate to the first lip portion, and as a result, the second inclined surface moves radially inward, allowing the pressing force to be released. Chain seal ring.

2. The side surface of the second lip portion on the second recess side is inclined so as to approach the radially inward direction as it moves away from the main body portion. The seal ring for a chain according to claim 1.

3. The inner end of the main body portion is shaped to bulge outward from the main body portion. The seal ring for a chain according to claim 1.

4. In the cross-sectional shape, the first inclined surface and the second inclined surface form a mountain-like shape that protrudes radially outward, and no recess is formed in the second inclined surface that forms the mountain-like shape from the outermost position in the radial direction of the mountain-like shape to the tip of the second lip portion. The seal ring for a chain according to claim 1.

5. When attaching to the chain, The contact position between the inner end of the main body and the outer plate, the contact position between the tip of the first lip and the outer plate, and the contact position between the second inclined surface and the inner plate are offset from one another in the radial direction of the chain seal ring. The seal ring for a chain according to claim 1.

6. A chain comprising the chain seal ring according to any one of claims 1 to 5.

7. A method for manufacturing a chain using the chain seal ring according to any one of claims 1 to 5, a step of loosely fitting the chain seal ring into the bushing attached to the inner plate; and sandwiching the chain seal ring between the outer plate and the inner plate, and further sandwiching the main body of the chain seal ring between the outer plate and the bushing, thereby deforming the chain seal ring and bringing the tip of the first lip portion into contact with the outer plate and the second inclined surface of the second lip portion into contact with the inner plate. Chain manufacturing method.

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