Chain sealing ring and chain equipped therewith

Abstract

Maintain the necessary sealing performance while keeping chain bending resistance low. [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 the 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 comes into contact with them. The tip of the first lip portion 3 comes into contact with the outer plate 5. The second inclined surface 41 comes into contact with the inner plate 6.

Description

Technical Field

[0001] The present invention relates to a seal ring for a chain and a chain provided with the same.

Background Art

[0002] In order to seal lubricating oil (so-called grease) filled between a pin and a bush constituting a chain, an O-ring interposed between an outer plate and an inner plate has been conventionally used. The O-ring can exhibit a high sealing effect, but the sliding resistance when the outer plate and the inner plate rotate relative to each other is high. For this reason, there is a problem that the bending resistance of the entire chain becomes high and the energy transmission efficiency deteriorates.

[0003] In Patent Document 1 below, a seal is proposed in which a contact surface with a large area is brought into contact with an inner plate, and two seal portions with a small area are brought into contact with an outer plate to enhance the sealing action. However, here, the bending resistance of the entire chain has not been focused on.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The inventor has obtained the knowledge that by making the seal ring for the chain into a specific shape, it is possible to keep the bending resistance of the chain low while maintaining the necessary sealing performance.

[0006] The present invention has been made based on this knowledge, and its main object is to provide a seal ring for a chain that can keep the bending resistance low while maintaining the necessary sealing performance.

Means for Solving the Problems

[0007] This invention can be expressed as the invention described in the following items.

[0008] (Item 1) A chain seal ring interposed between an outer plate and an inner plate, and fitted onto a bushing, for sealing the lubricating oil filled between the bushing and the pin, A main body portion that is formed in an annular shape and extends inward, A first lip portion protrudes from the main body portion on one side in the thickness direction of the main body portion, The main body comprises a second lip portion that protrudes from the main body portion on 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. The outer surface of the first lip portion is a first inclined surface that slopes toward the main body portion as it moves away from the main body portion. The outer surface of the second lip portion is a second inclined surface that slopes toward the main body portion as it moves away from the main body portion. When attaching to the chain, The inner end of the main body is sandwiched between the end of the bush and the outer plate and comes into contact with them. The tip of the first lip portion is positioned to contact the outer plate. The second inclined surface is in contact with the inner plate. Chain sealing ring.

[0009] (Item 2) In terms of cross-sectional shape, the chain seal ring is symmetrical with respect to the axis of symmetry extending radially. Chain seal ring as described in item 1.

[0010] (Item 3) The inner end of the main body is shaped to bulge outward from the main body. Chain sealing ring as described in item 2.

[0011] (Item 4) In the cross-sectional shape, the first inclined surface and the second inclined surface form a V-shaped projection that protrudes radially outward. Chain sealing ring as described in item 2.

[0012] (Item 5) When attaching to the chain, The contact positions between the inner end of the main body and the outer plate, the contact positions between the tip of the first lip and the outer plate, and the contact positions between the second inclined surface and the inner plate are offset from each other in the radial direction of the chain seal ring. Chain sealing ring as described in item 2.

[0013] (Item 6) A chain equipped with a chain sealing ring as described in any one of items 1 through 5.

[0014] (Item 7) A method for manufacturing a chain using a chain seal ring described in any one of items 1 to 5, The process of loosely fitting the chain seal ring onto the bushing attached to the inner plate, The process includes the steps of: 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 bush; thereby deforming the chain seal ring so that the tip of the first lip portion comes into contact with the outer plate and the second inclined surface of the second lip portion comes into contact with the inner plate. A method for manufacturing chains. [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 suppress the bending resistance while maintaining the necessary sealing performance.

Brief Description of the Drawings

[0016] [Figure 1] It is an enlarged end face view of the main part of the seal ring for a chain according to an embodiment of the present invention. [Figure 2] It is an explanatory view showing a part of the chain during the incorporation of the seal ring for the chain in FIG. 1. [Figure 3] It is an enlarged cross-sectional view taken along the line A-A in FIG. 2. [Figure 4] It is an enlarged cross-sectional view of part B in FIG. 3. [Figure 5] It is an explanatory view showing a part of the chain incorporating the seal ring for the chain in FIG. 1. [Figure 6] It is an enlarged cross-sectional view taken along the line C-C in FIG. 5. [Figure 7] It is an enlarged cross-sectional view of part D in FIG. 3. [Figure 8] It is a graph showing the bending load of the chain incorporating the seal ring for the chain in FIG. 1.

Embodiments for Carrying Out the Invention

[0017] Hereinafter, a seal ring for a chain (hereinafter sometimes simply referred to as "seal ring") according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0018] (Configuration of the Seal Ring) The seal ring 1 of the present embodiment is interposed between the outer plate 5 and the inner plate 6, and is fitted to the bush 8 to seal the lubricating oil filled between the bush 8 and the pin 7 (see FIG. 7). The structure of the chain will be described later.

[0019] This seal ring 1 has a main body portion 2 that is formed in an annular shape and extends inward (to the right in Figure 1), a first lip portion 3 that protrudes from the main body portion 2 on one side in the thickness direction of the main body portion 2 (upper side in Figure 1), and a second lip portion 4 that protrudes from the main body portion 2 on 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. Additionally, 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] In this embodiment, the seal ring 1 has a cross-sectional shape (see Figure 1) that is symmetrical with respect to a virtual axis of symmetry (not shown) that extends radially (horizontally in Figure 1) to the seal ring 1.

[0023] The inner end of the main body portion 2 is a bulging portion 21 that bulges outward from the main body portion 2 (up and down and to the right in Figure 1).

[0024] In the seal ring 1 of this embodiment, the cross-sectional shape is formed by the first inclined surface 31 and the second inclined surface 41, creating a V-shape that protrudes radially outward (see Figure 1).

[0025] (Chain configuration using the seal ring of this embodiment) Here, with reference to Figures 2 to 7, the configuration of the chain incorporating the seal ring of this embodiment will be described. This chain has an outer plate 5, an inner plate 6, a pin 7, a bushing 8, and a roller 9. Here, 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 the process of incorporating the seal ring 1 into the chain), and Figures 5 to 7 show the state when the outer plate 5 is sufficiently close to the inner plate 6 (i.e., the state when the seal ring 1 has been incorporated into the chain).

[0026] The pin 7 is enclosed within the bushing 8, and lubricating oil (not shown) is filled between the pin 7 and the bushing 8. Two inner plates 6 are attached to the bushing 8, one above and one below. A roller 9 is loosely fitted to the outside of the bushing 8, in a position where it contacts the sprocket (not shown). Two outer plates 5 are attached to the pin 7, one above and one below. As shown in Figure 3, this embodiment of the chain uses two seal rings 1, but for the sake 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 state before crimping. The chain configuration itself can be the same as conventional chains, so further detailed explanation will be omitted.

[0027] In this embodiment, when the seal ring 1 is assembled into the 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 comes into contact with them. The tip of the first lip portion 3 also comes into contact with the outer plate 5. Furthermore, the second inclined surface 41 comes into contact with the inner plate 6.

[0028] Furthermore, in the seal ring 1 of this embodiment, when assembled into the 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 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 (left-right direction in Figure 7) of the seal ring 1.

[0029] (Method of manufacturing a chain using the seal ring of this embodiment) Next, a method for incorporating the seal ring 1 of this embodiment into the chain will be described, mainly with reference to Figures 2 to 4.

[0030] First, before attaching the outer plate 5 to the pin 7, the seal ring 1 is loosely fitted onto the bushing 8 attached to the inner plate 6 (see Figures 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 the main body 2 of the seal ring 1 is further sandwiched between the outer plate 5 and the bush 8, thereby deforming the seal ring 1. Once the outer plate 5 is 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 installed, the seal ring 1 receives a pressing force along the axial direction of the bushing 8 when the bulging portion 21 of the main body 2 comes into contact with the end of the bushing 8. As a result, the seal ring 1 rotates counterclockwise in Figure 4, the tip of the first lip portion 3 comes into contact with the outer plate 5, and the second inclined surface 41 of the second lip portion 4 comes into contact with the inner plate 6 (see Figure 7). In this embodiment of the seal ring 1, the main body 2 is provided with a first recess 22 and a second recess 23, so the first lip portion 3 and the second lip portion 4 are easily deformed (i.e., easily tilted) relative to the main body 2, and as shown in Figure 7, there is an advantage that the second inclined surface 41 can easily come into close contact with the inner plate 6. Therefore, a high sealing effect can be achieved by the second inclined surface 41.

[0033] Furthermore, in the seal ring 1 of this embodiment, the first lip portion 3 and the main body portion 2 each contact the outer plate 5, so a high sealing effect can be achieved in this respect as well. Moreover, since the tip of the first lip portion 3 contacts the outer plate 5 linearly, the sliding resistance when the outer plate 5 and the inner plate 6 rotate relative to each other can be kept low, and as a result, the bending load of the chain can be kept low.

[0034] Furthermore, in the seal ring 1 of this embodiment, when assembled into the 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 portion 3 and the outer plate 5, and the contact position between the second inclined surface 41 and the inner plate 6 are designed to be offset from each other in the radial direction (left-right direction in Figure 7) of the seal ring 1. Therefore, the compressive stress generated in the seal ring 1 when it is crushed between the outer plate 5 and the inner plate 6 can be released in the radial direction of the seal ring 1. As a result, the sliding resistance when the outer plate 5 and the inner plate 6 rotate relative to each other can be kept low, and as a result, the bending resistance of the chain can be further reduced.

[0035] Furthermore, the seal ring 1 of this embodiment has a cross-sectional shape that is symmetrical with respect to the axis of symmetry extending in the radial direction of the seal ring 1 (see Figure 1). Therefore, there is no need to consider the front or back side when installing the seal ring, which has the advantage of good workability. This ease of workability is important not only for mass-produced vehicles but also when adjusting the chain under very short periods of time and harsh conditions, such as in motorcycle racing competitions.

[0036] (Characteristics of the seal) A bending load test was performed on a chain using the seal ring 1 of this embodiment. The test conditions were as follows: with the chain bent into an M shape, a pressing load was applied from above to the center of the bent portion, and this pressing load was gradually increased to deform the chain, and the maximum load at the time of deformation was read. The results are shown in Figure 8. In Figure 8, the vertical axis shows the maximum load (N) at the time of chain deformation in the bending load test. The horizontal axis of Figure 8 corresponds to examples where the gap (set height) between the outer plate 5 and the inner plate 6 was changed, and the horizontal axis shows examples of set heights of 1.10 mm, 1.20 mm, and 1.30 mm from left to right. The maximum value (max), minimum value (min), and average value (ave) are plotted for each example.

[0037] Even when the set height is reduced (i.e., the amount of deformation of the seal ring 1 is increased), the bending load hardly increases. Reducing the set height allows the chain width (the width of the chain in the axial direction of the pin) to be reduced. Therefore, this result shows that the bending load of the chain can be reduced while reducing the chain width. In addition, although not shown in the figures, preliminary tests using a normal O-ring showed that the bending load in the chain using the O-ring was about twice that of the result in Figure 8. From this result, it can be seen that the seal ring 1 of this embodiment can achieve a lower bending load for the chain compared to an O-ring.

[0038] Therefore, the seal ring 1 of this embodiment can improve the energy transfer efficiency of the chain.

[0039] It should be noted that the content of the present invention is not limited to the embodiments described above. The present invention can be modified in various ways to a specific configuration within the scope of the claims.

[0040] For example, the specific configuration of the chain is not limited to those mentioned above; various configurations are possible. [Explanation of Symbols]

[0041] 1 Chain sealing ring 2 Main body 21 Bulge 22 First recess 23 Second recess 3. First lip section 31 1st slope 4. Second lip section 41 Second slope 5. Outer plate 6. Inner plate 7 pins 8 Bush 9 Laura

Claims

1. A chain seal ring interposed between an outer plate and an inner plate, and fitted onto a bushing, for sealing the lubricating oil filled between the bushing and the pin, A main body portion that is formed in an annular shape and extends inward, A first lip portion protrudes from the main body portion on one side in the thickness direction of the main body portion, The main body comprises a second lip portion that protrudes from the main body portion on 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. The outer surface of the first lip portion is a first inclined surface that slopes toward the main body portion as it moves away from the main body portion. The outer surface of the second lip portion is a second inclined surface that slopes toward the main body portion as it moves away from the main body portion. When attaching to the chain, The inner end of the main body is sandwiched between the end of the bush and the outer plate and comes into contact with them. The tip of the first lip portion is positioned to contact the outer plate. The second inclined surface is in contact with the inner plate. Chain sealing ring.

2. In terms of cross-sectional shape, the chain seal ring is symmetrical with respect to the axis of symmetry extending radially. A chain seal ring according to claim 1.

3. The inner end of the main body is shaped to bulge outward from the main body. The chain seal ring according to claim 2.

4. In the cross-sectional shape, the first inclined surface and the second inclined surface form a V-shape that protrudes radially outward. The chain seal ring according to claim 2.

5. When attaching to the chain, The contact positions between the inner end of the main body and the outer plate, the contact positions between the tip of the first lip and the outer plate, and the contact positions between the second inclined surface and the inner plate are offset from each other in the radial direction of the chain seal ring. The chain seal ring according to claim 2.

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

7. A method for manufacturing a chain using a chain seal ring according to any one of claims 1 to 5, The process of loosely fitting the chain seal ring onto the bushing attached to the inner plate, The process includes the steps of: 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 bush; thereby deforming the chain seal ring so that the tip of the first lip portion comes into contact with the outer plate and the second inclined surface of the second lip portion comes into contact with the inner plate. A method for manufacturing chains.

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