Durable bumper

Abstract

A rebound bumper for a shock absorber includes a first portion formed of a first material having a first spring rate and a second portion coupled to the first portion and formed of a second material having a second spring rate greater than the first spring rate. The first portion and the second portion are configured to fit over a piston rod between a piston and a rod guide assembly of the shock absorber. Further, the rebound bumper exhibits a load displacement relationship having the first spring rate, the second spring rate, and a third spring rate greater than the first spring rate but less than the second spring rate.

Description

Technical Field

[0001] The present invention relates to a buffer, and more particularly to a rebound buffer for a shock absorber. Background Technology

[0002] The statements in this section are provided only as background information in connection with this disclosure and do not constitute prior art.

[0003] A vehicle shock absorber has a pressure tube and a piston attached to a piston rod disposed within the pressure tube. Hydraulic fluid (e.g., oil) is contained in the pressure tube, and the piston slides within the pressure tube and "operates" on the hydraulic fluid to suppress shock pulses through viscous friction.

[0004] For example, when a vehicle's tires run over or hit a bump in the road, the tires shift toward the chassis and the piston slides against and / or through the hydraulic fluid in the pressure tube. The work done by the piston on the hydraulic fluid converts kinetic energy into heat, thus absorbing or cushioning the impact of the tires on the road surface.

[0005] After rolling over the bump, the shock absorber depressurizes or "rebounds," causing the piston to move away from the bottom of the pressure tube and slide towards the top. Depending on factors such as vehicle speed and the size of the bump, the piston may strike the top of the pressure tube, damaging the piston or the top of the pressure tube and producing undesirable noise (e.g., a clicking or knocking sound). Therefore, the shock absorber includes a "rebound damper" between the piston and the top of the pressure tube to absorb the piston's impact during such a "rebound event."

[0006] This disclosure addresses the durability issues of springback buffers and other problems associated with springback buffers. Summary of the Invention

[0007] This section provides a general overview of this disclosure and is not a full disclosure of its entire scope or all its features.

[0008] In one form of this disclosure, a rebound damper for a shock absorber having a pressure tube, a piston, a piston rod, and a rod guide assembly comprises: a first portion formed of a first material having a first spring stiffness, and a second portion connected to the first portion and formed of a second material having a second spring stiffness greater than the first spring stiffness. The first and second portions are configured to be disposed on (i.e., mounted on) a piston rod between the piston and the rod guide assembly. Furthermore, the rebound damper exhibits a load-displacement relationship having a first spring stiffness, a second spring stiffness, and a third spring stiffness greater than the first spring stiffness but less than the second spring stiffness.

[0009] In some variations, the first part is a first ring and the second part is a second ring. And in at least one variation, the first part is a first ring having multiple alternating thick and thin portions extending in the circumferential direction. In this variation, the first ring may have an undulating shape in the circumferential direction.

[0010] In some variations, the first part is a first ring formed of an elastic material, while the second part is a second ring formed of a material selected from the group consisting of metallic and polymeric materials. In at least one variation, the metallic material is steel and the polymeric material is a nylon blend.

[0011] In some variations, the first part is a first ring and the second part is a second ring disposed within the first ring. In such variations, the first ring may have an outer diameter between about 20 mm and about 75 mm, while the second ring may have an inner diameter between about 5 mm and about 40 mm.

[0012] In other variations, the first part is a first ring, the second part is a second ring, and the first ring is disposed within the second ring. In such variations, the first ring may have an inner diameter between about 5 mm and about 40 mm, while the second ring may have an outer diameter between about 20 mm and about 75 mm.

[0013] In some variations, the second part is a second ring with a wavy shape in the circumferential direction. For example, the second ring can be a wave spring.

[0014] In at least one variant, the rebound buffer is substantially composed of a first part and a second part, wherein the first part is a first ring formed of an elastic material, and the second part is a second ring formed of a material selected from the group consisting of metallic materials and polymeric materials.

[0015] In some variations, a shock absorber is included, comprising a pressure tube, a piston, a piston rod, and a rod guide assembly, with a first portion and a second portion disposed on the piston rod between the piston and the rod guide assembly.

[0016] In another form of this disclosure, a rebound damper for a shock absorber includes: a first ring formed of an elastic material having a first spring stiffness, and a second ring coupled to the first ring and formed of a second material having a second spring stiffness greater than the first spring stiffness. The first ring has a plurality of alternating thick and thin portions extending in a circumferential direction, and the first and second rings are configured to be disposed on a piston rod between a piston and rod guide assembly of the shock absorber. Furthermore, the rebound damper exhibits a load-displacement relationship having a first spring stiffness, a second spring stiffness, and a third spring stiffness greater than the first spring stiffness but less than the second spring stiffness.

[0017] In some variations, the second ring is located inside the first ring, while in other variations, the first ring is located inside the second ring.

[0018] In another form of this disclosure, the shock absorber includes a pressure tube, a piston rod, a piston, a rod guide assembly, and a rebound damper on the piston rod disposed within the pressure tube between the piston and the rod guide assembly. The rebound damper is substantially composed of a first ring and a second ring, the first ring being formed of a first material having a first spring stiffness, and the second ring being coupled to the first ring and formed of a second material having a second spring stiffness greater than the first spring stiffness. The first ring has a plurality of alternating thick and thin portions extending circumferentially, and the rebound damper exhibits a load-displacement relationship having a first spring stiffness, a second spring stiffness, and a third spring stiffness greater than the first spring stiffness and less than the second spring stiffness.

[0019] Other application areas will become more apparent from the description provided herein. It should be understood that the descriptions and specific examples are for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0020] To better understand this disclosure, various forms of the disclosure are described by way of example with reference to the accompanying drawings, wherein:

[0021] Figure 1 This is a cross-sectional side view of a shock absorber based on the teachings of this disclosure;

[0022] Figure 2 This is a perspective view of a springback buffer according to one form of the present disclosure;

[0023] Figure 3 It is along Figure 2 The cross-sectional view taken by section line 3-3 in the figure;

[0024] Figure 4 These are graphs showing the load versus displacement for three different types of rebound buffers;

[0025] Figure 5 This is a cross-sectional view of another form of springback buffer according to this disclosure; and

[0026] Figure 6 This is a perspective view of another form of springback buffer according to the present disclosure.

[0027] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this disclosure in any way. Detailed Implementation

[0028] The following description is exemplary in nature only and is not intended to limit this disclosure, its application, or its uses. It should be understood that in all the drawings, corresponding reference numerals denote the same or corresponding parts and features. Examples are provided to fully convey the scope of this disclosure to those skilled in the art. Numerous specific details, such as the types of particular components and devices, are set forth to provide a thorough understanding of variations of this disclosure. It will be apparent to those skilled in the art that specific details are not required and that the examples provided herein may include alternative forms or variations, and are not intended to limit the scope of this disclosure. In some examples, well-known processes, well-known device structures, and well-known techniques are not described in detail.

[0029] refer to Figure 1 The diagram illustrates a shock absorber 10 with a rebound damper 200 according to the teachings of this disclosure. The shock absorber 10 includes a pressure tube 100 having a lower (-z direction) end 102 and an upper end 104 (+z direction). A rod guide assembly 106 is disposed within the upper end 104 of the pressure tube 100, and a piston rod 140 is disposed within and slides within the rod guide assembly 106. A piston 146 is attached to the piston rod 140 near its lower end 142, and the piston 146 has an upper surface 147 and one or more valves (not shown) to allow fluid to pass through the piston 146 in a controlled manner. The piston rod 140 has a lower end 142 disposed within the pressure tube 100 and an upper end 144 disposed outside the pressure tube 100. The rebound damper 200 is disposed on the piston rod 140 and supported by a rod collar 149 between the piston 146 within the pressure tube 100 and the rod guide assembly 106. In some variations, mounting 170 is attached to lower end 102, thereby attaching or mounting lower end 102 to an unsprung load (e.g., a wheel) and upper end 102 of piston rod is attached or mounted to a sprung load (e.g., a vehicle frame).

[0030] In some variations, the shock absorber 10 is a dual-tube shock absorber 10, with an outer tube 160 disposed around and sealed to the pressure tube 100. In these variations, the outer tube 160 serves as a reservoir for hydraulic fluid (e.g., oil), and the lower end 102 of the pressure tube 100 includes at least one valve (not shown), thereby allowing hydraulic fluid to flow between the pressure tube 100 and the outer tube 160 during the use or operation of the shock absorber 10.

[0031] refer to Figure 2 and Figure 3 ,exist Figure 2 A perspective view of a springback buffer 200 according to one form of the present disclosure is shown in the figure. Figure 3 The middle shows along Figure 2A cross-sectional view taken from section line 3-3. The rebound buffer 200 includes a first portion 210 and a second portion 220. In some variations, the first portion 210 and the second portion 220 are formed of the same material. In other variations, the first portion 210 is formed of a first material and the second portion 220 is formed of a second material different from the first material. In such variations, the first material has a first elasticity and a first spring stiffness and the second material has a second elasticity and a second spring stiffness, respectively different from the first elasticity and the first spring stiffness. As used herein, the term or phrase "spring stiffness" refers to the change in displacement (D) of a material with respect to a load (L) on the material (i.e., ΔD / ΔL). In at least one variation, the first spring stiffness is less than the second spring stiffness.

[0032] Non-limiting examples of the first material include natural rubber and elastomers with viscoelasticity, low Young's modulus, and high strain failure rate, such as isoprene rubber, butadiene rubber, chloroprene rubber, butyl rubber, ethylene propylene rubber, epichlorohydrin rubber, polyacrylic acid rubber, silicone rubber, polyurethane, etc. Non-limiting examples of the second material include nylon, high-density polyethylene, polyurethane, steel, stainless steel, etc.

[0033] Part 210 has an undulating shape 'U' in the circumferential direction 'C', such as Figure 2 As shown. In some variations, multiple alternating thick (z-direction) portions 212 with thickness t1 and thin portions 214 with thickness t2 (t2 < t1) define an undulating shape U. In at least one variation, an upper space 'SA' and a lower space 'SB' exist or are provided between the alternating thick portions 212. Furthermore, the first portion 210 has an internal dimension 'd1' (e.g., inner diameter d1) and an external dimension 'd2' (e.g., outer diameter d2).

[0034] The second part 220 has an annular shape and is disposed within the first part 210. In some variations, the second part 220 has a constant thickness 'h1'. Figure 3 The first part 210 has a constant width (in the r direction), an internal dimension 'd3' (e.g., inner diameter d3), and an external dimension 'd1' (e.g., outer diameter d1). In some variations, the first part 210 is molded onto the second part 220.

[0035] The internal dimension d3 of the second part 220 allows the springback buffer 200 to slide relative to the piston rod 140 on the piston rod 140, and the external dimension d2 of the first part 210 allows the springback buffer to slide relative to the pressure tube 100 within the pressure tube 100. Non-limiting examples of the external dimension d2 are between about 20 mm and about 75 mm, and non-limiting examples of the internal dimension d3 are between about 5 mm and about 40 mm.

[0036] During a rebound event, the rebound damper 200 is compressed between the rod collar 149 and the rod guide assembly 106, and the upper surface 211 and lower surface 213 of the thick portion 212 are displaced (compressed) toward each other. Furthermore, the upper and lower spaces SA, SB provide deformable openings or volumes for the thick portion 212, and unlike conventional rebound dampers, the rebound damper 200 suppresses unwanted rebound noise and has enhanced durability as described below.

[0037] When the shock absorber 10 is in use, the upper end 144 of the piston rod 140 is attached to the vehicle frame (not shown), and the mount 170 is attached to the vehicle wheel (not shown). As described above, when the vehicle travels along a surface (e.g., a road) and the vehicle's tires impact a protrusion on or in the surface, the shock absorber receives an impact pulse, and the piston 146 slides within the pressure tube 100 toward the lower end 102 of the pressure tube 100 (i.e., the shock absorber 10 compresses). The impact pulse is suppressed by the piston 146 acting on hydraulic fluid, and after the tire rolls over the protrusion, the shock absorber 10 depressurizes or rebounds as the piston 146 slides within the pressure tube 100 toward the upper end 104 of the pressure tube 100. If forceful enough, the depressurization of the shock absorber 10 results in a rebound event, and the rebound damper 200 is compressed between the rod collar 149 and the lower surface 107 of the rod guide assembly 106. Furthermore, as described below, repeated rebound events can limit the durability (life) of the rebound damper.

[0038] refer to Figure 4 The figure shows load versus displacement (i.e., compression) curves simulating a conventional spring buffer (curve 1), a finite-stroke spring buffer (curve 2), and a spring buffer 200 (curve 3). The conventional spring buffer is simulated as a simple annular elastic buffer with a thickness (z-direction) of 5 mm. The finite-stroke spring buffer is simulated as a two-piece buffer, consisting of an annular elastic (soft) portion with a thickness of 5 mm and an annular rigid portion arranged within the annular elastic portion. Furthermore, after the annular elastic portion is compressed by 3.5 mm, the annular rigid portion exhibits high spring stiffness. The spring buffer 200 is simulated as... Figures 2-3 The diagram shows a two-piece buffer with a first portion 210 and a second portion 220. The first portion 210 has a thickness of 5 mm, and the second portion 110 exhibits high spring stiffness after the first portion 210 is compressed by 3.5 mm. The graphs are calculated / simulated using a conventional rebound buffer, the annular elastic portion of a finite-stroke buffer, and the first portion 210 of the rebound buffer 200 made of a material with low spring stiffness (e.g., natural rubber). The annular stiffness portion of the finite-stroke buffer and the second portion 220 of the rebound buffer are made of steel.

[0039] As shown in curve 1, the deformation of a conventional springback buffer is unconstrained, and the displacement increases with increasing load. Furthermore, curve 1 provides a baseline for comparison with materials with low spring stiffness. A finite-stroke springback buffer (curve 2) exhibits the same load and displacement (curve 1) as the conventional springback buffer (curve 1), with a maximum displacement of 3.5 mm. However, the finite-stroke springback buffer is limited by additional displacement; therefore, curve 2 has the same first segment as curve 1 between displacements of 0 to 3.5 mm and loads of 0 to approximately 5000 Newtons (N), and a second segment corresponding to loads greater than 5000 N. Thus, the finite-stroke springback buffer (curve 2) can withstand loads of approximately 5000 N to 10000 N without additional displacement. That is, the maximum load that the annular elastic portion of the finite-stroke springback buffer can withstand is only 5000 N, but the load that the annular rigid portion can withstand is greater than 5000 N.

[0040] Up to a displacement of approximately 1.5 mm, the rebound buffer 200 exhibits the same load-displacement relationship as a conventional rebound buffer (curve 1), but then exhibits higher spring stiffness between approximately 1.5 mm and 3.5 mm. Therefore, curve 3 has a first segment with the same low spring stiffness as curve 1 between a displacement of 0 to approximately 1.5 mm and a load of 0 to approximately 1000 N, a second segment with high spring stiffness between a displacement of approximately 1.5 mm to 3.5 mm and a load of 1000 to approximately 7500 N, and a third segment corresponding to a load greater than approximately 7500 N. In other words, the first portion 210 and the second portion 220 exhibit displacements with a first spring stiffness, a second spring stiffness, and a third spring stiffness greater than the first spring stiffness but less than the second spring stiffness. It should be understood that the intermediate (third) spring stiffness increases the load-carrying capacity of the rebound buffer 200 by 50% compared to a finite-stroke rebound buffer before reaching a displacement of 3.5 mm.

[0041] refer to Figure 5 , Figure 5 A perspective cross-sectional view of another form of spring buffer 200a according to the present disclosure is shown. Similar to spring buffer 200, spring buffer 200a includes a first portion 210a formed of a first material having low spring stiffness and a second portion 220a formed of a second material having high spring stiffness. However, unlike spring buffer 200, the second portion 220a, in the form of a ring, is disposed around or outside the first portion 210a.

[0042] Still referencing Figure 5The first portion 210a has a wavy shape 'U' in the circumferential direction 'C', and in some variations, multiple alternating thick (z-direction) portions 212a with a thickness t4 and multiple thin portions 214a with a thickness t5 (t5 < t4) define the undulating shape U. Furthermore, the first portion 210a has an internal dimension 'd4' (e.g., inner diameter d4) and an external dimension 'd5' (e.g., outer diameter d5).

[0043] The second portion 220a has an annular shape and is disposed around or outside the first portion 210a. In some variations, the second portion 220a has a constant thickness 'h2', a constant width (r direction), an outer dimension 'd6' (e.g., outer diameter d6), and an inner dimension 'd5' (e.g., inner dimension d5). In at least one variation, the first portion 210a is molded onto the second portion 220a.

[0044] The internal dimension d4 of the first part 210a allows the springback buffer 200a to slide relative to the piston rod 140 on the piston rod 140, while the external dimension d6 of the second part 220a allows the springback buffer 200a to slide relative to the pressure tube 100 within the pressure tube 100. Non-limiting examples of the external dimension d6 are between about 20 mm and about 75 mm, and non-limiting examples of the internal dimension d4 are between about 5 mm and about 40 mm.

[0045] Similar to the springback buffer 200, during a springback event, the springback buffer 200a is compressed between the piston 146 and the rod guide assembly 106, and the upper surface 211a and lower surface 213a of the thick portion 212a are displaced toward each other. Furthermore, the vertical space (not marked) between the alternating thick portions 212a provides openings or volumes for deformation of the thick portions 212a. And unlike conventional springback buffers, the springback buffer 200a has the enhanced durability of the springback buffer 200 as described above.

[0046] refer to Figure 6 A perspective view of another form of spring buffer 200b according to this disclosure is shown. Similar to spring buffers 200 and 200a, spring buffer 200b includes a first portion 210b formed of a first material having low spring stiffness and a second portion 220b formed of a second material having high spring stiffness. However, unlike spring buffer 200a, the second portion 220b has the form of a loop with a wave 'W' in the circumferential direction C (e.g., a wave spring). That is, the upper (+z direction) surface and the lower (-z direction) surface of the second portion 220b are not in the same plane, and the engagement of the second portion 220b is the distance between the crests of the wave in the +z and -z directions.

[0047] Still referencingFigure 6 The first portion 210b has an undulating shape 'U' in the circumferential direction 'C', and in some variations, multiple alternating first segments 212b with a first thickness (unmarked) in the z-direction and second segments 214b with a second thickness (unmarked) less than the first thickness define the undulating shape U. Furthermore, the first portion 210b has an internal dimension 'd7' (e.g., inner diameter d7) and an external dimension 'd8' (e.g., outer diameter d8).

[0048] As described above, the second portion 220b has an annular shape and is disposed around or outside the first portion 210b. In some variations, the second portion 220b has a constant thickness (not marked), a constant width (r direction), an outer dimension 'd9' (e.g., outer diameter d9), and an inner dimension 'd8' (e.g., inner diameter d8). In some variations, the first portion 210b is molded onto the second portion 220b.

[0049] The internal dimension d7 of the first part 210b causes the springback buffer 200b to slide relative to the piston rod 140 on the piston rod 140, while the external dimension d9 of the second part 220b causes the springback buffer 200b to slide relative to the pressure tube 100 within the pressure tube 100. Non-limiting examples of the external dimension d9 are between about 20 mm and about 75 mm, and non-limiting examples of the internal dimension d7 are between about 5 mm and about 40 mm.

[0050] Similar to springback buffer 200, during a springback event, springback buffer 200b is compressed between piston 146 and rod guide assembly 106, and the upper (unmarked) and lower (unmarked) surfaces of thick section 212b are displaced toward each other. Furthermore, the vertical space (unmarked) between the alternating thick sections 212b provides openings or volumes for deformation of the thick sections 212b. Additionally, springback buffer 200b has enhanced load-bearing capacity and durability, as described above with respect to springback buffer 200.

[0051] although Figure 6 The spring buffer 200b shown has a second portion 220b disposed around or outside the first portion 210b, but it should be understood that the first portion 210b may be disposed around or outside the second portion 220b, as described above with respect to the spring buffer 200.

[0052] It should be understood from the teachings of this disclosure that a durable rebound damper, such as a particularly durable rebound damper, is provided having a first portion made of a first material and a second portion made of a second material. The first material has a low spring stiffness and the second material has a high spring stiffness greater than the low spring stiffness. Combined, the first and second portions provide a rebound damper with three spring stiffnesses when subjected to load. Specifically, the rebound damper exhibits a low spring stiffness when subjected to low loads (e.g., less than 1000 N), a medium spring stiffness when subjected to medium loads (e.g., between 1000 and 7500 N), and a high spring stiffness when subjected to high loads (e.g., greater than 7500 N). The medium spring stiffness increases the load-bearing capacity of the first portion and increases the durability of the rebound damper.

[0053] When an element or layer is referred to as “on,” “mounted,” “joined to,” “connected to,” “attached to,” or “attached to” another element or layer, it can be directly on, joined, connected to, or attached to the other element or layer, or there may be intermediate elements or layers present. Conversely, when an element is referred to as “directly on,” “directly joined to,” “directly connected to,” or “directly attached to” another element or layer, there may be no intermediate elements or layers present. Other terms used to describe relationships between elements should be interpreted in a similar manner (e.g., “between” vs. “directly between,” “adjacent” vs. “directly adjacent,” etc.). As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0054] While the terms first, second, third, etc., may be used to describe various elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may only be used to distinguish one element, component, region, layer, and / or segment from another. Unless the context clearly indicates otherwise, terms such as “first,” “second,” and other numerical terms used herein do not imply order or sequence. Therefore, without departing from the teaching of the exemplified form, a first element, component, region, layer, or segment may be referred to as a second element, component, region, layer, or segment. Furthermore, where it is not necessary to refer to an element, component, region, layer, or segment as a “first” element, component, region, layer, or segment, it may be referred to as a “second” element, component, region, layer, or segment.

[0055] Spatial relation terms, such as “inside,” “outside,” “below,” “below,” “down,” “above,” “up,” etc., are used herein to describe the relationship between one element or feature and another element or feature as shown in the figure. In addition to the orientation depicted in the figure, spatial relative terms may be intended to cover different orientations of the device in use or operation. For example, if the device in the figure is flipped, an element described as “below” or “below” other elements or features would be oriented “above” other elements or features. Thus, the example term “below” can include an orientation above or below. The device may be oriented in other ways (rotated 90 degrees or otherwise) and the spatial relation descriptors used herein should be interpreted accordingly.

[0056] As used herein, the phrases A, B, and C at least one should be interpreted as representing logic (A or B or C), using non-exclusive logical OR, and should not be interpreted as representing "at least one A, at least one B, and at least one C".

[0057] Unless otherwise expressly stated, all numerical values ​​representing mechanical / thermal properties, percentage of composition, dimensions and / or tolerances or other characteristics should be understood to be modified by the terms "about" or "approximately" as described in the scope of this disclosure. Such modifications are necessary for a variety of reasons, including industrial practice, manufacturing techniques, and testing capabilities.

[0058] The terminology used herein is for the purpose of describing particular exemplary forms only and is not intended to be limiting. The singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. The terms “comprising” and “having” are inclusive and thus specify the presence of the stated feature, integer, step, operation, element, and / or component, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Unless explicitly identified as an order of execution, the method steps, processes, and operations described herein should not be construed as necessarily requiring performance in the specific order discussed or shown. It should also be understood that additional or alternative steps may be employed.

[0059] The description in this disclosure is exemplary in nature only, and therefore examples that do not depart from the spirit of this disclosure are intended to fall within its scope. Such examples should not be considered as departing from the spirit and scope of this disclosure. The broad teachings of this disclosure can be implemented in many forms. Therefore, although this disclosure includes specific examples, its true scope should not be so limited, as other modifications will become clearer upon examination of the drawings, description, and appended claims.

Claims

1. A rebound damper for a shock absorber having a pressure tube, a piston, a piston rod, and a rod guide assembly, for absorbing the impact of the piston and reducing noise during a rebound event, the rebound damper comprising: A first portion formed of a first material having a first spring stiffness, the first portion being a first ring having a plurality of alternating thick and thin portions extending in a circumferential direction; A second portion is formed by molding a second spring radially connected to the inner or outer side of the first portion, the second portion being formed of a second material having a second spring stiffness greater than that of the first spring. The height of the second part is between the height of the thick part and the height of the thin part of the first part. The first part and the second part are configured to be disposed on the piston rod between the piston and the rod guide assembly and exhibit a load-displacement relationship including a first spring stiffness, a second spring stiffness, and a third spring stiffness greater than the first spring stiffness but less than the second spring stiffness.

2. The rebound buffer according to claim 1, wherein the second part is a second ring.

3. The rebound buffer of claim 1, wherein the first portion is formed of an elastic material, and the second portion is a second ring formed of a material selected from the group consisting of metallic materials and polymeric materials.

4. The rebound buffer according to claim 3, wherein the metal material is steel and the polymer material is a nylon blend.

5. The rebound buffer according to claim 1, wherein the second part is a second ring disposed inside the first ring.

6. The rebound buffer according to claim 5, wherein the outer diameter of the first ring is between 20 mm and 75 mm, and the inner diameter of the second ring is between 5 mm and 40 mm.

7. The rebound buffer of claim 1, wherein the second portion is a second ring, and the first ring is disposed inside the second ring.

8. The rebound buffer according to claim 7, wherein the inner diameter of the first ring is between 5 mm and 40 mm, and the outer diameter of the second ring is between 20 mm and 75 mm.

9. The rebound buffer according to claim 1, characterized in that, The second part is a second ring that is wavy in the circumferential direction.

10. The rebound buffer of claim 9, wherein the second ring is a wave spring.

Images