Shock absorber bumper cover with collector

Abstract

A shock absorber is provided that includes a piston coupled to a piston rod slidably positioned in a shock absorber tube. A piston rod seal is positioned radially between the piston rod and the first end of the shock absorber tube. A cap is positioned over the first end of the shock absorber tube and includes a sidewall positioned in contact with and extending annularly around the first end of the shock absorber tube. The end wall extends radially inward from the sidewall. A collector extends radially outward from the sidewall. The cover includes a vent. The side wall includes an end face at an opposite end of the cover from the end wall. The collector is axially positioned between the vent and the end face of the sidewall. The collector includes a surface on which oil passing through the piston rod seal will accumulate.

Description

Technical Field

[0001] The present application relates to automotive shock absorbers. More specifically, the present application relates to a shock absorber bumper cover positioned at the piston rod end of the shock absorber. Background Art

[0002] The statements in this section merely provide background information related to the present application and may not constitute prior art.

[0003] Shock absorbers are often used in conjunction with automotive suspension systems or other suspension systems to absorb unwanted vibrations generated during the movement of the suspension system. To absorb these unwanted vibrations, automotive shock absorbers are often connected between the sprung (body) and unsprung (suspension / drivetrain) components of the vehicle.

[0004] A typical shock absorber includes a piston that is located in a fluid chamber defined by a shock absorber tube and is connected to the sprung mass of the vehicle by a piston rod. The shock absorber tube is connected to the unsprung mass of the vehicle. For the shock absorber to function properly, a seal must be maintained between the piston rod and the shock absorber tube. During standard operation of the shock absorber, dust particles and other contaminants may accumulate on the piston rod and the piston rod seal, which can cause damage to the piston rod and / or the piston rod seal. This damage can cause oil to leak from the fluid chamber.

[0005] There is also a phenomenon known as static oil leakage or "weeding," where very small amounts of oil continuously pass through the piston rod seal of the shock absorber. Large changes in operating temperature or pressure may increase static oil leakage. Oil that has leaked past the piston rod seal often flows along the outer surface of the shock absorber tube. This portion of the shock absorber is easily visible when viewing the underbody of a vehicle. While some oil leakage is typical during normal shock absorber operation, excessive fluid leakage may indicate a need for shock absorber service or replacement. Based on existing bumper cover designs, even the slightest amount of oil leakage will typically be directed toward the visible outer surface of the shock absorber tube, which may mislead the vehicle operator or inspector as to whether service is needed. Therefore, there remains a need for an improved bumper cover solution that directs minor oil leaks away from contact with the outer surface of the shock absorber. Summary of the invention

[0006] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0007] The shock absorber includes a piston coupled to a piston rod slidably positioned in a shock absorber tube. A piston rod seal is radially positioned between the piston rod and a first end of the shock absorber tube. A cover is positioned above the first end of the shock absorber tube and includes a side wall positioned to contact the first end of the shock absorber tube and to extend annularly around the first end of the shock absorber tube. An end wall extends radially inward from the side wall. A collector extends radially outward from the side wall. The cover includes a vent. The side wall includes an end face at an end of the cover opposite to the end wall. The collector is axially positioned between the vent and the end face of the side wall. The collector includes a surface on which oil passing through the piston rod seal will accumulate. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible embodiments, and are not intended to limit the scope of the present application.

[0009] Figure 1 is a schematic diagram of an example vehicle equipped with four shock absorbers constructed in accordance with the teachings of the present application; Figure 2 is a cross-sectional view of a shock absorber constructed according to the teachings of the present application; Figure 3 is an enlarged partial cross-sectional view of a shock absorber including an exemplary bumper cover constructed in accordance with the teachings of the present application; Figure 4 is a perspective view showing a bumper cover; Figure 5 Here is another stereoscopic view of the bumper cover; Figure 6 is a cross-sectional side view of the bumper cover; Figure 7 is a side view of the replacement bumper cover; Figure 8 yes Figure 7 A cross-sectional side view of the bumper cover is shown; Fig. 9 is a side view of another alternative bumper cover; and Fig.10 is a side view of another alternative bumper cover.

[0010] Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. DETAILED DESCRIPTION

[0011] The following description is merely exemplary and is not intended to limit the present application, applications, or uses.

[0012] Example embodiments are provided to make the present application more detailed and to fully convey the scope of the present application to those skilled in the art. Many specific details, such as examples of specific components, devices and methods, are set forth to provide a thorough understanding of the embodiments of the present application. It will be apparent to those skilled in the art that, without adopting specific details, example embodiments may be embodied in a variety of different forms, and none of them should be construed as limiting the scope of the present application. In some example embodiments, known processes, known device structures and known technologies are not described in detail.

[0013] The terms used herein are only used to describe specific example embodiments and are not restrictive. The singular forms "one", "an" and "the" used herein also include plural forms unless the context clearly indicates otherwise. The terms "comprise", "include", "contain" and "have" are inclusive and therefore specify the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or increase of one or more other features, integers, steps, operations, elements, parts and / or groups thereof. The method steps, processes and operations described herein should not be understood to be necessarily performed in the specific order discussed or described, unless the execution order is specifically specified. It should also be understood that other steps or alternative steps may also be used.

[0014] When an element or layer is referred to as being "on," "engaged to," "connected to," or "coupled to" another element or layer, it may be directly on, engaged to, connected to, or coupled to the other element or layer, or there may be intervening elements or layers. Conversely, when an element is referred to as being "directly on," "directly engaged to," "directly connected to," or "directly coupled to" another element or layer, there may be no intervening elements or layers. Other words used to describe the relationship between elements should also be interpreted in a similar manner (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.). The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0015] Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms may only be used to distinguish an element, component, region, layer or part from another region, layer or part. Unless the context clearly states, the "first", "second" and other numerical terms used herein do not mean order or sequence. Therefore, the first element, component, region, layer or part discussed below may be referred to as the second element, component, region, layer or part without departing from the teachings of the exemplary embodiments.

[0016] For ease of description, spatially relative terms such as "inside", "outside", "below", "beneath", "lower", "above", "upper", etc. may be used herein to describe the relationship between one element or feature and another element or feature shown in the figures. In addition to the orientations described in the figures, spatially relative terms may also include different orientations of the device in use or operation. For example, if the device in the figure is turned over, other elements or features described as "below" or "below" would be placed "above" the other elements or features. Therefore, the example term "below" can include both "above" and "below" orientations. The device can be oriented in other ways (rotated 90 degrees or other orientations), and the spatially relative descriptors used herein can be interpreted accordingly.

[0017] Reference Figure 1 , a vehicle 10 is shown, which includes a rear suspension 12, a front suspension 14, and a body 16. The rear suspension 12 is adapted to operably support rear wheels 18 of the vehicle. The rear axle assembly is operably connected to the body 16 via a pair of shock absorbers 20 and a pair of coil springs 22. Similarly, the front suspension 14 operably supports front wheels 24 of the vehicle. The front axle assembly is operably connected to the body 16 via a second pair of shock absorbers 26 and a pair of coil springs 28. The shock absorbers 20 and 26 are used to dampen relative movement of the unsprung portion (i.e., the front and rear suspensions 14 and 12) and the sprung portion (i.e., the body 16) of the vehicle 10. Although the vehicle 10 is described as a passenger vehicle having a front and rear axle assembly, the shock absorbers 20 and 26 may be used with other types of vehicles or machines, or for other types of applications, such as a vehicle including an independent front suspension system and / or an independent rear suspension system. Additionally, the term "shock absorber" as used herein refers generally to shock absorbers and shock absorber systems and thus will include MacPherson struts. It should also be understood that the subject matter of the present application is intended to include shock absorber systems for independent shock absorbers 20 and coil spring shock absorbers 26 .

[0018] Reference Figure 2 and Figure 3 , the shock absorber 26 is shown in more detail. The shock absorber 26 includes a shock absorber tube 30, a piston assembly 32, and a piston rod 34. The shock absorber tube 30 and the piston rod 34 extend coaxially along a longitudinal axis 35. The shock absorber tube 30 defines an inner cavity 42. The inner cavity 42 of the shock absorber tube 30 is filled with a hydraulic fluid, such as oil. The piston assembly 32 is slidably disposed in the inner cavity 42 of the shock absorber tube 30 and divides the inner cavity 42 into a first working chamber 44 and a second working chamber 46. A seal 48 is disposed between the piston assembly 32 and the shock absorber tube 30 to allow the piston assembly 32 to slide relative to the shock absorber tube 30 without generating excessive friction and to seal and isolate the first working chamber 44 from the second working chamber 46.

[0019] The piston rod 34 extends along the longitudinal axis 35 between a first piston rod end 49 and a second piston rod end 50. The shock absorber tube 30 extends longitudinally between a closed end 52 and a rod-side end 54. The second piston rod end 50 is disposed within the shock absorber tube 30 and is coupled to the piston assembly 32. Thus, the piston rod 34 extends longitudinally through the first working chamber 44 and through the rod-side end 54 of the shock absorber tube 30. The first piston rod end 49 includes a piston rod mount 56 that is configured to be connected to the body 16 of the vehicle 10 (i.e., the sprung portion of the vehicle 10). The closed end 52 of the shock absorber tube 30 includes an attachment fitting 58 that is configured to be connected to the unsprung portion of the suspension 12 and 14. Thus, the first working chamber 44 is positioned between the rod-side end 54 of the shock absorber tube 30 and the piston assembly 32, and the second working chamber 46 is positioned between the closed end 52 of the shock absorber tube 30 and the piston assembly 32. The rod guide 60 is positioned radially between the piston rod 34 and the rod-side end 54 of the shock absorber tube 30. A piston rod seal 62 is retained by the rod guide 60 and sealingly engages the piston rod 34.

[0020] Suspension movement of the vehicle 10 will cause extension / rebound or compression movement of the piston assembly 32 relative to the shock absorber tube 30. A valve within the piston assembly 32 controls the movement of hydraulic fluid between the first working chamber 44 and the second working chamber 46 during movement of the piston assembly 32 within the shock absorber tube 30. It should be appreciated that the shock absorber 26 may be mounted in reverse, with the piston rod mount 56 connected to the unsprung portion of the suspension 12 and 14, and the attachment fitting 58 of the shock absorber tube 30 connected to the vehicle body 16 (i.e., the sprung portion of the vehicle 10). Although Figure 2 Only the shock absorber 26 is shown, but it should be understood that the shock absorber 20 differs from the shock absorber 26 only in the manner in which it is adapted to be connected to the sprung and unsprung portions of the vehicle 10 and the mounting position of the coil spring 28 relative to the shock absorber 26. It should be further understood that the present application is related to twin-tube shock absorbers and other types of shock absorbers besides the monotube shock absorber shown in the figures. The bumper cover of the present application is configured to minimize the possibility of oil leakage through the piston rod seal 62 to prevent oil from contacting and flowing along the outer surface of the outermost tube of the shock absorber.

[0021] A shock absorber bumper cover 72 is positioned over the rod side end of the shock absorber tube 30 and the piston rod seal 62. The bumper cover 72 can be made of a variety of different materials, including but not limited to polypropylene, polyamide, or glass fiber reinforced polyamide. It should also be understood that the bumper cover 72 can be made using a variety of manufacturing processes, including but not limited to injection molding. The bumper cover 72 protects the piston rod seal 62 from contact with debris, dirt, or other shock absorber and suspension components (such as the bumper 74). The anti-fouling cover 75 is coupled to the piston rod mount 56 and at least partially encases the shock absorber tube 30.

[0022] See also Figures 4 to 6 , the bumper cover 72 includes a circumferentially extending side wall 76 and an end wall 78. The side wall 76 extends annularly around the rod side end 54 of the shock absorber tube 30 and extends longitudinally from the end wall 78 to the end face 80. The side wall 76 includes an inner surface 82, which is arranged to contact the shock absorber tube 30 in an interference fit manner. The inner surface 82 of the side wall 76 of the bumper cover 72 is cylindrical and smooth. The inner surface 82 does not have any ribs or protrusions like conventional shock absorber bumper covers. Therefore, oil flow cannot flow between the shock absorber tube 30 and the inner surface 82 of the side wall 76. This is different from conventional shock absorber bumper covers, in which ribs usually define a fluid channel between the shock absorber tube 30 and the side wall.

[0023] The end wall 78 extends radially inward from the side wall 76 and over at least a portion of the rod guide 60 to a rod hole 84. The piston rod 34 extends through the rod hole 84 in the end wall 78 of the bumper cover 72. The end wall 78 includes an inner surface 86 having a radially extending passage 88. The radially extending passage 88 on the inner surface 86 of the end wall 78 is provided in fluid communication with vents 90, which are configured as side wall openings in the illustrated embodiment that extend through the side wall 76 at circumferentially spaced locations adjacent to the junction between the side wall 76 and the end wall 78 of the bumper cover 72. The radially extending passage 88 and the vent 90 cooperate to allow air, water, dust, and contaminants to flow or drain from under the bumper cover 72 rather than accumulate between the end wall 78 of the bumper cover 72 and the piston rod seal 62. Optionally, the inner surface 86 of the end wall 78 may include a tapered surface 92 adjacent to the piston rod hole 84, which makes the inner surface 86 concave or conical around the rod hole 84. According to this structure, the radially extending passage 88 extends between the tapered surface 92 and the vent 90 to allow air, water, dust and contaminants to be discharged from the space formed by the tapered surface 92 on the inner surface 86 of the end wall 78.

[0024] The collector 96 extends radially outward from the sidewall 76. The collector 96 is used to increase the outer surface area of ​​the bumper cover 72. The increased surface area is used to drain oil that may pass through the piston rod seal 62 from the first working chamber 44. Since the shock absorber 26 is generally oriented vertically at least to some extent, Figure 2 Similar to the orientation shown, gravity forces the oil to flow past the piston rod seal 62 in a direction toward the attachment fitting 58. To minimize the possibility of oil impinging on or otherwise flowing through the shock absorber tube 30, the bumper cover 72 employs a combination of sealing engagement features between the inner surface 82 and the shock absorber tube 30, the vent 90, and the collector 96. Oil passing through the vent 90 passes through the outer surface 98 of the sidewall 76 to the collector 96. The outer surface 98 may have Figure 6Alternatively, the surface may be shaped as a right circular cylinder.

[0025] exist Figures 1 to 6 In the illustrated embodiment, the collector 96 includes a radially extending first flange 102, a radially extending second flange 104, and a radially extending third flange 106, which are axially spaced apart from each other. The first flange 102 includes a radially outwardly extending first surface 110, a radially outwardly extending opposite second surface 112, and an axially extending cylindrical surface 114 therebetween. The first flange 102 increases the surface area of ​​the bumper cover 72 by at least the area of ​​the first surface 110 and the second surface 112. The first flange 102 is substantially cylindrical and has a diameter D1. At an axial distance further from the vent 90, the second flange 104 is axially spaced apart from the first flange 102. The second flange 104 includes a radially outwardly extending third surface 118, a radially outwardly extending opposite fourth surface 120, and a cylindrical axially extending surface 122 therebetween. The second flange 104 is substantially cylindrical and has an outer diameter D2. The diameter D2 is greater than the diameter D1. Axially further away from the vent 90 is a third flange 106. The third flange 106 includes a radially outwardly extending fifth surface 124, an opposing radially extending sixth surface 126, and an axially extending circumferential surface 128 therebetween, the sixth surface 126 also being a portion of the end surface 80. The third flange 106 is substantially cylindrical and has a diameter D3 that is greater than D2.

[0026] As the oil flows through the piston rod seal 62 and through the vent 90, the oil will begin to be pushed by gravity along the surface 98. As the amount of oil increases, the oil will gather along and disperse around the first surface 110 of the first flange 102. If additional oil flows along this path, the surface 110 may no longer be sufficient to collect the entire amount of oil, and some of the oil may flow over the cylindrical surface 114. The oil may drip from this surface onto the third surface 118 of the second flange 104, or may continue to travel along the first flange 102 in contact with the second surface 112. The oil that reaches the third surface 118 of the second flange 104 will disperse along the circumference of the bumper cover 72 until the surface can no longer collect and retain the oil that passes through the vent 90. At this point, the oil may contact and flow over the circumferential surface 122 of the second flange 104. In a similar manner as described above, the oil may drip from the cylindrical surface 122 onto the fifth surface 124 of the third flange 106, or the oil may continue to adhere to the surface of the second flange 104 and contact the fourth surface 120. The oil on the second surface 112 of the first flange 102 may flow along the first intermediate surface 130, which is axially positioned between the first flange 102 and the second flange 104. Likewise, the oil flowing along the fourth surface 120 of the second flange 104 may continue to flow through the second intermediate surface 132, which is axially positioned between the second flange 104 and the third flange 106.

[0027] Oil contacting the fifth surface 124 of the third flange 106 will be dispersed around the bumper cover 72. If this surface is unable to collect additional oil and additional oil is provided, the oil will flow on the cylindrical surface 128. The diameter D3 is greater than the outer diameter of the shock absorber tube 30. Therefore, oil that may drip from the outer periphery of the third flange 106 is less likely to contact the outer surface of the shock absorber tube 30. It should be understood that the significant increase in surface area provided by the first flange 102, the second flange 104, and the third flange 106 reduces the possibility of oil seepage or small leakage from the piston rod seal 62 contacting the outer surface of the shock absorber tube 30. At least the provision of the collector 96 increases the amount of oil required for the oil to hit the outer surface of the shock absorber tube 30.

[0028] Figure 7An alternative bumper cover 150 is shown. The bumper cover 150 is substantially similar to the bumper cover 72 except for the configuration of the collector 152. The collector 152 includes a first protrusion 154 extending radially outward and a second protrusion 156 extending radially outward. The first protrusion 154 and the second protrusion 156 extend from a side wall 158 that is substantially similar to the side wall 76 described above. A vent 164 extends through the side wall 158 in a manner similar to the vent 90 described above. The first protrusion 154 and the second protrusion 156 extend circumferentially for a limited arc length and do not extend around the entire perimeter of the bumper cover 150. The first protrusion 154 is shaped as a reservoir that includes a first base 160 and a first retaining wall 162. The first base 160 may be tilted so that it does not extend completely transversely, but rather extends substantially transversely to the longitudinal axis 35 of the shock absorber 26. The first retaining wall 162 extends substantially parallel to the longitudinal axis 35. The first base 160 slopes downwardly toward the first retaining wall 162 so that an oil reservoir may be provided. The first protrusion 154 is aligned with the vent 164 so that oil flowing from the vent 164 may hit the first base 160. The first protrusion 154 extends radially outwardly from the side wall 158 a first distance.

[0029] The second protrusion 156 includes a second base 168 and a second retaining wall 170. The second base 168 extends substantially vertically in a slightly inclined manner in a different direction than the first base 160. The second retaining wall 170 extends substantially parallel to the longitudinal axis 35. The second protrusion 156 extends radially outward from the sidewall 158 a second distance that is greater than the first distance. The second protrusion 156 is positioned to capture oil that may no longer be collected and retained by the first protrusion 154. It should be understood that additional sets of first protrusions 154 and second protrusions 156 can be circumferentially spaced from each other and aligned with any other additional vents 164 provided on the bumper cover 150, such as Figure 8 A first protrusion 154a and a second protrusion 156a are shown.

[0030] Fig. 9A bumper cover of another alternative embodiment, identified by reference numeral 180, is shown. Bumper cover 180 is substantially similar to bumper cover 150. Bumper cover 180 includes a collector 182 including a first pool 184 and a second pool 186, which are axially spaced from each other and aligned with vent 190. First pool 184 includes a first floor 192 defined by first and second sidewalls 194, 196, respectively. First pool 184 includes a width W1. Second pool 186 includes a second floor 200 defined by first and second sidewalls 202, 204, respectively. Second pool 186 includes a width W2, which is greater than the width W1 of first pool 184. Therefore, oil leaving vent 190 can be retained in first pool 184 until the amount of oil exceeds its retention capacity. Additional oil will overflow from first pool 184 and be captured in second pool 186. Additional sets of first and second sumps 184, 186 may be circumferentially spaced from one another and associated with additional vents 190 disposed in the bumper cover 180. The first sump 184 extends radially outwardly a first distance from the sidewall 206. The second sump 204 extends radially outwardly a second distance from the sidewall 206 that is greater than the first distance.

[0031] Fig.10 Another alternative embodiment of a bumper cover is shown, identified by reference numeral 210. Bumper cover 210 is substantially similar to bumper cover 180. Similar elements will retain the same reference numerals including a prime suffix. Bumper cover 210 includes a first pool 184' and a second pool 186'. Bottom plate 192' includes a corrugated shape, thereby increasing the surface area of ​​bottom plate 192' relative to bottom plate 192. Similarly, bottom plate 200' of second pool 186' includes a corrugated shape having a surface area relative to bottom plate 192. Fig. 9 The surface area of ​​the bottom plate 200 is shown as an increased surface area. It is contemplated that the first pool 184' extends radially outwardly from the side wall 206' a first distance. The second pool 186' extends radially outwardly from the side wall 206' a second distance that is greater than the first distance.

[0032] The above description of the embodiments of the present invention is for the purpose of illustration and description. It is not intended to be exhaustive or to limit the present invention. The individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable and can be used for selected embodiments where applicable, even if not specifically shown or described. The same content can also have multiple variations. These variations should not be considered as departing from the subject matter of the present application, and all these modifications should be included in the scope of the subject matter of the present application.

Claims

1. A shock absorber for a vehicle, comprising: a shock absorber tube extending longitudinally between a first end and a second end; a piston rod extending along a longitudinal axis into a first end of the shock absorber tube; a piston coupled to the piston rod and slidably positioned in the shock absorber tube; a piston rod seal positioned radially between the piston rod and the first end of the shock absorber tube; as well as a cover positioned over the first end of the shock absorber tube, the cover comprising a side wall positioned to contact the first end of the shock absorber tube and extending annularly around the first end of the shock absorber tube, an end wall extending radially inwardly from the side wall, and a collector extending radially outwardly from the side wall relative to the longitudinal axis, wherein the end wall of the cover comprises a rod hole through which the piston rod extends, the cover comprises a vent, and the side wall comprises an end surface at an end of the cover opposite the end wall, Wherein, the collector is longitudinally positioned between the vent and the end surface of the side wall so that oil passing through the piston rod seal and through the vent will accumulate on the surface of the collector.

2. The shock absorber according to claim 1, wherein: The side wall of the cover extends longitudinally from the end wall to the end surface of the side wall.

3. The shock absorber according to claim 1, wherein: The collector includes a first flange extending radially outward from a sidewall, a second flange extending radially outward from the sidewall, and a third flange extending radially outward from the sidewall, wherein the first, second, and third flanges are longitudinally spaced apart from one another.

4. The shock absorber according to claim 3, wherein: Each of the first flange, the second flange, and the third flange extends uninterruptedly and circumferentially around the sidewall.

5. The shock absorber according to claim 4, wherein: The first flange includes a first outer diameter, the second flange includes a second outer diameter, and the third flange includes a third outer diameter, the third outer diameter being greater than the second outer diameter, the second outer diameter being greater than the first outer diameter.

6. The shock absorber according to claim 3, wherein: The third flange includes a surface that is coplanar with the end surface.

7. The shock absorber according to claim 1, wherein: The collector includes a first protrusion extending radially outward from the sidewall and a second protrusion extending radially outward from the sidewall, wherein the first protrusion extends a first distance from the sidewall and the second protrusion extends a second distance from the sidewall, wherein the first distance is less than the second distance.

8. The shock absorber according to claim 7, wherein: The first protrusion includes a first base extending substantially transverse to the longitudinal axis and a first wall extending substantially parallel to the longitudinal axis at one end of the first base.

9. The shock absorber according to claim 8, wherein: The second protrusion includes a second base extending substantially transverse to the longitudinal axis and a second wall extending substantially parallel to the longitudinal axis at one end of the second base.

10. The shock absorber according to claim 7, wherein: The first protrusion includes a first width, and the second protrusion includes a second width, the second width being greater than the first width.

11. The shock absorber according to claim 1, wherein: The piston rod extends longitudinally between a first end and a second end, the first end of the piston rod supporting a jounce bumper, the second end of the piston rod being coupled to a piston assembly, and the cap protecting the piston rod seal from contacting the jounce bumper when the shock absorber is in a compressed state.

12. The shock absorber according to claim 1, wherein: The side wall includes an inner surface that is cylindrical in shape, smooth, and arranged to be an interference fit with the shock absorber tube such that oil does not flow between the shock absorber tube and the inner surface of the side wall.

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