Damper with hydraulic end stop
By employing a sealing ring with multiple concave and convex surfaces and grooves in the damper, the problem of plastic deformation of the sealing ring during high-speed flow is solved, thereby achieving durability and noise reduction of the damper and improving the performance of the hydraulic rebound end stop.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ADVANCED SUSPENSION TECHNOLOGY LLC
- Filing Date
- 2020-07-10
- Publication Date
- 2026-06-05
AI Technical Summary
In existing hydraulic rebound end stop designs, the sealing ring is prone to plastic deformation during high-speed flow, leading to sealing ring failure, affecting damper function and increasing noise.
The sealing ring, designed with multiple concave and convex surfaces, combined with groove and channel structures, restricts fluid flow to control damping force, reduces plastic deformation of the sealing ring, and prevents leakage through a locking mechanism.
It improves the durability and adjustability of the damper, reduces noise, and enhances the performance stability and energy dissipation effect of the hydraulic rebound end stop.
Smart Images
Figure CN115435037B_ABST
Abstract
Description
[0001] This application is a divisional application of the international application filed on July 10, 2020, with international application number PCT / US2020 / 041500, national application number 202080050651.5, entitled "Damper with Hydraulic End Stop," which has entered the Chinese national phase.
[0002] Cross-references to related applications
[0003] This application claims priority and benefit to U.S. Patent Application No. 16 / 509,731, filed July 12, 2019, entitled “Damper with Hydraulic End Stop,” the entire contents of which are incorporated herein by reference. Technical Field
[0004] This disclosure generally relates to dampers. More specifically, this disclosure relates to dampers having hydraulically operated end stops. Background Technology
[0005] Shock absorbers / dampers are typically installed on various types of equipment, such as vehicles, to dampen vibrations during operation. For example, a damper is often connected between the vehicle's body and suspension system to absorb vibrations. A typical damper usually includes a pressure line, a reservoir, a piston, a piston rod, and one or more valves. During the compression and rebound strokes of the damper, the piston restricts the flow of damping fluid between chambers defined within the damper's body. The damper generates a damping force due to this flow to counteract vibrations. By further restricting the flow of damping fluid within the damper's chambers, the damper can generate an even greater damping force.
[0006] For comfort-related reasons, the damping force of a damper must not be increased beyond a certain threshold, as this could cause the vehicle's axles and damper to move at high speeds to the rebound limit. Hydraulic rebound end stops are typically provided to reduce the speed at which the damper moves to the rebound limit. Current hydraulic rebound end stop designs utilize sealing rings with controlled clearances, such as brass sealing rings. When such sealing rings enter the hydraulic rebound stop region toward the end of the rebound stroke, a high damping force is generated, which causes kinetic energy dissipation and contributes to noise reduction. Under certain conditions, such as when the sealing ring is outside the hydraulic rebound stop region or in a transition zone, high-velocity oil flowing around the sealing ring forces it to plastically deform and open. Such unlocking of the sealing ring can cause seal ring failure and subsequently affect the function of the hydraulic rebound end stop of the damper and the engagement within the damper. Summary of the Invention
[0007] In one aspect of this disclosure, a damper is provided. The damper includes a pressure tube defining a first end and a second end opposite to the first end. The damper also includes a piston slidably disposed within the pressure tube. The piston defines a rebound chamber and a compression chamber within the pressure tube. The damper further includes a piston rod adapted to reciprocate with the piston. The piston rod is partially received within the pressure tube. The damper includes a sealing ring slidably disposed around the piston rod. The sealing ring includes an inner surface facing the piston rod. The inner surface includes a plurality of concave surfaces and a plurality of convex surfaces. Each of the plurality of concave surfaces is positioned adjacent to a corresponding convex surface of the plurality of convex surfaces. The sealing ring also includes an upper surface extending between the outer surface and the inner surface. The upper surface defines a plurality of channels.
[0008] In another aspect of this disclosure, a damper is provided. The damper includes a pressure tube defining a first end and a second end opposite to the first end. The damper also includes a piston slidably disposed within the pressure tube. The piston defines a springback chamber and a compression chamber within the pressure tube. The damper further includes a piston rod adapted to reciprocate with the piston. The piston rod is partially received within the pressure tube. The damper includes a first collar disposed around the piston rod. The damper also includes a second collar disposed around the piston rod and axially spaced from the first collar. The damper further includes a sealing ring slidably disposed around the piston rod and between the first and second collars. The sealing ring includes an inner surface facing the piston rod. The inner surface includes a plurality of concave surfaces and a plurality of convex surfaces. Each of the plurality of concave surfaces is positioned adjacent to a corresponding convex surface of the plurality of convex surfaces. The sealing ring also includes an outer surface opposite to the inner surface. The outer surface defines at least one groove. The sealing ring also includes an upper surface extending between the outer and inner surfaces. The upper surface defines multiple channels.
[0009] In another aspect of this disclosure, a damper is provided. The damper includes a pressure tube defining a first end and a second end opposite to the first end. The damper also includes a piston slidably disposed within the pressure tube. The piston defines a springback chamber and a compression chamber within the pressure tube. The damper further includes a piston rod adapted to reciprocate with the piston. The piston rod is partially received within the pressure tube. The damper includes a first collar disposed around the piston rod. The damper also includes a second collar disposed around the piston rod and axially spaced from the first collar. The damper further includes a retaining ring disposed adjacent to the second collar and extending circumferentially along the piston rod. The retaining ring is at least partially received within an annular groove of the piston rod. The damper includes a sealing ring slidably disposed around the piston rod and between the first and second collars. The sealing ring includes an inner surface facing the piston rod. The inner surface includes a plurality of concave surfaces and a plurality of convex surfaces. Each of the plurality of concave surfaces is positioned adjacent to a corresponding convex surface of the plurality of convex surfaces. The sealing ring also includes an outer surface opposite to the inner surface. The outer surface defines at least one groove. The sealing ring also includes an upper surface extending between the outer and inner surfaces. The upper surface defines a plurality of channels.
[0010] Other features and aspects of this disclosure will become apparent from the following description and accompanying drawings. Attached Figure Description
[0011] Figure 1 This is an illustration of a vehicle with a suspension system incorporated according to aspects of this disclosure;
[0012] Figure 2 In accordance with the aspects of this disclosure Figure 1 A cross-sectional view of the dampers associated with the suspension system;
[0013] Figure 3A To show Figure 2 Another cross-sectional view of the detailed view of the damper;
[0014] Figure 3B To show with Figure 2 A cross-sectional view of another design of the first set of rings associated with the damper;
[0015] Figure 3C To show with Figure 2 A cross-sectional view of another design of the first set of rings associated with the damper;
[0016] Figure 4A To and Figure 2 A perspective view of the sealing ring associated with the damper;
[0017] Figure 4B for Figure 4A A top view of the sealing ring;
[0018] Figure 4C for Figure 4A Bottom view of the sealing ring;
[0019] Figure 4D for Figure 4A A perspective view of a portion of the sealing ring, showing the locking mechanism;
[0020] Figure 5 To show in Figure 2 A cross-sectional view of the fluid flow within the damper during the compression stroke of the damper;
[0021] Figure 6 To show in Figure 2 A cross-sectional view of the fluid flow within the damper during the rebound stroke of the damper;
[0022] Figure 7 To illustrate exemplary graphs of the peak damping force of sealing rings with different groove areas, these groove areas being defined by the grooves of the sealing ring; and
[0023] Figure 8 An exemplary graph illustrating a benchmark comparison between two different sealing rings.
[0024] In all the accompanying drawings, the same reference numerals will be used as much as possible to refer to the same or similar parts. Detailed Implementation
[0025] Figure 1 An exemplary vehicle 100 with an integrated suspension system 102 according to the present disclosure is shown. Vehicle 100 may include a vehicle powered by an internal combustion engine, an electric vehicle, or a hybrid vehicle. Vehicle 100 includes a body 104. The suspension system 102 of vehicle 100 includes a rear suspension 106 and a front suspension 108.
[0026] The rear suspension 106 includes a laterally extending rear axle assembly (not shown) adapted to operatively support a pair of rear wheels 110. The rear axle assembly is operatively connected to the body 104 via a pair of dampers 112 and a pair of coil springs 114. Similarly, the front suspension 108 includes a laterally extending front axle assembly (not shown) operatively supporting a pair of front wheels 116. The front axle assembly is operatively connected to the body 104 via another pair of dampers 112 and a pair of coil springs 118. In an alternative example, the vehicle 100 may include independent suspension units (not shown) for each of the four corners instead of the front and rear axle assemblies.
[0027] The damper 112 of the suspension system 102 is used to dampen the relative motion between the unsprung parts (i.e., the front suspension 108 and the rear suspension 106) and the sprung parts (i.e., the body 104) of the vehicle 100. Although the vehicle 100 is described as a passenger car, the damper 112 can be used with other types of vehicles or any equipment that requires damping. Examples of vehicles include buses, trucks, off-road vehicles, etc. Furthermore, the term "damper" as used herein generally refers to a damper and will include shock absorbers, MacPherson struts, and semi-active and active suspensions.
[0028] To automatically adjust each of the dampers 112, an electronic controller 120 is electrically connected to the damper 112. The controller 120 controls the operation of each damper 112 to provide appropriate damping characteristics generated by the movement of the body 104 of the vehicle 100. Additionally, the controller 120 can independently control each damper 112 to independently adjust the damping level of each damper 112. The controller 120 can be electrically connected to the dampers 112 via a wired connection, a wireless connection, or a combination thereof. In an example, each damper 112 may include a dedicated electronic controller, which may be located on the corresponding damper 112. Furthermore, the functions of the controller 120 can be executed by the electronic control unit (ECU) of the vehicle 100.
[0029] The controller 120 can independently adjust the damping level or characteristics of each damper 112 to optimize the riding performance of the vehicle 100. As used herein, the term "damping level" refers to the damping force generated by each damper 112 to counteract the motion or vibration of the vehicle body 104. A higher damping level can correspond to a larger damping force. Similarly, a lower damping level can correspond to a smaller damping force. Such adjustments to the damping level can be beneficial during braking and steering of the vehicle 100. The controller 120 may include a processor, memory, input / output (I / O) interfaces, communication interfaces, and other components. The processor can execute various instructions stored in the memory to perform various operations of the controller 120. The controller 120 can receive and transmit signals and data through the I / O interfaces and communication interfaces. Additionally, the controller 120 may include a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), etc.
[0030] Figure 2A cross-sectional view of damper 112 is shown. Damper 112 can be any one of the four dampers 112 of vehicle 100. Without any limitations, damper 112 may include a continuously variable semi-active suspension system (CVSA) damper or shock absorber. In the example shown, damper 112 is a two-tube damper. Alternatively, damper 112 may include a single-tube damper. Damper 112 may contain a fluid that may be hydraulic fluid or oil. Damper 112 includes a pressure tube 122 defining a first end 124 and a second end 126 opposite to the first end 124. Pressure tube 122 is implemented as a single-piece pressure tube. Pressure tube 122 may also be implemented as a generally cylindrical tube with an open end.
[0031] A piston 128 is slidably disposed within a pressure tube 122. The piston 128 defines a spring chamber 130 and a compression chamber 132 within the pressure tube 122. The spring chamber 130 is adjacent to a first end 124, while the compression chamber 132 is located away from the first end 124. Each of the spring chamber 130 and the compression chamber 132 contains fluid. The volume of each of the spring chamber 130 and the compression chamber 132 varies based on the reciprocating motion of the piston 128. Furthermore, a pair of piston valves (not shown) may be disposed within the piston 128 to regulate fluid flow between the spring chamber 130 and the compression chamber 132. More specifically, the piston valves may maintain a desired pressure in each of the spring chamber 130 and the compression chamber 132.
[0032] Additionally, piston 128 is connected to the body 104 of vehicle 100 via piston rod 134. Piston rod 134 is coupled to piston 128. Piston rod 134 is adapted to reciprocate with piston 128. Furthermore, piston rod 134 is partially received within pressure tube 122. Piston rod 134 extends through a first end 124 of pressure tube 122. Damper 112 also includes a piston rod guide assembly 136 disposed adjacent to the first end 124 of pressure tube 122 (see...). Figure 3A The movement of the piston rod 134 adjacent to the first end 124 is axially limited by the piston rod guide assembly 136.
[0033] In some examples, damper 112 may include a base valve (not shown). The base valve may be positioned adjacent to the second end 126 of pressure line 122. The base valve may allow fluid flow between compression chamber 132 and reservoir chamber 142. Additionally, at least one of the piston valve and the base valve may be controlled by controller 120. Figure 1 (As shown) to be electronically controlled, so that the controller 120 can adjust the piston valve and the base valve to control the damping level of the damper 112.
[0034] The damper 112 also includes a reservoir 138 disposed around the pressure pipe 122. In some examples, the reservoir 138 is concentrically disposed around the pressure pipe 122. The reservoir 138 defines a reservoir chamber 142. Specifically, the reservoir chamber 142 is disposed between the pressure pipe 122 and the reservoir 138. The reservoir chamber 142 may be in fluid communication with an external fluid reservoir (not shown), such as an accumulator. Additionally, the damper 112 may include a valve assembly (not shown) that provides fluid communication between the reservoir chamber 142 and the external fluid reservoir. In such examples, the valve assembly may regulate fluid flow between the reservoir chamber 142 and the external fluid reservoir. The valve assembly may be electronically controlled by a controller 120.
[0035] For reference Figure 3A The damper 112 includes a hydraulically rebound end stop system 300 disposed adjacent to a first end 124 of the damper 112. The hydraulically rebound end stop system 300 includes a rebound damper 302, a retaining ring 304, a first collar 306, a sealing ring 308, and a second collar 307. The damper 112 includes the rebound damper 302. The rebound damper 302 may embody an annular member made of plastic, polymer, elastic material, or metal, defining a through-hole (not shown) through which the piston rod 134 extends. The rebound damper 302 may be received within a space 140 defined between the piston rod 134 and the pressure tube 122. The rebound damper 302 surrounds the piston rod 134. In one example, the rebound damper 302 may be disposed around the piston rod 134 via a snap-fit arrangement. In some examples, the springback buffer 302 may be compressed when the piston 128 moves toward the first end 124 during the springback stroke or when the piston 128 is in a fully springback state against the springback buffer 302.
[0036] Additionally, the damper 112 includes a first collar 306. The first collar 306 is disposed around the piston rod 134 and adjacent to the springback buffer 302. The first collar 306 is embodied as an annular ring disposed around the piston rod 134, defining a through opening (not shown) for receiving the piston rod 134 passing therethrough. The first collar 306 includes a flat upper surface (not shown) and a flat lower surface (not shown) disposed opposite to the upper surface. The upper surface faces the springback buffer 302, while the lower surface faces the sealing ring 308. The first collar 306 may be made of plastic, polymer, or metal. In one example, the first collar 306 is slidable along the axis “A-A1” defined by the damper 112. Furthermore, the damper 112 includes a second collar 307 disposed around the piston rod 134 and axially spaced from the first collar 306. The second collar 307 includes a generally L-shaped cross-section defining a first portion 314, a second portion 316, and a through opening (not shown) for receiving the piston rod 134 therethrough. The second portion 316 of the second collar 307 contacts the outer surface 318 of the piston rod 134. Additionally, the second portion 316 defines an extension 320 that allows the second collar 307 to be crimped against the piston rod 134 for attaching the second collar 307 to the piston rod 134. Therefore, the second collar 307 is fixedly coupled to the piston rod 134 and does not slide along the axis “A-A1”. The second collar 307 may be made of plastic, polymer, or metal.
[0037] Additionally, the damper 112 includes a retaining ring 304 disposed adjacent to the second collar 307 and extending along the circumference of the piston rod 134. The retaining ring 304 is at least partially received within an annular groove 322 of the piston rod 134. The annular groove 322 is defined on the outer surface 318 of the piston rod 134. In the assembled state of the damper 112, a first collar 306 and a sealing ring 308 are disposed between the retaining ring 304 and the second collar 307, such that the first collar 306 and the sealing ring 308 are movable between the retaining ring 304 and the second collar 307 based on the movement of the piston rod 134. The retaining ring 304 is embodied as an annular ring and can be made of a suitable material. For example, the retaining ring 304 can be made of metal or a metal alloy.
[0038] Figure 3B Another design for the first collar 378 associated with the damper 112 is shown. In this example, the first collar 378 includes an extension 380 provided on the inner surface of the first collar 378. For example, the extension may include a ring extending from the inner surface of the first collar 378 and may be received within a recess 382 provided on the outer surface 318 of the piston rod 134. In one example, the extension 380 may include a flexible pad. This optimized design of the first collar 378 eliminates the need for a retaining ring 304 ( Figure 3A(as shown). In addition, the first ring 378 can reduce the cutoff length of the damper 112, which in turn reduces the total cost of the damper 112.
[0039] Figure 3C Another design for the first collar 384 associated with the damper 112 is shown. In this example, the first collar 384 is press-fitted or loosely fitted onto the first retaining ring 386. The piston rod 134 defines a first annular groove 388 provided on the outer surface 318 of the piston rod 134. Additionally, the first retaining ring 386 is received within the first annular groove 388. Furthermore, the second collar 390 of the damper 112 is press-fitted or loosely fitted onto the second retaining ring 392. The piston rod 134 defines a second annular groove 394 provided on the outer surface 318 of the piston rod 134. The second retaining ring 392 is received within the second annular groove 394. Therefore, the second collar 390 does not include features similar to those of the first collar 384. Figure 3A The extension of the second ring 307 is associated with the extension 320. Additionally, the first retaining ring 386 and the second retaining ring 394 are similar. Figure 3A The retaining ring 304 is shown. The design of the first retaining ring 384 and the second retaining ring 390 shown herein can be used in damper applications with high levels of top load, which prevents the transfer of top load to the sealing ring 308.
[0040] The damper 112 also includes a sealing ring 308 slidably disposed around the piston rod 134. More specifically, the sealing ring 308 is slidably disposed around the piston rod 134 and between a first collar 306 and a second collar 307. In some examples, the sealing ring 308 is configured such that an axial clearance (not shown) exists between the sealing ring 308 and the first collar 306 to allow a certain amount of fluid flow through the axial clearance. The sealing ring 308 may be made of plastic or polymer.
[0041] refer to Figure 4A The sealing ring 308 defines a space for receiving the piston rod 134 passing through it (see [link]). Figure 2 And the through opening 324 (Figure 3). Additionally, the sealing ring 308 defines the inner surface 326. In the assembled state of the damper 112, the inner surface 326 faces the piston rod 134. As shown... Figure 4B and Figure 4C As shown, inner surface 326 defines the inner diameter "D1". The inner diameter "D1" is greater than or equal to the piston rod 134 (see...). Figure 3AThe outer diameter of the piston rod 134 is specified. The inner surface 326 includes a plurality of concave surfaces 328 and a plurality of convex surfaces 330. Each of the plurality of concave surfaces 328 is positioned adjacent to a corresponding convex surface 330 of the plurality of convex surfaces 330. More specifically, the inner surface 326 includes six concave surfaces 328 and six convex surfaces 330. Thus, the inner surface 326 includes alternating concave surfaces 328 and convex surfaces 330. However, the total number of concave surfaces 328 and convex surfaces 330 may vary depending on system requirements. Each concave surface 328 is bent away from the piston rod 134. Therefore, space is defined between each concave surface 328 and the piston rod 134. Additionally, each convex surface 330 is bent toward the piston rod 134.
[0042] For reference Figure 5 A cross-sectional view of the damper 112 during the compression stroke is shown. During the compression stroke, the sealing ring 308 is contactable with the first collar 306 and spaced apart from the second collar 307. As shown, each of the concave surfaces 328 defines a proximate first end 124 (see Figure 1). Figure 2 The first flow path "F1" of the fluid within the high-pressure region 141. The high-pressure region 141 may correspond to the region defined in the springback chamber 130 with a reduced diameter pressure tube 122. The reduced diameter can be achieved through various processes, such as forging. Alternatively, the pressure tube 122 may include a sleeve insert (not shown) as an alternative to the forged design of the pressure tube 122. Each of the concave surfaces 328 allows fluid flow through the space defined between each concave surface 328 and the piston rod 134. The first flow path "F1" allows fluid flow toward the first end 124. More specifically, during the compression stroke, the concave surface 328 allows fluid flow along the first flow path "F1" through it.
[0043] Furthermore, the concave surface 328 and channel 340 allow fluid flow through them during the compression stroke and can help replenish the rebound chamber 130. Additionally, when the damper 112 switches from the compression stroke to the rebound stroke, the concave surface 328 may prevent fluid flow along the first flow path "F1" because the first flow path "F1" is restricted by the second collar 307. Therefore, under such conditions, fluid can flow through the groove 338 (see...). Figure 4A ) and emission pathway 374 (see Figure 4C and Figure 4D Furthermore, during the rebound stroke, any fluid flow along the first flow path "F1" can be restricted by the second ring 307, and fluid can flow only through the groove 338 and the discharge path 374. Additionally, the concave surface 328 provides an improved seal between the sealing ring 308 and the pressure tube 122, which in turn helps to approach the peak damping force, thereby providing increased energy dissipation.
[0044] like Figure 4A As shown, the sealing ring 308 also defines a plurality of first segments 332 spaced apart from each other. In the illustrated example, the sealing ring 308 includes six first segments 332. Each of the plurality of first segments 332 includes a corresponding concave surface 328 of a plurality of concave surfaces 328. The sealing ring 308 includes an outer surface 336 opposite to the inner surface 326. Figure 4B and Figure 4C As shown, outer surface 336 defines the outer diameter "D2". The outer diameter "D2" is less than or equal to the pressure tube 122 (see...). Figure 3A The inner diameter of the outer surface 336 defines at least one groove 338. In the illustrated example, the outer surface 336 defines a pair of grooves 338. However, the total number of grooves 338 may vary depending on system requirements. It should be noted that the sealing ring 308 may include a single groove, two grooves, or three grooves based on the adjustability requirements of the damper 112. More specifically, the number of grooves 338 and the area of the corresponding grooves 338 may be varied to change the peak damping force of the damper 112. Additionally, in some examples, the sealing ring 308 may be designed such that the sealing ring 308 does not include any of the grooves 338.
[0045] For reference Figure 6 A cross-sectional view of the damper 112 during the rebound stroke is shown. During the rebound stroke, the sealing ring 308 is accessible to the first collar 306 and the second collar 307. As shown, each of the recesses 338 defines a second flow path "F2" for fluid within the high-pressure region 141. More specifically, each of the recesses 338 allows fluid to flow through the space between each of the recesses 338 and the pressure tube 122. The second flow path "F2" allows flow toward the second end 126 (see Figure 126). Figure 2 The groove 338 allows for fluid flow during the springback stroke, as the pressure in the high-pressure region 141 increases. Therefore, the damping force of the damper 112 increases, and the speed of the piston rod 134 can decrease, thereby allowing for noise reduction. Additionally, when the damper 112 switches from the springback stroke to the compression stroke, the concave surface 328 and the channel 340 allow fluid flow along the first flow path "F1" and the third flow path "F3," respectively. Furthermore, when the damper 112 switches from the springback stroke to the compression stroke, the groove 338 also allows fluid flow along the second flow path "F2." Furthermore, during the compression stroke, the groove 338 is designed to allow fluid flow through it.
[0046] like Figure 4AAs shown, the sealing ring 308 includes an upper surface 334 extending between an outer surface 336 and an inner surface 326. The upper surface 334 defines a plurality of channels 340. Each of the plurality of channels 340 extends from the inner surface 326 to the outer surface 336. Additionally, each of the channels 340 defines a third flow path "F3" for the fluid. Figure 5 (As shown). Each of the channels 340 allows fluid flow through it. The third flow path "F3" allows flow toward the first end 124 (see...). Figure 2 The fluid flow is directed to the concave surface 328. More specifically, each of the channels 340 receives fluid that exits the space between each concave surface 328 and the piston rod 134 along a first flow path “F1”. Fluid flowing along a third flow path “F3” can then exit the sealing ring 308 and flow toward the first end 124. During the compression stroke, the channels 340 allow for the dissipation of kinetic energy. Therefore, the damping force of the damper 112 increases, and the velocity of the piston rod 134 can decrease, thereby allowing for noise reduction. Additionally, when the damper 112 switches from the compression stroke to the rebound stroke, the channels 340 may not allow fluid flow along the third flow path “F3” because the third flow path “F3” is restricted by the second collar 307. Therefore, under such conditions, fluid can only flow through the concave surface 338 and the discharge path 374. Furthermore, during the rebound stroke, any fluid flow along the third flow path “F3” can be restricted by the second collar 307, and fluid can only flow through the concave surface 338 and the discharge path 374.
[0047] Additionally, the sealing ring 308 defines a plurality of second segments 342, 368, 370 spaced apart from each other. In the illustrated example, the sealing ring 308 includes six second segments 342, 368, 370, each of which is adjacent to a corresponding first segment 332 of a plurality of first segments 332. Furthermore, each of the plurality of second segments 342, 368, 370 includes a corresponding convex surface 330 of a plurality of convex surfaces 330, wherein one of the second segments 368 or 370 defines at least one groove 338. Specifically, each of the second segments 368, 370 defines a groove 338. Additionally, the convex surfaces 330 of the sealing ring 308 allow for centering of the sealing ring 308. More specifically, the convex surfaces 330 allow for centering of the sealing ring 308 relative to the piston rod 134. Therefore, any misalignment of the sealing ring 308 relative to the piston rod 134 can be eliminated, especially when the damper is operating under high pressure. Additionally, the convex surface 330 provides an improved seal between the sealing ring 308 and the pressure tube 122.
[0048] Additionally, each of the plurality of second segments 342, 368, 370 includes a top surface 344 and a bottom surface 346 opposite to the top surface 344. At least one groove 338 extends from the top surface 344 of the second segments 368, 370 to the bottom surface 346. The bottom surface 346 may be generally flat. In the illustrated example, at least one groove 338 includes a plurality of grooves 338 defined on the outer surface 336 of the sealing ring 308. Each of the plurality of grooves 338 is defined by a corresponding second segment 368, 370 of the plurality of second segments 342, 368, 370. Furthermore, each of the plurality of second segments 342, 368, 370 includes a top surface 344 and a pair of side surfaces 348, 350 that extend laterally from the top surface 344. Each of the plurality of channels 340 is defined by a top surface 344 and an opposite side surface 348, 350 of a corresponding second segment 342, 368, 370 of a plurality of second segments 342, 368, 370. Each channel 340 is generally U-shaped. The sealing ring 308 also includes a third segment 352 disposed between two of the second segments 342. The third segment 352 includes a pair of concave surfaces 354, 356 and a convex surface 358 disposed between the pair of concave surfaces 354, 356. Each of the concave surfaces 354, 356 further defines a space through which fluid can flow during the rebound and compression strokes. In addition, the convex surface 358 helps to center the sealing ring 308.
[0049] The sealing ring 308 also includes a locking mechanism 360 adapted to lock the sealing ring 308 around the piston rod 134. The locking mechanism 360 is configured to be diametrically opposed to the third segment 352. The locking mechanism 360 includes a first tongue 362 and a second tongue 364. The first tongue 362 is adapted to engage the second tongue 364 to lock the sealing ring 308 around the piston rod 134. Additionally, the locking mechanism 360 includes a protrusion 366 that extends generally parallel to the upper surface 334 of the sealing ring 308. Figure 4D As shown, the protrusion 366 is disposed below the first tongue 362 and the second tongue 364. More specifically, the protrusion 366 defines a platform disposed below the locking mechanism 360. The protrusion 366 minimizes fluid leakage through the leakage path 372, which exists between the first tongue 362 and the second tongue 364. The protrusion 366 covers the leakage path 372 from below, thereby minimizing fluid leakage.
[0050] The locking mechanism 360 also defines the discharge path 374. Additionally, the locking mechanism 360 includes a leakage prevention feature 376. Figure 4C(As shown). Leakage prevention feature 376 eliminates any axial or radial leakage of fluid through it, thereby eliminating fluid leakage through discharge path 374. In one example, leakage prevention feature 376 may include a first tab that engages a second tab to seal discharge path 374. It should be noted that the leakage prevention feature 376 described herein is exemplary in nature, and leakage prevention feature 376 may include any other design features that allow sealing of discharge path 374. Locking mechanism 360 is designed to eliminate unintentional opening of sealing ring 308 due to high hydraulic pressure during operation of damper 112.
[0051] The design of the sealing ring 308 associated with the damper 112 explained above can include simplified construction and robust design, and is easy to manufacture. Furthermore, the sealing ring 308 described above can be incorporated into the damper 112 at a lower cost compared to existing sealing rings. The sealing ring 308 improves the durability and adjustability of the hydraulic rebound end stop system 300. This design of the sealing ring 308 can result in repeatable and consistent performance. Additionally, the application of the damper 112 described herein is not limited to vehicles and can be used in any application in which the damper 112 is incorporated.
[0052] refer to Figure 2 As the piston 128 travels toward the first end 124 during the rebound stroke, the volume of the compression chamber 132 increases and the volume of the rebound chamber 130 decreases. Figure 6 As shown, during the springback stroke, the sealing ring 308 is held between the first ring 306 and the second ring 307, and along the first flow path "F1" and the third flow path "F3" (see...). Figure 5 Any fluid flow is restricted. Additionally, due to the reduced volume of the spring chamber 130, the pressure within the spring chamber 130 increases. As the pressure in the spring chamber 130 increases, the sealing ring 308 allows controlled flow of fluid through the second flow path "F2" within the high-pressure region 141. During the springback stroke, the second flow path "F2" directs fluid flow to the second end 126 (see...). Figure 2 Additionally, as the piston 128 moves from the springback stroke to the compression stroke, the concave surface 328, groove 338, and channel 340 allow fluid flow through them.
[0053] refer to Figure 5 During the compression stroke, the upper surface 334 of the sealing ring 308 (see...) Figure 4A The first sleeve ring 306 contacts the lower surface of the second sleeve ring 307. Additionally, an axial clearance is defined between the sealing ring 308 and the second sleeve ring 307. During the compression stroke, the sealing ring 308 allows fluid to pass through the first flow path "F1" and the third flow path "F3" toward the first end 124 (see...). Figure 2 Controlled flow. More specifically, the concave surface 328 and channel 340 allow fluid flow through them along the corresponding first flow path "F1" and third flow path "F3" within the high-pressure region 141. Furthermore, during the compression stroke, the groove 338 is designed such that fluid flow through it is also permitted. As the piston 128 moves from the compression stroke to the rebound stroke, the concave surface 328 and channel 340 may not allow fluid flow through them along the first flow path "F1" and third flow path "F3" respectively, because flow paths "F1" and "F3" are restricted by the second collar 307.
[0054] The sealing ring 308 allows fluid to pass through the first flow path "F1", the second flow path "F2", and the third flow path "F3" (see...). Figure 5 and Figure 6 The controlled flow of the piston rod 134 dissipates a certain amount of kinetic energy, thereby eliminating any hard stop. More specifically, the concave surface 328, the groove 338, and the channel 340 (see...) Figure 4A The provision of kinetic energy allows for the dissipation of kinetic energy. The dissipation of kinetic energy causes a decrease in the speed of the piston rod 134, thereby allowing for a reduction in the noise generated by the damper 112 and a reduction in the forces experienced by various components of the vehicle.
[0055] Figure 7 To illustrate sealing rings 308 with different groove areas (see...) Figure 4A An exemplary curve 700 of the peak damping force is provided, where the groove areas are defined by grooves formed on the sealing ring 308. Exemplary groove areas, expressed in square millimeters (mm²), are marked on the X-axis, while the peak damping force, expressed in kilonewtons (kN), is marked on the Y-axis. The curve 700 is produced by plotting the results for different groove areas. More specifically, the pattern 702 is generated by plotting points “P1,” “P2,” “P3,” and “P4” corresponding to different groove areas. As shown, point “P1” corresponds to the sealing ring 308 without grooves, thus the groove area is zero. Additionally, point “P2” corresponds to the sealing ring 308 with a single groove, point “P3” corresponds to the sealing ring 308 with two grooves, and point “P4” corresponds to the sealing ring 308 with three grooves. It can be concluded that as the groove area and / or the number of grooves increases, the peak damping force of the damper 112 decreases. The number and / or area of the grooves can be tuned or adjusted according to application requirements.
[0056] Figure 8An exemplary graph 800 is provided to illustrate a benchmark comparison between two different sealing rings. Graph 800 is generated by moving piston rod 134 at a desired speed and displacing piston rod 134 beyond the full springback state of damper 112 by a desired displacement. Exemplary displacements of the sealing rings, expressed in millimeters (mm), are marked on the X-axis, while peak damping forces, expressed in kilonewtons (kN), are marked on the Y-axis.
[0057] Curve 800 is created by plotting the results of two different sealing rings. More specifically, pattern 802 is created by plotting the corresponding... Figure 4A Pattern 802 is generated by drawing points corresponding to the sealing ring 308, while pattern 804 is generated by drawing points corresponding to a conventional sealing ring. For pattern 802, point "P5" represents the initial rate of the hydraulic rebound end stop, and point "P6" represents the final rate of the hydraulic rebound end stop. More specifically, the initial and final rates of the hydraulic rebound end stop correspond to the initial and final speeds of the piston rod 134, respectively, which can be controlled based on the design of the sealing ring 308 to achieve desired adjustability.
[0058] It can be concluded that, at similar speeds and displacements of the piston rod 134, the sealing ring 308 corresponding to pattern 802 exhibits a larger peak damping force compared to the sealing ring corresponding to pattern 804. Furthermore, the energy dissipated by the damper 112 is represented by area 806. Therefore, it can be concluded that the energy dissipated by the damper 112 with sealing ring 308 is greater than the energy dissipated by the damper 112 with a conventional sealing ring.
[0059] Although aspects of this disclosure have been specifically shown and described with reference to the above embodiments, those skilled in the art will understand that various additional embodiments can be conceived by modifying the disclosed machines, systems, and methods without departing from the spirit and scope of the disclosure. Such embodiments should be understood to fall within the scope of this disclosure as defined by the claims and any equivalents.
Claims
1. A damper, comprising: A pressure tube, the pressure tube defining a first end and a second end opposite to the first end; A piston, slidably disposed within the pressure tube, the piston defining a springback chamber and a compression chamber within the pressure tube; A piston rod adapted to reciprocate with the piston, wherein the piston rod is partially received within the pressure tube; and The first ring is disposed around the piston rod; The second ring is disposed around the piston rod and is axially spaced from the first ring; A retaining ring, the retaining ring being configured adjacent to the second ring and extending along the circumference of the piston rod, wherein the retaining ring is at least partially received within an annular groove of the piston rod; as well as A sealing ring, slidably disposed around the piston rod, the sealing ring comprising: Facing the inner surface of the piston rod, the inner surface includes a plurality of concave surfaces and a plurality of convex surfaces, each of the plurality of concave surfaces being positioned as a corresponding convex surface adjacent to the plurality of convex surfaces; An outer surface opposite the inner surface, the outer surface defining at least one groove; and An upper surface extending between the outer surface and the inner surface defines a plurality of channels extending from the inner surface to the outer surface; The first collar and the sealing ring are disposed between the retaining ring and the second collar, such that the first collar and the sealing ring can move between the retaining ring and the second collar based on the movement of the piston rod.
2. The damper of claim 1, wherein the sealing ring further comprises a locking mechanism adapted to lock the sealing ring around the piston rod.
3. The damper of claim 2, wherein the locking mechanism comprises a first tongue and a second tongue, wherein the first tongue is adapted to engage the second tongue to lock the sealing ring around the piston rod.
4. The damper of claim 3, wherein the locking mechanism further comprises a protrusion extending substantially parallel to the upper surface of the sealing ring, wherein the protrusion is disposed below the first tongue and the second tongue.
5. The damper according to claim 1, further comprising: A plurality of first segments spaced apart from each other, each of the plurality of first segments including a corresponding concave surface of the plurality of concave surfaces; and A plurality of second segments spaced apart from each other, each of the plurality of second segments being adjacent to a corresponding first segment of the plurality of first segments, each of the plurality of second segments including a corresponding convex surface of the plurality of convex surfaces, wherein one of the plurality of second segments defines at least one groove.
6. The damper of claim 5 further includes a third section disposed between two of the second sections, the third section comprising a pair of concave surfaces and a convex surface disposed between the pair of concave surfaces.
7. The damper of claim 5, wherein each of the plurality of second segments includes a top surface and a bottom surface opposite to the top surface, and wherein the at least one groove extends from the top surface of the one second segment to the bottom surface.
8. The damper of claim 5, wherein each of the plurality of second segments includes a top surface and a pair of side surfaces extending upward from opposite sides of the top surface, and wherein each of the plurality of channels is defined by the top surface and the pair of side surfaces of a corresponding second segment of the plurality of second segments.