Truck shock absorber and method of assembling the same

Abstract

The application discloses a truck shock absorber and an assembling method thereof, and relates to the technical field of vehicle suspensions, and has the technical scheme as follows: the truck shock absorber comprises an outer tube, an inner tube, a connecting rod, a piston assembly, a guide and a ring. The ring is clamped in an annular clamping groove of the connecting rod, and the guide is provided with a composite stress structure. When the ring approaches the guide, the ring and the composite stress structure form a hydraulic buffer gap with gradually changed flow area, and the ring is clamped between the composite stress structure and the annular clamping groove after reaching a stretching limiting position, so that the axial limiting load is dispersed. The application can reduce the impact peak value of the stretching end and improve the upper limit of the load of the stretching limiting structure.

Description

Technical Field

[0001] This invention relates to the field of vehicle suspension technology, and in particular to a truck shock absorber and its assembly method. Background Technology

[0002] When a truck is under heavy load, its wheels are suspended in the air and then fall back down, or it is continuously traversing roads with significant undulations, the shock absorber's connecting rod may stretch outwards at high speeds and reach the end of its stretch stroke. Existing truck shock absorbers typically have a retaining sleeve mounted on the connecting rod and a buffer groove or channel within the guide. When the retaining sleeve enters the buffer groove or channel, it compresses the internal hydraulic oil to reduce the speed at which the retaining sleeve collides mechanically with the guide. The retaining sleeve is generally fixed to the mounting groove of the connecting rod by a retaining spring, a portion of which protrudes from the mounting groove and engages with the inner groove surface of the retaining sleeve.

[0003] The limiting sleeve has a large end face area, which can reduce the average pressure at the contact point between the limiting sleeve and the guide. However, the axial limiting load borne by this end face still needs to be transmitted to the connecting rod through the snap-fit ​​part and the snap spring inside the limiting sleeve. Since there are multiple sequentially connected force interfaces between the limiting sleeve, snap spring, and connecting rod, the load will concentrate when transmitted from the larger end face of the limiting sleeve to the smaller snap-fit ​​area. Especially when hydraulic oil is not fully discharged, the connecting rod tension speed is high, or the vehicle is subjected to extreme impact loads, the remaining impact load after hydraulic buffering may exceed the bearing capacity of the snap-fit ​​part of the limiting sleeve. This can cause high local stress at the groove root, end, or snap spring contact point of the limiting sleeve, potentially leading to cracking or breakage of the limiting sleeve, deformation of the snap spring, or failure of the limiting position. Summary of the Invention

[0004] The purpose of this invention is to provide a truck shock absorber that has the advantages of gradually building up hydraulic damping at the end of the tension, reducing the peak impact value during mechanical limiting, shortening the axial load transmission path, improving the radial stability of the retaining ring, and increasing the upper limit of the load of the tension limiting structure.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A truck shock absorber includes an outer tube, an inner tube disposed inside the outer tube, a connecting rod movably passing through a working chamber inside the inner tube, a piston assembly mounted on the connecting rod, and a guide disposed at the port of the inner tube, and further includes: A retaining ring is provided, wherein an annular groove is formed on the outer peripheral surface of the connecting rod located between the guide and the piston assembly, and the retaining ring is engaged in the annular groove, with the radially outer portion of the retaining ring protruding from the outer peripheral surface of the connecting rod; The guide has a composite force-bearing structure inside for accommodating the retaining ring, and the composite force-bearing structure is located on the path of axial movement of the retaining ring; The composite force-bearing structure is configured to form a hydraulic buffer gap with a gradually changing flow area with the retaining ring to apply hydraulic damping force as the retaining ring moves toward the guide along with the connecting rod, and to make mechanical contact with the retaining ring to radially position the retaining ring and to receive the axial limiting load transmitted by the annular groove through the retaining ring.

[0006] Further configuration: The composite force-bearing structure, along the direction in which it moves towards the guide along the connecting rod, sequentially includes an annular guide arc surface, an annular abutment groove, and an annular clearance groove; The radial distance between the annular guide arc surface and the connecting rod axis gradually decreases along the moving direction of the retaining ring toward the guide, thereby gradually reducing the flow cross-sectional area of ​​the hydraulic oil. The annular abutment groove matches the outer contour of the retaining ring and provides mechanical support to the retaining ring; The radial distance between the annular clearance groove and the connecting rod axis gradually decreases along the moving direction of the retaining ring toward the guide, and is configured to provide temporary storage space for the extruded hydraulic oil.

[0007] Further configuration: The end face of the guide facing the piston assembly is provided with an inclined end face, one end of the annular guide arc surface is connected to the side of the annular abutment groove facing the piston assembly, and the other end of the annular guide arc surface extends towards the piston assembly to the inclined end face, so as to guide the hydraulic oil to flow to the annular guide arc surface. The radial distance between the annular guide arc surface and the connecting rod axis gradually decreases along the direction close to the annular abutment groove; the inclined end face is radially inclined from the outside to the inside toward the annular guide arc surface, and the radial inner edge of the inclined end face is connected to the annular guide arc surface.

[0008] Further configuration: The groove surface of the annular groove forms a multi-segment mating surface, the multi-segment mating surface includes a buffer mating segment and a limiting abutment segment arranged along the moving path of the retaining ring toward the guide, and the radial distance between the buffer mating segment and the connecting rod axis gradually decreases in the direction closer to the limiting abutment segment; When the connecting rod moves to the tension limit position, the radial inner surface of the retaining ring abuts against the limit abutment section, and the outer peripheral surface of the retaining ring abuts against the annular abutment groove.

[0009] Further configuration: The buffer mating section includes a straight section surface, a first arc surface, an inclined side surface, and a second arc surface connected in sequence; The straight section is formed at the bottom of the annular groove and connected to the limiting abutment section, which is suitable for providing radial positioning to the retaining ring; The first arc surface, the inclined side surface, and the second arc surface are sequentially connected between the straight section surface and the groove of the annular groove near the guide, so as to decompose the axial shear force transmitted by the retaining ring into normal pressure and tangential distributed force.

[0010] Further configuration: The retaining ring has a circular cross-section; The limiting abutment section has an arcuate profile that matches the radial inner surface of the retaining ring; The annular abutment groove has an arcuate profile that matches the radial outer surface of the retaining ring.

[0011] Further configuration: the radius of the arc profile of the limiting abutment section and the radius of the arc profile of the annular abutment groove are both equal to the radius of the circular cross-section of the retaining ring.

[0012] Further configuration: also includes an oil seal, which is installed at the port of the inner tube and located on the side of the guide opposite to the piston assembly, adapted to seal the connecting rod passing through the guide.

[0013] Further configuration: The oil seal includes an elastic base, a first skeleton, and a second skeleton; The first frame extends axially along the connecting rod, and the second frame extends radially toward the connecting rod; The elastic base includes a first elastic matrix and a second elastic matrix; A first cavity is formed between one side of the first elastic matrix and the first skeleton, facing the guide and recessed inward. An installation gap is provided between the end face of the first skeleton and the guide facing away from the piston assembly, and the installation gap communicates with the first cavity. A second cavity is formed between the other side of the first elastic matrix and the second elastic matrix, and the second cavity opens toward the axis of the connecting rod.

[0014] The present invention also provides a method for assembling a truck shock absorber, for assembling the above-mentioned truck shock absorber, comprising at least: A tapered oil seal transition sleeve is provided, and the oil seal transition sleeve is fitted onto the connecting rod; Insert the retaining ring into the small end of the oil seal transition sleeve and push the retaining ring along the outer circumferential surface of the oil seal transition sleeve toward the large end, so that the retaining ring gradually expands. Continue pushing the retaining ring so that it passes over the oil seal transition sleeve and moves to the position corresponding to the annular retaining groove, so that the retaining ring elastically resets and snaps into the annular retaining groove; Remove the oil seal transition sleeve from the connecting rod.

[0015] In summary, the present invention has the following beneficial effects: First, the increased load limit of this invention comes from two complementary mechanical mechanisms. Firstly, the gradually varying hydraulic buffer gap dissipates kinetic energy before mechanical contact, reducing the peak impact load actually received by the mechanical limiting structure. Secondly, the composite load-bearing structure, the retaining ring, and the annular groove constitute a circumferentially distributed, radially double-sided supported mechanical load-bearing structure, increasing the axial load that the mechanical limiting structure itself can withstand.

[0016] Second, the retaining ring of this invention is engaged within the annular groove of the connecting rod, with its radially outer portion protruding beyond the outer circumference of the connecting rod. As the connecting rod moves toward the end of its extension stroke, the retaining ring first enters the composite force-bearing structure within the guide, forming a hydraulic buffer gap between the retaining ring and the composite force-bearing structure. As the retaining ring continues to move, the flow cross-sectional area of ​​the hydraulic buffer gap gradually decreases, and the flow resistance encountered by the hydraulic oil as it exits through the hydraulic buffer gap gradually increases, causing the hydraulic damping force to gradually build up with the connecting rod stroke. This structure does not bear the full impact only after the retaining ring reaches the extension limit position, but rather utilizes hydraulic oil to dissipate the kinetic energy of the connecting rod, piston assembly, and related moving parts before mechanical contact.

[0017] Third, compared to existing structures using a limiting sleeve, this invention no longer concentrates all axial loads to the retaining ring through the snap-fit ​​groove on the inner side of the limiting sleeve. When the connecting rod reaches the tension limit position, the radially outer surface of the retaining ring abuts against the annular abutment groove on the guide side, and the radially inner surface of the retaining ring abuts against the limiting abutment section in the annular groove. The retaining ring is supported by the composite force-bearing structure and the annular groove from both the radially outer and radially inner sides. After the axial limiting load is transmitted to the retaining ring by the guide, it can be distributed along the circumference of the retaining ring and then transmitted to the connecting rod through the annular groove, forming a short-path load transmission structure of "composite force-bearing structure, retaining ring, annular groove, and connecting rod".

[0018] Fourth, even with a large end face area, the axial load of the existing retaining sleeve still concentrates at the inner groove and the protruding position of the retaining ring. The inner snap-fit ​​part of the retaining sleeve is equivalent to the cross-sectional contraction area in the load transmission path, which is prone to simultaneously bearing local compression, shear, and bending loads caused by assembly gaps under extreme loads. This invention eliminates the retaining sleeve as an intermediate load-bearing component, allowing the retaining ring to directly transmit the load between the guide and the connecting rod, reducing the number of series-loaded locations such as the inner groove of the retaining sleeve, the outer protrusion of the retaining ring, and the weak section of the retaining sleeve. With the number of load-bearing interfaces reduced, the load does not need to repeatedly converge from a large cross-section to a small cross-section and then be transmitted to the connecting rod, thereby reducing the probability that a single connection position will become a bottleneck in the structural load-bearing capacity.

[0019] Fifth, the composite force-bearing structure and the annular groove of the present invention restrict the position of the retaining ring from the outside and inside sides, respectively. When the retaining ring is subjected to an axial limiting load, the annular abutment groove prevents the retaining ring from continuing to move axially, and the limiting abutment section bears the corresponding load from the inside of the retaining ring, so that the retaining ring is supported on both the inner and outer radial sides. This double-sided support method can reduce the cantilever length of the portion of the retaining ring protruding from the annular groove, reduce the bending moment of the retaining ring cross-section caused by unilateral pressure, and suppress the tendency of the retaining ring to flip or come out of the annular groove.

[0020] Sixth, the buffer mating section of the annular groove of the present invention includes a straight section surface, a first arc surface, an inclined side surface, and a second arc surface. The straight section surface provides radial positioning for the retaining ring, while the first and second arc surfaces create a continuous transition between adjacent surfaces, reducing stress concentration at the groove surface transition points. The inclined side surface allows the axial load transmitted by the retaining ring to be transferred to the connecting rod through the normal action of the contact surface, preventing the load from acting only on a single edge of the annular groove. Multiple surfaces sequentially bear the contact load of the retaining ring, creating a continuous force transition for the retaining ring as it enters the annular groove, undergoes compression deformation, and reaches the limiting state.

[0021] Seventh, the circular cross-sectional radius of the retaining ring, the circular arc contour radius of the limiting abutment section, and the circular arc contour radius of the annular abutment groove of the present invention are equal, so that the retaining ring and the abutment contours on the radial inner and outer sides have matching curvature. After the retaining ring undergoes elastic deformation and enters the limiting position, a larger fitting arc segment can be formed between the retaining ring, the limiting abutment section, and the annular abutment groove, reducing the situation where the load is concentrated at a single point or a single edge. Under the same axial limiting load, the expansion of the contact area can reduce the local contact compressive stress and reduce the probability of indentation, plastic deformation, or fatigue cracks in the retaining ring, annular retaining groove, and annular abutment groove.

[0022] Eighth, the oil seal of the present invention is disposed on the side of the guide away from the piston assembly, and the first skeleton and the second skeleton support the elastic base along the axial and radial directions of the connecting rod, respectively. The first cavity communicates with the space on the end face side of the guide through the installation gap, providing space for the elastic deformation of the first elastic base after being compressed; the second cavity opens towards the axis of the connecting rod, providing deformation margin for the first and second elastic bases to adapt to the reciprocating movement and radial offset of the connecting rod. The double skeleton, double elastic base and double cavity together maintain the sliding sealing state between the oil seal and the connecting rod, reducing the probability of local overturning, abnormal friction or seal failure caused by extreme tensile impact transmitted to the oil seal.

[0023] Ninth, the present invention utilizes a conical oil seal transition sleeve to guide the retaining ring to gradually expand, so that the retaining ring can elastically reset and snap into the annular retaining groove after passing the oil seal transition sleeve. This reduces the local deformation or assembly pop-out caused by directly using tools to forcibly open the retaining ring, making the installation of the retaining ring more convenient and faster, reducing the dependence on special assembly equipment, and lowering assembly costs. Attached Figure Description

[0024] Figure 1 This is an overall cross-sectional view of a truck shock absorber in a compressed state according to an embodiment of the present invention.

[0025] Figure 2 for Figure 1 A magnified structural diagram of point A in the middle.

[0026] Figure 3 This is an overall cross-sectional view of a truck shock absorber in a tension-limited state according to an embodiment of the present invention.

[0027] Figure 4 for Figure 3 A magnified structural diagram at point B in the middle.

[0028] Figure 5 This is a partial cross-sectional view of the guide, retaining ring, oil seal and piston assembly in one embodiment of the present invention.

[0029] Figure 6 This is an enlarged structural schematic diagram of the annular groove and multi-segment mating surface in one embodiment of the present invention.

[0030] Figure 7 for Figure 5 A magnified structural diagram at point C.

[0031] Figure 8 This is a schematic diagram illustrating the process of assembling the retaining ring into the annular retaining groove using an oil seal transition sleeve in one embodiment of the present invention.

[0032] In the diagram, 10 is the working chamber; 20 is the oil storage chamber; 30 is the first lifting ring; 40 is the second lifting ring; and 50 is the oil seal transition sleeve. 100, outer tube; 200, inner tube; 300. Guide; 310. Composite load-bearing structure; 311. Annular guide arc surface; 312. Annular abutment groove; 313. Annular clearance groove; 301. Inclined end face; 400, Card Circle; 500. Connecting rod; 510. Annular groove; 520. Multi-segment mating surface; 530. Limiting and abutting section; 540. Buffer mating section; 541. Straight section surface; 543. Inclined side surface; 542. First arc surface; 544. Second arc surface; 600. Piston assembly; 700. Bottom valve assembly; 800. Dust cover; 900, Oil seal; 901, First skeleton; 902, Second skeleton; 910, Elastic base; 911, First elastic matrix; 912, Second elastic matrix; 913, First cavity; 914, Second cavity; 920. Installation gap. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings.

[0034] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0035] like Figure 1 and Figure 3 As shown, the truck shock absorber in this embodiment includes an outer tube 100, an inner tube 200, a guide 300, a retaining ring 400, a connecting rod 500, a piston assembly 600, a bottom valve assembly 700, a dust cover 800, and an oil seal 900. The inner tube 200 is disposed inside the outer tube 100, the guide 300 is disposed at one end of the inner tube 200, and the bottom valve assembly 700 is disposed at the other end of the inner tube 200. The connecting rod 500 passes axially through the guide 300 and the oil seal 900 and extends into the inner tube 200. The piston assembly 600 is connected to the end of the connecting rod 500 that extends into the inner tube 200. A first lifting ring 30 is connected to the end of the connecting rod 500 that extends out of the outer tube 100, and a second lifting ring 40 is connected to the end of the outer tube 100 away from the first lifting ring 30. The first lifting ring 30 and the second lifting ring 40 are respectively used to connect two positions in the vehicle that generate relative movement. The dust cover 800 is fitted on the outside of the outer tube 100 and covers the protruding area of ​​the connecting rod 500.

[0036] like Figure 1 and Figure 3 As shown, a working chamber 10 is formed inside the inner tube 200, and an oil reservoir 20 is formed between the inner tube 200 and the outer tube 100. The piston assembly 600 reciprocates axially within the working chamber 10 along with the connecting rod 500, and the bottom valve assembly 700 controls the flow of hydraulic oil between the working chamber 10 and the oil reservoir 20. When the connecting rod 500 moves toward the bottom valve assembly 700, the piston assembly 600 compresses the hydraulic oil in the working chamber 10, and the hydraulic oil in the working chamber 10 flows on both sides of the piston assembly 600 and between the working chamber 10 and the oil reservoir 20, thereby forming compression damping. When the connecting rod 500 moves toward the guide 300, the hydraulic oil flows in the opposite direction, thereby forming restoring damping.

[0037] like Figure 1 and Figure 3As shown, during vehicle operation, the distance between the first lifting ring 30 and the second lifting ring 40 changes with the relative movement between the frame and the axle. When the distance between the first lifting ring 30 and the second lifting ring 40 decreases, the connecting rod 500 drives the piston assembly 600 to move towards the bottom valve assembly 700, and the truck shock absorber enters the compression stroke. When the distance between the first lifting ring 30 and the second lifting ring 40 increases, the connecting rod 500 drives the piston assembly 600 to move towards the guide 300, and the truck shock absorber enters the recovery stroke. As the connecting rod 500 continues to move towards the guide 300 and approaches the maximum extension position, the recovery damping generated by the piston assembly 600 and the bottom valve assembly 700 continues to act. The retaining ring 400 and the composite force-bearing structure 310 in the guide 300 begin to cooperate, and the final stage of the tension hydraulic buffer is superimposed on the recovery damping. After the retaining ring 400 reaches the tension limit position, the composite force-bearing structure 310, the retaining ring 400, and the annular groove 510 jointly bear the remaining axial load.

[0038] like Figure 2 , Figure 4 and Figure 5 As shown, an annular groove 510 is formed on the outer peripheral surface of the connecting rod 500 between the guide 300 and the piston assembly 600, and the retaining ring 400 is engaged within the annular groove 510. The radially inner portion of the retaining ring 400 is located in the annular groove 510, and the radially outer portion of the retaining ring 400 protrudes from the outer peripheral surface of the connecting rod 500. The annular groove 510 restricts the axial movement of the retaining ring 400 relative to the connecting rod 500, allowing the retaining ring 400 to reciprocate synchronously with the connecting rod 500. The annular groove 510 restricts the radial and axial positions of the retaining ring 400 through its groove surface.

[0039] like Figure 2 , Figure 4 and Figure 5 As shown, a composite force-bearing structure 310 is formed within the guide 300, located on the path of the retaining ring 400 as it moves with the connecting rod 500. When the connecting rod 500 is in its normal working stroke, the retaining ring 400 and the composite force-bearing structure 310 maintain an axial distance, and there is space around the retaining ring 400 for hydraulic oil flow. After the connecting rod 500 enters the final stretching stage, the retaining ring 400 gradually approaches the composite force-bearing structure 310. The oil flow area between the retaining ring 400 and the composite force-bearing structure 310 changes with the position of the connecting rod 500, thereby applying hydraulic damping to the retaining ring 400 before mechanical contact.

[0040] like Figure 2 , Figure 4 and Figure 5As shown, the composite force-bearing structure 310 includes an annular guide arc surface 311, an annular abutment groove 312, and an annular clearance groove 313 arranged sequentially along the direction of the retaining ring 400 near the guide 300. The guide 300 has an inclined end face 301 on the side facing the piston assembly 600, and the radially inner side of the inclined end face 301 connects with the annular guide arc surface 311. The inclined end face 301, the annular guide arc surface 311, the annular abutment groove 312, and the annular clearance groove 313 are continuously arranged around the moving path of the retaining ring 400, so that oil introduction, flow area reduction, mechanical abutment, and oil volume release occur in the moving sequence of the retaining ring 400.

[0041] like Figure 2 and Figure 4 As shown, the inclined end face 301 is radially inclined from the outside to the inside towards the annular guide arc surface 311, and the nominal inclination angle of the inclined end face 301 is 3 degrees. Before the retaining ring 400 enters the corresponding position of the annular guide arc surface 311, a large oil flow space is maintained between the inclined end face 301 and the retaining ring 400. As the retaining ring 400 continues to approach the guide 300, hydraulic oil enters from the working chamber 10 between the inclined end face 301 and the retaining ring 400, and flows along the inclined end face 301 towards the annular guide arc surface 311. The inclined end face 301 causes the oil flow direction and flow area to change gradually, reducing the abrupt change in cross-section when the oil enters the corresponding position of the annular guide arc surface 311.

[0042] like Figure 2 and Figure 4 As shown, the radial distance between the annular guide arc surface 311 and the axis of the connecting rod 500 gradually decreases along the direction of the retaining ring 400 approaching the annular abutment groove 312. After the retaining ring 400 enters the corresponding position of the annular guide arc surface 311, a gap is formed between the radially outer surface of the retaining ring 400 and the annular guide arc surface 311 for hydraulic oil to pass through. As the retaining ring 400 continues to move, this gap gradually narrows, and the flow area of ​​the hydraulic oil decreases accordingly. The hydraulic oil generates resistance on the retaining ring 400 in the opposite direction to the tension of the connecting rod 500.

[0043] like Figure 2 and Figure 4 As shown, when the retaining ring 400 enters the front section of the annular guide surface 311, the oil flow area is relatively large, and the additional resistance generated by the composite force-bearing structure 310 is relatively small. As the retaining ring 400 gradually approaches the annular abutment groove 312, the oil flow area continues to decrease, increasing the difficulty of hydraulic oil discharge, and consequently increasing the hydraulic resistance acting on the retaining ring 400 and connecting rod 500. The hydraulic resistance gradually builds up according to the position of the retaining ring 400, causing the connecting rod 500 to decelerate before mechanical contact with the annular abutment groove 312, and dissipating some of the kinetic energy through the flow of hydraulic oil.

[0044] like Figure 2 , Figure 4 and Figure 5 As shown, the annular clearance groove 313 is located on the side of the annular abutment groove 312 opposite to the annular guide arc surface 311. Before the retaining ring 400 forms mechanical contact with the annular abutment groove 312, an oil flow gap is maintained between the radially outer surface of the retaining ring 400 and the annular abutment groove 312. When the retaining ring 400 compresses the hydraulic oil, the hydraulic oil discharged from the gradually narrowing gap between the retaining ring 400 and the annular guide arc surface 311 enters the annular clearance groove 313 through the oil flow gap between the retaining ring 400 and the annular abutment groove 312. The annular clearance groove 313 provides a space for the hydraulic oil and remains in communication with the oil area around the retaining ring 400. When the connecting rod 500 moves in the opposite direction, the gap between the retaining ring 400, the annular abutment groove 312, and the annular guide arc surface 311 increases, and the hydraulic oil in the annular clearance groove 313 flows back through the opposite path to the space between the retaining ring 400 and the guide 300.

[0045] like Figures 3 to 5 As shown, when the retaining ring 400 reaches the tension limit position, the radially outer surface of the retaining ring 400 enters and contacts the annular abutment groove 312. The annular abutment groove 312 extends circumferentially along the guide 300 and has an arcuate profile that matches the radially outer surface of the retaining ring 400. The annular abutment groove 312 restricts the retaining ring 400 from further axial movement from the radially outer side of the retaining ring 400 and transfers the reaction load borne by the guide 300 to the retaining ring 400. The arcuate profile of the annular abutment groove 312 creates a circumferentially extending contact area between the retaining ring 400 and the guide 300, reducing load concentration at local edges.

[0046] like Figures 4 to 6 As shown, when the retaining ring 400 reaches the tension limit position, its radially inner surface simultaneously contacts the limiting abutment section 530 within the annular retaining groove 510. The annular abutment groove 312 supports the retaining ring 400 radially outward, and the limiting abutment section 530 supports the retaining ring 400 radially inward, thus clamping the retaining ring 400 between the guide 300 and the connecting rod 500. The axial limiting load is transmitted from the guide 300 to the retaining ring 400 via the annular abutment groove 312, and then from the retaining ring 400 to the connecting rod 500 via the limiting abutment section 530 and the annular retaining groove 510.

[0047] like Figures 4 to 6 As shown, the annular abutment groove 312 and the limiting abutment section 530 respectively restrict the movement of the retaining ring 400 radially outward and radially inward. When the retaining ring 400 is subjected to axial load, the supports on both the radially inward and outward sides keep the retaining ring 400 within the annular retaining groove 510 and reduce the possibility of the retaining ring 400 deflecting, flipping, or disengaging from the annular retaining groove 510. The annular abutment groove 312 forms an outer support for the portion of the retaining ring 400 protruding from the outer circumference of the connecting rod 500, shortening the free deformation length of the retaining ring 400 and thus reducing the local bending effect on the retaining ring 400.

[0048] like Figures 2 to 6 As shown, the composite load-bearing structure 310 reduces the movement speed of the connecting rod 500 through hydraulic oil resistance before the retaining ring 400 contacts the annular abutment groove 312, and then mechanically bears the remaining axial load after the retaining ring 400 contacts the annular abutment groove 312. Hydraulic buffering reduces the impact load entering the mechanical limiting stage, and the load transfer path formed by the annular abutment groove 312, retaining ring 400, and annular groove 510 improves the load-bearing capacity during the mechanical limiting stage. Hydraulic buffering and mechanical bearing occur continuously along the same movement path, ensuring that the load at the end of the tension is not concentrated at the moment of the first mechanical contact.

[0049] like Figure 5 and Figure 6 As shown, the groove surface of the annular groove 510 forms a multi-segment mating surface 520. The multi-segment mating surface 520 includes a limiting abutment section 530 and a buffer mating section 540. The limiting abutment section 530 is located on the side of the annular groove 510 near the piston assembly 600, and is used to receive the axial limiting load transmitted from the radially inner surface of the retaining ring 400 when the retaining ring 400 reaches the tension limiting position. The buffer mating section 540 extends from the limiting abutment section 530 toward the side of the annular groove 510 near the guide 300, and is used to define the position of the retaining ring 400 within the annular groove 510, and to gradually change the contact position and load transmission direction of the retaining ring 400 after being loaded.

[0050] like Figure 6 As shown, the buffer mating section 540 includes a straight surface 541, a first arc surface 542, an inclined side surface 543, and a second arc surface 544 connected in sequence. The straight surface 541 is formed at the bottom of the annular groove 510, and one end of the straight surface 541 is connected to the limiting abutment section 530. When the retaining ring 400 is installed in the annular groove 510, the radially inner portion of the retaining ring 400 is correspondingly positioned with the straight surface 541. The straight surface 541 restricts the retaining ring 400 from moving in the direction of the connecting rod 500 axis and maintains the radial installation position of the retaining ring 400 in the annular groove 510.

[0051] like Figure 6 As shown, the first arc surface 542 connects the straight section surface 541 and the inclined side surface 543, forming a continuous arc transition between the straight section surface 541 and the inclined side surface 543. When the retaining ring 400 is subjected to an axial limiting load, the contact position between the retaining ring 400 and the buffer mating section 540 can gradually move along the first arc surface 542 towards the inclined side surface 543, reducing the possibility of load concentration at the connection position between the straight section surface 541 and the inclined side surface 543.

[0052] like Figure 6As shown, the inclined side 543 gradually approaches the axis of the connecting rod 500 along the direction close to the limiting abutment section 530. When the retaining ring 400 transmits the axial limiting load to the inclined side 543, the axial limiting load forms a normal pressing component perpendicular to the inclined side 543 and a tangential transmission component along the extension direction of the inclined side 543. The normal pressing component keeps the retaining ring 400 abutting against the multi-segment mating surface 520, and the tangential transmission component is transmitted along the inclined side 543 towards the first arc surface 542, the straight section surface 541, and the bottom of the annular groove 510, causing the load to diffuse from the groove opening area of ​​the annular groove 510 into the interior of the connecting rod 500.

[0053] like Figure 6 As shown, the second arc surface 544 connects the inclined side surface 543 and the outer peripheral surface of the connecting rod 500, making the inclined side surface 543 and the outer peripheral surface of the connecting rod 500 transition continuously. When the retaining ring 400 is under load, the second arc surface 544 reduces the possibility of local pressure between the retaining ring 400 and the edge of the annular retaining groove 510, and reduces the geometric abrupt change and load concentration at the position of the annular retaining groove 510.

[0054] like Figures 4 to 6 As shown, when the retaining ring 400 enters the tensile limiting state from the normal installation state, the straight section surface 541 maintains the radial position of the retaining ring 400. The first arc surface 542 guides the contact position of the retaining ring 400 to continuously transfer from the straight section surface 541 to the inclined side surface 543. The inclined side surface 543 changes the transmission direction of the axial limiting load and diffuses the axial limiting load towards the bottom of the annular retaining groove 510. The second arc surface 544 reduces the load concentration at the opening of the annular retaining groove 510. The limiting abutment section 530 receives the main axial limiting load transmitted by the retaining ring 400, and the buffer mating section 540 restricts the deformation direction of the retaining ring 400 and expands the range of the annular retaining groove 510 participating in the load-bearing.

[0055] like Figures 4 to 6 As shown, the retaining ring 400 has a circular cross-section. The limiting abutment section 530 has an arcuate profile that matches the radially inner surface of the retaining ring 400, and the annular abutment groove 312 has an arcuate profile that matches the radially outer surface of the retaining ring 400. The arcuate profile radii of the limiting abutment section 530 and the arcuate profile radii of the annular abutment groove 312 are both equal to the circular cross-sectional radius of the retaining ring 400. The actual machining dimensions are allowed to vary within the design tolerance range, so that the retaining ring 400 can simultaneously achieve curvature matching with both the limiting abutment section 530 and the annular abutment groove 312 at the tension limiting position.

[0056] like Figure 4As shown, since the limiting abutment section 530 and the annular abutment groove 312 are located radially inner and radially outer sides of the retaining ring 400, respectively, and the accompanying drawings use partial sectional views and schematic drawing methods, the arc contours of the limiting abutment section 530 and the annular abutment groove 312 differ in arc length, opening direction, and display scale as shown in the figures, thus they may appear to be different sizes. The aforementioned display differences do not indicate that their arc contour radii are different. In this embodiment, the arc contour radii of the limiting abutment section 530, the arc contour radii of the annular abutment groove 312, and the circular cross-sectional radius of the retaining ring 400 are equal; the three only differ in their position, the arc segment being cut, and the drawing representation method, resulting in different visual effects in the accompanying drawings.

[0057] like Figures 4 to 6 As shown, when the retaining ring 400 is subjected to an axial load, the matching arc profile causes the contact range between the retaining ring 400 and the annular abutment groove 312 and the limiting abutment section 530 to expand along the arc direction. With the expanded contact range, the same axial load can be distributed over a larger contact area, and the contact effect borne by the retaining ring 400, the annular abutment groove 312, and the limiting abutment section 530 at local locations is correspondingly reduced. The radial double-sided support simultaneously restricts the cross-sectional rotation of the retaining ring 400, causing the stress on the retaining ring 400 to shift from local bending to contact bearing and cross-sectional bearing.

[0058] like Figures 4 to 6 As shown, the guide 300 transmits the load to the retaining ring 400 through the annular abutment groove 312. The retaining ring 400 transmits the load to the annular retaining groove 510 and the connecting rod 500 through the limiting abutment section 530 and the multi-segment mating surface 520. The annular abutment groove 312 and the limiting abutment section 530 expand the contact range on both radial sides of the retaining ring 400, the buffer mating section 540 reduces the load concentration at the opening of the annular retaining groove 510, and the composite force-bearing structure 310 reduces the impact load before mechanical contact. The above-mentioned mating simultaneously reduces the actual impact degree borne by the mechanical limiting structure and increases the load-bearing capacity between the guide 300, retaining ring 400, and connecting rod 500, thereby increasing the upper limit of the load that the tensile limiting position can withstand.

[0059] like Figures 1 to 5 As shown, when the connecting rod 500 moves in the opposite direction from the tension limit position toward the bottom valve assembly 700, the retaining ring 400 first leaves the annular abutment groove 312, and then exits the composite force-bearing structure 310 along the annular guide arc surface 311. The gap between the retaining ring 400 and the annular guide arc surface 311 gradually increases, and hydraulic oil re-enters between the retaining ring 400 and the guide 300. After the retaining ring 400 leaves the composite force-bearing structure 310, the composite force-bearing structure 310 no longer applies additional resistance at the end of the tension to the connecting rod 500, and the truck shock absorber returns to the normal compression damping formed by the piston assembly 600 and the bottom valve assembly 700.

[0060] like Figures 1 to 5As shown, the composite force-bearing structure 310 only engages when the connecting rod 500 approaches the end of its extension stroke. During the normal compression and recovery strokes, the piston assembly 600 and the bottom valve assembly 700 control the flow of hydraulic oil in the working chamber 10 and the oil reservoir 20. In the final extension phase, the inclined end face 301 and the annular guide arc surface 311 gradually reduce the oil flow area, the annular clearance groove 313 provides a volume release position for the compressed hydraulic oil, and the annular abutment groove 312, the retaining ring 400, and the annular retaining groove 510 bear the axial load after the connecting rod 500 reaches the extension limit position. The above working sequence ensures that normal damping, final stage buffering, and mechanical limiting function within their respective strokes.

[0061] like Figure 5 and Figure 7 As shown, the oil seal 900 is located on the side of the guide 300 opposite to the piston assembly 600, and the connecting rod 500 passes through the oil seal 900 and slides in engagement with it. The oil seal 900 includes a first frame 901, a second frame 902, and an elastic base 910. The first frame 901 extends axially along the connecting rod 500, and the second frame 902 extends radially along the connecting rod 500. The first frame 901 and the second frame 902 support the elastic base 910 from different directions, so that the elastic base 910 remains on one side of the guide 300 during the reciprocating movement of the connecting rod 500 and the change in hydraulic oil pressure within the working chamber 10.

[0062] like Figure 7 As shown, the first frame 901 restricts the elastic base 910 from displacing or flipping along the axial direction of the connecting rod 500, while the second frame 902 restricts the elastic base 910 from expanding radially. When the connecting rod 500 reciprocates, alternating forces are generated between the elastic base 910 and the connecting rod 500. The first frame 901 maintains the axial position of the elastic base 910, while the second frame 902 maintains the radial shape of the elastic base 910. Thus, the first frame 901 and the second frame 902 jointly restrict the overall deformation of the elastic base 910.

[0063] like Figure 7 As shown, the elastic base 910 includes a first elastic base 911 and a second elastic base 912. The first elastic base 911 is located on the side closer to the guide 300, and the second elastic base 912 is located on the side of the first elastic base 911 away from the guide 300. The first elastic base 911 and the second elastic base 912 respectively mate with the outer peripheral surface of the connecting rod 500 and can elastically deform according to the position change of the connecting rod 500 and the hydraulic oil pressure change. The first elastic base 911 first restricts the hydraulic oil from moving outward along the connecting rod 500, and the second elastic base 912 continues to restrict the hydraulic oil from moving outward on the side of the first elastic base 911 away from the guide 300.

[0064] like Figure 7As shown, a first cavity 913 is formed between one side of the first elastic substrate 911 and the first frame 901, and the first cavity 913 is recessed towards the guide 300. The first cavity 913 provides deformation space for the first elastic substrate 911, allowing the first elastic substrate 911 to deform towards the outer peripheral surface of the connecting rod 500 after being subjected to oil pressure from the guide 300 side. The pressure inside the first cavity 913 changes with the oil pressure on the guide 300 side, allowing the contact state between the first elastic substrate 911 and the connecting rod 500 to change with the pressure.

[0065] like Figure 5 and Figure 7 As shown, a mounting gap 920 is formed between the first frame 901 and the end face of the guide 300 on the side opposite to the piston assembly 600. The mounting gap 920 communicates with the first cavity 913. The hydraulic oil pressure on the guide 300 side can be transmitted to the first cavity 913 through the mounting gap 920. The mounting gap 920 preserves a pressure transmission path between the first frame 901 and the guide 300, and provides axial space between the first frame 901 and the guide 300, reducing the possibility of rigid pressure due to assembly dimensional deviations.

[0066] like Figure 7 As shown, when the hydraulic oil pressure in the working chamber 10 increases, the pressure on one side of the guide 300 is transmitted to the first cavity 913 through the installation gap 920. The pressure in the first cavity 913 pushes the first elastic base 911 to deform towards the outer peripheral surface of the connecting rod 500, thereby increasing the degree of contact between the first elastic base 911 and the connecting rod 500. When the hydraulic oil pressure in the working chamber 10 decreases, the first elastic base 911 recovers through its own elasticity, preventing the first elastic base 911 from maintaining the same compressed state for a long time.

[0067] like Figure 7 As shown, a second cavity 914 is formed between the other side of the first elastic matrix 911 and the second elastic matrix 912, and the second cavity 914 opens towards the axial direction of the connecting rod 500. The second cavity 914 provides relatively independent deformation spaces for the first elastic matrix 911 and the second elastic matrix 912. After being subjected to pressure within the first cavity 913, the first elastic matrix 911 undergoes elastic deformation towards the outer peripheral surface of the connecting rod 500, and can generate local elastic displacement using the space provided by the second cavity 914; the second elastic matrix 912 can also adapt to the reciprocating movement and radial offset of the connecting rod 500 using the space provided by the second cavity 914.

[0068] like Figure 7As shown, the second cavity 914 separates the main deformation locations of the first elastic substrate 911 and the second elastic substrate 912, reducing the direct impact of the first elastic substrate 911 on the second elastic substrate 912 during deformation. The first elastic substrate 911 can respond to pressure changes in the first cavity 913, and the second elastic substrate 912 can maintain its engagement with the connecting rod 500 on the side of the first elastic substrate 911 away from the guide 300. The first cavity 913 and the second cavity 914 are located on both sides of the first elastic substrate 911, providing pressure and deformation conditions for the first elastic substrate 911 from both sides.

[0069] like Figure 5 and Figure 7 As shown, the first frame 901, the second frame 902, the elastic base 910, the first elastic substrate 911, the second elastic substrate 912, the first cavity 913, the second cavity 914, and the mounting gap 920 together constitute the support and deformation relationship of the oil seal 900. The first frame 901 and the second frame 902 restrict the overall displacement of the elastic base 910. The mounting gap 920 transmits the oil pressure on the guide 300 side to the first cavity 913. The first cavity 913 causes the first elastic substrate 911 to press against the connecting rod 500 as the pressure changes. The second cavity 914 allows the first elastic substrate 911 and the second elastic substrate 912 to deform separately. The oil seal 900 thus adapts to the reciprocating movement of the connecting rod 500 and the pressure changes within the working chamber 10, and restricts the leakage of hydraulic oil along the connecting rod 500.

[0070] like Figure 8 As shown, this embodiment also uses a conical oil seal transition sleeve 50 to assist in the installation of the retaining ring 400. During assembly, the oil seal transition sleeve 50 is first fitted onto the connecting rod 500, and then the retaining ring 400 is inserted from the small end of the oil seal transition sleeve 50, and the retaining ring 400 is pushed to move along the outer circumferential surface of the oil seal transition sleeve 50 towards the large end. Since the outer diameter of the oil seal transition sleeve 50 gradually increases along the moving direction of the retaining ring 400, the retaining ring 400 gradually undergoes elastic expansion during the movement.

[0071] After the retaining ring 400 passes the oil seal transition sleeve 50, it continues to move along the outer circumference of the connecting rod 500 to the corresponding position in the annular retaining groove 510. Once in the annular retaining groove 510, the retaining ring 400 returns to its original position due to its own elasticity and snaps into the groove. Then, the oil seal transition sleeve 50 is removed from the connecting rod 500. This assembly method allows the retaining ring 400 to gradually expand and enter the annular retaining groove 510, reducing localized deformation caused by directly opening the retaining ring 400 and making the installation process more convenient and faster.

[0072] The above embodiments are merely explanations of the present invention and are not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to these embodiments without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A truck shock absorber, comprising an outer tube (100), an inner tube (200) disposed inside the outer tube (100), a connecting rod (500) movably passing through a working chamber (10) within the inner tube (200), a piston assembly (600) mounted on the connecting rod (500), and a guide (300) disposed at the port of the inner tube (200), characterized in that, Also includes: A retaining ring (400) is provided. The connecting rod (500) has an annular groove (510) on its outer peripheral surface between the guide (300) and the piston assembly (600). The retaining ring (400) is engaged in the annular groove (510). The radially outer portion of the retaining ring (400) protrudes from the outer peripheral surface of the connecting rod (500). The guide (300) has a composite force-bearing structure (310) inside for accommodating the retaining ring (400), and the composite force-bearing structure (310) is located on the path of axial movement of the retaining ring (400). The composite force-bearing structure (310) is configured to form a hydraulic buffer gap with a gradually changing flow area with the retaining ring (400) to apply hydraulic damping force as the retaining ring (400) moves toward the guide (300) with the connecting rod (500), and to mechanically contact the retaining ring (400) to radially position the retaining ring (400) and to receive the axial limiting load transmitted by the annular groove (510) through the retaining ring (400).

2. The truck shock absorber according to claim 1, characterized in that, The composite force-bearing structure (310) along the direction of the connecting rod (500) moving closer to the guide (300) includes, in sequence, an annular guide arc surface (311), an annular abutment groove (312), and an annular clearance groove (313). The radial distance between the annular guide arc surface (311) and the axis of the connecting rod (500) gradually decreases along the moving direction of the retaining ring (400) toward the guide (300), so that the flow cross-sectional area of ​​the hydraulic oil gradually decreases. The annular abutment groove (312) matches the outer contour of the retaining ring (400) and provides mechanical support to the retaining ring (400); The radial distance between the annular clearance groove (313) and the axis of the connecting rod (500) gradually decreases along the moving direction of the retaining ring (400) toward the guide (300), and is configured to provide temporary storage space for the extruded hydraulic oil.

3. The truck shock absorber according to claim 2, characterized in that, The guide (300) has an inclined end face (301) on the side facing the piston assembly (600). One end of the annular guide arc surface (311) is connected to the side of the annular abutment groove (312) facing the piston assembly (600), and the other end of the annular guide arc surface (311) extends towards the piston assembly (600) to the inclined end face (301) to guide hydraulic oil to flow to the annular guide arc surface (311). The radial distance between the annular guide arc surface (311) and the axis of the connecting rod (500) gradually decreases along the direction close to the annular abutment groove (312); the inclined end face (301) is inclined radially from the outside to the inside toward the annular guide arc surface (311), and the radial inner edge of the inclined end face (301) is connected to the annular guide arc surface (311).

4. The truck shock absorber according to claim 3, characterized in that, The groove surface of the annular groove (510) forms a multi-segment mating surface (520), which includes a buffer mating section (540) and a limiting abutment section (530) arranged along the moving path of the retaining ring (400) toward the guide (300). The radial distance between the buffer mating section (540) and the axis of the connecting rod (500) gradually decreases in the direction close to the limiting abutment section (530). When the connecting rod (500) moves to the tension limit position, the radial inner surface of the retaining ring (400) abuts against the limit abutment section (530), and the outer peripheral surface of the retaining ring (400) abuts against the annular abutment groove (312).

5. The truck shock absorber according to claim 4, characterized in that, The buffer mating section (540) includes a straight section surface (541), a first arc surface (542), an inclined side surface (543), and a second arc surface (544) connected in sequence. The straight section surface (541) is formed at the bottom of the annular groove (510) and connected to the limiting abutment section (530), and is adapted to provide radial positioning to the retaining ring (400); The first arc surface (542), the inclined side surface (543) and the second arc surface (544) are connected in sequence between the straight section surface (541) and the groove of the annular groove (510) near the guide (300) to decompose the axial shear force transmitted by the retaining ring (400) into normal pressure and tangential distributed force.

6. The truck shock absorber according to claim 5, characterized in that, The retaining ring (400) has a circular cross-section; The limiting abutment section (530) has an arcuate profile that matches the radial inner surface of the retaining ring (400); The annular abutment groove (312) has an arcuate profile that matches the radial outer surface of the retaining ring (400).

7. The truck shock absorber according to claim 6, characterized in that, The radius of the arc profile of the limiting abutment section (530) and the radius of the arc profile of the annular abutment groove (312) are both equal to the radius of the circular cross section of the retaining ring (400).

8. The truck shock absorber according to claim 1, characterized in that, It also includes an oil seal (900) installed at the port of the inner tube (200) and located on the side of the guide (300) away from the piston assembly (600), adapted to seal the connecting rod (500) passing through the guide (300).

9. The truck shock absorber according to claim 8, characterized in that, The oil seal (900) includes an elastic base (910), a first skeleton (901), and a second skeleton (902); The first frame (901) extends axially along the connecting rod (500), and the second frame (902) extends radially toward the connecting rod (500); The elastic base (910) includes a first elastic base (911) and a second elastic base (912); A first cavity (913) is formed between one side of the first elastic matrix (911) and the first skeleton (901) facing the guide (300) and recessed inward. An installation gap (920) is provided between the end face of the first skeleton (901) and the guide (300) on the side opposite to the piston assembly (600). The installation gap (920) communicates with the first cavity (913). A recessed second cavity (914) is formed between the other side of the first elastic matrix (911) and the second elastic matrix (912), and the second cavity (914) opens toward the axis of the connecting rod (500).

10. A method for assembling a truck shock absorber, used for assembling the truck shock absorber according to any one of claims 1 to 9, characterized in that, It should include at least the following steps: A tapered oil seal transition sleeve (50) is provided and fitted onto the connecting rod (500). Insert the retaining ring (400) into the small end of the oil seal transition sleeve (50) and push the retaining ring (400) along the outer circumferential surface of the oil seal transition sleeve (50) toward the large end, so that the retaining ring (400) gradually expands. Continue pushing the retaining ring (400) so that it passes over the oil seal transition sleeve (50) and moves to the position corresponding to the annular retaining groove (510), so that the retaining ring (400) elastically resets and snaps into the annular retaining groove (510). Remove the oil seal transition sleeve (50) from the connecting rod (500).

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