A plain bearing with a polytetrafluoroethylene antifriction pad

Abstract

This invention provides a sliding bearing with a polytetrafluoroethylene (PTFE) anti-friction pad, relating to the field of bearing technology. When the anti-friction pad and friction ring reduce their axial thickness due to wear, the upper and lower covers will move closer together axially along the centerline, reducing the safety clearance to a preset value. The drive unit pulls the coiling rope, reducing the length of the coiling rope remaining in the deformation and friction sections, causing all deformation sections to continue to compress. All friction sections slide radially inward and move closer together along the centerline, meaning the friction ring as a whole moves closer to and contracts towards the centerline. The friction sections push the anti-friction pad and upper cover away from the lower cover synchronously through the conical surface, increasing the safety clearance. This, to a certain extent, avoids rigid interference and severe wear at the edges of the upper and lower covers, ensuring sealing integrity and preventing plastic dust contamination of the interior. It also ensures the smoothness of relative rotation between the upper and lower covers, guaranteeing steering feel; maintains the oil reservoir volume and retains grease in the oil reservoir, ensuring the bearing's lubrication performance.

Description

Technical Field

[0001] This invention relates to the field of bearing technology, and in particular to a sliding bearing with a polytetrafluoroethylene anti-friction pad. Background Technology

[0002] With the rapid development of automotive electrification technology, the increase in vehicle weight and the higher demands for driving comfort have placed higher requirements on the performance of sliding bearings, a core component of the shock absorber system. Automotive shock absorber sliding bearings are mainly used to connect the vehicle body and the suspension system, and must simultaneously withstand axial and radial alternating loads as well as impact loads, maintaining stable operation in temperatures ranging from -40℃ to 100℃. Currently, the industry commonly uses a two-way thrust bearing structure to meet multi-directional force requirements. Structurally, it typically includes upper and lower covers, friction plates, and lubricating grease. Regarding materials, the upper and lower covers are often made of materials such as polyoxymethylene (POM), which provides support through its good mechanical strength; the friction plates are commonly made of materials such as polypropylene (PP), forming a friction pair with the upper and lower covers to reduce wear. In terms of sealing design, labyrinth seals are widely used due to their low impact on torque and low cost, while rubber seals are used in scenarios with higher dustproof performance requirements. In addition, to optimize bearing friction performance, a friction-reducing pad made of polytetrafluoroethylene (PTFE) is installed between the bearing cover and the friction plate. Due to the super-lubricating properties of PTFE, it can effectively reduce the coefficient of friction and torque, and improve product life.

[0003] In sliding bearings employing labyrinth seals, a small axial safety clearance is typically designed between the upper and lower covers to form a non-contact labyrinth seal, while simultaneously defining a specific volume of the internal oil reservoir. However, as the core friction components wear down and their axial thickness decreases during long-term service, irreversible axial proximity occurs between the upper and lower covers under axial loads. This axial proximity leads to two main consequences: First, the safety clearance decreases, causing the edges of the upper and lower covers to bear part of the axial load, resulting in rigid interference and severe wear at the edges, compromising the seal integrity, generating plastic dust that contaminates the interior, and affecting the smoothness of relative rotation between the upper and lower covers, thus worsening steering feel. Second, the volume of the oil reservoir between the upper and lower covers is compressed, and the resulting pumping effect forces the previously retained grease out of the sealing interface, causing the bearing to rapidly dry out and fail due to irreversible grease loss.

[0004] The information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention, and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] Therefore, it is necessary to provide a sliding bearing with a polytetrafluoroethylene anti-friction pad to address the problems existing in current sliding bearings.

[0006] The above objectives are achieved through the following technical solutions:

[0007] A sliding bearing with a polytetrafluoroethylene (PTFE) anti-friction pad includes an upper cover, a lower cover, and an anti-friction pad and a friction ring located between them, all with their axes coincident with a centerline. When the upper cover and the lower cover rotate relative to each other, the anti-friction pad and the friction ring rotate relative to each other. The friction ring includes multiple alternating deformation sections and friction sections in the circumferential direction of the centerline. The deformation sections are capable of deformation in the circumferential direction of the centerline and are always in a compressed state. The friction sections are slidably connected to the lower cover in the radial direction of the centerline. The upper surface of the friction section contacts the lower surface of the anti-friction pad, and the contact surface is... A conical surface; a drawstring is threaded circumferentially along the centerline within the deformation section and the friction section. The drawstring is taut and its two ends are closed. A drive unit is provided between the upper and lower covers to pull the drawstring, reducing the length of the drawstring remaining within the deformation and friction sections. The upper and lower covers have a safety gap along the axial direction of the centerline. When the safety gap decreases to a preset value, the drive unit pulls the drawstring to compress all deformation sections, causing all friction sections to slide radially inward along the centerline and push the friction-reducing pad and the upper cover away from the lower cover synchronously through the conical surface.

[0008] Furthermore, the drive component is ring-shaped and its axis coincides with the center line. The lower surface of the drive component contacts the lower cover and generates a first frictional force. When the safety gap decreases to a preset value, the upper surface of the drive component contacts the upper cover and generates a second frictional force. The first frictional force is less than the second frictional force. When the safety gap decreases to a preset value and the lower cover rotates relative to the upper cover, the friction ring rotates relative to the drive component. The drive component pulls the retractable rope to move the upper cover away from the lower cover, and the upper surface of the drive component disengages from the upper cover.

[0009] Furthermore, the drive unit has multiple connection points for pulling the coiled rope, and these connection points are evenly distributed circumferentially along the center line; when the friction ring rotates relative to the drive unit, the drive unit pulls the coiled rope through the multiple connection points.

[0010] Furthermore, a connecting part is provided between the lower cover and the driving component. When the safety gap is reduced to a preset value, the lower cover first rotates relative to the upper cover in a first rotation direction, and the connecting part allows the friction ring to rotate relative to the driving component in a first rotation direction; the lower cover then rotates relative to the upper cover in a second rotation direction, and the connecting part causes the friction ring and the driving component to rotate synchronously in the second rotation direction.

[0011] Furthermore, the lower cover is provided with an inner ring located inside the drive member and whose axis coincides with the center line. The connecting part includes a toothed groove located on the inner wall of the drive member and a toothed protrusion located on the outer wall of the inner ring. Multiple toothed grooves and protrusions are evenly distributed around the center line. The protrusions can extend into the toothed grooves or retract from the toothed grooves, and the protrusions have a tendency to extend into the toothed grooves. When the protrusions extend into the toothed grooves, the friction ring can rotate relative to the drive member in a first rotational direction, so that the friction ring and the drive member rotate synchronously in a second rotational direction.

[0012] Furthermore, along the axial direction of the centerline, the upper surface of the deformation section and the lower surface of the friction-reducing pad are spaced apart.

[0013] Furthermore, in the axial direction of the centerline, there is a first distance between the upper surface of the deformation segment and the lower surface of the friction-reducing pad; in the circumferential direction of the centerline, the first distance gradually increases from the middle to both ends of the deformation segment.

[0014] Furthermore, in the circumferential direction of the centerline, the end of the upper surface of the deformation segment is lower than the end of the upper surface of the friction segment, and there is a transition segment between the end of the upper surface of the deformation segment and the end of the upper surface of the friction segment.

[0015] Furthermore, at least two drawstrings should be provided, arranged side by side, inside and out.

[0016] Furthermore, the taper of the upper surface of the friction section and the lower surface of the friction-reducing pad is less than 1:3.

[0017] The present invention has at least the following beneficial effects:

[0018] (1) When the axial thickness of the anti-friction pad and friction ring decreases due to wear, the upper cover and the lower cover will move closer together in the axial direction of the center line and reduce the safety clearance to the preset value. The drive unit pulls the retracting rope, and the length of the retracting rope left in the deformation section and friction section decreases, so that all deformation sections continue to be compressed. All friction sections slide inward and move closer along the radial direction of the center line. That is, the friction ring moves closer and contracts towards the center line as a whole. The friction section pushes the anti-friction pad and the upper cover away from the lower cover synchronously through the conical surface to increase the safety clearance. To a certain extent, it avoids rigid interference and severe wear between the edges of the upper cover and the lower cover, ensures the integrity of the seal, avoids plastic dust pollution inside, and at the same time ensures the smoothness of the relative rotation of the upper cover and the lower cover, and ensures the steering feel; maintains the volume of the oil reservoir and keeps the grease in the oil reservoir to ensure the lubrication performance of the bearing.

[0019] (2) The friction ring is divided into alternating deformation sections and friction sections, and is circumferentially elastically bound by a certain elastic binding rope. When the friction ring is subjected to radial impact load and internal stress, the elasticity of the binding rope and the setting of the deformation sections enable the friction ring to deform radially along the center line. That is, the friction ring can move closer to the center line and contract to absorb radial impact load and release internal stress, thereby adapting to external impact and temperature changes and ensuring the performance of the friction ring to a certain extent. Attached Figure Description

[0020] Figure 1 A schematic diagram of the structure of a sliding bearing with a polytetrafluoroethylene anti-friction pad provided in an embodiment of the present invention;

[0021] Figure 2 for Figure 1 Top view;

[0022] Figure 3 for Figure 2 Sectional view along axis AA;

[0023] Figure 4 for Figure 3 A magnified view of a section at point B in the middle;

[0024] Figure 5 for Figure 2 CC-direction sectional view;

[0025] Figure 6 for Figure 5 A magnified view of a section at point D;

[0026] Figure 7 for Figure 1 Exploded view of the parts;

[0027] Figure 8 for Figure 1 A schematic diagram of the structure after the top and bottom covers are hidden;

[0028] Figure 9 for Figure 8 Exploded view of the parts;

[0029] Figure 10 for Figure 9 A magnified view of a section at point E in the middle;

[0030] Figure 11 for Figure 8 The front view;

[0031] Figure 12 for Figure 11 A magnified view of a section at point F in the middle;

[0032] Figure 13 This is a perspective view of the deformation section and the friction section;

[0033] Figure 14 This is a schematic diagram of the bottom of the deformation section and the friction section.

[0034] in:

[0035] 101. Top cover; 102. Bottom cover; 103. Anti-friction pad; 104. Friction ring; 105. Deformation section; 106. Friction section; 107. Reeling rope; 108. Drive component; 109. Slide groove; 110. Protrusion; 111. Inner ring; 112. Tooth groove; 113. Convex tooth; 114. Transition section. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0037] The component designations used in this document, such as "first" and "second," are merely for distinguishing the described objects and do not have any sequential or technical meaning. The terms "connection" and "linkage" used in this invention, unless otherwise specified, include both direct and indirect connections (linkages). It should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description. They 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, and therefore should not be construed as limiting the invention.

[0038] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0039] like Figures 1 to 14As shown, this embodiment of the invention provides a sliding bearing with a polytetrafluoroethylene (PTFE) anti-friction pad (hereinafter referred to as the sliding bearing), including an upper cover 101 and a lower cover 102 whose axes are both coincident with the center line, and an anti-friction pad 103 and a friction ring 104 located between them. When the upper cover 101 and the lower cover 102 rotate relative to each other, the anti-friction pad 103 and the friction ring 104 rotate relative to each other. The friction ring 104 includes a plurality of alternating deformation sections 105 and friction sections 106 in the circumferential direction of the center line. The deformation sections 105 can deform in the circumferential direction of the center line, and the deformation sections 105 are always in a compressed state. The friction sections 106 are slidably connected to the lower cover 102 and the sliding direction is radial to the center line. The upper surface of the friction section 106 is in contact with the lower surface of the anti-friction pad 103. Furthermore, the contact surface is a conical surface; a drawstring 107 is circumferentially threaded through the deformation section 105 and the friction section 106 along the center line. The drawstring 107 is in a taut state and its two ends are closed. A driving member 108 is provided between the upper cover 101 and the lower cover 102. The driving member 108 is used to pull the drawstring 107, so that the length of the drawstring 107 remaining in the deformation section 105 and the friction section 106 is reduced. The upper cover 101 and the lower cover 102 have a safety gap in the axial direction of the center line. When the safety gap is reduced to a preset value, the driving member 108 pulls the drawstring 107 so that all deformation sections 105 continue to be compressed, and all friction sections 106 slide radially inward along the center line, and push the anti-friction pad 103 and the upper cover 101 away from the lower cover 102 synchronously through the conical surface.

[0040] When the anti-friction pad 103 and friction ring 104 decrease in axial thickness due to wear, the upper cover 101 and lower cover 102 will move closer together axially along the centerline, reducing the safety clearance to a preset value. The drive unit 108 pulls the retractable rope 107, reducing the length of the retractable rope 107 within the deformation section 105 and friction section 106, causing all deformation sections 105 to continue to compress. All friction sections 106 slide radially inward and move closer together along the centerline, meaning the friction ring 104 moves closer to and contracts towards the centerline as a whole. The friction sections 106 push the anti-friction pad 103 and upper cover 101 away from the lower cover 102 simultaneously through the conical surface, increasing the safety clearance. This, to a certain extent, avoids rigid interference and severe wear at the edges of the upper cover 101 and lower cover 102, ensuring sealing integrity and preventing plastic dust contamination of the interior. It also ensures the smoothness of relative rotation between the upper cover 101 and lower cover 102, guaranteeing steering feel; maintaining the oil reservoir volume and retaining grease in the oil reservoir, ensuring the lubrication performance of the bearing.

[0041] Furthermore, during vehicle operation, severe road bumps can generate radial impact loads on the friction ring 104. Additionally, drastic temperature changes causing thermal expansion and contraction can lead to stress buildup within the friction ring 104. Traditional sliding bearings typically have a closed, rigid circular ring structure with limited radial deformation freedom. This makes it unable to mitigate impact loads or release accumulated stress, potentially leading to brittle fracture, seizing, or loosening of the friction ring 104 with the upper cover 101 or lower cover 102, resulting in abnormal noise or failure. This invention divides the friction ring 104 into alternating deformation sections 105 and friction sections 106, and uses a retractable rope 107 with a certain elasticity for circumferential elastic restraint. When the friction ring 104 is subjected to radial impact load and internal stress accumulation, the elasticity of the retractable rope 107 and the arrangement of the deformation sections 105 enable the friction ring 104 to deform radially along the centerline. That is, the friction ring 104 can move closer to and contract towards the centerline to absorb radial impact load and release internal stress accumulation, thereby adapting to external impact and temperature changes and ensuring the performance of the friction ring 104 to a certain extent.

[0042] The aforementioned sliding bearing can be applied to automotive shock absorbers. The upper end of the shock absorber is connected to the vehicle body via a top mounting bracket, and the sliding bearing is located within this top mounting bracket. When the driver turns the steering wheel, the steering gear drives the steering tie rod, causing the wheel to rotate around the kingpin. The shock absorber and lower cover 102 rotate relative to the upper cover 101 and the vehicle body, thus converting the rotational motion of the wheel and shock absorber relative to the vehicle body into a frictional rotational motion of the lower cover 102 relative to the upper cover 101. After the sliding bearing is installed between the shock absorber and the vehicle body, the sliding bearing bears the weight of the vehicle body and the spring force of the shock absorber. Both forces are axial and opposite along the centerline, creating a safety gap between the upper cover 101 and the lower cover 102 to form a non-contact labyrinth seal between them. This also limits the specific volume of the internal oil reservoir, which is filled with grease. Meanwhile, since the upper surface of the friction section 106 contacts the lower surface of the anti-friction pad 103 and the contact surface is conical, the anti-friction pad 103 generates a horizontal component force along the radial direction of the centerline on the friction section 106, which tends to push the friction section 106 outward. The deformation section 105 and the coiling rope 107 both have a certain degree of elasticity, with the deformation section 105 in a compressed state and the coiling rope 107 in a tensioned state. The coiling rope 107 exerts a circumferential elastic restraint effect on the friction ring 104 as a whole, ensuring that the initial position of the friction section 106 is in full contact with the anti-friction pad 103. The specific structure of the aforementioned sliding bearing, as well as its specific settings and working principle when applied to automotive shock absorbers, are existing technologies and will not be elaborated here.

[0043] It is worth noting that the centerline is the axis of the sliding bearing. Both the upper cover 101 and the lower cover 102 can be made of polyoxymethylene (POM), the friction-reducing pad 103 is made of polytetrafluoroethylene (PTEF), and the friction section 106 can be made of polypropylene (PP) or nylon (PA6). This ensures that the friction between the friction-reducing pad 103 and the friction section 106 is less than the friction between the upper cover 101 and the friction-reducing pad 103, and also less than the friction between the lower cover 102 and the friction section 106. Therefore, when the upper cover 101 and the lower cover 102 rotate relative to each other, only the friction-reducing pad 103 and the friction ring 104 rotate relative to each other, while the upper cover 101 and the friction-reducing pad 103 remain relatively stationary, and the lower cover 102 and the friction section 106 also remain relatively stationary. Furthermore, the friction-reducing pad 103, made of polytetrafluoroethylene (PTEF), effectively reduces the coefficient of friction and torque of the sliding bearing, thus improving product lifespan.

[0044] Additionally, the deformation section 105 can be made of materials such as rubber, which can at least produce elastic deformation in the circumferential direction of the centerline, and can also produce adaptive deformation in other directions. The specific selection of the deformation section 105 can be chosen and set according to the actual application, and there are no restrictions here. The deformation section 105 is initially in a compressed state. After the sliding bearing is installed between the shock absorber and the vehicle body, the sliding bearing bears the weight of the vehicle body and the spring force of the shock absorber. Since the upper surface of the friction section 106 contacts the lower surface of the friction-reducing pad 103 and the contact surface is a conical surface, the friction ring 104 moves away from and expands slightly relative to the centerline, thereby slightly stretching the deformation section 105. However, under the action of the coiling rope 107, the deformation section 105 is still in a compressed state. See also Figure 7 and Figure 14 The lower cover 102 has a radial groove 109 along its center line, and the friction section 106 has a protrusion 110 along its center line at the bottom, which is slidably connected to the groove 109. Alternatively, the deformation section 105 and the friction section 106 can be fixed by adhesive bonding, or other methods can be used for fixing.

[0045] It is worth noting that, in the circumferential direction of the centerline, the size of the friction segment 106 is larger than that of the deformation segment 105, that is, the central angle corresponding to the friction segment 106 is larger than that corresponding to the deformation segment 105. This makes the overall change in the friction ring 104 as a whole towards the centerline and the amount of contraction smaller. Based on this, after the driving component 108 pulls the retracting rope 107, all the deformation segments 105 continue to compress, and all the friction segments 106 slide inward and move closer along the radial direction of the centerline. The retracting rope 107 can cause the friction segments 106 to undergo slight deformation, thereby reducing the radius of the friction segments 106. As a result, after the friction segments 106 slide inward and move closer along the radial direction of the centerline, the axis of the friction segments 106 still coincides with the centerline. At the same time, it ensures that the upper surface of the friction segments 106 is in full contact with the lower surface of the friction-reducing pad 103, thus ensuring the stability of the friction contact surface.

[0046] In one embodiment, see [link to relevant documentation] Figure 4 and Figure 6 The driving member 108 is ring-shaped and its axis coincides with the center line. The lower surface of the driving member 108 contacts the lower cover 102 and generates a first frictional force. When the safety gap decreases to a preset value, the upper surface of the driving member 108 contacts the upper cover 101 and generates a second frictional force. The first frictional force is less than the second frictional force. When the safety gap decreases to a preset value and the lower cover 102 rotates relative to the upper cover 101, the friction ring 104 rotates relative to the driving member 108. The driving member 108 pulls the retractable rope 107 to make the upper cover 101 move away from the lower cover 102, and the upper surface of the driving member 108 disengages from the upper cover 101.

[0047] When the safety gap decreases to a preset value, the upper surface of the drive member 108 contacts the upper cover 101, keeping them relatively stationary. Then, when the lower cover 102 rotates relative to the upper cover 101, the lower cover 102 drives the friction ring 104 to rotate relative to the drive member 108 and the upper cover 101. That is, the friction ring 104 and the drive member 108 rotate relative to each other. The drive member 108 pulls the coiling rope 107 to increase the safety gap, the upper cover 101 moves away from the lower cover 102, and the upper surface of the drive member 108 disengages from the upper cover 101 and resets.

[0048] The lower surface of the drive component 108 may be provided with a lower contact pad, which is made of polytetrafluoroethylene (PTEF) material, so that the first frictional force between the lower surface of the drive component 108 and the lower cover 102 is small. The upper surface of the drive component 108 may be provided with an upper contact pad, which may be made of polypropylene (PP) or nylon (PA6) material, so that the second frictional force between the upper surface of the drive component 108 and the upper cover 101 is large.

[0049] The distance between the upper surface of the drive component 108 and the upper cover 101 is a first value, which is less than the safety gap, and the sum of the first value and the preset value is equal to the safety gap.

[0050] In one embodiment, the drive member 108 has a plurality of connection points for pulling the drawstring 107, and the plurality of connection points are evenly distributed circumferentially along the center line; when the friction ring 104 rotates relative to the drive member 108, the drive member 108 pulls the drawstring 107 through the plurality of connection points.

[0051] The drawstring 107 is pulled by the tension of the drive member 108. Multiple connection points are evenly distributed along the circumference of the center line, which enables the drawstring 107 to be pulled evenly in the circumference of the center line, so that the deformation degree of all deformation sections 105 is basically the same, thereby making the friction ring 104 move closer to and contract evenly towards the center line.

[0052] Among them, see Figure 8 and Figure 9Initially, the two ends of the drawstring 107 are broken. It is then passed sequentially through the deformation section 105 and the friction section 106, and the two ends are fixed. The fixing method can be injection molding or secondary injection molding, etc. Preferably, the drive member 108 has two through holes along its radial direction. After the drawstring 107 passes through a set of deformation sections 105 and friction sections 106, the end of the drawstring 107 first passes through the first through hole and is located inside the drive member 108, then reverses and passes through the second through hole and is located outside the drive member 108, before passing through the next set of deformation sections 105 and friction sections 106. This ensures that each set of deformation sections 105 and friction sections 106 has a connection point, for example... Figure 8 and Figure 9 There are a total of 6 connection points. Each deformation segment 105 is subjected to a basically uniform tension from the coiling rope 107, making the deformation degree of all deformation segments 105 basically uniform, thereby causing the friction ring 104 to uniformly move closer to and contract towards the center line. Of course, other connection point settings can also be used, such as directly fixing the coiling rope 107 and the drive component 108 at the connection point.

[0053] In one embodiment, a connecting portion is provided between the lower cover 102 and the drive member 108. When the safety gap is reduced to a preset value, the lower cover 102 first rotates relative to the upper cover 101 in a first rotation direction, and the connecting portion allows the friction ring 104 to rotate relative to the drive member 108 in the first rotation direction; the lower cover 102 then rotates relative to the upper cover 101 in a second rotation direction, and the connecting portion causes the friction ring 104 and the drive member 108 to rotate synchronously in the second rotation direction.

[0054] In each rotation cycle of the lower cover 102, it must first rotate clockwise relative to the upper cover 101, and then rotate counterclockwise relative to the upper cover 101 to reset. The connecting part plays a unidirectional driving role between the lower cover 102 and the driving member 108. When the safety gap decreases to a preset value, in each rotation cycle of the lower cover 102, only one rotation process will cause the friction ring 104 and the driving member 108 to rotate relative to each other to increase the safety gap, while in another rotation process, the safety gap remains unchanged.

[0055] In one embodiment, see [link to relevant documentation] Figures 8 to 10 The lower cover 102 is provided with an inner ring 111 located inside the drive member 108 and whose axis coincides with the center line. The connecting part includes a toothed groove 112 located on the inner wall of the drive member 108 and a protruding tooth 113 located on the outer wall of the inner ring 111. Multiple toothed grooves 112 and protruding teeth 113 are evenly distributed around the center line. The protruding teeth 113 can extend into the toothed groove 112 or retract from the toothed groove 112, and the protruding teeth 113 have a tendency to extend into the toothed groove 112. When the protruding teeth 113 extend into the toothed groove 112, the friction ring 104 can rotate relative to the drive member 108 in a first rotation direction, so that the friction ring 104 and the drive member 108 rotate synchronously in a second rotation direction.

[0056] When the lower cover 102 rotates relative to the upper cover 101 in the first direction of rotation, the protruding teeth 113 extend into different tooth grooves 112 in sequence to allow the friction ring 104 to rotate relative to the drive member 108 in the first direction of rotation; when the lower cover 102 rotates relative to the upper cover 101 in the second direction of rotation, the protruding teeth 113 can only extend into a certain tooth groove 112, so that the friction ring 104 and the drive member 108 rotate synchronously in the second direction of rotation.

[0057] The inner ring 111 can be connected to the lower cover 102 via a key connection, allowing the two to rotate synchronously. (See also...) Figure 10 The protruding tooth 113 can be a spring-loaded structure, with its first end connected to the inner ring 111 and its second end free. The length direction of the protruding tooth 113 is set at an angle to the radial direction of the inner ring 111, and under normal conditions, the second end of the protruding tooth 113 extends into the tooth groove 112. When the safety gap decreases to a preset value, the drive member 108 contacts the upper cover 101 and remains relatively stationary. Then, when the lower cover 102 rotates relative to the upper cover 101 in the first direction of rotation, the second end of the protrusion 113 is squeezed, and the protrusion 113 swings around its first end, causing the second end of the protrusion 113 to retract from the first tooth groove 112. As the lower cover 102 continues to rotate relative to the upper cover 101 in the first direction of rotation, the protrusion 113 swings back and resets under its own elasticity. The second end of the protrusion 113 then extends into the second tooth groove 112. This cycle repeats, thereby allowing the friction ring 104 to rotate relative to the drive member 108 in the first direction of rotation. The drive member 108 pulls the drawstring 107 to move the upper cover 101 away from the lower cover 102, thereby increasing the safety gap. The upper surface of the drive member 108 is also detached from the upper cover 101 and is in a free state. When the lower cover 102 rotates relative to the upper cover 101 in the second rotation direction, the protruding tooth 113 is always located in the current tooth groove 112, driving the drive member 108 to rotate in the second rotation direction, so that the friction ring 104 and the drive member 108 rotate synchronously in the second rotation direction, and the safety gap remains unchanged.

[0058] For example, see Figure 9From a top-to-bottom perspective along the center line, the first rotation direction is counterclockwise, and the second rotation direction is clockwise. When the safety gap decreases to a preset value, the drive member 108 contacts the upper cover 101 and remains relatively stationary. Then, when the lower cover 102 rotates counterclockwise relative to the upper cover 101, the lower cover 102, the inner ring 111, and the friction ring 104 all rotate counterclockwise. The second end of the protrusion 113 is squeezed, and the protrusion 113 swings around its first end, causing the second end of the protrusion 113 to retract from the first tooth groove 112. As the lower cover 102 continues to rotate counterclockwise relative to the upper cover 101, the protrusion 113 swings in the opposite direction and resets under its own elasticity. The second end of the protrusion 113 extends into the second tooth groove 112 again. This cycle repeats, thereby allowing the friction ring 104 to rotate counterclockwise relative to the drive member 108. The drive member 108 pulls the drawstring 107 to move the upper cover 101 away from the lower cover 102, thereby increasing the safety gap. The upper surface of the drive member 108 is detached from the upper cover 101 and is in a free state. Then, when the lower cover 102 rotates clockwise relative to the upper cover 101, the lower cover 102, the inner ring 111 and the friction ring 104 all rotate clockwise. The convex tooth 113 is always located in the current tooth groove 112, which drives the driving member 108 to rotate clockwise, so that the friction ring 104 and the driving member 108 rotate clockwise synchronously, and the safety gap remains unchanged.

[0059] In one embodiment, the upper surface of the deformation segment 105 and the lower surface of the wear-reducing pad 103 are spaced apart along the axial direction of the centerline to avoid contact between the deformation segment 105 and the wear-reducing pad 103 and thus prevent wear.

[0060] In one embodiment, see [link to relevant documentation] Figure 12 Along the axial direction of the centerline, there is a first distance between the upper surface of the deformation section 105 and the lower surface of the friction-reducing pad 103; along the circumferential direction of the centerline, the first distance gradually increases from the middle to both ends of the deformation section 105.

[0061] Existing sliding bearings, when used in automotive shock absorbers, typically employ a horizontal friction contact surface. This makes it difficult for grease to be drawn into the center of the friction contact surface, hindering the formation of a stable hydrodynamic oil film. Consequently, the friction pair remains in a state of boundary lubrication or even dry friction for extended periods, resulting in a high coefficient of friction and increased wear on the anti-friction pad 103 due to localized high temperatures. In this invention, the upper surface of the deformation section 105 and the lower surface of the anti-friction pad 103 are spaced apart, allowing grease to enter the center of the friction contact surface between the anti-friction pad 103 and the friction section 106 along this gap, facilitating the formation of a stable hydrodynamic oil film. Meanwhile, the upper surface of the deformation section 105 forms two opposing inclined surfaces. When the upper cover 101 and the lower cover 102 rotate relative to each other, the friction-reducing pad 103 and the friction ring 104 rotate relative to each other. The grease between the friction-reducing pad 103 and the friction section 106 will flow along one of the inclined surfaces, and the space in which the grease can move gradually becomes smaller and is gradually squeezed, thereby forming a supporting force along the centerline between the friction-reducing pad 103 and the friction section 106, reducing the pressure between the friction-reducing pad 103 and the friction ring 104, reducing the friction coefficient of the friction pair and the high-temperature wear of the friction-reducing pad 103, and improving the lubrication conditions.

[0062] For example, see Figure 12 When the lower cover 102 rotates to the right relative to the upper cover 101, the friction-reducing pad 103 rotates to the left, causing the grease between the deformation section 105 and the friction-reducing pad 103 to flow to the left. As the grease flows along the left half of the inclined surface and the flow space gradually decreases, it is gradually compressed, thus forming an axial support force along the centerline between the friction-reducing pad 103 and the friction section 106. This reduces the pressure between the friction-reducing pad 103 and the friction ring 104, lowers the friction coefficient of the friction pair, and reduces the high-temperature wear of the friction-reducing pad 103. The principle is the same when the lower cover 102 rotates to the left relative to the upper cover 101, and will not be elaborated here.

[0063] In one embodiment, see [link to relevant documentation] Figure 12 In the circumferential direction of the centerline, the end of the upper surface of the deformation section 105 is lower than the end of the upper surface of the friction section 106, and there is a transition section 114 between the end of the upper surface of the deformation section 105 and the end of the upper surface of the friction section 106.

[0064] Even after the friction section 106 has been worn to a certain extent, the deformation section 105 will still not come into contact with the wear-reducing pad 103 and wear will not occur.

[0065] The transition section 114 gradually decreases from top to bottom and from both ends of the deformation section 105 to the middle, which can guide the grease from between the deformation section 105 and the anti-friction pad 103 to between the anti-friction pad 103 and the friction section 106.

[0066] In one embodiment, see [link to relevant documentation] Figure 9 At least two drawstrings 107 should be provided, arranged side by side, inside and out.

[0067] Compared to setting only one drawstring 107, setting at least two drawstrings 107 can avoid the torsional force that may be generated between the friction section 106 and the deformation section 105 when the drawstring 107 is pulled by the drive member 108, and to a certain extent ensure the deformation process of the deformation section 105 and the stability of its connection with the friction section 106.

[0068] Among them, at least two drawstrings 107 are independent to avoid mutual interference.

[0069] In one embodiment, the taper of the upper surface of the friction section 106 and the lower surface of the friction-reducing pad 103 is less than 1:3.

[0070] When an axial force is applied to the conical surface, a horizontal component force is generated along the radial direction of the centerline, which tends to push the friction section 106 outward. The taper of the conical surface is set as small as possible, that is, its angle with the horizontal plane is small, so that the horizontal component force is small, and the coiling rope 107 can smoothly pull the friction section 106 and make it slide inward along the radial direction of the centerline.

[0071] The working principle of this invention is as follows:

[0072] A sliding bearing is installed between the shock absorber and the vehicle body, creating a safety clearance between the upper cover 101 and the lower cover 102 to form a non-contact labyrinth seal between them, while also defining a specific volume of the internal oil reservoir. When the wheels turn, the shock absorber rotates relative to the vehicle body, the lower cover 102 rotates relative to the upper cover 101, and the friction section 106 rotates relative to the friction pad 103.

[0073] The friction ring 104 is divided into alternating deformation sections 105 and friction sections 106, and is circumferentially elastically bound by a certain elastic binding rope 107. When the friction ring 104 is subjected to radial impact load and internal stress, the elasticity of the binding rope 107 and the arrangement of the deformation sections 105 enable the friction ring 104 to deform radially along the centerline. That is, the friction ring 104 can move closer to and contract towards the centerline to absorb radial impact load and release internal stress, thereby adapting to external impact and temperature changes and ensuring the performance of the friction ring 104 to a certain extent.

[0074] Because the upper surface of the deformation section 105 is spaced apart from the lower surface of the friction-reducing pad 103, grease can enter the center of the friction contact surface between the friction-reducing pad 103 and the friction section 106 along this gap, facilitating the formation of a stable hydrodynamic oil film. Simultaneously, the upper surface of the deformation section 105 forms two opposing inclined surfaces. When the upper cover 101 and lower cover 102 rotate relative to each other, the friction-reducing pad 103 and the friction ring 104 rotate relative to each other. The grease between the friction-reducing pad 103 and the friction section 106 flows along one of the inclined surfaces, and the space in which the grease can move gradually decreases, causing it to be gradually compressed. This creates an axial support force along the centerline between the friction-reducing pad 103 and the friction section 106, reducing the pressure between the friction-reducing pad 103 and the friction ring 104, lowering the coefficient of friction of the friction pair, reducing high-temperature wear of the friction-reducing pad 103, and improving lubrication conditions.

[0075] When the anti-friction pad 103 and friction ring 104 decrease in axial thickness due to wear, the upper cover 101 and lower cover 102 will move closer together axially along the center line, reducing the safety gap. When the safety gap decreases to a preset value, the upper surface of the drive member 108 contacts the upper cover 101, keeping them relatively stationary. Then, in each rotation cycle of the lower cover 102, it must first rotate clockwise relative to the upper cover 101, and then counterclockwise relative to the upper cover 101 to reset. When the lower cover 102 rotates relative to the upper cover 101 in the first direction of rotation, the second end of the protrusion 113 is compressed, and the protrusion 113 swings around its first end, causing the second end of the protrusion 113 to retract from the first tooth groove 112. As the lower cover 102 continues to rotate relative to the upper cover 101 in the first direction of rotation, the protrusion 113 swings back and resets under its own elasticity, and the second end of the protrusion 113 extends into the second tooth groove 112. This cycle repeats, allowing the friction ring 104 to rotate relative to the drive member 108 in the first direction of rotation. The drive member 108 pulls the drawstring 107, and the length of the drawstring 107 remaining in the deformation section 105 and the friction section 106 is... The friction ring 104 shrinks and shrinks as a whole, causing all deformation sections 105 to continue to compress and all friction sections 106 to slide radially inward and move closer to each other along the center line. The friction sections 106 push the anti-friction pad 103 and the upper cover 101 away from the lower cover 102 through the conical surface to increase the safety clearance. This avoids rigid interference and severe wear between the edges of the upper cover 101 and the lower cover 102 to a certain extent, ensuring the integrity of the seal and preventing plastic dust from contaminating the interior. At the same time, it ensures the smoothness of the relative rotation of the upper cover 101 and the lower cover 102 and ensures the steering feel. It also maintains the volume of the oil reservoir and keeps the grease in the oil reservoir to ensure the lubrication performance of the bearing. After the safety clearance increases, the upper surface of the drive member 108 is separated from the upper cover 101 and is in a free state. Then, when the lower cover 102 rotates relative to the upper cover 101 in the second rotation direction, the protrusion 113 is always located in the current tooth groove 112, driving the drive member 108 to rotate in the second rotation direction, so that the friction ring 104 and the drive member 108 rotate synchronously in the second rotation direction, and the safety clearance remains unchanged.

[0076] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0077] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A sliding bearing with a polytetrafluoroethylene anti-friction pad, characterized in that, The system includes an upper cover and a lower cover, both with their axes coinciding with the center line, as well as a friction-reducing pad and a friction ring located between them. When the upper cover and the lower cover rotate relative to each other, the friction-reducing pad and the friction ring rotate relative to each other. The friction ring includes multiple alternating deformation sections and friction sections in the circumferential direction of the center line. The deformation sections can deform in the circumferential direction of the center line and are always in a compressed state. The friction sections are slidably connected to the lower cover and the sliding direction is radial to the center line. The upper surface of the friction section contacts the lower surface of the friction-reducing pad, and the contact surface is a conical surface. A drawstring is threaded through the deformation section and the friction section along the circumferential direction of the center line. The drawstring is in a taut state and its two ends are closed. A driving component is provided between the upper cover and the lower cover. The driving component is used to pull the drawstring, so that the length of the drawstring remaining in the deformation section and the friction section is reduced. The upper and lower covers have a safety gap along the centerline. When the safety gap decreases to a preset value, the drive unit pulls the retractor rope to compress all deformation sections, and all friction sections slide radially inward along the centerline. The conical surface pushes the friction-reducing pad and the upper cover away from the lower cover simultaneously.

2. The sliding bearing with a polytetrafluoroethylene anti-friction pad according to claim 1, characterized in that, The driving component is ring-shaped with its axis coinciding with the center line. The lower surface of the driving component contacts the lower cover and generates a first frictional force. When the safety gap decreases to a preset value, the upper surface of the driving component contacts the upper cover and generates a second frictional force. The first frictional force is less than the second frictional force. When the safety gap decreases to a preset value and the lower cover rotates relative to the upper cover, the friction ring rotates relative to the driving component. The driving component pulls the retractable rope to move the upper cover away from the lower cover, and the upper surface of the driving component disengages from the upper cover.

3. The sliding bearing with a polytetrafluoroethylene anti-friction pad according to claim 2, characterized in that, The drive unit has multiple connection points for pulling the coiling rope, and these connection points are evenly distributed circumferentially along the center line; when the friction ring rotates relative to the drive unit, the drive unit pulls the coiling rope through the multiple connection points.

4. The sliding bearing with a polytetrafluoroethylene anti-friction pad according to claim 2 or 3, characterized in that, A connecting part is provided between the lower cover and the driving component. When the safety gap is reduced to a preset value, the lower cover first rotates relative to the upper cover in a first rotation direction, and the connecting part allows the friction ring to rotate relative to the driving component in a first rotation direction; the lower cover then rotates relative to the upper cover in a second rotation direction, and the connecting part makes the friction ring and the driving component rotate synchronously in the second rotation direction.

5. The sliding bearing with a polytetrafluoroethylene anti-friction pad according to claim 4, characterized in that, The lower cover has an inner ring located inside the drive member with its axis coinciding with the center line. The connecting part includes a toothed groove on the inner wall of the drive member and a toothed protrusion on the outer wall of the inner ring. Multiple toothed grooves and protrusions are evenly distributed around the center line. The protrusions can extend into the toothed grooves or retract from them, and they tend to extend into the toothed grooves. When the protrusions extend into the toothed grooves, the friction ring can rotate relative to the drive member in a first rotational direction, so that the friction ring and the drive member rotate synchronously in a second rotational direction.

6. The sliding bearing with a polytetrafluoroethylene anti-friction pad according to claim 1, characterized in that, Along the axial direction of the centerline, the upper surface of the deformation section and the lower surface of the friction-reducing pad are spaced apart.

7. The sliding bearing with a polytetrafluoroethylene anti-friction pad according to claim 6, characterized in that, Along the axial direction of the centerline, there is a first distance between the upper surface of the deformation section and the lower surface of the friction-reducing pad; along the circumferential direction of the centerline, the first distance gradually increases from the middle to both ends of the deformation section.

8. The sliding bearing with a polytetrafluoroethylene anti-friction pad according to claim 7, characterized in that, In the circumferential direction of the centerline, the end of the upper surface of the deformation section is lower than the end of the upper surface of the friction section, and there is a transition section between the end of the upper surface of the deformation section and the end of the upper surface of the friction section.

9. The sliding bearing with a polytetrafluoroethylene anti-friction pad according to claim 1, characterized in that, At least two drawstrings should be installed, arranged side by side, inside and out.

10. The sliding bearing with a polytetrafluoroethylene anti-friction pad according to claim 1, characterized in that, The taper of the upper surface of the friction section and the lower surface of the friction-reducing pad is less than 1:3.

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