A guide bearing for a rear wheel steering shock absorber air spring

Abstract

This invention discloses a guide bearing for an air spring in a rear-wheel steering shock absorber, comprising: an upper cover, which is a load-bearing body disposed on the top of the bearing; a lower cover, which is a support body disposed at the bottom of the bearing; a bushing, which is a middle support and positioning structure of the bearing; a sealing ring, which is a sealing and protective structure at the bottom of the bearing; and a bushing gasket, which is a self-lubricating gasket for the upper and lower friction surfaces. This invention employs a composite friction pair of gasket and long-life grease, which reduces the rotational friction coefficient compared to traditional metal bearings, resulting in more sensitive and linear rear-wheel steering response without jamming or abnormal noise. The main body is made of engineering plastic, reducing weight compared to traditional metal bearings while meeting the load-bearing strength requirements under rear-wheel steering conditions. The self-lubricating material and composite friction pair effectively attenuate vibration and noise, solving the common bearing noise problem in rear-wheel steering vehicles and improving ride comfort.

Description

Technical Field

[0001] This invention relates to the field of bearing technology, and more specifically, to a guide bearing for an air spring in a rear wheel steering damper. Background Technology

[0002] With the widespread adoption of rear-wheel steering technology in automobiles, the connecting bearing between the shock absorber and the air spring must simultaneously meet four core requirements: low-friction rotation, high load capacity, long lifespan, and high sealing performance. Existing bearings of this type generally suffer from the following defects: 1. Insufficient sealing protection: The rear wheel shock absorber area is exposed to mud, water and gravel environment for a long time. The traditional labyrinth seal structure is prone to failure, resulting in grease loss and impurity intrusion, which greatly shortens the service life. 2. Insufficient thrust bearing capacity: The planar thrust structure is poorly designed and cannot withstand the axial thrust transmitted by the air spring and the radial impact of the shock absorber. It is prone to deformation and failure after long-term use. 3. Insufficient lightweighting: Traditional metal bearings are heavy, which does not conform to the trend of automotive lightweighting. 4. Poor NVH performance: The lack of effective friction noise reduction design makes it easy to generate abnormal noises during vehicle driving and turning, affecting ride comfort; 5. Poor assembly compatibility: Insufficient assembly space for air springs affects the overall performance of air spring shock absorbers. Summary of the Invention

[0003] In view of the problems of heavy weight and poor load-bearing and buffering capacity in the existing technology, the purpose of this invention is to provide a guide bearing for the air spring of the rear wheel steering shock absorber.

[0004] To solve the above problems, the present invention adopts the following technical solution; A guide bearing for an air spring in a rear wheel steering damper, comprising: The upper cover is a load-bearing body disposed on the top of the bearing; The lower cover is a support body located at the bottom of the bearing; Bushing, the bushing being a bearing intermediate support and positioning structure; The sealing ring is a sealing and protective structure at the bottom of the bearing; The bushing gasket is a self-lubricating gasket with upper and lower friction surfaces.

[0005] As a further description of the above technical solution: The upper and lower covers are fastened together by a snap-fit ​​structure, and the bushing, sealing ring and bushing gasket are all installed between the upper and lower covers.

[0006] As a further description of the above technical solution: The bushing is in the shape of an annular cylinder. The upper cover, lower cover and bushing are all injection molded from engineering plastics. The inner and outer rings of the bushing are both rounded to form rounded portions in the inner and outer rings, respectively. The rounded radius (R) of the inner and outer rings gradually decreases from the middle to the upper and lower end faces.

[0007] As a further description of the above technical solution: Both the inner and outer rings of the bushing have spiral microgrooves on their arc-shaped portions. The spiral microgrooves are distributed in the upper and lower halves of the arc-shaped portions. The spiral microgrooves in the upper and lower halves of the arc-shaped portions are staggered and do not communicate with each other. The spiral microgrooves extend from one end away from the middle of the arc-shaped portion to the transition point between the arc-shaped portion and the upper and lower bearing surfaces of the bushing.

[0008] As a further description of the above technical solution: The number of bushing gaskets is two. The bushing gaskets are cut and formed from PTFE material and are set on the upper and lower parts of the bushing. The two bushing gaskets are respectively attached to the inner friction surfaces of the upper cover and the lower cover.

[0009] As a further description of the above technical solution: The space between the upper and lower covers is filled with grease, which fills the friction surfaces of the upper and lower covers, bushings and bushing gaskets. The grease is polyurea-based grease.

[0010] As a further description of the above technical solution: The upper and lower surfaces of the bushing each have two coaxial annular grooves. The grease is filled into the interior of the annular grooves. The cross-sectional shape of the annular grooves is V-shaped or trapezoidal, with the long side of the trapezoid facing the outside of the bushing.

[0011] As a further description of the above technical solution: The sealing ring is stepped, and the inner and outer rings of the sealing ring are respectively embedded in the lower cover and the upper cover. The inner and outer rings of the sealing ring are provided with asymmetrical sealing lips, and the inclination angle of the outer sealing lip is greater than that of the inner sealing lip.

[0012] As a further description of the above technical solution: The top of the lower cover has two integrally formed positioning rings, which are located on the inner and outer sides of the bushing, respectively, and the bottom of the bushing extends between the two positioning rings.

[0013] As a further description of the above technical solution: The lower bushing gasket is located between the two locating rings.

[0014] Compared with the prior art, the advantages of this invention are: (1) In this design, the sealing ring forms a fully enclosed cavity, effectively preventing the intrusion of mud, water, sand and gravel, and improving the service life of the lubricating grease compared with the traditional structure.

[0015] (2) In this scheme, a composite friction pair of gasket and long-lasting grease is used. The coefficient of rotational friction is lower than that of traditional metal bearings, and the steering response of the rear wheel is more sensitive and linear, without jamming or abnormal noise.

[0016] (3) In this scheme, the main body is made of engineering plastics, which reduces the weight compared to traditional metal bearings, while meeting the load-bearing strength requirements under rear wheel steering conditions.

[0017] (4) In this solution, the self-lubricating material and the composite friction pair effectively attenuate vibration and noise, solve the common bearing noise problem in rear wheel steering vehicles, and improve ride comfort.

[0018] (5) All components of this solution adopt mature technology, which is suitable for mass production and significantly reduces the cost compared with traditional metal bearings; the integrated ring structure simplifies the assembly steps, has high coaxiality accuracy, greatly improves the assembly efficiency of the main engine manufacturer, and reduces the risk of installation deviation. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the front sectional view of the present invention; Figure 2 This is a schematic diagram of the disassembled structure of the steering bearing of the present invention; Figure 3 For the present invention Figure 1 Enlarged structural diagram of section A in the middle; Figure 4 This is a schematic diagram of the V-shaped structure of the annular groove in this invention; Figure 5 A schematic diagram showing the spiral microgrooves formed on the arcuate portions of the inner and outer rings of the bushing of this invention; Explanation of the labels in the diagram: 1. Top cover; 2. Bottom cover; 21. Positioning ring; 3. Bushing; 31. Annular groove; 32. Spiral micro-groove; 4. Sealing ring; 5. Bushing gasket. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0021] Please see Figure 1-5 A guide bearing for an air spring in a rear wheel steering damper, comprising: Upper cover 1, upper cover 1 is a load-bearing body set on the top of the bearing; Lower cover 2, which is a support body located at the bottom of the bearing; The upper cover 1 and the lower cover 2 are fastened together by a snap-fit ​​structure. The convex ring of the upper cover 1 can be engaged with the matching concave ring on the lower cover 2. The bushing 3, the sealing ring 4 and the bushing gasket 5 are all installed between the upper cover 1 and the lower cover 2 to form a closed annular cavity and increase the sealing performance. The bushing 3 serves as the intermediate support and positioning structure for the bearing. The bushing 3 is in the shape of an annular cylinder. The upper cover 1, the lower cover 2, and the bushing 3 are all injection molded from engineering plastics. The inner and outer rings of the bushing 3 are both rounded, forming rounded portions on the inner and outer rings respectively. The rounded radius (R) of the inner and outer rings of the bushing 3 gradually decreases from the middle to the upper and lower end faces.

[0022] When the rear wheel turns, it will compress the bushing 3. The arc makes the force transmission path smooth, and the stress flow line spreads evenly along the arc. This can reduce the peak stress and effectively prevent the bushing 3 from developing fatigue cracks from the edge under long-term alternating loads, especially for bushings made of engineering plastics such as PEEK. At the same time, it can enhance the load-bearing capacity of the bushing 3.

[0023] In reciprocating oscillating bearings, the establishment of the lubricating oil film depends on the "wedge effect". When the shaft rotates eccentrically relative to the bushing, the inner / outer wall edges with rounded transitions will form a smooth guide slope, which facilitates the grease to form a continuous pressure oil film on the upper and lower surfaces of the bushing 3 more smoothly.

[0024] Compared to a fixed arc angle, the arc section with a gradually changing R angle results in more uniform stress diffusion and a further reduction in peak load; the oil film wedge effect is more stable during oscillation, and the friction coefficient fluctuates less. Meanwhile, during cold starts at low temperatures, the gradually rounded arc section guides the viscous grease to spread and form a film more quickly; at high temperatures, the narrowed outlet creates a throttling effect, maintaining oil film pressure.

[0025] In essence, the gradual arc section facilitates the rapid formation or replenishment of grease on the side of the bushing 3 by passing over the connection between the upper and lower surfaces and the side surfaces, thereby reducing the coefficient of friction during cold starts. At high temperatures, the bushing 3 expands to a certain extent due to thermal expansion and contraction. The upper and lower outlets of the bushing 3 shrink, which affects the flow of grease and creates a throttling effect, thereby maintaining the oil film pressure and ensuring the stability of the oil film.

[0026] Both the inner and outer rings of the bushing 3 are provided with spiral microgrooves 32. The spiral microgrooves 32 are distributed in the upper and lower halves of the arc portion. The spiral microgrooves 32 in the upper and lower halves of the arc portion are staggered and do not communicate with each other. The spiral microgrooves 32 extend from one end away from the middle of the arc portion to the transition point between the arc portion and the upper and lower bearing surfaces of the bushing 3. During the rotation of the bushing 3, when it rotates relative to the grease between the lower cover 2 and the upper cover 1, it carries the grease to a certain extent. Combined with the arc-shaped part of the bushing 3, it guides the grease through the arc part into the bearing surface of the bushing 3, which is conducive to the formation of an oil film. This allows the grease between the lower cover 2 and the upper cover 1 to be in a flowing state, making full use of the grease between the lower cover 2 and the upper cover 1.

[0027] like Figure 5 The spiral microgrooves 32 in the upper and lower regions guide the grease in the middle to the upper and lower receiving surfaces, respectively. At the same time, the spiral microgrooves 32 in the upper and lower regions are staggered at the middle end to avoid the spiral microgrooves 32 in the upper and lower regions guiding the grease in the same area at the same time, which can improve the utilization rate of the grease in the middle.

[0028] The sealing ring 4 is a sealing and protective structure at the bottom of the bearing. The sealing ring 4 is stepped. The inner ring and outer ring of the sealing ring 4 are respectively embedded in the lower cover 2 and the upper cover 1. The inner ring and outer ring of the sealing ring 4 are provided with asymmetrical sealing lips. The inclination angle of the outer sealing lip is greater than that of the inner sealing lip.

[0029] For rear wheel shock absorbers in muddy, sandy, and dusty environments, a double-lip sealing ring 4 and a closed cavity are designed to effectively prevent impurities from entering, and the service life of the lubricating grease is improved compared to the traditional structure. The outer sealing lip is more resistant to mud and water impact, while the inner sealing lip has lower contact pressure, reducing frictional resistance. The outer sealing lip hooks back to prevent sand and gravel from directly impacting the main sealing lip. Even if the outer sealing lip is slightly worn, the inner sealing lip still maintains the main seal, achieving secondary protection. The inner and outer sealing lips have a clear division of labor, extending the sealing life.

[0030] The bushing gasket 5 is a self-lubricating gasket for the upper and lower friction surfaces. There are two bushing gaskets 5. The bushing gaskets 5 are cut and formed from PTFE material and are set above and below the bushing 3. The two bushing gaskets 5 are respectively attached to the inner friction surfaces of the upper cover and the lower cover.

[0031] This invention uses a bushing 3 made of engineering plastic to replace the traditional bearing balls, and adds bushing shims 5 made of PTEE material to the friction surfaces of the bushing 3, the upper cover 1, and the lower cover 2 as friction surfaces, replacing the traditional high-hardness surface approach. The bearing is mounted as a whole between the shock absorber upper seat and the air spring. The lower cover 2 is bolted to the vehicle body. The inner hole of the bushing 3 is precisely matched with the air spring and the shock absorber piston rod. Since the air spring of the rear wheel steering shock absorber needs to have good load-bearing capacity, when the rear wheel is steering, the shock absorber and the air spring rotate synchronously, driving the upper cover 1 and the bushing 3 to rotate relative to the lower cover 2. The upper cover 1, the lower cover 2, and the bushing 3 are all softer than metal, which can buffer the impact load and reduce the steering impact vibration. This soft composite friction pair achieves extremely low and stable relative rotation, smooth steering without jamming, and improves the stability of the guide bearing.

[0032] The upper cover 1, lower cover 2, and bushing 3 are made of engineering plastic injection molding, while the added bushing gasket is made of 5PTEE material. The overall weight is reduced by more than 50% compared with traditional metal bearings, while meeting the load-bearing strength requirements of rear wheel steering conditions. The integrated packaging adopts a snap-fit ​​structure, which simplifies the assembly steps, ensures high coaxiality accuracy, greatly improves the assembly efficiency of the OEM, and reduces the risk of installation deviation.

[0033] Meanwhile, engineering plastics and PTEE materials effectively dampen vibration and noise, solving the problem of abnormal noise from the bearings in rear-wheel steering vehicles and improving vehicle ride comfort; all components adopt mature processes such as injection molding, slitting, stamping, and vulcanization, which are suitable for mass production and significantly reduce costs compared to traditional metal bearings.

[0034] The space between the upper cover 1 and the lower cover 2 is filled with grease, which fills the friction surfaces of the upper cover 1, the lower cover 2, the bushing 3 and the bushing gasket 5; the grease is polyurea-based grease. By using grease to fill the gaps and combining it with a soft composite friction pair, the high surface hardness approach is abandoned, and a low coefficient of friction is the core design goal. The rotational friction coefficient is lower than that of traditional metal bearings, resulting in more sensitive and linear rear wheel steering response without sticking or abnormal noise. The viscous state of the grease can further buffer vibrations and absorb vibrations and noise, thus allowing the steering bearing to operate with low noise and improving ride comfort.

[0035] The upper and lower surfaces of the bushing 3 are provided with two coaxial annular grooves 31. The grease is filled into the interior of the annular grooves 31. The cross-sectional shape of the annular grooves 31 is V-shaped or trapezoidal, with the long side of the trapezoid facing the outside of the bushing 3. The annular groove 31 facilitates the filling of grease and provides an additional oil supply channel when the bushing 3 and the bushing gasket 5 rotate relative to each other, ensuring the replenishment of the oil film under the boundary lubrication state, maintaining the stability of the friction coefficient to a certain extent, and extending the long-term performance of the grease. In the actual use of the rear wheel steering bearing, the V-shaped or trapezoidal annular groove 31 inclined surface is used to guide the grease back to the friction surface under the centrifugal force of the bearing rotation, thereby improving the self-replenishing ability of the oil film, quickly forming an oil film during cold start, and reducing the starting torque. The chamfer at the edge of the annular groove 31 is changed from a right angle to a "flared opening expansion angle" (approximately 15°). After standing, the grease separates and settles, and the flared opening guides the deposited grease to be more easily dragged out of the groove; the oil film establishment time is shortened at startup, avoiding dry friction and seizing.

[0036] Compared to ball bearings, the upper and lower surfaces of the bushing 3 and the bearing area of ​​the bushing gasket 5 are increased, thus ensuring stable contact between the friction surfaces and improving the stability of the steering bearing when the rear wheels are turning.

[0037] The top of the lower cover 2 is integrally formed with two positioning rings 21, which are located on the inner and outer sides of the bushing 3 respectively. The bottom of the bushing 3 extends between the two positioning rings 21; the bushing gasket 5 below is located between the two positioning rings 21. The positioning ring 21 positions the bushing 3 and the lower bushing shim 5 to ensure the stability of the bushing 3 when the steering bearing rotates.

[0038] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concepts, should be covered within the scope of protection of the present invention.

Claims

1. A guide bearing for an air spring in a rear wheel steering shock absorber, characterized in that, include: The upper cover (1) is a load-bearing body disposed on the top of the bearing; The lower cover (2) is a support body located at the bottom of the bearing; Bushing (3), the bushing (3) is the intermediate support and positioning structure of the bearing; The sealing ring (4) is a sealing and protective structure at the bottom of the bearing; The bushing gasket (5) is a self-lubricating gasket for the upper and lower friction surfaces.

2. The guide bearing for an air spring in a rear wheel steering shock absorber according to claim 1, characterized in that: The upper cover (1) and the lower cover (2) are fastened together by a snap-fit ​​structure. The bushing (3), the sealing ring (4) and the bushing gasket (5) are all installed between the upper cover (1) and the lower cover (2).

3. A guide bearing for an air spring in a rear wheel steering shock absorber according to claim 1, characterized in that: The bushing (3) is in the shape of an annular cylinder. The upper cover (1), lower cover (2) and bushing (3) are all made of engineering plastic injection molding. The inner and outer rings of the bushing (3) are both made of arc transition, which is used to form arc parts in the inner and outer rings of the bushing (3). The arc R angle of the inner and outer rings of the bushing (3) gradually decreases from the middle to the upper and lower end faces.

4. A guide bearing for an air spring in a rear wheel steering shock absorber according to claim 3, characterized in that: The inner and outer rings of the bushing (3) are provided with spiral microgrooves (32). The spiral microgrooves (32) are distributed in the upper and lower halves of the arc portion. The spiral microgrooves (32) in the upper and lower halves of the arc portion are staggered and do not communicate with each other. The spiral microgrooves (32) extend from one end away from the middle of the arc portion to the transition between the arc portion and the upper and lower bearing surfaces of the bushing (3).

5. A guide bearing for an air spring in a rear wheel steering shock absorber according to claim 1, characterized in that: The upper cover (1) and the lower cover (2) are filled with grease, wherein the grease is filled to the friction surfaces of the upper cover (1), the lower cover (2), the bushing (3) and the bushing gasket (5), and the grease is polyurea grease.

6. A guide bearing for an air spring in a rear wheel steering shock absorber according to claim 5, characterized in that: The upper and lower surfaces of the bushing (3) each have two coaxial annular grooves (31). The grease is filled into the interior of the annular grooves (31). The cross-sectional shape of the annular grooves (31) is V-shaped or trapezoidal. When the cross-sectional shape is trapezoidal, the long side of the trapezoid faces the outside of the bushing (3).

7. A guide bearing for an air spring in a rear wheel steering shock absorber according to claim 1, characterized in that: The sealing ring (4) is stepped. The inner ring and outer ring of the sealing ring (4) are respectively embedded in the lower cover (2) and the upper cover (1). The inner ring and outer ring of the sealing ring (4) are provided with asymmetrical sealing lips. The inclination angle of the outer sealing lip is greater than that of the inner sealing lip.

8. A guide bearing for an air spring in a rear wheel steering shock absorber according to claim 1, characterized in that: The top of the lower cover (2) has two positioning rings (21) integrally formed. The two positioning rings (21) are located on the inner and outer sides of the bushing (3) respectively, and the bottom of the bushing (3) extends between the two positioning rings (21).

9. A guide bearing for an air spring in a rear wheel steering damper according to claim 8, characterized in that: The number of bushing gaskets (5) is two. The bushing gaskets (5) are cut and formed from PTFE material and are set above and below the bushing (3). The two bushing gaskets (5) are respectively attached to the inner friction surfaces of the upper cover (1) and the lower cover (2), and the lower bushing gasket (5) is located between the two positioning rings (21).

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