JP4788803B2 - Thrust sliding bearing - Google Patents

Description

  The present invention relates to a thrust slide bearing, and more particularly to a thrust slide bearing that is preferably incorporated as a slide bearing of a strut suspension (McPherson type) in a four-wheeled vehicle.

  Generally, a strut suspension is mainly used for a front wheel of a four-wheeled vehicle, and is a combination of a coil spring and a strut assembly in which a hydraulic shock absorber is incorporated in an outer cylinder integrated with a main shaft. Such a suspension has a structure in which the axis of the coil spring is positively offset with respect to the axis of the strut to smoothly slide the piston rod of the shock absorber built in the strut, and the axis of the strut. On the other hand, there is a structure in which the axis of the coil spring is arranged to coincide. In any structure, when the strut assembly rotates together with the coil spring by a steering operation, a thrust bearing is disposed between the mounting member of the vehicle body and the upper spring seat of the coil spring so that the rotation is smoothly performed.

Japanese Patent Laid-Open No. 11-303873 JP 2002-257146 A

  As this thrust bearing, a rolling bearing using a ball or a needle or a synthetic resin sliding bearing is used. However, the rolling bearing has a problem that it may be difficult to maintain a smooth steering operation because the ball or needle may be damaged due to a slight swing and vibration load. Sliding bearings have higher frictional torque than rolling bearings, so when the thrust load increases, the frictional torque increases, and the steering operation becomes heavy, and depending on the combination of synthetic resins, a stick-slip phenomenon often occurs. There is a problem of generating a frictional noise caused by the stick-slip phenomenon.

  In addition, a lubricant such as grease is applied to the sliding bearing. As long as such a lubricant is present on the sliding surface as desired, the frictional noise as described above hardly occurs. There may be a case where friction noise starts to occur due to the disappearance of the lubricant due to use.

  The above-mentioned problem does not occur only in the thrust sliding bearing incorporated in the strut type suspension, and can occur in the general thrust sliding bearing as well.

  The present invention has been made in view of the above-mentioned points. The object of the present invention is to allow a lubricant such as grease to be interposed on the sliding surface over a long period of time, and to add such a lubricant to the thrust. It can also be used as a load receiver. Thus, even if the thrust load increases, the friction torque hardly changes, and the sliding surface can be configured with a low friction torque, and such a low coefficient of friction can be maintained even during long-term use. In addition, there is no thrust noise generated on the sliding surface, and even if it is incorporated into a strut suspension as a thrust slide bearing, it can ensure smooth steering operation equivalent to a rolling bearing and can improve riding comfort. It is to provide.

  A thrust slide bearing according to the present invention includes a first bearing body having an annular surface, and a first bearing body that is superposed on the first bearing body so as to be rotatable around the axis of the first bearing body. A second bearing body having an annular surface facing the annular surface of the one bearing body, an annular thrust sliding bearing piece and an elastic ring that are overlapped with each other and interposed between the annular surfaces, Here, the thrust sliding bearing piece is formed integrally with the annular plate portion and one surface of the annular plate portion, and is slidable with respect to the annular surface on the annular surface of the first bearing body. And at least two annular protrusions that cooperate with the annular surface to form a sealed annular space, and the elastic ring includes the other surface of the annular plate portion and the second bearing body. Between the thrust sliding bearing piece and the second bearing body in contact with the annular surface of the Are, lubricant is filled in the hermetically sealed annular space.

According to the thrust slide bearing of the present invention, since the lubricant is hermetically filled in the sealed annular space formed by the two annular protrusions, the lubricant is supplied to the two annular protrusions and the first bearing body. Since it is possible to supply only the necessary minute amount to the sliding surface between the annular surface and the thrust load even with the lubricant in the sealed annular space, lubrication in contact with the annular surface of the first bearing body The surface of the agent also becomes a sliding surface in the rotation of the second bearing body relative to the first bearing body, and thus the sliding surface can be configured with a lower friction torque, and the frictional noise is generated on the sliding surface. In addition, it ensures smooth steering operation equivalent to a rolling bearing, and in addition, even if a biased load is applied to the two annular projections, the elastic ring is first caused to undergo elastic deformation to reduce its thickness, and the two annular Prevents deformation from occurring in the protrusion As a result of effectively preventing leakage of the lubricant from the sealed annular space to the outside due to a decrease in the volume of the sealed annular space due to the bending deformation of the two annular projections, the lubricant disposed in the sealed annular space can be prevented for a long time. The lubricant maintained in the sealed annular space can be supplied in a minute amount to the sliding surface between the two annular projections and the annular surface of the first bearing body, and the lubricant can be supplied over a long period of time. It is possible to stably interpose on the sliding surface. Therefore, the friction torque hardly changes even when the thrust load is increased in combination with the above action, and the sliding surface can be configured with a low friction torque. Since the shock applied to the first or second bearing body is buffered and transmitted to the second or first bearing body by the elasticity of the elastic ring, the riding comfort can be improved.

  The thrust slide bearing piece preferably further includes at least two other annular protrusions integrally formed on the other surface of the annular plate portion, and in this case, the elastic ring has two in the radial direction. According to the thrust sliding bearing of this aspect, which is arranged between the other annular projections, the elastic ring can always be positioned at a normal position with respect to the thrust sliding bearing piece, and the thrust sliding bearing piece and the elastic ring Normal superposition of each other can always be maintained.

  In the present invention, the thrust slide bearing piece is integrally formed on one surface of the annular plate portion between the two annular projections in the radial direction, and the annular surface on the annular surface of the first bearing body. At least one of which is slidable with respect to each other and divides the sealed annular space so as to cooperate with the annular surface and the two annular projections to form a plurality of separated sealed annular spaces separated from each other. An intermediate annular protrusion may be provided, and as a result of receiving the thrust load in such an intermediate annular protrusion, the occurrence of bending deformation of the two annular protrusions can be more reliably avoided. Even if a large amount of the lubricant filled in one divided sealed annular space leaks out of the plurality of divided sealed annular spaces, this leakage is prevented from affecting other divided sealed annular spaces, and other remaining Split enclosed annular space with the above The results can perform a use, it becomes a fail-safe.

  The elastic ring is preferably made of natural rubber, synthetic rubber or thermoplastic elastomer, and the cross-sectional shape of the elastic ring may be substantially rectangular or substantially elliptical.

  The lubricant preferably fills the sealed annular space without a gap under a thrust load. In some cases, the lubricant may fill the sealed annular space without a gap under no thrust load.

  The lubricant contains at least one of grease and lubricating oil, and preferably consists of silicone grease.

  In the thrust slide bearing of the present invention, it is preferable that both the bearing body and the thrust slide bearing piece are made of a synthetic resin, and the synthetic resin constituting the thrust slide bearing piece accommodated between the both bearing bodies is particularly self-lubricating. Preferably, the synthetic resin constituting both bearing bodies is preferably excellent in sliding characteristics such as wear resistance, impact resistance and creep resistance, and mechanical characteristics such as rigidity. The both bearing bodies may be made of a synthetic resin including at least one of polyacetal resin, polyamide resin, thermoplastic polyester resin, polyolefin resin, polycarbonate resin, and fluororesin, and the thrust sliding bearing piece is Including at least one of polyacetal resin, polyamide resin, thermoplastic polyester resin, polyolefin resin and fluororesin It may have made from synthetic resin. Synthetic resin similar to the synthetic resin that constitutes the thrust sliding bearing piece can be used for both bearing bodies, but in particular, the synthetic resin used for the thrust sliding bearing piece and the synthetic resin with good friction characteristics are used. As an example of a desirable combination thereof, a thrust sliding bearing piece and both bearing bodies are combined with a polyacetal resin and a polyamide resin, a polyolefin resin, particularly a combination of a polyethylene resin and a polyacetal resin, and a polyacetal resin. There are combinations of thermoplastic polyester resins, particularly polybutylene terephthalate resins, and combinations of polyacetal resins and polyacetal resins.

  In the thrust slide bearing of the present invention, preferably, the first bearing body is elastically fitted to the second bearing body at the outer peripheral edge portion in the radial direction at the outer peripheral edge portion in the radial direction of the second bearing body. Further, a labyrinth is formed between the bearing bodies in at least one of the outer peripheral edge and the inner peripheral edge in the radial direction of the two bearing bodies, and the thrust slide bearing The labyrinth can be preferably prevented from entering dust, muddy water, and the like into the space between the first and second bearing bodies on which the piece and the elastic ring are mounted.

  In the present invention, the second bearing body has large-diameter and small-diameter annular protrusions integrally formed on the annular surface, and the thrust slide bearing piece and the elastic ring are larger than the large-diameter annular protrusion. The thrust sliding bearing piece and the elastic ring can be positioned with respect to the radial direction by the pair of annular projections and arranged in the radial direction. By causing the sliding bearing piece to slidably contact with the large-diameter and small-diameter annular projections on the outer circumferential surface and the inner circumferential surface in the radial direction, the bending of the thrust sliding bearing piece under a thrust load can be prevented.

  According to the present invention, a lubricant such as grease can be interposed on the sliding surface for a long period of time, and such a lubricant can also be used for a thrust load receiver, thus increasing the thrust load. However, the friction torque is almost the same, and the sliding surface can be constructed with a low friction torque, so that the low friction coefficient can be maintained even after long-term use, and there is no generation of friction noise on the sliding surface. It is possible to provide a thrust sliding bearing that can ensure a smooth steering operation equivalent to that of a rolling bearing and can improve riding comfort even when incorporated as a thrust sliding bearing in a mold suspension.

It is sectional drawing of a preferable example of embodiment of this invention. It is a top view of the lower case and thrust sliding bearing piece of the example shown in FIG. It is a perspective view of the elastic ring of the example shown in FIG. It is explanatory drawing of the example integrated in the example shown in FIG. 1 in a strut type suspension. It is a partial sectional view of other desirable examples of an embodiment of the invention.

  Next, the present invention and its embodiments will be described with reference to preferred examples shown in the drawings. The present invention is not limited to these examples.

  1 to 3, a thrust slide bearing 1 for use in a strut suspension in the four-wheeled vehicle of this example has an annular surface 2 and is a first bearing body made of synthetic resin, for example, polyacetal resin. A synthetic resin having a case 3 and an upper surface 3, which is superposed on the upper case 3 so as to be rotatable in the R direction around the axis O of the upper case 3 and has an annular surface 4 facing the annular surface 2 of the upper case 3. For example, an annular lower case 5 as a second bearing body made of, for example, polyacetal resin, an annular thrust slide bearing piece 6 and an elastic ring 7 which are overlapped with each other and interposed between the annular surfaces 2 and 4 are provided. is doing.

  An annular upper case 3 having a through hole 12 defined by the inner peripheral surface 11 is formed integrally with an annular upper case main body 13 having an annular surface 2 and an annular surface 2 of the upper case main body 13. The innermost cylindrical drooping portion 14 that hangs down toward the lower case 5 and the radially outer side of the innermost circumferential cylindrical drooping portion 14 and are formed integrally with the annular surface 2. In addition, an inner circumferential cylindrical hanging portion 15 that hangs down toward the lower case 5, a cylindrical hanging engagement portion 16 that is integrally formed on the outer peripheral edge in the radial direction of the upper case main body portion 13, and a cylinder It is arranged on the inner side in the radial direction of the pendant engaging portion 16 and on the outer side in the radial direction of the inner cylindrical side hanging portion 15, and is formed integrally with the annular surface 2. Of the outer circumferential side cylindrical drooping portion 17 that hangs down and the cylindrical drooping engagement portion 16. Engagement hook portion 18 formed on the inner peripheral surface in the direction, and cylindrical portion 20 formed integrally with outer surface 19 of upper case main body portion 13 on the inner peripheral side in the radial direction of upper case main body portion 13. It is provided and is integrally formed.

  An annular lower case 5 having a through hole 22 that is concentric and the same diameter as the through hole 12 and is defined by the inner peripheral surface 21 includes an annular lower case body 23 having an annular surface 4, and a lower case The innermost cylinder formed integrally with the inner peripheral edge in the radial direction of the main body 23 and projecting toward the upper case 3 so as to be arranged on the inner side in the radial direction of the innermost cylindrical hanging part 14. The cylindrical protrusion 24 and the innermost cylindrical protrusion 24 are arranged on the outer side in the radial direction and are formed integrally with the annular surface 4. An inner peripheral cylindrical protrusion 25 that protrudes toward the upper case 3 so as to be disposed between the peripheral cylindrical hanging parts 15, and a radially outer side of the inner peripheral cylindrical protrusion 25. And is formed integrally with the annular surface 4, and the radially outer side of the inner circumferential side cylindrical hanging portion 15. A small-diameter annular projection 26 projecting toward the upper case 3 and a radially outer peripheral edge of the lower case main body 23 are integrally formed, and the cylindrical hanging engagement portion 16 and the outer peripheral cylinder are arranged. A cylindrical protruding engagement portion 27 protruding toward the upper case 3 so as to be disposed between the hanging portions 17, and a radial inner side of the cylindrical protruding engagement portion 27 in the radial direction of the cylindrical protrusion 26. It is arranged on the outer side and is formed integrally with the annular surface 4, and projects toward the upper case 3 so as to be arranged on the inner side in the radial direction of the outer cylindrical hanger 17, and the annular projection 26. An annular projection 28 having a larger diameter and an engaging hook portion 29 that is formed on the radially outer peripheral surface of the cylindrical protruding engaging portion 27 and engages with the engaging hook portion 18. Has been.

  The upper case 3 has an engagement hook portion 18 of the cylindrical hanging engagement portion 16 at the outer peripheral edge portion in the radial direction and an engagement hook portion of the cylindrical protrusion engagement portion 27 at the outer peripheral edge portion in the radial direction in the lower case 5. 29 is elastically engaged with the lower case 5 by snap-fitting.

  At least one of the outer peripheral edge and the inner peripheral edge in the radial direction of the upper case 3 and the lower case 5, in this example, at both edges, the upper case body 13, The labyrinth is formed by the innermost cylindrical drooping portion 14 and the inner circumferential cylindrical drooping portion 15 and the lower case main body 23, the innermost circumferential cylindrical projection 24, the inner circumferential cylindrical projection 25, and the annular projection 26. The labyrinth 32 is composed of the (maze) 31 by the upper case main body portion 13, the cylindrical hanging engagement portion 16 and the outer circumferential cylindrical hanging portion 17, the lower case main body portion 23, the cylindrical protruding engagement portion 27 and the annular protrusion 28. The thrust slide bearing piece 6 and the elastic ring 7 between the upper case main body 13 and the lower case main body 23 are formed by the labyrinth 31 at the inner peripheral edge and the labyrinth 32 at the outer peripheral edge, respectively. A ring fitted with Dust from the outside into the space 33, invasion of muddy water or the like is prevented.

  The thrust sliding bearing piece 6 made of synthetic resin, for example, polyacetal resin, slidably contacts the annular protrusions 26 and 28 on the annular inner peripheral surface 41 and the outer peripheral surface 42 in the radial direction. Further, it is arranged on the inner side in the radial direction than the annular protrusion 26 and on the outer side in the radial direction.

  The thrust slide bearing piece 6 is formed integrally with the annular plate portion 45 and one surface 46 of the annular plate portion 45 so as to be separated from each other in the radial direction and to the annular surface 2 of the upper case 3. Concentric small- and large-diameter annular protrusions 48 and 49 that are slidable with respect to the annular surface 2 and contact with each other so as to form a sealed annular space 47, and the other of the annular plate portion 45. The surface 50 includes concentric small-diameter and large-diameter annular protrusions 51 and 52 that are integrally formed separately from each other in the radial direction. A lubricant 53 made of silicone grease is contained in the sealed annular space 47. It is hermetically filled.

The sealed annular space 47 has a width larger than the width of the small-diameter annular projection 48 and the large-diameter annular projection 49 in the radial direction, and the sealed annular space 47 has a sealed annular space 47 under no thrust. The amount of the lubricant 53 that fills the sealed annular space 47 without gap is filled, and the amount of the lubricant 53 fills the sealed annular space 47 without a gap even under a thrust load. The lubricant 53 is brought into contact with the annular surface 2 together with the annular protrusions 48 and 49 so as to receive a thrust load and to support the annular surface 2 .

  The elastic ring 7 made of natural rubber, synthetic rubber or thermoplastic elastomer and having a substantially rectangular cross section is in contact with the surface 50 and the annular surface 4 of the annular plate portion 45 and between the thrust slide bearing piece 6 and the lower case 5. It is interposed between the annular protrusions 51 and 52 in the radial direction, and is disposed on the radially outer side of the annular protrusion 26 and on the radially inner side of the annular protrusion 28. The elastic ring 7 is bent and deformed under a thrust load to reduce its thickness.

  The thrust sliding bearing 1 described above is mounted between the upper spring seat 62 of the coil spring 61 and the mounting member 64 on the vehicle body to which the piston rod 63 of the hydraulic damper is fixed in the strut type suspension assembly as shown in FIG. To be used. In this case, the upper part of the piston rod 63 is inserted into the through holes 12 and 22 so as to be rotatable in the R direction around the axis O with respect to the upper case 3 and the lower case 5.

  As shown in FIG. 4, in the strut suspension assembly mounted via the thrust slide bearing 1, the relative rotation in the R direction around the axis O of the upper spring seat 62 via the coil spring 61 is performed during the steering operation. Is smoothly performed by relative rotation in the same direction on the sliding surface between the annular surface 2 of the upper case 3 and the annular protrusions 48 and 49 and the lubricant 53.

  According to the thrust slide bearing 1, since the lubricant 53 is hermetically filled in the sealed annular space 47 formed by the annular protrusions 48 and 49, the lubricant 53 is added to the annular protrusions 48 and 49 and the annular surface 2. Since only a necessary minute amount can be supplied to the sliding surface between them, and even the lubricant 53 in the sealed annular space 47 receives the thrust load, the lubricant 53 in contact with the annular surface 2 The surface also becomes a sliding surface when the lower case 5 rotates in the R direction with respect to the upper case 3, and thus the sliding surface can be configured with a lower friction torque, and there is no generation of friction noise on the sliding surface. A smooth steering operation equivalent to that of the rolling bearing is ensured. Moreover, even if an uneven load is applied to the annular protrusions 48 and 49, the elastic ring 7 is first caused to undergo elastic deformation to reduce its thickness, thereby the annular protrusion 48. And 49 It is possible to prevent the bending deformation from occurring, and to effectively prevent the leakage of the lubricant 53 from the sealed annular space 47 due to the volume reduction of the sealed annular space 47 due to the bending deformation of the annular protrusions 48 and 49. As a result, the lubricant 53 disposed in the sealed annular space 47 can be maintained for a long period of time, and the lubricant 53 kept sealed in the sealed annular space 47 is slid between the annular protrusions 48 and 49 and the annular surface 2. A small amount can always be supplied to the surface, and the lubricant 53 can be stably interposed on the sliding surface over a long period of time. Therefore, even if the thrust load increases, the friction torque Since the sliding surface can be constructed with a low friction torque and the impact applied to the lower case 5 from the coil spring 61 is buffered and transmitted to the upper case 3 by the elasticity of the elastic ring 7, Ri comfort can be improved.

  Further, according to the thrust slide bearing 1, since the elastic ring 7 is disposed between the annular projections 51 and 52 in the radial direction, the elastic ring 7 can always be positioned at a normal position with respect to the thrust slide bearing piece 6, The normal sliding of the thrust sliding bearing piece 6 and the elastic ring 7 can always be maintained, and the thrust sliding bearing piece 6 and the elastic ring 7 are radially outward from the annular protrusion 26 and from the annular protrusion 28. Since the thrust slide bearing piece 6 and the elastic ring 7 can be positioned with respect to the radial direction by the pair of annular projections 28 and 26, the thrust slide bearing piece 6 can be positioned in the radial direction. Since the annular protrusions 26 and 28 are slidably brought into contact with the peripheral surface 41 and the outer peripheral surface 42, the thrust sliding bearing piece 6 can be prevented from bending under a thrust load.

  By the way, in the above-described thrust slide bearing 1, the thrust slide bearing piece 6 in which the annular protrusions 51 and 52 are provided on the surface 50 of the annular plate portion 45 is used. Instead, as shown in FIG. The thrust slide bearing piece 6 without the annular projections 51 and 52 may be used. Further, in addition to the annular projections 48 and 49, the annular plate portion 45 is provided between the annular projections 48 and 49 in the radial direction. The annular surface 2 of the upper case 3 is slidable with respect to the annular surface 2 and the sealed annular space 47 is divided into the annular surface 2 and the annular protrusion 48. And a plurality of (two in this example) concentric divided sealed annular spaces 71 and 72 which are in contact with each other and have an intermediate annular projection 73 which contacts the thrust sliding bearing piece 6. May be configured here Similarly as above, it may be filled with the lubricant 53 without clearance each of the divided sealing the annular space 71 and 72.

  In the thrust sliding bearing 1 shown in FIG. 5, the thrust load is also distributed and received by the intermediate annular protrusion 73, so that the occurrence of bending deformation of the annular protrusions 48 and 49 can be avoided more reliably, and the divided sealing is performed. Even if the lubricant 53 filled in one divided sealed annular space of the annular spaces 71 and 72 leaks in a large amount, this leakage is prevented from affecting the other divided sealed annular space, and the other remaining As a result of being able to perform the above-described action in the divided sealed annular space, it becomes fail-safe.

DESCRIPTION OF SYMBOLS 1 Thrust sliding bearing 2, 4 Annular surface 3 Upper case 5 Lower case 6 Thrust sliding bearing piece 7 Elastic ring 46, 50 surface 47 Sealed annular space 48, 49 Annular protrusion 53 Lubricant

Claims (5)

A first bearing body having an annular surface, and the first bearing body so as to be rotatable about the axis of the first bearing body, and overlaid on the annular surface of the first bearing body A second bearing body having annular faces facing each other, and an annular thrust slide bearing piece and an elastic ring which are overlapped with each other and interposed between the annular faces, the thrust slide bearing piece being an annular plate And an annular surface of the annular plate portion that are integrally formed with a space in the radial direction and are slidable relative to the annular surface of the first bearing body. A small-diameter and a large-diameter annular protrusion that come into contact with each other so as to form a sealed annular space, and the elastic ring is formed on the other surface of the annular plate portion and the annular surface of the second bearing body. DOO is interposed between the thrust sliding bearing piece and the second bearing body in contact with, close The annular space has a small diameter of the annular projection of the width and diameter of greater width than the width of the annular projection in the radial direction, the closed annular space and the lubricant is filled, lubricants, The sealed annular space is filled without a gap under no thrust and under a thrust load, and the lubricant filled in the sealed annular space without a gap contacts the annular surface of the first bearing body and receives a thrust load. A thrust slide bearing configured to support the annular surface of the first bearing body .   The thrust slide bearing piece further includes at least two other annular projections integrally formed on the other surface of the annular plate portion, and the elastic ring is provided between the two other annular projections in the radial direction. The thrust slide bearing according to claim 1, wherein The thrust slide bearing piece is formed integrally with one surface of the annular plate portion between the small-diameter and large-diameter annular projections in the radial direction, and is formed on the annular surface of the first bearing body. A plurality of separate sealed annular rings separated from each other in cooperation with the annular surface of the first bearing body , the small-diameter annular protrusion and the large-diameter annular protrusion by dividing the sealed annular space. The thrust slide bearing according to claim 1, further comprising at least one intermediate annular protrusion that contacts to form a space.   The second bearing body has large-diameter and small-diameter annular protrusions integrally formed on the annular surface, and the thrust slide bearing piece and the elastic ring are radially inward of the large-diameter annular protrusion. The thrust sliding bearing according to any one of claims 1 to 3, wherein the thrust sliding bearing is disposed on the outer side in a radial direction with respect to the annular protrusion having a small diameter.   The thrust sliding bearing piece according to claim 4, wherein the thrust sliding bearing piece is slidably in contact with each of the large-diameter and small-diameter annular projections on an outer peripheral surface and an inner peripheral surface in the radial direction.

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