JPH0447445Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Field of Application] The present invention relates to a synthetic resin thrust bearing, and particularly to a synthetic resin thrust bearing suitable for use in a strut thrust type suspension of a four-wheeled vehicle. [Prior art] Strut thrust type suspensions are generally used mainly for the front wheels of four-wheeled vehicles, and are made by combining a coil spring with a strut assembly that has a hydraulic shock absorber built into an outer cylinder that is integrated with the main shaft. It has a suspension. In the above suspension, when the strut assembly rotates with the coil spring due to steering operation,
The piston rod of the assembly rotates;
There are models in which the piston rod does not rotate, but all models require a bearing between the mounting member of the vehicle body and the upper spring seat of the coil spring to allow the strut assembly to rotate smoothly. Ru. Conventionally, a rolling bearing using balls or needles or a sliding bearing made of synthetic resin has been used as a bearing at this location. FIG. 15 shows a conventional example of a strut assembly using a synthetic resin sliding bearing. In the figure, strut 1 with a built-in shock absorber that constitutes strut assembly A is shown.
The piston rod 2 has one end connected to the strut 1.
It is inserted into the shock absorber of the vehicle, and its other end protrudes from the shock absorber and is fixed with a nut 4 to a mounting member 3 which is supported by the vehicle body via a mount insulator made of a rubber elastic body. A coil spring 7 is disposed between a lower spring seat 5 fixed to the outer circumferential surface of the strut 1 and an upper spring seat 6 facing oppositely and loosely inserted around the outer periphery of the piston rod 2. Between the flat part 8 of the upper spring seat sheet 6 and the mounting member 3, there is a cylindrical part 10 having an insertion hole 9 on the inner surface, and a wide flange part 11 integrally formed at one end of the cylindrical part 10. It consists of
A synthetic resin thrust bearing 13 having a dust seal 12 made of a rubber elastic body attached to the outer circumferential surface of the wide flange 11 fits the inner insertion hole 9 of the cylindrical portion 10 into the outer circumferential surface of the piston rod 2. The upper spring seat sheet 6 is arranged such that its surface is fitted into a hole in the flat surface section 8 of the upper spring seat sheet 6. [Problems to be solved by the invention] In the above-mentioned conventional technology, the dust seal attached to the outer circumferential surface of the wide flange of the thrust bearing is a relatively rotating sliding member for the purpose of preventing dust from entering the sliding surface of the bearing. Since the steering wheel is disposed in close sliding contact between the moving surfaces, there is a drawback that the sliding friction force is high during steering operation, increasing the steering force. In view of the above-mentioned shortcomings, the applicant has previously filed a
In No. 196803 and Japanese Utility Model Application No. 196804 (hereinafter referred to as "prior art"), we proposed a synthetic resin thrust bearing that solved the above-mentioned drawbacks. In these prior art, a synthetic resin bearing piece is disposed between a synthetic resin lower case and a synthetic resin upper case, and the upper and lower cases are combined by elastic attachment. A sealing part is formed between the upper and lower cases of the bearing by a labyrinth action on the outer surface side or inner and outer surface side of the elastic mounting part, and the sealing part prevents dust etc. from entering into the sliding surface of the bearing. By making all the materials from synthetic resin, the dust seal attached to the conventional thrust bearing is not required, and sliding frictional resistance can be significantly reduced. The present invention relates to an improvement on the prior art described above, and even if dust or the like intrudes from the elastic mounting part and the sealed part by labyrinth action in the prior art, the sliding friction caused by the intrusion of the dust, etc. The object of the present invention is to obtain a synthetic resin thrust bearing that does not cause an increase in resistance or, by extension, an increase in steering force. [Means for solving the problems] In order to achieve the above-mentioned object, the present invention adopts the following technical means (configuration). That is, it is a synthetic resin thrust bearing consisting of a lower case made of synthetic resin, an upper case made of synthetic resin, and a bearing piece made of synthetic resin. a cylindrical protrusion having an inner diameter surface continuous with the circular hole on the upper surface of the part; and an annular lower lip part forming an annular groove between the cylindrical protrusion and the cylindrical protrusion at a distance radially outward. The annular protrusion includes an annular protrusion formed on the outer peripheral edge of the disc-shaped part at a distance radially outward from the annular lower lip part, and an engaging part formed on the outer circumferential surface of the annular protrusion. , the upper case has a disc-shaped part having a circular hole in the center, and an annular part formed on the lower surface of the disc-shaped part concentrically with the circular hole and spaced radially outward from the circular hole. An upper lip part, an annular hanging part formed on the outer peripheral edge of the disc-shaped part at a distance radially outward from the annular lip part, and an engaging hook part formed at the lower end of the annular hanging part. The upper case has an engaging hook part of the annular hanging part elastically attached to the engaging part of the lower case, and the end of the annular upper lip part overlaps with the annular lower lip part in the radial direction so that relative rotation is possible. A labyrinth sealing portion is formed in the elastic mounting portion and the upper and lower lip portions, and a circular hole is provided in the center of the upper and lower cases. Disc-shaped synthetic resin bearing pieces each having one annular groove on the lower surface and a plurality of dead-end radial grooves continuous to the annular groove are disposed within the annular groove of the lower case, and are arranged on the upper and lower surfaces. The synthetic resin thrust bearing is characterized in that the synthetic resin thrust bearing is disposed in sliding contact with the disc-shaped lower surface of the upper case and the bottom surface of the annular groove, respectively. Another configuration is that, in addition to the above configuration, the cylindrical protrusion formed on the upper surface of the disc-shaped portion of the lower case has a circular hole in the center and an inner diameter surface that expands in diameter with a step portion outward in the radial direction. A cylindrical part is formed at the periphery of the circular hole at the center of the disc-shaped part of the upper case, and has an inner diameter surface that is continuous with the circular hole and projects downward. It is combined with the cylindrical protrusion of the lower case so as to overlap in the radial direction, and a sealing part is formed there by a labyrinth effect. In yet another configuration, a cylindrical portion that protrudes downward and has an inner diameter surface that is continuous with the circular hole in the central portion is integrally formed in the disc-shaped portion of the lower case. Another structure of the synthetic resin bearing piece in the above-mentioned configuration is an inner annular groove formed on the periphery of the circular hole surrounding the circular hole in the center on the lower surface, and an inner annular groove radially outward from the inner annular groove. The bearing piece includes an outer annular groove formed at intervals on the outer peripheral edge of the bearing piece, and a plurality of radial grooves communicating with the inner and outer annular grooves. Further, the synthetic resin bearing piece has roughened actual sliding surfaces on the upper and lower surfaces. In other words, the actual sliding surface is formed on a textured satin surface consisting of a large number of continuous fine recesses and a large number of convex parts separated by the recesses and scattered in a regular or amorphous shape, or Alternatively, a plurality of independent recesses are formed on the actual sliding surface. The synthetic resin that makes up the upper and lower cases must have excellent mechanical properties such as wear resistance, impact resistance, and creep resistance. For example, polyacetal resins, polyamide resins, polyester resins such as polybutylene terephthalate (PBT), polyolefin resins such as polyethylene and polypropylene, etc. are preferably used, and polycarbonate resins are also used. Can be used. The upper and lower cases are made of the same synthetic resin as the bearing piece, but in particular, it has a good combination of friction and wear characteristics with the synthetic resin used for the bearing piece, and has relatively high rigidity. It is preferable to use a synthetic resin material. Examples of desirable combinations are shown in the table below.

【table】

[Action/Effect]

The synthetic resin thrust bearing constructed as described above has the following unique functions and effects. Even if dust or the like intrudes through the elastic attachment part between the upper and lower cases and the labyrinth sealed part formed on the outer surface, inner and outer surfaces, the composite structure between the upper and lower cases The radial grooves formed on the upper and lower surfaces of the resin bearing piece are dead-end grooves that do not open (penetrate) the inner and outer diameter surfaces of the bearing piece, so the dust etc. will not reach the bearing sliding surface. It is difficult for dust to enter, and even if it does, it will be contained in the radial grooves formed on the upper and lower surfaces of the bearing piece and the annular groove that communicates with the radial grooves, so there will be no sliding friction caused by the intrusion of dust, etc. An increase in resistance is prevented. A synthetic resin thrust bearing using a synthetic resin bearing piece having an inner annular groove, an outer annular groove, and radial grooves communicating with the inner and outer annular grooves on the upper and lower surfaces, respectively, further increases the above effects. By forming annular grooves and radial grooves on the upper and lower surfaces of the synthetic resin bearing piece, the actual sliding surface of the bearing piece is reduced, in other words, the load per unit surface (surface pressure: Kg/cm ² ) is reduced. This will reduce sliding friction resistance and, in turn, reduce steering force. A synthetic resin bearing piece on which a matte surface is formed by texture processing, which consists of a large number of fine concave portions that are continuous with each other on the actual sliding surface and a large number of convex portions separated by the concave portions and scattered in a regular or amorphous manner. Alternatively, a synthetic resin thrust bearing using a synthetic resin bearing piece in which a plurality of independent recesses are formed on the actual sliding surface improves the retention of lubricants such as grease on the sliding surface, and the above-mentioned... In addition to the effect of
Furthermore, the sliding friction resistance is reduced, which in turn reduces the steering force. [Embodiments] Hereinafter, the present invention will be explained in detail with reference to the accompanying drawings showing embodiments thereof. 20 is a synthetic resin thrust bearing, and the thrust bearing 20 includes a synthetic resin lower case 30, a synthetic resin upper case 40, and the upper and lower cases 40, 3.
0, and a synthetic resin bearing piece 50 disposed within the bearing piece 50. The lower case 30 includes a disk-shaped portion 32 having a circular hole 31 in the center and a circular hole 3 on the upper surface of the disk-shaped portion 32.
1, an annular lower lip part 35 forming an annular groove 34 with the cylindrical protrusion 33 having an inner diameter surface continuous with the cylindrical protrusion 33 and the cylindrical protrusion 33 with an interval radially outward; An annular protrusion 36 formed on the outer circumferential edge of the disc-shaped portion 32 with an interval radially outward from the annular lower lip portion 35; and an engaging portion 37 formed on the outer circumferential surface of the annular protrusion 36; It is equipped with The engaging portion 37 is continuous with a tapered surface portion 37a formed from the outer circumferential surface of the end of the annular protrusion 36 to the lower surface of the disk-shaped portion 32, and is continuous with the tapered surface portion 37a and continues to the lower surface of the disk-shaped portion 32. Tapered surface part 3
7b. The upper case 40 includes a disc-shaped part 42 having a circular hole 41 in the center and a circular hole 41 in the lower surface of the disc-shaped part 42.
an annular upper lip part 43 formed concentrically with the circular hole 41 and spaced radially outward from the circular hole 41; It has an annular hanging part 44 formed on the outer peripheral edge of the annular hanging part 44 and an engaging hook part 45 formed at the lower end of the annular hanging part 44. The engaging hook portion 45 includes a tapered surface portion 45a corresponding to the tapered surface portion 37b forming the engaging portion 37 of the lower case 30, and a cylindrical surface portion 45b continuous with the tapered surface portion 45a. The upper case 40 elastically attaches the engagement hook part 45 of the annular hanging part 44 to the engagement part 37 of the lower case 30, and connects the end of the annular upper lip part 43 to the annular lower lip part 35 of the lower case 30. The elastic mounting portion and the upper and lower lip portions 43 and 35 form a sealed portion by a labyrinth effect at the overlapping portion. The synthetic resin bearing piece 50 has a circular hole 51 in the center having an inner diameter larger than the outer diameter of the cylindrical protrusion 33 of the lower case 30 and a circle having an outer diameter smaller than the inner diameter of the annular lower lip part 35 of the lower case 30. It consists of a plate. The bearing piece 50 has an annular groove 52 formed on its upper and lower surfaces to surround the circular hole 51 and communicate with the annular groove 52 and have a phase difference of 15° in the circumferential direction. A plurality of dead-end radial grooves 53 are provided. An annular groove 52 and a radial groove 53 formed on the upper and lower surfaces of the bearing piece 50 serve as grooves for containing dust and the like that have entered the bearing sliding surface, and as a reservoir for lubricant such as grease. The bearing piece 50 further includes:
The surface excluding the annular groove 52 and radial groove 53 formed on the lower surface forms an actual sliding surface. The bearing piece 50 is attached to the disc-shaped portion 32 of the lower case 30.
It is positioned within the annular groove 34 formed on the upper surface, and the actual sliding surfaces of the upper and lower surfaces are slidably contacted with the lower surface of the disc-shaped portion 42 of the upper case 40 and the bottom surface of the annular groove 34 of the lower case 30, respectively. The upper and lower cases 40 and 30 are arranged in the same manner. 5 to 7 show other configurations of the synthetic resin bearing piece 50 in the configuration described above. A circular hole 51 having an inner diameter larger than the outer diameter of the cylindrical protrusion 33 of the lower case 30 in the center and a disc-shaped synthetic resin bearing having an outer diameter smaller than the inner diameter of the annular lower lip 35 of the lower case 30. The piece 50 has an inner annular groove 52a formed on the periphery of the circular hole 51 surrounding the circular hole 51 in the center on the upper and lower surfaces thereof, and an inner annular groove 52a of the bearing piece that is spaced outwardly in the radial direction from the inner annular groove 52a. A plurality of radial grooves 53 are provided, which communicate with the outer annular groove 52b formed on the outer peripheral edge and the inner and outer annular grooves 52a and 52b, and are formed with a phase difference of 15 degrees in the circumferential direction. The bearing piece 50 has the following parts formed on the upper and lower surfaces thereof.
The surface excluding the outer annular grooves 52a and 52b and the radial groove 53 forms an actual sliding surface. Furthermore, FIGS. 8 to 9 show the synthetic resin thrust bearing 20 shown in FIG. This shows a bearing piece 50 made of synthetic resin that has a matte surface 54 formed by texture processing on the moving surface or a plurality of independent recesses. That is, an annular groove 52 formed on the upper and lower surfaces of the bearing piece 50, a dead-end radial groove 53 communicating with the annular groove, or inner and outer annular grooves 52a and 52b.
The actual sliding surface, excluding the radial grooves 53 communicating with the annular groove, consists of a plurality of continuous minute recesses 54a and a large number of convex portions 54b separated by the recesses 54a and scattered in a regular or amorphous manner. It is formed on a satin surface 54 by a texture process. In this way, the synthetic resin bearing piece 50 with the matte surface 54 on the actual sliding surface has a load per unit of the actual sliding surface (surface pressure: Kg/cm ² ).
The sliding frictional resistance is further reduced by increasing the frictional resistance, and by increasing the retention of lubricant such as grease filled on the actual sliding surface. FIG. 10 shows another configuration of the synthetic resin thrust bearing 20 shown in FIG.
This shows that. That is, the cylindrical protrusion 33 formed on the upper surface of the disc-shaped portion 32 of the synthetic resin lower case 30 has a circular hole 31 in the center and an inner diameter surface that expands in diameter with a step 38 radially outward. A cylindrical portion 46 is formed at the periphery of a circular hole 41 at the center of the disk-shaped portion 42 of the synthetic resin upper case 40, and has an inner diameter surface that is continuous with the circular hole 41 and projects downward. case 40
The cylindrical portion 46 is connected to the cylindrical protrusion 3 of the lower case 30.
3 and are combined in a radial direction so as to overlap each other in the radial direction, and a sealed portion is formed there by a labyrinth effect. FIG. 11 shows still another configuration of the synthetic resin thrust bearing 20 shown in FIG. That is, the cylindrical protrusion 33 of the synthetic resin lower case 30 is integrally formed with a cylindrical portion 39 that protrudes downward and has an inner diameter surface that is continuous with the circular hole 31 in the center. With respect to the lateral load acting on the thrust bearing 20,
The lower case 30 is slidably supported by the cylindrical portion 39 thereof. FIG. 12 shows another configuration of the synthetic resin thrust bearing 20 shown in FIG. That is, a cylindrical portion 39 that protrudes downward and has an inner diameter that is continuous with the circular hole 31 in the center is integrally formed in the disk-shaped portion 33 of the lower case 30 made of synthetic resin, and acts on the thrust bearing 20. The lower case 30 is slidably supported by the cylindrical portion 39 against the lateral load. FIG. 13 is a longitudinal sectional view showing an example in which the synthetic resin thrust bearing 20 shown in FIG. 1 is incorporated into a strut assembly A. That is, the inner surface of the cylindrical protrusion 33 of the lower case 30 and the circular hole 41 at the center of the disc-shaped portion 42 of the upper case 40
is inserted into the outer peripheral surface of the piston rod R of the assembly A, and the disc-shaped portion 32 of the lower case 30 is inserted into the outer peripheral surface of the piston rod R of the assembly A.
The lower surface of the upper spring seat S is attached to the flat surface S ₁ of the upper spring seat S.
Engagement protrusion formed on the lower surface and upper spring seat sheet S
is placed on _{the flat surface part S1 of} the upper spring seat sheet S, and the upper surface of the disc-shaped part 42 of the upper case 40 is attached to the vehicle body. It is arranged in contact with the side mounting member B. Furthermore, FIG. 14 shows an example in which the synthetic resin thrust bearing shown in FIG. 12 is similarly incorporated into a strut assembly A. That is, the inner surface of the cylindrical portion 39 protruding from the lower surface of the disc-shaped portion 33 of the lower case 30 and the inner surface of the cylindrical portion 46 protruding from the lower surface of the disc-shaped portion 42 of the upper case 40 are inserted into the outer peripheral surface of the piston rod R of the assembly A. The cylindrical portion 39 protruding from the lower surface of the disc-shaped portion 33 of the lower case 30 is rotated by means (not shown).
It is fitted into the hole _S2 of the plane part _S1 of the upper spring seat S, and the upper surface of the disc-shaped part 42 of the upper case 40 is placed in contact with the mounting member B on the vehicle body side.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing a synthetic resin thrust bearing of the present invention, Fig. 2 is a plan view showing a synthetic resin bearing piece, Fig. 3 is a sectional view taken along the - line in Fig. 2, and Fig. 4 is a longitudinal sectional view showing a synthetic resin thrust bearing of the present invention. Fig. 5 is a plan view showing another configuration of the synthetic resin bearing piece, Fig. 6 is a sectional view taken along the - line in Fig. 5, and Fig. 7 is a sectional view taken along the - line in Fig. 5. , FIG. 8 is a partially enlarged plan view showing still another configuration of the synthetic resin bearing piece, and FIG. 9 is a view of FIG.
10, 11, and 12 are longitudinal sectional views showing other configurations of the synthetic resin thrust bearing, and FIG. 13 shows the synthetic resin thrust bearing shown in FIG. 1 as a strut assembly. 14 is a vertical sectional view showing an example in which the synthetic resin thrust bearing shown in FIG. 12 is incorporated into a strut assembly, and FIG. FIG. 2 is a vertical cross-sectional view showing a conventional example. 20... Synthetic resin thrust bearing, 30... Synthetic resin lower case, 31... Circular hole, 32... Disc-shaped portion, 33... Cylindrical protrusion, 34... Annular groove, 3
5...Annular lower lip part, 36...Annular protrusion part, 3
7... Engaging portion, 40... Synthetic resin upper case,
41... Circular hole, 42... Disc-shaped portion, 43... Annular upper lip portion, 44... Annular hanging portion, 45... Engaging hook portion, 50... Synthetic resin bearing piece, 51...
Circular hole, 52... Annular groove, 53... Radial groove, 52a
...Inner annular groove, 52b...Outer annular groove, 54...
...Pear surface.

Claims (1)

[Scope of claim for utility model registration] (1) A synthetic resin thrust bearing consisting of a synthetic resin lower case, a synthetic resin upper case, and a synthetic resin bearing piece, the lower case having a circular hole in the center. an annular recess formed by a disc-shaped part, a cylindrical protrusion having an inner diameter surface continuous with the circular hole on the upper surface of the disc-shaped part; An annular lower lip portion forming a groove, an annular protrusion portion formed on the outer peripheral edge of the disc-shaped portion with a space radially outward from the annular lower lip portion, and an annular protrusion portion formed on the outer peripheral surface of the annular protrusion portion. The upper case has a disc-shaped part having a circular hole in the center, and a lower surface of the disc-shaped part that is concentric with the circular hole and radially outward from the circular hole. An annular upper lip portion formed at a distance from the annular upper lip portion, an annular hanging portion formed on the outer peripheral edge of the disc-shaped portion with an interval radially outward from the annular upper lip portion, and a lower end of the annular hanging portion. The upper case has an engaging hook portion of the annular hanging portion elastically attached to the engaging portion of the lower case, and an end of the annular upper lip portion is attached to the annular lower lip portion. The elastic fitting part and the upper and lower lip parts are formed with a labyrinth sealing part.
The lower case has a circular hole in the center, and
Disc-shaped synthetic resin bearing pieces each having one annular groove on the lower surface and a plurality of dead-end radial grooves communicating with the annular groove are disposed within the annular groove of the lower case, and are arranged on the upper and lower surfaces. A synthetic resin thrust bearing, characterized in that the synthetic resin thrust bearing is arranged in sliding contact with the disc-shaped lower surface of the upper case and the bottom surface of the annular groove, respectively. (2) The synthetic resin bearing piece has an inner annular groove formed on the periphery of the circular hole surrounding the circular hole in the center on the upper and lower surfaces thereof, and an inner annular groove that is spaced outwardly in the radial direction from the inner annular groove. The synthetic resin thrust according to claim 1, which is a registered utility model, characterized by comprising an outer annular groove formed on the outer peripheral edge of the bearing piece and a plurality of radial grooves communicating with the inner and outer annular grooves. bearing. (3) The cylindrical protrusion formed on the upper surface of the disc-shaped portion of the lower case has a circular hole in the center and an inner diameter surface that expands in diameter with a stepped portion outward in the radial direction. A cylindrical part is formed at the periphery of the circular hole in the center of the disc-shaped part, and has an inner diameter surface that is continuous with the circular hole and projects downward, and the upper case connects the cylindrical part with the cylindrical protrusion of the lower case. A synthetic resin thrust bearing according to claim 1 or 2, characterized in that the synthetic resin thrust bearing is radially superimposed and combined to form a sealing portion by a labyrinth effect. (4) A utility model registration claim characterized in that the disc-shaped portion of the lower case is integrally formed with a cylindrical portion that protrudes downward and has an inner diameter surface that is continuous with the circular hole in the central portion. A synthetic resin thrust bearing according to any one of items 1 to 3. (5) The synthetic resin bearing piece according to any one of claims 1 to 4 of the claims for utility model registration, characterized in that the actual sliding surface on the lower surface is roughened. Resin thrust bearing. (6) In addition, the actual sliding surface of the synthetic resin bearing piece on the lower surface consists of a large number of interconnected fine recesses and a large number of convex parts separated by the recesses and scattered in a regular or amorphous shape. A synthetic resin thrust bearing according to claim 5, which is characterized in that the synthetic resin thrust bearing is formed on a textured surface or has a plurality of independent recesses formed on the actual sliding surface.