JPH0741055U - Synthetic resin thrust bearing - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to obtain a synthetic resin thrust bearing which is arranged between two objects that rotate relative to each other and can smoothly allow the relative rotation without causing frictional fluctuations. [Structure] An upper bearing case 3 made of synthetic resin, a lower bearing case 2 made of synthetic resin, and a bearing body 4 made of synthetic resin having lower rigidity than the synthetic resin forming the upper and lower bearing cases. The body 4 is the annular groove 2 of the lower bearing case.
9 is embedded with one end surface slightly protruding,
In the upper bearing case, the lower surface of the cylindrical block portion 30 is slidably contacted with the bearing body, and the ends of the cylindrical hanging portion 33 and the annular hanging portion 36 are connected to the first annular protruding portion 23 and the second annular protruding portion of the lower bearing case 2. 25 and the engaging hook portions 39 of the annular engaging hanging portions 38 are elastically attached to the engaging portions 28 of the annular engaging protrusions 27 of the lower bearing case. Are combined.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is a synthetic resin thrust bearing that is arranged between two objects that rotate relative to each other and allows the rotation smoothly. Specifically, it is suitable for a synthetic resin thrust bearing (McPherson type) incorporated in a four-wheeled vehicle. The present invention relates to thrust bearings.

[0002]

[Prior art]

 Strut suspensions are generally used for the front wheels of four-wheeled vehicles, and are suspensions in which a coil spring is combined with a strat assembly that has a hydraulic shock absorber inside an outer cylinder that is integrated with the main shaft. There are two types of suspensions, one in which the piston rod of the assembly rotates when the strut assembly rotates with the coil spring by steering operation, and the other in which the piston rod does not rotate. A bearing is required between the mounting member of the vehicle body and the upper spring seat of the coil spring to allow the assembly to rotate smoothly.

Conventionally, rolling bearings using balls or needles or sliding bearings made of synthetic resin have been used for the bearings at this location. However, in the conventional synthetic resin slide bearing, a dust seal made of a rubber elastic body is attached to the outer peripheral surface of the slide bearing in order to prevent dust and the like from entering the sliding surface. Since the dust seals are arranged in close contact with each other between the rotating sliding surfaces, there is a disadvantage that the sliding frictional force is high during steering operation and the steering force is increased. In order to solve the above-mentioned drawbacks of the synthetic resin slide bearings in the prior art, the applicant of the present invention first disclosed in Japanese Patent Application No. 1-16171 (Actual No. 2-107823: hereinafter referred to as “prior art”) from a rubber elastic body. We proposed a synthetic resin thrust bearing that can prevent dust and other foreign matter from entering the sliding surface without using a separate dust seal and can prevent an increase in steering force during steering operation. This prior art synthetic resin thrust bearing consists of a synthetic resin upper and lower case and synthetic resin bearing pieces arranged in the upper and lower cases, and an inner annular hanging part and an outer part formed on the lower surface of the upper case. The annular hanging parts are respectively engaged with the annular grooves formed on the upper surface of the lower case, and the upper case is elastically mounted on the outer peripheral surface of the lower case, and the elastic mounting part and each engaging part are provided with a labyrinth. They are combined by forming a sealed part by action.

[0004]

[Problems to be solved by the device]

 The above-mentioned synthetic resin thrust bearing of the prior art prevents the increase in steering force during steering operation, which is a drawback of the conventional synthetic resin slide bearings described above, and prevents the sliding surface from sliding due to the sealing portion due to the labyrinth action. It was possible to prevent the intrusion of dust and the like and maintain a smooth steering force for a long period of time. However, since the spring force of the coil spring that constitutes the strut type suspension in which the thrust bearing is incorporated differs depending on the vehicle type, depending on the vehicle type in which the thrust bearing is incorporated, the synthetic resin that forms the upper and lower cases of the thrust bearing and In combination with the synthetic resin forming the bearing pieces arranged in the upper and lower cases, it causes frictional fluctuation between the upper case and the bearing piece or between the lower case and the bearing piece, and the frictional fluctuation is caused. As a result, a problem was raised that the smooth steering feel (feeling) changes. Therefore, the inventors of the present invention conducted further experiments on the cause of this friction fluctuation, and as a result, by using a synthetic resin having a rigidity lower than that of the synthetic resin forming the upper and lower cases, the friction fluctuation was It was found that a smooth steering feeling can be maintained without causing a steering. However, a bearing piece made of a synthetic resin with low rigidity exhibits excellent friction and wear characteristics between the upper case and the bearing piece, but the bearing piece itself is inferior in creep resistance. At the same time, a new problem was raised in that creep occurred in the bearing pieces, making it difficult to smoothly allow relative rotation between the upper and lower bearing cases. In consideration of the advantages of the prior art, the present inventors have found that the above-mentioned problems can be solved by adopting a configuration capable of suppressing the occurrence of creep as much as possible based on the above findings, and have completed the present invention. Therefore, the present invention relates to the improvement of the above-mentioned prior art, and an object thereof is to obtain a synthetic resin thrust bearing capable of maintaining a smooth steering feeling without causing frictional fluctuations.

[0005]

[Means for Solving the Problems]

 According to the present invention, the above object is to provide a disk-shaped portion having an insertion hole at the center and an annular flat surface portion connected to the insertion hole on the upper surface of the disk-shaped portion so as to project concentrically with the insertion hole. A first annular projection, the first annular projection, and the first annular projection, the first annular projection and the first annular projection being spaced apart from each other by a distance, and defining an annular recess between the outer peripheral surface of the first annular projection and the upper surface of the disk-shaped portion. (2) An annular engaging protrusion and an annular engaging protrusion that are provided on the outer peripheral edge of the annular protrusion and define an annular engaging groove between the outer peripheral surface of the second annular protrusion and the upper surface of the disc-like portion. A synthetic resin lower bearing case having an engaging portion formed on the outer peripheral surface of the joint projection and an annular groove formed on the bottom surface of the annular recess, and one of the annular groove of the lower bearing case. A synthetic resin bearing body having an end face slightly protruded from the annular groove and embedded therein, a cylindrical block portion, and an inward direction at the upper end of the inner peripheral surface of the cylindrical block portion. A first annular engaging groove is defined by the extended inner annular flange portion and the inner peripheral surface of the cylindrical block portion extending downward at the peripheral end portion of the inner annular collar portion and the lower surface of the inner annular collar portion. In addition, a cylindrical hanging portion having an insertion hole having the same diameter as the insertion hole, an outer annular flange portion extending outward at the upper end of the outer peripheral surface of the cylindrical block portion, and a lower surface of the outer annular flange portion protruding from the outer annular flange portion. An outer circumferential surface of the cylindrical block portion and a lower surface of the outer annular collar portion define a second annular engaging groove. An annular hanging portion and a downwardly extending outer peripheral edge of the outer annular collar portion. An upper bearing case made of synthetic resin, comprising: an annular engaging hanging part that defines an annular engaging groove with the lower surface of the flange part; and an engaging hook part formed on the inner peripheral surface of the annular engaging hanging part. The upper bearing case slides the lower surface of the cylindrical block portion on the bearing body embedded in the annular groove of the lower bearing case. , The end of the cylindrical hanging portion and the end of the annular hanging portion are overlapped with the end portion of the first annular protruding portion and the end portion of the second annular protruding portion of the lower bearing case respectively in the radial direction. And the engaging hook portion of the annular engaging hanging portion is elastically attached to the engaging portion of the outer peripheral surface of the annular protruding portion of the lower bearing case, and the elastic attaching portion, the cylindrical hanging portion, the first annular protruding portion, and the annular portion. A sealing portion by a labyrinth action is formed in each overlapping portion of the hanging portion and the second annular projection portion and combined with the lower bearing case, and the bearing body is made of synthetic resin forming the upper and lower bearing cases. This is achieved by a synthetic resin thrust bearing made of synthetic resin having low rigidity.

Further, according to the present invention, the above-mentioned object is to concentric circles with the insertion hole, leaving a disk-shaped portion having an insertion hole in the center and an annular flat surface portion connected to the insertion hole on the upper surface of the disk-shaped portion. Of the first annular protrusion and the first annular protrusion that are radially outwardly spaced apart from the first annular protrusion, and the outer peripheral surface of the first annular protrusion and the upper surface of the disc-shaped portion. A second annular protrusion that defines an annular recess and an annular engagement that projects on the outer peripheral edge of the disc-shaped portion and defines an annular engagement groove between the outer peripheral surface of the second annular protrusion and the upper surface of the disc-shaped portion. A lower bearing case made of synthetic resin having a protrusion and an engagement portion formed on the outer peripheral surface of the annular engagement protrusion, and a cylindrical block portion and an inner peripheral surface of the cylindrical block portion, which are inwardly provided at the upper end. The inner annular flange portion that is extended and the inner peripheral surface of the cylindrical block portion that is extended downward at the peripheral end portion of the inner annular collar portion and the lower surface of the inner annular collar portion are the first annular members. A cylindrical hanging part that defines a fitting groove and has an insertion hole of the same diameter as the insertion hole, an outer annular flange part that extends outwardly at the upper end of the outer peripheral surface of the cylindrical block part, and a lower surface of the outer annular flange part. An annular hanging portion that protrudes from the outer peripheral surface of the cylindrical block portion and a lower surface of the outer annular collar portion to define a second annular engaging groove, and extends downward to the outer peripheral edge of the outer annular collar portion. Of the cylindrical engaging portion formed on the inner peripheral surface of the annular engaging hanging portion that defines the annular engaging groove between the outer peripheral surface of the annular portion and the lower surface of the outer annular flange portion, and the cylindrical block portion. An upper bearing case made of synthetic resin having an annular groove formed on the lower surface and an annular groove formed on the lower surface of the cylindrical block portion are embedded with one end surface slightly protruding from the groove. , A synthetic resin formed of a synthetic resin having lower rigidity than the synthetic resin forming the upper and lower bearing cases. The upper bearing case is slidably in contact with the bottom surface of the annular recess of the lower bearing case, and the upper bearing case is slidably in contact with the bottom surface of the annular recess of the lower bearing case. And an end portion of the annular hanging portion is overlapped and engaged with an end portion of the first projecting portion and an end portion of the second annular protruding portion of the lower bearing case, respectively, and the annular engaging hanging portion is engaged. The engaging hook portion of is elastically attached to the engaging portion of the outer peripheral surface of the annular engaging protrusion of the lower bearing case, and the elastic attaching portion, the cylindrical hanging portion and the first annular protruding portion, and the annular hanging portion and the second annular protruding portion. This is also achieved by a synthetic resin thrust bearing formed by forming a sealing portion by a labyrinth action in each overlapping portion of the portions and being combined with the lower bearing case.

In the synthetic resin thrust bearing configured as described above, an annular notch step is formed in the annular flat surface portion of the lower bearing case, and an inner surface side end surface is formed in the cylindrical hanging portion of the upper bearing case. The upper bearing case is assembled to the lower bearing case by engaging the annular protrusion of the cylindrical hanging portion with the annular notch step formed on the annular flat surface of the lower bearing case. A combined configuration can be adopted. In the above-mentioned structure, the synthetic resin bearing body is composed of a disc having a circular hole in the central portion, and one end face of the disc is formed in the annular groove of the lower bearing case or the lower surface of the cylindrical block portion of the upper bearing case. It is projected from the annular groove and is embedded in the annular groove. In another aspect, the synthetic resin bearing body includes a disc-shaped portion having a circular hole in the central portion, and an annular collar portion extending on the outer peripheral surface of one end of the disc-shaped portion. The annular flange is projected from the annular groove of the lower bearing case or the annular groove of the lower surface of the cylindrical block of the upper bearing case, and the disc-shaped portion is embedded in the annular groove. There is. In synthetic resin thrust bearings, polyacetal resin and polyamide resin are recommended as the synthetic resin forming the upper and lower bearing cases, and the synthetic resin forming the upper and lower bearing cases is the synthetic resin forming the bearing body. Made of synthetic resin with lower rigidity than polyolefin resin such as high molecular weight or ultra high molecular weight polyethylene resin, fluororesin such as tetrafluoroethylene resin or tetrafluoroethylene / hexafluoropropylene copolymer. Recommended.

[0008]

[Action]

 The synthetic resin bearing body is embedded in an annular groove formed in the annular recess of the synthetic resin lower bearing case or an annular groove formed in the lower surface of the cylindrical block of the synthetic resin upper bearing case, and one end surface of the synthetic resin bearing body is embedded. Since it is arranged so as to slightly project from the groove, the open surface of the bearing body, in other words, the outer peripheral surface of the protruding portion projecting from the groove can be made as small as possible. Creep resistance is enhanced. Therefore, the relative rotation between the upper bearing case and the lower bearing case via the bearing body having the increased creep resistance is caused by the friction and wear characteristics between the bearing body and the upper bearing case or between the bearing body and the lower bearing case. Due to the combination of excellent synthetic resin, they are allowed smoothly without causing frictional fluctuation between them, and the smooth steering feeling is maintained for a long time. Also, synthetic resin upper and lower bearing case elastic mounting parts, cylindrical hanging parts and first annular projecting parts, and annular hanging parts and second annular projecting parts, which are formed on the overlapping parts, are sealed by the labyrinth action. This prevents dust and the like from entering the bearing sliding surface. Furthermore, in addition to the effect of preventing dust and the like from entering the sliding surface of the bearing by the above-mentioned sealing portion, an annular notch step formed on the annular flat surface portion of the lower bearing case and the inner surface side of the cylindrical hanging portion of the upper bearing case. By adopting the mode of engaging with the annular protrusion formed at the end, the thrust bearing is enhanced in the effect of preventing dust and the like from entering the bearing sliding surface from the inner surface side.

[0009]

【Example】

 Hereinafter, the present invention will be described with reference to the accompanying drawings showing its embodiments. 1 to 3 show a first embodiment. In the figure, a synthetic resin thrust bearing 1 comprises a synthetic resin lower bearing case 2, a synthetic resin upper bearing case 3 and a synthetic resin bearing body 4. The lower bearing case 2 made of synthetic resin has a disk-shaped portion 21 having an insertion hole 20 at the center and an annular flat surface portion 22 at the periphery of the insertion hole on the upper surface of the disk-shaped portion 21, and is projected concentrically with the insertion hole. The first annular protruding portion 23 is provided so as to project radially outward from the first annular protruding portion 23 with a space therebetween, and the outer peripheral surface of the first annular protruding portion 23 and the upper surface of the disk-shaped portion form an annular shape. The second annular protrusion 25 that defines the recess 24 and the outer peripheral edge of the disc-shaped portion 21 are provided so as to project, and an annular engagement groove 26 is formed between the outer peripheral surface of the second annular protrusion 25 and the upper surface of the disc-shaped portion. The annular engaging protrusion 27 that defines the above-mentioned annular engaging protrusion 27, the engaging portion 28 formed on the outer peripheral surface of the annular engaging protrusion 27, and the annular concave groove 29 formed on the bottom surface of the annular concave portion 24. Protrusions 21a are formed on the lower surface of the disk-shaped portion 21 so as to face each other in the radial direction. The protrusions 21a play a role of positioning when the synthetic resin thrust bearing 1 to be described later is incorporated and fixed in the strut assembly. . The engaging portion 28 formed on the outer peripheral surface of the annular engaging protrusion 27 has a tapered surface portion 28 a that extends outward from the upper end of the outer periphery of the annular engaging protrusion portion 27, and a continuous inner surface of the tapered surface portion 28 a. It is composed of a taper surface portion 28b that converges toward one side and continues to the outer peripheral cylindrical surface of the disk-shaped portion 21.

The synthetic resin upper bearing case 3 includes a cylindrical block portion 30, an inner annular flange portion 31 extending inward at an upper end of an inner peripheral surface of the cylindrical block portion 30, and a peripheral end of the inner annular flange portion 31. Is formed in the center of the disk-shaped portion of the lower bearing case 2 while defining the first annular engaging groove 32 by the inner peripheral surface of the cylindrical block portion 30 and the lower surface of the inner annular flange portion. The cylindrical hanging portion 33 having an insertion hole having the same diameter as the insertion hole 20, the outer annular flange portion 34 extending outward at the upper end of the outer peripheral surface of the cylindrical block portion 30, and the lower surface of the outer annular flange portion 34. The outer peripheral surface of the cylindrical block portion 30 and the lower surface of the outer annular flange portion define a second annular engaging groove 35 and an outer peripheral edge of the outer annular flange portion 34. A ring defining an annular engagement groove 37 by the outer peripheral surface of the annular hanging portion 36 and the lower surface of the outer annular flange portion. The annular engaging hanging portion 38 and the engaging hook portion 39 formed on the inner peripheral surface of the annular engaging hanging portion 38. The engagement hook portion 39 formed on the inner peripheral surface of the annular engagement hanging portion 38 is formed by a taper surface portion 39a extending outward from the outer upper end of the annular engagement groove 37 and an inner surface continuous with the taper surface portion 39a. It is composed of a tapered surface portion 39b that converges toward one side and a cylindrical surface portion 39c that is continuous with the tapered surface portion 39b.

The synthetic resin bearing body 4 is composed of a circular plate having a circular hole 41 in the central portion, which is made of synthetic resin having lower rigidity than the synthetic resin forming the upper and lower bearing cases 3 and 2. A plurality of grooves 42 penetrating from the peripheral edge of the circular hole 41 to the outer peripheral surface are formed on one of the end faces at equal intervals in the circumferential direction. The groove 42 serves as a reservoir for a lubricant such as grease. The bearing body 4 is embedded in an annular groove 29 formed in the annular recess 24 of the lower bearing case 2 with the end surface on the side where the groove 42 is formed slightly protruding from the groove 29. There is.

In the synthetic resin upper bearing case 3 having the above structure, the lower surface of the cylindrical block portion 30 is slidably contacted with the synthetic resin bearing body 4 embedded in the annular recessed groove 29 of the lower bearing case 2 to form a cylindrical hanging portion. The end portion of 33 and the end portion of the annular hanging portion 36 are engaged with the end portion of the first annular protruding portion 23 and the end portion of the second annular protruding portion 25 of the lower bearing case 2 so as to overlap each other in the radial direction. At the same time, the engaging hook portion 39 of the annular engaging hanging portion 38 is elastically attached to the engaging portion 28 on the outer peripheral surface of the annular engaging protruding portion 27 of the lower bearing case 2, and the elastic attaching portion, the cylindrical hanging portion 33 and the A synthetic resin thrust bearing 1 is constructed by forming a sealing portion by a labyrinth action on each of the overlapping portions of the one annular protruding portion 23 and the annular hanging portion 36 and the second annular protruding portion 25 and combining them with the lower bearing case 2. To be done.

FIG. 3 shows a state in which the synthetic resin thrust bearing 1 having the above-described structure is incorporated in the strut assembly A. Insert the through hole 20 of the disk-shaped portion 21 of the synthetic resin lower bearing case 2 and the through hole of the cylindrical hanging portion 33 of the synthetic resin upper bearing case 3 into the center of the flat portion 71 of the upper spring seat 7 of the strut 5. A projection 21a formed on the lower surface of the disk-shaped portion 21 of the lower bearing case 2 so as to face each other. The lower surface of the disk-shaped portion 21 is brought into contact with the flat surface portion 71 while fitting into the hole 73 formed in the flat surface portion 71 of the spring seat 7, and the upper surface of the upper bearing case 3 is attached to the vehicle body side. The synthetic resin thrust bearing 1 is placed between the upper vane seat 7 and the vehicle body side mounting member 8 by abutting against the member 8. In the strut assembly A incorporating the synthetic resin thrust bearing 1 in this way, when relative rotation occurs between the vehicle body side mounting member 8 and the upper spring seat 7 by steering operation, The rotation is smoothly allowed by the sliding contact between the bearing body 4 embedded in the lower bearing case 2 and the lower surface of the cylindrical block portion 30 of the upper bearing case 3.

The synthetic resin bearing body 4 is made of synthetic resin having lower rigidity than the synthetic resin forming the upper lower bearing case, and the annular groove 29 is formed in the annular recess 24 of the lower bearing case 2. Since one end surface of the bearing body 4 is embedded so as to slightly project from the groove, the creep resistance of the bearing body 4 is enhanced. Therefore, the relative rotation between the upper bearing case 3 and the lower bearing case 2 does not cause frictional fluctuation between the bearing body 4 and the lower surface of the cylindrical block portion 30 of the upper bearing case 3, and a small frictional resistance (low friction coefficient). ), The steering feeling is smoothly maintained for a long period of time.

FIG. 4 shows another embodiment of the synthetic resin thrust bearing 1 having the above-mentioned structure. This embodiment is provided on the lower surface of the disk-shaped portion 21 of the synthetic resin lower bearing case 2 in the thrust bearing 1. Instead of the formed projection 21a for positioning to the mating mounting portion, the cylindrical protruding portion 21b is connected to the lower surface of the disk-shaped portion 21 of the lower bearing case 2 so as to communicate with the central insertion hole 20 of the disk-shaped portion 21. And the other configurations are indicated by the same reference numerals as those in the above-mentioned embodiment. In the synthetic resin thrust bearing 1 according to this embodiment, the cylindrical protrusion 21b is press-fitted and fixed in the hole 72 formed in the center of the flat portion 71 of the upper spring seat 7.

FIG. 5 shows still another embodiment. In this embodiment, one end face is formed in an annular groove 29 formed in the annular recess 24 of the lower bearing case 2 made of synthetic resin. 7 shows another embodiment of the synthetic resin bearing body 4 which is embedded so as to project slightly more. That is, the synthetic resin bearing body 4 has a disk-shaped portion 43 having a circular hole 41 in the central portion, and an annular flange portion 44 extending on the outer peripheral surface of one end of the disk-shaped portion 43, 45 and the upper surface of the disk-shaped portion 43 including the upper surfaces of the annular flange portions 44, 45 are formed at equal intervals in the circumferential direction from the peripheral edge of the inner annular flange portion 44 to the peripheral edge of the outer flange portion 45. It is provided with a single groove (not shown), and other configurations in the figure are the same as those in the above-mentioned embodiment and are indicated by the same reference numerals. The bearing body 4 is arranged such that the annular flange portions 44 and 45 are projected from the annular recessed groove 29 formed in the annular recessed portion 24 of the lower bearing case 2, and the disc-shaped portion 43 is embedded in the recessed groove 29. ing.

FIG. 6 shows another embodiment of the synthetic resin thrust bearing of the present invention. In this embodiment, the synthetic resin bearing body 4 in the synthetic resin thrust bearing 1 shown in FIG. 1 is used as the upper bearing. It is embedded in the lower surface of the cylindrical block portion of the case 3. That is, in place of the annular groove 29 formed in the bottom surface of the annular recess 24 of the synthetic resin lower bearing case 2 described above, the cylindrical block portion of the synthetic resin upper bearing case 3 facing the bottom surface of the annular recess 24. An annular groove 30a is formed on the lower surface of the bearing 30, and a synthetic resin bearing body 4 is embedded in the annular groove 30a such that one end surface of the bearing body 4 projects from the groove, and the bearing body 4 is embedded in the lower bearing case 2. Since it is slidably brought into contact with the bottom surface of the annular recess 24, other configurations in the drawing are the same as those in the above-described embodiment and are designated by the same reference numerals.

FIG. 7 shows a synthetic resin thrust bearing 1 having the structure shown in FIG. 6, in which one end face is formed in an annular groove 30 a formed in the lower surface of the cylindrical block portion 30 of the upper bearing case 3. As a synthetic resin bearing body 4 which is embedded so as to slightly project from 30a, a bearing body having the same structure as the synthetic resin bearing body 4 shown in FIG. 5 is used. In the bearing body 4, the annular flange portions 44 and 45 are projected from the annular groove 30a formed in the lower surface of the cylindrical block portion 30 of the upper bearing case 3, and the disk-shaped portion 43 is embedded in the groove 30a. Has been done. The other components in the figure are the same as those in the above-described embodiment and are designated by the same reference numerals.

FIG. 8 is a vertical sectional view showing still another embodiment of the synthetic resin thrust bearing of the present invention, and FIG. 9 is a plan view showing the synthetic resin lower bearing case 2 and the synthetic resin bearing body 4 shown in FIG. FIG. 3 is a diagram showing a synthetic resin thrust bearing according to this embodiment in which a structure for enhancing the effect of preventing foreign matter such as dust from entering is added to the inner peripheral surface side of the thrust bearing. That is, an annular notch step portion 22a continuous with the insertion hole 20 is formed at the periphery of the insertion hole 20 of the disk-shaped portion 21 of the synthetic resin lower bearing case 2, while an inner annular flange portion of the synthetic resin upper bearing case 3 is formed. An annular protrusion 33a is formed on the inner diameter side end surface of a cylindrical hanging portion 33 extending downward at the peripheral end of 31, and the annular protrusion 33a is engaged with the annular notch step 22a. The portion is also formed with a sealing portion by a labyrinth action, and other configurations in the drawings are the same as those in the embodiment described above and are denoted by the same reference numerals.

FIG. 10 shows a synthetic resin thrust bearing having the structure shown in FIG. 8 in which one end face is slightly smaller than the annular groove 29 formed in the annular recess 24 of the lower bearing case 2. An example in which a bearing body having the same structure as the synthetic resin bearing body 4 shown in FIGS. 5 to 7 is used as the protruding synthetic resin bearing body 4 is shown. Reference numeral 4 indicates that the annular flanges 44 and 45 are projected from the annular recessed groove 29 formed in the bottom surface of the annular recessed portion 24 of the lower bearing case 2, and the disk-shaped portion 43 is embedded in the annular recessed groove 29. ing. The other components in the figure are the same as those in the above-mentioned embodiment and are designated by the same reference numerals.

FIG. 11 shows still another embodiment of the synthetic resin thrust bearing of the present invention. The synthetic resin thrust bearing of this embodiment has the synthetic resin bearing body 4 having the structure shown in FIG. The bearing case 3 is embedded in the lower surface of the cylindrical block portion. That is, instead of the annular groove 29 formed on the bottom surface of the annular recess 24 of the synthetic resin lower bearing case 2, an annular ring is formed on the lower surface of the cylindrical block portion 30 of the synthetic resin upper bearing case 3 facing the annular recess 24 bottom surface. A groove 30a is formed, and a synthetic resin bearing body 4 is embedded in the annular groove 30a with one end surface of the bearing body 4 protruding from the groove, and the bearing body 4 is embedded in the annular groove 24 of the lower bearing case 2. The other components in the drawing are the same as those in the above-described embodiment and are designated by the same reference numerals.

FIG. 12 shows the synthetic resin thrust bearing having the structure shown in FIG. 11, in which the synthetic resin bearing body 4 embedded in the annular groove 30a in the lower surface of the cylindrical block portion 30 of the synthetic resin upper bearing case 3 is shown in FIG. 5 to 7 show an embodiment in which a bearing having the same structure as the synthetic resin bearing body 4 shown in FIGS. 5 to 7 is used. The synthetic resin bearing body 4 includes the annular flange portions 44 and 45 in the lower bearing case. The disk-shaped portion 43 is arranged so as to be projected from an annular groove 29 formed on the bottom surface of the second annular recess 24 and the disk-shaped portion 43 is embedded in the annular groove 29. The other components in the figure are the same as those in the above-mentioned embodiment and are designated by the same reference numerals.

Also in the synthetic resin thrust bearing having the configuration of FIG. 5 to FIG. 8 and FIG. 10 to FIG. 12 described above, the synthetic resin thrust bearing is attached to the mating mounting portion formed on the lower surface of the disk-shaped portion 21 of the lower bearing case 2. Instead of the positioning protrusion 21a, as shown in FIG. 4, a cylindrical protrusion 21b communicating with the central insertion hole 20 of the disc-shaped portion 21 may be formed on the lower surface of the disc-shaped portion 21.

[Effect of device]

 As described above, according to the synthetic resin thrust bearing of the present invention, the synthetic resin bearing body disposed between the synthetic resin upper and lower bearing cases is formed in the annular recess of the synthetic resin lower bearing case. Since it is embedded in the annular groove or the annular groove formed on the lower surface of the cylindrical block of the synthetic resin upper bearing case and one end surface of the groove is slightly projected from the groove, The open surface, in other words, the outer peripheral surface of the protruding portion that protrudes from the concave groove, can be made as small as possible, and as a result, the creep resistance of the bearing body can be improved. It enables the use of synthetic resins with lower rigidity than the synthetic resin that constitutes the bearing case. As a result, the relative rotation of the upper and lower bearing cases is smoothly allowed through the bearing body without causing frictional fluctuation, and the smooth steering force is maintained for a long period of time. In addition, the synthetic rubber upper and lower bearing case's elastic mounting part and the sealing part formed by the labyrinth action on the inner and outer peripheral overlapping parts prevent foreign matter such as dust from entering the bearing sliding surface and prevents sliding. In combination with the above effect, a smooth steering force is maintained for a long period of time without deteriorating the friction and wear characteristics due to the entry of foreign matter into the surface.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a preferred embodiment of a synthetic resin thrust bearing according to the present invention.

2 is a plan view showing a synthetic resin lower bearing case and a synthetic resin bearing body of FIG. 1. FIG.

3 is a vertical cross-sectional view showing a state in which the synthetic resin thrust bearing shown in FIG. 1 is incorporated in a strut assembly.

4 is a vertical sectional view showing another embodiment of the synthetic resin thrust bearing shown in FIG.

5 is a longitudinal sectional view showing still another embodiment of the synthetic resin thrust bearing shown in FIG.

FIG. 6 is a longitudinal sectional view showing another embodiment of the synthetic resin thrust bearing according to the present invention.

7 is a longitudinal sectional view showing another embodiment of the synthetic resin thrust bearing shown in FIG.

FIG. 8 is a longitudinal sectional view showing still another embodiment of the synthetic resin thrust bearing according to the present invention.

9 is a plan view showing the synthetic resin lower bearing case and the synthetic resin bearing body of FIG. 8;

10 is a longitudinal sectional view showing another embodiment of the synthetic resin thrust bearing shown in FIG.

FIG. 11 is a vertical sectional view showing another embodiment of the synthetic resin thrust bearing according to the present invention.

12 is a longitudinal sectional view showing another embodiment of the synthetic resin thrust bearing shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Synthetic resin thrust bearing 2 Synthetic resin lower bearing case 21 Disc-shaped part 22 Annular plane part 22a Annular notch step 23 First annular protrusion 24 Annular recess 26 Annular engagement groove 27 Annular engagement protrusion 28 28 Engagement Part 29 Annular groove 3 Synthetic resin upper bearing case 30 Cylindrical block part 30a Annular groove 31 Inner annular flange 32 First annular engagement groove 33 Cylindrical hanging part 33a Annular protrusion 34 Outer annular flange 35 Second annular engagement Mating groove 36 Annular hanging part 37 Annular engaging groove 38 Annular engaging hanging part 39 Engaging hook part 4 Synthetic resin bearing body

Claims (8)

[Scope of utility model registration request] 1. A disc-shaped portion (21) having an insertion hole (20) in the center and an annular flat portion (22) connected to the insertion hole on the upper surface of the disc-shaped portion, concentric with the insertion hole. -Shaped first annular protrusion (23) and the first annular protrusion that are radially outwardly spaced apart from each other and are spaced apart from each other in the radial direction. And a second annular protrusion (25) defining an annular recess (24) with an outer peripheral surface of the disc-shaped portion and an annular engagement between the outer peripheral surface of the second annular protrusion and the upper surface of the disc-shaped portion. An annular engagement protrusion (27) defining a mating groove (26), an engagement portion (28) formed on the outer peripheral surface of the annular engagement protrusion, and an annular formation formed on the bottom surface of the annular recess (24). A synthetic resin lower bearing case (2) having a groove (29) and one end surface of the lower bearing case (2) slightly protruding from the annular groove (29). The synthetic resin bearing body (4) embedded and embedded, the cylindrical block portion (30), and the inner annular flange portion (3) extending inward at the upper end of the inner peripheral surface of the cylindrical block portion.
1) and the inner circumferential surface of the inner annular flange portion, and the inner circumferential surface of the cylindrical block portion and the lower surface of the inner annular collar portion extend downward to define a first annular engagement groove (32) and the insertion. A cylindrical hanging part (33) having an insertion hole of the same diameter as the hole, an outer annular flange part (34) extending outward at the upper end of the outer peripheral surface of the cylindrical block part, and a projecting part on the lower surface of the outer annular flange part. An annular hanging portion (36) that defines a second annular engaging groove (35) by the outer peripheral surface of the cylindrical block portion and the lower surface of the outer annular collar portion, and extends downward to the outer peripheral edge of the outer annular collar portion, An annular engagement hanging portion (38) defining an annular engagement groove (37) between the outer peripheral surface of the annular hanging portion and the lower surface of the outer annular collar portion, and the engagement formed on the inner peripheral surface of the annular engaging hanging portion. And a synthetic resin upper bearing case (3) having a hook portion (39), the upper bearing case (3) including the cylindrical block portion (3). Lower surface of said lower bearing case) (2)
Slidingly contact the synthetic resin bearing body (4) embedded in the annular groove (29), and the end of the cylindrical hanging portion (33) and the end of the annular hanging portion (36) are connected to the lower bearing case. (2) The end of the first annular protrusion (23) and the end of the second annular protrusion (25) are overlapped and engaged with each other in the radial direction thereof, and the annular engagement hanging part (38) is engaged. The engagement hook portion (39) is elastically attached to the engagement portion (28) on the outer peripheral surface of the annular engagement protrusion (27) of the lower bearing case (2), and the elastic attachment portion and the cylindrical hanging portion (33) are provided. First annular protrusion (2
3) and the annular hanging part (36) and the second annular protrusion (2).
A sealing portion by a labyrinth action is formed in each overlapping portion of 5) and is combined with the lower bearing case (2), and the bearing body (4) is higher than the synthetic resin forming the upper and lower bearing cases. A synthetic resin thrust bearing characterized by being formed of a synthetic resin having low rigidity. 2. An annular notch step portion (22a) is formed in an annular flat surface portion (22) of a synthetic resin lower bearing case (2), and a cylindrical hanging portion (3) of the upper bearing case (3) is formed.
3) has an annular protrusion (33a) formed on the inner end surface thereof, and the upper bearing case (3) has the annular protrusion (33a) of the cylindrical hanging portion formed on the annular flat portion of the lower bearing case. The synthetic resin thrust bearing according to claim 1, wherein the synthetic resin thrust bearing is engaged with and combined with the annular cutout step portion (22a). 3. A synthetic resin bearing body (4) is composed of a disc having a circular hole (41) at its center, and one end face of the disc is an annular groove (29) of the lower bearing case (2). 3.) The synthetic resin thrust bearing according to claim 1 or 2, wherein the synthetic resin thrust bearing is embedded in the annular groove so as to project slightly from the above. 4. A synthetic resin bearing body (4) has a disk-shaped portion (43) having a circular hole (41) in the central portion and one end portion of the disk-shaped portion extending to the outer peripheral surface. The annular flange (4
4) and (45), the bearing body projects the annular flange portion from the annular groove (29) of the lower bearing case (2), and the disc-shaped portion (43) is formed into the annular shape. The synthetic resin thrust bearing according to claim 1 or 2, wherein the synthetic resin thrust bearing is embedded in the groove. 5. A disc-shaped portion (21) having an insertion hole (20) in the center and an annular flat portion (22) connected to the insertion hole on the upper surface of the disc-shaped portion, concentric with the insertion hole. -Shaped first annular protrusion (23) and the first annular protrusion that are radially outwardly spaced apart from each other and are spaced apart from each other in the radial direction. And a second annular protrusion (25) defining an annular recess (24) with an outer peripheral surface of the disc-shaped portion and an annular engagement between the outer peripheral surface of the second annular protrusion and the upper surface of the disc-shaped portion. A lower bearing case (2) made of synthetic resin, comprising an annular engagement protrusion (27) defining a mating groove (26) and an engagement portion (28) formed on the outer peripheral surface of the annular engagement protrusion. A cylindrical block portion (30), an inner annular flange portion (31) extending inward at an upper end of an inner peripheral surface of the cylindrical block portion, and a lower portion extending downward at a peripheral end portion of the inner annular flange portion. A cylindrical hanging part (3) having a first annular engaging groove (32) defined by the inner peripheral surface of the cylindrical block portion and the lower surface of the inner annular collar portion and having an insertion hole having the same diameter as the insertion hole.
3) and an outer annular flange portion (34) extending outward at the upper end of the outer peripheral surface of the cylindrical block portion, and an outer peripheral surface of the cylindrical block portion and an outer annular flange portion projecting from the lower surface of the outer annular flange portion. An annular hanging portion (36) defining a second annular engaging groove (35) with the lower surface
And an outer peripheral surface of the outer annular collar portion extending downward, and an annular engaging groove (3) is formed between the outer peripheral surface of the annular hanging portion and the lower surface of the outer annular collar portion.
7) defining an annular engaging hanging part (38), an engaging hook part (39) formed on the inner peripheral surface of the annular engaging hanging part, and an annular groove (39) formed on the lower surface of the cylindrical block part. Upper bearing case (3) made of synthetic resin having an annular groove (30) formed in the lower surface of the cylindrical block (30).
a) a synthetic resin bearing body (4) which is embedded in one end surface so as to slightly project from the groove and which is made of synthetic resin having rigidity lower than that of synthetic resin forming the upper and lower bearing cases; And the upper bearing case (3) has the bearing body (4) embedded in the annular groove (30a) on the lower surface of the cylindrical block portion and the annular recess (2) of the lower bearing case (2).
4) The bottom surface of the lower bearing case (2) is brought into sliding contact with the bottom surface, and the end of the cylindrical hanging part (33) and the end of the annular hanging part (36) are brought into contact with each other.
Of the first annular protrusion (23) and the end of the second annular protrusion (25) in the radial direction so as to overlap and engage with each other, and the engagement hook of the annular engagement hanging portion (38). The portion (39) is elastically attached to the engagement portion (28) on the outer peripheral surface of the annular engagement protrusion (27) of the lower bearing case (2), and the elastic attachment portion, the cylindrical hanging portion (33) and the first annular shape. Protrusion (2
3) and the annular hanging part (36) and the second annular protrusion (2).
A synthetic resin thrust bearing characterized in that a sealing portion by a labyrinth action is formed in each overlapping portion of 5) and is combined with the lower bearing case (2). 6. A synthetic resin lower bearing case (2) has an annular flat surface portion (22) formed with an annular notch step portion (22a), and a cylindrical hanging portion (3) of the upper bearing case (3).
3) has an annular protrusion (33a) formed on the inner end surface thereof, and the upper bearing case (3) has the annular protrusion (33a) of the cylindrical hanging portion formed on the annular flat portion of the lower bearing case. The synthetic resin thrust bearing according to claim 5, wherein the thrust thrust bearing (22a) is engaged with and combined with the annular cutout step portion (22a). 7. The bearing body (4) made of synthetic resin comprises a disc having a circular hole (41) in the central part, and one end face of the disc is a cylindrical block part (30) of the upper bearing case (2). 7. The synthetic resin thrust bearing according to claim 5 or 6, which is slightly protruded from the lower surface of the annular groove (30a) and is embedded in the annular groove. 8. A synthetic resin bearing body (4) has a disc-shaped portion (43) having a circular hole (41) in the central portion and one end portion of the disc-shaped portion extending to the outer peripheral surface, respectively. The annular flange (4
4) and (45), the bearing body projects the annular flange portion from the annular groove (30a) in the lower surface of the cylindrical block portion (30) of the upper bearing case (2), Shaped part (4
The synthetic resin thrust bearing according to claim 5 or 6, wherein 3) is embedded in the annular groove.