JPH0339614Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Field of Industrial Application) The present invention relates to a synthetic resin thrust bearing, particularly a synthetic resin thrust bearing suitable for being incorporated into a strut thrust type suspension (McPherson type) in a four-wheeled vehicle. (Prior art) Strut-type suspensions are generally used mainly for the front wheels of four-wheeled vehicles, and are suspensions that combine coil springs with a strut assembly that has a hydraulic shock absorber built into an outer cylinder that is integrated with the main shaft. It is. Among the above suspensions, when the strut assembly rotates with the coil spring due to steering operation, there are types in which the piston rod of the assembly rotates, and there are types in which the piston rod does not rotate, but in both types, the strut assembly does not rotate. In order to allow smooth rotation of the coil spring, a bearing is required between the mounting member of the vehicle body and the upper spring seat of the coil spring. Conventionally, rolling bearings using balls or needles, or sliding bearings made of synthetic resin have been used for bearings at this location. However, conventionally used synthetic resin sliding bearings have a dust seal made of rubber elastic material attached to the outer circumferential surface of the thrust bearing in order to prevent dust from entering the sliding surface. Since it 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 order to solve the above-mentioned conventional drawbacks, the present applicant previously filed Utility Application No. 61-133932 (Utility Model Application No. 63-40622).
(hereinafter referred to as "prior art"), a synthetic resin thrust bearing that prevents dust from entering the sliding surface without using a dust seal made of a rubber elastic body and prevents an increase in steering force during steering operation. proposed. FIG. 6 is a longitudinal sectional view showing a prior art synthetic resin thrust bearing. In the figure, the synthetic resin thrust bearing 1 includes a cylindrical part 2 having an insertion hole on the inner surface, a wide flange part 3 integrally formed with a part of the cylindrical part protruding from the outer peripheral surface of the cylindrical part, and the flange. A case 6 made of synthetic resin includes an annular protrusion 4 integrally formed on the outer periphery of the part, an engaging part 5 formed on the outer circumferential surface of the annular protrusion, a cylindrical part 7, and an inner periphery of the cylindrical part. Flange portion 8 formed at the upper end of the surface
and a flat part 9 formed at the upper end of the outer peripheral surface of the cylindrical part, an annular hanging part 10 formed at the peripheral edge of the flat part, and an engaging hook part 11 formed at the lower end of the hanging part. The bearing body 12 has the lower surface of the cylindrical portion 7 in sliding contact with the upper surface of the wide collar portion 3 of the case 6, and the engaging hook portion 11 of the annular hanging portion 10 is connected to the engaging portion 5 of the case 6. The elastic mounting portion is elastically mounted to allow relative rotation, and a sealing portion is formed in the elastic mounting portion. (Problems to be solved by the invention) The above-mentioned prior art can prevent the shortcomings of conventional synthetic resin sliding bearings, especially the increase in steering force during steering operation, and can maintain smooth steering force for a long period of time. However, the sealing part formed on the elastic mounting part is not enough to prevent dust from entering, and dust can enter from the sealing part, affecting the sliding characteristics. This was confirmed by subsequent experiments. The present invention was developed to solve the above-mentioned drawbacks of the prior art, and it prevents dust from entering the sliding surface without using a dust seal made of rubber elastic material, and reduces the steering force during steering operation. The object of the present invention is to obtain a synthetic resin thrust bearing that can prevent the increase in the number of particles. (Means for solving the problems) In order to achieve the above-mentioned object, the present invention adopts the following technical means, that is, the configuration. A synthetic resin thrust bearing 20 is composed of a synthetic resin case 21 and a synthetic resin bearing body 22 that is slidably fitted into the case 21, and the synthetic resin case 21 has a wide flange having an insertion hole 23 on the inner surface. part 25, an annular protrusion 26 integrally formed on the outer peripheral edge of the flange, an engaging part 27 formed on the outer periphery of the protrusion 26, and integrally formed on the upper surface of the flange in communication with the insertion hole. The cylindrical protrusion 24a and the cylindrical protrusion 24a are formed concentrically with the insertion hole 23 on the upper surface of the flange, and are separated from the inner surface of the annular protrusion 26 by an annular space S1 radially inward. Annular groove 28
The synthetic resin bearing body 22 includes a cylindrical bearing part 30 and an annular collar part 3 integrally formed at the upper end of the inner peripheral surface of the bearing part.
1, a flat part 32 formed on the upper end of the outer peripheral surface of the bearing part, an annular upper lip part 35 hanging down from the lower surface of the flat part with an annular gap S2 between the outer peripheral surface of the cylindrical bearing part 30 and the flat surface. An annular hanging part 33 formed integrally with an annular deep groove part S3 continuously formed on the outer circumferential surface of the lip part 35 on the peripheral edge of the lip part and an engagement formed at the lower end of the hanging part. The bearing body 22 has a hook portion 34 , and the bearing body 22 slides the lower surface of the cylindrical bearing portion 30 onto the bottom surface of the annular groove 28 formed on the upper surface of the wide flange 25 of the case 21 . and the end of the annular upper lip portion 35 is overlapped with the end of the annular lower lip portion 29 in the radial direction thereof, so as to be located within the annular gap S1,
The annular deep groove portion S3 is engaged with the engaging portion 27 formed on the outer periphery of the wide flange portion 25 of the case 21, and the engaging hook portion 34 of the annular hanging portion 33 is engaged with the engaging portion 27 formed on the outer periphery of the annular protruding portion 26. The joint portion 27 is elastically attached, and the elastic attachment portion and the upper and lower lip portions 35,
This is a synthetic resin thrust bearing formed by forming a sealing part 29 that acts as a labyrinth and being combined with the case 21 so that it can rotate relative to the case 21. In the above configuration, the synthetic resin that makes up the case must have excellent mechanical properties such as wear resistance, impact resistance, and creep resistance. Particularly preferred are those having self-lubricating properties, such as polyester resins such as polyacetal resin, polyamide resin, polybutylene terephthalate (PBT),
Polyolefin resins such as polyethylene and polypropylene are preferably used, and polycarbonate resins may also be used. The case is made of the same synthetic resin as the above-mentioned bearing body, but the case is made of a synthetic resin material that has a good combination of frictional properties with the synthetic resin used for the bearing body, and is relatively rigid. It is desirable that there be. Examples of desirable combinations are shown in the table below.

〔Test conditions〕

Thrust load: 350Kg, Swing angle: ±35° Swing speed: 60cpm, Lubrication: Apply silicone grease to the sliding surface during instruction.The amount of wear is the size of the bearing piece after 1 million cycles of the above test. Indicates the amount of change (mm). In addition, the bearing sliding surface, that is, the cylindrical lower surface of the bearing body and the annular groove bottom surface of the case that comes into sliding contact with the lower surface,
The labyrinth sealing portions formed at the elastic attachment portion and the overlapping portion of the annular upper and lower lip portions protect against the intrusion of dust and the like. (Embodiments) Hereinafter, the present invention will be explained in detail with reference to FIGS. 1 to 4 of the accompanying drawings showing embodiments thereof. Reference numeral 20 denotes a synthetic resin thrust bearing, and the thrust bearing 20 includes a synthetic resin case 21 and the case 2.
A synthetic resin bearing body 22 that is slidably fitted to 1.
It is composed of. The synthetic resin case 21 has an insertion hole 23 on the inner surface.
A wide flange 25 having a wide flange 25 , an annular protrusion 26 integrally formed on the outer periphery of the flange 25 , an engaging portion 27 formed on the outer periphery of the protrusion 26 , and an engagement portion 27 that is inserted into the upper surface of the flange 25 . A cylindrical protrusion 24a communicating with the hole 23 and an annular cylindrical protrusion 24a formed concentrically with the insertion hole 23 on the upper surface of the flange and on the inner surface and radial direction of the annular protrusion 26.
It is provided with an annular lower lip part 29 which is separated by a gap S1 and which forms an annular groove 28 with the cylindrical protrusion part 24a. Reference numeral 24 denotes a cylindrical portion integrally formed on the lower surface of the wide collar portion 25 in communication with the insertion hole 23, and the cylindrical portion 24 is formed as appropriate depending on the intended use of the thrust bearing. The engaging portion 27 includes a tapered surface portion 27a formed from the outer peripheral surface of the annular protrusion 26 to the lower surface of the wide flange portion 25, and a cylindrical surface portion 27b that is continuous with the tapered surface portion 27a and continues to the lower surface of the flange portion 25. . The synthetic resin bearing body 22 includes a cylindrical bearing part 30, an annular collar part 31 integrally formed at the upper end of the inner peripheral surface of the bearing part, and a flat part 32 formed at the upper end of the outer peripheral surface of the bearing part. The cylindrical bearing part 30 is provided on the lower surface of the flat part.
An annular upper lip part 35 that hangs down with an annular gap S2 between the outer circumferential surface of the case 21 and an annular upper lip part 35 formed with an inner diameter larger than an outer diameter of an annular lower lip part 29 formed on the upper surface of the wide flange part 25 of the case 21. The lip part 35 is formed on the periphery of the flat part, the annular hanging part 33 is integrally formed with an annular deep groove part S3 continuously formed on the outer peripheral surface of the lip part, and the lower end of the hanging part is formed. The engaging hook portion 34 is provided. Reference numeral 36 denotes a plurality of hollow portions formed radially in the circumferential direction on the upper surface of the cylindrical bearing portion 30, and the hollow portions 36 allow the bearing body 22 to have a uniform wall thickness. ing. Reference numeral 37 denotes a plurality of grooves formed radially from the inner circumferential surface to the outer circumferential surface of the lower surface of the cylindrical bearing portion 30, and the grooves 37 serve as reservoirs for lubricating oil such as grease. The engaging hook portion 34 includes a tapered surface portion 34a corresponding to the tapered surface portion 27a forming the engaging portion 27 of the case 21, and a cylindrical surface portion 34a continuous with the tapered surface portion 34a and corresponding to the cylindrical surface portion 27a of the engaging portion 27. It consists of The synthetic resin bearing body 22 configured in this manner has the lower surface of its cylindrical bearing portion 30 in sliding contact with the bottom surface of the annular groove 28 formed on the upper surface of the wide flange 25 of the case 21. At the same time, the end portion of the annular upper lip portion 35 is overlapped with the end portion of the annular lower lip portion 29 in the radial direction, and the annular deep groove portion S3 is positioned within the annular gap S1. It is engaged with the annular protrusion 26 formed on the outer peripheral edge of the collar part 25, and the engagement hook part 34 of the annular hanging part 33 is elastically attached to the engagement part 27 on the outer circumferential surface of the annular protrusion 26. Attachment part and top,
The lower lip portions 35 and 29 are formed with a sealing portion that acts as a labyrinth and are combined with the case 21 so as to be relatively rotatable. A synthetic resin thrust bearing 20 is constructed by combining in this way, and the sliding surface of the thrust bearing 20,
That is, the cylindrical bearing portion 30 of the synthetic resin bearing body 22
Dust and the like can not enter the sliding surface between the lower surface and the bottom surface of the annular groove 28 formed on the upper surface of the wide flange 25 of the synthetic resin case 21 due to the overlap between the elastic mounting portion and the annular upper and lower lip portions 35 and 29. This is prevented by labyrinth-acting seals formed in each section. FIG. 5 shows a synthetic resin thrust bearing 20 having the above-mentioned structure used in an automobile strut assembly A.
This is an example of an application incorporated into the system. In this application example, a synthetic resin case 21 constituting the synthetic resin thrust bearing 20 is integrally provided with a cylindrical portion 24 communicating with the insertion hole 23 on the lower surface of the wide collar portion 25. By forming this cylindrical portion 24, the cylindrical portion 24 plays the role of positioning when the bearing 20 is assembled into the strut assembly A. That is, the cylindrical portion 24 of the synthetic resin case 21
The insertion hole 23 of the strut 38 is inserted into the outer peripheral surface of the piston rod 39 of the strut 38, and the outer peripheral surface of the cylindrical portion 24 is fitted into the hole of the upper spring seat sheet 40. The case 21 is positioned on the spring seat sheet 40 by contacting the flat surface, and the upper surface of the synthetic resin bearing body 22 is brought into contact with the vehicle body mounting member 41 to assemble the thrust bearing 20 into a strut assembly. This is to be incorporated into A. In this application example, during steering operation, the operation is facilitated by sliding between the lower surface of the cylindrical bearing portion 30 of the synthetic resin bearing body 22 and the bottom surface of the annular groove 28 formed on the upper surface of the wide flange portion 25 of the synthetic resin case 21. have it done. By employing the above-mentioned combination of synthetic resins for the bearing body 22 and the case 21, frictional resistance can be reduced and the steering operation can be performed even more smoothly. Furthermore, the sliding surfaces are the elastic mounting portion between the case 21 and the bearing body 22, and the annular upper and lower lip portions 35, 29.
The above-mentioned steering operation can be maintained over a long period of time because the steering operation is protected by a sealing part formed in the shaft which acts as a labyrinth. (Effects) The synthetic resin thrust bearing of the present invention having the above-described configuration has the following unique effects. An elastic attachment part between the engaging part of the annular protrusion formed on the outer periphery of the wide brim of the synthetic resin case and the engaging hook part formed in the annular hanging part of the synthetic resin bearing body, and the annular upper and lower lips. Since the sliding surface is protected by a sealing part that acts as a labyrinth formed at the overlapped part with the sliding part, it not only completely prevents dust from entering the sliding surface, but also prevents dust from entering the sliding surface. Since the dust seal made of rubber elastic material used to protect the moving surface is not required, there is no increase in sliding friction resistance caused by the dust seal, and smooth sliding can be maintained over a long period of time. . Since the sliding surface is formed of a combination of synthetic resins with excellent self-lubricating properties, the coefficient of friction is small and stable sliding can be performed. Since the synthetic resin case and the synthetic resin bearing body are assembled by elastic attachment, the assembly work is extremely simple.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing the synthetic resin thrust bearing of the present invention, Fig. 2 is a plan view of the synthetic resin bearing body, Fig. 3 is a bottom view of the synthetic resin bearing body, and Fig. 4 is a view of the case and bearing body. FIG. 5 is a longitudinal sectional view showing an example in which the bearing is applied to a strut assembly, and FIG. 6 is a longitudinal sectional view showing a prior art synthetic resin thrust bearing. 21...Synthetic resin case, 22...Synthetic resin bearing body, 24...Cylindrical part, 24a...Partial protrusion part, 25...Wide flange part, 26...Annular protrusion part, 2
7... Engaging part, 28... Annular groove, 29... Annular lower lip part, 30... Cylindrical bearing part, 31... Annular collar part, 32... Plane part, 33... Annular hanging part, 3
4... Engaging hook portion, 35... Annular upper lip portion.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A synthetic resin thrust bearing 20 consisting of a synthetic resin case 21 and a synthetic resin bearing body 22 that is slidably fitted into the case 21, wherein the synthetic resin case 21 comprises: Insertion hole 23 on the inner surface
A wide flange 25 having a wide flange, an annular protrusion 26 integrally formed on the outer periphery of the flange, an engaging portion 27 formed on the outer periphery of the protrusion 26, and an upper surface of the flange communicating with the insertion hole. A cylindrical protrusion 24a is formed integrally with the cylindrical protrusion 24a, and a cylindrical protrusion 24a is formed on the upper surface of the flange concentrically with the insertion hole 23, and an annular space S1 is separated from the inner surface of the annular protrusion 26 in the radial direction. The synthetic resin bearing body 22 includes a cylindrical bearing part 30 and an annular lower lip part 29 that forms an annular groove 28 with the part 24a. A flange part 31, a flat part 32 formed at the upper end of the outer peripheral surface of the bearing part, and an annular upper lip part 35 hanging down from the lower surface of the flat part with an annular gap S2 between the outer peripheral surface of the cylindrical bearing part 30 and the outer peripheral surface of the cylindrical bearing part 30. The lip part 35 is formed on the periphery of the flat part, the annular hanging part 33 is integrally formed with an annular deep groove part S3 continuously formed on the outer peripheral surface of the lip part, and the lower end of the hanging part is formed. The bearing body 22 is provided with an engaging hook portion 34, and the bearing body 22 has a lower surface of the cylindrical bearing portion 30 in sliding contact with the bottom surface of the annular groove 28 formed on the upper surface of the wide flange portion 25 of the case 21. located within the groove 28 and the annular upper lip portion 35
overlap the end of the annular lower lip portion 29 in the radial direction thereof and position it within the annular gap S1;
The annular deep groove portion S3 is connected to the wide flange portion 25 of the case 21.
The engagement hook portion 34 of the annular hanging portion 33 is engaged with the annular protrusion 27 formed on the outer peripheral edge of the annular protrusion 26 .
A synthetic resin thrust bearing, which is elastically mounted on the case 21, and is assembled to the case 21 so as to be relatively rotatable by forming a sealing part that acts as a labyrinth in the elastic mounting part and the upper and lower lip parts 35 and 29. 2. The synthetic resin thrust bearing according to claim 1, wherein a cylindrical portion 24 communicating with the insertion hole 23 is integrally formed on the lower surface of the wide collar portion 25 of the synthetic resin case 21.