JPH082500Y2 - Synthetic resin thrust bearing - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a synthetic resin thrust bearing, and particularly to a synthetic resin thrust bearing suitable for being incorporated in a strut suspension (McPherson type) in a four-wheeled vehicle.

[Prior art]

Generally, a strut type suspension used for a front wheel of a four-wheeled vehicle has a structure in which a coil spring is combined with a strut assembly having a hydraulic shock absorber built in an outer cylinder integrated with a main shaft. The suspension has a type in which the piston rod rotates when the strut assembly rotates with the coil spring by steering operation and a type in which the piston rod does not rotate.However, in any type, the strut assembly is rotated. A bearing is required between the mounting member of the vehicle body and the upper spring seat of the coil spring in order to allow smoothness.

Conventionally, rolling bearings using balls or sliding bearings made of synthetic resin have been used as the bearings at this location.

However, in order to prevent dust and other foreign matter from entering the sliding surfaces of conventional synthetic resin slide bearings, a dust seal made of a rubber elastic body should be slid in close contact between the sliding surfaces that rotate relative to each other. Since the dust seals are arranged, the dust seal directly participates between the sliding surfaces during steering operation to increase the sliding frictional force and increase the steering force.

Therefore, in order to solve the above-mentioned conventional drawbacks, the present applicant previously proposed a dust seal made of a rubber elastic body in Japanese Utility Model Application No. Sho 61-196804 (Act No. 2-6263, hereinafter referred to as “conventional technology”). We proposed a synthetic resin thrust bearing that can prevent dust from entering the sliding surface without using it and can prevent an increase in steering force during steering operation.

 Hereinafter, this conventional technique will be described.

FIG. 6 is a vertical sectional view showing a conventional synthetic resin thrust bearing, and FIG. 7 is a vertical sectional view showing a state in which the thrust bearing is incorporated into a strut suspension.

A synthetic resin thrust bearing 1 according to the prior art has a wide flange portion integrally formed with a cylindrical portion 4 having an insertion hole 3 on an inner surface thereof and a portion 4a of the cylindrical portion protruding from an outer peripheral surface of an end portion of the cylindrical portion. 5, an annular projecting portion 6 integrally formed on the outer peripheral edge of the collar portion, an engaging portion 7 formed on the outer peripheral surface of the annular projecting portion, and an upper surface of the collar portion formed concentrically with the insertion hole, A synthetic resin lower case 2 having an annular lower lip portion 9 that forms an annular groove 8 with a part of the cylindrical portion, and one surface of the lower case 2 in the annular groove 8 of the lower case 2. A synthetic resin bearing piece 17 arranged in sliding contact with the bottom surface, a disk-shaped portion 13 having a circular hole 11 and an annular protruding portion 12 continuously protruding downward from the circular hole in the central portion, and the circular plate. An annular hanging part 14 formed integrally with the outer peripheral edge of the plate-like part, an engaging hook part 15 formed at the lower end of the hanging part, and a concentric shape with the circular hole on the lower surface of the disk-like part. An upper case 10 made of synthetic resin having an annular upper lip portion 16 formed therein, and the upper case 10 has a bearing piece 17 in which the lower surface of the disk-shaped portion 13 is arranged in the annular groove 8 of the lower case 2. The annular projection 12 and the annular upper lip portion 16 are respectively brought into sliding contact with the other surface of the lower case 2, and the respective end portions of the cylindrical projection portion 4a of the lower case 2 and the annular lower lip portion 9 are connected to each other. The engaging hook portion 15 of the annular hanging portion 14 is elastically mounted on the engaging portion 7 on the outer peripheral surface of the annular protruding portion 6 of the lower case 2, and the elastic mounting, the annular protruding portion 12 and the partial protruding portion 4a of the cylindrical portion, and the annular upper lip portion 16 and the annular lower lip portion 9 are overlapped with each other to form a sealing portion by a labyrinth action and are formed in combination with the lower case 2.

The synthetic resin thrust bearing 1 having the above-mentioned configuration is the seventh
As shown in the figure, the insertion hole 3 of the cylindrical portion 4 of the lower case 2
And the circular hole 11 of the upper case 10 is inserted into the outer peripheral surface of the piston rod R of the strut 18, and the cylindrical portion 4 of the lower case 2 is inserted.
The outer peripheral surface is fitted into the hole S ₂ of the upper spring seat S, and the lower surface of the wide brim portion 5 of the lower case 2 is brought into contact with the flat surface S ₁ of the spring seat S to form a disc shape of the upper case 10. Part 13
It is arranged with its upper surface abutting on the vehicle body side mounting member 19. In the drawing, reference numeral E is a coil spring, and G is a bump stopper (rubber) arranged on the lower surface of the spring seat S so as to surround the outer peripheral surface of the piston rod R.

[Problems to be solved by the invention]

The synthetic resin thrust bearing made of the above-mentioned conventional technology is
Due to a drawback of conventional synthetic resin thrust bearings, that is, a dust seal made of a rubber elastic body mounted between the sliding surfaces so as to surround the sliding surfaces for the purpose of preventing dust and the like from entering the bearing sliding surfaces. It is possible to solve the drawback of an increase in the steering force, and to prevent dust and the like from entering the sliding surface as much as possible to obtain a stable and smooth steering force.

However, the strut type suspension in which the above-mentioned synthetic resin thrust bearing is incorporated is
It is an extremely harsh condition as a usage environment of the synthetic resin thrust bearing incorporated in the part where muddy water or the like directly acts.

The synthetic resin thrust bearing made of the above-mentioned conventional technology,
Sealing parts are formed on the inner and outer peripheral surfaces by the labyrinth effect, and the sealing means prevents the intrusion of dust and the like into the bearing sliding surface. It was difficult to say, and it was confirmed by subsequent experiments that dust and the like would particularly enter from the inner peripheral surface side of the bearing, which would affect the sliding characteristics, such as reduced wear resistance of the bearing and fluctuations in the friction coefficient.

The reason why dust and the like enter the sliding surface from the inner peripheral surface side of the bearing is not known, but the present inventors have found that in the strut suspension, the lower surface side of the upper spring seat that incorporates the synthetic resin thrust bearing is incorporated. A bump stopper (rubber) arranged surrounding the piston rod is displaced by abutting against the strut body while the vehicle is running, and the displacement acts as a pump, and dust, mud, etc. are caused by the pump action and the piston rod and the bearing. It is presumed that this is because pressure is fed to the inner peripheral surface of the bearing from the sliding clearance between the inner peripheral surface and the bearing.

The present invention relates to the improvement of the above-mentioned conventional technology, and the advantages of the conventional technology are effectively utilized as they are. In particular, the above-mentioned problems of the conventional technology are solved by further providing a measure for preventing dust and the like from entering the inner peripheral surface of the bearing. It is an object of the present invention to provide a synthetic resin thrust bearing that can solve the problem and can maintain a smooth steering force during a steering operation for a long period of time.

[Means for solving problems]

According to the present invention, the above-described object is to provide a disk-shaped portion having an insertion hole in the center and a circular flat portion at the periphery of the insertion hole on the upper surface of the disk-shaped portion so as to project concentrically with the insertion hole. An annular protrusion, an annular protrusion protruding from the annular protrusion and forming an annular groove radially outward, and an annular protrusion protruding radially outward from the inner annular protrusion. An outer ring-shaped ridge portion that forms a wide annular recessed groove between the inner ring-shaped ridge portion and the upper surface of the disk-shaped portion, and an annular groove formed radially outward with the outer ring-shaped ridge portion A lower case made of synthetic resin, which has an annular engaging protrusion protruding from the outer peripheral edge of the portion, and an inner diameter larger than the outer diameter of the inner annular protrusion of the lower case and an inner diameter of the outer annular protrusion. Has a small outer diameter, and one end face is slidably in contact with the bottom surface of the wide annular groove of the lower case, and the other end surface is arranged so as to protrude from the wide annular groove. A synthetic resin bearing piece forming a grayed-shaped,
A disk-shaped portion having an insertion hole of the same diameter as the insertion hole in the central portion, an annular hanging part that hangs on the lower surface of the disk-shaped part with an inner diameter of the insertion hole, and an outer radial direction of the annular hanging part. An inner annular hanging part that forms an annular groove on one side, and a wide annular concave groove that hangs radially outwardly from the inner annular hanging part at a distance from the inner annular hanging part and the lower surface of the disk-shaped portion. A synthetic resin upper case having an outer annular hanging part that forms the outer annular hanging part, an outer annular hanging part, and an annular engaging hanging part that forms an annular groove and hangs down to the outer peripheral edge of the disc-shaped portion, In the upper case, the bottom surface of the wide annular groove is slidably contacted with the other end surface of the bearing piece arranged in the wide annular groove of the lower case, and the annular hanging portion, the inner annular hanging portion and the outer annular hanging portion are The respective end portions are respectively arranged in the radial direction and the respective end portions of the annular protrusion portion, the inner annular protrusion portion and the outer annular protrusion portion of the lower case. The inner peripheral surface of the annular engaging hanging portion is elastically attached to the outer peripheral surface of the annular engaging protruding portion of the lower case, the elastic attaching portion, the annular hanging portion and the annular protruding portion Inner and outer periphery double sealing portions are formed by a labyrinth action at the overlapping portions of the annular hanging portion and the inner annular protruding portion, and the outer annular hanging portion and the outer annular protruding portion, respectively, and combined with the lower case. Is achieved by a synthetic resin thrust bearing.

The synthetic resin thrust bearing configured as described above has a bearing sliding surface, that is, upper and lower end surfaces of the synthetic resin bearing piece,
The bearing sliding surface, which is formed by sliding contact with the lower end surface and the bottom surface of the wide annular groove of the lower case, has an elastic mounting portion between the annular engaging hanging portion of the upper case and the annular engaging protruding portion of the lower case, and the annular hanging portion. Portion and annular protrusion, inner annular hanging part and inner annular protruding part, and inner and outer double sealing parts by labyrinth action formed on respective overlapping parts of outer annular hanging part and outer annular protruding part Of these, it is protected from intrusion of dust and the like from the outer peripheral surface.

The synthetic resin forming the upper and lower cases must have excellent sliding and mechanical properties such as wear resistance, impact resistance, and creep resistance, and between the upper and lower cases. It is particularly preferable that the synthetic resin bearing pieces to be housed have self-lubricating properties. For example, polyacetal resin, polyamide resin, polyester resin such as polybutylene terephthalate, polyolefin resin such as polyethylene and polypropylene are preferably used. Polycarbonate resin or the like may also be used. The upper and lower cases are made of the same synthetic resin as that used for the bearing piece, but in particular, the combination of the synthetic resin used for the bearing piece and the sliding characteristics is excellent, and the rigidity is relatively high. It is preferably a synthetic resin.

The following table illustrates the desirable combinations.

In the table, the coefficient of friction and the amount of wear are the results obtained under the following test conditions.

〔Test condition〕

Thrust load: 350 kg Oscillation angle: ± 35 ° Oscillation speed: 60 cpm Lubrication: Apply grease to the sliding surface at the start Note that the amount of wear is the amount of dimensional change in the bearing piece after the above test is performed 1 million cycles ( mm) is shown.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to FIGS. 1 to 5 of the accompanying drawings showing an embodiment thereof.

In the figure, A is a synthetic resin thrust bearing, and the thrust bearing A is a synthetic resin lower case B, a synthetic resin upper case C, and a synthetic resin bearing piece D housed between the upper and lower cases C and B. It consists of

The lower case B is provided in a concentric shape with the disc-shaped portion 21 having the insertion hole 20 in the center and the annular flat portion 22 at the peripheral edge of the insertion hole on the upper surface of the disc-shaped portion, concentrically with the insertion hole. The annular protruding portion 23, the annular protruding portion, and the inner annular protruding portion 25 formed by protrudingly forming an annular groove 24 outward in the radial direction, and the inner annular protruding portion protruding radially outward from the annular protruding portion 25. An outer annular protrusion 27 that forms a wide annular recessed groove 26 between the inner annular protrusion and the upper surface of the disc-shaped portion, and an annular groove 28 is formed radially outward with the outer annular protrusion. Further, it is provided with an annular engagement protrusion 29 which is provided so as to protrude on the outer peripheral edge of the disc-shaped portion.

The annular engaging protrusion 29 is continuous with the inclined surface portion 29a, which extends downward from the upper end portion on the outer peripheral surface thereof, and the inclined surface portion 29a, converges inward, and is continuous with the outer peripheral surface of the disc-shaped portion 21. An engaging portion including the inclined surface portion 29b is provided.

A plurality of recessed grooves 30 along the axial direction of the insertion hole 20 are formed in the insertion hole 20 of the disk-shaped portion 21 in the circumferential direction, and the recessed grooves 30 are reservoirs for a lubricant such as grease. Becomes

On the lower surface of the disk-shaped portion 21 of the lower case B, there are formed convex portions 31 which are opposed to each other with the insertion hole 20 interposed therebetween, and the convex portions 31 are fitted into mating mounting holes which will be described later and the lower case. It plays the role of stopping B.

The upper case C has a disc-shaped portion 33 having an insertion hole 32 having the same diameter as the insertion hole 20 in the center and an annular hanging portion having a diameter equal to that of the insertion hole 32 on the lower surface of the disc-shaped portion. The portion 34, the annular hanging portion, and the inner annular hanging portion 36 that hangs down by forming an annular groove 35 radially outward, and the portion 34 that hangs radially outward from the inner annular hanging portion, and the inner annular hanging portion Portion and the lower surface of the disk-shaped portion form an outer annular hanging portion 38 that forms a wide annular concave groove 37, and an annular engagement that forms the outer annular hanging portion and the annular groove 39 and hangs on the outer peripheral edge of the disk-shaped portion. And a drooping portion 40.

The annular engaging hanging portion 40 has an inclined surface portion 40a and an inclined surface portion 40a which extend outward from the outer upper end of the annular groove 39 on the inner peripheral surface thereof.
And an engaging portion composed of an inclined surface portion 40b which is continuous with the above and converges inward.

The bearing piece D has a ring shape having an inner diameter larger than the outer diameter of the inner annular protruding portion 25 of the lower case B and smaller than the inner diameter of the outer annular protruding portion 27.

A plurality of grooves 41 are radially formed on the end surface of the bearing piece D.
The a and 41b are formed with a phase difference of 30 degrees in the circumferential direction, and the grooves 41a and 41b serve as a reservoir for a lubricant such as grease.

The bearing piece D is disposed in the wide annular groove 26 of the lower case B with one end surface slidingly contacting the bottom surface of the wide annular groove 26.

In the upper case C, the bottom surface of the wide annular groove 37 is slidably contacted with the other end surface of the bearing piece D arranged in the wide annular groove 26 of the lower case B, and the annular hanging portion 34 and the inner annular hanging portion are provided. The respective end portions of 36 and the outer annular hanging portion 38 are overlapped with the respective end portions of the annular protruding portion 23, the inner annular protruding portion 25 and the outer annular protruding portion 27 of the lower case B in the radial direction and engaged. The engaging portion of the inner peripheral surface of the annular engaging hanging portion 40 is elastically attached to the engaging portion of the outer peripheral surface of the annular engaging protruding portion 29 of the lower case B. Portion 34 and annular protrusion 23, inner annular hanging portion 36, inner annular protruding portion 25, and outer annular hanging portion 38.
Synthetic resin thrust bearings A are formed by forming a double sealed portion on each of the inner and outer circumferences by a labyrinth action at each overlapping portion of the outer ring-shaped projection 27 and the outer ring-shaped ridge portion 27 so as to be rotatable relative to the lower case B. .

Thus, by combining the upper and lower cases C and B and the bearing piece D, the upper and lower end surfaces of the bearing piece D and
Wide bottom annular groove 37, 26 on the lower case
The bearing sliding surface formed by the bottom surface is an elastic mounting portion between the annular engaging hanging portion 40 of the upper case C and the annular engaging protruding portion 29 of the lower case B, the annular hanging portion 34 and the annular protruding portion 23, and the inner annular shape. Hanging part 36
By the labyrinth action formed in the overlapping portion of each of the inner ring-shaped ridge 25 and the outer ring-shaped hanging part 38 and the outer ring-shaped ridge 27, the inner and outer double sealing portions are provided, respectively. Protected against ingress of dust, etc.

FIG. 4 shows an example in which the synthetic resin thrust bearing A according to the above-described embodiment is applied to a strut assembly.

That is, the insertion hole 20 of the disk-shaped portion 21 of the lower case B and the insertion hole 32 of the disk-shaped portion 33 of the upper case C are inserted into the outer peripheral surface of the piston rod R of the strut assembly, and the lower case B is inserted. The lower surface of the disk-shaped portion 21 of the upper spring seat S is brought into contact with the flat surface portion S ₁ of the upper spring seat S, and the convex portion of the lower surface of the disk-shaped portion 21 is
31 is fitted in the fitting hole S ₂ provided in the flat surface S ₁ of the upper spring seat S, and the upper surface of the disk-shaped portion 33 of the upper case C is placed in contact with the vehicle body side mounting member 42. To do.

In the figure, reference numeral E is a coil spring, and G is a bump stopper (rubber).

The synthetic resin thrust bearing A assembled in the strut assembly as described above is operated by steering operation so that the lower case B and the upper case C are inserted through the bearing piece D, the lower case B and the bearing piece D, and the upper case C and the bearing. One of the pieces D, whichever has a smaller coefficient of friction, makes relative rotation and a smooth steering force is obtained.

Further, the bearing sliding surface formed by the upper and lower end surfaces of the bearing piece D and the upper and lower end surfaces of the bearing piece D, and the bottom surface of the wide annular groove 37, 26 of the lower case is the annular engaging surface of the upper case C. An elastic mounting portion between the joint hanging portion 40 and the annular engaging protrusion 29 of the lower case B, the annular hanging portion 34 and the annular protruding portion 23, the inner annular hanging portion 36 and the inner annular protruding portion 25, and the outer annular hanging portion 38. The inner and outer double sealing portions formed by the labyrinth action formed on the overlapping portions of the inner and outer annular protrusions 27 protect the inside and outer surfaces from dust and the like, so that the bearing slides. A stable and smooth steering force can be maintained for a long period of time without causing deterioration of sliding characteristics due to intrusion of dust or the like into the surface.

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

In this embodiment, in addition to the components of the synthetic resin thrust bearing according to the above-mentioned embodiment, a cylindrical portion 20a communicating with the central insertion hole 20 is formed on the lower surface of the lower case B.
The other structure is the same as that of the above embodiment.

The cylindrical portion 20a facilitates the assembly of the synthetic resin thrust bearing to the flat surface portion S ₁ of the upper spring seat S of the strut assembly.

[Effect of device]

The synthetic resin thrust bearing of the present invention described above has the following unique effects.

The bearing sliding surface formed by the upper and lower end surfaces of the bearing piece and the sliding contact with the upper and lower end surfaces and the bottom surface of the wide annular groove of the lower case is an annular engaging hanging part of the upper case and an annular shape of the lower case. Labyrinths formed on the elastic mounting portion with the engaging protrusion, the annular hanging portion and the annular protruding portion, the inner annular hanging portion and the inner annular protruding portion, and the overlapping portion of the outer annular hanging portion and the outer annular protruding portion, respectively. Due to the double sealing inside and outside,
Among them, since it is protected from intrusion of dust from the outer peripheral surface, stable and smooth steering steering force is maintained for a long period without deterioration of sliding characteristics caused by intrusion of dust into the bearing sliding surface. Is maintained.

The bearing sliding surface is composed of a combination of synthetic resins with excellent self-lubricating properties, so the friction coefficient is low,
Stable steering force is maintained for a long period of time.

Since the upper and lower cases are combined by elastic mounting, the work is extremely easy.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the synthetic resin thrust bearing of the present invention, FIG. 2 is a plan view of a synthetic resin lower case, and FIG.
FIG. 4 is a plan view of a synthetic resin bearing piece, FIG. 4 is a longitudinal sectional view showing an example in which the synthetic resin thrust bearing shown in FIG. 1 is applied to a strut assembly, and FIG. 5 is another synthetic resin thrust bearing of the present invention. FIG. 6 is a vertical sectional view showing an embodiment, FIG. 6 is a vertical sectional view showing a conventional synthetic resin thrust bearing, and FIG.
It is a longitudinal cross-sectional view showing an example in which the synthetic resin thrust bearing shown in the figure is applied to a strut assembly. A: Synthetic resin thrust bearing, B: Lower case, C: Upper case D: Bearing piece, 21: Disc part, 22: Annular flat part, 23: Annular protrusion, 24: Annular groove 25: Inner annular protrusion Part, 26: wide annular groove, 27: outer annular protrusion, 28: annular groove 29: annular engaging protrusion, 33: disc-shaped part, 34: annular hanging part, 36:
Inner annular hanging part 37: Wide annular concave groove, 38: Outer annular hanging part, 40: Annular engaging hanging part

Claims (1)

[Scope of utility model registration request] 1. A disk-shaped portion (21) having an insertion hole (20) in the center and an annular flat surface (22) at the periphery of the insertion hole on the upper surface of the disk-shaped portion, leaving a circular concentric circle with the insertion hole. And an annular groove (24) projecting radially outward from the annular projection (23) and the annular projection.
And the inner ring-shaped ridge portion (25) protruding from the inner ring-shaped ridge portion and the disk-shaped portion upper surface. An outer annular ridge (27) forming a wide annular groove (26), and an annular groove (28) radially outwardly of the outer annular ridge and forming an outer peripheral edge of the disc-shaped portion. A synthetic resin lower case (B) having a protruding annular engaging protrusion (29), an inner diameter larger than the outer diameter of the inner annular protrusion (25) of the lower case, and an outer annular protrusion. It has an outer diameter smaller than the inner diameter of the part (27), and one end surface is slidably contacted with the bottom surface of the wide annular groove (26) of the lower case, and the other end surface is protruded from the wide annular groove. Ring-shaped synthetic resin bearing piece (D), a disk-shaped part (33) having an insertion hole (32) of the same diameter as the insertion hole (20) in the center, and the lower surface of the disk-shaped part To the insertion hole (32) An annular hanging part (34) having an inner diameter of the same diameter, an inner annular hanging part (36) having an annular groove (35) formed radially outward from the annular hanging part and hanging, and an inner annular hanging part. An outer annular hanging portion (38) that hangs outwardly in the direction at a distance to form a wide annular concave groove (37) between the inner annular hanging portion and the lower surface of the disk-shaped portion, and the outer annular hanging portion and the annular groove. (3
9) An upper case (C) made of synthetic resin, which is provided with an annular engaging hanging part (40) that forms a circular shape and hangs on the outer peripheral edge of the disc-shaped part.
And the upper case (C) has a wide annular groove (3
The bottom surface of 7) to the wide annular groove (26) of the lower case (B).
Slidably in contact with the other end surface of the bearing piece (D) arranged in the lower part, and the respective end portions of the annular hanging part (34), the inner annular hanging part (36) and the outer annular hanging part (38) are made into the lower part. The annular projection (23), the inner annular projection (25), and the outer annular projection (27) of the case (B) are engaged with the respective ends of the annular projection so as to overlap each other in the radial direction thereof. The inner peripheral surface of the hanging portion (40) is elastically attached to the outer peripheral surface of the annular engaging protrusion (29) of the lower case (B), and the elastic mounting portion, the annular hanging portion (34) and the annular protrusion ( 23), the inner annular hanging part (36) and the inner annular protruding part (2
5), and the outer annular hanging part (38) and the outer annular protrusion (27).
The synthetic resin thrust bearing is characterized in that a double sealed portion is formed on each of the inner and outer peripheries by the labyrinth action in each of the overlapping portions and is combined with the lower case (B).