JPH0139937Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] "Field of industrial application" This invention relates to thrust ball bearings, particularly thrust ball bearings used in suspension systems of automobiles.

``Prior Art'' In the thrust ball bearings used in automobile suspension systems, especially those of the McPherson strut type, the mating material to which the thrust ball bearings are attached is the body or spring seat, which is usually a press-formed sheet metal. It is made by

Therefore, because the flatness of these mating materials is extremely poor, the contact surface with the thrust ball bearing is partially touched, and the raceway is deformed, causing uneven contact between the balls and the raceway, resulting in the contact between several balls. Frequently, problems occurred in which the balls or raceway rings were damaged in order to support the load. In addition, in such a situation, if the metal bearing ring is directly supported by the sheet metal member of the suspension system, fretting corrosion occurs due to minute slippage, which causes problems such as noise. Furthermore, the environment inside the tire house where such thrust ball bearings are used is extremely poor, with muddy water splashing around, and the steel seal plates becoming rusty, causing rust or dust to enter the rolling surfaces and cause damage. There was a problem.

Therefore, a unit has been proposed in which such a metal thrust ball bearing is housed in a synthetic resin case. An example of this is shown in the longitudinal sectional view of FIG. A thrust ball bearing 7 is a rolling element 4 held between bearing rings 1 and 2.
A lower case 13 made of synthetic resin containing the bearing ring 2 is sealed and covered by an upper case 12 made of synthetic resin containing the bearing ring 1.

Fig. 9 is a longitudinal cross-sectional view of a separate input suspension type suspension, showing an example of a suspension system of the McPherson strut type for an automobile, which uses a thrust ball bearing unit in which a thrust ball bearing is housed in a synthetic resin case, on the body side. Only shown. In FIG. 9, the upper mount 3 is fixed to the body 33 by a mounting bolt nut 47.
4, a shock absorber rod 37 is fixed to the rod end plate 32 via a rubber mount 35 by a nut 38 screwed into the rod 37. The upper mount 34 also serves as a bearing holder, and the upper case 12 is fitted into a cylindrical portion 45 of the upper mount 34. Thrust ball bearing unit lower case 1
The cylindrical part 4 of the spring seat 39 is located on the inner diameter of the spring seat 39.
1 is fitted into the spring seat 39, and one end of a coil spring 42 of the suspension device is fitted into the spring seat 39 via an elastic sheet 40 made of rubber or the like. coil spring 42
The other end is supported by a spring seat 44 provided on the shock absorber body 43.

Thrust ball bearings require strict dimensional accuracy, especially flatness and flatness, of the mating member that houses them, but in the above suspension system, the upper mount 34 is usually press-formed from sheet metal, so the above accuracy can be satisfied. There are few parts, and there is damage due to uniform stress concentration that causes partial impressions on the bearing rings 1 and 2 due to uneven contact. For this reason, some require a separate member with sufficient flatness and flatness to attach the upper mount 34.
Alternatively, there is also a structure arranged on a spring seat 39. In addition, in the case of the structure described above, since there is a bolt head of the bolt nut 47 that fastens the upper mount 34 and the body 33, the upper case 12 is provided with a recess 46, which results in uneven wall thickness and tends to warp due to manufacturing. There are drawbacks.

Therefore, as shown in FIG. 10, an annular groove 49 was provided in the upper case 12, and a number of radial protrusions 51 were provided around the center of the bearing, which were expanded along the circumference along the cross-sectional line A-A in FIG. As shown in FIG. 11, which is a cross-sectional view, there is one in which the bearing ring 1 is brought into contact with the protrusion 51. In this case, the protrusion 51 is eliminated from the portion where the bolt head for fastening the body 33 and the upper mount 34 is located, so that the wall thickness can be made uniform.

``Problems to be solved by the invention'' In the thrust ball bearing unit shown in Fig. 10, the surface of the upper case 12 in contact with the upper mount is flat, so uneven loads due to unevenness of the upper mount seating surface are Although the upper case 12 is made of synthetic resin, it is recognized that it is applied to the thrust ball bearing 7. These are the outer peripheral member 21 and inner peripheral member 21' of the upper case 12.
The protrusions 51 are continuous, and if the number of protrusions 51 is small, the bearing ring 1 receives a concentrated load even if it is uniform due to the protrusions 51 themselves. This is thought to be because it adapts to the unevenness of the upper mount and is less likely to deform.

Furthermore, if a thrust ball bearing unit such as this, which is housed in a synthetic resin case, is used in an input-separated suspension in which the bearing is placed directly on the body, rolling vibrations will occur due to the deformation of the bearing ring. Small rolling vibrations may be transmitted directly to the body.

Therefore, the applicant regarding the present invention first applied for a practical application in 1983.
No. 99740 proposed the ``Thrust Ball Bearing Unit'' to solve the above problems. Either one of the inventions of this earlier application shown as an embodiment, or a cushioning material interposed between both bearing rings and the case, is provided in the case and the groove has a rectangular cross section in the circumferential direction. A circular cushioning material with a rectangular cross section is fitted into the bottom and both sides of the case. However, when the cushioning material was made of rubber and tried to fit into the groove of the case, air was trapped in the bottom of the case, making it impossible to completely assemble it. It moves to the bottom side of the groove of the case, producing the same result as if the cushioning material were deformed due to cold flow. Therefore, in the invention of the above-mentioned earlier application, the width of the cushioning material (the difference in the inner and outer diameters in the radial direction) is shown in the examples as being smaller than the groove width of the case, but in this case, cold flow is less likely to occur. There is a problem in that the type of material and cushioning material must be selected.

The present invention solves the above-mentioned problems with thrust ball bearing units housed in synthetic resin cases and is easy to assemble, and also prevents the bearing ring from deforming and even if bearing vibration noise occurs. It is an object of the present invention to provide a thrust ball bearing unit in which rolling vibration noise is difficult to transmit to a mating member.

[Structure of the idea]

``Means for solving the problem'' This idea is designed to provide a solution between the synthetic resin upper and lower cases, the metal upper and lower bearing rings held in the upper and lower cases, and the raceway surfaces of the upper and lower bearing rings. The thrust ball bearing unit is a thrust ball bearing unit consisting of rolling elements arranged in the upper case, and the upper case has inner and outer cylindrical hanging parts each having a lower end lip at the tip on the outer periphery, and the lower case has a cylindrical hanging part on the inner periphery. , the upper case has inner and outer cylindrical protrusions each having an upper lip at the tip, and the upper case has a lower lip of the inner and outer cylindrical hanging portions which is connected to an upper lip of the inner and outer cylindrical protrusion of the lower case. The outer circumferential surface of the lower case is surrounded by elastically attached parts, and combined with the lower case, and a sealing part by a labyrinth action is formed in the elastic attached part, and one or both of the upper and lower cases. A circumferential groove with a rectangular cross section is provided on the inside of the case, and a buffer material is fitted into the groove so as to have a slight gap with the inner and/or outer side surfaces of the groove during assembly. and/or a lower bearing ring is arranged, and the minute
This is a thrust ball bearing unit characterized in that the gap is large enough to allow air to pass through during assembly and disappear due to elastic deformation of the buffer material due to static load after assembly.

"Operation" When inserting the cushioning material into the groove inside the synthetic resin case, the air in the space facing the bottom of the case of the cushioning material escapes from the space between the groove side of the case and the opposite side of the cushioning material. , the surface of the cushioning material facing the bottom of the case is seated. When a static load is applied to the thrust ball bearing unit during assembly, the cushioning material is elastically deformed, causing a small gap between the groove side surface and the side surface of the cushioning material.
The gap disappears, and the inner and outer circumferential surfaces of the cushioning material come into close contact with the inner and outer circumferential surfaces of the groove.

Even if the synthetic resin case deforms to accommodate the mating member, the cushioning material absorbs the deformation and does not deform the bearing ring. Even if an impact load is applied to the thrust ball bearing unit, the cushioning material absorbs it.
No impact load is applied to the thrust ball bearing. The rolling vibration of the thrust ball bearing is absorbed by the cushioning material and is not easily transmitted to the mounting member.

"Example" FIG. 1 is a longitudinal sectional view. Outer diameter of metal bearing ring 1 that is usually installed on the casing side
D ₁ is equal to the outer diameter D ₂ of the metal bearing ring 2, and the outer diameter D ₁ of the bearing ring 1 is made to be exactly concentric with the raceway surface 8 of the bearing ring 1. Bearing ring 2 usually fitted on the shaft side
The inner diameter d ₂ of the bearing ring 1 is equal to the inner diameter d ₁ of the bearing ring 1, and the inner diameter d 2 of the bearing ring 2
It is made exactly concentric with the orbital surface 9 of.

The end surface 5 of the bearing ring 1 and the end surface 11 of the bearing ring 2 form a plane perpendicular to the axis, and the corners between the end surfaces 5, 11 and the inner and outer peripheries that follow these surfaces are chamfered. The raceway surfaces 8 and 9 have an arcuate cross section with a radius slightly larger than the radius of the ball of the rolling element 4.
Both sides following the are finished smoothly with opposing planes perpendicular to the axis. The rolling elements 4 are held between raceway surfaces 8 and 9.

The lower bearing ring 2 is fitted into the upper circumferential groove 6 of the lower case 13 with an annular cushioning member 25 having a square cross section, and the upper bearing ring 1
is fitted into the inner cylindrical portion 24 of the upper case 12.

FIGS. 2 and 3 are partial radial cross-sectional views for explaining the relationship between the thrust ball bearing unit when it is assembled, ie, in an unloaded state, and when a static load is applied after assembly.

Figure 2 shows the circumferential groove 6 when assembled and under no load.
There is a distance δ between the side surface of the buffer material 25 and the side surface of the buffer material 25, and the distance δ is between the bottom of the circumferential groove 6 and the circumference of the buffer material 25 when the buffer material 25 is fitted into the circumferential groove 6. It is large enough to allow air in the space between the bottom of the groove 6 and the corresponding plane to completely escape, and this distance δ disappears under static load after assembly, as shown in Figure 3, and the circumferential groove 6
Both inner and outer sides of the cushioning material 25 are in close contact with each other.

The upper and lower cases 12 and 13 are both made of synthetic resin, such as polyacetal resin, polyamide resin, etc., and have an annular shape centered on the axis in the illustrated cross section except for the recess 46.

The upper and lower cases 12 and 13 are fitted to form a shaft seal such as a labyrinth seal or a contact seal on the inner and outer diameter sides. The shaft sealing portion on the inner diameter side is formed by a lip portion 15 at the tip of an inner cylindrical protrusion 14 provided on the inner periphery of the lower case 13, which tapers toward the shaft center, and the inner cylindrical hanging portion of the upper case 12. 16 is on the inner diameter side of the inner cylindrical protrusion 14 of the lower case, and there is a gap between the lip 15 of the inner cylindrical protrusion 14 of the lower case 13 and the inner cylindrical hanging part 16 of the upper case; The lip portion 15 and the inner cylindrical hanging portion 16 rub against each other.

At the tip of the inner cylindrical hanging portion 16 of the upper case, a lip portion 17 is provided which tapers toward the outer diameter side, and is close to or sliding against the inner cylindrical protrusion 14 of the lower case. The root side of the inner cylindrical protruding portion 14 of the lower case is thicker, and the inner diameter d ₄ of the inner periphery of the root is slightly smaller than the inner diameter d ₃ of the inner cylindrical hanging portion 16 of the upper case.

The shaft sealing portion on the outer diameter side is formed by bending the end of the outer peripheral cylindrical hanging portion 21 of the upper case 12 toward the inner diameter side to form a lip portion 22, which approaches the outer peripheral cylindrical protruding portion 23 in the circumferential direction of the lower case. A lip portion 20 is provided at the tip of the outer circumferential cylindrical projection portion 23. The inner diameter of the lip portion 22 is slightly smaller than the outer diameter of the lip portion 20.

As you can see from this explanation, the upper and lower cases 12 and 13
becomes integral when the shaft sealing part is pressed into place and assembled by elastic mounting.

The recess 46 is provided to prevent the bolt head of a bolt nut 47 shown in FIG. 10 for attaching the strut to the body from coming into contact with it. Depending on the structure of the strut, the bolt head may not come out onto the bearing surface of the thrust ball bearing, and in such a case, this recess 46 is not provided.

Figures 4 and 5 are partial radial cross-sectional views showing other embodiments of this invention. Figure 4 shows the no-load state during assembly, and Figure 5 shows the static load after assembly. This shows the added state. Cushioning material 25 of the previous example
During assembly, there is a gap between both side surfaces of the buffer material 25 and the circumferential groove 6, but in this embodiment, only the outer circumferential side surface of the buffer material 25 is connected to the circumferential groove 6 in the no-load state during assembly. The cushioning material 2 has a slight distance δ between the side surface and the side surface, which serves as an air vent that performs the same function as in the previous embodiment, and allows the two side surfaces to come into close contact with each other in the static load state after assembly.
The inner peripheral side surface of the groove 5 is in close contact with the side surface of the circumferential groove 6.
The parts other than this difference are the same as the previous embodiment. This embodiment has the advantage that the center of the buffer material 25 correctly coincides with the center of the circumferential groove 6 from the beginning.

FIGS. 6 and 7 each show another embodiment for achieving the object of this invention. In this embodiment, each of the cushioning materials 25 is shown in a perspective view, and in FIG.
In the figure, the same groove 26 is provided on the inner periphery.
The cushioning material 25 of this embodiment is dimensioned to be in close contact with the bottom, inner and outer surfaces of the circumferential groove 6, and the portion of the groove 26 where the cushioning material 25 is provided in the no-load state during assembly. Only minute gaps are formed. The rest is the same as the previous embodiment, and the buffer material 25 is elastically deformed in a static load state after assembly, and the slight gap disappears.

In the embodiment, the circumferential groove 6 was provided in the lower case 13, but the circumferential groove 6 was provided in the upper case 12, and also in the upper and lower cases 12 and 13, and the cushioning material 25 was fitted into the circumferential groove 6, and the thrust ball It may also carry bearings.

[Effect of idea]

This device consists of a synthetic resin upper and lower case, metal upper and lower bearing rings held in the upper and lower cases, and rolling elements arranged between the raceway surfaces of the upper and lower bearing rings. The ball bearing unit is a ball bearing unit, wherein the upper case has inner and outer cylindrical hanging parts having lower lip parts at the tips on the inner and outer edges thereof, and the lower case has upper lip parts at the tips on the inner and outer edges thereof. The upper case has inner and outer cylindrical protrusions, and the lower end lip of the inner and outer cylindrical hanging parts surrounds the outer circumferential surface of the upper end lip of the inner and outer cylindrical protrusion of the lower case, respectively. It is mounted and combined with the lower case, and a sealing part is formed in the elastic mounting part by a labyrinth effect, and a circumference having a rectangular cross section is formed inside one or both of the upper and lower cases. A groove in the direction is provided, and the upper and/or lower bearing rings are arranged in the groove through a buffer material fitted so as to have a slight gap with the inner or outer side surface of the groove during assembly, Since the thrust ball bearing unit is characterized in that the minute gap is large enough to allow air to pass through during assembly and disappear due to elastic deformation of the buffer material due to static load after assembly, (1) The cushioning material can be easily inserted into the groove of the case during assembly.

(2) After assembly, under static load due to vehicle weight, the cushioning material is in close contact with the groove in the case of the bearing unit, and cold flow does not occur in the cushioning material. Furthermore, the life of the cushioning material against repeated loads is significantly improved.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of an embodiment of this invention;
3 shows a part of FIG. 1 and is a vertical sectional view showing the operation, FIGS. 4 and 5 are longitudinal sectional views showing the operation of other embodiments, and FIGS. 6 and 7 are 8 to 11 show conventional examples, FIG. 8 is a vertical cross-sectional view of a thrust ball bearing in a synthetic resin case, and FIG. 9 is a thrust ball bearing in a synthetic resin case. Fig. 10 is a vertical cross-sectional view showing another conventional example.
FIG. 11 is a developed cross-sectional view taken along the line AA in FIG. 10. 1, 2... Raceway ring, 4... Rolling element, 5... End face, 6... Circumferential groove, 7... Thrust ball bearing, 8, 9... Raceway surface, 10... Cylindrical part, 11
... End face, 12 ... Upper case, 13 ... Lower case, 14 ... Inner circumference cylindrical protruding part, 15 ... Lip part, 16 ... Inner circumference cylindrical hanging part, 17, 20 ... Lip part, 21 ... ...Outer circumference cylindrical hanging part, 21'...Inner circumference member, 22...Rip part, 23...Outer circumference cylindrical protrusion part, 24...Inner cylindrical part, 25...Buffer material, 26
...Groove, 32...Rod end plate, 33...
...Body, 34...Upper mount, 35...
Rubber mount, 37...Shock absorber rod, 38...Nut, 39...Spring seat, 40...Elastic seat, 41...Cylindrical part, 4
2... Coil spring, 43... Shock absorber body, 44... Spring seat, 45... Cylindrical part, 46
... recess, 47 ... bolt nut, 49 ... annular groove, 51 ... protrusion, D ₁ , D ₂ ... outer diameter, d ₁ to _{d 4} ...
...inner diameter.

Claims (1)

[Claims for Utility Model Registration] Upper and lower cases 12 and 13 made of synthetic resin;
A metal top held in the lower case 12, 13,
This is a thrust ball bearing unit consisting of lower bearing rings 1 and 2 and rolling elements 4 arranged between raceway surfaces 8 and 9 of the upper and lower bearing rings 1 and 2, and the upper case 12 has inner and outer parts. The lower case 13 is provided with inner and outer cylindrical hanging parts 16 and 21 having lower end lip parts 17 and 22 at the tips, respectively, on the outer periphery thereof, and upper end lip parts 15 and 2 at the tips, respectively, on the outer periphery thereof.
The upper case 12 is provided with inner and outer cylindrical protruding parts 14 and 23 having inner and outer circumferential cylindrical hanging parts 1.
The lower end lip portions 17 and 22 of the lower case 13 surround the outer peripheral surfaces of the upper end lip portions 15 and 20 of the outer cylindrical protrusions 14 and 23 and are elastically attached to the lower case 13 and assembled with the lower case 13, respectively. The upper and lower cases 12,
A circumferential groove 6 having a rectangular cross section is provided on the inside of one or both cases of 13, and the case is fitted into the groove 6 so as to have a slight gap with the inner and/or outer side surfaces of the groove during assembly. Combined buffer material 25
The upper raceway ring 1 and/or the lower raceway ring 2 are disposed through the spacer, and the minute gap is large enough to allow air to pass through during assembly and disappear due to elastic deformation of the cushioning material due to static load after assembly. A thrust ball bearing unit characterized by: