FR2836965A1 - Integral type thrust bearing has flanges, provided on inner-diameter side of inner ring and outer-diameter side of outer ring, which restrict radial gap in bearing to prevent bearing rings and retainer separating from each other - Google Patents

Abstract

The bearing includes a retainer (2) formed with pockets for radially housing multiple rollers, and inner and outer rings (3,4) having flanges (4a) on their inner-diameter side and outer-diameter side, respectively. The flanges restrict a radial gap in the bearing, so that both bearing rings and retainer are inseparable from each other. The bearing rings and retainer are assembled together with rollers into a bearing body with the bearing rings and retainer not hardened, thus the bearing body is subjected to carburizing, hardening and tempering.

Description

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BEARING BEARING
The present invention relates to an integral thrust bearing model in which a bearing ring and a cage for accommodating rollers are mounted inseparably.

 Among the thrust bearings, there is an integral model in which the races and the cage for housing rollers are mounted inseparable so that the thrust bearing can be easily mounted in a housing or on a shaft.

 FIGS. 10A and 10B show an example of such a model of integral thrust bearing. It is a three-part model provided with a cage 2 for radially accommodating a plurality of rollers 1, an inner ring 3 provided with a flange 3a on its inner diameter face, and an outer ring 4 provided with a flange 4a on its outer diameter face. The inner and outer edges of the cage 2 are engaged by forks 5 protruding from the outside and forks 6 protruding from the inside formed by stapling the ends of the flanges 3a and 4a, respectively, so that the inner and outer rings 3 , 4 and the cage 2 are inseparable from each other. Among the models of integral thrust bearings, there are two-piece models which comprise only one of the two inner and outer rings and whose cage is inseparable from the inner or outer ring.

 In these models of integral thrust bearings, the bearing rings, the cage and the rollers are previously heat-treated, and are then assembled into a unitary unit. In general,

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 Bearing rings and the cage undergo carburizing, hardening and tempering after forming.

The rolls are cured and are tempered after rough forming and are then finished sanding. The cage is sometimes soft nitrided instead of carburizing, hardening and tempering.

 With such a model of conventional fixed abutment bearing, since the bearing rings, the cage and the rollers are heat-treated individually before assembly, the heat treatment steps are more numerous, which increases the cost of the heat treatment. In addition, the manufacturing time tends to be long with regard to the steps of setting the heat treatment for each respective element.

 So that even in the case of an increase of the radial gap in the bearing, the races and the cage can be inseparable in order to increase the eccentricity tolerance of an integral thrust bearing model, the present Applicant JP patent application 2001-272336 proposes to form the flanges of the bearing rings by folding rather than stapling, thereby increasing the values of overtaking of the forks. In order to form these forks protruding in a known manner by folding, such folding must be carried out after assembly of the cage. Thus, during the heat treatment of the bearings, it is necessary to prevent the hardening of the parts to be bent, or to add a step of annealing the folded parts after heat treatment.

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 One of the objects of this invention is to reduce the heat treatment steps during the manufacture of the integral bearing stop model.

 According to this invention, there is provided a thrust bearing comprising a cage formed of pockets for radially accommodating a plurality of rollers, and at least one of an inner ring provided with a flange on its inner diameter face and a outer ring provided with a flange on its outer diameter face, the flange preventing the formation of a radial gap in the thrust bearing, so that the bearing ring and the cage can not be separated from each other , characterized in that after assembly of the bearing ring and the cage with the rollers in a bearing, the bearing ring and the cage are not sintered, the abutment bearing thus formed undergoes carburizing, hardening and income. By this method, it is not necessary to thermally treat the bearing ring and the cage individually, thus reducing the heat treatment steps of the bearings. For the rollers, they may be of those that have been heat treated before assembly of the bearing or those that have not been heat treated.

 According to the invention, the forks are formed by stapling or folding the ends of the flanges of the inner or outer ring so that they protrude towards the cage and engage the outer or inner circumferential edge of the cage, the bearing ring and the cage are inseparable by means of the forks.

 The cage can be made from a thin steel plate and the radial section of the pockets of

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 Roller housing can be W-shaped or inverted V so that the cage is not expensive.

 If the cage is formed with pockets having an inverted V-shaped radial section, the radial center of the roller guide surfaces on both sides of the inverted V-shaped pockets is substantially compressed to form forks. plastic flow roll stop protruding from the interior of the pockets from the respective surfaces of the roller guide. The roller stop forks are used to prevent the rollers from coming out of the bearing assembly. In particular, for a two-element abutment bearing design in which the pockets are open on one side, they are also effective in preventing the rolls from exiting during carburizing, hardening and tempering after bearing assembly. .

 By forming notches to receive excess plastic flow material from the compression formed cage on both sides of the roller guide surface portion where the roller stopper fork is to be formed, it is It is possible to prevent localized wear of the rolls by eliminating the formation of excess plastic flow material on the surfaces of the roll guide.

 Other features and objects of the present invention will become apparent from the following description referring to the attached figures, in which: Figure 1A is a plan view showing a thrust bearing according to the first embodiment; Figure 1B is a longitudinal sectional view thereof;

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 Figure 1C is a front view showing the forks of the outer ring of the thrust bearing of Figure 1A before folding; Figure 2A is a plan view of the thrust bearing cage of Figure 1; Figure 2B is a longitudinal sectional view of the cage of Figure 2A; Fig. 3A is a partially enlarged bottom view of the cage of Fig. 2A; Fig. 3B is a sectional view along the line IIIb-IIIb of Fig. 3A; Figure 3C is a sectional view along the line IIIc-IIIc of Figure 3A; Figure 4 is a longitudinal sectional view showing a modified example of the thrust bearing of Figure 1; Fig. 5A is a plan view showing the bearing according to a second embodiment; Figure 5B is a longitudinal sectional view thereof; Fig. 6A is a plan view showing the thrust bearing according to a third embodiment; Figure 6B is a longitudinal sectional view thereof; Fig. 7 is a longitudinal sectional view showing a modified example of the thrust bearing of Fig. 6; Fig. 8A is a plan view showing the thrust bearing according to a fourth embodiment; Figure 8B is a longitudinal sectional view thereof; Fig. 9A is a plan view showing the thrust bearing according to a fifth embodiment;

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 Figure 9B is a longitudinal sectional view thereof; Fig. 10A is a plan view showing a conventional thrust bearing; and Fig. 10B is a longitudinal sectional view thereof.

 Below, with reference to Figures 1 to 9, embodiments of this invention are described. Figures 1 to 3 show the first embodiment. This thrust bearing is, as shown in FIGS. 1A and 1B, a three-part model provided with a cage 2 for accommodating a plurality of rollers 1, an inner ring 3 having a flange 3a on its diameter face. inside, and an outer ring 4a on its outside diameter face. A radial gap in the bearing is set at a large value so that the inner and outer peripheral surfaces of the cage 2 do not come into contact with the flanges 3a or 4a even if a marked eccentric rotation occurs.

 The inner ring 3 and the outer ring 4 have their own flanges 3a and 4a formed by pressing thin steel plates (SPC or SCM). At the end of the flange 4a of the outer ring 4, a plurality of forks 6 are formed by folding to protrude from the inside a greater distance than the inner gap of the bearing. These forks 6 engage the outer peripheral edge of the cage 2 so that the cage 2 and the outer ring 4 are inseparable. Each fork 6 has its thickness reduced beforehand by the formation of a step facilitating folding. As shown in FIG. 1C, on both sides of the base of

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 each fork 6, cutouts are formed. The cage 2 and the inner ring 3 are rendered inseparable by the outer forks 5 formed by stapling at the end of the flange 3a.

r
Tel que représenté sur les figures 3A, 3B et 3C, sur des parties sensiblement centrales de manière radiale des surfaces du guidage à rouleaux 8 sur les deux faces de chacune des poches en forme de V inversé 7, les fourches d'arrêt des rouleaux 9 qui dépassent de l'intérieur des surfaces du guidage à rouleau 8 sont formées par écoulement plastique par compression de ces parties. Sur les deux faces de celles-ci, des encoches 10 sont formées afin de recevoir l'excès de matériau de l'écoulement plastique provoqué par compression. Ainsi, les rouleaux 1, qui sont logés dans les poches respectives 7, ne peuvent sortir des fourches d'arrêt des rouleaux 9 sur les deux faces, et sont guidés par les surfaces lisses de guidage à rouleau 8 qui sont exemptes de gonflage formé par un excès de matériau. Ainsi leur vie ne sera par réduite par une usure localisée. The cage 2 is formed by pressing a thin steel plate (SPC). As shown in Figures 2A and 2B, the pockets 7 of the cage 2 for receiving the rollers 1 radially have an inverted V-shaped radial section, and the outer and inner peripheral edges of the cage 2 which engage the forks 5 and 6 respectively are flat.

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As shown in FIGS. 3A, 3B and 3C, on substantially radially central portions of the surfaces of the roller guide 8 on both sides of each of the inverted V-shaped pockets 7, the roll stop forks 9 protruding from the inside of the surfaces of the roller guide 8 are formed by compression plastic flow of these portions. On both sides thereof, notches 10 are formed to receive excess material from the plastic flow caused by compression. Thus, the rollers 1, which are housed in the respective pockets 7, can not come out of the stop forks of the rollers 9 on both sides, and are guided by the smooth roller guide surfaces 8 which are free of inflation formed by an excess of material. Thus their life will not be reduced by localized wear.

 After assembly into a unitary unit as shown in Figures 1A and 1B, the thrust bearing is cemented in a carburizing atmosphere, hardened in oil and returned. The rollers 1, which are formed

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 from a bearing steel (SUJ2), undergo hardening and tempering before assembly of the bearing.

 The abutment bearings of the embodiments below and modified examples undergo, as in the first embodiment, carburizing, hardening and tempering after assembly, and the materials of the parts are identical to those of the first embodiment.

 Fig. 4 shows a modification of the first embodiment. It differs in that the cage is made in the form of W in radial section by stamping. The shapes of the rollers 1, inner and outer rings 3,4 are identical to those of the first embodiment.

 Figures 5A and 5B show the second embodiment. It is also a three-part model, it differs in that the forks 5 and 6 placed at the ends of the flanges 3a and 4a of the inner and outer rings 3,4 are formed by stapling.

Apart from this, it is identical to the first embodiment.

 Figs. 6A and 6B show the third embodiment. This is a two-part model provided with a cage 2 for radially accommodating a plurality of rollers 1 and an inner ring 3 provided with a flange 3a at the end of its inside diameter. At the end of the flange 3a of the inner ring 3, a fork 5 protruding from the outside is formed over the entire circumference. The fork 5 engages the inner peripheral edge of the cage 2 so that the cage 2 and the inner ring are inseparable. The thickness of

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 forks 5 is reduced beforehand by forming a step facilitating folding.

 Like the first embodiment, the cage 2 is provided with pockets 7 having their radial section made in the form of inverted V by stamping. Although not shown, on substantially radially central portions of the surfaces of the roller guide 8 on both sides of each pocket 7, forks projecting from the inside 9 are formed. On both sides thereof, the notches 10 for receiving the excess material are formed. Figure 7 shows a variant of the third embodiment. It differs in that the shape of the radial section of the cage 2 is W-shaped by stamping. The shapes of the rollers 1, inner and outer rings 3,4 are identical to that of the third embodiment.

 Figures 8A and 8B show the fourth embodiment. It is a two-part model provided with a cage 2 for radially accommodating a plurality of rollers 1, and an outer ring 4 provided with a flange 4a on its outer diameter face.

The forks protruding from the inside 6 are partially formed at the end of the flange 4a. the forks 6 engage the outer peripheral edge of the cage 2 so that the cage 2 and the outer flange 4 are inseparable from each other. The cage 2 is identical to that of the first embodiment, and the radial section of each pocket 7 is made V-shaped inverted by stamping.

 Figs. 9A and 9B show the fifth embodiment. It is also a two-element model and differs from the third mode of

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 in that the forks 5 at the end of the flange 3a provided on the inner diameter face of the inner ring 3 are formed by stapling.

On the other hand, it is identical to the third embodiment.

 With respect to the bearings of the embodiments described above, both the bearing ring or the rings and the cage are formed by stamping thin steel plates. But either can be formed by machining steel material.

 The example and the comparative example are presented below.

(Example)
The thrust bearings that have been prepared correspond to a three-element model shown in FIG. 1 and having been carburized / hardened and returned after assembly.

As for the heat treatment conditions, they were case hardened by maintaining them at 850 ° C. for 35 minutes in a carburizing atmosphere, quenched with oil and experienced an income at 1650 ° C. for 60 minutes.

The rollers 1 used were preliminarily oil soaked at 840 C for 30 minutes, and then were tempered at 180 OC for 90 minutes. The dimensions of the bearing are as follows: internal diameter: 56 mm, outer diameter: 76 mm and thickness: 4.8 mm.

(Comparative example)
The abutment bearings that have been prepared correspond to a three-element model shown in FIG. 10, the respective elements of which have been heat-treated individually before assembly.

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In consideration of the heat treatment conditions, the rolls 1 were oil quenched at 840 ° C for 30 minutes, and then were tempered at 180 ° C for 90 minutes. Cage 2 was nitrated gently at 5800C for 35 minutes. The inner and outer rings 3,4 were case hardened by holding them at 8500C for 60 minutes in a carburizing atmosphere, oil quenched, and then sustained at 165 OC for 60 minutes.

The dimensions of the bearing and the number of rollers 1 are identical to those of the example.

 For the thrust bearings of the example and the comparative example, a running time test was conducted. During the running time test, the inner ring 3 was mounted on the rotating face and the outer ring 4 on the fixed face, they were mounted on a bearing rotation test bench and the test was carried out. for the two cases, in the following conditions, a case in which the eccentricity of the axis existed and the other for which it did not exist.

For the example and the comparative example, the number of samples was ten, and the running time was evaluated in terms of life L10 (for which 90% of the samples can be used without being destroyed).

Axial effort: 4300 N
Rotation speed: 3000 rpm
Eccentricity of the axis: 0.0 mm, 0.5 mm
Lubricating oil: ATF (automatic transmission fluid).

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TABLEAU 1

TABLE 1

<Tb>
<tb> Example
<tb> Example <SEP> Example
<tb> comparative
<tb> Surface <SEP> 765 <SEP> 700-800
<tb> - <SEP> Roll
<tb> Interior <SEP> 790 <SEP> 700-800
<tb> Hardness <SEP> Surface <SEP> 730 <SEP> 380-500
<tb> Cage
<tb> Vickers <SEP> Inside <SEP> 175 <SEP> 150-220
<tb> Rings <SEP> inner <SEP> Surface <SEP> 710 <SEP> 650-800
<tb> and <SEP> outside <SEP> Inside <SEP> 380 <SEP> 350-500
<tb> Proportion <SEP> No <SEP> of axis <SEP> of eccentricity <SEP> 1,1 <SEP> 1,0
<tb> of <SEP> life <SEP> Existing <SEP><SEP> Axis <SEP><SEP> 1.0 <SEP> 0.5
<Tb>

The results are shown in Table 1.

The running times of the example and of the comparative example are represented in terms of proportion of life compared with the duration L10 of the comparative example in the absence of eccentricity of the axis of rotation. In Table 1, the Vickers Hv hardnesses on the surface and inside the bearing elements are also shown. The Hv hardnesses of the respective parts of the example do not differ much from those of the comparative example for which the parts have been heat treated individually.

The hardness Hv of the parts of the example are the values actually measured on this occasion. The hardnesses Hv of the parts of the comparative example, which is a conventional article, are the values obtained previously.

 The results of the test indicate that the rolling times of the abutment bearings of the example are substantially equal to the running time of the comparative example, despite the existence or not of axial eccentricity. Thus it has been confirmed that

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 Rolling time equivalent to that of conventional articles can be achieved even if the heat treatment steps are reduced by carburizing, hardening and post-assembly income. The reason why, in the comparative example, when the eccentricity of the axis existed, the running time decreased by half is due, as described above, for conventional articles, that the cage had a inseparable by the forks formed by stapling, thus the radial gap in the bearing was reduced.

 As described above, in the abutment bearing of this invention, after assembly of the bearing rings and cage with the rollers in a bearing provided with unsintered rings and cage, the thus assembled bearing undergoes carburizing, hardening and income. Thus, it is not necessary to heat treat the bearing rings and the cage individually, and it is possible to reduce the steps of heat treatment of the bearing and thus considerably reduce the cost of manufacture. Also, the manufacturing steps are simplified, so that it is possible to reduce the manufacturing time.

Claims (5)

1. Thrust bearing comprising a cage (2) provided with pockets (7) for radially accommodating a plurality of rollers (1), and at least one inner ring (3) provided with a flange (3a) on its an inner diameter face and an outer ring (4) provided with a flange (4a) on its outer diameter face, said flange preventing the formation of a radial gap in the thrust bearing, so that said bearing ring and said cage are inseparable from one another, characterized in that after assembly of said bearing ring and said cage with said rollers in a bearing with the aid of said rolling ring and said cage uncured, the bearing thus assembled undergoes carburizing, hardening and tempering.  A thrust bearing according to claim 1, wherein the forks (6) are formed by stapling or folding at the end of said flange of said inner or outer ring to protrude towards said cage (2) and engage the inner or outer peripheral edge of said cage, and said bearing ring and said cage are inseparable from each other by means of said forks (6).  3. Rolling bearing according to claim 1 or 2, wherein said cage (2) is composed of a thin steel plate, and the radial section of said pockets (7) for accommodating said rollers (1) is shaped W or inverted V.  The thrust bearing according to claim 3, wherein said pockets (7) of said cage (2) are V-shaped inverted in radial section, the material of <Desc / Clms Page number 15>  the cage substantially at the radial center of the surfaces of the roller guide on both sides of said inverted V-shaped pockets is compressed to form plastic flow stop forks protruding from the interior of said pockets from the respective surfaces of the guide to roller.  The thrust bearing of claim 4, wherein on both sides of the portion of said roller guide surfaces where said roller stopper fork is to be formed, notches (10) are formed to receive the excess material of said cage which undergoes plastic flow by compression.