JP2009174669A - Self-alignment roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a self-alignment rolling bearing capable of preventing any skew of a plurality of spherical rollers 4, 4 during the operation, reducing the friction at rolling contact parts of the spherical rollers 4, 4 an outer ring raceway 7 and a pair of inner ring raceways 8, 8 with each other, and reducing the friction heat generated during the operation. <P>SOLUTION: The axial elastic force is imparted to a pair of holders 5b, 5c and the spherical rollers 4, 4 by an elastic member 21 provided in an annular space 20a between side faces in the axial direction opposite to the axial direction of rim parts 9a, 9a constituting the holders 5b, 5c. The postures of the spherical rollers 4, 4 are regulated thereby. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an improvement in a self-aligning roller bearing that is incorporated in various mechanical devices and supports a rotating shaft inside a housing, for example. Specifically, a plurality of spherical rollers are prevented from skewing during operation, and friction is reduced at the rolling contact portion between the rolling surface of each spherical roller and the outer ring raceway and the inner ring raceway.

  For example, in order to rotatably support a heavy shaft on the inside of a housing, a self-aligning roller bearing as described in Patent Documents 1 and 2 has been used. FIG. 5 shows a self-aligning roller bearing 1 that has been widely known so far, as described in Patent Documents 1 and 2, for example. The self-aligning roller bearing 1 includes a plurality of spherical rollers 4 and 4 arranged in a freely rollable manner between an outer ring 2 and an inner ring 3 that are concentrically combined with each other. The cage 5 and the guide wheel 6 regulate the position and posture of each of the spherical rollers 4 and 4.

  An outer ring raceway 7, which is a spherical concave surface having a single center, is formed on the inner peripheral surface of the outer ring 2. Further, a pair of inner ring raceways 8 and 8 are formed on both sides of the outer peripheral surface of the inner ring 3 in the width direction (left and right direction in FIG. 5). Further, the plurality of spherical rollers 4 and 4 are beer barrel types having a maximum diameter portion in an axially intermediate portion of each spherical roller 4 or 4 (generally, a symmetrical shape in which the maximum diameter portion is in the axial center portion). ) Between the outer ring raceway 7 and the pair of inner ring raceways 8, 8.

  The cage 5 was made as a whole by cutting a metal material having self-lubricating properties such as a copper-based alloy such as brass, or by injection molding a synthetic resin. It is provided with an annular rim portion 9 and a plurality of column portions 10 and 10 protruding in opposite directions from both axial side surfaces of the rim portion 9. Then, pockets 11 and 11 for holding the respective spherical rollers 4 and 4 are respectively surrounded by three sides by the side surfaces of the column portions 10 and 10 adjacent to each other in the circumferential direction and the side surface in the axial direction of the rim portion 9. It is said.

  Further, the guide wheel 6 is formed in an annular shape as a whole by a material having a low coefficient of friction such as a self-lubricating metal such as a copper-based alloy, an oil-impregnated metal, or a synthetic resin. The guide wheel 6 has a trapezoidal cross section with an axial width that is larger on the outer diameter side and smaller on the inner diameter side, and has an inner diameter that is slightly larger than the outer diameter of the intermediate portion in the axial direction of the inner ring 3. It has an outer diameter that is slightly smaller than the inner diameter of the rim portion 9. Such a guide wheel 6 is disposed between the inner peripheral surface of the inner ring 3 and the inner peripheral surface of the rim portion 9 so as to be able to rotate relative to the inner ring 3 and the rim portion 9. In this state, both side surfaces 12 and 12 of the guide wheel 6 in the axial direction are the inner end surfaces in the axial direction of the spherical rollers 4 and 4 (“inner” in the axial direction means the center side in the width direction of the self-aligning roller bearing 1. On the contrary, the outer side in the width direction of the self-aligning roller bearing 1 is referred to as “outer” with respect to the axial direction, which is the same throughout the present specification. The planes connecting each other are parallel).

  For example, when the rotating shaft is supported inside the housing by the self-aligning roller bearing 1 configured as described above, the outer ring 2 is fitted and fixed to the housing, and the inner ring 3 is fixed to the rotating shaft. When the inner ring 3 rotates together with the rotating shaft, the spherical rollers 4 and 4 roll to allow this rotation. When the shaft center of the housing and the shaft center of the rotary shaft do not match, the inner ring 3 is aligned inside the outer ring 2 (the central axis of the inner ring 3 is inclined with respect to the central axis of the outer ring 2). To compensate for this discrepancy. In this case, since the outer ring raceway 7 is formed in a single spherical shape, the rolling of the spherical rollers 4 and 4 is performed smoothly even after the mismatch compensation. The postures of the spherical rollers 4 and 4 are controlled based on the engagement between the axial inner end surfaces 13 and 13 and the axial side surfaces 12 and 12 of the guide wheel 6. That is, the skew in which the rotation center axes of the spherical rollers 4 and 4 are deviated from their original positions is suppressed, and the rolling surfaces of the spherical rollers 4 and 4 and the outer ring raceway 7 and the inner ring raceways 8 and 8 roll. Reduce friction at the contact area.

The conventional self-aligning roller bearing 1 includes inner surfaces 15 and 15 of flanges 14 and 14 formed at both ends in the axial direction of the outer peripheral surface of the inner ring 3 constituting the self-aligning roller bearing 1 and the guide wheel 6. The distance between the axial side surfaces 12 and 12 is designed to be larger than the axial length of the spherical rollers 4 and 4. That is, in the assembled state of the self-aligning roller bearing 1, the portion between the axial side surfaces 12, 12 and the axial inner end surfaces 13, 13 of the spherical rollers 4, 4 and the flanges 14 are provided. , 14 and an axial gap is provided in at least one of the portions between the inner side surfaces 15, 15 of the spherical rollers 4, 4 and the portions between the axial outer end surfaces 16, 16 of the spherical rollers 4, 4.
The reason for this is that the distance between the side surfaces 12 and 12 in the axial direction of the guide wheel 6 and the inner surfaces 15 and 15 of the flange portions 14 and 14 formed at both ends in the axial direction of the outer peripheral surface of the inner ring 3 This is because when the spherical roller bearing 1 is assembled, the spherical rollers 4 and 4 cannot be inserted between the both side surfaces 12 and 15 when the self-aligning roller bearing 1 is assembled.

  However, during operation of the self-aligning roller bearing 1, the portions between the axial side surfaces 12, 12 of the guide wheel 6 and the axial inner end surfaces 13, 13 of the spherical rollers 4, 4, If there is a gap in the axial direction between at least one of the inner side surfaces 15 and 15 of the flange portions 14 and 14 and the portion between the outer circumferential surfaces 16 and 16 of the spherical rollers 4 and 4, These spherical rollers 4 and 4 can be displaced by the gap. When the displacement of each of the spherical rollers 4 and 4 appears as a skew, the sliding friction at the rolling contact portion between the rolling surface of each of the spherical rollers 4 and 4 and the outer ring raceway 7 and the inner ring raceways 8 and 8 is obtained. Increases the frictional heat.

Therefore, there is a self-aligning roller bearing structure described in Patent Documents 3 to 4 as a structure considering the above-described problems.
FIG. 6 shows the structure of the self-aligning roller bearing 1a described in Patent Document 3. In this self-aligning roller bearing 1a, a pair of outer rings 2a, 2b is connected to the axial outer end faces 17, 17 of both outer rings 2a, 2b, and the axial inner end faces 18, 18 of both outer rings 2a, 2b are connected to each other. In order to make a match, they are assembled in the axial direction with the preloads F facing each other. The preload F applied to the outer rings 2a and 2b is transmitted to the spherical rollers 4 and 4, and the spherical flanges 4 and 4 are connected to the central collar portion formed in the central portion in the axial direction of the inner ring 3a. 19, the spherical rollers 4, 4 are positioned in the axial direction during operation to suppress the occurrence of skew.

  In the case of the self-aligning roller bearing 1a described in Patent Document 3, the dimensions and shape of each part and the position of the outer rings 2a and 2b in the axial direction unless the preload F is set to an appropriate value. The relationship may be inappropriate. Further, based on the radial load, there is a possibility that the center axes of the outer rings 2a and 2b are not coincident with each other. In any case, the outer ring raceways 7a and 7b formed on the inner peripheral surfaces of the two outer rings 2a and 2b do not exist on the single spherical surface, and the aligning property of the self-aligning roller bearing 1a is impaired. Can be considered.

  FIG. 7 shows the structure of the self-aligning roller bearing 1b described in Patent Document 4. This self-aligning roller bearing 1b has a pair of annular guide wheels 6a, 6a between the central projection 24 of the inner ring 3b and a pair of cages 5a, 5a, with the inner surfaces in the axial direction facing each other. Provided. Further, a wave washer 22, which is an elastic member that elastically expands and contracts the axial dimension, is provided in the annular gap 20 between the axially inner side surfaces of the two guide wheels 6 a, 6 a facing each other. The wave washer 22 gives an axially outward elastic force to the guide wheels 6a and 6a. The elastic force causes the side surfaces of the guide wheels 6a, 6a and the axial inner end surfaces 13, 13 of the spherical rollers 4, 4 to engage with each other during the operation of the self-aligning roller bearing 1b. Therefore, the spherical rollers 4 and 4 are positioned in the axial direction to suppress skew.

  In the case of such a self-aligning roller bearing 1b described in Patent Document 4, the guide wheels 6a and 6a pressed by the elastic force of the wave washer 22 are used in the axial direction of the spherical rollers 4 and 4 respectively. Of the inner end faces 13, 13, the inner portion (the lower portion in FIG. 7) is pressed in the radial direction of the outer ring 2 and the inner ring 3b. In this part, the lengths of the axial inner end surfaces 13 and 13 of the spherical rollers 4 and 4 with respect to the circumferential direction of the outer ring 2 and the inner ring 3b (front and rear direction in FIG. 7) are short. It is difficult to secure the length and the pressing area in the circumferential direction of the facing portion between the guide 13 and the side surfaces of the both guide wheels 6a, 6a. If it is difficult to secure the length and the pressing area, the effect of preventing the skew of the spherical rollers 4 and 4 is reduced.

Japanese Patent Laid-Open No. 11-30232 JP 2000-352418 A JP 2005-9669 A JP 2001-82467 A

  In view of the circumstances as described above, the present invention prevents a plurality of spherical rollers from skewing during operation, and friction at the rolling contact portion between the rolling surface of each spherical roller and the outer ring raceway and the inner ring raceway. The present invention has been invented to achieve a structure that can reduce the frictional heat generated during the operation of the self-aligning roller bearing as the whole self-aligning roller bearing.

A self-aligning roller bearing that is an object of the present invention includes an outer ring, an inner ring, a plurality of spherical rollers, and a pair of cages.
Among these, the outer ring has an outer ring raceway which is a spherical concave surface having a single center on the inner peripheral surface.
The inner ring has a pair of inner ring raceways opposed to the outer ring raceway on the outer peripheral surface.
Each of the spherical rollers is provided between the outer ring raceway and the inner ring raceways so as to roll in two rows.
Each of the pair of cages includes a plurality of pockets for holding the spherical rollers in a rollable manner.

In particular, in the self-aligning roller bearing of the present invention, the axial dimension is elastically set in the annular gap between the mutually facing side surfaces of the pair of cages. An elastic member for expanding and contracting is provided.
When carrying out the present invention as described above, for example, as in the second aspect of the present invention, both the cages are provided with an annular rim portion and a plurality of column portions. . Each of the column portions has one end portion coupled to one side surface in the axial direction of the rim portion at equal intervals in the circumferential direction and the other end portion as a free end not coupled to the other portion. Further, a portion surrounded by the one side surface of the rim portion and the circumferential side surface of each column portion adjacent in the circumferential direction is a pocket for holding the spherical rollers in a rollable manner. Then, the two cages are combined in the axial direction in a state in which the side surfaces opposite to the side surfaces to which the column portions are coupled are opposed to each other among the axial side surfaces of the respective rim portions.

  Further, when the invention described in claims 1 and 2 is carried out, for example, the elastic member may be a wave washer or the invention described in claim 4 as in the invention described in claim 3. Similarly, let it be a disc spring.

As described above, according to the self-aligning roller bearing of the present invention, the two cages are provided by the elastic member provided in the annular gap between the side surfaces facing each other among the axial side surfaces of the pair of cages. An elastic force that is outward in the axial direction is applied. And by this elastic force, each pocket of these both cages and the axial direction inner end surface of each said spherical roller are engaged.
In this way, if the skew of each spherical roller in the operation of the self-aligning roller bearing is suppressed, the rolling contact portion between the rolling surface of each spherical roller and the outer ring raceway and the inner ring raceway is based on this skew. Therefore, it is possible to suppress an increase in the slip factor. Therefore, the amount of heat generated during the operation of the entire self-aligning roller bearing can be suppressed, and the self-aligning roller bearing can be operated at a higher speed and the durability can be improved.

[First example of embodiment]
1 to 3 show a first example of an embodiment of the invention corresponding to all the claims. The feature of the present invention including this example is that the self-aligning roller bearing 1c is provided with a structure for preventing the skew of the spherical rollers 4 and 4 constituting the self-aligning roller bearing 1c. Since the configuration and operation of the other parts are the same as those of the above-described conventional structure, the same parts are denoted by the same reference numerals, and duplicated explanations are omitted or simplified. Hereinafter, the characteristic parts of this example will be mainly described. .

Each of the pair of cages 5b, 5c constituting the self-aligning roller bearing 1c of this example includes annular rim portions 9a, 9a and a plurality of column portions 10, 10.
Each of the column portions 10 and 10 has an inner end portion in the axial direction (the right end portion in FIG. 1 for the retainer 5b and the left end portion in FIG. 1 for the retainer 5c). The outer rim portions 9a and 9a are coupled to the circumferentially equidistant positions on the outer circumferential surfaces of the rim portions 9a, 9a, and are axially outer end portions (the left end portion in FIG. In this case, the right end portion in FIG. 1 is a free end that is not coupled to other portions. A portion surrounded by the axial inner side surfaces of the rim portions 9a and 9a and the circumferential side surfaces of the column portions 10 and 10 adjacent to each other in the circumferential direction is connected to the spherical rollers 4 and 4. The pockets 11 and 11 are provided so as to be freely rollable.

In addition, among the axial side surfaces of the rim portions 9a and 9a constituting both the cages 5b and 5c, the axial dimension is elastically expanded and reduced in the annular gap 20a between the axial inner side surfaces facing each other. An elastic member 21 is provided.
As the elastic member 21, a wave washer 22a as shown in FIG. 2 or a disc spring 23 as shown in FIG. 3 can be used. In addition, an elastomer such as rubber can be used as the elastic member 21 as long as it is a member that can elastically expand and contract the axial dimension.

As described above, the self-aligning roller bearing 1c of the present example gives an axially outward elastic force to the cages 5b and 5c by the elastic member 21 provided in the annular gap 20a. Of the inner surfaces of the pockets 11 and 11 of both the cages 5b and 5c, the axially outer surfaces of the rim portions 9a and 9a and the axially inner end surfaces 13 and 13 of the spherical rollers 4 and 4 are engaged. It is combined.
In this way, the skew of the spherical rollers 4 and 4 during the operation of the spherical roller bearing 1c is suppressed, and based on this skew, the rolling surfaces of the spherical rollers 4 and 4 and the outer ring raceway 7 and The rolling contact portion with each of the inner ring raceways 8 and 8 suppresses an increase in the slip factor. For this reason, the amount of heat generated during the operation of the self-aligning roller bearing 1c as a whole can be suppressed, and the self-aligning roller bearing 1c can be operated at a higher speed and the durability can be improved.

In the case of the self-aligning roller bearing 1c of this example, both the cages 5b and 5c pressed by the elastic force of the elastic member 21 are connected to the axial inner end surfaces 13 and 13 of the spherical rollers 4 and 4, respectively. Among them, the central portion (the portion including the rotation axis of each of the spherical rollers 4 and 4 indicated by a chain line α in FIG. 1) is pressed in the radial direction (vertical direction in FIG. 1) of the outer ring 2 and the inner ring 3b. In this pressed portion, the lengths of the axial inner end surfaces 13 and 13 of the spherical rollers 4 and 4 with respect to the circumferential direction (front and back direction in FIG. 1) of the outer ring 2 and the inner ring 3b are long. Therefore, it is easy to ensure the length in the circumferential direction and the pressing area of the facing portion between the axial inner end surfaces 13 and 13 and the outer surfaces of the rim portions 9a and 9a of the cages 5b and 5c. For this reason, compared with the structure of Patent Document 4 described above, a stable elastic force can be applied to the spherical rollers 4 and 4 in terms of directionality, and the skew of the spherical rollers 4 and 4 is increased. The effect to prevent can be made high.
Further, in the structure of the self-aligning roller bearing 1c of this example, the radial thickness of the cages 5b and 5c constituting the self-aligning roller bearing 1c is equal to the radial thickness of the guide wheel 6. Bigger than that. For this reason, as in this example, if the members engaged with the axial inner end surfaces 13 and 13 of the spherical rollers 4 and 4 are the retainers 5b and 5c, the members to be engaged are the guide wheels 6. Compared with the case where it makes, it is easy to ensure the length regarding the circumferential direction of the part which presses these spherical rollers 4 and 4, and a press area. For this reason, the effect which prevents the skew of these spherical rollers 4 and 4 can be made higher.

In the self-aligning roller bearing 1c of this example, the positions and postures of the spherical rollers 4 and 4 are restricted by the two cages 5b and 5c. For this reason, the guide wheel 6 does not restrict the position and posture of the spherical rollers 4 and 4, but only restricts the radial position and posture of the cages 5b and 5c.
The self-aligning roller bearing 1c of the present example is similar to the self-aligning roller bearing 1 of the conventional example shown in FIG. The distance between the inner surfaces 15 and 15 of the fourteen and fourteen is greater than the axial length of the spherical rollers 4 and 4. For this reason, when assembling the self-aligning roller bearing 1c, it is not difficult to insert the spherical rollers 4 and 4 between the side surfaces 12 and 15.

[Second Example of Embodiment]
FIG. 4 also shows a second example of an embodiment of the invention corresponding to all claims. Also in this example, like the self-aligning roller bearing 1c of the first example of the above-described embodiment, the shafts of both rim portions 9a and 9a of both cages 5b and 5c constituting the self-aligning roller bearing 1d. An elastic member 21 that elastically expands and contracts the axial dimension is provided in an annular gap 20a between axially opposite inner side surfaces facing each other.
However, the flanges 14 and 14 (see FIG. 1) as in the first example of the above embodiment are not provided on the outer peripheral surfaces of both ends of the inner ring 3b. In this case, both the cages 5b and 5c can hold the spherical rollers 4 and 4 in the pockets 11 and 11 of the cages 5b and 5c, respectively. It is preferable to use one having a structure capable of preventing the spherical rollers 4 and 4 from being displaced in the axial direction.

Also in the case of such a self-aligning roller bearing 1d of this example, the elastic member 21 provided in the annular gap 20a applies an outward elastic force to the cages 5b and 5c. Of the inner surfaces of the pockets 11 and 11 of both the cages 5b and 5c, the axially outer surfaces of the rim portions 9a and 9a and the axially inner end surfaces 13 and 13 of the spherical rollers 4 and 4 Is engaged.
Further, the spherical rollers 4, 4 are engaged with the spherical rollers 4, 4 by engaging the rolling surfaces of the spherical rollers 4, 4 with the outer ring raceway 7 and the pair of inner ring raceways 8, 8. The force in the direction of pressing toward the guide wheel 6 is acting.
Therefore, as in the structure of this example, even if the flanges 14 and 14 are omitted, the axially outward elastic force applied by the elastic member 21 and the direction of pressing toward the guide wheel 6 ( The skew of the spherical rollers 4 and 4 during operation of the self-aligning roller bearing 1d can be suppressed by the force in the axial direction.
Since the structure and operation of the other parts are the same as those of the first example of the above-described embodiment, the same parts are denoted by the same reference numerals, and redundant description is omitted.

  The present invention is not limited to the structure in which the guide wheels 6a, 6 are provided as in each of the above-described conventional examples or the first to second examples of the embodiment, and the guide wheels 6a, 6 are not provided. It is also applied to a self-aligning roller bearing having a rolling element guide cage that guides both the cages 5b and 5c by engaging the pockets 11 and 11 of the 5b and 5c with the spherical rollers 4 and 4, respectively. With this, the same effect can be obtained.

The fragmentary sectional view of the self-aligning roller bearing which shows the 1st example of embodiment of this invention. Similarly, the perspective view which shows the wave washer which is a 1st example of an elastic member. Similarly, the perspective view (a) of the disc spring which is the 2nd example of an elastic member, and AA sectional view (b) of (a). The fragmentary sectional view of the self-aligning roller bearing which shows the 2nd example of embodiment of this invention. The fragmentary sectional view which shows the 1st example of the self-aligning roller bearing of the conventional structure. The fragmentary sectional view which shows the 2nd example. The fragmentary sectional view which shows the 3rd example.

Explanation of symbols

1, 1a, 1b, 1c, 1d Spherical roller bearing 2, 2a, 2b Outer ring 3, 3a, 3b Inner ring 4 Spherical roller 5, 5a, 5b, 5c Cage 6, 6a Guide wheel 7, 7a, 7b Outer ring raceway DESCRIPTION OF SYMBOLS 8 Inner ring raceway 9, 9a Rim part 10 Column part 11 Pocket 12 Side surface 13 Inner end face 14 Gutter part 15 Inner side face 16 Outer end face 17 Axial outer end face 18 Axial inner end face 19 Central collar part 20, 20a Annular gap 21 Elastic member 22 , 22a Wave washer 23 Disc spring 24 Center protrusion

Claims (4)

  An outer ring raceway that is a spherical concave surface having a single center, an outer ring formed on its inner peripheral surface, a pair of inner ring races facing the outer ring raceway, an inner ring formed on its outer peripheral surface, and the outer ring raceway A plurality of spherical rollers provided so as to be able to roll in two rows between the inner ring raceway and a pair of cages provided with a plurality of pockets for holding each of these spherical rollers so as to roll. In the self-aligning roller bearing provided, an elastic member that elastically expands and contracts the axial dimension is provided in the annular gap between the opposing side surfaces of each of the cages. Spherical roller bearings characterized by Each of the pair of cages includes an annular rim portion and a plurality of column portions, and each of the column portions has one end portion coupled to one axial side surface of the rim portion at equal intervals in the circumferential direction. The other end portion is a free end that is not coupled to the other portion, and the portion surrounded by the one side surface of this rim portion and the circumferential side surface of each column portion adjacent in the circumferential direction is replaced with each spherical roller. It is a pocket for holding it freely,
The both cages are combined in the axial direction in a state where the side surfaces opposite to the side surfaces to which the column portions are coupled are opposed to each other among the axial side surfaces of the respective rim portions. Spherical roller bearing described.   The self-aligning roller bearing according to any one of claims 1 and 2, wherein the elastic member is a wave washer.   The self-aligning roller bearing according to any one of claims 1 and 2, wherein the elastic member is a disc spring.

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