JP5953905B2 - Multi-row rolling bearing - Google Patents

Description

  The present invention relates to a multi-row rolling bearing, and more particularly to a 4-row tapered roller bearing used for a roll neck of a rolling mill.

  A four-row tapered roller bearing, which is a typical multi-row rolling bearing, includes a four-row bearing portion, an outer ring spacer, and an inner ring spacer, and is used for a roll neck of a rolling mill. It is known that the load generated by rolling in a rolling mill is not always constant, and depending on the rolling situation, it acts on the roll neck bearing of the rolling mill as a combined load of radial load, moment load, and thrust load.

  Under the condition of the above-mentioned combined load, the load on the bearing portions in each row of the four-row tapered roller bearing becomes uneven, and the life of the bearing portions in some rows may be extremely shortened. As a countermeasure, there has been proposed a multi-row roller bearing device for adjusting the rigidity of the bearing portions in each row to equalize the load on the bearing portions in each row. (See Patent Document 1)

JP-A 61-175312

  However, the above-mentioned multi-row roller bearing device in which the rigidity of the bearing portion of each row is adjusted also gives consideration to the rigidity of the bearing portion, but no consideration is given to the rigidity of the outer ring spacer and the inner ring spacer constituting the bearing device. It has not been. Multi-row roller bearings in applications where thrust loads are applied, while the load on the bearing portion of the row that is loaded through the spacer having high rigidity due to the difference in axial rigidity between the outer ring spacer and the inner ring spacer is low It becomes larger than the load of the bearing part of the row | line | column loaded via a seat. As a result, the life of one row of bearing portions with a large load is extremely shortened.

  The object of the present invention is to equalize the thrust load of each row by equalizing the axial rigidity of the outer ring spacer and the inner ring spacer in applications where thrust load acts, and to achieve a multi-row rolling bearing with excellent service life. Is to provide.

In order to solve the above-mentioned problem, the structural features of the invention according to claim 1 are: a plurality of outer ring members having outer ring raceways formed on the inner peripheral portion; and a plurality of inner ring members having inner ring raceways formed on the outer periphery. A plurality of rolling elements rotatably interposed between the outer ring raceways and the inner ring raceways opposed to the outer ring raceways to form a multi-row bearing portion having equal axial rigidity , A multi-row rolling bearing having an outer ring spacer interposed in an axial intermediate portion and an inner ring spacer interposed in an axial intermediate portion of the plurality of inner ring members, wherein the outer ring spacer and the inner ring spacer are identical to each other The ratio of the axial width and the radial cross-sectional area of the outer ring spacer is equal to the ratio of the axial width and the radial cross-sectional area of the inner ring spacer, and the outer ring spacer and The axial rigidity of the inner ring spacer is equal.

  When a thrust load is applied with the outer ring spacer and the inner ring spacer disposed, the bearings in each row are loaded and deformed in the axial direction. At the same time, the outer ring spacer and the inner ring spacer are compressed in the axial direction. Is done. According to the configuration of the present invention, the axial rigidity of the outer ring spacer and the inner ring spacer are equal, the axial deformation amount of the outer ring spacer and the inner ring spacer loaded with the thrust load is equal, and the thrust load is The load is applied substantially evenly to two or more rows of bearing portions.

  In order to solve the above-described problem, a structural feature of the invention according to claim 2 is that a resin portion is provided on at least one end face in the axial direction of the outer ring spacer and the inner ring spacer.

  In principle, the axial length of the outer ring spacer is equal to the interval between the axial middle portions of the plurality of outer ring members, and the axial length of the inner ring spacer is the axial middle portion of the plurality of inner ring members. Equal to the interval. However, actually, due to an error in manufacturing the axial lengths of the outer ring spacer and the inner ring spacer, between the plurality of outer ring members and the outer ring spacer or between the plurality of inner ring members and the inner ring spacer. A gap is generated between the two.

  According to the configuration of the present invention, the end surface of the outer ring spacer and the inner ring spacer, which are thrust load pressure receiving surfaces, has a resin portion with low rigidity, so that the end surface on the side on which the thrust load is loaded is easily compressed, The gaps between the other outer ring members and the outer ring spacers or between the plurality of inner ring members and the inner ring spacers disappear, and the thrust load is equally applied to the bearings in two or more rows.

  According to the present invention, in an application in which a thrust load acts, by equalizing the axial rigidity of the outer ring spacer and the inner ring spacer, the load of the thrust load of each row is equalized, and the multi-row rolling with excellent life is achieved. A bearing can be provided.

It is sectional drawing of the multi-row rolling bearing of embodiment of this invention. It is an expanded sectional view of the outer ring spacer in the multi-row rolling bearing of FIG. It is an expanded sectional view of the inner ring spacer in the multi-row rolling bearing of FIG. It is explanatory drawing explaining the usage example of the multi-row rolling bearing of FIG. (A) It is explanatory drawing explaining the other example of an assembly of the multi-row rolling bearing of FIG. (B) It is explanatory drawing explaining the effect | action of the other example of a multi-row rolling bearing of FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a multi-row rolling bearing according to an embodiment of the present invention.
In FIG. 1, a four-row tapered roller bearing 1 which is a multi-row roller bearing is composed of three outer rings 2A, 2B and 2C which are outer ring members and inner rings 3A and 3B which are two inner ring members and a plurality of tapered rollers 4 in four rows. And two outer ring spacers 5A and 5B, and an inner ring spacer 6.

  The outer ring 2A has an annular shape, the outer peripheral surface 2Ab has a cylindrical shape, and an outer ring raceway 2Aa having a conical surface shape is formed on the inner peripheral portion. The outer ring raceway 2Aa is hardened to a predetermined hardness. A small end surface 2Ac extends from the large-diameter end of the outer ring raceway 2Aa, and a large end surface 2Ad extends from the small-diameter side end of the outer ring raceway 2A to the outer peripheral surface 2Ab radially outward.

  The outer ring 2B has an annular shape, the outer peripheral surface 2Bc has a cylindrical shape, and two rows of outer ring raceways 2Ba and 2Bb having a conical angle equal to the conical angle of the outer ring raceway 2Aa on the inner peripheral portion have a small diameter on the axially central portion side. The outer ring raceways 2Ba and 2Bb are hardened to a predetermined hardness. Small end surfaces 2Bd and 2Be are formed extending radially outward from both ends on the large diameter side of both outer ring raceways 2Ba and 2Bb to the outer peripheral surface 2Bc.

  The outer ring 2C has an annular shape, the outer circumferential surface 2Cb has a cylindrical shape, and an outer ring raceway 2Ca having a conical surface shape having a conical angle equal to the conical angle of the outer ring raceway 2Aa is formed on the inner circumferential portion. Hardened to hardness. A small end surface 2Cc extends from the large-diameter side end of the outer ring raceway 2Ca, and a large end surface 2Cd extends from the small-diameter side end of the outer ring raceway 2Ca to the outer peripheral surface 2Cb.

  The inner ring 3A includes a cylindrical inner peripheral surface 3Ac on the inner peripheral part and two rows of conical inner ring raceways 3Aa, 3Ab and inner ring raceways 3Aa, 3Ab formed on the outer peripheral part facing the large diameter side. It has a large collar 3Ad that protrudes outward in the radial direction and small end faces 3Ag and 3Ah that extend radially outward from both ends of the inner peripheral surface 3Ac. Both end surfaces of the large collar 3Ad are large collar surfaces 3Ae and 3Af extending obliquely outward from the large diameter side ends of the inner ring raceways 3Aa and 3Ab toward the inner ring raceways 3Aa and 3Ab. The inner ring raceways 3Aa, 3Ab and the large collar surfaces 3Ae, 3Af are hardened to a predetermined hardness.

  The inner ring 3B includes a cylindrical inner peripheral surface 3Bc on the inner peripheral part and two rows of conical inner ring raceways 3Ba, 3Bb and inner ring raceways 3Ba, 3Bb formed on the outer peripheral part facing the large diameter side. It has a large flange 3Bd that protrudes radially outward, and small end surfaces 3Bg and 3Bh that extend radially outward from both ends of the inner peripheral surface 3Bc. Both end surfaces of the large collar 3Bd are large collar surfaces 3Be and 3Bf extending obliquely outward from the large diameter side ends of the inner ring raceways 3Ba and 3Bb toward the inner ring raceways 3Ba and 3Bb. The inner ring raceways 3Ba and 3Bb and the large collar surfaces 3Be and 3Bf are hardened to a predetermined hardness.

  The plurality of tapered rollers 4 have a conical surface-shaped rolling surface 4a and a large end surface 4b. The rolling surface 4a is in contact with each outer ring raceway and the inner ring raceway between each outer ring raceway and the inner ring raceway, and the large end face 4b is provided respectively. It is arranged so as to be able to roll in contact with the surface of the ridge.

  Here, the outer ring raceway 2a, the inner ring raceway 3a, and one row of the plurality of tapered rollers 4 have a bearing portion A, and the outer ring raceway 2a, the inner ring raceway 3a, and the one row of a plurality of tapered rollers 4 have a bearing portion B, and the outer ring raceway 2a. The inner ring raceway 3a and one row of the plurality of tapered rollers 4 constitute a bearing portion C, and the outer ring raceway 2a, the inner ring raceway 3a and the one row of a plurality of tapered rollers 4 constitute a bearing portion D. Further, since the number of tapered rollers 4 in each row constituting the bearing portions A, B, C, and D is equal, the axial rigidity of the bearing portions A, B, C, and D is equal.

  FIG. 2 is an enlarged cross-sectional view of an outer ring spacer in the multi-row rolling bearing 1 of FIG. 3 is an enlarged cross-sectional view of an inner ring spacer in the multi-row rolling bearing 1 of FIG. The outer ring spacers 5A and 5B have the same material and dimensions, and the reference numerals of the respective parts are the same.

  The outer ring spacers 5A and 5B are hollow cylindrical circular rings whose base material part 5e is made of steel such as S25C, and have resin layers 5f and 5g made of fiber reinforced polyamide or the like at both axial ends. The inner peripheral surface 5d and the outer peripheral surface 5c are concentric, and end surfaces 5a, 5b extend radially outward from both ends of the inner peripheral surface 5d to the outer peripheral surface 5c.

  The inner ring spacer 6 is a hollow cylindrical ring whose base material part 6e is made of a steel material such as S25C. The inner ring spacer 6 is made of the same fiber reinforced polyamide as the resin layers 5f and 5g of the outer ring spacers 5A and 5B at both axial ends. The resin layers 6f and 6g are formed. The inner peripheral surface 6d and the outer peripheral surface 6c are concentric, and end surfaces 6a and 6b extend radially outward from both ends of the inner peripheral surface 6d to the outer peripheral surface 6c.

Here, the ratio between the axial width L5 of the outer ring spacers 5A and 5B and the resin layer thickness δ5 is equal to the ratio between the axial width L6 of the inner ring spacer 6 and the resin layer thickness δ6. The ratio between the axial width L5 and the cross-sectional area of the outer ring spacers 5A and 5B is equal to the ratio between the axial width L6 and the cross-sectional area of the inner ring spacer 6. That is, the diameter of the inner peripheral surface 5d of the outer ring spacers 5A and 5B is d5, the diameter of the outer peripheral surface 5c is D5, the axial width L5, the diameter of the inner peripheral surface 6d of the inner ring spacer 6 is d6, and the diameter of the outer peripheral surface 6c. Assuming D6 and axial width L6,
^{L5 / (D5 2 -d5 2)} = L6 / (D6 2 -d6 2) are in the relationship.

  Usually, the axial rigidity of the cylindrical member with respect to the axial load is determined by the area of the radial section, the axial shape, the axial width, and the elastic modulus of the material. The outer ring spacers 5A and 5B and the inner ring spacer 6 are formed of the same material and in the same shape. By satisfying the above relationship, the outer ring spacers 5A and 5B and the inner ring spacer 6 have the same axial rigidity. .

  As shown in FIG. 1, the outer ring spacer 5A is disposed with the end surfaces 5a and 5b in contact between the small end surface 2Ac of the outer ring 2A and the small end surface 2Bd of the outer ring 2B, and the outer ring spacer 5B is connected to the small end surface 2Be of the outer ring 2B. Between the small end surface 2Cc of the outer ring | wheel 2C, it arrange | positions in contact with end surface 5a, 5b. The inner ring spacer 6 is disposed such that the end faces 6a and 6b are in contact with the small end face 3Ah of the inner ring 3A and the small end face 3Bg of the inner ring 3B.

FIG. 4 is an explanatory view illustrating an example of use of the multi-row rolling bearing 1 of FIG.
FIG. 4 shows a state in which the multi-row rolling bearing 1 of FIG. 1 is incorporated in a roll neck of a rolling mill. The thrust load is input from the roll 7 to the inner ring 3A via the thrust ring 8, and is transmitted to the housing 9 through two paths, and the thrust reaction force from the housing 9 acts on the outer ring 2C. One path passes from the inner ring 3A to the bearing part B, outer ring 2B, outer ring spacer 5B, outer ring 2C, and the other path passes from the inner ring 3A to the inner ring spacer 6, inner ring 3B, bearing part D, outer ring 2C. It is transmitted to 9.

  Here, in the embodiment of the present invention, since the axial rigidity of the outer ring spacer 5B and the inner ring spacer 6 is equal, the load of the thrust load of the bearing portion B in the path passing through the outer ring spacer 5B, and the inner ring spacer The thrust load of the bearing portion D of the path passing through 6 becomes equal. In other words, the multi-row rolling bearing 1 according to the embodiment of the present invention does not have a reduced life due to an increase in the load only in one row of both bearing portions in an application where a thrust load acts.

FIG. 5A is an explanatory view for explaining another example of incorporation of the multi-row rolling bearing 1 of FIG. FIG. 5B is an explanatory view for explaining the operation of another example of incorporation of the multi-row rolling bearing 1 of FIG.
FIG. 5A shows a state of the multi-row rolling bearing 1 in a state where the outer ring spacers 5A and 5B are incorporated. Due to the variation in width due to the processing error of the outer ring spacers 5A and 5B, the axial width L6 of the inner ring spacer 6 becomes smaller than the interval l between the small end surface 3Ah of the inner ring 3A and the small end surface 3Bg of the inner ring 3B. An axial gap Δ is interposed between the seat 6 and the inner rings 3A, 3B.

  In the state of FIG. 5A, when a thrust load acts on the inner ring 1A and a thrust reaction force acts on the outer ring 2C, an axial load is generated only in the path of the bearing portion B and the outer ring spacer 5B. As shown, the outer ring spacer 5B is compressed in the axial direction, and the inner ring 3A and the outer ring 2B move in the direction of the inner ring 3B in the axial direction. The amount of movement is equal to the sum of the compression amount of the outer ring spacer 5B and the axial deformation amount of the bearing portion B. When the amount of movement becomes equal to the gap Δ, the axial gap Δ between the inner ring spacer 6 and the inner rings 3A, 3B disappears, and a load due to a thrust load is generated on both bearing parts of the bearing part B and the bearing part D. To do.

  At this time, the outer ring spacer 5B has resin layers 5f and 5g having rigidity lower than that of the metal on both end faces, and the load caused by the thrust load corresponding to the axial compression amount equal to the gap Δ is the outer ring made of only the metal material. Much smaller than in the case of the spacer. As a result, the difference in load between the negative bearing portion B and the bearing portion D becomes smaller than in the case of the outer ring spacer made of only the metal material, and the life of the entire bearing portion is improved.

  The multi-row roller bearing of the above-described embodiment is a 4-row tapered roller bearing, but other types of multi-row roller bearings may be used in the present invention.

  In the multi-row rolling bearing of the above-described embodiment, the outer ring spacer and the inner ring spacer have a resin layer at both ends. However, in the present invention, the outer ring spacer and the inner ring spacer are resin layers only at one end. It may be a structure having

  In the multi-row rolling bearing of the above-described embodiment, the outer ring spacer and the inner ring spacer have a structure in which the base material is steel and has resin layers at both ends, but in the present invention, the outer ring spacer and the inner ring spacer are only metal materials. Alternatively, it may be formed of only resin.

  The multi-row rolling bearing of the above-described embodiment is composed of an outer ring spacer and an inner ring spacer whose rigidity in the axial direction is adjusted by adjusting the cross-sectional area and the width in the axial direction. It may be a multi-row roller bearing composed of an outer ring spacer and an inner ring spacer whose axial rigidity is made equal by another stiffness adjusting method.

10 ... 4 row tapered roller bearing (multi-row roller bearing)
2A, 2B, 2C ... outer ring members 2Aa, 2Ba, 2Bb, 2Ca ... outer ring raceways 3A, 3B ... inner ring members 3Aa, 3Ab, 3Ba, 3Bb ... inner ring raceways 4 ... tapered rollers (rolling elements)
A, B, C, D ... Bearing parts 5A, 5B ... Outer ring spacer 5f, 5g, 6f, 6g ... Resin part 6 ... Inner ring spacer

Claims (2)

A plurality of outer ring members having outer ring raceways formed on the inner periphery, a plurality of inner ring members having inner ring raceways formed on the outer periphery, and each inner ring raceway facing each outer ring raceway and each outer ring raceway. A plurality of rolling elements interposed in the shaft constitute a multi-row bearing portion having the same axial rigidity, and an outer ring spacer interposed in an axial intermediate portion of the plurality of outer ring members, and an axial intermediate portion of the plurality of inner ring members A multi-row rolling bearing having an inner ring spacer interposed in the part,
The outer ring spacer and the inner ring spacer are formed of the same material,
The ratio of the axial width of the outer ring spacer and the cross-sectional area in the radial direction is equal to the ratio of the axial width of the inner ring spacer and the cross-sectional area in the radial direction,
A multi-row roller bearing, wherein the outer ring spacer and the inner ring spacer have the same axial rigidity. The multi-row rolling bearing according to claim 1, further comprising a resin portion on at least one side surface in the axial direction of the outer ring spacer and the inner ring spacer.

Images