Roller bearings

Abstract

To provide a roller bearing capable of preventing the falling of a fastening member which fastens a flange member to an inner ring boss part.SOLUTION: At one axial end of an inner ring, a brim part integral with the inner ring is formed, and at the other axial end of the inner ring, the brim member separate from the inner ring is fastened by a fastening member extending in the axial direction. The fastening member has a head part and a shaft part extending from the head part to one axial end side, and the brim member has a base part which abuts on the inner ring in the axial direction and on which the head part of the fastening member is seated. Into the outer peripheral face of the brim member, a cover member is pressed and fixed. The cover member has a body part fixed to the outer peripheral face of the brim member and extending in the axial direction, and a flange part extending from the body part to the radial inside. The radial inside end of the flange part is located on the radial inside further than the radial outside end of the head part of the fastening member.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a roller bearing.

Background Art

[0002] In recent years, in industrial machines, not only functions and prices but also life cycle costs have been emphasized. For this reason, there are increasing demands for repair and reuse of roller bearings assembled in industrial machines, and a bearing structure that can be disassembled for inspection is required.

[0003] The tapered roller bearing described in Patent Document 1 includes an inner ring having an inner ring raceway surface, an outer ring having an outer ring raceway surface, a plurality of tapered rollers that are rolling elements that roll between the inner ring raceway surface and the outer ring raceway surface, and a cage for holding the tapered rollers at equal intervals in the circumferential direction. A large flange is integrally formed at the large-diameter side end of the inner ring, and a separate small flange member for preventing the tapered rollers from falling off is provided at the small-diameter side end of the inner ring. The small flange member is locked to the inner ring by bolts. Therefore, when inspecting the inside of the tapered roller bearing or replacing the cage, it can be disassembled by removing the small flange member.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the tapered roller bearing of Patent Document 1, bolt loosening may occur when the bolts are not fastened with an appropriate tightening force, and there is a risk that the bolts may fall off from the bearing. If the bolts fall off, there is a possibility that the bolts may flow into the surrounding drive parts (for example, a speed reducer), causing damage to the parts.

[0006] The present invention has been made in view of the above circumstances, and aims to provide a roller bearing that can prevent the fastening member that fastens the flange member to the inner ring from falling off. [Means for solving the problem]

[0007] The above objective of the present invention is achieved by the following configuration.

[0008] (1) An inner ring having an inner ring raceway surface on its outer circumference, An outer ring having an outer ring raceway surface on its inner circumference, Multiple rollers are arranged to roll freely between the inner ring raceway surface and the outer ring raceway surface, A roller bearing comprising, A flange portion, which is integral with the inner ring, is formed at one axial end of the inner ring. A flange member, separate from the inner ring, is fastened to the other axial end of the inner ring by a fastening member extending in the axial direction. The fastening member has a head and a shaft portion extending from the head toward one axial end, The flange member abuts the inner ring in the axial direction and has a base on which the head of the fastening member sits. A cover member is press-fitted and fixed to the outer circumferential surface of the flange member. The cover member is A main body portion is fixed to the outer circumferential surface of the flange member and extends in the axial direction, A flange portion extending radially inward from the main body portion, It has, The radially inner end of the flange portion is located radially inward from the radially outer end of the head of the fastening member. A roller bearing characterized by the following features. (2) The outer circumferential surface of the flange member is recessed with a groove that extends radially inward, The main body portion of the cover member is provided with a projection that extends radially inward. The projection of the cover member engages with the groove of the flange member. (1) The roller bearing described above. (3) A through-hole that penetrates the base portion of the flange member in the axial direction and has a female screw portion on the outer peripheral surface is formed in the base portion. A screw hole having a female screw portion on the outer peripheral surface is formed in the inner ring so as to extend in the axial direction at a position axially opposed to the through-hole. The shaft portion of the fastening member A screw portion having a male screw portion on the outer peripheral surface, which is located at one axial end of the shaft portion, and A body portion that is located on the other axial end side of the screw portion and does not have a male screw portion on the outer peripheral surface, are included. The outer diameter of the body portion is smaller than the outer diameter of the screw portion. In the fastening state of the flange member and the inner ring by the fastening member, the screw portion does not engage with the through-hole and engages with the screw hole. The tapered roller bearing according to (1) or (2).

Advantages of the Invention

[0009] According to the present invention, it is possible to provide a tapered roller bearing that can prevent the fastening member for fastening the flange member to the inner ring portion from falling off.

Brief Description of the Drawings

[0010] [Figure 1] It is a cross-sectional view of a tapered roller bearing according to the first embodiment of the present invention. [Figure 2] It is a cross-sectional view of the main part of the tapered roller bearing of FIG. 1. [Figure 3] It is a cross-sectional view of a tapered roller bearing according to the second embodiment of the present invention. [Figure 4] It is a cross-sectional view of the main part of the tapered roller bearing of FIG. 3. [Figure 5] It is a cross-sectional view of a bolt. [Figure 6] It is a cross-sectional view of a tapered roller bearing according to a modified example of the second embodiment of the present invention. [Figure 7] It is a cross-sectional view of the main part of the tapered roller bearing of FIG. 6.

Modes for Carrying Out the Invention

[0011] (First Embodiment) FIG. 1 is a cross-sectional view of a tapered roller bearing 1 according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view of the main part of the tapered roller bearing 1 in FIG. 1.

[0012] The tapered roller bearing 1 includes an inner ring 10 having a tapered inner ring raceway surface 11 on the outer peripheral surface, an outer ring 20 having a tapered outer ring raceway surface 21 on the inner peripheral surface, and a plurality of tapered rollers 30 disposed so as to be freely rotatable between the inner ring raceway surface 11 and the outer ring raceway surface 21.

[0013] The tapered rollers 30 are held at regular intervals in the circumferential direction by an annular cage 40 incorporated between the inner ring raceway surface 11 and the outer ring raceway surface 21. The cage 40 is a pin-type cage and has a pair of annular portions 41 and 42 and pins 43 for fastening the pair of annular portions 41 and 42.

[0014] Note that the type of the cage 40 is not limited. For example, a press cage (basket-type cage) made of a steel plate, which has a large-diameter ring portion, a small-diameter ring portion, a plurality of column portions for axially connecting the large-diameter ring portion and the small-diameter ring portion, and pocket portions defined between the large-diameter ring portion, the small-diameter ring portion, and adjacent column portions, may be applied.

[0015] A flange portion 13 integral with the inner ring 10 is formed at one axial end portion of the inner ring 10 (the left side in the figure, the large-diameter side end portion). The flange portion 13 protrudes radially outward from the inner ring raceway surface 11 and prevents the tapered rollers 30 from falling off to one axial end side. The flange portion 13 constitutes a large flange of the inner ring 10.

[0016] An inner ring boss portion 15 is formed at the other axial end of the inner ring 10 (right side in the figure; the smaller diameter end), protruding axially from the inner ring raceway surface 11. Figure 2 shows a virtual plane A extending perpendicularly from the inner ring raceway surface 11 from the other axial end 11a of the inner ring raceway surface 11, and a virtual plane B extending radially from the other axial end 11a. The inner ring boss portion 15 protrudes axially from these virtual planes A and B. The inner ring boss portion 15 is a convex portion that extends axially from a position radially inward from the other axial end 11a of the inner ring raceway surface 11, and therefore a stepped portion 17 is formed between the inner ring boss portion 15 and the other axial end 11a of the inner ring raceway surface 11.

[0017] A flange member 50, made of steel or resin material and separate from the inner ring 10, is fastened to the inner ring boss portion 15 by a bolt 60. In this example, the bolt 60 is a socket head cap bolt, but the type of bolt is not particularly limited, and it goes without saying that other types of fastening members such as screws may be used. The bolt 60 has a head 61 and a shaft portion 63 that extends from the head 61 to one axial end and has a male threaded portion formed on its outer circumference.

[0018] The fastening members, such as the bolts 60, extend axially and fasten the inner ring boss portion 15 and the flange member 50 in the axial direction, making it easy to fasten the bolts regardless of the cage configuration. Furthermore, since the flange member 50 can be easily attached and detached, the assembly of the tapered roller bearing 1 becomes easier, as does the inspection of the inside of the tapered roller bearing 1 and the replacement of the tapered rollers 30 or the cage 40.

[0019] The inner ring boss portion 15 has a female threaded portion on its outer circumferential surface and a screw hole 15a formed therein that faces axially. Preferably, the female threaded portion of the screw hole 15a is formed so as not to overlap with a virtual plane A in the axial direction, and more specifically, it is preferable that the female threaded portion of the screw hole 15a is positioned on the other end side in the axial direction relative to the virtual plane A. In this case, the male threaded portion of the shaft portion 63 of the bolt 60 that is screwed into the female threaded portion of the screw hole 15a is also positioned so as not to overlap with the virtual plane A in the axial direction, and more specifically, it is positioned on the other end side in the axial direction relative to the virtual plane A.

[0020] Furthermore, more preferably, the female thread portion of the screw hole 15a of the inner ring boss portion 15 is formed so as not to overlap with the other axial end 11a (virtual plane B) of the inner ring raceway surface 11 in the axial direction, and more specifically, is positioned on the other axial end side of the other axial end 11a (virtual plane B) of the inner ring raceway surface 11. In this case, the male thread portion of the shaft portion 63 of the bolt 60 that screws into the female thread portion of the screw hole 15a is also positioned so as not to overlap with the other axial end 11a (virtual plane B) of the inner ring raceway surface 11 in the axial direction, and more specifically, is positioned on the other axial end side of the other axial end 11a (virtual plane B) of the inner ring raceway surface 11.

[0021] In this way, by arranging the male threaded portion of the shaft portion 63 of the bolt 60 so as not to overlap the inner ring raceway surface 11 in the axial direction, the bolt fastening portion is avoided from being positioned directly below the inner ring raceway surface 11 in the radial direction. Therefore, even if a large load is generated on the raceway surface when the bearing is in use, it is possible to suppress the generation of high stress at the bolt fastening portion.

[0022] However, the above description does not exclude configurations in which the bolted fastening portion coincides with virtual planes A and B in the axial direction.

[0023] The flange member 50 may be composed of an annular member, or it may be composed of a plurality of annular pieces that form part of an annular ring and are arranged at intervals in the circumferential direction. The flange member 50 has an annular base portion 51 that extends radially outward from the inner ring boss portion 15, and a protrusion 53 that projects axially in one direction from the radially outer end of the base portion 51. The base portion 51 abuts with the inner ring boss portion 15 in the axial direction. The protrusion 53 fits into the stepped portion 17 of the inner ring 10.

[0024] As shown in Figure 2, the base portion 51 has a recess 51b that is recessed from the other axial end face 51a toward one axial side. The recess 51b functions as a seating portion on which the head 61 of the bolt 60 is seated. In this example, the recess 51b is formed around the entire circumference of the base portion 51 and opens radially inward, but the shape of the recess 51b is not particularly limited.

[0025] Furthermore, a through hole 51e is formed in the base portion 51, which penetrates the base portion 51 in the axial direction. The through hole 51e extends from the bottom surface 51c (the other end surface in the axial direction) of the recess 51b to the one end surface 51d in the axial direction of the base portion 51. The through hole 51e is provided at a position opposite the screw hole 15a of the inner ring boss portion 15 in the axial direction. Therefore, the same number of through holes 51e as screw holes 15a are provided.

[0026] The bolt 60 then passes through the through hole 51e of the base 51 and is screwed into the threaded hole 15a of the inner ring boss portion 15, extending axially and fastening the inner ring boss portion 15 and the flange member 50 in the axial direction. At this time, the head 61 of the bolt 60 is located in the recess 51b of the base 51 and sits on the bottom surface 51c of the recess 51b.

[0027] The protrusion 53 of the flange member 50 fastened to the inner ring boss portion 15 is located radially outward from the other axial end 11a of the inner ring raceway surface 11 and faces the tapered roller 30 in the axial direction, preventing the tapered roller 30 from falling off towards the other axial end. In this way, the flange member 50 constitutes a small flange of the inner ring 10.

[0028] A cover member 70 is press-fitted and fixed to the outer circumferential surface 50a of the flange member 50 to prevent the bolt 60 from falling out. The cover member 70 is fixed to the outer circumferential surface 50a of the flange member 50 and has a roughly L-shaped cross-section, with a main body portion 71 extending in the axial direction and a flange portion 73 extending radially inward from the other axial end of the main body portion 71. The cover member 70 may be an annular shape provided around the entire circumference of the outer circumferential surface 50a of the flange member 50, or it may be a partial annular shape provided intermittently in multiple locations in the circumferential direction that overlap the bolt 60.

[0029] A groove 50b extending radially inward is recessed in the outer circumferential surface 50a of the flange member 50. In addition, a projection 71a extending radially inward is provided at one axial end of the main body portion 71 of the cover member 70. The projection 71a of the cover member 70 fits into and engages with the groove 50b of the flange member 50, making it difficult for the cover member 70 to come off the flange member 50. However, if, for example, press-fitting ensures sufficient fitting force between the main body portion 71 of the cover member 70 and the outer circumferential surface 50a of the flange member 50, and the possibility of the cover member 70 coming off the flange member 50 is sufficiently low, then it is not necessarily required to provide the groove 50b or the projection 71a that fits into the groove 50b.

[0030] The flange portion 73 of the cover member 70 is located axially on the other end side of the head 61 of the bolt 60, and the radially inner end of the flange portion 73 is located radially inward of the radially outer end of the head 61 of the bolt 60. In other words, when viewed from the axial direction, the flange portion 73 and the head 61 of the bolt 60 overlap at least partially. As a result, even if the bolt 60 loosens and moves axially, the head 61 of the bolt 60 will catch on the flange portion 73, preventing the bolt 60 from falling out in the axial direction.

[0031] (Second Embodiment) Next, the roller bearing 1 according to the second embodiment will be described. The roller bearing 1 of the second embodiment differs from that of the first embodiment mainly in the structure of the bolt 60. The other components are generally the same as those of the first embodiment, so the same reference numerals are used in the drawings to omit or simplify their explanation.

[0032] Figure 3 is a cross-sectional view of a tapered roller bearing 1 according to a second embodiment of the present invention. Figure 4 is a cross-sectional view of the main part of the tapered roller bearing 1 of Figure 3. Figure 5 is a cross-sectional view of a bolt 60.

[0033] The bolt 60 in this example is a so-called anti-loosening bolt in which a male thread is formed only on the tip side of the shaft portion 63, and has a structure that prevents it from falling out of the flange member 50 after it has been inserted into the through hole 51e of the flange member 50.

[0034] The through hole 51e in this embodiment has a female thread on its outer surface along its entire length. The shaft portion 63 of the bolt 60 includes a threaded portion 63a located at one axial end (tip) of the shaft portion 63 and having a male thread on its outer surface, and a body portion 63b located at the other axial end of the threaded portion 63a (between the threaded portion 63a and the head 61) and not having a male thread on its outer surface. That is, the outer surface of the body portion 63b is a cylindrical surface.

[0035] The outer diameter D1 of the threaded portion 63a is approximately the same as that of the through hole 51e of the flange member 50 and the threaded hole 15a of the inner ring boss portion 15, allowing the male threaded portion of the threaded portion 63a to be screwed into the female threaded portion of the through hole 51e and the female threaded portion of the threaded hole 15a. In contrast, the outer diameter D2 of the body portion 63b is smaller than the outer diameter D2 of the threaded portion 63a. Furthermore, the axial length of the body portion 63b is longer than the axial length of the through hole 51e, so when the body portion 63b is inserted into the through hole 51e, the body portion b 63 protrudes axially beyond the through hole 51e to the other end (left side in Figure 4).

[0036] As shown in Figure 4, in order to fasten the flange member 50 and the inner ring boss portion 15 with the bolt 60, the flange member 50 and the inner ring boss portion 15 are kept separate. First, the threaded portion 63a at the tip of the bolt 60 is screwed into the female thread of the through hole 51e of the inner ring boss portion 15, passing through the female thread and bringing the body portion 63b to the position of the through hole 51e. Then, the threaded portion 63a of the bolt 60 is screwed into the female thread of the screw hole 15a and tightened until the flange member 50 and the inner ring boss portion 15 are in close contact. As shown in Figure 4, in the state of fastening the flange member 50 and the inner ring boss portion 15 with the bolt 60, the threaded portion 63a does not screw into the through hole 51e, but only into the screw hole 15a. Furthermore, since the outer diameter D2 of the body portion 63b is smaller than the diameter of the through hole 51e, a gap exists between the body portion 63b and the through hole 51e.

[0037] With this structure, even if the bolt 60 loosens and the fastening between the flange member 50 and the inner ring boss portion 15 is lost, the threaded portion 63a of the bolt 60 will catch on the through hole 51e of the flange member 50, so it will not easily fall off the flange member 50.

[0038] Furthermore, as in the first embodiment, a cover member 70 is also provided in this embodiment. Therefore, even if the bolt 60 loosens, the head 61 of the bolt 60 will catch on the flange portion 73. Thus, the combination of the cover member 70 preventing detachment and the bolt 60 being a detachment-preventing bolt provides more reliable detachment prevention.

[0039] (Modified version of the second embodiment) Figure 6 is a cross-sectional view of a tapered roller bearing 1 according to a modified example of the second embodiment of the present invention. Figure 7 is a cross-sectional view of the main part of the tapered roller bearing 1 of Figure 6. As shown in Figures 3 to 5, a cover member 70 was provided in the tapered roller bearing 1 according to the second embodiment, but as shown in Figures 6 to 7, the cover member 70 is not necessarily required. Even in this case, the bolt 60, which is used as a fall prevention bolt, will not easily fall off the flange member 50.

[0040] It should be noted that the present invention is not limited to the embodiments described above and can be modified in various ways. For example, the present invention can be applied to any roller bearing, such as cylindrical roller bearings, in addition to tapered roller bearings.

[0041] For example, in the above example, an inner ring boss portion 15 was formed at the other axial end of the inner ring 10, protruding axially from the inner ring raceway surface 11. However, this inner ring boss portion 15 is not necessarily required. If the inner ring boss portion 15 is not formed, a flange member 50 is positioned at the other axial end of the inner ring 10 (adjacent to the other axial end 11a of the inner ring raceway surface 11), similar to the above-mentioned Patent Document 1 (Japanese Patent Application Publication No. 2014-190352). In this case, since the inner ring boss portion 15 is not formed, the inner ring 10 does not have a stepped portion 17, and the flange member 50 does not have a protrusion 53. Furthermore, the screw hole 15a is formed at a position opposite to the through hole 51e of the flange member 50, extending axially from the other axial end surface of the inner ring 10 toward the one axial end.

[0042] Furthermore, in the example described above, the flange member 50 had a recess 51b formed in the axial direction from the other axial end face 51a of the base 51 toward one axial side, on which the head 61 of the bolt 60 sat. However, the flange member 50 does not necessarily need to have a recess 51b. In this case, the through hole 51e is formed to penetrate from the other axial end face 51a of the base 51 to the axial end face 51d, and the head 61 of the bolt 60 sits on the other axial end face 51a of the base 51. In this case as well, the flange portion 73 of the cover member 70 is located axially toward the other end than the head 61 of the bolt 60, and the radially inner end of the flange portion 73 is located radially inward than the radially outer end of the head 61 of the bolt 60. As a result, even if the bolt 60 loosens and moves axially, the head 61 of the bolt 60 will catch on the flange portion 73, preventing the bolt 60 from falling out axially. [Explanation of Symbols]

[0043] 1 Tapered roller bearing (roller bearing) 10 Inner Ring 11 Inner ring raceway surface 11a Other axial end 13. Tsuba (guard) 15 Internal Boss Section 15a Screw hole 17 Step section 20 Outer ring 21 Outer ring raceway surface 30 yen water roller 40 Retainer 41,42 Annular section 43 pins 50 Flange member 50a Outer surface 50b Groove 51 Base 51a Other end surface in axial direction 51b Recess 51c bottom 51d One end surface in the axial direction 51e Through hole 53 Convex part 60 bolts (fastening members) 61 Head 63 Shaft 63a Threaded portion 63b Torso 70 Cover component 71 Main body 71a Protrusion 73 Flange section A,B virtual plane D1,D2 Outer diameter

Claims

1. An inner ring having an inner ring raceway surface on its outer circumference, An outer ring having an outer ring raceway surface on its inner circumference, Multiple rollers are arranged to roll freely between the inner ring raceway surface and the outer ring raceway surface, A roller bearing comprising, A flange portion, which is integral with the inner ring, is formed at one axial end of the inner ring. A flange member, separate from the inner ring, is fastened to the other axial end of the inner ring by a fastening member extending in the axial direction. The fastening member has a head and a shaft portion extending from the head toward one axial end, The flange member abuts the inner ring in the axial direction and has a base on which the head of the fastening member sits. A cover member is press-fitted and fixed to the outer circumferential surface of the flange member. The cover member is A main body portion is fixed to the outer circumferential surface of the flange member and extends in the axial direction, A flange portion extending radially inward from the main body portion, It has, The radially inner end of the flange portion is located radially inward from the radially outer end of the head of the fastening member. The base of the flange member has a through hole formed therein, which penetrates the base axially and has a female threaded portion on its outer surface. The inner ring has a screw hole with an internal thread on its outer surface, which extends axially, at a position opposite the through hole in the axial direction. The shaft portion of the fastening member is A threaded portion located at one axial end of the aforementioned shaft portion, having a male threaded portion on its outer surface, A body portion located on the other axial end side of the aforementioned threaded portion, which does not have a male threaded portion on its outer circumference, Includes, The outer diameter of the body is smaller than the outer diameter of the threaded portion. A roller bearing characterized in that, in the fastening state between the flange member and the inner ring by the fastening member, the threaded portion does not engage with the through hole but is screwed into the threaded hole.

2. The outer circumferential surface of the flange member is recessed with a groove extending radially inward. The main body portion of the cover member is provided with a projection that extends radially inward. The projection of the cover member engages with the groove of the flange member. The roller bearing according to claim 1.

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