JP2009092120A - Bearing supporting structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing supporting structure by which a rotary bearing can be reduced in press-fitting resistance and a variation thereof and its accuracy after press-fitting work can be more improved and further, a cutting scrap is not generated. <P>SOLUTION: Recesses 13 are formed on the outer circumferential surface 11a of a rotary shaft 11 in a mounting region where the rotary bearing 12 is mounted or on the inner circumferential surface of a housing. Upstream-side protrusions 14a crushed flatly by the rotary bearing 12 are formed at an upstream side in the recesses 13 and in the press-fitting direction of the rotary bearing 12. At the downstream side in the recesses 13 and in the press-fitting direction of the rotary bearing 12, downstream-side protrusions 14b are formed which have outer diameters smaller than that of the upstream-side protrusion 14a in the rotary shaft 11 and has an inner diameter larger than those of the upstream-side protrusions 14a in the housing. By press-fitting the rotary bearing 12, the upstream-side protrusions 14a and the downstream-side protrusions 14b are flatly crushed, and besides, the upstream-side protrusions 14a are flatly crushed so as to be pressed into the depressions 13. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a bearing support structure, and more particularly to a bearing support structure suitable for mounting a rotary bearing by press-fitting it into a rotary shaft or a housing.

  In general, a rotary bearing needs to be fixed by press-fitting an inner ring to a rotating shaft or an outer ring of the rotating shaft to a housing.

  The press-fitting allowance in this case is, for example, about 7 / 10,000 or less of the diameter of the rotating shaft, but if the outer peripheral surface of the rotating shaft or the inner peripheral surface of the housing is manufactured with such accuracy, the processing cost increases. There was a point. Further, when plating for the purpose of rust prevention is performed after pressing the housing, there is a problem that it is very difficult to manage the press-fitting allowance even if the plating thickness is μm level.

  Therefore, conventionally, a rotating shaft or a housing is made of a material that does not need to be plated, or a minute protrusion is formed on the rotating shaft or the housing side, and the minute protrusion is crimped by the rotating bearing to fix the rotating bearing. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 05-10340

  FIG. 5 shows, as in the case of Patent Document 1, a pressing tool 2 having a conical tip on the outer peripheral surface 1a of the rotating shaft 1 is pressed a plurality of times from the direction orthogonal to the rotating shaft 1 to surround each recess 3 In this example, the minute protrusions 4 are raised and formed.

  However, as shown in FIG. 6A in which the recess 3 and the minute protrusion 4 are enlarged, the minute protrusion 4 is located upstream of the rotary bearing 5 in the recess 3 in the press-fitting direction (the arrow direction in the figure). ) And the downstream side (left side of the figure) have the same size.

  As shown in FIGS. 6A to 6B, when the press-fitting of the rotary bearing 5 proceeds, the upstream microprojections 4a are crimped by plastic deformation and accommodated in the recesses 3, and the downstream microprojections 4b are accommodated. Further, it is similarly subjected to plastic deformation or cutting action. As shown in FIG. 5C, when the press-fitting of the rotary bearing 5 is completed, the minute protrusion 4b on the downstream side is cut and the shavings 6 are generated and fall off, adversely affecting the adjacent equipment, There were inconveniences such as rusting. Further, as shown in FIG. 4D, when the press-fitting of the rotary bearing 5 is completed, the minute protrusion 4b on the downstream side is plastically deformed and buried between the rotary bearing 5 and the rotary shaft 1 or adhered. As a result, the press-fit resistance increases, and the coaxial accuracy between the rotary shaft 1 and the rotary bearing 5 decreases.

  The present invention has been made in view of these problems, and can reduce the press-fit resistance of the rotary bearing and suppress variations, further improve the coaxial accuracy after press-fit, and generate shavings. Bearing support structure that can be applied to press-fitting of shafts using highly brittle materials and shafts with plating that is easy to peel off, and can be applied to cost-reduced and highly functional shafts. The purpose is to provide.

  In order to achieve the above object, the bearing support structure tooth of the present invention according to claim 1, the bearing for supporting the inner ring of the rotary bearing on the outer peripheral surface of the rotary shaft or the outer ring of the rotary bearing by press-fitting on the inner peripheral surface of the housing. In the support structure, a recess is formed on the outer peripheral surface of the rotary shaft or the inner peripheral surface of the housing in the mounting region where the rotary bearing is mounted, and the rotary bearing is located upstream of the rotary bearing in the press-fitting direction of the rotary bearing. An upstream convex portion that is crushed by the rotary bearing is formed downstream of the rotary bearing in the press-fitting direction of the rotary bearing, and the rotary shaft has an outer diameter that is smaller than the outer diameter of the upstream convex portion. Is formed with a downstream convex portion having an inner diameter larger than the inner diameter of the upstream convex portion, and the upstream convex portion is crushed by press-fitting the rotary bearing, and the upstream convex portion is Characterized in that it is crushed to push useless within.

  According to the present invention thus formed, an upstream convex portion that is crushed is formed on the upstream side in the press-fitting direction of the rotary bearing of the concave portion, The rotary bearing is press-fit because the housing has a downstream convex portion having an outer diameter smaller than an outer diameter of the upstream convex portion and an inner diameter larger than the inner diameter of the upstream convex portion in the housing. Thus, the upstream convex portion is crushed and the upstream convex portion is crushed so as to be pushed into the concave portion, so that the rotary bearing can be mounted on the outer peripheral surface of the rotating shaft or the inner peripheral surface of the housing. As a result, the press-fit resistance of the rotary bearing can be reduced and the variation can be kept small, the coaxial accuracy after press-fit can be further improved, the generation of shavings is eliminated, and a shaft using a highly brittle material It can also be applied to press-fitting of a shaft that has been plated so that it can be easily peeled off, and can be applied to cost reduction and a highly functional shaft.

  Further, in the bearing support structure according to claim 2, an inner diameter of the inner ring of the rotary bearing is formed to be larger than an outer diameter of the rotary shaft and smaller than an outer diameter of the downstream convex portion, and the rotary bearing The downstream convex portion is crushed by press fitting.

  According to the present invention formed as described above, since the inner ring of the rotary bearing is press-fitted into the rotary shaft, both the upstream convex portion and the downstream convex portion formed on the outer peripheral surface of the rotary shaft are crushed. The inner ring of the bearing can be press-fitted and mounted on the rotating shaft with extremely high accuracy.

  Further, in the bearing support structure according to claim 3, an outer diameter of the outer ring of the rotary bearing is formed to be smaller than an inner diameter of the housing and larger than an outer diameter of the downstream convex portion, and The downstream convex portion is crushed by press-fitting.

  According to the present invention formed in this way, both the upstream convex portion and the downstream convex portion formed on the inner peripheral surface of the housing are crushed by press-fitting the outer ring of the rotary bearing into the housing. The outer ring can be fitted into the housing with extremely high accuracy.

  Further, the bearing support structure according to claim 4 is characterized in that a plurality of recesses are formed on the outer peripheral surface of the rotating shaft or the inner peripheral surface of the housing so as to be arranged at equal positions in the circumferential direction.

  According to the present invention thus formed, the plurality of recesses are arranged in a balanced manner in the circumferential direction on the outer peripheral surface of the rotary shaft or the inner peripheral surface of the housing, so that the rotary bearing can be mounted with higher accuracy. .

  In the bearing support structure according to claim 5, the concave portion, the upstream convex portion, and the downstream convex portion are in a direction opposite to the press-fitting direction of the rotary bearing with respect to the outer peripheral surface of the rotating shaft or the inner peripheral surface of the housing. It is formed by inclining and pushing the crushing tool toward.

  According to the present invention formed in this way, while forming the recess with the crushing tool, the crushing tool is crushed to the downstream side in the press-fitting direction of the rotary bearing and the upstream convex part that is largely crushed in the press-fitting direction upstream of the rotary bearing. The downstream convex portion can be formed.

  Further, in the bearing support structure according to claim 6, the concave portion, the upstream convex portion, and the downstream convex portion are formed in the concave portion, the upstream convex portion, and the downstream side with respect to the outer peripheral surface of the rotating shaft or the inner peripheral surface of the housing. The rotary crushing tool provided with at least one protrusion on the outer peripheral surface for transferring the convex part is formed by being pushed in from the direction orthogonal to the rotary shaft or the housing.

  According to the present invention thus formed, a plurality of concave portions, upstream convex portions, and downstream convex portions can be formed by rolling with a rotary crushing tool.

  The bearing support structure according to claim 7 is characterized in that at least one recess is formed as an annular groove continuous in the circumferential direction on the outer peripheral surface of the rotating shaft or the inner peripheral surface of the housing.

  According to the present invention formed as described above, the concave portion formed of the annular groove that is continuous in the circumferential direction is formed on the outer peripheral surface of the rotating shaft or the inner peripheral surface of the housing. be able to.

  In the bearing support structure according to claim 8, the concave portion, the upstream convex portion, and the downstream convex portion are recessed, upstream convex portion, and downstream side with respect to the outer peripheral surface of the rotating shaft or the inner peripheral surface of the housing. The rotary crushing tool having a cross section for transferring the convex portion is formed by pressing it in a direction orthogonal to the rotation axis.

  According to the present invention formed as described above, it is possible to form the concave portion, the upstream convex portion, and the downstream convex portion that are formed by the annular groove continuous in the circumferential direction by rolling with the rotary crushing tool.

  As described above, since the bearing support structure of the present invention is configured and operates, the press-fit resistance of the rotary bearing can be reduced and the variation can be suppressed, and the coaxial accuracy after press-fit can be further improved. It can be applied to shafts using highly brittle materials and shafts with easy-to-peel plating, eliminating the generation of shavings. Excellent effects such as adaptability can be exhibited.

  Embodiments of the bearing support structure of the present invention will be described below with reference to FIGS.

  1 and 2 show a first embodiment of the bearing support structure of the present invention.

  As shown in FIGS. 1 and 2, the bearing support structure of the present embodiment shows a case where the inner ring 12 a of the rotary bearing 12 is mounted on the outer peripheral surface 11 a of the rotary shaft 11.

  A plurality of recesses 13 are formed on the outer peripheral surface 11 a of the rotary shaft 11 in a mounting region 11 b where the rotary bearing 12 is mounted. In each recess 13, as shown in FIG. 2A, which shows an enlarged cross-section, an upstream convex portion that is largely crushed by the rotary bearing 12 on the upstream side in the press-fitting direction of the rotary bearing 12 (arrow direction in the figure). 14a is formed, and on the downstream side of the concave portion 13 in the press-fitting direction of the rotary bearing 12, a downstream convex portion 14b that is crushed by the rotary bearing 12 is formed. Explaining these dimensional relationships, the inner diameter of the inner ring 12a of the rotary bearing 12 is larger than the outer diameter of the outer peripheral surface 11a of the rotating shaft 11, and smaller than the outer diameter of the downstream convex portion 14b. Of course, the outer diameter of the upstream convex portion 14a is larger than the outer diameter of the downstream convex portion 14b. Further, as shown in FIGS. 1A and 1B, the plurality of recesses 13 are formed by being arranged on the outer circumferential surface 11a of the rotating shaft 11 at equally divided positions in the circumferential direction (in this embodiment, eight equal parts). Has been. In the present embodiment, a total of 16 recesses 13 are formed in two rows in the axial direction. Further, the recesses 13 may be arranged in three rows in the axial direction, and these may be arranged in a staggered manner.

  Next, the manufacturing method of each recessed part 13 is demonstrated.

  As shown in FIGS. 1 (a) to 1 (c), the crushing tool 15 having a cut surface 15 a obtained by slightly cutting the front end surface of the cylindrical rod-shaped crushing tool 15 is opposite to the press-fitting direction of the rotary bearing 12. The concave portion 13, the upstream convex portion 14 a, and the downstream convex portion 14 b are formed by inclining with respect to the outer peripheral surface 11 a of the rotating shaft 11 and pushing in a predetermined depth. To explain further. As shown in FIG.1 (c), the upstream convex part 14a is formed uplifting by the front end surface 15b of the crushing tool 15, and the rotating shaft 11 is formed by a component component inclined with respect to the axial direction of the crushing tool 15 on the cut surface 15a. By pressing the outer peripheral surface 11a in the diametrical direction, the downstream convex portion 14b is raised and formed.

  Next, an assembly method of the rotary shaft 11 and the rotary bearing 12 will be described with reference to FIG.

  As shown in FIG. 2A, when the inner ring 12a of the rotary bearing 12 is pressed into the outer peripheral surface 11a of the rotary shaft 11 in the press-fitting direction indicated by the left-pointing arrow in FIG. First, the upstream convex portion 14 a that largely protrudes from the outer peripheral surface 11 a is crimped so as to be plastically deformed by the R-chamfered end portion of the inner ring 12 a and is crushed to be pushed into the concave portion 13. If the press-fitting of the rotary bearing 12 is further continued, as shown in FIG. 2 (c), the end of the inner ring 12a exceeds the recess 13, and the downstream convex part 14b protruding slightly from the outer peripheral surface 11a is then the inner ring 12a. It is crimped so as to be plastically deformed by the R-chamfered end portion. Furthermore, press-fitting is completed by press-fitting the inner ring 12a to a predetermined position.

  In the bearing support structure of the present embodiment assembled in this way, the upstream convex portion 14a that is largely crushed is formed on the upstream side of the concave bearing 13 in the press-fitting direction of the rotary bearing 12, and the concave bearing 13 press-fits the rotary bearing 12 Since the downstream convex portion 14b that is crushed small is formed on the downstream side in the direction, the upstream convex portion 14a and the downstream convex portion 14b are crushed and the upstream convex portion 14a by press-fitting the rotary bearing 12. And the rotary bearing 12 is mounted on the outer peripheral surface 11 a of the rotary shaft 11 by being crushed so as to be pushed into the concave portion 13 which is covered with the inner peripheral surface of the inner ring 12 a and finally becomes a closed space when press-fitting of the rotary bearing 12 is completed. Can do. As a result, the press-fit resistance of the rotary bearing 12 can be reduced and variations can be suppressed, and the coaxial accuracy after press-fit can be further improved. Further, as shown in FIGS. 1 (a) and 1 (b), the rotating shaft 11 is partially cut away so as to form a facing surface 11c facing in the diametrical direction so that the cross section becomes an oval shape. Even if formed, it can eliminate the generation of shavings, and can be applied to the press-fitting of a shaft using a highly brittle material or a plated shaft that is easy to peel off. It can be adapted to any axis.

  In addition, since the inner diameter of the inner ring 12a is larger than the outer diameter of the outer peripheral surface 11a of the rotating shaft 11 and smaller than the outer diameter of the downstream convex portion 14b, the inner ring 12a of the rotating bearing 12 can be made to the rotating shaft 11 with extremely high accuracy. Can be press-fitted into and installed.

  Further, since the plurality of recesses 13 are arranged in a balanced manner on the outer peripheral surface 11a of the rotating shaft 11 at equal positions in the circumferential direction, the rotary bearing 12 can be mounted with higher accuracy.

  FIG. 3 shows a second embodiment of the bearing support structure of the present invention. An annular groove in which the concave portion 13, the upstream convex portion 14a, and the downstream convex portion 14b are continuously connected to the outer peripheral surface 11a of the rotating shaft 11 in the circumferential direction. At least one (in this embodiment, two). As shown in FIGS. 3A, 3 </ b> C, and 3 </ b> D, the annular concave portion 13, the upstream convex portion 14 a, and the downstream convex portion 14 b are formed on the concave portion 13 and the upstream side with respect to the outer peripheral surface 11 a of the rotating shaft 11. The rotary crushing tool 16 having a cross section for transferring the side convex portion 14a and the downstream side convex portion 14b is formed by pressing it from the direction orthogonal to the rotary shaft 11 and rolling it. As shown in FIG. 3C, the cross-section of the rotary crushing tool 16 is formed by a slope 16a that forms an upstream convex portion 14a and a slope 16b that forms a downstream convex portion 14b. Angles θa and θb formed between the inclined surfaces 16a and 16b and the pressing direction x of the rotary crushing tool 16 with respect to the rotary shaft 11 (a direction perpendicular to the rotary shaft 11) are formed as θa> θb.

  In the present embodiment, the annular concave portion 13, the upstream convex portion 14 a and the downstream convex portion 14 b that are continuous in the circumferential direction are formed on the outer peripheral surface 11 a of the rotating shaft 11. Can be worn.

  FIG. 4 shows a third embodiment of the bearing support structure of the present invention. Instead of the rotary crushing tool 16 of FIG. 3, a crushing surface 17c that can crush the tip of the downstream convex portion 14b slightly in advance. The crushing tool 17 having a crushing portion is provided with at least one concave groove 13, an upstream convex portion 14a and a downstream convex portion 14b as an annular groove continuous in the circumferential direction with the outer peripheral surface 11a of the rotating shaft 11 (in this embodiment, 2) formed. The slope 17a forming the upstream convex portion 14a and the slope 17b forming the downstream convex portion 14b of the rotary crushing tool 17 are formed in the same manner as the slopes 16a and 16b of the rotary crushing tool 16 of FIG. A crushing surface 17c is formed continuously with the slope 17b forming the downstream convex portion 14b.

  In the present embodiment, the annular downstream convex portion 14b continuous in the circumferential direction is slightly crushed in advance, so that the caulking operation of the inner ring 12a of the rotary bearing 12 is easier than in the embodiment of FIG. At the same time, the rotary bearing 12 can be mounted with higher accuracy.

  By forming notches (not shown) in the circumferential direction of the inclined surfaces 16a, 16b, 17a, 17b and the crushing surface 17c of the rotary crushing tools 16, 17, the annular grooves are discontinuous. It is preferable to form the plurality of concave portions 13, the upstream convex portions 14a, and the downstream convex portions 14b as shown in FIG. Thus, the plurality of concave portions 13, the upstream convex portions 14a, and the downstream convex portions 14b can be formed by rolling with a rotary crushing tool.

  In addition, although each said embodiment showed the case where the rotating bearing 12 was mounted | worn with the rotating shaft 11, it can apply similarly when mounting the rotating bearing 12 to a housing, and exhibits the same effect. be able to. Specifically, the concave portion 13, the upstream convex portion 14a and the downstream convex portion 14b formed on the outer peripheral surface 11a of the rotating shaft 11 are formed on the inner peripheral surface of the housing (not shown), and the outer ring ( (Not shown) may be press-fitted.

  In addition, this invention is not limited to each embodiment mentioned above, A various change is possible as needed.

  For example, the convex portion to be crushed by the rotary bearing 12 may be only the upstream convex portion 14a. At this time, the inner diameter of the inner ring of the rotary bearing 12 may be formed smaller than the outer diameter of the upstream convex portion 14a formed on the rotary shaft 11 and larger than the outer diameter of the downstream convex portion 14b. Further, the outer diameter of the outer ring of the rotary bearing 12 may be formed larger than the inner diameter of the upstream convex portion 14a formed in the housing and smaller than the inner diameter of the downstream convex portion 14b.

1 shows a first embodiment of a bearing support structure according to the present invention, in which (a) is a front view of a rotating shaft, (b) is a right side view of (a), and (c) is an enlarged sectional view of a recess. (A) to (c) is an enlarged cross-sectional view showing a process of press-fitting a rotary bearing into the rotary shaft in the first embodiment. 2 shows a second embodiment of a bearing support structure according to the present invention, (a) is a front view of a rotating shaft, (b) is a right side view of (a), (c) is an enlarged sectional view of a rotary crushing tool, (D) is an enlarged sectional view of the recess. The same figure as FIG. 1 which shows 3rd Embodiment of the bearing support structure which concerns on this invention (A) (b) is the same figure as FIG. 1 which shows the example of the conventional bearing support structure (A) to (d) is a view similar to FIG. 2 showing an example of a conventional bearing support structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Rotating shaft 11a Outer peripheral surface 12 Rotary bearing 12a Inner ring 13 Concave part 14a Upstream convex part 14b Downstream convex part 15 Crushing tool 16, 17 Rotary crushing tool

Claims (8)

In a bearing support structure in which an inner ring of a rotary bearing is press-fitted and supported on an outer peripheral surface of a rotary shaft, or an outer ring of a rotary bearing is pressed into an inner peripheral surface of a housing, the outer peripheral surface of the rotary shaft in a mounting region where the rotary bearing is mounted Alternatively, a concave portion is formed on the inner peripheral surface of the housing, and an upstream convex portion that is crushed by the rotary bearing is formed on the upstream side of the concave bearing in the press-fitting direction of the rotary bearing. On the downstream side in the direction, a downstream convex portion having an outer diameter smaller than the outer diameter of the upstream convex portion in the rotating shaft and having an inner diameter larger than the inner diameter of the upstream convex portion is formed in the housing. A bearing support structure, wherein the upstream convex portion is crushed by press-fitting the rotary bearing, and the upstream convex portion is crushed so as to be pushed into the concave portion. The inner diameter of the inner ring of the rotary bearing is larger than the outer diameter of the rotating shaft and smaller than the outer diameter of the downstream convex portion, and the downstream convex portion is crushed by press-fitting the rotary bearing. The bearing support structure according to claim 1, wherein: The outer diameter of the outer ring of the rotary bearing is smaller than the inner diameter of the housing and larger than the outer diameter of the downstream convex portion, and the downstream convex portion is crushed by press-fitting the rotary bearing. The bearing support structure according to claim 1. The said recessed part is formed in multiple numbers by arrange | positioning in the circumferential direction equal position in the outer peripheral surface of the said rotating shaft, or the inner peripheral surface of a housing, The any one of Claims 1-3 characterized by the above-mentioned. The bearing support structure described in 1. The concave portion, the upstream convex portion, and the downstream convex portion are inclined and pressed against the outer peripheral surface of the rotary shaft or the inner peripheral surface of the housing in a direction opposite to the press-fitting direction of the rotary bearing. The bearing support structure according to claim 4, wherein the bearing support structure is formed. The concave portion, the upstream convex portion, and the downstream convex portion are formed on the outer peripheral surface of the protrusion that transfers the concave portion, the upstream convex portion, and the downstream convex portion to the outer peripheral surface of the rotating shaft or the inner peripheral surface of the housing. 5. The bearing support structure according to claim 4, wherein at least one rotary crushing tool is inserted in a direction orthogonal to the rotary shaft or the housing. The said recessed part is formed in the outer peripheral surface of the said rotating shaft or the internal peripheral surface of a housing at least 1 piece as an annular groove which continues in the circumferential direction, The any one of Claims 1-3 characterized by the above-mentioned. The bearing support structure described. The concave portion, the upstream convex portion, and the downstream convex portion have a cross section that transfers the concave portion, the upstream convex portion, and the downstream convex portion to the outer peripheral surface of the rotating shaft or the inner peripheral surface of the housing. The bearing support structure according to claim 7, wherein the crushing tool is pushed in from a direction orthogonal to the rotation shaft.

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