JP5912413B2 - Solid lubricant embedded bearing and manufacturing method thereof - Google Patents

Description

  The present invention relates to a solid lubricant embedded bearing, and more particularly to a solid lubricant embedded structure on a sliding surface.

  Solid lubricant embedded bearings are plain bearings in which a solid lubricant is embedded in the sliding surface of the bearing body that is the base. Durability that can be used under high load conditions compared to general sliding bearings. Further, it has advantages such as excellent performance stability. In such a solid lubricant embedded bearing, a solid lubricant embedded structure with respect to the sliding surface is a plug-shaped solid lubricant in a through-hole or a blind hole formed perpendicular to the sliding surface. The inserted type (for example, FIG. 5 of Patent Document 1), a type of fluid lubricant that is poured into a spiral groove formed on the sliding surface, and this is cured to form a solid lubricant (for example, Patent Document 2). ) Etc. are known. However, the latter type is limited in the types of lubricants that can be used, and lacks versatility and increases the manufacturing cost. Yes.

JP 11-166539 A Japanese Patent Laid-Open No. 6-200946

  By the way, when the shaft supported by the solid lubricant embedded bearing moves relative to the solid lubricant embedded bearing, the solid lubricant is caused to slide by sliding between the shaft surface and the solid lubricant. Wrap and lubricate. Therefore, the lubrication range of the shaft surface is determined by the relative amount of movement between the shaft and the solid lubricant embedded bearing. For example, when the shaft rotates slightly relative to the solid lubricant embedded bearing, the relative rotation amount (movement amount in the circumferential direction) between the shaft and the solid lubricant embedded bearing is in the circumferential direction. If the pitch is shorter than the arrangement pitch of the solid lubricants in the above, a region that is not wrapped with the solid lubricants is generated on the surface of the bearing body. For this reason, lubricity may deteriorate, and in order to prevent this, it is necessary to narrow the arrangement pitch of the solid lubricants in the circumferential direction.

  However, in the former type of solid lubricant embedded bearing, there is a limit to narrowing the arrangement pitch of the solid lubricant in the circumferential direction. In other words, in order to overlap the lap region with the solid lubricant in the axial direction, it is necessary to arrange a plurality of circumferential solid lubricant rows in the axial direction at a pitch shorter than the diameter of the solid lubricant. For this reason, the solid lubricant in the circumferential solid lubricant row in the upper and lower stages of the solid lubricant row in the axial direction must be positioned between adjacent solid lubricants in the circumferential solid lubricant row. I must. Therefore, if the holes for inserting the solid lubricant are punched out at a narrow pitch in the circumferential direction, the distance between the adjacent holes becomes too close and the strength of the bearing body is reduced.

  Further, in the former type solid lubricant embedded type bearing, since the hole for embedding the solid lubricant is formed perpendicular to the sliding surface of the bearing body, the inner peripheral surface of the hole and the solid lubricant The contact area with the outer peripheral surface depends on the thickness (thickness from the inner peripheral surface (sliding surface) to the outer peripheral surface) of the solid lubricant embedded bearing. For this reason, when the bearing body is thinned, a sufficient contact area with the solid lubricant cannot be ensured, and the solid lubricant easily falls out of the hole.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a solid lubricant-embedded bearing that has good lubricity with respect to the relative minute rotation of the shaft to be supported and the solid lubricant is difficult to come off. To provide a structure.

  In order to solve the above problems, the present invention forms a plurality of axial grooves from one end face to the other end face on the inner peripheral surface or outer peripheral surface of the bearing body, and fills the inside of these grooves. A rod-shaped solid lubricant was inserted into each groove.

For example, one embodiment of the present invention provides
A solid lubricant embedded bearing having a sliding surface for supporting a rotating body,
A cylindrical bearing body in which a plurality of axial grooves from one end surface to the other end surface are formed on the inner peripheral surface or the outer peripheral surface;
A plurality of rod-shaped solid lubricants fitted in each of the grooves so as to fill the interior of each of the grooves in the axial direction ,
The inner peripheral surface or the outer peripheral surface in which the axial groove is formed,
Together with the solid lubricant exposed at the inner peripheral surface side or the outer peripheral surface side opening of the axial groove, the sliding surface is configured,
The axial groove is
The groove width of the opening on the sliding surface, has a narrow trapezoidal radial cross-section than the groove width of the flat groove bottom along the axial direction,
The rod-shaped solid lubricant is
It has a surface in surface contact with the groove bottom of the axial groove in the axial direction, and is formed in a trapezoidal shape that aligns with the axial groove.
Another aspect of the present invention is as follows:
A method of manufacturing a solid lubricant embedded bearing having a sliding surface for supporting a rotating body,
It is formed along the axial direction from one end surface of the bearing body to the other end surface on the inner or outer peripheral surface of the cylindrical bearing body, and the groove width of the opening on the sliding surface is in the axial direction. Each of the grooves having a trapezoidal radial cross-sectional shape narrower than the groove width of the flat groove bottom along the trapezoidal shape having a surface in surface contact with the groove bottom of the groove in the axial direction and matching the groove The solid lubricant formed on the one end face or the other end face is inserted,
The exposed surface of the solid lubricant from the groove is shaved along the inner or outer peripheral surface of the cylindrical bearing body in which the groove is formed .

  According to the present invention, a plurality of axial grooves are formed on the sliding surface of the bearing body, and the solid lubricant is fitted into these grooves. There is no need to punch in close proximity. For this reason, the strength of the bearing body can be kept higher than in the prior art, and the arrangement pitch in the circumferential direction on the sliding surface of the solid lubricant can be reduced. Therefore, the portion that is not wrapped by the solid lubricant generated on the surface of the bearing body can be reduced with respect to the relative minute rotation of the supporting rotating body. Can be improved. Also, since the groove of the bearing body can make the contact area between the inner wall and the solid lubricant longer in the axial direction, the contact area between the solid lubricant and the bearing body is sufficient even when the bearing body is thinned. Therefore, it is possible to make it difficult to remove the solid lubricant from the groove of the bearing body.

FIG. 1A is a front view of a solid lubricant embedded bearing 1 according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line AA of FIG. . 2 (A) and 2 (B) are diagrams for explaining a method of embedding the solid lubricant 3 in the solid lubricant embedded bearing 1 using an enlarged view of part B of FIG. 1 (A). . 3 (A) and 3 (B) show an embedded solid lubricant 3a in a modified example of the solid lubricant embedded bearing 1 using a partially enlarged view corresponding to the enlarged view of the B part in FIG. 1 (A). It is a figure for demonstrating a method.

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

  FIG. 1A is a front view of a solid lubricant embedded bearing 1 according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line AA of FIG. .

  As shown in the figure, a solid lubricant embedded bearing 1 according to the present embodiment includes a metal bearing body 2 made of iron, copper alloy, or the like, and a plurality of resin solid lubricants embedded in the bearing body 2. Agent 3 is provided.

  The bearing body 2 has a cylindrical shape, and a groove 25 connected from one end surface 23 to the other end surface 24 along the axial direction α is formed in the inner peripheral surface 21 in the circumferential direction β. A plurality are formed at an array pitch γ. Each groove 25 has a groove width d1 that is smaller than the maximum groove width d2 of the groove 25 in the opening 26 on the inner peripheral surface 21 of the bearing body 2 (see FIG. 2B). In the present embodiment, the cross section of each groove 25 perpendicular to the axial direction α has a circular shape partially cut away by the opening 26 on the inner peripheral surface 21. The width d1 is narrower than the maximum groove width d2 at the position of the outer peripheral surface 22 side (inside the groove) 27. In order to facilitate the handling of the bearing body 2, the inner and outer peripheral edges 29 of the end faces 23 and 24 on both sides of the bearing body 2 may be chamfered.

  The solid lubricant 3 is molded into a rod shape having a cross-sectional shape that matches the cross-sectional shape perpendicular to the axial direction α of the groove 25, and is fitted into the groove 25 so as to fill the inside of the groove 25. Is partially exposed. Thereby, the inner peripheral surface 21 of the bearing body 2 constitutes a sliding surface that supports a shaft (not shown) inserted into the bearing body 2 together with the solid lubricant 3 exposed from the opening 26 of the groove 25. Yes. The solid lubricant 3 is made of, for example, a fired graphite alone, a resin made of fired graphite, or a soft metal such as indium, zinc or tin, or a hard adhesive such as wax. A material and a resin-made material including a tetrafluoroethylene resin are used.

  Next, a method for embedding the solid lubricant 3 in each groove 25 formed on the inner peripheral surface 21 of the bearing body 2 will be described.

  2 (A) and 2 (B) are diagrams for explaining a method of embedding the solid lubricant 3 using the enlarged view of the B part in FIG. 1 (A).

  As shown in FIG. 2A, the cylindrical solid lubricant 3 is fitted into the groove 25 from either one of the end faces 23 and 24 of the bearing body 2. At this time, the solid lubricant 3 may be inserted into the groove 25 by cold fitting. That is, utilizing the fact that the thermal expansion coefficient of the resin is larger than the thermal expansion coefficient of the metal, the solid lubricant 3 is cooled with dry ice or the like and sufficiently contracted to fit in the groove 25 of the bearing body 2. To be inserted into the groove 25. Thereafter, the solid lubricant 3 is expanded by returning to room temperature, and the solid lubricant 3 is fitted into the groove 25. Alternatively, the solid lubricant 3 may be bonded to the inner wall of the groove 25 using an adhesive.

  Next, as shown in FIG. 2B, the end surfaces 23 and 24 of the bearing body 2 are cut to align the end surfaces 31 of the solid lubricant 3 with the end surfaces 23 and 24 of the bearing body 2. Then, by cutting the inner peripheral surface 21 of the bearing body 2, the protruding portion 32 of the solid lubricant 3 from the opening 26 of the groove 25 formed in the inner peripheral surface 21 of the bearing body 2 is removed, The exposed surface 33 of the solid lubricant 3 from the opening 26 of the groove 25 is finished so as to be smoothly aligned with the surface shape of the inner peripheral surface 21 of the bearing body 2.

  In this way, the solid lubricant 3 is fitted into each of the grooves 25 so as to fill the inside of each groove 25 formed on the inner peripheral surface 21 of the bearing body 2.

  The embodiment of the present invention has been described above.

  In the present embodiment, on the inner peripheral surface 21 of the bearing body 2, a plurality of grooves 25 in the axial direction α continuously connected from one end surface 23 to the other end surface 24 are formed, and the inside of these grooves 25 is filled. In addition, the rod-like solid lubricant 3 is inserted into the groove 25 respectively.

  For this reason, since it is not necessary to punch a plurality of holes for embedding the solid lubricant close to the bearing body 2, the solid lubricant is inserted into the plurality of through holes formed perpendicular to the sliding surface. Compared with a conventional solid lubricant embedded bearing of the type, the strength of the bearing body 2 can be kept higher. In the sliding surface (the inner peripheral surface 21 of the bearing body 2), the solid lubricant 3 reaches the other end surface 24 from one end surface 23 of the bearing body 2, and the arrangement pitch in the circumferential direction β. γ can be narrowed. As a result, the portion that is not wrapped by the solid lubricant 3 generated on the surface of the bearing body 2 can be reduced with respect to the relative minute rotation of the supporting shaft, so that the lubricity against the relative rotation of the supporting shaft is improved. Can be made.

  Further, since the contact area between the bearing body 2 and the solid lubricant 3 can be increased in the axial direction α, a sufficient contact area with the solid lubricant 3 can be ensured even when the bearing body 2 is thinned. Can do. For this reason, the solid lubricant 3 fitted in the groove 25 of the bearing body 2 can be made difficult to come off.

  Further, in the present embodiment, the cross section perpendicular to the axial direction α of the groove 25 has a circular shape partially cut away by the opening 26 of the groove 25 formed on the inner peripheral surface 21 of the bearing body 2. The groove width d1 of the opening 26 is smaller than the maximum groove width d2 of the groove interior 27. For this reason, the solid lubricant 3 does not fall off from the opening 26 of the groove 25, and therefore the solid lubricant 3 fitted in the groove 25 of the bearing body 2 can be further prevented from coming off.

  In the present embodiment, a plurality of grooves 25 in the axial direction α that are continuously connected from one end surface 23 to the other end surface 24 are formed. It is also possible to apply a groove shape that is formed through a recess and that extends from both end surface portions toward the recess end surface portion.

  Further, the bearing body 2 is not limited to a cylindrical shape, for example, a form having a sliding surface partially having a shape complementary to the outer peripheral surface or inner peripheral surface of the rotating body, such as a semi-cylindrical shape that is a half of a cylindrical shape. It is also applicable to.

  Further, in the present embodiment, the cross section perpendicular to the axial direction α of the groove 25 has a circular shape in which a part is notched by the opening 26 of the groove 25 formed on the inner peripheral surface 21. However, the present invention is not limited to this. The groove 25 only needs to have a groove width d1 smaller than the maximum groove width d2 of the groove 25 in the opening 26 on the inner peripheral surface 21 of the bearing body 2, and a cross section perpendicular to the axial direction α of the groove 25. The shape may be a shape other than a circle. Hereinafter, as a modified example of the solid lubricant embedded bearing 1, a solid lubricant embedded bearing in which a groove 25a having a cross-sectional shape other than a circle is formed in the bearing body 21 will be described.

  3 (A) and 3 (B) show an embedded solid lubricant 3a in a modified example of the solid lubricant embedded bearing 1 using a partially enlarged view corresponding to the enlarged view of the B part in FIG. 1 (A). It is a figure for demonstrating a method.

  In the solid lubricant embedded bearing according to this modification, the cross section perpendicular to the axial direction α of the groove 25a is such that the groove width d1 in the opening 26a on the inner peripheral surface 21 is the maximum groove width d2 (groove) in the groove inner 27a. It has a trapezoidal shape smaller than the groove width at the bottom surface 28 of 25a.

  In order to fabricate this solid lubricant embedded bearing, first, as shown in FIG. 3A, a columnar solid lubricant 3a is inserted into the groove 25a from either one of the end faces 23, 24 of the bearing body 2. insert. At this time, as in the above embodiment, the solid lubricant 3a may be tightly fitted in the groove 25a by cold fitting. Alternatively, the solid lubricant 3a may be bonded to the inner wall of the groove 25a using an adhesive. Next, as shown in FIG. 3B, the end surfaces 23 and 24 of the bearing body 2 are cut to align the end surfaces 31 a of the solid lubricant 3 a with the end surfaces 23 and 24 of the bearing body 2. Further, by cutting the inner peripheral surface 21 of the bearing body 2, the protruding portion 32a of the solid lubricant 3a from the opening 26a of the groove 25a formed on the inner peripheral surface 21 of the bearing body 2 is removed, The exposed surface 33a of the solid lubricant 3a from the opening 26a of the groove 25a is finished so as to be smoothly aligned with the surface shape of the inner peripheral surface 21 of the bearing body 2.

  In this way, the solid lubricant 3a is fitted into each of the grooves 25a so as to fill the inside of each groove 25a formed on the inner peripheral surface 21 of the bearing body 2.

  In the embodiment described above, the solid lubricants 3 and 3a are inserted into the grooves 25 and 25a formed on the inner peripheral surface 21 of the bearing body 2, but a rotating body such as a pulley can be rotated on the outer peripheral surface. As for the solid lubricant embedded bearing to be supported on the bearing body 2, a plurality of grooves in the axial direction α extending from one end surface 23 of the bearing body 2 to the other end surface 24 are arranged at a predetermined arrangement pitch in the circumferential direction β. The solid lubricant may be embedded in these grooves. Also in this case, each groove has a cross-sectional shape (for example, a circular shape or a trapezoidal shape) in which the groove width in the opening is narrower than the maximum groove width inside the groove, as in the above embodiment.

  1: solid lubricant embedded bearing, 2: bearing body, 3, 3a: solid lubricant, 21: bearing body, 2 inner circumferential surface, 22: outer circumferential surface of bearing body 2, 23, 24: bearing body 2 25, 25a: groove, 26, 26a: opening of groove 25, 25a, 27, 27a: inside of groove, 28: bottom surface of groove 25a, 29: edge of bearing body 2, 31, 31a: solid lubrication End surfaces of the agents 3, 3a, 32, 32a: protruding portions (cut portions) of the solid lubricants 3, 3a, 33, 33a: exposed surfaces of the solid lubricants 3, 3a from the openings 26, 26a of the grooves 25, 25a

Claims (4)

A solid lubricant embedded bearing having a sliding surface for supporting a rotating body,
A cylindrical bearing body in which a plurality of axial grooves from one end surface to the other end surface are formed on the inner peripheral surface or the outer peripheral surface;
A plurality of rod-shaped solid lubricants fitted in each of the grooves so as to fill the interior of each of the grooves in the axial direction ,
The inner peripheral surface or the outer peripheral surface in which the axial groove is formed,
Together with the solid lubricant exposed at the inner peripheral surface side or the outer peripheral surface side opening of the axial groove, the sliding surface is configured,
The axial groove is
The groove width of the opening on the sliding surface, has a narrow trapezoidal radial cross-section than the groove width of the flat groove bottom along the axial direction,
The rod-shaped solid lubricant is
A solid lubricant embedded bearing having a surface in surface contact with the groove bottom of the axial groove in the axial direction and formed in a trapezoidal shape aligned with the axial groove. The solid lubricant embedded bearing according to claim 1,
The axial groove is continuously connected in the axial direction from one end surface to the other end surface of the bearing body. A solid lubricant embedded bearing. A solid lubricant embedded bearing according to claim 1 or 2,
A plurality of the axial grooves are arranged in a circumferential direction of the bearing body at a predetermined arrangement pitch. A solid lubricant embedded bearing, wherein: A method of manufacturing a solid lubricant embedded bearing having a sliding surface for supporting a rotating body ,
It is formed along the axial direction from one end surface of the bearing body to the other end surface on the inner or outer peripheral surface of the cylindrical bearing body, and the groove width of the opening on the sliding surface is in the axial direction. Each of the grooves having a trapezoidal radial cross-sectional shape narrower than the groove width of the flat groove bottom along the surface has a surface in surface contact with the groove bottom of the groove in the axial direction and aligned with the groove A solid lubricant formed in a trapezoidal shape is inserted from the one end surface or the other end surface,
The exposed surface of the solid lubricant from the grooves, the solid lubricant embedded bearings, characterized in that that cutting along the inner peripheral surface or outer peripheral surface of the cylindrical bearing body in which the groove is formed Manufacturing method .

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