JP2018155346A - Slide bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slide bearing device which can be fixed to a rotor with a structure that does not have a locking claw, which can receive a shaft by a bearing inner diameter whole surface, which does not impair a rotation force at a thrust receiver, and which can suppress generation of sliding noise.SOLUTION: A slide bearing device 1 supports a rotor in a manner rotatable with respect to a support shaft and it includes: a substantially cylindrical resin bearing body 2 in which the support shaft 7 can be fitted and inserted; and a fitting part 3a of the rotor 3 for fitting and storing the bearing body 2. The bearing body 2 has a projection part 2a at a cylinder inner diameter bottom part, and a tip outer peripheral part of the support shaft 7 is supported by a cylinder inner diameter surface and a tip surface of the support shaft 7 is supported by the projection part 2a respectively. Between a bottom part 3b of the fitting part 3a and a bottom part 2b of the bearing body 2, a rubber ball 4' which is an elastic body is provided. On the opposite side form the bottom part of the fitting part 3a, a shaft stopping ring 5 for stopping the support shaft 7 from falling off, and a fixing member 6 for fixing the shaft stopping ring 5 are provided.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sliding bearing device in which a bearing body is made of resin, and more particularly to a sliding bearing device that is incorporated and fixed in a rotating body and rotatably supports the rotating body with respect to a support shaft.

  Synthetic resin sliding bearings are widely used as bearings that rotatably support a rotating body on a support shaft. Synthetic resin sliding bearings are often used in rotating parts with light loads and low rotational speeds because they are lighter in weight, simple in structure, less in number of parts, and less expensive than rolling bearings. Conventionally, such a sliding bearing made of resin is manufactured in a substantially cylindrical shape by injection molding of synthetic resin.

  As a sliding bearing made of resin, in Patent Document 1, a latching claw that can be elastically deformed protrudes from a part of a cylindrical body, and a resin sliding bearing that can be fixed to a rotating body by this latching claw. Proposed. This sliding bearing has a substantially cylindrical bearing body into which a support shaft can be inserted, a locking claw for fixing a rotating body to the sliding bearing, and a locking claw arranged on the outer peripheral side. And an elastic piece that can be elastically pushed into the inside of the cylinder of the bearing body. With this structure, the rotating body can be assembled and removed.

  Moreover, in the sliding bearing of patent document 1, an elastic piece has the gate trace by injection molding, and is integrally formed with the bearing main body. For this reason, the molten resin at the time of injection molding flows from the elastic piece to the bearing body, the flow at the boundary between the bearing body and the elastic piece is smooth, and the mechanical strength of the boundary is excellent. For this reason, even when the rotating body is installed incorrectly or when the rotating body is forcibly removed, the elastic piece supporting the locking claw is prevented from being damaged from the base boundary. it can.

Japanese Patent Laying-Open No. 2006-74127

  In Patent Document 1, the gate trace of the tunnel gate is on the inner peripheral surface of the elastic piece and the locking claw, but the inner peripheral surface is arranged outside the cylindrical inner diameter surface serving as a bearing surface and is not in contact with the support shaft. Since it is in a state, the gate trace and the locking claw do not contact the support shaft, and no extra sliding resistance is added during use. On the other hand, the inner peripheral surface such as the locking claw, unlike the cylindrical inner surface, does not function as a bearing surface of the sliding bearing and cannot receive a radial load. Therefore, depending on the use conditions, it may be desired to receive the shaft over the entire cylindrical inner surface of the slide bearing, such as stably supporting the shaft against a heavy load.

  Further, in a sliding bearing that supports one end of the shaft, it is necessary to support not only the radial load but also the thrust load received from the shaft end surface. In a conventional substantially cylindrical plain bearing, a closed cylindrical bottom or a retaining ring on the opposite side serves as a thrust receiver and supports the shaft end surface. In such a thrust receiver, depending on the use conditions, there may be a case where the rotational force loss becomes large and smooth rotation cannot be obtained, or a sliding noise may be generated on the thrust sliding surface.

  The present invention has been made to cope with such a problem, and can be fixed to a rotating body with a structure without a locking claw, can receive a shaft over the entire inner diameter of the bearing, and can be a thrust receiver. An object of the present invention is to provide a sliding bearing device that can suppress generation of sliding noise without impairing rotational force.

  The sliding bearing device of the present invention is a sliding bearing device that rotatably supports a rotating body on a support shaft, and the sliding bearing device includes a substantially cylindrical resin bearing body into which the support shaft can be inserted. And a fitting portion of the rotating body that fits and accommodates the bearing body, the bearing body has a convex portion at the bottom of the cylindrical inner diameter, and the tip outer peripheral portion of the support shaft is the cylindrical inner diameter. The support shaft supports the tip surface of the support shaft with the convex portion, and an elastic body is provided between the bottom portion of the fitting portion and the bottom portion of the bearing body. A shaft retaining ring for retaining the support shaft and a fixing member for fixing the shaft retaining ring are provided.

  The convex portion is a hemispherical convex portion formed integrally with the bearing body. The elastic body is a rubber material or a spring material.

  The fixing member is fixed to the rotating body by heat welding, ultrasonic welding, or an adhesive.

  The shaft retaining ring is a C-shaped retaining ring, and has a gap between an outer peripheral portion thereof and the rotating body, and expands the retaining ring in the radial direction when the support shaft is inserted into the bearing body. Thus, it is characterized by being elastically deformable.

  The sliding bearing device of the present invention includes a substantially cylindrical resin-made bearing body into which a support shaft can be inserted. The bearing body has a convex portion at the bottom of the inner diameter of the cylinder, and the outer periphery of the tip of the support shaft is cylindrical. Since the front end surface of the support shaft is supported by the convex portion on the inner diameter surface, the convex portion becomes a thrust receiver, and the rotational resistance can be reduced as compared with the case where the thrust receiver is a retaining ring or the like. Further, since the bearing body does not have a locking claw for fixing the rotating body, the support shaft can be received over the entire inner diameter of the bearing. As a result, the sliding bearing device can smoothly receive the load even when a strong load is applied to the rotating body while rotating smoothly even when receiving a load in the thrust direction.

  In addition, since an elastic body is disposed between the bottom of the fitting portion of the rotating body and the bottom of the bearing body, an appropriate thrust load due to the elastic force is applied to the bearing body to eliminate axial backlash. Can do. In particular, by using a rubber material or a spring material as the elastic body, a sufficient elastic force (repulsive force) can be stably exhibited over a long period of time.

  Furthermore, the shaft retaining ring is incorporated on the opposite side of the fitting portion of the rotating body, so that the supporting shaft can be prevented from coming off, and the fixing member is provided on the same side so that the shaft retaining ring can be removed. And can be prevented from coming off. As a result, the fixing force of the rotating body with respect to the support shaft is improved and stabilized, and the rotating body can be completely integrated with the rotating body, and the rotating body can be prevented from coming off the support shaft.

  Since the convex portion at the bottom of the cylindrical inner diameter of the bearing body is a hemisphere formed integrally with the bearing body, the tip end surface of the support shaft can be supported in a point-sliding manner, and the rotational resistance can be further reduced. Further, for example, the number of manufacturing steps can be reduced as compared with a case where the thrust receiving portion including the convex portion is a separate body. Furthermore, there is no possibility that the strength is inferior at the joint location as in the case of the separate body.

  Since the fixing member is fixed to the rotating body by heat welding, ultrasonic welding, or an adhesive, the fixing force is improved and stabilized as compared with the case of simple fitting and fixing.

  The shaft retaining ring is a C-shaped retaining ring, which has a gap between the outer peripheral portion and the rotating body, and is elastically deformed so that the retaining ring is radially expanded when the support shaft is inserted into the bearing body. Therefore, after the bearing body and the retaining ring are completely fixed to the rotating body, the support shaft can be incorporated and fixed by snap fitting.

It is sectional drawing which shows an example of the sliding bearing apparatus of this invention. It is sectional drawing in the case of inserting a support shaft in the sliding bearing apparatus of FIG. It is a perspective view of a bearing main body. It is sectional drawing of a bearing main body.

  The sliding bearing device of the present invention is a device configured by combining a resin-made sliding bearing body, a fitting portion of a rotating body that accommodates the resin bearing, a plurality of fixing means, and the like. In addition, the fitting part of the rotating body is a part constituted by a recess opened in a part of the rotating body so that the sliding bearing body can be accommodated regardless of the outer shape (cylindrical shape, spherical shape, etc.) of the rotating body. It is.

  The sliding bearing device of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view showing an example of a plain bearing device of the present invention. As shown in FIG. 1, the sliding bearing device 1 of the present invention includes a resin bearing body 2 and a fitting portion 3 a of a rotating body 3 that fits and accommodates the bearing body 2. The bearing body 2 has a substantially cylindrical shape into which a support shaft can be inserted. The bearing body 2 has a shape in which one cylindrical end (bottom 2b) is closed and the other cylindrical end (opening 2c) is opened. The bearing body 2 is accommodated in the fitting portion 3a of the rotating body 3 from the bottom 2b side. The bearing body 2 has a convex portion 2a at the cylindrical inner diameter bottom portion which is the inner diameter side of the bottom portion 2b. The convex portion 2a is a thrust receiver that supports the end surface of the support shaft, and is a so-called pivot bearing. Further, the sliding bearing device 1 includes an elastic body 4, a shaft retaining ring 5, and a fixing member 6 in order to fix the bearing body 2 to the fitting portion 3 a of the rotating body 3 while preventing the support shaft from coming off. . The elastic body 4 is provided between the bottom 3 b of the fitting portion 3 a and the bottom 2 b of the bearing body 2. The shaft retaining ring 5 is provided on the opening 2c side of the bearing body 2 on the opposite bottom side of the fitting portion 3a. The shaft retaining ring 5 is a member for preventing the support shaft from coming off from the bearing device. The fixing member 6 is provided outside the shaft retaining ring 5 on the side opposite to the bottom of the fitting portion 3 a and on the opening 2 c side of the bearing body 2. The fixing member 6 is a member for preventing the shaft retaining ring 5 from coming off (disengaging) from the bearing device.

  With reference to FIG. 2, the assembly procedure of this slide bearing apparatus 1 and the insertion procedure of a support shaft are demonstrated in detail. 2 is a cross-sectional view when the support shaft is inserted into the slide bearing device of FIG. 1, FIG. 2 (a) shows a state before the support shaft is inserted, and FIG. 2 (b) shows a state after the support shaft is inserted. Each state is shown. As shown in FIG. 2A, first, a rubber ball 4 ′ is disposed as an elastic body on the bottom 3 b of the fitting portion 3 a of the rotating body 3. The cylindrical bearing body 2 is inserted and fitted into the fitting portion 3a. The inner diameter surface of the portion of the fitting portion 3 a that fixes the bearing body is a cylindrical inner surface along the outer shape of the bearing body 2. Next, the shaft retaining ring 5 is assembled on the opening 2 c side of the bearing body 2. The shaft retaining ring 5 is incorporated in a stepped portion 3 c having a diameter wider than that of the fixed portion of the bearing body 2 in the fitting portion 3 a of the rotating body 3. A gap 3d is provided between the outer periphery of the shaft retaining ring 5 and the rotating body 3 (the inner diameter of the stepped portion 3c). The shaft retaining ring 5 having a C shape or the like can be expanded in the radial direction in such a manner that the diameter is increased in the gap portion. Next, on the side of the opening 2c of the bearing body 2, a ring-shaped fixing member 6 is incorporated outside the shaft retaining ring 5 and fixed by ultrasonic welding or the like. The fixing member 6 is fixed to the stepped portion 3e having a diameter wider than that of the fixing portion of the shaft retaining ring 5 in the fitting portion 3a of the rotating body 3.

  As shown in FIG. 2B, in this state, the support shaft 7 is fitted into the bearing body 2 from the opening 2 c side while passing through the hollow portions of the fixing member 6 and the shaft retaining ring 5. The support shaft 7 is inserted while spreading the shaft retaining ring 5, and the end surface 7 b of the support shaft 7 is brought into point contact with the hemispherical convex portion 2 a of the bottom portion 2 b of the bearing body 2. At this time, the rubber ball 4 ′ between the rotating body 3 and the bearing body 2 is pushed and deformed, and the elastic force (repulsive force) eliminates the backlash in the axial direction of the bearing body 2 with respect to the rotating body 3. Can do. Further, in this state, the shaft retaining ring 5 is fixed in a state where the diameter expansion is released and the shaft retaining ring 5 is fitted in the recessed step portion 7 a of the support shaft 7. The support shaft 7 is supported by the slide bearing device 1 by the above procedure. Specifically, the support shaft 7 has a front end outer peripheral portion 7c supported by the entire surface of the cylindrical inner diameter surface 2e, and a front end surface 7b supported by the convex portion 2a. With these configurations, the sliding bearing device 1 supports the rotating body 3 fixed to the bearing device so as to be rotatable with respect to the support shaft 7. Further, according to these configurations, the support shaft can be easily fixed by being snap-fit after the bearing body, the shaft retaining ring, and the fixing member are completely fixed to the rotating body.

  The outer shape of the rotating body 3 is not particularly limited, and may be a cylindrical or spherical rotating body. Further, the material and application of the rotating body are not particularly limited.

  The elastic body 4 is not particularly limited as long as it is provided between the bottom portion of the fitting portion and the bottom portion of the bearing body, and can prevent the above-described rattling and the like, in addition to the rubber material such as the rubber ball described above, Spring material (spring material) can be used. As the shape of the rubber material, a cylindrical shape, a bellows shape, a ring shape or the like can be used in addition to the above-described spherical shape, and the detailed shape, size, and hardness can be appropriately set so as to absorb the backlash in the axial direction. Moreover, as a spring material (spring material), a disc spring, a coil spring, etc. can be used. As the material, a material that does not rust is preferable, and stainless steel, surface-plated products, and the like can be used.

  The shaft retaining ring 5 can be used without limitation as long as it can be expanded in diameter by elastic deformation when the support shaft is inserted and can be fixed to the recessed step portion of the support shaft. As a shape, the above-mentioned C shape is preferable, and a metal or resin can be used as a material. The shaft retaining ring 5 itself is not fixed to the rotating body, but is disposed at a step portion of the rotating body and is held between the bearing body and the fixing member.

  The fixing member 6 can be used without limitation as long as it can be fixed to a predetermined portion of the rotating body. As a shape, the above-mentioned ring shape is preferable. The inner diameter of the ring must be such that the support shaft can be inserted and the retaining ring for the shaft cannot be removed. A material made of metal or resin can be used. As a fixing method to the rotating body, thermal welding, ultrasonic welding, or a method of fixing by fixing with an adhesive, a screw thread is provided on the outer diameter of the fixing member, and a screw groove is provided on the inner diameter portion of the rotating body. A method of fixing by screwing can be adopted. In the fixing method by fixing or screwing, the fixing force is improved as compared with the case of simple fitting and fixing, and the bearing body and the like can be stably held on the fitting portion of the rotating body. Which fixing method is used can be determined according to the material of the fixing member and the rotating body.

  A bearing body in the sliding bearing device of the present invention will be described with reference to FIGS. FIG. 3 is a perspective view of the bearing body, and FIG. 4 is a cross-sectional view of the bearing body. As shown in FIGS. 3 and 4, the bearing body 2 has a bottomed substantially cylindrical shape with one cylindrical end (bottom 2 b) closed and the other cylindrical end (opening 2 c) opened. The bearing body 2 is an injection molded body formed by injection molding a synthetic resin. The cylindrical inner diameter surface 2e is a complete cylindrical inner diameter surface that is free from unevenness due to claws or the like. The cylindrical inner diameter bottom portion, which is the inner diameter side of the bottom portion 2b, has a hemispherical convex portion 2a. As described above, the hemispherical convex portion 2a is a thrust receiver that supports the end surface of the support shaft. The shape of the convex portion is not particularly limited as long as the pivot bearing can be configured by dot-sliding contact, and may be a semi-conical shape, a substantially conical shape, a substantially polygonal conical shape, or the like.

  Since this convex portion is in point-sliding contact with the end surface of the support shaft, it is necessary to provide a gate for injection molding at a position where a weld line generated in the injection molded body does not occur in the convex portion. In the example shown in FIG. 4, the gate is provided in the gate mark escape portion 2d outside the convex portion 2a. The gate mark escape portion 2d is a recess provided so that the gate mark 8 does not protrude from the end face of the cylinder.

  Further, in order to obtain a smooth rotation of the cylindrical bearing body, it is necessary to increase the accuracy of the inner diameter roundness. By arranging the gate position at the time of injection molding of this bearing body outside the bottom of the cylindrical bearing body, there is no generation of a weld line at the hemispherical convex portion of the bottom of the cylindrical inner diameter, and the gate position is cylindrical. By using a so-called disc gate outside the bottom of the bearing, it is possible to finish the bearing with a high accuracy even in the roundness of the inner diameter of the bearing and the cylindricity.

  Further, in the sliding bearing device of the present invention, a radial bearing surface portion formed of a cylindrical inner diameter surface and a thrust bearing surface formed of a cylindrical inner diameter bottom portion and the convex portion may be separately formed and combined. In the case of a separate body, the inner diameter surface of the cylinder can be finished with high accuracy by using a disk gate. In addition, as a thrust bearing surface, it is good also as a structure which combined the metal-made or resin-made ball | bowl as a convex part on the resin-made cylindrical bottom part.

  The synthetic resin used for the bearing body of the sliding bearing device of the present invention is not particularly limited as long as it has sliding characteristics as a sliding bearing material. For example, polyacetal (POM) resin, polyphenylene sulfide (PPS) resin, polyamide (PA) resin, polyamideimide (PAI) resin, polytetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA) resin, tetrafluoroethylene / hexa Fluoropropylene copolymer (FEP) resin, ethylene-tetrafluoroethylene copolymer (ETFE) resin and other injection-moldable fluororesins, polyether ether ketone (PEEK) resin, injection-moldable polyimide (PI) resin, And polytetrafluoroethylene (PTFE) resin. Among these, injection-moldable synthetic resins are preferable. Each of these synthetic resins may be used alone or a polymer alloy in which two or more kinds are mixed.

  These synthetic resins may be blended with a solid lubricant such as PTFE resin or oil-impregnated resin blended with a lubricating oil in order to enhance sliding properties. Moreover, you may provide electroconductivity by mix | blending electrically conductive agents, such as carbon black. Furthermore, an inorganic filler such as iron oxide or carbon black may be blended to increase the hardness.

  The sliding bearing device of the present invention supports the outer peripheral portion of the tip of the support shaft with a cylindrical inner surface (entire surface), and supports the tip surface of the support shaft with a hemispherical convex portion or the like. Since the sliding contact is made, the rotational resistance can be reduced and the generation of sliding noise can be suppressed as compared with the case where the thrust receiver is a retaining ring or the like. In addition, in order to have a structure that does not have a locking claw so as to receive the support shaft on the entire surface of the cylindrical inner surface, the above-described predetermined structure including an elastic body, a shaft retaining ring, and a fixing member is provided around the bearing body. To prevent omissions and rattling. As a result, the sliding bearing device of the present invention can easily receive the load even when a strong load or the like is applied to the rotating body while rotating smoothly without rattling even when receiving a load in the thrust direction.

  The sliding bearing device of the present invention can be fixed to a rotating body with a structure without a locking claw, can receive a shaft over the entire inner diameter of the bearing, and does not impair rotational force with a thrust receiver, Since generation | occurrence | production can also be suppressed, it can utilize widely as a bearing apparatus for supporting a rotary body rotatably at the edge part with respect to arbitrary support shafts.

DESCRIPTION OF SYMBOLS 1 Sliding bearing apparatus 2 Bearing main body 3 Rotating body 4 Elastic body 5 Retaining ring for shaft 6 Fixing member 7 Support shaft 8 Gate trace

Claims (5)

A sliding bearing device that rotatably supports a rotating body on a support shaft,
The sliding bearing device includes a substantially cylindrical resin bearing body into which the support shaft can be inserted, and a fitting portion of the rotating body that fits and accommodates the bearing body.
The bearing main body has a convex portion at the bottom of the cylindrical inner diameter, and supports the outer peripheral portion of the tip of the support shaft with the cylindrical inner diameter surface, and supports the tip surface of the support shaft with the convex portion, respectively.
An elastic body is provided between the bottom of the fitting portion and the bottom of the bearing body,
A sliding bearing device comprising: a retaining ring for a shaft that prevents the supporting shaft from coming off; and a fixing member for securing the retaining ring for the shaft.   The sliding bearing device according to claim 1, wherein the convex portion is a hemispherical convex portion formed integrally with the bearing body.   The sliding bearing device according to claim 1, wherein the elastic body is a rubber material or a spring material.   The sliding bearing device according to any one of claims 1 to 3, wherein the fixing member is fixed to the rotating body by heat welding, ultrasonic welding, or an adhesive.   The shaft retaining ring is a C-shaped retaining ring, has a gap between the outer peripheral portion thereof and the rotating body, and expands the retaining ring in the radial direction when the support shaft is inserted into the bearing body. The sliding bearing device according to any one of claims 1 to 4, wherein the sliding bearing device is elastically deformable.

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