JPH05272544A - Bearing and manufacutre thereof - Google Patents

Abstract

PURPOSE:To reduce the number of constituting elements of a bearing, improve the precision of a shaft hole such as the circularity and concentricity of the inner diameter, and easily remove the machining powder generated during sizing. CONSTITUTION:A cylindrical bearing member 2 provided with a bearing cylindrical hole 2a having a constant inner diameter is pressed into an outer member 1 having a hole diameter smaller than the outer diameter of the bearing member 2 only near both end sections 1a, 1b. The bearing member 2 is pressed into the outer member 1 at both end sections 1a, 1b, and the inner diameter of the bearing cylinder hole 2a of the bearing member 2 is elastically deformed (DELTA) into a small diameter only at both end sections.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing and a method for manufacturing the same, and more particularly to a bearing used for a tape device and the like and a method for manufacturing the same.

[0002]

2. Description of the Related Art Audio recording and reproducing by rotating a recording medium,
Image recorders have many rotating parts. For these rotating parts, the bearing accuracy such as the circularity of the inner diameter and the concentricity is determined according to the functional purpose, and a bearing according to the purpose is used. Many of these rotating parts are lightly loaded, and resin bearings or oil-impregnated bearings are used as bearings, except for special ones. The resin bearing uses a resin material for the bearing material, and as the resin material, a fluororesin-based material having wear resistance and a small friction coefficient is often used. Oil-impregnated bearings use a sintered metal as the bearing material, and this sintered metal is impregnated with oil.The composition of the sintered metal is determined by the axial load and rotation speed, but is not a constant component ratio, but iron is the main component. ,copper,
Tin, manganese, etc. are included. These are molded as a viscous material that is uniformly mixed with a binder and sintered to form a porous material, and the pores of the porous material are impregnated with lubricating oil such as turbine oil. After the resin bearing and the oil-impregnated bearing are press-fitted into the bearing holder, the cylindrical hole of the bearing is sized so as to have a specified dimension.

FIG. 4 is a longitudinal sectional view for explaining the structure of a conventional bearing. In the figure, 10 is a holder (outer peripheral member), 1
Reference numerals 1 and 12 are metals (oil-impregnated bearings), and 13 is a hollow portion.
In FIG. 4, the bearing is a holder 1 having a through hole 10a.
A pair of metal 11 having bearing cylindrical holes 11a, 12a of which length is equal to 0 and is shorter than 1/2 of the length of the holder 10.
And 12, and the metal 11 and 12 are press-fitted into both ends of the holder 10 so that the metal 1
A hollow portion 13 is formed between 1 and 12. Metal 11,1
The holder assembly into which 2 is press-fitted is subjected to sizing processing, and inner diameter dimensional accuracy and coaxiality are secured.

[0004]

The conventional bearing shown in FIG. 4 comprises a holder 10 and metals 11 and 12, and not only has a large number of parts but also metals 11 and 12 are separate pieces. The dimensions of the metals 11 and 12 before press-fitting have an error within an allowable range, but the size difference between them is large depending on the combination of the metals 11 and 12, and since they are press-fitted individually to the holder 10, Each press-fitting condition is not always constant, and the circularity and the concentricity of the inner diameters of the cylindrical holes of the metals 11 and 12 are insufficient, there are many variations, and when the metals 11 and 12 are sintered metal, The small holes were crushed and the oil supply was insufficient. In addition, after the metal 11 and 12 are press-fitted into the holder 10, a tool having a reference outer diameter is press-fitted into the cylindrical holes 11a and 12a to perform sizing processing for expanding the cylindrical holes 11a and 12a. When the roundness and the coaxiality of 12a are insufficient, the size is locally enlarged. Therefore, when the sizing amount is large, the sintered metal of the metals 11 and 12 peels off, and the peeled powder is hollow. Since there is a step remaining in the hollow space 13 and between the hollow portion 13 and the metal 11, 12 and corresponding to the thickness of the metal 11, 12, it is difficult to remove it.
This causes foreign matter to interfere with the function of the bearing, and there is a defect in the function of the bearing.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks. (1) A cylindrical bearing member having a cylindrical hole having a constant inner diameter, and the bearing member being press-fitted. In the bearing comprising an outer peripheral member having a through hole, the bearing member is press-fitted into the through hole of the outer peripheral member,
The inner diameter of the through hole of the outer peripheral member with respect to the outer diameter of the bearing member is made slightly smaller at both ends and equal or slightly larger at the middle portion, and elastic deformation is applied to both end portions of the bearing member by press fitting of the bearing member. The diameter of both ends of the cylindrical hole is made smaller than that of the middle part and both ends of the bearing member are used as bearing portions, or (2) a cylindrical bearing member having a cylindrical hole with a constant inner diameter, and the bearing. An outer peripheral member having a through hole for press-fitting a member is prepared, and a bearing manufacturing method for manufacturing a bearing in which the bearing member is press-fitted into the through hole of the outer peripheral member, the inner diameter of the through hole of the outer peripheral member. Is formed so that both end portions are slightly smaller than the outer diameter of the bearing member and the middle portion is equal or slightly larger, and the outer diameter of the bearing member is slightly smaller than the inner diameter of the both end portions of the outer peripheral member. Largely formed, and the bearing member It is characterized in that the bearing member is press-fitted into the outer peripheral member, and (3) after the bearing member is press-fitted into the through hole of the outer peripheral member, the elastically deformed both ends of the bearing cylindrical hole are finished with an inner diameter. It is a thing.

[0006]

In the bearing according to the present invention, a bearing member having a cylindrical hole to serve as a bearing is configured such that the outer peripheral member and the bearing member are pressed against each other only at their both ends. Due to this elastic deformation, both end portions of the cylindrical hole of the bearing member have a smaller diameter than the intermediate portion, so that the cylindrical holes of both end portions of the bearing member are used as bearing portions. If there are no variations at both ends of the bearing member and the dimensions of the outer peripheral member and the bearing member are secured, it is easy to secure the dimensions after press fitting, and even if metal is used as the bearing member, the press fit dimensions can be managed sufficiently. If it is done, it is easy to secure the circularity and coaxiality of the inner diameter, there is little variation, and even if the sintered metal is peeled off by the sizing process, both ends of the bearing member are elastically deformed and a small diameter continuous toward the middle part is obtained. Therefore, since the removal is easy, these peeling powders are less likely to remain, and the factor that hinders the function of the bearing can be largely removed.

[0007]

Embodiments of the present invention will be described in detail below with reference to FIG. 1 (a) and 1 (b) are side sectional views for explaining one embodiment of a bearing and a manufacturing method thereof according to the present invention. FIG. 1 (a) shows a bearing member and an outer peripheral member (hereinafter,
1 (b), which is an exploded view of FIG.
FIG. 1 is a sectional view when these are combined to form a bearing, and FIG. 1 shows an example in which the present invention is applied to a bearing member such as resin. In FIG. 1, a bearing member 2 is a cylindrical body having a cylindrical hole 2a having a constant inner diameter to serve as a bearing, and an outer peripheral surface 2b having a radius r, and is made of a fluororesin having a small friction coefficient and excellent wear resistance. ing. The holder 1 is a tubular body into which the bearing member 2 is press-fitted, and the through-holes of the press-fitting part are holes 1a and 1b at both ends and these holes 1
It consists of a hole 1c sandwiched between a and 1b.
The portions a and 1b serve as press-fitting portions, and these portions have a radius slightly smaller than the radius r, and this radius difference serves as a press-fitting margin, and the hole 1c is a hole having a diameter slightly larger than the radius r. Therefore, the bearing member 2 of FIG.
When press-fitted in the direction of arrow P into the cylindrical hole 2a of the bearing member 2
Both end portions of the sheet are subjected to compressive stress based on the radius difference, and
As shown in (b), elastic deformation such that the radius of the cylindrical hole 2a is reduced by Δ (exaggerated in the figure, the actual amount of deformation is several to several tens of μm), and bearings are provided at both ends. To form a part.

FIG. 2 is a view for explaining another embodiment in which the bearing member of the bearing according to the present invention is made of resin. In FIG.
Is a roller, 4 is a bearing member, and the roller 3 corresponds to the outer peripheral member 1 described above, and is an impedance roller having a roller surface 3d on the outer periphery of the upper end portion. The through hole of the roller 3 is processed into a three-stage hole which is coaxial and has different diameters 3a, 3c and 3b. Here, the hole 3a at the upper end has the largest hole diameter, and the hole 3b at the lower end has the smallest hole diameter. The bearing member 4 which is press-fitted into the through hole of the roller 3 is made of a resin material such as a fluorine resin and has a cylindrical hole 4a.
Has a constant inner diameter (it has a different diameter since it is shown after press-fitting in FIG. 2), and the outer diameter is coaxial with the press-fitting direction, and the hole 3a of the roller 3 is
The upper end is the largest and the lower end is the smallest corresponding to 3b and 3c. At this time, holes 3a and holes 3b at both ends
The inner diameter of the bearing member 4 is slightly smaller than the outer diameter of the bearing member 4 at the corresponding position, and the inner diameter of the hole 3c in the middle portion is the same as that of the corresponding bearing member 4.
The same as or slightly larger than the outer diameter of the intermediate portion of Therefore, when the bearing member 4 is press-fitted into the roller 3, both ends of the bearing member 4 are elastically deformed to have a small diameter as illustrated.

According to the above-mentioned bearing, since the bearing member is made of resin, it is suitable for bearings such as an impedance roller having a large inertia in order to stabilize the running of the magnetic tape, in which oil should not leak to the outer peripheral portion. Is effective, and a bearing with excellent roundness and coaxiality can be obtained.

FIG. 3 is a view for explaining another embodiment of the bearing according to the present invention, in which 5 is a metal (sintered metal) and 6 is a tool, which is the same as the embodiment shown in FIG. The parts that operate are given the same reference numerals as in FIG. In this embodiment, therefore, the bearing member 2 shown in FIG. 1 is constituted by the metal 5, and the metal 5 is subjected to the sizing process. The hole of the holder 1 before press-fitting is shown. The diameter 1a and the outer diameter of the metal 5 are different from those in the case of FIG. 1 due to the difference in the material, but the both ends have a press-fitting margin that is elastically deformed by the press-fitting, as in the case of FIG. is there.
After press-fitting, the hole drilling tool 6 is rotated in the direction of the arrow for sizing, so that both ends 5a and 5b of the metal 5 corresponding to both ends 1a and 1b of the holder 1 have the same shaft and the same inner diameter by sizing. Since it can be formed in the bearing portion, it is possible to provide a bearing that can withstand high loads. It should be noted that the bearing member 5 is not limited to metal, but may be made of resin.

[0011]

As is apparent from the above description, according to the present invention, the bearing member is an integral cylindrical body, and the bearing cylindrical hole is formed as if the separate bearing member was press-fitted into both ends of the holder. There is no variation in roundness and coaxiality at both ends of the, and it is easy to secure dimensions after press fitting, and even when metal is used as the bearing member, it is easy to secure circularity and coaxiality of the inner diameter Even if the powder is peeled off due to sizing, the axial change of the bore diameter of the bearing cylindrical hole gradually changes from both ends to the middle part, and the inner surface is finished in a smooth shape, so it is easy to remove. Yes, the factors that hinder the function of the bearing can be largely removed.

[Brief description of drawings]

FIG. 1 is a side sectional view for explaining an embodiment of a bearing and a manufacturing method thereof according to the present invention.

FIG. 2 is a half cross-sectional view for explaining another embodiment in which the bearing member of the bearing according to the present invention is made of resin.

FIG. 3 is a diagram for explaining another embodiment of the bearing and the manufacturing method thereof according to the present invention.

FIG. 4 is a vertical cross-sectional view for explaining the structure of a conventional bearing.

[Explanation of symbols]

1 ... Holder, 3 ... Roller, 2, 4 ... Bearing member, 5 ...
Metal, 10 ... Conventional holder, 11, 12 ... Conventional metal.

Claims (3)

[Claims] 1. A cylindrical bearing member having a cylindrical hole with a constant inner diameter, and an outer peripheral member having a through hole for press-fitting the bearing member, wherein the bearing member is press-fit into the through hole of the outer peripheral member. In the bearing, the inner diameter of the through hole of the outer peripheral member with respect to the outer diameter of the bearing member is slightly smaller at both ends and equal or slightly larger at the middle portion, and the bearing member is press-fitted to both end portions of the bearing member. A bearing characterized in that elastic deformation is applied to make the hole diameters of both ends of the cylindrical hole smaller than that of an intermediate part, and both ends of the bearing member are used as bearing parts. 2. A tubular bearing member having a cylindrical hole with a constant inner diameter, and an outer peripheral member having a through hole for press-fitting the bearing member are prepared, and the bearing member is press-fit into the through hole of the outer peripheral member. In the method of manufacturing a bearing for manufacturing the bearing, the inner diameter of the through hole of the outer peripheral member is formed such that both end portions are slightly smaller than the outer diameter of the bearing member, and the middle portion is equal or slightly larger, A method for manufacturing a bearing, wherein an outer diameter of the bearing member is formed slightly larger than inner diameters of the both ends of the outer peripheral member, and the bearing member is press-fitted into the outer peripheral member. 3. The method of manufacturing a bearing according to claim 2, wherein after the bearing member is press-fitted into the through hole of the outer peripheral member, the inner diameter finish processing of the elastically deformed both ends of the bearing cylindrical hole is performed.