JPH0544716A - Dynamic pressure groove shaped sliding bearing - Google Patents

Abstract

PURPOSE:To provide a dynamic pressure groove shaped sliding bearing maintaining high dimensional accuracy against temperature variation and having excellent heat resistance, water resistance, solvent resistance, and also excellent productivity. CONSTITUTION:An outer cylinder 22 and an inner cylinder 23 made of resin to be joined on the inner circumferential face of the former are stuck together with thermal reaction type film-like bonding agent into one body, and dynamic pressure grooves 21 are formed on the inner circumferential face of the inner cylinder 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a two-layer structure comprising an outer cylindrical body and an inner cylindrical body made of resin bonded to the inner peripheral surface of the inner cylindrical body with an adhesive. The present invention relates to improvement of a dynamic pressure groove type slide bearing having a dynamic pressure groove.

[0002]

2. Description of the Related Art As a conventional dynamic pressure groove type sliding bearing of this type, for example, a thermosetting resin inner cylinder is insert-molded on the inner peripheral surface of a metal outer cylinder, It is known that a cylinder is bonded with an adhesive or a concavo-convex surface is formed for mechanical bonding, and a dynamic pressure groove is molded on the inner peripheral surface of the inner cylinder at the same time when molding. In that case, the die cutting is performed by axially releasing the dynamic pressure groove on the inner peripheral surface without damaging it by utilizing the expansion of the inner diameter due to the volume contraction of the resin inner cylinder during curing. JP-A-63-203916,
First conventional example).

Further, a metal or synthetic resin rectangular plate having a dynamic pressure groove formed on one surface is joined by abutting the rounded ends to form a sleeve, and the sleeve is formed on the outer peripheral surface of the shaft or the bearing member. A hydrodynamic bearing fixed to the inner peripheral surface by fitting is also known (Japanese Utility Model Laid-Open No. 60-93012, second conventional example). In addition, a large-sized resin sheet with the dynamic pressure groove rolled in advance on one surface is cut into strips, and the other surface on which the dynamic pressure groove is not rolled is placed outside and rolled into a tubular shape. The applicant of the present invention has proposed a dynamic pressure grooved bearing which is inserted into the inner peripheral surface of the outer cylinder body and is joined to the outer peripheral surface of the outer cylinder body by using an adhesive agent. As the adhesive in this case, a thermoplastic adhesive, a rubber adhesive, or a thermosetting adhesive (mainly epoxy liquid adhesive) is used (Japanese Patent Application No. 2-260176, third conventional example).

[0004]

However, the first conventional example has the following problems. When you want to form the inner cylinder with a resin whose main component is PTFE (polytetrafluoroethylene), the resin cannot be injection-molded, so another resin that can be injection-molded is molded on the outside of the PTFE-based resin formed by compression molding. Must be done, which complicates the manufacturing process.

Since the insert-molded resin inner cylindrical body shrinks in volume when cured, it is difficult to obtain the inner diameter dimensional accuracy of the product bearing. When the outer cylinder and the inner cylinder are mechanically joined with unevenness, there is a gap between the two cylinders due to temperature changes, or the resin causes creep, which causes a decrease in the joining force and changes in the inner diameter. ..

Also, in the second conventional example, the outer cylinder and the inner cylinder are mechanically joined by means of fitting, and similarly, a gap is generated between both cylinders due to temperature change, or the resin creeps. As a result, there is a problem in that the joining force is easily reduced and the inner diameter is changed. Furthermore, the third conventional example has the following problems due to the adhesive used.

In the case of a thermoplastic adhesive: heat resistance and solvent resistance are insufficient. Also, creep easily occurs,
The occurrence is often recognized even at room temperature. For rubber adhesives: Low heat resistance, strength under high load, and creep resistance. For thermosetting adhesives: Room temperature curing two-part adhesives have short pot life after mixing and poor workability. Also, if there is no dry-touch property (the property that can be pasted in a non-sticky state after taking an open time), the pasting must be performed while the tackiness remains, and the adhesive is applied. It is extremely difficult to cut the large-sized resin sheet into strips or to roll the cut sheet into the outer cylinder, which is extremely difficult, and mass productivity is significantly impaired.

Therefore, the present invention has been made by paying attention to the above-mentioned conventional problems, and solves the above-mentioned conventional problems by using a heat-reactive film adhesive for joining the outer cylinder and the inner cylinder. As a result, high dimensional accuracy is maintained even with changes in temperature, and heat resistance, water resistance, oil resistance, and solvent resistance are excellent.
The purpose of the present invention is to provide a dynamic pressure groove type slide bearing which is excellent in mass productivity.

[0009]

SUMMARY OF THE INVENTION The present invention which achieves the above object comprises an outer cylindrical body and a resin inner cylindrical body joined to the inner peripheral surface of the outer cylindrical body with an adhesive. The present invention relates to a dynamic pressure groove type slide bearing having a dynamic pressure groove on its inner peripheral surface, wherein the adhesive is a heat-reactive film adhesive.

[0010]

The heat-reactive film adhesive used in the present invention comprises a phenol-modified epoxy resin having hot melt property and tackiness as a main component, and is applied to release paper to form a film having a uniform thickness. In addition, it has excellent adhesive strength, heat resistance, water resistance, chemical resistance, and oil resistance, has dry touch characteristics, and has a long pot life.

The inner cylinder of the present invention is formed from a resin sheet containing PTFE as a main component and having a uniform thickness. After rolling a dynamic pressure groove on one surface of this resin sheet in a pattern according to the mode of use of the bearing, the above heat-reactive film adhesive is laminated on multiple surfaces of the resin sheet. After that, a strip-shaped sheet of a required size is cut out from the resin sheet. This strip-shaped sheet is rolled so that the adhesive layer is on the outer surface and inserted into the inner peripheral surface of the outer cylindrical body, and the adhesive is applied while pressing the inner cylindrical body inserted into the inner surface of the outer cylindrical body by heating and pressing. The inner and outer cylinders are integrated by curing or by pressure-bonding the inner cylinder and then curing the adhesive.

In this manufacturing process, due to the dry touch property of the film-like adhesive, all of the cutting work of the strip-shaped sheet, the rolling work and the insertion work into the outer cylinder can be efficiently carried out and mass production is possible. Both the resin sheet and the film adhesive have a uniform thickness, and therefore the inner diameter dimension accuracy of the product bearing is good. Further, the expansion of the resin inner cylinder body integrated with the outer cylinder body by the film adhesive is suppressed by the outer cylinder body having a smaller linear expansion coefficient, and as a result, the stability of the product dimensional accuracy with respect to the temperature change is high. ..

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a dynamic pressure groove type slide bearing 20 of the present invention.
It is a longitudinal cross-sectional view showing an example of. This is a case where the dynamic pressure groove type slide bearing 20 is used in such a manner as to perform linear forward and reverse linear movement relative to the shaft body, and a dynamic pressure groove 21 having a wavy pattern is formed on the inner peripheral surface of the bearing. Has been done. As the dynamic pressure groove pattern, one-directional rotary motion, forward / reverse rotary motion, spiral motion, and the like are adopted in addition to the above depending on the mode of relative motion between the bearing and the shaft.

In this dynamic pressure groove type slide bearing 20, an inner cylinder 23 formed of a resin sheet 23A containing PTFE as a main component to be described later is heated on the inner diameter surface of an outer cylinder 22 made of metal such as aluminum. It is adhered via a reactive film adhesive 24, and the dynamic pressure groove 21 is formed on the inner surface of an inner cylinder 23 thereof. As shown in FIG. 2, the heat-reactive film adhesive 24 is a release paper 24 obtained by applying an adhesive 24A containing a phenol-modified epoxy resin as a main component.
It is applied to one side of B and semi-dried to form a film of uniform thickness. It has excellent adhesive strength, heat resistance, water resistance, chemical resistance, oil resistance, and has dry touch property, and has a pot life. Is also long.

The dynamic pressure groove type slide bearing 20 is manufactured as follows. The resin sheet 23A containing PTFE as a main component is made of a mixed material of a PTFE resin and an abrasion-property improving substance such as glass fiber. For example, the dispersion is poured onto a metal surface and fired into a sheet. Alternatively, it may be formed by any other known resin sheet manufacturing method, and the thickness is preferably 0.1 to 2.0 mm.

First, one surface of the resin sheet 23A (bonding surface to the outer cylinder 22) is subjected to defluorination treatment which is a pretreatment for adhesion. This is a treatment for improving the adhesiveness of the sheet, and a surface treatment using a primer for fluororesin or a so-called sodium treatment method can be applied.
Next, the dynamic pressure groove 21 is rolled on the non-bonded surface of the resin sheet 23A which has not been subjected to the above-mentioned pretreatment. This work is performed by a rolling machine, and a large-sized resin sheet having a dynamic pressure groove 21 having a predetermined depth (preferably 5 to 60 μm) can be efficiently and continuously formed. The plastic working of the dynamic pressure groove 21 may be press working instead of rolling. Also,
The defluorination treatment may be performed after the plastic working of the groove for generating the dynamic pressure.

Subsequently, a laminate layer of the heat-reactive film adhesive 24 is formed on the surface of the resin sheet 23A which has been subjected to the above-mentioned pretreatment. As shown in FIG. 2, the film-like adhesive 24A applied to the release paper 24B is superposed on the adhered surface of the resin sheet 23A, and is processed by passing between the upper and lower heating and pressing rolls 26, 26. Can be continuously and efficiently performed.

Thereafter, the large resin sheet 23A is cut (or punched) into small strip-shaped sheets 23B having a predetermined length and width. This cutting is done with release paper 24B
Even after peeling off, since the heat-reactive film adhesive 24 has dry touch property, it can be easily done without stickiness. However, the resin sheet 23A and the heat-reactive film adhesive can be attached with the release paper 24B. If it is cut so as to be cut with 24, the cut strip-shaped sheets 23B do not have to be separated, which is convenient for automating the subsequent steps.

The cut-out strip-like sheet 23B is rolled into a tubular shape with the adhesive side being the outside (the dynamic pressure groove 21 is the inside),
It is inserted inside the outer cylinder 22. This insertion work can be easily performed without stickiness due to the dry touch property of the heat-reactive film adhesive 24. Then, a tubular strip-shaped sheet 23B inserted into the outer cylinder 22 is attached to the lower roller 27 of the thermocompression device shown in FIG. 4, and the upper roller 28 is pressed to roll it to a temperature of about 100. The inner cylinder 23 is temporarily adhered to the inner peripheral surface of the outer cylinder 22 in a few seconds by rotating it 1 to 2 times at a temperature of 4.degree. However, the temporary adhesion is not limited to the above method, and a heated rod having an outer diameter slightly larger than the inner diameter of the inner cylinder 23 may be lightly press-fitted and thermocompression bonded.

Finally, by temporarily heating the outer cylinder 22 and the inner cylinder 23 to heat them in a heating furnace to cure the heat-reactive film adhesive 24, the dynamic pressure groove-shaped slide shown in FIG. The bearing 20 is obtained. As described above, in the dynamic pressure groove type slide bearing 20 of this embodiment, the inner surface of the outer cylinder 22 has P
A resin inner cylinder 23 containing TFE as a main component is bonded via a heat-reactive film adhesive 24,
The resin sheet 23B forming the inner cylinder 23 is a composite material in which PTFE and a wear resistant material are mixed, and therefore has good wear characteristics and a long life.

Further, according to this embodiment, heat resistance, water resistance,
The inner cylinder 23 made of a resin sheet 23B using a PTFE resin having excellent chemical resistance and oil resistance is also heat-resistant.
Since the heat-reactive film adhesive 24, which is mainly composed of phenol-modified epoxy resin having excellent water resistance, chemical resistance, oil resistance and high adhesive strength, is integrally bonded to the outer cylinder 22, the product bearing is extremely heat resistant, A product with excellent water resistance, chemical resistance, and oil resistance can be obtained.

Further, since both the resin sheet 23B and the heat-reactive film adhesive 24 can be easily formed to have a uniform thickness, it is possible to obtain a product bearing having a high inner diameter dimension accuracy. Further, since the heat-reactive film adhesive 24 is used, it is possible to prevent a gap between the outer cylinder 22 and the inner cylinder 23 due to temperature change, and to prevent the adhesive layer from creeping. The outer cylinder 22 having a small diameter suppresses the expansion of the inner cylinder 23 having a large linear expansion coefficient, the change in dimensional accuracy due to the temperature change is reduced, and a very stable product bearing is obtained.

In addition, a heat-reactive film adhesive 24
Is a film with dry touch property, so it can be laminated to the resin sheet 23A, cut into strips 23B, rolled up and inserted into the outer cylinder 22, temporary adhesion thereafter, curing of adhesive, etc. It is easy to handle in the above work, and it greatly contributes to productivity improvement. FIG. 5 shows another embodiment of the dynamic pressure groove type slide bearing of the present invention.

The dynamic pressure groove type slide bearing 30 is composed of the outer cylinder 2
Inner cylinders 23 and 23 in which two strip-shaped sheets 23B and 23B are axially spaced on the inner peripheral surface of 2 respectively.
Are bonded via a heat-reactive film adhesive 24. The manufacturing process is almost the same as that of the first embodiment, but in the process of inserting and joining two rolled sheets 23B into the inner peripheral surface of the outer cylinder 22, the two steps are performed.
The sheets are simultaneously pressed by heating while passing through the same rod (or roller). In this way, by utilizing the plastic deformation due to the compression of the rod, both strip-shaped sheets 23B are made to conform to the inner surface of the outer cylinder 21 and the outer diameter surface of the rod, and when the adhesive hardens after a predetermined time, the rod is fixed to the sheet 23B. Pull out from the inner diameter surface. In this way, the two glued at a distance in the axial direction.
By pressing the single strip-shaped sheet 23B in common by one rod and plastically deforming it, excellent inner diameter dimensional accuracy and concentricity of inner diameters at both ends in the axial direction are guaranteed.

Alternatively, as in the first embodiment, heating and pressing are performed by a roller for temporary adhesion, or a heated rod having an outer diameter slightly larger than the inner diameter of the inner cylinder 23 is lightly press-fitted for temporary adhesion. Is also good. At this time, two sheets may be simultaneously heated and pressure-bonded by the same rod (or roller). After that, the outer cylinder 2
The reaction film adhesive 24 is cured by heating a temporary adhesion of 2 and the inner cylinder 23 in a heating furnace. in this way,
Since two strip-shaped sheets 23B having a uniform thickness are adhered to the outer cylinder 22 at two axial positions on the same inner peripheral surface, excellent inner diameter dimensional accuracy and coaxiality of inner diameters at both ends in the axial direction are guaranteed. It

Therefore, even if two bearings are usually required, one dynamic pressure groove type slide bearing 30 will suffice, and it is not necessary to provide coaxiality when assembling the bearings, which facilitates the assembling work. At the same time, there is an advantage that the cost can be reduced. The same applies to the one having two or more inner cylinders 23. FIG. 6 shows still another embodiment of the dynamic pressure groove type slide bearing of the present invention.

In this dynamic pressure groove type slide bearing 40, an outer cylinder 42 having a non-cylindrical outer surface is formed with an insertion hole 44 for a shaft 43, and an inner peripheral surface thereof is made of PTFE as a main component and is made of a wear property improving substance. The two inner cylinders 23, 23 formed by rounding the mixed resin sheet 23B are incorporated in the inner peripheral surface of the rectangular outer cylinder 42 at intervals in the axial direction, and the heat-reactive film adhesive 24 is interposed therebetween. Are integrally joined together. There is no difference in operation and effect as a dynamic pressure groove type slide bearing from the above-mentioned embodiment. As described above, the outer surface of the outer cylindrical body is not limited to the cylindrical shape, and a rectangular shape or any other shape may be used as needed.

The present invention can also be applied to a slide bearing in which there is no dynamic pressure groove on the inner peripheral surface of the resin inner cylinder.

[0029]

As described above, according to the dynamic pressure groove type sliding bearing of the present invention, the outer peripheral surface of the inner peripheral surface of which the synthetic resin sheet is rolled is joined through the heat-reactive film adhesive. The following various effects can be obtained. It has excellent heat resistance, water resistance, chemical resistance, solvent resistance, and oil resistance.

Both the resin sheet and the film adhesive have a uniform thickness, and therefore the inner diameter dimension accuracy of the product bearing is good. And, as a result of the expansion of the resin inner cylindrical body integrated with the outer cylindrical body with the film adhesive being suppressed by the outer cylindrical body,
High dimensional accuracy can be maintained even with changes in temperature. Due to the dry-touch property of the heat-reactive film adhesive, all of the work of cutting out the synthetic resin sheet, rolling, and inserting it into the outer cylinder are performed efficiently, and it is excellent in mass productivity.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of a dynamic pressure groove type slide bearing of the present invention.

FIG. 2 is a schematic diagram illustrating a step of laminating a heat-reactive film adhesive on a resin sheet used in the present invention.

FIG. 3 is a plan view of a resin sheet used in the present invention in which a dynamic pressure groove is formed.

FIG. 4 is a schematic diagram illustrating a step of joining an inner cylinder to an outer cylinder of the bearing shown in FIG.

FIG. 5 is a vertical cross-sectional view of another embodiment of the dynamic pressure groove type sliding bearing of the present invention.

FIG. 6 is a longitudinal sectional view of still another embodiment of the dynamic pressure groove type sliding bearing of the present invention.

[Explanation of symbols]

 20, 30, 40 Dynamic pressure groove type slide bearing 21 Dynamic pressure groove 22, 32, 42 Outer cylinder (body) 23 Inner cylinder (body) 24 Heat-reactive film adhesive

Claims (1)

[Claims] 1. A dynamic pressure groove type slide having an outer cylindrical body and a resin inner cylindrical body bonded to the inner peripheral surface of the outer cylindrical body with an adhesive, and having a dynamic pressure groove on the inner peripheral surface of the resin inner cylindrical body. In the bearing, the dynamic pressure groove type slide bearing is characterized in that the adhesive is a heat-reactive film adhesive.