JPH0419421A - Dynamic pressure grooved bearing and its manufacturing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hydrodynamic grooved bearing used in office equipment, audio equipment, measuring equipment, etc., and a method for manufacturing the same.

[Conventional technology]

Conventional cylindrical sliding bearings made of synthetic resin, especially dynamic pressure grooved bearings with grooves for generating dynamic pressure on the inner diameter surface, are made of elastic thermoplastic synthetic resin with graphite, carbon fiber, molybdenum disulfide, and fluorine. It is manufactured by injection molding using a mold using a composite material mixed with a lubricating substance such as resin, and then being pulled out of the mold using the elasticity of the resin. However, when using a thermoplastic resin material other than PTFE, Although it is possible to manufacture bearings with hydrodynamic grooves, they suffer from large molding shrinkage and insufficient dimensional accuracy, and their frictional properties are not sufficient, so the performance of hydrodynamic grooved bearings cannot be fully demonstrated. do not have.

On the other hand, Japanese Patent Application Laid-Open No. 63-203916 (hereinafter referred to as the first conventional example) proposes a hydrodynamic grooved bearing using a highly accurate thermosetting resin and a method for manufacturing the same. This is epoxy resin.

A thin inner cylinder made of thermosetting resin such as phenolic resin, unsaturated polyester resin, diallyl phthalate resin, etc., with grooves for generating dynamic pressure formed on the inner diameter surface, is fixed to the inner diameter surface of a metallic outer cylinder body. This is a dynamic pressure grooved bearing.

When manufacturing this bearing with hydrodynamic pressure grooves, an outer cylindrical body with many grooves or fixing means such as adhesive applied to the inner diameter surface is fitted into the outer mold in advance, and the grooves for generating dynamic pressure are shaped. A molding material made by heating and melting a thermosetting resin is supplied into a narrow annular space between an inner mold in which protrusions corresponding to the above are arranged on the outer peripheral surface and an outer cylinder fitted in the outer mold. This molding material is cured to form an inner cylindrical body, and this is fixed to the outer cylindrical body via a fixing means to form a laminated structure in which the inner cylindrical body and the outer cylindrical body are integrated. , the laminated structure of the inner cylinder and the outer cylinder is extracted from the outer mold and the inner mold in the axial direction and released from the mold.

Further, in Japanese Utility Model Application Publication No. 60-93012 (second conventional example), grooves for generating dynamic pressure are formed in advance on one side of a flat plate by etching or plastic working, and this flat plate is attached to the outer peripheral surface of the shaft or the shaft. A fluid formed by fitting and fixing a sleeve formed by rolling the sleeve so as to match the shape of the inner circumferential surface of the support member to be supported and joining the two ends together, and fitting and fixing the sleeve to the outer circumferential surface of the shaft or the inner circumferential surface of the support member. It is a bearing.

Further, in Japanese Utility Model Publication No. 63-27143 (third conventional example), the shaft body and the bearing are capable of relative movement in forward and reverse directions via mutual sliding surfaces, and an arrowhead is provided on at least one of the sliding surfaces. This is a dynamic pressure sliding bearing in which a groove for generating dynamic pressure is formed. The groove for generating dynamic pressure consists of a groove whose arrowhead direction coincides with the movement direction of the shaft body and the bearing in one direction, and a groove whose arrowhead direction coincides with the movement direction of the shaft body and the bearing in the other direction. It is a sliding bearing that generates dynamic pressure in both forward and reverse directions of movement.

(Problems to be Solved by the Invention) However, in the first conventional example, although the thermosetting resin has excellent molding accuracy, the resin itself has poor friction and wear characteristics, and even graphite.

Even if lubricating substances such as carbon fiber and molybdenum disulfide are mixed, there is a problem in that good friction and wear characteristics cannot be obtained.

Further, when a plurality of single bearings are assembled into a unit, there is a problem in that it is difficult to achieve coaxiality of the inner diameters of the plurality of bearings.

Furthermore, the second conventional example is a radial fluid bearing that supports the shaft by generating fluid dynamic pressure in a dynamic pressure generation groove by rotation of the shaft, and the dynamic pressure generation groove is located on the outer periphery of the shaft. It is formed continuously over the entire circumference of the surface or the inner circumferential surface of the support member, and the sleeve is formed by rolling up a flat plate with grooves for generating dynamic pressure formed on one side in advance and butting both ends together. Since it is fitted and fixed to the outer circumferential surface of the supporting member or the inner circumferential surface of the support member, there is a problem that the manufacturing process is complicated and the production cost is high. Furthermore, there is the problem that it is difficult to obtain uniform quality due to variations in the cut length of the flat plate, unevenness of the butt parts of both ends of the flat plate, and fit with the shaft or support member when fitting the formed sleeve. there were.

Furthermore, if a soft synthetic resin flat plate (sheet) such as PTFE is rolled up, butted against both ends, and then fitted and fixed to the inner peripheral surface of the support member, the accuracy (roundness, cylindricity, etc.) cannot be achieved. However, there was a problem in that it was difficult to achieve the accuracy required for hydrodynamic bearings.

On the other hand, in the hydrodynamic sliding bearing of the third conventional example, when the mutual sliding surfaces between the shaft body and the bearing are cylindrical, an arrowhead-shaped groove for generating dynamic pressure is formed around the entire circumference of at least one sliding surface. Although shown in the figure, it is not easy to actually manufacture this on a mass production basis.

Therefore, the present invention has been made by focusing on the above-mentioned problems of the conventional art, and its purpose is to provide an arrow mark not on the entire circumference of the cylindrical inner circumferential surface but only within a predetermined circumferential angular range. It is an object of the present invention to provide a bearing with a dynamic pressure groove that is easy to manufacture, inexpensive, excellent in dimensional accuracy, and capable of maintaining concentricity by forming hydrodynamic grooves in the shape of a shape, and a method for manufacturing the same.

[Means for Solving the Problems] The dynamic pressure grooved bearing of the present invention has a sheet adhered to the inner circumferential surface of an outer cylinder, a groove for generating dynamic pressure is formed on the inner surface of the sheet, and a groove for generating dynamic pressure is formed on the inner surface of the sheet. are bonded to each other with a gap at the edge of the sheet in the circumferential direction.

Further, in the method for manufacturing a dynamic pressure grooved bearing of the present invention, the seat has grooves for generating dynamic pressure formed on one surface by plastic working, and has a length shorter than the distance between the inner peripheral surfaces of the outer cylinder. The sheet is wound so that the other surface of the sheet faces the inner circumferential surface of the outer cylinder via an adhesive, a cylindrical body is inserted into the inner surface of the sheet, and after the adhesive hardens, A hydrodynamic grooved bearing is manufactured by removing the cylindrical body.

The present invention will be explained in detail below.

In the present invention, the thermoplastic resin used, especially PTF
The resin containing E as a main component is a mixture of PTFE and a wear property improving substance. PTFE content is 50-90
wt% is preferred.

If it is less than 50 wt%, the frictional properties, which are the characteristics of PTFE, will deteriorate. On the other hand, if the amount is more than 90 wt%, the amount of the abrasion-improving substance added will be too small, and the abrasion resistance will not improve. However, it is not necessarily limited to the above range, and may be less than 50 wt% or more than 90 wt%.

As the wear property improving substance to be mixed, for example, graphite, carbon fiber, molybdenum disulfide, polyimide, econol, glass fiber, etc. can be used.

The resin sheet containing PTFE as a main component according to the present invention may be formed by a well-known resin sheet manufacturing method using a mixed material of the above-mentioned PTFE resin and a wear property improving substance. It is formed by adding a solvent to make a paste, making it into a sheet in a calender, then evaporating the solvent and then firing it in a heating furnace, or by pouring a dispersion of mixed materials onto a metal surface and firing it. You can use the one made by peeling off the film, or the one cut from the molded cylindrical block. The thickness of the sheet is 0.1 to 2.
0 am is preferred.

When adhering this sheet of resin whose main component is PTFE to the inner diameter surface of the outer cylinder, the surface of the sheet to be adhered is subjected to a preheating chemical treatment (removal) and nitrogen treatment according to a conventional method. This is a treatment for improving the adhesiveness of the sheet, and surface treatment using a primer specifically for fluororesin, a so-called sodium treatment method, etc. can be applied.

As the adhesive, a rubber adhesive dissolved in a solvent to an appropriate viscosity, a thermosetting adhesive, or the like can be used. These adhesives are uniformly applied to the chemically treated surface of the resin sheet containing PTFE as a main component, and then semi-dried. Alternatively, instead of applying the adhesive to the sheet, the adhesive may be applied to the inner diameter surface of the outer cylinder.

Note that the depth of the groove for generating dynamic pressure is preferably 5 to 60 μm in order to obtain an appropriate dynamic pressure effect. However, PTFE
It is preferable that the depth of the groove for generating dynamic pressure formed on the inner surface of the resin sheet mainly composed of is slightly deeper than 5 to 60 μm before the sheet is bonded to the outer cylinder. This groove for generating dynamic pressure is formed in advance by plastic working on one surface of a resin sheet whose main component is PTFE. For example, after chemically treating the other surface to be adhered for adhesion, grooves for generating dynamic pressure are rolled by a rolling machine on the surface that is not chemically treated, and the sheet thickness is made uniform. The heating temperature during this rolling is preferably 100 to 200°C. However, the chemical treatment for adhesion may be performed after the above-mentioned plastic working of the groove for generating dynamic pressure.

In addition, the plastic working of this miso may be press working instead of rolling.

After the adhesive is applied to the surface to be bonded (if the adhesive is applied to the outer cylinder side, the surface to be bonded is simply subjected to chemical treatment for adhesion), the above dynamic pressure is generated on the other surface. A resin sheet mainly composed of PTFE with plastic grooves is cut to the required length, rolled up and inserted into the outer cylinder with the surface to be adhered facing outward.

At this time, in the method for manufacturing dynamic pressure grooved bearings for linear motion and rotary motion of the present invention, the length of the resin sheet is made shorter than the total circumferential length of the inner peripheral surface of the outer cylinder. That is, in the present invention, the resin sheet adhered to the inner peripheral surface of the outer cylinder is
The sheets are bonded with a gap in the circumferential direction without butting the sheet ends together. The reason for this is that the shaft body is inserted into the bearing and used as a bearing with dynamic pressure grooves for linear and rotary motion.
In many cases, the load that the bearing surface receives from the shaft body is often in one direction, and the load area rarely extends to the anti-load side, so the anti-load side is not practical even if there is no 2-way for generating dynamic pressure. This is because there are no problems. If a gap is provided at the end of the sheet by cutting out a portion that does not affect the applied load as shown in C, there is no need for butting, and manufacturing is extremely easy and an inexpensive bearing can be obtained.

In order to maintain the concentricity between the inner peripheral surface of the outer cylinder and the bearing surface with grooves for generating dynamic pressure, the adhesive range of the sheet formed with grooves for generating dynamic pressure must be at a circumferential angle of 240° or more. Good to have. In other words, the gap between the ends of the bonded sheets is preferably 120 degrees or less in terms of the intermediate IC angle on the inner circumferential surface of the outer cylinder.

In addition, in the manufacturing method of hydrodynamic grooved bearings, after the sheet is rolled up and inserted into the outer cylinder, the inner surface of the rolled sheet is
A mouth consisting of a metal or plastic cylindrical body with a diameter somewhat larger than the inner circumferential diameter of the final hydrodynamic grooved bearing.

Lightly press in.

With the lot still inserted, heat it to cure the adhesive. If a rubber adhesive is used as the adhesive, for example, it may be heated to a temperature of 60 to 1.50''C for 10 to 60 minutes.

During this heating, it is preferable that the inner surface of the sheet is compressed by the lot and undergoes some plastic deformation, as this makes it easier to ensure concentricity between the inner circumferential surface of the outer cylinder and the bearing surface for generating dynamic pressure. Therefore, we made the coefficient of linear expansion of the lot larger than that of the outer cylinder, and the coefficient of linear expansion of the sheet larger than that of the outer cylinder.
Furthermore, if you select the linear expansion coefficients of the outer cylinder, rod, and sort by making the linear expansion coefficients of the lot and sheet larger than those of the outer cylinder, you can insert the lot relatively easily at first, and it will be easier to insert the lot during heating. The inner surface of the sheet can be compressed into the rod by thermal expansion, resulting in desired plastic deformation. To do this, the materials of the lot and the outer cylinder may be appropriately selected by taking advantage of the fact that aluminum has a larger coefficient of linear expansion than steel, and that resin whose main component is PTFE has an even larger coefficient of linear expansion than aluminum.

In addition, by selecting the linear expansion coefficients of the outer cylinder, the lot, and the seat, even if the lot is inserted into the inner surface of the seat with a gap,
During heating, the inner surface of the sheet can be compressed by the lot, causing some plastic deformation.

Note that when a room temperature curing adhesive is used, there is no need to heat it, and the lot may be left press-fitted into the inner surface of the sheet at room temperature for the time required for curing.

After the adhesive has hardened and the sheet has been adhered to the inner circumferential surface of the outer cylinder, the rod is removed from the inner surface of the sheet.

A plurality of the above-mentioned rolled sheets may be inserted into the outer cylinder at intervals in the axial direction and adhered to each other. In this case, each sheet is also bonded to the inner diameter surface of the outer cylinder with some plastic deformation due to the pressure of the lot, and excellent inner diameter dimensional accuracy and coaxiality can be obtained.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

In a hydrodynamic grooved bearing, the shaft body and the bearing relatively perform unidirectional rotational movement, forward/reverse rotational movement, or linear movement in the axial direction via mutual sliding surfaces. Therefore, the pattern for generating dynamic pressure is also determined according to the mode of their relative motion.

The first embodiment is shown in FIG. 1 and the second circle.
The dynamic pressure grooved bearing 20 is a bearing that performs linear interlocking in the forward and reverse directions relative to the shaft body 10 in the axial direction.

In this dynamic pressure grooved bearing 20, resin sheets 22 mainly composed of PTFE are adhered to the inner diameter surface of a metal outer cylinder 21 at intervals in the axial direction. A palm-shaped groove 60,70 for generating dynamic pressure is formed as shown in FIGS. 1(b), 1(c) and 1(d).

The grooves shown in FIG. 6(b) include grooves 60 whose arrow tips point to the right in the axial direction and grooves 70 which point to the left in the axial direction, which are arranged alternately at approximately the same intervals in the axial direction, and at appropriate intervals in the circumferential direction. Arranged at intervals.

The grooves shown in the same figure (C) connect grooves 60 whose arrowheads point to the right in the axial direction and grooves 70 which point to the left in the axial direction facing each other in a rhombic shape, and the grooves are arranged at approximately the same intervals in the axial direction around the circumference. They are arranged at appropriate intervals in the direction.

The grooves shown in FIG. 6(d) are formed by connecting a groove 60 whose arrow tip points to the right in the axial direction and a groove 7o which points to the left in the axial direction in a wave shape in a direction perpendicular to the axis, and which are arranged at approximately the same intervals in the axial direction. It is.

Note that the depth of the grooves 60 and 70 is several μm to several tens of μm.
Appropriately selected within the range of.

Further, as a lubricant for the above-mentioned bearing, any one of oil, grease, water, air, etc. is used.

When the shaft body 10 moves linearly in the direction of the arrow sign,
A groove 6 facing right in the axial direction whose arrow tip coincides with this movement direction A.
Due to the pumping action of 0, the pressure of the fluid at the tip of the arrow increases, and the fluid film of the lubricant flowing into the bearing clearance 23 supports the shaft body 1o. When the shaft body 10 moves linearly in the direction of the opposite arrow B, the lubricant flows out from the tip of the groove 70 into the bearing clearance 23 due to the pumping action of the groove 70 facing leftward in the axial direction, the arrow tip of which coincides with the direction of movement B. A fluid film is formed by the agent.

The hydrodynamic grooved bearing 20 described above was manufactured as follows.

First, one surface of a resin sheet 22 made of PTFE as a main component and mixed with, for example, glass fiber as an abrasion property improving substance, is subjected to a fluorine-free treatment as a pretreatment for adhesion. This example was carried out in a conventional manner using a primer specifically designed for fluororesin. Thereafter, while the sheet 22 was heated under pressure using a rolling machine, grooves 60 and 70 for generating dynamic pressure were formed on the other surface that was not subjected to the fluorination treatment. Next sheet 2
A rubber adhesive adjusted to an appropriate viscosity with a solvent was uniformly applied to the defluorinated surface of No. 2, and after volatilizing the solvent and semi-drying, the sheet 22 was cut into desired dimensions. The two sheets 22 are rolled up so that the adhesive-applied surfaces are on the outside, and inserted into the metal (or plastic) outer cylinder 21 with a gap in the axial direction, as shown in FIG. 2(a). Installed as shown. Let the inner diameter of the seat in that state be d. Thereafter, a cylindrical rod R having an outer diameter is press-fitted into the inner surface of the inserted sheet 22. This lot outer diameter is slightly larger than the seat inner diameter d, but since the seat 22 is elastically deformable and the coefficient of friction between the seat 22 and the outer cylinder 21 is large at the time of insertion, the insertion of the rod R is is possible. After that, when heated to a predetermined temperature, the sheet 22 is heated to the outer cylinder 21.
Since the coefficient of linear expansion is larger, the compressive force received from the rod R is on the plate when inserted into the inner surface of the sheet 22 of the lot R.

Note that aluminum is used as the outer cylinder 21, and the rod R
If steel is used as the material, the difference in linear expansion coefficient between the outer cylinder 21 and the rod R is small, and the linear expansion coefficient of the sheet 22 is several times larger than that of the outer cylinder 21. is greater than when the rod R is press-fitted into the inner surface of the seat 22.

By utilizing the plastic deformation caused by the compression of the rod R, the sheet 22 is made to conform to the inner surface of the outer cylinder 21 and the outer diameter surface of the rod R. After the adhesive has hardened after a predetermined period of time, lot R
is extracted from the inner diameter surface of the sheet 22.

In this way, axial spacing! 2 glued together
By commonly pressing and plastically deforming the sheets 22 in one lot R, a hydrodynamic grooved bearing 20 with excellent inner diameter dimensional accuracy and guaranteed coaxiality at both ends in the axial direction can be obtained.

FIG. 3 shows a modification only for generating dynamic pressure. This is a groove pattern when the shaft body 10 and the dynamic pressure grooved bearing 20 are radial dynamic pressure grooved bearings that rotate relative to each other.

FIG. 6A shows the case of unidirectional rotation, in which downward grooves 60 whose arrowheads coincide with the rotational direction are arranged at substantially the same intervals in the circumferential direction via land portions 80.

The same figure (b) shows the case of forward and reverse rotation, in which grooves 60 whose arrowheads point downward and grooves 70 whose arrowheads point upward are connected in an axial direction in a waveform and arranged alternately. They are arranged at approximately the same intervals in the circumferential direction.

In FIG. 2C, a pattern similar to that in FIG. 2A is formed, except for both ends of the sheet 22 in the axial direction.

Next, a second embodiment will be described based on FIG. 4. This embodiment can be applied whether the groove pattern of the resin sheet 22 is for linear motion or rotational motion.

As shown in FIG.
, 23b are bonded with a sheet end gap 24 in the circumferential direction, and are not butted. and,
The seat end gap 24 is adjusted so that the center angle θ at the inner circumferential surface of the outer cylinder 21 is 120° or less.

Here, the grooves 60 and 70 for generating dynamic pressure may be formed only in the range where the bearing surface substantially receives the load from the shaft body 10. Since the range is usually arbitrarily limited to a circumferential angle of 240° or more on the inner circumferential surface of the outer cylinder 21, the seat end gap 24 of the sheet 22 is preferably 120° or less.

Furthermore, even if a circumferential angle of nearly 360° may be required depending on the load conditions, it is not necessary that the pattern of the grooves 60 and 70 for generating dynamic pressure be continuous on both ends of the sheet 22 in the circumferential direction. .

The other structures and the manufacturing method thereof are the same as those in the first embodiment, so their explanations will be omitted.

As described above, in this embodiment, since it is not necessary to butt the sheet ends together when adhering the sheet 22 to the outer tube 21, the sheet 22 can be formed by the method described below.

That is, one surface of a large resin sheet 22A made of PT'FE as a main component and mixed with, for example, glass fiber as an abrasion property improving substance, is subjected to fluorine removal treatment as a pretreatment for adhesion. This example was carried out in a conventional manner using a primer specifically designed for fluororesin. Thereafter, while the large resin sheet 22A is pressurized and heated in a rolling machine, the other surface that is not subjected to the defluorination treatment has a pattern as shown in FIG. 1(d) or FIG. 3(a), for example, for dynamic pressure generation. Groove 6
0°70 was molded to form a fire-type sheet 22A with dynamic pressure grooves as shown in FIGS. 5(a) to 5d).

Next, a rubber adhesive adjusted to an appropriate viscosity with a solvent is uniformly applied to the defluorinated surface of the fire-type sheet 22A with dynamic pressure grooves, and after the solvent is volatilized and semi-dried, as shown in FIG. (a
) to d) were cut into a plurality of sheets 22 having required dimensions.

FIGS. 5(a) and (C) show a fire type sheet 22 with dynamic pressure grooves.
To cut out multiple sheets 22 from A, each sheet 2
When the upper and lower ends of 2 are brought together, grooves 60 and 7 are formed for generating dynamic pressure.
This is a case where the 0 pattern is strictly continuous,
In contrast, FIGS. 5(b) and 5(d) show cases in which the patterns of the grooves 60, 70 for generating dynamic pressure are cut at arbitrary points where the upper and lower ends are not continuous.

Therefore, when manufacturing dynamic pressure grooved bearings 20 with different widths and inner diameter dimensions, simply changing the cutting length and cutting width from the wide dynamic pressure grooved fire-type sheet 22A made by the rolling method.
Since the sheet 22 of a required unit can be easily cut out, there is an advantage that efficiency is extremely high and productivity is increased.

Further, a third embodiment will be explained based on FIG. 6.

In this embodiment, a load F is applied to one side of a shaft body 10 that rotates in one direction, resulting in a moment load, and the shaft body 10 is inclined slightly downward toward the load side. Therefore, the bearing clearance 23 between the bearing surface of the seat 22 of the bearing 20 and the outer surface of the shaft body 10 changes in the axial direction. In this case as well, since the range where the bearing surface receives the load from the shaft body 10 is determined, the groove 60 for generating dynamic pressure is limited to the range where the bearing surface receives the load, and the seat end in the circumferential direction of the seat 22 are not butted, but are provided with a gap 24 at the sheet end. However, the sheet end gap 2 of both sheets 22
The phase of No. 4 is shifted by 180°.

FIG. 7 shows a fourth embodiment.

In this embodiment, on the inner peripheral surface of the outer cylinder 30 whose outer surface is non-cylindrical,
It has grooves for generating dynamic pressure and incorporates a resin sheet 22 made of PTFE as a main component mixed with a wear property improving substance. Function as a hydrodynamic grooved bearing
There is no difference in effect from the above embodiment. In this way, the outer surface of the outer cylinder is not limited to a cylindrical shape, but may be square or any other shape as required.

[Effects of the Invention] As explained above, in the dynamic pressure grooved bearing of the present invention, a sheet of resin mainly composed of PTFE with grooves for generating dynamic pressure formed on the inner surface is adhered to the inner diameter surface of the outer cylinder. Because of this configuration, the dimensional accuracy of the inner diameter of the bearing is sufficiently high, and extremely good friction characteristics can be obtained. In addition, excellent wear characteristics can be obtained by the pumping action only for generating dynamic pressure.

Further, in the hydrodynamic grooved bearing of the present invention, a resin sheet having grooves for generating dynamic pressure formed on the inner surface is adhered to the inner circumferential surface of the outer cylinder with a sheet end gap at the circumferential end. With this structure, there is no need to butt the edges of the sheets together when adhering them, resulting in a structure that is easy to assemble.

In addition, in this bearing with dynamic pressure grooves, there are no strict requirements for the pattern of the dynamic pressure grooves in the seat or the width of the seat, so the grooves for generating dynamic pressure in the seat are made from a large resin sheet formed by plastic processing. Cutting width without considering the continuity of the grooves above,
It is possible to cut a single sheet by changing the cutting length and glue it inside the outer cylinder without the need to butt the ends of the sheet. Therefore, it is possible to freely accommodate multiple bearing inner diameters and bearing widths, making mass production possible. Dynamic pressure type belly bearings for linear motion, two-rotation motion, etc. can be easily and inexpensively provided.

Furthermore, according to the hydrodynamic grooved bearing and the manufacturing method of the hydrodynamic grooved bearing of the present invention, the groove for generating dynamic pressure is formed in advance on one surface of the resin sheet by plastic working, so that the groove depth can be increased. , groove shape, and sheet thickness can be uniformly formed with desired dimensions.

Furthermore, depending on the manufacturing method, the rod is inserted into the inner surface of the seat to correct the dimensions, so the bearing clearance can be arbitrarily controlled, and the run-out of the shaft and bearing can be suppressed to achieve high-precision performance. Furthermore, even when multiple single bearings are installed at intervals in the axial direction to form a unit, it is easy to make the inner diameters of the multiple bearings coaxial, and the friction and wear characteristics are excellent. It is possible to manufacture high-quality hydrodynamic grooved bearings with excellent dimensional accuracy.

[Brief explanation of drawings]

FIG. 1(a) is a joint cross-sectional view of a dynamic pressure grooved bearing according to the first embodiment of the present invention, and FIGS. Plan view shown, 2nd
Figures (a) and (b) are longitudinal cross-sectional views illustrating the manufacturing process of the hydrodynamic grooved bearing of the present invention, and Figures (a), (b), (
C) is a plan view showing other patterns of grooves for generating dynamic pressure, FIGS. 4(a) and (b) are longitudinal sectional views of the bearing with hydrodynamic grooves of the second embodiment, and FIG. a), (b), (
c), (a) is a plan view of a large resin sheet cut out from the sheet in the second embodiment, FIG. 6 is a vertical cross-sectional view of the hydrodynamic grooved bearing of the third embodiment, and FIG. 7 is a fourth embodiment. FIG. In the figure, 20 is a dynamic pressure grooved bearing, 21 is an outer cylinder, 22 is a seat, 23 is a bearing clearance, 24 is a seat end clearance (gap), 60.70 is a groove for generating dynamic pressure, 2 is a spacing, R is a rod (cylindrical body). Figure 1 Figure 2 Figure 3 Figure 4 (b) Figure 6 Figure 7

Claims (2)

[Claims] (1) A sheet is adhered to the inner peripheral surface of the outer cylinder, a groove for generating dynamic pressure is formed on the inner surface of the sheet, and the sheet is adhered with a gap at the sheet end in the circumferential direction of the sheet. Bearings with dynamic pressure grooves. (2) In a method for manufacturing a dynamic pressure grooved bearing in which a sheet made of resin is bonded to the inner circumferential surface of an outer cylinder, the sheet has grooves for generating dynamic pressure formed on one surface by plastic working, and the width is increased. The length of the sheet is shorter than the distance between the inner peripheral surfaces of the outer cylinder, and the sheet is wound so that the other surface of the sheet faces the inner peripheral surface of the outer cylinder with an adhesive interposed therebetween, and the inner surface of the sheet is covered with a cylinder. A method for manufacturing a hydrodynamic grooved bearing, characterized in that the cylindrical body is removed after the cylindrical body is inserted and the adhesive material is cured.