JP2008025727A - Plastic molded product and rolling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plastic molded product having excellent lubricity and usable as a component part of a rolling device and to provide a high precision rolling device having excellent lubricity and durability. <P>SOLUTION: A linear guide device 100 consists of a guide rail 11, a slider 12, a plurality of balls provided in a ball rolling passage 15 formed by ball raceway grooves 11a, 12a and separators 18 provided between adjoining balls 13. The separator 18 is compounded by polyether-ether-ketone resin and its surface is contacted with compatible subject of supercritical carbon dioxide and alkyl diphenyl ether and treated with impregnation for removing only the supercritical carbon dioxide from permeated alkyl diphenyl ether and supercritical carbon dioxide. A most concentrated part which has highest concentration of alkyl diphenyl ether is formed at least at a part of a section from the surface to 1,500 μm in depth. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a plastic molded product and a rolling device used as components of a rolling device such as a rolling bearing, a linear guide device, a ball screw, a linear motion bearing, and an XY stage.

  As a method for modifying a plastic molded product using supercritical carbon dioxide, for example, there is one disclosed in Patent Document 1. This method for modifying a plastic molded article includes a step of immersing the plastic molded article in supercritical carbon dioxide containing a lubricating oil to allow the lubricant and carbon dioxide to penetrate into the plastic molded article, And a step of removing only carbon dioxide from the lubricating oil and carbon dioxide that have permeated the water.

Thus, when the surface layer portion of the plastic molded product is impregnated with the lubricating oil, excellent lubricity is imparted to the plastic molded product. Therefore, if a plastic molded product impregnated with lubricating oil is used as a component of a rolling device, the rolling device has excellent lubricity and durability (see Patent Document 2).
JP 2005-60473 A JP 2005-299923 A

However, if the plastic molded product is impregnated with a large amount of lubricating oil, not only the surface layer portion but also the inside is impregnated, which may cause a large dimensional change in the plastic molded product. When a plastic molded product in which such a dimensional change has occurred is used as a component of a rolling device, there is a possibility that a problem may occur in the accuracy of the rolling device.
Accordingly, an object of the present invention is to solve the above-described problems of the prior art and to provide a plastic molded product that has excellent lubricity and can be used as a component of a rolling device. Another object of the present invention is to provide a highly accurate rolling device that is excellent in lubricity and durability.

  In order to solve the above problems, the present invention has the following configuration. That is, the plastic molded product according to claim 1 of the present invention has an inner member having a raceway surface on the outer surface and a raceway surface opposite to the raceway surface of the inner member, and is disposed on the outer side of the inner member. A plastic molded product used as a component part of a rolling device comprising a formed outer member and a plurality of rolling elements arranged to roll between the raceway surfaces, wherein the supercritical fluid and lubrication It is impregnated with the lubricating oil by contacting the compatibilized product with the oil to infiltrate the supercritical fluid and lubricating oil, and removing only the supercritical fluid from the infiltrated supercritical fluid and lubricating oil. The thickest part having the highest lubricating oil concentration is formed in at least a part of the part up to 1500 μm.

  According to a second aspect of the present invention, there is provided a plastic molded product comprising an inner member having a raceway surface on an outer surface and a raceway surface facing the raceway surface of the inner member, and is disposed outward of the inner member. A plastic molded product used as a component part of a rolling device comprising a formed outer member and a plurality of rolling elements arranged to roll between the raceway surfaces, wherein the supercritical fluid and lubrication It is impregnated with the lubricating oil by contacting the compatibilized product with the oil to infiltrate the supercritical fluid and lubricating oil, and removing only the supercritical fluid from the infiltrated supercritical fluid and lubricating oil. The thickest part having the highest lubricating oil concentration is formed in at least a part of the part up to 100 μm.

Furthermore, the plastic molded article of claim 3 according to the present invention is characterized in that, in the plastic molded article of claim 1 or claim 2, the supercritical fluid is supercritical carbon dioxide.
Furthermore, the plastic molded product of Claim 4 which concerns on this invention is comprised with the crystalline polymer in the plastic molded product as described in any one of Claims 1-3.
Furthermore, the plastic molded product according to claim 5 of the present invention is the plastic molded product according to claim 4, wherein the crystalline polymer is polyethylene, polyoxymethylene, polyvinylidene fluoride, polyamide 6, polyamide 66, polyphenylene. It is at least one of sulfide and polyetheretherketone.

Furthermore, the plastic molded product according to claim 6 of the present invention is the plastic molded product according to any one of claims 1 to 5, wherein the lubricating oil is a poly α-olefin, an alkyl diphenyl ether, a diester, and a polyol. It is at least one of esters.
Furthermore, the rolling device according to claim 7 of the present invention includes an inner member having a raceway surface on the outer surface, and a raceway surface facing the raceway surface of the inner member, and is disposed outward of the inner member. A rolling device comprising: an outer member that is formed, and a plurality of rolling elements that are arranged to freely roll between the both raceway surfaces. At least one of the components is any one of claims 1 to 6. It is comprised with the plastic molded product of description.

Furthermore, the rolling device according to claim 8 of the present invention is the rolling device according to claim 7, wherein the rolling device is a rolling bearing, a linear guide device, a ball screw, a linear motion bearing, or an XY stage. .
Such a plastic molded article has excellent lubricity because most of the impregnated lubricating oil is impregnated in a portion from the surface to a predetermined depth, and the dimensional change accompanying the impregnation of the lubricating oil. Is small and has dimensional accuracy that can be used as a component of a rolling device. If the thickest part is formed in a part deeper than 1500 μm (preferably 100 μm), the lubricity may be insufficient, and the dimensional change accompanying the impregnation of the lubricating oil becomes large, and the rolling device When used as a component, the accuracy of the rolling device may be reduced.

The inward member in the present invention means an inner ring when the rolling device is a rolling bearing, a screw shaft when the ball screw is also used, a guide rail when the linear guide device is used, and a linear motion bearing. Means each axis. The outer member is the outer ring when the rolling device is a rolling bearing, the nut when it is a ball screw, the slider when it is a linear guide device, and the outer cylinder when it is also a linear bearing. Each means.
Moreover, the component in this invention means the component which comprises a rolling device, for example, an inner member, an outer member, a rolling element, a separator, a holder | retainer, and a sealing device are mention | raise | lifted.

  The plastic molded product of the present invention is excellent in lubricity and can be used as a component of a rolling device. Further, the rolling device of the present invention is excellent in lubricity and durability and is highly accurate.

DESCRIPTION OF EMBODIMENTS Embodiments of a plastic molded product and a rolling device according to the present invention will be described in detail with reference to the drawings.
[About impregnation of lubricating oil]
The impregnation treatment with a lubricating oil for a plastic molded product used as a component of a rolling device includes an immersion treatment process and an evaporation removal process. The immersion treatment step is a step of immersing the plastic molded article in supercritical carbon dioxide containing lubricating oil. Carbon dioxide in the supercritical state becomes compatible with the lubricating oil and penetrates from the surface of the plastic molded product to the inside.

  To explain with a specific example, a dried plastic molded article and lubricating oil are placed in a pressure vessel, and carbon dioxide is further filled until the internal pressure becomes 4.5 to 6.5 MPa. And the temperature in a pressure vessel is raised more than a critical temperature, maintaining an internal pressure more than a critical pressure with a pressure reducing valve. Supercritical carbon dioxide is carbon dioxide in a region having a temperature higher than the critical temperature and a pressure higher than the critical pressure. Incidentally, the critical temperature of carbon dioxide is 31 ° C., and the critical pressure is 72.8 atm (7.38 MPa).

  The immersion temperature in the immersion treatment step is not less than the critical temperature of carbon dioxide, more preferably not less than 80 ° C. and less than the melting point of the resin constituting the plastic molded product. Further, when the temperature of the resin exceeds the glass transition temperature, the free volume increases until the micro-brown motion of the molecular main chain becomes possible, and the carbon dioxide in the supercritical state becomes more easily penetrated into the plastic molded product. Therefore, it is preferable that the immersion temperature in the immersion treatment process is equal to or higher than the glass transition point of the resin constituting the plastic molded product.

Further, the pressure in the immersion treatment step is equal to or higher than the critical pressure of carbon dioxide, and a higher pressure is preferable because the penetration degree of supercritical carbon dioxide into the resin is improved and the efficiency of reforming is improved. However, since it is necessary to make it possible to withstand the high pressure of an apparatus used in the immersion treatment process (hereinafter referred to as an immersion treatment apparatus), the immersion treatment apparatus becomes large and expensive. Therefore, in consideration of the operability and equipment costs of the immersion treatment apparatus, the pressure is suitably in the range of 100 to 300 atmospheres (10.13 to 30.4 MPa).
Furthermore, the immersion time in the immersion treatment process is not particularly limited, and is appropriately set in consideration of the thickness and size of the plastic molded product.

  Next, the evaporation removal process will be described. The apparatus used for the evaporation removal process (hereinafter referred to as the evaporation removal apparatus) is set to a temperature lower than the critical temperature of carbon dioxide (for example, 30 ° C.) and lower than the critical pressure, and then gradually removed to remove the carbon dioxide. Slowly lower the pressure inside to return to atmospheric pressure. As a result, only the carbon dioxide of the lubricating oil and carbon dioxide that has penetrated into the plastic molded product is evaporated and removed, and the lubricating oil remains in the plastic molded product.

  When almost all the carbon dioxide in the evaporative removal device is evaporated, only the lubricating oil remains in the evaporative removal device, and the plastic molded product is immersed in the lubricating oil. Remove from inside. At this time, if necessary, the lubricating oil adhering to the surface of the plastic molded article may be removed by washing. Thereafter, the carbon dioxide can be removed more completely by holding it in a vacuum desiccator or the like for a certain period (for example, 10 days).

  Through the two processes as described above, the molecules of the lubricating oil penetrate into the plastic molded product, and exist stably in the free volume between the molecules of the resin. In this way, unlike the so-called simple oil impregnation treatment, in which the plastic molded product is immersed in the lubricating oil under conditions such as high temperature and high pressure, the lubricating oil is not limited to the vicinity of the surface of the plastic molded product, but relatively in the interior. To penetrate. Since the lubricating oil is present in the free volume originally possessed, the lubricating oil hardly oozes out to the outside, and the reforming effect is maintained semipermanently, and at the same time, the mechanical strength may be lowered. rare.

The amount of lubricating oil impregnation varies depending on conditions such as the immersion temperature, pressure, and immersion time, but the influence of the lubricating oil impregnation amount is the largest among the above three conditions.
Further, the depth impregnated with the lubricating oil can be controlled by changing the operation procedure of the impregnation treatment with the lubricating oil. For example, in the above-described example, after evaporating and removing the inside of the evaporation removing apparatus below the critical temperature of carbon dioxide and below the critical pressure in the evaporation removing step, the carbon dioxide is gradually discharged to slowly return the pressure in the evaporation removing apparatus to atmospheric pressure. The operation procedure was, but the pressure inside the evaporative removal device was suddenly lowered to atmospheric pressure in a short time of about 30 seconds, so that the temperature inside the evaporative removal device was drastically lowered and the inside of the evaporative removal device was in a supercritical state. If the operating procedure is changed from normal to normal, the depth impregnated with the lubricating oil can be changed. Moreover, the depth which a lubricating oil impregnates can further be changed by further combining the method of impregnating lubricating oil to the inside of a plastic molded product.

[About supercritical fluids]
In the present invention, various supercritical fluids can be used. For example, carbon dioxide, nitrogen dioxide, ammonia, ethane, propane, ethylene, methanol, ethanol and the like can be mentioned. However, carbon dioxide is most preferred because it becomes a supercritical fluid under relatively mild conditions, and is non-toxic and non-flammable.

[About lubricating oil]
The type of lubricating oil that can be used in the present invention is not particularly limited. For example, poly α-olefin oil, polyphenyl ether oil (for example, alkyldiphenyl ether oil), aromatic or aliphatic carboxylic acid ester oil (for example, diester oil), and polyol ester oil (for example, pentaerythritol tetraester) are suitable. Note that the type of lubricating oil to be used may be selected in accordance with the type of lubricating oil in the lubricant used when lubricating resin components. Then, the wettability between the component parts and the lubricant becomes better.

[Resin]
The type of resin constituting the component in the present invention is not particularly limited, but as a resin to which the lubricating oil impregnation treatment can be suitably applied, the glass transition temperature (Tg) is higher than the critical temperature of the supercritical fluid. Is also preferable. Examples thereof include polyethylene, polyoxymethylene, polyvinylidene fluoride, polyamide 6, polyamide 66, polyamide 46, aromatic polyamide, polyphenylene sulfide, polyether ether ketone, and the like.

  These resins may contain fibrous fillers such as glass fibers, carbon fibers, and aramid fibers, and whiskers such as potassium titanate whiskers and aluminum borate whiskers. Moreover, you may contain additives, such as a heat stabilizer and antioxidant. However, among the aforementioned resins, general-purpose resins often contain the aforementioned additives, and it is expected that the additives will be extracted depending on the conditions of the impregnation treatment with the lubricating oil. Be careful.

Next, an example will be described in which the plastic molded product that has been impregnated with lubricating oil as described above is used as a component part of a linear guide device, a ball screw, and a rolling bearing.
[First embodiment]
FIG. 1 is a partial plan view showing a structure of a linear guide device which is an embodiment of a rolling device according to the present invention. However, in the plan view, the main part is shown broken away. FIG. 2 is an enlarged view of the separator and the ball of the linear guide device of FIG. However, in the enlarged view, the separator is shown broken.

  A linear guide device 100 in FIG. 1 includes a guide rail (inner member) 11 having a substantially square cross section extending in the axial direction, a slider (outer member) 12 having a substantially U-shaped cross section assembled to the guide rail 11, and In a ball rolling path 15 formed by a ball raceway groove (track surface) 11 a provided on both side surfaces of the guide rail 11 and a ball raceway groove (track surface) 12 a provided on the inner side of both sleeve portions of the slider 12. And a plurality of balls (rolling elements) 13 arranged so as to be freely rollable.

  The slider 12 includes a slider body 12A and end caps 12B and 12B that are detachably attached to both ends of the slider body 12A in the axial direction. In this end cap 12B, a substantially U-shaped ball return passage for communicating the ball circulation passage 16 and the ball rolling passage 15 for returning the ball 13 rolling from one end of the ball rolling passage 15 to the other end. 17 is provided so that the ball 13 can repeatedly roll on the ball rolling path 15 via the ball circulation path 16. The slider 12 performs a linear motion in the longitudinal direction of the guide rail 11 through a rolling motion of the ball 13 along the ball rolling path 15.

  In the linear guide device 100, as shown in FIG. 2, a separator 18 is interposed between adjacent balls 13, so that competition between the balls 13 is suppressed. The separator 18 has a substantially cylindrical shape as shown in FIG. 2, and both bottom surfaces 18a and 18a, which are contact surfaces with the ball 13, are concave as shown in FIG. When the surface is concave, the contact area with the ball 13 is increased, and the contact surface pressure is reduced. The cross-sectional shape of the concave surface 18a may be a Gothic arch shape (substantially V-shape combining two identical arcs with different centers) or an arc shape. The bottom surfaces 18a and 18a, which are contact surfaces with the ball 13, may be planar.

  Of the components of the linear guide device 100, the slider body 12A is made of martensitic stainless steel SUS440C, and the end cap 12B is made of austenitic stainless steel SUS304. Moreover, the guide rail 11 and the ball | bowl 13 among the components of the linear guide apparatus 100 are comprised with the martensitic stainless steel SUS440C.

  Further, the separator 18 is made of a polyether ether ketone resin (PEEK450G manufactured by Victrex) and is subjected to the following impregnation treatment with a lubricating oil. That is, it is a process for removing only supercritical carbon dioxide from the permeated lubricating oil and supercritical carbon dioxide by bringing a compatibilized product of supercritical carbon dioxide and lubricating oil (alkyl diphenyl ether) into contact with each other.

  Here, the detailed procedure of the impregnation process will be described. First, a separator and several ml of alkyl diphenyl ether (manufactured by Matsumura Oil Research Institute) were charged into a pressure vessel of a supercritical carbon dioxide test apparatus manufactured by Pressure Glass Industrial Co., Ltd. Furthermore, carbon dioxide was filled into the pressure vessel from the liquefied carbon dioxide cylinder using a pump until the internal pressure of the pressure vessel reached 6.5 MPa. Next, the internal temperature of the pressure vessel was raised to 150 ° C. while maintaining the internal pressure of the pressure vessel at 20 MPa using a pressure reducing valve. After maintaining at 150 ° C. for 1 hour, it was allowed to cool to 30 ° C., the internal pressure was returned to atmospheric pressure, and the separator was taken out from the pressure vessel.

By such impregnation treatment, the lubricating oil permeates the surface layer of the separator 18 and imparts lubricity, so that the lubricity and durability of the linear guide device 100 are improved. Further, if a lubricant based on alkyl diphenyl ether is used for the linear guide device 100, the affinity (wetting property) between the lubricant and the separator 18 is improved, so that the lubricity of the linear guide device 100 is further improved. Improved and more durable.
Furthermore, when the surface layer of the separator 18 was analyzed by the method described later, the lubricating oil was impregnated in a portion from the surface to a depth of 500 μm. Therefore, the dimensional change due to the impregnation treatment is only within the error range even when used in a rolling device such as the linear guide device 100.

[Second Embodiment]
FIG. 3 is a perspective view showing a structure of a ball screw which is another embodiment of the rolling device according to the present invention. However, in the perspective view, the main part is shown broken away.
The ball screw 200 shown in FIG. 3 has a screw shaft (inner member) 21 having a spiral thread groove (track surface) 21a on the outer peripheral surface and a screw groove (track surface) 22a facing the screw groove 21a on the inner periphery. It comprises a nut (outer member) 22 on the surface, and a plurality of balls (rolling elements) 23 arranged so as to roll on a ball rolling path formed between both screw grooves 21a, 22a. Yes. The nut 22 is attached with a return tube (ball circulation path) 27 that scoops up the ball 23 rolling to one end of the ball rolling path and sends it to the other end. In the ball screw 200, the screw shaft 21 and the nut 22 are relatively moved in the axial direction by rotating the screw shaft 21 and the nut 22 relative to each other through rolling of the plurality of balls 23. Yes.

In the ball screw 200, a separator (not shown) similar to that of the first embodiment is interposed between the adjacent balls 23 so that competition between the balls 23 is suppressed.
Among the components of the ball screw 200, the nut 22 is made of martensitic stainless steel SUS440C, and the return tube 27 is made of austenitic stainless steel SUS304. Of the components of the ball screw 200, the screw shaft 21 and the ball 23 are made of martensitic stainless steel SUS440C.

Further, the separator is made of a polyether ether ketone resin as in the first embodiment, and the surface is subjected to the same impregnation treatment as in the first embodiment. Therefore, the same effect as that of the linear guide device 100 of the first embodiment can be obtained.
Furthermore, when the surface layer of the separator was analyzed by the method described later, the lubricating oil was impregnated in a portion from the surface to a depth of 500 μm. Therefore, the dimensional change due to the impregnation treatment is only within the error range even when used in a rolling device such as the ball screw 200.

[Third embodiment]
FIG. 4 is a sectional view showing a structure of a rolling bearing (deep groove ball bearing) which is another embodiment of the rolling device according to the present invention. FIG. 5 is a perspective view of a cage incorporated in the rolling bearing of FIG.
The rolling bearing 300 in FIG. 4 has an inner ring (inner member) 31 having a raceway surface 31 a on the outer peripheral surface and a raceway surface 32 a facing the raceway surface 31 a of the inner ring 31 and is disposed on the outer side of the inner ring 31. (Outer member) 32, a plurality of rolling elements (balls) 33 that are arranged to freely roll between both raceway surfaces 31a and 32a, and a cage 34 that holds the rolling element 33 between both raceway surfaces 31a and 32a. And shields 35, 35.

  Among the components of the rolling bearing 300, the inner ring 31, the outer ring 32, and the rolling element 33 are made of martensitic stainless steel SUS440C. The cage 34 of the rolling bearing 300 is manufactured by injection molding ETFE (Pochicon FT24 manufactured by Otsuka Chemical Co., Ltd.) containing 15% by mass of potassium titanate whiskers. An impregnation treatment similar to that of the embodiment is performed. Therefore, the same effect as that of the linear guide device 100 of the first embodiment can be obtained.

Furthermore, when the surface layer of the cage 34 was analyzed by the method described later, the portion from the surface to a depth of 500 μm was impregnated with lubricating oil. Therefore, the dimensional change due to the impregnation treatment is only within the error range even when used in a rolling device such as the rolling bearing 300.
In the third embodiment, the crown-shaped cage has been described as an example. However, the type of the cage is not particularly limited. For example, a cage-shaped cage, a single shape cage, a waveform cage, and the like. There is no problem.

  Further, in the present embodiment, the deep groove ball bearing has been described as an example of the rolling bearing, but the present invention can be applied to various types of rolling bearings. For example, radial rolling bearings such as angular contact ball bearings, self-aligning ball bearings, cylindrical roller bearings, tapered roller bearings, needle roller bearings, and self-aligning roller bearings, and thrust types such as thrust ball bearings and thrust roller bearings This is a rolling bearing.

FIG. 6 shows an example of an angular ball bearing, and FIG. 7 shows a cage provided in the angular ball bearing of FIG. Also in this example, as in the third embodiment, the inner ring 41, the outer ring 42, and the rolling element 43 among the components of the rolling bearing are made of martensitic stainless steel SUS440C. The cage 44 is manufactured by injection-molding a thermoplastic polyimide resin containing 30% by mass of carbon fiber (AURUM JCN3030 manufactured by Mitsui Chemicals), and the surface thereof is the same as in the first embodiment. Is impregnated. Therefore, the same effect as that of the linear guide device 100 of the first embodiment can be obtained.
Further, when the surface layer of the cage 44 was analyzed by a method described later, the lubricating oil was impregnated in a portion from the surface to a depth of 500 μm. Therefore, the dimensional change due to the impregnation treatment is only within the error range even when used in a rolling device such as a rolling bearing.

〔Example〕
Hereinafter, the present invention will be described more specifically with reference to examples. A disk having a diameter of 35 mm and a thickness of 3 mm was prepared using an extruded product of ultrahigh molecular weight polyethylene (PE) or polyamide 66 (PA66) (both manufactured by Nippon Polypenco Co., Ltd.). Then, the impregnation treatment as described above was performed and impregnated with diethylhexyl adipate (DOA) or alkyldiphenyl ether (ADE) as a lubricating oil. In this example, the immersion temperature was 40, 60, 80, 100, or 150 ° C., the pressure was 10, 15, or 20 MPa, and the immersion time was 1, 2, 3, 4, or 6 hours.

In addition, Tg of ultra high molecular weight polyethylene is -125 degreeC and Tm is 130 degreeC, Tg of polyamide 66 is 66 degreeC, Tm is 262 degreeC. Moreover, the kinematic viscosity at 40 ° C. of diethylhexyl adipate is 18.26 mm ² / s, the kinematic viscosity at 40 ° C. of alkyldiphenyl ether is 16.47 mm ² / s, and the alkyl group as a functional group is —C ₁₃ H _27. (The number of functional groups is 1 or 2).
By measuring the mass of the disc before and after the impregnation treatment, the ratio of the impregnated lubricating oil in the impregnated disc (hereinafter referred to as oil content) was measured. The results are shown in the graph of FIG. Although the oil content increases with the immersion time, it can be seen that the rate of increase varies depending on the type of resin. In this test, the saturation amount of oil content could not be confirmed.

  Next, the relationship between immersion temperature, pressure and oil content is shown in the graph of FIG. The influence of the immersion temperature was large, and the oil content rapidly increased at 80 ° C. or higher. From this result, it is understood that the immersion temperature is preferably not less than the critical temperature of carbon dioxide, more preferably not less than 80 ° C. and less than the melting point of the resin constituting the plastic molded product. On the other hand, although there was a tendency that the higher the pressure, the higher the oil content, the effect was not so great. Such a tendency was common regardless of the type of resin or lubricant.

Next, the impregnated disc (PE disc impregnated with DOA) was cut, and a cross section having a thickness of 5 μm was prepared by a microtome. And the distribution situation of the depth direction of the lubricating oil impregnated in the disk was investigated by analyzing the cross section with a transmission type Fourier transform micro infrared spectrophotometer (FT-IR). The analysis was performed using the characteristic absorption 1739.8 cm ⁻¹ of the carbonyl group of DOA. Since the measurement is performed using a functional group having only DOA, this absorbance can be regarded as the concentration of DOA. The analysis results are shown in FIG.

It can be seen from FIG. 10 that DOA is impregnated from the surface to the center (depth 1500 μm). The highest concentration portion where the concentration of DOA is the highest is formed in the portion from the surface to a depth of 100 μm, the plateau portion continues to a depth of 500 μm, and the concentration rapidly decreases from there to the center portion. I understand that.
The depth up to the depth where the concentration starts to decrease rapidly is defined as the concentrated portion, and the size change due to the difference in the thickness of the concentrated portion was investigated. The magnitude of the dimensional change was evaluated by measuring the thickness of the disk before and after the impregnation treatment with a micrometer. The results are shown in the graph of FIG. From this graph, it can be seen that when the thickness of the concentrated portion exceeds 500 μm, the dimensional change increases rapidly. If the thickness of the concentrated portion is 500 μm or less, the size change is preferably 10 μm or less, and if the thickness of the concentrated portion is 100 μm or less, the size change is 5 μm or less. More preferred.

  The rolling device of the present invention can be suitably used even when a general lubricant cannot be used. For example, it is also suitable when the rolling device is used in a vacuum environment such as a liquid crystal panel manufacturing facility, a semiconductor manufacturing facility, or the like. Furthermore, it is also suitable when the rolling device is used in a space environment such as an artificial satellite.

It is a top view which shows the structure of the linear guide apparatus which is one Embodiment of the rolling device which concerns on this invention. It is an enlarged view of the separator and ball | bowl of the linear guide apparatus of FIG. It is a perspective view which shows the structure of the ball screw which is another embodiment of the rolling device based on this invention. It is sectional drawing which shows the structure of the rolling bearing (deep groove ball bearing) which is another embodiment of the rolling device which concerns on this invention. It is a perspective view of the holder | retainer integrated in the rolling bearing of FIG. It is sectional drawing which shows the structure of the rolling bearing (angular ball bearing) which is another embodiment of the rolling device which concerns on this invention. It is a side view of the holder | retainer integrated in the rolling bearing of FIG. It is a graph which shows the relationship between the immersion time of an impregnation process, and oil content. It is a graph which shows the relationship between the immersion temperature of an impregnation process, a pressure, and oil content. It is a figure which shows the analysis result of FT-IR. It is a graph which shows the relationship between the thickness of a concentration part, and the magnitude | size of a dimensional change.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Guide rail 11a Ball raceway groove 12 Slider 12a Ball raceway groove 13 Ball 18 Separator 21 Screw shaft 21a Screw groove 22 Nut 22a Screw groove 23 Ball 31,41 Inner ring 32,42 Outer ring 33,43 Rolling element 34,44 Cage 100 Linear Guide device 200 Ball screw 300 Rolling bearing

Claims (8)

An inner member having a raceway surface on the outer surface, an outer member having a raceway surface opposite to the raceway surface of the inner member, and arranged on the outer side of the inner member, and rolling between the both raceway surfaces A plastic molded product used as a component of a rolling device comprising a plurality of freely arranged rolling elements,
The supercritical fluid and the lubricating oil are brought into contact with each other and the supercritical fluid and the lubricating oil are infiltrated, and only the supercritical fluid is removed from the permeated supercritical fluid and the lubricating oil. A plastic molded product characterized in that a thickest portion having the highest concentration of lubricating oil is formed in at least a part of a portion from the surface to a depth of 1500 μm. An inner member having a raceway surface on the outer surface, an outer member having a raceway surface opposite to the raceway surface of the inner member, and arranged on the outer side of the inner member, and rolling between the both raceway surfaces A plastic molded product used as a component of a rolling device comprising a plurality of freely arranged rolling elements,
The supercritical fluid and the lubricating oil are brought into contact with each other and the supercritical fluid and the lubricating oil are infiltrated, and only the supercritical fluid is removed from the permeated supercritical fluid and the lubricating oil. A plastic molded product characterized in that a thickest portion having the highest concentration of lubricating oil is formed in at least a part of a portion from the surface to a depth of 100 μm.   The plastic molded article according to claim 1 or 2, wherein the supercritical fluid is supercritical carbon dioxide.   The plastic molded article according to any one of claims 1 to 3, wherein the plastic molded article is made of a crystalline polymer.   5. The crystalline polymer according to claim 4, wherein the crystalline polymer is at least one of polyethylene, polyoxymethylene, polyvinylidene fluoride, polyamide 6, polyamide 66, polyphenylene sulfide, and polyether ether ketone. Plastic molded product.   The plastic molded article according to any one of claims 1 to 5, wherein the lubricating oil is at least one of a poly α-olefin, an alkyl diphenyl ether, a diester, and a polyol ester. An inner member having a raceway surface on the outer surface, an outer member having a raceway surface opposite to the raceway surface of the inner member, and arranged on the outer side of the inner member, and rolling between the both raceway surfaces In a rolling device comprising a plurality of freely arranged rolling elements,
A rolling device characterized in that at least one of the components is made of the plastic molded product according to any one of claims 1 to 6.   The rolling device according to claim 7, wherein the rolling device is a rolling bearing, a linear guide device, a ball screw, a linear motion bearing, or an XY stage.

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