JP2006138773A - Method for reducing amount of wear in sliding component, low-friction sliding component pair, and component thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for reducing the amount of wear in a sliding component made of a thermoplastic resin without using any materials of complex composition, and to provide an inexpensive sliding component using the method. <P>SOLUTION: The pair of sliding components is made of the sliding component A made of a thermoplastic resin and the sliding component B made of a thermoplastic resin having smaller amount of wear by sliding as compared with the sliding component A, stores abrasion powder generated by sliding on the sliding surfaces of the sliding component A and has a recess for supplying the stored abrasion powder between the sliding surfaces. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for reducing the amount of wear of a sliding component, a low wear sliding component pair, and the component.

Examples of the power transmission component having the sliding portion include a gear, a bearing, a cam, a clutch, a washer, and a roller. Metals, ceramics, glass, resin, wood, and the like are also used for the materials used therefor. Particularly for resins, polyacetal, polybutylene terephthalate, polyamide, polyphenylene sulfide, and the like are employed because they are inexpensive and easy to mold, and can be used without lubrication.
As the power transmission parts increase in speed, weight, and sophistication of required performance, the burden on the sliding part is increasing. In response to this, blending of high-performance lubricants into materials, the use of expensive grease, and the installation of cooling mechanisms have been taken, but manufacturing costs increased, physical properties decreased due to blending of lubricants, and materials due to grease There were problems such as deterioration.

The document “oilless bearings” recommends reducing the product of the coefficient of friction, surface pressure and sliding speed, and reducing the roughness of the sliding surface to prevent wear and damage to the friction surface. Yes. (See Non-Patent Document 1)
However, if the grease is applied or the lubricant is blended in order to reduce the friction coefficient, the above-described problems occur. In order to reduce the sliding speed, reducing the power transmission speed directly leads to a decline in product performance. Further, in order to reduce the roughness of the sliding surface, it is necessary to polish the surface, which increases costs.

In JP-A-5-65877, in a reciprocating compressor in which a metal piston moves up and down in a metal cylinder, an inner periphery of a piston pin support bearing that swingably supports a connecting rod with respect to the piston pin. There has been introduced a technique for improving abnormal wear and rocking by forming a groove penetrating one end face of a bearing surface. In order to prevent the generated metal wear powder from becoming abrasive grains and promoting abnormal wear, a groove is formed and the metal wear powder is allowed to escape into the groove to prevent abnormal wear. (See Patent Document 1)
However, in this technique, resin wear powder generated from resin sliding parts is accommodated in the recesses, and the wear powder in the recesses is automatically supplied between the sliding surfaces as the slide slides. There is no disclosure or suggestion that a film is formed between the sliding surfaces to reduce the amount of wear on the sliding surfaces.

Japanese Utility Model Publication No. 6-7924 discloses a sliding direction of a metal tie bar on an inner wall sliding portion of a tie bar bush made of a synthetic resin obtained by adding polytetrafluoroethylene, lubricating oil, and molybdenum disulfide to a resin base material such as PPS. An oil-free tie bar bush with a dust-absorbing groove that intersects is introduced. (See Patent Document 2)
However, with this technology, the specific combination of fillers described above must be blended, resulting in a decrease in the physical properties of the resin tie bar bush, an increase in cost, and a resin sliding surface combined with metal. When providing the dust absorption groove, the dust absorption groove scrapes and absorbs the wear powder adhering to the metal side one after another. Even if the surface of the metal is seemingly smooth, there is roughness, and if the rough surface of the metal with extremely high hardness is always in direct contact with the resin to scrape the resin, or if metal wear particles are generated as abrasive grains, Since iron tie bars have extremely poor wear resistance against iron powder, there is a problem that the generation of abrasive iron powder is accelerated and wear proceeds rapidly.

JP-A-5-65877 (Claims 1 and 3, [0008], FIG. 2) Japanese Utility Model Publication No. 6-7924 (Claims 1 and 2, [0010] to [0011], [0016], FIG. 1) "Oilless bearing", published by Agne Co., Ltd., written by Keisumi Kawasaki, revised on October 10, 1980, first edition (p.227 (reducing the product of friction coefficient, surface pressure and sliding speed), p.249 (Reduction of sliding surface roughness)

  Provided are a method for reducing the amount of wear of a sliding part made of a thermoplastic resin that does not use a material having a complicated composition, and an inexpensive sliding part using the same.

In the conventional technique, since the generated wear powder is not normally desirable to be present on the sliding surface as a foreign substance, it is discharged into a hole or a recess.
When the present inventors combine resin materials having different wear characteristics as sliding parts, the recesses are provided in a shape where the opening of the recessed part intersects the sliding direction on the sliding surface of the part having inferior wear characteristics. , Wear powder generated from parts with inferior wear characteristics is stored in the recesses, and the stored wear powder is naturally supplied to the sliding surface and adheres to the film to protect the sliding surface, thereby reducing wear. The inventors have found that this is possible and have completed the present invention.

That is, the first of the present invention consists of a sliding part (A) made of a thermoplastic resin and a sliding part (B) made of a thermoplastic resin in which the amount of wear due to sliding is less than that of the sliding part (A). A pair of sliding parts, on the sliding surface of the sliding part (A),
Provided is a pair of sliding parts having a recess for accommodating the wear powder generated by sliding and supplying the contained wear powder between sliding surfaces.
A second aspect of the present invention provides the sliding component pair according to the first aspect of the present invention, wherein the recess is a groove and / or a bottomed hole.
A third aspect of the present invention provides the sliding component pair according to the first or second aspect of the present invention, wherein at least a part of the opening of the recess has an angle with respect to the sliding direction.
A fourth aspect of the present invention is the first to third aspects of the present invention in which at least a part of the top of the rear concave portion in the sliding direction has an angle with respect to the sliding direction when viewed from the sliding component provided with the concave portion. A sliding component pair according to any of the above is provided.
A fifth aspect of the present invention provides the sliding molded product pair according to the third or fourth aspect of the present invention, wherein an angle with respect to the sliding direction is within 90 ± 80 degrees.
A sixth aspect of the present invention provides the sliding component pair according to any one of the first to fifth aspects of the present invention, wherein at least a part of the top of the opening of the recess is chamfered into a flat shape or a curved shape. .
A seventh aspect of the present invention provides the sliding component pair according to any one of the first to sixth aspects of the present invention, wherein the recess has a width of 0.02 mm or more and a depth of 0.01 to 20 mm.
8th of this invention provides the sliding component (A) used for the sliding component pair in any one of 1st-7th of this invention.
A ninth aspect of the present invention is a sliding part made of a thermoplastic resin sliding part (A) and a sliding part (B) made of a thermoplastic resin that does not wear much more by sliding than the sliding part (A). A pair of moving parts is used to provide a recess on the sliding surface of the sliding component (A), and wear powder generated during sliding is accommodated in the recess, and the wear powder in the recess automatically moves with the sliding. Provided is a method for reducing the amount of wear of a sliding component, characterized in that it is supplied between sliding surfaces.

  By using the sliding component manufactured according to the present invention, a low-wear sliding component can be manufactured at low cost without using an expensive or complicated composition material.

The sliding form is classified into three types as shown below, and the present invention is suitably used for any sliding form.
(B) Both continuous sliding forms: The test form described in the JIS K7218 / A method is a representative example, but the sliding contact surface is a surface and the entire sliding surface of each sliding component is apparent. Above, it is a form which is always in sliding contact. Specifically, a flat friction clutch, a fuel impeller, etc. correspond to this.
(B) Continuous-intermittent sliding configuration: The test configuration described in the JIS K7218 / B method is a representative example, but the entire sliding surface of one of the combined components is always in sliding contact with the counterpart component, and the other component. Is a form in which the sliding portion of the entire sliding surface changes with time, and the entire sliding surface is not in sliding contact with the counterpart component. Specifically, a cam mechanism or the like is applicable.
(C) Both intermittent sliding forms: The sliding parts of the combined parts change with time, and all the sliding surfaces are not in sliding contact at the same time. This applies to gears.

For example, in the hollow cylindrical test piece (see FIG. 1) described in the JIS K7218 / A method, the wear powder generated by sliding is discharged from the inner periphery and outer periphery of the sliding portion.
In the present invention, the concave portion is provided only in the sliding component (A). The present invention is characterized in that a concave portion is provided on only one of the component pairs.
Note that the material of the sliding component (B) is a material that does not have much wear due to sliding compared to the sliding component (A), and may be the same as the material of the sliding component (A).
Although the example of various recessed parts is shown in FIG. 2, this invention is not limited to these.
FIG. 2A shows an example in which, for example, eight slit grooves are provided at an intersecting angle of 90 degrees with the sliding direction by cutting the test piece shown in FIG. In the present invention, the angle of intersection between the rear opening (hereinafter sometimes referred to as the rear top) and the sliding direction is particularly important in the sliding direction of the recess. The opening on the front side in the sliding direction of the recess may be referred to as the front top.
As a modification thereof, the front top may have a depth of 0 to the bottom of the recess, and the rear top may have a depth to the bottom of the recess.
In addition, even if the width | variety of a groove | channel is constant, it may become wide toward the outer side from the center part of a cylinder, and it may be the same or narrow. Each groove may have the same shape, width or depth or may be different.
When the sliding method changes with time, the position of the rear side top at a certain time may become the front side top or the middle position between them.
FIG. 2B shows an example in which eight parallel slit grooves are provided at equal intervals, for example, at an intersecting angle of 30 degrees with the sliding direction by cutting the test piece shown in FIG.
FIG. 2 (c) shows, for example, that the concentric annular groove is divided into four parts by cutting the test piece shown in FIG. 1, and the crossing angle with the sliding direction is 0 degree. Are provided so as to have a crossing angle with the sliding direction. In this case, a sliding surface is formed between the divided grooves.
By providing a specific recess, the wear powder once accumulates in the recess, and then is supplied and adhered to the sliding surface again. That is, at least a part of the resin wear powder is film-like between the sliding surfaces. By being maintained in this state, it works as a protective film and wear is greatly suppressed.
The film-like material may not be completely integrated, but most of the resin wear powder should not remain as the resin wear powder.
Formation of a film-like object is confirmed by performing a sliding test by combining two sliding parts having different colors.

Specifically, the recess is a groove (including a notch) and / or a bottomed hole.
The groove may be a combination of these, such as a straight line, a broken line, a curved line, a U-shape, a V-shape, and a semicircular shape.
The cross-sectional shape of the groove is not particularly limited, and examples thereof include a concave shape, a U shape, a V shape, a semicircular shape, and combinations thereof. The concave wall surface may have an angle with respect to the sliding direction. It is preferable that at least a part of the top of the opening of the recess is chamfered into a flat shape or a curved shape as shown in FIG.
In addition, when sliding is always performed only in a certain direction, it is only necessary to accommodate the wear powder, and the front top portion is less likely to damage the mating sliding part, that is, the front top portion of the groove and the sliding surface are smaller than 90 degrees. You may make it a bowl shape, or may make the back side top part into the structure which is easy to supply abrasion powder, ie, the obtuse angle shape where the back side top part of a groove | channel and a sliding surface are larger than 90 degree | times. Therefore, the top of the groove may be chamfered.
The groove may be provided with an end wall at one end or both ends in the longitudinal direction, or a partition at an appropriate intermediate position from both ends, but these may not be provided.
In the hollow cylindrical test piece described in JIS K7218 / A method, the groove is radial from the center of the cylinder on the sliding surface of the cylinder (that is, when the longitudinal direction of the groove is 90 degrees with respect to the sliding direction). From the state of being provided to extend to the state of being provided in a quasi-concentric shape having end walls or a continuous concentric meandering shape, at least a part of the resin wear powder is supplied between the sliding surfaces to form a film. There is no limitation as long as the shape is maintained.
The angle of at least a part of the opening of the groove with respect to the sliding direction is preferably within 90 ± 80 degrees, and more preferably within 90 ± 60 degrees. By making it within this angle range, the accommodation and supply of the wear are improved, and the resin wear powder is easily maintained in the form of a film between the sliding surfaces.
Even in shapes other than the cylinder, there is no limitation as long as the sliding surface is a shape in which at least a part of the resin wear powder is maintained in a film shape between the sliding surfaces.
The opening width of the groove is 0.02 mm or more, preferably 100 mm or less, more preferably 0.1 to 20 mm, at least at the rear side top, although it depends on the dimensions of the molded product and the use conditions. If the opening width is too small, it is difficult to accommodate the wear powder, and if it is too large, the mechanical strength of the component is lowered.
The depth of the groove is 0.01 to 20 mm, preferably 0.05 to 5 mm, at least at the rear top, although it depends on the dimensions of the molded product and the use conditions. From the above range, if the depth is too shallow, it becomes difficult to accommodate the wear powder, and if it is too deep, the mechanical strength as a component is lowered.
The number of grooves depends on the size of the molded product, the size of the recess, and the use conditions, but may be 1 or more, preferably 2 or more, more preferably 4 or more, and particularly preferably 8 or more. When the number is too large, the mechanical strength as a part is lowered, and the reduction in size is accelerated even if the wear weight is reduced.
In the bottomed hole, the hole may be circular or oval, and if the oval is further elongated, it substantially corresponds to the groove having the end walls at the both ends. The dimension of the hole is provided according to the dimension of the groove.

Further, since wear powder adheres to the sliding surface, it has been found that providing the concave portion is more effective when it is provided on the component side where much wear occurs.
The number, shape, and size of the recessed portions to be provided are not limited, and it is sufficient that the wear powder is once accumulated in the recessed portions and can be supplied again to the sliding surface. By providing only one extremely small recess, the wear of the component provided with the recess is greatly suppressed.
However, since wear powder adheres to the sliding surface, the number of concave portions can be increased or the volume can be increased within a range that does not affect the performance as a sliding component.

  In order to apply this technique, it is essential to use a component that is not provided with a recess and grasp the wear resistance of each paired component that is combined in advance. For example, when combining resin A and resin B, the amount of wear when combining resins A and the amount of wear when combining resins B are measured. By comparing this data and providing a large number of recesses or a large volume on the sliding surface of a part with a large amount of wear, the effects found in the present invention can be remarkably obtained.

  The mechanism of the present invention is suitably used for all sliding forms because of the mechanism in which the wear powder is once accumulated in the recess and supplied again to the sliding portion. The range of applications such as gears, bearings, cams, clutches, washers and rollers is very wide.

  In the present invention, the material of the sliding part is a resin, and the resin may be a thermoplastic resin or a non-thermoplastic resin (where the non-thermoplastic resin is a thermosetting resin or a pressure thermoforming such as polytetrafluoroethylene. Or polyacetal, polybutylene terephthalate, polyamide, polyphenylene sulfide, ABS resin, polyethylene, polypropylene, polyphenylene oxide, liquid crystal polymer, biodegradable resin, etc .; pressure of polytetrafluoroethylene, etc. Thermosetting resins such as thermoformable resins, phenol resins, epoxy resins, urea (-melamine) resins, polyurethane resins and the like can be mentioned. At least the sliding component A is a thermoplastic resin. Furthermore, it is most effective when both of the sliding component pairs are thermoplastic resins.

In the present invention, the following combinations can be taken for the sliding component (A) and the sliding component (B) in which the amount of wear due to sliding is less than that of the sliding component (A).
(I) The sliding component (A) and the sliding component (B) are both made of thermoplastic resin, and a groove is provided only in the sliding component (A).
(Ii) The sliding component (A) is made of a thermoplastic resin, the sliding component (B) is made of a non-thermoplastic resin, and a groove is provided only in the sliding component (A).
Although any combination is effective, the combination (i) is the most effective.

Either the sliding component (A) or the sliding component (B) may be used as the movable component or the fixed component, or both may be used as the movable component.
There are no particular restrictions on the shape of the sliding surface of the sliding component, the way of sliding, and the sliding direction. The sliding surface may be a flat surface, a curved surface, or a combination thereof. Examples of the sliding surface include a disk shape, a square shape, an annular shape, a cylindrical shape, and a spherical shape.
The sliding method may be linear, curvilinear, rotational, and combinations thereof, and the sliding direction may be one direction, the opposite direction, or a combination thereof.

  In addition, because the amount of wear of the resin is predicted and calculated at the design stage, the amount of wear may be calculated using the specific amount of wear as an index. Therefore, the value of the predicted calculation result is much larger than the actual wear amount. More accurate prediction is possible by measuring in advance the specific wear amount when the concave portion is provided on the rocking surface, and performing wear prediction calculation at the time of design.

  The above is the detailed description of the present invention. By using the sliding parts manufactured according to the present invention, it is possible to produce low-wear parts at low cost without using expensive materials and to give to the industry. The impact is enormous.

(Example)
Hereinafter, although an Example is described, this invention is not limited to this.

(Comparative Example I-1)
A hollow cylindrical test piece (test piece A) designated by JIS K7218 / A method having an outer diameter of 25.6 mm, an inner diameter of 20.0 mm, and a length of 15 mm as shown in FIG. 1 was produced by injection molding of polyacetal. The polyacetal is a polyacetal copolymer, Duracon M90, manufactured by Polyplastics Co., Ltd.
The surface roughness of the sliding surface of the test piece (according to JIS B0601; the same shall apply hereinafter) is as follows.
Ra = 0.031 μm, Ry = 0.543 μm, Rz = 0.356 μm
As shown in FIG. 3, the sliding test without grooves on the sliding surfaces thus obtained was carried out at room temperature and under the following sliding conditions as shown in FIG. It was. Linear velocity 15 cm / sec, load 19.6 N, sliding time 24 hours, no grease.
The results are shown in Table 1.

(Comparative Example I-2)
A sliding test was conducted in the same manner as in Comparative Example I-1, except that both the test pieces obtained in Comparative Example I-1 were subjected to the following sliding conditions. The results are shown in Table 1.
Linear velocity 30 cm / sec, load 11.77 N, sliding time 24 hours, no grease.

(Comparative Example I-3)
A sliding test was conducted in the same manner as in Comparative Example I-1, except that both the test pieces obtained in Comparative Example I-1 were subjected to the following sliding conditions. The results are shown in Table 1.
Comparative Example I-3: Linear velocity 5.5 cm / sec, load 344 N, sliding time 3 hours, with grease.

(Comparative Example I-4)
A sliding test was conducted in the same manner as in Comparative Example I-2 except that the material of both test pieces was made of Polyplastics Co., Ltd., polyacetal copolymer, Duracon SW-01 and the following surface roughness was used. The results are shown in Table 1.
Ra = 0.111 μm, Ry = 1.720 μm, Rz = 1.090 μm

(Comparative Example I-5)
A sliding test was conducted in the same manner as in Comparative Example I-3 except that the materials of both test pieces were made of Polyplastics Co., Ltd., polybutylene terephthalate, and DURANEX B5330C, and the following surface roughness was used. The results are shown in Table 1.
Ra = 0.271 μm, Ry = 2.250 μm, Rz = 1.524 μm

Example 1
16 slit grooves (groove width of 0.5 mm, depth of 2 mm) are formed at equal intervals on the sliding surface of one test piece without a recess obtained in Comparative Example I-1 by sliding. And an intersection angle of 90 degrees. The opening end of the groove was chamfered (meaning C surface finishing, indicated as C in the table).
A sliding test was conducted in the same manner as in Comparative Example I-1 using a test piece without a recess as a rotating side part and a test piece having a groove as a fixed side part. The results are shown in Table 2.
In addition, when only one of the fixed side component and the rotary side component colored in black was used, a black film-like material was also attached to the sliding surface of the white rotary side component or fixed side component.
On the other hand, when using a test piece that does not have both recesses, if one of the fixed side component or the rotating side component is colored black, the sliding surface of the white rotating side component or fixed side component is used. Almost no black film was observed.
Thus, it is thought that by forming and maintaining a film-like material between the sliding surfaces, it acts as a protective film and wear is greatly suppressed.

(Comparative Example 1)
Duracon SW-01 is used as the material for the stationary side, and eight slit grooves (groove width 0.5 mm, depth 2 mm) are provided by cutting at an intersecting angle of 90 degrees with the sliding direction. The same procedure as in Comparative Example I-7 was performed except that Duracon M90 was used as the material and no recess was provided. When a groove was provided only on the Duracon SW-01 side with less wear than Duracon M90, the amount of wear increased compared to the case where no groove was provided on both sides. The results are shown in Table 3.

(Example 2)
Duracon M90 is used as the rotation side component material, and eight slit grooves (groove width 0.5 mm, depth 2 mm) are provided at equal intervals by cutting, with a crossing angle of 90 degrees with the sliding direction. The same procedure as in Comparative Example I-7 was performed except that Duracon SW-01 was used as the side material and no recess was provided. The results are shown in Table 3.

(Example 3)
Duracon M90 is used as the material for the fixed side, and eight slit grooves (groove width 0.5 mm, depth 2 mm) are provided at equal intervals by cutting, at an intersecting angle of 90 degrees with the sliding direction. The same procedure as in Comparative Example I-7 was conducted except that a concave portion was not provided by using Duranex B5330PC as a component material. The results are shown in Table 3.

FIG. 1A is a perspective view of an example of a JIS K7218 / A method designated hollow cylindrical test piece (test piece A). FIG. 1B is a side view of the test piece A. FIG. 1C is a top view of the test piece A. FIG. It is an example of the sliding component which provided the recessed part in the sliding surface. It is an example of the sliding component which provided the recessed part in the sliding surface. FIG. 2A shows an example in which slit grooves are provided at an intersecting angle of 90 degrees with the sliding direction. FIG. 2B shows an example in which slit grooves are provided at an intersecting angle of 30 degrees with respect to the sliding direction. FIG. 2C shows an example in which a concentric circular groove is divided into four parts. It is a conceptual diagram of a sliding test. Fig.4 (a) is a perspective view of the example of the slit groove | channel of Fig.2 (a). FIG. 4B is an example in which the chamfering process is performed on the opening of the groove in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sliding parts 1 'Fixed side sliding parts 1 "Rotating side sliding parts 2 Sliding surfaces 3 Recessed parts 4a Front top part 4b Rear top part 5 C surface

Claims (9)

A sliding part pair made up of a sliding part made of thermoplastic resin (A) and a sliding part made of thermoplastic resin (B) that does not wear much more than the sliding part (A). On the sliding surface of the moving part (A),
A pair of sliding parts having a recess for accommodating wear powder generated by sliding and supplying the contained wear powder between sliding surfaces.   The sliding component pair according to claim 1, wherein the recess is a groove and / or a bottomed hole.   The sliding component pair according to claim 1, wherein at least a part of the opening of the recess has an angle with respect to the sliding direction.   The sliding component according to any one of claims 1 to 3, wherein at least a part of the top of the concave portion on the rear side in the sliding direction has an angle with respect to the sliding direction when viewed from the sliding component provided with the recess. versus.   The sliding molded product pair according to claim 3 or 4, wherein an angle with respect to the sliding direction is within 90 ± 80 degrees.   The sliding component pair according to claim 1, wherein at least a part of the top of the opening of the recess is chamfered into a flat shape or a curved shape.   The pair of sliding parts according to claim 1, wherein the recess has a width of 0.02 mm or more and a depth of 0.01 to 20 mm.   The sliding component (A) used for the sliding component pair in any one of Claims 1-7.   Using a sliding part (A) made of a thermoplastic resin and a sliding part pair made of a sliding part (B) made of a thermoplastic resin that does not wear much more by sliding than the sliding part (A) The sliding surface of the sliding part (A) is provided with a recess, and the wear powder generated during sliding is accommodated in the recess, and the wear powder in the recess is automatically supplied between the sliding surfaces as the sliding occurs. A method for reducing the amount of wear of sliding parts.