JPH1026142A - Slide member for bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slide member for a bearing which improves the sliding property in the slide direction in consideration of anisotropy of a C/C composite material (carbon fiber reinforced carbon composite material) while utilizing the excellent nature thereof. SOLUTION: A slide member 2 accompanied with the relative slide under the load receiving condition in a bearing is formed of a carbon fiber reinforced carbon composite material in which the carbon fiber laminates radially circumferentially cloths 7 disposed two dimensionally. The slide surface of an outer ring 3 is disposed on a plane nearly parallel to the two dimensional plane, i.e., the surface of the cloth 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding member which undergoes relative sliding under a load, and more particularly to a bearing and a sliding member for a bearing which constitutes the receiving member, and more particularly to a carbon fiber reinforced carbon composite material. (Hereinafter also referred to as C / C composite material)
With respect to those formed in

[0002]

2. Description of the Related Art In recent years, bearings which are not lubricated in a high temperature range, are further in a corrosive atmosphere, and are required to have high mechanical strength have recently been required.

[0003] Fluid lubricants cannot be used in the high temperature range, and solid lubricants are difficult to handle because they have neither fluidity nor wettability.
It has been studied to use a graphite material having self-lubricating properties for a sliding member for a bearing. Since this graphite material has excellent properties such as good lubricity, non-melting property, heat conductivity, heat resistance, and corrosion resistance and a small coefficient of thermal expansion, it is a sliding member for a bearing that satisfies the above conditions. Can be used as

[0004]

However, graphite materials have low mechanical strength, so they are reinforced with metal when used.
It is necessary to increase the mechanical strength by impregnating the metal. Therefore, it is conceivable to use a C / C composite material having the same carbon material but having increased mechanical strength. However, since the C / C composite material is reinforced with carbon fibers, its physical and mechanical properties have anisotropy, and the lubricating properties differ depending on the carbon fibers used. There was a point.

Accordingly, the present invention according to claim 1 of the present invention provides a bearing slide having improved slipperiness in a sliding direction in consideration of the anisotropy thereof while taking advantage of the excellent properties of the C / C composite material. It is an object to provide a moving member. According to a second aspect of the present invention, in addition to the object of the first aspect, the bearing is further improved in the sliding direction in the sliding direction by appropriately setting the material of the carbon fiber used for the C / C composite material. It is intended to provide a sliding member for use.

[0006]

In order to achieve the above-mentioned object, an invention according to claim 1 of the present invention is a sliding member having a relative slip under a load and comprising a bearing. And a sliding member for a bearing constituting the receiving member,
The sliding member is formed of a carbon fiber reinforced carbon composite material, and carbon fibers in the carbon fiber reinforced carbon composite material are obtained by laminating two-dimensionally arranged carbon fibers, and are substantially parallel to the two-dimensional plane. A sliding surface of the sliding member is provided in a direction substantially parallel to one of a surface and the two-dimensional two directions. A plane substantially parallel to the two-dimensional plane of the two-dimensionally arranged carbon fibers (2D woven fabric) (A1, A2 directions parallel to the mesh as shown in FIG. 7A, or a mesh as shown in FIG. 7B) When the sliding surface is formed in the directions A1 'and A2' intersecting with each other, the coefficient of friction becomes lowest.
A direction parallel to one of the two-dimensional directions of the two-dimensionally arranged carbon fibers (2D woven fabric) (B1, B1 in FIG. 7C).
If the sliding surface is formed in a direction substantially parallel to the direction of (B2, B3, B4), the coefficient of friction will decrease next. Further, in the thickness direction of the laminated CF cloth (C1, C2, C
When the sliding surface is formed in a direction substantially parallel to (3, C4), the friction coefficient becomes the largest. In addition, the surface substantially parallel to the two-dimensional surface is a curved surface (for example, an inner circumferential surface) of a carbon fiber formed into a 2D woven fabric, and includes a state along the curved surface.
Similarly, the direction substantially parallel to any one of the two-dimensional two directions includes a state in which the carbon fibers are arranged in a curved surface direction (for example, a circumferential direction) and along the curved surface direction.

According to a second aspect of the present invention, the carbon fibers in the first aspect of the present invention are anisotropic pitch-based carbon fibers. The anisotropic pitch-based carbon fiber is manufactured using petroleum or coal as a starting material, is being crystallized, and the abrasion powder is formed into a film. This film improves abrasion resistance.

According to a third aspect of the present invention, in the first aspect of the present invention, the carbon fiber is a PAN-based carbon fiber, and the crystallinity of the carbon fiber is determined by an X-ray diffraction plane spacing d by Gakushin method.
(002) is 3.45 or less. The PAN-based carbon fiber is manufactured using polyacrylonitrile as a starting material, and has a low crystallinity as it is,
After forming into 2D fabric, heat-treat at 2000 ° C or more and d
The crystallinity is increased so that (002) becomes 3.45 or less.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to illustrated examples. FIG. 1 is a perspective view of a ball bearing in which the bearing sliding member of the present invention is incorporated.

In FIG. 1, reference numeral 1 denotes a bearing body, and 2 denotes a receiving member thereof, and these constitute a bearing. The bearing body 1 has a retainer 5 that holds a rolling element between an outer ring 3 and an inner ring 4. Although the receiving member 2 holds the bearing main body 1, the bearing main body 1 is slidable in the direction of the arrow with respect to the receiving member 2, and the centering function of the shaft inserted into the bearing main body 1 is secured. It has a structure.

In the illustrated example of a bearing, a C / C composite material is used for the receiving member 2 and the retainer 5. First,
The receiving member 2 is a carbon fiber cloth 7 arranged two-dimensionally.
(2D woven fabric) are arranged along the circumference and further laminated in the radial direction. That is, the sliding direction of the outer ring 3 as indicated by the arrow is a surface substantially parallel to the two-dimensional surface of the 2D fabric 7, and is preferably the lowest in friction coefficient. In this case, 2
The weave of the D fabric 7 may be a plain weave, a satin weave, a twill weave, or any other two-dimensional weave. When the carbon fiber cloth is laminated in the thickness direction of the receiving member 2, FIG.
When the directions of B1 and B2 are made to coincide with the arrows in FIG. 1, the sliding surface is formed in a direction substantially parallel to the direction parallel to the two-dimensional direction, and then the friction coefficient decreases.

FIG. 2 shows an example of a cage used for a ball bearing. Here, the retaining wheel 5 is obtained by integrating the axially divided two with a fastening member, and a spherical seat for holding the rolling element 6 is formed in the divided two. Rolling element 6
Slides in the direction of the arrow with respect to the holding wheel 5 by the relative rotation between the outer ring 3 and the inner ring 4 (not shown). This retaining ring 5 is a carbon fiber cloth 7 (2D woven fabric) arranged two-dimensionally.
Are arranged in a direction perpendicular to the axis and stacked in the axial direction. The direction of the arrow in which the rolling element 6 slides is a direction substantially parallel to any one of the two directions in two dimensions, and is shown in FIG.
Due to B1, B2, B3 or B4, contact with the rolling element 6 occurs and the coefficient of friction is reduced. Further, when contact occurs with the retaining ring in the direction of the rotation axis of the arrow, that is, in the end face of the cylindrical rolling element, the contact occurs more than A1 and A2 in FIG.

FIG. 3 shows a spherical washer of a thrust ball bearing with C
The case where a / C composite material is used is shown. The bearing body 11 is installed on a spherical washer (receiving member) 12. The spherical seat 12a of the washer 12 is a spherical surface having a radius R, along which the bearing body 11 slides. Therefore, the 2D woven fabric 7 constituting the washer 12 is changed to a radius R
And is laminated in the direction of the radius R. Then, the sliding direction of the bearing body 11 with respect to the washer 12 is 2D.
The curved surface is substantially parallel to the two-dimensional curved surface of the woven fabric, and preferably has the lowest friction coefficient similarly to the receiving member 2 of FIG.

FIG. 4 shows a case where a C / C composite material is used for a sliding bearing different from the rolling bearings as shown in FIGS. A cylindrical slide bearing 22 is fitted to the shaft 21, and the shaft 21 slides in the direction of the arrow with respect to the slide bearing 22. This sliding bearing 22 is entirely C
/ C composite material, and the 2D fabric 7 is wound around the axis like a bandage. Sliding direction is 2D
It is a curved surface that is substantially parallel to the two-dimensional curved surface of the woven fabric, and has the lowest coefficient of friction and is preferable.

FIG. 5 is a partially cutaway view of a roller bearing in which the bearing sliding member of the present invention is incorporated. In FIG. 5, 2
Reference numeral 3 denotes a bearing body, which has a rolling element 26 between the inner ring 24 and the outer ring 25 as shown in the figure, and a retainer 27 for holding the rolling element 26 is provided.

FIG. 6 shows the structure of the retainer 27. Rolling element 2
6 slides relative to the retainer 27 in the direction of the arrow due to the relative rotation between the inner race 24 and the outer race 25. The retainer 27 is formed by arranging two-dimensionally arranged carbon fiber cloth (2D woven fabric) planes in a direction perpendicular to the axis and laminating them in the axial direction. The direction of the arrow on which the rolling element 26 slides is substantially parallel to one of the two directions in two dimensions.
Contact with the rolling element 26 occurs from B1, B2, B3 or B4 of (c), and the friction coefficient decreases. Further, when contact occurs with the retaining ring in the direction of the rotation axis of the arrow, that is, in the end face of the cylindrical rolling element, contact occurs due to A1 and A2 in FIG. 7A, and the friction coefficient is further reduced.

[0017]

EXAMPLES Next, specific experimental examples will be described below using tables.

Experimental Example 1 Coal pitch-based carbon fiber (Dialead K3214K manufactured by Mitsubishi Chemical Corporation) was plain-woven into the used fiber to form a carbon fiber cloth that was not subjected to a special heat treatment. Phenolic resin (PR-502 manufactured by Sumitomo Durez) is applied to this carbon fiber cloth.
73) was impregnated, and the amount of the cured resin was adjusted to 35 mass%. This resin-impregnated cloth was dried in a 70 ° C. oven for 2 hours to obtain a sheet-shaped prepreg. Forty layers of this prepreg are laminated and hot-pressed at 160 ° C., and CFRP (Carbon Fiber of 20 t) is formed.
(Rainforced Plastics) molded product was obtained. 20 ° C / h, 1000 ° C in nitrogen gas atmosphere
, And pitch impregnation and firing were repeated to increase the density, thereby obtaining a C / C composite material having a bulk density d = 1.7. 12.5mm from this C / C composite material
A test piece having a cross section of × 20 mm was cut out, and three directions (A1, A1 ', B1, C1) were determined with reference to the surface of the carbon fiber cloth 7 as shown in FIGS. 7 (a), (b), (c), and (d). A friction test was performed. In this friction test, SU100 mm
Pressing against the S-ring with a load of 1kg / f, peripheral speed 8.24m
/ S was slid for 24 hours, and the friction coefficient and the amount of wear at that time were measured.

EXPERIMENTAL EXAMPLE 2 A PAN-based carbon fiber plain-woven as a fiber to be used (Torae T-300 3K plain weave CO # manufactured by Toray Industries, Inc.)
6343 cloth) was once heat-treated at 2000 ° C. to promote crystallization to increase the elastic modulus of the carbon fiber. The crystallinity of the carbon fiber was determined by the plane spacing d (002) by the Gakushin method of 3.4.
It was 3. Using this carbon fiber cloth 7 as a C / C composite material in the same manner as in Experimental Example 1, the same friction test as in Experimental Example 1 was performed. In addition, the bulk density d of the C / C composite material was 1.65.

EXPERIMENTAL EXAMPLE 3 The fibers used were the same as those in Experimental Example 2 except that they were not subjected to a heat treatment at 2000 ° C.
A composite material was obtained. The bulk density d was 1.6.

Table 1 shows the results of measurement of the coefficient of friction and the amount of wear in each of the sliding directions A1, B1, and C1 in Experimental Examples 1, 2, and 3.

[0022]

[Table 1]

In Table 1, in each of Experimental Example 1, Experimental Example 2 and Experimental Example 3, both the coefficient of friction and the amount of wear were lower in the sliding direction A1 <B1 <C1 based on the carbon fiber cloth 7. It can be seen that although the sliding directions A1 and B1 can be used, the sliding direction C1 is difficult to use.

In Experimental Example 1 using coal pitch-based carbon fiber, the coefficient of friction and the amount of abrasion were the lowest as compared with the others.
In Experimental Example 2 using the PAN-based carbon fiber heat-treated at 000 ° C., the coefficient of friction and the amount of wear were the second lowest. When the experimental example 3 using the PAN-based carbon fiber without heat treatment is compared with the experimental example 2 using the heat treatment, the friction coefficient is not inferior but there is a difference in the amount of abrasion. It is understood that it is desirable to increase the crystallinity by performing the above heat treatment.

[0025]

As described above, according to the first aspect of the present invention, the sliding member is formed of a carbon fiber reinforced carbon composite material, and the carbon fibers in the carbon fiber reinforced carbon composite material are two or more. The two-dimensionally arranged ones are stacked, and the sliding surface of the sliding member is in a direction substantially parallel to one of the two-dimensional surface or the surface substantially parallel to the two-dimensional surface. It is characterized by being provided. In this way, by appropriately arranging the two-dimensional cloth of carbon fibers with respect to the sliding surface, not only the friction coefficient but also the friction coefficient can be reduced while taking advantage of the excellent characteristics of the carbon fiber reinforced carbon composite material. Therefore, there is an effect that the bearing can be used as a sliding member.

According to a second aspect of the present invention, the carbon fibers are anisotropic pitch-based carbon fibers. Therefore,
Due to the high degree of crystallinity of the pitch-based carbon fiber, the friction coefficient is small and the amount of wear can be reduced.

According to a third aspect of the present invention, the carbon fiber is P
AN-based carbon fiber whose crystallinity is X
The plane spacing d (002) of the line diffraction is 3.45 or less. Therefore, there is an effect that the crystallization rate of the PAN-based carbon fiber can be increased, the coefficient of friction can be reduced, and the amount of wear can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of a ball bearing in which a bearing sliding member of the present invention is incorporated.

FIG. 2 is a structural view of a cage in the bearing of FIG.

FIG. 3 is a perspective view of another bearing in which the sliding member for bearing of the present invention is incorporated.

FIG. 4 is a perspective view of still another bearing in which the bearing sliding member of the present invention is incorporated.

FIG. 5 is a perspective view of a roller bearing in which the bearing sliding member of the present invention is incorporated.

FIG. 6 is a structural view of a cage in the bearing of FIG. 5;

FIG. 7 is a perspective view showing a sliding direction characteristic of the bearing sliding member.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Bearing main body 2 Receiving member (C / C composite material) 3 Outer ring 4 Inner ring 5 Cage (C / C composite material) 6 Rolling element 7 Carbon fiber cloth 11 Bearing main body 12 Washer 12a Spherical seat 21 Shaft 22 Bearing 23 Bearing main body 24 Inner ring 25 Outer ring 26 Rolling element 27 Cage 28 Carbon fiber cloth (2D fabric) A1, A2, A1 ', A2' Direction of plane B1, B2, B3, B4, C1, substantially parallel to two-dimensional plane of carbon fiber C2, C3, C4 Direction substantially parallel to the thickness direction of the carbon fiber cloth

Claims (3)

[Claims] 1. A sliding member for bearings and a bearing member thereof, which is a sliding member that relatively slides under a load, wherein said sliding member is made of carbon fiber reinforced carbon composite material. The carbon fiber in the carbon fiber reinforced carbon composite material is formed by laminating two-dimensionally arranged ones, and any one of a plane substantially parallel to the two-dimensional plane and the two-dimensional two directions A sliding member for a bearing, wherein a sliding surface of the sliding member is disposed in a direction substantially parallel to the heel. 2. The sliding member for a bearing according to claim 1, wherein the carbon fibers are anisotropic pitch-based carbon fibers. 3. The carbon fiber according to claim 1, wherein the carbon fiber is a PAN-based carbon fiber having a crystallinity of 3.45 or less in a plane distance d (002) of X-ray diffraction by Gakushin method. A sliding member for a bearing.