JP2003343741A - Sliding part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the coefficient of friction on the sliding face of a sliding part and to improve the sealing performance of the sliding part. <P>SOLUTION: The sliding part 2 has a plurality of slim and long dimples 5A and 5B, whose directions of inclination are different between the outer peripheral side and the inner peripheral side with a boundary reference line X as the boundary, on the sliding face 3. The tip 5A1 in the rotation direction of each dimple 5A on the outer peripheral side is inclined toward the outer peripheral side, while the tip 5B1 in the rotation direction of each dimple 5B on the inner peripheral side is inclined toward the inner peripheral side. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the technical field of sliding parts such as mechanical seals. In particular, the present invention relates to a sliding component that reduces the friction coefficient of the sliding surface and prevents the sealed fluid from leaking on the sliding surface.

[0002]

2. Description of the Related Art There is a mechanical seal shown in FIG. 8 as a related art of a sliding part according to the present invention [eg,
See Patent Document 1].

[0003]

[Patent Document 11] Japanese Patent Publication No. 5-69066 (1-
(Page 3) (Corresponding US Pat. No. 5,080,378-FIG. 1)

FIG. 8 is a half sectional view of a mechanical seal 100 used in a pump and a refrigerator.
In FIG. 8, the mechanical seal 100 is arranged between the rotary shaft 130 and the casing 140. The mechanical seal 100 is used in a pump, a refrigerator or the like to seal a liquid such as water.

In the mechanical seal 100, a seal ring 101 made of sintered porous silicon carbide is fitted on a rotary shaft 130. The rotating seal ring 101 is provided with a seal surface 102 on its side surface. Further, the rotary shaft 130 is attached to the step portion 103 on the inner diameter surface of the seal ring 101.
Packing 120A, 120 to seal between
B is provided. This packing 120A, 120
B is pressed by the presser ring 105 so that the rotary shaft 13
A seal is made between 0 and the seal ring 101. Further, the support ring 109 fixed to the rotary shaft 130 by the socket screw 108 supports the spring device 106, and also elastically supports the pressing ring 105 by the spring device 106.

Further, the fixed ring 110 is provided with an opposed seal surface 111 that slides in close contact with the seal surface 102.
The fixing ring 110 is fixed to a hole of the casing 140 through which the rotary shaft 130 penetrates via O-rings 115 and 115. The material of the fixing ring 110 is carbon. The conventional mechanical seal 100 configured as described above includes a seal ring 101 and a fixed ring 1.
The close contact with 10 seals the high pressure P1 side and the low pressure P2 side. The seal ring 101 is a silicon carbide sintered body in which spherical resistance is improved by sliding pores having an average pore diameter of 0.010 to 0.04 mm in the crystal structure.

The pores on the sliding surface of this silicon carbide sintered body are formed by adding polystyrene beads before sintering and decomposing / sublimating during pre-sintering to form pores. Because of this,
Since the silicon carbide sintered body has pores scattered in the crystal grains, it is difficult to perform high-pressure compression molding even in the manufacturing method. For this reason, a problem occurs in the dimensional accuracy of the molding. Also, since it decomposes polystyrene beads by sintering,
There is a problem in the strength of the sintered product as a sliding part.

Next, there is a mechanical seal shown in FIG. 9 for improving the strength of the sliding parts and the leak amount of the sealed fluid on the sealing surface (see, for example, Patent Document 2).

[0009]

[Patent Document 2] Japanese Patent Application Laid-Open No. 57-161368 (Specification page 4-10, FIG. 2)

This mechanical seal has the same structure as that shown in FIG. Then, the sliding surfaces of the fixed ring held in the housing and the driven ring 5'shown in FIG. 9 fixed to the rotating shaft come into close contact with each other to seal the sealed fluid. A large number of recesses 6'are formed on the sliding surface 5A 'of the driven ring 5'. The recess 6'has a minimum width of 30 × 10 ⁻⁶ m to 100 × 10 ⁻⁶ m and a maximum width of 60 × 10 ⁻⁶ m.
To 500 × 10 ⁻⁶ m, and the dimensional ratio of the maximum width to the minimum width is doubled or more.
As shown in, the concave portion 6'is formed so as to be inclined with respect to the rotation direction of the sliding surface 5A '.

This recess 6'is a sliding surface 5 of the driven ring 5 '.
It serves to prevent leakage of the sealed fluid that has entered between A ′ and the sliding surface of the fixed ring. That is, the sealed fluid that has entered from the outer peripheral side of the driven ring is supplemented and stored in the recess 6'before reaching the inner peripheral end side. The stored fluid to be sealed moves toward the outer periphery of the recess 6'due to its viscous action and the rotation direction of the driven ring, and when it exceeds the storage capacity of the outer periphery, it leaks from the outer periphery of the recess 6'between sliding surfaces. After that, it is supplemented in the next recess 6 '. In this way, the fluid to be sealed, which is sequentially repeated, is returned to the outer peripheral end side of the sliding surface.

However, as shown in FIG. 9, such recesses 6'are formed by intermittently arranging the conventional spiral grooves and designing the interspersed recesses 6'in an elliptical shape. Therefore, the pumping action for pushing back the sealed fluid is small.
Moreover, while the recess 6'can be easily manufactured by etching or the like and the material can be configured so as not to reduce the strength of the driven ring 6 ', the spiral groove has the effect of reducing the friction coefficient of the sliding surface and the sliding heat generation. A big effect cannot be expected in comparison.

Further, as another related art, there is a sliding part for mechanical seal. The sliding surface of this mechanical seal sliding component is formed with dimples aligned in the shape of a groove extending in the longitudinal direction at right angles to the sliding direction. Since the dynamic pressure generated in the dimples becomes large, a lubricating oil film is formed by the sealed fluid, but the lubricating oil film is stored in the dimples and the friction coefficient of the sliding surface cannot be made as small as expected. Can not.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to form a lubricating film for a sealed fluid on a sliding surface. To reduce the sliding resistance and effectively retain the sealed fluid that has entered the sliding surface, prevent the sealed fluid from leaking to the outside from the sliding surface, and improve the sealing performance. is there. At the same time, the sliding heat of the sliding surface is prevented. Further, it is to maintain the strength of the sliding parts and prevent wear to improve durability.

[0015]

The present invention has been made to solve the above-mentioned technical problems, and the means for solving the problems are configured as follows.

A sliding part of the present invention according to claim 1 is a sliding part in which a stationary sliding part and a rotating sliding part slide relative to each other, and a boundary is provided on a sliding surface of the sliding part. The outer peripheral side and the inner peripheral side have a plurality of slender dimples whose inclination directions are different from each other with the reference line as a boundary, and the outer peripheral side dimples are inclined toward the outer peripheral side in the rotational direction and the inner peripheral side dimples are The tip in the rotational direction is inclined toward the inner peripheral side.

In the sliding part of the present invention according to claim 1, the dimples on the outer peripheral side incline the longitudinal distal end side in the rotational direction toward the outer peripheral side, and the inner dimples on the longitudinal distal end side in the rotational direction. Since it is inclined toward the inner peripheral side, it is expected that the lubricating ability of the sealed fluid is thickly held on the sliding surface between the dimples on the outer peripheral side and the inner peripheral side to improve the sealing ability. Further, the friction film held on the sliding surface can reduce the friction coefficient of the sliding surface. Therefore, in addition to the sealing ring that seals the sealed fluid, it can be used as a sliding component such as a piston ring and a bearing.

According to a second aspect of the present invention, there is provided a sliding member for sealing a sealed fluid existing on one side between sliding surfaces on which a stationary sliding member and a rotating sliding member slide relative to each other. The sliding part of the sliding part has a plurality of slender dimples having different inclination directions on the outer peripheral side and the inner peripheral side with respect to the boundary reference line, and the outer peripheral side dimples and the inner peripheral side Dimples form a row in the radial direction and incline into each other in a C shape,
The rows are arranged in a plurality of rows in the circumferential direction.

In the sliding part of the present invention according to claim 2, since the dimples can be arranged in a C shape, the coating of the fluid to be sealed is gathered by the dimples on the inner and outer circumferences and concentrated near the boundary reference line, The film of the sealed fluid interposed between the sliding surfaces can be expected to improve the coefficient of friction and the sealing ability. Further, the sliding component configured as described above is excellent as a sealing ring such as a mechanical seal.

In the sliding component of the present invention according to claim 3, the number of dimples on the inner peripheral side and the number of dimples on the outer peripheral side are smaller in the number of dimples on the sealed fluid side of the sliding surface. .

In the sliding component of the present invention according to claim 3,
When the sealed fluid exists on the outer peripheral side, the sealed fluid can be pushed back to the outer peripheral side by increasing the number of dimples on the inner peripheral side by the dimples on the inner peripheral side. When the sealed fluid is present on the inner peripheral side, if the number of dimples on the outer peripheral side is increased, the sealed fluid can be pushed back to the inner peripheral side by the number of dimples on the outer peripheral side. For this,
Sealing ability is dramatically improved. Further, the film of the sealed fluid interposed on the sliding surface can effectively reduce the coefficient of friction of the sliding surface.

In the sliding component of the present invention according to claim 4, the dimples have an elliptical or rectangular shape in plane and have a width of 5
The length is 0 × 10 ⁻⁶ m to 1000 × 10 ⁻⁶ m, the length is twice the width or more and the sliding surface width is 1/2 or less, and the depth is 1 × 10 ⁻⁶ m to 25 × 10. It is formed to ^-6 mm.

In the sliding component of the present invention according to claim 4, the experimental result shows that the friction coefficient is in the minimum range and the sealing ability is in the maximum range. It is possible to form both effects in a shared range.

The sliding component of the present invention according to claim 5 is formed of a sliding material containing a carbide such as silicon carbide, titanium carbide or tungsten carbide.

This sliding material can reduce the coefficient of friction and reduce crying and linking that occur during sliding. Moreover, the effect of preventing the blister phenomenon can be expected even when the sliding component is slid against the carbon material.

According to a sixth aspect of the present invention, the sliding component is made of cast iron, stainless steel, silicon nitride, or aluminum nitride.

In the sliding component of the present invention according to claim 6, the material of the sliding component is cast iron, stainless steel, silicon nitride, aluminum nitride or the like, and dimples are formed on the sliding surface. Moreover, the friction coefficient of the sliding surface is reduced. Further, it is possible to prevent cracking of the sliding surface that occurs during low temperature initial motion. Further, seizure that occurs at high temperatures is effectively prevented. Therefore, it is useful not only as a seal ring of a mechanical seal but also as a piston ring or a bearing as a sliding component. On the other hand, conventionally, when the sliding surface is a flat surface, even if this sliding component is made of cast iron or stainless steel, cracking or seizure of the sliding surface cannot be prevented.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION A sliding member according to a preferred embodiment of the present invention will be described in detail below with reference to the drawings. Figure 1
[FIG. 3] is a front view showing a sliding surface of a sliding component 2 showing a first embodiment according to the present invention. FIG. 2 is a plan view showing a combination of two dimples 5B on the inner peripheral side and two dimples 5A on the outer peripheral side in the arrangement of the dimples 5 on the sliding surface 3. FIG. 3 is a plan view of one dimple on the sliding surface 3. FIG. 4 is a front view showing a sliding surface of a sliding component showing a second embodiment according to the present invention. FIG. 5 is a sectional view of a mechanical seal to which the sliding component of the present invention is attached. Further, FIG. 6 shows a mechanical seal type tester which tests the sliding parts of the present invention. FIG. 7 shows FIG.
3 is a graph showing a friction coefficient when the sliding component of the present invention and a flat sliding member slide on each other in Examples and Comparative Examples tested by the testing machine shown in FIG.

FIG. 1 is an embodiment showing the arrangement of the entire dimples 5 provided on the sliding surface 3 of the sliding component 2 of the present invention. The boundary reference line X is the middle of the dimples 5A on the outer peripheral side and the dimples 5B on the inner peripheral side, and the outer peripheral radius of the dimples 5A arranged on the outer peripheral side is r1.
Also, the inner peripheral radius of the dimples 5B arranged on the inner peripheral side is r
It is 2. The radius of the boundary reference line X is rh.
The boundary reference line X is divided into an outer peripheral side region R1 and an inner peripheral side region R2 with a circumference of a diameter designed considering the sealing ability of the sliding surface as a boundary. In the first embodiment, the boundary reference line X is determined at the center of the sliding surface 3, and the dimples 5A on the outer peripheral side and the dimples 5B on the inner peripheral side are designed to have the same number. Further, the dimples 5A and 5B are formed in a rectangular shape or an elliptical shape when viewed from above.
The inclination angles C and C'of each are 60 ° to 80 ° with respect to the radial direction.
And the inclination angles C and C ′ are 60 in a specific embodiment.
It is tilted to °. The sliding component 2 provided with the dimples 5 has an effect of reducing the coefficient of friction in cooperation with the material of the dimples 5. This material is preferably silicon carbide, titanium carbide, tungsten carbide, cast iron, stainless steel, silicon nitride, aluminum nitride, or the like. Furthermore, seizure of the sliding surface during high-speed rotation and cracks that occur when sliding at low temperatures are caused by the dimples 5 and cast iron or stainless steel or silicon nitride or aluminum nitride (hereinafter referred to as aluminum nitride). This can be effectively prevented by the cooperation of materials such as (abbreviated).

FIG. 2 shows a boundary reference line X as a second embodiment.
2 is an enlarged view of two dimples 5 on both sides. The arrangement of the dimples 5 on the sliding surface 3 is such that the plurality of dimples 5 on the outer peripheral side are arranged in a row in the radial direction.
A and the dimple 5B on the inner peripheral side are arranged in a C shape in the rotation direction. And, the dimples 5A, 5 in this one row
B are arranged in a large number of rows at equal intervals along the sliding surface 3. The dimple 5 has a rectangular shape as the second embodiment. Width A of the rectangle of this dimple 5
Is formed in the range of 50 × 10 ⁻⁶ m to 1000 × 10 ⁻⁶ m. Further, the length B in the longitudinal direction is twice the width A or more, and is formed to be 1/2 the width of the sliding surface 3 or less. The dimple 5 has a depth of 1 × 10 ⁻⁶ m to 25 × 10 ⁻⁶ m.

In the dimple 5A on the outer peripheral side, the rotational direction tip 5A1 is inclined from the boundary reference line X toward the outer peripheral side in the rotational direction with respect to the rotational direction N or the relative rotational direction N of the sliding component. This inclination angle C is 30 ° with respect to the radial direction.
Is formed (the inclination angle C is in a state close to the minimum). The inclination angles C and C ′ are set according to the design of the friction constant, the sealing ability and the like. This inclination angle C, C '
When is smaller, the sealing ability tends to be improved. or,
If the inclination angles C and C'are increased, the sliding resistance tends to decrease. The range of the inclination angle C of the dimple 5A on the outer peripheral side is preferably 30 ° to 85 °, and more preferably 45 ° to 80 ° to reduce the friction coefficient. Further, the dimple 5B on the inner peripheral side has a rotational direction tip 5B1 inclined from the boundary reference line X toward the inner peripheral side in the rotational direction with respect to the rotational direction N or the relative rotational direction N of the sliding component. This inclination angle C'is 3 with respect to the radial direction.
It is formed at 0 °. Further, the inclination angle C'is set according to the design of the friction constant, the sealing ability and the like. Further, when the inclination angle C'is increased, the sliding resistance tends to decrease. Further, if a large number of dimples 5B on the inner peripheral side are provided, the sealing ability is improved. The range of the inclination angle C ′ of the dimple 5B on the inside is preferably 30 ° to 85 °,
Preferably, when the angle is in the range of 45 ° to 80 °, the effect of reducing the friction coefficient is exhibited.

FIG. 3 shows a third embodiment of the dimple 5.
The inclination angle C of the dimple 5A in FIG. 3 shows a state close to the minimum angle of 30 °. The dimple 5A on the outer peripheral side has a rotational direction front end 5A1 formed in an arc shape, and a rotational direction rear end formed in an arc shape.
Further, although not shown, there is a fourth embodiment in which the planar shape is an ellipse. These dimples 5 are also formed in the same size as in the first embodiment. In addition to this, although not shown, the shape of the dimple 5 on the sliding surface 3 may be a gourd shape when seen from a plane.
By devising the shape of the dimples 5 in this way, it becomes possible to improve the sealing ability and the friction coefficient of the sliding surface. Further, by setting the inclination angles C and C ′ and the number of the dimples 5, both the friction coefficient and the sealing ability are improved.

FIG. 4 shows the positional relationship of the dimples 5 on the sliding surface 3 of the sliding component 2 according to the third embodiment of the present invention. The arrangement of the dimples 5 shows the arrangement of the dimples 5 when the sealed fluid is present on the outer peripheral side of the sliding surface. The sliding surface 3 has an inner peripheral dimple 5B.
Is formed into six pieces. The number of dimples 5A on the outer peripheral side is two, which is smaller than the number of dimples 5B on the inner peripheral side. The shape of the dimple 5 is also formed as in the first, second, third, and fourth embodiments. In this way, by selecting the shape of the dimples 5, the number of arrangements on the outer and inner circumference sides of the dimples 5, and the inclination angles C and C ′ of the shape of the dimples 5, the sliding resistance and the sealing ability can be improved. Will be possible. In the sliding component of the second embodiment, a large number of dimples 5B on the inner peripheral side are formed, and therefore the pumping action of the large number of dimples 5B improves the sealing performance. Further, the sliding resistance can be reduced by increasing the arrangement angle of the dimples 5 on the sliding surface 3.

The shape of the dimples 5 is preferably a shape that does not easily disappear due to abrasion powder. Therefore, the shape and directionality of the dimples 5 and the shape of the lubricating film of the sealed fluid should be increased. As a method of processing the dimples 5, a sandblasting photosensitive film can be used. In this method, a photosensitive film for sandblast is attached to the sliding surface 3. Then, a positive film having the shape of the dimples 5 baked thereon is brought into close contact with the photosensitive film for sandblasting to expose it. After that, the photosensitive film for sandblasting is developed and subjected to sandblasting, so that the dimples 5 that match the pattern of the positive film can be formed. Since the photosensitive film for sandblasting is produced by developing with a positive film produced by CAD data, it is easy to produce the shape. As another processing method, the dimple 5 may be processed by a reaction with solid metal or the like.

FIG. 5 is a sectional view of the mechanical seal 1 to which the sliding component 2 of the present invention is attached. The mechanical seal 1 is mounted in a mounting space between the rotary shaft 50 and the housing 60. The sliding component 2 is fitted as a rotary seal ring to the rotary shaft 50 via an O-ring 34 so as to be movable in the axial direction. Moreover, the sliding component 2 is fitted to the rotary shaft 50.
It is pressed by the coil spring 37 via the O-ring retainer 35. The coil spring 37 is supported by the support portion 36 fitted to the rotating shaft 50.

In the sliding component 2, the opposite sealing surface 3 of the stationary sealing ring 31, which is opposed to the sliding surface 3 by the coil spring 37.
It is pressed so as to be in close contact with 1A. The outer peripheral surface 31B of the stationary seal ring 31 is fitted and mounted in the mounting hole 42 of the housing 60. Further, an O-ring groove 43 is provided between the joint surfaces of the stationary seal ring 31 and the mounting hole 42, and the O-ring 33 is attached to the O-ring groove 43 to fit the stationary seal ring 31. Sealing is done between the joints. In this way, the sealed fluid side A of the housing 60
And the atmosphere side B are tightly sealed by the sealing surface 3 of the sliding component 2 and the opposing sealing surface 31A of the stationary seal ring 31.

Although this sliding component 2 is used as the rotary seal ring 2, it is also used as the stationary seal ring 31. Alternatively, the sliding component 2 may be used for both the rotary seal ring 2 and the stationary seal ring 31. The sliding component 2 is made of a sliding material containing a carbide-based material such as silicon carbide, titanium carbide, or tungsten carbide. It is also possible to use a cemented carbide such as tungsten carbide. This makes it possible to use a hard alloy because the dimples 5 are formed on the sliding surface 3 of the sliding component 2.

FIG. 6 is a cross-sectional view of a mechanical seal type tester that tests the sliding component 2 of the present invention. In FIG. 6, the testing machine 10 for the sliding component 2 is provided with a rotatable cylindrical housing 20 at the center thereof. A stationary seal ring 11 is hermetically fitted to an attachment surface provided in the sealed fluid chamber 20A inside the housing 20 via an O-ring. A rotary seal ring 12 is elastically held by a spring in a holding device 13 fixed to the rotary shaft 15 so as to be movable in the axial direction. And the sealing ring 12 for rotation
The sealing surface is closely contacted with the opposing sealing surface of the stationary sealing ring 11 to seal the sealed fluid in the sealed fluid chamber 20A so as not to leak to the outside.

A flow passage 15A is provided at the axis of the rotary shaft 15 rotated by the motor 16. This flow passage 15
A passage pipe 14 is arranged so as to penetrate through A. The sealed fluid introduced from the passage pipe 14, for example, oil flows into the sealed fluid chamber 20A and flows out from the flow passage 15A. The flow passage 15A and the end of the passage pipe 14 are connected to a circulation pipe (not shown), and a sealed fluid controlled to a set temperature and a set pressure by a pump device connected to the pipe is circulated. . The motor 16 can be controlled in rotation speed by an inverter (not shown).

Housing 2 holding a stationary seal ring 11
Zero is fixed to a shaft 19 rotatably held in a bearing 18. The stationary seal ring 11 and the rotary seal ring 12 are configured to rotate due to sliding resistance during rotation.

On the other hand, a hole having a diameter of 2 mm is provided at a position 1 mm near the opposing sealing surface of the stationary sealing ring 11, and a platinum rhodium-platinum or alumel-chromel wire connected to a thermoelectric thermometer (not shown) is used. The other end of the conductor wire 17 is connected to the hole. Then, with this thermoelectric thermometer, the stationary seal ring 1
The temperature of the sliding surface of No. 1 is measured.

Further, a load cell 21 is provided on a support base for supporting the shaft 19, and the sliding torque M can be detected via the cantilever 22. The friction coefficient F is calculated from the value of the sliding torque M. The formula to be calculated is F = M / (W × Rm). However, W = load Rm = average radius of sliding surface.

The test machine 10 is an inflow / unbalance type. Then, the seal surface is pressed by the pressure of the sealed fluid and the elastic force of the spring. Also, the pressure of the sealed fluid is 0
At this time, the sliding surface is pressed only by the spring of the holding device 13. The measurement items in the test thus measured are the sliding torque M of the sliding component 2, the temperature of the sliding surface, the temperature of the sealed fluid, and the amount of the sealed fluid leaking from the sliding surface. .

[0044]

EXAMPLES Example 1 Example 1 is a test of the sliding component 2 shown in FIG. This sliding component 2 was tested by the testing machine 10 shown in FIG.

The sliding conditions are as follows. 1) Sliding parts 2 The sealing ring for rotation is a silicon carbide sliding part (inner diameter 25 mm x outer diameter 44 mm x length 12 mm). The stationary seal ring is a silicon carbide sliding part (inner diameter 28 mm x outer diameter 50 mm x length 14 mm). The diameter of the sliding surface is (inner diameter 32 mm × outer diameter 40 mm). The dimple 5 is provided on one sliding surface 3 of the sealing ring, and the other sliding surface 3 is a smooth flat surface without the dimples 5. . The shape of the dimple 5 is as shown in FIGS. That is, the width A of the dimple 5 is 1
50 × 10 ⁻⁶ m, length B is 600 × 10 ⁻⁶ m, depth
H is 8 × 10 ⁻⁶ m. The ratio of the area ratio of all dimples to all the sliding surfaces is 8%. Dimple 5
The outer inclination angle C and the inner inclination angle C ′ of both are 60 °
(30 ° from the boundary reference line X). 2) The surface roughness of the sliding surface is Rz 0.2 × 10 ⁻⁶ m. 3) Flatness is 1 band (helium light). 4) The test time is 30 minutes. 5) The temperature of the sealed fluid is 30 ° C. 6) The pressure of the sealed fluid is 0.07MPa. 7) Peripheral speed 1, 2, 5, 10 m / s. 8) Spring load is 20N. 9) The radius Rh of the boundary reference line is 18 mm. 10) The sealed fluid is Super Multi Oil 10 manufactured by Idemitsu Kosan.

The friction coefficient as a result of the test under these conditions is as shown in Table 1. Further, the ratio (%) of the friction coefficient of the above-mentioned sliding component 2 to the friction coefficient between the smooth sliding surfaces without the dimples 5 [friction coefficient of the sliding component 2 /
Table 2 shows the friction coefficient of a sliding component having a dimple-free sliding surface. Further, Table 3 shows the leak amount (g / h) of the sealed fluid. In each table below, A
Is the sliding speed (m / s) of the sliding component 2. Also, B
Is the pressure (MPa) of the sealed fluid.

[0047]

[Table 1]

[0048]

[Table 2]

[0049]

[Table 3]

The leakage amount (g / h) of the sealed fluid in Table 3 will be examined. First, when the pressure of the sealed fluid is 0 MPa, the leakage amount of the sealed fluid is 0 g / h,
In the case of 0.07 MPa, the leak of the sealed fluid cannot be measured due to the pressure, but it is considered to occur minutely. The reason for this is that when the sealed fluid is 0 MPa, the dimples 5A on the outer peripheral side and the dimples 5B on the inner peripheral side are formed as targets, and the pressure generated by the pumping action of the dimples 5 is balanced, so It is considered that the flow of the sealed fluid across the moving surfaces 3 does not occur. Further, when the pressure of the sealed fluid is 0.07 MPa, no leakage occurs due to the pumping action of the dimples 5, but the leakage of the sealed fluid is considered to occur minutely as the pressure of the sealed fluid increases. is there.

The basis for this is that the leakage amount of the sealed fluid is proportional to the pressure of the sealed fluid according to Poiseuille's theoretical formula regarding the radial leakage between the sliding surfaces of the parallel stationary sealing ring and the rotating sealing ring. Recognize.

Example 2 Next, Example 2 is a test of the sliding component 2 shown in FIG. On this sliding surface, as shown in FIG. 4, the ratio of the arrangement width r1-rh of the outer dimples 5A to the arrangement width rh-r2 of the inner dimples 5B is set to a value of 1/3. The other conditions of the second embodiment are the same as those of the first embodiment.
Under the same conditions as. The friction coefficient as a result of testing the sliding component 2 of Example 2 under these conditions is as shown in Table 4. Further, the ratio (%) of the friction coefficient between the smooth sliding surfaces (sliding surfaces) without dimples and the friction coefficient of Example 2
Table 5 shows [friction coefficient of sliding component 2 / friction coefficient of sliding component formed with dimple-free sliding surface]. Further, Table 6 shows the leakage amount (g / h) of the sealed fluid.

[0053]

[Table 4]

[0054]

[Table 5]

[0055]

[Table 6]

The friction coefficient in Table 4 of Example 2 and the friction coefficient ratio (%) between the sliding component 2 and the sliding component without dimples in Table 5 are both corresponding Tables 16 and 17 in Comparative Example 1. The friction coefficient is smaller than that of. Therefore, the ability to reduce friction is excellent. In particular, since sliding heat is small during high-speed sliding, seizure does not occur. Further, Table 6 shows the leakage amount (g / h) of the sealed fluid, but even if the pressure of the sealed fluid is increased, the leakage of the sealed fluid is not recognized. That is, the sliding component 2 has a small friction coefficient and excellent sealing ability.

Example 3 1) Test conditions The sliding component 2 of Example 3 was tested under the same conditions as in Example 1 using the same tester. 2) Sliding part 2 (1) This sliding part 2 has the same sliding surface as the sliding part 2 shown in FIG. That is, the array width r1-rh of the outer dimples 5 and the array width rh-r2 of the inner dimples 5
Was set to 1/3. (2) The material and diameter of the rotary seal ring are chromium molybdenum cast iron (inner diameter 25 mm x outer diameter 44 mm x length 12 mm) (3) The material and diameter of the stationary seal ring are chromium molybdenum cast iron (inner diameter 25 mm x outer diameter (50 mm x length 14 mm) (4) The diameter of the rotary sliding surface is (inner diameter 32 mm x outer diameter 40 m)
m) (5) Other conditions are the same as in Example 1.

The friction coefficient as a result of the test under these conditions is shown in Table 7. Further, the ratio (%) of the friction coefficient between the smooth sliding surfaces having no dimples to the friction coefficient of the third embodiment [friction coefficient of sliding component 2 / friction of sliding components having sliding surfaces without dimples] Coefficient] is shown in Table 8
Is the street. Further, the leak amount (g / h) of the sealed fluid is as shown in Table 9. Similar results are obtained with cast iron FC35.

[0059]

[Table 7]

[0060]

[Table 8]

[0061]

[Table 9]

The friction coefficient in Table 7 of Example 3 and the friction coefficient ratio (%) between the sliding component 2 and the sliding component without dimples in Table 8 are both Tables 16 and 17 corresponding to Comparative Example 1. The friction coefficient is smaller than that of. Therefore, the ability to reduce friction is excellent. In particular, it does not cause seizure because the sliding heat generation is small during high-speed sliding. Further, Table 9 shows the leakage amount (g / h) of the sealed fluid, but even if the pressure of the sealed fluid is increased, the leakage of the sealed fluid is not recognized. That is, the sliding component 2 has a small friction coefficient and excellent sealing ability.

Example 4 1) Test Conditions The sliding component 2 of Example 4 was tested under the same conditions as in Example 1 using the same tester. 2) Sliding component 2 (1) This sliding component 2 has the same shape as the sliding surface of the sliding component 2 shown in FIG. That is, the array width r1-rh of the outer dimples 5 and the array width rh-r2 of the inner dimples 5
Was set to 1/3. (2) The material and diameter of the rotary seal ring are stainless steel (SUS
420J2) (25mm inner diameter x 44mm outer diameter x 12mm length) (3) The material and diameter of the stationary seal ring are stainless steel (SUS
420J2) (25mm inner diameter x 50mm outer diameter x 14mm length) (4) The diameter of the rotary sliding surface is (32mm inner diameter x 40m outer diameter)
m) (5) Other conditions are the same as in Example 1.

Table 10 shows the friction coefficient as a result of the test under these conditions. Further, the ratio (%) of the friction coefficient between the smooth sliding surfaces without dimples and the friction coefficient of the fourth embodiment [friction coefficient of sliding part 2 / friction of sliding parts having sliding surfaces without dimples] Table 11 shows the results showing the coefficient. Furthermore, the leakage amount of the sealed fluid (g /
Table 12 shows h).

[0065]

[Table 10]

[0066]

[Table 11]

[0067]

[Table 12]

The friction coefficient in Table 10 of Example 4 and the friction coefficient ratio (%) between the sliding component 2 and the sliding component without dimples in Table 11 are both corresponding Tables 16 and 17 in Comparative Example 1. Has a smaller friction coefficient than Therefore, the ability to reduce friction is excellent. In particular, since the sliding heat generation is small at high speed sliding, seizure does not occur. Further, Table 12 shows the leakage amount (g / h) of the sealed fluid, but even if the pressure of the sealed fluid is increased, the leakage of the sealed fluid is not recognized. That is, the sliding component 2 has a small friction coefficient and excellent sealing ability.

Example 5 1) Test conditions The sliding part 2 of Example 5 was tested under the same conditions as in Example 1 using the same tester. 2) Sliding part 2 (1) It has the same shape as the sliding part 2 and sliding surface shown in FIG. That is, the arrangement width r1-rh of the outer dimples 5A
And the ratio of the array width rh-r2 of the dimples 5B on the inner circumference is 1
/ 3. (2) The material and diameter of the rotating seal ring are silicon nitride (inner diameter 2
5 mm x outer diameter 44 mm x length 12 mm) (3) The material and diameter of the stationary seal ring are silicon nitride (inner diameter 2
5mm x outer diameter 50mm x length 14mm) (4) The diameter of the rotary sliding surface is (inner diameter 32mm x outer diameter 40m)
m) (5) Other conditions are the same as in Example 1.

The friction coefficient as a result of the test under these conditions is as shown in Table 13. Further, the ratio (%) of the friction coefficient between the smooth dimple-free sliding surfaces to the friction coefficient of Example 5 [friction coefficient of sliding component 2 / friction of sliding component having dimple-free sliding surface formed] The result of
Is the street. Further, Table 15 shows the leakage amount (g / h) of the sealed fluid.

[0071]

[Table 13]

[0072]

[Table 14]

[0073]

[Table 15]

The friction coefficient in Table 13 of Example 5 and the friction coefficient ratio (%) between the sliding component 2 and the sliding component without dimples in Table 14 are both corresponding Tables 16 and 17 in Comparative Example 1. Has a smaller friction coefficient than Therefore, the ability to reduce friction is excellent. In particular, since the sliding heat generation is small at high speed sliding, seizure does not occur. Further, although Table 15 shows the leakage amount (g / h) of the sealed fluid, the leakage of the sealed fluid is not recognized even if the pressure of the sealed fluid is increased. That is, the sliding component 2 has a small friction coefficient and excellent sealing ability.

Comparative Example 1 As Comparative Example 1, a sliding member for mechanical seal as shown in FIG. 1 of Japanese Patent No. 3026252 was tested. This sliding member is formed by arranging a plurality of elliptical dimples that are long in the direction perpendicular to the sliding direction on the sliding surface in the radial and circumferential directions. This elliptical dimple has a width of 50 × 10 ⁻⁶ m and a longitudinal length of 200.
× a ^{10 -6} m, is 8 × ^{10 -6} m depth. or,
The arrangement on the sliding surface is about 40 in the circumferential direction of sliding.
0 × 10 ⁻⁶ m, about 200 × 10 ⁻⁶ m in the radial direction
It is arranged at intervals of. The area ratio of all the dimples to the area of all the sliding surfaces was formed to be about 8%.

Table 16 shows the friction coefficient as a result of testing the sliding component of Comparative Example 1 under these conditions.
Table 17 shows the ratio (%) of the friction coefficient between the sliding surfaces having no dimples 5 to the friction coefficient of Comparative Example 1 [friction coefficient of Comparative Example 1 / friction coefficient between sliding surfaces having no dimples]. On the street. Furthermore, the leakage amount of the sealed fluid (g /
h) is as shown in Table 18.

[0077]

[Table 16]

[0078]

[Table 17]

[0079]

[Table 18]

From the above test results, Example 1 is reduced to 1/3 or less in all points in comparison with Comparative Example 1 in terms of the ratio (%) of the friction coefficient under the same conditions. or,
Example 2 has the same leakage amount of the sealed fluid as Comparative Example 1, but the ratio of the friction coefficient is reduced to 28% or less at the maximum. Further, in Example 3, as compared with Comparative Example 1, almost no leakage amount (g / h) of the sealed fluid is recognized. However, in comparison with Comparative Example 1, the maximum value of the coefficient of friction is 3
It is recognized that the amount is reduced to 0% or less. Further, in Example 4, as compared with Comparative Example 1, the amount of leakage of the sealed fluid (g /
h) is hardly recognized. However, it is recognized that the ratio of the friction coefficient is reduced to 29% or less at the maximum value as compared with Comparative Example 1. Furthermore, Example 5 is a comparative example 1.
On the other hand, the leakage amount (g / h) of the sealed fluid is hardly recognized. However, it is recognized that the ratio of the friction coefficient is reduced to 26% or less at the maximum value as compared with Comparative Example 1.

Further, with respect to the above test results, the ratio (%) of the friction coefficient between the sliding surfaces without the dimples 5 to the friction coefficient of the sliding parts 2 of Examples 1 and 2 and the sliding part of Comparative Example 1 is shown. FIG. 7 shows the graph. Furthermore, since the same graphs are obtained for Examples 3, 4, and 5, the graph display is omitted. Judging from the graph of FIG. 7, all the values such as the coefficient of friction are reduced as compared with Comparative Example 1 in all of Example 1, Example 2, Example 3, Example 4, and Example 5. Furthermore, in the third, fourth and fifth embodiments, even if the sliding parts made of the same material as the sliding part 2 are not provided with the dimples 5, seizure will occur during high-speed rotation and they will be unusable. However, by providing the sliding surface 3 with the dimples 5 according to the present invention, seizure can be prevented. Moreover, in the sliding parts made of a silicon carbide material without the dimples 5, cracks may occur on the sliding surface at low temperatures in cold regions. However, cast iron forks provided with the dimples 5 or stainless steel or nitrided In the sliding part 5 made of a material such as silicon or aluminum nitride, cracking is not recognized in the sliding surface even at low temperature or when the sliding surface is frozen. For this,
The durability of sliding parts is improved. The sliding component 2 of the present invention can also be used as a sliding component having a sliding surface such as a piston ring that slides on a bearing or a cylinder.

[0082]

According to the sliding component of the present invention as set forth in claims 1 to 3, the dimples on the outer peripheral side incline the longitudinal distal end side in the rotational direction toward the outer peripheral side, and the dimples on the inner peripheral side. When the longitudinal tip end in the direction of rotation is inclined toward the inner peripheral side, a lubricating film is formed between the dimples on the outer peripheral side and the inner peripheral side to hold the lubricating film of the sealed fluid on the sliding surface, and the sealing ability Has the effect of improving. Further, the retained lubricating film has an effect of reducing the friction coefficient of the sliding surface. And the heat generation of the sliding surface is effectively reduced. Therefore, it is useful as a sliding surface of a seal ring, a piston ring, a bearing and the like.

Further, since the dimples can be arranged in a c-shape, the lubricating film of the sealed fluid is gathered and concentrated near the boundary reference line by the dimples on the inner and outer peripheries, and the sealed fluid interposed between the sliding surfaces is concentrated. The lubricating film of 1 exhibits the effect of improving both the friction coefficient and the sealing ability.

Furthermore, since the sealed fluid is pushed back to the sealed fluid side by the large number of dimples on the opposite side to the sealed fluid on the sliding surface, the sealing ability of the sealed fluid can be dramatically improved. Further, the lubricating film of the sealed fluid present on the sliding surface at this time has an effect of reducing the friction coefficient of the sliding surface.

According to the sliding component of the present invention according to claim 4, the friction coefficient is in the minimum range and the sealing ability is in the maximum range, so that both effects are exhibited in common. .

According to the sliding component of the present invention according to claim 5, when the sliding member made of carbide is used, the coefficient of friction can be reduced and crying and linking that occur during sliding can be reduced. Moreover, the effect of preventing the blister phenomenon can be expected even when the sliding component is slid against the carbon material.

According to the sliding parts of the present invention according to claim 6 and claim 7, the sliding parts made of materials such as cast iron, stainless steel, silicon nitride, aluminum nitride can reduce the friction coefficient and Since cracks on the sliding surface that occur at times can be prevented, both the sealing ability and the durability ability are improved. Further, it is possible to effectively prevent seizure of the sliding surface that occurs during high speed sliding. In addition, sliding parts such as bearings and piston rings also have a small friction coefficient to improve durability.

[Brief description of drawings]

FIG. 1 is a front view of a sliding surface of a sliding component according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a part of an array of dimples showing a second embodiment according to the invention.

FIG. 3 is a plan view of a dimple showing a third embodiment according to the present invention.

FIG. 4 is a plan view of a sliding surface of a sliding component showing a third embodiment according to the present invention.

FIG. 5 is a cross-sectional view of a mechanical seal equipped with a sliding component according to the present invention.

FIG. 6 is a cross-sectional view of a sliding component testing machine according to the present invention.

FIG. 7 is a graph showing a comparison ratio of friction coefficients between a sliding component and a dimple-free sliding surface in Examples and Comparative Examples according to the present invention.

FIG. 8 is a cross-sectional view of a mechanical seal disclosed in Patent Document.

FIG. 9 is a plan view showing a sliding surface of a sliding component disclosed in Patent Document.

[Explanation of symbols]

1 mechanical seal 2 Sliding parts 3 sliding surface 5 dimples 5A Dimple on outer peripheral side 5B Inner peripheral dimple 5A1 Rotation direction tip 5B1 Rotation direction tip X boundary reference line N rotation direction R1 outer peripheral area R2 inner circumference area r1 The radius of the outer circumference of the dimple array r2 Inner radius of dimple array rh Radius of boundary reference line C Inclination angle of outer dimple C'Inclination angle of inner dimple

Claims (6)

[Claims] 1. A sliding component in which sliding surfaces of a stationary sliding component and a rotating sliding component slide relative to each other, the outer peripheral side and the inner periphery of the sliding surface with a boundary reference line as a boundary. Side has a plurality of elongated dimples whose inclination directions are different from each other, the dimples on the outer peripheral side incline the tip in the rotational direction toward the outer peripheral side, and the dimples on the inner peripheral side direct the tip in the rotational direction toward the inner peripheral side. Sliding parts characterized by being tilted. 2. A sliding component for sealing a sealed fluid existing on one side between sliding surfaces where a stationary sliding component and a rotating sliding component slide relative to each other, said sliding component The surface has a plurality of elongated dimples having different inclination directions on the outer peripheral side and the inner peripheral side with a boundary reference line as a boundary, and the outer peripheral side dimples and the inner peripheral side dimples form a row in the radial direction. A sliding component, wherein the rows are arranged in a plurality of rows in the circumferential direction while being inclined in a C-shape. 3. The number of dimples on the sealed fluid side of the sliding surface is smaller than the number of dimples on the inner peripheral side and the number of dimples on the outer peripheral side. The sliding component according to 2. 4. The dimple has an elliptical shape or a rectangular shape in a plane and a width of 50 × 10 ⁻⁶ m to 1000 × 1.
0 ^-6 1/2 or less the length of the sliding surface width more than twice of the width as well as a m, and a depth from ^{1 × 10 -6 m 25 × 10} - formed ⁶ m ⁽²⁰ ft) of The sliding component according to claim 1, 2 or 3, wherein 5. The sliding component is silicon carbide, titanium carbide,
The sliding component according to claim 1, which is formed of a sliding material containing a carbide such as tungsten carbide. 6. The sliding component is made of a material such as cast iron, stainless steel, silicon nitride, or aluminum nitride, as claimed in claim 1, claim 2, claim 3, or claim 4. The sliding component described in.