sliding member

Abstract

The present application is a pair of sliding members (3, 5) in which the sliding surfaces (S) slide against each other, wherein at least one of the sliding surfaces (S) is provided with a pocket group (60) in which pockets (11) are arranged in the radial and circumferential directions, the opening portion (11a) of the pocket (11) has a shape with an orthogonal major axis (L) and a minor axis (K), and the pocket angle (θ) formed by the radius direction axis (r) and the major axis (L), which passes through the intersection point (G) of the major axis (L) and the minor axis (K) of the pocket (11) and the center (C) of the sliding surface (S), varies in at least one of the radial and circumferential directions of the sliding surface (S).

Description

Technical Field

[0001] This invention relates to a pair of sliding components that slide relative to each other on sliding surfaces, such as mechanical seals, sliding bearings, and other sliding components suitable for sliding portions. In particular, it relates to sliding components such as sealing rings or bearings that require fluid to be trapped on the sliding surfaces to reduce friction and prevent fluid leakage from the sliding surfaces. Background Technology

[0002] As a sealing device to prevent leakage of the sealed fluid, a device consisting of a pair of sliding parts sliding relative to each other on sliding surfaces (e.g., a mechanical seal) is known. In such a sealing device, a fluid lubricating film formed by the sealed fluid needs to be formed between the sliding surfaces to reduce sliding torque and maintain high sealing performance. Furthermore, as a method to achieve high sealing performance and low sliding torque, a technique of arranging multiple dimples on the sliding surfaces is known.

[0003] For example, it is known that arranging the recesses with circular openings on the sliding surface in a virtual circle centered on the rotation center of the sliding component can achieve high sealing performance and low sliding torque. (See, for example, Patent Document 1).

[0004] Furthermore, it is known that by configuring a recess with an elongated track-shaped opening at a predetermined recess angle θ, and setting the ratio L1 / L2 of the circumferential length L1 of the recess on a circle passing through the center of the recess to the circumferential length L2 of the platform surface between adjacent recesses on the circle to 0.001≤L1 / L2≤0.1, the sealing performance and sliding torque of the recess as a whole are optimal (for example, see Patent Document 2).

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2010-133496

[0008] Patent Document 2: Japanese Patent No. 5456772 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] In the technology of Patent Document 1, even if high sealing performance and low slip torque can be achieved under specific operating conditions, high sealing performance and low slip torque cannot be achieved over a wide speed range.

[0011] Furthermore, in the technology of Patent Document 2, since the recess angle is fixed, even if the leakage and sliding torque of the sealed fluid can be reduced under specific operating conditions, it is impossible to achieve high sealing performance and low sliding torque over a wide speed range.

[0012] The purpose of this invention is to provide a sliding component that achieves high sealing performance and low sliding torque even when used over a wide range of rotational speeds in a pair of sliding components with sliding surfaces sliding relative to each other.

[0013] Solution for solving the problem

[0014] To solve the above problems, the sliding component of the present invention is a pair of sliding components that slide relative to each other on a sliding surface, characterized in that...

[0015] At least one of the sliding surfaces has a group of recesses arranged radially and circumferentially, the openings of the recesses having orthogonal major and minor axes.

[0016] The angle of the recess formed by the radial direction axis and the major axis varies in at least one direction of the sliding surface, either radially or circumferentially, and the radial direction axis passes through the intersection of the major axis and the minor axis of the recess and the center of the sliding surface.

[0017] Based on this feature, the angle of the cavity varies in at least one direction, either radial or circumferential. This changes the suction effect and dynamic pressure effect of the cavities constituting the cavity group, thus enabling the configuration of cavities suitable for various operating conditions, thereby achieving high sealing performance and low sliding torque.

[0018] The sliding component of the present invention is characterized in that,

[0019] The angle of the recess varies in the radial direction at a constant rate.

[0020] Based on this feature, by changing the angle of the concave cavity constituting the concave cavity group at a constant ratio in the radial direction, the suction effect and dynamic pressure effect of the concave cavity can be changed in the radial direction.

[0021] The sliding component of the present invention is characterized in that,

[0022] The angle of the cavity varies discontinuously in the radial direction.

[0023] Based on this feature, by making the angle of the cavity discontinuous in the radial direction, the suction effect and dynamic pressure effect of the cavities constituting the cavity group can be made to vary discontinuously in the radial direction, and a cavity group suitable for operating conditions can be configured within a specific range.

[0024] The sliding component of the present invention is characterized in that,

[0025] The radial variation rate of the concave angle varies radially.

[0026] Based on this feature, by varying the radial variation rate of the recess angle in the radial direction, recesses suitable for various usage conditions can be easily configured in the radial direction.

[0027] The sliding component of the present invention is characterized in that,

[0028] The angle of the recess is larger on the leakage side of the sliding surface and smaller on the sealed fluid side of the sliding surface.

[0029] Based on this characteristic, for the recess located on the leakage side, the large angle of the recess gives it an advantage in suction effect, allowing it to draw fluid in from the leakage side and significantly reduce leakage. Furthermore, for the recess located on the side of the sealed fluid, the small angle of the recess gives it an advantage in hydrodynamic effect, allowing it to discharge high-pressure fluid and reduce sliding torque.

[0030] The sliding component of the present invention is characterized in that,

[0031] The angle of the recess varies at a constant rate in the circumferential direction.

[0032] Based on this feature, by changing the angle of the concave cavity constituting the concave cavity group at a constant ratio in the circumferential direction, the fluid retention effect, suction effect, and sealing effect of the concave cavity can be varied in the circumferential direction.

[0033] The sliding component of the present invention is characterized in that,

[0034] The angle of the concave cavity varies discontinuously in the circumferential direction.

[0035] Based on this feature, by making the angle of the cavity discontinuous in the circumferential direction, the suction effect and dynamic pressure effect of the cavities constituting the cavity group can be made discontinuous in the circumferential direction, and a cavity group suitable for operating conditions can be configured within a specific range.

[0036] The sliding component of the present invention is characterized in that,

[0037] The circumferential variation rate of the concave angle varies in the circumferential direction.

[0038] Based on this feature, by varying the circumferential variation rate of the recess angle in the circumferential direction, recesses suitable for various usage conditions can be easily configured in the circumferential direction.

[0039] The sliding component of the present invention is characterized in that,

[0040] The sliding surface has multiple regions divided by a platform extending radially.

[0041] The cavity group is disposed in the area.

[0042] Based on this feature, recesses suitable for various operating conditions can be configured in each region, thereby achieving high sealing performance and low sliding torque.

[0043] The sliding component of the present invention is characterized in that,

[0044] The opening of the recess is elliptical in shape.

[0045] Based on this characteristic, by utilizing the different suction effects and dynamic pressure effects of the long and short axes of the elliptical cavity, it is possible to configure cavities suitable for various operating conditions, thereby achieving high sealing performance and low sliding torque. Attached Figure Description

[0046] Figure 1 This is a longitudinal sectional view showing an example of applying the sliding component of the present invention to a mechanical seal.

[0047] Figure 2 yes Figure 1 The W-W view is a diagram showing an example of the sliding surface of the sliding member according to Embodiment 1 of the present invention.

[0048] Figure 3 yes Figure 1 The W-W view is a diagram showing an example of the sliding surface of the sliding member according to Embodiment 2 of the present invention.

[0049] Figure 4 yes Figure 1 The W-W view is a diagram showing an example of the sliding surface of the sliding member of Embodiment 3 of the present invention.

[0050] Figure 5 yes Figure 1 The W-W view is a diagram showing an example of the sliding surface of the sliding member according to Embodiment 4 of the present invention.

[0051] Figure 6 This is a diagram illustrating another embodiment of the recess of the present invention.

[0052] Figure 7 middle, Figure 7 A- Figure 7 D represents a variation of the scheme for changing the concave angle θ in the radial direction of the sliding surface S.

[0053] Figure 8 middle, Figure 8 A- Figure 8 D represents a variation of the scheme for changing the concave angle θ of the sliding surface S in the circumferential direction. Detailed Implementation

[0054] Hereinafter, with reference to the accompanying drawings, embodiments are exemplarily described to illustrate how to implement the present invention. Unless otherwise explicitly stated, the dimensions, materials, shapes, and relative arrangements of the constituent components described in this embodiment are not intended to limit the scope of the invention to these aspects.

[0055] Example 1

[0056] Reference Figure 1 and Figure 2 The sliding component of Embodiment 1 of the present invention will be described below. In the following embodiments, a mechanical seal is used as an example of a sliding component, but the description is not limited thereto. For example, it can also be used as a sliding component of a bearing that slides with a rotating shaft while sealing lubricating oil to one axial side of a cylindrical sliding surface. It should be noted that the outer peripheral side of the sliding component constituting the mechanical seal is described as the sealed fluid side (high-pressure fluid side), and the inner peripheral side is described as the leakage side (low-pressure fluid side, such as the atmospheric side).

[0057] Figure 1 This is a longitudinal sectional view showing an example of a mechanical seal 1. It is an internal mechanical seal designed to seal the fluid leaking from the outer periphery of the sliding surface S towards the inner periphery. It consists of a rotating cartridge and a fixed cartridge. The rotating cartridge includes: a sleeve 2 fitted into the rotating shaft 100; an annular rotating sealing ring 3, which is a sliding component; and packing 8 sealing the space between the sleeve 2 and the rotating sealing ring 3. The rotating cartridge rotates together with the rotating shaft 100.

[0058] The fixed-side filter cartridge includes: a housing 4, which is assembled into a casing 9; an annular fixed-side sealing ring 5, which is a sliding component of the other side; a bellows 7, which seals the fixed-side sealing ring 5 and the housing 4; and a helical bellows spring 6, which applies force to the fixed-side sealing ring 5 towards the rotating-side sealing ring 3 via the bellows 7. The housing 4 is fixed relative to the casing 9 in the rotational direction and axial direction.

[0059] In the mechanical seal 1 with the above configuration, the sliding surface S of the rotating side sealing ring 3 and the sliding surface S of the fixed side sealing ring 5 slide against each other to prevent the sealed fluid from flowing out from the outer peripheral side to the inner peripheral side. It should be noted that... Figure 1 The illustration shows a case where the width of the sliding surface of the rotating side sealing ring 3 is wider than the width of the sliding surface of the fixed side sealing ring 5, but it is not limited to this case. Of course, the invention can also be applied in the opposite case.

[0060] The materials of the rotating side sealing ring 3 and the fixed side sealing ring 5 are selected from silicon carbide (SiC) which has excellent wear resistance and carbon which has excellent self-lubricating properties. For example, both can be SiC or a combination of rotating side sealing ring 3 being SiC and fixed side sealing ring 5 being carbon.

[0061] like Figure 2As shown, the fixed-side sealing ring 5 is provided with a plurality of recesses 11. In this invention, a recess 11 refers to a portion having an opening 11a surrounded by a flat sliding surface S and a recessed portion with a bottom recessed from the sliding surface S. The opening 11a of the recess 11 is formed by a shape having orthogonal major axis L and minor axis K. Furthermore, the recesses 11 are arranged separately from each other with a platform surface R between them. In this invention, the major axis L is an imaginary line that passes through the center G of the shape of the opening 11a and connects the maximum width portion of the opening 11a, and the minor axis K is an imaginary line that passes through the center G of the opening 11a and connects the opposing openings 11a in a direction orthogonal to the major axis L. The opening 11a of the recess 11 in this embodiment is described as an example of an ellipse having orthogonal major axis L and minor axis K. However, it is not limited to an ellipse; any shape having orthogonal major and minor axes is acceptable, and it can also be an oval shape, rhombus, triangle, rectangle, polygon, or similar shape. Figure 6 The shape shown is formed by arbitrary closed curves 91, 92, 93, and 94.

[0062] Next, the function of the recess 11 will be explained. When the fixed-side sealing ring 5 with the recess 11 moves relative to the opposing rotating-side sealing ring 3, the fluid between the sliding surfaces S and the fluid inside the recess 11 move in the direction of movement of the rotating-side sealing ring 3 due to their viscosity. For the fluid flowing into the recess 11, its flow path expands sharply, thus creating a negative pressure on the upstream side of the recess 11, generating cavitation. However, the magnitude of the negative pressure in the cavitation is limited by the value of the fluid's vapor pressure, so it does not become a large negative pressure. Furthermore, on the downstream side of the recess 11, the flow path narrows sharply, thereby increasing the pressure to positive pressure through the wedge effect (dynamic pressure effect). Through the negative pressure generated on the upstream side of the recess 11, the recess 11 exerts a suction effect by drawing in the surrounding fluid. On the other hand, on the downstream side of the recess 11, the fluid that has been pressurized due to the wedge effect is supplied to the sliding surfaces S, maintaining a fluid lubrication state between the sliding surfaces S.

[0063] Explain the angle of the concave cavity. For example... Figure 2 As shown, the concave angle θ is the angle between the radial direction axis r and the major axis L. This radial direction axis r passes through the center C of the sliding surface S and the intersection of the major axis L and the minor axis K of the concave 11 (center G).

[0064] Furthermore, the suction effect and dynamic pressure effect of the cavity 11 vary depending on the size of the cavity angle θ. When the cavity angle θ = 90°, that is, when the major axis L of the cavity 11 is arranged circumferentially, the fluid retention function of the cavity 11 is enhanced. When the cavity angle θ = approximately 45°, the suction effect of the cavity 11 is enhanced. Moreover, when the cavity angle = 0°, that is, when the major axis L of the cavity 11 is arranged radially, the dynamic pressure effect is enhanced. In this way, even cavities 11 with the same elliptical shape and the same depth can be configured by changing the cavity angle to enhance either the suction effect or the dynamic pressure effect. By further changing the elliptical shape and depth, cavities with more diverse characteristics can be created.

[0065] Next, the concave group 60 will be explained. For example... Figure 2 As shown, the cavity group 60 arranges a predetermined number of sub-cavity groups 62 and 63, which are neatly arranged in a radial row, at equal intervals in the circumferential direction. Figure 2 In the example, it is configured as 120). On one periphery of the sliding surface S (leaking side), the sub-cavity group 62 is arranged in a row radially, and on the other periphery of the sliding surface (sealed fluid side), the sub-cavity group 63 is arranged in a row radially. The cavities 62a, 62b, 62c, 62d, and 62e constituting the sub-cavity group 62 on the leaking side are configured with a cavity angle θ = 45°. Furthermore, the cavities 63a, 63b, 63c, 63d, and 63e constituting the sub-cavity group 63 on the sealed fluid side are configured with a cavity angle θ = 0°. That is, the cavity angle θ of the sub-cavity group 62 and the sub-cavity group 63 are set to vary discontinuously in the radial direction.

[0066] Here, the depressions 62a, 62b, 62c, 62d, 62e, 63a, 63b, 63c, 63d, and 63e are formed as ellipses with essentially the same shape and depth of opening. It should be noted that... Figure 2 In the embodiments, sub-concave group 62 and sub-concave group 63 are each composed of 5 concave holes, but are not limited to this. Regarding the number of concave holes constituting sub-concave group 62 and sub-concave group 63, they can be 5 or more, 5 or less, or they can be composed of different numbers of each other. Furthermore, regarding the number of sub-concave group 62 and sub-concave group 63, 120 are respectively arranged on the sliding surface, but this number can be more than 120 or less than 120. Moreover, the sub-concave groups 62 and 63 arranged radially are arranged at equal intervals in the circumferential direction, but they can also be arranged unequally in the circumferential direction.

[0067] The depressions 62a, 62b, 62c, and 62d constituting sub-depression group 62 are arranged at a depression angle θ = 45°. Therefore, for depressions 62a, 62b, 62c, and 62d, the suction effect is superior to the dynamic pressure effect, and the sub-depression group 62 as a whole exhibits a high suction effect. Furthermore, the depressions 63a, 63b, 63c, and 63d constituting sub-depression group 63 are arranged at a depression angle θ = 0°. Therefore, for depressions 63a, 63b, 63c, and 63d, the dynamic pressure effect is superior to the suction effect, and the sub-depression group 63 as a whole exhibits a high dynamic pressure effect.

[0068] Therefore, by arranging the sub-cavity assembly 62, which has a high suction effect, on the leakage side of the sliding surface, the sub-cavity assembly 62 draws fluid from the leakage side, thereby greatly reducing leakage. Furthermore, by arranging the sub-cavity assembly 63, which has a high dynamic pressure effect, on the sealed fluid side of the sliding surface, the sub-cavity assembly 63 supplies high-pressure fluid to the sliding surface S, thereby greatly reducing sliding torque.

[0069] As described above, the sliding component of Embodiment 1 achieves the following effects.

[0070] 1. Due to the negative pressure generated upstream of the recess 11, the recess 11 exerts a suction effect to draw in the surrounding fluid. On the other hand, downstream of the recess 11, fluid pressurized by the wedge effect is supplied to the sliding surface S, thereby improving the fluid lubrication effect of the sliding surface S.

[0071] 2. The cavity 11 has an elliptical opening with orthogonal major and minor axes. Therefore, its suction effect and dynamic pressure effect can be altered by changing the cavity angle θ. When the cavity 11 is configured with a cavity angle θ = 90°, its fluid retention capacity is enhanced. When the cavity angle θ = approximately 45°, the suction effect of the cavity 11 is enhanced. Furthermore, for a cavity angle of 0°, the dynamic pressure effect of the cavity 11 is enhanced. In this way, even for cavities 11 with the same elliptical shape, the suction effect or dynamic pressure effect can be strengthened by changing the cavity angle.

[0072] 3. Regarding the sub-cavity group 62 in which the cavities 11 are arranged at a cavity angle θ = approximately 45°, the suction effect is increased. Therefore, by placing the sub-cavity group 62 with high suction effect on the leakage side of the sliding surface, the sub-cavity group 62 draws fluid from the leakage side, thereby greatly reducing leakage.

[0073] 4. Regarding the sub-cavity group 63 in which the cavities 11 are arranged at a cavity angle θ = approximately 0°, the dynamic pressure effect becomes higher. Therefore, by placing the sub-cavity group 63 with a high dynamic pressure effect on the sealed fluid side of the sliding surface, the sub-cavity group 63 supplies the sliding surface S with a high-pressure fluid, thereby greatly reducing the sliding torque.

[0074] 5. By arranging the sub-cavity assembly 62, which has a high suction effect, on the leakage side of the sliding surface, the sealing performance can be improved. Furthermore, by arranging the sub-cavity assembly 63, which has a high dynamic pressure effect, on the sealed fluid side of the sliding surface, the sliding torque can be greatly reduced. Therefore, as a whole, the cavity assembly 60 can achieve both high sealing performance and low sliding torque. Thus, it can be configured as a sliding component with both high sealing performance and low sliding torque.

[0075] Example 2

[0076] The sliding component of Example 2 will be described. Figure 3 This is a diagram showing the sliding surface S of the sliding member in Embodiment 2. The recess group 70 of Embodiment 2 differs from Embodiment 1 in that the recess angle θ varies radially at a constant rate. Hereinafter, the same reference numerals are used for components and structures identical to those in Embodiment 1, and repeated descriptions are omitted.

[0077] like Figure 3 As shown, the cavity group 70 is arranged with a predetermined number of sub-cavity groups 72 arranged in a radial row at equal intervals in the circumferential direction (in... Figure 3 In the example, it is configured as 120). The sub-concave group 72 is configured such that concave holes 72a, 72b, 72c, 72d, 72e, 72f, 72g, 72h, 72i, and 72j are arranged radially with the platform surface R in between. (Hereinafter, concave holes 72a, 72b, 72c, 72d, 72e, 72f, 72g, 72h, 72i, and 72j will be referred to as "concave holes 72a-72j").

[0078] In the sub-cavity group 72, the cavity 72a located on the leakage side of the sliding surface S is configured with a cavity angle of 45°, and the cavity 72j located on the sealed fluid side of the sliding surface S is configured with a cavity angle of 0°. Then, the cavity angle θ of the cavities 72a-72j constituting the sub-cavity group 72 varies radially from 45° to 0° from the cavity 72a toward the cavity 72j.

[0079] Regarding the recesses 72a-72j constituting the sub-recession group 72, even if they are ellipses with the same shape, the suction effect and dynamic pressure effect can continuously change due to the different recess angles θ. Among the recesses 72a-72j constituting the sub-recession group 72, the recess 72a located on the leakage side periphery 5a of the sliding surface has a recess angle of 45° and has the highest suction effect. Furthermore, as it approaches the sealed fluid side, the suction effect gradually weakens due to the decrease in recess angle, and the dynamic pressure effect of the recess 72j located on the sealed fluid side periphery 5b of the sliding surface becomes the highest.

[0080] The recess angles of the recesses 72a-72j constituting the recess group 70 change continuously in the radial direction at a constant ratio, thus allowing for continuous variation in suction effect and dynamic pressure effect. Therefore, even under varying operating conditions such as speed and pressure, there will be recesses 72a-72j suitable for each operating condition. Consequently, the mechanical seal 1 can reduce leakage and sliding torque even under varying operating conditions.

[0081] As described above, in addition to the effects of Embodiment 1, the sliding component of Embodiment 2 also has the following effects.

[0082] The recess angle θ of the recesses 72a-72j constituting the recess group 70 changes continuously in the radial direction at a constant ratio, thus allowing the suction effect and dynamic pressure effect to change continuously. Therefore, even under varying operating conditions such as speed and pressure, there will be recesses 72a-72j suitable for each operating condition. Consequently, the mechanical seal 1 can reduce leakage and sliding torque even under varying operating conditions.

[0083] Example 3

[0084] The sliding component of Embodiment 3 of the present invention will be described. Figure 4 This diagram shows the sliding surface S of the sliding member in Embodiment 3. It differs from Embodiment 2 in that the recess group 10 has a recess 12a with a recess angle θ = 90° on the leakage side of the sliding surface S, and a recess 12j with a recess angle θ = 0° on the sealed fluid side. Other configurations are the same as in Embodiment 2. Hereinafter, the same reference numerals will be used to denote the same components and configurations as in Embodiment 2, and repeated descriptions will be omitted.

[0085] like Figure 4 As shown, the cavity group 10 arranges a predetermined number of sub-cavity groups 12, which are arranged in a radial row, at equal intervals in the circumferential direction. Figure 4In the example, it is configured as 120). The sub-cavity group 12 is configured such that the cavities 12a, 12b, 12c, 12d, 12e, 12f, 12g, 12h, 12i, and 12j are arranged radially with respect to the platform surface R (hereinafter, the cavities 12a, 12b, 12c, 12d, 12e, 12f, 12g, 12h, 12i, and 12j are referred to as "cavities 12a-12j"). The cavity angle θ of the cavities 12a-12j constituting the sub-cavity group 12 changes radially from 90° to 0° at a constant ratio from the cavity 12a on the leakage side toward the cavity 12j on the sealed fluid side. Here, for each of the cavities 12a-12j, the shape and size of the ellipse of the opening are substantially the same. It should be noted that the number of recesses constituting the sub-recess group 12 can be more than 10 or less than 10. In addition, the number of sub-recess groups 12 disposed on the sliding surface S can be more than 120 or less than 120.

[0086] Even if the cavities 12a-12j constituting the sub-cavity group 12 are ellipses with the same shape, the suction effect and dynamic pressure effect can be continuously varied because the cavity angle θ of the cavities 12a-12j constituting the sub-cavity group 12 varies in the radial direction at a constant ratio. Specifically, when the cavities are configured with a cavity angle θ = 90°, the fluid retention function of the cavities is enhanced. When the cavity angle θ = approximately 45°, the suction effect of the cavities is enhanced. Furthermore, when the cavity angle = 0°, the dynamic pressure effect of the cavities is enhanced.

[0087] Therefore, for the recesses 12a, 12b, and 12c arranged on the leakage side where the circumferential speed is low, the fluid retention function is improved due to the large recess angle θ. In particular, when operating at low speeds, the inner diameter side of the sliding surface S, where the circumferential speed is low, is prone to poor lubrication, by arranging the recesses 12a, 12b, and 12c with recess angles θ = 90° to 70° on the inner diameter side of the sliding surface S, the fluid retained in the recesses 12a, 12b, and 12c can be supplied to the sliding surface S, thus preventing poor lubrication.

[0088] In the center of the sliding surface S, for the recesses with an angle θ = 45°, 12d, 12e, and 12f are arranged, thereby increasing the suction effect. As a result, since fluid is drawn from the sealed fluid side into the recesses 12d, 12e, and 12f, flow to the leakage side is suppressed, thus improving the sealing performance.

[0089] Furthermore, on the sealed fluid side with high circumferential speed, recesses 12g, 12h, 12i, and 12j are provided for recesses with small recess angles θ, thereby improving the hydrodynamic effect. Thus, the recesses 12g, 12h, 12i, and 12j provided on the sealed fluid side with high circumferential speed utilize the hydrodynamic effect to supply high-pressure fluid to the sliding surface S, thereby maintaining fluid lubrication between the sliding surfaces S.

[0090] As described above, in addition to the effects of Embodiment 1, the sliding component of Embodiment 3 also has the following effects.

[0091] 1. Even if the cavities 12a-12j constituting the cavity group 10 are ellipses with the same shape, the suction effect and dynamic pressure effect can be continuously varied because the cavity angle θ of the cavities 12a-12j changes continuously in the radial direction at a constant ratio.

[0092] 2. By arranging recesses 12a, 12b, and 12c with recess angles θ = 90° to 70° on the leakage side where the circumferential speed is low, the fluid retention function is improved. In particular, even when operating at low speeds, by arranging the recesses 12a, 12b, and 12c with high fluid retention function on the inner diameter side of the sliding surface S where the circumferential speed is low, and supplying fluid retained in the recesses 12a, 12b, and 12c to the sliding surface S, poor lubrication conditions can be prevented.

[0093] 3. Recesses 12d, 12e, and 12f with an angle θ = 45° are provided in the center of the sliding surface S, thereby increasing the suction effect. As a result, since the fluid is drawn from the sealed fluid side into the recesses 12d, 12e, and 12f, the flow to the leakage side is suppressed, thus improving the sealing performance.

[0094] 4. Cavities 12g, 12h, 12i, and 12j with small angles θ are provided on the side of the sealed fluid with high circumferential speed, thereby improving the hydrodynamic effect. Thus, the cavities 12g, 12h, 12i, and 12j on the side of the sealed fluid with high circumferential speed utilize the hydrodynamic effect to supply high-pressure fluid to the sliding surface S, thereby maintaining fluid lubrication between the sliding surfaces S.

[0095] Example 4

[0096] The sliding component of Embodiment 4 of the present invention will be described. Figure 5 This diagram shows the sliding surface S of the sliding member in Embodiment 4. It differs from Embodiment 1 in that the recess angle θ of the recesses constituting the recess group 80 is arranged in a manner that is constant in the radial direction but continuously varies in the circumferential direction. Other configurations are the same as in Embodiment 1. Hereinafter, the same reference numerals are used to denote components and configurations identical to those in Embodiment 1, and repeated descriptions are omitted.

[0097] like Figure 5 As shown, the sliding surface S of the fixed-side sealing ring 5 is divided into a predetermined number of sections (in...) by a platform R that spans from the sealed fluid side to the leakage side. Figure 5 In the example, region 20 is 4). Recesses 80 are provided in each region. Within recesses 80, 30 sub-recesses, from sub-recesses 21 to sub-recesses 50, are arranged at equal intervals in the circumferential direction, separated by the platform surface R. Nine recesses are equally spaced in each sub-recesse 21-50, and these nine recesses are arranged in a row radially. It should be noted that in… Figure 5 In the embodiments, each sub-concave group 21-50 is provided with 9 concave holes, but it is not limited to this; there may be more or fewer than 9. In addition, the number of sub-concave groups provided in each region is not limited to 30; there may be more or fewer than 30.

[0098] like Figure 5 As shown, a sub-cavity group 21 is provided at one end of region 20 (upstream side in the direction of rotation), and a sub-cavity group 50 is provided at the other end of region 20 (downstream side in the direction of rotation). The sub-cavity group 21 is configured such that cavities 21a, 21b, 21c, 21d, 21e, 21f, 21g, 21h, and 21i (hereinafter referred to as "cavities 21a-21i") are arranged in a row from the periphery of one side of the sliding surface S (leaking side) to the periphery of the other side (sealed fluid side), separated by the platform surface. The cavity angles of the cavities 21a-21i constituting the sub-cavity group 21 are constant in the radial direction, that is, each cavity 21a-21i has a cavity angle of 90°. Furthermore, the sub-cavity group 50 is configured such that cavities 50a, 50b, 50c, 50d, 50e, 50f, 50g, 50h, and 50i (hereinafter referred to as "cavities 50a-50i") are arranged in a row from the leakage side of the sliding surface S to the sealed fluid side across the platform surface. The cavity angles of cavities 50a-50i are constant in the radial direction, that is, the cavity angles of cavities 50a-50i are each set to cavity angle = 0°. Furthermore, the cavity angles of the cavities in sub-cavity groups 22-49 are configured to change at a constant ratio in the circumferential direction from sub-cavity group 21 toward sub-cavity group 50, from cavity angle θ = 90° to cavity angle θ = 0°.

[0099] Because a sub-cavity group 21 with a cavity angle of 90° is arranged upstream of region 20 in the direction of rotation, the retention effect of keeping the fluid within the cavity is superior compared to the suction effect and the dynamic pressure effect. Furthermore, because a sub-cavity group 50 with a cavity angle of 0° is arranged downstream of region 20 in the direction of rotation, the dynamic pressure effect is superior compared to the suction effect. Moreover, because a cavity group with a cavity angle of 45° is arranged in the intermediate flow area between the upstream and downstream sides of region 20, the suction effect is superior. That is, the cavity angles of sub-cavity groups 22-49 are varied circumferentially from sub-cavity group 21 towards sub-cavity group 50, changing from a cavity angle of θ = 90° to a cavity angle of θ = 0°. Thus, cavity groups with different characteristics are distributed from sub-cavity group 21 to sub-cavity group 50 without omission. Therefore, a cavity group suitable for various operating conditions is configured, achieving high sealing performance and low sliding torque under various operating conditions.

[0100] As described above, the sliding component of Embodiment 4 achieves the following effects.

[0101] 1. Because a sub-cavity group 21 with a cavity angle of 90° is arranged upstream of region 20 in the direction of rotation, the retention effect of holding the fluid within the cavity is superior to both the suction effect and the dynamic pressure effect. Furthermore, because a sub-cavity group 50 with a cavity angle of 0° is arranged downstream of region 20 in the direction of rotation, the dynamic pressure effect is superior to the suction effect. Moreover, because a cavity group with a cavity angle of 45° is arranged in the intermediate flow area between the upstream and downstream sides of region 20, the suction effect is superior.

[0102] 2. The angle of the recesses in the circumferential recess group arranged in region 20 varies in the circumferential direction. Therefore, the fluid retention effect, suction effect, and sealing effect of the recesses can be continuously varied in the circumferential direction from the upstream side to the downstream side in the direction of rotation. As a result, recess groups with different characteristics are distributed from sub-recessed recess group 21 to sub-recessed recess group 50 without omission. Therefore, recess groups suitable for various operating conditions are configured, and high sealing performance and low sliding torque can be achieved under various operating conditions.

[0103] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the specific configuration is not limited to these embodiments. Any changes or additions that do not depart from the spirit of the present invention are also included in the present invention.

[0104] Figure 7 A- Figure 7 D represents a variation of the scheme for changing the recess angle θ in the radial direction of the sliding surface S. It can be configured to vary the recess angle θ radially to suit the required operating conditions.

[0105] Figure 7A represents and Figure 2 The corresponding figure for the embodiment shows a case where the cavity angle varies discontinuously in the radial direction of the sliding surface S. The cavity angle θ of the cavity constituting the leakage side of the sub-cavity group disposed on the sliding surface S and the cavity angle θ of the cavity constituting the sealed fluid side of the sliding surface S are set to different sizes.

[0106] Figure 7 B is Figure 7 A variation represents a case where the rate of change of the cavity angle on the leakage side of the sliding surface differs from the rate of change of the cavity angle on the sealed fluid side of the sliding surface. The cavities constituting the cavity group on the leakage side of the sliding surface S all have a constant cavity angle θ, which does not change. However, the cavity angle θ of the cavities constituting the cavity group on the sealed fluid side of the sliding surface S changes at a constant rate in the radial direction.

[0107] Figure 7 C is with Figure 3 , Figure 4 In the corresponding figure of the embodiment, the cavity angle θ of the cavity constituting the cavity group is set to vary at a constant rate in the radial direction.

[0108] Figure 7 D represents the case where the rate of change of the cavity angle on the leakage side of the sliding surface differs from the rate of change of the cavity angle on the sealed fluid side of the sliding surface. The cavity angle θ of the cavity group constituting the cavity group disposed on the leakage side of the sliding surface S varies at a constant rate in the radial direction. On the other hand, the cavity angle θ of the cavity constituting the sub-cavity group disposed on the sealed fluid side of the sliding surface S is a constant cavity angle θ, and the cavity angle does not change.

[0109] Figure 8 A- Figure 8 D represents a variation of the circumferential concave angle θ of the sliding surface S. It allows for configuration in which the concave angle θ varies circumferentially to suit the required operating conditions.

[0110] Figure 8 A represents the case where the angle of the recess changes discontinuously from one side to the other in the circumferential region of the sliding surface.

[0111] Figure 8 B indicates a situation where the rate of change of the concave angle on one side of the region differs from the rate of change of the concave angle on the other side of the region.

[0112] Figure 8 C is with Figure 5 The diagram corresponding to the embodiment shows the case where the angle of the cavity changes at a constant rate in the circumferential direction.

[0113] Figure 8D indicates a situation where the rate of change of the concave angle on one side of the region differs from the rate of change of the concave angle on the other side of the region.

[0114] In Examples 1-3, the angle of the recesses constituting the recess group varies radially and remains constant circumferentially. Furthermore, in Example 4, the angle of the recesses constituting the recess group varies circumferentially and remains constant radially. However, this is not a limitation; the angle of the recesses constituting the recess group can be set to vary both radially and circumferentially to suit the required operating conditions.

[0115] In the above embodiments, the shape, size, and depth of the recesses 11 constituting the recess group are set to be the same, but at least one of the shape, size, and depth of adjacent recesses can be set to be different. Furthermore, the shape, size, and depth of the recesses can be set to be different for each sub-recession group. By arranging recesses on the sliding surface S that are not only different in angle but also in size, shape, and depth, recesses suitable for a wide range of operating conditions can be arranged on the sliding surface S, thereby enabling a sliding component with high sealing performance and low sliding torque corresponding to a wide range of operating conditions.

[0116] Although the outer circumference is used as the sealed fluid side and the inner circumference as the leakage side, it is not limited to this and can also be applied to situations where the inner circumference is the sealed fluid side and the outer circumference is the leakage side.

[0117] Explanation of reference numerals in the attached figures

[0118] 1: Mechanical seals;

[0119] 2: Sleeve;

[0120] 3: Rotary side sealing ring;

[0121] 4: Casing;

[0122] 5: Fixed side sealing ring;

[0123] 5a: Peripheral edge of the leakage side;

[0124] 5b: Peripheral edge of the sealed fluid side;

[0125] 6: Helical corrugated spring;

[0126] 7: Corrugated pipe;

[0127] 8: Packing material;

[0128] 9: Box;

[0129] 100: Rotation axis;

[0130] 10: Depression group;

[0131] 11: Depression;

[0132] 11a: Opening;

[0133] 12: Zi'ao acupoint group;

[0134] 12a: Depression;

[0135] 12b: Depression;

[0136] 12c: concave cavity;

[0137] 12d: Depression;

[0138] 12e: concave cavity;

[0139] 12f: concave cavity;

[0140] 12g: Depression;

[0141] 12h: Depression;

[0142] 12i: concave cavity;

[0143] 12i: concave cavity;

[0144] 12j: concave cavity;

[0145] 20: Region;

[0146] 21: Zi'ao acupoint group;

[0147] 21a: Depression;

[0148] 21b: Depression;

[0149] 21c: concave cavity;

[0150] 21d: Depression;

[0151] 21e: concave cavity;

[0152] 21f: concave cavity;

[0153] 21g: concave acupoint;

[0154] 21h: Depression;

[0155] 21j: concave cavity;

[0156] 22: Depression group;

[0157] 30: Zi'ao acupoint group;

[0158] 40: Zi'ao acupoint group;

[0159] 49: Zi'ao acupoint group;

[0160] 50: Zi'ao acupoint group;

[0161] 50a: Depression;

[0162] 50b: Depression;

[0163] 50c: Depression;

[0164] 50d: Depression;

[0165] 50e: concave cavity;

[0166] 50f: Depression;

[0167] 50g: concave acupoint;

[0168] 50h: Depression;

[0169] 50j: Depression;

[0170] 60: Depression group;

[0171] 62: Zi'ao acupoint group;

[0172] 62a: Depression;

[0173] 62b: Depression;

[0174] 62c: Depression;

[0175] 62d: Depression;

[0176] 62e: concave cavity;

[0177] 63: Zi'ao acupoint group;

[0178] 63a: Depression;

[0179] 63b: Depression;

[0180] 63c: Depression;

[0181] 63d: Depression;

[0182] 63e: Depression;

[0183] 70: Depression group;

[0184] 72: Zi'ao acupoint group;

[0185] 72a: Depression;

[0186] 72b: Depression;

[0187] 72c: Depression;

[0188] 72d: Depression;

[0189] 72e: concave cavity;

[0190] 72f: concave cavity;

[0191] 72g: concave acupoint;

[0192] 72h: Depression;

[0193] 72i: concave cavity;

[0194] 72j: Depression;

[0195] 80: Depression group;

[0196] K: Short axis;

[0197] L: Major axis;

[0198] R: Platform surface;

[0199] S: Sliding surface;

[0200] θ: Angle of the concave cavity.

Claims

1. A sliding member, which is one of a pair of sliding members that slide against each other on sliding surfaces, characterized by: the sliding surface of at least one of the pair of sliding members has a pocket group in which a plurality of pockets are arranged in the radial direction and the circumferential direction, the opening portion of each of the plurality of pockets has a major axis and a minor axis that are orthogonal to each other, a pocket angle formed by a radius direction axis and the major axis of the pocket, the radius direction axis passing through the intersection of the major axis and the minor axis of the pocket and the center of the sliding surface, varies in the radial direction of the sliding surface within 0 to 90 degrees, a straight line connecting the intersection of the major axis and the minor axis of a plurality of the pockets is arranged in a row in the radial direction along an r line passing through the center of the sliding surface to form a sub-pocket group, the sub-pocket group is arranged so that the pocket angle of the pocket on the leakage side of the sliding surface is greater than the pocket angle of the pocket on the sealed fluid side of the sliding surface, a plurality of the sub-pocket groups arranged in a row in the radial direction are arranged at intervals from each other in the circumferential direction, thereby forming a pocket group, the plurality of pockets in the pocket group are not connected to each other and are not connected to the sealed fluid side and the leakage side.

2. The sliding member according to claim 1, characterized in that: the pocket angle varies at a constant ratio in the radial direction.

3. The sliding member according to claim 1, characterized in that: the pocket angle varies discontinuously in the radial direction.

4. The sliding member according to claim 1, characterized in that: the ratio of variation of the pocket angle in the radial direction varies in the radial direction.

5. The sliding member according to any one of claims 1 to 4, characterized in that: the pocket angle varies in the circumferential direction of the sliding surface.

6. The sliding member according to claim 5, characterized in that: the pocket angle varies at a constant ratio in the circumferential direction.

7. The sliding member according to claim 5, characterized in that: the pocket angle varies discontinuously in the circumferential direction.

8. The sliding member according to claim 5, characterized in that: the ratio of variation of the pocket angle in the circumferential direction varies in the circumferential direction.

9. A sliding member according to any one of claims 1 to 4, characterised in that the sliding surface has a plurality of regions divided by a terrace portion extending in the radial direction, the pocket group is provided in the region.

10. A sliding member according to any one of claims 1 to 4, characterised in that the shape of the opening portion of the pocket is an ellipse.

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