A comb-like dynamic and static pressure combined mechanical seal end face structure

Abstract

A comb-like dynamic and static pressure combined mechanical seal end face structure, including a dynamic ring and a static ring of a mechanical seal, one side of the dynamic ring or static ring end face is a high pressure side, i.e., upstream, and the other side of the dynamic ring or static ring end face is a low pressure side, i.e., downstream; at least one seal end face of the dynamic ring or static ring has a comb-type combined groove on its upstream conical surface side, and a circular texture on its downstream flat end surface side; the comb-type combined grooves are periodically arranged along the circumferential direction, and the comb-type combined grooves are composed of a large-depth rectangular groove along the radial direction and a plurality of shallower rectangular groove bands perpendicular to the radial direction, and face the flow direction of the lubricating liquid film. The present invention can not only avoid end face contact and reduce wear in the early stage of seal operation, but also has a strong fluid dynamic pressure effect.

Description

Technical Field

[0001] The invention relates to a comb-like dynamic and static pressure combined mechanical seal end face structure, which is suitable for sealing liquid media at the shaft end of rotating machinery, such as the shaft end seal of centrifugal pump equipment. Background Art

[0002] In order to improve the performance of the mechanical seal end face friction pair, people apply fluid dynamic pressure lubrication technology to the seal ring end face, and use various fluid dynamic pressure grooves on the seal end face to improve the performance of the mechanical seal. In order to increase the dynamic pressure opening force of the mechanical seal, reduce the friction temperature rise of the seal end face, and prevent early wear of the seal end face, it is necessary to develop a seal end face groove structure with better performance. Summary of the invention

[0003] In order to overcome the deficiencies in the existing mechanical seal technology, the present invention provides a dynamic and static pressure combined mechanical seal based on the liquid film lubrication theory, which can not only avoid end face contact and reduce wear in the early stage of seal operation, but also has a strong fluid dynamic pressure effect.

[0004] The technical solution adopted by the present invention to solve its technical problem is:

[0005] A comb-like dynamic and static pressure combined mechanical seal end face structure, comprising a dynamic ring and a static ring of the mechanical seal, wherein one side of the dynamic ring or static ring end face is a high-pressure side, i.e., upstream, and the other side of the dynamic ring or static ring end face is a low-pressure side, i.e., downstream; at least one sealing end face of the dynamic ring or static ring has a comb-shaped combined groove on its upstream conical surface side, and a circular texture on its downstream flat end surface side; the comb-shaped combined grooves are periodically arranged along the circumferential direction, and the comb-shaped combined grooves are composed of a large-depth rectangular groove along the radial direction and a plurality of shallower rectangular groove bands perpendicular to the radial direction, and face the flow direction of the lubricating liquid film.

[0006] Furthermore, the radial rectangular groove is along the radial direction and communicates with the upstream side of the seal, and the texture depth is 0.1 to 0.3 mm.

[0007] Furthermore, the number of rectangular grooves is 6 to 12 and they are perpendicular to the radial direction, and the groove depth is 3 to 12 μm.

[0008] Furthermore, a single groove of the rectangular groove belt has a length of 0.6-3 mm, a width of 0.1-0.5 mm, and an aspect ratio of 6-10.

[0009] The working principle of the present invention is that the fluid flows from the outer diameter side to the inner side along the radial convergence gap due to the pressure difference between the inner and outer diameters, so that the end face is opened, ensuring that the sealing end face is non-contact at the initial stage of operation and at low speed. At the same time, the rotational movement of the sealing dynamic ring causes the fluid to flow in the circumferential direction, and the radial large-depth rectangular groove introduces the upstream side fluid into the sealing end face, forming a high-pressure area at the tail end of multiple rectangular texture bands perpendicular to the radial direction, thereby further increasing the load-bearing capacity and maintaining the non-contact of the sealing end face. On the downstream side of the sealing ring, the circular texture can also enhance the dynamic pressure effect of the seal, further reduce the end face wear, and improve the liquid film load-bearing capacity.

[0010] The beneficial effects of the present invention are mainly manifested in:

[0011] (1) The unique comb-shaped combined texture on the end face of the sealing ring can inhibit cavitation, form a continuous high-pressure area on the upstream side of the sealing end face, increase the bearing capacity of the liquid film, and the deep rectangular groove can also store oil to achieve good lubrication effect.

[0012] (2) Due to the convergent gap on the upstream cone side, the seal can open at low speeds, avoiding end face contact and reducing wear.

[0013] (3) Due to the fluid dynamic pressure effect of the circular texture on the downstream side, the full film lubrication of the sealing end face can be further ensured, friction and wear can be reduced, and the service life can be extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the geometric structure of the open texture end face of the mechanical seal of the present invention, in which: 1 is a circular texture; 2 is a radial rectangular texture; 3 is a rectangular texture band perpendicular to the radial direction.

[0015] Figure 2 It is a schematic diagram of the definition of the length parameters of the geometric structure of the comb-type combined groove on the sealing end face;

[0016] Figure 3 yes Figure 1 AA cross-section diagram.

[0017] Figure 4 yes Figure 1 BB cross-section diagram.

[0018] Figure 5 This is a schematic diagram of the geometric structure of the combined grooves on the end face of the mechanical seal of Example 2 of the present invention;

[0019] Figure 6 Schematic diagram of the geometric structure of the combined groove on the end face of the mechanical seal of Example 3 of the present invention;

[0020] Figure 7 It is a schematic diagram of the definition of the geometric structure depth parameters of the combined groove of the mechanical seal end face in Example 4 of the present invention. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings.

[0022] Embodiment 1

[0023] Reference Figure 1 to Figure 4 A comb-like dynamic and static pressure combined mechanical seal end face structure, including a dynamic ring and a static ring of a mechanical seal, one side of the dynamic ring or static ring end face is a high pressure side, i.e., upstream, and the other side of the dynamic ring or static ring end face is a low pressure side, i.e., downstream. At least one of the sealing end faces of the dynamic ring or static ring has a comb-shaped texture 2 and 3 on the upstream conical surface side, and a circular texture 1 on the downstream flat end surface side. The comb-shaped combined grooves 2 and 3 are periodically arranged along the circumferential direction, and the comb-shaped combined grooves are composed of a large-depth rectangular groove 2 along the radial direction and a plurality of shallower rectangular groove bands 3 perpendicular to the radial direction, and face the flow direction of the lubricating liquid film.

[0024] The radial rectangular groove is along the radial direction and communicates with the upstream side of the seal, and the groove depth h2 is 0.1-0.3 mm.

[0025] The number of the rectangular groove bands is 6 to 12 and they are perpendicular to the radial direction, and the groove depth h3 is 3 to 12 μm.

[0026] The comb-shaped combined grooves face the flow direction of the liquid film to facilitate the generation of a high-pressure area.

[0027] The length a of a single groove of the rectangular groove belt is 0.6-3 mm in length direction, the width b is 0.1-0.5 mm in width direction, and the aspect ratio a / b is 6-10.

[0028] Reference Figure 1 The upstream conical surface of the dynamic ring is provided with comb-shaped grooves 2 and 3, and the downstream flat end surface is provided with a circular texture 1. Due to the pressure difference between the inner and outer diameters, the fluid flows from the outer diameter side to the inner side along the radial convergence gap, so that the end surface is opened to ensure that the sealing end surface is non-contact at the initial stage of operation and at low speed. Figure 1 As shown, the rotation of the seal ring causes the fluid to flow in the circumferential direction, and the deep radial rectangular groove 2 guides the high-pressure side fluid into the seal end face. The presence of the radial large-depth rectangular texture 2 can inhibit cavitation and oil storage, and form a high-pressure area at the end of multiple rectangular grooves 3 perpendicular to the radial direction, thereby further increasing the load-bearing capacity and maintaining the non-contact of the seal end face. On the downstream side of the seal ring, the circular texture 1 can also enhance the dynamic pressure effect of the seal, further reduce the end face wear, and improve the liquid film load-bearing capacity.

[0029] Embodiment 2

[0030] refer to Figure 5The difference between this embodiment and the first embodiment is that the groove band perpendicular to the radial direction is triangular, and the rest of the structure and implementation method are the same as the first embodiment.

[0031] Embodiment 3

[0032] refer to Figure 6 The difference between this embodiment and the first embodiment is that the groove band perpendicular to the radial direction is semi-elliptical, and the rest of the structure and implementation method are the same as the first embodiment.

[0033] refer to Figure 7 The difference between this embodiment and the first embodiment is that the depth of the texture band perpendicular to the radial direction is equal to the groove depth, and the rest of the structure and implementation method are the same as the first embodiment.

[0034] The contents described in the embodiments of this specification are merely an enumeration of implementation forms of the inventive concept. The protection scope of the present invention should not be regarded as limited to the specific forms described in the embodiments. The protection scope of the present invention also includes equivalent technical means that can be thought of by those skilled in the art based on the inventive concept.

Claims

1. A comb-like dynamic and static pressure combined mechanical seal end face structure, comprising a dynamic ring and a static ring of the mechanical seal, wherein one side of the dynamic ring or static ring end face is the high-pressure side, i.e., the upstream side, and the other side of the dynamic ring or static ring end face is the low-pressure side, i.e., the downstream side; characterized in that: At least one sealing end face of the dynamic ring or the static ring has a comb-shaped combined groove on its upstream conical surface side, and a circular texture on its downstream flat end face side. The comb-shaped combined grooves are periodically arranged in the circumferential direction. The comb-shaped combined grooves are composed of a large-depth rectangular groove along the radial direction and multiple shallower rectangular groove bands perpendicular to the radial direction, and are oriented in the direction of flow of the lubricating liquid film. There are 6 to 12 rectangular groove bands.

2. The comb-like dynamic and static pressure combined mechanical seal end face structure according to claim 1, characterized in that: The radial large-depth rectangular groove is along the radial direction and communicates with the upstream side of the seal, and the depth of the radial large-depth rectangular groove is 0.1~0.3mm.

3. The comb-like dynamic and static pressure combined mechanical seal end face structure according to claim 1, characterized in that: The length of a single groove of the rectangular groove belt is 0.6~3mm, the width is 0.1~0.5mm, and the aspect ratio is 6~10.

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