阅读说明：本技术 一种用于油气两相润滑轴承箱的螺旋磁流体密封结构 (spiral magnetic fluid sealing structure for oil-gas two-phase lubricating bearing box ) 是由 肖云皓 刘文彬 李双喜 王昕� 李庆展 吴圆圆 于 2019-09-08 设计创作，主要内容包括：本发明提供一种用于油气两相润滑轴承箱的螺旋磁流体密封结构。该结构实现密封的基本原理是：在磁流体密封导磁极齿结构的两侧分别设计一段螺纹结构,且所述两段螺纹的旋向相反(具体旋向依据主轴旋转方向确定)；当主轴静止时,磁场力作用下的磁流体在极齿处形成4～20道密封环,起到密封油气的作用；当主轴旋转时(线速度小于24m/s),其运动带动磁流体通过导磁极齿两侧旋向相反的两段螺纹结构,将磁流体介质输送并挤压至密封中段,形成压力略高于被密封介质压力的液封,加强并确保密封效果。通过上述螺旋磁流体密封结构,可以为油气两相润滑的轴承箱提供效果良好的密封方案,使得设备污染物排放水平达满足我国日益严格化的环保标准。(The invention provides a spiral magnetic fluid sealing structure for an oil-gas two-phase lubricating bearing box. The basic principle of the structure for realizing sealing is as follows: respectively designing a section of thread structure on two sides of the magnetic fluid seal magnetic guide pole tooth structure, wherein the rotation directions of the two sections of threads are opposite (the specific rotation direction is determined according to the rotation direction of a main shaft); when the main shaft is static, 4-20 sealing rings are formed at the pole teeth by the magnetic fluid under the action of the magnetic field force, and the effect of sealing oil gas is achieved; when the main shaft rotates (the linear velocity is less than 24m/s), the movement drives the magnetic fluid to rotate to opposite two sections of thread structures through two sides of the magnetic pole teeth, the magnetic fluid medium is conveyed and extruded to the sealing middle section, a liquid seal with the pressure slightly higher than that of the sealed medium is formed, and the sealing effect is enhanced and ensured. By the spiral magnetic fluid sealing structure, a sealing scheme with a good effect can be provided for the bearing box lubricated by oil and gas in two phases, so that the emission level of equipment pollutants reaches the increasingly strict environmental protection standard of China.)

1. A spiral magnetic fluid sealing structure for an oil-gas two-phase lubricating bearing box is characterized by comprising: the magnetic coupler comprises a magnetic conductor (71), a permanent magnet (72), a magnetic conductor (73), a shaft sleeve (4) and a sealing ring (6) arranged in a sealing ring mounting groove of the shaft sleeve (4), wherein the magnetic conductor (71), the permanent magnet (72) and the magnetic conductor (73) are sleeved outside the shaft sleeve (4), and the permanent magnet (72) is clamped between the magnetic conductor (71) and the magnetic conductor (73);

the inner surfaces of the magnetic conductor (71) and the magnetic conductor (73) are respectively processed with magnetic pole teeth; the side, close to a sealed medium, of a magnetic pole tooth on the inner surface of the magnetic conductor (73) is provided with a forward thread structure, and the side, close to the atmosphere, of the magnetic pole tooth on the inner surface of the magnetic conductor (71) is provided with a reverse thread structure; and the length of the forward thread structure is less than the length of the reverse thread structure;

the magnetic conductor (71) is provided with a first permanent magnet clamping groove, the magnetic conductor (73) is provided with a second permanent magnet clamping groove, one end of the permanent magnet (72) is clamped in the first permanent magnet clamping groove, and the other end of the permanent magnet (72) is clamped in the second permanent magnet clamping groove;

The outer circumferential surfaces of the magnetic conductors (71) and the magnetic conductors (73) are respectively matched and connected with the inner circumferential surface of a bearing (8) arranged on the bearing box shell; the end surface of the magnetic conductor (73) close to the sealed medium side is tightly attached to the end surface of the outer ring of the bearing (8) close to the atmosphere side;

the shaft sleeve (4) is matched with the sealing ring (6) and sleeved on the main shaft (5), and the end face of the shaft sleeve (4) close to the side of the sealed medium is contacted with the end face of the inner ring of the bearing (8) close to the atmosphere side;

the gap area among the magnetic conductor (71), the permanent magnet (72), the magnetic conductor (73) and the shaft sleeve (4) forms a sealing gap which is a leakage channel of a sealed medium.

2. The sealing structure of claim 1, wherein the structure is suitable for the sealing working condition of the bearing box or other pure gas phase working conditions under the environment of any oil-gas medium ratio, wherein the sealed pressure is less than or equal to 0.5Mpa, the linear speed of the main shaft (5) is less than 24 m/s.

3. the sealing structure according to claim 1, characterized in that when the spindle (5) rotates clockwise, the rotation direction of the forward thread structure is left-hand rotation and the rotation direction of the reverse thread structure is right-hand rotation; when the main shaft (5) rotates anticlockwise, the rotation direction of the forward thread structure is right rotation, and the rotation direction of the reverse thread structure is left rotation.

4. the seal structure of claim 1, wherein the magnetic pole teeth satisfy at least one of:

The number of the magnetic poles is more than or equal to 4 and less than or equal to 20;

the pole teeth are made of iron or nickel steel.

5. The seal structure according to claim 1, wherein the size of the seal gap is 1.6d/1000mm or more and 2.6d/1000mm or less, d being a seal shaft diameter.

6. the seal structure of claim 1, wherein at least one of the forward thread structure and the reverse thread structure satisfies at least one of:

the helix angle is more than or equal to 7 degrees and less than or equal to 15 degrees and 19';

The shape ratio of the spiral groove is more than or equal to 4;

The width of the relative thread groove is more than or equal to 0.5 and less than or equal to 0.8;

The relative thread groove depth is more than or equal to 4 and less than or equal to 8;

the number of the thread starts is less than or equal to 4.

7. A mechanical device comprising a helical magnetic fluid seal structure for an oil and gas two-phase lubricated bearing housing as claimed in any one of claims 1 to 6.

Technical Field

The embodiment of the invention relates to the technical field of sealing, in particular to a spiral magnetic fluid sealing structure for an oil-gas two-phase lubricating bearing box.

Background

At present, compared with the traditional oil bath lubrication, an oil-gas medium lubrication system consisting of an oil-gas medium generator, an oil-gas medium conveying pipeline, an oil-gas medium control part and a throttling part can generate an oil-gas medium flow with the oil content of about five percent (5PPM), and the oil-gas medium is conveyed to the parts, needing lubrication, of each machine pump device through pipelines to form a reliable oil film so as to realize lubrication. For the bearing box equipped with the lubricating system, the sealing mode is mainly labyrinth sealing. In general, labyrinth seal refers to: the kinetic energy of the sealed medium is converted into heat energy or other forms of energy to be dissipated by utilizing the intercepting gap and the expansion cavity formed between the rotating part and the fixed part, so that the pressure of the sealed medium is reduced, and the sealing is realized. The disadvantages of this seal are: good sealing of the lubricant gas medium cannot be achieved, and failure occurs after the equipment is shut down. Therefore, the overflow of a large amount of oil and gas media can cause potential safety hazards and also have negative effects on the health of operators.

Disclosure of Invention

the embodiment of the invention provides a spiral magnetic fluid sealing structure for an oil-gas two-phase lubricating bearing box, which solves the problem of leakage caused by the fact that the existing seal cannot effectively seal an oil-gas medium in the oil-gas two-phase lubricating bearing box.

in one aspect, an embodiment of the present invention provides a spiral magnetic fluid sealing structure for an oil-gas two-phase lubrication bearing box, including: the magnetic coupling comprises a first magnetic conductor, a permanent magnet, a second magnetic conductor, a shaft sleeve and a sealing ring arranged in a shaft sleeve sealing ring installation groove, wherein the first magnetic conductor, the permanent magnet and the second magnetic conductor are all sleeved outside the shaft sleeve, and the permanent magnet is clamped between the first magnetic conductor and the second magnetic conductor;

The inner surfaces of the first magnetic conductor and the second magnetic conductor are respectively processed with magnetic pole teeth; a positive thread structure is processed on the side, close to a sealed medium, of a magnetic pole tooth on the inner surface of the first magnetic conductor, and a reverse thread structure is processed on the side, close to the atmosphere, of a magnetic pole tooth on the inner surface of the second magnetic conductor; and the length of the forward thread structure is less than the length of the reverse thread structure;

the first magnetic conductor is provided with a first permanent magnet clamping groove, the second magnetic conductor is provided with a second permanent magnet clamping groove, one end of the permanent magnet is clamped in the first permanent magnet clamping groove, and the other end of the permanent magnet is clamped in the second permanent magnet clamping groove.

the outer circumferential surfaces of the first magnetic conductor and the second magnetic conductor are respectively connected with the inner circumferential surface of a bearing arranged on the bearing box shell in a matching way; the end surface of the second magnetic conductor close to the sealed medium side is tightly attached to the end surface of the bearing outer ring close to the atmosphere side;

the shaft sleeve is matched with the sealing ring and sleeved on the main shaft, and the end face of the shaft sleeve, which is close to the side of the sealed medium, is contacted with the end face of the bearing inner ring, which is close to the atmosphere side;

And a gap region among the first magnetic conductor, the permanent magnet, the second magnetic conductor and the shaft sleeve forms a sealing gap, and the sealing gap is a leakage channel of a sealed medium.

Optionally, the structure is suitable for the bearing box sealing working condition or other pure gas phase working conditions under the environment of any oil-gas medium ratio, wherein the sealed pressure is less than or equal to 0.5Mpa, the linear velocity of the main shaft is less than 24 m/s.

Optionally, when the main shaft rotates clockwise, the rotation direction of the forward thread structure is left-handed, and the rotation direction of the reverse thread structure is right-handed; when the main shaft rotates anticlockwise, the rotation direction of the forward threaded structure is right rotation, and the rotation direction of the reverse threaded structure is left rotation.

optionally, the magnetic conductive pole teeth satisfy at least one of:

The number of the teeth is more than or equal to 4 and less than or equal to 20;

The pole teeth are made of iron or nickel steel.

optionally, the size of the seal gap is greater than or equal to 1.6d/1000mm and less than or equal to 2.6d/1000mm, and d is the seal shaft diameter.

optionally, at least one of the forward thread formation and the reverse thread formation satisfies at least one of:

The helix angle is more than or equal to 7 degrees and less than or equal to 15 degrees and 19';

The shape ratio of the spiral groove is more than or equal to 4;

the width of the relative thread groove is more than or equal to 0.5 and less than or equal to 0.8;

the relative thread groove depth is more than or equal to 4 and less than or equal to 8;

the number of thread starts is less than or equal to 4;

In another aspect, an embodiment of the present invention provides a mechanical device, including the above spiral magnetic fluid sealing structure for an oil-gas two-phase lubrication bearing box.

In the embodiment of the invention, a pair of thread structures with opposite rotation directions are arranged on two sides of the traditional magnetic fluid seal by integrating a spiral seal principle and elements with a magnetic fluid seal principle and elements; in the operation process of the equipment, the spindle rotates to drive the magnetic fluid medium to move, the friction force on the surface of the thread structure provides an axial driving force for the magnetic fluid medium, and the magnetic fluid medium is axially conveyed to the pole tooth structure to form 4-20 magnetic fluid sealing rings so as to prevent the sealed medium from leaking; meanwhile, the conveying function of the thread structure improves the pressure of the magnetic fluid medium, so that a liquid high-pressure area is formed, and the leakage of the sealed medium is prevented; when the equipment stops running, the spiral sealing structure fails, but the magnetic fluid sealing structure still keeps the sealing function; it is noted that in the pair of opposite-handed thread structures, the length of the forward thread is smaller than that of the reverse thread, so as to achieve the purpose of reducing the loss or escape of the magnetic fluid medium. Provides a better oil-gas medium sealing method for the bearing box adopting oil-gas two-phase lubrication.

Drawings

Various other advantages and benefits will become more apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Further, like reference numerals are used to denote like parts throughout the drawings. In the drawings:

FIG. 1 is a schematic structural diagram of a spiral magnetic fluid sealing structure for an oil-gas two-phase lubrication bearing box provided by an embodiment of the invention;

FIG. 2 is a diagram of the relationship of the thread size in the spiral magnetic fluid sealing structure for the oil-gas two-phase lubricating bearing box provided by the embodiment of the invention;

fig. 3 is a working principle diagram of the spiral magnetic fluid sealing structure for the oil-gas two-phase lubricating bearing box provided by the embodiment of the invention.

Detailed Description

The present embodiment will be described in more detail below with reference to the accompanying drawings. While the present embodiments are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, the present embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

the spiral magnetic fluid sealing structure for the oil-gas two-phase lubricating bearing box provided by the embodiment of the invention is explained below.

Referring to fig. 1, a schematic diagram of a spiral magnetic fluid sealing structure provided by an embodiment of the present invention is shown. As shown in fig. 1, the sealing structure includes: gland 1, magnetic conductor 71, permanent magnet 72, magnetic conductor 73, axle sleeve 4, sealing washer 6, sealing washer 3, bolt 2, fastener 10.

Wherein, the materials of the magnetic conductor 71, the magnetic conductor 73 and the shaft sleeve 4 are selected from iron, low carbon steel, silicon steel or nickel steel; the permanent magnet 72 is made of ferrite permanent magnet materials (such as H10, H20, etc.), alnico permanent magnet materials (such as LNC3, LNCT20, FLNC28, FLNCT28, etc.), and rare earth cobalt permanent magnet materials (such as SmCo5, PrCo5, MHCo5, YX16A, etc.), which are not listed herein.

The inner surfaces of the magnetic conductor 71 and the magnetic conductor 73 are respectively processed with magnetic pole teeth; a positive thread structure is processed on the side, close to a sealed medium, of a magnetic pole tooth on the inner surface of the magnetic conductor 73, and a reverse thread structure is processed on the side, close to the atmosphere, of the magnetic pole tooth on the inner surface of the magnetic conductor 71; and the length of the forward thread structure is less than the length of the reverse thread structure.

the magnetic conductive pole teeth satisfy at least one of the following:

The number of the teeth is more than or equal to 4 and less than or equal to 20;

The pole teeth are made of iron or nickel steel.

In the embodiment of the present invention, the forward thread structure and the reverse thread structure may be disposed on the outer circumferential surface of the shaft sleeve 4, or disposed on the inner circumferential surfaces of the magnetic conductors 71 and 73, respectively, or disposed directly on the outer circumferential surface of the main shaft, and other forms are not illustrated here.

the permanent magnet 72 is clamped between a first permanent magnet clamping groove formed in the magnetic conductor 71 and a second permanent magnet clamping groove formed in the magnetic conductor 73, the permanent magnets are connected and combined into an integral component 7 through the action of magnetic field force, and meanwhile, the outer circumferential surfaces of the magnetic conductor 71 and the magnetic conductor 73 are respectively connected with the inner circumferential surface of the bearing box shell, which is provided with the bearing 8 in a matched mode.

the shaft sleeve 4 is matched with the sealing ring 6 to be sleeved on the main shaft 5, and the end face of the shaft sleeve 4 close to the sealed medium side is contacted with the end face of the bearing 8 inner ring close to the atmosphere side;

The gap region between the magnetic conductor 71, the permanent magnet 72, the magnetic conductor 73 and the shaft sleeve 4 forms a sealing gap, which is a leakage path for the sealed medium.

it can be seen that when the main shaft 5 is in a static state, the magnetic fluid forms 6 magnetic fluid sealing rings between the magnetic conductive teeth arranged on the magnetic conductors 71 and 73 and the shaft sleeve 4 to seal the oil-gas medium; when the main shaft 5 is in a rotating state, the magnetic fluid is extruded to the middle of the sealing gap to form a high-pressure liquid area with pressure slightly higher than that of the sealed medium, so that the sealed medium is prevented from escaping.

Wherein the linear speed of the main shaft 5 is less than 24 m/s.

Optionally, the size of the sealing gap is greater than or equal to 1.6d/1000mm and less than or equal to 2.6d/1000mm, and d is the diameter of the sealing shaft.

Alternatively, the number of magnetic poles formed by the magnetic conductors 71 and 73 is equal to or greater than 1 and equal to or less than 20.

optionally, at least one of the forward thread formation and the reverse thread formation satisfies at least one of:

The helix angle is more than or equal to 7 degrees and less than or equal to 15 degrees and 19';

the shape ratio of the spiral groove is more than or equal to 4; it should be noted that: the shape ratio has influence on the flow condition of the magnetic fluid in the thread groove, and the thread shape ratio is more than 4 and is more suitable for ensuring the laminar flow state;

The width of the relative thread groove is more than or equal to 0.5 and less than or equal to 0.8; it should be noted that: too large a relative tooth width is disadvantageous for the seal itself, so it is recommended to choose a relative tooth width of 0.5;

The relative thread groove depth is more than or equal to 4 and less than or equal to 8;

The number of the thread heads is determined according to the diameter of a shaft of a specific device, the number of the thread heads is less than or equal to 4, wherein the fact that the number of the thread heads is determined by fully considering specific working condition environment and device size needs to be emphasized, and meanwhile the principle of maximizing effect and optimizing size needs to be followed. It should be noted that the thread pattern may be a regular triangular thread, a zigzag thread, a trapezoidal thread, etc. in addition to the rectangular thread in the embodiment, which is not listed here.

Optionally, the specific handedness relationship of a pair of oppositely handed thread configurations includes at least one of:

Aiming at the thread structure, the thread structure is in a thread sleeve type:

The main shaft 5 rotates clockwise, and the rotation direction of the spiral structure close to the sealed side is left-handed; the rotation direction of the thread structure close to the atmosphere end is right;

the main shaft 5 rotates anticlockwise, and the rotating direction of the spiral structure close to the sealed side is right-handed; the screwing direction of the thread structure close to the atmosphere end is left-handed;

the screw thread structure is suitable for screw type:

The main shaft 5 rotates clockwise, and the rotating direction of the spiral structure close to the sealed side is right rotating; the screwing direction of the thread structure close to the atmosphere end is left-handed;

The main shaft 5 rotates anticlockwise, and the rotation direction of the spiral structure close to the sealed side is left-handed; the rotation direction of the thread structure close to the atmosphere end is right;

a gap area exists between the shaft sleeve 4 and the main shaft 5; and is positioned in the gap area, and the inner side wall of the shaft sleeve 4 close to the main shaft 5 is provided with a sealing ring mounting groove along the circumferential direction; and the sealing ring 6 is arranged in the sealing ring mounting groove.

Optionally, the number of seal rings and the associated mounting grooves is determined by the size of the particular bearing housing.

it should be noted that the number of the seal rings should be 1 or more.

in order to facilitate the understanding of the present solution by those skilled in the art, the following describes the assembly process and the operation principle of the spiral magnetic fluid seal provided by the embodiment of the present invention with reference to fig. 1, fig. 2 and fig. 3.

as shown in figure 1, an oil-gas medium is arranged in a cavity on the left side of the shaft sleeve 4, and an air medium is arranged on the right side of the shaft sleeve 4.

during actual assembly, an operator firstly sleeves the shaft sleeve 4 with the sealing ring, the shaft sleeve 4 is close to the end face of the side of the sealed medium and contacts with the end face of the side, close to the atmosphere, of the inner ring of the bearing 8, and the shaft sleeve 4 is fixed through the fastener 10, then the permanent magnet 72 is clamped in the first permanent magnet clamping groove formed in the magnetic conductor 71 and the second permanent magnet clamping groove formed in the magnetic conductor 73, the integral component 7 formed by connecting the three components is sleeved in the inner circular hole formed in the bearing box shell and used for installing the bearing 8, and finally the integral component 7 is fixed through the gland 1 and the sealing ring 3.

The selected magnetic fluid is dropped by a dropper into the gap region between the integrated unit of the magnetic conductor 71, the permanent magnet 72 and the magnetic conductor 73 and the sleeve 4 in the embodiment. In addition, before assembly, a part of magnetic fluid liquid can be pre-added into magnetic conduction pole tooth grooves formed in the magnetic conductors 71 and 73.

After all parts of the spiral magnetic fluid seal are assembled, when the main shaft 5 is in a static state, 6 magnetic fluid sealing rings are formed between the magnetic guide pole teeth on the magnetic conductors 71 and 73 and the shaft sleeve 4 by the magnetic fluid, and oil-gas media are sealed; (in conjunction with fig. 3) when the main shaft 5 is in a rotating state, the magnetic fluid medium is conveyed to the middle part of the sealing gap to form a high-pressure liquid region under the combined action of the main shaft 5, the magnetic conductor 71 and the forward and reverse thread structures contained in the magnetic conductor 73, so as to realize sealing; meanwhile, the magnetic fluid still can form a magnetic fluid sealing ring between the magnetic conductive teeth included on the magnetic conductors 71 and 73 and the shaft sleeve 4, so that the sealing effect on oil-gas media is ensured and improved. It should be noted that, during the sealing process, the magnetic fluid sealing ring may deform, perforate, or even break under the action of pressure, resulting in loss of the magnetic fluid. The reverse thread structure with longer thread length arranged at the end close to the atmosphere can convey the magnetic fluid to the reverse direction of leakage, so that the loss of the magnetic fluid is reduced.

In conclusion, in the embodiment of the invention, the spiral sealing principle and elements are integrated with the magnetic fluid sealing principle and elements, so that a better sealing method is provided for the bearing box adopting two-phase lubrication, namely, the good sealing effect on oil and gas media can be ensured in the operation and shutdown stages of equipment, and the loss of the magnetic fluid in the sealing operation is effectively reduced based on the characteristics of the sealing structure.

The embodiment of the invention also provides mechanical equipment which comprises the spiral magnetic fluid sealing structure for the oil-gas two-phase lubricating bearing box. The specific implementation process of the sealing structure may refer to the above description, and the embodiment of the present invention is not limited in any way.

Because the sealing structure has the technical effects, the mechanical equipment comprising the sealing structure also has corresponding technical effects, and the description is omitted.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.