CN116717596A - Air mechanical seal structure for spindle - Google Patents

Abstract

The application discloses an air mechanical seal structure for a main shaft, which is positioned between a gear box end and a medium conveying end and comprises a mechanical seal movable ring seat and a mechanical seal static ring seat which are sleeved on the main shaft, wherein the mechanical seal static ring seat is sleeved outside the mechanical seal movable ring seat and forms a containing cavity with the mechanical seal movable ring seat; the sealing cavity is sleeved outside the mechanical seal static ring seat, a slotted hole and a containing cavity which are processed on the mechanical seal static ring seat are separated by a sealing ring, and the slotted hole is communicated with an air separating cavity of the sealing cavity. The dynamic sealing pair is inlaid on the metal sealing movable ring, the metal dissipates heat quickly, the static sealing pair is provided with a heat dissipation groove, heat generated by friction of the sealing pair is taken away by a medium in the accommodating cavity, and the elastic O-shaped ring plays a role in heat insulation.

Description

Air mechanical seal structure for spindle

Technical Field

The application relates to the technical field of improved design of a main shaft sealing heat dissipation structure, in particular to an air mechanical seal structure for a main shaft.

Background

Various conveying pumps or mixers are required to be provided with shaft sealing devices, such as a rotor pump for conveying fluid materials, the mechanical shaft sealing devices are rotating pairs which are formed by mutually clinging the end faces of a movable ring which moves along with a rotating shaft and a static ring which is relatively static by utilizing a compression spring, and peripheral gaps are sealed by sealing rings. When the rotating shaft works, the rotating ring and the static ring are rubbed, the mechanical sealing parts comprising the rotating ring, the static ring and the sealing ring are required to bear heating abrasion, and the heat dissipation mode of the rotating pair is usually to dissipate heat by using a conveyed medium. The existing mechanical seal is free of grooves on the seal pair, is not embedded on the metal movable ring, is small in contact area between the seal pair and a medium, and mainly dissipates heat by normal-temperature medium oil in a seal cavity.

In the prior art, the patent with publication number CN103746493B discloses a main shaft sealing device for an ORC high-speed turbine-generator, comprising a high-speed turbine expander, a high-speed generator, a fastening bolt, a high-speed shaft seal and an air sealing and cooling system; the high-speed shaft seal is arranged on a main shaft at one side of the back of the impeller of the high-speed turboexpander, and leakage of organic working medium steam is reduced by utilizing contact seal; the core of the air sealing and cooling system is that a high-pressure air chamber is established at the back side of the high-speed shaft seal, and the pressure of the high-pressure air chamber is regulated by a pressure relief valve; the air pressure of the high-pressure air chamber provides back pressure for the high-speed shaft seal, and has the function of gas sealing; the air flowing in the high-pressure air chamber can cool the high-speed shaft seal and can also take away the trace leakage quantity at the high-speed shaft seal; the application can solve the problems of high-speed generator thermal safety, overlarge wind mill loss and the like caused by main shaft air leakage.

In the technical scheme, the high-pressure air chamber is formed by the back surface of the high-speed shaft seal, the outer rotating surface of the main shaft and the annular cavity formed between the inner rotating surfaces of the end covers, the air pressure of the high-pressure air chamber provides back pressure for the high-speed shaft seal, the high-pressure air chamber has a gas sealing function, and the air flowing in the high-pressure air chamber can cool the high-speed shaft seal and can also take away trace leakage quantity at the high-speed shaft seal. Because of the need to use an external high-pressure air pump device to provide a high-pressure air source for the air sealing and cooling system, the application scenarios are limited for the host configuration of various delivery pumps or mixers.

The application provides an air mechanical seal structure for a spindle in order to solve one of the problems.

Disclosure of Invention

The application aims to solve the problems in the prior art, and provides an air mechanical seal structure for a main shaft, which is characterized in that a dynamic seal pair is inlaid on a metal seal movable ring, the metal heat dissipation is fast, a heat dissipation groove is formed in a static seal pair, heat generated by friction of the seal pair is taken away by a medium in a containing cavity, the friction heat of the seal pair is effectively blocked by an elastic O-shaped ring, and the whole service life of the elastic O-shaped ring is prolonged.

In order to achieve the above purpose, the present application adopts the following technical scheme: the air mechanical seal structure is positioned on the main shaft between a gear box end and a medium conveying end, and comprises a mechanical seal movable ring seat and a mechanical seal static ring seat which are sleeved on the main shaft, wherein the mechanical seal static ring seat is sleeved outside the mechanical seal movable ring seat and forms a containing cavity with the mechanical seal movable ring seat, a static seal pair, a dynamic seal pair and a sealing ring are arranged in the containing cavity, the containing cavity is communicated with the medium conveying end, the sealing ring is clamped on the static seal pair or the dynamic seal pair, the static seal pair and the dynamic seal pair are in surface contact, and the dynamic seal pair is arranged on the mechanical seal movable ring seat; the sealing cavity is sleeved outside the mechanical sealing static ring seat, a slotted hole and a containing cavity which are processed on the mechanical sealing static ring seat are separated by a sealing ring, and the slotted hole is communicated with an air separating cavity of the sealing cavity.

Further, the mechanical seal movable ring seat is a first mechanical seal movable ring seat, an annular groove is axially machined on the first mechanical seal movable ring seat so as to be embedded with a first dynamic seal pair, the mechanical seal static ring seat is a first mechanical seal static ring seat, the end part of the first mechanical seal static ring seat is lapped on the first mechanical seal movable ring seat, and the lap joint part of the end parts of the first mechanical seal movable ring seat and the first mechanical seal static ring seat is communicated with a slotted hole on the first mechanical seal static ring seat.

Further, the first static sealing pair is sleeved outside the first mechanical sealing ring seat, and a first elastic O-shaped ring is arranged between the first static sealing pair and the first mechanical sealing static ring seat.

Further, the mechanical seal static ring seat comprises two second mechanical seal static ring seats respectively embedded with a second static seal pair, and the mechanical seal ring seat comprises a second mechanical seal ring seat and a third mechanical seal ring seat sleeved on the second mechanical seal ring seat.

Further, the second mechanical seal moving ring seat and the third mechanical seal moving ring seat are respectively provided with annular grooves in the axial direction to accommodate two second dynamic seal pairs and two second elastic O-shaped rings, and the second elastic O-shaped rings are positioned outside the second dynamic seal pairs.

Further, the mechanical seal moving ring seat comprises a fourth mechanical seal moving ring seat and a fifth mechanical seal moving ring seat which are respectively embedded with a third dynamic seal pair, and the fifth mechanical seal moving ring seat is sleeved on the fourth mechanical seal moving ring seat; the machine seal static ring seat is a third machine seal static ring seat which is sleeved on the fourth machine seal dynamic ring seat and the fifth machine seal dynamic ring seat at the same time.

Further, a third static sealing pair and a third elastic O-shaped ring are sleeved on the fourth mechanical seal moving ring seat, the third elastic O-shaped ring is located between the fourth mechanical seal moving ring seat and the third mechanical seal static ring seat, and a gap is reserved between the two third static sealing pairs and is communicated with a slotted hole machined in the third mechanical seal static ring seat.

Further, the mechanical seal moving ring seat comprises a sixth mechanical seal moving ring seat which is embedded with two fourth dynamic seal pairs, and the mechanical seal stationary ring seat is a fourth mechanical seal stationary ring seat which is sleeved on the sixth mechanical seal moving ring seat at the same time.

Further, as described above, two annular grooves are machined in the axial direction of the sixth mechanical seal ring seat so as to embed a fourth dynamic seal pair, the fourth dynamic seal pair surface contacts a fourth static seal pair, and the fourth static seal pair is sleeved on the sixth mechanical seal ring seat and a fourth elastic O-ring is arranged between the fourth static seal ring seat and the fourth mechanical seal ring seat.

Further, the dynamic sealing pair and the static sealing pair are in partial surface contact, a radiating groove is processed on the part of the static sealing pair, which is positioned in the accommodating cavity, the mechanical sealing ring seat is made of metal, and a framework seal is arranged at the end part of the mechanical sealing static ring seat, which is close to the end of the gear box.

Compared with the prior art, the application has the beneficial effects that: the device inlays the dynamic seal pair on the metal seal movable ring, the metal dissipates heat fast, the heat that the friction of seal pair produced is very fast effective to be transmitted away, open on the static seal pair has the heat dissipation groove and takes away the heat that the friction of seal pair produced through holding intracavity medium, elasticity O type circle separates holding chamber and air and cuts off the chamber, the normal atmospheric temperature medium has taken most seal pair friction heat, the effectual seal pair friction heat that has blocked, in this way, then need not refuel in the sealed chamber and dispel the heat, can rely on the air to dispel the heat, can also avoid improving the leak problem that the refuel in the sealed intracavity before the improvement appears, can not pollute the medium that holds the intracavity, elasticity O type circle has prolonged whole life.

Drawings

FIG. 1 is a top view of an embodiment of the present application;

FIG. 2 is a cross-sectional view taken along the direction A-A in FIG. 1;

FIG. 3 is a side view of a second embodiment of the present application;

FIG. 4 is a sectional view taken in the direction B-B in FIG. 3;

FIG. 5 is a third side view of an embodiment of the present application;

FIG. 6 is a cross-sectional view taken in the direction C-C of FIG. 5;

FIG. 7 is a top view of a fourth embodiment of the present application;

fig. 8 is a sectional view in the direction D-D of fig. 5.

In the figure: 1. a main shaft; 2. a first mechanically sealed stationary ring seat; 3. a second mechanically sealed stationary ring seat; 41. a first dynamic seal pair; 42. the second dynamic sealing pair; 43. a third dynamic seal pair; 44. a fourth dynamic seal pair; 5. the first mechanical seal ring seat; 61. a first static seal pair; 62. the second static sealing pair; 63. a third static seal pair; 64. a fourth static seal pair; 71. a first elastic O-ring; 72. a second elastic O-ring; 73. a third elastic O-ring; 74. a fourth elastic O-ring; 8. an air blocking cavity; 9. sealing the cavity; 10. sealing a framework; 11. the second mechanical seal ring seat; 12. the third mechanical seal ring seat; 13. a fourth mechanical seal ring seat; 14. a fifth mechanical seal ring seat; 15. a third mechanical seal static ring seat; 16. a sixth mechanical seal ring seat; 17. and a fourth mechanical seal static ring seat.

Detailed Description

In the description of the present application, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of the present application and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "fixed," "mounted," "connected," "disposed," and the like are to be construed broadly, e.g., when an element is referred to as being "fixed" to another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "mounted" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements.

The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

Example 1

Referring to fig. 1 and 2, the air sealing structure for a spindle of the present application is located on a spindle 1 between a gear box end and a medium conveying end, and comprises a first sealing ring seat 5 and a first sealing static ring seat 2 which are sleeved on the spindle 1, wherein the first sealing static ring seat 2 is sleeved outside the first sealing ring seat 5 and forms a containing cavity with the first sealing ring seat 5, a first static sealing pair 61, a first dynamic sealing pair 41 and a first elastic O-ring 71 are installed in the containing cavity, the containing cavity is communicated with the medium conveying end, most of heat generated by friction of the sealing pair is taken away by the medium flowing in the conveying process, the first elastic O-ring 71 is clamped on the first static sealing pair 61, the first static sealing pair 61 and the first dynamic sealing pair 41 are in surface contact, and the first dynamic sealing pair 41 is fixed on the first sealing ring seat 5; the sealing cavity 9 is sleeved outside the first mechanical seal static ring seat 2, a slotted hole and a containing cavity which are processed on the first mechanical seal static ring seat 2 are separated by a first elastic O-shaped ring 71, heat generated by a friction pair is prevented from being transferred to the sealing cavity 9, and the slotted hole is communicated with an air separation cavity 8 of the sealing cavity 9.

Further, the first mechanical seal moving ring seat 5 and the first mechanical seal static ring seat 2 are designed in a step mode, an annular groove is machined in the axial direction of the first mechanical seal moving ring seat 5 so as to be embedded with the first dynamic seal pair 41, the end part of the first mechanical seal static ring seat 2 is lapped on the first mechanical seal moving ring seat 5, and the lap joint part of the end parts of the first mechanical seal moving ring seat 5 and the first mechanical seal static ring seat 2 is communicated with the groove hole on the first mechanical seal static ring seat 2.

Example two

Referring to fig. 3 and 4, an air seal structure for a main shaft is located on the main shaft 1 between a gear box end and a medium conveying end, and comprises a second seal moving ring seat 11, a third seal moving ring seat 12 and a second seal static ring seat 3 which are sleeved on the main shaft 1, wherein the third seal moving ring seat 12 is sleeved on the second seal moving ring seat 11, the second seal static ring seat 3 is sleeved outside the second seal moving ring seat 11 and the third seal moving ring seat 12, two accommodating cavities are formed between the second seal moving ring seat 3 and the third seal moving ring seat 12 and outside the second seal moving ring seat 11, a second static seal pair 62, a second dynamic seal pair 42 and a second elastic O-shaped ring 72 are installed in the accommodating cavities, one accommodating cavity is communicated with the medium conveying end, most of heat generated by friction of the medium flowing the seal pair in the conveying process is blocked on the second dynamic seal pair 42, the second static seal pair 62 and the second dynamic seal pair 42 are carried away, and the second static seal pair 62 is contacted with the second static seal moving pair 3; the slotted hole and the accommodating cavity processed on the second mechanical seal static ring seat 3 are separated by a second elastic O-shaped ring 72, and heat generated by the friction pair is prevented from being transferred to the slotted hole.

Further, the second mechanical seal ring seat 11 and the third mechanical seal ring seat 12 are respectively provided with annular grooves in the axial direction to accommodate two second dynamic seal pairs 42 and two second elastic O-rings 72, one second static seal pair 62 is embedded in a clamping groove on the second mechanical seal static ring seat 3, and the other second static seal pair 62 is clamped between the second mechanical seal static ring seat 3 and the second mechanical seal ring seat 11.

Example III

Referring to fig. 5 and 6, an air seal structure for a spindle is located on the spindle 1 between a gear box end and a medium conveying end, and comprises a fourth seal ring seat 13, a fifth seal ring seat 14 and a third seal static ring seat 15 which are sleeved on the spindle 1, wherein the fifth seal ring seat 14 is sleeved on the fourth seal ring seat 13, the third seal static ring seat 15 is sleeved outside the fourth seal ring seat 13 and the fifth seal ring seat 14 at the same time, two accommodating cavities are formed between the third seal static ring seat 15 and the outsides of the fifth seal ring seat 14 and the fourth seal ring seat 13, a third static seal pair 63, a third movable seal pair 43 and a third elastic O-shaped ring 73 are installed in the accommodating cavities, one accommodating cavity is communicated with the medium conveying end, most of heat generated by friction of the seal pair is taken away by the medium flowing in the conveying process, the third elastic O-shaped ring 73 is clamped on the third static seal pair 63, the third static seal pair 63 is contacted with the third movable seal pair 43, and the third movable seal pair 43 is contacted with the fourth movable seal ring seat 13; the slot hole and the accommodating cavity processed on the third mechanical seal static ring seat 15 are separated by a third elastic O-shaped ring 73, and heat generated by the friction pair is prevented from being transferred to the slot hole.

Further, a third dynamic sealing pair 43 is embedded in an axial annular groove at one end of the fourth mechanical seal moving ring seat 13, the other third dynamic sealing pair 43 is installed between the axial annular groove at one end of the fifth mechanical seal moving ring seat 14 and the fourth mechanical seal moving ring seat 13, and the fifth mechanical seal moving ring seat 14 is sleeved on the fourth mechanical seal moving ring seat 13. In addition, a third static sealing pair 63 and a third elastic O-ring 73 are sleeved on the fourth mechanical seal ring seat 13, the third elastic O-ring 73 is located between the fourth mechanical seal ring seat 13 and the third mechanical seal static ring seat 15, and a space is reserved between the two third static sealing pairs 63 and is communicated with a slotted hole machined in the third mechanical seal static ring seat 15.

Example IV

Referring to fig. 7 and 8, an air seal structure for a spindle is located on the spindle 1 between a gear box end and a medium conveying end, and comprises a sixth mechanical seal movable ring seat 16 and a fourth mechanical seal static ring seat 17 sleeved on the spindle 1, wherein the fourth mechanical seal static ring seat 17 is sleeved outside the sixth mechanical seal movable ring seat 16 and forms a containing cavity with the sixth mechanical seal movable ring seat 16, a fourth static seal pair 64, a fourth movable seal pair 44 and a fourth elastic O-ring 74 are installed in the containing cavity, the containing cavity is communicated with the medium conveying end, most of heat generated by friction of the seal pair is taken away by the medium flowing in the conveying process, the fourth elastic O-ring 74 is clamped on the fourth static seal pair 64, and the fourth static seal pair 64 and the fourth movable seal pair 44 are in surface contact and are respectively arranged on the sixth mechanical seal movable ring seat 16; the slotted hole and the accommodating cavity processed on the fourth mechanical seal static ring seat 17 are separated by a fourth elastic O-shaped ring 74, and heat generated by the friction pair is prevented from being transferred to the sealing cavity 9.

Further, the sixth mechanical seal moving ring seat 16 is embedded with two fourth dynamic seal pairs 44 at the same time, specifically, two annular grooves are machined in the axial direction of the sixth mechanical seal moving ring seat 16 to embed the fourth dynamic seal pairs 44, the two axial annular grooves can be arranged opposite to each other or can be arranged reversely, the opening directions of the two axial annular grooves in fig. 8 are opposite, and the cross section of the sixth mechanical seal moving ring seat 16 is i-shaped.

In the above embodiment, the dynamic seal pair and the static seal pair are in partial surface contact, a heat dissipation groove is processed on the part of the static seal pair located in the accommodating cavity, the mechanical seal ring seat is made of metal, the sealing ring is an elastic O-shaped ring, and the end part of the mechanical seal static ring seat, which is close to the end of the gear box, is provided with the skeleton seal 10, so that lubricating oil in the gear box is prevented from leaking.

The traditional mechanical seal design, sealing pair is last not to have fluting, also not to inlay on the metal rotating ring, and sealing pair is little with the area of carrying medium contact, mainly is sealed the oil in the cavity 9 and dispel the heat, and sealed cavity 9 needs the supplementary sealed pair heat dissipation cooling of oiling promptly, has like this that the oil in the sealed cavity 9 leaks to the risk of medium delivery end, if the rotor pump draws water in the long-term work after oil leakage to the aquatic, influences quality of water. The improved dynamic sealing pair is inlaid on the metal sealing movable ring, the heat generated by friction of the sealing pair is quickly and effectively transferred out due to quick heat dissipation of metal, the other static sealing pair is provided with a heat dissipation groove, a medium flows into the groove to take away the heat generated by friction of the sealing pair, the elastic O-shaped ring separates the medium in the medium conveying end from the sealing cavity 9, and the elastic O-shaped ring effectively blocks friction heat of the sealing pair due to the fact that most of friction heat of the sealing pair is taken away by the medium at normal temperature, so that the service life is prolonged, and finally, the traditional sealing cavity 9 is filled with oil to dissipate heat.

The assembly and matching relation of all the components involved in the device are selected from the prior art or materials, and the technicians can directly purchase or order the components according to the required product types and specifications.

In the foregoing description, only the preferred embodiment of the present application is described, but the common general knowledge of the specific structure and characteristics of the present application is not described in any detail. It will be evident to those skilled in the art that the application is not limited to the details of the foregoing illustrative embodiments, and that the present application may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the present embodiments are to be considered in all respects as illustrative and not restrictive, and any equivalents and modifications thereof according to the technical scheme and the inventive concept thereof, which are within the scope of the present disclosure, are intended to be included in the scope of the present disclosure.

Claims (10)

1. The air mechanical seal structure is positioned on a main shaft (1) between a gear box end and a medium conveying end and is characterized by comprising a mechanical seal moving ring seat and a mechanical seal static ring seat which are sleeved on the main shaft (1), wherein the mechanical seal static ring seat is sleeved outside the mechanical seal moving ring seat and forms a containing cavity with the mechanical seal moving ring seat, a static seal pair, a dynamic seal pair and a sealing ring are arranged in the containing cavity, the containing cavity is communicated with the medium conveying end, the sealing ring is clamped on the static seal pair or the dynamic seal pair, the static seal pair and the dynamic seal pair are in surface contact, and the dynamic seal pair is arranged on the mechanical seal moving ring seat; the sealing cavity (9) is sleeved outside the mechanical sealing static ring seat, a slotted hole and a containing cavity which are processed on the mechanical sealing static ring seat are separated by a sealing ring, and the slotted hole is communicated with an air separating cavity (8) of the sealing cavity (9).

2. The air mechanical seal structure for the main shaft according to claim 1, wherein the mechanical seal moving ring seat is a first mechanical seal moving ring seat (5), an annular groove is machined in the axial direction of the first mechanical seal moving ring seat (5) to be embedded with a first dynamic seal pair (41), the mechanical seal stationary ring seat is a first mechanical seal stationary ring seat (2), the end part of the first mechanical seal stationary ring seat (2) is lapped on the first mechanical seal moving ring seat (5), and the lap joint of the end parts of the first mechanical seal moving ring seat (5) and the first mechanical seal stationary ring seat (2) is communicated with a slotted hole in the first mechanical seal stationary ring seat (2).

3. An air sealing structure for a spindle according to claim 2, wherein the first sealing ring seat (5) is sleeved with a first static sealing pair (61), and a first elastic O-ring (71) is arranged between the first static sealing pair (61) and the first sealing ring seat (2).

4. An air sealing structure for a main shaft according to claim 1, wherein the sealing stationary ring seat comprises two second sealing stationary ring seats (3) respectively embedded with a second stationary sealing pair (62), and the sealing ring seat comprises a second sealing ring seat (11) and a third sealing ring seat (12) sleeved on the second sealing ring seat (11).

5. An air sealing structure for a spindle according to claim 4, wherein the second sealing ring seat (11) and the third sealing ring seat (12) are respectively provided with annular grooves in the axial direction to accommodate two second dynamic sealing pairs (42) and two second elastic O-rings (72), and the second elastic O-rings (72) are located outside the second dynamic sealing pairs (42).

6. An air sealing structure for a main shaft according to claim 1, wherein the sealing moving ring seat comprises a fourth sealing moving ring seat (13) and a fifth sealing moving ring seat (14) which are respectively embedded with a third dynamic sealing pair (43), and the fifth sealing moving ring seat (14) is sleeved on the fourth sealing moving ring seat (13); the machine seal static ring seat is a third machine seal static ring seat (15) which is sleeved on the fourth machine seal ring seat (13) and the fifth machine seal ring seat (14) at the same time.

7. The air sealing structure for the spindle according to claim 6, wherein a third static sealing pair (63) and a third elastic O-ring (73) are sleeved on the fourth sealing ring seat (13), the third elastic O-ring (73) is located between the fourth sealing ring seat (13) and the third sealing static ring seat (15), and a space is reserved between the two third static sealing pairs (63) and is communicated with a slot hole machined in the third sealing static ring seat (15).

8. An air sealing structure for a spindle according to claim 1, wherein the sealing ring seat comprises a sixth sealing ring seat (16) embedded with two fourth dynamic sealing pairs (44), and the sealing stationary ring seat is a fourth sealing stationary ring seat (17) sleeved on the sixth sealing ring seat (16) at the same time.

9. An air sealing structure for a main shaft according to claim 8, characterized in that, two annular grooves are machined in the axial direction of the sixth sealing ring seat (16) to embed a fourth dynamic sealing pair (44), the fourth dynamic sealing pair (44) contacts with a fourth static sealing pair (64), the fourth static sealing pair (64) is sleeved on the sixth sealing ring seat (16) and a fourth elastic O-ring (74) is arranged between the fourth sealing ring seat (17).

10. An air sealing structure for a spindle according to any one of claims 1 to 9, wherein the dynamic sealing pair and the static sealing pair are in partial surface contact, a heat dissipation groove is formed in the portion, located in the accommodating cavity, of the static sealing pair, the sealing ring seat is made of metal, and a framework seal (10) is arranged at the end, close to the end of the gear box, of the sealing ring seat.