CN112065997A - Spring absorption vibration type rigidity-adjustable hole type damping seal - Google Patents

Abstract

A spring absorption vibration type rigidity-adjustable hole type damping seal comprises a sealing lining and a sealing shell which are sleeved from inside to outside, wherein a plurality of bolt-spring rigidity adjusting structures are arranged between the sealing lining and the sealing shell; bolt holes are uniformly distributed in the wall surface of the sealing shell, regular damping holes are uniformly distributed in the inner wall surface of the sealing lining, and cylindrical pins which correspond to the bolt holes one by one are arranged on the outer wall surface of the sealing lining; the bolt-spring stiffness adjusting structure comprises a bolt and a spring, the bolt is installed in a bolt hole of the sealing shell, and the tail end of the bolt does not extend out of the sealing shell; the tail end of the spring is sleeved on the cylindrical pin of the sealing lining, and the head end of the spring extends into the bolt hole to be abutted against the tail end of the bolt. The invention has better dynamic response capability, shock and vibration resistance capability, longer service life and the like.

Description

A spring-absorbing shock-absorbing adjustable-stiffness hole-type damping seal

technical field

The invention relates to the technical field of rotary turbine mechanical seals, in particular to a spring-absorbing vibration-type adjustable stiffness hole-type damping seal.

Background technique

Labyrinth seal, also known as comb seal, is a non-contact cylindrical seal. Mainly used to seal gas medium or steam, widely used in interstage seal, shaft end seal and blade tip seal in steam turbine, gas turbine, centrifugal compressor, blower and other machines, or the front seal of other dynamic seals. The labyrinth seal has a simple structure and low cost, and its leakage is proportional to the size of the throttling gap. At present, the rotating machinery is developing in the direction of high working condition parameters, which is accompanied by the phenomenon that the rotating machinery will be disturbed by various factors during the operation process and will vibrate greatly. Therefore, the sealing teeth of the labyrinth seal are more prone to wear and lodging, which brings great hidden danger to the safe operation of the unit.

For example, in the process of starting and stopping the rotation, when the rotating machine passes the critical speed, the deflection of the rotating shaft is serious, and the vibration of the unit will increase sharply, so the labyrinth seal or honeycomb seal will rub or even collide with the rotating shaft, resulting in the throttle teeth. The gap becomes larger, and the labyrinth seal may even lose its sealing effect due to excessive wear of the labyrinth seal teeth. In addition, the traditional honeycomb seal is made of nickel-based alloy. If the clearance is too small and the vibration of the rotating shaft is too large, sparks will be generated when the seal body collides with the rotating shaft, which affects the safety of the unit, especially the unit that transports flammable, explosive and toxic media. At present, aluminum cell damping seals have been widely studied as an excellent substitute for steel honeycomb seals. Since the aluminum alloy material of the hole type damping seal is soft, it is not easy to generate sparks when it touches the rotating shaft, but it is more likely to cause wear, which will lead to the loss of sealing properties of the sealing components. In order to avoid or reduce the possibility of the above problems, the traditional method is to enlarge the safety margin of the sealing gap in the design stage of the honeycomb seal. The leakage of the unit increases by 20%, and the inter-stage efficiency decreases by 1%, which will lead to a great waste of energy during the operation of the equipment, which is inconsistent with the current basic national policy of energy conservation and emission reduction called by the state, and makes the production efficiency of the enterprise low.

In response to the above problems, relevant scholars have proposed the concept of a cylindrical seal that can adaptively adjust the stiffness and damping of the sealing structure according to the degree of yaw vibration of the rotating shaft, and mainly use corrugated foils, airbags, springs, etc. as elastic elements to control the stiffness of the sealing structure. Damping, although the above elastic elements can achieve the function of regulating the sealing structure to a certain extent, but due to the limited compensation ability of the pure elastic elements, when the vibration of the unit is severe, the elastic elements are deformed greatly, and irreversible plastic compression will often occur, so that the The elastic element fails. For example, simply using a spring as the elastic element often requires not only multiple springs to form a spring group to control the gap, but also the deformation of the spring group is often inconsistent with the prolongation of use time, resulting in an inclined gap between the sealing component and the rotating shaft after adjustment. Or skewed like patent CN 107559199 A. Secondly, since the yaw direction and frequency of the rotating shaft often vary in the whole cycle of the unit operation, the stiffness and damping of the required sealing device should also be adjusted according to different working conditions.

SUMMARY OF THE INVENTION

In order to overcome the above problems, the present invention provides a spring-absorbing shock-absorbing adjustable stiffness hole-type damping seal with excellent dynamic characteristics and strong adaptability.

The technical scheme adopted in the present invention is: a spring-absorbing vibration type adjustable stiffness hole-type damping seal, comprising a sealing inner liner and a sealing outer shell which are fitted from the inside to the outside, and a plurality of bolts are arranged between the sealing inner lining and the sealing outer shell. The spring adjusts the stiffness structure; the sealing lining and the sealing shell are cylindrical and the axis line is on the same straight line, the side close to the axis line is the inner side, and the opposite is the outer side;

Bolt holes are evenly distributed on the wall surface of the sealing shell, and the bolt holes are countersunk holes that penetrate the sealing shell; regular damping holes are evenly distributed on the inner wall surface of the sealing lining, and the damping holes do not penetrate the sealing lining, and the sealing The outer wall surface of the inner lining is provided with cylindrical pins corresponding to the bolt holes one-to-one;

The bolt-spring adjusting stiffness structure includes a bolt and a spring, the bolt is installed in the bolt hole of the sealing shell, and the tail end of the bolt does not extend out of the sealing shell; the tail end of the spring is sleeved on the cylindrical pin of the sealing liner, and the spring The head end of the bolt extends into the bolt hole and abuts against the tail end of the bolt; the axis lines of the cylindrical pin, the spring and the bolt are collinear, and are located in the radial direction of the sealing lining and the sealing shell.

One end of the sealing shell is opened and an annular edge extends inward, and the other end of the sealing shell is provided with an annular shell end cover; both ends of the sealing lining are respectively provided with a circle of positioning steps, and the two positioning steps are respectively connected with the shell The end cap and the edge are matched for positioning.

Further, a first annular sealing groove is arranged on the edge of the sealing casing, and a first sealing gasket is placed in the first annular sealing groove; the inner wall of the casing end cover is provided with a first annular sealing groove on the side close to the sealing casing. Two annular sealing grooves are placed in the second annular sealing groove;

Further, 2-5 of the bolt-spring adjusting stiffness structures are arranged in the axial direction and 15-25 in the circumferential direction.

Further, the hole type of the damping hole is a hexagonal hole, a circular hole, a triangular hole or an elongated hole.

The beneficial effects of the present invention are:

(1) This structure can adaptively adjust the stiffness and damping of each part of the sealing structure according to the change of working conditions, and because each screw-spring is set independently, each part of the sealing structure can be independently controlled and form stiffness and damping along the shaft. Compared with the non-uniform sealing structure in the radial and circumferential directions, the adaptive sealing structure with the traditional elastic element as a spring has better dynamic response, shock and vibration resistance and longer service life.

(2) Introduce the spring preloaded by the bolt as the spring element, so that when the individual springs produce plastic compression and lose their resilience, the bolt can be further compressed to enhance the compensation ability and prevent the sealing assembly from being inclined due to the inconsistency of the deformation degree of the spring group. or skewed seal gap. It can make the new cylindrical seal as a whole have the ability to adapt to the abnormal working conditions such as deflection, misalignment and instantaneous vibration of the rotating shaft, so as to maintain the excellent sealing effect and stability.

Description of drawings

FIG. 1 is a three-dimensional cross-sectional view of the present invention.

Figure 2 is a three-dimensional structural view of the sealing liner.

FIG. 3 is a three-dimensional structural diagram of the sealed enclosure.

Figure 4 is a schematic diagram of the cooperation between the bolt and the spring.

FIG. 5 is a three-dimensional structural diagram of the housing end cover.

Explanation of reference numerals: 1. Housing end cover; 1-1, End cover threaded hole; 1-2, Second annular sealing groove; 2. Bolt; 3. Sealing shell; 3-1, Bolt hole; , the threaded hole of the sealing shell; 3-3, the first annular sealing groove; 4, the spring; 5, the sealing lining; 5-1, the cylindrical pin; 5-2, the positioning step; 5-3, the damping hole; 6, The first sealing gasket; 7. The second sealing gasket.

Detailed ways

The technical solutions of the patent of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that when the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" appear. The orientation or positional relationship indicated by ” and the like is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, a specific orientation, and a specific orientation. The orientation configuration and operation of the device should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," and "third," as they appear, are for descriptive purposes only and should not be construed to indicate or imply relative importance.

In the description of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a Removable connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

Referring to the accompanying drawings, a spring-absorbing shock-absorbing adjustable stiffness hole-type damping seal is characterized in that: it includes a sealing liner 5 and a sealing outer shell 3 that are fitted from the inside to the outside, and the sealing liner 5 and the sealing outer shell 3 are along the axis along the axis. Arrange 2 to 5 bolts-springs to adjust the stiffness structure in the circumferential direction, and arrange 15 to 25 bolts-springs to adjust the stiffness structure in the circumferential direction; the sealing lining 5 and the sealing shell 3 are cylindrical and the axis lines are on the same straight line , with the side close to the axis as the inner side, and the opposite side as the outer side;

Bolt holes 3-1 are evenly distributed on the wall surface of the sealing shell 3, and the bolt holes 3-1 are countersunk holes penetrating the sealing shell 3; regular damping holes 5 are evenly distributed on the inner wall surface of the sealing lining 5 -3, the hole type of the damping hole 5-3 is a hexagonal hole, a circular hole, a triangular hole or an elongated hole, the damping hole 5-3 does not penetrate the sealing lining 5, and the outer wall surface of the sealing lining 5 is provided with Bolt holes 3-1 correspond one-to-one with cylindrical pins 5-1;

The bolt-spring adjusting stiffness structure includes a bolt 2 and a spring 4, the bolt 2 is installed in the bolt hole 3-1 of the sealing casing 3, and the tail end of the bolt 2 does not extend out of the sealing casing 3; the tail end of the spring 4 is sleeved On the cylindrical pin 5-1 of the sealing liner 5, the head end of the spring 4 extends into the bolt hole 3-1 and abuts against the tail end of the bolt 2; the axis lines of the cylindrical pin 5-1, the spring 4 and the bolt 2 Colinear, and located in the radial direction of the sealing liner 5 and the sealing shell 3.

One end of the sealing shell 3 is opened with an annular edge extending inward, and the other end of the sealing shell 3 is provided with an annular shell end cover 1; The two positioning steps 5-2 are positioned in cooperation with the housing end cover 1 and the edge, respectively. A first annular sealing groove 3-3 is arranged on the edge of the sealing casing 3, and a first sealing gasket 6 is placed in the first annular sealing groove; the inner wall of the casing end cover 1 is on the side close to the sealing casing 3 A second annular sealing groove 1-2 is provided, and a second sealing gasket 7 is placed in the second annular sealing groove 1-2; the mounting surface of the casing end cover 1 for assembling with the sealing casing 3 is uniformly distributed along the circumferential direction. The cover threaded hole 1-1, the sealing shell 3 is provided with a sealing shell threaded hole 3-2 corresponding to the end cover threaded hole 1-1 one-to-one, the shell end cover 1 and the sealing shell 3 are connected by bolts, and the first sealing The gasket 6 and the second sealing gasket 7 are compressed.

The invention is essentially a cartridge type cylindrical seal, which can be pushed into the shaft end sealing position along the rotating shaft or the shaft sleeve of the turbine unit after being assembled externally, and then fixed on the stator part of the turbine machine. The bolt-spring adjustment stiffness structure is introduced. The head end of the bolt is fixed in the countersunk head hole on the sealing shell. The tail end of the bolt does not exceed the height of the countersunk head hole. On the cylindrical pin on the outer surface of the sealing liner, the cylindrical pin provides a guiding and positioning function for the spring at this time, preventing the spring from twisting and jumping when the sealing liner vibrates. Both ends of the sealing liner are turned with a positioning step with a small outer diameter to prevent the displacement of the sealing liner from being too large when the shaft vibrates violently. The synergy of the two parts of the structure can easily and quickly adjust the radial elastic force of the new type of cylindrical seal of the unit under different working conditions, and adjust the bolt to compensate for the deformation when the spring deformation is too large, and then adjust the sealing gap. shape to prevent skew, misalignment gaps.

When the vibration is large and the working conditions are bad, the bolts are loosened so that the spring preload is reduced, the rigidity of the sealing structure is reduced, and the damping is increased. At the same time, the followability of the sealing lining and the rotating shaft is enhanced, the spring automatically returns to its original state after the vibration condition ends, and the sealing gap returns to parallel. On the contrary, when the unit is running stably, the required sealing structure has high rigidity and small damping, and the stability of the sealing lining can be increased after pressing the bolts. At the same time, when the rotating shaft vibrates or yaw regularly, the tightness of the circumferential or axial bolts can be adjusted, and the sealing structure can be formed into a sealing structure with uneven axial or circumferential stiffness damping and adapting to the vibration.

The content described in the embodiments of the present specification is only an enumeration of the realization forms of the inventive concept, and the protection scope of the present invention should not be regarded as limited to the specific forms stated in the embodiments, and the protection scope of the present invention also extends to those skilled in the art. Equivalent technical means that can be conceived by a person based on the inventive concept.

Claims (4)

1. A spring-absorbing shock-type adjustable stiffness hole-type damping seal is characterized in that: comprising a sealing lining (5) and a sealing outer shell (3) that are fitted from the inside to the outside, the sealing inner lining (5) and the sealing outer shell ( 3) There are multiple bolt-spring adjusting stiffness structures between; the sealing lining (5) and the sealing outer shell (3) are cylindrical and the axis lines are on the same straight line, so as to be close to one side of the axis line for the inside, and vice versa for the outside; Bolt holes (3-1) are evenly distributed on the wall surface of the sealing casing (3), and the bolt holes (3-1) are countersunk holes penetrating the sealing casing (3); Regular damping holes (5-3) are evenly distributed on the wall surface, the damping holes (5-3) do not penetrate the sealing lining (5), and the outer wall surface of the sealing lining (5) is provided with bolt holes (3-1) One-to-one corresponding cylindrical pins (5-1); The bolt-spring adjusting stiffness structure comprises a bolt (2) and a spring (4), the bolt (2) is installed in the bolt hole (3-1) of the sealing housing (3), and the tail end of the bolt (2) is not extended out of the sealing shell (3); the tail end of the spring (4) is sleeved on the cylindrical pin (5-1) of the sealing liner (5), and the head end of the spring (4) extends into the bolt hole (3-1) Abutting with the tail end of the bolt (2); the axis of the cylindrical pin (5-1), the spring (4) and the bolt (2) are collinear, and are located between the sealing lining (5) and the sealing shell (3) radial. One end of the sealing shell (3) is opened with an annular edge extending inward, and the other end of the sealing shell (3) is provided with an annular shell end cover (1); both ends of the sealing lining (5) are respectively provided with There is a circle of positioning steps (5-2), and the two positioning steps (5-2) are respectively positioned in cooperation with the housing end cover (1) and the edge. 2. A spring-absorbing shock-absorbing adjustable stiffness hole-type damping seal according to claim 1, wherein a first annular sealing groove (3-3) is provided on the edge of the sealing shell (3) , a first sealing gasket (6) is placed in the first annular sealing groove; the inner wall ring of the casing end cover (1) is provided with a second annular sealing groove (1- 2), a second sealing gasket (7) is placed in the second annular sealing groove (1-2); the casing end cover (1) is connected with the sealing casing (3) by fasteners, and the first sealing gasket is The sheet (6) and the second sealing gasket (7) are pressed tightly. 3. A spring-absorbing vibration type adjustable stiffness hole-type damping seal according to claim 1, characterized in that: the bolt-spring adjustable stiffness structures are arranged 2-5 in the axial direction, and 15-5 in the circumferential direction. 25. 4. A spring-absorbing vibration-type adjustable stiffness hole-type damping seal according to claim 1, wherein the hole-type of the damping hole (5-3) is a hexagonal hole, a circular hole, and a triangular hole or elongated holes.

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