CN113606183A

CN113606183A - Mechanical seal for pump

Info

Publication number: CN113606183A
Application number: CN202110864152.6A
Authority: CN
Inventors: 王家昊
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-07-29
Filing date: 2021-07-29
Publication date: 2021-11-05

Abstract

The invention discloses a pump mechanical seal, which comprises a pump rod and a seal outer cover body, wherein the pump rod penetrates through the seal outer cover body, a fixed ring assembly and a movable ring assembly are sleeved on the pump rod in the seal outer cover body, a connecting gap between the pump rod and the seal outer cover body is sealed through the mutual matching of the fixed ring assembly and the movable ring assembly, the fluid leakage of a pump body impeller during fluid extraction is prevented, a left half pressure plate is pressed and attached on a convex block through the spring thrust of a jacking spring in the high-speed rotation process of the pump rod, so that a first seal is formed by jacking a seal ring IV, an elastic ring plug is outwards expanded under the centrifugal force of the pump rod through an expansion unit, and is outwards annularly attached on the inner wall of a seal casing to form a second seal, so that the fluid is prevented from leaking out through the gap, and then a third seal is formed by the first seal ring assembly, a second seal ring and a third seal ring through the first seal ring in the inner wall of the seal casing, and then guarantee the inseparable leakproofness of pump pole connection structure.

Description

Mechanical seal for pump

Technical Field

The invention belongs to the technical field related to mechanical seal, and particularly relates to a mechanical seal of a pump.

Background

The mechanical seal (mechanical seal) is a device for preventing fluid leakage, which is composed of at least one pair of end faces perpendicular to the rotation axis, and the end faces are kept in contact and relatively slide under the action of fluid pressure and the elastic force (or magnetic force) of a compensation mechanism and the matching of an auxiliary seal.

The elastic force loading mechanism and the auxiliary seal are mechanical seals of metal corrugated pipes, and the mechanical seals are called metal corrugated pipe seals. In light sealing, a rubber corrugated pipe is used as auxiliary sealing, the elasticity of the rubber corrugated pipe is limited, and a spring is generally required to be supplemented to meet the loading elasticity. "mechanical seal" is often referred to by one as "mechanical seal" for short.

The mechanical seal is a shaft seal device of a rotating machine. Such as centrifugal pumps, centrifuges, reaction kettles, compressors, and the like. Since the drive shaft extends through the inside and outside of the apparatus, there is a circumferential gap between the shaft and the apparatus through which the medium in the apparatus leaks out, and if the pressure in the apparatus is lower than atmospheric pressure, air leaks into the apparatus, so that a shaft seal device must be provided to prevent leakage. The shaft seal has many kinds, and the mechanical seal has the advantages of small leakage amount, long service life and the like, so the mechanical seal is the most important shaft sealing mode in the devices in the world.

The existing pump mechanical sealing technology has the following problems: traditional pump mechanical seal adopts rotating ring, quiet ring and spring as basic mechanical seal structure mostly, and in the use, rotating ring rampart and pump case lead to wearing and tearing comparatively seriously owing to press the effect of pasting, cause the service life of sealing washer shorter, influence the leakproofness, easily cause the condition of seepage, and in order not to influence sealed effect, need often change to cause certain inconvenience.

Disclosure of Invention

The invention aims to provide a pump mechanical seal to solve the problems of serious abrasion, easy leakage and frequent replacement in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: a pump mechanical seal comprises a pump rod and a seal outer cover body, wherein the pump rod penetrates through the seal outer cover body, a fixed ring assembly and a movable ring assembly are sleeved on the pump rod in the seal outer cover body, the fixed ring assembly and the movable ring assembly are provided with a jacking spring, one end of the jacking spring is fixedly connected with the fixed ring assembly, and the other end of the jacking spring abuts against the movable ring assembly;

the sealing outer cover body comprises a sealing sleeve shell and a sealing gland, the fixed ring assembly and the sealing gland are fixedly arranged at the right end of the sealing sleeve shell through screws, and a circle of sealing ring III is nested on the inner wall of the right end of the sealing sleeve shell;

the fixed ring assembly comprises a sealing fixed ring and a fixed barrel sleeve, the fixed barrel sleeve is sleeved in the sealing gland, the left end of the fixed barrel sleeve abuts against the sealing fixed ring, a circle of sealing ring I is nested on the inner wall of the left end of the fixed barrel sleeve, and a circle of sealing ring II is nested on the inner wall of the sealing fixed ring;

the rotating ring assembly comprises a left half pressure plate, a right half pressure plate and a rotating sleeve, the left half pressure plate and the right half pressure plate are symmetrically fixed on the outer wall of the rotating sleeve, a convex ring is arranged on the rotating sleeve between the left half pressure plate and the right half pressure plate, a plurality of expanding units and a plurality of elastic ring plugs are distributed on the outer wall of the convex ring at equal intervals, and the outer sides of the expanding units are provided with annular elastic ring plugs.

Preferably, the expanding unit comprises a guide pipe and a telescopic push rod, the telescopic push rod is slidably clamped in the guide pipe, the guide pipe is fixedly connected with the outer wall of the convex ring, one end of the outer side of the telescopic push rod is fixedly connected with a jacking push block, a pressing spring is wound outside the guide pipe, and two ends of the pressing spring are fixedly connected with the jacking push block and the convex ring respectively.

Preferably, a layer of lubricant is smeared on the inner walls of the sealing fixed ring and the fixed cylinder sleeve.

Preferably, the left half pressure plate and the right half pressure plate are axially overlapped with the pump rod.

Preferably, an annular convex block is arranged on the inner wall of the left end of the sealing sleeve shell, and a sealing ring IV is arranged between the left half pressure plate and the convex block.

Preferably, the outer end surface of the jacking and pushing block is an inward-concave smooth arc surface, and the arc surface of the jacking and pushing block is matched with the elastic ring plug in shape.

Preferably, the elastic ring plug is of a double-layer structure, the outer layer is a PTFE coating layer, and the inner layer is a silicon rubber inner core layer.

Compared with the prior pump mechanical seal technology, the invention provides a pump mechanical seal, which has the following beneficial effects:

1. according to the invention, through the mutual matching of the fixed ring assembly and the movable ring assembly, a connecting gap between the pump rod and the sealing outer cover body is sealed, fluid leakage of a pump body impeller during fluid extraction is prevented, the pump rod is enabled to press and attach the left half pressure plate on the bump through the spring thrust of the jacking spring in the high-speed rotation process, so that the sealing ring IV is jacked, the pump rod and the sealing sleeve shell are sealed together, the expanding unit is subjected to the centrifugal force action of the pump rod and can be propped open outwards, the elastic ring plug is outwards annularly attached to the inner wall of the sealing sleeve shell under the action of the bracing force to form two seals, so that fluid is prevented from leaking out through the gap, and three seals are formed through the pressing and attaching of the sealing ring I, the sealing ring II and the sealing ring III in the inner wall of the sealing sleeve shell, so that the tightness of a connecting structure of the pump rod is ensured;

2. the elastic ring plug is of a double-layer structure, the outer layer is a PTFE coating layer, the inner layer is a silicon rubber inner core layer, so that the outer layer material has excellent wear resistance and a good sealing effect, and the elastic material of the inner layer enables the integral structure of the elastic ring plug to have certain elasticity and expand outwards under the supporting force of the jacking push block, so that the elastic ring plug can be pressed and sealed, and is good in sealing effect and long in service life.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention without limiting the invention in which:

FIG. 1 is a schematic view of a mechanical seal for a pump according to the present invention;

FIG. 2 is a schematic structural diagram of a rotating ring assembly according to the present invention;

FIG. 3 is a schematic side sectional view of a rotating ring assembly according to the present invention;

FIG. 4 is an enlarged schematic view of the structure at A in FIG. 1 according to the present invention;

in the figure: 1. a pump rod; 2. a rotating ring assembly; 3. a sealing housing; 4. the spring is tightly propped; 5. sealing and fixing the ring; 6. fixing the cylinder sleeve; 7. a first sealing ring; 8. a second sealing ring; 9. a sealing gland; 10. a third sealing ring; 11. an elastic ring plug; 12. a left half platen; 13. a right platen half; 14. rotating the sleeve; 15. a guide tube; 16. pressing the push block; 17. a telescopic push rod; 18. a pressing spring; 19. a convex ring; 20. and a sealing ring IV.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-4, the present invention provides a technical solution: a pump mechanical seal comprises a pump rod 1 and a seal outer cover body, wherein a fixed ring assembly and a movable ring assembly 2 are sleeved on the pump rod 1 in the seal outer cover body, a jacking spring 4 is arranged on the fixed ring assembly and the movable ring assembly 2, one end of the jacking spring 4 is fixedly connected with the fixed ring assembly, the other end of the jacking spring 4 abuts against the movable ring assembly 2, and the fixed ring assembly and the movable ring assembly 2 are mutually matched, so that a gap is sealed by the pump rod 1 in a high-speed rotation process, and fluid leakage of a pump body impeller during fluid extraction is prevented;

the sealing outer cover body comprises a sealing sleeve 3 and a sealing gland 9, a fixed ring assembly and the sealing gland 9 are fixedly arranged at the right end of the sealing sleeve 3 through screws, the fixed ring assembly is assembled on the sealing gland 9 through screws with two different specifications and is plugged into the sealing sleeve 3 for pressing and fixing, and a circle of sealing ring III 10 is nested on the inner wall of the right end of the sealing sleeve 3 to prevent fluid from leaking out from gaps among the fixed ring assembly, the sealing gland 9 and the sealing sleeve 3;

in addition, the fixed ring assembly comprises a sealing fixed ring 5 and a fixed barrel sleeve 6, the fixed barrel sleeve 6 is sleeved in a sealing gland 9, the left end of the fixed barrel sleeve 6 is abutted against the sealing fixed ring 5, the sealing fixed ring 5 and the fixed barrel sleeve 6 are fixedly assembled on the sealing gland 9 under the fastening of a screw, so that the sealing fixed ring 5 and the fixed barrel sleeve 6 are kept in a fixed state in the working process of the pump rod 1, the pump rod 1 cannot rotate along with the rotation of the pump rod 1, a circle of sealing ring I7 is nested on the inner wall of the left end of the fixed barrel sleeve 6, a circle of sealing ring II 8 is nested on the inner wall of the sealing fixed ring 5, the sealing effect of the contact surface of the right end of the pump rod 1 is achieved through the pressing and pasting effect of the sealing ring I7 and the sealing ring II 8, and the sealing effect is further improved;

in addition, the movable ring assembly 2 comprises a left half pressing plate 12, a right half pressing plate 13 and a rotating sleeve 14, the left half pressing plate 12 and the right half pressing plate 13 are symmetrically fixed on the outer wall of the rotating sleeve 14, the left half pressing plate 12 and the right half pressing plate 13 have the same structure and a certain distance in the middle, a convex ring 19 is arranged on the rotating sleeve 14 between the left half pressing plate 12 and the right half pressing plate 13, a plurality of expanding units are equidistantly distributed on the outer wall of the convex ring 19, annular elastic ring plugs 11 are arranged on the outer sides of the circumferences of the expanding units, when the pump rod 1 is in a normal working state, the expanding units are under the action of centrifugal force of the pump rod 1, the expanding units can be outwards expanded, the elastic ring plugs 11 are outwards attached to the inner wall of the sealing sleeve housing 3 in an annular mode under the action of supporting force, and fluid is prevented from leaking out through gaps.

Expanding unit between half 12 on the left side half 13 on the right side of pressure disk includes stand pipe 15 and telescopic push rod 17, telescopic push rod 17 slip joint is in stand pipe 15, stand pipe 15 and the outer wall fixed connection of bulge loop 19, telescopic push rod 17's outside one end fixedly connected with roof pressure ejector pad 16, make roof pressure ejector pad 16 can outwards expand under the exogenic action, and it has pressing spring 18 to twine in stand pipe 15's outside, pressing spring 18's both ends respectively with roof pressure ejector pad 16 and bulge loop 19 fixed connection, through the supplementary elasticity of pressing spring 18, make roof pressure ejector pad 16 push up elasticity ring stopper 11.

In order to reduce the friction loss between the fixed ring assembly and the pump rod 1, a layer of lubricant is smeared on the inner walls of the sealed fixed ring 5 and the fixed cylinder sleeve 6, so that the sealed fixed ring 5 and the fixed cylinder sleeve 6 can be slidably sleeved on the pump rod 1 in the installation process, and the friction between the pump rod 1 and the sealed fixed ring 5 and between the pump rod 1 and the fixed cylinder sleeve 6 is reduced, so that the sealed fixed ring 5 and the fixed cylinder sleeve 6 cannot synchronously rotate along with the rotation of the pump rod 1.

In order to enable the moving ring component 2 to be matched with the rotation of the pump rod 1 to form mechanical seal, the left half pressure plate 12 and the right half pressure plate 13 are axially overlapped with the pump rod 1, the rotating sleeve 14 is sleeved on the pump rod 1 in a sealing welding mode, and when the pump rod 1 rotates, the left half pressure plate 12 and the right half pressure plate 13 can be synchronously driven to rotate together, so that the mechanical seal for connecting the pump rod 1 and the sealing outer cover body is realized.

In order to cooperate the top force effect of the top tight spring 4, an annular convex block is arranged on the inner wall of the left end of the sealing sleeve shell 3, a sealing ring four 20 is arranged between the left half pressure plate 12 and the convex block, and when the pump rod 1 rotates, the spring thrust of the top tight spring 4 is used for pressing and pasting the left half pressure plate 12 on the convex block, so that the top tight sealing ring four 20 is used for sealing the pump rod 1 and the sealing sleeve shell 3 together.

In order to realize the annular expansion of the elastic ring plug 11, the outer end face of the jacking and pushing block 16 is designed to be an inward-concave smooth cambered surface, and the cambered surface of the jacking and pushing block 16 is matched with the shape of the elastic ring plug 11, so that the jacking and pushing block 16 props up the elastic ring plug 11 outwards in a natural state, and when the jacking and pushing block 16 is under the action of centrifugal force, the jacking and pushing block 16 can push the elastic ring plug 11 to expand outwards in an annular shape.

In order to improve the sealing effect, the elastic ring plug 11 is of a double-layer structure, the outer layer is a PTFE coating layer, the inner layer is a silicon rubber inner core layer, the outer layer material has excellent wear resistance and good sealing effect, and the elastic material of the inner layer enables the integral structure of the elastic ring plug 11 to have certain elasticity and can expand outwards under the supporting force action of the jacking and pushing block 16.

The working principle and the using process of the invention are as follows: the mechanical sealing mechanism adopted in the invention mainly comprises a fixed ring component and a movable ring component 2, wherein the fixed ring component is fixedly sleeved in a sealing outer cover body and is of a fixed structure, the movable ring component 2 is fixed on a pump rod 1 and is of a synchronous rotating structure, a connecting gap between the pump rod 1 and the sealing outer cover body is sealed through the mutual matching of the fixed ring component and the movable ring component 2, the fluid leakage of a pump body impeller during fluid extraction is prevented, a left half pressure plate 12 is pressed and attached on a convex block through the spring thrust of a jacking spring 4 in the high-speed rotating process of the pump rod 1, so that a sealing ring four 20 is jacked, the pump rod 1 and a sealing sleeve shell 3 form a seal, the expanding unit is subjected to the centrifugal force action of the pump rod 1 and can be outwards expanded, and an elastic ring plug 11 is outwards annularly attached on the inner wall of the sealing sleeve shell 3 under the action of the supporting force, form two sealings to prevent that fluid from going out through the gap seepage, the subsides of seal ring 7, two 8 of seal ring and three 10 of seal ring in rethread fixed ring subassembly and the 3 inner walls of sealed cover shell form three sealings, guarantee pump rod connection structure's inseparable leakproofness.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a pump mechanical seal, includes pump rod (1) and sealed outer lid, its characterized in that: the pump rod (1) penetrates through the outer sealing cover body, a fixed ring assembly and a movable ring assembly (2) are sleeved on the pump rod (1) inside the outer sealing cover body, a jacking spring (4) is arranged on the fixed ring assembly and the movable ring assembly (2), one end of the jacking spring (4) is fixedly connected with the fixed ring assembly, and the other end of the jacking spring (4) abuts against the movable ring assembly (2);

the sealing outer cover body comprises a sealing casing (3) and a sealing gland (9), the fixed ring assembly and the sealing gland (9) are fixedly installed at the right end of the sealing casing (3) through screws, and a circle of sealing ring III (10) is nested on the inner wall of the right end of the sealing casing (3);

the fixed ring assembly comprises a sealing fixed ring (5) and a fixed barrel sleeve (6), the fixed barrel sleeve (6) is sleeved in a sealing gland (9), the left end of the fixed barrel sleeve (6) abuts against the sealing fixed ring (5), a circle of sealing ring I (7) is nested on the inner wall of the left end of the fixed barrel sleeve (6), and a circle of sealing ring II (8) is nested on the inner wall of the sealing fixed ring (5);

the rotating ring assembly (2) comprises a left half pressing plate (12), a right half pressing plate (13) and a rotating sleeve (14), the left half pressing plate (12) and the right half pressing plate (13) are symmetrically fixed on the outer wall of the rotating sleeve (14), a convex ring (19) is arranged on the rotating sleeve (14) between the left half pressing plate (12) and the right half pressing plate (13), a plurality of expanding units are distributed on the outer wall of the convex ring (19) at equal intervals, and a plurality of elastic ring plugs (11) are arranged outside the circumference of the expanding units.

2. A pump mechanical seal according to claim 1, wherein: expand and prop the unit and include stand pipe (15) and flexible push rod (17), flexible push rod (17) slip joint in stand pipe (15), the outer wall fixed connection of stand pipe (15) and bulge loop (19), outside one end fixedly connected with roof pressure ejector pad (16) of flexible push rod (17), the outside winding of stand pipe (15) has pressing spring (18), the both ends of pressing spring (18) respectively with roof pressure ejector pad (16) and bulge loop (19) fixed connection.

3. A pump mechanical seal according to claim 1, wherein: and a layer of lubricant is smeared on the inner walls of the sealing fixed ring (5) and the fixed cylinder sleeve (6).

4. A pump mechanical seal according to claim 1, wherein: the left half pressure plate (12) and the right half pressure plate (13) are axially overlapped with the pump rod (1).

5. A pump mechanical seal according to claim 1, wherein: an annular convex block is arranged on the inner wall of the left end of the sealing sleeve shell (3), and a sealing ring four (20) is arranged between the left half pressure plate (12) and the convex block.

6. A pump mechanical seal according to claim 2, wherein: the outer end surface of the jacking and pushing block (16) is an inward-concave smooth cambered surface, and the cambered surface of the jacking and pushing block (16) is matched with the shape of the elastic ring plug (11).

7. A pump mechanical seal according to claim 1, wherein: the elastic ring plug (11) is of a double-layer structure, the outer layer is a PTFE coating layer, and the inner layer is a silicon rubber inner core layer.