A three-channel oil seal structure for a high-sealing centrifugal pump

Abstract

This utility model discloses a three-channel oil seal structure for a high-sealing centrifugal pump, including a rotating ring sleeved on the outer circumference of the pump shaft and a stationary ring installed in the inner bores of the upper and lower bearing chambers. Between the rotating and stationary rings, an oil-side labyrinth channel, an intermediate bypass channel, and a water-side labyrinth channel are formed sequentially. The oil-side labyrinth channel has a two-stage clearance structure. The intermediate bypass channel is equipped with an oil-side isolation groove, comb teeth, and an oil collection groove, and communicates with the vertical oil channel, horizontal oil channel, and external oil channel through an oil groove opening. The water-side labyrinth channel is equipped with a water-side baffle, an isolation groove, a water collection groove, and a water groove opening. This structure can classify and isolate and recover the lubricating oil in the bearing chamber, and isolate and guide the water outlet of the mechanical seal or labyrinth seal, reducing the risk of lubricating oil leakage and water ingress into the bearing chamber, and improving the sealing reliability of the centrifugal pump bearing chamber.

Description

Technical Field

[0001] This utility model relates to the technical field of oil seal structure for centrifugal pump bearing chambers, and more specifically to a three-channel oil seal structure for a high-sealing centrifugal pump. Background Technology

[0002] During the operation of a centrifugal pump, lubricating oil in the bearing housing lubricates and cools the sliding or rolling bearings. The bearing housing oil seal needs to prevent lubricating oil from leaking out of the bearing housing. However, in the event of mechanical seal failure or a decline in labyrinth seal performance, the pump medium may enter the bearing housing through the mechanical seal or labyrinth seal, causing the lubricating oil in the bearing housing to be diluted or emulsified, leading to increased bearing temperature and failure.

[0003] Existing centrifugal pump bearing housing oil seals mostly adopt a double-channel comb-tooth structure or a cartridge oil seal structure. Double-channel comb-tooth oil seals typically consist of moving and stationary parts, relying on a labyrinth clearance to prevent lubricating oil leakage. However, a large gap exists between the moving and stationary parts, making it difficult to fully isolate the lubricating oil, often resulting in dripping and seepage during actual use. Cartridge oil seals generally transmit torque through a clearance fit between the moving ring and the pump shaft, as well as one or two O-rings. Over long-term operation, O-rings are prone to deformation and aging, causing the moving ring and pump shaft to rotate asynchronously. This can lead to the formation of multiple annular grooves on the pump shaft surface, thus affecting the safe operation of the centrifugal pump.

[0004] Therefore, a novel centrifugal pump bearing chamber oil seal structure with reasonable structure is needed to improve the sealing performance of the bearing chamber lubricating oil, enhance the isolation effect of water from mechanical seals or labyrinth seals, reduce the risk of lubricating oil leakage and water ingress into the bearing chamber, and improve the long-term operational reliability of the centrifugal pump. Utility Model Content

[0005] The purpose of this invention is to provide a three-channel oil seal structure for a centrifugal pump with high sealing performance, so as to solve the problems of insufficient sealing performance of existing centrifugal pump bearing chamber oil seals and water leakage into the bearing chamber.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A three-channel oil seal structure for a high-sealing centrifugal pump includes a rotating ring and a stationary ring. The rotating ring is sleeved on the outer circumference of the pump shaft, and the stationary ring is installed in the inner holes of the upper and lower bearing chambers. The structure is characterized by: an oil-side labyrinth channel, an intermediate bypass channel, and a water-side labyrinth channel being formed sequentially between the rotating ring and the stationary ring; the oil-side labyrinth channel is an oil-side channel including a two-stage sealing structure; the intermediate bypass channel includes a rotating ring oil-side isolation groove, a stationary ring comb tooth, and an oil collecting groove, with an oil groove opening at the bottom of the oil collecting groove; the water-side labyrinth channel is formed by the radial gap between the rotating ring and the stationary ring water-side baffles, and communicates with the rotating ring water-side isolation groove, the stationary ring water collecting groove, and the water groove opening.

[0008] Preferably, in the two-stage sealing structure of the oil-side labyrinth channel, the first-stage sealing structure is a radial clearance fit between the moving ring oil-throwing baffle and the stationary ring sleeve, and the second-stage sealing structure is a radial clearance fit between the outer circle of the moving ring and the first stationary ring comb teeth.

[0009] Preferably, the oil-side isolation groove, stationary ring comb teeth, and oil collection groove in the intermediate bypass channel are arranged sequentially along the axial direction, and the oil-side isolation groove, stationary ring comb teeth, and oil collection groove are of one or more stages.

[0010] Preferably, the oil trough opening at the bottom of the oil collection trough forms a through trough, and together with the vertical oil channel, the horizontal oil channel and the external oil channel, forms an integral through channel.

[0011] Preferably, the water-side isolation trough, water collection trough, and water trough opening in the water-side maze channel are arranged centrally in the axial direction, and the water-side isolation trough and water collection trough are one or more locations.

[0012] Preferably, the inner groove of the rotating ring fits into the O-ring, the outer circle of the pump shaft fits into the O-ring, and multiple screws are provided on the rotating ring.

[0013] Preferably, the stationary ring is engaged with the pin hole of the upper bearing chamber via a locating pin.

[0014] Preferably, the stationary ring has a horizontal split structure, with the inner hole and outer circle of the stationary ring being complete circles, the upper half transitioning to the upper bearing chamber, and the lower half transitioning to the lower bearing chamber.

[0015] Compared with the prior art, this utility model sets up three independent channels in sequence between the dynamic ring and the stationary ring: an oil-side labyrinth channel, an intermediate bypass channel, and a water-side labyrinth channel. These channels provide graded isolation and diversion for the bearing chamber lubricating oil and the water outlet of the mechanical seal or labyrinth seal. The intermediate bypass channel works in conjunction with the through vertical oil channel, horizontal oil channel, and external oil channel to achieve centralized recovery of the lubricating oil in the bearing chamber, reducing the risk of lubricating oil leakage to the outside and entering non-target areas, and improving the sealing performance of the centrifugal pump bearing chamber.

[0016] The oil-side labyrinth channel employs a two-stage radial clearance structure, allowing lubricating oil from the radial bearing area to be depressurized and diverted step by step within the channel. The intermediate bypass channel, through a multi-stage arrangement of the moving ring oil-side isolation groove, stationary ring comb teeth, and oil collecting groove, ensures that residual lubricating oil is collected within the channel and discharged through the oil groove opening and the through-oil channel, reducing lubricating oil retention in the external area of ​​the bearing chamber. The water-side labyrinth channel, through the radial clearance between the moving ring and stationary ring water-side baffles, and the combination of the water-side isolation groove, water collecting groove, and water groove opening, intercepts and diverts any media that may enter from the mechanical seal or labyrinth seal side to the intermediate chamber and water collection device before entering the bearing chamber, thus reducing the possibility of water or other media entering the bearing chamber.

[0017] The inner groove of the rotating ring fits snugly against the O-ring, and the outer diameter of the pump shaft also fits snugly against the O-ring. Multiple recessed set screws further ensure a reliable seal and fixation between the rotating ring and the pump shaft, reducing slippage of the rotating ring relative to the pump shaft and contributing to the stability of the channel structure. The stationary ring engages with the pin hole in the upper bearing chamber via a locating pin, employing a horizontal split structure. This facilitates the positioning and assembly of the stationary ring within the upper and lower bearing chambers, as well as subsequent inspection and maintenance. Combined with the sealing fit between the stationary ring and the bearing chamber, this further reduces the risk of lubricating oil leakage from the bearing chamber, improving the long-term reliability of the centrifugal pump. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0019] Figure 1 This is a three-dimensional structural diagram of the three-channel oil seal structure of the high-sealing centrifugal pump of this utility model;

[0020] Figure 2 for Figure 1 The diagram shows a partial cross-sectional view of the three-channel oil seal structure of the high-sealing centrifugal pump.

[0021] In the diagram: 1-Upper bearing housing; 2-Concave end set screw; 3-Pump shaft; 4-Dynamic ring; 5-Static ring; 6-Lower bearing housing; 7-Radial bearing; 8-Locking pin; 9-O-ring; 10-Locking pin; 41-Dynamic ring oil slinger baffle; 42-Dynamic ring oil-side isolation groove; 43-Dynamic ring water-side isolation groove; 51-Static ring sleeve; 52-Static ring comb teeth; 53-Oil collection groove; 54-Oil groove opening; 55-Static ring water-side baffle; 56-Water collection groove; 57-Water groove opening; 61-Vertical oil channel; 62-Horizontal oil channel; 63-External oil channel; S1-Oil-side labyrinth channel; S2-Intermediate bypass channel; S3-Water-side labyrinth channel. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] Example

[0024] Reference Figure 1and Figure 2 This embodiment provides a three-channel oil seal structure for a high-sealing centrifugal pump. The oil seal structure mainly includes an upper bearing chamber 1, a pump shaft 3, a rotating ring 4, a stationary ring 5, a lower bearing chamber 6, and a locating pin 10 disposed between the upper bearing chamber 1 and the stationary ring 5. The rotating ring 4 is connected to the pump shaft 3 via a recessed set screw 2, forming a dynamic seal that rotates synchronously with the pump shaft 3 at the outer circumference of the pump shaft 3. The stationary ring 5 is installed in the inner holes of the upper bearing chamber 1 and the lower bearing chamber 6, serving as a relatively stationary seal. The rotating ring 4 and the stationary ring 5 constitute a sealing structure on the bearing chamber side.

[0025] A rotating ring 4 is fitted onto the outer circumference of the pump shaft 3. The inner bore of the rotating ring 4 has a groove, within which an O-ring 9 is installed. The O-ring 9 fits snugly against the groove in the inner bore of the rotating ring 4, and the outer circumference of the pump shaft 3 fits snugly against the O-ring 9, forming a radial seal between the rotating ring 4 and the pump shaft 3. Multiple recessed set screws 2 are evenly distributed along the circumference of the outer circumference of the rotating ring 4. The end faces of the recessed set screws 2 are interference-fitted with the outer circumference of the pump shaft 3, used to reliably fix the rotating ring 4 onto the pump shaft 3, restricting the relative movement of the rotating ring 4 along the axial and radial directions of the pump shaft 3.

[0026] The stationary ring 5 is installed in the inner holes of the upper bearing chamber 1 and the lower bearing chamber 6. The stationary ring 5 adopts a horizontal split structure. After assembly, the inner hole and outer circle of the stationary ring 5 are complete circles. The upper half is radially transition-fitted with the upper bearing chamber 1, and the lower half is radially transition-fitted with the lower bearing chamber 6. The stationary ring 5 can be sealed with sealant between the upper bearing chamber 1 and the lower bearing chamber 6 to reduce lubricating oil leakage at the assembly surface. The back of the stationary ring 5 is provided with a groove that mates with the locating pin 10. The locating pin 10 is installed in the pin hole in the middle of the top of the groove in the upper bearing chamber 1 and fits against one side of the end face of the groove on the back of the stationary ring 5, which provides support and constraint for the stationary ring 5 and prevents the stationary ring 5 from axially rotating and shifting during the operation of the centrifugal pump.

[0027] Based on the above structure, three independent channels are formed sequentially along the axial direction between the moving ring 4 and the stationary ring 5: an oil-side labyrinth channel S1, an intermediate bypass channel S2, and a water-side labyrinth channel S3. The oil-side labyrinth channel S1 is located near the bearing chamber and is used to classify and block the lubricating oil from the radial bearing 7 area; the intermediate bypass channel S2 is located between the oil-side labyrinth channel S1 and the water-side labyrinth channel S3, forming a bypass separation and return channel for the lubricating oil; the water-side labyrinth channel S3 is located near the mechanical seal or labyrinth seal and is used to block and guide the water outflow on that side.

[0028] like Figure 2As shown, the oil-side labyrinth channel S1 is an oil-side channel including a two-stage sealing structure. The first-stage sealing structure is formed by the radial clearance fit between the moving ring oil slinger baffle 41 and the stationary ring sleeve 51. The moving ring oil slinger baffle 41 and the stationary ring sleeve 51 are arranged axially opposite each other, forming the first throttling and blocking effect on the lubricating oil from the radial bearing 7 region during the rotation of the pump shaft 3. The second-stage sealing structure is formed by the radial clearance fit between the outer circle of the moving ring 4 and the first stationary ring comb teeth 52. The first stationary ring comb teeth 52 are set at the oil-side end of the stationary ring 5 and are toothed along the circumferential direction. The gap between the outer circle of the moving ring 4 and the stationary ring comb teeth 52 forms the second throttling sealing structure. Through the cooperation of the above two-stage sealing structures, the lubricating oil entering the oil seal region can be depressurized and diverted step by step, improving the labyrinth sealing effect of the oil-side channel.

[0029] The intermediate bypass channel S2 consists of a rotating ring oil-side isolation groove 42, a stationary ring comb tooth 52, and an oil collection groove 53. The rotating ring oil-side isolation groove 42 is located on the outer circumference of the rotating ring 4 on the oil side. The stationary ring comb tooth 52 and the oil collection groove 53 are located at corresponding positions on the stationary ring 5. The oil-side isolation groove 42, the stationary ring comb tooth 52, and the oil collection groove 53 are arranged sequentially along the axial direction and can be configured as a single-stage or multi-stage structure to further classify and separate the small amount of lubricating oil leaking from the oil-side labyrinth channel S1. After passing through the oil-side labyrinth channel S1, the lubricating oil enters the intermediate bypass channel S2, changes its flow direction at the rotating ring oil-side isolation groove 42, is thrown into the gap between the stationary ring comb teeth 52 when the rotating ring rotates, and finally collects in the stationary ring oil collection groove 53.

[0030] The bottom of the oil collecting trough 53 is provided with an oil groove opening 54, which forms a through groove and together with the vertical oil channel 61, the horizontal oil channel 62 and the external oil channel 63 to form an integral through channel. The lubricating oil collected in the oil collecting trough 53 enters the vertical oil channel 61 through the oil groove opening 54, and then flows to the external oil channel 63 through the horizontal oil channel 62. The external oil channel 63 is connected to the return oil pipeline or return oil header outside the lower bearing chamber 6, and guides the remaining lubricating oil collected from the intermediate bypass channel S2 to the external recovery device, realizing the centralized discharge and recovery of lubricating oil and reducing the retention of lubricating oil in the area around the oil seal.

[0031] The water-side labyrinth channel S3 is located between the rotating ring 4 and the stationary ring water-side baffle 55. The rotating ring 4 and the stationary ring water-side baffle 55 form a micro-gap water-blocking structure through a radial clearance fit. The stationary ring water-side baffle 55 is located on the side of the stationary ring 5 closest to the mechanical seal or labyrinth seal. The water-side labyrinth channel S3 communicates with the rotating ring water-side isolation groove 43, the water collection groove 56, and the water groove opening 57. The water-side isolation groove 43, the water collection groove 56, and the water groove opening 57 are centrally arranged axially. The water-side isolation groove 43 and the water collection groove 56 can be set as one or more locations. Water from the mechanical seal or labyrinth seal side is first blocked at the gap between the dynamic ring 4 and the stationary ring water-side baffle 55. A small amount of liquid entering the water-side labyrinth channel S3 is collected in the dynamic ring water-side isolation tank 43 and the stationary ring water collection tank 56, and flows to the bottom of the water collection tank 56 under the action of gravity. It is then introduced into the intermediate chamber between the oil seal and the mechanical seal or labyrinth seal through the water tank opening 57, and finally flows to the water collection device, reducing the possibility of water entering the bearing chamber 6.

[0032] In this embodiment, the intermediate bypass channel S2 of the oil seal is jointly formed by the oil-side isolation groove 42 of the rotating ring, the comb teeth 52 of the stationary ring, and the oil return passage at the bottom of the lower bearing chamber. The remaining lubricating oil flowing in from the oil-side labyrinth channel S1 flows axially to the oil-side isolation groove 42 of the rotating ring, stops axial flow in the isolation groove, and is thrown towards the oil collection area between the comb teeth 52 under the action of centrifugal force generated by the rotation of the rotating ring 4. The lubricating oil flows to the bottom of the oil collection groove 53 of the stationary ring under the action of gravity, and is discharged in sequence through the oil groove opening 54 at the bottom of the oil collection groove, the vertical oil channel 61, the horizontal oil channel 62 and the external oil channel 63, so as to achieve effective recovery of lubricating oil.

[0033] On the side of the oil seal closest to the centrifugal pump's mechanical seal or labyrinth seal, the water-side labyrinth channel S3 blocks and diverts the water outlet from the mechanical seal or labyrinth seal. A stationary ring water-side baffle 55 is installed on the water side of the stationary ring 5, forming a clearance fit with the rotating ring 4, blocking most of the water outlet from the mechanical seal or labyrinth seal. A small amount of water splashed into the water-side gap of the oil seal flows along the outer circumference of the rotating ring 4 to the rotating ring water-side isolation groove 43. Axial flow stops within the water-side isolation groove 43, and under the centrifugal force generated by the rotation of the rotating ring 4, it is thrown towards the water collection groove 56 on the water-side side of the stationary ring. Under gravity, the water flows to the bottom of the water collection groove 56, then through the water groove opening 57 into the intermediate chamber, and finally flows to the water collection device, preventing water from entering the bearing chamber 6.

[0034] The structural combination described in the above embodiments enables the three-channel oil seal structure of the centrifugal pump in this embodiment to achieve multi-stage lubricating oil separation and return through the oil-side labyrinth channel S1 and the intermediate bypass channel S2 on the bearing chamber side, and to achieve multi-stage water blocking and diversion through the water-side labyrinth channel S3 on the mechanical seal or labyrinth seal side. At the same time, in conjunction with the O-ring 9 seal between the dynamic ring 4 and the pump shaft 3, and the sealing cooperation between the stationary ring 5 and the upper bearing chamber 1 and the lower bearing chamber 6, the sealing performance of the bearing chamber lubricating oil is improved, the risk of water entering the bearing chamber is reduced, and the operational reliability of the centrifugal pump is improved.

[0035] Those skilled in the art can adjust or replace the specific structural forms in the above embodiments without departing from the concept of this utility model. For example, they can change the number of stages of the oil-side isolation groove 42 and the oil collection groove 53, adjust the relative positions of the vertical oil channel 61 and the horizontal oil channel 62, etc. All such modifications and improvements should fall within the protection scope of this utility model.

[0036] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-sealing centrifugal pump three-channel oil seal structure, comprising a dynamic ring (4) and a static ring (5), the dynamic ring (4) is sleeved on the outer circle of the pump shaft (3), and the static ring (5) is installed in the inner hole of the upper bearing chamber (1) and the lower bearing chamber (6), characterized in that: The moving ring (4) and the stationary ring (5) sequentially form an oil-side labyrinth channel (S1), an intermediate bypass channel (S2), and a water-side labyrinth channel (S3); the oil-side labyrinth channel (S1) is an oil-side channel including a two-stage sealing structure; the intermediate bypass channel (S2) includes a moving ring oil-side isolation groove (42), a stationary ring comb tooth (52), and an oil collection groove (53), and the bottom of the oil collection groove (53) is provided with an oil groove opening (54); the water-side labyrinth channel (S3) is formed by the radial gap between the moving ring (4) and the stationary ring water-side baffle (55), and is connected to the moving ring water-side isolation groove (43), the stationary ring water collection groove (56), and the water groove opening (57).

2. The high containment centrifugal pump triple seal structure of claim 1, wherein: In the two-stage sealing structure of the oil-side labyrinth channel (S1), the first-stage sealing structure is a radial clearance fit between the moving ring oil slinger baffle (41) and the stationary ring sleeve (51), and the second-stage sealing structure is a radial clearance fit between the outer circle of the moving ring (4) and the first stationary ring comb teeth (52).

3. The high containment centrifugal pump triple seal structure of claim 1, wherein: The oil-side isolation groove (42), stationary ring comb teeth (52) and oil collection groove (53) in the intermediate bypass channel (S2) are arranged sequentially along the axial direction, and the oil-side isolation groove (42), stationary ring comb teeth (52) and oil collection groove (53) are one or more levels.

4. The high containment centrifugal pump triple seal structure of claim 1, wherein: The oil trough opening (54) at the bottom of the oil collection trough (53) forms a through groove, and together with the vertical oil channel (61), the horizontal oil channel (62) and the external oil channel (63), they form an integral through channel.

5. The high containment centrifugal pump triple seal structure of claim 1, wherein: The water-side isolation trough (43), water collection trough (56) and water trough opening (57) in the water-side maze passage (S3) are arranged centrally in the axial direction, and the water-side isolation trough (43) and water collection trough (56) are one or more locations.

6. The high containment centrifugal pump triple seal structure of claim 1, wherein: The inner groove of the moving ring (4) fits with the O-ring (9), the outer circle of the pump shaft (3) fits with the O-ring (9), and multiple screws (2) are provided on the moving ring (4).

7. The high containment centrifugal pump triple seal structure of claim 1, wherein: The stationary ring (5) is engaged with the pin hole of the upper bearing chamber (1) by a positioning pin (10).

8. The high containment centrifugal pump triple seal structure of claim 1, wherein: The stationary ring (5) has a horizontal split structure. The inner hole and outer circle of the stationary ring (5) are complete circles. The upper half is transitionally fitted with the upper bearing chamber (1), and the lower half is transitionally fitted with the lower bearing chamber (6).

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