INDEPENDENT OIL CAVITY SEALING STRUCTURE FOR A SUBMERSIBLE ELECTRIC PUMP

Abstract

An independent oil cavity sealing structure for a submersible electric pump. The structure comprises a housing, upper and lower moving rings, upper and lower static rings, a transmission sleeve and upper and lower pressing plates; the housing is sleeved on the main shaft of the electric pump, the outer sides of the upper and lower static rings are supported on the upper and lower static ring supporting bosses through O-shaped rings respectively, the inner sides of the upper and lower static rings are tightly pressed by the O-shaped rings through the upper and lower pressing plates, the main shaft of the electric pump between the upper and lower static rings are fixedly connected with the transmission sleeve through bolts, upper and lower moving ring seats are provided in the cavity which is formed between the inner wall of the transmission sleeve and the main shaft of the electric pump.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority under 35 U.S.C. .sctn. 119 to Chinese Patent Application No. 201910719314.X, which was filed on Aug. 6, 2019, the entire contents of which is hereby expressly incorporated by reference in its entirety.

TECHNICAL FIELD

[0002] The present invention relates to a sealing structure, in particular to an independent oil cavity sealing structure for a submersible electric pump.

BACKGROUND

[0003] In the design of a submersible electric pump, the submersible electric pump needs mechanical sealing parts to prevent the transmission medium from entering the motor cavity. To ensure the normal use of mechanical seals, the traditional design of an oil cavity filled with mechanical oil uses a single or a plurality of mechanical seals for cooperation. An oil film is formed on the friction surface of the moving and static rings with full lubrication, ensuring the heat transfer and diffusion of the friction both at the same time. Because the volume of the oil cavity for a submersible electric pump is very large, and especially in the design of the submersible axial mixed-flow pump, the volume of the oil cavity will be larger, and it will waste a lot of mechanical oil and have a bloated structure, poor assembly performance, and reduced reliability.

[0004] In the prior art, a double-end mechanical sealing structure is also used, and the static ring at the outer end is in contact with the transmission medium. The static ring at the end is subjected to a certain thrust force opposite to the direction of the spring force under the action of the medium pressure. If the thrust force is longer or larger than the reverse pressure of the spring for a long time, the static seal at the static ring part fails, so that the transmission medium enters the sealing structure. The moving and static rings at the inner end of the sealing structure are easily damaged, leading to leakage and seal failure.

SUMMARY

[0005] In view of the above problems in the prior art, at least one embodiment of the present invention provides an independent oil cavity sealing structure for a submersible electric pump with a compact structure, convenient assembly and use, and good lubricating and sealing effect.

[0006] The technical scheme adopted by various embodiments of the present invention is: an independent oil cavity sealing structure for a submersible electric pump, comprising a housing, upper and lower moving rings, upper and lower static rings, and a transmission sleeve, wherein the independent oil cavity sealing structure further comprises upper and lower pressing plates, the housing is sleeved on the main shaft of the electric pump, the inner walls of upper and lower parts of the housing are provided with upper and lower static ring supporting bosses facing inwards respectively, the outer sides of the upper and lower static rings are supported on the upper and lower static ring supporting bosses through O-shaped rings respectively, the inner sides of the upper and lower static rings are tightly pressed by the O-shaped rings through the upper and lower pressing plates which are fixedly connected with the upper and lower inner walls of the housing, the main shaft of the electric pump between the upper and lower static rings are fixedly connected with the transmission sleeve through bolts, upper and lower moving ring seats are provided in the cavity which is formed between the inner wall of the transmission sleeve and the main shaft of the electric pump, a plurality of groups of springs provided in the axial direction of the main shaft of the electric pump abut against the part between the upper and lower moving ring seats, the upper and lower moving rings which are provided in the transmission sleeve are supported by the parts, opposite to each other, of the upper and lower moving ring seats through the O-shaped rings, and the upper and lower moving rings abut against the upper and lower static rings outwards respectively.

[0007] In some embodiments, the housing comprises an upper housing cover plate and a lower housing cavity, the upper and lower static ring supporting bosses are provided on the upper housing cover plate and the lower housing cavity, respectively, and the upper housing cover plate is tightly connected to the end cover of the support bearing of the main shaft of the electric pump via a plurality of screws.

[0008] In some embodiments, the spring sleeved on the main shaft of the electric pump in the axial direction of the main shaft of the electric pump abuts against the part between the upper and lower moving ring seats.

[0009] In various embodiments, the housing is filled with lubricant.

[0010] In various embodiments, the mechanical sealing structure of the present invention is designed as an independent structure body comprising a static ring seat, a housing, a moving ring, a static ring and other auxiliary parts. The bearing end cover is connected through the upper housing cover plate. The amount of lubricant filled in the housing is only related to the size of the mechanical seal itself, without being related to the structure of the pump, which can greatly reduce the amount of mechanical seal lubricant. The heat generated by its friction pair can be transmitted and diffused by the medium circulating around the oil cavity, reducing the production cost of the pump and improving the product reliability.

[0011] In various embodiments, the upper and lower static rings are added with upper and lower pressing plates to be pressed in the upper housing cover plate and the lower housing cavity combined with O-shaped rings, which effectively avoids the problem of seal damage and failure caused by the traditional static ring due to being subjected to the medium pressure for a long time.

[0012] The double-end mechanical seal of certain embodiments of the present invention has an independent integral structure, and the performance of the mechanical seal is no longer limited by the technical level of the installer or influenced by the cumulative processing error of the water pump parts, the quality is more reliable, the mechanism is compact, easy to assemble, and easy to form a universal modularized component, the application range is increased, and the cost can be saved.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is a schematic diagram of the structure according to an example of the present invention;

[0014] FIG. 2 is a diagram of the using state according to an example of the present invention.

[0015] The following reference numbers are used in the drawings: a main shaft of the electric pump 1, a lower end cover 2, a bearing end cover 3, an upper housing cover plate 4, a lower housing cavity 5, an upper static ring supporting boss 6, a lower static ring supporting boss 7, an O-shaped ring 8, an upper static ring 9, a lower static ring 10, an upper pressing plate 11, a lower pressing plate 12, a transmission sleeve 13, an upper moving ring seat 14, a lower moving ring seat 15, a spring 16, an upper moving ring 17, and a lower moving ring 18.

DESCRIPTION OF THE EMBODIMENTS

[0016] The following is a further description of examples consistent with the invention, with reference to the drawings and embodiments.

[0017] As shown in FIGS. 1 and 2: an independent oil cavity sealing structure for a submersible electric pump comprises a main shaft of the electric pump 1, a lower end cover 2, a bearing end cover 3, an upper housing cover plate 4, a lower housing cavity 5, an upper static ring supporting boss 6, a lower static ring supporting boss 7, an O-shaped ring 8, an upper static ring 9, a lower static ring 10, an upper pressing plate 11, a lower pressing plate 12, a transmission sleeve 13, an upper moving ring seat 14, a lower moving ring seat 15, a spring 16, an upper moving ring 17, and a lower moving ring 18.

[0018] The upper housing cover plate 4 and the lower housing cavity 5 are locked via screws through the flanges and are integrally connected by the upper housing cover plate 4 to the lower part between the bearing end cover 3 and the lower end cover 2 of the main shaft 1 of the electric pump. The upper housing cover plate 4 and the lower housing cavity 5 are connected across the main shaft 1 of the electric pump and its inner cavity is filled with lubricant. The upper housing cover plate 4 and the lower housing cavity 5 are provided with upper and lower static ring supporting bosses 6 and 7 facing inwards respectively, the outer sides of the upper and lower static rings 9 and 10 are supported on the upper and lower static ring supporting bosses 6 and 7 through O-shaped rings 8 respectively, the inner sides of the upper and lower static rings 9 and 10 are tightly pressed by the O-shaped rings through the upper and lower pressing plates 11 and 12 which are fixedly connected with the inner walls of the upper housing cover plate 4 and the lower housing cavity 5, the main shaft of the electric pump between the upper and lower static rings 9 and 10 are fixedly connected with the transmission sleeve 13 through bolts, upper and lower moving ring seats 14 and 15 are provided in the cavity which is formed between the inner wall of the transmission sleeve 13 and the main shaft 1 of the electric pump, a plurality of groups of springs 16 provided in the axial direction of the main shaft of the electric pump abut against the part between the upper and lower moving ring seats, the upper and lower moving rings 17 and 18 which are provided in the transmission sleeve are supported by the parts, opposite to each other, of the upper and lower moving ring seats 14 and 15 through the O-shaped rings, and the upper and lower moving rings abut against the upper and lower static rings outwards respectively.

Claims

1. An independent oil cavity sealing structure for a submersible electric pump, comprising: a housing, upper and lower moving rings, upper and lower static rings, and a transmission sleeve, wherein the independent oil cavity sealing structure further comprises: upper and lower pressing plates, and wherein: the housing is sleeved on the main shaft of the electric pump, the inner walls of upper and lower parts of the housing are provided with upper and lower static ring supporting bosses facing inwards respectively, the outer sides of the upper and lower static rings are supported on the upper and lower static ring supporting bosses through O-shaped rings respectively, the inner sides of the upper and lower static rings are tightly pressed by the O-shaped rings through the upper and lower pressing plates which are fixedly connected with the upper and lower inner walls of the housing, the main shaft of the electric pump between the upper and lower static rings are fixedly connected with the transmission sleeve through bolts, upper and lower moving ring seats are provided in the cavity which is formed between the inner wall of the transmission sleeve and the main shaft of the electric pump, a plurality of groups of springs provided in the axial direction of the main shaft of the electric pump abut against the part between the upper and lower moving ring seats, the upper and lower moving rings which are provided in the transmission sleeve are supported by the parts, opposite to each other, of the upper and lower moving ring seats through the O-shaped rings, and the upper and lower moving rings abut against the upper and lower static rings outwards respectively.

2. The independent oil cavity sealing structure for a submersible electric pump according to claim 1, wherein: the housing comprises an upper housing cover plate and a lower housing cavity, the upper and lower static ring supporting bosses are provided on the upper housing cover plate and the lower housing cavity, respectively, and the upper housing cover plate is tightly connected to the end cover of the support bearing of the main shaft of the electric pump via a plurality of screws.

3. The independent oil cavity sealing structure for a submersible electric pump according to claim 1, wherein: the spring sleeved on the main shaft of the electric pump in the axial direction of the main shaft of the electric pump abuts against the part between the upper and lower moving ring seats.

4. The independent oil cavity sealing structure for a submersible electric pump according to claim 1, wherein the housing is filled with lubricant.

5. The independent oil cavity sealing structure for a submersible electric pump according to claim 2, wherein the housing is filled with lubricant.

6. The independent oil cavity sealing structure for a submersible electric pump according to claim 3, wherein the housing is filled with lubricant.