Sealing structure of submersible motor for well

Abstract

The utility model belongs to the technical field of motors, in particular to a sealing structure of a submersible motor for a well, which comprises a static ring mounted on a motor seat and a moving ring component sleeved on a motor shaft, the moving ring component comprises a friction ring and a spring which enables the friction ring to cling to the static ring through elastic force, and a shield circumferentially fixed on the motor shaft is covered outside the moving ring component. A limiting part for limiting the shield is arranged between the shield and the motor shaft, the shield comprises a mounting sleeve, a protective sleeve and a connecting plate for connecting the mounting sleeve and the protective sleeve, a rubber bushing in close fit with the motor shaft is fixed to the inner ring of the mounting sleeve, and the mounting sleeve is circumferentially fixed to the motor shaft through the rubber bushing; the upper end of the spring abuts against the connecting plate, and the lower end of the spring is pressed on the friction ring. Water flow can be effectively prevented from impacting the moving ring assembly, the moving ring assembly is further prevented from swinging due to the water flow, and sealing is not prone to failure; and the spring is free of sediment scouring, abrasion caused by sediment scouring is effectively avoided, and the service life of the mechanical seal is long.

Description

Technical fields:

[0001] This utility model belongs to the field of motor technology, and specifically refers to a sealing structure for a submersible motor used in wells. Background technology:

[0002] Submersible motors typically use mechanical seals to seal the motor shaft 1 and the motor base 2, such as Figure 1 As shown, the mechanical seal includes a stationary ring 3 mounted on the motor mount 2 and a rotating ring assembly fitted on the motor shaft 1. The rotating ring assembly includes, from top to bottom, an upper spring seat 4, a spring 5, a lower spring seat 6, a rubber sleeve 7, and a friction ring 8. The upper end of the spring 5 abuts against the upper spring seat 4, and the lower end abuts against the lower spring seat 6. The upper end of the rubber sleeve 7 is tightly fitted to the pump shaft 1, and the lower end is tightly fitted to the friction ring 8. The lower spring seat 6 is fitted outside the rubber sleeve 7 and pressed against the friction ring 8 by the rubber sleeve 7. The sealing of the mechanical seal is mainly achieved by the contact between the friction ring 8 and the stationary ring 3.

[0003] The shortcomings of the above-mentioned sealing structure are: during operation, the pumped water will impact the upper spring seat 4, spring 5, lower spring seat 6, rubber sleeve 7 and friction ring 8 of the mechanical seal, causing the dynamic ring assembly to swing, which in turn leads to seal failure; at the same time, the pumped water often contains silt, and the wear caused by the silt on the spring 5 reduces the pressure of the spring 5, thereby accelerating the failure of the mechanical seal. Summary of the Invention:

[0004] The purpose of this invention is to provide a sealing structure for a submersible motor used in wells, which can effectively prevent water flow from impacting the moving ring assembly, thereby avoiding the moving ring assembly from swinging due to water flow and making the seal less prone to failure; moreover, the spring is not eroded by mud and sand, effectively avoiding wear caused by mud and sand erosion, and the mechanical seal has a long service life.

[0005] This utility model is implemented as follows:

[0006] A sealing structure for a submersible motor for well applications includes a stationary ring mounted on a motor base and a rotating ring assembly fitted onto a motor shaft. The rotating ring assembly includes a friction ring whose lower end face abuts and seals against the stationary ring, and a spring that keeps the friction ring tightly against the stationary ring. The rotating ring assembly is covered by a protective cover circumferentially fixed to the motor shaft. A limiting member is provided between the protective cover and the motor shaft to limit the upper position of the protective cover. The protective cover includes a mounting sleeve circumferentially fixed to the motor shaft, a protective sleeve covering the rotating ring assembly, and a connecting plate connecting the mounting sleeve and the protective sleeve. A rubber bushing that fits tightly against the motor shaft is fixed to the inner ring of the mounting sleeve, and the mounting sleeve is circumferentially fixed to the motor shaft through the rubber bushing. The upper end of the spring abuts against the connecting plate, and the lower end presses against the friction ring.

[0007] In the above-mentioned sealing structure for a submersible motor for wells, the rubber bushing is integrally formed into the inner ring of the mounting sleeve by vulcanization.

[0008] In the sealing structure of the submersible motor for well, the mounting sleeve and the protection sleeve are located below the connecting plate and form an annular groove, and the upper end of the spring is arranged in the annular groove.

[0009] In the sealing structure of the submersible motor for well, the upper and lower end faces of the rubber bushing are flush with the upper and lower ends of the mounting sleeve respectively, and the inner diameter D of the rubber bushing is 3.5-4.5 times of the length H of the rubber bushing.

[0010] In the sealing structure of the submersible motor for well, the motor shaft is provided with an annular clamping groove, and the limiting piece is an elastic retaining ring arranged on the annular clamping groove.

[0011] In the sealing structure of the submersible motor for well, the limiting piece can also be a limiting step arranged on the motor shaft.

[0012] In the sealing structure of the submersible motor for well, the protection sleeve is in the form of a step, comprising a small sleeve located above and a large sleeve located below the small sleeve, and the upper end of the small sleeve is connected to the connecting plate, the small sleeve surrounds the outer periphery of the spring, and the large sleeve surrounds the outer periphery of the friction ring.

[0013] In the sealing structure of the submersible motor for well, the friction ring is fixed on the motor shaft through a rubber sleeve, the upper end of the rubber sleeve is sleeved on the outer periphery of the motor shaft and tightly fitted with the motor shaft, the lower end of the rubber sleeve is sleeved on the outer periphery of the friction ring and tightly fitted with the friction ring, the rubber sleeve is sleeved with a spring seat, the lower end of the spring abuts against the spring seat, and the spring is pressed on the friction ring through the spring seat and the rubber sleeve.

[0014] In the sealing structure of the submersible motor for well, the large sleeve surrounds the outer periphery of the spring seat.

[0015] In the sealing structure of the submersible motor for well, the protective cover is integrally formed of stainless steel.

[0016] In the sealing structure of the submersible motor for well, the thickness S of the protective cover is 1-5 mm.

[0017] Compared with the prior art, the utility model has the advantages of:

[0018] 1. The protective cover is arranged on the motor shaft, the protection sleeve of the protective cover is arranged outside the dynamic ring assembly, water flow impact on the dynamic ring assembly can be effectively prevented, the dynamic ring assembly is prevented from swinging due to water flow, and the sealing is not easy to fail; the spring is not subjected to silt scouring, wear caused by silt scouring is effectively avoided, the service life of the mechanical seal is long; and the tight fit between the rubber bushing and the motor shaft can effectively prevent silt from entering the inner side of the protective cover through the gap between the rubber bushing and the motor shaft.

[0019] 2, the inner diameter D of the rubber bushing is 3.5-4.5 times of the length H of the rubber bushing, so that the mounting sleeve can be radially limited on the motor shaft, and the effective guarantee that the shield does not swing when being washed by water. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a sectional view of the prior art;

[0021] Figure 2 is a sectional view of the utility model;

[0022] Figure 3 is a sectional view of the shield and the rubber bushing of the utility model.

[0023] REFERENCE NUMERALS

[0024] Figure 1 In the figure: 1, motor shaft; 2, motor base; 3, static ring; 4, upper spring seat; 5, spring; 6, lower spring seat; 7, rubber sleeve; 8, friction ring.

[0025] Figure 2 , 3 In the figure: 1, motor base; 2, static ring; 3, motor shaft; 4, friction ring; 5, spring; 6, shield; 6a, mounting sleeve; 6b, protective sleeve; 6b1, small sleeve; 6b2, large sleeve; 6c, connecting plate; 7, rubber bushing; 8, annular groove; 9, annular clamping groove; 10, elastic check ring; 11, rubber sleeve; 12, spring seat. DETAILED DESCRIPTION

[0026] The utility model will be further described below with specific embodiments, referring to Figure 2 , 3 :

[0027] A submersible motor sealing structure for well comprises a static ring 2 installed on a motor base 1 and a dynamic ring assembly sleeved on a motor shaft 3, the dynamic ring assembly comprises a friction ring 4 with a lower end face abutting against the static ring 2 for sealing and a spring 5 with elastic force to make the friction ring 4 tightly adhere to the static ring 2, a shield 6 is fixed in the circumferential direction on the motor shaft 3 and covers the dynamic ring assembly, a limiting piece is arranged between the shield 6 and the motor shaft 3 to limit the upper position of the shield 6, the shield 6 comprises a mounting sleeve 6a fixed in the circumferential direction on the motor shaft 3, a protective sleeve 6b covering the dynamic ring assembly and a connecting plate 6c connecting the mounting sleeve 6a and the protective sleeve 6b, a rubber bushing 7 is fixed on the inner ring of the mounting sleeve 6a and tightly fits the motor shaft 3, the mounting sleeve 6a is fixed in the circumferential direction on the motor shaft 3 through the rubber bushing 7, and the upper end of the spring 5 abuts against the connecting plate 6c and the lower end is pressed on the friction ring 4.

[0028] The working principle of the utility model is as follows: Figure 2 、 3As shown, when the motor shaft 3 rotates, the dynamic ring assembly, the rubber bushing 7 and the shield 6 rotate together, the shield 6 and the dynamic ring assembly rotate to drive the spring 5 to rotate, so that the mechanical seal operates normally, and the lower end surface of the friction ring 4 is tightly attached to the static ring 2 under the elastic force of the spring 5, so that the abutting sealing structure is formed.

[0029] The utility model discloses a shield 6 is arranged on the motor shaft 3, the protection sleeve 6b of shield 6 is covered in dynamic ring assembly outside, can effectively prevent water flow and swing dynamic ring assembly, and further avoid dynamic ring assembly to swing because of water flow, and sealing is not easy to fail, and spring 5 is not silt scouring, effectively avoid the abrasion that silt scouring produces, and the service life of mechanical seal is long, and simultaneously, the rubber bushing 7 is closely fitted with the motor shaft 3, can effectively avoid silt and enter the inside of shield 6 between the rubber bushing 7 and the motor shaft 3.

[0030] In order to connect firm and reliable, processing is convenient, the rubber bushing 7 is integrated in the inner ring of mounting sleeve 6a by vulcanization.

[0031] Further, the mounting sleeve 6a and the protection sleeve 6b are located below the connecting plate 6c and form an annular groove 8, and the upper end of the spring 5 is arranged in the annular groove 8.

[0032] Further, the upper and lower end surfaces of the rubber bushing 7 are flush with the upper and lower ends of the mounting sleeve 6a respectively, and the inner diameter D of the rubber bushing 7 is 3.5-4.5 times the length H of the rubber bushing 7, so that the mounting sleeve 6a can be radially limited on the motor shaft 3, and the shield 6 is effectively prevented from swinging when being washed by water.

[0033] In the embodiment, the inner diameter D of the rubber bushing 7 is 4 times the length H of the rubber bushing 7.

[0034] The structure of the limiting piece is as shown in the figure. Figure 2 As shown, the motor shaft 3 is provided with an annular clamping groove 9, and the limiting piece is an elastic retaining ring 10 arranged on the annular clamping groove 9.

[0035] Further, the elastic retaining ring 10 is located above the shield 6, and the elastic retaining ring 10 abuts against and limits the rubber bushing 7.

[0036] The utility model discloses a simple structure, and the installation process does not need special technology and high-skilled workers, and is convenient to install.

[0037] In order to better protect the dynamic ring assembly, as shown in the figure. Figure 2 , 3 As shown, the protection sleeve 6b is in a stepped shape, including a small sleeve 6b1 located above and a large sleeve 6b2 arranged below the small sleeve 6b1, the upper end of the small sleeve 6b1 is connected to the connecting plate 6c, the small sleeve 6b1 surrounds the outer periphery of the spring 5, and the large sleeve 6b2 surrounds the outer periphery of the friction ring 4.

[0038] The specific structure of the dynamic ring assembly: the friction ring 4 is fixed on the motor shaft 3 in the circumferential direction through the rubber sleeve 11, the upper end of the rubber sleeve 11 is sleeved on the outer side of the motor shaft 3 and tightly fitted with the motor shaft 3, the lower end of the rubber sleeve 11 is sleeved on the outer side of the friction ring 4 and tightly fitted with the friction ring 4, the spring seat 12 is sleeved on the outer side of the rubber sleeve 11, the lower end of the spring 5 abuts against the spring seat 12, and the spring 5 is pressed on the friction ring 4 through the spring seat 12 and the rubber sleeve 11. The friction ring 4 is driven by the rubber sleeve 11 to rotate with the motor shaft 3.

[0039] Further, the large sleeve 6b2 is arranged around the outer periphery of the spring seat 12.

[0040] In order to reduce the assembly steps and firm connection, the shield 6 is integrally formed by stainless steel.

[0041] Further, the thickness S of the shield 6 is 1mm-5mm. In the embodiment, the thickness S of the shield 6 is 3mm. The weight is light, and the cost is low.

[0042] The utility model adopts the shield 6 to replace the original upper spring seat of the mechanical seal, although the cost increases 1.5 yuan-3.5 yuan, the cost increment is 3%-8%, but can effectively resist the scouring of silt water, and the service life of the mechanical seal is prolonged by 5 times-8 times.

[0043] The above embodiment is only one of the preferred embodiments of the utility model, and does not limit the implementation range of the utility model, so: all equivalent changes made according to the shape, structure and principle of the utility model should be covered in the protection range of the utility model.

Claims

1. A sealing structure for a submersible motor for wells, comprising a stationary ring (2) mounted on a motor base (1) and a rotating ring assembly fitted on a motor shaft (3), the rotating ring assembly comprising a friction ring (4) whose lower end face abuts against and seals the stationary ring (2), and a spring (5) whose elasticity causes the friction ring (4) to press tightly against the stationary ring (2), characterized in that: The outer cover of the rotating ring assembly is provided with a protective cover (6) circumferentially fixed on the motor shaft (3). A limiting member is provided between the protective cover (6) and the motor shaft (3) to limit the upper limit of the protective cover (6). The protective cover (6) includes a mounting sleeve (6a) circumferentially fixed on the motor shaft (3), a protective sleeve (6b) covering the rotating ring assembly, and a connecting plate (6c) connecting the mounting sleeve (6a) and the protective sleeve (6b). The inner ring of the mounting sleeve (6a) is fixed with a rubber bushing (7) that fits tightly with the motor shaft (3), and the mounting sleeve (6a) is circumferentially fixed to the motor shaft (3) through the rubber bushing (7). The upper end of the spring (5) abuts against the connecting plate (6c) and the lower end presses against the friction ring (4).

2. The sealing structure for a submersible motor for wells according to claim 1, characterized in that: The rubber bushing (7) is integrally formed on the inner ring of the mounting sleeve (6a) by vulcanization.

3. The sealing structure for a submersible motor for wells according to claim 1, characterized in that: The mounting sleeve (6a) and the protective sleeve (6b) are both located below the connecting plate (6c) and form an annular groove (8), with the upper end of the spring (5) set in the annular groove (8).

4. The sealing structure for a submersible motor for wells according to claim 1, characterized in that: The upper and lower end faces of the rubber bushing (7) are flush with the upper and lower end faces of the mounting sleeve (6a), respectively. The inner diameter of the rubber bushing (7) is 3.5 to 4.5 times the length of the rubber bushing (7).

5. The sealing structure for a submersible motor for wells according to claim 1, characterized in that: The motor shaft (3) is provided with an annular groove (9), and the limiting member is an elastic retaining ring (10) provided on the annular groove (9).

6. The sealing structure for a submersible motor for wells according to claim 1, characterized in that: The protective sleeve (6b) is stepped and includes a small sleeve (6b1) located at the top and a large sleeve (6b2) located below the small sleeve (6b1). The upper end of the small sleeve (6b1) is connected to the connecting plate (6c). The small sleeve (6b1) surrounds the outer periphery of the spring (5), and the large sleeve (6b2) surrounds the outer periphery of the friction ring (4).

7. The sealing structure for a submersible motor for wells according to claim 1, characterized in that: The friction ring (4) is circumferentially fixed to the motor shaft (3) by a rubber sleeve (11). The upper end of the rubber sleeve (11) is fitted outside the motor shaft (3) and is tightly fitted to the motor shaft (3). The lower end of the rubber sleeve (11) is fitted outside the friction ring (4) and is tightly fitted to the friction ring (4). A spring seat (12) is fitted outside the rubber sleeve (11). The lower end of the spring (5) abuts against the spring seat (12) and is pressed onto the friction ring (4) by the spring seat (12) and the rubber sleeve (11).

8. The sealing structure for a submersible motor for wells according to claim 1, characterized in that: The protective cover (6) is integrally formed from stainless steel.

9. A sealing structure for a submersible motor for wells according to claim 8, characterized in that: The thickness of the protective cover (6) is 1mm-5mm.

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