A new axial force balancing device for multi-stage pumps

Abstract

The present invention discloses a novel axial force balancing device for a multistage pump, which relates to the field of vertical multistage centrifugal pumps, including a moving ring assembly and a stationary ring assembly, wherein a cavity is provided at the bottom of the moving ring assembly to place the moving ring; a pump shaft hole which is connected to the cavity is provided at the top of the transmission seat, and the pump shaft is inserted into the pump shaft hole and connected to the inner wall of the transmission seat to fix and drive the moving ring assembly; a stationary ring is embedded and installed in a slot-type manner at the upper part of the sealing seat of the stationary ring assembly, one end of an anti-rotation pin is inserted and installed on the sealing seat, and the other end of the anti-rotation pin is inserted into the stationary ring, so that relative rotation does not occur between the stationary ring and the sealing seat; a liquid high-pressure cavity is provided in the sealing seat, and a plurality of connecting holes are provided radially on the outer wall of the sealing seat, one end of the connecting hole is connected to the liquid high-pressure cavity, and the other end is connected to the water outlet. The present invention changes the conventional motor bearing of the original structure to use a thrust bearing, and the balance disc or balance hub structure is used in the last stage of the water pump to a novel axial force balancing device at the shaft head end which is simple in structure, easy to replace, and has a long service life.

Description

Technical Field

[0001] The invention relates to the field of vertical multi-stage centrifugal pumps, and in particular to a novel axial force balancing device for a multi-stage pump. Background Art

[0002] In the structure of the existing vertical multi-stage centrifugal pump, the axial force points to the impeller outlet. The axial force of the low-stage is small and acts on the motor bearing, and the bearing balances part of the axial force. The axial force of the high-stage is large. If the bearing is used for load, it will definitely have a serious impact on the service life of the bearing, and then the whole pump will be damaged, which will reduce customer satisfaction and damage the company's quality and reputation.

[0003] In general, the existing vertical multistage centrifugal pumps have the following defects:

[0004] 1. The cost of the motor increases and its versatility deteriorates;

[0005] 2. When disassembling and replacing, the motor and the entire pump need to be removed, which is inconvenient to replace;

[0006] 3. It is more difficult to control the clearance of the balancing disc or balancing hub, or the motor is equipped with a thrust bearing, the pump structure is complicated, the axial dimension is lengthened, and the cost becomes higher;

[0007] 4. Poor balancing effect affects the service life of the pump and motor;

[0008] 5. Increase inventory costs. Summary of the invention

[0009] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a novel axial force balancing device for a multi-stage pump, which has the advantages of easy disassembly and long service life.

[0010] The objective of the present invention is achieved through the following technical scheme: this new axial force balancing device of a multi-stage pump is arranged in the inlet and outlet water sections of the multi-stage pump, a pressure-resistant cylinder is arranged on the outside of the multi-stage pump, a motor is fixedly mounted on one end of the pressure-resistant cylinder through a pump head, an output shaft of the motor drives the pump shaft through a coupling, the other end of the pressure-resistant cylinder is connected and fixed to the inlet and outlet water sections, a water inlet and a water outlet are arranged on the inlet and outlet water sections, the device comprises a moving ring assembly and a stationary ring assembly arranged below the moving ring assembly, the moving ring assembly comprises a transmission seat, a spring and a moving ring, the transmission seat is a bottle cap-shaped structure, a cavity is opened in its lower part for placing the moving ring; a pump shaft hole is opened on the top of the transmission seat, the pump shaft hole is connected to the cavity, the pump shaft of the multi-stage pump is inserted into the pump shaft hole and is connected and fixed to the inner wall of the transmission seat, thereby driving the moving ring assembly to rotate; a spring hole is also opened on the inner wall of the transmission seat, the spring One end of the spring is pressed against the spring hole, and the other end of the spring is pressed against the moving ring, so that the moving ring moves up and down in the cavity of the transmission seat; the stationary ring assembly includes a stationary ring, an anti-rotation pin and a sealing seat, and the upper part of the sealing seat is embedded with a stationary ring in a slot-like manner, one end of the anti-rotation pin is inserted and installed on the sealing seat, and the other end of the anti-rotation pin is inserted into the stationary ring, so that no relative rotation occurs between the stationary ring and the sealing seat; the lower surface of the moving ring and the upper surface of the stationary ring are in contact and fit to form a friction pair, thereby sealing the low-pressure liquid at the water inlet and the high-pressure liquid at the water outlet; a liquid high-pressure chamber is provided in the sealing seat, and a plurality of connecting holes are radially provided on the outer wall of the sealing seat, one end of the connecting hole is connected to the liquid high-pressure chamber, and the other end of the connecting hole is connected to the water outlet, the high-pressure liquid at the water outlet enters the liquid high-pressure chamber through the connecting hole, and forms a pressure difference with the low-pressure liquid at the water inlet, thereby realizing axial force balance.

[0011] As a further technical solution, a step is provided on the outer wall of the moving ring to cooperate with the inner wall of the transmission seat to limit the upward movement of the moving ring; an anti-slip bend is provided at the bottom of the transmission seat to limit the downward movement of the moving ring.

[0012] As a further technical solution, an O-ring A is used to seal the outer wall of the dynamic ring and the inner wall of the transmission seat.

[0013] As a further technical solution, there are a plurality of spring holes, which are evenly distributed along the outer circumference of the pump shaft hole.

[0014] As a further technical solution, an O-ring B is used to seal between the static ring and the sealing seat.

[0015] As a further technical solution, an O-ring C is used to seal the outer wall of the sealing seat and the inner wall of the water inlet and outlet sections.

[0016] The lower part of the sealing seat extends outward to form a bottom plate, and the bottom plate is threadedly connected to the bottom of the water inlet and outlet sections to form a bottom seal.

[0017] As a further technical solution, there are four connecting holes, which are evenly distributed along the circumference of the outer wall of the sealing seat.

[0018] The beneficial effects of the present invention are:

[0019] 1. The force generated by the pressure difference between the high and low pressures of the water pump inlet and outlet can well balance the axial force generated by the water pump, and the dynamic force compensation of the axial force acting on the shaft can reduce the force absorbed by the axial bearing to a minimum;

[0020] 2. It can reduce the influence of axial force on bearing life, and can be used with standard motors, which has strong versatility;

[0021] 3. Easy to manufacture, simple structure, low cost, reliable sealing and long service life;

[0022] 4. Wide range of applications, suitable for a variety of media;

[0023] 5. Simple installation and maintenance, convenient for users to install, repair and replace on site. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The structure diagram of the present invention after being assembled with a multi-stage centrifugal pump Figure 1 .

[0025] Figure 2 The structure diagram of the present invention after being assembled with a multi-stage centrifugal pump Figure 2 .

[0026] Figure 3 It is a structural schematic diagram of the present invention.

[0027] Figure 4 It is a structural schematic diagram of the dynamic ring assembly.

[0028] Figure 5 It is a structural schematic diagram of the stationary ring assembly.

[0029] Explanation of the accompanying drawings: water inlet and outlet section 3, water inlet 3-1, water outlet 3-2, motor 17, coupling 20, pump head 21, pressure-resistant cylinder 25, pump shaft 28, moving ring assembly 31, transmission seat 31-1, spring 31-2, O-ring A 31-3, moving ring 31-4, pump shaft hole 31-5, step 31-6, anti-slip bend 31-7, stationary ring assembly 34, stationary ring 34-1, O-ring B 34-2, anti-rotation pin 34-3, O-ring C 34-4, sealing seat 34-5, liquid high-pressure chamber 34-6, connecting hole 34-7, chassis 34-8. DETAILED DESCRIPTION

[0030] The present invention will be described in detail below with reference to the accompanying drawings:

[0031] Example: As attached Figures 1 to 5 As shown, this new axial force balancing device for a multistage pump is arranged in the water inlet and outlet section 3 of the multistage pump. A pressure-resistant cylinder 25 is provided on the outside of the multistage pump. The motor 17 is fixedly mounted on one end of the pressure-resistant cylinder 25 through a pump head 21. The output shaft of the motor 17 is connected to drive the pump shaft 28 through a coupling 20. The other end of the pressure-resistant cylinder 25 is connected and fixed to the water inlet and outlet section 3. A water inlet 3-1 and a water outlet 3-2 are provided on the water inlet and outlet section 3. The device comprises a moving ring assembly 31 and a stationary ring assembly 34 arranged below the moving ring assembly 31. The moving ring assembly 31 comprises a transmission seat 31-1, a spring 31-2 and a moving ring 31-4. The transmission seat 31-1 is a bottle cap-shaped structure, and a cavity is opened at its lower part for placing the moving ring 31-4. A pump shaft hole 31-5 is opened at the top of the transmission seat 31-1, and the pump shaft hole 31-5 is connected with the cavity. The pump shaft 28 of the multistage pump is inserted into the pump shaft hole 31-5 and connected with the transmission seat 31- 1 is connected and fixed to the inner wall of the transmission seat 31-1, thereby driving the dynamic ring assembly 31 to rotate; a plurality of spring holes are also opened on the inner wall of the transmission seat 31-1 (the spring holes are evenly distributed along the outer circumference of the pump shaft hole 31-5), one end of the spring 31-2 is pressed into the spring hole, and the other end of the spring 31-2 is pressed on the dynamic ring 31-4, so that the dynamic ring 31-4 moves up and down in the cavity of the transmission seat 31-1; the stationary ring assembly 34 includes a stationary ring 34-1, an anti-rotation pin 34-3 and a sealing seat 34-5, the sealing seat The static ring 34-1 is embedded in the upper slot of 34-5, one end of the anti-rotation pin 34-3 is inserted and installed on the sealing seat 34-5, and the other end of the anti-rotation pin 34-3 is inserted into the static ring 34-1, so that the static ring 34-1 and the sealing seat 34-5 do not rotate relative to each other; the lower surface of the dynamic ring 31-4 and the upper surface of the static ring 34-1 are in contact and fit to form a friction pair, thereby sealing the low-pressure liquid at the water inlet 3-1 and the high-pressure liquid at the water outlet 3-2; in the sealing seat 34 -5 is provided with a liquid high-pressure chamber 34-6, and four connecting holes 34-7 are radially provided on the outer wall of the sealing seat 34-5 (evenly distributed along the circumference of the outer wall of the sealing seat 34-5). One end of the connecting hole 34-7 is connected with the liquid high-pressure chamber 34-6, and the other end of the connecting hole 34-7 is connected with the water outlet 3-2. The high-pressure liquid at the water outlet 3-2 enters the liquid high-pressure chamber 34-6 through the connecting hole 34-7, and forms a pressure difference with the low-pressure liquid at the water inlet 3-1, thereby achieving axial force balance.

[0032] Reference Figure 4 A step 31-6 is provided on the outer wall of the moving ring 31-4, which is used to cooperate with the inner wall of the transmission seat 31-1 to limit the upward movement of the moving ring 31-4; an anti-slip bend 31-7 is provided at the bottom of the transmission seat 31-1 to limit the downward movement of the moving ring 31-4.

[0033] like Figure 4 , 5As shown, the outer wall of the dynamic ring 31-4 and the inner wall of the transmission seat 31-1 are sealed by an O-ring A31-3. The static ring 34-1 and the sealing seat 34-5 are sealed by an O-ring B34-2. The outer wall of the sealing seat 34-5 and the inner wall of the water inlet and outlet section 3 are sealed by an O-ring C34-4. The lower part of the sealing seat 34-5 extends outward to form a chassis 34-8, and the chassis 34-8 is threadedly connected to the bottom of the water inlet and outlet section 3 to form a bottom seal; at the same time, the dynamic ring assembly 31 and the static ring assembly 34 can be disassembled and replaced from the bottom of the water inlet and outlet section 3.

[0034] Working principle of the present invention: Figure 1 , 2 , a friction pair is formed between the dynamic ring and the static ring, sealing the low-pressure liquid at the water inlet and the high-pressure liquid at the water outlet. The dynamic ring assembly rotates with the pump shaft, and the static ring assembly is connected to the inlet and outlet sections to form a bottom seal. The high-pressure liquid at the outlet passes through the pressure-resistant cylinder and returns to the outlet of the inlet and outlet sections, and then reaches the liquid high-pressure chamber through the connecting hole on the sealing seat to form a pressure difference with the low-pressure liquid at the water inlet. The direction of the pressure is opposite to the direction of the axial force, thereby achieving the effect of balancing part of the axial force.

[0035] It is understandable that, for those skilled in the art, any equivalent replacement or change to the technical solution and inventive concept of the present invention should fall within the protection scope of the claims attached to the present invention.

Claims

1. A novel axial force balancing device for a multistage pump, arranged in a water inlet and outlet section (3) of the multistage pump, wherein a pressure-resistant cylinder (25) is arranged outside the multistage pump, a motor (17) is fixedly mounted on one end of the pressure-resistant cylinder (25) through a pump head (21), an output shaft of the motor (17) is connected to drive a pump shaft (28) through a coupling (20), the other end of the pressure-resistant cylinder (25) is connected and fixed to the water inlet and outlet section (3), a water inlet (3-1) and a water outlet (3-2) are arranged on the water inlet and outlet section (3), and the characteristics are as follows: The invention comprises a moving ring assembly (31) and a stationary ring assembly (34) arranged below the moving ring assembly (31); the moving ring assembly (31) comprises a transmission seat (31-1), a spring (31-2) and a moving ring (31-4); the transmission seat (31-1) is a bottle cap-shaped structure, and a cavity is formed at its lower part for receiving the moving ring (31-4); a pump shaft hole (31-5) is formed at the top of the transmission seat (31-1), the pump shaft hole (31-5) is connected to the cavity, and a pump shaft (28) of the multistage pump is inserted into the pump shaft hole (31-5). ) and is connected and fixed to the inner wall of the transmission seat (31-1), thereby driving the moving ring assembly (31) to rotate; a spring hole is also opened on the inner wall of the transmission seat (31-1), one end of the spring (31-2) is pressed into the spring hole, and the other end of the spring (31-2) is pressed on the moving ring (31-4), so that the moving ring (31-4) moves up and down in the cavity of the transmission seat (31-1); the stationary ring assembly (34) includes a stationary ring (34-1), an anti-rotation pin (34-3) and a sealing seat (34-5), and the sealing seat (3 4-5) A static ring (34-1) is embedded in the upper slot, one end of the anti-rotation pin (34-3) is inserted and installed on the sealing seat (34-5), and the other end of the anti-rotation pin (34-3) is inserted into the static ring (34-1), so that relative rotation does not occur between the static ring (34-1) and the sealing seat (34-5); the lower surface of the dynamic ring (31-4) and the upper surface of the static ring (34-1) are in contact and fit to form a friction pair, thereby sealing the low-pressure liquid at the water inlet (3-1) and the high-pressure liquid at the water outlet (3-2). A liquid high-pressure chamber (34-6) is provided in the sealing seat (34-5), and a plurality of connecting holes (34-7) are provided radially on the outer wall of the sealing seat (34-5). One end of the connecting hole (34-7) is connected to the liquid high-pressure chamber (34-6), and the other end of the connecting hole (34-7) is connected to the water outlet (3-2). The high-pressure liquid at the water outlet (3-2) enters the liquid high-pressure chamber (34-6) through the connecting hole (34-7) and forms a pressure difference with the low-pressure liquid at the water inlet (3-1), thereby achieving axial force balance. The outer wall of the moving ring (31-4) is provided with a step (31-6) for cooperating with the inner wall of the transmission seat (31-1) to limit the upward movement of the moving ring (31-4); the bottom of the transmission seat (31-1) is provided with an anti-slip bend (31-7) for limiting the downward movement of the moving ring (31-4); The outer wall of the dynamic ring (31-4) and the inner wall of the transmission seat (31-1) are sealed via an O-ring A (31-3).

2. The novel axial force balancing device for a multi-stage pump according to claim 1 is characterized in that: There are a plurality of spring holes, which are evenly distributed along the outer circumference of the pump shaft hole (31-5).

3. The novel axial force balancing device for a multi-stage pump according to claim 1 is characterized in that: The stationary ring (34-1) and the sealing seat (34-5) are sealed via an O-ring B (34-2).

4. The novel axial force balancing device for a multi-stage pump according to claim 1 is characterized in that: The outer wall of the sealing seat (34-5) and the inner wall of the water inlet and outlet section (3) are sealed via an O-ring C (34-4).

5. The novel axial force balancing device for a multi-stage pump according to claim 1 is characterized in that: The lower part of the sealing seat (34-5) extends outward to form a bottom plate (34-8), and the bottom plate (34-8) is threadedly connected to the bottom of the water inlet and outlet section (3) to form a bottom seal.

6. The novel axial force balancing device for a multi-stage pump according to claim 1 is characterized in that: There are four connecting holes (34-7) in total, which are evenly distributed along the circumference of the outer wall of the sealing seat (34-5).

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