A wet runner pump unit

Abstract

The present application relates to a kind of wet rotor pump units, the pump unit includes shielded motor, impeller, pump housing and bearing group, the pump housing includes the impeller chamber of impeller placement, the suction port of liquid medium and discharge port, when the pump unit operates, the centrifugal force generated by the rotation of the impeller makes the area corresponding to the low-pressure chamber and the high-pressure chamber of the impeller chamber respectively with suction port and discharge port are connected, when the pump unit operates, liquid medium flows from low-pressure chamber into high-pressure chamber, and returns to low-pressure chamber again through the internal liquid path of shielded motor, to form liquid path circulation;The demagnetization buffer zone is arranged between the high-pressure chamber and the internal liquid path of shielded motor, and the magnetic ring for adsorbing magnetic substance in liquid is arranged in the demagnetization buffer zone.Compared with prior art, the present application has the advantages of adsorbing magnetic substance in liquid, improving motor cooling efficiency and the like.

Description

Technical Field

[0001] This invention relates to the field of wet-operation pump technology, and in particular to a wet rotor pump unit. Background Technology

[0002] In heating systems, centrifugal pumps typically operate in wet environments, and motor cooling is achieved through a designed liquid circulation system. This typically involves the liquid medium flowing through the rotor chamber and then returning to the impeller inlet via the central bore of the shaft or other channels, forming a circulation loop. Since the medium inevitably contains magnetic materials, these materials are attracted to the magnetic rotor as it flows through. This accumulation of magnetic materials increases rotor friction losses and reduces the lifespan of the shielding sleeve.

[0003] A search of existing technologies revealed that patent document CN113137396A discloses a pump bearing retainer. This retainer is divided into a radially inner section and a radially outer section. The radially inner section forms a first flow channel gap with the bearing, while the radially outer section has multiple flow channel holes to provide a second flow channel in opposite directions, thereby forming a liquid circulation path. When the pump is running, the medium circulates without passing through the magnetic rotor, reducing the adsorption of magnetic materials. However, this design, which allows the medium to circulate without passing through the rotor, can lead to insufficient motor cooling, causing the motor to overheat and affecting the pump unit's lifespan.

[0004] In order to solve the above-mentioned problems in the existing technology, there is an urgent need to propose a pump unit that can provide a reasonable liquid circulation supply for sufficient cooling of the motor, and at the same time prevent magnetic materials in the liquid medium from accumulating in the gap between the motor rotor and the shielding sleeve. Summary of the Invention

[0005] The purpose of this invention is to overcome the defects of the prior art and provide a wet rotor pump unit.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] According to one aspect of the present invention, a wet rotor pump unit is provided, the pump unit including a shielded motor, an impeller, a pump housing and a bearing assembly, the pump housing including an impeller chamber for housing the impeller, a liquid medium inlet and an outlet, when the pump unit is running, the centrifugal force generated by the rotation of the impeller causes the areas in the impeller chamber connected to the inlet and outlet to respectively form a low-pressure chamber and a high-pressure chamber, respectively. When the pump unit is running, the liquid medium flows from the low-pressure chamber into the high-pressure chamber, and the motor cooling liquid returns to the low-pressure chamber through the internal liquid circuit of the shielded motor, forming a liquid circuit circulation.

[0008] A demagnetizing buffer zone is provided between the high-pressure chamber and the internal liquid circuit of the shielded motor. The demagnetizing buffer zone is equipped with a magnetic ring for adsorbing magnetic substances in the liquid.

[0009] As a preferred technical solution, the shielded motor includes a rotating shaft and a shielding sleeve. The space inside the shielding sleeve forms a rotor cavity. The rotating shaft is placed in the impeller cavity and the rotor cavity. An impeller is installed at the shaft end of the rotating shaft. The rotating shaft has a stepped center hole F3 inside that connects the low-pressure cavity and the rotor cavity. The shielding sleeve includes a flange end face and a stepped shaft section.

[0010] As a preferred technical solution, the bearing assembly includes a front bearing bracket and a rear sliding bearing mounted on the rotating shaft. The front bearing bracket includes a radially outer flange and an axially inner flange. The radially outer flange is provided with one or more cooling holes. The axially inner flange and the stepped shaft section of the shielding sleeve have a radial fitting clearance F1 at the mating surface. The rear sliding bearing and the rotating shaft have a rear sliding bearing fitting clearance F2 at the mating surface.

[0011] As a preferred technical solution, the liquid medium flows from the demagnetizing buffer into the internal liquid path of the shielded motor, and flows sequentially through the cooling hole, the radial fitting clearance F1 of the shielding sleeve, the rotor cavity, the fitting clearance F2 of the rear sliding bearing, and the stepped center hole F3 to the low-pressure cavity.

[0012] As a preferred technical solution, the demagnetizing buffer is formed by the gap created by the cooperation of the end face structure of the shielding sleeve and the front bearing bracket.

[0013] As a preferred technical solution, the magnetic ring is in the shape of a circular ring or an irregular ring.

[0014] As a preferred technical solution, the magnetic ring is mounted on the flange end face of the shielding sleeve or on the radial outer flange face of the front bearing bracket facing the shielding sleeve.

[0015] As a preferred technical solution, when the magnetic ring is installed on the shielding sleeve, the shielding sleeve is provided with a mating structure adapted to the magnetic ring.

[0016] As a preferred technical solution, when the magnetic ring is installed on the front bearing bracket, the front bearing bracket is provided with a mating structure adapted to the magnetic ring.

[0017] As a preferred technical solution, the magnetic ring is a magnetic material made of permanent magnet material neodymium iron boron or samarium cobalt; when the magnetic ring is made of neodymium iron boron, it needs to be phosphated on the surface.

[0018] Compared with the prior art, the present invention can achieve the following technical effects:

[0019] 1. The present invention rationally arranges the various components of the pump unit and designs a liquid circulation loop that flows through the motor rotor, which can achieve sufficient cooling of the motor. The liquid medium flows through all components in the impeller chamber and rotor chamber, and finally returns to the low-pressure chamber from the stepped hollow shaft of the rotor. This can effectively discharge the air in the pump when the pump is working, assist the pump unit to operate smoothly, and improve the cooling efficiency of the motor.

[0020] 2. The wet rotor pump unit proposed in this invention has a magnetic ring installed on the necessary path of the liquid medium from the high pressure chamber to the rotor chamber. The magnetic ring is made of a permanent magnet material that is resistant to high temperature and corrosion and has strong magnetic force. It can effectively adsorb magnetic substances in the liquid medium, avoid the deposition and accumulation of magnetic substances between the rotor and the shielding sleeve when the pump unit is working for a long time, effectively improve the operating efficiency of the pump unit and extend its service life. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of one embodiment of the present invention;

[0022] Figure 2 for Figure 1 A magnified view of the structure at point I;

[0023] Figure 3 for Figure 1 Enlarged view of the structure at point II.

[0024] Wherein, 1 is the shaft, 2 is the impeller, 3 is the pump housing, 4 is the stator, 5 is the rotor, 6 is the stator housing, 7 is the shielding sleeve, 8 is the front bearing bracket, 9 is the front sliding bearing, 10 is the axial thrust sliding bearing, 11 is the cooling hole, 12 is the magnetic ring, 13 is the rear bearing bracket, 14 is the rear sliding bearing, 15 is the suction port, 16 is the discharge port, 17 is the low-pressure chamber, 18 is the high-pressure chamber, 19 is the rotor chamber, F1 is the shielding radial fit clearance, F2 is the rear sliding bearing fit clearance, and F3 is the stepped center hole. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0026] like Figure 1As shown, the wet rotor pump unit proposed in this invention includes a shielded motor, an impeller 2, a pump housing 3, and a bearing assembly. The shielded motor includes a shaft 1, a stator 4, a rotor 5, a shielding sleeve 7, and a rotor cavity 19. The pump housing 3 includes an impeller chamber, a liquid inlet, and a outlet. The impeller 2 is placed in the impeller chamber. The bearing assembly includes a front bearing support 8, a front sliding bearing 9, a rear bearing support 13, and a rear sliding bearing 14. The impeller 2, the front sliding bearing 9, the rotor 5, and the rear sliding bearing 14 are sequentially installed on the shaft 1 from the pump head to the pump tail. When the pump unit is running, the rotor 5 drives the impeller 2 on the shaft 1 to rotate. The centrifugal force generated causes the areas in the impeller chamber connected to the inlet 15 and the outlet 16 to form a low-pressure chamber 17 and a high-pressure chamber 18, respectively. The front bearing bracket 8 includes a radially outer flange and an axially inner flange. The shielding sleeve 7 includes a flange end face and a stepped shaft section. Cooling holes 11 are provided on the radially outer flange. A radial fitting clearance F1 exists between the mating surface of the axially inner flange and the stepped shaft section. A rear sliding bearing fitting clearance F2 exists between the mating surface of the rotor 1 and the rear sliding bearing 14. A stepped center hole F3 is provided inside the rotor shaft 1. During pump unit operation, the liquid medium flows from the low-pressure chamber 17 into the high-pressure chamber 18, passes through the internal liquid path of the shielded motor, and returns to the low-pressure chamber 17, forming a liquid circulation. The liquid medium flows sequentially through the cooling holes 11, the radial fitting clearance F1 of the shielding sleeve, the rotor chamber 19, the rear sliding bearing fitting clearance F2, and the stepped center hole F3 within the internal liquid path of the shielded motor.

[0027] like Figure 2 As shown, the demagnetizing buffer zone where the liquid medium enters the rotor cavity 19 from the high-pressure chamber is equipped with a magnetic ring 12 for adsorbing magnetic substances in the liquid. The magnetic ring 12 is a circular ring or an irregular ring shape. The magnetic ring 12 is mounted on the flange end face of the shielding sleeve 7, or it can also be mounted on the radially outer flange face of the front bearing bracket 8 facing the shielding sleeve 7. The mounting surface of the magnetic ring has a corresponding mating structure. The magnetic ring 12 is made of permanent magnet material samarium cobalt or surface-phosphated neodymium iron boron, which has high temperature resistance, corrosion resistance and strong magnetic force. It can effectively adsorb magnetic substances in the liquid medium, avoid the accumulation of magnetic substances in the gap between the rotor and the shielding sleeve, so that the liquid flow inside the rotor cavity is unobstructed, improving the cooling efficiency and service life of the motor.

[0028] like Figure 3 As shown, the front bearing bracket 8 is provided with one or more radially arranged cooling holes 11, which allow liquid medium to easily and in small amounts to enter the demagnetizing buffer zone between the shielding sleeve and the front bearing bracket, so that the magnetic ring can fully absorb the magnetic substances in the liquid.

[0029] The positive and progressive effects of this embodiment are as follows: This invention solves the problem that magnetic rotors in conventional circulating pumps easily attract magnetic substances from the medium, avoids wear on the rotor and shield head caused by magnetic substances, and does not reduce the amount of cooling medium for the motor, resulting in good cooling effect.

[0030] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A wet rotor pump unit, comprising a shielded motor, an impeller (2), a pump housing (3), and a bearing assembly, wherein the pump housing (3) includes an impeller chamber for housing the impeller (2), a liquid medium inlet (15), and an outlet (16), wherein when the pump unit is running, the centrifugal force generated by the rotation of the impeller (2) causes the regions within the impeller chamber connected to the inlet (15) and the outlet (16) to respectively form a low-pressure chamber (17) and a high-pressure chamber (18), characterized in that, When the pump unit is running, the liquid medium flows from the low-pressure chamber (17) into the high-pressure chamber (18), and the motor cooling liquid returns to the low-pressure chamber (17) after passing through the internal liquid circuit of the shielded motor, forming a liquid circuit circulation; A demagnetizing buffer zone is provided between the high-pressure chamber (18) and the internal liquid circuit of the shielded motor. The demagnetizing buffer zone is provided with a magnetic ring (12) for adsorbing magnetic substances in the liquid. The front bearing bracket (8) includes a radial outer flange, on which one or more cooling holes (11) are provided. The liquid medium flows from the demagnetizing buffer into the internal liquid path of the shielded motor, and flows sequentially through the cooling hole (11), the radial fitting clearance F1 of the shielding sleeve, the rotor cavity (19), the fitting clearance F2 of the rear sliding bearing and the stepped center hole F3 to the low-pressure cavity (17).

2. The wet rotor pump unit according to claim 1, characterized in that, The shielded motor includes a rotating shaft (1) and a shielding sleeve (7). The space inside the shielding sleeve (7) forms a rotor cavity (19). The rotating shaft (1) is placed inside the impeller cavity and the rotor cavity (19). An impeller (2) is installed at the shaft head of the rotating shaft (1). The rotating shaft (1) has a stepped center hole F3 inside that connects the low-pressure cavity (17) and the rotor cavity (19). The shielding sleeve (7) includes a flange end face and a stepped shaft section.

3. A wet rotor pump unit according to claim 2, characterized in that, The bearing assembly includes a front bearing bracket (8) and a rear sliding bearing (14) mounted on a rotating shaft (1). The front bearing bracket (8) also includes an axial inner flange. The axial inner flange and the stepped shaft section of the shielding sleeve (7) have a radial fitting clearance F1 on the mating surface. The rear sliding bearing (14) and the rotating shaft (1) have a rear sliding bearing fitting clearance F2 on the mating surface.

4. A wet rotor pump unit according to claim 1, characterized in that, The demagnetizing buffer zone is formed by the gap created by the cooperation of the end face structure of the shielding sleeve (7) and the front bearing bracket (8).

5. A wet rotor pump unit according to claim 1, characterized in that, The magnetic ring (12) is circular or irregularly shaped.

6. A wet rotor pump unit according to claim 1 or 5, characterized in that, The magnetic ring (12) is installed on the flange end face of the shielding sleeve (7) or on the radial outer flange face of the front bearing bracket (8) facing the shielding sleeve (7).

7. A wet rotor pump unit according to claim 6, characterized in that, When the magnetic ring (12) is installed on the shielding sleeve (7), the shielding sleeve (7) is provided with a matching structure adapted to the magnetic ring (12).

8. A wet rotor pump unit according to claim 6, characterized in that, When the magnetic ring (12) is installed on the front bearing bracket (8), the front bearing bracket (8) is provided with a mating structure adapted to the magnetic ring (12).

9. A wet rotor pump unit according to claim 6, characterized in that, The magnetic ring (12) is a magnetic material made of permanent magnet material neodymium iron boron or samarium cobalt; when the magnetic ring (12) is made of neodymium iron boron, it needs to be phosphated on the surface.

Images