Shaftless impeller shield pump with anti-erosion stator

Abstract

The utility model relates to the technical field of shaftless impeller shield pumps, in particular to a shaftless impeller shield pump with an anti-erosion stator. According to the utility model, the annular stator is coaxially and fixedly connected to the inner wall of the pump shell, and the stator shielding sleeve capable of isolating a liquid working medium is ingeniously sleeved on the outer side of the stator in a sealing manner, so that the stator is effectively prevented from being eroded by the corrosive liquid working medium, and the service life of the pump is prolonged. The stator shielding sleeve is exquisite in structural design and comprises the shielding ring, the first shielding plate and the second shielding plate, the shielding ring, the first shielding plate and the second shielding plate are matched to form the annular containing groove, the annular containing groove is attached to the inner wall of the pump shell in a sealed mode, a sealing cavity completely wrapping the stator is formed, and stable operation of the stator under severe working conditions is guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of shaftless impeller shielded pump technology, specifically a shaftless impeller shielded pump with stator corrosion protection. Background Technology

[0002] Most pumps currently used in production connect the motor shaft to the impeller. The motor drives the shaft to rotate, which in turn drives the impeller to rotate, thus pressurizing the fluid. However, in this type of pump, the motor shaft is prone to damage due to vibration during prolonged use, affecting pump performance. Shaftless pump technology has emerged to effectively solve this problem. Shaftless pumps integrate the shaftless impeller and rotor, resulting in lower leakage, longer service life, and broader application prospects and development value compared to shaft-driven pump technology.

[0003] Shaftless pump technology is disclosed in patents such as CN110500287B, CN208474138U, and CN110714927B. The shaftless impeller pump technology in these patents typically integrates the shaftless impeller with the motor rotor into a single structure, achieving shaftless operation—a relatively advanced pump design. However, in these prior art, the rotor is in constant contact with the liquid working fluid during operation, accompanied by vibration. This operating condition can easily lead to intermittent seal failure between the rotor and the pump casing, creating gaps through which the liquid working fluid can enter the interior of the shielded motor. Because the rotor generates significant centrifugal force during operation, the liquid working fluid is unlikely to adhere to its surface, thus preventing significant corrosion. In contrast, the stator in these prior art is exposed inside the shielded motor and fixed in place. The liquid working fluid can adhere to the stator, causing corrosion and ultimately leading to stator failure. Even more seriously, although the outer surface of the stator is coated with a protective layer, the liquid working fluid splashes and impacts the stator under the centrifugal force of the rotor. Over time, the protective layer will gradually thin and eventually break down under the impact of the liquid working fluid, further accelerating the rate of stator erosion.

[0004] Therefore, it is evident that the current stator anti-corrosion measures in shaftless impeller canned pumps still need further improvement. Utility Model Content

[0005] To avoid and overcome the technical problems existing in the prior art, this utility model provides a shaftless impeller shielded pump with stator corrosion protection. This utility model can effectively reduce the degree of stator corrosion by liquid working fluid.

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

[0007] A shaftless impeller canned pump with stator corrosion protection, comprising a stator, rotor, and shaftless impeller installed inside the pump casing, characterized in that the annular stator is coaxially fixed to the inner wall of the pump casing, and the outer side of the stator is sealed with a stator shielding sleeve that can isolate the liquid working medium; the stator shielding sleeve includes a shielding ring coaxially fitted in the stator shaft hole, and a first shielding plate and a second shielding plate coaxially distributed on both sides of the stator, wherein the first shielding plate, the shielding ring, and the second shielding ring are sequentially connected and cooperate to form an annular receiving groove covering the outer side of the stator; the opening of the receiving groove is sealed and fitted to the inner wall of the pump casing to form a sealed cavity covering the stator.

[0008] As a further embodiment of this utility model: a rotation gap is formed between the rotor and the stator, the inlet of the rotation gap is connected to the outlet of the flow channel of the shaftless impeller, the outlet of the rotation gap is connected to the inlet of the flow channel, and the pressure at the outlet of the rotation gap is lower than the pressure at the inlet of the rotation gap, so as to drive the liquid working medium to circulate back in the rotation gap through the pressure difference.

[0009] As a further embodiment of this utility model: a bearing seat is fixedly installed at both ends inside the pump casing, and the two ends of the sleeve in the shaftless impeller are respectively installed on the corresponding bearing seats through bearings; the stator shielding sleeve and the rotor coaxially fixed to the outer wall of the sleeve do not contact each other, and an installation gap is formed between them; both bearing seats are provided with a return channel that connects the fitting gap and the flow channel, and the two return channels and the installation gap are connected and fitted in sequence to form the rotation gap.

[0010] As a further embodiment of this utility model: both ends of the sleeve are fixedly connected to thrust plates, the two thrust plates are located between the two bearings, and a first gap is formed between the two thrust plates and the inner end face of the adjacent bearing seat, and the two first gaps are directly connected to the adjacent return channels respectively; the rotor is located between the two thrust plates, and the rotor is in close contact with one of the thrust plates, and an annular groove arranged coaxially with the sleeve is formed between the rotor and the other thrust plate; the stator shield sleeve is coaxially embedded in the annular groove, and a fourth gap is formed between the stator shield sleeve and the annular groove; a second gap is formed between the outer circular surface of the two thrust plates and the inner wall of the pump casing, and a third gap is formed between the outer circular surface of the rotor and the inner wall of the pump casing, and the two first gaps, two second gaps, third gaps and fourth gaps are sequentially connected and cooperate to form the installation gap.

[0011] As a further improvement of this utility model, the bearing is a thrust bearing, and the thrust disc and its adjacent thrust bearing cooperate to form a friction pair.

[0012] As a further improvement of this utility model: both ends of the pump casing are covered with end caps, and each end cap has a flow hole arranged coaxially with the sleeve, and both flow holes are connected to the flow channel.

[0013] As a further improvement of this utility model: a lead-in port is provided on the pump casing, and the lead-in wire on the stator for connecting to the external power source passes through the lead-in port and out of the pump casing.

[0014] As a further improvement of this utility model, blades are installed in the flow channel of the sleeve.

[0015] As a further improvement of this utility model, a spiral groove is provided on the end face of the rotor facing the stator.

[0016] As a further improvement of this utility model, a diamond-like coating is provided at the position on the outer side of the sleeve where it mates with the bearing.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] 1. This utility model uses a circular stator coaxially fixed to the inner wall of the pump casing, and cleverly seals its outer side with a stator shielding sleeve that isolates it from the liquid working medium. This effectively prevents the stator from being corroded by the liquid working medium and extends the service life of the pump. The stator shielding sleeve has an ingenious structural design, including a shielding ring and first and second shielding plates, which cooperate to form an annular receiving groove that seals tightly against the inner wall of the pump casing, forming a sealed cavity that completely covers the stator, ensuring stable operation of the stator under harsh working conditions.

[0019] 2. The rotational clearance formed by the fit between the rotor and stator, and the connection between this clearance and the flow channel of the shaftless impeller, enables the circulation and return of the liquid working medium within the rotational clearance. This rotational clearance design not only improves the pump's efficiency but also drives the circulation of the liquid working medium through pressure difference, helping to reduce the pump's operating temperature and wear, thus enhancing the pump's reliability and durability.

[0020] 3. The bearing housings fixed at both ends inside the pump casing, and the bearing mounting method at both ends of the sleeve in the shaftless impeller, ensure the stable operation of the shaftless impeller. Simultaneously, the return flow channel on the bearing housing, connected to the installation gap, forms a rotational clearance, further optimizing the circulation path of the liquid working medium and improving the pump's performance and efficiency.

[0021] 4. The thrust discs fixed to both ends of the sleeve not only enhance the stability of the structure, but also form a complex installation clearance system through the first gap formed between them and the inner end face of the adjacent bearing housing, and the second gap formed between them and the inner wall of the pump casing. The ingenious design of these gaps ensures the smooth flow of the liquid working fluid while avoiding direct contact between components, thus reducing friction and wear.

[0022] 5. The use of a thrust bearing for support, which cooperates with the thrust disc to form a friction pair, improves the pump's load-bearing capacity and stability, ensuring smooth operation of the shaftless impeller at high speeds. Simultaneously, the selection of the thrust bearing reduces pump noise and vibration, enhancing the overall performance of the pump.

[0023] 6. The flow holes on the end covers at both ends of the pump casing are connected to the flow channels of the shaftless impeller, ensuring smooth flow of the liquid working medium, simplifying the pump structure, and improving the pump's reliability and ease of maintenance.

[0024] 7. The lead-in holes on the pump casing provide a path for the stator to connect to external power while ensuring the sealing of the pump casing. This design satisfies the requirements of electrical connection and prevents the liquid working fluid from corroding the electrical components.

[0025] 8. The blades installed inside the sleeve flow channel enhance the pump's suction and discharge capabilities, improving its operating efficiency. The blade design also optimizes the flow path of the liquid working fluid, reducing energy consumption and noise.

[0026] 9. The helical grooves on the rotor's end face facing the stator further improve the flow state of the liquid working fluid, increasing the pump's head and efficiency. The helical groove design also enhances the fit between the rotor and stator, improving the pump's reliability and stability.

[0027] 10. The diamond-like carbon (DLC) coating applied to the outer side of the sleeve where it mates with the bearing significantly improves the hardness and wear resistance of the components, extending the pump's service life. Simultaneously, the DLC coating also provides excellent lubrication, reducing friction and wear between components and improving the pump's operating efficiency and reliability. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the assembly structure of the stator shield and the stator in this utility model.

[0029] Figure 2 This is a schematic diagram of the overall structure of this utility model.

[0030] Figure 3 This is a schematic diagram of the structure after adding a rotor in this utility model.

[0031] In the diagram: 1. Pump body assembly; 10. Pump casing; 101. Lead wire port; 11. End cover; 11a. Front bearing end cover; 11a1. Pump inlet; 11b. Rear bearing end cover; 11b1. Pump outlet; 12. Bearing housing; 12a. Front bearing housing; 12b. Rear bearing housing; 121. Return channel; 2. Shielded motor; 20. Stator; 201. Lead wire; 21. Rotor; 211. Third clearance; 21 2. Spiral groove; 22. Stator shielding sleeve; 221. First shielding plate; 222. Second shielding plate; 223. Shielding ring; 23. Bearing; 23a. Front bearing; 22b. Rear bearing; 24. Fourth clearance; 3. Shaftless impeller; 31. Sleeve; 32. Blade; 33. Thrust plate; 33a. Front thrust plate; 33b. Rear thrust plate; 34. First clearance; 25. Second clearance; 4. Rotation clearance. Detailed Implementation

[0032] 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.

[0033] Please see Figures 1-3 In this embodiment of the present invention, a shaftless impeller shielded pump with stator corrosion protection includes a pump body assembly 1, a shielded motor 2, and a shaftless impeller 3.

[0034] The pump body assembly 1 includes a cylindrical pump casing 10, within which end covers 11 and bearing seats 12 are installed. The end covers 11 are divided into a front bearing end cover 11a and a rear bearing end cover 11b, and the bearing seats 12 are divided into a front bearing seat 12a and a rear bearing seat 12b. Both the front bearing end cover 11a and the front bearing seat 12a are installed at the inlet of the pump casing 10, with the front bearing seat 12a located inside the front bearing end cover 11a, and the two are arranged in close contact with each other. Similarly, the rear bearing end cover 11b and the rear bearing seat 12b are installed at the outlet of the pump casing 10 in the same manner. Each of the front bearing end cover 11a, front bearing seat 12a, rear bearing end cover 11b, and rear bearing seat 12b has a flow hole at its axial center, and these flow holes are coaxially arranged and connected to both ends of the sleeve 31.

[0035] The shielded motor 2 includes an annular stator 20, which is coaxially fixedly mounted on the inner wall of the pump casing 10. For convenient power supply, a lead-in port 101 is provided on the pump casing 10. Leads 201 from the stator 20 pass through the lead-in port 101 and are connected to an external power source to provide power to the shielded motor 2. To improve the sealing performance of the stator 20 during operation, a stator shielding sleeve 22 is provided on the outer side of the stator 20. The stator shielding sleeve 22 includes a shielding ring 223 coaxially fitted in the central hole of the stator 20, and a first shielding plate 221 and a second shielding plate 222 coaxially distributed on both sides of the stator 20. The first shielding plate 221, the shielding ring 223, and the second shielding ring 223 are sequentially connected and cooperate to form an annular receiving groove covering the outer side of the stator 20. The opening of the receiving groove is sealed against the inner wall of the pump casing 10 to form a sealed cavity covering the stator 20.

[0036] The shielded motor 2 also includes a hollow disc-shaped rotor 21, which is coaxially fixed to the outer wall of the sleeve 31 of the shaftless impeller 3. Both ends of the sleeve 31 are rotatably connected to their corresponding bearing seats 12 via bearings 23. The front end of the sleeve 31 is rotatably connected to the front bearing seat 12a via a front bearing 23a, and the rear end of the sleeve 31 is rotatably connected to the rear bearing seat 12b via a rear bearing 23b. Thus, the sleeve 31 is coaxially and rotatably installed inside the pump casing 10. Two thrust discs 33 are also coaxially fixedly installed at both ends of the sleeve 31, and both thrust discs 33 are located inside the corresponding bearings 23, forming a friction pair with the bearings 23. The bearings 23 used in this embodiment are thrust bearings.

[0037] The rotor 21 is fitted to one of the thrust bearings and forms an annular groove with the other thrust plate 33. The stator 20 is coaxially embedded in the annular groove, and a fourth gap 24 with a U-shaped cross-section is formed between the shielding sleeve on the outside of the stator 20 and the annular groove.

[0038] A first gap 34 is formed between each of the two thrust discs 33 and the inner end face of their adjacent bearing housings 12. Return channels 121 are provided on both the front bearing housing 12a and the rear bearing housing 12b. One end of the return channel is located on the inner side of the bearing housing 12, and the other end is located on the wall of the shaft hole of the bearing housing 12, thus directly communicating with the flow channel in the sleeve 31. A second gap 25 is formed between the outer circular surface of each of the two thrust discs 33 and the inner wall of the pump housing 10, and a third gap 211 is formed between the outer circular surface of the rotor 21 and the inner wall of the pump housing 10. The two first gaps 34, the two second gaps 25, the third gap 211, and the fourth gap 24 are sequentially connected and fitted to form the installation gap. The two return channels 121 and the installation gap are sequentially connected and fitted to form the rotational gap 4.

[0039] In the process of using this invention after assembly, liquid enters the flow channel from the pump inlet 11a1 and flows out from the pump outlet 11b1 along the flow channel. During the liquid flow, because the pressure at the pump inlet is lower than the pressure at the pump outlet 11b1, a portion of the liquid flows along the return channel 121 on the rear bearing housing 12b to the first gap 34 at the rear end, and then flows sequentially through the second gap 25, the fourth gap 24, the third gap 211 at the rear end, the second gap 25 at the front end, and the first gap 34 at the front end, and finally flows back into the flow channel through the return channel 121 in the front bearing housing 12a. This process repeats, effectively carrying away the heat inside the shielded motor 2 through the liquid working fluid, thereby reducing its internal temperature and preventing overheating and burnout.

[0040] like Figure 3 As shown, to further improve the efficiency of the shielded motor 2, a rotor 21 is also installed on the other side of the stator 20, and the two rotors 21 are arranged symmetrically. At this time, a corresponding annular groove is formed between the two rotors 21, resulting in a fourth gap 24. Simultaneously, a spiral groove 212 is formed on the inner surface of the rotor 21 near the pump outlet 11b1. When the shaftless impeller 330 rotates, the liquid working fluid is drawn into the spiral groove 212, thus forming a high-pressure zone at this location, which serves to balance the axial force. A third gap 211 is also formed between the newly added rotor 21 and the pump casing 10, through which the liquid working fluid flows during its flow.

[0041] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A shaftless impeller shielded pump with stator corrosion resistance, comprising a pump casing (10), wherein a stator (20), a rotor (21), and a shaftless impeller (3) are installed inside the pump casing (10) and cooperate with each other, characterized in that, The annular stator (20) is coaxially fixed to the inner wall of the pump housing (10), and the outer side of the stator (20) is sealed with a stator shielding sleeve (22) that can isolate the liquid working medium; the stator shielding sleeve (22) includes a shielding ring (223) coaxially fitted in the central hole of the stator (20), and a first shielding plate (221) and a second shielding plate (222) coaxially distributed on both sides of the stator (20), and the first shielding plate (221), the shielding ring (223) and the second shielding ring (223) are connected in sequence and cooperate to form an annular receiving groove covering the outside of the stator (20); the opening of the receiving groove is sealed and fitted with the inner wall of the pump housing (10) to cooperate with the pump housing (10) to form a sealed cavity covering the stator (20).

2. The shaftless impeller shielded pump with stator corrosion protection according to claim 1, characterized in that, A rotation gap (4) is formed between the rotor (21) and the stator (20). The inlet of the rotation gap (4) is connected to the outlet of the flow channel of the shaftless impeller (3). The outlet of the rotation gap (4) is connected to the inlet of the flow channel. The pressure at the outlet of the rotation gap (4) is lower than the pressure at the inlet of the rotation gap (4) so ​​as to drive the liquid working medium to circulate back in the rotation gap (4) through the pressure difference.

3. A shaftless impeller shielded pump with stator corrosion protection according to claim 2, characterized in that, A bearing seat (12) is fixedly installed at both ends inside the pump casing (10). The two ends of the sleeve (31) in the shaftless impeller (3) are respectively installed on the corresponding bearing seat (12) through bearings (23). The stator shield sleeve (22) and the rotor (21) coaxially fixed on the outer wall of the sleeve (31) do not contact each other, and there is an installation gap between them. Both bearing seats (12) are provided with a return channel (121) that connects the fitting gap and the flow channel. The two return channels (121) and the installation gap are connected and fitted in sequence to form the rotation gap (4).

4. A shaftless impeller shielded pump with stator corrosion protection according to claim 3, characterized in that, Both ends of the sleeve (31) are fixed with thrust plates (33). The two thrust plates (33) are located between the two bearings (23), and a first gap (34) is formed between the two thrust plates (33) and the inner end face of the adjacent bearing seat (12). The two first gaps (34) are directly connected to the adjacent return channels (121). The rotor (21) is located between the two thrust plates (33), and the rotor (21) is in contact with one of the thrust plates (33) and forms a gap with the sleeve (31) between the rotor (21) and the other thrust plate (33). A coaxially arranged annular groove; the stator shield sleeve (22) is coaxially embedded in the annular groove, and a fourth gap (24) is formed between the stator shield sleeve (22) and the annular groove; a second gap (25) is formed between the outer circular surface of the two thrust plates (33) and the inner wall of the pump casing (10), and a third gap (211) is formed between the outer circular surface of the rotor (21) and the inner wall of the pump casing (10). The two first gaps (34), the two second gaps (25), the third gap (211) and the fourth gap (24) are connected and cooperated in sequence to form the installation gap.

5. A shaftless impeller shielded pump with stator corrosion protection according to claim 4, characterized in that, The bearing (23) is a thrust bearing, and the thrust plate (33) and its adjacent thrust bearing form a friction pair.

6. A shaftless impeller shielded pump with stator corrosion protection according to any one of claims 1-5, characterized in that, Both ends of the pump casing (10) are covered with end caps (11), and each end cap (11) has a flow hole arranged coaxially with the sleeve (31), and both flow holes are connected to the flow channel.

7. A shaftless impeller shielded pump with stator corrosion protection according to claim 6, characterized in that, A lead wire port (101) is provided on the pump casing (10), and the lead wire (201) on the stator (20) for connecting to the outside power supply passes through the lead wire port (101) and exits the pump casing (10).

8. A shaftless impeller shielded pump with stator corrosion protection according to claim 7, characterized in that, Blades (32) are installed in the flow passage of the sleeve (31).

9. A shaftless impeller shielded pump with stator corrosion protection according to claim 8, characterized in that, A helical groove (212) is provided on the end face of the rotor (21) facing the stator (20).

10. A shaftless impeller shielded pump with stator corrosion protection according to claim 9, characterized in that, A diamond-like coating is provided at the position where the sleeve (31) mates with the bearing (23).

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