Liquid pump

Abstract

A liquid pump, comprising a pump casing (1), an impeller (2), a rotor (3), a stator (4), a first wear ring (5) and a second wear ring (6). The pump casing (1) comprises an impeller housing (11) and an electric motor housing (12), which has a stator chamber and a rotor chamber (121), the stator chamber circumferentially surrounding the rotor chamber (121), and the rotor chamber (121) being in communication with the impeller housing (11). The impeller (2) is positioned inside the impeller housing (11); the rotor (3) is located in the rotor chamber (121), and the impeller (2) is fixedly connected to the rotor (3); the stator (4) is located in the stator chamber; the first wear ring (5) is fixed to an inner wall of the rotor chamber (121), and the second wear ring (6) is fixed to an outer wall of the rotor (3); and the first wear ring (5) and the second wear ring (6) are disposed opposite each other in the radial direction of the rotor (3).

Description

Liquid pump

[0001] This disclosure claims priority to Chinese Patent Application No. 202411522280.2, filed on October 28, 2024, entitled "Liquid Pump", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to the field of power equipment technology, and in particular to a liquid pump. Background Technology

[0003] A liquid pump is a power device that transports or pressurizes fluids. It is used to transfer the mechanical energy provided by an electric motor to the liquid being transported, thereby increasing the liquid's energy. For example, an impeller-type liquid pump transfers mechanical energy to the liquid being transported by driving the impeller to rotate at high speed.

[0004] So, the impeller-type liquid pump mainly consists of an impeller, a motor, and a pump shaft. One end of the pump shaft is fixedly connected to the impeller, and the other end passes through the rotor of the motor. The rotor of the motor rotates in the magnetic field generated by the stator of the motor, thereby driving the impeller to rotate through the pump shaft. The impeller continuously draws in liquid and discharges liquid during rotation, so that the liquid is transferred from one position to another.

[0005] To reduce wear between the pump shaft and the inner wall of the housing, bearings are usually installed at both ends of the pump shaft. The pump shaft is supported in the housing by the two bearings on the left and right sides, which can reduce wear between the pump shaft and the inner wall of the housing. However, the axial dimension of this type of liquid pump is generally relatively large. Summary of the Invention

[0006] This disclosure provides a liquid pump that can shorten the axial dimension of the liquid pump, simplify the assembly process, and improve assembly efficiency.

[0007] This disclosure provides a liquid pump, which includes a pump casing, an impeller, a rotor, a stator, a first wear ring, and a second wear ring;

[0008] The pump casing includes an impeller casing and a motor casing. The motor casing has a stator chamber and a rotor chamber. The stator chamber circumferentially surrounds the rotor chamber, and the rotor chamber communicates with the impeller casing.

[0009] The impeller is located in the impeller housing, the rotor is located in the rotor chamber, and the impeller is fixedly connected to the rotor. The stator is located in the stator chamber.

[0010] The first wear-resistant ring is fixed on the inner wall of the rotor chamber, and the second wear-resistant ring is fixed on the outer wall of the rotor. The first wear-resistant ring and the second wear-resistant ring are positioned opposite each other in the radial direction of the rotor.

[0011] In the scheme disclosed herein, the impeller of the impeller-type liquid pump is directly fixed to the rotor, rather than being fixed to the rotor via a pump shaft. Eliminating the pump shaft can shorten the axial dimension of the liquid pump. Furthermore, a first wear-resistant ring is fixed on the inner wall of the rotor chamber where the rotor is located, and a second wear-resistant ring is fixed on the outer surface of the rotor. The first and second wear-resistant rings cooperate to form a friction pair, which does not occupy axial space, further shortening the axial dimension of the liquid pump.

[0012] In the solution disclosed herein, the first wear ring and the second wear ring can serve as the support and wear-resistant function of the bearing. Compared with multiple bearings assembled on the pump shaft, the first wear ring and the second wear ring do not need to be aligned, which can simplify the assembly process of the liquid pump and improve the assembly efficiency.

[0013] In one possible implementation, both the first wear-resistant ring and the second wear-resistant ring are tubular in shape, with the tube wall of the first wear-resistant ring fixed to the inner wall of the rotor chamber and the tube wall of the second wear-resistant ring fixed to the outer wall of the rotor.

[0014] Alternatively, both the first wear-resistant ring and the second wear-resistant ring are barrel-shaped. The barrel wall of the first wear-resistant ring is fixed to the inner wall of the rotor chamber, and the barrel bottom of the first wear-resistant ring is fixed to the bottom of the rotor chamber away from the impeller shell. The barrel wall of the second wear-resistant ring is fixed to the outer wall of the rotor, and the barrel bottom of the second wear-resistant ring is fixed to the end face of the rotor away from the impeller.

[0015] In the scheme disclosed herein, both the first and second wear-resistant rings are tubular in shape, which can prevent wear between the inner wall of the rotor chamber and the outer wall of the rotor. Both the first and second wear-resistant rings are barrel-shaped, which not only prevents wear between the inner wall of the rotor chamber and the outer wall of the rotor, but also prevents wear between the bottom wall of the rotor chamber away from the impeller casing and the end face of the rotor away from the impeller.

[0016] In one possible implementation, the axial length of the first wear-resistant ring is greater than or equal to half the axial length of the rotor chamber, and less than or equal to the axial length of the rotor chamber.

[0017] The axial length of the second wear-resistant ring is greater than or equal to half the axial length of the rotor, and less than or equal to the axial length of the rotor.

[0018] In the scheme shown in this disclosure, the axial lengths of the first wear-resistant ring and the second wear-resistant ring are relatively long, so even if the rotor tilts in the rotor chamber, wear between the outer wall of the rotor and the inner wall of the rotor chamber can be avoided.

[0019] In one possible implementation, the first wear ring is made of one or more of ceramic, stainless steel, graphite, and brass.

[0020] The second wear-resistant ring is made of one or more of the following materials: ceramic, stainless steel, graphite, and brass.

[0021] In the scheme disclosed herein, the materials of the first wear ring and the second wear ring can be the same or different.

[0022] In one possible implementation, the first wear-resistant ring is embedded in the inner wall of the rotor chamber.

[0023] In the scheme shown in this disclosure, the first wear-resistant ring is embedded in the inner wall of the rotor chamber, which can enhance the fastening relationship between the first wear-resistant ring and the rotor chamber, so that the first wear-resistant ring is firmly fixed in the rotor chamber.

[0024] In one possible implementation, the end faces at both ends of the first wear-resistant ring along the axial direction have a tangent between them and the outer surface located outside the ring;

[0025] The inner wall of the rotor chamber has a cross-section that matches the cross-section of the first wear-resistant ring, and the cross-section of the first wear-resistant ring and the cross-section of the rotor chamber are in contact.

[0026] In the scheme shown in this disclosure, the cross-section of the first wear-resistant ring matches the cross-section of the rotor chamber, which serves as an axial limiting function, making it difficult for the first wear-resistant ring to translate axially relative to the rotor chamber.

[0027] In one possible implementation, the outer surface of the first wear-resistant ring has a first limiting structure, and the inner wall of the rotor chamber has a second limiting structure. The first limiting structure and the second limiting structure cooperate to restrict the first wear-resistant ring from rotating in the circumferential direction relative to the rotor chamber.

[0028] In the scheme shown in this disclosure, the first limiting structure can be a protrusion, and the second limiting structure can be a groove; alternatively, the first limiting structure can be a groove, and the second limiting structure can be a protrusion. By having the protrusion engage with the groove, circumferential limiting can be achieved, making it difficult for the first wear-resistant ring to rotate relative to the rotor chamber in the circumferential direction.

[0029] In one possible implementation, the second wear-resistant ring is interference-fitted onto the outer wall of the rotor.

[0030] In the scheme shown in this disclosure, the second wear-resistant ring is interference-fitted onto the outer wall of the rotor, making the fixed relationship between the second wear-resistant ring and the rotor more secure.

[0031] In one possible implementation, one axial end of the second wear-resistant ring has a radial lug that hooks onto the end face of the rotor and engages with the rotor.

[0032] In the scheme shown in this disclosure, the radial lug is attached to the end face of the rotor, and the radial lug is also engaged with the rotor, which can restrict the relative movement between the second wear ring and the rotor in the axial direction.

[0033] In one possible implementation, the impeller includes an impeller portion and a rod portion, the impeller portion being located in the impeller housing, and the rod portion extending into the rotor chamber and fixed to the rotor.

[0034] In the scheme shown in this disclosure, the impeller is fixed to the rotor directly through its rod, rather than being driven to the rotor through the pump shaft. Eliminating the pump shaft allows for the arrangement of more rotors in the space occupied by the pump shaft, increasing the volume of the rotor and thus increasing the output torque of the liquid pump. Attached Figure Description

[0035] Figure 1 is a schematic diagram of the structure of a liquid pump provided in an exemplary embodiment of the present disclosure;

[0036] Figure 2 is a schematic longitudinal section of a liquid pump provided in an exemplary embodiment of this disclosure;

[0037] Figure 3 is a partial longitudinal cross-sectional schematic diagram of a liquid pump provided in an exemplary embodiment of the present disclosure;

[0038] Figure 4 is a partial longitudinal cross-sectional schematic diagram of a liquid pump provided in another exemplary embodiment of this disclosure;

[0039] Figure 5 is a schematic longitudinal section diagram of the impeller and rotor after being fixed, provided in another exemplary embodiment of this disclosure.

[0040] Explanation of reference numerals in the attached drawings: 1. Pump casing; 11. Impeller casing; 111. Impeller chamber; 112. Inlet; 113. Outlet; 12. Motor casing; 121. Rotor chamber; 122. Inner cover. 2. Impeller; 21. Impeller section; 22. Rod section. 3. Rotor; 31. First layer; 32. Second layer; 33. Third layer. 4. Stator. 5. First wear ring. 6. Second wear ring; 61. Radial lug. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0042] This embodiment relates to a liquid pump, specifically an impeller-type liquid pump. Structurally, the impeller-type liquid pump mainly includes a pump casing, an impeller, and a motor. The pump casing comprises an impeller housing and a motor housing. The impeller is located within the impeller housing, and the motor is located within the motor housing. The impeller housing, for example, can be a volute, having an inlet and an outlet to allow liquid to enter the impeller housing from the inlet and exit from the outlet. Since the motor drives the impeller to rotate, the impeller-type liquid pump may also include a pump shaft. One end of the pump shaft is fixedly connected to the impeller, and the other end passes through the motor rotor. In this way, the motor stator generates a magnetic field, and the motor rotor rotates under the influence of the magnetic field. During this rotation, the rotor drives the impeller to rotate via the pump shaft.

[0043] To prevent wear between the pump shaft and the inner wall of the pump casing, bearings are arranged near both ends of the pump shaft in the axial direction. The pump shaft is then supported in the pump casing by the two bearings on the left and right sides, so that the pump shaft does not come into contact with the inner wall of the pump casing, thus avoiding wear.

[0044] However, this type of impeller-type liquid pump has two main drawbacks. First, the bearings installed at both ends of the pump shaft result in a relatively large axial dimension, which hinders miniaturization. Second, aligning the two bearings during assembly presents certain difficulties, increasing the overall assembly complexity.

[0045] Therefore, this embodiment provides a liquid pump that does not arrange two bearings in the axial direction. Instead, two wear-resistant rings are arranged on the outer wall of the rotor and the inner wall of the rotor chamber where the rotor is located. The wear-resistant rings on the outer wall of the rotor and the wear-resistant rings on the inner wall of the rotor chamber cooperate to act as bearings. This can save the axial dimension of the liquid pump and eliminate the problem of bearing alignment during assembly, thus reducing the assembly difficulty of the liquid pump.

[0046] The structural features of a liquid pump will be described in detail below.

[0047] Figure 1 shows a schematic diagram of the liquid pump structure, and Figure 2 shows a cross-sectional view of the liquid pump in Figure 1 along its axial direction. Referring to Figure 1, the liquid pump includes a pump casing 1, which includes an impeller casing 11 and a motor casing 12. The impeller casing 11 can be, for example, a volute, and has an inlet 112 and an outlet 113, which are generally connected to pipes. It should be noted that the motor casing 12 in Figure 1 is only shown in a partial schematic diagram, and the housing portion accommodating the stator is not shown in Figure 1.

[0048] Referring to Figure 2, the impeller housing 11 has a chamber for accommodating the impeller 2 (denoted as impeller chamber 111), the motor housing 12 has a chamber for accommodating the stator 4 (denoted as stator chamber, not shown in Figure 2), and the motor housing 12 also has a chamber for accommodating the rotor 3 (denoted as rotor chamber 121). Since the rotor 3 is cylindrical, the rotor chamber 121 is also cylindrical, as shown in Figure 2. Because the stator 4 surrounds the rotor 3 circumferentially, the stator chamber is specifically an annular chamber surrounding the rotor chamber 121 circumferentially. Therefore, the stator chamber and the rotor chamber 121 share a common wall, and the wall of the rotor chamber 121 is also the inner annular wall of the stator chamber. Continuing to refer to Figure 2, the motor housing 12 also includes an inner cover 122, which covers the opening of the barrel-shaped rotor chamber 121.

[0049] In one example, the impeller 2 is no longer connected to the rotor 3 via a pump shaft; instead, the impeller 2 is directly fixed to the rotor 3. For example, referring to Figure 2, the impeller 2 includes an impeller portion 21 and a rod portion 22, which can be integrally formed. The center of the impeller portion 21 is located on the axial center line of the rod portion 22. Continuing to refer to Figure 2, the inner cover 122 has a through hole through which the rod portion 22 passes, directly fixing it to the rotor 3. The axial center line of the rod portion 22 is collinear with the axial center line of the rotor 3. Thus, as the rotor 3 rotates, it directly drives the impeller 2 to rotate.

[0050] This scheme of eliminating the pump shaft (which can also be understood as integrating the rotor and pump shaft together) allows the space originally occupied by the pump shaft to be used to arrange the rotor 3, thereby increasing the volume of the rotor 3. With the output power of the motor being constant, the larger the volume of the rotor, the greater the rated torque of the motor, which in turn increases the electromagnetic power and output torque of the motor.

[0051] Referring to Figure 2, after the impeller housing 11 and the motor housing 12 are fixed, the impeller chamber 111 and the rotor chamber 121 are connected through the through hole on the inner cover 122. However, the impeller chamber 111 is not connected to the stator chamber. In this way, the impeller 2 and the rotor 3 are located in the wet area, and the stator 4 is located in the dry area. The stator chamber isolates or shields the stator 4. The magnetic field generated after the stator 4 is energized passes through the cavity wall of the stator chamber and acts on the rotor 3, driving the rotor 3 to rotate.

[0052] In one example, when the liquid pump is working, the rotor chamber 121 is filled with liquid, and the rotor 3 is suspended in the rotor chamber 121. In order to allow the liquid in the impeller chamber 111 to flow into the rotor chamber 121 more quickly, the inner cover 122 may have multiple through holes that penetrate the thickness of the inner cover 122. Thus, when the liquid pump is working, the liquid in the impeller chamber 111 can flow into the rotor chamber 121 through the through holes and the via holes on the inner cover 122.

[0053] Because rotor 3 is suspended in rotor chamber 121, it will tilt and come into contact with the inner wall of rotor chamber 121 during rotation. Once contact occurs, wear will occur. To avoid wear between rotor 3 and the inner wall of rotor chamber 121, as shown in Figure 3 (a partial schematic diagram of Figure 2), the pump also includes a first wear-resistant ring 5 and a second wear-resistant ring 6. The first wear-resistant ring 5 has a ring-shaped cross-section in the radial direction, and the second wear-resistant ring 6 also has a ring-shaped cross-section in the radial direction. Referring to Figure 3, the first wear-resistant ring 5 is fixed to the inner wall of rotor chamber 121, and the second wear-resistant ring 6 is fixed to the outer wall of rotor 3. Furthermore, the first wear-resistant ring 5 and the second wear-resistant ring 6 are positioned opposite each other in the radial direction, with a gap between them, forming a friction pair.

[0054] In this way, when the pump is working, the rotor chamber 121 is filled with liquid, and the rotor 3 is suspended and rotates within the rotor chamber 121. The gap between the first wear ring 5 and the second wear ring 6 is filled with liquid, which reduces the coefficient of friction between the first wear ring 5 and the second wear ring 6. The liquid filling the gap also lubricates the first wear ring 5 and the second wear ring 6. Moreover, under the action of the first wear ring 5 and the second wear ring 6, the rotor 3 will not touch the inner wall of the rotor chamber 121, thereby preventing wear between the rotor 3 and the rotor chamber 121.

[0055] In one example, if the axial lengths of the first wear-resistant ring 5 and the second wear-resistant ring 6 are relatively short, then when the rotor 3 tilts during rotation, it will come into contact with the inner wall of the rotor chamber 121, causing wear between the rotor 3 and the rotor chamber 121. Therefore, the axial length of the first wear-resistant ring 5 is greater than or equal to L1, and less than or equal to the axial length of the rotor chamber 121, where L1 is the axial length of the first wear-resistant ring 5 when the rotor 3 is tilted and just contacts the inner wall of the rotor chamber 121. For example, the axial length of the first wear-resistant ring 5 is greater than or equal to half the axial length of the rotor chamber 121, and less than or equal to the axial length of the rotor chamber 121.

[0056] Similarly, the axial length of the second wear-resistant ring 6 is greater than or equal to L2, and less than or equal to the axial length of the rotor 3, where L2 is the axial length of the second wear-resistant ring 6 when the rotor 3 is tilted and just in contact with the inner wall of the rotor chamber 121. For example, the axial length of the second wear-resistant ring 6 is greater than or equal to half the axial length of the rotor 3, and less than or equal to the axial length of the rotor 3.

[0057] As an example, referring to Figure 2, the axial length of the first wear-resistant ring 5 is substantially equal to the axial length of the rotor chamber 121, and the axial length of the second wear-resistant ring 6 is substantially equal to the axial length of the rotor 3. Thus, regardless of the rotor 3's tilt within the rotor chamber 121, contact is always made between the first wear-resistant ring 5 and the second wear-resistant ring 6. The outer wall of the rotor 3 does not contact the inner wall of the rotor chamber 121, thereby preventing wear between the outer surface of the rotor 3 and the inner wall of the rotor chamber 121.

[0058] As described above, during operation, the rotor 3 is suspended in the rotor chamber 121 under the influence of the liquid. Therefore, the axial length of the rotor chamber 121 is typically greater than the axial length of the rotor 3. Referring to Figure 2, the axial length of the first wear ring 5 is greater than the axial length of the second wear ring 6. Of course, the axial length of the first wear ring 5 can also be equal to the axial length of the second wear ring 6, or even less. This embodiment does not specifically limit the relationship between the axial lengths of the first wear ring 5 and the second wear ring 6.

[0059] Regarding the shapes of the first wear-resistant ring 5 and the second wear-resistant ring 6: As mentioned above, both the first wear-resistant ring 5 and the second wear-resistant ring 6 have annular cross-sections in the radial direction. As an example, referring to Figure 2, the first wear-resistant ring 5 and the second wear-resistant ring 6 can be tubular. As another example, as shown in Figure 4, which is a schematic cross-section of the liquid pump shown in Figure 1 along the axial direction, both the first wear-resistant ring 5 and the second wear-resistant ring 6 are barrel-shaped. In this case, the outer surface of the barrel wall of the first wear-resistant ring 5 is fixed to the inner wall of the rotor chamber 121, the outer surface of the barrel bottom of the first wear-resistant ring 5 is fixed to the bottom wall of the rotor chamber 121, the inner surface of the barrel wall of the second wear-resistant ring 6 is fixed to the circumferential outer surface of the rotor 3, and the inner surface of the barrel bottom of the second wear-resistant ring 6 is fixed to the end face of the rotor 3 away from the impeller 2. In this design where both the first wear-resistant ring 5 and the second wear-resistant ring 6 are barrel-shaped, wear between the outer circumferential surface of the rotor 3 and the inner wall of the rotor chamber 121 can be avoided, as well as wear between the lower end face of the rotor 3 and the bottom wall of the rotor chamber 121 can be avoided.

[0060] Regarding the specific materials of the first wear-resistant ring 5 and the second wear-resistant ring 6: In one example, the first wear-resistant ring 5 can be made of one or more of the following: ceramic (such as zirconium oxide or silicon carbide), stainless steel (such as 304 stainless steel or 316 stainless steel), graphite, and brass. For example, the first wear-resistant ring 5 can be a ceramic ring, or a stainless steel ring, or a graphite ring, or a brass ring. As another example, the first wear-resistant ring 5 can have a multi-layered structure, comprising multiple layers in the radial direction, each layer being made of a different material. As an example, the first wear-resistant ring 5 may include two layers, one made of ceramic and the other of graphite, or one made of stainless steel and the other of brass. In another example, the first wear-resistant ring 5 may also include three layers, each made of two or three of the following materials: ceramic, stainless steel, graphite, and brass. In yet another example, the first wear-resistant ring 5 may also include four layers, each made of two, three, or four of the following materials: ceramic, stainless steel, graphite, and brass. The first wear-resistant ring 5 can also have more than one layer, which will not be elaborated further.

[0061] Similarly, the material of the second wear-resistant ring 6 can also be one or a mixture of ceramic, stainless steel, graphite, and brass. For example, the second wear-resistant ring 6 may specifically be a ceramic ring, or a stainless steel ring, or a graphite ring, or a brass ring. As another example, the second wear-resistant ring 6 can have a multi-layered structure, comprising multiple layers in the radial direction, each layer being made of a different material. As an example, the second wear-resistant ring 6 may include two layers, one made of ceramic and the other of graphite, or one made of stainless steel and the other of brass. In another example, the second wear-resistant ring 6 may also include three layers, each made of two or three of ceramic, stainless steel, graphite, and brass. In yet another example, the second wear-resistant ring 6 may also include four layers, each made of two, three, or four of ceramic, stainless steel, graphite, and brass. The second wear-resistant ring 6 can also have more layers, which will not be elaborated further.

[0062] In one example, the materials of the first wear ring 5 and the second wear ring 6 can be the same or different. As an example, the first wear ring 5 can be made of ceramic or graphite, and the second wear ring 6 can be made of stainless steel or brass. Ceramic and graphite are heat-resistant and can be integrally molded with the motor housing 12 during injection molding. For example, during the injection molding process of the motor housing 12, the first wear ring 5 made of ceramic can be placed in a preset position in the mold, and then molten injection molding liquid is poured into the mold. After cooling and solidification, the first wear ring 5 is embedded in the inner wall of the rotor chamber 121. The second wear ring 6 made of stainless steel or brass, due to its relatively thin thickness, has a certain degree of deformation elasticity and can be interference-fitted with the rotor 3. For example, the second wear ring 6 is interference-fitted onto the outer wall of the rotor 3.

[0063] In one example, to prevent relative movement between the first wear ring 5 and the rotor chamber 121, the first wear ring 5 and the rotor chamber 121 are respectively provided with axial and circumferential limits, thereby restricting the first wear ring 5 from axial translation or circumferential rotation relative to the rotor chamber 121.

[0064] For example, referring to Figure 2, the first wear-resistant ring 5 is tubular in shape. Both end faces of the first wear-resistant ring 5 along its axial direction have cross-sections with the outer surface located outside the ring. For instance, the end face of the first end of the first wear-resistant ring 5 has a cross-section with the outer surface, and the end face of the second end also has a cross-section with the outer surface. On the inner wall of the rotor chamber 121, there are also cross-sections at positions corresponding to the cross-sections at the first end of the first wear-resistant ring 5 and at positions corresponding to the cross-sections at the second end of the second wear-resistant ring 5. In this way, the cross-sections of the first wear-resistant ring 5 fit snugly against the cross-sections of the rotor chamber 121, thereby restricting the axial translational movement of the first wear-resistant ring 5 relative to the rotor chamber 121.

[0065] For example, the outer surface of the first wear-resistant ring 5 has at least one first limiting structure, and the inner wall of the rotor chamber 121 has at least one second limiting structure. The first limiting structure and the second limiting structure play a limiting role in the circumferential direction. With the cooperation of the first limiting structure and the second limiting structure, the first wear-resistant ring 5 is difficult to rotate in the radial direction relative to the rotor chamber 121.

[0066] The first limiting structure can be a protrusion, and the second limiting structure can be a groove, or the first limiting structure can be a groove and the second limiting structure can be a protrusion.

[0067] In one example, if the first limiting structure is located between the two axial ends of the first wear-resistant ring 5 and the second limiting structure is located between the two axial ends of the rotor chamber 121, then the first limiting structure and the second limiting structure can also play a limiting role in the axial direction. For example, with the cooperation of the first limiting structure and the second limiting structure, the first wear-resistant ring 5 is also difficult to translate relative to the rotor chamber 121 in the axial direction.

[0068] For example, the outer surface of the first wear-resistant ring 5 has a protrusion, and the inner wall of the rotor chamber 121 has a groove. If the protrusion is located between the two ends of the first wear-resistant ring 5 in the axial direction, then the protrusion and the groove can cooperate to play a limiting role in the axial direction.

[0069] Regarding the limiting of the second wear-resistant ring 6 and the rotor 3, in one example, the second wear-resistant ring 6 and the rotor 3 are interference-fitted, which can achieve circumferential limiting, so that the second wear-resistant ring 6 and the rotor 3 rotate synchronously in the circumferential direction, making it difficult for relative rotation to occur.

[0070] The axial limiting method between the second wear-resistant ring 6 and the rotor 3 can be as shown in Figure 2. One axial end of the second wear-resistant ring 6 can have a radial lug 61, which is hooked onto the end face of the rotor 3 and engaged with it. In this way, the second wear-resistant ring 6 is difficult to translate relative to the rotor 3 in the axial direction. The radial lug 61 of the second wear-resistant ring 6 can be located at either the first or second axial end of the second wear-resistant ring 6.

[0071] It should be noted that if the second wear-resistant ring 6 is barrel-shaped, then the radial lug 61 of the second wear-resistant ring 6 is located on the end of the second wear-resistant ring 6 away from the bottom of the barrel. For a second wear-resistant ring 6 with a radial lug 61 at one end and a bottom at the other end, and the second wear-resistant ring 6 is interference-fitted with the rotor 3, in this scheme, the radial lug 61 can have multiple radial openings, which are arranged circumferentially. The radial length of the radial openings is equal to the radial length of the radial lug 61, or the radial openings are slightly smaller than the radial length of the radial lug. This can reduce the rigidity of the barrel wall of the second wear-resistant ring 6, making the second wear-resistant ring 6 easier to deform, thereby achieving the interference fit between the second wear-resistant ring 6 and the rotor 3. In another example, if the second wear ring 6 is barrel-shaped, then the second wear ring 6 may not have the radial lug 61 described above. The bottom of the barrel of the second wear ring 6 is fixed to the end face of the rotor 3, which can also achieve the axial positioning of the second wear ring 6 and the rotor 3, making it difficult for the two to translate relative to each other in the axial direction.

[0072] The above describes the features of the first wear-resistant ring 5 and the second wear-resistant ring 6. The following will introduce the fixing method of the impeller 2 and the rotor 3, as well as the features of the rotor 3.

[0073] As described above, the impeller 2 is directly fixed to the rotor 3. One fixing method is that the impeller 2 and the rotor 3 are integrally formed and fixed. Another fixing method is that the rotor 3 has an axial hole, the centerline of which is collinear with the centerline of the rotor 3. The impeller 2 includes an impeller portion 21 and a rod portion 22, and the rod portion 22 can be interference-fitted into the axial hole of the rotor 3. The axial hole of the rotor 3 can be a through hole extending through the axial length of the rotor 3, or a blind hole not extending through the axial length of the rotor 3.

[0074] In one example, due to limitations in the manufacturing process, and to ensure that the rod portion 22 of the impeller 2 is interference-fitted into the axial bore of the rotor 3, as shown in Figure 5, a longitudinal cross-sectional view is taken along the axial direction after the rod portion 22 of the impeller 2 is interference-fitted onto the rotor 3. Referring to Figure 5, the rotor 3 comprises multiple layers arranged radially, with the innermost layer having an axial bore. The rod portion 22 of the impeller 2 is fixed in the axial bore of the innermost layer, and the second wear-resistant ring 6 is fixed on the outer surface of the outermost layer. For ease of explanation, Figure 5 illustrates the rotor 3 as comprising three layers, and the following description will also use three layers, referred to as the first layer 31 (the innermost layer), the second layer 32, and the third layer 33 (the outermost layer).

[0075] In one example, to allow the rod 22 to be interference-fitted into the axial bore, the thickness of the first layer 31 of the rotor 3 is relatively thinner than the thickness of the other layers, making the first layer 31 more prone to deformation and allowing the rod 22 to be interference-fitted into the axial bore. The sidewall of the first layer 31 of the rotor 3 may have an axial groove, which can reduce the stiffness of the first layer 31, making it easier for the rod 22 of the impeller 2 to be interference-fitted into the axial bore. The other layers of the rotor 3 are arranged radially from the inside out, successively wrapping around the innermost layer to form the rotor 3.

[0076] In one example, the first layer 31 of the rotor 3 has an axial groove. Then, the inner surface of the second layer 32 adjacent to the first layer 31 can have an axial protrusion. In this way, the second layer 32 wraps around the outer surface of the first layer 31, and the axial protrusion on the inner surface of the second layer 32 is engaged with the axial groove on the outer surface of the first layer 31, thereby achieving circumferential limiting and making it difficult for the first layer 31 and the second layer 32 to rotate relative to each other in the circumferential direction.

[0077] In another example, the outer surface of the first layer 31 may also have an axial protrusion, and the inner surface of the second layer 32 may have an axial groove. After the second layer 32 wraps around the first layer 31, the axial protrusion on the outer surface of the first layer 31 is stuck in the axial groove on the inner surface of the second layer 32, further achieving circumferential positioning.

[0078] Similarly, the third layer 33 of the rotor 3 wraps around the second layer 32. The inner surface of the third layer 33 may have an axial groove and / or an axial protrusion. The outer surface of the second layer 32 has an axial protrusion and / or an axial groove. The third layer 33 wraps around the second layer 32 and is locked into the axial groove by the axial protrusion, thereby achieving circumferential restriction and making it difficult for the second layer 32 and the third layer 33 to rotate relative to each other in the circumferential direction.

[0079] In one example, referring to Figure 5, the longitudinal section of the first layer 31 cut along its axis can be I-shaped. The first layer 31 includes a vertical portion and transverse portions at both ends. Thus, the second layer 32 and the third layer 33 are both located between the two transverse portions of the first layer 31. Under the action of the two transverse portions of the first layer 31, it is difficult for the three layers—first layer 31, second layer 32, and third layer 33—to undergo relative displacement in the axial direction. In this way, the first layer 31, second layer 32, and third layer 33 of the rotor 3 are all limited in both the circumferential and axial directions, making the three layers rotate as a whole, and it is difficult for any two of them to undergo relative movement.

[0080] As described above, the radial lug 61 of the second wear-resistant ring 6 is not only attached to the end face of the rotor 3, but also snapped into the rotor 3. Therefore, referring to Figure 5, the radial lug 61 is attached to the outermost end face of the rotor 3 on one hand, and snapped into the innermost transverse part on the other hand.

[0081] In this embodiment of the present disclosure, the impeller of the impeller-type liquid pump is directly fixed to the rotor, rather than being fixed to the rotor through the pump shaft. Eliminating the pump shaft can shorten the axial dimension of the liquid pump. Moreover, a first wear-resistant ring is fixed on the inner wall of the rotor chamber where the rotor is located, and a second wear-resistant ring is fixed on the outer surface of the rotor. The first wear-resistant ring and the second wear-resistant ring cooperate to form a pair of friction pairs. This friction pair does not occupy axial space, further shortening the axial dimension of the liquid pump.

[0082] Furthermore, the axial dimension of the first wear-resistant ring is adapted to the axial dimension of the rotor chamber, and the axial dimension of the second wear-resistant ring is adapted to the axial dimension of the rotor. For example, the axial dimension of the first wear-resistant ring is slightly less than or equal to the axial dimension of the rotor chamber, and the axial dimension of the second wear-resistant ring is slightly less than or equal to the axial dimension of the rotor. In this case, the first and second wear-resistant rings can serve as the support and wear-resistant function of the bearing. Compared with multiple bearings assembled on the pump shaft, the first and second wear-resistant rings do not need to be aligned, which simplifies the assembly process of the liquid pump and improves the assembly efficiency.

[0083] The terminology used in the embodiments of this disclosure is for illustrative purposes only and is not intended to limit the disclosure. Unless otherwise defined, the technical or scientific terms used in the embodiments of this disclosure should be understood in their ordinary sense by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in this specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "a" or "an," and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising," "including," and similar terms mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, but do not exclude other elements or objects. "Upper," "lower," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly. "A plurality" refers to two or more, unless otherwise expressly defined.

[0084] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A liquid pump, characterized in that, The liquid pump includes a pump casing (1), an impeller (2), a rotor (3), a stator (4), a first wear ring (5), and a second wear ring (6); The pump casing (1) includes an impeller casing (11) and a motor casing (12). The motor casing (12) has a stator chamber and a rotor chamber (121). The stator chamber circumferentially surrounds the rotor chamber (121), and the rotor chamber (121) communicates with the impeller casing (11). The impeller (2) is located in the impeller housing (11), the rotor (3) is located in the rotor chamber (121), and the impeller (2) is fixedly connected to the rotor (3). The stator (4) is located in the stator chamber. The first wear-resistant ring (5) is fixed on the inner wall of the rotor chamber (121), and the second wear-resistant ring (6) is fixed on the outer wall of the rotor (3). The first wear-resistant ring (5) and the second wear-resistant ring (6) are positioned opposite each other in the radial direction of the rotor (3).

2. The liquid pump according to claim 1, characterized in that, The first wear-resistant ring (5) and the second wear-resistant ring (6) are both tubular in shape. The tube wall of the first wear-resistant ring (5) is fixed to the inner wall of the rotor chamber (121), and the tube wall of the second wear-resistant ring (6) is fixed to the outer wall of the rotor (3). Alternatively, both the first wear-resistant ring (5) and the second wear-resistant ring (6) are barrel-shaped. The barrel wall of the first wear-resistant ring (5) is fixed to the inner wall of the rotor chamber (121), and the barrel bottom of the first wear-resistant ring (5) is fixed to the bottom of the rotor chamber (121) away from the impeller shell (11). The barrel wall of the second wear-resistant ring (6) is fixed to the outer wall of the rotor (3), and the barrel bottom of the second wear-resistant ring (6) is fixed to the end face of the rotor (3) away from the impeller (2).

3. The liquid pump according to claim 1, characterized in that, The axial length of the first wear-resistant ring (5) is greater than or equal to half the axial length of the rotor chamber (121), and less than or equal to the axial length of the rotor chamber (121). The axial length of the second wear-resistant ring (6) is greater than or equal to half the axial length of the rotor (3), and less than or equal to the axial length of the rotor (3).

4. The liquid pump according to claim 1, characterized in that, The first wear-resistant ring (5) is made of one or more of ceramic, stainless steel, graphite and brass. The material of the second wear-resistant ring (6) is one or a mixture of ceramic, stainless steel, graphite and brass.

5. The liquid pump according to claim 1, characterized in that, The first wear-resistant ring (5) is embedded in the inner wall of the rotor chamber (121).

6. The liquid pump according to claim 1, characterized in that, The first wear-resistant ring (5) has a tangent surface between the end faces at both ends of the axial direction and the outer surface located outside the ring; The inner wall of the rotor chamber (121) has a cross-section that matches the cross-section of the first wear-resistant ring (5), and the cross-section of the first wear-resistant ring (5) and the cross-section of the rotor chamber (121) are in contact.

7. The liquid pump according to claim 1, characterized in that, The outer surface of the first wear-resistant ring (5) has a first limiting structure, and the inner wall of the rotor chamber (121) has a second limiting structure. The first limiting structure and the second limiting structure cooperate to restrict the first wear-resistant ring (5) from rotating in the circumferential direction relative to the rotor chamber (121).

8. The liquid pump according to claim 1, characterized in that, The second wear-resistant ring (6) is interference-fitted onto the outer wall of the rotor (3).

9. The liquid pump according to claim 1, characterized in that, The second wear-resistant ring (6) has a radial lug (61) at one end in the axial direction. The radial lug (61) is attached to the end face of the rotor (3) and is engaged with the rotor (3).

10. The liquid pump according to any one of claims 1 to 9, characterized in that, The impeller (2) includes an impeller portion (21) and a rod portion (22). The impeller portion (21) is located in the impeller housing (11), and the rod portion (22) extends into the rotor chamber (121) and is fixed to the rotor (3).

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