FLUID PUMP

CROSS REFERENCE TO RELATED APPLICATIONS

[0001]This non-provisional patent application claims priority under 35 U.S.C. § 119(a) from Patent Application No. 202411302994.2 filed in The People's Republic of China on Sep. 18, 2024.

FIELD OF THE INVENTION

[0002]This application relates to pumps, specifically to fluid pumps.

BACKGROUND OF THE INVENTION

[0003]A Pump is usually connected in series within a pipeline for transporting fluids such as water, coolant, gas, etc., for example, pumps can be used in the thermal management system of servers in data centers, to deliver cooling water to dissipate heat for the servers.

[0004]Typically, a pump consists of an impeller and a motor for driving the impeller to rotate. The motor includes a stator and a rotor that can rotate relative to the stator. The impeller is connected to the rotor to rotate accordingly, thus driving fluid to flow in the pipeline. The existing structure of the pump experiences vertical movement of its impeller and rotor during operation due to fluid impact, which not only generates significant noise but also affects the lifespan of components, necessitating further improvement.

SUMMARY OF THE INVENTION

[0005]In view of this, a purpose of this application is to provide a fluid pump that can limit axial movements of its motor rotor, effectively solving the problem of the impeller and rotor moving up and down during rotation.

[0006]For this reason, one aspect of the present invention provides a fluid pump including a pump casing, an impeller arranged in the pump casing, and a motor for driving the impeller to rotate in the pump casing. The motor includes a stator and a rotor connecting to the impeller. A motor shaft is fixed arranged in the fluid pump, with one end of the motor shaft connected to the pump casing. The impeller and the rotor are rotatably placed around the motor shaft, and a washer is placed around the motor shaft and axially sandwiched between the pump casing and the rotor, for limiting an axial movement of the rotor and the impeller.

[0007]The fluid pump may present one or several of the following aspects either solely or in combination.

[0008]Optionally, the washer includes a first end and a second end opposite to the first end, the first end is axially abutted against the pump casing, and the second end is axially abutted against the rotor, an outer diameter of the first end is less than an outer diameter of the second end.

[0009]Optionally, an end face of the second end of the washer defines one or more communicating grooves radially extending through the washer.

[0010]Optionally, a center of the pump casing is formed with a first shaft seat, one end of the motor shaft is inserted and fixed into the first shaft seat, the first end of the washer is abutted against an end surface of the first shaft seat, and the outer diameter of the first end is not greater than an outer diameter of the end surface of the first shaft seat.

[0011]Optionally, the washer further includes a flow-guiding portion disposed between the first end and the second end, and an outer diameter of the flow-guiding portion gradually increases from the first end to the second end.

[0012]Optionally, the washer further includes a neck portion arranged between the first end and the flow-guiding portion, an outer diameter of the neck portion is less than the outer diameter of the first end.

[0013]Optionally, the second end of the washer passes through the impeller and abuts against the rotor, the second end and the impeller are radially gap-fitted.

[0014]Optionally, the rotor includes a bearing mounted on the motor shaft adjacent to the impeller, the second end of the washer abuts against the bearing.

[0015]Optionally, an inner cavity of the second end of the washer is non-circular, and a cross-section of the end of the motor shaft corresponding to the washer is also non-circular, the washer and the motor shaft are circumferentially positioned through shape fitting.

[0016]Optionally, the fluid pump further includes a sleeve separating the stator from the rotor and impeller, wherein a second shaft seat is formed at a center of the sleeve, and the other end of the motor shaft is fixed in the second shaft seat.

[0017]Optionally, the rotor includes a rotor core, one or more permanent magnets, two bearings, and a rotor shell encapsulating the rotor core, the permanent magnets and the bearings through injection molding, the rotor is rotatably connected to the motor shaft through the two bearings.

[0018]Optionally, the impeller is also injection molded with the rotor shell.

[0019]Compared to the existing technology, the fluid pump provided by this application has a washer set on its motor shaft, the washer is axially sandwiched between the pump casing and the rotor, which can limit axial movements of the rotor and the impeller connected to the rotor. During the rotation around the motor shaft, even when impacted by fluid, the rotor and impeller will not move axially, making the operation of the fluid pump smoother, effectively reducing noise generation, and enhancing the service life and safety of the fluid pump.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020]FIG. 1 is a perspective view of a fluid pump in one embodiment of this application.

[0021]FIG. 2 is a top view of the fluid pump of FIG. 1.

[0022]FIG. 3 is a cross-sectional view of the fluid pump of FIG. 2, take along the line III-III thereof.

[0023]FIG. 4 is an enlarged view of the circle IV in FIG. 3.

[0024]FIG. 5 is a side view of the fluid pump of FIG. 1.

[0025]FIG. 6 is a cross-sectional view of the fluid pump of FIG. 5, take along the line VI-VI thereof.

[0026]FIG. 7 is an exploded view of the fluid pump of FIG. 1.

[0027]FIG. 8 is a cross-sectional view of an impeller and a rotor of the fluid pump o f FIG. 7.

[0028]FIG. 9 is another aspect view of a motor shaft of the fluid pump of FIG. 7.

[0029]FIG. 10 is another aspect view of a washer of the fluid pump of FIG. 7.

[0030]FIG. 11 is another aspect view of the washer of FIG. 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031]In order to facilitate the understanding of the present application, a more comprehensive description of the application is provided below with reference to the relevant drawings. One or more embodiments of the present application are given in the accompanying drawings illustratively, so as to make the understanding of the technical solution disclosed in the present application more accurate and thorough. It should be understood, however, that the present application may be realized in a number of different forms and is not limited to the embodiments described below.

[0032]The same or similar numbers in the drawings of the present application correspond to the same or similar parts. In the description of the present application, it is understood that if the terms “upper”, “lower”, “left”, “right”, etc., indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation. Therefore, the terms describing the positional relationship in the drawings are for illustrative purposes only and cannot be construed as limiting the present application. For those of ordinary skill in the art, the specific meaning of the above terms can be understood on a case-by-case basis.

[0033]In addition, if there are descriptions involving “first”, “second”, etc., in the embodiments of the present application, the descriptions of “first”, “second”, etc., are only for descriptive purposes and cannot be construed as indicating or implying their relative importance or implying the number of technical features indicated. Thus, the features that are defined as “first” and “second” may explicitly or implicitly include at least one of these features. In addition, if the words “and/or” or “and/or” appear in the whole text, the meaning includes three parallel options, taking “A and/or B” as an example, including the A plan, or the B plan, or the plan A and B meet at the same time.

[0034]In addition, the technical solutions between the various embodiments may be combined with each other, but only on the basis that they can be realized by a person skilled in the art. When the combination of technical solutions contradicts or cannot be realized, it shall be deemed that the combination of such technical solutions does not exist and is not within the scope of protection claimed in the present application.

[0035]The present application provides a fluid pump for driving fluids, such as water, coolant, etc., to flow in a pipeline. The fluid pump can be applied in thermal management systems of batteries, servers, etc., to quickly dissipate heat through the circulation of fluids. FIGS. 1-7 show an embodiment of the fluid pump of the present application. The fluid pump 100 includes a pump casing 10, an impeller 20 arranged in the pump casing 10 and a motor 30 for driving the impeller 20 to rotate in the pump casing 10.

[0036]Please also refer to FIGS. 6-8, the impeller 20 has an overall disc-like structure, rotatably arranged at a center of the pump casing 10. Specifically, the impeller 20 includes a base plate 22, a cover plate 24 spaced apart from the base plate 22, and a plurality of blades 26 arranged between the base plate 22 and the cover plate 24. In this embodiment, the blades 26 are integrally injection moulded with the base plate 22, and the cover plate 24 is connected to the blades 26 by means of a concave-convex fitting. In other embodiments, the cover plate 24 can also be connected to the blades 26 and/or the base plate 22 through snap-fitting, welding, bonding, or other methods. In other embodiments, the blades 26 can also be formed separately and then connected to the base plate 22 and the cover plate 24; alternatively, the blades 26 and the cover plate 24 can also be a one-piece structure; or, the impeller 20 can be a single integral structure overall.

[0037]Please also refer to FIGS. 1 and 7, the pump casing 10 is equipped with an inlet 12 and an outlet 14 to connect its internal space with external pipelines, thus forming a flow path for the fluid. After the fluid enters the pump casing 10 through the inlet 12, it is propelled by the rotating blades 26 and flows within the pump casing 10 until it reaches the outlet 14 and is discharged outward. As shown in FIG. 2, the inlet 12 extends radially along the pump casing 10 to the center above the impeller 20, while the outlet 14 extends outward tangentially along an outer peripheral surface of the pump casing 10, with both being set approximately parallel. In other embodiments, the position, direction, number, etc., of the inlet 12 and outlet 14 can be adjusted as needed. For instance, the inlet 12 and the outlet 14 can be set perpendicular to or at a certain angle to each other, and their quantity can also be multiple.

[0038]Please also refer to FIGS. 3 and 7-8, the motor 30 is preferably an inner rotor motor, which includes a motor housing 32, a stator 34 fixed within the motor housing 32, and a rotor 36 rotatably disposed at the center of the stator 34. The impeller 20 is connected to the rotor 36 to rotate with it.

[0039]The stator 32 includes a stator core 341 formed by stacking silicon steel sheets, a coil 343 wound around the stator core 341, and a circuit board 345 electrically connected to the coil 343. The motor housing 32 is equipped with a connection seat 321 for connecting the circuit board 345 to an external power supply. The rotor 36 includes a rotor core 361, one or more permanent magnets 363, and a rotor shell 365 that encapsulates the rotor core 361 and the permanent magnets 363. The rotor core 361 can be formed by stacking silicon steel sheets, and the permanent magnets 363 can be multiple, attached to the outer peripheral surface of the rotor core 361, together forming a surface-mounted permanent magnet motor (SPM motor). In some embodiments, assembly holes may also be provided in the rotor core 361 to receive the permanent magnets 363, together forming an interior permanent magnet motor (IPM motor).

[0040]When the motor 30 is started, the external power supply provides a periodically varying current to the coil 343 through the circuit board 345, enabling the stator 34 to generate a periodically varying rotating magnetic field. This magnetic field interacts with a magnetic field established by the permanent magnets 363 of the rotor 36, driving the rotor 36 to rotate and subsequently driving the impeller 20 connected to the rotor 36 to rotate.

[0041]In some embodiments, the rotor shell 365 is initially injection molded over the rotor core 361 and the permanent magnets 363, integrally encapsulating and securing the rotor core 361 and the permanent magnets 363. Then, the rotor shell 365 undergoes a secondary injection molding with the base plate 22 and the blades 26 of the impeller 20 to form an integrated structure. Once molded, the rotor 36 and the impeller 20 form a non-detachable integrated structure, always maintaining a unified connection and coaxial arrangement. This facilitates the synchronous rotation of the impeller 20 and the rotor 36, while effectively simplifying the assembly process of the rotor 36 and the impeller 20.

[0042]In some embodiments, the rotor shell 365 is integrally injection molded with the bottom plate 22 and blades 26 of the impeller 20 while encapsulating the rotor core 361 and the permanent magnet 363. This can further simplify the assembly process of the rotor 36 and impeller 20.

[0043]As shown in FIGS. 3 and 6, a motor shaft 38 is fixedly arranged in the motor housing 32, and the rotor 36 and impeller 20 are rotatably coupled on the motor shaft 38. A washer 40 is also placed around the motor shaft 38 to limit the axial movement of the rotor 36, thereby preventing the rotor 36 and the impeller 20 from moving axially.

[0044]Please also refer to FIGS. 10-11, the washer 40 is generally cylindrical and includes a first end 41 and a second end 43 that are axially opposite to each other. The first end 41 is axially abutted against the pump casing 10, and the second end 43 is axially abutted against the rotor 36. In other words, the washer 40 is axially sandwiched between the pump casing 10 and the rotor 36, such that there is no axial movement space for the rotor 36. As a result, it prevents axial movement of the rotor 36 and the impeller 20 connected to the rotor 36, allowing the rotor 36 and impeller 20 to rotate more smoothly, reducing noise generated during the operation of the fluid pump 100, and enhancing the safety and lifespan of fluid pump 100.

[0045]In some embodiments, as shown in FIG. 9, the motor shaft 38 defines a first notch 381 at a position corresponding to the washer 40, such that a cross-section of the motor shaft 38 at the position of the first notch 381 is non-circular, which can specifically be D-shaped, square, polygonal, etc. As shown in FIG. 10, the washer 40, specifically the inner cavity of the second end 43 of the washer 40, is non-circular, matching the shape and size of the motor shaft 38 at the first notch 381. After assembly, the washer 40 and the motor shaft 38 are circumferentially positioned through shape fitting, thereby the washer 40 is fixed on the motor shaft 38. It should be understood that the washer 40 and motor shaft 38 can also be fixed circumferentially by other means, such as tight fitting, bonding, etc., without limitation to specific embodiments.

[0046]As shown in FIGS. 3 and 8, the rotor shell 365 can also be equipped with bearings 367 and 368, such as ball bearings, sliding bearings, bushings, etc. The bearings 367 and 368 can be integrally fixed within the rotor shell 365 during the injection molding process of the rotor shell 365, or they can be fixed within the rotor shell 365 after the molding process of the rotor shell 365 through tight fitting, bonding, and other methods. Thus, the bearings 367, 368 can be considered as a part of the rotor 36. The motor shaft 38 is passed through the bearings 367, 368. When the motor 30 is started, the rotor 36 (including the bearings 367, 368) and the impeller 20 rotate together around the motor shaft 38. The bearings effectively reduce friction during the rotation of the rotor 36.

[0047]Preferably, the rotor shell 365 is provided with two bearings, namely the first bearing 367 and the second bearing 368, wherein the first bearing 367 is located near the position of the impeller 20, and the second bearing 368 corresponds to the position of the rotor core 361. This arrangement allows the rotor 36 and impeller 20 to experience more balanced forces, further enhancing the stability of the rotation of the impeller 20 and the rotor 36.

[0048]The second end 43 of the washer 40 passes through the impeller 20 and abuts against the first bearing 367 in the rotor 36, limiting the axial movement of the rotor 36 and impeller 20. An outer diameter of the second end 43 is slightly smaller than an inner diameter of the impeller 20 but larger than an inner diameter of the first bearing 367. After assembly, the second end 43 and the impeller 20 are radially gap-fitted to avoid affecting the rotation of the impeller 20.

[0049]As shown in FIGS. 4 and 10-11, an end face of the second end 43 of the washer 40 defines one or more communicating grooves 432. The communicating grooves 432 radially extend through the washer 40, allowing fluid to enter the washer 40 and fill the gaps between the washer 40, the motor shaft 38, and the bearings 367, 368. Preferably, there are multiple communicating grooves 432, distributed at intervals along the circumference of the second end 43. When the rotor 36 rotates, the fluid in the gaps between the washer 40, the motor shaft 38, and the bearings 367, 368 can provide some lubrication, reducing friction of the rotor 36, particularly between its bearings 367, 368, and the motor shaft 38 and the washer 40.

[0050]In some embodiments, as shown in FIGS. 3-4, the center of the pump casing 10 is formed with a first shaft seat 16, and a first shaft hole is defined in the first shaft seat 16. The center of the motor housing 32 is formed with a second shaft seat 323, and a second shaft hole is defined in the second shaft seat 323. Both ends of the motor shaft 38 extend outward relative to the rotor shell 365 and the impeller 20 and are respectively inserted and fixed into the first shaft hole and the second shaft hole.

[0051]In some embodiments, both ends of the motor shaft 38 are fixed into the first shaft hole and the second shaft hole through tight fittings. In some embodiments, the motor housing 32 is an integrated structure formed by injection molding, and the motor shaft 38 is integrally fixed into the second shaft hole of its second shaft seat 323 during the molding process of the motor housing 32, further enhancing the stability of the connection between the motor shaft 38 and the second shaft seat 323.

[0052]In some embodiments, the bottom end of the motor shaft 38 (i.e., the end connected to the second shaft seat 323) defines a second notch 383, so that a cross-section of the motor shaft 38 at the position of the second notch 383 is non-circular, which can specifically be D-shaped, square, polygonal, etc. The second shaft hole of the second shaft seat 323 is also non-circular, matching the shape and size of the motor shaft 38 at the second notch 383. The motor shaft 38 is circumferentially positioned through the shape fitting of the motor shaft 38 and the second notch 383.

[0053]In some embodiments, an outer diameter of the top end of the motor shaft 38 (i.e., the end connected to the first shaft seat 16) is smaller than an outer diameter of its bottom end, allowing the corresponding first shaft hole to have a smaller aperture, thereby enabling an overall size of the first shaft seat 16 to be smaller. Thus, even if the size of the fluid pump 100 itself is small, a small first shaft seat 16 can be set on its pump casing 10 to further secure the motor shaft 38. Additionally, the overall size of the first shaft seat 16 can be reduced to minimize its impact on an internal structure of the pump casing 10. Particularly when the inlet 12 of the fluid pump 100 extends to the center of the pump casing 10, a smaller first shaft seat 16 can minimize the interference with the fluid entering the pump casing 10.

[0054]As shown in FIGS. 4, 10, and 11, an outer diameter of the first end 41 of the washer 40 is equal to or slightly less than an outer diameter of an outer end surface of the first shaft seat 16, allowing the washer 40 and the first shaft seat 16 to have as large a contact area as possible. The outer diameter of the second end 43 of the washer 40 is greater than that of its first end 41, enabling the washer 40 to have as large a contact area as possible with the rotor 36, particularly with the first bearing 367 of the rotor 36, thereby providing better axial limitation for the rotor 36 and the impeller 20.

[0055]In some embodiments, the washer 40 also includes a flow-guiding portion 45 disposed between the first end 41 and the second end 43. The flow-guiding portion 45 is generally conical, with its outer diameter gradually increasing axially from the first end 41 to the second end 43, guiding the fluid entering the pump casing 10, as shown by the arrows in FIG. 4. This design allows the fluid to diffuse outwards while flowing downward, quickly entering the impeller 20, and then being driven by the impeller to flow towards the outlet 14, further enhancing the efficiency of the fluid pump 100.

[0056]In some embodiments, the washer 40 also includes a neck portion 47 arranged between the first end 41 and the flow-guiding portion 45. An outer diameter of the neck portion 47 is slightly less than the outer diameter of the first end 41, which helps to further reduce the overall size of the washer 40 while ensuring its overall strength, thereby further minimizing the impact of the washer 40 on the fluid entering the pump casing 10. Preferably, a top end of the motor shaft 38, including a section thereof corresponding to the first end 41 and the neck portion 47 of the washer 40, has a diameter that is smaller than diameters of other parts of the motor shaft 38. The entire washer 40 is generally trumpet-shaped, but there is sufficient thickness throughout the washer 40 to provide limitation for the rotor 36 and impeller 20.

[0057]The fluid pump 100 of this application is equipped with a washer 40 on its motor shaft 38. The washer 40 is axially sandwiched between the first shaft seat 16 of the pump casing 10 and the bearing 367 of the rotor 36, which can limit the axial movement of the rotor 36 and the impeller 20 connected to the rotor 36. During the rotation around the motor shaft 38, the rotor 36 and the impeller 20 will not move axially even when subjected to fluid impacts. Additionally, the washer 40 is generally made of wear-resistant materials such as rubber, which is capable of effectively buffering or even counteracting the axial forces acting on the rotor 36 and the impeller 20. This allows the rotor 36 and the impeller 20 to rotate more smoothly, significantly enhancing the operational safety and lifespan of the fluid pump 100.

[0058]In this embodiment, as shown in FIGS. 3 and 7, the motor housing 32 is generally cylindrical, with a sleeve 325 inside to separate the stator 34 from the rotor 36. The sleeve 325 is a cylindrical structure with an open top and a closed bottom, with the second shaft seat 323 formed at the center of the bottom of the sleeve 325. Preferably, the top of the sleeve 325 extends radially outward and is integrally connected to the top end of the motor housing 32. In some embodiments, the sleeve 325 can also be independently formed and then assembled into the motor housing 32. Alternatively, the sleeve 325 can be made of metal materials, such as stainless steel, which can provide better strength and allows for thinner dimensions, not limited to any specific embodiment.

[0059]The pump casing 10 is covered on the motor housing 32, defining a space therebetween for installing the impeller 20 and the rotor 36. The rotor 36 is arranged within the sleeve 325 and mounted on the motor shaft 38, while the impeller 20 is received in the pump casing 10 and is radially spaced apart from the pump casing 10. A space is defined between the motor housing 32 and the sleeve 325 for the installing the stator 34. Preferably, the circuit board 345 is in close contact with the sleeve 325, using the fluid inside the sleeve 325 to dissipate heat from the circuit board 345. An end cap 327 covers the bottom of the motor housing 32, enclosing the stator 34 within the motor housing 32. The pump casing 10, motor housing 32, and end cap 327 together form an enclosure of the fluid pump 100. The sleeve 325 separates an internal space of the enclosure into dry and wet areas, effectively preventing fluid from affecting electrical safety and ensuring the normal operation of fluid pump 100.

[0060]It should be noted that the above embodiments only express the preferred embodiments of this application, and the descriptions are relatively specific and detailed, but should not be understood as a limitation on this application. It should be pointed out that for an ordinary skilled person in the field, several modifications and improvements can be made without departing from the concept of this application, such as combining different features from various embodiments, and these should all fall within the protection scope of this application.