Fluid pump

Abstract

The utility model relates to a fluid pump in the technical field of general machinery. Comprising a pump shell, a motor and a control unit, a motor cavity is formed in the pump shell, and the motor is contained in the motor cavity; the motor comprises a stator, a rotor and a rotating shaft; the rotating shaft is fixedly mounted in the center of the rotor; the control unit comprises a magnetic part, a connecting part, a sensing element and a control part, the connecting part is provided with a clamping part and a fixing part which are connected, the clamping part is clamped with the rotating shaft, the magnetic part is fixed to the fixing part, the sensing element and the magnetic part are oppositely arranged, and the sensing element obtains a feedback signal by sensing the magnetic field change of the magnetic part; the control part receives the feedback signal and controls the rotating speed of the motor according to the feedback signal. The connecting part provided with the magnetic part is clamped with the rotating shaft, the connection is simple and reliable, and the magnetic field generated by the magnetic part stably rotating along with the rotating shaft can change periodically and is sensed by the sensing element, so that the monitoring and control of the rotating speed of the motor are realized, and the stability and accuracy of the monitoring of the rotating speed of the motor are improved.

Description

Technical Field

[0001] This utility model relates to the field of general mechanical technology, and in particular to a fluid pump. Background Technology

[0002] In the field of fluid pump technology, it is necessary to monitor the rotational speed of the motor rotor in order to accurately control the flow rate of fluid. For example, in fluid pumps such as electric drive pumps or oil pumps, a common measurement method is to use a magnetic induction position sensor in conjunction with a magnet fixed on the motor shaft. By measuring the periodic magnetic field changes passing through the sensor, the position change of the motor is obtained, thereby measuring the motor speed. Precise control of the motor speed is then achieved through signal feedback and compensation.

[0003] Currently, common methods for fixing magnets include adhesive bonding and interference fit with a metal block. Adhesive bonding uses adhesive to bond the magnet to the shaft. However, because the magnet and adhesive are constantly immersed in oil, the adhesive tends to age over time, making the magnet prone to detachment. Furthermore, adhesive bonding requires specialized curing equipment and processes, increasing production costs, and the curing cycle affects production speed. Interference fit with a metal block uses a copper block to press the magnet firmly against the shaft. Due to the high cost of copper and the need for machining, production costs increase significantly. Therefore, to achieve more stable and lower-cost speed monitoring, the magnet fixing method needs to be improved. Utility Model Content

[0004] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a fluid pump to solve the problems of high cost and poor stability of magnet installation and fixing in the prior art, so as to improve the stability of motor speed monitoring and reduce costs.

[0005] To achieve the above and other related objectives, this utility model provides a fluid pump, including a pump casing, a motor, and a control unit. The pump casing contains a motor cavity, and the motor is housed within the motor cavity. The motor includes a stator, a rotor, and a shaft. The stator is located radially outside the rotor, and the shaft is fixedly installed at the center of the rotor. The control unit includes a magnetic component, a connecting component, a sensing element, and a control component. The connecting component has a connected snap-fit ​​portion and a fixing portion. The snap-fit ​​portion snaps into the shaft, and the fixing portion has a magnetic component fixed to it. The sensing element is disposed on one axial side of the motor, opposite to the magnetic component. The sensing element obtains a feedback signal by sensing changes in the magnetic field of the magnetic component. The control component receives the feedback signal and controls the motor speed according to the feedback signal.

[0006] Optionally, the magnetic component is fixed to the end of the fixing part away from the motor by insert injection molding, and the magnetic component is restricted from detaching from the fixing part and / or rotating relative to it by an anti-detachment structure, and the magnetic component is coaxially arranged with the rotating shaft.

[0007] Optionally, the rotating shaft is provided with a first channel, and the connecting component is provided with a second channel, wherein the first channel is connected to the motor cavity through the second channel.

[0008] Optionally, the outer side wall of the snap-fit ​​part is provided with a buckle, and the inner side wall of the first channel is provided with a slot. The snap-fit ​​part extends into the first channel and snaps into the slot through the buckle.

[0009] Optionally, the snap-fit ​​portion is provided with a weakening structure. When the snap-fit ​​portion extends into the first channel, the weakening structure is compressed, resulting in an elastic deformation in the radial direction inward along the snap-fit ​​portion.

[0010] Optionally, the second channel extends axially along the snap-fit ​​portion and is coaxially arranged with the snap-fit ​​portion. The weakening structure includes a through groove, which is disposed on the outer side wall of the snap-fit ​​portion and penetrates the inner side wall of the snap-fit ​​portion to communicate with the second channel.

[0011] Optionally, the number of through slots is two, and the two through slots are distributed circumferentially along the snap-fit ​​portion and arranged opposite to each other.

[0012] Optionally, the through groove includes a first groove segment, and the two ends of the first groove segment extend along the axial direction of the snap-fit ​​portion to form a second groove segment, the width of the second groove segment gradually decreasing from the end closer to the first groove segment to the end farther away from the first groove segment.

[0013] Optionally, the fixing part is located outside the first channel, and the fixing part is provided with a through hole connecting the second channel and the motor cavity.

[0014] Optionally, the diameter of the fixing part is larger than the diameter of the snap-fit ​​part, and the fixing part forms a stepped surface at the connection with the snap-fit ​​part, the stepped surface abutting against the end face of the rotating shaft when the snap-fit ​​part and the rotating shaft are snapped into place.

[0015] Optionally, a positioning block is provided on the outer side wall of the snap-fit ​​part near the fixed part, and a positioning groove corresponding to the positioning block is provided on the rotating shaft, and the positioning block extends into the positioning groove and cooperates with the positioning groove for positioning.

[0016] Optionally, there are two positioning slots, which are evenly distributed around the circumference of the rotating shaft. The positioning block includes a first positioning block and a second positioning block corresponding to the two positioning slots respectively. The volume of the first positioning block is equal to the volume of the second positioning block. The length of the first positioning block is greater than the length of the second positioning block. The first positioning block extends into the corresponding positioning slot before the second positioning block. The width of the first positioning block is less than the width of the second positioning block. The first positioning block is clearance-fitted with the corresponding positioning slot, and the second positioning block is transition-fitted with the corresponding positioning slot.

[0017] Optionally, a rib is provided on the outer side wall of the snap-fit ​​part near the fixing part. The rib extends into the first channel and is interference-fitted with the inner side wall of the first channel. There are multiple ribs, and the multiple ribs are evenly arranged along the circumference of the snap-fit ​​part.

[0018] As described above, the fluid pump of this utility model has at least the following beneficial effects: the connecting component with magnetic elements is snapped into the rotating shaft through the snap-fit ​​part, which makes the connection simple, convenient, stable and reliable, and low in cost. The magnetic elements are not easy to detach from the rotating shaft, so that the magnetic field generated by the stable rotation of the magnetic elements with the rotating shaft can pass through the sensing element and change periodically and be sensed by the sensing element, thereby realizing the monitoring and control of the motor speed, which is beneficial to improving the stability and accuracy of motor speed monitoring. Attached Figure Description

[0019] Figure 1 The diagram shown is a structural schematic of a fluid pump according to a first embodiment of this utility model.

[0020] Figure 2 Displayed as Figure 1 Sectional view at point AA;

[0021] Figure 3 Displayed as Figure 2 A first-view structural diagram of the connecting component;

[0022] Figure 4 Displayed as Figure 2 A second-view structural diagram of the connecting component;

[0023] Figure 5 Displayed as Figure 2 Schematic diagram of the transfer shaft;

[0024] Figure 6 Displayed as Figure 2 Schematic diagram of the connection between the connecting component and the rotating shaft;

[0025] Figure 7 The diagram shown is a structural schematic of the connecting components of the fluid pump according to Embodiment 2 of this utility model.

[0026] Part Number Explanation

[0027] Pump housing 1, motor cavity 11, motor 2, rotating shaft 21, first channel 211, slot 212, positioning slot 213, conical guide surface 214, stator 22, rotor 23, connecting component 3, second channel 31, fixing part 32, stepped surface 321, snap-fit ​​part 33, stepped section 331, conical surface 3311, rib 332, buckle 34, inclined surface 341, through hole 35, weakening structure 36, first positioning block 37, second positioning block 38, magnetic component 4, control component 5, sensing element 51. Detailed Implementation

[0028] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model.

[0029] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this utility model. Therefore, the drawings only show components related to this utility model and are not drawn according to the actual number, shape, and size of the components in implementation. In actual implementation, the form, quantity, and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex. The structures, proportions, sizes, etc., shown in the accompanying drawings are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and purposes that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model. Meanwhile, the terms such as "upper", "lower", "left", "right", "middle" and "one" used in this specification are only for clarity of description and are not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as within the scope of implementation of this utility model.

[0030] Before describing the embodiments of this utility model in detail, the application environment of this utility model will be described first. The technology of this utility model is mainly applied to the field of fluid pumps, especially oil pumps, but it is not limited to oil pumps; for example, it can also be applied to electric drive pumps. This utility model solves the technical problems of high installation and fixing costs and poor stability of magnetic components. By using connecting components to achieve snap-fit ​​fixing of magnetic components to the motor shaft, it not only improves the installation stability of magnetic components, thereby ensuring the accuracy of motor speed monitoring, but also helps to reduce costs.

[0031] See Figure 1 , Figure 2 and Figure 7 In some optional embodiments, this application provides a fluid pump, which includes a pump housing 1, a motor 2, and a control unit. The pump housing 1 has a motor cavity 11, and the motor 2 is housed in the motor cavity 11. The motor 2 includes a rotor 23, a stator 22, and a rotating shaft 21. The stator 22 is located radially inside the rotor 23, and the rotating shaft 21 is fixedly installed at the center of the rotor 23. The rotor 23 drives the rotating shaft 21 to rotate together with it. The control unit includes a magnetic element 4, a connecting part 3, a sensing element 51, and a control unit 5. The connecting part 3 has a connected snap-fit ​​part 33 and a fixing part 32. The snap-fit ​​part 33 snaps into the rotating shaft 21, and the magnetic element 4 is fixed on the fixing part 32. The sensing element 51 is disposed on one axial side of the motor 2 and is disposed opposite to the magnetic element 4. The sensing element 51 obtains a feedback signal by sensing the change in the magnetic field of the magnetic element 4. The control unit 5 receives the feedback signal and controls the speed of the motor 2 according to the feedback signal.

[0032] Optionally, the magnetic component 4 is coaxially arranged with the rotating shaft 21.

[0033] Optionally, the control component 5 includes a printed circuit board assembly (PCB). The PCB is installed inside the pump housing 1 and located on one axial side of the motor 2. The sensing element 51 is disposed on the PCB and coaxially arranged with the magnetic element 4, so that the magnetic field generated by the magnetic element 4 can pass through the sensing element 51 and change periodically. Thus, the sensing element 51 can sense the change in the magnetic field of the magnetic element 4 to obtain a feedback signal. The control component 5 can measure the rotational speed of the rotating shaft 21 based on the feedback signal, which also realizes the measurement of the rotational speed of the motor 2. The control component 5 then controls and adjusts the rotational speed of the motor 2 based on the currently measured rotational speed of the motor 2, thereby realizing the monitoring and control of the motor speed.

[0034] Optionally, the magnetic component 4 is a magnet, and the sensing element 51 is a magnetic induction position sensor.

[0035] Optionally, the magnetic component 4 is fixed to the end of the fixing part 32 away from the motor 2 by insert injection molding, so that part of the magnetic component 4 can be exposed in the motor cavity 11 and positioned directly opposite the sensing element 51. The end of the fixing part 32 away from the motor 2 and the end of the fixing part 32 away from the snap-fit ​​part 33 are the same end. The magnetic component 4 is connected and fixed to the connecting part 3 by insert injection molding, ensuring a secure connection that is not easily detached. Even when immersed in machine oil for a long time, the stability of the connection structure is maintained, thus ensuring the installation stability of the magnetic component 4. Furthermore, the connecting part 3 can be made of plastic and injection molded, resulting in a small size and lower raw material and manufacturing costs. Further, the magnetic component 4 can also be prevented from detaching from the fixing part 32 and / or rotating relative to it by an anti-detachment structure. Specifically, the anti-detachment structure includes a first limiting part disposed on the fixing part 32 and a second limiting part disposed on the magnetic component 4. The upper end of the magnetic component 4 is provided with a plurality of second limiting parts distributed along its circumference, and the second limiting parts protrude outward along the radial direction of the magnetic component 4. During the process of the magnetic component 4 being injection molded and fixed on the fixing part 32, a portion of the fixing part 32 bends inward along the radial direction of the fixing part 32 and extends to wrap around the upper end of the magnetic component 4 and the second limiting parts, thereby realizing the axial movement limitation of the magnetic component 4 and the fixing part 32 and the relative rotation in the circumferential direction, thereby preventing the magnetic component 4 from detaching from the fixing part 32 and from rotating relative to it; or, the magnetic component 4 can also adopt other irregular shapes to achieve anti-detachment and anti-rotation.

[0036] In the fluid pump of the above embodiment, the magnetic component 4 is snapped onto the rotating shaft 21 through the connecting component 3. The connection is simple, reliable, stable, and low in cost. The magnetic component 4 is not easy to detach from the rotating shaft 21 and can rotate stably together with the rotating shaft 21 so that the magnetic field formed can pass through the sensing element 51 and change periodically, thereby obtaining the position change of the motor 2 and thus measuring the speed of the motor 2.

[0037] See Figures 1 to 6 In some optional embodiments, the rotating shaft 21 is provided with a first channel 211, which extends axially along the rotating shaft 21 and is coaxial with the rotating shaft 21. The connecting member 3 is provided with a second channel 31, which extends axially along the connecting member 3 and is coaxial with the connecting member 3. The first channel 211 communicates with the motor cavity 11 through the second channel 31, allowing fluid to enter from the first channel 211 and flow out from the second channel 31 into the motor cavity 11 to provide cooling for the motor 2. The fluid includes engine oil; for example, if the fluid pump is an oil pump, the fluid can be engine oil.

[0038] Optionally, the inner wall of the first channel 211 is provided with a slot 212, and the outer wall of the snap-fit ​​part 33 is provided with a buckle 34. The snap-fit ​​part 33 extends into the first channel 211 and snaps into the slot 212 through the buckle 34. The slot 212 can be a through hole, which makes the processing simpler and more convenient, and helps to reduce the processing difficulty. The connecting component 3 is coaxially arranged with the rotating shaft 21. The snap-fit ​​part 33 has a columnar structure, and its axis coincides with the axis of the rotating shaft 21. Specifically, the first channel 211 has a connected large-diameter section and a small-diameter section. The snap-fit ​​part 33 extends into the large-diameter section, and its outer sidewall fits against the inner sidewall of the large-diameter section. The second channel 31 is aligned with and connected to the small-diameter section of the first channel 211. Fluid flows out from the small-diameter section of the first channel 211 and then enters the second channel 31. The inner diameter of the large-diameter section of the first channel 211 is larger than that of the small-diameter section, which facilitates the assembly of the snap-fit ​​part 33 with the rotating shaft 21 and also facilitates the flow of fluid along a designated path. Furthermore, there can be multiple snap-fits 34, which can be evenly distributed around the circumference of the snap-fit ​​part 33. The slots 212 correspond one-to-one with the snap-fits 34. In this embodiment, there are two snap-fits 34, which facilitates assembly and prevents them from easily detaching.

[0039] Optionally, the fixing part 32 is located outside the first channel 211, and the fixing part 32 is provided with a through hole 35 connecting the second channel 31 and the motor cavity 11. Fluid enters from the first channel 211, flows through the second channel 31, and then flows into the motor cavity 11 through the through hole 35. Furthermore, the fixing part 32 has a cylindrical structure, and the axis of the fixing part 32 coincides with the axis of the rotating shaft 21. Multiple through holes 35 are evenly arranged along its circumference on the side wall of the fixing part 32 so that the fluid flows evenly into the motor cavity 11. In addition, the fixing part 32 and the snap-fit ​​part 33 are arranged along the axial direction of the connecting component 3. The diameter of the fixing part 32 is larger than the diameter of the snap-fit ​​part 33. The fixing part 32 forms a stepped surface 321 at the connection with the snap-fit ​​part 33. When the snap-fit ​​part 33 and the rotating shaft 21 are snapped into place, the stepped surface 321 abuts against the end face of the rotating shaft 21. The step surface 321 abuts against the end face of the rotating shaft 21 to further limit the axial movement of the limiting connecting component 3. The large contact area is conducive to ensuring the structural strength of the abutment, thereby helping to ensure the stability and reliability of the overall structural assembly.

[0040] Optionally, the engaging portion 33 is provided with a weakening structure 36. When the engaging portion 33 extends into the first channel 211, the weakening structure 36 is compressed, resulting in an elastic deformation in the radial direction inward of the engaging portion 33. This causes the overall structure of the engaging portion 33 to undergo an elastic deformation in the radial direction inward. The weakening structure 36 provides deformation space for the elastic deformation of the engaging portion 33 and reduces the difficulty of deformation of the engaging portion 33, thereby reducing the difficulty of inserting the engaging portion 33 into the first channel 211. Furthermore, the second channel 31 extends along the axial direction of the engaging portion 33 of the connecting member 3 and is coaxially arranged with the engaging portion 33. The axis of the engaging portion 33, the axis of the fixing portion 32, and the axis of the connecting member 3 coincide. The weakening structure 36 includes a through groove, which is provided on the outer side wall of the engaging portion 33 and penetrates through the inner side wall of the engaging portion 33 to communicate with the second channel 31, which helps to further reduce the difficulty of deformation of the engaging portion 33. In this embodiment, there are multiple through slots, which are evenly spaced along the circumference of the snap-fit ​​part 33 and staggered from the snap fastener 34. That is, the through slots are staggered from the snap groove 212, which prevents fluid from entering the snap groove 212 and facilitates the flow of fluid along a designated path. Specifically, there are two through slots, which are distributed along the circumference of the snap-fit ​​part 33 and arranged opposite to each other. This not only helps to reduce the deformation difficulty of the snap-fit ​​part 33, but also helps to ensure the structural strength of the snap-fit ​​part 33. In addition, the structure of the snap-fit ​​part 33 is symmetrical, which helps to generate uniform elastic deformation of the snap-fit ​​part 33 along its radial direction, which helps to improve the overall structural stability of the connecting part 3, thereby improving the stability and reliability of the snap-fit ​​between the connecting part 3 and the rotating shaft 21.

[0041] Optionally, the through groove can be a strip-shaped groove extending axially along the engaging portion 33. Specifically, the through groove includes a first groove segment, and the two ends of the first groove segment extend axially along the engaging portion 33 to form a second groove segment. The width of the second groove segment gradually decreases from the end closer to the first groove segment to the end farther away from the first groove segment. This structural design of the through groove helps to guide the deformation direction of the engaging portion 33, so that the engaging portion 33 can be smoothly inserted into the first channel 211 and engaged with the rotating shaft 21.

[0042] Optionally, a positioning block is provided on the outer wall of the snap-fit ​​part 33 near the fixed part 32, and a positioning groove 213 corresponding to the positioning block is provided on the rotating shaft 21. The positioning block extends into the positioning groove 213 and cooperates with the positioning groove 213 for positioning. Furthermore, there are two positioning grooves 213, evenly distributed along the circumference of the rotating shaft 21. The positioning blocks include a first positioning block 37 and a second positioning block 38 corresponding to the two positioning grooves 213 respectively. That is, the first positioning block 37 and the second positioning block 38 are evenly distributed along the circumference of the snap-fit ​​portion 33. The volume of the first positioning block 37 is equal to the volume of the second positioning block 38. The length H1 of the first positioning block 37 is greater than the length H2 of the second positioning block 38, and the first positioning block 37 extends into the corresponding positioning groove 213 before the second positioning block 38. The width W1 of the first positioning block 37 is less than the width W2 of the second positioning block 38. The first positioning block 37 is clearance-fitted with the corresponding positioning groove 213, and the second positioning block 38 is transition-fitted with the corresponding positioning groove 213, restricting the relative rotation of the connecting component 3 and the rotating shaft 21. Furthermore, the positioning groove 213 is formed on the end of the rotating shaft 21 near the magnetic component 4, and the first positioning block 37 and the second positioning block 38 are located at the connection between the snap-fit ​​portion 33 and the fixing portion 32.

[0043] During assembly, the first positioning block 37 is first fitted with the corresponding positioning groove 213 with a clearance, which facilitates the quick positioning and initial limiting of the connecting component 3 and the rotating shaft 21. This helps to prevent the connecting component 3 from rotating circumferentially and causing the buckle 34 to fail to align and engage with the groove 212. Then, the second positioning block 38 is fitted with the positioning groove 213 with a transition, which can further limit the positioning and restrict the circumferential rotation of the connecting component 3 within the rotating shaft 21. This helps to ensure that the connecting component 3 and the rotating shaft 21 can remain stably and relatively fixed. Specifically, firstly, the connecting component 3 is inserted into the first channel 211 of the rotating shaft 21. Then, the connecting component 3 is rotated so that the first positioning block 37 is aligned with the corresponding positioning groove 213 to ensure that the buckle 34 is aligned with the groove 212. Then, the connecting component 3 is pushed so that the buckle 34 is pushed into the groove 212, so that the connecting component 3 and the rotating shaft 21 are engaged and fixed. At the same time, the second positioning block 38 is also assembled into the corresponding positioning groove 213 to restrict the relative rotation of the connecting component 3 and the rotating shaft 21 in the circumferential direction of the rotating shaft 21. Since the buckle 34 is aligned with the groove 212 when the first positioning block 37 enters the positioning groove 213, it plays a circumferential positioning role, which is conducive to the buckle 34 being smoothly aligned and engaged with the groove 212, ensuring the accuracy and reliability of the positioning assembly. In addition, the first positioning block 37 and the second positioning block 38 have the same volume and are evenly distributed in the circumferential direction of the connecting component 3, which is beneficial for compensating for the dynamic balance of the rotor 23. Moreover, the first positioning block 37 and the second positioning block 38 are assembled into the corresponding positioning grooves 213 one after another, which serves as an assembly guide so that the connecting component 3 and the rotating shaft 21 can be quickly positioned and assembled, reducing the assembly difficulty and improving the assembly efficiency. On the other hand, it has a limiting function, which not only limits the depth of the connecting component 3 into the rotating shaft 21, but also limits the relative rotation of the connecting component 3 with the rotating shaft 21 in its circumferential direction.

[0044] The fluid pump described in the above embodiment has a simple structure, compact layout, and high space utilization. It can both monitor the speed of the motor 2 and cool the motor 2. Specifically, a part of the connecting component 3 extends into the first channel 211 and communicates with the first channel 211. This allows the fluid to flow from the second channel 31 in the connecting component 3 into the motor cavity 11, and by occupying the internal space of the rotating shaft 21, it reduces the occupation of other spaces and improves the space utilization.

[0045] See Figures 1 to 3 In some optional embodiments, the snap-fit ​​portion 33 can be a hollow cylindrical structure with an internal cavity. When the snap-fit ​​portion 33 extends into the first channel 211, it is compressed, thereby generating an elastic deformation along its radial inward to compress the cavity. The cavity can provide space for the elastic deformation of the snap-fit ​​portion 33. The cavity inside the snap-fit ​​portion 33 can be independent of the second channel 31; or, the second channel 31 can be directly formed as a cavity, which is beneficial for simplifying the structure.

[0046] See Figures 1 to 5 In some alternative embodiments, the snap-fit ​​34 is a wedge-shaped structure. The wedge-shaped structure has a bevel 341 for guidance, so that the snap-fit ​​portion 33 can smoothly extend into the first channel 211, which helps to reduce the difficulty of installation.

[0047] Optionally, a rib 332 is provided on the outer wall of the snap-fit ​​portion 33 near the fixed portion 32. The rib 332 extends into the first channel 211 and is interference-fitted with the inner wall of the first channel 211. This helps to restrict the axial movement of the connecting component 3, thereby helping to maintain relative fixation between the connecting component 3 and the rotating shaft 21. This also helps to prevent the connecting component 3 from detaching from the rotating shaft 21 due to temperature changes or vibration deformation, further improving the stability and reliability of the overall structural assembly. Multiple ribs 332 are evenly distributed along the circumference of the snap-fit ​​portion 33. This improves the connection strength and provides structural symmetry, which helps to compensate for the dynamic balance of the rotor 23. Furthermore, the outlet end of the first channel 211 facing the fixing part 32 has a tapered guide surface 214, which allows the snap-fit ​​part 33 to cooperate with the tapered guide surface 214 for guidance when it extends into the first channel 211 from the outlet end, thus reducing assembly difficulty. In addition, the snap-fit ​​part 33 has a stepped section 331 connected to the fixing part 32. One end of the stepped section 331 is a cylindrical structure and is connected to the fixing part 32. The outer diameter of the fixing part 32 is larger than the outer diameter of the cylindrical structure to form a stepped surface 321 at the end of the fixing part 32. The protruding rib 332 is provided on the side wall of the cylindrical structure. The other end of the stepped section 331 is a tapered structure with a tapered surface 3311 that cooperates with the tapered guide surface 214, which further reduces assembly difficulty.

[0048] The fluid pump of the above embodiment has a simple and convenient assembly method between the connecting component 3 and the rotating shaft 21, with low assembly difficulty, high production efficiency, and is conducive to reducing costs.

[0049] See Figure 3 and Figure 7 In some alternative embodiments, the buckle 34 is a cylindrical structure. The cylindrical buckle 34 and the slot 212 can simultaneously restrict the axial and circumferential movement of the connecting component 3, which is beneficial to simplifying the structure. In particular, the limiting can be achieved without machining the protruding rib 332 and the rotating shaft 21 through interference fit, thus reducing the cost.

[0050] In some alternative embodiments, the snap 34 is a hemispherical structure.

[0051] The fluid pump of this utility model has a magnetic component 4 fixedly mounted on the connecting component 3. The connecting component 3 is snapped into the rotating shaft 21 to achieve connection and fixation with the rotating shaft 21. The assembly is simple, convenient, fast and reliable, and the structure is stable. It is beneficial to improve the reliability of motor 2 speed measurement and reduce production costs.

[0052] In the description of this specification, the references to terms such as "this embodiment," "example," and "specific example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0053] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A fluid pump comprising a pump housing, a motor and a control unit, the pump housing is provided with a motor cavity, the motor is accommodated in the motor cavity; the motor comprises a stator, a rotor and a rotating shaft, the stator is located at the radial outer side of the rotor, and the rotating shaft is fixedly installed at the center of the rotor; the control unit comprises a magnetic part, a connecting part, a sensing element and a control part, characterized in that, The connecting component has a clamping portion and a fixing portion, the clamping portion is clamped with the rotating shaft, the fixing portion is fixed with a magnetic element, the sensing element is arranged on one side of the motor in the axial direction and opposite to the magnetic element, the sensing element obtains a feedback signal by sensing the magnetic field change of the magnetic element, and the control component receives the feedback signal and controls the rotating speed of the motor according to the feedback signal.

2. The fluid pump of claim 1, wherein, The magnetic element is fixed on the end of the fixing portion away from the motor by insert injection molding, and the magnetic element is limited from being separated from the fixing portion and / or rotating relatively by an anti-separation structure, and the magnetic element is coaxially arranged with the rotating shaft.

3. The fluid pump of claim 1, wherein, The rotating shaft is provided with a first channel, and the connecting component is provided with a second channel, and the first channel is communicated with the motor cavity through the second channel.

4. The fluid pump of claim 3, wherein, The outer side wall of the clamping portion is provided with a buckle, and the inner side wall of the first channel is provided with a clamping groove, the clamping portion extends into the first channel and is clamped with the clamping groove through the buckle.

5. The fluid pump of claim 4, wherein, The clamping portion is provided with a weakening structure, and when the clamping portion extends into the first channel, the weakening structure is extruded to produce elastic deformation along the radial direction of the clamping portion.

6. The fluid pump of claim 5, wherein, The second channel extends along the axial direction of the clamping portion and is coaxially arranged with the clamping portion, and the weakening structure includes a through groove, the through groove is arranged on the outer side wall of the clamping portion and communicates with the second channel through the inner side wall of the clamping portion.

7. The fluid pump of claim 6, wherein, The number of the through grooves is two, and the two through grooves are distributed along the circumferential direction of the clamping portion and are oppositely arranged.

8. The fluid pump of claim 6 or 7, wherein, The through groove includes a first groove segment, and the two ends of the first groove segment extend along the axial direction of the clamping portion to form a second groove segment, and the width of the second groove segment gradually decreases from one end close to the first groove segment to one end away from the first groove segment.

9. The fluid pump of claim 3, wherein, The fixing portion is located outside the first channel, and the fixing portion is provided with a through hole communicating the second channel and the motor cavity.

10. The fluid pump of claim 9, wherein, The diameter of the fixing portion is greater than the diameter of the clamping portion, and the fixing portion forms a step surface at the connection with the clamping portion, and the step surface abuts against the end surface of the rotating shaft when the clamping portion is clamped with the rotating shaft in place.

11. The fluid pump of claim 1, wherein, The outer side wall of one end of the clamping portion close to the fixing portion is provided with a positioning block, and the rotating shaft is provided with a positioning groove corresponding to the positioning block, and the positioning block extends into the positioning groove to be positioned with the positioning groove.

12. The fluid pump of claim 11, wherein, The number of the positioning grooves is two, and the two positioning grooves are uniformly distributed along the circumferential direction of the rotating shaft, the positioning block includes a first positioning block and a second positioning block corresponding to the two positioning grooves respectively, the volume of the first positioning block is equal to the volume of the second positioning block, the length of the first positioning block is greater than the length of the second positioning block, the first positioning block extends into the corresponding positioning groove earlier than the second positioning block, the width of the first positioning block is less than the width of the second positioning block, the first positioning block is gap-fitted with the corresponding positioning groove, and the second positioning block is transition-fitted with the corresponding positioning groove.

13. The fluid pump of claim 3, wherein, The outer side wall of the clamping part near one end of the fixed part is provided with a protruding rib, the protruding rib extends into the first channel and is in interference fit with the inner side wall of the first channel; the number of the protruding ribs is multiple, and the multiple protruding ribs are uniformly arranged along the circumference of the clamping part.

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