Micro pump with full-surrounding bearing and electronic device

Abstract

The invention belongs to the related technical field of micro pumps, and discloses a micro pump with a full-surrounding bearing and an electronic device.The micro pump comprises a body, a rotor, a shaft and the full-surrounding bearing, and a rotor cavity is formed in the body; the full-surrounding bearing is integrally formed by stainless steel or ceramic materials and is of a step-shaped structure, an inner hole is formed in one end of the full-surrounding bearing, and a bearing boss with steps is formed at the other end of the full-surrounding bearing. One end of the shaft is fixed on the bottom surface of the rotor cavity, and a ball head is formed at the other end of the shaft and is in point contact with the inner hole; the bearing boss is embedded into the rotor and forms axial limiting with the step; and a non-contact gap is formed between the full-surrounding bearing and the bottom surface of the rotor cavity. According to the integrated full-surrounding bearing, a traditional separation type gasket and the bearing are integrated into an integrated precise part, the perpendicularity deviation of the bearing caused by inclination of the gasket or poor flatness in the assembling process is eliminated, and the problem of collaborative optimization of assembling precision and friction loss in the field of micro pumps is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field related to micro pumps, and more specifically, relates to a micro pump with a fully enclosed bearing and an electronic device. Background Art

[0002] With the development of miniaturization and integration of electronic devices, traditional air-cooled heat dissipation solutions have been difficult to cope with the heat dissipation pressure brought by the sharp increase in the power density of chips, and the liquid-cooled solution driven by a micro pump has become the mainstream heat dissipation method. However, in the face of heat dissipation scenarios with limited volume, such as application fields such as laptops and microfluidic chips, the liquid-cooled heat dissipation solution poses higher requirements for the thickness and reliability of the micro pump. In the prior art, there are the following limitations for the thinning, shafting stability and wear problems of micro pumps.

[0003] There are structural contradictions in the thinning design in the prior art. The ultra-thin centrifugal micro pumps disclosed in Patent CN109356856B and Patent CN109372755B compress the thickness through horizontal arrangement and an outer rotor motor. However, due to the working principle of the centrifugal pump, a drainage structure must be additionally provided, resulting in an increase in flow resistance and high processing difficulty. Such solutions are difficult to balance between thickness and performance.

[0004] There are problems with rotor support and wear in the prior art. For example, Patent CN1558990A discloses a vortex pump type ultra-thin pump and its cooling system, which uses radial / axial protrusions to support the rotor. However, the large radial air gap results in low motor efficiency, and the large contact area is prone to cause friction and wear. Patent CN113187730B realizes rotor suspension through buoyancy grooves, but the grooves contact the wear-resistant sheet in the non-working state, and it is easy to wear and fail after repeated start and stop.

[0005] There are deficiencies in the assembly accuracy and stability of the shafting in the prior art. For example, Patent CN211082299U uses a combination of ceramic bearings and wear-resistant sheets. Although it has strong corrosion resistance, it relies on a high-precision assembly process, with high overall costs and limited performance. Patent CN112112815B uses the pump body and the impeller as ball bearing components. Although the resistance is reduced, the vibration and noise are large, and the long-term operation reliability is poor. Summary of the Invention

[0006] In view of the above defects or improvement requirements of the prior art, the present invention provides a micro pump with a fully enclosed bearing and an electronic device, aiming to solve the problems of low assembly accuracy and short service life of existing micro pumps.

[0007] To achieve the above object, according to one aspect of the present invention, there is provided a micro pump with a fully enclosed bearing, the micro pump includes a body, a rotor, a shaft and a fully enclosed bearing, the body is formed with a rotor cavity, and the rotor, the shaft and the fully enclosed bearing are arranged in the rotor cavity;

[0008] The rotor is provided with a shaft hole; the fully enclosed bearing is stepped, with an inner hole formed at one end and a bearing boss formed at the other end, and a step is formed between the bearing boss and the end where it is located; one end of the shaft is fixed on the bottom surface of the rotor cavity, and the other end is embedded in the inner hole to be connected to the fully enclosed bearing; the bearing boss is arranged in the bearing hole, and the rotor abuts against the step; a non-contact gap is formed between the fully enclosed bearing and the bottom surface of the rotor cavity.

[0009] Further, a non-contact gap is formed between the bottom of the rotor and the bottom surface of the rotor cavity.

[0010] Further, the rotor includes an impeller, the bearing hole is opened on the impeller, and the impeller and the fully enclosed bearing are of an integrally formed structure.

[0011] Further, the impeller is fixed on the step by a plastic coating process.

[0012] Further, the material of the fully enclosed bearing is a ceramic material or a ceramic-metal composite material.

[0013] Further, the fully enclosed bearing is also respectively provided with a through inner hole exhaust hole and an outer edge exhaust hole. The inner hole exhaust hole penetrates the side wall of the inner hole and is communicated with the inner hole; the outer edge exhaust hole penetrates the outer peripheral surface of the fully enclosed bearing.

[0014] Further, the micro pump further includes a stator arranged in the body. The stator includes a stator core and a stator winding arranged in the stator core; the rotor further includes a magnetic ring. One end of the magnetic ring is connected to the impeller, and the magnetic center line of the stator core is offset in a direction away from the impeller relative to the magnetic center line of the magnetic ring.

[0015] Further, the offset amount of the offset is 0.20 mm to 2.00 mm.

[0016] Further, the shaft forms a point contact with the inner hole end face of the inner hole.

[0017] The present invention also provides an electronic device, which includes a housing and the micro pump as described above, and the micro pump is arranged in the housing.

[0018] Generally speaking, compared with the prior art by the above technical solutions conceived by the present invention, the micro pump and the electronic device with a fully enclosed bearing provided by the present invention mainly have the following beneficial effects:

[0019] 1. A step is formed between the bearing boss and the end where it is located; one end of the shaft is fixed on the bottom surface of the rotor cavity, and the other end is embedded in the inner hole to be connected to the fully enclosed bearing; the bearing boss is arranged in the bearing hole, and the rotor abuts against the step, and an axial limit is formed between the rotor and the step; a non-contact gap is formed between the fully enclosed bearing and the bottom surface of the rotor cavity, so that the fully enclosed bearing has both radial and axial limit functions at the same time. The fully enclosed bearing integrates the traditional split gasket and the bearing into an integral component, eliminates the bearing perpendicularity deviation caused by gasket tilt or poor flatness during the assembly process, and can eliminate the split assembly gap, ensuring the assembly accuracy and operation stability of the micro pump. And due to the existence of the non-contact gap, the contact wear between the outer enclosed bearing and the rotor cavity is avoided, and the service life of the micro pump is extended.

[0020] 2. A non-contact gap is formed between the bottom of the rotor and the bottom surface of the rotor cavity, avoiding the contact wear between the rotor and the rotor cavity, and extending the service life of the micro pump.

[0021] 3. The impeller and the fully enclosed bearing are of an integrally formed structure, reducing the number of components and the assembly links, and improving the dynamic balance accuracy of the rotor.

[0022] 4. The magnetic center line of the stator core is offset in a direction away from the impeller relative to the magnetic center line of the magnetic ring to generate a downward magnetic pull force. The magnetic pull force acts together with the fluid dynamic pressure and gravity to maintain the balance state of the rotor during operation; by adjusting the offset amount of the magnetic pull force and the axial center height, it is ensured that a non-contact gap is maintained between the rotor and the bottom of the rotor cavity in both the working and non-working states.

[0023] 5. The shaft forms a point contact with the inner hole end face of the inner hole, reducing the friction area; the inner hole exhaust hole and the outer edge exhaust hole are jointly used to avoid assembly air resistance.

[0024] 6. The traditional drainage structure is cancelled. Through the integrated layout of the rotor cavity, the thickness of the pump body is compressed, and at the same time, the friction resistance is reduced due to the non-contact design; the application of ceramic matrix composite materials improves the corrosion resistance of the fully enclosed bearing, and the plastic coating process ensures the coaxiality of the impeller and the bearing, adapting to high-speed working conditions. Description of the Drawings

[0025] Figure 1 is an exploded view of a micro pump with a fully enclosed bearing provided by an embodiment of the present invention;

[0026] Figure 2 is Figure 1 the cross-sectional view of the micro pump with a fully enclosed bearing in

[0027] Figure 3 isFigure 1 Cross-sectional view of the rotor of the micro pump with a fully enclosed bearing and the fully enclosed bearing;

[0028] Figure 4 is Figure 3 Schematic three-dimensional view of the fully enclosed bearing in;

[0029] Figure 5 is Figure 4 Cross-sectional view of the fully enclosed bearing in;

[0030] Figure 6 Force analysis diagram of the rotor of the micro pump with a fully enclosed bearing provided by an embodiment of the present invention;

[0031] Figure 7 is Figure 1 Partial cross-sectional view of a micro pump with a fully enclosed bearing in.

[0032] In all the drawings, the same reference numerals are used to denote the same elements or structures, where: 1 - volute, 11 - sealing groove, 12 - upper rotor cavity, 2 - base, 21 - lower rotor cavity, 22 - axial center groove, 23 - stator cavity, 24 - control board groove, 25 - wire routing groove, 26 - inlet pipe, 27 - outlet pipe, 3 - rotor, 31 - impeller, 311 - bearing hole, 312 - impeller groove, 313 - impeller rib, 32 - motor housing, 33 - magnetic ring, 34 - fully enclosed bearing, 341 - internal control end face, 342 - inner hole side wall, 343 - inner hole exhaust hole, 344 - outer edge exhaust hole, 345 - bearing boss, 4 - stator, 41 - stator core, 42 - stator winding, 5 - shaft, 51 - ball head, 6 - control board, 7 - sealing ring, 8 - fastener. Detailed implementation manners

[0033] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various implementation manners of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0034] The present invention provides a micro pump with a fully enclosed bearing. The micro pump adopts a fully enclosed bearing, and the fully enclosed bearing has both radial limiting and axial limiting functions, can eliminate the split assembly gap, ensure the assembly accuracy and operation stability, and the fully enclosed bearing enables a non-contact gap to be maintained between the bottom of the rotor of the micro pump and the rotor cavity, avoiding contact wear between the rotor and the rotor cavity, extending the service life of the micro pump, and being applicable to electronic devices with strict requirements for thickness and reliability, such as laptop computers and microfluidic chips.

[0035] Please refer to Figure 1 and Figure 2 , the micro pump includes a volute 1, a base 2, a rotor 3, a stator 4, a shaft 5, a control board 6, a full-enclosure bearing 34, a sealing ring 7 and fasteners 8. The fasteners 8 connect the volute 1 and the base 2. The sealing ring 7 is located between the volute 1 and the base 2. The volute 1 and the base 2 together form a rotor cavity, and the base 2 forms a stator cavity 23. The stator 4 is arranged in the stator cavity 23, and the control board 6 is arranged in the base 2 and is electrically connected to the stator. The rotor 3 is arranged in the rotor cavity, and the shaft 5 is arranged in the rotor cavity. One end of the shaft 5 is fixedly connected to the base 2, and the other end is embedded in one end of the full-enclosure bearing 34. The other end of the full-enclosure bearing 34 is embedded in the rotor and connected to the rotor. A non-contact gap is formed between one end of the rotor facing the base 2 and the bottom surface of the rotor cavity. In this embodiment, the non-contact gap is 0.1 mm; the volute 1 and the base 2 form a body.

[0036] One end of the volute 1 is respectively provided with a sealing groove 11 and an upper rotor cavity 12. The upper rotor cavity 12 is located inside the sealing ring 7. The sealing ring 7 is arranged in the sealing groove 11 to seal the rotor cavity. One end of the base 2 is provided with a control board groove 24, a wiring groove 25 and a stator cavity 23. The wiring groove 25 is located between the stator cavity 23 and the control board groove 24. The control board is arranged in the control board groove 24 and is electrically connected to the stator through the wiring groove 25. The other end of the base 2 is provided with a lower rotor cavity 21. The lower rotor cavity 21 and the upper rotor cavity 12 form the closed rotor cavity, which is used to accommodate the rotor and guide the fluid flow. An axial center groove 22 is provided at the bottom of the rotor cavity. One end of the shaft is fixed in the axial center groove 22. One side of the base 2 is also provided with an inlet pipe 26 and an outlet pipe 27. The inlet pipe 26 and the outlet pipe 27 are respectively communicated with the rotor cavity. The inlet pipe 26 is used to suck the fluid, and the outlet pipe 27 is used to output the pressurized fluid.

[0037] Please refer to Figure 3 , the rotor includes an impeller 31, a motor housing 32 and a magnetic ring 33. The magnetic ring 33 is sleeved inside the motor housing 32. One ends of the magnetic ring 33 and the motor housing 32 are both arranged in the cavity of the impeller 31 and abut against the bottom surface of the cavity. A plurality of impeller ridges 313 are arranged at intervals on the outer periphery of the impeller 31. Impeller grooves 312 are formed between adjacent impeller ridges. The plurality of impeller grooves 312 are evenly arranged along the same circle. The impeller 31 is provided with a bearing hole 311, and the central axis of the bearing hole 311 coincides with the central axis of the impeller 31.

[0038] Please refer to Figure 4 and Figure 5 As shown, the fully enclosed bearing 34 is a stepped cylinder. One end is provided with an inner hole, and the other end is provided with a bearing boss 345. A step is formed between the bearing boss 345 and the body of the fully enclosed bearing 34. The fully enclosed bearing 34 is also provided with a through inner hole exhaust hole 343 and an outer edge exhaust hole 344. The inner hole exhaust hole 343 penetrates the side wall 342 of the inner hole and communicates with the inner hole. The outer edge exhaust hole 344 penetrates the outer peripheral surface of the fully enclosed bearing 34.

[0039] In this embodiment, the central axis of the inner hole, the central axis of the inner hole exhaust hole 343, and the central axis of the outer edge exhaust hole 344 are parallel to the central axis of the fully enclosed bearing 34; the number of the outer edge exhaust holes 344 is two, and the two outer edge exhaust holes 344 are symmetrically arranged with respect to the inner hole. The outer edge exhaust hole 344 penetrates the step; the number of the inner hole exhaust holes 343 is also two, and the two inner hole exhaust holes are also symmetrically arranged with respect to the inner hole.

[0040] The bearing boss 345 is arranged in the bearing hole 311 and the two are matched. The impeller 31 is fixed on the step by a plastic coating process. The coaxiality error between the circle formed by the arrangement of the impeller grooves 312 and the bearing boss 345 is ≤0.01 mm. The fully enclosed bearing 34 is made of ceramic material or ceramic-metal composite material. The inner hole end face of the inner hole is coated with a wear-resistant coating.

[0041] In the non-working state of the rotor, the inner hole end face abuts against the ball head at one end of the shaft, so that a non-contact gap of 0.1 mm is formed between the bottom surface of the impeller 31, the bottom surface of the motor housing 32, and the bottom surface of the magnetic ring 33 and the bottom surface of the rotor lower cavity 21. Among them, a point contact is formed between the inner hole end face and the ball head.

[0042] The stator includes a stator core 41 and a stator winding arranged in the stator core 41. The distance between the stator core 41 and the end face of the base 2 away from the volute 1 is less than the distance between the magnetic ring 33 and the end face of the base 2 away from the volute 1. The magnetic center line of the stator core 41 is lower than that of the magnetic ring 33, that is, it is offset downward to generate a downward magnetic pull force. The magnetic pull force acts together with the hydrodynamic pressure and gravity to maintain the balance state of the rotor during operation. The offset is 0.20 mm to 2.00 mm, and the stator winding is a distributed winding embedded in the slots of the stator core 41.

[0043] Please refer to Figure 7, in one embodiment, one end of the shaft is fixed within the axial center groove 22, and the other end is formed with a ball head 51. The ball head 51 is disposed within the inner hole, and the ball head forms a point contact with the end face of the inner hole, reducing the friction area. The inner hole exhaust hole 343 and the outer edge exhaust hole 344 are jointly used to avoid assembly air resistance.

[0044] The control board is embedded within the control board groove 24 and is connected to the stator winding through the wire groove 25 for driving the rotor to rotate.

[0045] Please refer to Figure 6 , after the control board is powered on, the stator winding generates an alternating magnetic field to drive the magnetic ring 33 to drive the impeller 31 to rotate;

[0046] Analyze the forces on the rotor:

[0047] Axial force system balance: Upward forces: When the rotor is immersed in the working fluid, it is subject to the fluid buoyancy and the supporting force of the shaft on the end face of the inner hole; Downward forces: The self-weight of the rotor and the downward magnetic pulling force generated by the stator through the offset of the magnetic force center line; By adjusting the magnetic pulling force offset and the axial center height, ensure that there is a non-contact gap of 0.1 mm between the rotor and the bottom of the rotor cavity in both the working and non-working states;

[0048] Circumferential forces symmetrically cancel each other out: When the impeller 31 rotates, the circumferential hydraulic pressure generated by the impeller groove 312 is symmetrically distributed; The alternating magnetic field generated by the stator distributed winding interacts with the magnetic ring 33 to form a circumferentially symmetric magnetic driving force, which balances with the hydraulic resultant force to prevent the rotor from wobbling.

[0049] The present invention also provides an electronic device. The electronic device includes a housing and the micro pump as described above. The micro pump is disposed within the housing and is used for dissipating heat from the heat within the housing. The electronic device can be a laptop computer or a mobile phone, and the micro pump is used for dissipating heat from electronic components such as circuit boards within the laptop computer.

[0050] Those skilled in the art can easily understand that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A micro pump with a fully enclosed bearing, characterized in that: The micro pump comprises a body, a rotor, a shaft and a fully enclosed bearing, wherein the body is formed with a rotor cavity, and the rotor, the shaft and the fully enclosed bearing are arranged in the rotor cavity; The rotor is provided with an axial hole; the fully enclosed bearing is stepped, with an inner hole formed at one end and a bearing boss formed at the other end, and a step is formed between the bearing boss and the end where it is located; one end of the shaft is fixed to the bottom surface of the rotor cavity, and the other end is embedded in the inner hole to be connected to the fully enclosed bearing; the bearing boss is arranged in the bearing hole, and the rotor abuts against the step; a non-contact gap is formed between the fully enclosed bearing and the bottom surface of the rotor cavity.

2. The micro pump with a fully enclosed bearing as claimed in claim 1, characterized in that: A non-contact gap is formed between the bottom of the rotor and the bottom surface of the rotor cavity.

3. The micro pump with a fully enclosed bearing according to claim 1, characterized in that: The rotor comprises an impeller, the bearing hole is arranged on the impeller, and the impeller and the fully enclosed bearing are an integrally formed structure.

4. The micro pump with a fully enclosed bearing as claimed in claim 3, characterized in that: The impeller is fixed on the step by a plastic coating process.

5. The micro pump with fully enclosed bearing according to claim 1, characterized in that: The material of the fully enclosed bearing is a ceramic material or a ceramic-metal composite material.

6. A micro pump with a fully enclosed bearing as claimed in any one of claims 1 to 5, characterized in that: The fully enclosed bearing is also provided with a through inner hole exhaust hole and an outer edge exhaust hole. The inner hole exhaust hole penetrates the inner hole side wall and is connected with the inner hole; the outer edge exhaust hole penetrates the outer peripheral surface of the fully enclosed bearing.

7. The micro pump with fully enclosed bearing according to claim 3, characterized in that: The micro pump also includes a stator arranged in the body, the stator includes a stator core and a stator winding arranged in the stator core; the rotor also includes a magnetic ring, one end of the magnetic ring is connected to the impeller, and the magnetic center line of the stator core is offset in a direction away from the impeller relative to the magnetic center line of the magnetic ring.

8. The micro pump with fully enclosed bearing according to claim 7, characterized in that: The offset amount is 0.20mm to 2.00mm.

9. The micro pump with a fully enclosed bearing according to any one of claims 1 to 5, characterized in that: The shaft forms point contact with an inner hole end surface of the inner hole.

10. An electronic device, characterized in that: The electronic device comprises a housing and the micro pump according to any one of claims 1 to 9, wherein the micro pump is arranged in the housing.

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