LVAD motor stator system and LVAD motor

Abstract

The utility model belongs to the technical field of artificial heart-left ventricle auxiliary circulation equipment, and particularly discloses an LVAD motor stator system, which comprises an outer stator, an inner stator and a winding arranged between the outer stator and the inner stator, the inner stator is formed by stacking a plurality of silicon steel ring sheets, an axial modulation groove is arranged along the circumferential direction of the inner side of the inner stator, and the inner side of the inner stator is connected with the winding. According to the utility model, the modulation grooves are arranged in the inner stator, so that the harmonic amplitude is reduced, and the fluctuation of the torque is reduced. The utility model also discloses a motor which is filled with epoxy resin, so that the relative positions of related parts are ensured, the coaxiality and dynamic balance of the related parts are ensured, the motor is stable in high-speed operation, the vibration can be reduced, the motor has relatively good biological safety, relatively high heat conductivity coefficient and chemical stability, and the heat is quickly dissipated when the motor is in high-speed operation. The device is suitable for being placed in a human body.

Description

Technical Field

[0001] This utility model belongs to the technical field of artificial heart - left ventricular assist circulation device, specifically relating to an LVAD motor stator system and an LVAD motor. Background Technology

[0002] A left ventricular assist device (LVAD) is a common treatment for advanced heart failure. It's a small device connected to the heart that mechanically draws blood from the left ventricle and delivers it to the aorta, reducing the workload on the left ventricle and helping the heart pump oxygenated blood throughout the body. An LVAD mainly consists of inflow lines, a pump system, outflow lines, a drive system, and an external controller. The drive system provides power to the LVAD, and its core component is the LVAD motor.

[0003] Since LVAD motors are installed inside the human body, their size should be as small as possible. This requires the stator, which forms the basis of the LVAD motor's magnetic circuit, to be small. Consequently, only a limited number of stator slots with restricted dimensions can be set on the stator. This results in problems such as high harmonic amplitude, large torque fluctuations, and unstable motor operation when the LVAD motor is working. Utility Model Content

[0004] The purpose of this invention is to provide an LVAD motor stator system that effectively suppresses high-order harmonics, reduces torque fluctuations, and ensures stable motor operation.

[0005] The purpose of this utility model is achieved through the following technical solution: a stator system for an LVAD motor is provided, including an outer stator, an inner stator, and a winding disposed between the outer stator and the inner stator. The inner stator is composed of several stacked silicon steel rings. Several winding slots are provided at intervals along the outer circumferential direction of the inner stator, and an axial modulation slot is provided along the inner circumferential direction of the inner stator. The modulation slot is located in the middle of adjacent winding slots.

[0006] Preferably, the cross-sectional shape of the modulation groove is one of rectangle, semicircle and triangle.

[0007] Preferably, the silicon steel ring is provided with positioning holes at intervals along the circumference.

[0008] Preferably, the winding includes a frame and a coil, with the coil wound on the frame, and the winding is connected in a star configuration.

[0009] Due to the adoption of the above technical solution, this utility model has the following advantages:

[0010] Adding axial modulation slots to the stator surface can increase the frequency of the positioning torque change during the motor's rotation cycle, thereby increasing the harmonic order of its main function and reducing harmonic components. This effectively suppresses higher-order harmonics and reduces torque fluctuations.

[0011] An LVAD motor includes a stator system and a rotor system disposed within the stator system.

[0012] Preferably, the rotor system includes a rotor support, a neodymium iron boron permanent magnet, a rotor ring, and a rotor cover plate. The rotor support is coaxially installed inside the inner stator, the neodymium iron boron permanent magnet is fixed to the outer periphery of the rotor support, the rotor ring is tightly fitted to the radial inner side of the neodymium iron boron permanent magnet, and the rotor cover plate is located at the bottom of the rotor support.

[0013] Preferably, the rotor system and stator system are vacuum-encapsulated with epoxy resin.

[0014] Due to the adoption of the above technical solution, this utility model has the following advantages:

[0015] The motor includes a stator system with modulation slots to suppress high-order harmonics, reduce torque ripple, and improve the motor's control characteristics. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of this utility model, the accompanying drawings used in the specific embodiments will be briefly described below. In all the drawings, the elements or parts are not necessarily drawn to scale.

[0017] Figure 1 This is a schematic diagram of the structure of an LVAD motor stator system according to the present invention;

[0018] Figure 2 A schematic diagram of the inner stator;

[0019] Figure 3 This is a schematic diagram of the winding;

[0020] Figure 4 This is a schematic diagram of the LVAD motor.

[0021] Figure 5 This is a schematic diagram of the UVW leads of the winding.

[0022] Figure label:

[0023] 1-Outer stator, 11-Outer stator positioning hole;

[0024] 2-Inner stator, 21-Silicon steel ring, 211-Positioning hole, 22-Modulation groove, 23-Magnetic yoke, 24-Wire embedding groove, 241-Slot opening;

[0025] 3-Winding, 31-Board, 32-Coil;

[0026] 4-Rotor system, 41-Rotor support, 42-NdFeB permanent magnet, 43-Rotor ring, 44-Rotor cover plate, 45-Shaft, 5-Epoxy resin layer. Detailed Implementation

[0027] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0028] Please see Figure 1 , Figure 2 and Figure 4 An LVAD motor stator system includes: an outer stator 1, an inner stator 2, and a winding 3 disposed between the outer stator 1 and the inner stator 2. The inner stator 2 is composed of several stacked silicon steel rings 21. Several winding slots 24 are spaced apart along the outer circumference of the inner stator 2, and axial modulation slots 22 are provided along the inner circumference of the inner stator 2, with the modulation slots 22 located in the middle of adjacent winding slots 24. Specifically, the inner stator 2 is stamped from high-permeability silicon steel rings 21, and after being stacked and riveted, it forms the basic magnetic circuit of the stator to reduce eddy current losses and hysteresis losses. The inner stator 2 adopts a closed-slot ring form, which can effectively reduce torque. The inner stator 2 also has a magnetic yoke 23, and the winding slots 24 are disposed in the middle of adjacent magnetic yokes 23. The front end of the winding slot 24 near the slot opening 241 is an isosceles trapezoid, and the rear end away from the slot opening 241 is an isosceles obtuse triangle. The winding 3 is installed in the winding slot 24. Preferably, there are twelve inlay slots 24 and twelve modulation slots 22. The outer stator 1 is made of high permeability silicon steel rings, which are stacked and riveted to form the external magnetic circuit of the stator and coupled with the magnetic circuit of the inner stator 2, effectively reducing leakage flux. The outer rings of the outer stator 1 and the inner stator 2 adopt a transition fit, which can effectively reduce magnetic resistance to the maximum extent.

[0029] This utility model discloses an LVAD motor stator system. By setting a modulation slot 22 on the inner wall of the inner stator 2, the waveform of the motor positioning torque is determined by the periodic coupling of the winding slot 24 and the magnetic field of the permanent magnet. Since the magnetic field passing through the air gap mainly passes through the yoke 23, it does not penetrate into the winding slot 24. The modulation slot 22 is located in the middle of the adjacent winding slots 24, which can change the spatial distribution of the air gap magnetic field during the motor's rotation cycle. The frequency of the motor positioning torque change increases, which increases the harmonic order of its main function, thereby reducing harmonic components and effectively suppressing high-order harmonics and reducing torque fluctuations.

[0030] Furthermore, the cross-sectional shape of the modulation groove 22 is one of rectangle, semicircle and triangle.

[0031] Furthermore, the silicon steel ring plates 21 are provided with positioning holes 211 spaced apart circumferentially. Specifically, the silicon steel ring plates 21 are riveted together with rivets whose shape matches the positioning holes 211. The use of positioning holes 211 for assembly ensures good coaxiality between the silicon steel ring plates 21. The inner stator 2 is formed by riveting the silicon steel ring plates 21 together, eliminating the need for adhesive fixation and ensuring the biosafety of the LVAD motor when inserted into the human body. Preferably, there are six positioning holes 211, evenly spaced circumferentially on the silicon steel ring plates 21. Similarly, the outer stator 1 is also provided with six outer stator positioning holes 11 spaced apart circumferentially.

[0032] Further, please refer to Figure 3 and Figure 5 The winding 3 includes a frame 31 and a coil 32. The coil 32 is wound on the frame 31, and the winding 3 adopts a star connection. Specifically, the coil 32 has a split structure (a single coil 32 is wound on the frame 31 and then combined with the inner stator 2). After the winding 3 is assembled, the coils 32 are connected by welding and then heat-sealed with heat-shrink tubing to ensure their insulation. The winding 3 is connected by UVW leads, which represent the three independent AC potentials of the motor and correspond to the three terminals U, V and W respectively.

[0033] Please see Figure 4 An LVAD motor includes a stator system and a rotor system 4, which is disposed within the stator system. Specifically, the rotor system 4 includes a rotor support 41, neodymium iron boron permanent magnets 42, rotor rings 43, and a rotor cover plate 44. The rotor support 41 is coaxially mounted inside the inner stator 2. The neodymium iron boron permanent magnets 42 are fixed to the outer periphery of the rotor support 41. The rotor rings 43 are tightly fitted to the radially inner side of the neodymium iron boron permanent magnets 42. The rotor cover plate 44 is disposed at the bottom of the rotor support 41. The rotor system 4 also includes a shaft 45. The rotor support 41 has a through hole 411 and a mounting cavity 412. The shaft 45 is installed in the through hole 411 and provides power output for the motor. The neodymium iron boron permanent magnets 42 and the rotor rings 43 are disposed in the mounting cavity 412. Neodymium iron boron permanent magnet 42 is coupled with the motor to form a magnetic flux, and the rotating electromagnetic field drives the rotor system 4 to rotate. The rotor ring 43 is used for magnetic field coupling inside the neodymium iron boron permanent magnet 42 to prevent magnetic leakage. The rotor cover plate 44 and the rotor support 41 are laser-welded into a whole in an argon atmosphere. After welding, the welded area is ground smooth to meet the airtightness and waterproof requirements of the motor. The rotor system 4 is magnetized as a whole and has eight poles.

[0034] Furthermore, the rotor system 4 and stator system are vacuum-encapsulated with epoxy resin. Specifically, after the motor assembly is completed, the stator system and rotor system 4 are vacuum-encapsulated with epoxy resin, and the LVAD motor is covered by an epoxy resin layer 5. The epoxy resin layer 5 uses medical-grade epoxy resin, such as a room-temperature curing two-component epoxy resin, model EP42HT-2Med, which has good biocompatibility, high thermal conductivity and chemical stability, and cytotoxicity meets the ISO10993-5 standard. It plays a role in rapid heat dissipation and vibration reduction during high-speed operation of the motor, making the LVAD motor suitable for placement inside the human body. After the rotor system 4 is assembled, it is filled with epoxy resin to fix the relative position of the neodymium iron boron permanent magnet 42 with the rotor support 41 and rotor ring 43, ensuring coaxiality and dynamic balance.

[0035] An LVAD motor stator system and motor are disclosed. Axial modulation grooves 22 are spaced circumferentially on the inner wall of the inner stator 2. This increases the frequency of the motor's positioning torque variation during the rotation cycle, thereby increasing the dominant harmonic order and reducing harmonic components. This effectively suppresses higher-order harmonics, reduces torque ripple, and improves motor operational stability. The LVAD motor is filled with medical-grade epoxy resin, which not only ensures the relative positions of related components, coaxiality, and dynamic balance, but also stabilizes the motor at high speeds and reduces vibration. Furthermore, it offers good biocompatibility, high thermal conductivity, and chemical stability, and facilitates rapid heat dissipation during high-speed operation, making it suitable for placement inside the human body. The inner stator 2 and outer stator 1 are joined using a stacked riveting process to ensure biocompatibility.

[0036] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific implementation method of this utility model and is not intended to limit this utility model. Any modifications, equivalent substitutions, and improvements made within the scope of the spirit of this utility model should be included within the protection scope of this utility model.

Claims

1. An LVAD motor stator system, characterized in that, include: The outer stator (1), the inner stator (2) and the winding (3) disposed between the outer stator (1) and the inner stator (2) are provided. The inner stator (2) is composed of several silicon steel ring plates (21) stacked together. Several winding grooves (24) are provided at intervals along the outer circumference of the inner stator (2). An axial modulation groove (22) is provided along the inner circumference of the inner stator (2). The modulation groove (22) is located in the middle of the adjacent winding grooves (24).

2. The LVAD motor stator system according to claim 1, characterized in that, The cross-sectional shape of the modulation groove (22) is one of rectangle, semicircle and triangle.

3. The LVAD motor stator system according to claim 1 or 2, characterized in that, The silicon steel ring (21) is provided with positioning holes (211) at intervals along the circumference.

4. The LVAD motor stator system according to claim 1 or 2, characterized in that, The winding (3) includes a frame (31) and a coil (32). The coil (32) is wound separately on the frame (31). The winding (3) adopts a star connection method.

5. The LVAD motor stator system according to claim 3, characterized in that, The winding (3) includes a frame (31) and a coil (32). The coil (32) is wound on the frame (31), and the winding (3) adopts a star connection.

6. An LVAD motor, characterized in that, The LVAD motor stator system includes any one of claims 1-5, and further includes a rotor system (4), which is disposed in the stator system.

7. The LVAD motor according to claim 6, characterized in that, The rotor system (4) includes a rotor support (41), a neodymium iron boron permanent magnet (42), a rotor ring (43), and a rotor cover plate (44). The rotor support (41) is coaxially installed inside the inner stator (2). The neodymium iron boron permanent magnet (42) is fixed to the outer periphery of the rotor support (41). The rotor ring (43) is tightly fitted to the radial inner side of the neodymium iron boron permanent magnet (42). The rotor cover plate (44) is located at the bottom of the rotor support (41).

8. The LVAD motor according to claim 6 or 7, characterized in that, The rotor system (4) and the stator system are vacuum potted with epoxy resin.

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