Drive device and blood pump
By utilizing the attraction between the stator and rotor and ceramic materials in the blood pump's drive unit, the contact area is increased and friction is reduced, solving the problems of severe shaft wear and difficult start-up in traditional blood pumps, thus achieving lower wear and faster start-up.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2022-07-08
- Publication Date
- 2026-03-27
AI Technical Summary
Traditional blood pumps suffer from severe shaft wear and are difficult to start, affecting their effectiveness.
A drive device is designed that uses the attraction between the stator and rotor to make the first surface abut against the first cavity wall of the accommodating cavity, thereby increasing the contact area and reducing the pressure per unit area. At the same time, the second surface does not contact the second cavity wall or reduces the coefficient of friction. Combined with ceramic materials and a guide channel structure, wear and frictional resistance are reduced.
It reduces shaft wear, improves start-up speed and response sensitivity, and enhances the lifespan and reliability of the blood pump.
Smart Images
Figure CN121731649A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of medical device technology, and in particular to a drive device and a blood pump including the drive device. Background Technology
[0002] An intravascular blood pump is a blood-pumping device that can be inserted into a patient's heart through a blood vessel. The pump is placed inside the opening of the heart valve, allowing blood to flow through the pump and into the artery. The pump consists of a drive unit and an impeller. The impeller is fixed to the drive unit's shaft, and the shaft's rotation drives the impeller. However, the shaft of traditional blood pumps wears out significantly during use and is difficult to start, affecting the pump's performance. Summary of the Invention
[0003] Therefore, it is necessary to provide a drive unit and blood pump that have less shaft wear and are easier to start.
[0004] A driving device for driving an impeller to rotate, the driving device comprising: The housing assembly has a receiving cavity, the receiving cavity having a first cavity wall and a second cavity wall that are opposite to and spaced apart from each other; A rotating shaft for connection with the impeller includes a connected straight shaft portion and a protruding portion. The protruding portion protrudes circumferentially from the straight shaft portion and is rotatably received in the receiving cavity. The protruding portion is located between the first cavity wall and the second cavity wall. The protruding portion has a first surface and a second surface. The first surface faces the first cavity wall, and the second surface faces the second cavity wall. The area of the first surface is greater than the area of the second surface, and the area of the first surface is less than or equal to the area of the first cavity wall. The rotor is fixedly connected to the straight shaft portion; and The stator is capable of driving the rotor to rotate, and there is an attractive force between the stator and the rotor, which causes the first surface to abut against the first cavity wall.
[0005] In one embodiment, the distance between the first cavity wall and the second cavity wall is greater than the distance between the first surface and the second surface, so that when the first surface abuts against the first cavity wall, the second surface and the second cavity wall are spaced apart by a distance. And / or, at least one of the first cavity wall and the first surface is made of ceramic; And / or, at least one of the second cavity wall and the second surface is made of ceramic.
[0006] In one embodiment, a first perforation and a first guide groove are provided on the first cavity wall. The first perforation is connected to the receiving cavity, and the first guide groove is connected to both the first perforation and the receiving cavity. The straight shaft portion is rotatably inserted through the first perforation.
[0007] In one embodiment, the protrusion further has a side peripheral surface connecting the first surface and the second surface, the accommodating cavity further has a side cavity wall connecting the first cavity wall and the second cavity wall, a gap is formed between the side cavity wall and the side peripheral surface, and a portion of the first guide groove extends beyond the range of the orthographic projection of the first surface onto the first cavity wall and communicates with the gap.
[0008] In one embodiment, the side peripheral surface includes a cylindrical facet and a tapered facet disposed around the axis of the straight shaft portion. The cylindrical facet is connected to the first surface, and the tapered facet is connected between the cylindrical facet and the second surface. From the first surface to the second surface, the distance from the tapered facet to the axis of the straight shaft portion gradually decreases. The distance between the first cavity wall and the second cavity wall is defined as a first distance, and the distance between the first surface and the second surface is defined as a second distance. The width of the gap between the side cavity wall and the tapered facet is greater than the difference between the first distance and the second distance.
[0009] In one embodiment, a second perforation and a second guide groove are provided on the second cavity wall. The second perforation is connected to the accommodating cavity, and the second guide groove is connected to both the second perforation and the accommodating cavity. The straight shaft portion is rotatably inserted through the second perforation, and a portion of the second guide groove extends beyond the range of the orthographic projection of the second surface onto the second cavity wall.
[0010] In one embodiment, the housing assembly includes a shaft tube, a first bushing, and a second bushing that together form the accommodating cavity. The first bushing and the second bushing are spaced apart and fixed inside the shaft tube. The first cavity wall is located in the first bushing, and the second cavity wall is located in the second bushing. The straight shaft portion is rotatably inserted through the first bushing and the second bushing.
[0011] In one embodiment, the rotor and the stator are spaced apart along the axis of the straight shaft portion; along the axis of the straight shaft portion, the rotating shaft is spaced apart from the stator, the stator includes a magnetic core and a coil wound on the magnetic core, the rotor is magnetic, and there is an attractive force between the rotor and the magnetic core.
[0012] In one embodiment, the rotor includes a first rotor unit and a second rotor unit, and the stator includes a first stator unit and a second stator unit. The first rotor unit, the first stator unit, the second rotor unit, and the second stator unit are arranged sequentially along the axis of the straight shaft portion, and the first rotor unit is closest to the protrusion. The first stator unit is capable of generating a rotating magnetic field that drives the first rotor unit to rotate, and the second stator unit is capable of generating a rotating magnetic field that drives the second rotor unit to rotate. The straight shaft portion is rotatably disposed through the first stator unit and spaced apart from the second stator unit. Both the first stator unit and the second stator unit have magnetic columns, and the cross-sectional dimension of the magnetic column of the second stator unit is larger than the cross-sectional dimension of the magnetic column of the first stator unit.
[0013] A blood pump includes an impeller and any of the aforementioned drive devices, wherein the impeller is fixedly connected to the straight shaft portion.
[0014] In one embodiment, the device further includes a sleeve connected to the housing assembly. The sleeve has a liquid outlet on its wall. The impeller is rotatably disposed within the sleeve, positioned near the liquid outlet. A portion of the straight shaft is housed within the housing assembly, and a portion is housed within the sleeve and fixedly connected to the impeller. A liquid-guiding surface is formed on the outer peripheral surface of the housing assembly near the impeller. This liquid-guiding surface is located within the sleeve and corresponds to the position of the liquid outlet. The proximal end of the liquid-guiding surface corresponds to the position of the proximal orifice wall of the liquid outlet. The distance from the liquid-guiding surface to the axis of the straight shaft gradually increases in the direction away from the impeller.
[0015] In one embodiment, along the axis of the straight shaft portion, the height of the liquid guiding surface is 20%-40% of the height of the liquid outlet.
[0016] The present invention has at least the following beneficial effects: Due to the attractive force between the stator and rotor of the aforementioned driving device, this attractive force causes the first surface to abut against the first cavity wall of the accommodating cavity, resulting in the first cavity wall being subjected to pressure from the first surface. By making the area of the first surface greater than the area of the second surface (i.e., increasing the area of the first surface), and making the area of the first surface less than or equal to the area of the first cavity wall, the contact area between the first surface and the first cavity wall when they contact is equal to the area of the first surface. The larger area of the first surface increases the contact area between the first surface and the first cavity wall when they contact, reducing the unit area of the first surface and the first cavity wall. The pressure of the area is reduced, that is, the pressure per unit area is reduced, thereby reducing the wear of the first surface and the first cavity wall; at the same time, since the attraction force will cause the first surface to press against the first cavity wall of the accommodating cavity, the second surface will tend to move away from the second cavity wall, so that the second surface and the second cavity wall do not contact each other, or reduce the friction coefficient when the second surface and the second cavity wall contact each other. During the start-up of the drive device, the frictional resistance between the second cavity wall and the protrusion can be reduced, thereby increasing the start-up speed of the shaft rotation, that is, increasing the sensitivity of the shaft to the drive response. Therefore, the above-mentioned blood pump and drive device can not only reduce the wear of the shaft during use, but also be started up faster. Attached Figure Description
[0017] Figure 1 This is a three-dimensional structural diagram of the blood pump according to the first embodiment; Figure 2 for Figure 1 A partial cross-sectional view of the blood pump shown; Figure 3 for Figure 1 Another partial cross-sectional view of the blood pump shown; Figure 4 for Figure 1 The diagram shows the exploded structure of a blood pump. Figure 5 for Figure 2 The diagram shows an exploded view of the blood pump's shaft, first bushing, and second bushing. Figure 6 for Figure 2 The diagram shows a three-dimensional structure of the stator in the blood pump. Figure 7 for Figure 2 A schematic diagram of the front view of the rotor of the blood pump shown; Figure 8 for Figure 7 A schematic cross-sectional view of the rotor is shown. Figure 9 for Figure 7 The diagram shows the exploded structure of the rotor; Figure 10This is a cross-sectional view of the blood pump according to the second embodiment. Detailed Implementation
[0018] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.
[0019] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "inner," "outer," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.
[0020] In this article, "proximal" is defined as the end closer to the operator or doctor, and "distal" is defined as the end farther away from the operator or doctor.
[0021] See Figure 1 The blood pump 1 provided in the first embodiment of the present invention includes a drive device 20, a cannula 30, an impeller 40 and a catheter 50. The cannula 30 is connected to the distal end of the drive device 20, and the catheter 50 is connected to the proximal end of the drive device 20. The impeller 40 is rotatably disposed inside the cannula 30 and is connected to the drive device 20. The drive device 20 can drive the impeller 40 to rotate so as to realize the blood pumping function of the blood pump 1.
[0022] Specifically, the cannula 30 has an inlet 31 and an outlet 32. The outlet 32 is closer to the drive unit 20 than the inlet 31. That is, the outlet 32 is located at the proximal end of the cannula 30, and the inlet 31 is located at the distal end of the cannula 30. The outlet 32 is located on the wall of the cannula 30. The impeller 40 is disposed near the outlet 32. In one embodiment, the cannula 30 extends through a heart valve, such as an aortic valve, while the inlet 31 is located inside the heart, and the outlet 32 and the drive unit 20 are located outside the heart in a blood vessel such as the aorta. When the impeller 40 rotates, blood flows into the cannula 30 from the inlet 31 and then flows out of the cannula 30 from the outlet 32 to enter blood vessels such as the aorta.
[0023] The conduit 50 is connected to the end of the drive unit 20 that is away from the sleeve 30. The conduit 50 is used to accommodate various supply lines, such as cleaning lines for introducing flushing fluid into the drive unit 20, wires for supplying power to the drive unit 20, and support components for supporting the conduit 50.
[0024] Please combine them together Figures 2-4 The drive unit 20 includes a housing assembly 100, a rotating shaft 200, a stator 300, and a rotor 400. The rotating shaft 200 is rotatably mounted in the housing assembly 100, with a portion housed within the housing assembly 100 and a portion extending into the sleeve 30 and fixedly connected to the impeller 40. Both the stator 300 and the rotor 400 are housed in the housing assembly 100. The rotor 400 is fixedly connected to the rotating shaft 200. The stator 300 drives the rotor 400 to rotate, and the rotor 400 drives the rotating shaft 200 to rotate, thereby enabling the blood pumping function of the blood pump 1.
[0025] The proximal and distal ends of the housing assembly 100 are fixedly connected to the conduit 50 and the sleeve 30, respectively. A wire in the conduit 50 extends into the housing assembly 100 and is electrically connected to the stator 300 to supply power to the stator 300. Specifically, the housing assembly 100 includes a first bushing 110, a second bushing 120, a shaft tube 130, and a pump housing 140. The first bushing 110 and the second bushing 120 are fixedly housed within the shaft tube 130. One end of the shaft tube 130 is fixedly connected to the pump housing 140, and the other end is fixedly connected to the sleeve 30. The end of the pump housing 140 remote from the shaft tube 130 is fixedly connected to the conduit 50. The end of the rotating shaft 200 remote from the impeller 40 is housed within the pump housing 140. The rotor 400 and the stator 300 are housed within the pump housing 140. In one embodiment, the first bushing 110, the second bushing 120, the shaft tube 130, and the pump housing 140 are separate units before assembly; that is, the housing assembly 100 is assembled from the separate first bushing 110, second bushing 120, shaft tube 130, and pump housing 140. It is understood that in other embodiments, the first bushing 110, second bushing 120, shaft tube 130, and pump housing 140 may also be a single-piece structure.
[0026] Please combine them together Figure 5 In some embodiments, the first bushing 110 can be fixed to the shaft tube 130 by adhesive bonding. In some embodiments, the first bushing 110 includes a large disc 111 and a small disc 112, which are coaxially arranged. The outer diameter of the large disc 111 is larger than the outer diameter of the small disc 112, and the gap between the small disc 112 and the shaft tube 130 can form an adhesive injection space. After the adhesive solidifies in the adhesive injection space, the entire first bushing 110 will be glued to the shaft tube 130. The second bushing 120 can also be fixed to the shaft tube 130 by adhesive bonding.
[0027] The first bushing 110 and the second bushing 120 are spaced apart along the axial direction of the shaft tube 130, with the first bushing 110 being positioned further away from the impeller 40 than the second bushing 120. The shaft tube 130, the first bushing 110, and the second bushing 120 together form a receiving cavity 150, which is located between the first bushing 110 and the second bushing 120.
[0028] The accommodating cavity 150 has a first cavity wall 151, a second cavity wall 152, and a side cavity wall 153. The side cavity wall 153 connects the first cavity wall 151 and the second cavity wall 152, so that the first cavity wall 151, the second cavity wall 152, and the side cavity wall 153 together define the boundary of the accommodating cavity 150. The first cavity wall 151 is located on the first bushing 110, the second cavity wall 152 is located on the second bushing 120, and the side cavity wall 153 is located on the shaft tube 130. The first cavity wall 151 and the second cavity wall 152 are arranged opposite to each other and spaced apart. The first cavity wall 151 is disposed towards the impeller 40, and the second cavity wall 152 is disposed away from the impeller 40. Specifically, the first cavity wall 151 and the second cavity wall 152 are arranged perpendicular to the axial direction of the shaft tube 130, that is, the first cavity wall 151 and the second cavity wall 152 are parallel. At least a portion of the surface of the first bushing 110 facing the impeller 40 forms a first cavity wall 151; at least a portion of the surface of the second bushing 120 facing away from the impeller 40 forms a second cavity wall 152. In the illustrated embodiment, the area of the first cavity wall 151 is larger than the area of the second cavity wall 152.
[0029] The first cavity wall 151 has a first through hole 113, which communicates with the receiving cavity 150. The first through hole 113 extends along the axial direction of the first bushing 110 and penetrates the entire first bushing 110. In the illustrated embodiment, the first cavity wall 151 is approximately circular, and the first through hole 113 is located at the center of the first cavity wall 151.
[0030] The first cavity wall 151 is also provided with a first guide groove 114, which communicates with both the first through hole 113 and the receiving cavity 150. In the illustrated embodiment, the first guide groove 114 extends radially along the first bushing 110. The number of first guide grooves 114 is at least three, and at least three first guide grooves 114 are evenly spaced along the circumference of the first through hole 113. In some embodiments, one end of the first guide groove 114 extends to and communicates with the first through hole 113, and the other end extends to the edge of the first cavity wall 151; in other embodiments, the end of the first guide groove 114 away from the first through hole 113 does not extend to the edge of the first cavity wall 151, in which case the end of the first guide groove 114 away from the first through hole 113 maintains a certain distance from the edge of the first cavity wall 151.
[0031] A second through hole 121 is provided on the second cavity wall 152, and the second through hole 121 communicates with the receiving cavity 150. The second through hole 121 extends along the axial direction of the second bushing 120 and passes through the entire second bushing 120. In the illustrated embodiment, the second cavity wall 152 is generally circular, and the second through hole 121 is located at the center of the second cavity wall 152.
[0032] The second cavity wall 152 is further provided with a second guide groove 122, which communicates with both the second through hole 121 and the receiving cavity 150. In the illustrated embodiment, the second guide groove 122 extends radially along the second bushing 120. The arrangement of the second guide groove 122 can be similar to that of the first guide groove 114, and will not be described again here. In some embodiments, one end of the second guide groove 122 extends to and communicates with the second through hole 121, and the other end extends to the edge of the second cavity wall 152; in other embodiments, the end of the second guide groove 122 away from the second through hole 121 does not extend to the edge of the second cavity wall 152, in which case the end of the second guide groove 122 away from the second through hole 121 maintains a certain distance from the edge of the second cavity wall 152.
[0033] The pump housing 140 is generally cylindrical. The pump housing 140 is connected to the receiving cavity 150 through the first perforation 113. The flushing fluid entering the pump housing 140 can enter the receiving cavity 150 through the first perforation 113 and flow out of the housing assembly 100 through the second perforation 121.
[0034] Specifically, the rotating shaft 200 is rotatably disposed through the first through hole 113, the second through hole 121, and the receiving cavity 150. The rotating shaft 200 includes a connected straight shaft portion 210 and a protrusion portion 220.
[0035] A portion of the straight shaft portion 210 is housed in the housing assembly 100, and a portion extends into the sleeve 30 and is fixedly connected to the impeller 40. The straight shaft portion 210 is rotatably disposed through the first through hole 113, the second through hole 121, and the receiving cavity 150. Specifically, the cross-section of the portion of the straight shaft portion 210 housed in the first through hole 113 and the second through hole 121 is circular, and the first through hole 113 and the second through hole 121 are approximately circular holes.
[0036] In the illustrated embodiment, a first gap 161 exists between the straight shaft portion 210 and the wall of the first through hole 113. This first gap 161 can be understood as the portion of the first through hole 113 not filled by the straight shaft portion 210. Cleaning fluid in the pump housing 140 can enter the receiving cavity 150 through this first gap 161. A second gap 162 exists between the straight shaft portion 210 and the wall of the second through hole 121. This second gap 162 can be understood as the portion of the second through hole 121 not filled by the straight shaft portion 210. Rinsing fluid in the receiving cavity 150 can flow out of the housing assembly 100 through this second gap 162. Specifically, at least a portion of the width of the second gap 162 is smaller than the width of the first gap 161.
[0037] The wall of the first through hole 113 has a chamfer at the end near the receiving cavity 150. If the rotating shaft 200 shakes and contacts the wall of the first through hole 113, this design can reduce the contact area between the straight shaft portion 210 and the wall of the first through hole 113, thereby reducing the friction of the straight shaft portion 210. The chamfer can also serve as an assembly guide, reducing interference and assembly resistance of the rotating shaft 200 during assembly, and improving the assembly efficiency of the rotating shaft 200. The wall of the second through hole 121 also has a chamfer at the end near the receiving cavity 150. If the rotating shaft 200 shakes and contacts the wall of the second through hole 121, this design can reduce the contact area between the straight shaft portion 210 and the wall of the second through hole 121, thereby reducing the friction of the straight shaft portion 210. The chamfer can also serve as an assembly guide, reducing interference and assembly resistance of the rotating shaft 200 during assembly, and improving the assembly efficiency of the rotating shaft 200.
[0038] A protrusion 220 protrudes circumferentially from the straight shaft portion 210 and is rotatably received within the receiving cavity 150. The protrusion 220 is located between the first cavity wall 151 and the second cavity wall 152. The first cavity wall 151 and the second cavity wall 152 can respectively abut against the protrusion 220 to limit the maximum amplitude of the axial vibration of the rotating shaft 200. Specifically, the cross-sectional dimension of the protrusion 220 is larger than the diameter of the first through hole 113 and also larger than the diameter of the second through hole 121, so that the protrusion 220 is confined within the receiving cavity 150 and cannot enter the first through hole 113 and the second through hole 121. In the illustrated embodiment, the protrusion 220 is annular and is fixedly sleeved on the straight shaft portion 20. The outer diameter of the protrusion 220 is larger than the diameter of the straight shaft portion 210, and the axis of the protrusion 220 coincides with the axis of the straight shaft portion 210. The outer diameter of the protrusion 220 is larger than the diameter of the first through hole 113 and also larger than the diameter of the second through hole 121.
[0039] The protrusion 220 has a first surface 221 and a second surface 222, which are spaced apart along the axis of the straight shaft portion 210. The first surface 221 faces the first cavity wall 151, and the second surface 222 faces the second cavity wall 152. The first cavity wall 151 abuts against the first surface 221, and the second cavity wall 152 abuts against the second surface 222, thereby limiting the maximum amplitude of the axial vibration of the rotating shaft 200. In the illustrated embodiment, both the first surface 221 and the second surface 222 are perpendicular to the axis of the straight shaft portion 210, and the first cavity wall 151 and the second cavity wall 152 are parallel to the first surface 221 and the second surface 222, respectively. The outer contours of both the first surface 221 and the second surface 222 are circular, and both the first surface 221 and the second surface 222 are coaxially arranged with the axis of the straight shaft portion 210, that is, the axis of the straight shaft portion 210 passes through the center of the circle containing the first surface 221 and the second surface 222.
[0040] In this embodiment, the area of the first surface 221 is greater than the area of the second surface 222, and the area of the first surface 221 is less than or equal to the area of the first cavity wall 151. In the illustrated embodiment, the area of the first surface 221 is less than the area of the first cavity wall 151; the area of the second surface 222 is less than the area of the second cavity wall 152. When the first cavity wall 151 abuts against the first surface 221, the area of the contact surface between the first cavity wall 151 and the first surface 221 is equal to the area of the first surface 221; when the second cavity wall 152 abuts against the second surface 222, the area of the contact surface between the second cavity wall 152 and the second surface 222 is equal to the area of the second surface 222. The rotor 400 is fixed to the straight shaft portion 410, and there is an attractive force between the stator 300 and the rotor 400, which causes the first surface 221 to abut against the first cavity wall 151. In other words, the attraction between the stator 300 and the rotor 400 causes the protrusion 220 to tend to abut against the first cavity wall 151, thereby enabling the first surface 221 to abut against the first cavity wall 151. Specifically, the direction of the attraction force on the rotor 400 is along the axis of the straight shaft portion 210 from the second cavity wall 152 to the first cavity wall 151, enabling the first surface 221 to abut against the first cavity wall 151.
[0041] Given that the area of the first surface 221 is larger than the area of the second surface 222, the larger area of the first surface 221 can increase the contact area between the first surface 221 and the first cavity wall 151, thereby reducing the pressure per unit area of the first surface 221 and the first cavity wall 151, that is, reducing the pressure per unit area, thereby reducing the wear of the first surface 221 and the protrusion 220.
[0042] The protrusion 220 also has a lateral peripheral surface 223, which connects the first surface 221 and the second surface 222. The lateral peripheral surface 223 is arranged around the axis of the straight shaft portion 210, and the annular structure formed by the lateral peripheral surface 223 is coaxial with the straight shaft portion 210. The side cavity wall 153 and the side peripheral surface 223 are spaced apart, forming a third gap 163 between them. This third gap 163 communicates with both the first guide channel 114 and the second guide channel 122. This ensures that even when the first surface 221 of the protrusion 220 abuts against the first cavity wall 151 of the accommodating cavity 150, the third gap 163 can still communicate with the first perforation 113 through the first guide channel 114. Similarly, when the second surface 222 of the protrusion 220 abuts against the second cavity wall 152 of the accommodating cavity 150, the third gap 163 can also communicate with the second perforation 121 through the second guide channel 122, thus maintaining smooth flow of the flushing fluid. Specifically, a portion of the first guide channel 114 extends beyond the orthographic projection of the first surface 221 of the protrusion 220 onto the first cavity wall 151 to communicate with the third gap 163. A portion of the second guide groove 122 extends beyond the orthographic projection of the second surface 222 of the protrusion 220 onto the second cavity wall 152, so as to communicate with the third gap 163.
[0043] Please combine Figure 2 The flushing fluid flows sequentially through the first gap 161, the third gap 163, and the second gap 162, and exits from the outlet 32. The flow direction of the flushing fluid is opposite to the flow direction of blood in the sleeve 30, which prevents blood in the sleeve 30 from entering the drive device 20 through the second perforation 121. Figure 2 The thin dashed arrows indicate the flow path of the flushing fluid, while the thick dashed lines indicate the flow path of the blood. The first guide groove 114 not only connects the first perforation 113 and the third gap 163, but also allows the flushing fluid to flow better between the first surface 221 and the first cavity wall 221, providing a certain degree of suspension for the protrusion 220, reducing the pressure between the first surface 221 and the first cavity wall 151, and reducing the wear of the protrusion 220. At the same time, the flushing fluid flowing between the first surface 221 and the first cavity wall 221 also acts as a lubricant, reducing the coefficient of friction between the first surface 221 and the first cavity wall 221, and reducing the wear of the protrusion 220 and the cavity wall of the accommodating cavity 150.
[0044] Specifically, there are multiple first guide channels 114. Increasing the number of first guide channels 114 has several advantages. First, it allows the flushing fluid to fill the space between the first surface 221 and the first cavity wall 151 more quickly, providing lubrication and reducing the coefficient of friction between the first surface 221 and the protrusion 220, thus reducing wear. Second, it allows for a more efficient increase in the flow rate and velocity of the flushing fluid between the first surface 221 and the first cavity wall 151, facilitating the rapid removal of heat generated by friction between the first cavity wall 151 and the protrusion 220, reducing excessive temperature and thus preventing increased wear. Third, it increases the suspending force of the flushing fluid on the protrusion 220, thereby reducing the pressure between the first cavity wall 151 and the protrusion 220, further reducing wear. Therefore, increasing the number of first guide channels 114 can effectively reduce wear on the first cavity wall 151 and the protrusion 220. Similarly, the wear of the second surface 222 and the protrusion 220 can be reduced by reasonably increasing the number of second guide grooves 122. In the illustrated embodiment, there are four first guide grooves 114, and the included angle between the extending directions of two adjacent first guide grooves 114 is 90°. It can be understood that in other embodiments, the number of first guide grooves 114 and second guide grooves 122 can be adjusted as needed.
[0045] Specifically, the lateral peripheral surface 223 includes a cylindrical surface 2231 and a conical surface 2232. The cylindrical surface 2231 and the conical surface 2232 are arranged along the axis of the straight axis portion 210. The cylindrical surface 2231 is connected to the first surface 221 and is disposed perpendicular to the first surface 221. One end of the conical surface 2232 is connected to the cylindrical surface 2231, and the other end of the conical surface 2232 is connected to the second surface 222. That is, the conical surface 2232 is connected between the cylindrical surface 2231 and the second surface 222. Along the axis of the straight axis portion 210 and in the direction from the first surface 221 to the second surface 222, the distance from the cylindrical surface 2231 to the axis of the straight axis portion 210 remains constant, while the distance from the conical surface 2232 to the axis of the straight axis portion 210 gradually decreases. The conical surface 2232 provided on the side peripheral surface 223 of the protrusion 220 can have a better guiding effect on the flushing fluid; at the same time, since the area of the second surface 222 is smaller than the area of the second cavity wall 152, the flushing fluid flows through the third gap 163 and flows in the direction of the second perforation 121, improving the flushing effect of the flushing fluid. The cylindrical facet 2231 has a certain length along the axial direction of the straight axis portion 210, which avoids the entire side circumferential surface 223 being a tapered protrusion 220 with an acute angle near the first surface 221. In simpler terms, it avoids the side circumferential surface 223 forming a sharp edge with the first surface 221. If the protrusion 220 causes radial swaying, and this edge comes into contact with the side cavity wall 153 to form a line-to-surface contact, it will cause a greater risk of scratching and damage to the side cavity wall 153. Furthermore, there is not a wide enough area for the flushing fluid to form a lubricating film layer between the protrusion 220 and the side cavity wall 153. The cylindrical facet 2231 can serve as a transition, ensuring that the side circumferential surface 223 and the side cavity wall 153 of the accommodating cavity 150 are in a face-to-face manner, reducing the risk of friction damage.
[0046] The shape of the side cavity wall 153 of the accommodating cavity 150 is adapted to the shape of the side peripheral surface 223, and has a structure similar to the straight and oblique surfaces of the cylindrical surface 2231 and the conical surface 2232 of the side peripheral surface 223.
[0047] Specifically, along the axial direction of the straight shaft portion 210, the distance between the first cavity wall 151 and the second cavity wall 152 is denoted as the first distance H, and the distance between the first surface 221 and the second surface 222 is denoted as the second distance h, wherein the first distance H is greater than the second distance h. In some embodiments, the first distance H is slightly greater than the second distance h, such that the first cavity wall 151 and the first surface 221 always remain in contact, and the second cavity wall 152 and the second surface 222 always remain in contact, thereby preventing the rotating shaft 200 from moving in the axial direction of the straight shaft portion 210. In some embodiments, the first spacing H is greater than the second spacing h, such that when the first surface 221 abuts against the first cavity wall 151, the second surface 222 and the second cavity wall 152 are spaced apart by a distance, creating a gap between the second surface 222 and the second cavity wall 152. This allows the protrusion 220 to have a certain floating space between the first cavity wall 151 and the second cavity wall 152, facilitating the entry of flushing fluid between the first surface 221 and the first cavity wall 151, and between the second surface 222 and the second cavity wall 152, thus providing lubrication and suspending the protrusion 220 and preventing dry friction between the protrusion 220 and the cavity wall of the accommodating cavity 150. Of course, the difference between the first spacing H and the second spacing h should not be too large to avoid excessive axial vibration amplitude of the rotating shaft 200.
[0048] Specifically, the width of the gap between the side cavity wall 153 and the tapered surface 2232 of the side peripheral surface 223 is greater than the difference between the first spacing H and the second spacing h. That is, the width of the third gap 163 at the position corresponding to the tapered surface 2232 is greater than the difference between the first spacing H and the second spacing h. This can prevent the contact probability between the side cavity wall 153 and the side peripheral surface 223 of the protrusion 220 from being radially and / or axially swayed, thereby reducing the friction between the protrusion 220 and the cavity wall of the receiving cavity 150.
[0049] In some embodiments, at least one of the first cavity wall 151 and the first surface 221 is made of ceramic; at least one of the second cavity wall 152 and the second surface 222 is also made of ceramic. Ceramic has high processing precision, high biocompatibility, high mechanical strength, and good wear and corrosion resistance. Furthermore, ceramic can have a smaller roughness, which can reduce friction when the first surface 221 contacts the first cavity wall 151, and reduce friction when the second surface 222 contacts the second cavity wall 152. Specifically, the first bushing 110 and the second bushing 120 are made of ceramic, and the protrusion 220 is also made of ceramic; that is, the first cavity wall 151, the first surface 221, the second cavity wall 152, and the second surface 222 are all made of ceramic.
[0050] In some embodiments, a liquid guiding surface 160 is formed on the outer peripheral surface of the housing assembly 100 near the impeller 40. The liquid guiding surface 160 is located in the sleeve 30 and corresponds to the position of the outlet 32. The proximal end of the liquid guiding surface 160 corresponds to the position of the proximal end wall of the outlet 32. The distance from the liquid guiding surface 160 to the axis of the straight shaft portion 210 gradually increases in the direction away from the impeller 40. Specifically, the liquid guiding surface 160 is located at the end of the shaft tube 130 away from the pump housing 140. The design of the liquid guiding surface 160 facilitates the discharge of liquid within the sleeve 30. In addition, the impeller 40 and the drive unit 20 are usually the rigid parts of the blood pump 1. The shorter the axial length of the rigid parts, the more beneficial it is for the blood pump 1 to deliver blood in the human body. The liquid guiding surface 160 provided on the housing assembly 100 of the drive unit 20 can shorten the axial length of the impeller 40 while ensuring the hydraulic performance at the outlet 32. At the same time, since the liquid guiding surface 160 is provided in the sleeve 30 as part of the housing assembly 100 of the drive unit 20, the overall length of the impeller 40 and the drive unit 20 (that is, the rigid part of the blood pump 1) can be reduced, which can facilitate the delivery of blood by the blood pump 1.
[0051] Specifically, the fluid guiding surface 160 is roughly arc-shaped. Along the axis of the straight shaft 210, the height L1 of the fluid guiding surface 160 is 20%-40% of the height L2 of the outlet 32. This height design can shorten the overall length of the impeller 40 and the drive unit 20 while giving the blood pump 1 better hydraulic performance.
[0052] See Figure 2 and Figure 6 The stator 300 is fixedly housed within the pump housing 140. Specifically, the stator 300 includes a magnetic core 310, a back plate 320, and coils 330. The back plate 320 is fixedly connected to the pump housing 140. Multiple magnetic cores 310 are arranged at intervals along a circumference. The extending direction of each magnetic core 310 is consistent with the extending direction of the straight shaft portion 210, that is, the central axis of the magnetic core 310 is parallel to the axis of the straight shaft portion 210. One end of each magnetic core 310 is fixedly connected to the back plate 320. The number of coils 330 is equal to the number of magnetic cores 310, forming a one-to-one correspondence. The coils 330 are wound around the magnetic cores 310, so that each magnetic core 310 has one coil wound around it.
[0053] In some embodiments, the magnetic core 310 includes a magnetic post 311 and a head (i.e., a pole shoe) disposed at one end of the magnetic post 311. The cross-sectional dimension of the head is larger than that of the magnetic post 311, and the extending direction of the magnetic post 311 is consistent with the extending direction of the straight shaft portion 210. The back plate 320 is engaged with the end of the magnetic post 311 away from the head. In the extending direction of the magnetic post 311, the magnetic post 311 is generally a columnar body of uniform size, that is, the cross-sectional dimension of the magnetic post 311 remains constant; in simpler terms, the magnetic post 311 is of uniform thickness. The coil 330 is wound around the magnetic post 311 of the magnetic core 310. In the illustrated embodiment, the magnetic core 310 only includes the magnetic post 311, that is, the magnetic core 310 does not have a wider head (i.e., a pole shoe). Therefore, the magnetic post 311 of the stator 300 is the magnetic core 310. At this point, the entire magnetic core 310 can be magnetically coupled to the rotor 400. Compared to a magnetic core 310 with pole shoes, a magnetic core 310 with only magnetic pillars 311 can reduce magnetic losses and increase the magnetic coupling density between the magnetic core 310 and the rotor 400, thereby increasing the torque of the stator 300 on the rotor 400 under the same current. On the other hand, a magnetic core 310 without a head can also greatly reduce the problem of power reduction in the drive unit 20 caused by local magnetic short circuits due to contact between adjacent magnetic cores 310.
[0054] It is understood that the magnetic core 310 is not limited to the two methods mentioned above. In some embodiments, some magnetic pillars 311 are provided with heads, while other magnetic pillars 311 are not provided with heads.
[0055] In some embodiments, the cross-sectional shape of the magnetic post 311 is approximately triangular prism, with one edge of each magnetic post 311 facing the axis of the direct shaft portion 210. In some embodiments, the edges of the magnetic posts 311 are rounded, i.e., the edges of the magnetic posts 311 are relatively smooth and blunt rounded edges, thereby eliminating sharp edges on the magnetic posts 311. This not only facilitates the subsequent winding of the coil 330 but also helps protect the insulating material covering the coil 330. In other embodiments, the cross-sectional shape of the magnetic post 311 can also be fan-shaped, circular, trapezoidal, or annular, etc.
[0056] The back plate 320 is generally flat. It is made of the same material as the magnetic core 310, such as soft magnetic materials like cobalt steel. With reference to the rotor 400 driven by the stator 300, the back plate 320 is fixed to the end of the magnetic post 311 away from the rotor 400. The back plate 320 functions to close the magnetic circuit of the stator 300, thereby promoting and increasing the generation of magnetic flux in the stator 300 and improving the coupling between the stator 300 and the rotor 400. In other words, the back plate 320 in the stator 300 promotes and increases the generation of magnetic flux in the stator 300 and improves the coupling between the stator 300 and the rotor 400. Since the back plate 320 can increase magnetic flux, providing back plates 320 in the stator 300 also helps to reduce the overall diameter of the drive device 20. It is understood that in some embodiments, the back plate 320 may be omitted.
[0057] The rotor 400 and stator 300 are arranged at intervals along the axis of the straight shaft portion 210. Along the axis of the straight shaft portion 210, the rotor 400 is located between the protrusion 220 and the stator 300. The first cavity wall 151 of the accommodating cavity 150 is located between the rotor 400 and the first surface 221 of the protrusion 220.
[0058] Please combine them together Figure 7 , Figure 8 and Figure 9 The rotor 400 is magnetic, and the stator 300 generates a rotating magnetic field that drives the rotor 400 to rotate. There is an attractive force between the rotor 400 and the magnetic core 310. Specifically, the rotor 400 includes a magnet 410, which is fixed to the straight shaft portion 210 of the rotating shaft 200. The magnetic core 310 of the stator 300 exerts an attractive force on the magnet 410 of the rotor 400, and this attractive force is directed along the axis of the rotating shaft 200 from the second surface 222 to the first surface 221, thereby causing the first surface 221 to abut against the first cavity wall 151.
[0059] The magnet 410 is a ring-shaped Heilbeck array magnet. Specifically, each magnet 410 includes multiple magnetic units 411 magnetized along the axial direction of the magnet 410. For example, the number of magnetic units 411 is four, six, eight or ten, etc. Each magnetic unit 411 is fan-shaped, and multiple magnetic units 411 are arranged around the straight axis portion 210 to form a ring structure of the magnet 410.
[0060] The rotor 400 also includes a flywheel 420, which is directly fixed to the straight shaft 210, and the magnet 410 is fixed to the flywheel 420. By setting the flywheel 420, the connection strength between the magnet 410 and the straight shaft 210 can be enhanced; in addition, it can reduce the shaking of the shaft 200 during rotation, making the entire shaft 200 more stable during rotation.
[0061] The flywheel 420 includes an inner tube 421, a disc-shaped portion 422, and an outer ring wall 423. Both the inner tube 421 and the outer ring wall 423 are cylindrical structures, and the disc-shaped portion 422 is an annular disc structure. Both the inner tube 421 and the outer ring wall 423 are fixedly connected to the disc-shaped portion 422. The outer ring wall 423 surrounds the disc-shaped portion 422, and the inner tube 421 and the outer ring wall 423 are coaxially arranged. The straight shaft portion 210 passes through the inner tube 421 and is fixedly connected to the inner tube 421. A mounting cavity 424 is formed between the inner tube 421 and the outer ring wall 423, and the mounting cavity 424 is an annular cavity. Magnets 410 are respectively housed in the mounting cavities 424. The shape of the mounting cavity 424 is adapted to the magnets 410 to facilitate the installation and positioning of the magnets 410. This design allows the flywheel 420 to limit the movement of the magnet 410, which not only facilitates the installation of the magnet 410 but also makes the connection between the magnet 410 and the flywheel 420 more stable.
[0062] It should be noted that the flywheel 420 is not limited to the structure described above. In some embodiments, the flywheel 420 does not have an outer ring wall 423; in some embodiments, the flywheel 420 does not have an outer ring wall 423 and an inner tube 421. In this case, the straight shaft portion 210 is fixedly inserted through the center of the disc-shaped portion 422. Compared to a flywheel 420 that only has a disc-shaped portion 422, providing an inner tube 421 allows for a more stable connection between the flywheel 420 and the straight shaft portion 210.
[0063] To facilitate the installation of the magnet 410 and improve its installation accuracy, the flywheel 420 is also provided with a marking section 4211 for determining the installation position of the magnetic unit 411. The marking section 4211 can be a groove, a scale line, or a mark, etc. When installing the magnet 410, by using the marking section 4211 to mark the position of one of the magnetic units 411 of the magnet 410, the installation positions of the remaining magnetic units 411 can be determined, thus facilitating the installation of the magnet 410. Specifically, the marking section 4211 is provided on at least one of the inner tube 421, the disc-shaped portion 422, and the outer ring wall 423; for example, the marking section 4211 is provided on the end face of the inner tube 421.
[0064] In the illustrated embodiment, the rotating shaft 200 and the stator 300 are spaced apart along the axis of the straight shaft portion 210, meaning the straight shaft portion 210 does not pass through the stator 300, so the rotating shaft 200 is located outside the stator 300. By increasing the cross-sectional area of the magnetic column 311, the larger the cross-sectional area of the magnetic column 311, the greater the magnetic flux generated, the greater the torque of the stator 300 on the rotor 400, and the smaller the required current, which helps to reduce power consumption and heat generation. Since the stator 300 does not have a rotating shaft 200, the rotating shaft 200 can avoid occupying the installation space of the magnetic column 311. This allows for an increase in the cross-sectional size of the magnetic column 311 of the stator 300 while keeping the outer diameter of the housing assembly 100 unchanged, thereby increasing the driving torque of the stator 300 on the rotor 400. Under the same required torque, this method can reduce the current supply to the stator 300, thereby reducing power consumption. At the same time, it also reduces the heat generated by the drive device 20, preventing the blood pump 10 from overheating during operation and causing discomfort or even harm to the human body.
[0065] The aforementioned drive device 20 and blood pump 1 have at least the following advantages: (1) Due to the attraction between the stator 300 and the rotor 400 of the aforementioned drive device 20, this attraction causes the first surface 221 to abut against the first cavity wall 151 of the receiving cavity 150, resulting in the first cavity wall 151 being subjected to pressure from the first surface 221. By making the area of the first surface 221 larger than the area of the second surface 222, i.e., increasing the area of the first surface 221, the area of the first surface 221 is made smaller than or equal to the area of the first cavity wall 151, so that when the first surface 221 contacts the first cavity wall 151, the contact area between the first surface 221 and the first cavity wall 151 is equal to the area of the first surface 221. The larger area of the first surface 221 can increase the contact area between the first surface 221 and the first cavity wall 151 when the first surface 221 contacts the first cavity wall 151, thereby reducing the contact area between the first surface 221 and the first cavity wall 151. The pressure per unit area is reduced, thus reducing the pressure per unit area, thereby reducing the wear of the first surface 221 and the first cavity wall 151. At the same time, the attraction force causes the first surface 221 to abut against the first cavity wall 151 of the accommodating cavity 150, causing the second surface 222 to tend to move away from the second cavity wall 152, so that the second surface 222 and the second cavity wall 152 do not contact each other, or reduce the coefficient of friction when the second surface 222 and the second cavity wall 152 are in contact. During the start-up process of the drive device 20, the frictional resistance of the second cavity wall 152 to the protrusion 220 can be reduced, thereby increasing the start-up speed of the rotating shaft 200, that is, increasing the sensitivity of the rotating shaft 200 to the drive response. Therefore, the blood pump 1 and the drive device 20 can not only reduce the wear of the rotating shaft 200 during use, but also be started up faster.
[0066] (2) By providing a first guide groove 122 on the first surface 221, the flushing fluid can flow quickly into the space between the first surface 221 and the first cavity wall 151 to provide lubrication between the first surface 221 and the first cavity wall 151, thereby reducing the coefficient of friction between the first surface 221 and the first cavity wall 221 and reducing the wear of the protrusion 220 and the cavity wall of the accommodating cavity 150. Furthermore, by making part of the first guide groove 114 located outside the range of the orthographic projection of the first surface 221 of the protrusion 220 onto the first cavity wall 151, it is also possible that even when the first surface 221 of the protrusion 220 abuts against the first cavity wall 151 of the accommodating cavity 150, the accommodating cavity 150 can still communicate with the first perforation 113 through the first guide groove 114 to ensure smooth flow of the flushing fluid.
[0067] (3) A portion of the housing assembly 100 is placed in the sleeve 30, and an arc-shaped liquid guiding surface 160 is provided on the outer circumferential surface of the portion of the housing assembly 100 located in the sleeve 30. This is beneficial to reduce the overall length of the impeller 40 and the drive device 20 (i.e., the rigid part of the blood pump 1) while ensuring the hydraulic performance of the blood pump 1, so as to facilitate the delivery of the blood pump 1.
[0068] (4) By setting the rotating shaft 200 and the stator 300 at intervals, it is beneficial to increase the driving torque of the stator 300 on the rotor 400 by increasing the cross-sectional area of the magnetic column 311 while keeping the outer diameter of the housing assembly 100 and the stator 300 unchanged. Under the same required torque, this method can reduce the current supply to the stator 300, thereby reducing power consumption. At the same time, it also reduces the heat generation of the drive device 20, avoiding the blood pump 10 from generating excessive temperature due to heat accumulation during operation, which may cause discomfort or even harm to the human body.
[0069] See Figure 10 The blood pump 2 of the second embodiment has a structure that is generally the same as that of the blood pump 1 of the first embodiment. The difference is that in this embodiment, the rotor 400' has two rotor units and the stator 300' has two stator units. The two stator units are respectively referred to as the first stator unit 301 and the second stator unit 302, and the two rotor units are respectively referred to as the first rotor unit 401 and the second rotor unit 402.
[0070] The first rotor unit 401, the first stator unit 301, the second rotor unit 402, and the second stator unit 302 are arranged sequentially along the axis of the straight shaft portion 210', with the first rotor unit 401 positioned closest to the protrusion 220'. Both the first rotor unit 401 and the second rotor unit 402 are fixedly connected to the straight shaft portion 200' of the rotating shaft 200'. There is an attractive force between the first stator unit 301 and the first rotor unit 401, and there is an attractive force between the second stator unit 302 and the second rotor unit 402. The attraction force exerted on the first rotor unit 401 by the first stator unit 301 is denoted as the first attraction force, and the attraction force exerted on the second rotor unit 402 by the second stator unit 302 is denoted as the second attraction force. The first attraction force and the second attraction force are in the same direction and act on the rotating shaft 200' through the first rotor unit 401 and the second rotor unit 402 respectively. Therefore, under the combined force of the first attraction force and the second attraction force, the first surface 221' of the protrusion 220' can abut against the first cavity wall 151'.
[0071] The straight shaft portion 210' of the rotating shaft 200' is rotatably inserted through the first stator unit 301 and spaced apart from the second stator unit 301. That is, the straight shaft portion 210' is not inserted into the second stator unit 302, so that the straight shaft portion 210' is located outside the second stator unit 302, thereby causing the rotating shaft 200' and the second stator unit 302 to be spaced apart by a certain distance along the axial direction of the straight shaft portion 210'. Both the first stator unit 301 and the second stator unit 302 have magnetic pillars 311', and the cross-sectional dimension of the magnetic pillars 311' of the second stator unit 302 is larger than the cross-sectional dimension of the magnetic pillars 311' of the first stator unit 301. Since the rotating shaft 200' is not installed in the second stator unit 302, that is, the rotating shaft 200' is located outside the second stator unit 302, the rotating shaft 200' can avoid occupying the installation space of the magnetic column 311' in the second stator unit 302. The cross-sectional size of the magnetic column 311' of the second stator unit 302 can be increased without increasing the outer diameter of the pump housing 140' and the second stator unit 302. At this time, although the outer diameters of the first stator unit 301 and the second stator unit 302 are the same, the cross-sectional size of the magnetic column 311' of the second stator unit 302 is larger than the cross-sectional size of the magnetic column 311' of the first stator unit 301. This increases the driving torque of the second stator unit 302 on the second rotor unit 402. Under the same torque requirement, this method can reasonably reduce the current supply to the second stator unit 302, thereby reducing power consumption. At the same time, it also reduces the heat generated by the drive device, preventing the blood pump from overheating due to heat accumulation during operation, which could cause discomfort or even harm to the human body.
[0072] In this embodiment, the structures of the first rotor unit 401 and the second rotor unit 402 can be similar to the structure of the rotor 400 of the blood pump 1 in the first embodiment; the structures of the first stator unit 301 and the second stator unit 302 can be similar to the structure of the stator 300 of the blood pump 1, and will not be described again here. Specifically, the back plate 320' of the first stator unit 301 is located at the end of the magnetic column 311' of the first stator unit 301 that is away from the first rotor unit 401, and the back plate 320' of the second stator unit 302 is located at the end of the magnetic column 311' of the second stator unit 302 that is away from the second rotor unit 402.
[0073] The structure of the blood pump 2 in the second embodiment is similar to that of the blood pump 1 in the first embodiment. Therefore, the blood pump 2 in the second embodiment also has the advantages of the blood pump 1 in the first embodiment.
[0074] It is understood that the structure of the blood pump drive device is not limited to the structure of the first and second embodiments. In other embodiments, the number of stator units can be adjusted as needed, and the positional relationship between the rotor unit and the stator unit can also be adjusted.
[0075] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0076] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.
Claims
1. A driving device for driving an impeller to rotate, characterized in that, The driving device includes: The housing assembly has a receiving cavity, the receiving cavity having a first cavity wall and a second cavity wall that are opposite to and spaced apart from each other; A rotating shaft for connection with the impeller includes a connected straight shaft portion and a protruding portion. The protruding portion protrudes circumferentially from the straight shaft portion and is rotatably received in the receiving cavity. The protruding portion is located between the first cavity wall and the second cavity wall. The protruding portion has a first surface and a second surface. The first surface faces the first cavity wall, and the second surface faces the second cavity wall. The area of the first surface is greater than the area of the second surface, and the area of the first surface is less than or equal to the area of the first cavity wall. The rotor is fixedly connected to the straight shaft portion; and The stator is capable of driving the rotor to rotate. There is an attractive force between the stator and the rotor. The direction of the attractive force is along the axis of the straight shaft from the second cavity wall to the first cavity wall. The attractive force can cause the first surface to abut against the first cavity wall.
2. The driving device according to claim 1, characterized in that, The distance between the first cavity wall and the second cavity wall is greater than the distance between the first surface and the second surface, so that when the first surface abuts against the first cavity wall, there is a distance between the second surface and the second cavity wall. And / or, at least one of the first cavity wall and the first surface is made of ceramic; And / or, at least one of the second cavity wall and the second surface is made of ceramic.
3. The driving device according to claim 1, characterized in that, A first through hole is provided on the first cavity wall, the first through hole is connected to the receiving cavity, and the straight shaft portion is rotatably inserted through the first through hole.
4. The driving device according to claim 3, characterized in that, There is a first gap between the straight shaft portion and the wall of the first perforation, and the flushing fluid in the housing assembly can enter the receiving cavity through the first gap; The end of the wall of the first perforation near the receiving cavity is chamfered; The cross-sectional dimension of the protrusion is larger than the diameter of the first perforation.
5. The driving device according to claim 3, characterized in that, The first cavity wall is also provided with a first guide groove, which is connected to the first perforation and the accommodating cavity.
6. The driving device according to claim 5, characterized in that, The protrusion also has a side peripheral surface connecting the first surface and the second surface, and the accommodating cavity also has a side cavity wall connecting the first cavity wall and the second cavity wall. There is a gap between the side cavity wall and the side peripheral surface. A portion of the first guide groove extends beyond the range of the orthographic projection of the first surface onto the first cavity wall and communicates with the gap.
7. The driving device according to claim 6, characterized in that, The lateral surface includes a cylindrical face and a tapered face surrounding the axis of the straight shaft portion. The cylindrical face is connected to the first surface, and the tapered face is connected between the cylindrical face and the second surface. In the direction from the first surface to the second surface, the distance from the cylindrical face to the axis of the straight shaft portion remains constant, while the distance from the tapered face to the axis of the straight shaft portion gradually decreases.
8. The driving device according to claim 7, characterized in that, The distance between the first cavity wall and the second cavity wall is defined as the first distance, and the distance between the first surface and the second surface is defined as the second distance. The first distance is greater than the second distance, such that when the first surface abuts against the first cavity wall, the second surface and the second cavity wall are spaced apart by a certain distance, so that the second surface and the second cavity wall have a gap.
9. The driving device according to claim 8, characterized in that, The width of the gap between the side cavity wall and the conical face is greater than the difference between the first spacing and the second spacing.
10. The driving device according to claim 7, characterized in that, The sidewall of the accommodating cavity has a straight portion and an inclined portion, such that the shape of the sidewall of the accommodating cavity is adapted to the shape of the side peripheral surface.
11. The driving device according to claim 1, characterized in that, A second through hole is provided on the second cavity wall, the second through hole is connected to the receiving cavity, and the straight shaft portion is rotatably inserted through the second through hole; The second cavity wall is also provided with a second flow guide groove, which is connected to the second perforation and the accommodating cavity. A portion of the second flow guide groove extends beyond the range of the orthographic projection of the second surface onto the second cavity wall.
12. The driving device according to claim 1, characterized in that, The housing assembly includes a shaft tube, a first bushing, and a second bushing that together form the accommodating cavity. The first bushing and the second bushing are spaced apart and fixed inside the shaft tube. The first cavity wall is located in the first bushing, and the second cavity wall is located in the second bushing. The straight shaft portion is rotatably inserted through the first bushing and the second bushing.
13. The driving device according to claim 1, characterized in that, Along the axis of the straight shaft portion, the rotating shaft is spaced apart from the stator, such that the straight shaft portion does not pass through the stator. The stator includes a magnetic core and a coil wound on the magnetic core. The rotor is magnetic, and there is an attractive force between the rotor and the magnetic core. Alternatively, the rotor is located between the protrusion and the stator, and the first cavity wall of the accommodating cavity is located between the rotor and the first surface of the protrusion.
14. The driving device according to claim 1, characterized in that, The rotor includes a first rotor unit and a second rotor unit, and the stator includes a first stator unit and a second stator unit. The first rotor unit, the first stator unit, the second rotor unit, and the second stator unit are arranged sequentially along the axis of the straight shaft portion, and the first rotor unit is closest to the protrusion. The first stator unit can generate a rotating magnetic field that drives the first rotor unit to rotate, and the second stator unit can generate a rotating magnetic field that drives the second rotor unit to rotate. The straight shaft portion is rotatably disposed through the first stator unit and spaced apart from the second stator unit. Both the first stator unit and the second stator unit have magnetic columns, and the cross-sectional dimension of the magnetic column of the second stator unit is larger than the cross-sectional dimension of the magnetic column of the first stator unit.
15. A blood pump, characterized in that, It includes an impeller and a drive device according to any one of claims 1 to 14, wherein the impeller is fixedly connected to the straight shaft portion.
16. The blood pump according to claim 15, characterized in that, It also includes a sleeve connected to the housing assembly, the sleeve having a liquid outlet on its wall, the impeller being rotatably disposed within the sleeve, the impeller being positioned near the liquid outlet, a portion of the straight shaft portion being housed within the housing assembly, and a portion being housed within the sleeve and fixedly connected to the impeller, the outer peripheral surface of the housing assembly near the impeller forming a liquid guiding surface, the liquid guiding surface being located within the sleeve and corresponding to the position of the liquid outlet, the proximal end of the liquid guiding surface corresponding to the position of the proximal end hole wall of the liquid outlet; the distance from the liquid guiding surface to the axis of the straight shaft portion gradually increases in the direction away from the impeller.
17. The blood pump according to claim 16, characterized in that, Along the axis of the straight shaft portion, the height of the liquid guiding surface is 20%-40% of the height of the liquid outlet.