Drive unit and blood pump
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- SHENZHEN CORE MEDICAL TECH CO LTD
- Filing Date
- 2023-06-05
- Publication Date
- 2026-06-05
Smart Images
Figure 0007870568000001 
Figure 0007870568000002 
Figure 0007870568000003
Abstract
Description
Technical Field
[0001] This application claims the priority of the Chinese patent application with the application number 202210800097.9, which was filed with the China National Intellectual Property Administration on July 8, 2022, and all of its content is incorporated herein by reference.
[0002] This application relates to the technical field of medical devices, and particularly to a drive device and a blood pump including the drive device.
Background Art
[0003] An intravascular blood pump is a blood pumping device that can enter the patient's heart through the patient's blood vessels. The intravascular blood pump is placed within the opening of the heart valve so that blood flows through the blood pump and into the arterial blood vessels. The blood pump includes a drive device and an impeller. The impeller is fixed to the rotating shaft of the drive device, and the rotation of the rotating shaft causes the impeller to rotate. However, the rotating shaft of the conventional blood pump is severely worn during the use process of the blood pump, is difficult to start, and affects the use of the blood pump.
Summary of the Invention
Problems to be Solved by the Invention
[0004] Based on this, this application provides a drive device and a blood pump that can reduce the wear of the rotating shaft and are easy to start.
Means for Solving the Problems
[0005] An embodiment of the first aspect of this application provides a drive device for driving an impeller to rotate. The drive device includes a housing assembly with a housing cavity formed therein, the housing cavity having a first cavity wall and a second cavity wall provided opposite to each other with a gap therebetween, and A rotating shaft comprising a connected straight shaft portion and a projection, configured to be connected to the impeller, wherein the projection is provided projecting circumferentially from the straight shaft portion, the projection is rotatably housed within the housing cavity, the projection is located between the first cavity wall and the second cavity wall, the projection has a first surface and a second surface, the first surface faces the first cavity wall, 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, A rotor fixedly connected to the straight shaft portion, A stator capable of driving and rotating the rotor, the stator having an attractive force between it and the rotor that can bring the first surface into contact with the first cavity wall.
[0006] An embodiment of a second aspect of the present application provides a blood pump including an impeller and a drive unit. The drive unit is A housing assembly having a housing cavity formed therein, the housing assembly having a first cavity wall and a second cavity wall provided opposite to each other and spaced apart, A rotating shaft comprising a connected straight shaft portion and a projection portion, wherein the straight shaft portion is fixedly connected to the impeller, the projection portion is provided protruding circumferentially from the straight shaft portion, the projection portion is rotatably housed within the housing cavity, the projection portion is located between the first cavity wall and the second cavity wall, the projection portion has a first surface and a second surface, the first surface faces the first cavity wall, 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, A rotor fixedly connected to the straight shaft portion, A stator capable of driving and rotating the rotor, the stator having an attractive force between it and the rotor that can bring the first surface into contact with the first cavity wall.
[0007] Details of one or more embodiments of the present invention are described in the following drawings and description. Other features, purposes and advantages of the present invention will become apparent from the specification, drawings and claims. [Brief explanation of the drawing]
[0008] To provide a clearer explanation of the technical means in the embodiments of this application, the drawings that may be used to describe the embodiments or the prior art are briefly described below. As will be apparent, the drawings in the following description are only a few embodiments of this application, and those skilled in the art can obtain other drawings based on these without any creative effort.
[0009] [Figure 1] This is a perspective view of a blood pump according to the first embodiment. [Figure 2] Figure 1 is a partial cross-sectional view of the blood pump shown. [Figure 3] Figure 1 shows another cross-sectional view of the blood pump. [Figure 4] Figure 1 is an exploded view of the blood pump. [Figure 5] Figure 2 shows an exploded view of the rotating shaft, first shaft sleeve, and second shaft sleeve of the blood pump. [Figure 6] Figure 2 is a perspective view of the stator in a blood pump. [Figure 7] Figure 2 is a front view of the rotor of the blood pump. [Figure 8] Figure 7 is a cross-sectional view of the rotor. [Figure 9] Figure 7 is an exploded view of the rotor. [Figure 10] This is a cross-sectional view of a blood pump according to the second embodiment. [Modes for carrying out the invention]
[0010] The present application will be described in more detail below with reference to the attached drawings and examples in order to provide a clearer understanding of its purpose, technical proposal and merits. It should be understood that the specific examples described herein are for interpretive purposes only and do not limit the present application.
[0011] When an element is described as being "fixed" or "attached" to another element, it may be directly or indirectly located on that other element. When an element is described as being "connected" to another element, it may be directly or indirectly connected to that other element.
[0012] Furthermore, the terms “first” and “second” are merely descriptive and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features to be presented. Accordingly, features defined as “first” and “second” may explicitly or implicitly include one or more such features. In the description of this application, “multiple” means two or more unless otherwise specified.
[0013] The following explanation will describe the technical means of this application with reference to specific drawings and embodiments.
[0014] In this specification, the end closest to the operator or physician is defined as the "proximal end," and the end away from the operator or physician is defined as the "distal end."
[0015] As shown in Figure 1, the blood pump 1 according to the first embodiment of the present invention includes a drive unit 20, a cannula 30, an impeller 40, and a catheter 50. The cannula 30 is connected to the distal end of the drive unit 20, the catheter 50 is connected to the proximal end of the drive unit 20, the impeller 40 is rotatably provided inside the cannula 30, and the impeller 40 is connected to the drive unit 20. The drive unit 20 drives the impeller 40 to rotate, thereby realizing the blood pumping function of the blood pump 1.
[0016] Specifically, the cannula 30 has an inlet 31 and an outlet 32. The outlet 32 is closer to the drive device 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 tube wall of the cannula 30. The impeller 40 is provided close to the outlet 32. In one embodiment, the cannula 30 penetrates a heart valve, for example, the aortic valve, the inlet 31 is located inside the heart, and the outlet 32 and the drive device 20 are located in a blood vessel such as the aorta outside the heart. When the impeller 40 rotates, blood flows into the cannula 30 through the inlet 31, and then flows out of the cannula 30 through the outlet 32 and into a blood vessel such as the aorta.
[0017] The catheter 50 abuts against one end of the drive device 20 away from the cannula 30. The catheter 50 accommodates various supply lines, and the supply line may be, for example, a cleaning line for introducing a cleaning liquid into the drive device 20, may be, for example, a conducting wire for supplying power to the drive device 20, or may be, for example, a support member for supporting the catheter 50.
[0018] As shown in FIGS. 2 to 4, the drive device 20 includes a housing assembly 100, a rotating shaft 200, a stator 300, and a rotor 400. The rotating shaft 200 is rotatably attached to the housing assembly 100. A part of the rotating shaft 200 is accommodated in the housing assembly 100, and a part extends into the cannula 30 and is fixedly connected to the impeller 40. Both the stator 300 and the rotor 400 are accommodated in the housing assembly 100. The rotor 400 is fixedly connected to the rotating shaft 200. The stator 300 can drive the rotor 400 to rotate. The rotor 400 can drive the rotating shaft 200 to rotate. The impeller 40 can rotate together with the rotating shaft 200 to realize the blood pumping function of the blood pump 1.
[0019] The proximal and distal ends of the housing assembly 100 are fixedly connected to the catheter 50 and the cannula 30, respectively. The conductors in the catheter 50 extend within the housing assembly 100 and are electrically connected to the stator 300, supplying power to the stator 300. Specifically, the housing assembly 100 includes a first axial sleeve 110, a second axial sleeve 120, an axial tube 130, and a pump housing 140. The first axial sleeve 110 and the second axial sleeve 120 are fixedly housed within the axial tube 130. One end of the axial tube 130 is fixedly connected to the pump housing 140, and the other end is fixedly connected to the cannula 30. The end of the pump housing 140 away from the axial tube 130 is fixedly connected to the catheter 50. The end of the rotating shaft 200 away from the impeller 40 is housed within the pump housing 140. The rotor 400 and stator 300 are housed within the pump housing 140. In one embodiment, the first shaft sleeve 110, the second shaft sleeve 120, the shaft tube 130, and the pump housing 140 are separate components before assembly; that is, the housing assembly 100 is assembled from the separate first shaft sleeve 110, second shaft sleeve 120, shaft tube 130, and pump housing 140. In other embodiments, the first shaft sleeve 110, second shaft sleeve 120, shaft tube 130, and pump housing 140 may be integrally molded.
[0020] As shown in Figure 5, in some embodiments, the first shaft sleeve 110 may be permanently connected to the shaft tube 130 by adhesive. In some embodiments, the first shaft sleeve 110 includes a large disk 111 and a small disk 112, which are coaxially mounted, with the outer diameter of the large disk 111 being greater than the outer diameter of the small disk 112, and the gap between the small disk 112 and the shaft tube 130 can form an adhesive injection space. After the adhesive solidifies in the adhesive injection space, the entire first shaft sleeve 110 is bonded to the shaft tube 130. The second shaft sleeve 120 may be permanently connected to the shaft tube 130 by adhesive.
[0021] The first shaft sleeve 110 and the second shaft sleeve 120 are spaced apart along the axial direction of the shaft tube 130, with the first shaft sleeve 110 being located further away from the impeller 40 than the second shaft sleeve 120. The shaft tube 130, the first shaft sleeve 110, and the second shaft sleeve 120 jointly define a housing cavity 150, which is located between the first shaft sleeve 110 and the second shaft sleeve 120.
[0022] The housing cavity 150 has a first cavity wall 151, a second cavity wall 152, and a cavity side wall 153. The cavity side wall 153 connects the first cavity wall 151 and the second cavity wall 152, and the three parties, the first cavity wall 151, the second cavity wall 152, and the cavity side wall 153, jointly define the boundary of the housing cavity 150. The first cavity wall 151 is located in the first shaft sleeve 110, the second cavity wall 152 is located in the second shaft sleeve 120, and the cavity side wall 153 is located in the shaft pipe 130. The first cavity wall 151 and the second cavity wall 152 are located opposite each other and spaced apart. The first cavity wall 151 is provided facing the impeller 40, and the second cavity wall 152 is provided facing away from the impeller 40. Specifically, the first cavity wall 151 and the second cavity wall 152 are provided perpendicular to the axial direction of the shaft pipe 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 shaft sleeve 110 facing the impeller 40 forms the first cavity wall 151, and at least a portion of the surface of the second shaft sleeve 120 facing away from the impeller 40 forms the 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.
[0023] A first through-hole 113 is formed in the first cavity wall 151, and the first through-hole 113 communicates with the housing cavity 150. The first through-hole 113 extends along the axial direction of the first shaft sleeve 110 and penetrates the entire first shaft sleeve 110. In the illustrated embodiment, the first cavity wall 151 is substantially circular, and the first through-hole 113 is located at the center of the first cavity wall 151.
[0024] A first flow guide groove 114 is further formed in the first cavity wall 151, and the first flow guide groove 114 communicates with both the first insertion hole 113 and the housing cavity 150. In the illustrated embodiment, the first flow guide groove 114 extends radially along the first shaft sleeve 110. There are at least three first flow guide grooves 114, and at least three first flow guide grooves 114 are provided at equal intervals along the circumferential direction of the first insertion hole 113. In some embodiments, one end of the first flow guide groove 114 extends to and communicates with the first insertion hole 113, and the other end extends to the edge of the first cavity wall 151. In some other embodiments, one end of the first flow guide groove 114 away from the first through hole 113 does not extend to the edge of the first cavity wall 151, and in this case, a constant distance is maintained between the end of the first flow guide groove 114 away from the first through hole 113 and the edge of the first cavity wall 151.
[0025] A second through-hole 121 is formed in the second cavity wall 152, and the second through-hole 121 communicates with the housing cavity 150. The second through-hole 121 extends along the axial direction of the second shaft sleeve 120 and penetrates the entire second shaft sleeve 120. In the illustrated embodiment, the second cavity wall 152 is substantially circular, and the second through-hole 121 is located at the center of the second cavity wall 152.
[0026] A second flow guide groove 122 is further formed in the second cavity wall 152, and the second flow guide groove 122 communicates with both the second insertion hole 121 and the housing cavity 150. In the illustrated embodiment, the second flow guide groove 122 extends along the radial direction of the second shaft sleeve 120. The installation method of the second flow guide groove 122 may be the same as that of the first flow guide groove 114, and this will not be explained here. In some embodiments, one end of the second flow guide groove 122 extends to the second insertion hole 121 and communicates with the second insertion hole 121, and the other end extends to the edge of the second cavity wall 152. In some other embodiments, one end of the second flow guide groove 122 away from the second insertion hole 121 does not extend to the edge of the second cavity wall 152, and in this case, a constant distance is maintained between the end of the second flow guide groove 122 away from the second insertion hole 121 and the edge of the second cavity wall 152.
[0027] The pump housing 140 is substantially cylindrical. The pump housing 140 communicates with the housing cavity 150 through a first insertion hole 113, and the cleaning fluid that flows into the pump housing 140 flows into the housing cavity 150 through the first insertion hole 113 and can flow out from the housing assembly 100 through a second insertion hole 121.
[0028] Specifically, the rotating shaft 200 is rotatably mounted through the first insertion hole 113, the second insertion hole 121, and the housing cavity 150. The rotating shaft 200 includes a connected straight shaft portion 210 and a projection portion 220.
[0029] The straight shaft portion 210 is partially housed in the housing assembly 100 and partially extends to the cannula 30 and is fixedly connected to the impeller 40. The straight shaft portion 210 is rotatably provided to pass through the first insertion hole 113, the second insertion hole 121 and the housing cavity 150. Specifically, the cross-section of the portion of the straight shaft portion 210 that is housed in the first insertion hole 113 and the second insertion hole 121 is circular, and the first insertion hole 113 and the second insertion hole 121 are substantially circular holes.
[0030] In the illustrated embodiment, there is a first gap 161 between the straight shaft portion 210 and the hole wall of the first through hole 113, which is understood as the portion of the first through hole 113 that is not filled by the straight shaft portion 210. The cleaning fluid in the pump housing 140 can flow into the housing cavity 150 through the first gap 161. There is a second gap 162 between the straight shaft portion 210 and the hole wall of the second through hole 121, which is understood as the portion of the second through hole 121 that is not filled by the straight shaft portion 210, and the cleaning fluid in the housing cavity 150 can flow out of the housing assembly 100 through the 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.
[0031] A chamfer is provided on one end of the hole wall of the first insertion hole 113 that is close to the housing cavity 150. When the rotating shaft 200 oscillates and contacts the hole wall of the first insertion hole 113, this design reduces the contact area between the straight shaft portion 210 and the hole wall of the first insertion hole 113, thereby reducing friction of the straight shaft portion 210. The chamfer also serves as an assembly guide, reducing interference and assembly resistance during the assembly process of the rotating shaft 200, and improving the assembly efficiency of the rotating shaft 200. A chamfer is provided on one end of the hole wall of the second insertion hole 121 that is close to the housing cavity 150. When the rotating shaft 200 oscillates and contacts the hole wall of the second insertion hole 121, this design reduces the contact area between the straight shaft portion 210 and the hole wall of the second insertion hole 121, thereby reducing friction of the straight shaft portion 210. The chamfer also serves as an assembly guide, reducing interference and assembly resistance during the assembly process of the rotating shaft 200, and improving the assembly efficiency of the rotating shaft 200.
[0032] The projection 220 is provided projecting circumferentially from the straight shaft portion 210, and is rotatably housed in the housing cavity 150. The projection 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 each abut against the projection 220, thereby limiting the maximum amplitude of axial vibration of the rotating shaft 200. Specifically, the cross-sectional size of the projection 220 is larger than the diameter of the first insertion hole 113 and larger than the diameter of the second insertion hole 121. Therefore, the projection 220 is confined within the housing cavity 150 and cannot enter the first insertion hole 113 and the second insertion hole 121. In the illustrated embodiment, the projection 220 is annular, fixedly fitted onto the straight shaft portion 20, the outer diameter of the projection 220 is larger than the diameter of the straight shaft portion 210, the axis of the projection 220 coincides with the axis of the straight shaft portion 210, and the outer diameter of the projection 220 is larger than the diameter of the first insertion hole 113 and larger than the diameter of the second insertion hole 121.
[0033] The projection 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 can contact the first surface 221, and the second cavity wall 152 can contact the second surface 222, thereby limiting the maximum amplitude of 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 coaxial 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 on which the first surface 221 and the second surface 222 are located.
[0034] 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 smaller than the area of the first cavity wall 151, and the area of the second surface 222 is smaller 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, and 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 fixedly connected to the straight shaft portion 210, and there is an attractive force between the stator 300 and the rotor 400 that allows the first surface 221 to come into contact with the first cavity wall 151. In other words, due to the attractive force between the stator 300 and the rotor 400, the projection 220 tends to come into contact with the first cavity wall 151, allowing the first surface 221 to come into contact with the first cavity wall 151. Specifically, the direction of the attractive force acting on the rotor 400 is directed from the second cavity wall 152 to the first cavity wall 151 along the axis of the straight shaft portion 210, allowing the first surface 221 to come into contact with the first cavity wall 151.
[0035] Since 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 allows for a larger 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 received per unit area, and thereby reducing wear on the first surface 221 and the projection 220.
[0036] The projection 220 further has a side circumferential surface 223, which connects the first surface 221 and the second surface 222. The side circumferential surface 223 is provided around the axis of the straight shaft portion 210, and the annular structure defined by the side circumferential surface 223 is coaxial with the straight shaft portion 210. The cavity side wall 153 and the side circumferential surface 223 are provided with a gap between them, thereby creating a third gap 163 between the cavity side wall 153 and the side circumferential surface 223. This third gap 163 communicates with both the first flow guide groove 114 and the second flow guide groove 122. As a result, even when the first surface 221 of the projection 220 abuts against the first cavity wall 151 of the housing cavity 150, the third gap 163 can communicate with the first insertion hole 113 via the first flow guide groove 114. Similarly, even when the second surface 222 of the projection 220 abuts against the second cavity wall 152 of the housing cavity 150, the third gap 163 can communicate with the second insertion hole 121 via the second flow guide groove 122, thereby ensuring that the cleaning fluid flows smoothly. Specifically, a portion of the first flow guide groove 114 communicates with the third gap 163 beyond the range of the orthogonal projection of the first surface 221 of the projection 220 onto the first cavity wall 151. A portion of the second flow guide groove 122 communicates with the third gap 163 beyond the range of the orthogonal projection of the second surface 222 of the projection 220 onto the second cavity wall 152.
[0037] As shown in Figure 2, the cleaning fluid flows sequentially through the first gap 161, the third gap 163, and the second gap 162, and exits from the outlet 32. Since the direction of the cleaning fluid flow is opposite to the direction of blood flow in the cannula 30, it is possible to prevent blood in the cannula 30 from flowing into the drive device 20 through the second insertion hole 121. In Figure 2, thin dashed arrows indicate the flow path of the cleaning fluid, and thick dashed lines indicate the flow path of the blood. The first flow guide groove 114 not only serves to connect the first insertion hole 113 and the third gap 163, but also allows the cleaning fluid to flow better between the first surface 221 and the first cavity wall 221, providing a certain degree of buoyancy to the projection 220, reducing the pressing force between the first surface 221 and the first cavity wall 151, thereby reducing wear on the projection 220. Furthermore, the cleaning fluid can flow between the first surface 221 and the first cavity wall 221 and act as a lubricant, reducing the coefficient of friction between the first surface 221 and the first cavity wall 221, thereby reducing wear between the projection 220 and the cavity wall of the housing cavity 150.
[0038] Specifically, the number of first flow guide grooves 114 is multiple. When the number of first flow guide grooves 114 is increased, on the one hand, the cleaning fluid is filled between the first surface 221 and the first cavity wall 151 in a shorter time, providing a lubricating effect on the first surface 221 and the first cavity wall 151, reducing the coefficient of friction between the first surface 221 and the projection 220 and reducing wear. On the other hand, the flow rate and velocity of the cleaning fluid flowing between the first surface 221 and the first cavity wall 151 can be rationally increased, which is advantageous for quickly removing heat caused by friction between the first cavity wall 151 and the projection 220, reducing wear that would occur if the temperature is too high. Furthermore, the buoyancy force of the cleaning fluid on the projection 220 can be increased, reducing the pressing force between the first cavity wall 151 and the projection 220, and reducing wear between the first cavity wall 151 and the projection 220. Therefore, by rationally increasing the number of first flow guide grooves 114, wear on the first cavity wall 151 and projections 220 can be reduced. Similarly, by rationally increasing the number of second flow guide grooves 122, wear on the second surface 222 and projections 220 can be reduced. In the illustrated embodiment, there are four first flow guide grooves 114, and the angle between two adjacent first flow guide grooves 114 in the direction of extension is 90°. In other embodiments, the number of first flow guide grooves 114 and second flow guide grooves 122 can be adjusted as needed.
[0039] Specifically, the side surface 223 includes a cylindrical surface portion 2231 and a tapered surface portion 2232, the cylindrical surface portion 2231 and the tapered surface portion 2232 are arranged along the axis of the straight shaft portion 210, the cylindrical surface portion 2231 is connected to the first surface 221 and is provided perpendicular to the first surface 221, one end of the tapered surface portion 2232 is connected to the cylindrical surface portion 2231 and the other end of the tapered surface portion 2232 is connected to the second surface 222, that is, the tapered surface portion 2232 is connected between the cylindrical surface portion 2231 and the second surface 222. In the direction from the first surface 221 to the second surface 222 along the axis of the straight shaft portion 210, the distance from the cylindrical surface portion 2231 to the axis of the straight shaft portion 210 is kept constant, while the distance from the tapered surface portion 2232 to the axis of the straight shaft portion 210 gradually decreases. By providing the tapered surface portion 2232 on the side circumferential surface 223 of the projection portion 220, a good flow guidance effect for the cleaning fluid can be achieved, and at the same time, because the area of the second surface 222 is smaller than the area of the second cavity wall 152, the cleaning fluid flows through the third gap 163 and flows towards the second insertion hole 121, improving the cleaning effect of the cleaning fluid. The cylindrical surface portion 2231 has a constant length along the axial direction of the straight shaft portion 210, preventing one end of the tapered projection 220 on the entire side surface 223 that is close to the first surface 221 from forming an acute angle. Generally speaking, this prevents the side surface 223 and the first surface 221 from forming a sharp corner. If radial vibration occurs in the projection 220, and this corner comes into contact with the cavity side wall 153, resulting in linear contact, there is a risk of causing significant scratches and damage to the cavity side wall 153. Furthermore, the cleaning fluid does not have a sufficiently large area to form a lubricating thin film layer between the projection 220 and the cavity side wall 153. By providing the cylindrical surface portion 2231, a transition effect is achieved, ensuring that the side surface 223 and the cavity side wall 153 of the housing cavity 150 face each other, thereby reducing the risk of friction damage.
[0040] The shape of the cavity side wall 153 of the housing cavity 150 matches the shape of the side surface 223 and has a structure of straight surface portion 1531 and inclined surface portion 1532 that are similar to the cylindrical surface portion 2231 and tapered surface portion 2232 of the side surface 223.
[0041] 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 defined as the first distance H, and the distance between the first surface 221 and the second surface 222 is defined as the second distance h, with the first distance H being greater than the second distance h. In some embodiments, because the first distance H is slightly greater than the second distance h, the first cavity wall 151 is always in contact with the first surface 221, and the second cavity wall 152 is always in contact with the second surface 222, thereby preventing the rotation axis 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. When the first surface 221 contacts the first cavity wall 151, there is a certain distance between the second surface 222 and the second cavity wall 152. This creates a gap between the second surface 222 and the second cavity wall 152, and the projection 220 has a certain floating space between the first cavity wall 151 and the second cavity wall 152. The cleaning fluid flows into the space between the first surface 221 and the first cavity wall 151, and between the second surface 222 and the second cavity wall 152, providing lubrication and lifting the projection 220, thus avoiding dry friction between the projection 220 and the cavity wall of the housing cavity 150. Naturally, it is preferable that the difference between the first spacing H and the second spacing h is not too large so that the amplitude in the axial direction of the rotating shaft 200 does not become too large.
[0042] Specifically, the width of the gap between the cavity side wall 153 and the tapered surface portion 2232 of the side circumferential surface 223 is greater than the difference between the first interval H and the second interval h. That is, the width of the third gap 163 at the position corresponding to the tapered surface portion 2232 is greater than the difference between the first interval H and the second interval h. As a result, when radial and / or axial vibration occurs in the projection 220, the probability of contact between the cavity side wall 153 and the side circumferential surface 223 of the projection 220 is reduced, and friction between the projection 220 and the cavity wall of the housing cavity 150 can be reduced.
[0043] In some embodiments, the material of at least one of the first cavity wall 151 and the first surface 221 is ceramic, and the material of at least one of the second cavity wall 152 and the second surface 222 is ceramic. Ceramics offer high processing accuracy, high biocompatibility, and also high mechanical strength, excellent wear resistance, and corrosion resistance. Furthermore, ceramics can have a finer surface, reducing friction during contact between the first surface 221 and the first cavity wall 151, and reducing friction during contact between the second surface 222 and the second cavity wall 152. Specifically, the material of the first shaft sleeve 110 and the second shaft sleeve 120 is ceramic, and the material of the projection 220 is ceramic; that is, the material of the first cavity wall 151, the first surface 221, the second cavity wall 152, and the second surface 222 are all ceramic.
[0044] In some embodiments, a fluid guide surface 160 is formed on the outer circumferential surface of one end of the housing assembly 100 adjacent to the impeller 40, the fluid guide surface 160 is located inside the cannula 30 and corresponds to the position of the outlet 32, the proximal end of the fluid guide surface 160 corresponds to the position of the proximal end hole wall of the outlet 32, and the distance from the fluid guide surface 160 to the axis of the straight shaft 210 gradually increases in the direction away from the impeller 40. Specifically, the fluid guide surface 160 is located at the end of the shaft tube 130 away from the pump housing 140. The design of the fluid guide surface 160 is advantageous for the discharge of liquid from the cannula 30. Furthermore, the impeller 40 and the drive unit 20 are typically the rigid parts of the blood pump 1. The shorter the axial length of the rigid parts, the more advantageous it is for the blood pump 1 to transport blood within the human body. By providing a fluid guide surface 160 on the housing assembly 100 of the drive unit 20, the axial length of the impeller 40 can be shortened while ensuring the hydraulic performance of the outlet 32. At the same time, since the fluid guide surface 160 is provided on the cannula 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 (i.e., the rigid parts of the blood pump 1) can be shortened, making the transport of blood by the blood pump 1 easier.
[0045] Specifically, the fluid guide surface 160 is roughly arc-shaped. Along the axis of the straight shaft 210, the height L1 of the fluid guide surface 160 is 20% to 40% of the height L2 of the outlet 32. This height design shortens the overall length of the impeller 40 and the drive unit 20, while also providing the blood pump 1 with good hydraulic performance.
[0046] As shown in Figures 2 and 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. There are multiple magnetic cores 310, which are spaced apart along a single circumference. The direction of extension of each magnetic core 310 coincides with the direction of extension of the straight shaft portion 210; that is, the central axis of the magnetic core 310 and the axis of the straight shaft portion 210 are parallel to each other, and 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, and there is a one-to-one correspondence between them. The coils 330 are wound around the magnetic cores 310, with one coil 330 wound around each magnetic core 310.
[0047] In some embodiments, the magnetic core 310 includes a magnetic column 311 and a head (i.e., a pole piece) provided at one end of the magnetic column 311, the cross-sectional size of which is larger than that of the magnetic column 311, and the direction of extension of the magnetic column 311 coincides with the direction of extension of the straight shaft portion 210. The backplate 320 is joined to the end of the magnetic column 311 away from the head. In the direction of extension of the magnetic column 311, the magnetic column 311 exhibits a columnar shape of substantially uniform size, that is, the cross-sectional size of the magnetic column 311 is kept constant, and generally speaking, the thickness of the magnetic column 311 is uniform. The coil 330 is wound around the magnetic column 311 of the magnetic core 310. In the illustrated embodiment, the magnetic core 310 includes only magnetic columns 311, that is, the magnetic core 310 does not have a wide head (i.e., a pole piece), and the magnetic columns 311 of the stator 300 are the magnetic core 310. In this case, the entire magnetic core 310 can be magnetically coupled to the rotor 400, and compared to a magnetic core 310 with a pole piece, the magnetic core 310 having only magnetic columns 311 reduces magnetic loss and increases the magnetic coupling density between the magnetic core 310 and the rotor 400, thereby increasing the torque from the stator 300 to the rotor 400 for the same current. On the other hand, the magnetic core 310 without a head can significantly reduce the problem of power reduction in the drive unit 20 due to localized magnetic short circuits caused by contact between adjacent magnetic cores 310.
[0048] Furthermore, the magnetic core 310 is not limited to the two methods described above, and in some embodiments, some magnetic columns 311 are provided with heads, while other magnetic columns 311 are not.
[0049] In some embodiments, the cross-sectional shape of the magnetic column 311 is approximately triangular prism-shaped, with one edge of each magnetic column 311 pointing toward the axis of the straight shaft portion 210. In some embodiments, the edges of the magnetic column 311 are all chamfered, i.e., the edges of the magnetic column 311 are relatively smooth and blunt chamfered edges, thereby removing sharp corners of the magnetic column 311, which is advantageous not only for winding the subsequent coil 330 but also for protecting the insulating material covering the coil 330. In other embodiments, the cross-sectional shape of the magnetic column 311 may be sector-shaped, circular, trapezoidal, annular sector-shaped, etc.
[0050] The backplate 320 has a substantially flat plate structure. The backplate 320 is manufactured from the same material as the magnetic core 310, for example, from a soft magnetic material such as cobalt steel. With respect to the rotor 400 driven by the stator 300, the backplate 320 is fixed to one end of the magnetic column 311 away from the rotor 400, and the backplate 320 can close the magnetic circuit of the stator 300, promoting and increasing the generation of magnetic flux in the stator 300 and improving the coupling ability between the stator 300 and the rotor 400. In other words, by providing the backplate 320 to the stator 300, the generation of magnetic flux in the stator 300 can be promoted and increased, and the coupling ability between the stator 300 and the rotor 400 can be improved. Since the backplate 320 can increase magnetic flux, providing a backplate 320 to each stator 300 is also advantageous in reducing the overall diameter of the drive unit 20. In some embodiments, the backplate 320 may be omitted.
[0051] The rotor 400 and the stator 300 are positioned at a distance from each other along the axis of the straight shaft portion 210. The rotor 400 is located between the projection 220 and the stator 300 along the axis of the straight shaft portion 210. The first cavity wall 151 of the housing cavity 150 is located between the rotor 400 and the first surface 221 of the projection 220.
[0052] As shown in Figures 7, 8, and 9, the rotor 400 is magnetic, and the stator 300 can generate 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 fixedly connected to the straight shaft portion 210 of the rotating shaft 200. The magnetic core 310 of the stator 300 has an attractive force to the magnet 410 of the rotor 400, and the direction of this attractive force is from the second surface 222 to the first surface 221 along the axis of the rotating shaft 200, causing the first surface 221 to come into contact with the first cavity wall 151.
[0053] The magnet 410 is an annular Halbach array magnet. Specifically, the magnet 410 includes a plurality of magnetic units 411 magnetized along the axial direction of the magnet 410, for example, the number of magnetic units 411 may be 4, 6, 8, or 10, and each magnetic unit 411 is an annular fan shape, and the plurality of magnetic units 411 are arranged around the straight shaft portion 210 so that the magnet 410 forms an annular structure.
[0054] The rotor 400 further includes a flywheel 420, in which case the flywheel 420 is directly fixed to the straight shaft portion 210, and the magnet 410 is fixed to the flywheel 420. By providing the flywheel 420, the connection strength between the magnet 410 and the straight shaft portion 210 can be increased, and the oscillation of the rotating shaft 200 during rotation can be reduced, thus making the entire rotating shaft 200 more stable during rotation.
[0055] The flywheel 420 includes an internal tube 421, a disc-shaped portion 422, and an outer ring wall 423. Both the internal tube 421 and the outer ring wall 423 have a cylindrical structure, and the disc-shaped portion 422 has an annular disc structure. Both the internal tube 421 and the outer ring wall 423 are fixedly connected to the disc-shaped portion 422. The outer ring wall 423 is provided so as to surround the disc-shaped portion 422, and both the internal tube 421 and the outer ring wall 423 are provided coaxially, and the straight shaft portion 210 is provided penetrating into the internal tube 421 and fixedly connected to the internal tube 421. A mounting cavity 424 is formed between the internal tube 421 and the outer ring wall 423, and the mounting cavities 424 are all annular cavities. The magnets 410 are each housed in the mounting cavities 424. The shape of the mounting cavity 424 is matched to the magnet 410 to facilitate the mounting and positioning of the magnet 410. In this way, the flywheel 420 can act as a position limiting force on the magnet 410, not only facilitating the mounting of the magnet 410 but also making the connection between the magnet 410 and the flywheel 420 more stable.
[0056] The flywheel 420 is not limited to the above structure. 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 or an internal tube 421. In this case, the straight shaft portion 210 is fixedly provided penetrating the center of the disc-shaped portion 422. By providing an internal tube 421 to a flywheel 420 having only a disc-shaped portion 422, the flywheel 420 and the straight shaft portion 210 can be connected more stably.
[0057] To facilitate the installation of the magnets 410 and improve the installation accuracy of the magnets 410, the flywheel 420 is further provided with marking sections 4211 for identifying the installation positions of the magnetic units 411. The marking sections 4211 may be provided as grooves, scale lines, or markings. When installing the magnets 410, by marking the position of one of the magnetic units 411 of the magnets 410 using the marking sections 4211, the installation positions of the remaining magnetic units 411 can be identified, thereby facilitating the installation of the magnets 410. Specifically, the marking sections 4211 are provided on at least one of the internal tube 421, the disc-shaped section 422, and the outer ring wall 423. For example, the marking sections 4211 are provided on the end face of the internal tube 421.
[0058] In the illustrated embodiment, the rotating shaft 200 and the stator 300 are spaced apart along the axis of the straight shaft portion 210, that is, the straight shaft portion 210 does not penetrate the stator 300, and as a result the rotating shaft 200 is located outside the stator 300. In order to increase 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 from the stator 300 to the rotor 400, the smaller the current required, which is advantageous for reducing power consumption and heat generation. Since the rotating shaft 200 does not penetrate the stator 300, it is possible to avoid the rotating shaft 200 occupying the mounting space for the magnetic column 311. If the outer diameter of the housing assembly 100 is kept the same, it is advantageous to increase the cross-sectional size of the magnetic column 311 of the stator 300 and increase the driving torque from the stator 300 to the rotor 400. If the required torque is the same, this method can reduce the current supply to the stator 300, lowering power consumption and reducing the amount of heat generated by the drive unit 20, thus avoiding discomfort and injury to the human body due to excessive heat concentration and high temperatures during the operation of the blood pump 10.
[0059] The above-mentioned drive unit 20 and blood pump 1 have at least the following advantages.
[0060] (1) Because there is an attractive force between the stator 300 and the rotor 400 of the drive unit 20, the first surface 221 comes into contact with the first cavity wall 151 of the housing cavity 150 due to this attractive force, and the first cavity wall 151 receives pressure from the first surface 221, making the area of the first surface 221 larger than the area of the second surface 222, that is, increasing the area of the first surface 221, and making the area of the first surface 221 less than or equal to the area of the first cavity wall 151, thereby reducing the area of the first surface 221 that contacts the first cavity wall 151. In this configuration, 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 increases the contact area between the first surface 221 and the first cavity wall 151 when the first surface 221 is in contact with the first cavity wall 151, thereby reducing the pressure per unit area between the first surface 221 and the first cavity wall 151, i.e., reducing the pressure received per unit area, and thereby reducing wear between the first surface 221 and the first cavity wall 151. Simultaneously, due to the suction force, the first surface 221 tends to contact the first cavity wall 151 of the housing cavity 150, and the second surface 222 tends to move away from the second cavity wall 152. This prevents the second surface 222 from contacting the second cavity wall 152, or reduces the coefficient of friction when the second surface 222 and the second cavity wall 152 do come into contact. This reduces the frictional resistance against the protrusion 220 of the second cavity wall 152 during the startup process of the drive unit 20, thereby improving the startup speed when the rotating shaft 200 rotates, that is, improving the sensitivity to the drive response of the rotating shaft 200. For this reason, the blood pump 1 and drive unit 20 not only reduce the degree of wear on the rotating shaft 200 during use, but can also start up quickly.
[0061] (2) By providing the first flow guide groove 122 on the first surface 221, the cleaning fluid is rapidly allowed to flow between the first surface 221 and the first cavity wall 151, providing a lubricating effect between the first surface 221 and the first cavity wall 151, reducing the coefficient of friction between the first surface 221 and the first cavity wall 221, thereby reducing wear between the projection 220 and the cavity wall of the housing cavity 150. Furthermore, by positioning a part of the first flow guide groove 114 outside the range of the orthographic projection of the first surface 221 of the projection 220 onto the first cavity wall 151, the housing cavity 150 can communicate with the first insertion hole 113 via the first flow guide groove 114 even when the first surface 221 of the projection 220 comes into contact with the first cavity wall 151 of the housing cavity 150, thereby allowing the cleaning fluid to flow smoothly.
[0062] (3) When the hydraulic performance of the blood pump 1 is guaranteed by providing a part of the housing assembly 100 inside the cannula 30 and providing an arc-shaped fluid guide surface portion 160 on the outer circumferential surface of the portion of the housing assembly 100 located in the cannula 30, it is advantageous to reduce the overall length of the impeller 40 and the drive unit 20 (i.e., the rigid part of the blood pump 1), and facilitates the transport of the blood pump 1.
[0063] (4) By providing a gap between the rotating shaft 200 and the stator 300, when the outer diameters of the housing assembly 100 and the stator 300 are not changed, it is advantageous to increase the cross-sectional area of the magnetic column 311, thereby increasing the driving torque from the stator 300 to the rotor 400. When the required torque is the same, this method can reduce the current supply to the stator 300, thereby reducing power consumption and the amount of heat generated by the drive unit 20, thus avoiding discomfort and injury to the human body due to excessive heat concentration and high temperatures during the operation of the blood pump 10.
[0064] As shown in Figure 10, the blood pump 2 according to the second embodiment has almost the same structure as the blood pump 1 according to 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 referred to as the first stator unit 301 and the second stator unit 302, respectively, and the two rotor units are referred to as the first rotor unit 401 and the second rotor unit 402, respectively.
[0065] Here, the first rotor unit 401, the first stator unit 301, the second rotor unit 402, and the second stator unit 302 are arranged in order along the axis of the straight shaft portion 210', with the first rotor unit 401 being positioned closest to the projection portion 220'. Both the first rotor unit 401 and the second rotor unit 402 are fixedly connected to the straight shaft portion 210' 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 attractive force that the first rotor unit 401 receives from the first stator unit 301 is denoted as the first attractive force, and the attractive force that the second rotor unit 402 receives from the second stator unit 302 is denoted as the second attractive force. Since the directions of the first attractive force and the second attractive force are the same and they act on the rotation axis 200' via the first rotor unit 401 and the second rotor unit 402, respectively, the resultant force of both the first attractive force and the second attractive force allows the first surface 221' of the projection 220' to come into contact with the first cavity wall 151'.
[0066] The straight shaft portion 210' of the rotating shaft 200' is rotatably inserted through the first stator unit 301, and the second stator unit 30 2They are spaced apart. That is, the straight shaft portion 210' is not provided penetrating the second stator unit 302, and as a result, the straight shaft portion 210' is located outside the second stator unit 302, and furthermore, the rotating shaft 200' and the second stator unit 302 are 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 columns 311', and 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. Since the rotating shaft 200' is not provided through the second stator unit 302, that is, the rotating shaft 200' is located outside the second stator unit 302, it is possible to avoid the rotating shaft 200' occupying the mounting space for the magnetic column 311' in the second stator unit 302. If the outer diameter of the pump housing 140' and the second stator unit 302 is not increased, the cross-sectional size of the magnetic column 311' of the second stator unit 302 can be increased. In this case, although the outer diameters of both 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 that of the magnetic column 311' of the first stator unit 301. In this way, the driving torque from the second stator unit 302 to the second rotor unit 402 can be increased, and if the required torque is the same, this method can rationally reduce the current supply to the second stator unit 302, thereby reducing power consumption and the amount of heat generated by the drive unit, thus avoiding discomfort and even injury to the human body caused by excessive heat concentration and high temperatures during the operation of the blood pump.
[0067] In this embodiment, the structures of the first rotor unit 401 and the second rotor unit 402 may be the same as the structure of the rotor 400 of the blood pump 1 according to the first embodiment, and the structures of the first stator unit 301 and the second stator unit 302 may be the same as the structure of the stator 300 of the blood pump 1, and such explanations are omitted here. The back plate 320' of the first stator unit 301 is located at one end of the magnetic column 311' of the first stator unit 301 away from the first rotor unit 401, and the back plate 320' of the second stator unit 302 is located at one end of the magnetic column 311' of the second stator unit 302 away from the second rotor unit 402.
[0068] Since the structure of the blood pump 2 according to the second embodiment is the same as the structure of the blood pump 1 according to the first embodiment, the blood pump 2 according to the second embodiment also has the advantages of the blood pump 1 according to the first embodiment.
[0069] Furthermore, the structure of the blood pump drive unit is not limited to the structures 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.
[0070] The above embodiments are merely for illustrating the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art will understand that the technical solutions described in each of the above embodiments can be modified or some of their technical features can be replaced with equivalents. These modifications and replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of each embodiment of the present invention, and should all be included within the scope of protection of the present invention.
Claims
1. A drive device that drives and rotates an impeller, A housing assembly having a housing cavity formed therein, the housing assembly having a first cavity wall and a second cavity wall provided opposite to each other and spaced apart, A rotating shaft comprising a connected straight shaft portion and a projection, configured to be connected to the impeller, wherein the projection is provided protruding circumferentially from the straight shaft portion, the projection is rotatably housed within the housing cavity, the projection is located between the first cavity wall and the second cavity wall, the projection has a first surface and a second surface, the first surface faces the first cavity wall, 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, A rotor fixedly connected to the straight shaft portion, A drive device characterized by including a stator capable of driving and rotating the rotor, wherein the stator has an attractive force between it and the rotor that allows the first surface to come into contact with the first cavity wall.
2. The drive 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 contacts the first cavity wall, the distance between the second surface and the second cavity wall is a certain distance.
3. The material of at least one of the first cavity wall and the first surface is ceramic. The drive device according to claim 1, characterized in that and / or, at least one of the second cavity wall and the second surface is made of ceramics.
4. The drive device according to claim 1, characterized in that the first surface and the second surface are both perpendicular to the axis of the straight shaft portion, and the first cavity wall and the second cavity wall are parallel to the first surface and the second surface, respectively.
5. The drive device according to claim 4, characterized in that the outer contours of the first surface and the second surface are both circular, and the center line of the first surface and the center line of the second surface are both coaxial with the axis of the straight shaft portion.
6. The drive device according to claim 1, characterized in that a first through hole and a first flow guide groove are formed in the wall of the first cavity, the first through hole communicates with the housing cavity, the first flow guide groove communicates with both the first through hole and the housing cavity, and the straight shaft portion is provided rotatably penetrating the first through hole.
7. The drive device according to claim 6, wherein the projection further has a side circumferential surface connecting the first surface and the second surface, the housing cavity further has a cavity side wall connecting the first cavity wall and the second cavity wall, there is a gap between the cavity side wall and the side circumferential surface, and a part of the first flow guide groove communicates with the gap beyond the range of the orthogonal projection of the first surface onto the first cavity wall.
8. The drive device according to claim 7, wherein the side circumferential surface includes a cylindrical surface portion and a tapered surface portion provided around the axis of the straight shaft portion, the cylindrical surface portion is connected to the first surface, the tapered surface portion is connected between the cylindrical surface portion and the second surface, the distance from the tapered surface portion to the axis of the straight shaft portion gradually decreases in the direction from the first surface to the second surface, the distance between the first cavity wall and the second cavity wall is defined as the first interval, and the distance between the first surface and the second surface is defined as the second interval, the width of the gap between the cavity side wall and the tapered surface portion is greater than the difference between the first interval and the second interval.
9. The drive device according to claim 8, wherein the cavity side wall includes a straight surface portion and an inclined surface portion connected to each other, the shape of the straight surface portion conforms to the shape of the cylindrical surface portion, and the shape of the inclined surface portion conforms to the shape of the tapered surface portion.
10. The drive device according to claim 6, characterized in that a chamfer is provided on one end of the hole wall of the first insertion hole that is close to the housing cavity.
11. The drive device according to claim 1, characterized in that a second through hole and a second flow guide groove are formed in the second cavity wall, the second through hole communicates with the housing cavity, the second flow guide groove communicates with both the second through hole and the housing cavity, the straight shaft portion is provided rotatably through the second through hole, and a portion of the second flow guide groove exceeds the range of the orthogonal projection of the second surface onto the second cavity wall.
12. The drive device according to claim 1, wherein the housing assembly includes a shaft tube, a first shaft sleeve, and a second shaft sleeve that jointly define the housing cavity, the first shaft sleeve and the second shaft sleeve being spaced apart and fixed within the shaft tube, the first cavity wall being located in the first shaft sleeve, the second cavity wall being located in the second shaft sleeve, and the straight shaft portion being provided rotatably through the first shaft sleeve and the second shaft sleeve.
13. The drive device according to claim 1, wherein the rotor and the stator are provided at an interval along the axis of the straight shaft portion, the rotating shaft and the stator are provided at an interval along the axis of the straight shaft portion, the stator includes a magnetic core and a coil wound around the magnetic core, the rotor is magnetic, and there is an attractive force between the rotor and the magnetic core.
14. The drive device according to claim 1, characterized in that the first cavity wall is located between the rotor and the first surface.
15. The drive device according to claim 1, characterized in that the rotating shaft and the stator are provided at an interval along the axis of the straight shaft portion.
16. The drive device according to claim 1, wherein the rotor includes a first rotor unit and a second rotor unit, 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 in order along the axis of the straight shaft portion, the first rotor unit is closest to the projection portion, the first stator unit is capable of generating a rotating magnetic field that drives and rotates the first rotor unit, the second stator unit is capable of generating a rotating magnetic field that drives and rotates the second rotor unit, the straight shaft portion is provided rotatably 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 size of the magnetic column of the second stator unit is larger than the cross-sectional size of the magnetic column of the first stator unit.
17. A blood pump comprising an impeller and a drive device for driving and rotating the impeller, wherein the drive device is A housing assembly having a housing cavity formed therein, the housing assembly having a first cavity wall and a second cavity wall provided opposite to each other and spaced apart, A rotating shaft comprising a connected straight shaft portion and a projection portion, wherein the straight shaft portion is fixedly connected to the impeller, the projection portion is provided protruding circumferentially from the straight shaft portion, the projection portion is rotatably housed within the housing cavity, the projection portion is located between the first cavity wall and the second cavity wall, the projection portion has a first surface and a second surface, the first surface faces the first cavity wall, 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, A rotor fixedly connected to the straight shaft portion, A blood pump characterized in that it includes a stator capable of driving and rotating the rotor, wherein the stator has an attractive force between it and the rotor that can bring the first surface into contact with the first cavity wall.
18. The blood pump according to claim 17, further comprising a cannula connected to the housing assembly, wherein an outlet is formed in the tubular wall of the cannula, the impeller is rotatably mounted within the cannula, the impeller is mounted in close proximity to the outlet, the straight shaft portion is partially housed in the housing assembly and partially housed within the cannula and fixedly connected to the impeller, the outer circumferential surface of one end of the housing assembly adjacent to the impeller forms a fluid guide surface, the fluid guide surface portion is located within the cannula and corresponds to the position of the outlet, the proximal end of the fluid guide surface portion corresponds to the position of the proximal end hole wall of the outlet, and the distance from the fluid guide surface portion to the axis of the straight shaft portion gradually increases in the direction away from the impeller.
19. The blood pump according to claim 18, characterized in that, along the axis of the straight shaft portion, the height of the fluid guide surface portion is 20% to 40% of the height of the outlet portion.
20. The housing assembly includes a shaft tube, a first shaft sleeve, and a second shaft sleeve that jointly define the housing cavity, wherein the first shaft sleeve and the second shaft sleeve are spaced apart and fixed within the shaft tube, the first cavity wall is located in the first shaft sleeve, the second cavity wall is located in the second shaft sleeve, and the straight shaft portion is provided rotatably through the first shaft sleeve and the second shaft sleeve. The blood pump according to claim 18, characterized in that the outer circumferential surface of one end of the shaft tube adjacent to the impeller forms the fluid guide surface.