Drive device and blood pump

Abstract

A blood pump (1) and a drive device (20) are disclosed. The drive device (20) includes a housing assembly (100), a rotating shaft (200), a rotor (400), and a stator (300). The accommodation cavity (150) of the housing assembly (100) has a first cavity wall (151) and a second cavity wall (152). The protrusion (220) of the rotating shaft (200) has a first surface (221) and a second surface (222). The first surface (221) faces the first cavity wall (151), and the second surface (222) faces the second cavity wall (152). The area of the first surface (221) is larger 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). There is an attractive force between the stator (300) and the rotor (400) that can bring the first surface (221) into contact with the first cavity wall (151).

Description

Technical Field

[0001] This application claims the priority of Chinese Patent Application No. 202210800097.9, filed with the State Intellectual Property Office of China 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 driving device and a blood pump including the driving device.

Background Art

[0003] An intravascular blood pump is a blood pumping device that can enter a patient's heart through the patient's blood vessels. The intravascular blood pump is placed within the opening of the heart valve such that blood flows through the blood pump and into the arterial blood vessels. The blood pump includes a driving device and an impeller, and the impeller is fixed to the rotating shaft of the driving device, and the rotation of the rotating shaft rotates the impeller. 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 driving device and a blood pump that can reduce 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 driving device for driving an impeller to rotate. The driving device includes a housing assembly with a formed accommodation cavity, the accommodation cavity having a first cavity wall and a second cavity wall provided opposite to each other with a space therebetween, and A rotating shaft configured to be connected to the impeller and including a connected straight shaft portion and a protrusion, wherein the protrusion is provided to protrude in the circumferential direction of the straight shaft portion, the protrusion is rotatably accommodated in the accommodation cavity, the protrusion is located between the first cavity wall and the second cavity wall, the protrusion 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 larger than the area of the second surface, and the area of the first surface is not more than the area of the first cavity wall; and A rotor fixedly connected to the straight shaft portion; A stator capable of driving the rotor to rotate, wherein there is an attractive force between the stator and the rotor capable of bringing the first surface into contact with the first cavity wall.

[0006] An embodiment of the second aspect of the present application provides a blood pump including an impeller and a drive device. The drive device Is a housing assembly in which an accommodation cavity is formed, the accommodation cavity having a first cavity wall and a second cavity wall provided opposite to each other with a space therebetween; A rotating shaft including a connected straight shaft portion and a protrusion, the straight shaft portion being fixedly connected to the impeller, the protrusion being provided to protrude in the circumferential direction of the straight shaft portion, the protrusion being rotatably accommodated in the accommodation cavity, the protrusion being located between the first cavity wall and the second cavity wall, the protrusion having a first surface and a second surface, the first surface facing the first cavity wall, the second surface facing the second cavity wall, the area of the first surface being larger than the area of the second surface, and the area of the first surface being not more than the area of the first cavity wall; and A rotor fixedly connected to the straight shaft portion; A stator capable of driving and rotating the rotor, wherein there is an attractive force between the stator 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 will be described in the following drawings and description. Other features, objects, and advantages of the present invention will become apparent from the specification, drawings, and claims.

Brief Description of the Drawings

[0008] Hereinafter, in order to more clearly explain the technical means in the embodiments of the present application, the drawings necessary for describing the embodiments or the prior art will be briefly described. As is obvious, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative labor.

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Modes for Carrying Out the Invention

[0010] Hereinafter, in order to more clearly understand the object, technical solution and advantages of the present application, the present application will be described in more detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for the purpose of interpreting the present application and do not limit the present application.

[0011] In addition, when an element is referred to as being "fixed to" or "provided on" another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or indirectly connected to the other element.

[0012] Also, the terms "first" and "second" are for illustrative purposes only and should not be understood as indicating relative importance or implying, or implicitly indicating the number of technical features shown. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present application, "a plurality" means two or more unless otherwise specified.

[0013] Hereinafter, in order to describe the technical means of the present application, it will be described with reference to specific drawings and embodiments.

[0014] In this specification, one end close to the operator or doctor is defined as the "proximal end", and one end away from the operator or doctor is defined as the "distal end".

[0015] As shown in FIG. 1, the blood pump 1 according to the first embodiment of the present invention includes a driving device 20, a cannula 30, an impeller 40, and a catheter 50. The cannula 30 is connected to the distal end of the driving device 20, the catheter 50 is connected to the proximal end of the driving device 20, the impeller 40 is rotatably provided in the cannula 30, the impeller 40 is connected to the driving device 20, and the driving device 20 can drive the impeller 40 to rotate to realize 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 through 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. 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 conducting wire in the catheter 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 shaft sleeve 110, a second shaft sleeve 120, a shaft tube 130, and a pump housing 140. The first shaft sleeve 110 and the second shaft sleeve 120 are fixedly accommodated 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 cannula 30. One end of the pump housing 140 away from the shaft tube 130 is fixedly connected to the catheter 50. One end of the rotating shaft 200 away from the impeller 40 is accommodated within the pump housing 140. The rotor 400 and the stator 300 are accommodated 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 before being assembled, 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, the second shaft sleeve 120, the shaft tube 130, and the pump housing 140 may have an integrally formed structure.

[0020] As shown in FIG. 5, in some embodiments, the first shaft sleeve 110 may be fixedly connected to the shaft tube 130 by adhesion. In some embodiments, the first shaft sleeve 110 includes a large disk 111 and a small disk 112, the large disk 111 and the small disk 112 are coaxially provided, the outer diameter of the large disk 111 is larger 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 within the adhesive injection space, the entire first shaft sleeve 110 is adhered to the shaft tube 130. The second shaft sleeve 120 may be fixedly connected to the shaft tube 130 by adhesion.

[0021] The first shaft sleeve 110 and the second shaft sleeve 120 are provided at intervals along the axial direction of the shaft tube 130, and the first shaft sleeve 110 is provided farther 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 an accommodation cavity 150, and the accommodation cavity 150 is located between the first shaft sleeve 110 and the second shaft sleeve 120.

[0022] The accommodation 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 of the first cavity wall 151, the second cavity wall 152, and the cavity side wall 153 jointly define the boundary of the accommodation cavity 150. The first cavity wall 151 is located on the first shaft sleeve 110, the second cavity wall 152 is located on the second shaft sleeve 120, and the cavity side wall 153 is located on the shaft tube 130. The first cavity wall 151 and the second cavity wall 152 are provided opposite to each other and at intervals. 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 tube 130, that is, the first cavity wall 151 and the second cavity wall 152 are parallel. At least a part of the surface of the first shaft sleeve 110 facing the impeller 40 forms the first cavity wall 151, and at least a part 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 insertion hole 113 is formed in the first cavity wall 151, and the first insertion hole 113 communicates with the accommodation cavity 150. The first insertion 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 insertion hole 113 is located at the center position of the first cavity wall 151.

[0024] On the first cavity wall 151, a first flow guiding groove 114 is further formed, and the first flow guiding groove 114 communicates with both the first insertion hole 113 and the accommodation cavity 150. In the illustrated embodiment, the first flow guiding groove 114 extends along the radial direction of the first shaft sleeve 110. The number of the first flow guiding grooves 114 is at least three, and at least three first flow guiding 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 guiding groove 114 extends to the first insertion hole 113 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 guiding groove 114 away from the first insertion hole 113 does not extend to the edge of the first cavity wall 151, and at this time, a certain interval is maintained between one end of the first flow guiding groove 114 away from the first insertion hole 113 and the edge of the first cavity wall 151.

[0025] On the second cavity wall 152, a second insertion hole 121 is formed, and the second insertion hole 121 communicates with the accommodation cavity 150. The second insertion 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 insertion hole 121 is located at the central position of the second cavity wall 152.

[0026] A second flow guiding groove 122 is further formed in the second cavity wall 152, and the second flow guiding groove 122 communicates with both the second insertion hole 121 and the accommodation cavity 150. In the illustrated embodiment, the second flow guiding groove 122 extends along the radial direction of the second shaft sleeve 120. The installation method of the second flow guiding groove 122 may be the same as that of the first flow guiding groove 114, and the description thereof is omitted here. In some embodiments, one end of the second flow guiding 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 guiding groove 122 away from the second insertion hole 121 does not extend to the edge of the second cavity wall 152, and at this time, a certain distance is maintained between one end of the second flow guiding 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 accommodation cavity 150 through the first insertion hole 113, and the cleaning liquid flowing into the pump housing 140 can flow into the accommodation cavity 150 through the first insertion hole 113 and flow out of the housing assembly 100 through the second insertion hole 121.

[0028] Specifically, the rotating shaft 200 is rotatably provided through the first insertion hole 113, the second insertion hole 121, and the accommodation cavity 150. The rotating shaft 200 includes a connected straight shaft portion 210 and a protrusion portion 220.

[0029] A part of the straight shaft portion 210 is accommodated in the housing assembly 100, a part of it extends to the cannula 30 and is fixedly connected to the impeller 40. The straight shaft portion 210 is rotatably provided through the first insertion hole 113, the second insertion hole 121, and the accommodation cavity 150. Specifically, the cross section of the portion of the straight shaft portion 210 accommodated 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 insertion hole 113, and the first gap 161 is understood as the portion not filled by the straight shaft portion 210 in the first insertion hole 113. The cleaning liquid in the pump housing 140 can flow into the accommodation 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 insertion hole 121, and the second gap 162 is understood as the portion not filled by the straight shaft portion 210 in the second insertion hole 121, and the cleaning liquid in the accommodation cavity 150 can flow out of the housing assembly 100 through the second gap 162. Specifically, the width of at least a part of the second gap 162 is smaller than the width of the first gap 161.

[0031] At one end of the hole wall of the first insertion hole 113 close to the accommodation cavity 150, a chamfer is provided. When the rotating shaft 200 sways and contacts the hole wall of the first insertion hole 113, with this design, the contact area between the straight shaft portion 210 and the hole wall of the first insertion hole 113 can be reduced, and the friction of the straight shaft portion 210 can be decreased. The chamfer can also play an assembly guiding role, reducing the interference and assembly resistance in the assembly process of the rotating shaft 200, and improving the assembly efficiency of the rotating shaft 200. At one end of the hole wall of the second insertion hole 121 close to the accommodation cavity 150, a chamfer is provided. When the rotating shaft 200 sways and contacts the hole wall of the second insertion hole 121, with this design, the contact area between the straight shaft portion 210 and the hole wall of the second insertion hole 121 can be reduced, and the friction of the straight shaft portion 210 can be decreased. The chamfer can also play an assembly guiding role, reducing the interference and assembly resistance in the assembly process of the rotating shaft 200, and improving the assembly efficiency of the rotating shaft 200.

[0032] The protruding portion 220 is provided to protrude in the circumferential direction of the straight shaft portion 210. The protruding portion 220 is rotatably accommodated in the accommodation cavity 150, and the protruding portion 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 respectively abut against the protruding portion 220, and can limit the maximum amplitude of the axial vibration of the rotating shaft 200. Specifically, since the cross-sectional size of the protruding portion 220 is larger than the aperture diameter of the first insertion hole 113 and larger than the aperture diameter of the second insertion hole 121, the protruding portion 220 is limited within the accommodation cavity 150, and the protruding portion 220 cannot enter the first insertion hole 113 and the second insertion hole 121. In the illustrated embodiment, the protruding portion 220 is annular, the protruding portion 220 is fixedly externally fitted to the straight shaft portion 20, the outer diameter of the protruding portion 220 is larger than the diameter of the straight shaft portion 210, the axis of the protruding portion 220 coincides with the axis of the straight shaft portion 210, the outer diameter of the protruding portion 220 is larger than the aperture diameter of the first insertion hole 113, and larger than the aperture diameter of the second insertion hole 121.

[0033] The protruding portion 220 has a first surface 221 and a second surface 222, and the first surface 221 and the second surface 222 are provided at intervals along the axis of the straight shaft portion 210. The first surface 221 is provided facing the first cavity wall 151, and the second surface 222 is provided facing the second cavity wall 152. The first cavity wall 151 can abut against the first surface 221, and the second cavity wall 152 can abut 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 the first surface 221 and the second surface 222 are both circular, and both the first surface 221 and the second surface 222 are provided coaxially 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 where the first surface 221 and the second surface 222 are located.

[0034] The area of the first surface 221 is larger 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. When the second cavity wall 152 contacts 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 can make the first surface 221 abut against the first cavity wall 151. In other words, due to the attractive force between the stator 300 and the rotor 400, the protrusion 220 tends to abut in the direction of the first cavity wall 151, and the first surface 221 can be made to abut against the first cavity wall 151. Specifically, the direction of the attractive force received by 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, and the first surface 221 can be made to abut against 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 first surface 221 with a larger area can increase the contact area between the first surface 221 and the first cavity wall 151, reduce the pressure per unit area of the first surface 221 and the first cavity wall 151, that is, reduce the pressure received per unit area, thereby reducing the wear of the first surface 221 and the protrusion 220.

[0036] The protrusion 220 further has a side peripheral surface 223, and the side peripheral surface 223 connects the first surface 221 and the second surface 222. The side peripheral surface 223 is provided around the axis of the straight shaft portion 210, and the annular structure defined by the side peripheral surface 223 is coaxial with the straight shaft portion 210. The cavity side wall 153 and the side peripheral surface 223 are provided at an interval, whereby there is a third gap 163 between the cavity side wall 153 and the side peripheral surface 223, and the third gap 163 communicates with both the first flow guiding groove 114 and the second flow guiding groove 122. Even when the first surface 221 of the protrusion 220 abuts against the first cavity wall 151 of the receiving cavity 150, the third gap 163 can communicate with the first insertion hole 113 through the first flow guiding groove 114. Even when the second surface 222 of the protrusion 220 abuts against the second cavity wall 152 of the receiving cavity 150, the third gap 163 can communicate with the second insertion hole 121 through the second flow guiding groove 122, thereby ensuring smooth flow of the cleaning liquid. Specifically, a part of the first flow guiding groove 114 communicates with the third gap 163 beyond the range of the orthographic projection of the first surface 221 of the protrusion 220 onto the first cavity wall 151. A part of the second flow guiding groove 122 communicates with the third gap 163 beyond the range of the orthographic projection of the second surface 222 of the protrusion 220 onto the second cavity wall 152.

[0037] As shown in FIG. 2, the cleaning liquid flows through the first gap 161, the third gap 163, and the second gap 162 in sequence and flows out from the outlet 32. Since the flow direction of the cleaning liquid is opposite to the flow direction of the blood in the cannula 30, it is possible to prevent the blood in the cannula 30 from flowing into the driving device 20 through the second insertion hole 121. In FIG. 2, the thin dashed arrow indicates the flow path of the cleaning liquid, and the thick dashed line indicates the flow path of the blood. The first guiding groove 114 not only serves to communicate the first insertion hole 113 and the third gap 163, but also allows the cleaning liquid to flow more easily between the first surface 221 and the first cavity wall 221, and exerts a certain floating action on the protrusion 220, reducing the pressing force between the first surface 221 and the first cavity wall 151, reducing the wear of the protrusion 220. At the same time, the cleaning liquid can flow between the first surface 221 and the first cavity wall 221 to serve as a lubricant, reducing the friction coefficient between the first surface 221 and the first cavity wall 221, and reducing the wear between the protrusion 220 and the cavity wall of the accommodating cavity 150.

[0038] Specifically, the number of the first flow guide grooves 114 is plural. When the number of the first flow guide grooves 114 increases, on the one hand, the cleaning liquid can be filled between the first surface 221 and the first cavity wall 151 in a shorter time, exert a lubricating effect on the first surface 221 and the first cavity wall 151, reduce the friction coefficient between the first surface 221 and the protrusion 220, and reduce wear. On the other hand, the flow rate and flow velocity of the cleaning liquid flowing between the first surface 221 and the first cavity wall 151 can be reasonably increased, which is advantageous for quickly taking away the heat generated by the friction between the first cavity wall 151 and the protrusion 220, and reducing the excessive temperature and severe wear. Furthermore, the buoyancy force of the cleaning liquid on the protrusion 220 can be increased, the pressing force between the first cavity wall 151 and the protrusion 220 can be reduced, and the wear between the first cavity wall 151 and the protrusion 220 can be reduced. Therefore, by reasonably increasing the number of the first flow guide grooves 114, the wear of the first cavity wall 151 and the protrusion 220 can be reduced. Similarly, by reasonably increasing the number of the second flow guide grooves 122, the wear of the second surface 222 and the protrusion 220 can be reduced. In the illustrated embodiment, the number of the first flow guide grooves 114 is four, and among the four first flow guide grooves 114, the included angle in the extending direction between two adjacent first flow guide grooves 114 is 90°. In other embodiments, the number of the first flow guide grooves 114 and the second flow guide grooves 122 can be adjusted as required.

[0039] Specifically, the side peripheral 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, and 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 peripheral surface 223 of the protrusion 220, a good flow guiding effect on the cleaning liquid can be achieved. At the same time, since the area of the second surface 222 is smaller than the area of the second cavity wall 152, the cleaning liquid flows through the third gap 163 and flows in the direction of the second insertion hole 121, improving the cleaning effect of the cleaning liquid. The cylindrical surface portion 2231 has a certain length along the axial direction of the straight shaft portion 210, avoiding that one end of the tapered protrusion 220 on the entire side peripheral surface 223 close to the first surface 221 forms an acute angle. Generally speaking, it avoids that the side peripheral surface 223 and the first surface 221 form a sharp angle. When radial sway occurs in the protrusion 220 and the angle comes into line contact with the cavity side wall 153, there is a risk of causing large scratches and damage to the cavity side wall 153, and the cleaning liquid does not have a sufficiently large area to form a lubricating thin film layer between the protrusion 220 and the cavity side wall 153. By providing the above-mentioned cylindrical surface portion 2231, a transition effect is achieved, ensuring that the side peripheral surface 223 and the cavity side wall 153 of the accommodation cavity 150 face each other, and the risk of frictional damage can be reduced.

[0040] The shape of the cavity side wall 153 of the accommodation cavity 150 conforms to the shape of the side peripheral surface 223 and has a structure of a straight surface portion 1531 and an inclined surface portion 1532 similar to the cylindrical surface portion 2231 and the tapered surface portion 2232 of the side peripheral 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 interval H, the distance between the first surface 221 and the second surface 222 is defined as the second interval h, and the first interval H is greater than the second interval h. In some embodiments, since the first interval H is slightly greater than the second interval h, the first cavity wall 151 always contacts the first surface 221, and the second cavity wall 152 always contacts the second surface 222, thereby avoiding the rotation shaft 200 from moving in the axial direction of the straight shaft portion 210. In some embodiments, since the first interval H is greater than the second interval h, when the first surface 221 abuts against the first cavity wall 151, there is a certain distance between the second surface 222 and the second cavity wall 152, there is a gap between the second surface 222 and the second cavity wall 152, the protrusion 220 has a certain floating space between the first cavity wall 151 and the second cavity wall 152, and the cleaning liquid 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, which has the effect of lubricating and floating the protrusion 220, and avoiding dry friction between the protrusion 220 and the cavity wall of the accommodating cavity 150. Of course, it is preferable that the difference between the first interval H and the second interval h is not too large so that the amplitude of the rotation shaft 200 in the axial direction is not 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. Thereby, when radial and / or axial sway occurs in the protrusion 220, the contact probability between the cavity side wall 153 and the side circumferential surface 223 of the protrusion 220 can be reduced, and the friction between the protrusion 220 and the cavity wall of the accommodating 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 ceramics, and the material of at least one of the second cavity wall 152 and the second surface 222 is ceramics. Ceramics have high processing accuracy, high biocompatibility, higher mechanical strength, excellent wear resistance and corrosion resistance. In addition, ceramics can have a smaller roughness, reduce the friction when the first surface 221 contacts the first cavity wall 151, and reduce the friction when the second surface 222 contacts the second cavity wall 152. Specifically, the materials of the first shaft sleeve 110 and the second shaft sleeve 120 are ceramics, and the material of the protrusion 220 is ceramics, that is, the materials of the first cavity wall 151, the first surface 221, the second cavity wall 152 and the second surface 222 are all ceramics.

[0044] In some embodiments, a liquid guiding portion 160 is formed on the outer peripheral surface of one end of the housing assembly 100 close to the impeller 40. The liquid guiding portion 160 is located in the cannula 30 and corresponds to the position of the liquid outlet 32. The proximal end portion of the liquid guiding portion 160 corresponds to the position of the proximal end hole wall of the liquid outlet 32. In the direction away from the impeller 40, the distance from the liquid guiding portion 160 to the axis of the straight shaft portion 210 gradually increases. Specifically, the liquid guiding portion 160 is located at one end of the shaft tube 130 away from the pump housing 140. The design of the liquid guiding portion 160 is beneficial for the derivation of the liquid in the cannula 30. Also, usually, the impeller 40 and the driving device 20 are the rigid parts of the blood pump 1. The shorter the axial length of the rigid part, the more beneficial it is for the transportation of the blood pump 1 in the human body. By providing the liquid guiding portion 160 on the housing assembly 100 of the driving device 20, the axial length of the impeller 40 can be shortened, and the hydraulic performance of the liquid outlet 32 can be ensured. At the same time, since the liquid guiding portion 160 is provided in the cannula 30 as a part of the housing assembly 100 of the driving device 20, the overall length of the impeller 40 and the driving device 20 (that is, the rigid part of the blood pump 1) can be shortened, and the transportation of the blood pump 1 can be made easier.

[0045] Specifically, the liquid guiding surface portion 160 is substantially arc-shaped. Along the axis of the straight shaft portion 210, the height L1 of the liquid guiding surface portion 160 is 20% to 40% of the height L2 of the liquid outlet 32. With this height design, the overall length of the impeller 40 and the driving device 20 can be shortened, and the blood pump 1 can be given good hydraulic performance.

[0046] As shown in FIGS. 2 and 6, the stator 300 is fixedly accommodated in the pump housing 140. Specifically, the stator 300 includes a magnetic core 310, a back plate 320, and a coil 330. The back plate 320 is fixedly connected to the pump housing 140. The number of magnetic cores 310 is plural, and the plural magnetic cores 310 are provided at intervals along one circumference. The extending direction of each magnetic core 310 coincides with the extending direction 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. 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 the two are in a one-to-one correspondence. The coil 330 is wound around the magnetic core 310, and one coil 330 is 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 the head is larger than that of the magnetic column 311, and the extending direction of the magnetic column 311 coincides with the extending direction of the straight shaft portion 210. The back plate 320 is joined to one end of the magnetic column 311 away from the head. In the extending direction of the magnetic column 311, the magnetic column 311 presents a columnar body with a substantially uniform size, that is, the cross-sectional size of the magnetic column 311 is kept constant. 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 the magnetic column 311, that is, the magnetic core 310 does not have a wide head (i.e., a pole piece), and the magnetic column 311 of the stator 300 is the magnetic core 310. In this case, the entire magnetic core 310 can be magnetically coupled to the rotor 400. Compared with the magnetic core 310 having a pole piece, the magnetic core 310 having only the magnetic column 311 can reduce magnetic loss and increase the magnetic coupling density between the magnetic core 310 and the rotor 400, so that for the same current, the torque from the stator 300 to the rotor 400 can be increased. On the other hand, the magnetic core 310 without a head can greatly reduce the problem that the power of the driving device 20 decreases due to local magnetic short circuit caused by the contact between adjacent magnetic cores 310.

[0048] Note that the magnetic core 310 is not limited to the above two methods. In some embodiments, heads are provided on some of the magnetic columns 311, and no heads are provided on some other magnetic columns 311.

[0049] In some embodiments, the cross-sectional shape of the magnetic poles 311 is substantially triangular prism-shaped, and one edge of each magnetic pole 311 faces the axis of the straight shaft portion 210. In some embodiments, the edges of the magnetic poles 311 are all chamfered, that is, the edges of the magnetic poles 311 are relatively smooth and blunt chamfered edges, thereby removing the sharp corners of the magnetic poles 311, not only facilitating the winding of the subsequent coil 330, but also being advantageous for protecting the insulating material coated on the coil 330. In other embodiments, the cross-sectional shape of the magnetic poles 311 may be fan-shaped, circular, trapezoidal, annular fan-shaped, etc.

[0050] The back plate 320 has a substantially flat plate-like structure. The back plate 320 is made of the same material as the magnetic core 310, for example, a soft magnetic material such as cobalt steel. With reference to the rotor 400 driven by the stator 300, the back plate 320 is fixed to one end of the magnetic poles 311 away from the rotor 400. The back plate 320 can play a role in closing the magnetic circuit of the stator 300, promoting and increasing the generation of magnetic flux of the stator 300, and improving the coupling ability between the stator 300 and the rotor 400. In other words, by providing the back plate 320 on the stator 300, the generation of magnetic flux of 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 back plate 320 can increase the magnetic flux, providing the back plate 320 on each of the stators 300 is also advantageous for reducing the diameter of the entire driving device 20. In some embodiments, the back plate 320 may be omitted.

[0051] The rotor 400 and the stator 300 are arranged at intervals along the axis of the straight shaft portion 210. The rotor 400 is located between the protrusion 220 and the stator 300 along the axis of the straight shaft portion 210. The first cavity wall 151 of the accommodation cavity 150 is located between the rotor 400 and the first surface 221 of the protrusion 220.

[0052] As shown in FIGS. 7, 8, and 9, the rotor 400 has magnetism, 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, and the magnet 410 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 with respect to the magnet 410 of the rotor 400, and the direction of the attractive force is from the second surface 222 to the first surface 221 along the axis of the rotating shaft 200, and the first surface 221 can be abutted in the direction of 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 is 4, 6, 8, 10, etc. Each magnetic unit 411 is an annular sector, and the plurality of magnetic units 411 are provided to go around the straight shaft portion 210 so that the magnet 410 forms an annular structure.

[0054] The rotor 400 further includes a flywheel 420. At this time, 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 sway during the rotation of the rotating shaft 200 can also be reduced. In this way, the entire rotating shaft 200 is more stable during rotation.

[0055] The flywheel 420 includes a built-in tube 421, a disk-shaped portion 422, and an outer annular wall 423. Both the built-in tube 421 and the outer annular wall 423 are of a circular tubular structure, and the disk-shaped portion 422 is of an annular disk structure. The built-in tube 421 and the outer annular wall 423 are both fixedly connected to the disk-shaped portion 422. The outer annular wall 423 is provided so as to surround the disk-shaped portion 422, and both the built-in tube 421 and the outer annular wall 423 are coaxially provided. The straight shaft portion 210 is provided to penetrate through the built-in tube 421 and is fixedly connected to the built-in tube 421. An attachment cavity 424 is formed between the built-in tube 421 and the outer annular wall 423, and the attachment cavities 424 are all annular cavities. The magnets 410 are respectively accommodated in the attachment cavities 424. The shape of the attachment cavity 424 is adapted to the magnet 410 so as to facilitate the attachment and positioning of the magnet 410. In this way, the flywheel 420 can exert a position-limiting effect on the magnet 410, which not only facilitates the attachment of the magnet 410 but also makes the connection between the magnet 410 and the flywheel 420 more stable.

[0056] Note that the flywheel 420 is not limited to the above structure. In some embodiments, the flywheel 420 does not have the outer annular wall 423. In some embodiments, the flywheel 420 does not have the outer annular wall 423 and the built-in tube 421. At this time, the straight shaft portion 210 is fixedly provided to penetrate through the center of the disk-shaped portion 422. By providing the built-in tube 421 for the flywheel 420 having only the disk-shaped portion 422, the flywheel 420 and the straight shaft portion 210 can be more stably connected.

[0057] In order to facilitate the attachment of the magnet 410 and improve the attachment accuracy of the magnet 410, the flywheel 420 is further provided with a marking portion 4211 for specifying the attachment position of the magnetic unit 411. The marking portion 4211 may be provided as a groove, a scale line, a mark, or the like. When attaching the magnet 410, if the positions of one of the magnetic units 411 of the magnet 410 are marked using the marking portion 4211 respectively, the attachment positions of the remaining magnetic units 411 can be specified, facilitating the attachment of the magnet 410. Specifically, the marking portion 4211 is provided on at least one of the built-in tube 421, the disk-shaped portion 422, and the outer ring wall 423. For example, the marking portion 4211 is provided on the end face of the built-in tube 421.

[0058] In the illustrated embodiment, along the axis of the straight shaft portion 210, the rotating shaft 200 and the stator 300 are provided at an interval, that is, the straight shaft portion 210 is not provided to penetrate the stator 300, whereby 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 larger the generated magnetic flux, the larger the torque on the rotor 400 from the stator 300, the smaller the required current, which is advantageous for reducing power consumption and heat generation. Since the rotating shaft 200 is not provided to penetrate the stator 300, it is possible to avoid the rotating shaft 200 occupying the mounting space of the magnetic column 311. When maintaining the outer diameter of the housing assembly 100 as it is, it is advantageous to increase the cross-sectional size of the magnetic column 311 of the stator 300 to increase the driving torque on the rotor 400 from the stator 300. When the required torque is the same, this method can reduce the current supply to the stator 300, reduce the power consumption, reduce the heat generation amount of the driving device 20, and avoid discomfort and even injury to the human body caused by heat concentration and too high temperature during the operation process of the blood pump 10.

[0059] The above driving device 20 and blood pump 1 have at least the following advantages.

[0060] (1) Since there is an attractive force between the stator 300 and the rotor 400 of the driving device 20, due to this attractive force, the first surface 221 abuts against the first cavity wall 151 of the accommodation cavity 150, the first cavity wall 151 receives the pressure of the first surface 221, making the area of the first surface 221 larger than the area of the second surface 222. That is, by 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, 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 first surface 221 with a large area 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, reduce the pressure per unit area between the first surface 221 and the first cavity wall 151, that is, reduce the pressure received per unit area, thereby reducing the wear between the first surface 221 and the first cavity wall 151. At the same time, due to the attractive force, the first surface 221 abuts against the first cavity wall 151 of the accommodation cavity 150 and the second surface 222 tends to move away from the second cavity wall 152. Therefore, the second surface 222 is not in contact with the second cavity wall 152, or the friction coefficient when the second surface 222 contacts the second cavity wall 152 is reduced, and the frictional resistance against the protrusion 220 of the second cavity wall 152 can be reduced during the startup process of the driving device 20. Thereby, the startup speed when the rotating shaft 200 rotates is improved, that is, the sensitivity of the driving response of the rotating shaft 200 is improved. For this reason, the blood pump 1 and the driving device 20 can not only reduce the wear degree of the rotating shaft 200 during use but also start quickly.

[0061] (2) By providing the first flow guiding groove 122 on the first surface 221, the cleaning liquid can be quickly introduced between the first surface 221 and the first cavity wall 151, so as to exert a lubricating effect between the first surface 221 and the first cavity wall 151, reduce the friction coefficient between the first surface 221 and the first cavity wall 221, and reduce the wear between the protrusion 220 and the cavity wall of the accommodating cavity 150. Furthermore, by positioning a part of the first flow guiding groove 114 outside the range of the orthographic projection of the first surface 221 of the protrusion 220 onto the first cavity wall 151, 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 communicate with the first insertion hole 113 through the first flow guiding groove 114, and the flow of the cleaning liquid can be made smooth.

[0062] (3) By providing a part of the housing assembly 100 inside the cannula 30 and providing an arc-shaped liquid guiding surface portion 160 on the outer peripheral surface of the portion of the housing assembly 100 located in the cannula 30, when ensuring the hydraulic performance of the blood pump 1, it is advantageous for reducing the overall length of the impeller 40 and the driving device 20 (i.e., the rigid part of the blood pump 1), and facilitating the transportation of the blood pump 1.

[0063] (4) By providing the rotating shaft 200 and the stator 300 at an interval, when not changing the outer diameters of the housing assembly 100 and the stator 300, by increasing the cross-sectional area of the magnetic column 311, it is advantageous for increasing the driving torque of the stator 300 on the rotor 400. When the required torque is the same, this method can reduce the current supply to the stator 300, reduce the power consumption, reduce the heat generation amount of the driving device 20, and avoid the discomfort and even injury to the human body caused by heat concentration and too high temperature during the operation process of the blood pump 10.

[0064] As shown in Fig. 10, the blood pump 2 according to the second embodiment is substantially the same as the structure of the blood pump 1 according to the first embodiment. The difference is that in this embodiment, the rotor 400' has two rotor units, the stator 300' has two stator units, the two stator units are respectively denoted as the first stator unit 301 and the second stator unit 302, and the two rotor units are respectively denoted as the first rotor unit 401 and the second rotor unit 402.

[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'. The first rotor unit 401 is provided 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 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 received by the first rotor unit 401 from the first stator unit 301 is denoted as the first attractive force, and the attractive force received by the second rotor unit 402 from the second stator unit 302 is denoted as the second attractive force. The directions of the first attractive force and the second attractive force are the same, and they act on the rotating shaft 200' through the first rotor unit 401 and the second rotor unit 402 respectively. Therefore, due to the combined action of both the first attractive force and the second attractive force, the first surface 221' of the protrusion 220' can abut toward the first cavity wall 151' direction.

[0066] The straight shaft portion 210' of the rotating shaft 200' is rotatably provided through the first stator unit 301 and is spaced apart from the second stator unit 301. That is, the straight shaft portion 210' is not provided through the second stator unit 302, whereby the straight shaft portion 210' is located outside the second stator unit 302, and further, 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 poles 311', and the cross-sectional size of the magnetic poles 311' of the second stator unit 302 is larger than the cross-sectional size of the magnetic poles 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 of the magnetic poles 311' in the second stator unit 302. When the outer diameters of the pump housing 140' and the second stator unit 302 are not increased, the cross-sectional size of the magnetic poles 311' of the second stator unit 302 can be increased. At this time, the outer diameters of both the first stator unit 301 and the second stator unit 302 are the same, but the cross-sectional size of the magnetic poles 311' of the second stator unit 302 is larger than the cross-sectional size of the magnetic poles 311' of the first stator unit 301. In this way, the driving torque on the second rotor unit 402 from the second stator unit 302 can be increased. When the required torque is the same, this method can reasonably reduce the current supply to the second stator unit 302, reduce the power consumption, reduce the heat generation amount of the driving device, and avoid discomfort and even injury to the human body caused by heat concentration and excessive temperature during the operation process 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 the description thereof is 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] It should be noted that the structure of the driving device of the blood pump is not limited to the structures of the first embodiment and the second embodiment. In other embodiments, the number of stator units can be adjusted as required, and the positional relationship between the rotor unit and the stator unit can also be adjusted.

[0070] The above embodiments are only for explaining the technical solutions of the present invention and do not limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that the technical solutions described in each of the foregoing embodiments can be modified or equivalent replacements can be made for some of the technical features thereof. These modifications and replacements do not depart from the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of each embodiment of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A drive device for driving and rotating an impeller, comprising: A housing assembly having a receiving cavity formed therein, wherein the receiving cavity has a first cavity wall and a second cavity wall provided opposite to each other with a gap therebetween; A rotating shaft configured to be connected to the impeller and including a connected straight shaft portion and a protrusion, wherein the protrusion is provided to protrude in the circumferential direction of the straight shaft portion, the protrusion is rotatably received in the receiving cavity, the protrusion is located between the first cavity wall and the second cavity wall, the protrusion 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 larger than the area of the second surface, and the area of the first surface is not more than 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, wherein there is an attractive force between the stator and the rotor that can bring the first surface into contact with the first cavity wall.

2. The distance between the first cavity wall and the second cavity wall is larger than the distance between the first surface and the second surface, so that when the first surface contacts the first cavity wall, there is a certain distance between the second surface and the second cavity wall. The drive device according to claim 1, characterized in that.

3. At least one of the materials of the first cavity wall and the first surface is ceramics; And / or at least one of the materials of the second cavity wall and the second surface is ceramics. The drive device according to claim 1, characterized in that.

4. Both the first surface and the second surface are 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. The drive device according to claim 1, characterized in that.

5. 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 provided coaxially with the axis of the straight shaft portion. The drive device according to claim 4, characterized in that.

6. A first insertion hole and a first flow guide groove are formed in the first cavity wall. The first insertion hole communicates with the accommodation cavity, the first flow guide groove communicates with both the first insertion hole and the accommodation cavity, and the straight shaft portion is rotatably provided through the first insertion hole. The drive device according to claim 1, characterized in that.

7. The protruding portion further has a side peripheral surface connecting the first surface and the second surface. The accommodation 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 peripheral surface. A part of the first flow guide groove communicates with the gap beyond the range of the orthographic projection of the first surface on the first cavity wall. The drive device according to claim 6, characterized in that.

8. The side peripheral 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. In the direction from the first surface to the second surface, the distance from the tapered surface portion to the axis of the straight shaft portion gradually decreases. Defining the distance between the first cavity wall and the second cavity wall as a first distance and the distance between the first surface and the second surface as a second distance, the width of the gap between the cavity side wall and the tapered surface portion is greater than the difference between the first distance and the second distance. The drive device according to claim 7, characterized in that.

9. 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. The drive device according to claim 8, characterized in that.

10. A chamfer is provided at one end of the hole wall of the first insertion hole close to the accommodation cavity. The drive device according to claim 6, characterized in that.

11. The second cavity wall is formed with a second insertion hole and a second flow guiding groove. The second insertion hole communicates with the accommodation cavity. The second flow guiding groove communicates with both the second insertion hole and the accommodation cavity. The straight shaft portion is rotatably provided to penetrate the second insertion hole. A part of the second flow guiding groove extends beyond the range of the orthographic projection of the second cavity wall on the second surface. The driving device according to claim 1, characterized in that.

12. The housing assembly includes a shaft tube, a first shaft sleeve, and a second shaft sleeve that jointly define the accommodation cavity. The first shaft sleeve and the second shaft sleeve are provided at an interval and fixed within the shaft tube. The first cavity wall is located on the first shaft sleeve. The second cavity wall is located on the second shaft sleeve. The straight shaft portion is rotatably provided to penetrate the first shaft sleeve and the second shaft sleeve. The driving device according to claim 1, characterized in that.

13. The rotor and the stator are provided at an interval along the axis of the straight shaft portion. Along the axis of the straight shaft portion, the rotating shaft and the stator are provided at an interval. The stator includes a magnetic core and a coil wound around the magnetic core. The rotor has magnetism, and there is an attractive force between the rotor and the magnetic core. The driving device according to claim 1, characterized in that.

14. The first cavity wall is located between the rotor and the first surface. The driving device according to claim 1, characterized in that.

15. The rotating shaft and the stator are provided at an interval along the axis of the straight shaft portion. The driving device according to claim 1, characterized in that.

16. 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, and the first rotor unit is closest to the protrusion. The first stator unit is capable of generating a rotating magnetic field for driving the first rotor unit to rotate, and the second stator unit is capable of generating a rotating magnetic field for driving the second rotor unit to rotate. The straight shaft portion is rotatably penetrated through the first stator unit and is provided at a distance 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. The drive device according to claim 1, characterized in that.

17. A blood pump including an impeller and a drive device for driving the impeller to rotate, wherein the drive device is A housing assembly in which a housing cavity is formed, the housing cavity having a first cavity wall and a second cavity wall provided opposite to each other with a space therebetween, A rotating shaft including a connected straight shaft portion and a protrusion, the straight shaft portion being fixedly connected to the impeller, the protrusion being provided to protrude in the circumferential direction of the straight shaft portion, the protrusion being rotatably accommodated in the housing cavity, the protrusion being located between the first cavity wall and the second cavity wall, the protrusion having a first surface and a second surface, the first surface facing the first cavity wall, the second surface facing the second cavity wall, the area of the first surface being larger than the area of the second surface, and the area of the first surface being 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 the rotor to rotate, there being an attractive force between the stator and the rotor capable of bringing the first surface into contact with the first cavity wall. A blood pump characterized by including.

18. It further includes a cannula connected to the housing assembly, an outlet is formed in the tube wall of the cannula, the impeller is rotatably provided in the cannula, the impeller is provided close to the outlet, a part of the straight shaft portion is accommodated in the housing assembly, and a part of it is accommodated in the cannula and fixedly connected to the impeller. The outer peripheral surface of one end of the housing assembly close to the impeller forms a liquid guiding surface portion, the liquid guiding surface portion is located in the cannula and corresponds to the position of the outlet. The proximal end portion of the liquid guiding surface portion corresponds to the position of the proximal end hole wall of the outlet. Along the direction away from the impeller, the distance from the liquid guiding surface portion to the axis of the straight shaft portion gradually increases. The blood pump according to claim 17, characterized in that.

19. Along the axis of the straight shaft portion, the height of the liquid guiding surface portion is 20% to 40% of the height of the outlet. The blood pump according to claim 18, characterized in that.

20. The housing assembly includes a shaft tube, a first shaft sleeve, and a second shaft sleeve that jointly define the accommodation cavity. The first shaft sleeve and the second shaft sleeve are provided at intervals and fixed in the shaft tube. The first cavity wall is located on the first shaft sleeve, the second cavity wall is located on the second shaft sleeve, and the straight shaft portion is rotatably penetrated through the first shaft sleeve and the second shaft sleeve. The outer peripheral surface of one end of the shaft tube close to the impeller forms the liquid guiding surface portion. The driving device according to claim 17, characterized in that.

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