Drive device and blood pump

Abstract

The application relates to a driving device and a blood pump, the driving device comprising: a shell assembly provided with a containing cavity, the containing cavity being provided with a first cavity wall and a second cavity wall which are opposite and spaced apart; a rotating shaft for being connected with an impeller, the rotating shaft comprising a connected straight shaft part and a protruding part, the protruding part being protrudingly arranged in the circumferential direction of the straight shaft part, the protruding part being rotatably accommodated in the containing cavity, the protruding part being located between the first cavity wall and the second cavity wall, the protruding part being provided with a first surface and a second surface, the first surface being faced to the first cavity wall, the second surface being faced to the second cavity wall, the area of the first surface being larger than the area of the second surface, the area of the first surface being less than or equal to the area of the first cavity wall; a rotor being fixedly connected to the straight shaft part; and a stator capable of driving the rotor to rotate, the stator and the rotor being provided with an attractive force, the attractive force being capable of making the first surface abut against the first cavity wall. The rotating shaft of the above-mentioned blood pump and driving device is less abraded and is easier to start.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a driving device and a blood pump comprising the same. BACKGROUND

[0002] An intravascular blood pump is a blood pumping device which can be inserted into a patient's heart through a blood vessel of the patient, and is placed in an opening of a heart valve so that blood can flow through the blood pump and into an arterial blood vessel. The blood pump comprises a driving device and an impeller, the impeller is fixed on a rotating shaft of the driving device and rotates by the rotating shaft to drive the impeller to rotate. However, the rotating shaft of the conventional blood pump is seriously worn during use of the blood pump, and is not easy to start, which affects the use of the blood pump. SUMMARY

[0003] In view of this, it is necessary to provide a driving device and a blood pump with less wear of the rotating shaft and easier starting.

[0004] A driving device for driving an impeller to rotate, the driving device comprising:

[0005] a housing assembly having a receiving cavity, the receiving cavity having a first cavity wall and a second cavity wall oppositely and spacedly arranged;

[0006] a rotating shaft for connecting with the impeller, the rotating shaft comprising a straight shaft portion and a protruding portion, the protruding portion being protrudingly arranged in a circumferential direction of the straight shaft portion, the protruding portion being rotatably accommodated in the receiving cavity, the protruding portion being located between the first cavity wall and the second cavity wall, the protruding portion having a first surface and a second surface, the first surface facing the first cavity wall, the second surface facing the second cavity wall, an area of the first surface being greater than an area of the second surface, the area of the first surface being less than or equal to an area of the first cavity wall;

[0007] a rotor fixedly connected to the straight shaft portion; and

[0008] a stator capable of driving the rotor to rotate, the stator and the rotor having an attractive force therebetween, the attractive force being capable of abutting the first surface against the first cavity wall.

[0009] In one of the embodiments, a distance between the first cavity wall and the second cavity wall is greater than a distance between the first surface and the second surface, so that the second surface and the second cavity wall are spaced apart by a distance when the first surface is abutted against the first cavity wall.

[0010] Furthermore, at least one of the first cavity wall and the first surface is made of ceramic.

[0011] Furthermore, at least one of the second cavity wall and the second surface is made of ceramic.

[0012] In one of the embodiments, the first cavity wall is provided with a first through hole and a first flow guide groove, the first through hole is in communication with the accommodating cavity, the first flow guide groove is in communication with the first through hole and the accommodating cavity, and the straight shaft portion is rotatably arranged in the first through hole.

[0013] In one of the embodiments, the protruding portion further has a side peripheral surface connecting the first surface and the second surface, the accommodating cavity further has a side cavity wall connecting the first cavity wall and the second cavity wall, the side cavity wall and the side peripheral surface have a gap therebetween, and a part of the first flow guide groove is beyond the range of the first surface in the orthogonal projection of the first cavity wall and is in communication with the gap.

[0014] In one of the embodiments, the side peripheral surface comprises a cylindrical surface portion and a conical surface portion arranged around the axis of the straight shaft portion, the cylindrical surface portion is connected with the first surface, and the conical 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 conical surface portion to the axis of the straight shaft portion gradually decreases; the interval between the first cavity wall and the second cavity wall is defined as a first interval, the interval between the first surface and the second surface is defined as a second interval, and the width of the gap between the side cavity wall and the conical surface portion is greater than the difference between the first interval and the second interval.

[0015] In one of the embodiments, the second cavity wall is provided with a second through hole and a second flow guide groove, the second through hole is in communication with the accommodating cavity, the second flow guide groove is in communication with the second through hole and the accommodating cavity, the straight shaft portion is rotatably arranged in the second through hole, and a part of the second flow guide groove is beyond the range of the second surface in the orthogonal projection of the second cavity wall.

[0016] In one of the embodiments, the housing assembly comprises a shaft tube, a first shaft sleeve and a second shaft sleeve which jointly form the accommodating cavity, the first shaft sleeve and the second shaft sleeve are arranged in interval and fixed in 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 rotatably arranged in the first shaft sleeve and the second shaft sleeve.

[0017] In one of the embodiments, the rotor and the stator are arranged in interval along the axis of the straight shaft portion; along the axis of the straight shaft portion, the rotor shaft and the stator are arranged in interval, the stator comprises a magnetic core and a coil wound on the magnetic core, the rotor has magnetism, and the rotor and the magnetic core have an attractive force.

[0018] In one of the embodiments, the rotor comprises a first rotor unit and a second rotor unit, the stator comprises 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 along the axis of the straight shaft portion in sequence, and the first rotor unit is closest to the protruding portion, the first stator unit is capable of generating a rotating magnetic field to drive the first rotor unit to rotate, the second stator unit is capable of generating a rotating magnetic field to drive the second rotor unit to rotate, the straight shaft portion is rotatably arranged in the first stator unit and is spaced from the second stator unit, the first stator unit and the second stator unit each have a magnetic column, and the cross-sectional dimension of the magnetic column of the second stator unit is greater than that of the magnetic column of the first stator unit.

[0019] A blood pump comprising an impeller and any of the above driving devices, the impeller is fixedly connected with the straight shaft portion.

[0020] In one of the embodiments, a sleeve connected with the housing assembly is further included, a liquid outlet is formed on the tube wall of the sleeve, the impeller is rotatably arranged in the sleeve, the impeller is arranged close to the liquid outlet, part of the straight shaft portion is accommodated in the housing assembly and part of the straight shaft portion is accommodated in the sleeve and is fixedly connected with the impeller, the outer peripheral surface of the end of the housing assembly close to the impeller forms a liquid guide surface portion, the liquid guide surface portion is located in the sleeve and corresponds to the position of the liquid outlet, the proximal end of the liquid guide surface portion corresponds to the position of the proximal end hole wall of the liquid outlet, and the distance between the liquid guide surface portion and the axis of the straight shaft portion gradually increases in the direction away from the impeller.

[0021] In one of the embodiments, along the axis of the straight shaft portion, the height of the liquid guide surface portion is 20%-40% of the height of the liquid outlet.

[0022] The present invention has at least the following beneficial effects: Due to the attractive force between the stator and rotor of the aforementioned driving device, this attractive force causes the first surface to abut against the first cavity wall of the accommodating cavity, resulting in the first cavity wall being subjected to pressure from the first surface. By making the area of ​​the first surface greater than the area of ​​the second surface (i.e., increasing the area of ​​the first surface), and making the area of ​​the first surface less than or equal to the area of ​​the first cavity wall, the contact area between the first surface and the first cavity wall when they contact is equal to the area of ​​the first surface. The larger area of ​​the first surface increases the contact area between the first surface and the first cavity wall when they contact, reducing the unit area of ​​the first surface and the first cavity wall. The pressure of the area is reduced, that is, the pressure per unit area is reduced, thereby reducing the wear of the first surface and the first cavity wall; at the same time, since the attraction force will cause the first surface to press against the first cavity wall of the accommodating cavity, the second surface will tend to move away from the second cavity wall, so that the second surface and the second cavity wall do not contact each other, or reduce the friction coefficient when the second surface and the second cavity wall contact each other. During the start-up of the drive device, the frictional resistance between the second cavity wall and the protrusion can be reduced, thereby increasing the start-up speed of the shaft rotation, that is, increasing the sensitivity of the shaft to the drive response. Therefore, the above-mentioned blood pump and drive device can not only reduce the wear of the shaft during use, but also be started up faster. Attached Figure Description

[0023] Figure 1 This is a three-dimensional structural diagram of the blood pump according to the first embodiment;

[0024] Figure 2 for Figure 1 A partial cross-sectional view of the blood pump shown;

[0025] Figure 3 for Figure 1 Another partial cross-sectional view of the blood pump shown;

[0026] Figure 4 for Figure 1 The diagram shows the exploded structure of a blood pump;

[0027] Figure 5 for Figure 2 The diagram shows an exploded view of the blood pump's shaft, first bushing, and second bushing.

[0028] Figure 6 for Figure 2 The diagram shows a three-dimensional structure of the stator in the blood pump.

[0029] Figure 7 for Figure 2 A schematic diagram of the front view of the rotor of the blood pump shown;

[0030] Figure 8 for Figure 7A cross-sectional structure schematic diagram of the rotor shown;

[0031] Figure 9 A cross-sectional structure schematic diagram of the rotor shown; Figure 7 A cross-sectional structure schematic diagram of the rotor shown;

[0032] Figure 10 A cross-sectional structure schematic diagram of the rotor shown; DETAILED DESCRIPTION

[0033] For the purpose of promoting an understanding of the principles of the application, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will, nevertheless, be understood that no limitation of the scope of the application is thereby intended, such alterations and further modifications in the illustrated device being contemplated as falling within the scope of the application. It is to be understood that the application is not limited to the embodiments described above and illustrated in the drawings; rather, the application is capable of numerous rearrangements, modifications and substitutions of parts and elements without departing from the scope of the claims.

[0034] It is also noted that as the elements of the present application, such as a rotor, can be in various orientations and configurations, the application can be implemented in any direction and configuration, unless otherwise specified herein, or unless two or more elements are directly connected, or one follows another, the orientation or configuration of one or those elements is interchangeable with the other elements or other orientation or configuration except where it is inherent that the prior action would necessarily dictate the later actions. Additionally, to facilitate an understanding of the principles of the application, reference is made to the drawings that form a part of this disclosure, and the specification below. It is to be understood that the claims are not limited to the arrangements, systems or methods shown herein, but are to be accorded the full scope consistent with the claims, wherein only the claims set forth the boundaries of the claims' scope.

[0035] In this document, "proximal" refers to the end closer to the operator or physician, and "distal" refers to the end further from the operator or physician.

[0036] Referring to Figure 1 The blood pump 1 of the first embodiment of the present application comprises 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 disposed in the cannula 30. The impeller 40 is connected to the driving device 20. The driving device 20 is capable of driving the impeller 40 to rotate, thereby realizing the blood pumping function of the blood pump 1.

[0037] Specifically, the cannula 30 has an inlet port 31 and an outlet port 32. The outlet port 32 is closer to the driving device 20 than the inlet port 31. That is, the outlet port 32 is located at the proximal end of the cannula 30, and the inlet port 31 is located at the distal end of the cannula 30. The outlet port 32 is located on the wall of the cannula 30. The impeller 40 is disposed close to the outlet port 32. In one embodiment, the cannula 30 extends through a heart valve, such as the aortic valve, and the inlet port 31 is located in the heart, while the outlet port 32 and the driving device 20 are located outside the heart, such as in the aorta. When the impeller 40 rotates, blood flows into the cannula 30 from the inlet port 31, and then flows out of the cannula 30 from the outlet port 32 to enter the aorta or other blood vessels.

[0038] The conduit 50 is connected to the end of the driving device 20 distal to the cannula 30. The conduit 50 is used to accommodate various supply lines, such as a cleaning line for supplying flushing liquid into the driving device 20, a wire for supplying power to the driving device 20, a support member for supporting the conduit 50, etc.

[0039] Please refer to Figures 2-4 The driving device 20 comprises a housing assembly 100, a rotating shaft 200, a stator 300 and a rotor 400. The rotating shaft 200 is rotatably mounted to the housing assembly 100, a portion of the rotating shaft 200 is accommodated in the housing assembly 100 and another portion of the rotating shaft 200 extends into the cannula 30 and is fixedly connected to the impeller 40. The stator 300 and the rotor 400 are both accommodated in the housing assembly 100. The rotor 400 is fixedly connected to the rotating shaft 200. The stator 300 is capable of driving the rotor 400 to rotate. The rotor 400 is capable of driving the rotating shaft 200 to rotate, and the impeller 40 is capable of rotating with the rotating shaft 200 to realize the blood pumping function of the blood pump 1.

[0040] The proximal end and the distal end of the housing assembly 100 are fixedly connected to the conduit 50 and the cannula 30, respectively. The wire in the conduit 50 extends into the housing assembly 100 and is electrically connected to the stator 300 to supply power to the stator 300. Specifically, the housing assembly 100 comprises a first shaft sleeve 110, a second shaft sleeve 120, a shaft tube 130 and a pump shell 140. The first shaft sleeve 110 and the second shaft sleeve 120 are fixedly accommodated in the shaft tube 130. One end of the shaft tube 130 is fixedly connected to the pump shell 140, and the other end of the shaft tube 130 is fixedly connected to the cannula 30. The end of the pump shell 140 distal to the shaft tube 130 is fixedly connected to the conduit 50. The end of the rotating shaft 200 distal to the impeller 40 is accommodated in the pump shell 140. The rotor 400 and the stator 300 are accommodated in the pump shell 140. In one embodiment, the first shaft sleeve 110, the second shaft sleeve 120, the shaft tube 130 and the pump shell 140 are separate before assembly, i.e., the housing assembly 100 is assembled by the separate first shaft sleeve 110, the second shaft sleeve 120, the shaft tube 130 and the pump shell 140. It can be understood that in other embodiments, the first shaft sleeve 110, the second shaft sleeve 120, the shaft tube 130 and the pump shell 140 can also be integrally formed.

[0041] Please refer to Figure 5 In some embodiments, the first shaft sleeve 110 can be fixedly connected to the shaft tube 130 by gluing. In some embodiments, the first shaft sleeve 110 comprises a large disc 111 and a small disc 112. The large disc 111 and the small disc 112 are coaxially arranged. The outer diameter of the large disc 111 is larger than the outer diameter of the small disc 112. The gap between the small disc 112 and the shaft tube 130 can form a glue injection space. After the glue solidifies in the glue injection space, the entire first shaft sleeve 110 will be glued to the shaft tube 130. The second shaft sleeve 120 can also be fixedly connected to the shaft tube 130 by gluing.

[0042] The first shaft sleeve 110 and the second shaft sleeve 120 are arranged along the axial direction of the shaft tube 130, and the first shaft sleeve 110 is arranged farther 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 receiving cavity 150 between the first shaft sleeve 110 and the second shaft sleeve 120.

[0043] The receiving cavity 150 has a first cavity wall 151, a second cavity wall 152, and a side cavity wall 153 connecting the first cavity wall 151 and the second cavity wall 152, so that the first cavity wall 151, the second cavity wall 152, and the side cavity wall 153 jointly define the boundary of the receiving 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 side cavity wall 153 is located on the shaft tube 130. The first cavity wall 151 and the second cavity wall 152 are oppositely and spacedly arranged. The first cavity wall 151 is arranged toward the impeller 40, and the second cavity wall 152 is arranged away from the impeller 40. Specifically, the first cavity wall 151 and the second cavity wall 152 are arranged perpendicular to the axial direction of the shaft tube 130, i.e., 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 toward the impeller 40 forms the first cavity wall 151; at least a portion of the surface of the second shaft sleeve 120 away from the impeller 40 forms the second cavity wall 152. In the illustrated embodiment, the area of the first cavity wall 151 is greater than the area of the second cavity wall 152.

[0044] The first cavity wall 151 is provided with a first through hole 113, which is in communication with the receiving cavity 150. The first through hole 113 extends along the axial direction of the first shaft sleeve 110 and penetrates through 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.

[0045] The first cavity wall 151 is also provided with a first flow guide groove 114, which is in communication with the first through hole 113 and the receiving cavity 150. In the illustrated embodiment, the first flow guide groove 114 extends along the radial direction of the first shaft sleeve 110. The number of the first flow guide grooves 114 is at least three, and the at least three first flow guide grooves 114 are uniformly and spacedly arranged along the circumferential direction of the first through hole 113. In some embodiments, one end of the first flow guide groove 114 extends to the first through hole 113 and is in communication with the first through hole 113, and the other end extends to the edge of the first cavity wall 151; in other embodiments, the end of the first flow guide groove 114 away from the first through hole 113 does not extend to the edge of the first cavity wall 151, and the end of the first flow guide groove 114 away from the first through hole 113 maintains a certain distance from the edge of the first cavity wall 151.

[0046] The second cavity wall 152 is provided with a second through hole 121, which is in communication with the accommodating 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.

[0047] The second cavity wall 152 is further provided with a second flow guide groove 122, which is in communication with the second through hole 121 and the accommodating cavity 150. In the illustrated embodiment, the second flow guide groove 122 extends along the radial direction of the second shaft sleeve 120. The second flow guide groove 122 can be similar to the first flow guide groove 114, and thus will not be described again. In some embodiments, one end of the second flow guide groove 122 extends to the second through hole 121 and is in communication with the second through hole 121, and the other end extends to the edge of the second cavity wall 152. In other embodiments, the end of the second flow guide groove 122 away from the second through hole 121 does not extend to the edge of the second cavity wall 152, and the end of the second flow guide groove 122 away from the second through hole 121 is spaced apart from the edge of the second cavity wall 152.

[0048] The pump shell 140 is substantially cylindrical. The pump shell 140 is in communication with the accommodating cavity 150 through the first through hole 113, and the flushing liquid entering the pump shell 140 can enter the accommodating cavity 150 through the first through hole 113 and flow out of the shell assembly 100 through the second through hole 121.

[0049] Specifically, the rotating shaft 200 is rotatably arranged in the first through hole 113, the second through hole 121, and the accommodating cavity 150. The rotating shaft 200 includes a straight shaft portion 210 and a protruding portion 220 connected to each other.

[0050] Part of the straight shaft portion 210 is accommodated in the shell assembly 100, and part of the straight shaft portion 210 extends into the sleeve 30 and is fixedly connected to the impeller 40. The straight shaft portion 210 is rotatably arranged in the first through hole 113, the second through hole 121, and the accommodating cavity 150. Specifically, the part of the straight shaft portion 210 accommodated in the first through hole 113 and the second through hole 121 has a circular cross section, and the first through hole 113 and the second through hole 121 are substantially circular holes.

[0051] In the illustrated embodiment, the straight shaft portion 210 has a first gap 161 with the hole wall of the first through hole 113, which can be understood as a portion of the first through hole 113 not filled by the straight shaft portion 210. The cleaning in the pump housing 140 can enter the accommodating cavity 150 through the first gap 161. The straight shaft portion 210 has a second gap 162 with the hole wall of the second through hole 121, which can be understood as a portion of the second through hole 121 not filled by the straight shaft portion 210, and the flushing liquid in the accommodating cavity 150 can flow out of the housing assembly 100 through the second gap 162. Specifically, the width of at least part of the second gap 162 is smaller than the width of the first gap 161.

[0052] The end of the hole wall of the first through hole 113 close to the accommodating cavity 150 is provided with a chamfer. If the rotating shaft 200 shakes and contacts the hole wall of the first through hole 113, this design can reduce the contact area between the straight shaft portion 210 and the hole wall of the first through hole 113, thereby reducing the friction of the straight shaft portion 210. The chamfer can also play a role in assembly guidance, reducing interference and assembly resistance of the rotating shaft 200 during assembly, and improving the assembly efficiency of the rotating shaft 200. The end of the hole wall of the second through hole 121 close to the accommodating cavity 150 is provided with a chamfer. If the rotating shaft 200 shakes and contacts the hole wall of the second through hole 121, this design can reduce the contact area between the straight shaft portion 210 and the hole wall of the second through hole 121, thereby reducing the friction of the straight shaft portion 210. The chamfer can also play a role in assembly guidance, reducing interference and assembly resistance of the rotating shaft 200 during assembly, and improving the assembly efficiency of the rotating shaft 200.

[0053] The protruding portion 220 is protrudingly arranged in the circumferential direction of the straight shaft portion 210, and is rotatably accommodated in the accommodating cavity 150. 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 can respectively abut against the protruding portion 220 to limit the maximum amplitude of the axial vibration of the rotating shaft 200. Specifically, the cross-sectional dimension of the protruding portion 220 is greater than the hole diameter of the first through hole 113 and also greater than the hole diameter of the second through hole 121, so that the protruding portion 220 is limited in the accommodating cavity 150 and cannot enter the first through hole 113 and the second through hole 121. In the illustrated embodiment, the protruding portion 220 is annular, and is fixedly sleeved on the straight shaft portion 210. The outer diameter of the protruding portion 220 is greater than the diameter of the straight shaft portion 210, and 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 greater than the hole diameter of the first through hole 113 and also greater than the hole diameter of the second through hole 121.

[0054] The protrusion 220 has a first surface 221 and a second surface 222, which are spaced 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 is capable of abutting against the first surface 221, and the second cavity wall 152 is capable of abutting against the second surface 222, so as to limit the maximum amplitude of the vibration of the rotating shaft 200 in the axial direction. In the illustrated embodiment, the first surface 221 and the second surface 222 are both perpendicular to the axis of the straight shaft portion 210, and the first cavity wall 151 and the second cavity wall 152 are both parallel to the first surface 221 and the second surface 222, respectively. The first surface 221 and the second surface 222 are both circular in outer contour, and are both coaxial with the axis of the straight shaft portion 210, i.e., the axis of the straight shaft portion 210 passes through the center of the circle in which the first surface 221 and the second surface 222 are located.

[0055] The area of the first surface 221 is greater than the area of the second surface 222, and the area of the first surface 221 is less than or equal to the area of the first cavity wall 151. In the illustrated embodiment, the area of the first surface 221 is less than the area of the first cavity wall 151, and the area of the second surface 222 is less than the area of the second cavity wall 152. When the first cavity wall 151 abuts against the first surface 221, the area of the contact surface between the first cavity wall 151 and the first surface 221 is equal to the area of the first surface 221, 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 fixed to the straight shaft portion 410, and the stator 300 and the rotor 400 have an attractive force therebetween, which causes the first surface 221 to abut against the first cavity wall 151. In other words, the attractive force between the stator 300 and the rotor 400 causes the protrusion 220 to have a tendency to abut against the first cavity wall 151, so that the first surface 221 is capable of abutting against the first cavity wall 151. Specifically, the direction of the attractive force acting on the rotor 400 is from the second cavity wall 152 to the first cavity wall 151 along the axis of the straight shaft portion 210, so that the first surface 221 is capable of abutting against the first cavity wall 151.

[0056] Due to the fact that the area of the first surface 221 is greater than the area of the second surface 222, the first surface 221 with a larger area is capable of increasing the contact area between the first surface 221 and the first cavity wall 151, thereby reducing the pressure per unit area of the first surface 221 and the first cavity wall 151, i.e., reducing the pressure intensity per unit area, so as to reduce the wear of the first surface 221 and the protrusion 220.

[0057] The protruding portion 220 also has a side circumferential surface 223 connecting the first surface 221 and the second surface 222. The side circumferential surface 223 is disposed around the axis of the straight shaft portion 210, and the annular structure surrounded by the side circumferential surface 223 is coaxial with the straight shaft portion 210. The side cavity wall 153 is spaced apart from the side circumferential surface 223, so that the third gap 163 is formed between the side cavity wall 153 and the side circumferential surface 223, and the third gap 163 is in communication with the first flow guide groove 114 and the second flow guide groove 122, so that even when the first surface 221 of the protruding portion 220 abuts against the first cavity wall 151 of the accommodating cavity 150, the third gap 163 can still be in communication with the first through hole 113 through the first flow guide groove 114; and when the second surface 222 of the protruding portion 220 abuts against the second cavity wall 152 of the accommodating cavity 150, the third gap 163 can also be in communication with the second through hole 121 through the second flow guide groove 122, so that the flow of the flushing liquid is kept smooth. Specifically, a part of the first flow guide groove 114 beyond the first surface 221 of the protruding portion 220 is within the range of the orthographic projection of the first cavity wall 151, so as to be in communication with the third gap 163. A part of the second flow guide groove 122 beyond the second surface 222 of the protruding portion 220 is within the range of the orthographic projection of the second cavity wall 152, so as to be in communication with the third gap 163.

[0058] Please refer to Figure 2 The flushing liquid sequentially passes through the first gap 161, the third gap 163, and the second gap 162, and flows out of the liquid outlet 32. The flow direction of the flushing liquid is opposite to the flow direction of the blood in the cannula 30, so that the blood in the cannula 30 can be prevented from entering the driving device 20 through the second through hole 121. Figure 2 The flow path of the flushing liquid is indicated by the thin dashed arrow, and the flow path of the blood is indicated by the thick dashed line. The first flow guide groove 114 not only serves to connect the first through hole 113 and the third gap 163, but also enables the flushing liquid to flow better between the first surface 221 and the first cavity wall 151, so as to suspend the protruding portion 220 to a certain extent, reduce the pressing force between the first surface 221 and the first cavity wall 151, and reduce the abrasion of the protruding portion 220. Meanwhile, the flushing liquid flowing between the first surface 221 and the first cavity wall 151 also serves as a lubricant, so as to reduce the friction coefficient between the first surface 221 and the first cavity wall 151, and reduce the abrasion of the protruding portion 220 and the cavity wall of the accommodating cavity 150.

[0059] Specifically, the number of the first flow guide grooves 114 is multiple. In the case of increasing the number of the first flow guide grooves 114, on the one hand, the flushing liquid can fill in the space between the first surface 221 and the first cavity wall 151 in a shorter time, playing a lubricating role on the first surface 221 and the first cavity wall 151, thereby reducing the friction coefficient between the first surface 221 and the protruding part 220 to reduce the abrasion. On the other hand, the flow and flow rate of the flushing liquid flowing through the space between the first surface 221 and the first cavity wall 151 can be reasonably increased, which is beneficial to quickly taking away the heat generated by the friction between the first cavity wall 151 and the protruding part 220, reducing the abrasion caused by the excessively high temperature. On the other hand, the suspension force of the flushing liquid on the protruding part 220 can be increased, thereby reducing the pressing force between the first cavity wall 151 and the protruding part 220 to reduce the abrasion between the first cavity wall 151 and the protruding part 220. Therefore, the abrasion between the first cavity wall 151 and the protruding part 220 can be reduced by reasonably increasing the number of the first flow guide grooves 114. Similarly, the abrasion between the second surface 222 and the protruding part 220 can be reduced by reasonably increasing the number of the second flow guide grooves 122. In the illustrated embodiment, the number of the first flow guide grooves 114 is four, and the included angle between the extension directions of two adjacent first flow guide grooves 114 is 90°. It can be understood that in other embodiments, the number of the first flow guide grooves 114 and the second flow guide grooves 122 can be adjusted as needed.

[0060] Specifically, the side peripheral surface 223 comprises a cylindrical surface portion 2231 and a tapered surface portion 2232, which are arranged along the axis of the straight shaft portion 210, the cylindrical surface portion 2231 is connected with the first surface 221 and is arranged perpendicularly to the first surface 221, one end of the tapered surface portion 2232 is connected with the cylindrical surface portion 2231, and the other end of the tapered surface portion 2232 is connected with the second surface 222, i.e., the tapered surface portion 2232 is connected between the cylindrical surface portion 2231 and the second surface 222. In the direction along the axis of the straight shaft portion 210 and from the first surface 221 to the second surface 222, the distance from the cylindrical surface portion 2231 to the axis of the straight shaft portion 210 remains constant, and the distance from the tapered surface portion 2232 to the axis of the straight shaft portion 210 gradually decreases. The tapered surface portion 2232 arranged on the side peripheral surface 223 of the protruding portion 220 can achieve a better flow guiding effect on the flushing liquid; at the same time, since the area of the second surface 222 is smaller than the area of the second cavity wall 152, the flushing liquid flows through the third gap 163 and flows in the direction of the second perforation 121 by inertia, thereby improving the flushing effect of the flushing liquid. The cylindrical surface portion 2231 has a certain length in the direction along the axis of the straight shaft portion 210, which avoids that the end of the protruding portion 220 close to the first surface 221 is an acute angle when the entire side peripheral surface 223 is tapered, in other words, avoids that the side peripheral surface 223 forms a sharp edge with the first surface 221, in the case of radial shaking of the protruding portion 220, if the edge contacts the side cavity wall 153 to form a line-surface contact, it will cause a greater risk of scratching and damage to the side cavity wall 153, and there is also not a wide enough area for the flushing liquid to form a lubricating film layer between the protruding portion 220 and the side cavity wall 153, and the above-mentioned cylindrical surface portion 2231 can play a transitional role to ensure that the side peripheral surface 223 and the side cavity wall 153 of the accommodating cavity 150 form a surface-to-surface contact mode, thereby reducing the risk of friction damage.

[0061] The shape of the side cavity wall 153 of the accommodating cavity 150 is adapted to the shape of the side peripheral surface 223, and has a structure similar to the straight surface portion and the inclined surface portion of the cylindrical surface portion 2231 and the tapered surface portion 2232 of the side peripheral surface 223.

[0062] Specifically, along the axial direction of the straight shaft portion 210, the distance between the first cavity wall 151 and the second cavity wall 152 is denoted as a first distance H, and the distance between the first surface 221 and the second surface 222 is denoted as a second distance h. The first distance H is greater than the second distance h. In some embodiments, the first distance H is slightly greater than the second distance h, such that the first cavity wall 151 and the first surface 221 are always in contact, and the second cavity wall 152 and the second surface 222 are always in contact, thereby avoiding movement of the rotating shaft 200 in the axial direction of the straight shaft portion 210. In some embodiments, the first distance H is greater than the second distance h, such that when the first surface 221 abuts against the first cavity wall 151, the second surface 222 is spaced apart from the second cavity wall 152 by a distance, so that the second surface 222 and the second cavity wall 152 have a gap, and the protruding portion 220 has a floating space between the first cavity wall 151 and the second cavity wall 152, so as to facilitate the flushing liquid to enter between the first surface 221 and the first cavity wall 151 and between the second surface 222 and the second cavity wall 152, thereby achieving the effects of lubrication and suspension of the protruding portion 220, and avoiding dry friction between the protruding portion 220 and the cavity wall of the accommodating cavity 150. Of course, the difference between the first distance H and the second distance h should not be too large, so as to avoid excessive vibration amplitude of the rotating shaft 200 in the axial direction.

[0063] Specifically, the width of the gap between the side cavity wall 153 and the tapered surface portion 2232 of the side peripheral surface 223 is greater than the difference between the first distance H and the second distance h, i.e., 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 distance H and the second distance h. Thus, in the case where the protruding portion 220 shakes in the radial and / or axial direction, the contact probability between the side cavity wall 153 and the side peripheral surface 223 of the protruding portion 220 can be reduced, and the friction between the protruding portion 220 and the cavity wall of the accommodating cavity 150 can be reduced.

[0064] In some embodiments, at least one of the first cavity wall 151 and the first surface 221 is made of ceramic; and at least one of the second cavity wall 152 and the second surface 222 is made of ceramic. Ceramic has high machining precision, high biocompatibility, high mechanical strength, good wear resistance, and good corrosion resistance. In addition, ceramic can have a smaller roughness, which can 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 first shaft sleeve 110 and the second shaft sleeve 120 are made of ceramic, and the protruding portion 220 is made of ceramic, i.e., the first cavity wall 151, the first surface 221, the second cavity wall 152, and the second surface 222 are all made of ceramic.

[0065] In some embodiments, the outer circumferential surface of the shell assembly 100 at the end close to the impeller 40 forms a liquid guiding surface 160, which is located in the sleeve 30 and corresponds to the position of the liquid outlet 32, and the proximal end of the liquid guiding surface 160 corresponds to the position of the proximal hole wall of the liquid outlet 32; in the direction away from the impeller 40, the distance between the liquid guiding surface 160 and the axis of the straight shaft portion 210 gradually increases. Specifically, the liquid guiding surface 160 is located at the end of the shaft tube 130 away from the pump shell 140. The design of the liquid guiding surface 160 is conducive to the guiding of the liquid in the sleeve 30. In addition, generally, the impeller 40 and the driving device 20 are rigid parts of the blood pump 1, and the shorter the axial length of the rigid parts, the more conducive to the delivery of the blood pump 1 in the human body. The provision of the liquid guiding surface 160 on the shell assembly 100 of the driving device 20 can shorten the axial length of the impeller 40 while ensuring the hydraulic performance at the liquid outlet 32. At the same time, since the liquid guiding surface 160 is provided in the sleeve 30 as part of the shell assembly 100 of the driving device 20, the overall length of the impeller 40 and the driving device 20 (i.e., the rigid parts of the blood pump 1) can be reduced, and the delivery of the blood pump 1 can be more convenient.

[0066] Specifically, the liquid guiding surface 160 is generally arc-shaped. Along the axis of the straight shaft portion 210, the height L1 of the liquid guiding surface 160 is 20%-40% of the height L2 of the liquid outlet 32. This height design can shorten the total length of the impeller 40 and the driving device 20 while enabling the blood pump 1 to have better hydraulic performance.

[0067] Referring to Figure 2 and Figure 6 , the stator 300 is fixedly accommodated in the pump shell 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 shell 140. The number of the magnetic cores 310 is plural, and the plural magnetic cores 310 are arranged along a circumference at intervals. The extension direction of each magnetic core 310 is consistent with the extension direction of the straight shaft portion 210, i.e., the central axis of the magnetic core 310 is parallel to the axis of the straight shaft portion 210. One end of each magnetic core 310 is fixedly connected to the back plate 320. The number of the coils 330 is equal to the number of the magnetic cores 310, and they form a one-to-one correspondence relationship. The coil 330 is wound around the magnetic core 310, so that one coil 330 is wound around each magnetic core 310.

[0068] In some embodiments, the magnetic core 310 comprises magnetic columns 311 and a head (i.e. pole shoe) arranged at one end of the magnetic columns 311, the head has a cross-sectional dimension larger than that of the magnetic columns 311, and the extension direction of the magnetic columns 311 is consistent with the extension direction of the straight shaft portion 210. The back plate 320 is engaged with the end of the magnetic columns 311 away from the head. In the extension direction of the magnetic columns 311, the magnetic columns 311 are substantially columnar bodies of uniform size, i.e. the cross-sectional dimension of the magnetic columns 311 remains constant, in plain terms, the magnetic columns 311 are of uniform thickness. The coil 330 is wound around the magnetic columns 311 of the magnetic core 310. In the illustrated embodiment, the magnetic core 310 only comprises the magnetic columns 311, i.e. the magnetic core 310 does not have a head (i.e. pole shoe) of larger width, and thus the magnetic columns 311 of the stator 300 are the magnetic core 310. At this time, the entire magnetic core 310 can be magnetically coupled with the rotor 400, compared with the magnetic core 310 having a pole shoe, the magnetic core 310 having only the magnetic columns 311 can reduce magnetic loss on the one hand, increase the magnetic coupling density between the magnetic core 310 and the rotor 400, and increase the torque of the stator 300 on the rotor 400 under the same current. On the other hand, the magnetic core 310 without the head can greatly reduce the problem of power reduction of the driving device 20 caused by local magnetic short circuit due to contact between adjacent magnetic cores 310.

[0069] It can be understood that the magnetic core 310 is not limited to the above two ways, in some embodiments, part of the magnetic columns 311 are provided with a head, and the other part of the magnetic columns 311 are not provided with a head.

[0070] In some embodiments, the cross-sectional shape of the magnetic columns 311 is substantially triangular prism, and one edge of each magnetic column 311 faces the axis of the straight shaft portion 210. In some embodiments, the edges of the magnetic columns 311 are rounded, i.e. the edges of the magnetic columns 311 are relatively smooth and blunt rounded edges, so as to eliminate sharp edges on the magnetic columns 311, which not only facilitates the subsequent winding of the coil 330, but also helps to protect the insulation material coated on the coil 330. In other embodiments, the cross-sectional shape of the magnetic columns 311 can also be fan-shaped, circular, trapezoidal, fan ring-shaped, etc.

[0071] The back plate 320 is substantially in a flat plate structure. The back plate 320 is made of the same material as the magnetic core 310, for example, soft magnetic material such as cobalt steel. With the rotor 400 driven by the stator 300 as a reference, the back plate 320 is fixed at the end of the magnetic column 311 away from the rotor 400, and the back plate 320 can play a role in closing the magnetic circuit of the stator 300, so as to promote and increase the generation of magnetic flux of the stator 300, and improve the coupling ability between the stator 300 and the rotor 400. In other words, the stator 300 is provided with the back plate 320, which can promote and increase the generation of magnetic flux of the stator 300, and improve the coupling ability between the stator 300 and the rotor 400. Since the back plate 320 can increase the magnetic flux, the back plate 320 is also beneficial to reduce the overall diameter of the driving device 20. It can be understood that the back plate 320 can also be omitted in some embodiments.

[0072] The rotor 400 is arranged along the axis of the straight shaft portion 210. Along the axis of the straight shaft portion 210, the rotor 400 is located between the protruding portion 220 and the stator 300. The first cavity wall 151 of the accommodating cavity 150 is located between the rotor 400 and the first surface 221 of the protruding portion 220.

[0073] Please refer to Figure 7 , Figure 8 and Figure 9 , the rotor 400 has magnetism, and the stator 300 can generate a rotating magnetic field to drive the rotor 400 to rotate. The rotor 400 has an attractive force with the magnetic core 310. Specifically, the rotor 400 includes a magnet 410 fixed 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 the attractive force is from the second surface 222 to the first surface 221 along the axis of the rotating shaft 200, so that the first surface 221 can abut in the direction of the first cavity wall 151.

[0074] The magnet 410 is a ring-shaped Halbach array magnet. Specifically, the magnet 410 includes a plurality of magnetic units 411 magnetized along the axis of the magnet 410, for example, the number of magnetic units 411 is four, six, eight or ten, etc., each magnetic unit 411 is in the shape of a fan ring, and the plurality of magnetic units 411 are arranged around the straight shaft portion 210 for one turn to form a ring structure of the magnet 410.

[0075] The rotor 400 further includes a flywheel 420, and the flywheel 420 is directly fixed to the straight shaft portion 210, and the magnet 410 is fixed to the flywheel 420. By arranging the flywheel 420, the connection strength between the magnet 410 and the straight shaft portion 210 can be enhanced; in addition, the shaking of the rotating shaft 200 during rotation can be reduced, so that the entire rotating shaft 200 is more stable during rotation.

[0076] The flywheel 420 comprises an inner tube 421, a disc-shaped part 422 and an outer ring wall 423. The inner tube 421 and the outer ring wall 423 are both in the shape of a circular tube, and the disc-shaped part 422 is in the shape of a circular disc. The inner tube 421 and the outer ring wall 423 are fixedly connected with the disc-shaped part 422. The outer ring wall 423 is arranged around the disc-shaped part 422, and the inner tube 421 and the outer ring wall 423 are coaxially arranged. The straight shaft part 210 is arranged in the inner tube 421 and fixedly connected with the inner tube 421. The installation cavities 424 are formed between the inner tube 421 and the outer ring wall 423, and the installation cavities 424 are all annular cavities. The magnets 410 are respectively arranged in the installation cavities 424. The installation cavities 424 are in a shape suitable for the magnets 410, so as to facilitate the installation and positioning of the magnets 410. In this way, the flywheel 420 can limit the magnets 410, which not only facilitates the installation of the magnets 410, but also makes the combination of the magnets 410 and the flywheel 420 more stable.

[0077] It should be noted that the flywheel 420 is not limited to the above structure. In some embodiments, the flywheel 420 does not have the outer ring wall 423. In some embodiments, the flywheel 420 does not have the outer ring wall 423 and the inner tube 421, and in this case, the straight shaft part 210 is fixedly arranged in the center of the disc-shaped part 422. Compared with the flywheel 420 having only the disc-shaped part 422, the arrangement of the inner tube 421 can make the flywheel 420 more stably connected with the straight shaft part 210.

[0078] In order to facilitate the installation of the magnets 410 and improve the installation accuracy of the magnets 410, the flywheel 420 further comprises an identification part 4211 for determining the installation positions of the magnets 410. The identification part 4211 can be in the form of a groove, a scale or an identification mark. When the magnets 410 are installed, as long as the positions of one of the magnets 410 are identified by the identification part 4211, the installation positions of the remaining magnets 410 can be determined, so as to facilitate the installation of the magnets 410. Specifically, the identification part 4211 is arranged on at least one of the inner tube 421, the disc-shaped part 422 and the outer ring wall 423, for example, the identification part 4211 is arranged on the end face of the inner tube 421.

[0079] In the illustrated embodiment, the rotating shaft 200 is spaced apart from the stator 300 along the axis of the straight shaft portion 210, that is, the straight shaft portion 210 is not arranged to pass through the stator 300, so that the rotating shaft 200 is located outside the stator 300. Due to the increase in the cross-sectional area of the magnetic column 311, the larger the cross-sectional area of the magnetic column 311, the greater the magnetic flux generated, the greater the torque of the stator 300 on the rotor 400, and the smaller the required current, which is conducive to reducing power consumption and reducing heat generation. Since the rotating shaft 200 is not arranged to pass through the stator 300, the installation space of the magnetic column 311 can be avoided, which is conducive to increasing the cross-sectional size of the magnetic column 311 of the stator 300 to increase the driving torque of the stator 300 on the rotor 400 while keeping the outer diameter of the housing assembly 100 unchanged. In the case of the same required torque, this method can reduce the current supply to the stator 300, thereby reducing power consumption and reducing the heat generation of the driving device 20, thereby avoiding the accumulation of heat in the blood pump 10 during operation to cause the temperature to be too high to cause discomfort or even harm to the human body.

[0080] The above-mentioned driving device 20 and blood pump 1 have at least the following advantages:

[0081] (1) Since the stator 300 and the rotor 400 of the above-mentioned driving device 20 have an attractive force, the first surface 221 is pressed against the first cavity wall 151 of the accommodating cavity 150, so that the first cavity wall 151 is pressed by the first surface 221. By increasing the area of the first surface 221, that is, increasing the area of the first surface 221, the area of the first surface 221 is less than or equal to the area of the first cavity wall 151, so that when the first surface 221 contacts the first cavity wall 151, the contact area of 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 larger 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, thereby reducing the pressure per unit area of the first surface 221 and the first cavity wall 151, that is, reducing the pressure per unit area, thereby reducing the wear of the first surface 221 and the first cavity wall 151. At the same time, due to the attractive force, the first surface 221 is pressed against the first cavity wall 151, so that the second surface 222 has a tendency to move away from the second cavity wall 152, so that the second surface 222 and the second cavity wall 152 are not in contact, or the friction coefficient between the second surface 222 and the second cavity wall 152 is reduced. During the start-up of the driving device 20, the frictional resistance of the second cavity wall 152 to the protruding portion 220 can be reduced, thereby improving the start-up speed of the rotating shaft 200, that is, improving the sensitivity of the rotating shaft 200 to the driving response. Therefore, the above-mentioned blood pump 1 and driving device 20 not only can reduce the wear degree of the rotating shaft 200 during use, but also can be started faster.

[0082] (2) By setting the first flow guide groove 122 on the first surface 221, the flushing liquid can quickly flow into the space between the first surface 221 and the first cavity wall 151, so as to play a lubricating role between the first surface 221 and the first cavity wall 151, and reduce the friction coefficient between the first surface 221 and the first cavity wall 151, so as to reduce the wear of the convex part 220 and the cavity wall of the accommodating cavity 150; further, the part of the first flow guide groove 114 is located outside the range of the orthographic projection of the first surface 221 of the convex part 220 on the first cavity wall 151, so that even when the first surface 221 of the convex part 220 abuts against the first cavity wall 151 of the accommodating cavity 150, the accommodating cavity 150 can still communicate with the first perforation 113 through the first flow guide groove 114, so as to ensure the smooth flow of the flushing liquid.

[0083] (3) The part of the housing assembly 100 is arranged in the sleeve 30, and the arc-shaped liquid guide surface 160 is arranged on the outer peripheral surface of the part of the housing assembly 100 located in the sleeve 30, which is beneficial to reducing the overall length of the impeller 40 and the driving device 20 (i.e. the rigid part of the blood pump 1) while ensuring the hydraulic performance of the blood pump 1, so as to facilitate the transportation of the blood pump 1.

[0084] (4) By arranging the rotating shaft 200 and the stator 300 at intervals, it is beneficial to increase the driving torque of the stator 300 on the rotor 400 by increasing the cross-sectional area of the magnetic column 311 while keeping the outer diameters of the housing assembly 100 and the stator 300 unchanged, and in the case of the same required torque, this way can reduce the current supply to the stator 300, thereby reducing the power consumption, and also reducing the heat generation of the driving device 20, avoiding the blood pump 10 from causing discomfort or even harm to the human body due to excessive temperature caused by heat accumulation during operation.

[0085] Referring to Figure 10 , the blood pump 2 of the second embodiment is substantially the same as the blood pump 1 of the first embodiment in structure, and the difference lies in that in the present embodiment, the rotor 400' has two rotor units, and the stator 300' has two stator units, which are respectively referred to as the first stator unit 301 and the second stator unit 302, and the two rotor units are respectively referred to as the first rotor unit 401 and the second rotor unit 402.

[0086] The first rotor unit 401, the first stator unit 301, the second rotor unit 402 and the second stator unit 302 are arranged along the axis of the straight shaft portion 210' in sequence, and the first rotor unit 401 is arranged closest to the protruding portion 220'. The first rotor unit 401 and the second rotor unit 402 are fixedly connected to the straight shaft portion 200' of the rotating shaft 200'. The first stator unit 301 has an attractive force with the first rotor unit 401, and the second stator unit 302 has an attractive force with the second rotor unit 402. The attractive force of the first rotor unit 401 to the first stator unit 301 is denoted as the first attractive force, and the attractive force of the second rotor unit 402 to 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 the first attractive force and the second attractive force act on the rotating shaft 200' through the first rotor unit 401 and the second rotor unit 402 respectively, so that the first surface 221' of the protruding portion 220' can be abutted in the direction of the first cavity wall 151' under the action of the resultant force of the first attractive force and the second attractive force.

[0087] The straight shaft portion 210' of the rotating shaft 200' is rotatably arranged in the first stator unit 301 and spaced from the second stator unit 301. That is, the straight shaft portion 210' is not arranged in the second stator unit 302, so that the straight shaft portion 210' is located outside the second stator unit 302, and then the rotating shaft 200' is spaced from the second stator unit 302 along the axial direction of the straight shaft portion 210'. The first stator unit 301 and the second stator unit 302 each have a magnetic column 311', and the cross-sectional size of the magnetic column 311' of the second stator unit 302 is greater than the cross-sectional size of the magnetic column 311' of the first stator unit 301. Since the rotating shaft 200' is not arranged in the second stator unit 302, that is, the rotating shaft 200' is located outside the second stator unit 302, the installation space of the magnetic column 311' in the second stator unit 302 can be avoided, and the cross-sectional size of the magnetic column 311' of the second stator unit 302 can be increased without increasing the outer diameter of the pump shell 140' and the second stator unit 302. At this time, although the outer diameters of the first stator unit 301 and the second stator unit 302 are the same, the cross-sectional size of the magnetic column 311' of the second stator unit 302 is greater than the cross-sectional size of the magnetic column 311' of the first stator unit 301. In this way, the driving torque of the second stator unit 302 to the second rotor unit 402 can be increased, and under the condition of the same required torque, the current supply to the second stator unit 302 can be reasonably reduced, thereby reducing the power consumption and the heat generation of the driving device, and avoiding the temperature of the blood pump being too high due to heat accumulation during operation, which causes discomfort or even harm to the human body.

[0088] In the present embodiment, the structure of the first rotor unit 401 and the second rotor unit 402 can be similar to that of the rotor 400 of the blood pump 1 of the first embodiment; the structure of the first stator unit 301 and the second stator unit 302 can be similar to that of the stator 300 of the blood pump 1, which will not be described here again. Among them, 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.

[0089] The structure of the blood pump 2 of the second embodiment is similar to that of the blood pump 1 of the first embodiment, therefore, the blood pump 2 of the second embodiment also has the advantages of the blood pump 1 of the first embodiment.

[0090] It can be understood 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 needed, and the positional relationship between the rotor unit and the stator unit can also be adjusted.

[0091] The technical features of the above-described embodiments can be combined arbitrarily, for the sake of brevity, not all possible combinations of the technical features in the above-described embodiments are described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0092] The above-described embodiments only express several embodiments of the present application, the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the protection scope of the present application patent should be subject to the appended claims.

Claims

1. A driving device for driving an impeller to rotate, characterized in that, The driving device includes: The housing assembly has a receiving cavity, which has a first cavity wall and a second cavity wall that are opposite to and spaced apart. A first perforation is formed on the first cavity wall, which communicates with the receiving cavity, allowing flushing fluid to enter the receiving cavity through the first perforation. A rotating shaft for connection with the impeller includes a straight shaft portion and a protrusion portion. The straight shaft portion is rotatably inserted through the first through hole. The protrusion portion protrudes circumferentially from the straight shaft portion and is rotatably received in the receiving cavity. The protrusion portion is located between the first cavity wall and the second cavity wall. The protrusion portion has a first surface and a second surface. The first surface faces the first cavity wall, and the second surface faces the second cavity wall. The area of ​​the first surface is greater than the area of ​​the second surface, and the area of ​​the first surface is less than or equal to the area of ​​the first cavity wall. The rotor is fixedly connected to the straight shaft portion; and The stator is capable of driving the rotor to rotate. There is an attractive force between the stator and the rotor. The direction of the attractive force is along the axis of the straight shaft from the second cavity wall to the first cavity wall. The attractive force can cause the first surface to abut against the first cavity wall.

2. The driving device according to claim 1, characterized in that, The distance between the first cavity wall and the second cavity wall is greater than the distance between the first surface and the second surface, so that when the first surface abuts against the first cavity wall, there is a distance between the second surface and the second cavity wall. And / or, at least one of the first cavity wall and the first surface is made of ceramic; And / or, at least one of the second cavity wall and the second surface is made of ceramic.

3. The driving device according to claim 1, characterized in that, A first guide groove is provided on the first cavity wall, and the first guide groove is connected to the first perforation and the accommodating cavity.

4. The driving device according to claim 3, characterized in that, The protrusion also has a side peripheral surface connecting the first surface and the second surface, and the accommodating cavity also has a side cavity wall connecting the first cavity wall and the second cavity wall. There is a gap between the side cavity wall and the side peripheral surface. A portion of the first guide groove extends beyond the range of the orthographic projection of the first surface onto the first cavity wall and communicates with the gap.

5. The driving device according to claim 4, characterized in that, The side peripheral surface includes a cylindrical surface and a conical surface arranged around the axis of the straight shaft portion. The cylindrical surface is connected to the first surface, and the conical surface is connected between the cylindrical surface and the second surface. From the first surface to the second surface, the distance from the conical surface to the axis of the straight shaft portion gradually decreases. The distance between the first cavity wall and the second cavity wall is defined as a first distance, and the distance between the first surface and the second surface is defined as a second distance. The width of the gap between the side cavity wall and the conical surface is greater than the difference between the first distance and the second distance.

6. The driving device according to claim 1, characterized in that, The second cavity wall is provided with a second through hole and a second guide groove. The second through hole is connected to the accommodating cavity, and the second guide groove is connected to both the second through hole and the accommodating cavity. The straight shaft portion is rotatably inserted through the second through hole, and a portion of the second guide groove extends beyond the range of the orthographic projection of the second surface onto the second cavity wall.

7. The driving device according to claim 1, characterized in that, The housing assembly includes a shaft tube, a first bushing, and a second bushing that together form the accommodating cavity. The first bushing and the second bushing are spaced apart and fixed inside the shaft tube. The first cavity wall is located in the first bushing, and the second cavity wall is located in the second bushing. The straight shaft portion is rotatably inserted through the first bushing and the second bushing.

8. The driving device according to claim 1, characterized in that, The rotor and the stator are spaced apart along the axis of the straight shaft portion; along the axis of the straight shaft portion, the rotating shaft and the stator are spaced apart, the stator includes a magnetic core and a coil wound on the magnetic core, the rotor is magnetic, and there is an attractive force between the rotor and the magnetic core.

9. The driving device according to claim 1, characterized in that, The rotor includes a first rotor unit and a second rotor unit, and the stator includes a first stator unit and a second stator unit. The first rotor unit, the first stator unit, the second rotor unit, and the second stator unit are arranged sequentially along the axis of the straight shaft portion, and the first rotor unit is closest to the protrusion. The first stator unit can generate a rotating magnetic field that drives the first rotor unit to rotate, and the second stator unit can generate a rotating magnetic field that drives the second rotor unit to rotate. The straight shaft portion is rotatably disposed through the first stator unit and spaced apart from the second stator unit. Both the first stator unit and the second stator unit have magnetic columns, and the cross-sectional dimension of the magnetic column of the second stator unit is larger than the cross-sectional dimension of the magnetic column of the first stator unit.

10. A blood pump, characterized in that, It includes an impeller and a drive device according to any one of claims 1 to 9, wherein the impeller is fixedly connected to the straight shaft portion.

11. The blood pump according to claim 10, characterized in that, It also includes a sleeve connected to the housing assembly, the sleeve having a liquid outlet on its wall, the impeller being rotatably disposed within the sleeve, the impeller being positioned near the liquid outlet, a portion of the straight shaft portion being housed within the housing assembly, and a portion being housed within the sleeve and fixedly connected to the impeller, the outer peripheral surface of the housing assembly near the impeller forming a liquid guiding surface, the liquid guiding surface being located within the sleeve and corresponding to the position of the liquid outlet, the proximal end of the liquid guiding surface corresponding to the position of the proximal end hole wall of the liquid outlet; the distance from the liquid guiding surface to the axis of the straight shaft portion gradually increases in the direction away from the impeller.

12. The blood pump according to claim 11, characterized in that, Along the axis of the straight shaft portion, the height of the liquid guiding surface is 20%-40% of the height of the liquid outlet.

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