Drive unit and blood pump

Abstract

A blood pump (1) and a drive device (20) are disclosed. The drive device (20) includes a housing assembly (100) and a rotating shaft (200). The housing assembly (100) is provided with a mounting hole (131). The rotating shaft (200) includes a first shaft segment (210). An arc-shaped convex surface (211) is provided in the circumferential direction of the first shaft segment (210). At least a part of the arc-shaped convex surface (211) is located in the mounting hole (131). The inflection point of the arc-shaped convex surface (211) faces the hole wall of the mounting hole (131). At the inflection point, the gap between the arc-shaped convex surface (211) and the hole wall of the mounting hole (131) is the smallest. When the first shaft segment (210) contacts the hole wall of the mounting hole (131), the inflection point contacts the hole wall of the mounting hole (131).

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to a Chinese patent application bearing application number 202210650440.6, filed with the State Intellectual Property Office of the People's Republic of China on June 10, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present application relates to the technical field of medical devices, and in particular to drives and blood pumps. [Background technology]

[0003] An intravascular blood pump is a blood pumping device that can enter a patient's heart through the patient's blood vessels and is placed within the opening of a heart valve so that blood flows through the blood pump and into the arterial vessels. The blood pump includes a drive unit and an impeller, and the impeller is fixed to a rotating shaft of the drive unit, which drives and rotates the impeller. However, in conventional drive units, the rotating shaft usually has significant wear. Summary of the Invention [Problem to be solved by the invention]

[0004] Based on this, the present application provides a drive device and a blood pump that can reduce wear on the rotating shaft. [Means for solving the problem]

[0005] An embodiment of the first aspect of the present application provides a drive device for driving an impeller to rotate, the drive device comprising: a housing assembly having mounting holes; a rotating shaft configured to be fixedly connected to the impeller and including a first shaft segment rotatably passing through the mounting hole, wherein the first shaft segment has an arc-shaped convex surface provided circumferentially thereof, at least a portion of the arc-shaped convex surface being located in the mounting hole, an inflection point of the arc-shaped convex surface facing a hole wall of the mounting hole, a gap between the arc-shaped convex surface and the hole wall of the mounting hole being smallest at the inflection point of the arc-shaped convex surface, and when the first shaft segment contacts the hole wall of the mounting hole, the inflection point of the arc-shaped convex surface contacts the hole wall of the mounting hole.

[0006] An embodiment of a second aspect of the present application provides a blood pump including an impeller and a drive device, the drive device comprising: a housing assembly having mounting holes; a rotating shaft configured to be fixedly connected to the impeller and including a first shaft segment rotatably passing through the mounting hole, wherein the first shaft segment has an arcuate convex surface formed in a circumferential direction thereof, at least a portion of the arcuate convex surface being located in the mounting hole, an inflection point of the arcuate convex surface facing a hole wall of the mounting hole, a gap between the arcuate convex surface and the hole wall of the mounting hole being smallest at the inflection point of the arcuate convex surface, and when the first shaft segment contacts the hole wall of the mounting hole, the inflection point of the arcuate convex surface contacts the hole wall of the mounting hole, The impeller is fixedly connected to the first shaft segment and is rotatable with the rotary shaft.

[0007] The details of one or more embodiments of the invention are set forth in the drawings and description which follow. Other features, objects, and advantages of the invention will become apparent from the description, drawings, and claims. [Brief explanation of the drawings]

[0008] In order to more clearly explain the technical solutions in the embodiments of the present application, the drawings necessary for describing the embodiments or prior art will be briefly introduced below. It is obvious that 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 any creative efforts.

[0009] [Figure 1] 1 is a perspective view of a blood pump according to a first embodiment. [Figure 2] 2 is an exploded view of the blood pump shown in FIG. 1, with a portion of the cannula assembly omitted. [Figure 3] 2 is a cross-sectional view of the blood pump shown in FIG. 1 with a portion of the cannula assembly omitted. [Figure 4] FIG. 2 is a structural schematic diagram of a first shaft sleeve of the blood pump shown in FIG. [Figure 5] FIG. 2 is a structural schematic diagram of a second shaft sleeve of the blood pump shown in FIG. [Figure 6] 2 is a cross-sectional view of the blood pump shown in FIG. 1 after the first shaft sleeve and the second shaft sleeve are assembled. FIG. [Figure 7] FIG. 2 is a structural schematic diagram of the shaft tube of the blood pump shown in FIG. [Figure 8] 2 is a cross-sectional view of the blood pump shown in FIG. 1 after the first shaft sleeve, the second shaft sleeve, and the rotating shaft are assembled. [Figure 9] FIG. 9 is a schematic diagram of a partial structure of part A in FIG. 8. [Figure 10] FIG. 2 is a structural schematic diagram of the rotor of the blood pump shown in FIG. [Figure 11] FIG. 11 is a cross-sectional view of the rotor shown in FIG. [Figure 12] FIG. 11 is an exploded view of the rotor shown in FIG. [Figure 13] FIG. 10 is a partial cross-sectional view of a blood pump drive device according to a second embodiment. [Figure 14] FIG. 10 is a partial schematic view of a blood pump drive device according to a third embodiment. [Figure 15] FIG. 10 is a partial schematic view of a blood pump drive device according to a fourth embodiment. [Figure 16] FIG. 10 is a partial schematic view of a blood pump drive device according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] In order to more clearly understand the objectives, technical solutions and advantages of the present application, the present application will be described in more detail below with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are only for the purpose of interpreting the present application, and are not intended to limit the present application.

[0011] It should be noted that when an element is referred to as being "fixed" or "mounted" 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] Additionally, the terms "first" and "second" are merely descriptive and should not be understood to denote or imply relative importance or the number of technical features shown. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "plurality" means two or more unless otherwise specified.

[0013] Hereinafter, the technical solution of the present application will be described with reference to specific drawings and examples.

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

[0015] As shown in Figures 1 and 2, the blood pump 1 according to the first embodiment of the present invention includes a drive unit 20, a cannula assembly 30, an impeller 41, and a catheter 42, wherein the cannula assembly 30 is connected to the distal end of the drive unit 20, the catheter 42 is connected to the proximal end of the drive unit 20, and the impeller 41 is rotatably disposed within the cannula assembly 30, which is connected to the drive unit 20, and the drive unit 20 can drive and rotate the impeller 41 to realize the blood pumping function of the blood pump 1.

[0016] Specifically, cannula assembly 30 has an inlet 301 and an outlet 302. Outlet 302 is closer to driver 20 than inlet 301. That is, outlet 302 is located at a proximal end of cannula assembly 30, and inlet 301 is located at a distal end of cannula assembly 30. In one embodiment, cannula assembly 30 penetrates a heart valve, e.g., the aortic valve, with inlet 301 located within the heart and outlet 302 and driver 20 located outside the heart within a blood vessel, such as the aorta. As impeller 41 rotates, blood flows into cannula assembly 30 through inlet 301 and then exits cannula assembly 30 through outlet 302 into a blood vessel, such as the aorta.

[0017] In some embodiments, the cannula assembly 30 includes an insertion tube 31 and an exit tube 32, both of which are fixedly connected, and the exit tube 32 is connected between the insertion tube 31 and the driver 20, i.e., the distal end of the exit tube 32 is connected to the proximal end of the insertion tube 31, and the proximal end of the exit tube 32 is connected to the driver 20. An inlet 301 is formed in the insertion tube 31, and an outlet 302 is formed in the outlet tube 32. An impeller 41 is housed in the outlet tube 32, and the position of the impeller 41 generally corresponds to the position of the outlet 302.

[0018] The catheter 42 is fitted to one end of the drive unit 20 remote from the cannula assembly 30. The catheter 42 houses various supply lines, which may be, for example, an irrigation line for introducing an irrigation solution into the drive unit 20, for example, a conductor for supplying power to the drive unit 20, or a support member for supporting the catheter 42.

[0019] 3 , in some embodiments, the drive unit 20 includes a housing assembly 100, a rotating shaft 200, a stator 330, and a rotor 340. The housing assembly 100 has a mounting hole 131, the rotating shaft 200 is rotatably disposed through the mounting hole 131, the impeller 41 is fixedly connected to the rotating shaft 200, the stator 330 and the rotor 340 are both housed in the housing assembly 100, the rotor 340 is fixedly connected to the rotating shaft 200, the stator 330 can drive the rotor 340 to rotate, the rotor 340 can drive the rotating shaft 200 to rotate, and the impeller 41 can rotate together with the rotating shaft 200 to realize the blood pumping function of the blood pump 1. The conductors of the catheter 42 extend within the housing assembly 100 and are electrically connected to the stator 330 to supply power to the stator 330.

[0020] In the illustrated embodiment, the housing assembly 100 includes a pump housing 110, a shaft tube 120, a first shaft sleeve 130, and a second shaft sleeve 140. The pump housing 110, the shaft tube 120, the first shaft sleeve 130, and the second shaft sleeve 140 are separate pieces before being assembled, i.e., the housing assembly 100 is assembled from the separate pump housing 110, the shaft tube 120, the first shaft sleeve 130, and the second shaft sleeve 140.

[0021] The pump housing 110 has a cylindrical structure with a generally circular cross section. The pump housing 110 has an accommodating cavity 112, and the stator 330 and the rotor 340 are both accommodated within the accommodating cavity 112 of the pump housing 110.

[0022] The axial tube 120 has one end fixedly connected to the pump housing 110 and the other end fixedly connected to the cannula assembly 30 (specifically, the outlet tube 32). The axial tube 120 has an attachment port 121, which is located at the end of the axial tube 120 adjacent to the cannula assembly 30.

[0023] The first shaft sleeve 130 and the second shaft sleeve 140 are fixedly housed in the shaft tube 120. Both the first shaft sleeve 130 and the second shaft sleeve 140 are fixedly connected to the shaft tube 120. The first shaft sleeve 130 and the second shaft sleeve 140 are provided along the axial direction of the shaft tube 120, with the first shaft sleeve 130 being provided closer to the impeller 41 than the second shaft sleeve 140. The mounting hole 131 is formed in the first shaft sleeve 130. The rotating shaft 200 is provided rotatably penetrating the first shaft sleeve 130 and the second shaft sleeve 140. Specifically, the first shaft sleeve 130 and the second shaft sleeve 140 are separate pieces, and both the first shaft sleeve 130 and the second shaft sleeve 140 can be assembled from the mounting port 121 of the shaft tube 120; that is, the maximum outer diameters of the first shaft sleeve 130 and the second shaft sleeve 140 are both slightly smaller than the diameter of the mounting port 121.

[0024] Specifically, a support protrusion 122 is provided on one end of the shaft tube 120 adjacent to the pump housing 110. The second shaft sleeve 140 abuts against the support protrusion 122, and the first shaft sleeve 130 abuts against the second shaft sleeve 140. As a result, the support protrusion 122 acts to restrict the position of the first shaft sleeve 130 and the second shaft sleeve 140 in the axial direction of the pump housing 110, facilitating assembly of the first shaft sleeve 130 and the second shaft sleeve 140. In one embodiment, the support protrusion 122 is substantially annular. The shaft tube 120 is further formed with an adhesive injection hole 123, which is filled with an adhesive. The adhesive firmly bonds the first shaft sleeve 130 and the second shaft sleeve 140 to the shaft tube 120 and firmly connects the first shaft sleeve 130 and the second shaft sleeve 140.

[0025] As shown in Figures 3, 4, 5, and 6, the first shaft sleeve 130 is formed with a position limiting hole 132, and the diameter of the position limiting hole 132 is larger than the diameter of the mounting hole 131. The mounting hole 131 is closer to the impeller 41 than the position limiting hole 132. The position limiting hole 132 and the mounting hole 131 are coaxially arranged and communicate with each other, so that the position limiting hole 132 and the mounting hole 131 jointly form a single stepped hole. The first shaft sleeve 130 has a first position limiting surface 133 that defines a part of the boundary of the position limiting hole 132. The first position limiting surface 133 may be arranged perpendicular to the axial direction of the rotating shaft 200 or may be arranged at an angle with respect to the axial direction of the rotating shaft 200.

[0026] The second shaft sleeve 140 includes a coarse segment 141 and a thin segment 142. The thin segment 142 has a smaller cross-sectional size than the coarse segment 141, and the coarse segment 141 has an abutment surface 1411. In the illustrated embodiment, the outer contours of the thin segment 142 and the coarse segment 141 are both circular. The smaller cross-sectional size of the thin segment 142 than the coarse segment 141 means that the outer diameter of the thin segment 142 is smaller than the outer diameter of the coarse segment 141. The thin segment 142 protrudes from the abutment surface 1411. The second shaft sleeve 140 has a through hole 143 that extends from one end face of the thin segment 142 away from the abutment surface 1411 to the side of the coarse segment 141 away from the abutment surface 1411, thereby passing through the coarse segment 141 and the thin segment 142. The diameter of the position limiting hole 132 is larger than the diameter of the through hole 143. The thin segment 142 is accommodated in the position limiting hole 132, and the abutment surface 1411 abuts against the first shaft sleeve 130. The position limiting action of the abutment surface 1411 and the guiding action of the thin segment 142 improve installation accuracy and installation efficiency. The side of the coarse segment 141 away from the abutment surface 1411 abuts against the support protrusion 122. The end face of the thin segment 142 away from the abutment surface 1411 is a second position limiting surface 144. The second position limiting surface 144 and the first position limiting surface 133 are spaced apart and face each other, so that the first position limiting surface 133 and the second position limiting surface 144 are spaced apart in the axial direction of the rotating shaft 200. The second position limiting surface 144 may be provided perpendicular to the axial direction of the rotation shaft 200, or may be inclined with respect to the axial direction of the rotation shaft 200. In the illustrated embodiment, the first position limiting surface 133 and the second position limiting surface 144 are both perpendicular to the axial direction of the rotation shaft 200, and the first position limiting surface 133 and the second position limiting surface 144 are parallel to and opposite each other.

[0027] The hole wall 132a of the position limiting hole 132, the first position limiting surface 133, and the second position limiting surface 144 collectively define a position limiting cavity 150, and the mounting hole 131 and the through hole 143 are both in communication with the position limiting cavity 150. In other words, the position limiting cavity 150 is actually a part of the position limiting hole 132, and the first position limiting surface 133 and the second position limiting surface 144 are two cavity walls of the position limiting cavity 150 in the axial direction of the rotating shaft 200.

[0028] The rotating shaft 200 is provided to penetrate the mounting hole 131, the position limiting cavity 150, and the through-hole 143, with one end of the rotating shaft 200 accommodated in the pump housing 110 and the other end extending into the cannula assembly 30 and fixedly connected to the impeller 41. Gaps through which a cleaning liquid can flow are provided between the rotating shaft 200 and the wall of the mounting hole 131, between the rotating shaft 200 and the cavity wall of the position limiting cavity 150, and between the rotating shaft 200 and the wall of the through-hole 143. The cleaning liquid can flow from the pump housing 110 through the gap between the rotating shaft 200 and the wall of the through-hole 143, the gap between the rotating shaft 200 and the cavity wall of the position limiting cavity 150, and the gap between the rotating shaft 200 and the mounting hole 131, into the cannula assembly 30, and out through the outlet 302. 8 indicates the flow direction of the cleaning fluid, which is opposite to the flow direction of the blood in the cannula assembly 30. In this way, it is possible to prevent the blood in the cannula assembly 30 from flowing into the drive unit 20 through the mounting hole 131. The cleaning fluid also functions as a lubricant, reducing frictional resistance between the rotating shaft 200 and the first shaft sleeve 130 and the second shaft sleeve 140, thereby reducing wear between the rotating shaft 200 and the first shaft sleeve 130 and the second shaft sleeve 140.

[0029] It should be noted that the housing assembly 100 is not limited to the above-described structure, and in some embodiments, two or more of the pump housing 110, the shaft tube 120, the first shaft sleeve 130, and the second shaft sleeve 140 may be of an integral structure, for example, the pump housing 110 may be integrally molded with the shaft tube 120, or for example, one of the first shaft sleeve 130 and the second shaft sleeve 140 may be integrally molded with the shaft tube 120, or for example, the first shaft sleeve 130 may have a disc-shaped ring structure, for example, the first shaft sleeve 130 may be composed of two separate tubular rings and a disc-shaped ring, and for example, the second shaft sleeve 140 may have only a rough segment 141.

[0030] As shown in Figures 3, 7, 8, and 9, in some embodiments, the rotating shaft 200 includes a first shaft segment 210, a second shaft segment 220, a third shaft segment 230, and a fourth shaft segment 240 connected in sequence. The axes of the first shaft segment 210, the second shaft segment 220, the third shaft segment 230, and the fourth shaft segment 240 overlap. The first shaft segment 210 is rotatably inserted through the mounting hole 131, and the first shaft segment 210 is fixedly connected to the impeller 41. The second shaft segment 220 is rotatably received in the position limiting cavity 150. The third shaft segment 230 is rotatably inserted through the through hole 143, and the fourth shaft segment 240 is received in the receiving cavity 112 of the pump housing 110. The fourth shaft segment 240 is fixedly connected to the rotor 340.

[0031] First shaft segment 210 is partially housed in housing assembly 100 and partially extends into cannula assembly 30 and is fixedly connected to impeller 41. First shaft segment 210 is provided with an arcuate convex surface 211 in the circumferential direction. Specifically, arcuate convex surface 211 protrudes radially away from the axis of first shaft segment 210 (the radial direction is a direction perpendicular to the axis of first shaft segment 210). At least a portion of arcuate convex surface 211 is located in mounting hole 131, and an inflection point of arcuate convex surface 211 faces the wall of mounting hole 131, and the gap between arcuate convex surface 211 and the wall of mounting hole 131 is smallest at the inflection point of arcuate convex surface 211. When the first shaft segment 210 contacts the wall of the mounting hole 131, the inflection point of the arc-shaped convex surface 211 contacts the wall of the mounting hole 131. Because the rotating shaft 200 experiences a certain amount of radial wobble during rotation, when the rotating shaft 200 wobbles, the first shaft segment 210 contacts the wall of the mounting hole 131. The larger the contact area between the first shaft segment 210 and the wall of the mounting hole 131, the greater the wear of the first shaft segment 210. By providing the arc-shaped convex surface 211 in the circumferential direction of the first shaft segment 210, when the first shaft segment 210 contacts the wall of the mounting hole 131, only the inflection point of the arc-shaped convex surface 211 contacts the wall of the mounting hole 131, resulting in point-surface contact. This reduces the contact area between the first shaft segment 210 and the wall of the mounting hole 131 and reduces wear of the rotating shaft 200.

[0032] In this application, the inflection point of the arc-shaped convex surface 211 refers to the point where the distance from the arc-shaped convex surface 211 to the axis OO' of the first axis segment 210 is longest, i.e., the most convex point of the arc-shaped convex surface 211. For example, in the illustrated embodiment, the inflection point of the arc-shaped convex surface 211 is the line segment PP'. Because the axes of the first axis segment 210, the second axis segment 220, the third axis segment 230, and the fourth axis segment 240 overlap, the axis OO' of the first axis segment 210 is the axis of the rotation shaft 200 and is also the axis of the second axis segment 220, the third axis segment 230, and the fourth axis segment 240.

[0033] Specifically, the arcuate convex surface 211 is provided so as to go around the axis OO' of the first shaft segment 210, and this type of arcuate convex surface 211 can facilitate the manufacture of the rotating shaft 200. In the illustrated embodiment, the arcuate convex surface 211 is provided continuously so as to go around the axis of the first shaft segment 210. Note that in other embodiments, a plurality of arcuate convex surfaces 211 may be provided spaced apart in the axial direction of the first shaft segment 210.

[0034] In some embodiments, the width of the gap from the inflection point (line segment PP′) of arcuate convex surface 211 to the wall of mounting hole 131 is 2 μm or less. The smallest red blood cells (approximately 8 μm in diameter and approximately 2 μm in thickness) have difficulty entering gaps less than 2 μm in width, and backwashed cleaning fluid passes through these gaps, preventing blood from flowing into these gaps.

[0035] Specifically, if the distance along the axial direction of the first shaft segment 210 from the inflection point (line segment PP') of the arcuate convex surface 211 to the plane on which the opening of the mounting hole 131 at one end adjacent to the impeller 41 is located is H, the value of H is in the range of H≦0.2 mm. In the illustrated embodiment, the plane on which the opening of the mounting hole 131 at one end adjacent to the impeller 41 is located is perpendicular to the axial direction of the first shaft segment 210 or perpendicular to the axis OO' of the first shaft segment 210. Furthermore, 0.1 mm≦H≦0.2 mm, and the inflection point (line segment PP') of the arc-shaped convex surface 211 is located within the mounting hole 131 and is slightly lower than the opening at one end of the mounting hole 131 that is close to the impeller 41, so that the wall of the mounting hole 131 provides better support for the rotating shaft 200, and when the rotating shaft 200 contacts the wall of the mounting hole 131, only the inflection point (line segment PP') of the arc-shaped convex surface 211 contacts the wall of the mounting hole 131, while ensuring strong cleaning power of the cleaning liquid.

[0036] Specifically, the arc-shaped convex surface 211 has a first arc-shaped surface portion 212 and a second arc-shaped surface portion 213 connected to the first arc-shaped surface portion 212, and the first arc-shaped surface portion 212 and the second arc-shaped surface portion 213 are arranged along the axial direction of the first shaft segment 210, and the connection point between the first arc-shaped surface portion 212 and the second arc-shaped surface portion 213 is the inflection point (line segment PP') of the arc-shaped convex surface 211, and along the axial direction of the first shaft segment 210 and toward the direction approaching the impeller 41, the distance from the first arc-shaped surface portion 212 to the axis OO' of the first shaft segment 210 gradually increases, and the distance from the second arc-shaped surface portion 213 to the axis OO' of the first shaft segment 210 gradually decreases. In the illustrated embodiment, the entire arc-shaped convex surface 211 is located within the mounting hole 131, and along the axis OO' of the first shaft segment 210 and toward the impeller 41, the width of the gap between the first arc-shaped surface portion 212 and the wall of the mounting hole 131 gradually decreases, and the width of the gap between the second arc-shaped surface portion 213 and the wall of the mounting hole 131 gradually increases, and the width of the gap between the arc-shaped convex surface 211 and the wall of the mounting hole 131 is smallest at the connection point between the first arc-shaped surface portion 212 and the second arc-shaped surface portion 213, i.e., at the line segment PP'.

[0037] In some embodiments, in order to prevent red blood cells in the blood from entering between the first shaft segment 210 and the wall of the mounting hole 131, the width of the gap between the wall of the opening at one end of the mounting hole 131 close to the impeller 41 and the first shaft segment 210 is 2 μm or less, and therefore the width of the gap between the inflection point (line segment PP′) of the arc-shaped convex surface 211 and the wall of the mounting hole 131 is less than 2 μm, i.e., smaller than the width of the gap between the wall of the opening at one end of the mounting hole 131 close to the impeller 41 and the first shaft segment 210.

[0038] In addition, the width of the gap between the inflection point of the arc-shaped convex surface 211 and the hole wall of the mounting hole 131, and the width of the gap between the hole wall of the opening at one end of the mounting hole 131 close to the impeller 41 and the first shaft segment 210 may be adjusted according to need and design.

[0039] In order to facilitate the flow of cleaning liquid from the position limiting cavity 150 into the mounting hole 131, the mounting hole 131 has a first hole portion 131a and a second hole portion 131b that are connected to each other, the hole diameter of the first hole portion 131a is constant, and the hole diameter of the second hole portion 131b gradually becomes smaller along the direction approaching the first hole portion 131a, the first axis segment 210 is provided to penetrate the first hole portion 131a and the second hole portion 131b, the inflection point (line segment PP') of the arc-shaped convex surface 211 faces the hole wall of the first hole portion 131a, and when the first axis segment 210 contacts the hole wall of the mounting hole 131, the inflection point (line segment PP') of the arc-shaped convex surface 211 contacts the hole wall of the first hole portion 131a. That is, the hole diameter of one end of the second hole portion 131b close to the position limiting cavity 150 is larger than the hole diameter of the first hole portion 131a, and the first hole portion 131a, which has a constant hole diameter, can better support the rotating shaft 200 and reduce the vibration amplitude of the rotating shaft 200, while the second hole portion 131b, whose hole diameter changes as described above, can act as a guide for the cleaning liquid so that the cleaning liquid flows into the mounting hole 131.

[0040] In some embodiments, an inner chamfer is formed on the wall of the through hole 143 at one end adjacent to the position limiting cavity 150, which is advantageous in reducing the contact area between the rotating shaft 200 and the second shaft sleeve 140 and reducing wear on the rotating shaft 200.

[0041] The second shaft segment 220 is fixedly connected to one end of the first shaft segment 210 remote from the impeller 41. The second shaft segment 220 is rotatably accommodated in the position limiting cavity 150; in other words, the cross-sectional size of the second shaft segment 220 is smaller than the cross-sectional size of the position limiting cavity 150. The cross-sectional diameter of the second shaft segment 220 is larger than the hole diameters of the mounting hole 131 and the through-hole 143, so that the second shaft segment 220 is limited to the position limiting cavity 150. In this way, the second shaft segment 220 does not enter the through-hole 143 and the mounting hole 131, and the second shaft segment 220 is located between the first position limiting surface 133 and the second position limiting surface 144, thereby limiting the position of the rotating shaft 200 in the axial direction of the rotating shaft 200.

[0042] Specifically, the second shaft segment 220 can abut against the first position limiting surface 133 and the second position limiting surface 144 to prevent axial movement of the rotating shaft 200 or limit the distance of axial movement. In some embodiments, the second shaft segment 220 always slidably abuts against the first position limiting surface 133 and the second position limiting surface 144. In other embodiments, the distance between the first position limiting surface 133 and the second position limiting surface 144 is slightly larger than the axial length of the second shaft segment 220, so that during rotation of the rotating shaft 200, the second shaft segment 220 has a certain floating space between the first position limiting surface 133 and the second position limiting surface 144 through which the cleaning liquid flows. A flow gap 151 through which the cleaning liquid flows is formed between the second shaft segment 220 and a cavity wall extending along the axis OO' of the position limiting cavity 150.

[0043] 4, 5, and 6, a portion of the first position limiting surface 133 is recessed to form a first flow guide groove 1331. The first flow guide groove 1331 extends from the hole wall 1311 of the mounting hole 131 toward the hole wall 132a of the position limiting hole 132, thereby connecting the mounting hole 131 and the position limiting hole 132. Since the position limiting cavity 150 is part of the position limiting hole 132, the first flow guide groove 1331 also connects to the position limiting cavity 150. A portion of the second position limiting surface 144 is recessed to form a second flow guide groove 1441. The second flow guide groove 1441 extends from the hole wall 1311 of the through hole 143 to the outer peripheral surface of the thin segment 142, thereby connecting the through hole 143 and the position limiting cavity 150. Since the flow gap 151 is actually part of the position limiting cavity 150, the flow gap 151 simultaneously communicates with the first flow guide groove 1331 and the second flow guide groove 1441. The provision of the first flow guide groove 1331 and the second flow guide groove 1441 is advantageous for the flow of the cleaning liquid.

[0044] In some embodiments, only one of the first guide groove 1331 and the second guide groove 1441 may be provided, or neither the first guide groove 1331 nor the second guide groove 1441 may be provided.

[0045] In some embodiments, chamfers 222 are provided at both axial ends of the second shaft segment 220, which on the one hand reduces the contact area between the rotating shaft 200 and the first position limiting surface 133 and / or the second position limiting surface 144, and further reduces the contact area between the rotating shaft 200 and the first shaft sleeve 130 and the second shaft sleeve 140, thereby further reducing wear of the rotating shaft 200. On the other hand, sharp edges of the second shaft segment 220 in contact with the first shaft sleeve 130 and the second shaft sleeve 140 can be prevented from wearing the first shaft sleeve 130 and the second shaft sleeve 140, and can also serve as a guide for the cleaning liquid.

[0046] The third shaft segment 230 is rotatably disposed through the through-hole 143. Between the third shaft segment 230 and the wall of the through-hole 143, there is a gap through which the cleaning liquid flows.

[0047] The fourth shaft segment 240 is connected to one end of the third shaft segment 230 remote from the second shaft segment 220, and the fourth shaft segment 240 is housed within the housing cavity 112. The cross-sectional size of the fourth shaft segment 240 is smaller than the cross-sectional size of the third shaft segment 230. The rotor 340 is fixedly connected to the fourth shaft segment 240. The fourth shaft segment 240 is at least partially housed within the stator 330.

[0048] Specifically, the rotating shaft 200, the first shaft sleeve 130 and the second shaft sleeve 140 may be manufactured from a ceramic material, thereby improving the wear resistance of the rotating shaft 200, the first shaft sleeve 130 and the second shaft sleeve 140 and further preventing wear of the rotating shaft 200, the first shaft sleeve 130 and the second shaft sleeve 140.

[0049] 3 , the stator 330 includes a first stator unit 332 and a second stator unit 333, and both the first stator unit 332 and the second stator unit 333 can drive the rotor 340 to rotate. Specifically, the first stator unit 332 and the second stator unit 333 are spaced apart along the extension direction of the rotating shaft 200. Both the first stator unit 332 and the second stator unit 333 are fixedly connected to the housing assembly 100. The fourth shaft segment 240 of the rotating shaft 200 is rotatably disposed through the first stator unit 332. That is, the rotor 340 is rotatable relative to the housing assembly 100, and the first stator unit 332 and the second stator unit 333 are non-rotatable relative to the housing assembly 100.

[0050] The first stator unit 332 and the second stator unit 333 may be connected in parallel or in series. In some embodiments, the first stator unit 332 and the second stator unit 333 may synchronously drive and rotate the rotor 340. The first stator unit 332 and the second stator unit 333 may both drive and rotate the rotor 340, or may drive and rotate the rotor 340 independently.

[0051] In some embodiments, the rotor 340 is magnetic, and the stator 330 can generate a rotating magnetic field that drives and rotates the rotor 340. Specifically, the first stator unit 332 and the second stator unit 333 can both generate a rotating magnetic field that drives and rotates the rotor 340.

[0052] Specifically, the first stator unit 332 includes a first magnetic core 3321, a first coil 3322, and a first back plate 3323. The first back plate 3323 is fixedly connected to the housing assembly 100, and in the illustrated embodiment, the first back plate 3323 is fixedly connected to the shaft tube 120. There are multiple first magnetic cores 3321, and the multiple first magnetic cores 3321 are arranged at intervals along the circumference. Specifically, the extension direction of each first magnetic core 3321 coincides with the extension direction of the rotating shaft 200. Each first magnetic core 3321 is fixedly connected to the first back plate 3323. The first coil 3322 is wound around the first magnetic core 3321. One first coil 3322 and one first magnetic core 3321 constitute one coil winding. As a result, the multiple coil windings of the first stator unit 332 are arranged to go around the fourth shaft segment 240 in one turn.

[0053] The second stator unit 333 has a structure similar to that of the first stator unit 332. The second stator unit 333 includes a second magnetic core 3331, a second coil 3332, and a second back plate 3333. The second back plate 3333 is fixedly connected to the housing assembly 100. There are multiple second magnetic cores 3331, and the multiple second magnetic cores 3331 are spaced apart along the circumference. Specifically, the extension direction of each second magnetic core 3331 is parallel to the axis of the fourth shaft segment 240 (i.e., the axis OO'). Each second magnetic core 3331 is fixedly connected to the second back plate 3333. The second coil 3332 is wound around the second magnetic core 3331. One second coil 3332 and one second magnetic core 3331 constitute one coil winding. Then, the plurality of coil windings of the second stator unit 333 are arranged to go around the axis of the fourth shaft segment 240 (ie, OO').

[0054] In some embodiments, the first magnetic core 3321 and the second magnetic core 3331 each include a magnetic pole and a head (i.e., a pole piece) at one end of the magnetic pole, and the extension direction of the magnetic pole coincides with the extension direction of the rotation axis. The first back plate 3323 is connected to the end of the magnetic pole of the first magnetic core 3321 remote from the head, and the second back plate 3333 is connected to the end of the magnetic pole of the second magnetic core 3331 remote from the head. In the extension direction of the magnetic pole, the magnetic pole presents a columnar body of approximately uniform size, i.e., the cross-sectional size of the magnetic pole 3331 remains constant, and generally speaking, the thickness of the magnetic pole 3331 is uniform. The first coil 3322 is wound around the magnetic pole of the first magnetic core 3321, and the second coil 3332 is wound around the magnetic pole of the second magnetic core 3331.

[0055] 3, in the illustrated embodiment, the first magnetic core 3321 and the second magnetic core 3331 include only magnetic columns, i.e., the first magnetic core 3321 and the second magnetic core 3331 do not have heads with large cross sections (i.e., pole pieces). Therefore, the magnetic columns of the first stator unit 332 are the first magnetic core 3321, and the magnetic columns of the second stator unit 333 are the second magnetic core 3331. In this case, the entire first magnetic core 3321 can be magnetically coupled to the rotor 340, and the entire second magnetic core 3331 can be magnetically coupled to the rotor 340. Compared to magnetic cores with pole pieces, magnetic cores with only magnetic columns can reduce magnetic loss and increase magnetic coupling density between the magnetic cores and the rotor 340, thereby increasing the torque from the stator units to the rotor 340 for the same current. On the other hand, a magnetic core without a head can significantly reduce the problem of a drop in power of the drive unit 20 due to a local magnetic short circuit caused by contact between adjacent magnetic cores.

[0056] In addition, the first magnetic core 3321 and the second magnetic core 3331 are not limited to the above two types, and in some embodiments, one of the first magnetic core 3321 and the second magnetic core 3331 may have both a magnetic pillar and a head, and the other may have only a magnetic pillar.

[0057] In some embodiments, the cross-sectional shape of the magnetic pillars of the first magnetic core 3321 and the second magnetic core 3331 is approximately triangular prism-shaped, with one edge of each magnetic pillar facing the axis of the rotation shaft. In some embodiments, the edges of the magnetic pillars are all chamfered, i.e., the edges of the magnetic pillars are relatively smooth and blunt, which eliminates sharp corners on the magnetic pillars and is advantageous not only for facilitating subsequent coil winding but also for protecting the insulating material coated on the coil. In other embodiments, the cross-sectional shape of the magnetic pillars of the first magnetic core 3321 and the second magnetic core 3331 may be sector-shaped, circular, trapezoidal, annular sector-shaped, etc.

[0058] In the illustrated embodiment, along the axis of the fourth shaft segment 240 (i.e., along the axis OO′), the rotating shaft 200 is spaced apart from the second stator unit 333, i.e., one end of the fourth shaft segment 240 remote from the third shaft segment 230 is spaced apart from the second stator unit 333, i.e., the fourth shaft segment 240 of the rotating shaft 200 does not penetrate the second stator unit 333. The cross-sectional size of the magnetic pillar of the second stator unit 333 is larger than the cross-sectional size of the magnetic pillar of the first stator unit 332.

[0059] The larger the cross-sectional area of ​​the magnetic column, the greater the generated magnetic flux, which increases the torque from the stator unit to the rotor 340 and reduces the required current, which is advantageous for reducing power consumption and heat generation. If the cross-sectional sizes of the first stator unit 332 and the second stator unit 333 are the same and the outer diameter of the housing assembly 100 remains the same, the rotating shaft 200 is located outside the second stator unit 333 and does not penetrate the second stator unit 333. This allows the cross-sectional size of the magnetic column of the second stator unit 333 to be reasonably increased without increasing the outer diameter of the pump housing 110, thereby increasing the driving torque from the second stator unit 333 to the rotor 340. If the required torque remains the same, this method allows the current supply to the stator 330 to be reasonably reduced, reducing power consumption and heat generation from the drive unit 20, and avoiding discomfort and even injury to the human body due to excessive heat concentration during operation of the blood pump 1.

[0060] In another embodiment, the rotating shaft 200 may be inserted into the second stator unit 333, in which case the cross-sectional sizes of the magnetic poles of the first stator unit 332 and the second stator unit 333 are the same.

[0061] The first back plate 3323 and the second back plate 3333 have a substantially flat plate-like structure and are made of the same material as the first magnetic core 3321 and the second magnetic core 3331, for example, a soft magnetic material such as cobalt steel.

[0062] The back plate can close the magnetic circuit of the stator unit, promote and increase the generation of magnetic flux in the stator unit, and improve the coupling ability between each stator unit and the rotor 340. In other words, providing the first back plate 3323 on the first stator unit 332 promotes and increases the generation of magnetic flux in the first stator unit 332, thereby improving the coupling ability between the first stator unit 332 and the rotor 340. Providing the second back plate 3333 on the second stator unit 333 promotes and increases the generation of magnetic flux in the second stator unit 333, thereby improving the coupling ability between the second stator unit 333 and the rotor 340. Because the back plate can increase the magnetic flux, providing a back plate on each of the first stator unit 332 and the second stator unit 333 is advantageous in reducing the overall diameter of the drive device 20.

[0063] Specifically, the drive device 20 further includes a positioning member 360, which is fixedly connected to the pump housing 110. The positioning member 360 has a positioning post 364. A positioning hole 3334 is formed in the second back plate 3333 of the second stator unit 333, and the positioning post 364 is provided to penetrate the positioning hole 3334. This allows the positioning member 360 to perform a positioning function with respect to the second stator unit 333, thereby improving the mounting accuracy and mounting efficiency of the second stator unit 333. Specifically, the central axis of the positioning post 364 and the central axis of the second stator unit 333 overlap each other. In some embodiments, the positioning member 360 further includes a through-hole 365. The through-hole 365 is connected to a cleaning line that introduces a cleaning liquid into the drive device 20, or is used to mount the cleaning line.

[0064] In some embodiments, the first stator unit 332 may not have the first back plate 3323, the second stator unit 333 may not have the second back plate 3333, or one of the first stator unit 332 and the second stator unit 333 may have a back plate and the other may not. When the second stator unit 333 does not have the second back plate 3333, a plurality of positioning holes may be directly formed in the positioning member 360, and one ends of the plurality of second magnetic cores 3331 may be positioned in the plurality of positioning holes, respectively.

[0065] In some embodiments, the positioning member 360 may be omitted, and in this case, an engagement portion for engaging with an edge of the second back plate 3333 may be provided in the pump housing 110, and the second stator unit 333 may be fixed by engaging the engagement portion with the second back plate 3333, or the second stator unit 333 may be adhesively fixed to the pump housing 110 with an adhesive. The first stator unit 332 may be adhesively fixed to the axial tube 120 with an adhesive, and the first stator unit 332 may be fixed by providing a corresponding engagement portion in the pump housing 110 and engaging the first back plate 3323.

[0066] 3 and 10 to 12, the rotor 340 is accommodated in the accommodation cavity 112 of the pump housing 110. In the illustrated embodiment, the rotor 340 is located between the first stator unit 332 and the second stator unit 333 along the axis OO′. Specifically, the rotor 340 includes a first magnet 342 and a second magnet 343, both of which are fixedly connected to the fourth shaft segment 240, and both of which are located between the first stator unit 332 and the second stator unit 333. That is, the first stator unit 332, the first magnet 342, the second magnet 343, and the second stator unit 333 are arranged in this order along the axis OO′. The first stator unit 332 can generate a rotating magnetic field that drives and rotates the first magnet 342, and the second stator unit 333 can generate a rotating magnetic field that drives and rotates the second magnet 343. The two stator units each provide torque to the rotor 340 with two magnets, thereby increasing the driving force that rotates the rotor 340.

[0067] Specifically, the rotor 340 further includes a flywheel 344, which is fixedly connected to the fourth shaft segment 240 of the rotating shaft 200, the flywheel 344 being located between the first stator unit 332 and the second stator unit 333, and the first magnet 342 and the second magnet 343 being both fixedly connected to the flywheel 344. More specifically, the flywheel 344 is fixedly connected to one end of the fourth shaft segment 240 remote from the third shaft segment 230.

[0068] By providing the flywheel 344, the connection strength between the first magnet 342 and the second magnet 343 and the fourth axis segment 240 can be improved, and by providing both the first magnet 342 and the second magnet 343 on the same flywheel 344, the shaking of the fourth axis segment 240 during rotation can be reduced, making the fourth axis segment 240 more stable during rotation.

[0069] In the illustrated embodiment, the flywheel 344 includes an internal tube 3442, a disk-shaped portion 3444, and an outer annular wall 3446. Both the internal tube 3442 and the outer annular wall 3446 have a cylindrical structure, and the disk-shaped portion 3444 has an annular disc structure. Both the internal tube 3442 and the outer annular wall 3446 are fixedly connected to the disk-shaped portion 3444. The outer annular wall 3446 is configured to surround the disk-shaped portion 3444, and both the internal tube 3442 and the outer annular wall 3446 are configured coaxially. The fourth shaft segment 240 is configured to penetrate through the internal tube 3442 and fixedly connected to the internal tube 3442. An accommodation space is formed between the internal tube 3442 and the outer annular wall 3446, and the disk-shaped portion 3444 divides the accommodation space into two mounting cavities 3448. The two mounting cavities 3448 are both annular cavities. The first magnet 342 and the second magnet 343 are respectively accommodated in the two mounting cavities 3448. The first magnet 342 and the second magnet 343 are both annular, and the shapes of the two mounting cavities 3448 are matched to the first magnet 342 and the second magnet 343, respectively, facilitating the mounting and positioning of the first magnet 342 and the second magnet 343. In this way, the flywheel 344 can act as a position limiter for the first magnet 342 and the second magnet 343, not only facilitating the mounting of the first magnet 342 and the second magnet 343 but also making the coupling between the first magnet 342 and the second magnet 343 and the flywheel 344 more stable.

[0070] The flywheel 344 is not limited to the above structure, and in some embodiments, the flywheel 344 does not have the outer annular wall 3446, and in some embodiments, the flywheel 344 does not have the outer annular wall 3446 and the built-in tube 3442, and in this case, the fourth shaft segment 240 is fixedly provided through the disk-shaped portion 3444, for example, at the center of the disk-shaped portion 3444. By providing the built-in tube 3442 in a flywheel 344 that only has the disk-shaped portion 3444, the flywheel 344 and the fourth shaft segment 240 can be connected more stably.

[0071] In some embodiments, the first magnet 342 and the second magnet 343 are both ring-shaped Halbach array magnets. Specifically, the first magnet 342 and the second magnet 343 each include a plurality of magnetic bodies, e.g., four, six, eight, or ten magnetic bodies, each of which has a ring-shaped sector shape. The plurality of magnetic bodies of the first magnet are arranged around the fourth shaft segment 240 to form a ring structure, and the plurality of magnetic bodies of the second magnet 343 are arranged around the rotor 340 to form a ring structure.

[0072] More specifically, the first magnet 342 has a first magnetic body 3422 magnetized along the axial direction of the first magnet 342, and the second magnet 343 has a second magnetic body 3432 magnetized along the axial direction of the second magnet 343, the first magnetic body 3422 and the second magnetic body 3432 being provided on opposite sides of the disk-shaped portion 3444, the first magnetic body 3422 and the second magnetic body 3432 being positioned in correspondence with each other, and the polarities of the first magnetic body 3422 and the second magnetic body 3432 on the sides facing the disk-shaped portion 3444 in the extension direction of the rotor 340 are opposite. In this way, the attachment of the first magnet 342 and the second magnet 343 is facilitated, and the problem of the first magnetic body 3422 and the second magnetic body 3432 repelling each other at positions corresponding to those of the first magnet 342 and the second magnet 343 located in the disk-shaped portion 3444, which makes assembly difficult, can be avoided. For example, if the polarity of the side of the first magnetic body 3422 facing the disk-shaped portion 3444 is an N pole, the polarity of the side of the second magnetic body 3432 facing the disk-shaped portion 3444 is an S pole, and based on the principle that the N pole and the S pole attract each other, interference of magnetic repulsion forces is eliminated and the attachment efficiency of the first magnet 342 and the second magnet 343 is improved.

[0073] To facilitate installation of the first magnet 342 and the second magnet 343 and improve their installation accuracy, the flywheel 344 is further provided with markers 345 for identifying the installation positions of the first magnetic body 3422 and the second magnetic body 4332. The markers 345 may be provided as grooves, scale lines, or markers. When installing the first magnet 342 and the second magnet 343, simply marking the position of one of the first magnet 342 and the second magnet 343 using the markers 445 allows the installation positions of the remaining magnetic bodies to be identified, making installation of the first magnet 342 and the second magnet 343 easier. Specifically, the markers 345 are provided on at least one of the internal tube 3442, the disk-shaped portion 3444, and the outer ring wall 3446. Specifically, in the illustrated embodiment, markers 345 are provided on both end faces of the internal tube 3442.

[0074] The above drive device and blood pump have at least the following advantages.

[0075] (1) As the rotating shaft 200 rotates, it experiences a certain amount of radial vibration. When the rotating shaft 200 vibrates, it comes into contact with the wall of the mounting hole 131. The larger the contact area between the rotating shaft 200 and the wall of the mounting hole 131, the greater the wear of the rotating shaft 200. The first shaft segment 210 of the rotating shaft 200 of the drive unit 20 has an arc-shaped convex surface 211 formed in the circumferential direction. The gap between the arc-shaped convex surface 211 and the wall of the mounting hole 131 is smallest at the inflection point PP′ of the arc-shaped convex surface 211. As a result, when the first shaft segment 210 comes into contact with the wall of the mounting hole 131 of the housing assembly 100, the inflection point PP′ of the arc-shaped convex surface 211 comes into contact with the wall of the mounting hole 131, resulting in point-surface contact. This reduces the contact area between the first shaft segment 210 and the wall of the mounting hole 131, thereby reducing wear of the rotating shaft 200.

[0076] (2) The separate housing assembly 100 of the above structure, i.e., the housing assembly 100 is assembled using the separate pump housing 110, shaft tube 120, first shaft sleeve 130, and second shaft sleeve 140, and the maximum outer diameter of the mounting opening 121 of the shaft tube 120 is made slightly smaller than the hole diameter of the mounting opening 121, thereby making it easier to assemble the drive unit 20. For example, the first shaft sleeve 130, the second shaft sleeve 140, and the rotating shaft 200 can be assembled from one direction, simplifying the assembly of the drive unit 20 and improving production efficiency.

[0077] (3) Because the fourth shaft segment 240 of the rotating shaft 200 penetrates the stator 330 and has a smaller cross-sectional size than the third shaft segment 230, the fourth shaft segment 240 can reduce the radial space occupied by the fourth shaft segment 240 relative to the stator 330 while ensuring the structural strength of the entire rotating shaft 200. While ensuring that the outer diameters of the stator 330 and the pump housing 110 remain unchanged, the cross-sectional size of the magnetic column within the stator 330 can be reasonably increased, and generally, the magnetic column can be designed to be reasonably thick. The larger the cross-sectional size of the magnetic column, the greater the generated magnetic flux, which increases the torque from the stator 330 to the rotor 340 and reduces the required current. This is beneficial for reducing power consumption and heat generation, and avoids human discomfort and even injury due to excessive heat concentration during operation of the blood pump 1. Increasing the cross-sectional size of the third shaft segment 230 allows the rotating shaft 200 to have greater structural strength at the through-hole 143.

[0078] (4) The rotating shaft 200 of the drive unit 20 is spaced apart from the second stator unit 333 in the axial direction, and the cross-sectional size of the magnetic column of the second stator unit 333 can be reasonably increased by a method that does not increase the outer diameter of the pump housing 110. In this way, the driving torque from the second stator unit 333 to the rotor 340 can be increased. When the required torque is the same, this method can reasonably reduce the current supply to the stator 330, thereby reducing power consumption and heat generation of the drive unit 20.

[0079] It should be noted that the structure of the drive unit 20 is not limited to the above-described form, and in some embodiments, the fourth shaft segment 240 of the rotating shaft 200 is also provided penetrating the second stator unit 333, and in other embodiments, the stator 330 may have only one stator unit, may have only the first stator unit 332, or may have only the second stator unit 333.

[0080] As shown in FIG. 13, the blood pump drive device of the second embodiment has almost the same structure as the drive device 20 of the first embodiment, but the main differences are as follows.

[0081] In this embodiment, the hole wall of the mounting hole 131' is provided with an arc-shaped concave portion 131c facing the arc-shaped convex surface 211', and the curvature of the concave portion 131c is smaller than the curvature of the arc-shaped convex surface 211'. When the first axis segment 210' contacts the hole wall of the mounting hole 131', the inflection point (line segment PP') of the arc-shaped convex surface 211' still contacts the concave portion 131c, resulting in point-surface contact.

[0082] In the illustrated embodiment, the position of the concave surface portion 131c faces the position of the second arcuate surface portion 213' of the arcuate convex surface 211', and the curvature of the concave surface portion 131c is smaller than the curvature of the second arcuate surface portion 213'. The hole wall of the mounting hole 131' further includes a first inner wall 131d, which faces the position of the first arcuate surface portion 212'. The first inner wall 131d is a straight wall extending parallel to the axis of the first shaft segment 210'. The first inner wall 131d may be an inclined wall inclined with respect to the axis of the first shaft segment 210'. Alternatively, the first inner wall 131d may be an arcuate concave wall. When the first inner wall 131d, which is the hole wall of the mounting hole 131' facing the position of the first arcuate surface portion 212', is an arcuate concave wall, the curvature of the hole wall of the mounting hole 131' facing the position of the first arcuate surface portion 212' may be the same as or different from the curvature of the concave surface portion 131c. The first arcuate surface portion 212' is closer to the second shaft segment 220' of the rotational axis than the second arcuate surface portion 213'.

[0083] The drive device of this embodiment has the same structure as the drive device of the first embodiment, and therefore blood pumps equipped with the drive device of this embodiment and the drive device of the second embodiment also achieve the same effects as the first embodiment.

[0084] As shown in FIG. 14, the blood pump drive device of the third embodiment has almost the same structure as the drive device 20 of the first embodiment, but the main differences are as follows.

[0085] In this embodiment, the width of the gap between the arcuate convex surface 211'' and the wall of the mounting hole 131'' gradually decreases along the axial direction of the first shaft segment 210'' and toward the impeller. That is, unlike the arcuate convex surface 211 of the first shaft segment 210 of the drive unit 20 of the first embodiment, the arcuate convex surface 211'' of this embodiment has only a first arcuate surface portion. At this time, the inflection point PP' of the arcuate convex surface 211'' is located at one end of the arcuate convex surface 211'' remote from the second shaft segment 220''. In the illustrated embodiment, the inflection point PP' of the arcuate convex surface 211'' is flush with the plane where the opening of the mounting hole 131'' at the end closest to the impeller is located.

[0086] In some embodiments, the position of the inflection point PP' of the arcuate convex surface 211'' may be lower than the plane on which the opening of the mounting hole 131'' at one end closest to the impeller is located, and the inflection point PP' of the arcuate convex surface 211'' is still accommodated within the mounting hole 131'', and the opening of the mounting hole 131'' at one end closest to the impeller is closer to the impeller than the position of the inflection point PP' of the arcuate convex surface 211''. That is, as shown in FIG. 9 , the distance H from the position of the inflection point PP' of the arcuate convex surface 211'' to the plane on which the opening of the mounting hole 131'' at one end closest to the impeller is located satisfies 0.1 mm≦H≦0.2 mm.

[0087] The drive device of this embodiment has the same structure as the drive device of the first embodiment, and therefore blood pumps equipped with the drive devices of this embodiment and the third embodiment also achieve the same effects as the first embodiment.

[0088] As shown in FIG. 15, the blood pump drive device of the fourth embodiment has almost the same structure as the drive device 20 of the first embodiment, but the main differences are as follows.

[0089] In this embodiment, the arcuate convex surface 211''' of the first shaft segment 210''' has a structure similar to that of the arcuate convex surface 211 of the first embodiment, and includes a first arcuate surface portion 212''' and a second arcuate surface portion 213''' connected to the first arcuate surface portion 212'''. The first arcuate surface portion 212''' of the arcuate convex surface 211''' is located within the mounting hole 131''', and at least a portion of the second arcuate surface portion 213''' is located outside the mounting hole 131'''. The distance H (as shown in FIG. 9) from the position of the inflection point PP' of the arcuate convex surface 211''' to the plane on which the opening of the mounting hole 131''' at one end closest to the impeller is located is 0.2 mm or less, and further satisfies 0.1 mm≦H≦0.2 mm.

[0090] The drive device of this embodiment has the same structure as the drive device of the first embodiment, and therefore the drive device of this embodiment and the blood pump including the same also achieve the same effects as the first embodiment.

[0091] As shown in FIG. 16, the blood pump drive device of the fifth embodiment has almost the same structure as the drive device 20 of the first embodiment, but the main differences are as follows.

[0092] In the illustrated embodiment, the first shaft segment 210'''' has a first pillar 214 housed in the housing assembly 110'''' and a second pillar 215 connected to the first pillar 214 and located outside the housing assembly 110, the second pillar 215 being used to fixedly connect to the impeller and being coaxial with the first pillar 214. The peripheral surface of one end of the second columnar portion 215 close to the first columnar portion 214 is a columnar surface 215a, and the arcuate convex surface 211'''' is located at one end of the first columnar portion 214 close to the second columnar portion 215. The arcuate convex surface 211'''' is connected to the columnar surface 215a, and the connection point between the arcuate convex surface 211'''' and the columnar surface 215a is an inflection point PP' of the arcuate convex surface 211'''', which is flush with the plane on which the opening of the mounting hole 131'''''' at one end close to the impeller is located. Specifically, the diameter of the one end of the second columnar portion 215 close to the first columnar portion 214 is equal to the diameter of the first columnar portion 214 at the inflection point PP' of the arcuate convex surface 211''''. That is, in this embodiment, the arcuate convex surface 211'''' still has only the first arcuate surface portion. The arcuate convex surface 211'''' is located at one end of the first post portion 214 remote from the second axial segment 220''''.

[0093] The drive device of this embodiment has the same structure as the drive device of the first embodiment, and therefore the drive device of this embodiment and the blood pump including the same also achieve the same effects as the first embodiment.

[0094] The above embodiments are only for illustrating the technical solutions of the present invention, and are not intended to be limiting. Although the present invention has been described in detail with reference to the above embodiments, it is understood that those skilled in the art may modify the technical solutions described in the above embodiments or make equivalent substitutions for some technical features thereof. These modifications and substitutions do not deviate from the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and all should be included in the protection scope of the present invention.

Claims

1. A drive device that drives and rotates the impeller, a housing assembly having mounting holes; a rotating shaft configured to be fixedly connected to the impeller and including a first shaft segment rotatably passing through the mounting hole, wherein the first shaft segment has an arc-shaped convex surface formed circumferentially thereof, at least a portion of the arc-shaped convex surface being located in the mounting hole, an inflection point of the arc-shaped convex surface facing a wall of the mounting hole, a gap between the arc-shaped convex surface and the wall of the mounting hole being smallest at the inflection point of the arc-shaped convex surface, and when the first shaft segment contacts the wall of the mounting hole, the inflection point of the arc-shaped convex surface contacts the wall of the mounting hole.

2. 2. The drive device according to claim 1, wherein when a distance H is defined as a distance along the axial direction of the first shaft segment from the inflection point of the arcuate convex surface to a plane on which an opening at one end of the mounting hole closest to the impeller is located, the value of H is in a range of H≦0.2 mm.

3. 2. The drive device according to claim 1, wherein the arc-shaped convex surface has a first arc-shaped surface portion, the first arc-shaped surface portion is located within the mounting hole, and the distance of the first arc-shaped surface portion to the axis of the first shaft segment gradually increases along the axial direction of the first shaft segment and toward the impeller, and an inflection point of the arc-shaped convex surface is located on the first arc-shaped surface portion.

4. 4. The drive device according to claim 3, wherein the arcuate convex surface further includes a second arcuate surface portion connected to the first arcuate surface portion, the second arcuate surface portion and the first arcuate surface portion being arranged along the axial direction of the first shaft segment, the connecting point between the second arcuate surface portion and the first arcuate surface portion being an inflection point of the arcuate convex surface, and the distance from the second arcuate surface portion to the axis of the first shaft segment gradually decreases along the axial direction of the first shaft segment and toward the impeller.

5. The drive device according to claim 4 , wherein the second arcuate surface portion is located within the mounting hole.

6. 2. The drive device according to claim 1, wherein the position of the inflection point of the arc-shaped convex surface is flush with a plane on which an opening at one end of the mounting hole adjacent to the impeller is located.

7. 7. The drive device of claim 6, wherein the first shaft segment has a first pillar portion accommodated in the housing assembly and a second pillar portion connected to the first pillar portion and located outside the housing assembly, the second pillar portion being configured to be fixedly connected to the impeller, the second pillar portion being coaxial with the first pillar portion, a peripheral surface of one end of the second pillar portion close to the first pillar portion being a cylindrical surface, the arcuate convex surface being located at one end of the first pillar portion close to the second pillar portion, the arcuate convex surface being connected to the cylindrical surface, and a connection point between the arcuate convex surface and the cylindrical surface being an inflection point of the arcuate convex surface.

8. 2. The drive device according to claim 1, wherein the entire arcuate convex surface is located within the mounting hole, and a width of a gap between the arcuate convex surface and a hole wall of the mounting hole gradually decreases along the axial direction of the rotation shaft and toward the impeller.

9. 2. The drive device according to claim 1, wherein the arcuate convex surface is provided continuously around the axis of the first shaft segment.

10. 2. The drive device according to claim 1, wherein the width of the gap from the inflection point of the arc-shaped convex surface to the wall of the mounting hole is 2 [mu]m or less.

11. 2. The drive device according to claim 1, wherein the hole wall of the mounting hole is provided with an arc-shaped concave surface portion opposing the arc-shaped convex surface, the curvature of the concave surface portion being smaller than the curvature of the arc-shaped convex surface, and when the first shaft segment contacts the hole wall of the mounting hole, an inflection point of the arc-shaped convex surface contacts the concave surface portion.

12. the arc-shaped convex surface has a first arc-shaped surface portion and a second arc-shaped surface portion, the first arc-shaped surface portion and the second arc-shaped surface portion are provided along the axial direction of the first shaft segment, the second arc-shaped surface portion is closer to the impeller than the first arc-shaped surface portion, and a connection point between the second arc-shaped surface portion and the first arc-shaped surface portion is an inflection point of the arc-shaped convex surface, The drive device according to claim 11, wherein the position of the concave surface portion faces the position of the second arcuate surface portion, and the curvature of the concave surface portion is smaller than the curvature of the second arcuate surface portion.

13. a hole wall of the mounting hole includes a first inner wall, the first inner wall facing the first arcuate surface portion; 13. The drive device according to claim 12, wherein the first inner wall is a straight wall parallel to the axis of the first shaft segment, or the first inner wall is an inclined wall inclined with respect to the axis of the first shaft segment, or the first inner wall is an arc-shaped concave wall.

14. 2. The drive device according to claim 1, wherein the mounting hole has a first hole portion and a second hole portion that communicate with each other, the diameter of the first hole portion is constant, and the diameter of the second hole portion gradually decreases along a direction approaching the first hole portion, the first shaft segment is provided to penetrate the first hole portion and the second hole portion, an inflection point of the arc-shaped convex surface faces a hole wall of the first hole portion, and when the first shaft segment contacts the hole wall of the mounting hole, the inflection point of the arc-shaped convex surface contacts the hole wall of the first hole portion.

15. the rotating shaft further includes a second shaft segment connected to one end of the first shaft segment and a third shaft segment connected to one end of the second shaft segment remote from the first shaft segment, the one end of the first shaft segment remote from the second shaft segment being configured to be fixedly connected to the impeller; 2. The drive device of claim 1, wherein the housing assembly further includes a position limiting cavity and a through hole, the position limiting cavity communicating with the mounting hole, the through hole communicating with the position limiting cavity, the second shaft segment rotatably housed in the position limiting cavity, the third shaft segment rotatably passing through the through hole, and a cross-sectional size of the second shaft segment larger than the diameter of the mounting hole and the diameter of the through hole.

16. 16. The drive device of claim 15, wherein the housing assembly further includes an accommodating cavity, the accommodating cavity communicating with the through hole, the rotating shaft further includes a fourth shaft segment connected to one end of the third shaft segment remote from the second shaft segment, the fourth shaft segment being accommodated in the accommodating cavity and being thinner than the third shaft segment, the drive device further includes a rotor and a stator accommodated in the accommodating cavity, the rotor being fixedly connected to the fourth shaft segment, the stator being capable of driving the rotor to rotate, the rotor being capable of driving the rotating shaft to rotate, and at least a portion of the fourth shaft segment being accommodated in the stator.

17. the rotor is magnetic, the stator includes a first stator unit and a second stator unit, each of which can generate a rotating magnetic field that drives the rotor to rotate; the first stator unit, the rotor, and the second stator unit are arranged in order along the axis of the fourth shaft segment; the fourth shaft segment is rotatably inserted through the first stator unit; the rotor is fixedly connected to one end of the fourth shaft segment remote from the third shaft segment; and the second stator unit and the rotating shaft are spaced apart along the axis of the fourth shaft segment; 17. The drive device of claim 16, wherein the first stator unit and the second stator unit each have a plurality of coil windings, the plurality of coil windings of the first stator unit are arranged around the fourth shaft segment, the plurality of coil windings of the second stator unit are arranged around the axis of the fourth shaft segment, the coil windings of the second stator unit and the coil windings of the first stator unit both have magnetic poles, and a cross-sectional size of the magnetic pole of the second stator unit is larger than a cross-sectional size of the magnetic pole of the first stator unit.

18. The housing assembly includes a pump housing provided separately, a shaft tube, a first shaft sleeve, and a second shaft sleeve, the pump housing having the accommodating cavity, one end of the shaft tube being fixedly connected to the pump housing, one end of the shaft tube being provided close to the pump housing with a support protrusion, and one end of the shaft tube being provided remote from the pump housing with an attachment port, The first shaft sleeve and the second shaft sleeve are fixedly accommodated in the axial tube through the mounting opening and are provided along the axial direction of the axial tube, the first shaft sleeve is closer to the impeller than the second shaft sleeve, and the second shaft sleeve abuts against the support projection, 17. The drive device according to claim 16, wherein the mounting hole is formed in the first shaft sleeve, and the rotating shaft is rotatably disposed to pass through the first shaft sleeve and the second shaft sleeve.

19. 16. The drive device according to claim 15, wherein an inner chamfer is formed on a hole wall at one end of the through hole adjacent to the position limiting cavity.

20. 1. A blood pump including an impeller and a drive device, the drive device comprising: a housing assembly having mounting holes; a rotating shaft configured to be fixedly connected to the impeller and including a first shaft segment rotatably passing through the mounting hole, wherein the first shaft segment has an arcuate convex surface formed in a circumferential direction thereof, at least a portion of the arcuate convex surface being located in the mounting hole, an inflection point of the arcuate convex surface facing a hole wall of the mounting hole, a gap between the arcuate convex surface and the hole wall of the mounting hole being smallest at the inflection point of the arcuate convex surface, and when the first shaft segment contacts the hole wall of the mounting hole, the inflection point of the arcuate convex surface contacts the hole wall of the mounting hole, The blood pump, wherein the impeller is fixedly connected to the first shaft segment and rotatable with the rotary shaft.

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