A ducted pump motor and method of manufacture thereof

Abstract

The application aims to provide a conduit pump motor and a manufacturing method thereof, comprising a shell, a stator assembly and a rotor assembly arranged in the shell, and a rotating shaft of the rotor assembly is supported by a proximal end bearing and a distal end bearing, a proximal end of the stator assembly is provided with an integral gel bearing seat formed by potting, an outer ring of the proximal end bearing is directly embedded and fixed in an inner hole of the gel bearing seat, and a protective cover is fixed at a proximal end of the gel bearing seat. The integral gel bearing seat is directly embedded with the proximal end bearing, an independent lower protective cover part is omitted, the axial dimension of the motor is shortened by 1.5-2.5 mm, and the bending performance of the conduit pump is significantly improved. Through twice potting processes, main body fixing and bearing seat forming are respectively optimized, the bearing installation precision is ensured, and process simplification and optimal distribution of material performance are realized.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a catheter pump motor and its manufacturing method. Background Technology

[0002] As a type of ventricular assist device, the catheter pump can be introduced percutaneously into the heart and can be configured to assist or replace the natural heart pumping function by pumping blood through circulation or continuous pumping, providing hemodynamic support for cardiogenic shock and acute heart failure. Since the catheter pump needs to be inserted into the heart via peripheral blood vessels such as the femoral artery, the miniaturization, lightweight design, and high reliability of its motor are crucial to the product's clinical performance. Among these challenges, minimizing the axial dimension while ensuring motor sealing and reliable operation is a core technical hurdle for improving the catheter pump's maneuverability and bending performance in tortuous blood vessels.

[0003] Currently, most mainstream duct pump motors employ the following structure for bearing sealing and installation: Near the motor assembly, an upper and lower protective cover are installed, forming a chamber to house and protect the near-end bearing, preventing potting compound from entering the bearing and also preventing external flushing fluid from reaching electrical components (PCB boards, etc.). However, the independent lower protective cover has a significant axial length and radial thickness, directly increasing the overall length of the motor. Furthermore, as a separate precision injection molded part, the lower protective cover requires separate molding, production, and quality control, increasing costs. In addition, the multiple sealing interfaces pose a high reliability risk. Summary of the Invention

[0004] The purpose of this invention is to provide a duct pump motor that can shorten the axial length and improve bending performance.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a duct pump motor, including a housing, and a stator assembly and a rotor assembly disposed within the housing. The rotor assembly's shaft is supported by a proximal bearing and a distal bearing. The proximal end of the stator assembly is provided with an integral colloid bearing seat formed by potting. The outer ring of the proximal bearing is directly embedded and fixed in the inner hole of the colloid bearing seat. A protective cover is fixed to the proximal end of the colloid bearing seat.

[0006] Furthermore, the stator assembly and the housing are formed into an integrated stator potting body through a first potting process, and the colloidal bearing housing is integrally formed by a second potting process at the proximal end of the stator potting body.

[0007] Furthermore, the stator assembly includes a coil and a magnetic sleeve, and the distal end of the housing includes a main body, a proximal end cap, and a distal end cap. The coil and the magnetic sleeve are encapsulated within the stator potting body, and the coil leads are encapsulated within the colloidal bearing housing during the second potting process.

[0008] Furthermore, the protective cover is provided with a PCB board, and the lead wires extending from the colloidal bearing seat are electrically connected to the PCB board.

[0009] Furthermore, one part of the proximal bearing is directly pressed into the inner hole of the colloid bearing housing and fixed with adhesive, while the other part is located in the cavity of the protective cover.

[0010] Furthermore, the protective cover includes a cover body for accommodating the proximal bearing and a connecting pipe for connecting the flushing pipe. A wiring groove for accommodating the lead wire is provided on the outer wall of the cover body along its axial direction, and the PCB board is disposed at the proximal end of the cover body.

[0011] Furthermore, the near end face of the cover is fixedly connected to the colloid bearing seat by a dotted adhesive. The inner diameter of the cover is larger than the inner diameter of the colloid bearing seat and the outer diameter of the cover is smaller than the outer diameter of the colloid bearing seat. The lead wire is led out from the colloid bearing seat at the position corresponding to the wiring groove.

[0012] Furthermore, the proximal end cap is fitted around the outer periphery of the colloid bearing seat and the protective cover, and is docked with and welded to the main body.

[0013] Furthermore, the distal end cap includes an external leakage section and an insertion section. The insertion section is inserted into the inner cavity of the main body. The step between the external leakage section and the insertion section abuts against and is fixed to the distal end face of the main body. The distal bearing is disposed inside the distal end cap.

[0014] Another objective of this invention is to provide a method for manufacturing a duct pump motor with short axial length and good safety performance.

[0015] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a method for manufacturing a guide pump motor, comprising the following steps:

[0016] S1) Place the stator assembly inside the main body, perform the first potting and curing to form the stator potting body, and initially fix the leads;

[0017] S2) A second potting is performed on the proximal end of the stator potting body, and after curing, a colloidal bearing seat is formed. During the potting process, the proximal end of the lead wire is fixed in the colloidal bearing seat.

[0018] S3) Press the proximal bearing into the inner hole of the colloid bearing housing, so that the outer ring of the proximal bearing is supported and fixed by the colloid bearing housing;

[0019] S4) Attach the protective cover to the near end face of the colloid bearing housing and electrically connect the lead wire from the colloid bearing housing to the PCB board on the protective cover.

[0020] S5) The near-end cap is fitted onto the outer periphery of the colloid bearing housing and the protective cover, and welded and fixed to the main body;

[0021] S6) After assembling the rotor assembly and the far end cover with the far end bearing, weld them in place to obtain the motor.

[0022] Compared with the prior art, the duct pump motor and its manufacturing method provided by the present invention have at least the following beneficial effects:

[0023] The use of an integrated colloid bearing housing with direct embedding of the near-end bearing eliminates the need for a separate lower protective cover, shortens the axial dimension of the motor by 1.5-2.5mm, and significantly improves the bending performance of the duct pump.

[0024] By employing a two-stage potting process, the main body fixing and bearing housing molding were optimized respectively, achieving process simplification and optimal allocation of material properties while ensuring bearing installation accuracy.

[0025] By directly encapsulating the lead wire inside the colloidal bearing housing, reliable sealing and fixation are achieved.

[0026] The overall structure is clearly layered, the assembly process is greatly simplified, manufacturing costs are reduced, and production efficiency and product consistency are improved. Attached Figure Description

[0027] Figure 1 This is an outline drawing of the duct pump motor;

[0028] Figure 2 for Figure 1 A sectional view;

[0029] Figure 3 for Figure 2 Enlarged diagram of the middle section;

[0030] Figure 4 This is a flowchart of the motor manufacturing process.

[0031] In the diagram: 10-Housing, 11-Main body, 12-Proximal end cap, 13-Distal end cap, 131-External exposed section, 132-Insertion section, 20-Stator assembly, 21-Coil, 211-Lead wire, 22-Magnetic sleeve, 30-Rotor assembly, 31-Shaft, 32-Rotor magnet, 41-Proximal bearing, 42-Distal bearing, 51-Colloidal bearing housing, 52-Protective cover, 521-Cover body, 522-Connecting pipe, 523-Wire routing groove, 524-PCB board. Detailed Implementation

[0032] To facilitate understanding, let's first define the orientation: "proximal" or "proximal" refers to the side closer to the operator / doctor, while "distal" or "distal" refers to the side farther from the operator / doctor, i.e., the side closer to the heart. Below, we'll combine these definitions... Figures 1-4 The present invention will be described in further detail below.

[0033] See Figures 1-3 A catheter pump motor includes a housing 10, and a stator assembly 20 and a rotor assembly 30 disposed within the housing 10. The rotor assembly 30's shaft 31 is supported by a proximal bearing 41 and a distal bearing 42. The proximal end of the stator assembly 20 is provided with an integrated gel bearing seat 51 formed by potting. The outer ring of the proximal bearing 41 is directly embedded and fixed in the inner hole of the gel bearing seat 51. A protective cover 52 is fixed to the proximal end of the gel bearing seat 51. By setting an integrated gel bearing seat 51 and directly embedding the proximal bearing 41 therein, the independent lower protective cover in the traditional structure is completely eliminated. This directly leads to a reduction in the axial length of the motor by 1.5-2.5 mm. In vascular interventional devices, every millimeter of reduction is crucial. This lays the core foundation for the overall miniaturization of the catheter pump and the improvement of vascular bending performance. At the same time, eliminating a separate part reduces the steps of mold making, processing, and assembly of that part, thereby reducing manufacturing costs and complexity. Furthermore, in the combination scheme of upper and lower protective covers, in order to prevent the flushing fluid from entering the outside of the protective cover, it is usually necessary to add an end potting to form an end shell or fill the cavity formed by the end metal shell, upper and lower protective covers and stator potting body. The end potting is much more complicated than the molding operation of the colloid bearing housing 51. The end potting will also increase the weight of the entire motor, which is not conducive to the lightweight requirements. In this invention, the end potting is not required, that is, the cavity between the colloid bearing housing 51, the protective cover 52 and the outer shell 10 does not need to be potted again. This not only simplifies the process and reduces the overall weight of the motor, but also further shortens the axial dimension of the motor.

[0034] To ensure the reliability of the core structure, the stator assembly 20 and the housing 10 are integrated into a stator encapsulation body through a first encapsulation process. The colloidal bearing housing 51 is integrally formed through a second encapsulation process near the end of the stator encapsulation body. The first encapsulation forms the stator encapsulation body, and the second encapsulation forms the colloidal bearing housing 51, decoupling the main body fixing function of the motor from the precision bearing housing forming function at the end. This independent second encapsulation allows for the use of specialized molds and targeted encapsulating adhesives to precisely control the size, roundness, and coaxiality of the inner hole of the colloidal bearing housing 51, ensuring the precision of bearing installation. Simultaneously, different adhesive formulations can be used for the two encapsulations (e.g., alumina powder can be added to the adhesive for the first encapsulation focusing on thermal conductivity and insulation, while silica powder can be added for the second encapsulation focusing on high strength and low shrinkage), achieving optimal overall performance.

[0035] Furthermore, the stator assembly 20 includes a coil 21 and a magnetic sleeve 22. The coil 21 is preferably a hollow cup coil, and its combination with the magnetic sleeve 22 achieves a high power density, low inertia motor. The distal end of the housing 10 includes a main body 11, a proximal end cover 12, and a distal end cover 13; this three-section structure facilitates motor assembly. The coil 21 and the magnetic sleeve 22 are encapsulated within the stator potting body. During the second potting process, the lead wire 211 of the coil 21 is encapsulated within the colloid bearing housing 51, achieving permanent, seamless, and sealed fixation of the lead wire 211 at that location. This eliminates the need for separate adhesive application to fix the lead wire 211 to the lower protective cover, fundamentally improving long-term reliability.

[0036] The protective cover 52 is provided with a PCB board 524. The lead wire 211 extending from the colloidal bearing seat 51 is electrically connected to the PCB board 524. This is the shortest and most direct electrical connection path, reducing space occupation and signal interference.

[0037] To further shorten the axial dimension of the motor, part of the near-end bearing 41 is directly pressed into the colloid bearing housing 51, and the other part is located in the cavity of the protective cover 52. Since the bearing housing and the protective cover are non-removable components, the space inside the two cavities is used as reasonably as possible to accommodate the near-end bearing 41, so as not to waste the axial space and to minimize the axial length of the entire motor.

[0038] The protective cover 52 includes a cover 521 for accommodating the proximal bearing 41 and a connecting pipe 522 for connecting the flushing pipe. In this invention, the protective cover 52 is provided for connecting the flushing fluid pipe. To prevent blood from entering the motor from the distal end during operation of the duct pump, flushing fluid is typically injected into the space between the stator assembly 20 and the rotor assembly 30. After entering the connecting pipe 522 from the flushing fluid pipe, the flushing fluid flows distally from the gap between the proximal bearing 41 into the gap between the stator potting body and the rotor magnet 32, and finally flows out from the gap between the distal bearing 42, thereby effectively preventing blood from entering the motor. A wiring groove 523 for accommodating the lead wire 211 is formed along its axial direction on the outer wall of the cover 521, and the PCB board 524 is disposed at the proximal end of the cover 521. The wiring channel 523 provides a protected and orderly path for the leads 211 from the colloid bearing housing 51 to the PCB board 524, effectively preventing the leads 211 from tangling, abrading, or being accidentally pulled and broken in the confined space. The inner cavity of the protective cover 52 is filled with rinsing fluid. Due to the isolation provided by the protective cover 52, the rinsing fluid will not enter the chamber where the leads 211 and the PCB board 524 are located, effectively protecting the safety of the electrical connection.

[0039] The near-end face of the cover 521 is fixedly connected to the colloid bearing housing 51 by a dotted adhesive, simplifying the assembly process and avoiding the risks associated with welding thermal stress. The inner diameter of the cover 521 is larger than the inner diameter of the colloid bearing housing 51, and the outer diameter of the cover 521 is smaller than the outer diameter of the colloid bearing housing 51. This design facilitates the assembly of the protective cover 52, and provides a larger space between the protective cover 52 and the inner wall of the outer near-end cap 12, preventing damage to the lead wire 211. The lead wire 211 is led out from the colloid bearing housing 51 at a position corresponding to the wiring groove 523, minimizing the risk of breakage.

[0040] The proximal end cap 12 is fitted around the outer periphery of the colloid bearing seat 51 and the protective cover 52, and is connected to and welded to the main body 11. Preferably, both the proximal end cap 12 and the main body 11 are made of metal to provide reliable strength and prevent the motor from deforming.

[0041] Furthermore, the distal end cap 13 includes an external protrusion section 131 and an insertion section 132. The insertion section 132 is inserted into the inner cavity of the main body 11. The step between the external protrusion section 131 and the insertion section 132 abuts against and is fixed to the distal end face of the main body 11. The distal bearing 42 is disposed inside the distal end cap 13. After assembling the distal bearing 42 and the distal end cap 13, the entire assembly is then performed.

[0042] like Figure 4 As shown, a method for manufacturing a duct pump motor includes the following steps:

[0043] S1) Place the stator assembly 20 inside the main body 11, and perform the first potting and curing to form a stator potting body, and initially fix the lead wire 211; in this step, a potting mold is needed, and potting glue is injected into the cavity of the mold. After curing, the stator potting body is obtained.

[0044] S2) A second potting is performed on the proximal end of the stator potting body, and after curing, a colloid bearing seat 51 is formed. During the potting process, the proximal end of the lead wire 211 is fixed in the colloid bearing seat 51. In this step, a glue injection shaft is inserted into the stator potting body, and glue is injected into the space enclosed by the glue injection shaft, the stator potting body and the main body 11. After the glue cures, the colloid bearing seat 51 is obtained.

[0045] S3) Press the proximal bearing 41 into the inner hole of the colloid bearing housing 51, so that the outer ring of the proximal bearing 41 is supported and fixed by the colloid bearing housing 51; the proximal bearing 41 and the colloid bearing housing 51 are also fixed with adhesive. The proximal bearing 41 and the distal bearing 42 can be sliding bearings or ball bearings.

[0046] S4) Bond the protective cover 52 to the near end face of the colloid bearing housing 51, and electrically connect the lead wire 211 from the colloid bearing housing 51 to the PCB board 524 on the protective cover 52.

[0047] S5) The near end cap 12 is fitted onto the outer periphery of the colloid bearing seat 51 and the protective cover 52, and is welded and fixed to the main body 11;

[0048] S6) After assembling the rotor assembly 30 and the distal end cover 13 with the distal bearing 42, weld them together to obtain the motor.

[0049] In this invention, by using a secondary potting molding process to form a colloidal bearing seat 51, several interconnected technical challenges, such as the long axial dimension of the duct pump motor, numerous parts, multiple sealing interfaces, difficulty in fixing the lead wire 211, and lightweighting, are simultaneously solved, resulting in systematic progress.

[0050] Of course, those skilled in the art will recognize that the present invention is not limited to the details of the exemplary embodiments described above, but also includes the same or similar structures that can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0051] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A duct pump motor, comprising a housing (10), and a stator assembly (20) and a rotor assembly (30) disposed within the housing (10), wherein the shaft (31) of the rotor assembly (30) is supported by a proximal bearing (41) and a distal bearing (42), characterized in that: The stator assembly (20) has an integral colloid bearing housing (51) formed by potting at its proximal end. The outer ring of the proximal bearing (41) is directly embedded and fixed in the inner hole of the colloid bearing housing (51). A protective cover (52) is fixed at the proximal end of the colloid bearing housing (51). The stator assembly (20) and the housing (10) are formed into an integrated stator potting body by a first potting process, and the colloidal bearing housing (51) is integrally formed by a second potting process at the proximal end of the stator potting body.

2. The duct pump motor according to claim 1, characterized in that: The stator assembly (20) includes a coil (21) and a magnetic sleeve (22). The distal end of the housing (10) includes a body (11), a proximal end cap (12), and a distal end cap (13). The coil (21) and the magnetic sleeve (22) are encapsulated in the stator potting body. The lead (211) of the coil (21) is encapsulated in the colloidal bearing housing (51) during the second potting process.

3. The duct pump motor according to claim 2, characterized in that: The protective cover (52) is provided with a PCB board (524), and the lead wire (211) led out from the colloid bearing seat (51) is electrically connected to the PCB board (524).

4. The duct pump motor according to claim 1, characterized in that: One part of the near-end bearing (41) is directly pressed into the inner hole of the colloid bearing seat (51) and fixed with glue, while the other part is located in the cavity of the protective cover (52).

5. The duct pump motor according to claim 1, characterized in that: The protective cover (52) includes a cover (521) for accommodating the proximal bearing (41) and a connecting pipe (522) for connecting the flushing pipe. A wiring groove (523) for accommodating the lead wire (211) is provided on the outer wall of the cover (521) along its axial direction. A PCB board (524) is disposed at the proximal end of the cover (521).

6. The duct pump motor according to claim 5, characterized in that: The near end face of the cover (521) is fixedly connected to the colloid bearing seat (51) by a dotted adhesive. The inner diameter of the cover (521) is larger than the inner diameter of the colloid bearing seat (51) and the outer diameter of the cover (521) is smaller than the outer diameter of the colloid bearing seat (51). The lead wire (211) is led out from the colloid bearing seat (51) at the position corresponding to the wiring groove (523).

7. The duct pump motor according to claim 2, characterized in that: The proximal end cap (12) is fitted around the outer periphery of the colloid bearing seat (51) and the protective cover (52), and is connected to the main body (11) and welded to fix it.

8. The duct pump motor according to claim 2, characterized in that: The distal end cap (13) includes an external leakage section (131) and an insertion section (132). The insertion section (132) is inserted into the inner cavity of the main body (11). The step between the external leakage section (131) and the insertion section (132) abuts against and is fixed to the distal end face of the main body (11). The distal bearing (42) is disposed inside the distal end cap (13).

9. A method for manufacturing a duct pump motor, comprising the duct pump motor according to any one of claims 1-8, characterized in that, Includes the following steps: S1) Place the stator assembly (20) inside the body (11), perform the first potting and curing to form a stator potting body, and initially fix the lead wire (211); S2) A second potting is performed on the proximal end of the stator potting body, and after curing, a colloidal bearing seat (51) is formed. During the potting process, the proximal end of the lead wire (211) is fixed in the colloidal bearing seat (51). S3) Press the near-end bearing (41) into the inner hole of the colloid bearing housing (51) so that the outer ring of the near-end bearing (41) is supported and fixed by the colloid bearing housing (51). S4) Bond the upper protective cover (52) to the near end face of the colloid bearing housing (51) and electrically connect the lead wire (211) led out from the colloid bearing housing (51) to the PCB board (524) on the protective cover (52); S5) The near end cap (12) is fitted onto the outer periphery of the colloid bearing seat (51) and the protective cover (51) and welded to the main body (11); S6) After assembling the rotor assembly (30) and the far end cover (13) with the far end bearing (42), weld them together to obtain the motor.

Images