Pumping device
The pump device addresses the issue of blocked air venting by using through-holes with a one-sided opening design, ensuring efficient air discharge and reducing wear, thereby improving reliability.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- NIDEC INSTR CORP
- Filing Date
- 2024-12-27
- Publication Date
- 2026-07-09
AI Technical Summary
Existing pump devices with rotating shafts face issues where air venting holes are blocked by thrust bearings, preventing effective air discharge and leading to potential dry sliding contact, which can cause wear and damage.
The pump device incorporates a rotor member with through-holes that extend axially and have a one-sided opening, where the inner circumference is blocked by a thrust bearing and the outer circumference remains open, allowing air and foreign matter to be discharged away from the second radial bearing, thus preventing blockage and promoting efficient airflow.
This design effectively prevents air and foreign matter from accumulating at the second radial bearing, reducing wear and enhancing the operational reliability of the pump by ensuring continuous air discharge and preventing dry sliding contact.
Smart Images
Figure 2026115294000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a pump device.
Background Art
[0002] Patent Documents 1 and 2 describe a pump device that rotates an impeller disposed in a pump chamber by a motor. In the pump devices of Patent Documents 1 and 2, a support shaft is fixed to a casing that forms the pump chamber, and a rotor that rotates integrally with the impeller is rotatably supported with respect to the support shaft via a bearing member disposed at the center in the radial direction.
[0003] In the pump devices of Patent Documents 1 and 2, the rotor includes a cylindrical portion (in Patent Document 2, a rotor hub) in which a bearing member is disposed at the center in the radial direction. One end of the cylindrical portion extends into the pump chamber and is connected to the impeller. The portion of the cylindrical portion on the side opposite to the impeller has a magnet fixed to its outer peripheral surface and is housed in a recess provided in the casing.
[0004] The fluid flowing into the pump chamber also flows through the gap between the recess of the casing and the magnet. The rotor of Patent Documents 1 and 2 is provided with a through portion formed by a groove extending in the axial direction in the gap between the cylindrical portion and the bearing member and in the gap between the bearing member and the support shaft. When fluid flows into the pump chamber, the through portion serves as a flow path and the fluid flows through it, so that the portions that come into sliding contact and become hot during the rotation of the rotor are cooled. Also, air around the sliding contact portions can be discharged to the pump chamber side from these through portions. Thereby, it is possible to prevent sliding contact in a dry state where the fluid does not reach.
Prior Art Documents
Patent Documents
[0005]
Patent Document 1
Patent Document 2
Summary of the Invention
[0006] As described above, the pump devices of Patent Documents 1 and 2 have a fixed shaft, which is positioned at the radial center of the rotor and fixed to the casing, and the bearing member rotates integrally with the rotor. A washer is placed at the location where the end of the support shaft fits, and the end face of the bearing member slides against the washer during rotation.
[0007] In contrast, in a pump system equipped with a rotating shaft that rotates integrally with the rotor, the bearing members are fixed to the casing and support both ends of the rotating shaft. Washers acting as thrust bearings are placed on the end faces of the rotor members that hold the rotating shaft.
[0008] In a pump device equipped with a rotating shaft, similar to a pump device equipped with a fixed shaft, it is preferable to provide a through-hole that penetrates the rotor member axially to allow air around the bearing member to escape, in order to prevent the rotating shaft and the bearing member from sliding against each other in a dry state.
[0009] However, if the through-hole that penetrates the rotor member opens on the end face facing the bearing member, components such as washers arranged as thrust bearings will overlap the through-hole. If the thrust bearing completely blocks the through-hole, air will not be able to escape.
[0010] In view of the above problems, the object of the present invention is a pump device equipped with a rotating shaft, The purpose is to prevent the air venting holes from being blocked by the bearings. [Means for solving the problem]
[0011] To solve the above problems, one embodiment of the pump device according to the present invention comprises a rotor having a rotating shaft, a rotor member to which the rotating shaft is fixed at the radial center, and magnets arranged on the outer circumferential surface of the rotor member; an impeller arranged on one side in the axial direction along the rotation axis of the rotor relative to the magnets and rotating integrally with the rotating shaft; a first case having a concave partition wall recessed on the other side in the axial direction, with a first radial bearing disposed at the bottom of the partition wall to rotatably support the rotating shaft; and a second radial bearing placed over the first case from one side in the axial direction, housing the rotor member and the magnets between itself and the partition wall, and rotatably supporting the rotating shaft. The rotor member comprises a second case and a third case which is placed over the second case from one side in the axial direction to form a pump chamber for housing the impeller between the second case and the third case, wherein a thrust bearing opposite to the second radial bearing is disposed at one end of the rotor member in the axial direction, the rotor member is provided with a through portion extending in the axial direction between the magnet and the rotating shaft, the through portion communicates with the pump chamber through a one-sided opening that opens to one end face of the rotor member in the axial direction, and the one-sided opening comprises an inner circumferential portion of the opening which is closed by the thrust bearing and an outer circumferential portion of the opening which opens on the outer side of the outer edge of the thrust bearing. [Brief explanation of the drawing]
[0012] [Figure 1] Figure 1 is a cross-sectional view and a partially enlarged view thereof of a pump device according to an embodiment of the present invention. [Figure 2] Figure 2 is an exploded perspective view of the pump device shown in Figure 1, showing the impeller, the second case to which the second radial bearing is fixed, the rotor member to which the rotating shaft is fixed, and the magnet, viewed from one side in the axial direction. [Figure 3] Figure 3 is an exploded perspective view of the pump device shown in Figure 1, showing the impeller, second case, second radial bearing, rotor member to which the rotating shaft is fixed, and magnet, viewed from the other side in the axial direction. [Figure 4]Figure 4 is an exploded perspective view of the thrust bearing and rotor components. [Figure 5] Figure 5 is a perspective view of the rotor component with the thrust bearing assembled. [Figure 6] Figure 6 is a cross-sectional perspective view of a rotor member with a thrust bearing assembled. [Modes for carrying out the invention]
[0013] An embodiment of the pump device 1 will be described below with reference to the drawings.
[0014] (Overall structure) Figure 1 is a cross-sectional view and a partially enlarged view of a pump device 1 according to an embodiment of the present invention. As shown in Figure 1, the pump device 1 comprises a motor 2, an impeller 3 rotated by the motor 2, and a casing 4 housing the motor 2 and the impeller 3. The motor 2 comprises a rotor 5 and a stator 6 surrounding the outer circumference of the rotor 5. The impeller 3 rotates integrally with the rotor 5. In this embodiment, the rotor 5 is provided with a rotating shaft 10 that is rotatably supported by the casing 4, and the impeller 3 is connected to the rotating shaft 10.
[0015] In the following description, the direction along the rotation axis L of the rotor 5 is referred to as the axial direction, with one side of the axial direction being L1 and the other side being L2. The rotor 5 comprises a rotor member 51 extending in the axial direction and a magnet 52 arranged on the outer circumferential surface of the rotor member 51. The rotation shaft 10 is positioned at the radial center of the rotor member 51 and protrudes from the rotor member 51 to one side L1 and the other side L2 in the axial direction. In this embodiment, the rotation shaft 10 is fixed to the rotor member 51 by insert molding. The impeller 3 is located along the axial direction of the rotor member 51 and the magnet 52. It is positioned on one side L1 and fixed to the end of one side L1 in the axial direction of the rotation axis 10.
[0016] The stator 6 includes an annular stator core 61 that surrounds the outer periphery of the rotor member 51 and the magnet 52, and a coil 63 wound around the salient poles of the stator core 61 via an insulator 62. On the other side L2 in the axial direction of the stator 6, a circuit board 64 for supplying a drive current to the coil 63 is arranged.
[0017] The casing 4 includes a first case 41 having a concave partition portion 40 recessed on the other side L2 in the axial direction, a second case 42 covering the first case 41 from one side L1 in the axial direction, and a third case 43 covering the second case 42 from one side L1 in the axial direction. The pump chamber 30 in which the impeller 3 is arranged is partitioned by the second case 42 and the third case 43. At the radial center of the third case 43, a suction pipe 44 extending to one side L1 in the axial direction of the pump chamber 30 is provided. Further, the third case 43 is provided with a discharge pipe (not shown) extending in the tangential direction of the outer peripheral surface of the pump chamber 30.
[0018] The casing 4 is fastened by bolts at a location where the outer peripheral end of the first case 41 and the outer peripheral end of the third case 43 contact each other in the axial direction. Thereby, the third case 43 is fixed to the first case 41. The outer peripheral end of the second case 42 is sandwiched between the first case 41 and the third case 43. Thereby, the second case 42 is fixed to the first case 41 and the third case 43.
[0019] The first case 41 includes an annular plate portion 45 that extends radially outward from the end of the partition portion 40 on one side L1 in the axial direction, and a cylindrical body portion 46 that extends from the outer peripheral edge of the annular plate portion 45 to the other side L2 in the axial direction and surrounds the outer periphery of the stator 6. The second case 42 abuts against the annular plate portion 45 from one side L1 in the axial direction. The rotor member 51 and the magnet 52 are arranged on the inner peripheral side of the partition portion 40 and are accommodated between the second case 42 and the partition portion 40. The space between the partition portion 40 and the second case 42 communicates with the pump chamber 30 through a hole portion 47 penetrating the second case 42.
[0020] The rotating shaft 10 of the rotor 5 is rotatably supported by a first radial bearing 11 disposed at the center of the bottom of the partition wall portion 40 and a second radial bearing 12 disposed at the radial center of the second case 42. The rotating shaft 10 passes through the second radial bearing 12 and extends to one side L1 in the axial direction of the second case 42, and is connected to the impeller 3 disposed in the pump chamber 30.
[0021] As shown in FIG. 1, a thrust bearing 13 facing the second radial bearing 12 is disposed at the end of the rotor member 51 on one side L1 in the axial direction. The thrust bearing 13 is mounted on the end of the rotating shaft 10 and fixed to the end face on one side L1 in the axial direction of the rotor member 51. In this embodiment, the thrust bearing 13 is a washer. When the rotor 5 rotates, the rotor 5 is urged toward one side L1 in the axial direction by the thrust force applied to the impeller 3, so that the thrust bearing 13 and the second radial bearing 12 are in sliding contact.
[0022] FIG. 2 is an exploded perspective view of the impeller 3, the second case 42 to which the second radial bearing 12 is fixed, the rotor member 51 to which the rotating shaft 10 is fixed, and the magnet 52 of the pump device 1 in FIG. 1 as viewed from one side L1 in the axial direction. FIG. 3 is an exploded perspective view of the impeller 3, the second case 42, the second radial bearing 12, the rotor member 51 to which the rotating shaft 10 is fixed, and the magnet 52 of the pump device in FIG. 1 as viewed from the other side in the axial direction.
[0023] As shown in FIGS. 1, 2, and 3, the impeller 3 includes a disk member 31 fixed to the tip of the rotating shaft 10 and an impeller member 32 fixed to the disk member 31 from one side L1 in the axial direction. The second case 42 is provided with a cylindrical bearing holding portion 48 for mounting the second radial bearing 12 at the radial center, and a fitting cylinder portion 49 that fits inside the partition wall portion 40 of the first case 41 is provided on the outer periphery of the bearing holding portion 48. A plurality of holes 47 penetrating the second case 42 in the axial direction are provided between the bearing holding portion 48 and the fitting cylinder portion 49 and on the outer peripheral side of the fitting cylinder portion 49, respectively.
[0024] The rotor member 51 comprises a cylindrical tube portion 53 extending in the axial direction and a seat portion 54 protruding radially outward from one end L1 in the axial direction of the tube portion 53. The tube portion 53 fits inside the cylindrical magnet 52 and holds the magnet 52. As shown in Figure 1, the seat portion 54 abuts against the magnet 52 from one side L1 in the axial direction and supports the magnet 52 from one side L1 in the axial direction. As shown in Figure 3, the seat portion 54 has a rotation-preventing projection 56 that fits into a rotation-preventing recess 55 formed on the end face L1 in the axial direction of the magnet 52.
[0025] (Opening shape of the penetration portion that goes through the rotor member) Figure 4 is an exploded perspective view of the thrust bearing 13 and rotor member 51. Figure 5 is a perspective view of the rotor member 51 with the thrust bearing 13 assembled. Figure 6 is a cross-sectional perspective view of the rotor member 51 with the thrust bearing 13 assembled. As shown in Figures 4 and 6, the rotor member 51 is provided with a through-hole 7 that penetrates the cylindrical portion 53 in the axial direction. The through-hole 7 comprises a straight portion 71 that extends linearly in the axial direction and a recess 72 that is recessed radially outward from the inner circumferential surface on the radially outer side of one end L1 of the straight portion 71 in the axial direction.
[0026] The rotor member 51 is provided with multiple through-holes 7. As shown in Figure 4, the multiple through-holes 7 are identical in shape. In this embodiment, the four through-holes 7 are evenly spaced in the circumferential direction. In each of the four through-holes, the straight section 71 is an arc-shaped hole that extends circumferentially around the axis of rotation L when viewed from the axial direction. The recess 72 has a narrower circumferential width than the straight section 71 and is recessed radially outward from the circumferential center of the straight section 71.
[0027] The through-section 7 includes a one-sided opening 73 that opens onto the end face of one side L1 in the axial direction of the rotor member 51. As described above, a recess 72 is provided at the end of one side L1 in the axial direction of the through-section 7, so the one-sided opening 73 is an opening that connects the straight section 71 and the recess 72.
[0028] As shown in the enlarged view of Figure 1, and in Figures 4 and 6, a circular projection 57 is provided at the center of the end face of one side L1 in the axial direction of the rotor member 51, projecting toward the one side L1 in the axial direction. The opening 73 on one side of the through-hole 7 opens toward the tip surface of the circular projection 57.
[0029] As shown in the partially enlarged view of Figure 1 and in Figure 6, the outer diameter of the circular protrusion 57 is larger than the outer diameter of the cylindrical portion 53 of the rotor member 51, and the outer peripheral end of the circular protrusion 57 extends to the inner peripheral portion of the seat portion 54. The recess 72 is recessed from the straight portion 71 to near the outer peripheral edge of the circular protrusion 57 and extends to the outer peripheral side of the outer peripheral surface of the cylindrical portion 53. As shown in the partially enlarged view of Figure 1, the axial depth D of the recess 72 is smaller than the axial thickness t of the inner peripheral portion of the seat portion 54 where the circular protrusion 57 is provided. Therefore, the recess 72 does not penetrate the seat portion 54 in the axial direction.
[0030] As shown in Figure 4, the thrust bearing 13 is a disc-shaped washer with multiple notches 14 cut out in an arc shape at multiple positions in the circumferential direction. As shown in Figures 5 and 6, each of the multiple protrusions 58 provided near the outer edge of the tip surface of the circular protrusion 57 fits into the notches 14 of the thrust bearing 13. This prevents the thrust bearing 13 from rotating relative to the rotor member 51 when attaching the thrust bearing 13 to one end face L1 in the axial direction of the rotor member 51.
[0031] As shown in Figures 5 and 6, the thrust bearing 13 is axially aligned with the entire straight section 71 of the through section 7. The shaft overlaps from one side L1 in the linear direction, blocking the straight section 71 from one side L1 in the axial direction. On the other hand, the recess 72 of the through section 7, excluding the inner circumference end that connects to the straight section 71, is located on the outer circumference side of the thrust bearing 13 and remains open to the thrust bearing 13. Therefore, the opening 73 on one side of the through section 7 comprises an inner circumference portion 73A of the opening that is blocked by the thrust bearing 13, and an outer circumference portion 73B of the opening that is not blocked by the thrust bearing 13.
[0032] At the end of the rotor member 51 on the pump chamber 30 side, when fluid flows through the through-hole 7, the fluid flows as shown by the arrow in the partially enlarged view of Figure 1. That is, because the inner circumference portion 73A of the opening 73 on one side of the through-hole 7 is blocked by the thrust bearing 13, a flow occurs from the straight section 71 towards the radially outward direction within the recess 72. Then, the fluid is discharged from the outer circumference portion 73B of the opening to the radially outward direction of the second radial bearing 12.
[0033] As shown in Figures 1 and 3, a second thrust bearing 15 is positioned opposite the first radial bearing 11 at the other end L2 in the axial direction of the rotor member 51. The second thrust bearing 15 is mounted on the end of the rotating shaft 10 and is positioned in a recess provided on the end face L2 in the axial direction of the rotor member 51. In this embodiment, the second thrust bearing 15 is a washer with the same shape as the thrust bearing 13 described above.
[0034] As shown in Figures 1 and 6, the through-section 7 includes a groove 74 extending radially outward from the other end L2 in the axial direction of the straight section 71. The groove 74 extends further outward than the outer peripheral edge of the second thrust bearing 15 and opens to the outer peripheral surface of the cylindrical section 53 of the rotor member 51. Therefore, of the other end L2 in the axial direction of the through-section 7, the straight section 71 is blocked by the second thrust bearing 15, but a portion of the groove 74 is not blocked.
[0035] As shown in Figure 1, the gap S between the bottom of the partition wall 40 and the other axial end L2 of the rotor member 51 communicates with the through-hole 7 via the groove 74. Therefore, when the fluid from the pump chamber 30 flows into the bottom of the partition wall 40 via the gap between the partition wall 40 and the outer surface of the magnet 52, the air in the gap S is discharged from the through-hole 7 to one axial side L1 of the rotor member 51 via the groove 74.
[0036] (Effects and Benefits) As described above, the pump device 1 of this embodiment comprises a rotor 5 having a rotating shaft 10, a rotor member 51 to which the rotating shaft 10 is fixed at the radial center, and a magnet 52 arranged on the outer circumferential surface of the rotor member 51; an impeller 3 arranged on one side L1 in the axial direction along the rotation axis L of the rotor 5 relative to the magnet 52 and rotating integrally with the rotating shaft 10; and a concave partition wall portion 40 recessed on the other side L2 in the axial direction, with the rotating shaft 10 rotatably supported at the bottom of the partition wall portion 40. The pump comprises a first case 41 in which a first radial bearing 11 is arranged, a second case 42 placed over the first case 41 from one axial side L1 and housing a rotor member 51 and a magnet 52 between it and a partition wall 40, and a second radial bearing 12 that rotatably supports the rotating shaft 10 is arranged therein, and a third case 43 placed over the second case 42 from one axial side L1 and forming a pump chamber 30 that houses an impeller 3 between it and the second case 42. A thrust bearing 13 facing the second radial bearing 12 is arranged at the end of one axial side L1 of the rotor member 51. The rotor member 51 is provided with a through-hole 7 that extends axially between the magnet 52 and the rotating shaft 10. The through-hole 7 communicates with the pump chamber 30 via a one-sided opening 73 that opens at the end face of one axial side L1 of the rotor member 51. The opening on one side 73 comprises an inner circumferential portion 73A of the opening that is closed by the thrust bearing 13, and an outer circumferential portion 73B of the opening that opens on the outer side of the outer edge of the thrust bearing 13.
[0037] Thus, in this embodiment, the through-hole 7 that penetrates the rotor member 51 in the axial direction has an opening (one-sided opening 73) at the end on the pump chamber 30 side, and the inner circumference of this opening is blocked by the thrust bearing 13. The outer circumference is open. Therefore, the thrust bearing 13 does not completely block the through-hole 7. Also, in this embodiment, if the inner circumference of the opening is blocked, the fluid that is obstructed by the thrust bearing 13 within the through-hole 7 will move toward the outer circumference, so the fluid discharged from the through-hole 7 to the area around the second radial bearing 12 will easily flow toward the outer circumference. Therefore, when air and foreign matter generated by sliding contact around the first radial bearing 11 at the bottom of the partition wall 40 are discharged through the through-hole 7 toward the pump chamber 30, it is possible to suppress the flow of air and foreign matter toward the second radial bearing 12.
[0038] In this embodiment, the through-section 7 comprises a straight section 71 extending in the axial direction and a recess 72 that extends radially outward from the inner circumferential surface of one end L1 of the straight section 71 in the axial direction, and the outer peripheral portion 73B of the opening is formed by the recess 72. By providing the recess 72 at the end of the through-section 7 in this way, a flow path shape can be created that facilitates fluid flow toward the outer periphery.
[0039] In this embodiment, the thrust bearing 13 closes the entire straight section 71 and the inner circumferential end of the recess 72. However, the position of the outer circumferential edge of the thrust bearing 13 may differ from that in this embodiment. That is, the position of the outer circumferential edge of the thrust bearing 13 may coincide with the position of the outer circumferential edge of the straight section 71. Alternatively, the outer circumferential edge of the thrust bearing 13 may be located on the inner circumferential side of the outer circumferential edge of the straight section 71. In this case, the outer circumferential portion 73B of the opening is composed of the outer circumferential portion of the straight section 71 and the entire recess 72.
[0040] In this embodiment, the rotor member 51 includes a cylindrical portion 53 that fits onto the inner circumference of the magnet 52, and a seat portion 54 that protrudes radially outward from one end of the cylindrical portion 53 in the axial direction and supports the magnet 52 from one side L1 in the axial direction. The straight portion 71 penetrates the cylindrical portion 53, and the recess 72 extends to the seat portion 54. In this way, even if the outer diameter of the cylindrical portion 53 is small, the outer peripheral portion 73B of the opening can be positioned on the outer circumference.
[0041] In this embodiment, the thrust bearing 13 has a plurality of notches 14 on its outer circumference, and the other end face L2 in the axial direction of the rotor member 51 is provided with a protrusion 58 that fits into each of the plurality of notches 14. This prevents the thrust bearing 13 from rotating relative to the rotor member 51.
[0042] In this embodiment, the rotor member 51 is provided with a plurality of through-holes 7 that are evenly arranged in the circumferential direction with respect to the rotation axis 10. This allows for the even discharge of air and foreign matter generated by sliding contact around the first radial bearing 11.
[0043] In this embodiment, a second thrust bearing 15 is positioned opposite the first radial bearing 11 at the other end L2 in the axial direction of the rotor member 51. The through portion 7 includes a groove 74 extending radially outward from the other end L2 in the axial direction of the straight portion 71, and the groove 74 extends outward from the outer edge of the second thrust bearing 15. This configuration allows for the discharge of air and foreign matter from around the first radial bearing 11 located at the bottom of the partition wall 40, even when the second thrust bearing 15 is installed.
[0044] (summary) The present invention can take the following forms. (1) A rotor comprising a rotating shaft, a rotor member to which the rotating shaft is fixed at the radial center, and a magnet arranged on the outer circumferential surface of the rotor member, An impeller is positioned on one side of the axial direction along the rotation axis of the rotor relative to the magnet and rotates integrally with the rotation axis, The partition wall portion has a concave shape that is recessed on the other side in the axial direction, and the rotating shaft is located at the bottom of the partition wall portion. A first case in which a first radial bearing providing rotatable support is arranged, A second case is placed over the first case from one side in the axial direction, housing the rotor member and the magnet between it and the partition wall, and a second radial bearing that rotatably supports the rotating shaft is positioned therein. The device comprises a third case which is placed over the second case from one side in the axial direction and forms a pump chamber for housing the impeller between it and the second case, A thrust bearing opposite the second radial bearing is positioned at one end of the rotor member in the axial direction. The rotor member is provided with a through portion extending in the axial direction between the magnet and the rotating shaft, and the through portion communicates with the pump chamber through a one-sided opening that opens on one end face of the rotor member in the axial direction. The pump device is characterized in that the one-sided opening comprises an inner circumferential portion of the opening that is closed by the thrust bearing, and an outer circumferential portion of the opening that opens on the outer side of the outer edge of the thrust bearing.
[0045] (2) The through portion comprises a straight portion extending in the axial direction and a recess that extends radially outward from the inner circumferential surface of one end of the straight portion in the axial direction. The pump device according to (1) above, characterized in that the outer peripheral portion of the opening is configured such that at least a part of it is formed by the recess.
[0046] (3) The rotor member comprises a cylindrical portion that fits onto the inner circumference of the magnet, and a seat portion that protrudes radially outward from one end of the cylindrical portion in the axial direction and supports the magnet from one side in the axial direction. The aforementioned straight section penetrates the aforementioned cylindrical section, The pump device according to (2) above, characterized in that the recess extends to the seat portion.
[0047] (4) The thrust bearing has a plurality of notches on its outer edge, The pump device according to any one of (1) to (3) above, characterized in that the other end face of the rotor member in the axial direction is provided with a protrusion that fits into each of the plurality of notches.
[0048] (5) The pump device according to any one of (1) to (4) above, characterized in that the rotor member is provided with a plurality of through portions that are evenly arranged in the circumferential direction with respect to the rotation axis.
[0049] (6) A second thrust bearing is positioned at the other end of the rotor member in the axial direction, opposite to the first radial bearing. The through portion includes a groove extending radially outward from the other end of the straight portion in the axial direction, The pump device according to (2) or (3) above, characterized in that the groove extends outward from the outer peripheral edge of the second thrust bearing. [Explanation of Symbols]
[0050] 1...Pump device, 2...Motor, 3...Impeller, 4...Casing, 5...Rotor, 6...Stator, 7...Through section, 10...Rotating shaft, 11...First radial bearing, 12...Second radial bearing, 1 3…Thrust bearing, 14…Notch, 15…Second thrust bearing, 30…Pump chamber, 31…Disc member, 32…Impeller member, 40…Partition wall, 41…First case, 42…Second case, 43…Third case, 44…Suction pipe, 45…Annular plate, 46…Body, 47…Hole, 48…Bearing holder, 49…Matching cylinder, 51…Rotor member, 52…Magnet, 53…Cylinder, 54… 55... Anti-rotation recess, 56... Anti-rotation protrusion, 57... Circular protrusion, 58... Protrusion, 61... Stator core, 62... Insulator, 63... Coil, 64... Circuit board, 71... Straight section, 72... Recess, 73... One-sided opening, 73B... Outer circumference of opening, 73A... Inner circumference of opening, 74... Groove, L... Rotation axis, L1... One side in the axial direction, L2... The other side in the axial direction, S... Gap
Claims
1. A rotor comprising a rotating shaft, a rotor member to which the rotating shaft is fixed at the radial center, and a magnet arranged on the outer circumferential surface of the rotor member, An impeller is positioned on one side of the axial direction along the rotation axis of the rotor relative to the magnet and rotates integrally with the rotation axis, A first case comprising a concave partition wall portion recessed on the other side in the axial direction, and a first radial bearing that rotatably supports the rotating shaft disposed at the bottom of the partition wall portion, A second case is placed over the first case from one side in the axial direction, housing the rotor member and the magnet between it and the partition wall, and a second radial bearing that rotatably supports the rotating shaft is positioned therein. The device comprises a third case which is placed over the second case from one side in the axial direction and forms a pump chamber for housing the impeller between it and the second case, A thrust bearing opposite the second radial bearing is positioned at one end of the rotor member in the axial direction. The rotor member is provided with a through portion extending in the axial direction between the magnet and the rotating shaft, and the through portion communicates with the pump chamber through a one-sided opening that opens on one end face of the rotor member in the axial direction. The pump device is characterized in that the one-sided opening comprises an inner circumferential portion of the opening that is closed by the thrust bearing, and an outer circumferential portion of the opening that opens on the outer side of the outer edge of the thrust bearing.
2. The through portion comprises a straight portion extending in the axial direction and a recess that extends radially outward from the inner circumferential surface of one end of the straight portion in the axial direction. The pump device according to claim 1, characterized in that at least a portion of the outer periphery of the opening is formed by the recess.
3. The rotor member comprises a cylindrical portion that fits onto the inner circumference of the magnet, and a seat portion that protrudes radially outward from one end of the cylindrical portion in the axial direction and supports the magnet from one side in the axial direction. The aforementioned straight section penetrates the aforementioned cylindrical section, The pump device according to claim 2, characterized in that the recess extends to the seat portion.
4. The thrust bearing has a plurality of notches on its outer edge, The pump device according to claim 1, characterized in that the other end face of the rotor member in the axial direction is provided with a protrusion that fits into each of the plurality of notches.
5. The pump device according to claim 1, characterized in that the rotor member is provided with a plurality of through-holes that are evenly arranged in the circumferential direction with respect to the rotation axis.
6. A second thrust bearing is positioned at the other end of the rotor member in the axial direction, opposite to the first radial bearing. The through portion includes a groove extending radially outward from the other end of the straight portion in the axial direction, The pump device according to claim 2, characterized in that the groove extends outward from the outer edge of the second thrust bearing.