JP7801964B2 - Pump equipment - Google Patents

Description

The present invention relates to a pump device in which an impeller is rotated by a motor.

Patent Document 1 describes a pump device in which an impeller located in a pump chamber is rotated by a motor. The motor has a rotor that rotates integrally with the impeller. The rotor has a cylindrical portion that holds a cylindrical radial bearing inside, and a cylindrical drive magnet is fixed to the outer periphery of the cylindrical portion.

JP 2010-246238 A

The rotor in Patent Document 1 is rotatably supported on a fixed shaft via a radial bearing. When the rotor rotates, friction and other factors cause the radial bearing to heat up, which in turn causes the drive magnet to heat up, resulting in problems such as a shortened component life and a deterioration in the magnetic properties of the drive magnet.

In view of the above problems, the objective of this invention is to suppress the temperature rise of the drive magnet and radial bearing when the rotor of the pump device rotates.

In order to solve the above problem, the pump device of the present invention comprises a motor including a rotor and a stator surrounding the outer periphery of the rotor, and an impeller disposed in a pump chamber on one side of the stator in the axial direction, where the direction along the rotational axis of the rotor is defined as the axial direction. The rotor comprises a cylindrical drive magnet and a rotor member provided with a cylindrical portion that fits inside the drive magnet. A radial bearing is held inside the cylindrical portion, and a bearing is provided on one of the outer periphery of the cylindrical portion and the inner periphery of the drive magnet. A first flow channel is provided that forms a flow channel between the other side of the inner circumferential surface of the dynamic magnet, and the first flow channel includes a first groove portion extending in the axial direction, a second groove portion extending in the axial direction rearward of the first groove portion in the direction of rotation of the rotor, and a third groove portion extending circumferentially and connecting the axial ends of the first groove portion and the second groove portion, and a gap that communicates with the pump chamber is provided between the outer circumferential side of the dynamic magnet and a partition member that covers the inner circumferential side of the stator, and the end of the first groove portion opposite the third groove portion in the axial direction communicates with the gap.

According to the present invention, a flow path communicating with the pump chamber is formed between the cylindrical portion of the rotor member and the drive magnet, thereby cooling the drive magnet and the cylindrical portion, and the radial bearing via the cylindrical portion. The first flow groove, provided on the outer peripheral surface of the cylindrical portion or the inner peripheral surface of the drive magnet to form this flow path, has a shape in which the first groove portion and the second groove portion, extending in the axial direction, are connected by the third groove portion in a U-shape, which is folded back once in the axial direction. This configuration increases the area in contact with the fluid compared to a case in which a linear flow path is simply provided, thereby improving the cooling effect. Furthermore, because the first groove portion located forward in the rotor rotation direction is connected to the space (gap) on the outer peripheral side of the drive magnet, the fluid in the pump chamber flows into the first groove portion. When the rotor rotates, inertial force causes the fluid to flow backward in the rotation direction. Therefore, by configuring the fluid to flow into the first groove portion located forward in the rotation direction, the fluid can more easily flow into the flow path, thereby improving the cooling effect. This suppresses temperature increases in the drive magnet and the radial bearing, thereby suppressing a decrease in component life. Furthermore, the deterioration of the magnetic properties of the drive magnet can be suppressed.

In the present invention, the rotor member preferably includes a seat portion that protrudes radially outward from the cylindrical portion and supports the axial end of the drive magnet, and an inlet port that connects the first groove portion to the gap is provided between the seat portion and the axial end of the drive magnet. By providing a seat portion in this way, the axial positioning accuracy of the drive magnet can be improved. Furthermore, even when a seat portion is provided, fluid can be allowed to flow into the first groove portion through the inlet port. Therefore, temperature increases in the drive magnet and radial bearing can be suppressed.

In the present invention, it is preferable that the seat portion has a recess formed radially outward of the first groove portion, and the inlet is the gap between the recess and the axial end of the drive magnet. By providing a recess in the seat portion in this way, the inlet can be made larger. This makes it easier for fluid to flow into the first groove portion, allowing a larger amount of fluid to flow, thereby improving the cooling effect.

In the present invention, it is preferable that the circumferential width of the recess is equal to or greater than the circumferential width of the first groove portion. This allows a larger amount of fluid to flow into the first groove portion, thereby enhancing the cooling effect.

In the present invention, it is preferable that the recessed portion have a circumferential width that increases radially outward. This increases the fluid pressure when the fluid flows from the recessed portion into the first groove portion, allowing a larger amount of fluid to flow. This improves the cooling effect.

In the present invention, it is preferable that the seat portion has a rotation prevention protrusion protruding from the inside of the recess toward the drive magnet, and that the drive magnet has a rotation prevention recess into which the rotation prevention protrusion fits. This makes it easy to position the drive magnet circumferentially. Furthermore, even if the radial dimension of the rotation prevention protrusion is increased, the circumferential positioning is not affected. Therefore, the radial length of the rotation prevention recess can be made larger than the rotation prevention protrusion, increasing the gap through which fluid flows. This allows more fluid to flow into the first groove portion, thereby improving the cooling effect.

In the present invention, the seat preferably includes a flat portion that abuts the drive magnet in the axial direction radially outside the third groove portion, and the flat portion preferably has a wider circumferential width than the third groove portion. In this way, by forming the seat portion flat on the radially outside of the third groove portion without providing a recess, the outlet end of the first flow channel can be blocked. By providing an inlet at the inlet end and blocking the outlet end, a pressure difference can be generated. This makes it easier for fluid to flow into the first flow channel, thereby enhancing the cooling effect.

In the present invention, it is preferable that the first flow path groove is formed on the outer peripheral surface of the cylindrical portion, and a second flow path groove is formed on the inner peripheral surface of the cylindrical portion, forming a flow path between the cylindrical portion and the outer peripheral surface of the radial bearing, and that the second flow path groove is positioned at a different circumferential position from the first flow path groove. This prevents the cylindrical portion from becoming thin at the location where the circumferential positions of the second flow path groove and the first flow path groove coincide. Therefore, the strength of the cylindrical portion can be ensured.

According to the present invention, a flow path communicating with the pump chamber is formed between the cylindrical portion of the rotor member and the drive magnet, thereby cooling the drive magnet and the cylindrical portion, and the radial bearing via the cylindrical portion. The first flow groove, provided on the outer peripheral surface of the cylindrical portion or the inner peripheral surface of the drive magnet to form this flow path, has a shape in which the first groove portion and the second groove portion, extending in the axial direction, are connected by the third groove portion in a U-shape, which is folded back once in the axial direction. This configuration increases the area in contact with the fluid compared to a case in which a linear flow path is simply provided, thereby improving the cooling effect. Furthermore, because the first groove portion located forward in the rotor rotation direction is connected to the space (gap) on the outer peripheral side of the drive magnet, the fluid in the pump chamber flows into the first groove portion. When the rotor rotates, inertial force causes the fluid to flow backward in the rotation direction. Therefore, by configuring the fluid to flow into the first groove portion located forward in the rotation direction, the fluid can more easily flow into the flow path, thereby improving the cooling effect. This suppresses temperature increases in the drive magnet and the radial bearing, thereby suppressing a decrease in component life. Furthermore, the deterioration of the magnetic properties of the drive magnet can be suppressed.

1 is a perspective view of the appearance of a pump device to which the present invention is applied; 2 is a cross-sectional view of the pump device shown in FIG. 1 taken along a plane including a rotation axis. FIG. 2 is an exploded perspective view of a rotor member, a drive magnet, a radial bearing, and a support shaft as viewed from one side in the axial direction. 10 is an exploded perspective view of the rotor member, the drive magnet, the radial bearing, and the support shaft as viewed from the other side in the axial direction. FIG. FIG. 2 is a perspective view of the rotor member as viewed from one side in the axial direction. 8 is a cross-sectional view of the rotor member, drive magnet, radial bearing, and support shaft cut along a plane including the rotation axis (cross-sectional view cut at position B-B in FIG. 7). 7 is a cross-sectional view of the rotor member, drive magnet, radial bearing, and support shaft cut along a plane perpendicular to the rotation axis (cross-sectional view taken along the line AA in FIG. 6). FIG. 2 is a perspective view of the rotor member as viewed from the side (X1 direction) on which the first flow channel is formed. FIG. 10 is a perspective view of the rotor member as viewed from the side (X2 direction) where the third flow channel is formed.

The pump device 1 according to an embodiment of the present invention will now be described with reference to the drawings. In the following description, the axial direction refers to the direction in which the rotation axis L of the motor 10 extends, the radial direction on the radially inner side and the radially outer side refers to the radial direction centered on the rotation axis L, and the circumferential direction refers to the rotation direction centered on the rotation axis L.

(Overall structure)
FIG. 1 is an external perspective view of a pump device 1 to which the present invention is applied. FIG. 2 is a cross-sectional view of the pump device 1 shown in FIG. 1 cut along a plane including a rotation axis L. As shown in FIGS. 1 and 2 , the pump device 1 includes a case 2 having a suction pipe 21 and a discharge pipe 22 extending to one axial side L1, a motor 10 disposed on the other axial side L2 of the case 2, and an impeller 25 disposed in a pump chamber 20 inside the case 2. The impeller 25 is driven to rotate about the rotation axis L by the motor 10. In the pump device 1 of this embodiment, the fluid flowing through the pump chamber 20 is a liquid. The pump device 1 is used, for example, under conditions where the environmental temperature and fluid temperature are prone to change.

The motor 10 includes an annular stator 3, a rotor 4 positioned inside the stator 3, a resin housing 6 that covers the stator 3, and a support shaft 5 that rotatably supports the rotor 4. The support shaft 5 is made of metal or ceramic. The impeller 25 rotates integrally with the rotor 4. As shown in Figure 2, in the pump device 1, the impeller 25 and pump chamber 20 are provided on one axial side L1 of the stator 3.

As shown in FIG. 2, the pump chamber 20 is located between the case 2 and the housing 6. The case 2 forms a wall surface 23 on one axial side L1 of the pump chamber 20 and a side wall 29 extending circumferentially. As shown in FIG. 1, the case 2 includes an intake pipe 21 extending along the rotational axis L of the motor 10, and a discharge pipe 22 extending perpendicular to the rotational axis L of the motor 10. The intake pipe 21 is arranged concentrically with the rotational axis L.

In the motor 10, the stator 3 includes a stator core 31, an insulator 32 overlapping the stator core 31 from one axial side L1, an insulator 33 overlapping the stator core 31 from the other axial side L2, and multiple coils 35 wound around multiple salient poles provided on the stator core 31 via the insulators 32 and 33. The motor 10 is a three-phase motor. Therefore, the multiple coils 35 are composed of a U-phase coil, a V-phase coil, and a W-phase coil.

The rotor 4 includes a rotor member 40 made of resin. The rotor member 40 includes a cylindrical portion 41 extending axially along the rotation axis L. The cylindrical portion 41 extends from the radially inner side of the stator 3 toward the pump chamber 20 and opens at the pump chamber 20. A cylindrical drive magnet 8 is held on the outer peripheral surface of the cylindrical portion 41. The drive magnet 8 faces the stator 3 radially inner side. The drive magnet 8 is made of, for example, a neodymium bonded magnet.

In the rotor member 40, a disk-shaped flange portion 45 is formed at the end of one axial side L1 of the cylindrical portion 41, and a disk 26 is connected to the flange portion 45 from one axial side L1. A central hole 260 is formed in the center of the disk 26. On the surface of the disk 26 facing the flange portion 45, multiple blade portions 261 are formed at equal angular intervals. The blade portions 261 extend radially outward while curving in an arc from the periphery of the central hole 260, and the disk 26 is fixed to the flange portion 45 via the blade portions 261. Therefore, the flange portion 45 and the disk 26 form the impeller 25 connected to the cylindrical portion 41 of the rotor member 40. In this embodiment, the disk 26 is inclined toward the flange portion 45 as it extends radially outward.

In the rotor member 40, a cylindrical radial bearing 11 is held radially inside the cylindrical portion 41. The rotor 4 is rotatably supported on the support shaft 5 via the radial bearing 11. The end of the other axial side L2 of the support shaft 5 is held in a shaft hole 65 formed in the bottom wall 63 of the housing 6. The case 2 is formed with a receiving portion 280 that faces the end of one axial side L1 of the support shaft 5 on the pump chamber 20 side and limits the range of movement of the support shaft 5 toward the pump chamber 20. The case 2 has three support portions 27 that extend from the inner surface of the suction pipe 21 toward the motor 10. A tubular portion 28 is formed at the end of the support portion 27, inside which the support shaft 5 is located, and a receiving portion 280 is provided at the bottom of one axial side L1 of the tubular portion 28.

An annular thrust bearing 12 is attached to the end of one axial side L1 of the support shaft 5, and the thrust bearing 12 is positioned between the radial bearing 11 and the cylindrical portion 28. At least a portion of the end of the other axial side L2 of the support shaft 5 and the shaft hole 65 have a D-shaped cross section (see Figures 3 and 4). The end of the one axial side L1 of the support shaft 5 and the hole of the thrust bearing 12 also have a D-shaped cross section. Therefore, rotation of the support shaft 5 and thrust bearing 12 relative to the housing 6 is prevented.

The housing 6 is a resin sealing member 60 that covers the stator 3 from both radial and axial sides. The resin sealing member 60 is made of polyphenylene sulfide (PPS). The stator 3 is integrated with the resin sealing member 60 by insert molding. The housing 6 is a partition member that has a first partition portion 61 facing the wall surface 23 on one axial side L1 of the pump chamber 20, a second partition portion 62 interposed between the stator 3 and the drive magnet 8, and a bottom wall 63 provided at the end of the second partition portion 62 on the other axial side L2. The housing 6 also has a cylindrical body portion 66 that covers the stator 3 from the radial outside.

As shown in Figures 1 and 2, a cover 18 is fixed to the end 64 of the housing 6 on the other axial side L2. As shown in Figure 2, a circuit board 19 is disposed between the cover 18 and the bottom wall 63 of the housing 6, and the circuit board 19 is provided with a circuit that controls the power supply to the coil 35. A metal winding terminal 71 that protrudes from the stator 3 through the bottom wall 63 of the housing 6 to the other axial side L2 is connected to the circuit board 19 by soldering.

The housing 6 has a first columnar portion 67 that protrudes from the bottom wall 63 toward the other axial side L2, and a second columnar portion (not shown) that protrudes from the bottom wall 63 toward the other axial side L2 at a position circumferentially spaced from the first columnar portion 67. The substrate 19 is fixed to the first columnar portion 67 and the second columnar portion (not shown) with screws.

As shown in FIG. 1, the housing 6 includes a cylindrical connector housing 69 that extends radially outward from a body portion 66 that surrounds the outer periphery of the stator 3. Connector terminals, one end of which is connected to the circuit board 19, are located inside the connector housing 69. When the connector is connected to the connector housing 69, a drive current generated by a circuit mounted on the circuit board 19 is supplied to each coil 35 via the winding terminals 71. As a result, the rotor 4 rotates around the rotation axis L of the motor 10. This rotates the impeller 25 within the pump chamber 20, creating a negative pressure inside the pump chamber 20. Fluid is sucked into the pump chamber 20 through the suction pipe 21 and discharged from the discharge pipe 22.

(Drive magnet and radial bearing holding structure)
3 and 4 are exploded perspective views of the rotor member 40, drive magnet 8, radial bearing 11, and support shaft 5. FIG. 3 is an exploded perspective view seen from one axial side L1, and FIG. 4 is an exploded perspective view seen from the other axial side L2. FIG. 5 is a perspective view of the rotor member 40 seen from one axial side L1. FIG. 6 is a cross-sectional view of the rotor member 40, drive magnet 8, radial bearing 11, and support shaft 5 taken along a plane including the rotation axis, and taken along line B-B in FIG. 7. FIG. 7 is a cross-sectional view of the rotor member 40, drive magnet 8, radial bearing 11, and support shaft 5 taken along a plane perpendicular to the rotation axis L, and taken along line A-A in FIG. 6.

In this specification, the three directions X, Y, and Z are perpendicular to each other. One side of the X direction is designated X1, the other side of the X direction is designated X2, one side of the Y direction is designated Y1, the other side of the Y direction is designated Y2, one side of the Z direction is designated Z1, and the other side of the Z direction is designated Z2. The Z direction coincides with the axial direction, the Z1 direction coincides with one side L1 of the axial direction, and the Z2 direction coincides with the other side L2 of the axial direction.

2 and 4, the rotor member 40 has an annular seat 42 that protrudes radially outward from the cylindrical portion 41 at a position spaced from the flange portion 45 toward the other side L2. As shown in FIG. 6, the cylindrical portion 41 has a magnet holding portion 410 that extends from the seat 42 toward the other side L2. The magnet holding portion 410 fits inside the cylindrical drive magnet 8 to hold the drive magnet 8. In this case, the seat 42 supports the end of the drive magnet 8 on one side L1 in the axial direction. A crimped portion 43 that overlaps the drive magnet 8 in the axial direction is formed on the end of the magnet holding portion 410 on the opposite side in the axial direction from the seat 42 (the other side L2 in the axial direction).

As shown in Figure 6, the inner circumferential surface of the cylindrical portion 41 is formed with annular first and second protrusions 441 and 442 that protrude radially inward. The first protrusion 441 is disposed on a step 116 on one axial side L1 of the radial bearing 11. The second protrusion 442 is disposed on a step 117 on the other axial side L2 of the radial bearing 11. When manufacturing the rotor member 40, the radial bearing 11 is formed as a resin molded product by insert molding. This allows the radial bearing 11 to be held between the first protrusion 441 and the second protrusion 442.

As shown in Figures 4 and 6, the end of the magnet holder 410 on the other axial side L2 has a protrusion 411 extending toward the other axial side L2 relative to the second convex portion 442, and a crimped portion 43 is formed at the tip of the protrusion 411. As shown in Figure 4, the protrusion 411 has two notches 412 cut out at radially opposite locations on one axial side L1. One notch 412 is located at an angular position in the X1 direction relative to the rotation axis L, and the other notch 412 is located at an angular position in the X2 direction relative to the rotation axis L. In this embodiment, the crimped portion 43 extends in an arc shape except for the portion where the notch 412 is formed.

As shown in Figure 4, the seat portion 42 of the rotor member 40 has recesses 421 recessed on one axial side L1 and anti-rotation protrusions 422 protruding from the bottom surface of each recess 421 on the other axial side L2. The recesses 421 are provided at multiple positions at equal angular intervals (in this embodiment, three positions at 120-degree intervals). The portion between adjacent recesses 421 in the circumferential direction is a flat portion 423 perpendicular to the axial direction.

The recess 421 extends from the inner edge to the outer edge of the seat 42. The anti-rotation protrusion 422 is located in the circumferential center of the recess 421 and extends from the inner edge of the seat 42 to a position halfway in the radial direction of the seat 42. Therefore, the anti-rotation protrusion 422 is surrounded by the recess 421 on both circumferential sides and on the radial outside. The axial height of the anti-rotation protrusion 422 is greater than the axial depth of the recess 421. Therefore, the anti-rotation protrusion 422 protrudes to a position on the other axial side L2 relative to the flat portion 423.

When the drive magnet 8 is fixed to the magnet holder 410, the end of one axial side L1 of the drive magnet 8 is brought into contact with the flat portion 423 of the seat 42 from the other axial side L2. At this time, the anti-rotation protrusion 422 fits into the anti-rotation recess 81 (see Figure 3) formed on the end face of one axial side L1 of the drive magnet 8. This defines the circumferential angular position of the drive magnet 8 and prevents rotation of the drive magnet 8 relative to the rotor member 40.

(flow passages for cooling the drive magnet and radial bearing)
As shown in FIGS. 3 and 4 , the rotor member 40 includes a first flow channel 46 formed in the outer circumferential surface of the magnet holder 410 of the cylindrical portion 41. The first flow channel 46 is a recess that is recessed radially inward to a certain depth. When the magnet holder 410 is fitted inside the drive magnet 8, a flow channel F1 (see FIG. 7 ) having a shape defined by the first flow channel 46 is formed between the inner circumferential surface of the drive magnet 8 and the magnet holder 410. This flow channel F1 communicates with a gap G1 (see FIG. 2 ) between the drive magnet 8 and the second partition wall portion 62 of the housing 6, as described below. Therefore, fluid from the pump chamber 20 flows through the flow channel F1 via the gap G1, thereby cooling the drive magnet 8 and the magnet holder 410.

As shown in FIG. 5 , the rotor member 40 has a second flow channel 47 formed on the inner circumferential surface of the cylindrical portion 41. The second flow channel 47 is a recessed portion with an arc-shaped cross section extending in the axial direction. The second flow channel 47 extends to the end of one axial side L1 of the cylindrical portion 41, opens at the inner circumferential edge of the flange portion 45, and communicates with the pump chamber 20. Openings 471 and 472 that penetrate the first convex portion 441 and the second convex portion 442 are formed on the inside of the cylindrical portion 41 at the same angular position as the second flow channel 47.

As shown in Figures 4 and 5, the second flow grooves 47 are formed at two radially opposite locations on the inner circumferential surface of the cylindrical portion 41. The angular positions of the two second flow grooves 47 match the angular positions of two notches 412 cut out from the end of the other side L2 of the cylindrical portion 41. Therefore, as shown in Figure 4, at the end of the other axial side L2 of the cylindrical portion 41, openings 472 that penetrate the second protrusion 442 are located radially inward of each of the two notches 412, and the radially outer sides of the openings 472 are not blocked by the crimped portion 43.

As shown in Figures 3 and 4, grooves 111 extending in the axial direction are formed on the outer peripheral surface of the radial bearing 11. Two of the grooves 111 are positioned at the same angular position as the second flow grooves 47. When the radial bearing 11 is held inside the cylindrical portion 41, as shown in Figure 7, the second flow grooves 47 and the grooves 111 form a flow path F2 (see Figure 7) extending in the axial direction between the inner peripheral surface of the cylindrical portion 41 and the outer peripheral surface of the radial bearing 11. One end of flow path F2 extends to the flange portion 45 as described above and communicates with the pump chamber 20. The other end of flow path F2 communicates with the gap G2 (see Figure 2) between the drive magnet 8 and the bottom wall 63 of the housing 6 via the opening 472 and the notch 412 in the second convex portion 442. Therefore, fluid from the pump chamber 20 flows through flow path F2, cooling the radial bearing 11 and the cylindrical portion 41.

(Shape and arrangement of flow channel grooves)
Fig. 8 is a perspective view of the rotor member 40 as viewed from the side where the first flow channel 46 is formed (X1 direction). Fig. 9 is a perspective view of the rotor member 40 as viewed from the side where the third flow channel 49 is formed (X2 direction). Figs. 8 and 9 are cross-sectional views of the end of the other side L2 of the cylindrical portion 41 taken along the CC position in Fig. 6. The R1 direction shown in Figs. 3, 4, 8, and 9 is the front side in the rotation direction of the rotor 4, and the R2 direction is the rear side in the rotation direction of the rotor 4.

As shown in Figures 4 and 8, the first flow channel 46 includes a first groove portion 461 extending in the axial direction, a second groove portion 462 extending in the axial direction on the rear side R2 of the first groove portion 461 in the rotational direction of the rotor 4, and a third groove portion 463 extending in the circumferential direction and connecting the ends of the first groove portion 461 and the second groove portion 462 on the other axial side L2. In other words, the first flow channel 46 is a groove that is folded back once in the axial direction, and is a substantially U-shaped groove. The first groove portion 461 and the second groove portion 462 have the same circumferential width.

The first flow channel 46 has an end portion on one axial side L1 of the first groove portion 461 that communicates with the gap G1 between the drive magnet 8 and the second partition wall portion 62 via the inlet 48 described below. Fluid from the pump chamber 20 flows into the first flow channel 46 from the first groove portion 461. The third groove portion 463 and the second groove portion 462 are located on the rear side R2 of the first groove portion 461 in the rotational direction. Therefore, when the rotor 4 rotates in the R1 direction, inertial force causes the fluid in the first groove portion 461 to move in the R2 direction and flow through the third groove portion 463 and the second groove portion 462, generating a flow in the D direction shown in Figure 4. This creates negative pressure within the first groove portion 461, allowing more fluid to flow in. In other words, while the rotor 4 is rotating, fluid continues to flow through the first flow channel 46 in the D direction shown in Figure 4.

As shown in FIG. 8 , a recess 421 is formed in the seat portion 42 of the rotor member 40, and an inlet 48 opening radially outward is formed between the end face of one axial side L1 of the drive magnet 8, indicated by the dashed line in FIG. 8 , and the bottom surface of the recess 421. Because the recess 421 is formed radially outward of the first groove portion 461, the first groove portion 461 communicates with the gap G1 (see FIG. 2 ) on the outer periphery of the drive magnet 8 via the inlet 48. In this embodiment, the radially inner end of the recess 421 is connected to the first groove portion 461, and the radially inner end of the recess 421 and the first groove portion 461 have the same circumferential width. Because the recess 421 has a sector shape whose circumferential width increases radially outward, fluid easily flows in from the radially outer side.

As shown in FIG. 7, the anti-rotation recess 81 formed in the drive magnet 8 has a radial dimension longer than the anti-rotation protrusion 422. Therefore, a gap G3, which serves as a flow path, is formed between the radially outer side surface of the anti-rotation protrusion 422 and the radially inner side surface of the anti-rotation recess 81. As shown in FIG. 6, the axial depth of the anti-rotation recess 81 is such that an axial gap G4 is formed between it and the anti-rotation protrusion 422. Therefore, the fluid flowing in from the inlet 48 not only flows around both circumferential sides of the anti-rotation protrusion 422, but can also flow into the first groove portion 461 via gaps G3 and G4.

As shown in FIG. 8 , on the outer peripheral surface of the magnet holding portion 410, the portion between the circumferentially adjacent first groove portion 461 and second groove portion 462 forms a first rib 51 extending axially from the seat portion 42 to the third groove portion 463. The radially outer portion of the second groove portion 462 in the seat portion 42 is a flat portion 423 that supports the drive magnet 8, and therefore a wide opening such as the inlet port 48 is not formed radially outward of the second groove portion 462. Therefore, a pressure difference occurs between the inlet and outlet sides of the first flow channel 46, making it easy for fluid to flow into the first flow channel 46.

As shown in FIG. 8, first flow grooves 46 are formed in two locations circumferentially side by side on the outer peripheral surface of the magnet holding portion 410. Furthermore, in the area of the outer peripheral surface of the magnet holding portion 410 where the first flow grooves 46 are not formed (the area in the X2 direction), as shown in FIG. 9, two third flow grooves 49 are formed side by side and extend in the axial direction with the same width as the first groove portion 461 and the second groove portion 462. The third flow grooves 49 extend to the end of the cylindrical portion 41 on the other axial side L2.

As shown in FIG. 8, two of the three recesses 421 formed in the seat 42 are located at angular positions corresponding to the first groove portion 461 of the first flow channel 46. On the other hand, the remaining recess 421 is located at an angular position corresponding to one of the two third flow channel grooves 49, as shown in FIG. 6. Therefore, fluid flows into one of the third flow channel grooves 49 via an inlet 48 formed between the recess 421 and the drive magnet 8.

As shown in Figures 8 and 9, on the outer peripheral surface of the magnet holding portion 410, the portions between adjacent first groove portions 461 in the circumferential direction, the portions between adjacent third flow grooves 49 in the circumferential direction, and the portions between adjacent first flow grooves 46 and third flow grooves 49 in the circumferential direction all form second ribs 52 extending in the axial direction. Therefore, four second ribs 52 are formed on the outer peripheral surface of the magnet holding portion 410. All four second ribs 52 extend to the end of the cylindrical portion 41 on the other axial side L2.

Two of the four second ribs 52 are located at angular positions on the opposite side in the X direction from the rotation axis L, and are located so as to overlap radially with the second flow groove 47 located on the inner circumferential surface of the cylindrical portion 41. The first rib 51 and the second rib 52 protrude radially outward from the bottom surfaces of the first flow groove 46 and the third flow groove 49. Therefore, by matching the angular position of the second flow groove 47 with the angular position of the second rib 52, it is possible to ensure the thickness of the magnet holding portion 410 in the area where the second flow groove 47 is formed.

(Main effects of this embodiment)
As described above, the pump device 1 of this embodiment includes the motor 10 including the rotor 4 and the stator 3 surrounding the outer periphery of the rotor 4, and the impeller 25 disposed in the pump chamber 20 provided on one axial side L1 of the stator 3 and rotating integrally with the rotor 4. The rotor 4 includes the cylindrical drive magnet 8 and the rotor member 40 provided with the cylindrical portion 41 that fits inside the drive magnet 8, and the radial bearing 11 is held inside the cylindrical portion 41. The outer periphery of the magnet holding portion 410 of the cylindrical portion 41 is provided with the first flow channel 46 that forms the flow channel F1 between the outer periphery of the magnet holding portion 410 and the inner periphery of the drive magnet 8. The first flow channel 46 includes a first groove portion 461 extending in the axial direction, a second groove portion 462 extending in the axial direction on a rear side R2 of the first groove portion 461 in the rotation direction of the rotor 4, and a third groove portion 463 extending in the circumferential direction and connecting ends of the first groove portion 461 and the second groove portion 462 on the other axial side L2. A gap G1 communicating with the pump chamber 20 is provided between the outer circumferential side of the drive magnet 8 and a second partition wall portion 62 of the housing 6 serving as a partition wall member covering the inner circumferential side of the stator 3. An end of the first groove portion 461 opposite the third groove portion 463 in the axial direction (i.e., an end on one axial side L1) communicates with the gap G1.

In this embodiment, a flow path F1 communicating with the pump chamber 20 is provided between the cylindrical portion 41 of the rotor member 40 and the drive magnet 8. Liquid in the pump chamber 20 flows through the flow path F1, cooling the drive magnet 8 and the cylindrical portion 41. The first flow groove 46, provided on the outer surface of the magnet holder 410 of the cylindrical portion 41 to form this flow path F1, has a U-shaped configuration in which the axially extending first groove portion 461 and second groove portion 462 are connected by a circumferentially extending third groove portion 463, forming a U-shape. Therefore, compared to a configuration in which a linear flow path F1 is provided, the area in contact with the fluid is larger, resulting in a higher cooling effect. Furthermore, because the first groove portion 461, located on the forward side R1 in the rotational direction of the rotor 4, is connected to the space (gap G1) on the outer periphery of the drive magnet 8, fluid from the pump chamber 20 can easily flow into the first groove portion 461. When the rotor 4 rotates, inertial force causes the fluid to flow toward the rear side R2 in the rotational direction. Therefore, by configuring the fluid to flow into the first groove portion 461 located on the front side R1 in the rotational direction, a large amount of fluid can flow through the flow path F1, resulting in a high cooling effect. This helps prevent temperature increases in the drive magnet 8 and cylindrical portion 41. Furthermore, temperature increases in the radial bearing 11 can be prevented via the cylindrical portion 41. By suppressing temperature increases, shortened component life can be prevented, and deterioration of the magnetic properties of the drive magnet 8 can be prevented.

In this embodiment, the rotor member 40 has a seat 42 that protrudes radially outward from the cylindrical portion 41 and supports the axial end of the drive magnet 8, and an inlet 48 that connects the first groove 461 to the gap G1 is provided between the seat 42 and the axial end of the drive magnet 8. By providing the seat 42 in this way, the axial positional accuracy of the drive magnet 8 can be improved. Furthermore, even when the seat 42 is provided, fluid can flow into the first groove 461 from the inlet 48, thereby suppressing temperature increases in the drive magnet 8 and radial bearing 11.

In this embodiment, the seat 42 has a recess 421 formed radially outward of the first groove 461, and the inlet 48 is the gap between the recess 421 and the axial end of the drive magnet 8. By providing the recess 421 in the seat 42 in this way, the inlet 48 can be made larger. Therefore, fluid can more easily flow into the first groove 461, allowing a larger amount of fluid to flow, resulting in a high cooling effect.

In this embodiment, the circumferential width of the recess 421 is equal to or greater than the circumferential width of the first groove portion 461. More specifically, the circumferential width of the recess 421 matches the circumferential width of the first groove portion 461 at the radially inner end, and increases radially outward. Increasing the circumferential width of the recess 421 makes it easier for more fluid to flow into the first groove portion 461, thereby improving the cooling effect. Note that the circumferential width of the recess 421 may differ from that of this embodiment. For example, the circumferential width of the recess 421 may be greater than that of this embodiment.

The recess 421 has a shape in which its circumferential width increases as it moves radially outward. For example, in this embodiment, the shape of the recess 421 when viewed from the axial direction is a fan shape in which its circumferential width increases as it moves radially outward. With this shape, fluid pressure increases when fluid flows from the recess 421 into the first groove portion 461, promoting the flow of fluid. As a result, a large amount of fluid flows, resulting in a high cooling effect.

In this embodiment, the seat portion 42 of the rotor member 40 has a rotation prevention protrusion 422 that protrudes toward the drive magnet 8 from the inside of the recess 421, and the drive magnet 8 has a rotation prevention recess 81 into which the rotation prevention protrusion 422 fits. Therefore, by fitting the rotation prevention protrusion 422 into the rotation prevention recess 81, the drive magnet 8 can be easily positioned circumferentially. Furthermore, even if the radial dimension of the rotation prevention recess 81 is increased, the circumferential positioning is not affected. In this embodiment, a radial gap G3 is formed between the rotation prevention protrusion 422 and the rotation prevention recess 81, increasing the gap G3 through which the fluid flows. This allows a large amount of fluid to flow into the first groove portion 461, resulting in a high cooling effect.

In this embodiment, the seat 42 of the rotor member 40 has a flat portion 423 that abuts the drive magnet 8 in the axial direction radially outside the third groove 463, and the flat portion 423 has a wider circumferential width than the third groove 463. That is, in this embodiment, the seat 42 does not have a recess 421 radially outside the third groove 463, leaving the flat portion 423, and the outlet end of the first flow channel 46 is blocked. By providing an inlet 48 at the inlet end and blocking the outlet end, a pressure difference can be generated. This makes it easier for fluid to flow into the first flow channel 46, thereby improving the cooling effect.

In this embodiment, a second flow channel 47 is formed on the inner peripheral surface of the cylindrical portion 41, forming a flow channel F2 between the inner peripheral surface of the radial bearing 11 and the second flow channel 47. The second flow channel 47 has a different circumferential position (angular position) than the first flow channel 46. That is, the cylindrical portion 41 has a second rib 52 that protrudes radially outward from the first flow channel 46, and the second flow channel 47 is positioned in the same circumferential position as the second rib 52. Therefore, by aligning the circumferential positions of the second flow channel 47 and the first flow channel 46, the thickness of the cylindrical portion 41 can be prevented from becoming thin, thereby ensuring the strength of the cylindrical portion 41.

(Other embodiments)
(1) Instead of forming the first flow channel 46 on the outer peripheral surface of the magnet holding portion 410 in the cylindrical portion 41, a U-shaped groove similar to the first flow channel 46 may be formed on the inner peripheral surface of the drive magnet 8, thereby allowing fluid to flow between the drive magnet 8 and the magnet holding portion 410.

(2) The first flow path groove 46 may have a shape that is opposite in the axial direction to the above embodiment. That is, in the above embodiment, the first flow path groove 46 is shaped to fold back from the end on the other axial side L2 of the first groove portion 461 to one axial side L1, and is configured so that fluid flows in from the end on one axial side L1 of the first groove portion 461 (i.e., the end on the pump chamber 20 side). However, the first flow path groove 46 may be shaped to fold back from the end on one axial side L1 of the first groove portion 461 to the other axial side L2, and so that fluid flows in from the end on the other axial side L2 of the first groove portion 461 (i.e., the end opposite the pump chamber 20).

(3) In the above embodiment, the first groove portion 461 and the second groove portion 462 of the first flow channel 46 are parallel to the axial direction, but they may also be inclined relative to the axial direction. In other words, in the present invention, the "first groove portion extending in the axial direction" and "second groove portion extending in the axial direction" include not only groove shapes that extend parallel to the axial direction, but also groove shapes that extend at an angle relative to the axial direction.

1...pump device, 2...case, 3...stator, 4...rotor, 5...support shaft, 6...housing, 8...drive magnet, 10...motor, 11...radial bearing, 12...thrust bearing, 18...cover, 19...substrate, 20...pump chamber, 21...suction pipe, 22...discharge pipe, 23...wall surface, 25...impeller, 26...disk, 27...support portion, 28...cylindrical portion, 29...side wall, 31...stator core, 32, 33...insulator, 35...coil, 40...rotor member, 41...cylindrical portion, 42...seat portion, 43...crimped portion, 45...flange portion, 46...first flow groove, 47...second flow groove, 48...inlet, 49...third flow groove, 51...first rib, 52...second rib, 60...resin sealing member, 61...first partition wall portion, 62...second partition wall portion, 63... Bottom wall, 64...end portion, 65...shaft hole, 66...body portion, 67...first columnar portion, 69...connector housing, 71...winding terminal, 81...rotation prevention recess, 111...groove portion, 116, 117...step portion, 260...central hole, 261...wing portion, 280...receiving portion, 410...magnet holding portion, 411...protrusion portion, 412...notch portion, 421...recess portion, 422...rotation prevention protrusion, 423...flat portion, 441...first convex portion, 442...second convex portion, 461...first groove portion, 462...second groove portion, 463...third groove portion, 471, 472...opening portion, F1, F2...flow path, G1, G2, G3, G4...gap, L...rotation axis, L1...one side in the axial direction, L2...other side in the axial direction, R1...front side in the rotation direction of the rotor, R2...rear side in the rotation direction of the rotor

Claims (8)

a motor including a rotor and a stator surrounding an outer periphery of the rotor;
an impeller disposed in a pump chamber provided on one side of the stator in the axial direction, the impeller rotating integrally with the rotor, when a direction along the rotation axis of the rotor is defined as an axial direction;
The rotor includes a cylindrical drive magnet and a rotor member having a cylindrical portion fitted inside the drive magnet, and a radial bearing is held inside the cylindrical portion.
a first flow path groove is provided on one of the outer circumferential surface of the cylindrical portion and the inner circumferential surface of the drive magnet, the first flow path groove forming a flow path between the other of the outer circumferential surface of the cylindrical portion and the inner circumferential surface of the drive magnet;
the first flow path groove includes a first groove portion extending in the axial direction, a second groove portion extending in the axial direction on a rear side of the first groove portion in the rotation direction of the rotor, and a third groove portion extending in a circumferential direction and connecting end portions of the first groove portion and the second groove portion in the axial direction,
a gap communicating with the pump chamber is provided between the outer circumferential side of the drive magnet and a partition member covering the inner circumferential side of the stator;
The pump device is characterized in that an end of the first groove portion opposite to the third groove portion in the axial direction communicates with the gap. the rotor member includes a seat portion that protrudes from the cylindrical portion toward an outer periphery and supports an end portion of the drive magnet in the axial direction,
2. The pump device according to claim 1, wherein an inlet that communicates with the first groove and the gap is provided between the seat and the axial end of the drive magnet. the seat portion includes a recess formed radially outward of the first groove portion,
3. The pump device according to claim 2, wherein the inlet is a gap between the recess and an end of the drive magnet in the axial direction. The pump device described in claim 3, characterized in that the circumferential width of the recess is equal to or greater than the circumferential width of the first groove portion. The pump device described in claim 3, characterized in that the recessed portion has a circumferential width that increases radially outward. the seat portion includes a rotation prevention protrusion that protrudes toward the drive magnet inside the recess,
4. The pump device according to claim 3, wherein the drive magnet has a rotation prevention recess into which the rotation prevention protrusion fits. the seat portion includes a flat portion that is radially outward of the third groove portion and abuts against the drive magnet in the axial direction,
The pump device according to claim 2, wherein the flat portion has a circumferential width greater than that of the third groove portion. The first flow channel is formed on the outer peripheral surface of the cylindrical portion,
a second flow path groove is formed on the inner circumferential surface of the cylindrical portion to form a flow path between the inner circumferential surface of the cylindrical portion and the outer circumferential surface of the radial bearing;
The pump device according to claim 1 , wherein the second flow groove is positioned at a different circumferential position from the first flow groove.