Pump unit

Abstract

This invention provides a pump device that can suppress the increase in the outer diameter of the cylindrical portion even when a through portion extending along the rotation axis is provided in the cylindrical portion of the rotor. In the pump device (1), since a through portion (15) extending along the rotation axis is provided between the rotor (4) and the radial bearing (11), a large pressure difference is not easily generated on both sides of the rotor in the direction of the rotation axis. The through portion (15) is composed of a first groove (48) formed on the inner circumferential surface of the cylindrical portion (40) of the rotor (4) and a second groove (111) formed on the outer circumferential surface of the radial bearing (11). Therefore, even when a through portion (15) with a sufficient opening area is formed, the opening area of ​​the first groove (48) can be relatively narrow. Therefore, the strength of the cylindrical portion (40) is not easily reduced by the first groove (48), and it is not necessary to increase the outer diameter of the cylindrical portion (40).

Description

Technical Field

[0001] This invention relates to a pump device that uses a motor to rotate an impeller. Background Technology

[0002] In a pump assembly, a motor rotates an impeller housed within a pump chamber. The motor's rotor includes a cylindrical section that holds a cylindrical radial bearing to its inner side, and a cylindrical drive magnet is fixed to the outer periphery of this cylindrical section. If a large pressure difference occurs on either side of the rotor along its rotational axis, the rotor may vibrate in that direction. Therefore, a technique has been proposed to suppress this pressure difference by providing a through-hole formed by a through-hole extending through the cylindrical section of the rotor along its rotational axis (see Patent Document 1).

[0003] Existing technical documents

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 5180907 Summary of the Invention

[0006] However, as described in Patent Document 1, when a through hole is provided in the cylindrical portion of the rotor, the cylindrical portion needs to be thicker in the radial direction to ensure its strength, resulting in an increase in the outer diameter of the cylindrical portion. In view of the above problems, the objective of the present invention is to provide a pump device that can suppress the increase in the outer diameter of the cylindrical portion even when a through portion extending along the rotation axis is provided in the cylindrical portion of the rotor.

[0007] To solve the above-mentioned problems, the pump device of the present invention is characterized by having: a motor; and an impeller disposed in a pump chamber on one side of the rotational central axis relative to the motor and connected to the rotor of the motor, wherein a cylindrical portion is provided on the rotor, the cylindrical portion extending along the rotational central axis, a drive magnet is held on the outer side, and a cylindrical radial bearing is held on the inner side, and a through portion is provided between the cylindrical portion and the radial bearing, the through portion passing through both sides of the rotational central axis via a first groove extending along the rotational central axis on the inner circumferential surface of the cylindrical portion and a second groove extending along the rotational central axis on the outer circumferential surface of the radial bearing.

[0008] In this invention, because a through portion extending along the rotation axis is provided between the rotor and the radial bearing, a large pressure difference is less likely to occur on both sides of the rotor in the direction of the rotation axis. Therefore, the rotor is less likely to vibrate in the direction of the rotation axis. Here, the through portion is composed of a first groove formed on the inner circumferential surface of the cylindrical portion and a second groove formed on the outer circumferential surface of the radial bearing. Therefore, even when a through portion with a sufficient opening area is formed, the opening area of ​​the first groove can be relatively narrow. Therefore, the strength of the cylindrical portion is less likely to be reduced due to the first groove, and thus it is not necessary to increase the outer diameter of the cylindrical portion.

[0009] In this invention, the rotor can be a resin molded article formed by molding the radial bearing insert. When molding the insert, if a pin is positioned in the second groove of the radial bearing within the mold, the rotor can be manufactured using a resin molded article with the radial bearing molded into the insert.

[0010] In this invention, the following method can be adopted: a mark indicating the position of the first groove is provided on one end of the radial bearing in the direction of the rotation axis.

[0011] In this invention, a plurality of ribs extending along the rotation center axis are provided on the outer peripheral surface of the cylindrical portion, and the driving magnet is pressed into the cylindrical portion in such a way that it contacts the plurality of ribs from the radially outer side. According to this method, when the driving magnet is pressed into the cylindrical portion, eccentricity between the driving magnet and the cylindrical portion can be suppressed. Furthermore, since the driving magnet and the cylindrical portion are in contact via the ribs, it is not easy to apply large stress to the driving magnet even when a rapid temperature change occurs, thus suppressing the breakage of the driving magnet.

[0012] In this invention, the first groove can be positioned at an angle that overlaps with the rib when viewed radially. According to this method, since the rib overlaps with the through portion, the wall thickness of the cylindrical portion can be prevented from becoming too thin.

[0013] Invention Effects

[0014] In this invention, because a through portion extending along the rotation axis is provided between the rotor and the radial bearing, a large pressure difference is less likely to occur on both sides of the rotor in the direction of the rotation axis. Therefore, the rotor is less likely to vibrate in the direction of the rotation axis. Here, the through portion is composed of a first groove formed on the inner circumferential surface of the cylindrical portion and a second groove formed on the outer circumferential surface of the radial bearing. Therefore, even when a through portion with a sufficient opening area is formed, the opening area of ​​the first groove can be relatively narrow. Therefore, the strength of the cylindrical portion is less likely to be reduced due to the first groove, and thus it is not necessary to increase the outer diameter of the cylindrical portion. Attached Figure Description

[0015] Figure 1 This is a perspective view showing one embodiment of the pump device and motor to which the present invention is applied.

[0016] Figure 2 yes Figure 1 The pump assembly and motor shown are longitudinal sectional views.

[0017] Figure 3 yes Figure 2 Explanatory diagram of impellers, etc.

[0018] Figure 4 yes Figure 2 A three-dimensional view of the rotor, etc., is shown.

[0019] Figure 5 It is shown in Figure 2 A longitudinal sectional view showing the fixed drive magnet on the rotor.

[0020] Figure 6 It is shown in Figure 2 A cross-sectional view showing the drive magnet fixed on the rotor.

[0021] Figure 7 yes Figure 2 The cross-sectional view of the rotor shown.

[0022] Figure 8 Viewed from the other side of the axis of rotation Figure 2 A three-dimensional view of the rotor, etc., is shown.

[0023] Figure 9 Viewed from the other side of the axis of rotation Figure 2 The image shows a bottom view of the rotor, etc.

[0024] Figure 10 This is viewed from one side along the axis of rotation. Figure 2 A top view of the rotor, etc., as shown. Detailed Implementation

[0025] Hereinafter, the motor 10 and pump device 1 according to embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the direction of the rotation center axis L refers to the direction in which the rotation center axis L extends, the radial direction of the inner radial direction and the radial direction of the outer radial direction refer to the radial direction centered on the rotation center axis L, and the circumferential direction refers to the rotational direction centered on the rotation center axis L.

[0026] (Overall structure)

[0027] Figure 1 This is a perspective view showing one embodiment of the pump device 1 and motor 10 to which the present invention is applied. Figure 2 yes Figure 1 The pump assembly 1 and motor 10 shown are longitudinal sectional views. Figure 3 yes Figure 2 The diagram shows an explanation of impeller 25, etc. In Figure 1 and Figure 2 In this embodiment, the pump device 1 includes: a housing 2 having an inlet 21a and an outlet 22a; a motor 10 disposed on the opposite side L2 of the housing 2 in the direction of the rotational central axis L; and an impeller 25 disposed in a pump chamber 20 inside the housing 2, the impeller 25 being driven by the motor 10 to rotate about the rotational central axis L. The motor 10 includes a cylindrical stator 3, a rotor 4 disposed inside the stator 3, a resin housing 6 covering the stator 3, and a rod-shaped support shaft 5 supporting the rotor 4 in a rotatable manner. The support shaft 5 is made of metal or ceramic. In the pump device 1 of this embodiment, the fluid is a liquid, and the pump device 1 is used under conditions where the ambient temperature or fluid temperature is easily changed.

[0028] The housing 2 forms a wall 23 on one side L1 along the rotational axis L of the pump chamber 20 and a side wall 29 extending circumferentially. The housing 2 has a suction pipe 21 extending along the rotational axis L and a discharge pipe 22 extending in a direction orthogonal to the rotational axis L. The suction pipe 21 and the discharge pipe 22 have a suction port 21a and a discharge port 22a at their respective ends. The suction pipe 21 is arranged concentrically with respect to the rotational axis L.

[0029] In the motor 10, the stator 3 has: a stator core 31; insulators 32 and 33 held in the stator core 31; and a coil 35 wound around the stator core 31 with the insulators 32 and 33 in between.

[0030] The rotor 4 has a cylindrical portion 40 that extends radially inward from a position opposite to the stator 3 along the rotational axis L toward the pump chamber 20, and the cylindrical portion 40 opens at the pump chamber 20. A cylindrical drive magnet 8 is held on the outer circumferential surface of the cylindrical portion 40, facing radially inward from the stator 3. The drive magnet 8 is, for example, a neodymium-bonded magnet.

[0031] like Figure 2 and Figure 3 As shown, in the rotor 4, a circular flange portion 45 is formed at one end of the cylindrical portion 40 along the rotational axis L direction L. A circular plate 26 is connected to this flange portion 45 from one end of the rotational axis L direction L1. A central hole 260 is formed in the center of the circular plate 26. On the surface of the circular plate 26 opposite to the flange portion 45, a plurality of blade portions 261 are formed at equal angular intervals, extending radially outward from the periphery of the central hole 260 in an arc shape. The circular plate 26 is fixed to the flange portion 45 via the blade portions 261. Therefore, the flange portion 45 and the circular plate 26 constitute an impeller 25 connected to the cylindrical portion 40 of the rotor 4. In this embodiment, the circular plate 26 is inclined such that its radially outer side is located further away from the flange portion 45 than its radially inner side.

[0032] Again in Figure 2 In the rotor 4, a cylindrical radial bearing 11 is held radially inside the cylindrical portion 40, and the rotor 4 is rotatably supported on the support shaft 5 via the radial bearing 11. The end 51 of the support shaft 5 on the other side L2 in the direction of the rotation center axis L is held in a shaft hole 65 formed in the bottom wall 63 of the housing 6. On the housing 2, a bearing portion 280 is formed opposite to the end 52 of the support shaft 5 on the pump chamber 20 side and restricts the movable range of the support shaft 5 towards the pump chamber 20 side. The housing 2 has three support portions 27 extending from the inner circumference of the suction pipe 21 towards the motor 10 side. At the end of the support portion 27, a cylindrical portion 28 is formed with the end 52 of the side L1 in the direction of the rotation center axis L of the support shaft 5 located inside, and the bearing portion 280 is formed by the bottom of the side L1 in the direction of the rotation center axis L of the cylindrical portion 28. A circular thrust bearing 12 is installed at the end 52 of the support shaft 5, and the thrust bearing 12 is disposed between the radial bearing 11 and the cylindrical portion 28. At least a portion of the end 51 of the support shaft 5 and the shaft hole 65 are formed with a D-shaped cross-section, and the end 52 of the support shaft 5 and the hole of the thrust bearing 12 are also formed with a D-shaped cross-section. Therefore, rotation of the support shaft 5 and the thrust bearing 12 is prevented.

[0033] The outer casing 6 is a partition wall component having a first partition wall portion 61 opposite to the wall surface 23 of the pump chamber 20 and a second partition wall portion 62 located between the stator 3 and the drive magnet 8. Additionally, the outer casing 6 has a cylindrical main body portion 66 that covers the stator 3 radially outward. Therefore, the resin sealing component 60 of the outer casing 6, which covers the stator 3 from both radial sides and both sides in the direction of the rotation center axis L, is a resin portion formed by insert molding the stator 3 using polyphenylene sulfide (PPS) or the like.

[0034] At end 64 on the other side L2 of the rotation center axis L of the outer casing 6, a cover 18 is fixed from the other side L2. A substrate 19 is disposed between the cover 18 and the bottom wall 63 of the outer casing 6. The substrate 19 is provided with circuitry for controlling the power supply to the coil 35. The substrate 19 is fixed to the outer casing 6 by screws 92. A metal winding terminal 71, which protrudes from the stator 3 through the bottom wall 63 of the outer casing 6 towards the other side L2 of the rotation center axis L, and a metal connector terminal 75, which is held in the outer casing 6, are connected to the substrate 19 by solder. Electronic components constituting the drive circuit are mounted on the substrate 19. In addition, wiring is formed on the substrate 19.

[0035] A cylindrical connector housing 69 is formed on the housing 6, and the end 750 of the connector terminal 75 is located inside the connector housing 69. Therefore, when the connector is connected to the connector housing 69 to provide signals, the signals are provided to each coil 35 via the connector terminal 75, the substrate 19, the winding terminal 71, and the metal connector terminal 75 held in the housing 6. As a result, the rotor 4 rotates about the rotation center axis L. As a result, the impeller 25 rotates inside the pump chamber 20, and the inside of the pump chamber 20 becomes negative pressure. Therefore, fluid is drawn into the pump chamber 20 from the suction pipe 21 and discharged from the discharge pipe 22.

[0036] (The fixing structure of the cylindrical part 40 of the drive magnet 8 to the rotor 4, etc.)

[0037] Figure 4 yes Figure 2 The three-dimensional view of rotor 4, etc. is shown. Figure 5 It is shown in Figure 2 A longitudinal sectional view showing the drive magnet 8 fixed on the rotor 4. Figure 6 It is shown in Figure 2 A cross-sectional view showing the drive magnet 8 fixed on the rotor 4. Figure 7 yes Figure 2 The longitudinal sectional view of rotor 4 shown. Figure 8 Viewed from the other side L2 of the axis of rotation L Figure 2 The three-dimensional view of rotor 4, etc. is shown. Figure 9 Viewed from the other side L2 of the axis of rotation L Figure 2 The bottom view of rotor 4, etc., is shown.

[0038] like Figure 2 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 As shown, in the motor 10, on the outer periphery of the cylindrical portion 40 of the rotor 4, a circularly extending annular seat portion 42 is formed at a position away from the flange portion 45 towards the other side L2. The cylindrical portion 40 extends from the seat portion 42 towards the other side L2 to form a magnet holding portion 43. The seat portion 42 is embedded inside the cylindrical drive magnet 8 to hold the drive magnet 8. At this time, the seat portion 42 supports the end 81 of one side L1 of the drive magnet 8.

[0039] On the inner circumferential side of the cylindrical portion 40 of the rotor 4, a first annular protrusion 441 extending radially inward is formed at a position overlapping the seat portion 42 when viewed radially, and a second annular protrusion 442 extending radially inward is formed at a position L2 on the other side of the first protrusion 441.

[0040] Additionally, a flange portion 45 is provided between the seat portion 42 and the flange portion 45. Figure 8 The through hole 44 is shown. The through hole 44 extends radially through the cylindrical portion 40. In this embodiment, the through holes 44 are provided at two locations on the cylindrical portion 40 that are offset from each other by 180 degrees. Therefore, when the impeller 25 rotates, a portion of the fluid flows from the pump chamber 20 into the inner side of the cylindrical portion 40 of the rotor 4, and then flows back into the pump chamber 20 along the bottom wall 24 through the through hole 44 of the cylindrical portion 40. Therefore, air and other fluids mixed in with the fluid are discharged from the pump chamber 20.

[0041] In the rotor 4 configured in this way, ribs 46 extending along the rotation center axis L are provided at multiple circumferential locations on the outer peripheral surface of the magnet holding part 43. The driving magnet 8 is pressed into the magnet holding part 43 in such a way that it contacts the multiple ribs 46 from the radially outer side. Therefore, a gap G is formed between the magnet holding part 43 and the driving magnet 8, between two adjacent ribs 46 in the circumferential direction (see reference). Figure 6 ).

[0042] Furthermore, a protrusion 421 is formed at the base portion 42, which engages with a recess 811 formed at the end 81 of one side L1 of the drive magnet 8. The protrusion 421 defines the circumferential angular position of the drive magnet 8 by engaging with the recess 811, and prevents the drive magnet 8 from rotating. Additionally, a recess 422 is formed at the base portion 42 at a position where it is separated from the protrusion 421 in the circumferential direction, extending from the inner edge to the outer edge of the base portion 42. When the drive magnet 8 is fixed to the magnet holding portion 43, the recess 422 connects with the gap G between two adjacent ribs 46 in the circumferential direction.

[0043] At the end 47 of the cylindrical portion 40, opposite to the seat portion 42, there are multiple circumferentially arranged riveting portions 471 that overlap with the driving magnet 8 (see reference). Figure 9 At least a portion of the gap G opens between two adjacent rivet portions 471 in the circumferential direction of the rivet portions 471 in the plurality of locations.

[0044] In this embodiment, ribs 46 are formed at equal angular intervals in six circumferential locations, and recesses 811, protrusions 421, recesses 422, and riveting portions 471 are formed at equal angular intervals in three circumferential locations. Furthermore, at the end 81 of the drive magnet 8, located circumferentially away from the recesses 811, gate marks 812 formed at equal angular intervals in three circumferential locations are provided for molding the drive magnet 8.

[0045] In the pump assembly 1 equipped with the motor 10 configured in this way, when the drive magnet 8 is pressed into the cylindrical portion 40, the drive magnet 8 abuts against the rib 46 formed on the cylindrical portion 40 of the rotor 4 from the radially outer side. Therefore, eccentricity between the drive magnet 8 and the cylindrical portion 40 can be suppressed. In addition, since the drive magnet 8 is connected to the cylindrical portion 40 via the rib 46, it is not easy to apply large stress to the drive magnet 8 even when a rapid temperature change occurs, thus suppressing the breakage of the drive magnet 8.

[0046] Furthermore, on the seat portion 42 of the end 81 supporting the drive magnet 8 of the rotor 4, recesses 422 are provided at multiple circumferential locations. Between the cylindrical portion 40 and the drive magnet 8, a gap G formed by two adjacent ribs 46 in the circumferential direction connects to the recesses 422. Therefore, fluid flowing through the pump device 1 can flow through the recesses 422 of the seat portion 42 and the gap G between the cylindrical portion 40 and the drive magnet 8. Thus, cooling of the rotor 4 and the drive magnet 8 is possible, thereby suppressing heat generation from the drive magnet 8 and the like.

[0047] Furthermore, at the end 47 of the cylindrical portion 40 opposite to the seat portion 42, multiple circumferentially oriented riveting portions 471 overlapping with the drive magnet 8 are provided, and at least a portion of the gap G opens between two circumferentially adjacent riveting portions 471. Therefore, fluid flowing in the recess 422 of the seat portion 42 and in the gap G between the cylindrical portion 40 and the drive magnet 8 can pass between the riveting portions 471, thereby efficiently suppressing heat generation in the drive magnet 8 and the like.

[0048] (Structure of the through section 15 of rotor 45)

[0049] Figure 10 This is observed from one side L1 along the axis of rotation L. Figure 2 The top view of rotor 4, etc., is shown. Figure 4 , Figure 5 , Figure 6 , Figure 7 As shown, in the motor 10 and pump assembly 1, a through portion 15 is provided between the cylindrical portion 40 of the rotor 4 and the radial bearing 11, through a first groove 48 extending along the rotational axis L on the inner circumferential surface of the cylindrical portion 40 and a second groove 111 extending along the rotational axis L on the outer circumferential surface of the radial bearing 11, allowing passage through both sides of the rotational axis L. More specifically, the second groove 111 overlaps with the first groove 48 from the radially inner side, forming the through portion 15 together with the first groove 48. The first groove 48 and the second groove 111 are both grooves with a semi-circular cross-section. Therefore, the through portion 15 extends linearly as a hole with a circular cross-section.

[0050] In the cylindrical portion 40, the first groove 48 is provided at an angle that overlaps with the rib 46 when viewed radially. Therefore, the rib 46 can be used to prevent the wall thickness of the cylindrical portion 40 from becoming too thin due to the formation of the first groove 48.

[0051] Here, annular first protrusions 441 and second protrusions 442 are formed on the cylindrical portion 40, extending radially inward and overlapping with a stepped portion 116 on one side L1 and a stepped portion 117 on the other side L2 of the rotational center axis L of the radial bearing 11. On the other hand, a first groove 48 is formed along the inner circumferential surface of the cylindrical portion 40. Therefore, the first groove 48, as a circular hole, penetrates the first protrusion 441 and the second protrusion 442, but does not reach the inner edges of the first protrusion 441 and the second protrusion 442. Thus, the inner edges of the first protrusion 441 and the second protrusion 442 are both continuous arc shapes.

[0052] Thus, in this embodiment, since a through portion 15 is provided that extends through both sides of the rotational axis L of the rotor 4, a large pressure difference is less likely to occur on both sides of the rotor 4 in the direction of the rotational axis L. Therefore, the rotor 4 is less likely to vibrate in the direction of the rotational axis L. Here, the through portion 15 is formed by a first groove 48 formed on the inner circumferential surface of the cylindrical portion 40 and a second groove 111 formed on the outer circumferential surface of the radial bearing 11 overlapping radially. Therefore, even when a through portion 15 with a sufficient opening area is formed, the opening area of ​​the first groove 48 can be relatively narrow. Therefore, the strength of the cylindrical portion 40 is less likely to be reduced by the first groove 48, and thus there is no need to increase the outer diameter of the cylindrical portion 40.

[0053] Furthermore, the first groove 48 and the second groove 111 extend in a straight line. Therefore, the rotor 4 can be configured as a resin molded article with the radial bearing 11 inserted. More specifically, during insert molding, after insert molding by placing a pin with a circular cross-section in the second groove 111 of the radial bearing 11 in the mold, if the pin is removed, the rotor 4 can be manufactured by insert molding while forming the through portion 15.

[0054] Furthermore, a groove-shaped mark 119 indicating the position of the second groove 111 is provided on the end 118 of the radial bearing 11 on one side L1 in the direction of the rotation center axis L. Therefore, during insert molding, the pin can be configured, etc., based on the mark 119 provided at the end 118 of the radial bearing 11.

[0055] [Other Implementation Methods]

[0056] In the above embodiment, the housing 6 is a resin sealing member 60 that covers the stator 3 from both radial sides and both sides in the direction of the rotation center axis L. However, the present invention can also be applied when the housing 6 is a member that only covers the radial inner side of the stator 3 and the other side L2 in the direction of the rotation center axis L.

[0057] Symbol Explanation

[0058] 1…pump assembly, 2…casing, 3…stator, 4…rotor, 5…shaft, 6…outer shell, 8…drive magnet, 10…motor, 11…radial bearing, 15…through section, 18…cover, 19…base plate, 20…pump chamber, 25…impeller, 35…coil, 40…cylindrical section, 42…seat section, 43…magnet holding section, 45…flange section, 46…rib, 48…first groove, 60…resin sealing component, 65…shaft hole, 111…second groove, 119…marker, 261…blade section, 471…riveting section, G…gap, L…rotation center axis.

Claims

1. A pump device, characterized in that, It has a motor and an impeller, the impeller being configured in a pump chamber located on one side relative to the motor's central axis of rotation and connected to the motor's rotor. The rotor has a cylindrical section that extends along the axis of rotation, holding the drive magnet on the outer side and a cylindrical radial bearing on the inner side. A through portion is provided between the cylindrical portion and the radial bearing. This through portion allows passage between the two sides of the rotational center axis via a first groove extending along the rotational center axis on the inner circumferential surface of the cylindrical portion and a second groove extending along the rotational center axis on the outer circumferential surface of the radial bearing and overlapping the first groove from the radially inner side. The outer circumferential surface of the cylindrical portion is provided with multiple ribs extending along the axis of rotation. The driving magnet is pressed into the cylindrical portion in such a way that it contacts the multiple ribs from the radially outer side. The first groove is positioned at an angle that overlaps with the rib when viewed radially.

2. The pump device according to claim 1, characterized in that, The rotor is a resin-molded article with the radial bearing inserted as an insert.

3. The pump device according to claim 2, characterized in that, A mark indicating the position of the first groove is provided on one end of the radial bearing in the direction of its rotation axis.

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