Electric pump

Abstract

To make it possible to endure high-speed rotation and various vibrations by making a magnet hardly become detached from a rotating member.SOLUTION: A magnet 22 of an axial gap motor of an electric pump is formed of a resin magnet fixed to a surface on the other side in a rotation axis direction in a rotating member 4. In the rotating member 4, a supporting part 47 supporting the other side in the rotation axis direction in the magnet 22 is provided so as to extend in a radial direction.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to an electric pump that sucks and discharges fluid by the rotational operation of a rotating member.

Background Art

[0002] For example, Patent Document 1 discloses a centrifugal pump including a pump chamber that houses an impeller and an axial gap type electric motor that rotates a rotating shaft to which the impeller is fixed. A bearing member is fixed to the radially inner side of a cylindrical portion that forms the axial center portion of the impeller of Patent Document 1, while a radially inner end portion of the impeller is supported between a surface on which the blades of the impeller are formed and a support portion formed at an end portion of the bearing member. On the surface of the impeller opposite to the surface on which the blades are formed, a radially inner end portion of the anisotropic magnet is supported between the impeller and a support portion of the bearing member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, the impeller may rotate at high speed. When rotating at high speed, it is necessary to fix the magnet fixed to the impeller so that it does not come off from the impeller. However, the anisotropic magnet of Patent Document 1 is fixed to the surface opposite to the blades of the impeller, and only the radially inner end portion is supported between the impeller and the support portion of the bearing member, and most of the surface of the anisotropic magnet opposite to the impeller is not supported. For this reason, when the impeller rotates at high speed, when various vibrations, fluctuations in the output (torque) of the motor, fluctuations in the load of the pump, etc. occur, or when a long period of time has passed since manufacturing, it is conceivable that the anisotropic magnet will come off from the impeller.

[0005] The present disclosure is made in view of such a point, and its object is to make it difficult for the magnet to come off from the rotating member so that it can withstand high-speed rotation, various vibrations, fluctuations in the output (torque) of the motor, fluctuations in the load of the pump, etc.

Means for Solving the Problem

[0006] In order to achieve the above object, in one aspect of the present disclosure, an axial-gap motor and a rotating member disposed on one side in the rotational axis direction of the axial-gap motor and rotationally driven by the axial-gap motor are provided, and a centrifugal electric pump configured to send fluid by the rotation of the rotating member can be assumed. The axial-gap motor includes a stator in which a plurality of coils are arranged side by side in the circumferential direction, and a magnet arranged to face one side in the rotational axis direction of the stator. The magnet is a resin magnet fixed to the surface on the other side in the rotational axis direction of the rotating member, and the rotating member is provided with a support portion that supports the other side in the rotational axis direction of the magnet so as to extend in the radial direction.

[0007] According to this configuration, since the rotating member having blades is disposed on one side in the rotational axis direction of the axial-gap motor, fluid is sucked from one side in the rotational axis direction and discharged in the radial direction by the rotation of the rotating member. Since the magnet of the axial-gap motor is a resin magnet fixed to the rotating member, it is molded along the surface shape of the rotating member during the molding of the magnet and adheres closely to the rotating member. In addition, since the other side in the rotational axis direction of the magnet is supported by the support portion extending in the radial direction, the magnet is fixed or supported with respect to the rotating member over a wide range on both sides in the rotational axis direction. Therefore, it becomes difficult for the magnet to come off from the rotating member.

[0008] The plurality of the supporting portions for supporting the magnet may be provided at intervals in the circumferential direction of the rotating member. As a result, since a plurality of portions of the magnet are supported by the supporting portions, it becomes more difficult for the magnet to come off from the rotating member. The plurality of supporting portions may be provided at equal intervals or at unequal intervals.

[0009] Part or all of the supporting portions for supporting the magnet may be embedded on the other side in the rotation axis direction of the magnet. Thereby, it is possible to prevent the supporting portion from protruding from the magnet and to suppress the amount of protrusion of the supporting portion from the magnet. As a result, the surface of the magnet and the stator can be brought closer to each other, so that high output can be obtained efficiently.

[0010] The magnet can be a magnet with magnetic anisotropy in which N poles and S poles are alternately arranged in the circumferential direction of the rotating member. In this case, the supporting portion can be arranged at the boundary between the N pole and the S pole of the magnet. That is, the boundary between the N pole and the S pole of the magnet is a portion where the magnetic flux density is 0 or close to 0. By arranging the supporting portion in such a portion where the magnetic flux density is relatively low, a decrease in the magnetic force due to the provision of the supporting portion is suppressed.

[0011] The rotating member may include a substrate portion extending in the radial direction and blades provided on one side of the substrate portion in the rotation axis direction. In this case, by forming a fitting hole into which one side in the rotation axis direction of the magnet fits so as to penetrate in the rotation axis direction in the substrate portion, it becomes more difficult for the magnet to come off from the rotating member.

[0012] On the surface of the substrate portion on the other side in the rotation axis direction, protrusions embedded in the magnet may be provided so as to extend in the circumferential direction. Thereby, since the magnet can also be held by the protrusions, it becomes more difficult for the magnet to come off from the rotating member. A plurality of protrusions can be provided.

Advantages of the Invention

[0013] As described above, since the resin magnet fixed to the rotating member is supported from the side opposite to the side fixed to the rotating member by the support portion extending in the radial direction, the magnet is less likely to come off from the rotating member and can withstand high-speed rotation and various vibrations.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiments is merely illustrative in nature and is not intended to limit the present invention, its applications, or its uses.

[0016] FIG. 1 is a diagram showing the appearance of a centrifugal electric pump 1 according to an embodiment of the present invention. In this embodiment, the case where the electric pump 1 is an electric water pump will be described. Therefore, the electric pump 1 according to the embodiment of the present invention is for circulating cooling water (an example of a fluid) that cools various devices mounted on a vehicle within a predetermined cooling water path. The cooling water is also called a coolant. The electric pump 1 may be, for example, an oil pump.

[0017] Examples of the various devices include a driving motor, a battery, a charging circuit, an inverter circuit, an engine, a transmission, an air-conditioning device, etc., but are not limited thereto, and the cooling water of other devices can also be circulated. In the description of this embodiment, as shown in each figure, one side and the other side in the rotation axis direction are defined, but this definition is only for convenience of explanation and does not limit the actual use posture, and the electric pump 1 can be used in any posture. For example, the rotation axis direction may be horizontal, vertical, or inclined. Also, the relationship between the rotation axis direction and the front-rear direction or left-right direction of the vehicle can be arbitrarily set. Also, the front side of the electric pump 1 is taken as one side in the rotation axis direction, and the back side is taken as the other side in the rotation axis direction. The front side of the electric pump 1 is the fluid suction side.

[0018] In the following description, the case where the present invention is applied to the centrifugal electric pump 1 will be described, but the present invention is not limited thereto, and the present invention can also be applied to electric pumps that send various liquids and gases. Also, the electric pump that sends gas may be a blower, a fan, a compressor, etc.

[0019] Figure 2 is a cross-sectional view of the electric pump 1. As shown in this Figure 2, the electric pump 1 includes an axial gap motor 2, a motor housing 3, a rotating member 4 having blades 41 rotationally driven by the axial gap motor 2, a housing 5, a circuit board (control board) 6, and a back member 7. The circuit board 6 is formed to extend in the vertical direction in Figure 2 and is disposed on the back side of the electric pump 1. The back member 7 is a member that constitutes the back cover of the electric pump 1, and the circuit board 6 is covered by this back member 7. The rotating member 4 is housed in the housing 5, and the rotating member 4 housed in this housing 5 is rotationally driven in a predetermined direction by the axial gap motor 2.

[0020] (Configuration of the housing 5) The housing 5 is an injection molded product formed by injection molding a resin material or the like. As shown in Figure 1, an intake pipe portion 50 that protrudes toward one side in the rotational axis direction of the rotating member 4 is integrally molded at a portion located at the center of the housing 5. The rotational axis direction of the rotating member 4 coincides with the rotational axis direction of the axial gap motor 2. In this embodiment, the right side in Figure 2 is defined as one side in the rotational axis direction of the axial gap motor 2, and the left side in Figure 2 is defined as the other side in the rotational axis direction of the axial gap motor 2. The rotational axis center is indicated by reference numeral A.

[0021] An intake port 50a is open at the tip (upstream end) of the intake pipe portion 50. Cooling water that has flowed through an intake side pipe (not shown) is inhaled into the intake port 50a. The housing 5 has a pump chamber forming wall portion 51 that extends radially from the base end portion (downstream end) of the intake pipe portion 50, and the side opposite to the protruding direction of the intake pipe portion 50 has a substantially entirely open shape. A pump chamber S1 (shown in Figure 2) that communicates with the downstream end of the intake pipe portion 50 is formed inside the pump chamber forming wall portion 51, and the rotating member 4 is housed in this pump chamber S1. The rotating member 4 is disposed on one side in the rotational axis direction of the axial gap motor 2. It is configured to send fluid by the rotation of this rotating member 4.

[0022] As shown in Fig. 1, an outflow passage S2 (shown in Fig. 2) communicating with the pump chamber S1 is formed in the pump chamber forming wall portion 51. That is, the electric pump 1 is configured to suck fluid in the direction along the rotation center line (rotation axis direction) by the rotation of the rotating member 4 and then discharge it in the radial direction.

[0023] (Configuration of the motor housing 3) As shown in Fig. 2, the motor housing 3 is an injection molded product formed by injection molding a resin material or the like, and is formed to cover the housing 5 from the open side. As shown in Fig. 1, a discharge pipe portion 52 is integrally molded on the motor housing 3 at a portion corresponding to the downstream end of the outflow passage S2. The discharge pipe portion 52 is formed to protrude in the tangential direction of a virtual circle centered on the rotation center of the rotating member 4. The base end portion (upstream end portion) of the discharge pipe portion 52 communicates with the downstream end portion of the outflow passage S2. A discharge port 52a (shown only in Fig. 1) is opened at the tip end portion (downstream end portion) of the discharge pipe portion 52. A discharge side pipe (not shown) communicates with the discharge port 52a, and the cooling water flowing through the discharge pipe portion 52 flows into the discharge side pipe.

[0024] As shown in Fig. 2, the motor housing 3 has a stator embedding portion 31 in which a plurality of stator cores 20 and a plurality of coils 21 of the stator 20A constituting the axial gap motor 2 to be described later are embedded and fixed. The stator embedding portion 31 has a thick plate shape. The pump chamber S1 is formed between the stator embedding portion 31 and the pump chamber forming wall portion 51 of the housing 5.

[0025] The outer peripheral portion of the motor housing 3 and the inner peripheral portion of the pump chamber forming wall portion 51 are in close contact with each other. By bringing the outer peripheral portion of the motor housing 3 and the inner peripheral portion of the pump chamber forming wall portion 51 into close contact, the watertightness between the motor housing 3 and the pump chamber forming wall portion 51 is ensured.

[0026] By closely adhering or bonding the outer peripheral portion of the motor housing 3 and the inner peripheral portion of the pump chamber forming wall portion 51, watertightness and airtightness between the two are ensured. As another example of joining, the motor housing 3 and the pump chamber forming wall portion 51 can be, for example, spin welded (welded), thereby joining the two parts while eliminating bolt fastening of sealing parts such as gaskets and ensuring watertightness and airtightness. Also, without performing fusion welding (welding), etc., the motor housing 3 and the pump chamber forming wall portion 51 may be bolted together with a sealing part (not shown) such as a gasket interposed therebetween to join the two. Since the joining structure between the motor housing 3 and the pump chamber forming wall portion 51 only needs to ensure watertightness and airtightness, it is also possible to use a joining structure other than the above-described structure.

[0027] The electric pump 1 can be, for example, floating mounted on an engine or the like, but the mounting structure is not limited to this and can be changed as necessary. Also, the electric pump 1 may be attached to the vehicle body.

[0028] (Configuration of the Axial Gap Motor 2) As shown in FIG. 2, the axial gap motor 2 includes a stator core 20 having a plurality of protrusions fixed to the motor housing 3, a plurality of coils 21 wound around each stator core 20, a magnet 22, a support shaft 24, a radial bearing 25, a suction side thrust bearing 26, and a stator side thrust bearing 27. In FIG. 2, the rotating member 4 is disposed on the right side (one side in the rotation axis direction) of the stator core 20 and the coils 21, and the circuit board 6 is disposed on the left side (the other side in the rotation axis direction) of the stator core 20 and the coils 21. In this embodiment, the magnet 22 is disposed only on the other side in the rotation axis direction, and no magnet is disposed on one side. Therefore, a low-cost and small-sized electric pump 1 can be achieved.

[0029] The protrusions of the stator core 20 are annularly arranged so as to surround the rotating shaft of the axial gap motor 2, and the circumferential intervals of the protrusions of the plurality of stator cores 20 are set at equal intervals. The stator core 20 is made of, for example, a soft magnetic material and has columnar protrusions that are long in the rotating shaft direction. Note that the number of stator cores 20 is not limited to a specific number and can be set to any number. Hereinafter, the number and shape of the coils 21 can be changed according to the number of protrusions of the stator core 20.

[0030] The core holder 60 is a member that holds the stator core 20 and is integrally formed of a resin material having electrical insulation properties. Since the core holder 60 is interposed between the stator core 20 and the coil 21, the stator core 20 and the coil 21 are insulated by the core holder 60.

[0031] Each coil 21 is arranged so as to surround each stator core 20. Therefore, the coil 21 is also held by the core holder 60. Further, the core holder 60 that holds the stator core 20 and holds the plurality of coils 21 is insert-molded into the motor housing 3.

[0032] A support shaft 24 for rotatably supporting the rotating member 4 is fixed to the motor housing 3. The support shaft 24 is positioned at the center of rotation of the axial gap motor 2. While the base end side (the other side in FIG. 2) of the support shaft 24 is fixed in a state of being embedded in the motor housing 3, the tip end side (one side in FIG. 2) of the support shaft 24 protrudes into the pump chamber S1. The tip end side of the support shaft 24 is inserted through a radial bearing 25.

[0033] A base end side screw hole 24b is formed on the base end side of the support shaft 24. The base end side screw hole 24b opens to the base end surface of the support shaft 24. On the other hand, a nut 24c is screwed onto the tip end side of the support shaft 24.

[0034] The radial bearing 25 is fixed to the rotation center of the rotating member 4 and is formed in a cylindrical shape with an axis extending in the direction of the rotation axis of the rotating member 4. The radial bearing 25 is rotatable relative to the support shaft 24. Therefore, when the rotating member 4 rotates, the inner peripheral surface of the radial bearing 25 and the outer peripheral surface of the support shaft 24 slide against each other.

[0035] The suction side thrust bearing 26 and the stator side thrust bearing 27 are disk-shaped. The suction side thrust bearing 26 is disposed on the suction side (one side in the rotational shaft direction) of the radial bearing 25, and the support shaft 24 is inserted through the center of the suction side thrust bearing 26. The stator side thrust bearing 27 is disposed on the stator 20A side (the other side in the rotational shaft direction) of the radial bearing 25, and the support shaft 24 is inserted through the center of the stator side thrust bearing 27. As a result, the radial bearing 25 is sandwiched between the suction side thrust bearing 26 and the stator side thrust bearing 27 from both sides in the rotational shaft direction.

[0036] When the rotating member 4 rotates, the stator-side thrust bearing 27 slides on the surface of the radial bearing 25 on the other side in the rotational axis direction. In addition, the suction-side thrust bearing 26 slides on the surface of the radial bearing 25 on one side in the rotational axis direction. By threading the bolt B into the base-end screw hole 24b and tightening the nut 24c, the suction-side thrust bearing 26, the stator-side thrust bearing 27, and the rotating member 4 can be attached to the support shaft 24, and the rotating member 4 can be supported in a rotatable state.

[0037] (Configuration of rotating member and magnet) 3 and 4 show a state in which the magnet 22 is fixed to the rotating member 4, and Fig. 5 is a view of the rotating member 4 as seen from the side opposite to the side to which the magnet 22 is fixed. Figs. 7 and 8 show the rotating member 4 to which the magnet 22 is not fixed.

[0038] The rotating member 4 is formed by injection molding a resin material or the like, and has a substantially circular substrate portion 40 extending in the radial direction and a plurality of blades 41 provided on one side in the rotation axis direction of the substrate portion 40. The substrate portion 40 and the blades 41 are integrally formed. The rotating member 4 may be made of a metal such as stainless steel. The plurality of blades 41 are provided at intervals in the circumferential direction. A covering portion 42 is fixed to the plurality of blades 41 by thermal caulking. The covering portion 42 is formed so as to cover the side of the rotating member 4 where the blades 41 are formed. The outer shape of the covering portion 42 is substantially the same circular shape as the substrate portion 40. The central side portion of the covering portion 42 is a cylindrical curved portion 42a curved so as to protrude toward one side in the rotation axis direction.

[0039] The covering portion 42 may be provided as necessary. Further, the covering portion 42 may be a member constituting a part of the rotating member 4, or may be a member different from the member constituting the rotating member 4.

[0040] The magnet 22 is a resin magnet fixed to the surface on the other side in the rotation axis direction of the substrate portion 40. For example, after the rotating member 4 is molded, the rotating member 4 is fixed at a predetermined position inside a mold (not shown), and then the molten resin magnet is filled into the mold. Thus, the resin magnet is molded by the inner surface of the mold and the surface of the rotating member 4 and is molded into a desired shape as shown in each figure. That is, since the magnet 22 can be obtained by insert molding, the shape of the magnet 22 conforms to the surface of the rotating member 4, and the magnet 22 can be brought into close contact with the surface of the rotating member 4.

[0041] By applying an external magnetic force when molding a molten resin magnet, it is possible to obtain a polar-anisotropic magnet 22 in which N poles 22a and S poles 22b are arranged alternately in the circumferential direction of the rotating member 4, as shown only in FIG. 4. Methods for obtaining this polar-anisotropic magnet 22 are conventionally well known, so detailed explanations will be omitted. In this embodiment, the magnet 22 has four N poles 22a and four S poles 22b, but this is not limiting and the number of N poles 22a and S poles 22b can be set to any number. In the following explanation, we will describe a case in which there are four N poles 22a and four S poles 22b, but the present invention can be applied whether the number of N poles 22a and S poles 22b is more or less than four.

[0042] A cylindrical portion 44 into which the radial bearing 25 is fitted is provided in the central portion of the base plate portion 40. The axis of the cylindrical portion 44 is located on the rotation axis. The cylindrical portion 44 protrudes from the base plate portion 40 on both sides in the rotation axis direction, and the radial bearing 25 is fixed inside the cylindrical portion 44.

[0043] An annular portion 45 is formed on the outside of the cylindrical portion 44 of the base portion 40, protruding toward the other side in the rotation axis direction and extending continuously in a circular ring shape in the circumferential direction. The center of the annular portion 45 is located on the rotation axis, so that the cylindrical portion 44 and the annular portion 45 are arranged concentrically. The magnet 22 is provided in a circular ring shape so as to surround the outer periphery of the annular portion 45. The outer peripheral surface of the magnet 22 extends along the outer peripheral edge of the base portion 40.

[0044] As shown in FIG. 7 , a plurality of fitting holes 40a, into which one side of the magnet 22 in the rotational axis direction fits, are formed in a portion of the base plate 40 outside the annular portion 45 so as to penetrate in the rotational axis direction (thickness direction of the base plate 40). In this embodiment, eight fitting holes 40a are provided at equal intervals in the circumferential direction. Each fitting hole 40a extends radially and is slit-shaped. The radial inner end of each fitting hole 40a is positioned near the outer circumferential surface of the annular portion 45. The radial outer end of each fitting hole 40a is positioned near the outer circumferential edge of the base plate 40. When the magnet 22 is molded, the molten resin magnet flows into each fitting hole 40a and solidifies, so that one side of the magnet 22 in the rotational axis direction fits into each fitting hole 40a.

[0045] Because the magnet 22 has four N poles 22a and four S poles 22b, there are eight boundaries between the N poles 22a and the S poles 22b on the magnet 22. Because the circumferential dimensions of the N poles 22a and the S poles 22b are set to be the same, the boundaries between the N poles 22a and the S poles 22b are arranged at equal intervals in the circumferential direction. The circumferential position of each fitting hole 40a is set to correspond to the boundaries between the N poles 22a and the S poles 22b. In other words, when the rotating member 4 to which the magnet 22 is fixed is viewed from the direction of the rotation axis, the boundaries between the N poles 22a and the S poles 22b of the magnet 22 and the fitting holes 40a are arranged to overlap each other.

[0046] Furthermore, the rotating member 4 is provided with a plurality of support portions 47 extending radially to support the other side of the magnet 22 in the rotation axis direction. Eight support portions 47 are provided at intervals in the circumferential direction of the rotating member 4, similar to the fitting holes 40a.

[0047] As shown in FIG. 7 , each support portion 47 is disposed away from the substrate portion 40 on the other side in the rotational axis direction, and a filling space that can be filled with a molten resin magnet is formed between each support portion 47 and the substrate portion 40. By filling this filling space with a molten resin magnet and solidifying it, each support portion 47 becomes embedded on the other side in the rotational axis direction of the magnet 22. By providing the support portions 47, the magnet 22 is supported at multiple points by the support portions 47, making it difficult for the magnet 22 to come off the rotating member 4. The entire support portion 47 may be completely embedded in the magnet 22, or the outer surface of the support portion 47 may be exposed from the surface of the magnet 22. Alternatively, a portion of the support portion 47 may protrude from the surface of the magnet 22. In other words, it is sufficient that at least a portion of the support portion 47 is embedded in the magnet 22.

[0048] The support portions 47 and the fitting holes 40a are arranged so as to overlap each other when the rotating member 4 is viewed along the rotation axis direction. That is, the longitudinal direction of the support portions 47 and the longitudinal direction of the fitting holes 40a coincide with each other, and the circumferential positions of the support portions 47 and the fitting holes 40a are set to be the same. Therefore, each support portion 47 is arranged at the boundary between the north pole 22a and the south pole 22b of the magnet 22.

[0049] The boundary between the north pole 22a and south pole 22b of the magnet 22 is a part where the magnetic flux density is 0 or close to 0, and by arranging the support part 47 in such a part where the magnetic flux density is relatively low, the reduction in magnetic force caused by the provision of the support part 47 is suppressed.

[0050] In order to adopt a structure in which the support portion 47 is separated from the substrate portion 40 toward the other side in the rotation axis direction, in the present embodiment, a protruding plate portion 48 that protrudes toward the other side in the rotation axis direction is formed on the outer peripheral edge portion of the substrate portion 40. Eight protruding plate portions 48 are formed in the same manner as the support portion 47 and are arranged at equal intervals in the circumferential direction. The protruding plate portion 48 extends in the circumferential direction of the substrate portion 40 and is formed such that the dimension in the circumferential direction becomes shorter toward the tip in the protruding direction. In other words, the protruding plate portion 48 is formed such that the width of its base end portion is the widest and the tip portion is the narrowest. Note that the protruding plate portion 48 may have the same width from its base end portion to its tip portion.

[0051] The protruding plate portion 48 is embedded in the outer peripheral portion of the magnet 22. Further, since the protruding plate portion 48 extends in the circumferential direction, the outer peripheral portion of the magnet 22 can be partially supported by the protruding plate portion 48. Thereby, the centrifugal force acting on the magnet 22 during rotation can be received by the protruding plate portion 48.

[0052] The radially outer end portion of the support portion 47 is continuous with the tip portion in the protruding direction of the protruding plate portion 48. The support portion 47 extends radially inward from the tip portion in the protruding direction of the protruding plate portion 48, and the radially inner end portion is continuous with the outer peripheral surface of the annular portion 45. That is, the support portion 47 is a portion that connects the tip portion in the protruding direction of the protruding plate portion 48 and the annular portion 45. The support portion 47, the protruding plate portion 48, and the annular portion 45 are integrally formed with the substrate portion 40.

[0053] As shown in FIG. 9, the width H1 of the support portion 47 is set to be substantially the same as the width H2 of the fitting hole 40a. Further, a rib 47a that protrudes in a direction approaching the surface 40A on the other side in the rotation axis direction of the substrate portion 40 is formed on the support portion 47. This rib 47a is continuously formed over the entire length direction of the support portion 47. By forming the rib 47a, the rigidity can be improved while narrowing the width H1 of the support portion 47. Note that the rib 47a may be provided as needed.

[0054] As shown in Figures 7 and 8, the surface 40A of the substrate portion 40 on the other side in the rotation axis direction is provided with a circumferentially extending protrusion 40b embedded in the magnet 22. The surface 40A of the substrate portion 40 is the surface to which the magnet 22 is fixed, and the protrusion 40b protrudes from this surface 40A. The protrusion 40b extends in the circumferential direction of the substrate portion 40. Because the fitting holes 40a are formed in the substrate portion 40, the protrusion 40b is not formed in the portion where the fitting holes 40a are formed. Therefore, the protrusion 40b is discontinuous in the circumferential direction and has an arc shape. The shape of the protrusion 40b is not limited to an arc shape and may be, for example, linear. The protrusion 40b may be continuous in the circumferential direction. Furthermore, the protrusion 40b may be formed as needed.

[0055] The number of protrusions 40b may be one or more. In this embodiment, three protrusions 40b are formed on the surface 40A of the base plate 40. When the molten resin magnet is filled and solidified, the protrusions 40b become embedded in the magnet 22. Therefore, the magnet 22 is also held in place by the protrusions 40b, which prevents deformation of the ring-shaped magnet 22 due to centrifugal force during rotation.

[0056] (Effects of the embodiment) When the axial gap motor 2 is controlled to rotate by a control device (not shown) mounted on the circuit board 6 of the electric pump 1 configured as described above, the rotating member 4 is disposed on one side in the rotational axis direction of the axial gap motor 2, and therefore, fluid is sucked in from the pump chamber S1 on one side in the rotational axis direction due to the rotation of the rotating member 4. The sucked fluid flows out into the outflow passage S2 and is then discharged from the discharge pipe portion 52.

[0057] Since the magnet 22 of the axial gap motor 2 is a resin magnet fixed to the rotating member 4, it is molded along the surface shape of the rotating member 4 during the molding of the magnet 4 and adheres to the surface 40A of the rotating member 4. In addition, since the other side in the rotation axis direction of the magnet 22 is supported by the support portion 47 extending in the radial direction, both sides of the magnet 22 in the rotation axis direction are fixed or supported with respect to the rotating member 4 over a wide range. Therefore, it becomes difficult for the magnet 22 to come off from the rotating member 4.

[0058] Further, the support portion 47 can be embedded in the other side in the rotation axis direction of the magnet 22 so as not to protrude from the magnet 22 or the protruding amount of the support portion 47 from the magnet 22 can be suppressed. Thereby, since the surface of the magnet 22 and the stator 20A can be brought closer to each other, a high output can be obtained efficiently.

[0059] The above-described embodiments are merely illustrative in all respects and should not be construed in a limiting sense. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

Industrial Applicability

[0060] As described above, the electric pump according to the present invention can be applied to, for example, an electric water pump mounted on an automobile.

Explanation of Reference Numerals

[0061] 1 Electric pump 2 Axial gap motor 4 Rotating member 22 Magnet 40 Substrate portion 40a Fitting hole 41 Blade 47 Support portion

Claims

1. A centrifugal electric pump comprising an axial gap motor and a rotating member disposed on one side in the rotational axis direction of the axial gap motor and rotationally driven by the axial gap motor, wherein the rotating member is configured to send fluid by rotation. The axial gap motor includes a stator in which a plurality of coils are arranged side by side in the circumferential direction, and a magnet disposed so as to face one side in the rotational axis direction of the stator. The magnet is a resin magnet fixed to the surface on the other side in the rotational axis direction of the rotating member. An electric pump, wherein the rotating member is provided with a support portion that supports the other side in the rotational axis direction of the magnet so as to extend in the radial direction.

2. The electric pump according to claim 1, wherein the support portion is embedded in the other side in the rotational axis direction of the magnet.

3. The electric pump according to claim 2, wherein the magnet is an anisotropic magnet in which N poles and S poles are alternately arranged in the circumferential direction of the rotating member, and the support portion is disposed at a boundary portion between the N pole and the S pole of the magnet.

4. The electric pump according to claim 1, wherein a plurality of the support portions are provided at intervals in the circumferential direction of the rotating member.

5. The electric pump according to claim 1, wherein the rotating member has a substrate portion extending in the radial direction and blades provided on one side in the rotational axis direction of the substrate portion. An electric pump, wherein the substrate portion is formed with a fitting hole into which the one side in the rotational axis direction of the magnet is fitted so as to penetrate in the rotational axis direction.

6. The electric pump according to claim 5, wherein the support portion and the fitting hole are arranged so as to overlap each other when the rotating member is viewed along the rotational axis direction.

7. The electric pump according to claim 5, wherein a ridge portion to be embedded in the magnet is provided on the surface on the other side in the rotational axis direction of the substrate portion so as to extend in the circumferential direction.

Images