JP2014173585A - Electric fluid pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric fluid pump capable of restraining abrasion of a supporting shaft and the like.SOLUTION: The electric fluid pump comprises: a rotor 31 (magnetic pole holding part 31a) having a permanent magnet 32; and an impeller 20 provided on one axial side of the rotor 31. An outer periphery of the rotor 32 (magnetic holding part 31a) at least outside in a radial direction is covered with resin. The electric fluid pump has: a support shaft 4 provided in a support hole 313 penetrating through a radial inner side of the rotor 31 and the impeller 20 in an axial direction; first bushes 7a, 7b (sliding shaft receiving parts) rotatably supporting the rotor 31 and the impeller 20 to the support shaft 4; and a first groove part 316 provided to extend from one axial side to the other axial side of the rotor 31 (magnetic pole holding part 31a) on the outer periphery of the rotor 31 (magnetic pole holding part 31a) outside in the radial direction.

Description

  The present invention relates to an electric fluid pump.

  2. Description of the Related Art Conventionally, there is known an electric fluid pump that includes a rotor and an impeller, and rotatably supports the rotor and the impeller with respect to a support shaft that is installed in a hole penetrating the rotor and the impeller in the radial direction in the radial direction ( For example, Patent Document 1).

JP 2006-296125 A

  However, in the conventional electric fluid pump, if the foreign matter stays between the support shaft and the hole, the support shaft or the like may be worn. An object of the present invention is to provide an electric fluid pump capable of suppressing wear of a support shaft and the like.

  In order to achieve the above object, the electric fluid pump of the present invention preferably has means for promoting the outflow of fluid from between the support shaft and the hole.

  Therefore, it can suppress that a foreign material stays between a support shaft and a hole, and can suppress wear of a support shaft.

It is sectional drawing which passes along the axis | shaft of an electric fluid pump. It is a perspective view of the rotary body (an impeller, a rotor, etc.) of an electric fluid pump. It is the front view which looked at the rotary body (impeller, rotor, etc.) of the electric fluid pump from the axial direction other end side. It is a schematic diagram of the cross section which passes along the axis | shaft of the rotary body of an electric fluid pump, and shows the flow path | route of a part of fluid. It is a fragmentary sectional view in the direction of an axis of a rotor of an example and a comparative example, and shows a magnetizing yoke together.

  Hereinafter, embodiments of the present invention will be described in detail using examples.

[Example 1]
First, the configuration will be described. The electric fluid pump of the first embodiment (hereinafter simply referred to as “pump 1”) is a water pump that uses refrigerant (cooling water) as a working fluid to be sucked and discharged. The pump 1 is connected to a heat exchanger (radiator). For example, in a hybrid vehicle, cooling water is supplied to an engine (internal combustion engine), a drive motor, an inverter, and the like in a hybrid circuit. The pump 1 includes a pump unit 2, a motor unit 3 as a drive unit that drives the pump unit 2, a support shaft 4, and a control unit 5 that controls the operation of the motor unit 3 in the same housing 6. It is configured as one unit. The housing 6 is formed by coupling a pump cover 61, a pump body 62, and a substrate housing 63. FIG. 1 is a cross-sectional view of the pump 1 taken along a plane passing through the central axis O thereof. FIG. 2 is a perspective view of a rotating body (impeller 20, rotor 31 and the like) of the pump 1. The axis O is an ideal rotation axis of the rotating body defined on the basis of the housing 6, and is also the axis of the support shaft 4. Further, let P be the central axis (rotary axis) of the rotating body. For the sake of explanation, the x-axis is provided in the direction of the axis O (P), and the pump part 2 (impeller 20) side is the forward direction with respect to the motor part 3 (rotor 31). FIG. 3 is a front view of the rotating body as viewed from the x-axis negative direction side.

(Pump part)
The pump unit 2 has an impeller 20. The impeller 20 is rotatably accommodated in a pump chamber R1 formed by the pump cover 61 and the pump body 62. The housing 6 has a suction port IN extending on the shaft O and opening into the pump chamber R1, and a discharge port OUT extending from the outer periphery of the pump chamber R1 in a plane perpendicular to the shaft O and opening outside the pump chamber R1. have. When the impeller 20 rotates, the cooling water is sucked into the pump chamber R1 from the suction port IN, and discharged (pressure-fed) from the discharge port OUT through the discharge channel on the outer peripheral side of the impeller 20. The pump 1 is a centrifugal pump that applies pressure to the cooling water in the radial direction using a centrifugal force acting on the cooling water as the impeller 20 rotates. The impeller 20 is an impeller having a plurality of blades 201 (see FIG. 2) and is formed of a resin material. The impeller 20 is formed substantially coaxially and integrally with the rotor 31 on one axial side (the x-axis positive direction end) of the rotor 31 and is disposed so as to face the suction port IN in the x-axis direction. Each blade 201 is arranged radially about the axis P. Each blade 201 is disposed, for example, so as to incline to the opposite side of the rotation direction of the impeller 20 from the axis P toward the radially outer side, and is installed in a spiral shape as a whole. A shroud (side plate) 21 for guiding the flow of cooling water is provided on the positive side of the impeller 20 in the x-axis positive direction so as to cover the radially outer half of the impeller 20. An O-ring S1 as a seal member is installed between the pump cover 61 and the pump body 62, thereby ensuring liquid tightness of the pump chamber R1.

(Motor part)
The motor unit 3 is a rotary field type motor in which a permanent magnet 32 as a field source is provided on the rotor 31 side, and is a DC brushless motor. The motor unit 3 is a so-called inner rotor type, and has a cylindrical stator (stator) 30 housed in a motor chamber R2 formed by the pump body 62 and the like, and an inner peripheral side (radially inner side) of the stator 30. And a provided rotor (rotor) 31. The motor unit 3 is a permanent magnet embedded (IPM) motor in which a permanent magnet 32 is embedded in a rotor 31. The stator 30 has an annular stator core 30a and a plurality of coils 30b wound around the stator core 30a, and generates a magnetic flux on the inner peripheral side of the stator core 30a by energizing the coil 30b.

  The rotor 31 has a magnetic pole holding part 31a and a shaft part 31b. The magnetic pole holding part 31a is a cylindrical part that includes the rotor core 310 and the permanent magnet 32 and is installed so as to face the inner peripheral surface of the stator 30 with a slight radial gap. The outer peripheral surface on the radially outer side of the magnetic pole holding portion 31a is covered with resin, and the top surface on the x-axis positive direction side and the bottom surface on the x-axis negative direction side of the magnetic pole holding portion 31a are covered with resin. Inside the magnetic pole holding portion 31a, a plurality of magnetic poles are held in the circumferential direction (so that N poles and S poles are alternately arranged) corresponding to the plurality of coils 30b of the stator 30. The magnetic pole holding part 31a is rotationally driven by electromagnetic interaction (electromagnetic force) with the stator 30. The shaft portion 31b is a shaft member formed on the substantially same shaft P as the magnetic pole holding portion 31a with a resin material. The radial dimension of the outer periphery of the shaft portion 31b is slightly smaller than the radial dimension of the inner periphery of the rotor core 310 described later. One axial direction side of the shaft portion 31b is fixed to the negative x-axis direction side of the impeller 20, and the other axial direction side is fixed to the positive x-axis direction side of the magnetic pole holding portion 31a. The shaft portion 31b transmits power for rotating the impeller 20 by rotating integrally with the magnetic pole holding portion 31a.

  The rotor 31 (the magnetic pole holding portion 31a and the shaft portion 31b) is formed integrally with the impeller 20 by injection molding a resin material into a mold. The impeller 20 may be fixed to the rotor 31 as a separate member from the rotor 31. A support hole 313 that penetrates the rotor 31 (and the impeller 20) in the axial direction is formed around the axis P on the inner peripheral side (radially inner side) of the rotor 31 (and the impeller 20). The radial dimension of the support hole 313 (the main body portion thereof) is provided so as to gradually increase from the x-axis positive direction side toward the x-axis negative direction side. A cylindrical first bearing holding portion 314 is provided at the end of the shaft portion 31b in the x-axis positive direction (connection portion between the shaft portion 31b and the impeller 20) and at the end of the support hole 313 on the x-axis positive direction side. The support hole 313 is formed to have a larger diameter than the support hole 313 (the x-axis positive direction end of the main body). A cylindrical second bearing holding portion 315 is provided at the end of the magnetic pole holding portion 31a in the negative x-axis direction and at the end of the support hole 313 in the negative x-axis direction. The diameter is larger than the end in the negative x-axis direction.

  A first bush 7 a as a first bearing is fixedly installed on the first bearing holding portion 314. The outer periphery of the cylindrical main body portion 70 of the first bush 7 a is fitted to the inner periphery of the first bearing holding portion 314, and the flange portion 71 provided on one end side in the axial direction of the main body portion 70 is the x-axis of the impeller 20. Locked to the positive direction side. A second bush 7 b as a second bearing is fixedly installed on the second bearing holding portion 315. The outer periphery of the cylindrical main body portion 70 of the second bush 7b is fitted to the inner periphery of the second bearing holding portion 315, and the flange portion 71 provided on one end side in the axial direction of the main body portion 70 is the magnetic pole holding portion 31a. Locked to the x-axis negative direction side. The first and second bushes 7a and 7b are both sliding bearings, and are formed of, for example, a resin material that is relatively excellent in wear resistance.

  The support shaft 4 is a shaft member, and is fixedly installed on the housing 6 so as to penetrate the support hole 313 of the rotor 31 (and the impeller 20). The support shaft 4 installed in the support hole 313 rotatably supports the rotor 31 and the impeller 20 via the first and second bushes 7a and 7b. The radial dimension (diameter) of the inner peripheral surfaces of the first and second bushes 7a, 7b is smaller than the radial dimension (diameter) of the support hole 313 (the x-axis positive end of the main body portion), and the support shaft 4 It is provided slightly larger than the radial dimension (diameter) of the outer peripheral surface. That is, there is a slight radial gap between the inner periphery of the first and second bushes 7a and 7b fixed to the rotor 31 and the outer periphery of the support shaft 4, and the first and second bushes 7a and 7b are supported. It is slidable with respect to the shaft 4. The first and second bushes 7 a and 7 b support the rotor 31 and the impeller 20 so as to be rotatable with respect to the support shaft 4. A large-diameter portion 40 is provided on one end side (end portion in the negative x-axis direction) of the support shaft 4. The radial dimension (diameter) of the main body portion excluding the large diameter portion 40 of the support shaft 4 is substantially equal in the x-axis direction. The radial dimension of the gap between the inner peripheral surface of the support hole 313 (main body portion) and the outer peripheral surface of the support shaft 4 (main body portion) gradually increases from the x-axis positive direction side to the x-axis negative direction side. (Gap becomes wider).

  A movement restricting portion 610 is formed in the pump cover 61. The movement restricting portion 610 is supported by a rib 611 protruding from the inner periphery of the suction port IN on the x-axis negative direction side of the pump cover 61 and is disposed on the axis O. The end of the support shaft 4 on the positive side in the x-axis direction is fixedly installed on the movement restricting portion 610 so as to fit into the through hole 612 of the movement restricting portion 610. Thereby, the x-axis positive direction side of the support shaft 4 is held by the housing 6. The x-axis negative direction end surface of the movement restricting portion 610 and the flange portion 71 of the first bush 7a are opposed to each other with a slight gap in the x-axis direction so that the support shaft 4 is surrounded by this axial gap. A washer 8 is installed. The movement of the impeller 20 (and the rotor 31) in the positive x-axis direction is restricted by the first bush 7 a (the flange portion 71) slidably contacting the washer 8. A holder member 64 is fixedly installed at the end of the pump body 62 on the x-axis negative direction side. The large diameter portion 40 of the support shaft 4 is fixedly installed on the holder member 64 so as to be fitted into the through hole 640 of the holder member 64. Thereby, the x-axis negative direction side of the support shaft 4 is held by the housing 6. The movement of the rotor 31 (and the impeller 20) in the negative x-axis direction is restricted by the second bush 7b (the flange portion 71) slidably contacting the large diameter portion 40.

(Stator storage chamber and rotor storage chamber)
A partition wall 620 is provided on the x-axis positive direction side of the pump body 62 so as to protrude from the outer periphery of the pump body 62 toward the radially inner side. A cylindrical projecting portion 621 projecting toward the x-axis negative direction side is formed inside the partition wall portion 620 in the radial direction. A recessed portion 622 is provided on the radially inner side of the partition wall portion 620 in the x-axis positive direction side to accommodate the x-axis negative direction side portion of the outer peripheral portion of the impeller 20. The motor chamber R2 in the pump body 62 is defined by a partition member 65 into a stator housing chamber R21 and a rotor housing chamber R22. The partition member 65 has a thin cylindrical shape made of a non-magnetic metal material. The partition wall member 65 includes a cylindrical outer wall portion 650, a flange portion 651 provided so as to spread outward in the radial direction in the opening portion on the x-axis positive direction side of the outer wall portion 650, and the outer peripheral edge of the flange portion 651 in the x-axis direction. A cylindrical large-diameter portion 652 extending in the positive direction side, a flange portion 653 provided so as to spread radially inward in the opening portion on the x-axis negative direction side of the outer wall portion 650, and x from the inner peripheral edge of the flange portion 653 And a cylindrical small-diameter portion 654 extending in the negative axis direction. The radial dimension (diameter) of the inner periphery of the outer wall portion 650 is substantially the same as the radial dimension (diameter) of the inner periphery of the partition wall portion 620 (projecting portion 621) of the pump body 62. The inner peripheral surface of the partition wall 620 (projection 621) forms substantially the same surface that is continuous without a step.

  The x-axis positive direction end (flange portion 651) of the partition wall member 65 is installed at the x-axis negative direction end of the protruding portion 621 of the partition wall portion 620 of the pump body 62. Further, the x-axis positive direction end of the cylindrical portion 641 (projecting toward the x-axis positive direction side outside the through hole 640 in the radial direction) of the holder member 64 is connected to the x-axis negative direction end (flange portion 653) of the partition wall member 65. Install. Accordingly, the radially outer side of the partition member 65, specifically, the inner peripheral surface of the pump body 62 (including the surface of the partition wall portion 620 on the x-axis negative direction side) and the outer peripheral surface of the partition member 65 on the radially outer side. And the stator housing chamber R21 is formed between the holder member 64 and the surface on the x-axis positive direction side of the radially outer portion from the cylindrical portion 641 (including the outer circumferential surface on the radially outer side of the cylindrical portion 641). The stator accommodating chamber R21 is a donut-shaped closed space, and the stator 30 is installed and accommodated in the stator accommodating chamber R21.

  Further, the radially inner side of the partition member 65, specifically, the radially inner side inner peripheral surface of the partition wall portion 620 (projecting portion 621) of the pump body 62, and the radially inner side inner peripheral surface of the partition member 65, A rotor accommodating chamber R22 is formed between the cylindrical portion 641 of the holder member 64 and the surface on the x-axis positive direction side in the radially inner portion. A rotor 31 is rotatably installed and accommodated in the rotor accommodating chamber R22. The rotor housing chamber R22 is connected to the pump chamber R1 via a gap between the outer peripheral portion of the impeller 20 on the x axis negative direction side and the partition wall portion 620 (recess 622) of the pump body 62 on the x axis positive direction side. It is an open space that always communicates, and is filled with cooling water from the pump chamber R1. The rotor housing chamber R22 communicates with the pump chamber R1 through a gap between the support hole 313 (and the inner peripheral surfaces of the first and second bushes 7a and 7b) and the support shaft 4.

  An O-ring S <b> 2 as a seal member is installed between the radially outer side of the protruding portion 621 of the partition wall 620 in the pump body 62 and the radially inner side of the large diameter portion 652 of the partition wall member 65. In addition, an O-ring S3 as a seal member is installed between the radially inner side of the cylindrical portion 641 in the holder member 64 and the radially outer side of the small diameter portion 654 of the partition wall member 65. Thereby, the communication between the radially inner side and the radially outer side of the partition wall member 65 is blocked. That is, the stator housing chamber R21 and the rotor housing chamber R22 are liquid-tightly separated by the O-rings S2 and S3, and cooling water flows from the rotor housing chamber R22 to the stator housing chamber R21 (and a substrate housing chamber R3 described later). It is provided so as not to enter.

(Control part)
The substrate housing 63 is attached so as to close the opening on the x-axis negative direction side of the pump body 62, and forms a substrate accommodating chamber R3 therein. The substrate housing chamber R3 is defined between the substrate housing 63 and the holder member 64. The control unit 5 is a driver that supplies a drive current for the motor unit 3, and includes a substrate 50 accommodated in the substrate accommodation chamber R3, a capacitor (capacitor), and the like. An electronic circuit (CPU, transistor, etc.) is mounted on the substrate 50, and a converter and a control circuit are constituted by these circuit elements and capacitors. The converter receives power supply from a battery that is a DC power supply and supplies AC power to the motor unit 3 (coil 30b), and the control circuit controls the converter. A heat sink is formed on the end surface in the negative x-axis direction of the substrate housing 63 disposed substantially parallel to the substrate 50.

(Details of rotor)
The magnetic pole holding part 31a includes a hollow cylindrical rotor core 310 formed by laminating a plurality of donut disk-shaped electromagnetic steel plates in the direction of the axis P (see FIGS. 1 and 5). The rotor core 310 is provided with a plurality (6 in this embodiment) of insertion holes 311 for inserting and installing the permanent magnets 32. Each insertion hole 311 is provided so as to extend in the x-axis direction, and its end on the x-axis positive direction side is closed by the end surface of the rotor core 310 in the x-axis positive direction, while each insertion hole 311 is on the x-axis negative direction side. Is opened at the end surface of the rotor core 310 in the negative x-axis direction. The openings of the insertion holes 311 are arranged side by side around the axis P so as to form the sides of a regular hexagon when viewed from the x-axis direction. The permanent magnet 32 has a plate shape and is provided in plural (six in this embodiment). Each permanent magnet 32 is inserted and installed in the insertion hole 311 of the rotor core 310 in a non-magnetized state so as to be embedded in the magnetic pole holding portion 31 a and then magnetized by the magnetizing yoke 9. Thereby, a plurality of magnetic poles are formed to be aligned in the circumferential direction.

  As shown in the left half of FIG. 5, the outer periphery of the rotor core 310 of this embodiment has a recess 312 extending in the axial direction in the vicinity of the end in the circumferential direction (around the axis P) of each insertion hole 311. It is provided in the shape. The recess 312 has a relatively shallow first recess 312a provided in the vicinity between two adjacent insertion holes 311 and a substantially central position in the circumferential direction of the first recess 312a between the adjacent insertion holes 311. A relatively deep second recess 312b provided so as to enter inward in the radial direction. By providing such a recess 312, the distance from the circumferential end of each insertion hole 311 to the outer peripheral surface of the rotor core 310 (recess 312) is set to be as small as possible. The same number of recesses 312 as the insertion holes 311 (six in this embodiment) are provided.

  When the rotor 31 and the impeller 20 are integrally formed, the holder member 33 (see FIG. 1) is assembled to the rotor core 310 on which the permanent magnets 32 are installed in the previous stage. The holder member 33 is a magnet pressing part made of a resin material. When the cylindrical portion 33a of the holder member 33 is fitted and fixed to the inner peripheral side of the rotor core 310 from the x-axis negative direction side, the flange portion 33b of the holder member 33 is an opening on the x-axis negative direction side of each insertion hole 311. The permanent magnets 32 are prevented from falling off from the respective insertion holes 311. On the surface on the negative x-axis direction side of the holder member 33, a plurality of recesses 330 (six in the present embodiment) extending radially (in the radial direction) are provided around the axis P and arranged at substantially equal intervals. These concave portions 330 are fitted into the first convex portion (jig) on the mold side, so that the rotor core 310 (the assembly of the permanent magnet 32 and the holder member 33) is positioned and installed in the mold. Is done. By this positioning, the rotor core 310 (the above assembly) is arranged so that the second convex portion provided so as to extend in the x-axis direction on the mold side slightly enters each concave portion 312 provided on the outer periphery of the rotor core 310. Is placed in the mold. In this state, the rotor 31 and the impeller 20 are integrally formed of resin by injection molding a resin material in the mold. Note that the flange 33b of the holder member 33 may be provided so as to partially close the opening of each insertion hole 311 on the x-axis negative direction side (ie, each insertion hole 311 is partially opened). In this case, since the resin material is injected into each insertion hole 311 from the partial opening at the time of the injection molding, a process for fixing the permanent magnet 32 to the insertion hole 311 becomes unnecessary, and the manufacturing cost can be reduced. .

  On the outer peripheral surface on the radially outer side of the rotor 31 created in this way, the second convex portion of the mold is pulled out, so that the concave portion (hereinafter referred to as the first convex portion) extends in the axial direction similarly to the concave portion 312 of the rotor core 310. 1 (referred to as FIG. 2 and FIG. 3). On the surface in the negative x-axis direction of the rotor 31, the first convex portion on the mold side is pulled out, so that the concave portion (hereinafter referred to as a second groove portion 317) extends radially like the concave portion 330 of the holder member 33. ) Are formed (six in this embodiment). As shown in FIG. 2, the first groove 316 has one axial side (the x-axis positive direction side) of the rotor 31 on the radially outer peripheral surface of the rotor 31 (magnetic pole holding part 31 a) covered with resin. Is provided over the entire axial range of the rotor 31 (the magnetic pole holding portion 31a) so as to extend from the axial direction to the other side in the axial direction (negative side in the x-axis). In other words, the first groove 316 is not closed when viewed from the x-axis direction, and both ends in the x-axis direction of the first groove 316 are open to both ends in the axial direction of the rotor 31 (magnetic pole holding portion 31a). . As shown in FIG. 5, the 1st groove part 316 is provided so that it may extend between the permanent magnets 32 (insertion hole 311) adjacent in the circumferential direction. The (circumferential direction) width and (radial direction) depth of the first groove 316 are such that a part of the magnetizing yoke 9 that is a coil used for magnetizing the permanent magnet 32 enters the first groove 316. Is provided to the extent possible.

  As shown in FIG. 3, the second groove portion 317 extends from the radially inner side of the rotor 31 to the radially outer side on the bottom surface on the other axial side (x-axis negative direction side) of the rotor 31 (the magnetic pole holding portion 31a). Is provided. An end portion on the radially outer side of the second groove portion 317 is provided on a radially inner side with respect to an outer peripheral surface on the radially outer side of the rotor 31 (magnetic pole holding portion 31a), and the first groove portion in the circumferential direction of the rotor 31 is provided. It is offset from 316 (specifically, substantially in the middle of the two adjacent first groove portions 316). As shown in FIG. 1, the second groove portion 317 is provided so as to extend from the radially inner side to the radially outer side than the permanent magnet 32. More specifically, the second groove 317 is provided so as to extend slightly radially inward from the rotor core 310 to radially outward.

[Action]
Next, the operation will be described. The rotor 31 of the motor unit 3 is rotatably supported by the support shaft 4 and is given a rotational force by magnetic flux generated by the stator 30 (in response to a control signal output from the control unit 5). Thereby, the impeller 20 rotates and the pump part 2 operates. Most of the fluid sucked into the pump chamber R1 from the x-axis positive direction side by the rotation of the impeller 20 is discharged from the discharge port OUT. In the present embodiment, a part of the sucked fluid is provided so as to smoothly flow between the support shaft 4 and the support hole 313. FIG. 4 schematically illustrates a part of the cross-sectional view of FIG. 1, and the flow of a part of the fluid is indicated by a dashed line arrow. The rotor accommodating chamber R22 communicates with the pump chamber R1 via a gap CL4 between the outer peripheral portion of the impeller 20 on the negative side in the x-axis direction and the partition wall portion 620 (recess 622) of the pump body 62. The accommodation room R22 is filled with cooling water. Further, a gap CL1 between the support hole 313 (and the inner peripheral surfaces of the first and second bushes 7a and 7b) and the support shaft 4 communicates with the pump chamber R1 on the x-axis positive direction side, and the x-axis negative direction. It communicates with the rotor accommodating chamber R22 on the side, and the clearance CL1 is also filled with cooling water. The clearance CL2 between the surface on the x-axis positive direction side of the holder member 64 or the surface on the x-axis positive direction side of the flange portion 653 of the partition wall member 65 and the surface on the x-axis negative direction side of the magnetic pole holding portion 31a, and the magnetic pole A gap CL3 between the outer peripheral surface on the radially outer side of the holding portion 31a and the inner peripheral surface on the radially inner side of the outer wall portion 650 of the partition wall member 65 constitutes a part of the rotor accommodating chamber R22. CL2 and CL3 are also filled with cooling water.

  The centrifugal force acts on the cooling water in the gap CL2 by the rotation of the rotor 31 (the magnetic pole holding part 31a), so that the cooling water in the gap CL2 is pushed outward in the radial direction, and the magnetic pole holding part 31a is passed through the gap CL3. To the space on the positive side of the x axis. As the cooling water in the gap CL2 is pushed outward in the radial direction (in the gap CL3), the cooling water is sucked into the gap CL2 from the gap CL1 (centrifugal pump function). Therefore, as shown in FIG. 4, a part of the fluid sucked into the pump chamber R1 from the x-axis positive direction side by the rotation of the impeller 20 (rotor 31) is sucked into the gap CL2 from the gap CL1. Then, it is sent from the gap CL2 through the gap CL3 to the space on the positive side in the x-axis direction of the magnetic pole holding part 31a, and further discharged from the discharge port OUT through the gap CL4.

  Here, the first and second bushes 7a and 7b function as sliding bearing portions in the cooling water, and are a severe environment against wear. That is, if foreign matter is caught between the first and second bushes 7a and 7b and the support shaft 4 and stays, the first and second bushes 7a and 7b and / or the support shaft 4 may be worn. . On the other hand, in the present Example, the distribution promotion means for promoting the partial flow of the fluid was provided. Therefore, it is possible to prevent foreign matter from staying in the gap CL1 (in particular, the gap between the first and second bushes 7a and 7b and the support shaft 4), and thereby the first and second bushes 7a and 7b to the support shaft 4 are prevented. Wear can be suppressed.

  Specifically, a first groove 316 extending in the x-axis direction is provided on the outer circumferential surface on the radially outer side of the rotor 31 (the magnetic pole holding portion 31a). The first groove portion 316 increases the flow path cross-sectional area of the water flow in the gap CL3, thereby facilitating the outflow of cooling water from the gap CL2 to the gap CL3 due to centrifugal force, and thereby, from the gap CL1 into the gap CL2. To promote the cooling water outflow. As described above, the first groove 316 allows a part of the fluid to flow out to the gap CL2 through the gap CL1 (particularly, the gap between the first and second bushes 7a and 7b and the support shaft 4). The outflow facilitating means is constructed to promote the centrifugal force acting on the fluid. In this embodiment, the first groove portion 316 is provided over the entire axial range of the rotor 31 (magnetic pole holding portion 31a), and both ends in the x-axis direction of the first groove portion 316 are open ends. Therefore, the inflow of the cooling water from the clearance CL2 to the clearance CL3 and the outflow of the cooling water from the clearance CL3 to the positive side of the magnetic pole holding portion 31a are facilitated, and the circulation of the cooling water in the clearance CL1 is promoted. be able to. The first groove 316 may not be provided over the entire range of the magnetic pole holding portion 31a in the axial direction, and one or both ends of the first groove 316 in the axial direction may not be opened. In the present embodiment, the radially outer peripheral surface of the rotor 31 (the magnetic pole holding portion 31a) is covered with resin, and the first groove portion 316 is provided on the outer peripheral surface. Therefore, the above-described effects can be obtained while suppressing corrosion of the rotor core 310 and the like.

  A second groove 317 extending in the radial direction is provided on the bottom surface of the rotor 31 (the magnetic pole holding portion 31a) on the x-axis negative direction side. The second groove portion 317 promotes the flow of cooling water from the gap CL1 into the gap CL2 due to centrifugal force by increasing the flow path cross-sectional area of the water flow in the gap CL2. As described above, the second groove 317 allows a part of the fluid to flow out to the gap CL2 through the gap CL1 (particularly, the gap between the first and second bushes 7a and 7b and the support shaft 4). The outflow facilitating means is constructed to promote the centrifugal force acting on the fluid. In the present embodiment, the second groove portion 317 is provided so as to extend from the radially inner side to the radially outer side than the permanent magnet 32. Therefore, the distance from the gap CL1 to the radially inner end of the second groove 317 is shortened, thereby facilitating the flow of the cooling water from the gap CL1 to the gap CL2, and the circulation of the cooling water in the gap CL1. Can be promoted. More specifically, the second groove portion 317 is provided so as to extend from the radially inner side to the radially outer side than the rotor core 310 (in which the permanent magnet 32 is embedded). Therefore, the distance from the gap CL1 to the radially inner end of the second groove 317 can be further shortened, and the above-described effects can be improved.

  The second groove 317 may not be provided on the radial straight line passing through the axis P, and may be provided in a linear shape extending from the radial inner side to the radial outer side without passing through the axis P. Further, the second groove 317 does not have to be linear as viewed from the x-axis direction, and may be curved. In addition, at least one of the radial ends of the second groove 317 may be an open end. For example, the second groove portion 317 may be provided over the entire radial range of the bottom surface of the rotor 31 (the magnetic pole holding portion 31a) on the x-axis negative direction side, and both radial ends of the second groove portion 317 may be open ends. .

  In the present embodiment, the radially outer end of the second groove 317 is provided on the radially inner side with respect to the radially outer peripheral surface of the rotor 31 (the magnetic pole holding portion 31a), and the first in the circumferential direction. The groove portion 316 is provided with a deviation. That is, since the actual water flow in the gap CL2 has not only a radial direction passing through the axis P but also a circumferential component, the radially outer end of the second groove 317 is opened to the gap CL3 as in this embodiment. Even in the case where the configuration is not performed, the water flow path from the radially outer end portion of the second groove portion 317 to the x-axis negative direction end portion of the first groove portion 316 is shortened (compared to the case where no deviation is provided). can do. Accordingly, it is possible to facilitate the flow of the cooling water from the gap CL2 to the gap CL3, and to promote the circulation of the cooling water in the gap CL1. In addition, it is good also as providing the groove part from the radial direction outer side edge part of the 2nd groove part 317 to the x-axis negative direction edge part of the 1st groove part 316.

  In this embodiment, not only the radially outer peripheral surface of the rotor 31 (the magnetic pole holding portion 31a) but also the outer peripheral surfaces on both sides in the axial direction are covered with resin. A groove 317 is provided. Therefore, the above-described effects can be obtained while the corrosion of the rotor core 310 and the permanent magnet 32 is more reliably suppressed. Further, by using the concave portion formed by the first convex portion (jig) on the mold side coming out as the second groove portion 317, the positioning means at the time of creating the rotor 31 (and the impeller 20) and the above-mentioned The outflow promotion means can be shared to reduce costs. Furthermore, by using the concave portion 330 formed in the holder member 33 for forming the second groove portion 317, it is possible to prevent the permanent magnet 32 from falling off by the holder member 33 and to facilitate forming by positioning using the concave portion 330, Effects such as cost reduction due to the common use of the above means can be obtained at the same time.

  Further, in the gap CL1, the gap (flow channel cross-sectional area) between the inner peripheral surface of the support hole 313 (the main body portion) and the outer peripheral surface of the support shaft 4 (the main body portion) is x from the x-axis positive direction side. It is provided so as to gradually increase toward the negative axis direction. Therefore, it is possible to promote the flow of the cooling water from the x-axis positive direction side to the x-axis negative direction side in the gap CL1.

  When the outer peripheral surface of the rotor 31 (the magnetic pole holding portion 31a) is covered with resin as in this embodiment, the efficiency of magnetization of the permanent magnet 32 may be reduced. FIG. 5 partially shows a cross section obtained by cutting the rotor 31 (magnetic pole holding portion 31a) in a plane perpendicular to the axis P. FIG. The left half of FIG. 5 shows the present embodiment in which the rotor core 310 is provided with the concave portion 312 and the first groove portion 316 is provided on the outer peripheral surface on the radially outer side of the magnetic pole holding portion 31a. The right half of FIG. 5 shows a comparative example in which the concave portion 312 and the groove portion 316 are not provided. The lines of magnetic force are indicated by a plurality of lines surrounding one of the magnetized yokes 9. When the outer peripheral surface on the radially outer side of the magnetic pole holding portion 31a is covered with resin, the distance from the magnetized yoke 9 to the permanent magnet 32 is increased by the amount of the resin coating (as compared with the case where the magnetic pole holding portion 31a is not covered). Therefore, in the comparative example in which the first groove portion 316 is not provided, the magnetic lines of force of the magnetizing yoke 9 that does not reach the permanent magnet 32 may increase, and the magnetizing efficiency may decrease.

  In contrast, in the present embodiment, the first groove 316 is provided between the permanent magnets 32 adjacent in the circumferential direction so that a part of the magnetized yoke 9 can enter the first groove 316. The 1st groove part 316 was provided in this. Therefore, by performing the magnetization in a state where a part of the magnetized yoke 9 enters the first groove 316, the distance from the magnetized yoke 9 to the permanent magnet 32 is shortened by the amount of the intrusion. The magnetic lines of force of the magnetizing yoke 9 reaching the permanent magnet 32 can be increased. As a result, the magnetization efficiency can be improved. In other words, the means for improving the magnetization efficiency and the outflow promoting means can be made common to simplify the configuration and reduce costs. From the viewpoint of the magnetizing step by the magnetizing yoke 9, it is preferable to provide the first groove 316 in a straight line along the x-axis direction.

  When the first groove 316 is to be formed without providing the recess 312 in the rotor core 310, the thickness of the resin covering the outer peripheral surface on the radially outer side of the magnetic pole holding part 31a forms the first groove 316. It becomes non-uniform in the part and other parts, which is disadvantageous in terms of moldability. Further, the radial dimension of the magnetic pole holding portion 31a may increase. In contrast, in this embodiment, the rotor core 310 is provided with the recess 312 and the first groove 316 is formed at a position corresponding to the recess 312, so that the outer peripheral surface of the magnetic pole holding portion 31 a is covered with resin. While improving the magnetization efficiency as much as possible, it is possible to obtain effects such as improving the moldability by making the thickness of the resin substantially uniform. Even when the outer peripheral surface on the radially outer side of the magnetic pole holding portion 31a is not covered with the resin, the magnetizing yoke 9 is magnetized by performing magnetization while part of the magnetizing yoke 9 enters the recess 312 of the rotor core 310. Needless to say, the magnetic efficiency can be improved. Further, the second groove portion 317 provided on the bottom surface of the rotor 31 (the magnetic pole holding portion 31a) on the x-axis negative direction side can be used for positioning (as a concave portion engaging with the jig) at the time of magnetization. That is, the positioning means and the outflow promoting means at the time of magnetization can be made common to reduce costs.

[effect]
Hereinafter, effects of the pump 1 ascertained from the present embodiment will be listed.
(1) A rotor 31 (magnetic pole holding portion 31a) including a permanent magnet 32 and an impeller 20 provided on one axial side of the rotor 31 are provided, and at least radially outside of the rotor 32 (magnetic pole holding portion 31a). The outer peripheral surface is covered with resin, and the rotor 31 and the impeller 20 are mounted on the support shaft 4 installed in the support hole 313 that passes through the radially inner side of the rotor 31 and the impeller 20 in the axial direction. The first and second bushes 7a and 7b (sliding bearing portions) that are rotatably supported and one axial side of the rotor 31 (magnetic pole holding portion 31a) on the outer circumferential surface on the radially outer side of the rotor 31 (magnetic pole holding portion 31a) And a first groove 316 provided so as to extend to the other side in the axial direction.
Accordingly, the fluid flow in the gap CL1 between the support shaft 4 and the support hole 313 is promoted by the first groove portion 316, whereby the support shaft 4 and the second bushes 7a and 7b (sliding bearing portions) are interposed. By suppressing the foreign matter from staying, wear of the support shaft 4 and the like can be suppressed. Moreover, corrosion of the rotor core 310 and the like can be suppressed by covering the outer peripheral surface of the rotor 31 (the magnetic pole holding portion 31a) in the radial direction with resin.

(2) A second groove portion 317 is provided on the bottom surface of the rotor 31 (the magnetic pole holding portion 31a) on the x-axis negative direction side (the other side in the axial direction) so as to extend from the radially inner side to the radially outer side of the rotor 31. .
Therefore, the flow of the fluid in the gap CL1 between the support shaft 4 and the support hole 313 is promoted by the second groove portion 317, and thereby, between the support shaft 4 and the second bushes 7a and 7b (sliding bearing portions). By suppressing the foreign matter from staying, wear of the support shaft 4 and the like can be suppressed.

(3) The permanent magnet 32 is installed inside the rotor 31 (the magnetic pole holding portion 31a), and the second groove portion 317 is provided so as to extend from the radially inner side to the radially outer side than the permanent magnet 32. .
Therefore, the distance from the gap CL1 between the support shaft 4 and the support hole 313 to the radially inner end of the second groove 317 can be shortened, thereby promoting the fluid flow in the gap CL1.

(4) The rotor 31 (the magnetic pole holding portion 31a) includes the rotor core 310 on which the permanent magnet 32 is installed, and the second groove portion 317 is provided so as to extend from the radially inner side to the radially outer side than the rotor core 310. .
Therefore, the distance from the gap CL1 between the support shaft 4 and the support hole 313 to the radially inner end of the second groove 317 can be shortened, thereby promoting the fluid flow in the gap CL1.

(5) The end portion on the radially outer side of the second groove portion 317 is provided on the radially inner side with respect to the outer circumferential surface on the radially outer side of the rotor 31 (the magnetic pole holding portion 31a), and The first groove portion 316 is provided so as to be shifted (biased) with respect to the end in the negative x-axis direction (the other axial direction) side.
Therefore, even if the end portion on the radially outer side of the second groove portion 317 is not opened to the outer peripheral surface on the radially outer side of the rotor 31 (the magnetic pole holding portion 31a), the second groove portion 317 can be separated from the end portion on the radially outer side of the second groove portion 317. It is possible to shorten the flow path of the water flow to the end portion in the negative x-axis direction of the one groove portion 316, thereby promoting the fluid flow in the gap CL1.

(6) A plurality of permanent magnets 32 are installed inside the rotor 31 (the magnetic pole holding portion 31a), and the first groove portion 316 is provided so as to extend between the permanent magnets 32 adjacent in the circumferential direction. A part of the magnetizing coil (magnetizing yoke 9) of the permanent magnet 32 is provided so as to be able to enter the first groove 316.
Therefore, the magnetization efficiency of the permanent magnet 32 can be improved.

(7) The rotor 31 that is rotationally driven by electromagnetic force, the impeller 20 that is provided coaxially with the rotor 31, and the support hole 313 that passes through the radially inner side of the rotor 31 and the impeller 20 in the axial direction. 1. A support shaft 4 that rotatably supports the rotor 31 and the impeller 20 via the second bushes 7a and 7b (sliding bearing portions), and a positive x-axis direction (axial direction) of the impeller 20 and the rotor 31 by the rotation of the impeller 20 On the other hand, a part of the cooling water (fluid) sucked from the side passes through the gap CL1 between the support shaft 4 and the support hole 313 and flows out to the x-axis negative direction (the other axial direction) side. It has the 1st groove part 316 or the 2nd groove part 317 (outflow promotion means) promoted using the centrifugal force which acts on (fluid).
Therefore, the flow of the fluid in the gap CL1 is promoted by the first groove 316 or the second groove 317 (outflow accelerating means), and thereby, between the support shaft 4 and the second bushes 7a and 7b (sliding bearing portions). By suppressing the foreign matter from staying, wear of the support shaft 4 and the like can be suppressed.

(8) A water pump that sucks and discharges cooling water by rotation of the impeller 20.
Therefore, the above-described effects can be obtained in the water pump. In particular, by covering the outer peripheral surface of the rotor 31 (the magnetic pole holding portion 31a) with resin, it is possible to prevent the coolant from contacting the rotor core 310 and the like and corroding them.

[Other Examples]
Although the present invention has been described based on the embodiments, the specific configuration of each invention is not limited to the embodiments, and even if there is a design change or the like without departing from the scope of the invention, Included in the invention. In this embodiment, the working fluid of the pump is cooling water as a refrigerant, and the above configuration is applied to the water pump. However, the working fluid is installed in a hole that penetrates the radial inner side of the rotor and impeller in the axial direction. As long as the electric fluid pump includes a support shaft that rotatably supports the rotor and the impeller via the slide bearing, the configuration of the first groove portion or the like is not limited to the water pump. For example, the refrigerant is not limited to water.

  Moreover, you may form a sliding bearing part integrally with a rotor or a support shaft. In other words, the outer periphery of the support shaft or the inner periphery of the hole in which the support shaft is installed may be used as the sliding bearing portion. In this case, the number of parts and assembly man-hours can be reduced. In the present embodiment, the first and second bushes 7 a and 7 b as the sliding bearing portions are provided as separate members separated from the rotor 31. Therefore, as the material of the first and second bushes 7a and 7b, a material having excellent bearing function such as wear resistance can be selected regardless of the material of the rotor 31, so that the first and second bushes 7a and 7b can be selected. Function can be improved. The position, size, and number of the first and second bushes 7a and 7b in the x-axis direction are not limited to those of the present embodiment. In the present embodiment, the first and second bushes 7a and 7b are fixed to the rotor 31, and the first and second bushes 7a and 7b slide relative to the member on the housing 6 (support shaft 4 and the like). However, the first and second bushes 7a and 7b are fixed to members (support shaft 4 and the like) on the housing 6 side so that the rotor 31 slides with respect to the first and second bushes 7a and 7b. It may be configured.

DESCRIPTION OF SYMBOLS 1 Electric fluid pump 20 Impeller 31 Rotor 31a Magnetic pole holding | maintenance part 310 Rotor core 313 Support hole 316 1st groove part (outflow promotion means)
317 Second groove (outflow promoting means)
32 Permanent magnet 4 Support shaft 7a First bush (sliding bearing)
7b Second bush (sliding bearing)
9 Magnetized yoke (magnetizing coil)

Claims (10)

A rotor with permanent magnets;
An impeller provided on one axial side of the rotor,
The outer peripheral surface of at least the radially outer side of the rotor is covered with resin,
A support shaft installed in a hole penetrating the inner side in the radial direction of the rotor and the impeller; and
A sliding bearing portion that rotatably supports the rotor and the impeller with respect to the support shaft;
An electric fluid pump comprising: a first groove portion provided on an outer peripheral surface on the radially outer side of the rotor so as to extend from one axial side of the rotor to the other axial side. The electric fluid pump according to claim 1,
An electric fluid pump comprising: a second groove portion provided on a bottom surface on the other axial side of the rotor so as to extend from a radially inner side to a radially outer side of the rotor. A rotor with permanent magnets;
An impeller provided on one axial side of the rotor;
A support shaft installed in a hole penetrating the inner side in the radial direction of the rotor and the impeller; and
A sliding bearing portion that rotatably supports the rotor and the impeller with respect to the support shaft;
A first groove portion provided on the outer circumferential surface on the radially outer side of the rotor so as to extend from one axial side of the rotor to the other axial side;
An electric fluid pump comprising: a second groove portion provided to extend from a radially inner side to a radially outer side of the rotor on a bottom surface on the other axial side of the rotor. In the electric fluid pump according to claim 3,
An electric fluid pump, wherein an outer peripheral surface of the rotor is covered with resin. The electric fluid pump according to any one of claims 2 to 4,
The permanent magnet is installed inside the rotor,
The electric fluid pump, wherein the second groove portion is provided so as to extend from a radially inner side to a radially outer side than the permanent magnet. In the electric fluid pump according to any one of claims 2 to 5,
The rotor includes a rotor core on which the permanent magnet is installed,
The electric fluid pump, wherein the second groove portion is provided so as to extend from a radially inner side to a radially outer side than the rotor core. The electric fluid pump according to any one of claims 2 to 6,
An end portion on the radially outer side of the second groove portion is provided on a radially inner side with respect to an outer circumferential surface on the radially outer side of the rotor, and the other axial direction side of the first groove portion in the circumferential direction of the rotor. An electric fluid pump characterized in that it is provided to be biased with respect to the end. The electric fluid pump according to any one of claims 1 to 7,
A plurality of the permanent magnets are installed inside the rotor,
The first groove portion is provided so as to extend between the permanent magnets adjacent in the circumferential direction, and a part of the magnetizing coil for the permanent magnet can enter the first groove portion. The electric fluid pump characterized by being provided in the. A rotor driven to rotate by electromagnetic force;
An impeller provided coaxially with the rotor;
A support shaft that is installed in a hole penetrating in the radial direction inside the rotor and the impeller in the axial direction, and rotatably supports the rotor and the impeller via a sliding bearing;
A part of the fluid sucked from one side in the axial direction of the impeller and the rotor by the rotation of the impeller flows out to the other side in the axial direction through a gap between the support shaft and the hole. And an outflow facilitating means that promotes using centrifugal force acting on the electric fluid pump. The electric fluid pump according to any one of claims 1 to 9,
An electric fluid pump characterized by being a water pump for sucking and discharging water by rotation of the impeller.

Images