JP6296872B2 - Rotor and liquid pump - Google Patents

Description

  The present invention relates to a rotor and a liquid pump.

  Patent Document 1 below discloses a so-called continuous pole type rotor (rotor). The rotor includes a rotor core (rotor core), a permanent magnet (magnet), and a cover. Specifically, the rotor core has a boss portion that is fixed to the rotation shaft, and a plurality of protrusions that protrude from the boss portion to the outside in the radial direction of the rotor core. A plurality of permanent magnets are provided on the outer periphery of the rotor core between the protrusions. Thereby, the protrusions and the permanent magnets are alternately arranged in the circumferential direction of the rotor core. A rotor core is inserted into the cover, and the cover is fixed to the rotor core.

  Further, in a state where the cover is fixed to the rotor core, the center portion of the first diameter outer surface of the projecting portion is in contact with the inner surface of the cover, and the entire surface of the second diameter outer surface of the permanent magnet is in contact with the inner surface of the cover. It is configured. Thereby, it is avoided that a permanent magnet and a cover contact locally, and damage to a permanent magnet can be prevented.

JP 2014-3841 A

  However, in the rotor described above, although the permanent magnet is prevented from locally contacting the cover, a load on the radially inner side of the rotor core acts on the permanent magnet from the cover. For this reason, in the said rotor, there exists room for improvement in the point which suppresses the said load which acts on a permanent magnet from a cover.

  In consideration of the above facts, an object of the present invention is to provide a rotor capable of suppressing a load acting on a magnet from a cover and a liquid pump using the rotor.

  The rotor according to the present invention includes a rotor main body portion in which a magnet magnetic pole portion is formed by arranging a plurality of magnets in a circumferential direction of a rotor core made of a magnetic material, and a cylindrical cover fixed to the outer side in the radial direction of the rotor main body portion. And a part of the outer peripheral portion of the rotor main body portion, and a gap with respect to the magnet magnetic pole portion in the circumferential direction of the rotor core, and a distance from the axial center of the rotor core to the outer peripheral surface of the rotor core A load receiving portion that is set longer than a distance from the shaft center to the outer peripheral surface of the magnet magnetic pole portion and receives a load from the cover.

  According to the rotor having the above configuration, the rotor includes the rotor main body, and a cylindrical cover is fixed to the outer side in the radial direction of the rotor main body. In the rotor main body, a plurality of magnets are arranged in the circumferential direction of a rotor core made of a magnetic material to form a magnet magnetic pole part. Further, a part of the outer peripheral portion of the rotor main body portion is constituted by a load receiving portion, and the load receiving portion is formed with a gap with respect to the magnet magnetic pole portion in the circumferential direction of the rotor core.

  Here, the distance from the axial center of the rotor core to the outer peripheral surface of the load receiving portion is set to be longer than the distance from the axial center of the rotor core to the outer peripheral surface of the magnet magnetic pole portion. And the load receiving part has received the load to the radial direction inner side of the rotor main body part which acts on a rotor main body part from the cover by fixing a cover to the radial direction outer side of a rotor main body part. Thereby, since the said load is suppressed from acting on a magnet magnetic pole part, the load which acts on a magnet from a cover can be suppressed.

  In the rotor of the present invention, in addition to the above configuration, the load receiving portions are arranged at equal intervals in the circumferential direction of the rotor core.

  According to the rotor configured as described above, since the load receiving portions are arranged at equal intervals in the circumferential direction of the rotor core, the cover can be fixed to the rotor body portion in a balanced manner in the circumferential direction of the rotor body portion. Further, by fixing the cover to the outer side in the radial direction of the rotor main body, the load from the cover to the inner side in the radial direction of the rotor main body acting on the rotor main body can be distributed to the rotor core in a balanced manner.

  In the rotor according to the present invention, in addition to the above configuration, the magnet magnetic pole portions and the load receiving portions are alternately formed in the circumferential direction of the rotor core.

  According to the rotor having the above-described configuration, the load receiving portion is disposed so as to sandwich the magnet magnetic pole portion in the circumferential direction of the rotor core, so that the load acting on the magnet from the cover can be effectively suppressed.

  In the rotor of the present invention, in addition to the above configuration, the magnet is set as one magnetic pole, and the load receiving portion functions as a pseudo magnetic pole portion functioning as the other magnetic pole.

  According to the rotor having the above configuration, the load receiving portion can have a function as a pseudo magnetic pole portion and a function of receiving a load from the cover. Thereby, the structure of a rotor can be simplified compared with the case where it comprises so that the said part may have the said function in a rotor core.

  In the rotor of the present invention, in addition to the above configuration, the distance from the center of the rotor core to the outer peripheral surface of the load receiving portion is set to be the same in the plurality of load receiving portions.

  According to the rotor having the above-described configuration, for example, when the stator is disposed on the radially outer side of the rotor, the interval (magnetic gap) between the stator and the load receiving portion functioning as the pseudo magnetic pole portion is substantially the same. Therefore, the rotation balance of the rotor can be ensured.

  In the rotor of the present invention, in addition to the above configuration, an insertion hole into which the magnet is inserted is formed in the rotor core, and the insertion hole and the gap are arranged adjacent to each other in the circumferential direction of the rotor core. .

  According to the rotor configured as described above, since the magnet is inserted into the insertion hole of the rotor core, the rotor is configured as a so-called magnet-embedded rotor. For this reason, in a rotor configured as a magnet-buried rotor, deformation of the insertion hole in the rotor core can be suppressed by the load receiving portion.

  The liquid pump of the present invention includes an impeller that pumps the liquid in the pump unit by rotating, the rotor that is configured to rotate integrally with the impeller, and the cover that is made nonmagnetic, and the radial direction of the rotor A stator provided on the outer side, and a resin mold part that covers the rotor main body part and constitutes the outer shell of the rotor together with the cover, and is formed integrally with the impeller.

  According to the liquid pump having the above configuration, the stator is provided on the radially outer side of the rotor. Moreover, the rotor main body is covered with a resin mold part, and the resin mold part constitutes the outer shell of the rotor together with the cover. And the impeller which pumps the liquid in a pump part is integrally formed with the resin mold part. For this reason, the waterproof property with respect to a rotor main-body part is securable by the resin mold part and a cover.

  Moreover, the cover which comprises the outline in the radial direction outer side part of a rotor is made nonmagnetic. For this reason, it can prevent that the magnetic flux in a rotor main-body part leaks to a cover.

It is a top view which shows the rotor main-body part used for the rotor which concerns on this Embodiment. It is a longitudinal cross-sectional view which shows the water pump to which the rotor which concerns on this Embodiment was applied. It is a disassembled perspective view which decomposes | disassembles and shows the principal part of the rotor which concerns on this Embodiment. It is a longitudinal cross-sectional view which expands and shows the rotor and impeller shown by FIG. FIG. 6 is a plan view showing another example of the rotor body shown in FIG. 1.

  Hereinafter, the water pump 10 as a “liquid pump” to which the rotor 52 according to the present embodiment is applied will be described with reference to the drawings.

  The water pump 10 according to the present embodiment is used as a pump for pumping cooling water (liquid) for an air conditioner heater of a vehicle (automobile), for example. As shown in FIG. 2, the water pump 10 includes a pump unit 12 that accommodates the impeller 70 and pumps cooling water, and a motor unit 50 that rotates the impeller 70. Further, the water pump 10 includes a motor housing 30 (which is an element grasped as a “housing” in a broad sense) that houses the motor unit 50, and a circuit device 90 for driving and controlling the motor unit 50. ing.

  Hereinafter, each said structure is demonstrated in order of the pump part 12, the motor housing 30, the motor part 50, and the circuit apparatus 90. FIG. In addition, the water pump 10 is formed in a substantially cylindrical shape as a whole, and in the following description, an arrow A direction appropriately shown in the drawings is an upper side, and an arrow B direction is a lower side.

(About the pump unit 12)
As shown in FIG. 2, the pump unit 12 constitutes the upper part of the water pump 10. The pump unit 12 includes a pump case 14, and the pump case 14 constitutes an outer peripheral portion of the pump unit 12. The pump case 14 has a case main body portion 16, and the case main body portion 16 is formed in a substantially bottomed cylindrical shape opened downward. An impeller accommodating portion 18 that accommodates the impeller 70 is formed in the center portion of the case body portion 16, and the impeller accommodating portion 18 is formed in a substantially concave shape that is opened downward. Further, a flow path 20 is formed inside the case main body portion 16 on the radially outer side of the case main body portion 16 with respect to the impeller housing portion 18. The flow path 20 is formed in a substantially U-shaped cross section that is open downward, and extends along the circumferential direction of the case body 16.

  In addition, an inlet pipe 22 is integrally formed on the upper wall of the case main body 16 at the center (the axial center of the water pump 10). The inlet pipe 22 is formed in a tubular shape and extends upward from the case body 16. In addition, the inlet pipe 22 communicates with the impeller accommodating portion 18 so that cooling water flows from the inlet pipe 22 into the case main body portion 16.

  Further, an outlet pipe (not shown) is integrally formed on the outer peripheral portion of the case main body 16. The outlet pipe is formed in a tubular shape and extends from the side wall of the case main body 16 in a direction orthogonal to the axis of the water pump 10. The outlet pipe communicates with the flow path 20 so that the cooling water that has flowed into the case body 16 flows out of the outlet pipe.

  A pump-side flange portion 26 is integrally formed at the open end portion of the case body portion 16, and the pump-side flange portion 26 projects from the case body portion 16 to the outside in the radial direction of the case body portion 16. At the same time, it is formed in a substantially ring shape over the entire circumference of the case body 16. A substantially cylindrical rib 26A is erected on the lower surface of the pump-side flange portion 26. The rib 26A is formed over the entire circumference of the case main body portion 16, and extends downward from the pump-side flange portion 26. It is protruding.

(About motor housing 30)
As shown in FIG. 2, the motor housing 30 constitutes an intermediate portion in the vertical direction of the water pump 10 and is disposed on the lower side with respect to the pump portion 12. The motor housing 30 is formed in a substantially bottomed cylindrical shape that is opened downward as a whole, and is arranged coaxially with the inlet pipe 22 (the axis of the water pump 10). Specifically, the motor housing 30 has an outer cylindrical portion 32 that constitutes a radially outer portion of the motor housing 30, and the outer cylindrical portion 32 is formed in a substantially bottomed cylindrical shape that is opened downward. ing. Further, the motor housing 30 has an inner cylinder portion 34 that constitutes a radially inner portion of the motor housing 30. The inner cylinder part 34 is formed in a substantially bottomed cylindrical shape opened upward, and the open end (upper end) of the inner cylinder part 34 is coupled to the bottom wall of the outer cylinder part 32.

  A space between the outer cylindrical portion 32 and the inner cylindrical portion 34 is a stator accommodating portion 36 for accommodating a stator 80 described later, and the stator accommodating portion 36 is a substantially annular shape opened downward. It is formed in the space. Furthermore, the space inside the inner cylinder part 34 is a rotor accommodating part 38 for accommodating the rotor 52 mentioned later.

  A first coupling portion 40 is integrally formed at the upper end portion of the outer cylinder wall 32 </ b> A constituting the outer peripheral portion of the outer cylinder portion 32. The first coupling portion 40 protrudes from the outer cylinder wall 32A to the outside in the radial direction of the motor housing 30, is formed in a substantially ring shape over the entire circumference of the outer cylinder wall 32A, and the pump-side flange portion 26 described above. They are arranged facing each other in the vertical direction. Further, a rib housing recess 40A is formed on the upper surface of the first coupling portion 40 at a position corresponding to the rib 26A of the pump-side flange portion 26 described above. 40 A of rib accommodating recessed parts are open | released upwards, and are formed in the annular | circular shape (ring shape) seeing from the axial direction of the motor housing 30. FIG. And the 1st coupling | bond part 40 and the pump side flange part 26 are couple | bonded in the state in which the rib 26A of the pump case 14 was accommodated in the rib accommodating recessed part 40A. Further, in this state, the bottom wall of the outer cylindrical portion 32 enters the pump case 14 and the pump case 14 and the rotor accommodating portion 38 are communicated with each other.

  On the other hand, a second coupling portion 42 is integrally formed at the lower end portion of the outer cylindrical wall 32A. The second coupling portion 42 projects from the outer cylinder wall 32A to the outside in the radial direction of the motor housing 30, and is formed in a predetermined shape over the entire circumference of the outer cylinder wall 32A. Further, an encircling wall 42 </ b> A is integrally formed on the lower surface of the second coupling portion 42 at the outer peripheral portion of the second coupling portion 42. The surrounding wall 42 </ b> A protrudes downward from the second coupling portion 42 and is formed in a frame shape over the entire circumference of the second coupling portion 42.

  Further, the second coupling portion 42 is integrally formed with a connector portion (not shown). The connector portion is formed in a substantially bottomed rectangular tube shape that is opened downward, and protrudes downward from the second coupling portion 42, and an external connector (not shown) is fitted into the connector portion. It has become so. Although not shown, the motor housing 30 is provided with a connector terminal connected to an external connector, and one end portion of the connector terminal is disposed inside the connector portion. Further, the connector terminal is bent into a predetermined shape, and the other end of the connector terminal extends downward from the motor housing 30 and is connected to a circuit board 96 described later.

  Further, a substantially cylindrical support portion 44 is integrally formed on the bottom wall of the inner cylinder portion 34 at the center portion. The support portion 44 is disposed coaxially with the inlet pipe 22 of the pump portion 12 and protrudes upward from the bottom wall of the inner cylinder portion 34. Further, a cylindrical rotation shaft 46 is provided in the inner cylinder portion 34, and the rotation shaft 46 is disposed coaxially with the support portion 44. The lower end portion of the rotation shaft 46 is fixedly supported by the support portion 44, and the rotation shaft 46 protrudes upward from the support portion 44.

(About motor unit 50)
As shown in FIG. 2, the motor unit 50 includes a rotor 52 and a stator 80. Hereinafter, the rotor 52 will be described first, and then the stator 80 will be described.

  The rotor 52 is formed in a substantially cylindrical shape as a whole, and is housed in the rotor housing portion 38 of the motor housing 30 on the radially outer side of the rotating shaft 46. 3 and 4, the rotor 52 includes a rotor core 54, a plurality of (four in the present embodiment) rotor magnets 60 as “magnets”, and a rotor cover 62 as “covers”. The resin mold part 64 (refer FIG. 4) is comprised. The rotor body 53 of the present invention is constituted by the rotor core 54 and the rotor magnet 60.

  As shown in FIG. 3, the rotor core 54 is composed of a plurality of steel plates punched in a substantially annular shape, and the steel plates are stacked in the vertical direction with the vertical direction as the thickness direction. The rotor core 54 is formed in a substantially cylindrical shape as a whole and is disposed coaxially with the rotating shaft 46 (see FIG. 2). The rotor core 54 is formed with a plurality (four in this embodiment) of magnet attachment holes 54A as “insertion holes” penetrating in the vertical direction (the axial direction of the rotor core 54). 54 A of magnet attachment holes are formed in the cross-sectional substantially rectangular shape which made the direction orthogonal to the radial direction of the rotor core 54 a longitudinal direction seeing from the axial direction of the rotor core 54, and along the circumferential direction of the rotor core 54, etc. They are arranged at intervals (every 90 °).

  As shown in FIG. 1, a pair of slits 54 </ b> B is formed on the outer peripheral portion of the rotor core 54 at a position on the outer side in the longitudinal direction of the magnet mounting hole 54 </ b> A (that is, eight slits in this embodiment). 54B is formed). The slit 54 </ b> B is formed in a substantially U shape opened to the outside in the radial direction of the rotor core 54 when viewed from the axial direction of the rotor core 54, and penetrates in the vertical direction. Further, the side surface 54BA adjacent to the magnet mounting hole 54A in the slit 54B is arranged in parallel with both longitudinal end surfaces 54AA of the magnet mounting hole 54A. A portion of the rotor core 54 between the magnet mounting hole 54A and the slit 54B is a side guide portion 54C.

  As shown in FIG. 3, the rotor magnet 60 is configured as a neodymium magnet and is formed in a substantially rectangular column shape. The rotor magnet 60 is inserted (inserted) into the magnet mounting hole 54A with the vertical direction as the longitudinal direction. Accordingly, the rotor magnet 60 is embedded in the rotor core 54 in the circumferential direction of the rotor core 54. In other words, the rotor 52 is a so-called IPM type (Internal Permanent Magnet) type (magnet embedded type) rotor. In the outer peripheral portion of the rotor core 54, a portion between the pair of slits 54B where the rotor magnet 60 is disposed is a magnet magnetic pole portion 56. In the present embodiment, four magnet magnetic pole portions 56 are formed. Yes.

  Further, a portion of the outer peripheral portion of the rotor core 54 adjacent to the magnet magnetic pole portion 56 in the circumferential direction of the rotor core 54 is a load receiving portion 58. That is, in this embodiment, four load receiving portions 58 are formed. A gap G (see FIG. 1) is formed between the load receiving portion 58 and the magnet magnetic pole portion 56 by the slit 54B described above. As a result, the load receiving portions 58 are arranged at equal intervals (every 90 °) in the circumferential direction of the rotor core 54, similarly to the magnet magnetic pole portion 56, and the outer peripheral portion of the rotor main body 53 is connected to the magnet magnetic pole portion 56 and The load receiving portion 58 is configured. The rotor magnet 60 is set to the same magnetic pole (one magnetic pole in the present invention, for example, N pole), and the load receiving portion 58 is different from the magnetic pole portion 56 due to the magnetic action of the rotor magnet 60. (The other magnetic pole in the present invention, for example, the S pole) is configured as a pseudo magnetic pole portion. Thereby, in the rotor 52, the magnet magnetic pole portions 56 and the load receiving portions 58 having different magnetic poles are alternately arranged in the circumferential direction of the rotor core 54, and the rotor 52 is a so-called continuous pole type rotor (half magnet type). Also referred to as a rotor).

  Further, as shown in FIG. 1, the outer peripheral surface 56 </ b> A of the magnet magnetic pole portion 56 is formed in an arc shape having a certain curvature around the axial center C of the rotor core 54 when viewed from the axial direction of the rotor core 54. The distance (radius) from the axial center C of the rotor core 54 to the outer peripheral surface 56A is R1. Further, when viewed from the axial direction of the rotor core 54, the outer peripheral surface 58 </ b> A of the load receiving portion 58 is also formed in an arc shape having a certain curvature around the axial center C of the rotor core 54, and the axial center C of the rotor core 54. The distance from the outer peripheral surface 58A to R2 is R2. The distance R2 is set slightly larger than the distance R1. The distances R2 in the four load receiving portions 58 are all set to the same value.

  In addition, recessed portions 56 </ b> B are formed on both sides in the circumferential direction of the rotor core 54 on the outer peripheral surface 56 </ b> A of the magnet magnetic pole portion 56. The recessed portion 56B is formed in a substantially arc shape that is open to the outside in the radial direction of the rotor core 54, and is formed to be slightly recessed toward the inside in the radial direction of the rotor core 54.

  Note that the surfaces of the rotor core 54 and the rotor magnet 60 described above are each subjected to rust prevention treatment (for example, nickel plating or resin coating). Thereby, the corrosion prevention and rust prevention of the rotor core 54 and the rotor magnet 60 are enhanced.

  As shown in FIGS. 3 and 4, the rotor cover 62 is made of a metal (for example, an aluminum alloy) made of a nonmagnetic material that is softer than the rotor core 54 (in this embodiment, a thickness of 0.25 mm). And is formed in a substantially bottomed cylindrical shape opened upward, and the surface of the rotor cover 62 is subjected to rust prevention treatment. Specifically, the rotor cover 62 has a cylindrical portion 62A formed in a substantially cylindrical shape. Further, the rotor cover 62 has a bottom wall portion 62B (see FIG. 4). The bottom wall portion 62B is formed in a substantially annular plate shape with the vertical direction being the plate thickness direction, and the lower end of the cylindrical portion 62A. Extends inward in the radial direction of the cylindrical portion 62A. The rotor core 54 is fitted (inserted) into the rotor cover 62. Specifically, the magnet magnetic pole portion 56 of the rotor core 54 is fitted into the cylindrical portion 62 </ b> A, and the outer peripheral surface 56 </ b> A of the magnet magnetic pole portion 56 of the rotor core 54 is in contact with the inner peripheral surface 62 </ b> C of the rotor cover 62. When the rotor core 54 is fitted in the rotor cover 62 (in other words, the rotor cover 62 is fixed to the outer side in the radial direction of the rotor core 54), the load on the inner peripheral surface 62C of the rotor cover 62 and the rotor core 54 is obtained. A slight gap is formed between the outer peripheral surface 58 </ b> A of the receiving portion 58.

  As a result, the radially outer peripheral surface of the rotor core 54 is covered from the radially outer side of the rotor 52 by the cylindrical portion 62 </ b> A of the rotor cover 62, and the cylindrical portion 62 </ b> A constitutes the radially outer portion of the rotor 52. Further, the lower surface of the rotor core 54 and the lower surface of the rotor magnet 60 are covered from below by the bottom wall portion 62B of the rotor cover 62, and the bottom wall portion 62B constitutes the lower end portion of the rotor 52.

  As shown in FIG. 4, the resin mold portion 64 is integrally formed with the rotor cover 62 by a technique such as insert molding, and constitutes the outer shell of the rotor 52 together with the rotor cover 62. Specifically, the resin mold part 64 has a substantially cylindrical inner mold part 64 </ b> A, and the inner mold part 64 </ b> A is integrated with the rotor core 54 so as to cover the inner peripheral surface on the radially inner side of the rotor core 54. Is formed. Further, the lower end portion of the inner mold portion 64 </ b> A is formed integrally with the bottom wall portion 62 </ b> B of the rotor cover 62.

  Furthermore, the resin mold part 64 has an upper mold part 64B. The upper mold part 64B extends from the upper end of the inner mold part 64A to the outside in the radial direction of the rotor 52, and is formed in a substantially annular shape. The upper mold portion 64 </ b> B is formed integrally with the upper surface (the other axial end surface) of the rotor core 54 and the upper surface of the rotor magnet 60. Further, the radially outer end portion of the upper mold portion 64B is formed integrally with the upper end portion of the cylindrical portion 62A of the rotor cover 62, and the upper mold portion 64B closes the rotor cover 62. Thereby, the rotor core 54 and the rotor magnet 60 are covered with the rotor cover 62 and the resin mold part 64 in a state where the liquid tightness of the joint part between the rotor cover 62 and the resin mold part 64 is ensured.

  On the other hand, a bearing 66 formed in a substantially cylindrical shape is integrally provided inside the inner mold portion 64A in the radial direction. The bearing 66 is disposed coaxially with the rotating shaft 46 and is rotatably supported by the rotating shaft 46 (see FIG. 2). As a result, the rotor 52 is rotated about the axis of the rotary shaft 46 via the bearing 66.

  A connecting shaft portion 65 for connecting the resin mold portion 64 and the impeller 70 is integrally formed on the upper side of the resin mold portion 64. The connecting shaft portion 65 is formed in a substantially cylindrical shape, is disposed coaxially with the rotating shaft 46, and extends upward from the upper mold portion 64 </ b> B of the resin mold portion 64.

  A first disk portion 72 and a blade 74 constituting the impeller 70 are integrally formed at the upper end of the connecting shaft portion 65. The first disk portion 72 is formed in a substantially disk shape, and is disposed coaxially with the rotation shaft 46 with the plate thickness direction being the axial direction of the rotation shaft 46. The blade 74 projects upward from the first disk portion 72. Further, on the upper side of the blade 74, a second disk portion 76 constituting the impeller 70 is provided. The second disk portion 76 is formed in a substantially disk shape, is disposed so as to face the first disk portion 72 via the blade 74, and is integrally coupled to the blade 74.

  Next, the stator 80 will be described. As shown in FIG. 2, the stator 80 includes a stator core 82 formed in an annular shape and a winding 84 having conductivity, and is accommodated in the stator accommodating portion 36 of the motor housing 30. Yes. The stator core 82 is composed of a plurality of steel plates punched into a predetermined shape, and the steel plates are stacked in the vertical direction with the vertical direction being the thickness direction. The stator core 82 is formed with a plurality of tooth portions 82A extending outward in the radial direction of the stator core 82.

  Winding 84 is wound around tooth portion 82 </ b> A of stator core 82. Thereby, winding part 84A wound along the outer peripheral part of teeth part 82A is formed. A terminal portion of the winding 84 extends downward from the motor housing 30 (stator accommodating portion 36) and is connected to a circuit board 96 described later. An insulating member 85 is interposed between the winding portion 84A and the tooth portion 82A.

  The stator 80 is covered with a stator holder 86. The stator holder 86 is made of a steel plate and has a substantially bottomed cylindrical shape that is open downward. A circular arrangement hole 86 </ b> A is formed through the bottom wall of the stator holder 86 in the vertical direction. The stator 80 and the stator holder 86 are accommodated in the stator accommodating portion 36 in a state where the stator 80 is disposed (inserted) in the stator holder 86. In this state, the inner cylindrical portion 34 of the motor housing 30 is disposed inside the arrangement hole 86A.

  In addition, a holder-side flange portion 86 </ b> B is integrally formed at the open end (lower end) of the stator holder 86. The holder-side flange portion 86B extends from the open end (lower end) of the stator holder 86 to the radially outer side of the stator holder 86, and is located below the second coupling portion 42 of the motor housing 30 and inside the surrounding wall 42A. Is arranged.

(About the circuit device 90)
As shown in FIG. 2, the circuit device 90 constitutes a lower portion of the water pump 10 and is disposed on the lower side of the motor housing 30. The circuit device 90 includes a plate unit 92, a circuit board 96, and a circuit cover 98.

  The plate unit 92 is formed in a substantially disk shape and is disposed on the lower side with respect to the motor housing 30. The plate unit 92 includes a plate main body 93 made of a resin material, and a ring plate 94 made of a steel plate and formed in a substantially ring shape. The plate main body 93 and the ring plate 94 are integrally formed with the ring plate 94 disposed above the plate main body 93.

  Further, the ring plate 94 is disposed to face the holder side flange portion 86B of the stator holder 86 in the vertical direction, and the plate unit 92 is fastened and fixed to the holder side flange portion 86B at a position not shown.

  The ring plate 94 is integrally formed with a plurality of fixing pieces 94B for fixing a circuit board 96 to be described later. The fixed piece 94 </ b> B extends downward from the outer peripheral portion of the ring plate 94, and the distal end portion of the fixed piece 94 </ b> B is bent inward in the radial direction of the ring plate 94. A burring 94C for fastening a circuit board 96, which will be described later, is formed at the distal end of the fixed piece 94B. The burring 94C is formed in a substantially bottomed cylindrical shape that is opened downward.

  Further, a guide hole (not shown) is formed in the plate unit 92 so as to penetrate in the vertical direction, and the other end portion of the connector terminal and the terminal portion of the winding 84 are inserted into the guide hole. Yes.

  The circuit board 96 is formed in a substantially disc shape, and is disposed on the lower side of the plate unit 92 with the plate thickness direction being the vertical direction. A screw (not shown) is inserted into the burring 94C of the ring plate 94 described above, and the circuit board 96 is fixed to the plate unit 92 by the screw. A plurality of circuit elements 96A are mounted on the circuit board 96, and the other end of the connector terminal and the terminal of the winding 84 are connected.

  The circuit cover 98 is made of a steel plate and is formed in a substantially bottomed cylindrical shape opened upward. Further, a cover-side flange portion 98A is integrally formed at the open end (upper end) of the circuit cover 98, and the cover-side flange portion 98A protrudes radially outward of the circuit cover 98 from the open end of the circuit cover 98. In addition, it is formed over the entire circumference of the circuit cover 98. The circuit cover 98 covers the circuit board 96 and the plate unit 92 and closes the lower end portion of the motor housing 30. Specifically, the cover side flange portion 98A is disposed inside the surrounding wall 42A of the motor housing 30 and opposed to the holder side flange portion 86B of the stator holder 86, and is fastened to the holder side by a fastening member such as a screw (not shown). It is fastened and fixed to the flange portion 86B.

  Next, the operation and effect of the present embodiment will be described.

  In the water pump 10 configured as described above, the inside of the pump portion 12 (pump case 14) and the inside of the rotor housing portion 38 of the motor housing 30 are communicated with each other. An impeller 70 is accommodated in the impeller accommodating portion 18 of the pump case 14, and a rotor 52 of the motor unit 50 is accommodated in the rotor accommodating portion 38. Further, the impeller 70 and the rotor 52 are configured to be integrally rotatable. In addition, a stator 80 of the motor unit 50 is disposed outside the rotor 52 in the radial direction, and the stator 80 is accommodated in the stator accommodating portion 36 of the motor housing 30.

  Then, when the external connector is connected to the connector portion and electric power for driving and controlling the motor portion 50 is supplied from the external connector to the circuit device 90, the motor portion 50 is driven and the rotor 52 of the motor portion 50 is rotated. It is rotated about 46 axes. As a result, the impeller 70 rotates around the axis of the rotating shaft 46, and the cooling water that has flowed into the pump case 14 from the inlet pipe 22 of the pump unit 12 is pumped and flows out of the outlet pipe of the pump unit 12.

  Here, in the rotor core 54, the distance R2 from the axial center C of the rotor core 54 to the outer peripheral surface 58A of the load receiving portion 58 is larger than the distance R1 from the axial center C of the rotor core 54 to the outer peripheral surface 56A of the magnet magnetic pole portion 56. It is set large (long). For this reason, by fixing the rotor cover 62 to the outer side in the radial direction of the rotor main body 53, the load receiving portion receives the load from the rotor cover 62 to the rotor main body 53 on the inner side in the radial direction of the rotor core 54 (rotor main body 53). 58 can be received. Thereby, since the said load is suppressed from acting on the magnet magnetic pole part 56, the load which acts on the rotor magnet 60 from the rotor cover 62 can be suppressed.

  Further, in the rotor 52, the load receiving portions 58 are arranged at equal intervals (every 90 °) in the circumferential direction of the rotor core 54. Therefore, the rotor cover 62 can be fixed to the rotor body 53 in a balanced manner in the circumferential direction of the rotor core 54 (rotor body 53). Further, by fixing the rotor cover 62 to the outer side in the radial direction of the rotor main body 53, the load on the inner side in the radial direction of the rotor core 54 (rotor main body 53) acting on the rotor main body 53 from the rotor cover 62 is balanced to the rotor core 54. Can be well dispersed.

  Further, in the rotor 52, the magnet magnetic pole portions 56 and the load receiving portions 58 are alternately formed in the circumferential direction of the rotor core 54. For this reason, the load which acts on the rotor magnet 60 from the rotor cover 62 can be suppressed effectively.

  Further, in the rotor 52, the rotor magnet 60 is one magnetic pole, and the load receiving portion 58 is a pseudo magnetic pole portion that functions as the other magnetic pole. That is, the load receiving portion 58 has a function as a pseudo magnetic pole portion and a function of receiving a load acting on the rotor main body portion 53 from the rotor cover 62. For this reason, the structure of the rotor 52 can be simplified as compared with the case where the two functions are provided in different parts of the rotor core 54.

  Further, in each load receiving portion 58, the distance R2 from the axial center C of the rotor core 54 to the outer peripheral surface 58A of the load receiving portion 58 is all set to the same value. For this reason, since the interval (magnetic gap) between the load receiving portion 58 functioning as a pseudo magnetic pole portion and the stator 80 becomes substantially the same, the rotation balance of the rotor 52 can be ensured.

  Further, since a gap G is formed between the magnet magnetic pole portion 56 and the load receiving portion 58, the gap G transmits the load acting on the load receiving portion 58 from the rotor cover 62 to the magnet magnetic pole portion 56. Can be suppressed.

  In the rotor 52, the rotor magnet 60 is inserted into the magnet mounting hole 54A of the rotor core 54, and the rotor 52 is configured as a so-called magnet-embedded rotor. For this reason, in the rotor 52 configured as a magnet-embedded rotor, deformation or the like of the magnet attachment hole 54A in the rotor core 54 can be suppressed by the load receiving portion 58. Specifically, when the rotor core 54 is fitted into the rotor cover 62, the outer peripheral surface 58A of the load receiving portion 58 is brought into contact with the inner peripheral surface 62C of the rotor cover 62 and the outer peripheral surface 56A of the magnet magnetic pole portion 56. And a slight gap is formed between the inner peripheral surface 62 </ b> C of the rotor cover 62. Accordingly, when the rotor core 54 is fitted into the rotor cover 62, the side guide portion 54C of the rotor core 54 is suppressed from being deformed (that is, the magnet mounting hole 54A is suppressed from being deformed). Thereby, the rotor magnet 60 can be satisfactorily inserted (inserted) into the magnet mounting hole 54A.

  Further, in the water pump 10, the outer surface of the rotor 52 is configured by the rotor cover 62 and the resin mold portion 64. Specifically, the rotor cover 62 is formed in a substantially bottomed cylindrical shape, and the rotor core 54 is inserted into the rotor cover 62. A resin mold portion 64 is formed integrally with the rotor cover 62 so as to cover the radially inner portion and the upper surface side of the rotor core 54. As a result, the rotor cover 62 and the resin mold part 64 can ensure waterproofness to the rotor body 53 (the rotor core 54 and the rotor magnet 60).

  The radially outer portion of the rotor 52 is constituted by a metal rotor cover 62 made of a nonmagnetic material. For this reason, the space | interval between the rotor core 54 and the stator 80 can be narrowed compared with the case where the rotor cover 62 is resin. That is, if the rotor cover 62 is made of a resin material, it is necessary to ensure the thickness of the rotor cover 62 to 1 mm to 2 mm, for example, from the viewpoint of moldability and the like. On the other hand, when the rotor cover 62 is made of a metal plate, the thickness of the rotor cover 62 can be set to 0.25 mm, for example. As a result, the distance (magnetic gap) between the rotor core 54 and the stator 80 can be reduced. Further, since the rotor cover 62 is made of a nonmagnetic material, the magnetic flux in the rotor main body 53 can be prevented from leaking to the rotor cover 62.

  Further, the rotor cover 62 is made of a softer metal than the rotor core 54. For this reason, the load from the rotor cover 62 acting on the rotor main body 53 to the inner side in the radial direction of the rotor core 54 (rotor main body 53) is further suppressed from acting on the magnet magnetic pole portion 56. The load acting on can be further suppressed.

  In the present embodiment, the rotor 52 is configured as a so-called magnet-embedded rotor, but the rotor 52 may be configured as a so-called magnet surface fixed type rotor. That is, as shown in FIG. 5, a recess 59 that is opened radially outward of the rotor core 54 is formed in a portion between the load receiving portions 58 in the outer peripheral portion of the rotor core 54, and the rotor magnet 60 is formed in the recess 59. May be arranged. In this case, the outer peripheral surface 60A of the rotor magnet 60 is formed in an arc shape when viewed from the axial direction of the rotor core 54, and the distance from the axial center C of the rotor core 54 to the outer peripheral surface 60A corresponds to the distance R1. Composed.

  In this embodiment, the rotor core 54 is formed with four magnet magnetic pole portions 56 and four load receiving portions 58. That is, the rotor core 54 is configured as a so-called 8-pole rotor core, but the rotor core 54 may be configured as a 4-core or more rotor core.

  In the present embodiment, the outer peripheral surface 56A of the magnet magnetic pole portion 56 and the outer peripheral surface 58A of the load receiving portion 58 are formed in an arc shape having a constant curvature when viewed from the axial direction of the rotor core 54. The shapes of the surfaces 56A and 58A are not limited to this. For example, the curvatures of the outer peripheral surfaces 56A and 58A are changed so that the outer circumferential portions of the rotor core 54 on the outer peripheral surfaces 56A and 58A are spaced radially inward of the rotor core 54 with respect to the inner peripheral surface 62C of the rotor cover 62. May be. Further, for example, a protruding portion that protrudes radially outward of the rotor cover 62 is formed on the outer peripheral surface 58A of the load receiving portion 58, and the protruding portion contacts the inner peripheral surface 62C of the rotor cover 62. Also good. That is, the distance R2 from the axial center C of the rotor core 54 in the load receiving portion 58 to the outer peripheral surface 58A is the maximum distance R2.

  In the present embodiment, the slit 54B is formed between the magnet magnetic pole portion 56 and the load receiving portion 58 to form the slit-shaped gap G. However, the shape of the gap G is not limited to this. For example, instead of the slit 54B, a hole that penetrates the rotor core 54 in the axial direction may be provided in the rotor core 54 to form the gap G. In other words, the gap G only needs to be formed so as to suppress transmission of a load acting from the rotor cover 62 to the load receiving portion 58 to the magnet magnetic pole portion 56.

  Further, in the present embodiment, the surfaces of the rotor core 54 and the rotor magnet 60 are subjected to rust prevention treatment (for example, nickel plating or resin coating), but the rust prevention of either the rotor core 54 or the rotor magnet 60 is performed. The treatment may be omitted, or both rust prevention treatments may be omitted.

  In this embodiment, the rotor cover 62 is made of, for example, an aluminum alloy, but the rotor cover 62 may be made of a SUS plate material. Furthermore, although the plate thickness of the rotor cover 62 is set to 0.25 mm, the plate thickness of the rotor cover 62 may be appropriately changed in consideration of the motor efficiency of the motor unit 50.

DESCRIPTION OF SYMBOLS 10 ... Water pump (liquid pump), 12 ... Pump part, 52 ... Rotor, 53 ... Rotor main body part, 54 ... Rotor core, 54A ... Magnet attachment hole (insertion hole), 56: Magnet magnetic pole part, 56A: Outer peripheral surface, 58 ... Load receiving part, 58A: Outer peripheral surface, 60 ... Rotor magnet (magnet), 62 ... Rotor cover (cover), 64 ... Resin mold part, G ... Gap, R1 ... Distance from the axial center of the rotor core to the outer peripheral surface of the magnet magnetic pole part, R2 ... From the axial center of the rotor core to the outer peripheral surface of the load receiving part distance

Claims (7)

A rotor main body portion in which a magnet magnetic pole portion is formed by arranging a plurality of magnets in a circumferential direction of a rotor core made of a magnetic material;
A cylindrical cover fixed to the outside of the rotor body in the radial direction;
A part of the outer peripheral part of the rotor main body part is formed, and a gap is formed with respect to the magnet magnetic pole part in the circumferential direction of the rotor core, and the distance from the axial center of the rotor core to the outer peripheral surface is the axial center of the rotor core A load receiving portion that is set longer than the distance from the magnet magnetic pole portion to the outer peripheral surface and receives a load from the cover;
With a rotor.   The rotor according to claim 1, wherein the load receiving portions are arranged at equal intervals in a circumferential direction of the rotor core.   The rotor according to claim 1 or 2, wherein the magnet magnetic pole portion and the load receiving portion are alternately formed in a circumferential direction of the rotor core. The magnet is set as one magnetic pole,
The rotor according to claim 3, wherein the load receiving portion is a pseudo magnetic pole portion that functions as the other magnetic pole.   The rotor according to claim 4, wherein a distance from an axial center of the rotor core to an outer peripheral surface of the load receiving portion is set to be the same in the plurality of load receiving portions. The rotor core has an insertion hole into which the magnet is inserted,
The rotor according to any one of claims 1 to 5, wherein the insertion hole and the gap are arranged adjacent to each other in a circumferential direction of the rotor core. An impeller that pumps the liquid in the pump section by rotating;
The rotor according to any one of claims 1 to 6, wherein the rotor is integrally rotatable with the impeller, and the cover is nonmagnetic.
A stator provided on the radially outer side of the rotor;
A resin mold portion that is integrally formed with the impeller, and covers the rotor main body portion and constitutes the outer shell of the rotor together with the cover.
With liquid pump.

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