JP6686664B2 - Electric pump - Google Patents

Description

  The present invention relates to an electric pump.

  Patent Document 1 below discloses an electric pump that circulates cooling water flowing inside an engine or the like. This electric pump includes a casing, a shaft member fixed to the casing, a cylindrical bearing portion inserted outside the shaft member, and a member separate from the bearing portion, and rotates integrally with the bearing portion. A rotor and an impeller fixed to one end of the rotor and integrally rotatable with the rotor are provided. Further, a discharge passage is formed between the bearing portion and the rotor for returning the fluid flowing out from the outer peripheral side of the impeller and circulating in the casing to the impeller side. This prevents foreign matter mixed in the cooling water from being discharged through the discharge path, thereby preventing the foreign matter from staying inside the casing, and the foreign matter impedes the rotation of the rotor arranged in the casing. Are suppressed.

JP, 2016-23635, A

  By the way, as described in Patent Document 1, from the viewpoint of the stability of the operation of the electric pump and the like, it is important to prevent foreign matter mixed in the liquid from staying inside the electric pump. .

  The present invention has been made in consideration of the above facts, and an object thereof is to obtain an electric pump that can prevent foreign matter mixed in a liquid from staying inside.

The electric pump according to claim 1, wherein a motor housing that supports a stator, a rotor that rotates by receiving a magnetic field of the stator, and a shaft that is arranged at an axial center portion of the rotor, and an inflow portion into which a liquid flows. An outflow part through which the liquid flows, a pump chamber in which an impeller rotated by the rotor is provided between the inflow part and the outflow part, and a coating covering one end of the shaft. And a pump housing having a communication hole that communicates the inside and the outside of the covering portion, the communication hole including an end portion of the covering portion on one side of the shaft and a rotation shaft of the rotor. It is formed at positions separated in the direction .

  According to the electric pump of the first aspect, when the stator generates the magnetic field, the rotor rotates around the shaft. Further, when the rotor rotates, the impeller is rotated, and the liquid flowing from the inflow portion of the pump housing is pressurized in the pump chamber and flows out from the outflow portion. Here, in the electric pump according to the first aspect, a communication hole that communicates the inside and the outside of the cover that covers one end of the shaft is formed in the cover. As a result, the foreign matter in the liquid that has entered the inside of the covering portion can be discharged to the outside of the covering portion through the communication hole. That is, it is possible to prevent foreign matter in the liquid that has entered the inside of the covering portion from staying inside the covering portion.

  According to a second aspect of the present invention, in the electric pump according to the first aspect, a side of the communication hole opposite to the shaft is open to a shaft center side of the impeller.

  According to the electric pump of claim 2, the side of the communication hole opposite to the shaft is opened to the shaft center side of the impeller in which the fluid flows, so that the foreign matter in the liquid that has penetrated into the inside of the cover communicates. Discharge through the holes can be facilitated.

  The electric pump according to claim 3 is the electric pump according to claim 1 or 2, wherein the covering portion has a restriction surface for restricting movement of the rotor in a rotation axis direction, and the communication hole is It is formed at a position different from the regulation surface in the covering portion.

According to the electric pump of claim 3, the communication hole is formed in the restriction surface by forming the communication hole at a position apart from the restriction surface with which the rotor or the member rotating with the rotor may come into sliding contact. With such a configuration, it is possible to suppress the wear of the restriction surface due to the rotor and a member rotating together with the rotor slidingly contacting each other.
The electric pump according to claim 4 is the electric pump according to any one of claims 1 to 3, wherein the covering portion has a plurality of support ribs arranged at intervals along the circumferential direction. Is supported by the inflow portion via a plurality of communication holes are formed in the covering portion, and the plurality of communication holes are intermediate portions in the circumferential direction of a pair of support ribs adjacent in the circumferential direction. Are located in each.

It is sectional drawing which shows the electric pump which concerns on this embodiment. (A) is a plan view showing the pump housing, and (B) is an enlarged plan view of the rotor bearing retainer in the pump housing as seen from the opening direction of the inlet pipe. (A) is a bottom view showing the pump housing, and (B) is an enlarged bottom view of the rotor bearing retainer in the pump housing as seen from the pump chamber side.

  The electric pump according to the embodiment of the present invention will be described with reference to FIGS. 1 to 3.

  As shown in FIG. 1, the electric pump 10 of the present embodiment is a water pump for pumping cooling water to the inside of an engine or the like of a vehicle. Specifically, the electric pump 10 increases the pressure of the cooling water that has flowed into the pump chamber 12 by rotating the pump housing 14 that forms the outer shell of the pump chamber 12 in which the pressure of the cooling water that has flowed in is increased, and the impeller 16. And a rotor 18. The electric pump 10 also includes a stator 20 that rotates the rotor 18 by generating a rotating magnetic field, and a motor housing 22 that supports the stator 20 and the like. Further, the electric pump 10 includes a circuit device 24 for controlling energization of the stator 20. Note that the arrow Z direction, arrow R direction, and arrow C direction that are shown in the drawings as appropriate indicate the rotation axis direction, rotation radial direction, and rotation circumferential direction of the rotor 18, respectively. Further, hereinafter, when simply indicating the axial direction, the radial direction, and the circumferential direction, the rotational axis direction, the rotational radial direction, and the rotational circumferential direction of the rotor 18 are indicated unless otherwise specified.

  Hereinafter, first, a schematic configuration of the electric pump 10 will be described, and then a detailed configuration of the pump housing 14, which is a main part of the present embodiment, will be described.

(Schematic configuration of electric pump 10)
As shown in FIG. 1, the pump housing 14 includes an inlet pipe 26 as an inflow portion into which cooling water flows and an outlet pipe 28 (see FIG. 2A) as an outflow portion from which cooling water flows, and a substantially cochlea. And a pump chamber forming portion 30 that forms an outer shell of the pump chamber 12 in which an impeller 16 described later is arranged. The inlet pipe 26 extends from the axial center of the pump chamber forming portion 30 to one side in the axial direction, and the outlet pipe 28 extends outward from the outer peripheral portion of the pump chamber forming portion 30 in the radial direction. . In addition, a coating portion 32 that covers the end portion of the shaft 40 while restricting the movement of the rotor bearing 46, which will be described later, to one side in the axial direction is provided in the axial center portion of the pump housing 14. The pump housing 14 is fixed to the motor housing 22 by joining the outer peripheral portion of the pump housing 14 described above to the motor housing 22 described later.

  The motor housing 22 is an integrally molded product having a rotor housing recess 34 in which the rotor 18 is disposed on one axial side and a stator housing recess 36 in which the stator 20 is disposed on the other axial side. . At the axial center of the bottom of the rotor accommodating recess 34, a cylindrical shaft fixing portion 38 that projects toward one side in the axial direction is provided upright. A cylindrical shaft 40 is fixed to the shaft fixing portion 38 by press fitting or the like. Further, the stator housing recess 36 is an annular space formed radially outside the rotor housing recess 34, and the stator 20 is arranged in the stator housing recess 36, so that the stator 20 and the rotor 18 are radially separated. They are arranged so as to face each other.

  The rotor 18 is configured integrally with the impeller 16 so that the rotor 18 can rotate integrally with the impeller 16. The rotor 18 includes a rotor magnet support portion 42 formed in a thick-walled cylindrical shape, and a rotor magnet 44 is fixed to the outer peripheral portion of the rotor magnet support portion 42. Further, a rotor bearing 46 having an inner diameter set to an inner diameter corresponding to the outer diameter of the shaft 40 is fixed to the inner peripheral portion of the rotor magnet support portion. By inserting the rotor bearing 46 into the shaft 40, the rotor 18 can rotate around the shaft 40.

  The impeller 16 is formed by arranging a plurality of blades 52 upright between a first disk portion 48 and a second disk portion 50 that extend in the radial direction and are formed in a disk shape. A covering portion 32, which will be described in detail later, is arranged at the shaft center portion of the impeller 16, that is, at the shaft center portions of the first disk portion 48 and the second disk portion 50.

  The stator 20 includes a stator core 54 formed in an annular shape and a conductive winding 56 as main elements. The stator core 54 is formed with a plurality of teeth 54 </ b> A that extend radially outward and around which the winding 56 is wound. Then, the winding 56 is wound around each tooth portion 54A, so that the coil 56A is formed along the tooth portion 54A. Further, the terminal portion of the winding wire 56 that forms the coil 56A is connected to a circuit board 60 described later. The stator 20 is supported by the stator support member 58.

  The circuit device 24 is mainly configured by a disk-shaped circuit board 60 extending in the radial direction and a plurality of circuit elements 62 attached to the circuit board 60. The circuit board 60 is fixed to the stator support member 58 via screws 64. As a result, the circuit device 24 is supported by the stator support member 58. The circuit device 24 is covered with a cover member 66.

(Detailed structure of the pump housing 14)
Next, the configuration of the covering portion 32 of the pump housing 14 that is a main portion of this embodiment will be described.

  As shown in FIG. 1, the covering portion 32 is formed in a shallow bottomed columnar shape that is arranged coaxially with the shaft 40 on one axial side of the shaft 40. As shown in FIGS. 1, 2A and 2B, the covering portion 32 is supported by the inlet pipe 26 via three support ribs 68 arranged at equal intervals along the circumferential direction. There is.

  Further, the shaft 40 side is opened at the axial center of the end portion on the other axial direction side (shaft 40 side) of the covering portion 32, and the axially one side end portion 40A of the shaft 40 is disposed therein. A hollow portion 70 is formed.

  The end face of the covering portion 32 on the other side in the axial direction is moved toward the one side in the axial direction of the rotor 18 (rotor bearing 46) by the washer 72 interposed between the covering portion 32 and the rotor bearing 46 abutting. Is a regulation surface 74 that regulates the movement of the. The regulation surface 74 is formed in a planar shape corresponding to the end surface 72A on one axial side of the washer 72 as viewed in the axial direction. That is, the restriction surface 74 is not provided with slits or irregularities.

  In addition, a plurality of (three in the present embodiment) communication holes 76 that communicate the inside and the outside of the covering portion 32 are provided at the end portion of the covering portion 32 on one axial side (opposite the shaft 40). It is formed along the axial direction. As a result, the space inside the recess 70 formed in the covering portion 32 and the pump chamber 12 side are connected via the communication hole 76. As shown in FIGS. 2A and 2B and FIGS. 3A and 3B, the three communication holes 76 are arranged at equal intervals along the circumferential direction when viewed in the axial direction. In addition, as shown in FIGS. 2A and 2B, the three communication holes 76 are respectively arranged at the circumferential center portions of the pair of support ribs 68 that are circumferentially adjacent to each other.

  The shaft 40 side of each of the communication holes 76 is open toward the radially outer portion of the axially one end 40 </ b> A of the shaft 40. Further, the side of each communication hole 76 opposite to the shaft 40 is opened to the axial center side of the impeller 16 (rotation center side of the impeller 16). More specifically, the end of each communication hole 76 on the side opposite to the shaft 40 is arranged radially inward of the blade 52 of the impeller 16.

(Operation and effect of this embodiment)
Next, the operation and effect of this embodiment will be described.

  As shown in FIG. 1, according to the electric pump 10 of the present embodiment, when the circuit device 24 controls the energization of the winding 56 of the stator 20, a rotating magnetic field is generated around the stator 20. The rotating magnetic field causes the rotor 18 to rotate.

  Further, when the rotor 18 rotates, the impeller 16 formed integrally with the rotor 18 also rotates. As a result, the pressure of the cooling water flowing from the inlet pipe 26 of the pump housing 14 is increased in the pump chamber 12 and flows out from the outlet pipe 28.

  Here, the space formed between the motor housing 22 and the pump housing 14 is filled with cooling water, and the inside of the recess 70 of the covering portion 32 that covers the shaft 40 is also filled with cooling water. Therefore, in the structure in which the communication hole 76 is not formed in the covering portion 32, the foreign matter mixed in the cooling water easily stays inside the recess 70 of the covering portion 32. However, in the present embodiment, since the communication hole 76 described above is formed in the covering portion 32, foreign matter that has entered the inside of the recess 70 of the covering portion 32 can be discharged to the pump chamber 12 side through the communication hole 76. You can The foreign matter mixed in the cooling water is a residue that remains inside the water jacket or piping of the engine or a precipitate that is deposited due to deterioration of the cooling water.

  Further, in the present embodiment, the side of the communication hole 76 opposite to the shaft 40 is open to the axial center side of the impeller 16. In this way, by opening the side of the communication hole 76 opposite to the shaft 40 to the space where the flow velocity of the cooling water is high, the discharge of the foreign matter entering the inside of the recess 70 of the covering portion 32 through the communication hole 76 is promoted. be able to.

  Further, in the present embodiment, the communication hole 76 is formed in the restriction surface 74 by forming the communication hole 76 at a position apart from the restriction surface 74 with which the washer 72 rotating with the rotor 18 may slide. With such a configuration, it is possible to suppress the wear of the regulation surface 74 due to the washer 72 and the regulation surface 74 slidingly contacting each other.

  In the present embodiment, an example in which the side of the communication hole 76 opposite to the shaft 40 is opened to the axial center side of the impeller 16 has been described, but the present invention is not limited to this. Whether to open the side of the communication hole 76 opposite to the shaft 40 to the shaft center side of the impeller 16 may be appropriately set in consideration of the size of the assumed foreign matter, the inner diameter of the communication hole 76, and the like. .

  Further, in the present embodiment, an example in which the communication hole 76 is formed along the axial direction has been described, but the present invention is not limited to this. For example, the communication hole 76 may be formed along a direction intersecting the axial direction. As described above, whether or not to form the communication hole 76 along the axial direction may be appropriately set in consideration of the drawing direction of the mold forming the pump housing 14 and the like.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and various modifications other than the above can be carried out without departing from the spirit of the invention. Of course.

10 Electric Pump 12 Pump Chamber 14 Pump Housing 16 Impeller 18 Rotor 20 Stator 22 Motor Housing 26 Inlet Pipe (Inlet Port)
28 Outlet pipe (outflow part)
40 Shaft 40A Shaft's one end 74 74 Control surface 76 Communication hole

Claims (4)

A motor housing that supports a stator, a rotor that rotates by receiving the magnetic field of the stator, and a shaft that is arranged at the axial center of the rotor;
An inflow part into which the liquid flows, an outflow part from which the liquid flows out, a pump chamber in which an impeller rotated by the rotor is provided between the inflow part and the outflow part, and one side of the shaft A pump housing having a covering portion that covers an end portion of the pump, and a communication hole that communicates the inside and the outside of the covering portion,
Equipped with
The communication hole is an electric pump which is formed at a position separated from an end portion of the covering portion on one side of the shaft in a rotation axis direction of the rotor .   The electric pump according to claim 1, wherein a side of the communication hole opposite to the shaft is opened to a shaft center side of the impeller. The covering portion includes a restriction surface that restricts movement of the rotor in the rotation axis direction,
The electric pump according to claim 1 or 2, wherein the communication hole is formed at a position different from the regulation surface of the covering portion. The covering portion is supported by the inflow portion via a plurality of supporting ribs arranged at intervals along the circumferential direction,
A plurality of the communication holes are formed in the covering portion,
The electric pump according to any one of claims 1 to 3, wherein the plurality of communication holes are respectively arranged at intermediate portions in the circumferential direction of a pair of support ribs adjacent to each other in the circumferential direction.