JP4630123B2 - Fluid pump - Google Patents

Description

  The present invention relates to a fluid pump, and more particularly to an improvement of a fluid pump including an axial gap type motor in which a rotor and a stator are arranged so as to face each other in the rotation axis direction.

  Conventionally, there is a fluid pump including an axial gap type motor in which a rotor and a stator are arranged so as to face each other in the rotation axis direction (see, for example, Patent Document 1). For example, in the fluid pump disclosed in Patent Document 1, a partition is provided in a pump case, and a stator and a substrate including a coil and a yoke are accommodated on the upper side across the partition.

  In addition, a shaft supported by a shaft support portion and a fan (rotor) that is supported by the shaft and includes a magnet and a plurality of blades are provided below the partition wall. When a drive circuit is controlled by a DC power source and a current is passed through the coil, the fan rotates, and the fluid sucked from the water intake port is discharged from the pumping port through a predetermined path.

  In general, in a fluid pump, heat is generated in the stator as the motor continues to operate. Therefore, in the fluid pump described in Patent Document 1, a water channel communicating with the pump chamber is provided in the gap between the rotor and the stator.

  In the fluid pump disclosed in Patent Document 1, when the fluid is sent out radially outward with the rotation of the fan, the pressure of the fluid at the radially outer position in the pump chamber increases, and the radially outer position of the pump chamber is increased. The flow of fluid from the pump chamber to the gap between the fan and the stator is formed. In addition, the fresh fluid is sequentially conveyed to the gap between the fan and the stator in this way, so that the stator is cooled.

  By the way, in the fluid pump as shown in Patent Document 1, when the fan rotates and fluid is sucked into the pump chamber, the water inlet (inlet) becomes negative pressure. For this reason, a thrust thrust acts on the fan in the direction opposite to the fluid suction direction.

  At this time, if a thrust thrust acts on the fan in the direction opposite to the fluid suction direction, the fan is sucked toward the water suction port by the thrust thrust. Therefore, a structure in which a boss portion is provided at the water inlet and receives thrust thrust is usually employed (see, for example, Patent Document 2).

  Moreover, in the structure which receives a thrust thrust by providing a boss portion at the water intake port, the water flow resistance of the water intake port increases and the pump efficiency decreases due to the provision of the boss portion. Therefore, various structures have been proposed for reducing the thrust thrust acting on the fan while preventing a decrease in pump efficiency due to an increase in the water flow resistance of the water inlet (see, for example, Patent Documents 3 and 4). .

Japanese Patent Laid-Open No. 9-291893 JP 2004-19546 A JP 9-42190 A JP-A-6-241186

  However, in the fluid pump as described in Patent Document 1, the fluid is sequentially sent from the pump chamber to the gap between the fan and the stator, so that the fluid pressure at the radially outer position in the pump chamber and the fan and stator are The fluid pressure in the gap is equal (both pressures are high) and the fluid flow from the pump chamber to the fan / stator gap is reduced. Therefore, this causes a problem that the cooling efficiency of the stator is lowered.

  Further, when the fluid pressure is increased in the gap between the fan and the stator by sequentially feeding the fluid into the gap between the fan and the stator, the thrust thrust in the direction opposite to the fluid suction direction acting on the fan increases.

  Therefore, as the thrust thrust in the direction opposite to the fluid suction direction acting on the fan increases, the structure for reducing the thrust thrust acting on the fan also becomes large. Accordingly, there is a problem that the manufacturing cost increases accordingly.

  The present invention has been made in view of the above circumstances, and an object thereof is to reduce the thrust thrust in the direction opposite to the fluid suction direction acting on the rotor and the impeller as well as efficiently cooling the stator with a simple configuration. An object of the present invention is to provide a fluid pump capable of performing the above-described operation.

In order to solve the above-mentioned problem, a fluid pump according to claim 1, wherein a rotor provided with an impeller on a rotation shaft, a stator disposed so as to face the rotor in the direction of the rotation shaft with a gap therebetween, A casing having a pump chamber in which the impeller is rotatably accommodated and a fluid flow is formed around a rotation axis by the rotation of the impeller, and the pump chamber is configured to communicate with the gap. In the fluid pump, the outer diameter of the rotor is made larger than the outer diameter of the impeller, and the rotor is positioned on the outer side of the outer peripheral portion of the stator in the radial direction and on the stator side along the rotation axis direction. An overlap portion extending in the direction and overlapping the outer peripheral portion of the stator in the radial direction is formed.

  Thus, according to the fluid pump of the first aspect, the rotor is positioned on the outer side of the outer peripheral portion of the stator in the radial direction and extends to the stator side along the rotation axis direction to extend radially from the outer peripheral portion of the stator. Overlapping overlap portions are formed. Therefore, since the fluid flow from the pump chamber to the gap between the rotor and the stator can be regulated by the overlap portion, the pressure of the fluid at the radially outer position in the pump chamber can be controlled by the fluid in the gap between the rotor and the stator. It can be maintained higher than the pressure. Thereby, the thrust thrust in the direction opposite to the fluid suction direction acting on the rotor and the impeller can be reduced.

  Further, as described above, by maintaining the fluid pressure at the radially outer position in the pump chamber higher than the fluid pressure at the gap between the rotor and the stator, the radially outer position in the pump chamber and the gap between the rotor and the stator are maintained. , The fluid flow circulating from the pump chamber to the gap between the rotor and the stator can be continuously formed. Thereby, the stator contacts the flow of fluid formed in the gap between the rotor and the stator, and the stator can be efficiently cooled.

  Furthermore, according to the fluid pump according to claim 1, the rotor is positioned on the outer side in the radial direction of the outer peripheral portion of the stator and extends to the stator side along the rotation axis direction so as to overlap the outer peripheral portion of the stator in the radial direction. With the simple configuration of adding the wrap portion, the stator can be efficiently cooled and the thrust thrust in the direction opposite to the fluid suction direction acting on the rotor can be reduced. Thereby, the manufacturing cost of the fluid pump can also be reduced.

  At this time, as described in claim 2, the stator is integrated with the stator housing by molding at least the stator coil and the stator core, and an annular recess is formed radially outward from the stator of the stator housing. When the portion is disposed in the annular recess so that the protruding front end surface of the overlap portion faces the bottom surface of the annular recess, the overlap portion and the annular recess constitute a labyrinth structure.

  Therefore, the labyrinth structure can enhance the restriction effect on the flow of fluid from the pump chamber to the gap between the rotor and the stator. As a result, the fluid pressure at the radially outer position in the pump chamber can be reliably maintained higher than the fluid pressure in the gap between the rotor and the stator.

  Further, as described in claim 3, when the stator coil is disposed on the rotor side of the stator and the overlap portion is disposed at a position overlapping with the stator coil in the radial direction, the overlap portion wraps around the overlap portion. The stator coil can be cooled by the fluid flowing into the gap between the rotor and the stator.

Furthermore, if the overlap part is comprised by the cylindrical rib as described in Claim 4, the outer peripheral part of a stator can be wrapped with the overlap part comprised by the cylindrical rib. Thereby, during the rotation of the rotor, it is possible to always maintain a state in which the overlap portion overlaps the outer peripheral portion of the stator in the radial direction.
In addition, as described in claim 5, the first water channel formed in the radial direction is in contact with the end surface of the stator on the rotor side, and the end surface on the opposite side of the stator in the axial direction is in the radial direction. The first water channel and the second water channel communicate with the pump chamber, and the impeller is configured to convey the fluid in the pump chamber radially outward when rotating, The outer diameter and the outer diameter of the first water channel and the second water channel are configured to be substantially the same, and the radially outer position of the pump chamber and the radially outer position of the first water channel and the second water channel extend in the rotation axis direction. It is preferable that they are communicated by a communication path.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. It should be noted that members, arrangements, and the like described below do not limit the present invention, and it goes without saying that various modifications can be made in accordance with the spirit of the present invention.

[First embodiment]
First, the configuration of a water pump 10 as a fluid pump according to a first embodiment of the present invention will be described with reference to FIG.

  The water pump 10 according to the first embodiment of the present invention is suitably used for, for example, an automobile engine cooling system. The water pump 10 uses an axial gap type motor 12 in which a rotor 14 and a stator 16 are arranged so as to face each other in the rotation axis direction with a gap therebetween.

  The rotor 14 is rotatably supported on a shaft 50 provided in the stator housing 36 via a bearing member 15. A magnet 18 and a rotor yoke 20 are provided around the rotation axis of the rotor 14, and an impeller 22 is integrally formed on the rotation axis of the rotor 14. In the present embodiment, the diameter of the rotor 14 is increased in order to increase the motor output, whereby the outer diameter of the rotor 14 is larger than the outer diameter of the impeller 22.

  The impeller 22 is configured to have a plurality of blades 24, and the rotor 14 side of the plurality of blades 24 is connected by a connecting portion 25 extending in the radial direction. The impeller 22 is configured to rotate with the rotor 14 so as to apply a centrifugal force radially outward to the fluid in the pump chamber 42 and convey the fluid to the radially outer side of the pump chamber 42.

  The stator 16 includes a stator core 26 and a stator coil 28. The stator core 26 is formed with a plurality of salient poles 30 around the rotation axis, and a stator coil 28 is wound around each salient pole 30. The stator 16 according to the present embodiment is configured to be integrated with the stator housing 36 by molding a stator core 26, a plurality of stator coils 28, and a terminal (not shown). Further, the stator 16 has a canned structure covered with a mold resin by being molded.

  The casing 32 includes a pump housing 34, a stator housing 36, and an end housing 38. The end housing 38 includes a partition wall 38A that is in contact with a later-described second water passage 58 and extends in the radial direction. The end housing 38 has an axially opposite side to the second water passage 58 based on a control signal from an external control device. A circuit unit 40 mounted with a switching element 41 and the like for sequentially energizing the stator coil 28 is mounted.

  A shaft support portion 37 is formed in the stator housing 36, and a shaft 50 is fixed to the shaft support portion 37. A spiral pump chamber 42 is configured in the pump housing 34, and the impeller 22 is rotatably accommodated inside the pump chamber 42. A fluid suction port 44 for sucking fluid into the pump chamber 42 is provided on the rotation shaft of the pump housing 34, and the fluid in the pump chamber 42 is discharged in the tangential direction of the pump housing 34. A fluid discharge port 46 is provided.

  In the water pump 10 of the present embodiment, the first water channel 56 extending in the radial direction is formed in the gap between the stator 16 and the rotor 14, and the stator housing is disposed on the opposite side of the stator 16 from the rotor 14. A second water channel 58 extending in the radial direction is formed between the end housing 38 and the end housing 38. With this configuration, the first water channel 56 is in contact with the end surface 16A of the stator 16 on the rotor side, and the second water channel 58 is in contact with the end surface 16B of the stator 16 on the side opposite to the rotor 14 in the axial direction.

  The outer diameters of the first water channel 56 and the second water channel 58 are substantially the same as the outer diameter of the pump chamber 42, and the respective radially outer positions of the first water channel 56 and the second water channel 58 are from the stator 16. Further, the pump chamber 42 is communicated with an annular communication passage 60 extending along the axial direction from the radially outer position of the pump chamber 42 on the radially outer side.

  In this embodiment, when the impeller 22 rotates with the rotation of the motor 12, fluid is sucked into the pump chamber 42 from the fluid suction port 44, and the sucked fluid is pumped by the centrifugal force generated by the impeller 22. Is conveyed radially outward. Further, the fluid conveyed to the outside in the radial direction of the pump chamber 42 by the centrifugal force by the impeller 22 is conveyed around the rotation axis along the spiral wall surface of the pump chamber 42, and is tangential to the outside from the fluid discharge port 46. It is discharged toward.

  Here, when the impeller 22 is rotated, the radially outer position of the pump chamber 42 is in a pressurized state with the rotation of the impeller 22, and the first water channel 56 and the first water channel 56 are connected from the radially outer position of the pump chamber 42 through the communication passage 60. A fluid flow to the two water channels 58 is formed. Thus, in the water pump 10 according to the present embodiment, a fluid flow is formed by the pressure difference between the radially outer position of the pump chamber 42 and the communication passage 60 and the first water passage 56 and the second water passage 58 as described above. The In this embodiment, the stator 16 and the circuit unit 40 are cooled by the plurality of water channels.

  By the way, the fluid is sequentially sent from the pump chamber 42 to the gap between the rotor 14 and the stator 16, so that the pressure of the fluid at the radially outer position in the pump chamber 42 and the fluid in the gap between the rotor 14 and the stator 16 are increased. When the pressure is equal (both are in a high pressure state), the flow of fluid from the pump chamber 42 to the gap between the rotor 14 and the stator 16 decreases, and the cooling efficiency of the stator 16 decreases.

  Further, when the fluid pressure in the gap between the rotor 14 and the stator 16 is increased by sequentially feeding the fluid into the gap between the rotor 14 and the stator 16, the thrust in the direction opposite to the fluid suction direction acting on the rotor 14 and the impeller 22 is increased. The thrust is increased, and the rotor 14 and the impeller 22 are moved in the direction opposite to the fluid suction direction.

  Therefore, in the present embodiment, the following configuration is adopted as a structure that can efficiently cool the stator 16 and reduce the thrust thrust in the direction opposite to the fluid suction direction acting on the rotor 14 and the impeller 22.

  That is, as shown in FIG. 2, the rotor 14 is positioned on the outer side in the radial direction of the outer peripheral portion 16 </ b> C of the stator 16 and extends toward the stator 16 along the rotational axis direction. An overlap portion 17 is formed so as to overlap the. The overlap portion 17 is configured by a cylindrical rib along the outer periphery of the rotor 14. Further, in the present embodiment, the stator coil 28 is disposed on the rotor side of the stator 16, and the overlap portion 17 is disposed at a position overlapping the stator coil 28 in the radial direction.

  Further, an annular recess 39 is formed on the outer side of the stator housing 36 in the radial direction from the stator 16, and the overlap portion 17 has a protruding front end surface of the overlap portion 17 facing the bottom surface of the annular recess 39. Is disposed in the annular recess 39. Thereby, in this embodiment, the labyrinth structure is comprised by the overlap part 17 and the cyclic | annular recessed part 39. FIG.

  Next, the operation and effect of the water pump 10 according to the first embodiment of the present invention will be described.

  According to the water pump 10 according to the present embodiment, as illustrated in FIG. 2, the fluid flow F from the pump chamber 42 to the gap between the rotor 14 and the stator 16 can be restricted by the overlap portion 17. The fluid pressure P1 at the radially outer position in the pump chamber 42 can be maintained higher than the fluid pressure P2 in the gap between the rotor 14 and the stator 16. Thereby, the thrust thrust in the direction opposite to the fluid suction direction acting on the rotor 14 and the impeller 22 can be reduced.

  Further, by maintaining the fluid pressure P1 at the radially outer position in the pump chamber 42 higher than the fluid pressure P2 in the gap between the rotor 14 and the stator 16 as described above, the radially outer position in the pump chamber 42 is maintained. As shown in FIG. 2, the fluid flow F circulating from the pump chamber 42 to the gap between the rotor 14 and the stator 16 is continuously formed by the pressure difference between the rotor 14 and the stator 16 as shown in FIG. Can do. Thereby, the stator 16 contacts the fluid flow F formed in the gap between the rotor 14 and the stator 16, and the stator 16 can be efficiently cooled.

  Furthermore, according to the water pump 10 of the present embodiment, the stator 16 can be efficiently cooled by a simple configuration in which the overlap portion 17 is added to the rotor 14 and the thrust in the direction opposite to the fluid suction direction acting on the rotor 14 is also achieved. Thrust can be reduced. Thereby, the manufacturing cost of the water pump 10 can also be reduced.

  In addition, when the labyrinth structure is configured by the overlap portion 17 and the annular recess 39 as in the present embodiment, the fluid flow F from the pump chamber 42 to the gap between the rotor 14 and the stator 16 is caused by this labyrinth structure. The regulatory effect can be enhanced. As a result, as shown in FIG. 2, the fluid pressure P <b> 1 at the radially outer position in the pump chamber 42 can be reliably maintained higher than the fluid pressure P <b> 2 in the gap between the rotor 14 and the stator 16. Become.

  Further, as in the present embodiment, when the stator coil 28 is disposed on the rotor side of the stator 16 and the overlap portion 17 is disposed at a position overlapping the stator coil 28 in the radial direction, the overlap portion 17 is The stator coil 28 can be cooled by the fluid that has flowed into the gap between the rotor 14 and the stator 16.

  Furthermore, when the overlap part 17 is comprised by the cylindrical rib like this embodiment, the outer peripheral part 16C of the stator 16 can be wrapped with the overlap part 17 comprised by this cylindrical rib. Thereby, during the rotation of the rotor 14, the state where the overlap portion 17 overlaps the outer peripheral portion 16 </ b> C of the stator 16 in the radial direction can be always maintained.

  In addition, according to the water pump 10 of the present embodiment, the rotor 14 and the stator 16 are arranged so as to face each other in the rotation axis direction, whereby the stator 16 sucks the rotor 14 toward the rotation axis direction stator (thrust). Directional magnet coupling). Therefore, even with this configuration, the thrust thrust in the direction opposite to the fluid suction direction acting on the rotor 14 can be reduced. This eliminates the need for a mechanical structure for receiving a thrust thrust, such as providing a boss portion in the fluid suction port 44, thereby reducing water flow resistance at the fluid suction port 44 and improving pump efficiency.

  Furthermore, according to the water pump 10 of the present embodiment, it is possible to prevent foreign matter from entering the gap between the rotor 14 and the stator 16 by the labyrinth structure including the overlap portion 17 and the annular recess 39. Thereby, the acceleration of wear of the bearing member 15 can be suppressed.

[Second Embodiment]
Next, the configuration of the water pump 110 as a fluid pump according to the second embodiment of the present invention will be described with reference to FIG.

  As in the first embodiment, the water pump 110 according to the second embodiment of the present invention is of an axial gap type in which the rotor 114 and the stator 116 are arranged so as to face each other with a gap therebetween in the rotation axis direction. A motor 112 is used.

  The rotor 114 is rotatably supported on a shaft 150 provided in the pump housing 134 via a bearing member 115. A magnet 118 and a rotor yoke 120 are provided around the rotation axis of the rotor 114, and an impeller 122 is formed on the rotation axis of the rotor 114. Also in this embodiment, the outer diameter of the rotor 114 is configured to be larger than the outer diameter of the impeller 122.

  The stator 116 has a stator core 126 and a stator coil 128. The stator 116 according to the present embodiment is configured to be integrated with the stator housing 136 by molding the stator core 126, the plurality of stator coils 128, and the terminal 129. The stator 116 has a canned structure covered with a mold resin by being molded.

  The casing 132 includes a pump housing 134, a stator housing 136, and an end housing 138. A cylindrical connecting portion 135 formed in the stator housing 136 protrudes from a central hole formed in the center of the end housing 138. Inside the connection portion 135, the terminal of the terminal 129 connected to the stator coil 128 is located.

  On the opposite side of the end housing 138 from the stator 116, a circuit unit 140 is mounted on which switching elements and the like for sequentially energizing the stator coil 128 are mounted based on a control signal from an external control device. The terminal of the terminal 129 is connected to the circuit unit 140.

  A spiral pump chamber 142 is configured in the pump housing 134, and the impeller 122 is rotatably accommodated inside the pump chamber 142. A fluid suction port 144 for sucking fluid into the pump chamber 142 is provided on the rotation shaft of the pump housing 134, and the fluid in the pump chamber 142 is discharged in the tangential direction of the pump housing 134. A fluid discharge port 146 is provided.

  A connecting portion 145 extending in the radial direction is formed inside the fluid suction port 144 of the pump housing 134, and a shaft support portion 137 is formed at the tip of the connecting portion 145. The shaft support 137 supports the shaft 150. The shaft 150 extends in the pump chamber 142 toward the end housing 138 along the rotation axis direction. Further, the shaft 150 is formed with a circumferential groove 150A along the circumferential direction, and an E-ring 153B is engaged with the circumferential groove 150A. A washer 153A is inserted between the bearing member 115 and the E ring 153B.

  Further, in the water pump 110 of the present embodiment, a first water channel 156 extending in the radial direction is formed in the gap between the stator 116 and the rotor 114, and the outer diameter of the first water channel 156 has a pump chamber 142. Is substantially the same as the outer diameter. The first water channel 156 communicates with the pump chamber 142 via an annular communication passage 160 that extends radially outside the stator 116 from the radially outer position of the pump chamber 142 along the axial direction.

  In this embodiment, when the impeller 122 rotates with the rotation of the motor 112, fluid is sucked into the pump chamber 142 from the fluid suction port 144, and the sucked fluid is pumped by the centrifugal force generated by the impeller 122. Is conveyed radially outward. Further, the fluid conveyed to the outside in the radial direction of the pump chamber 142 by the centrifugal force by the impeller 122 is conveyed around the rotation axis along the spiral wall surface of the pump chamber 142 and is tangentially outward from the fluid discharge port 146. It is discharged toward.

  Here, when the impeller 122 rotates, the radially outer position of the pump chamber 142 is pressurized with the rotation of the impeller 122, and the first outer water channel 56 passes from the radially outer position of the pump chamber 142 through the communication passage 160. A fluid flow is formed. Thus, in the water pump 110 according to the present embodiment, a fluid flow is formed by the pressure difference between the radially outer position of the pump chamber 142 and the communication passage 160 and the first water passage 56 as described above. In this embodiment, the stator 116 is cooled by the plurality of water channels.

  Further, in the present embodiment, the following configuration is adopted as a structure that can efficiently cool the stator 116 and reduce the thrust thrust in the direction opposite to the fluid suction direction acting on the rotor 114 and the impeller 122.

  That is, as illustrated in FIG. 4, the rotor 114 is positioned on the outer side of the outer peripheral portion 116 </ b> C of the stator 116 in the radial direction and extends toward the stator 116 along the rotational axis direction. An overlapping portion 117 is formed so as to overlap with. The overlap portion 117 is formed by a cylindrical rib along the outer periphery of the rotor 114. Further, in the present embodiment, the stator coil 128 is disposed on the rotor side of the stator 116, and the overlap portion 117 is disposed at a position overlapping the stator coil 128 in the radial direction.

  Further, an annular recess 139 is formed on the outer side in the radial direction of the stator housing 136 from the stator 116, and the overlapped portion 117 has a protruding front end surface of the overlapped portion 117 facing the bottom surface of the annular recess 139. Are disposed in the annular recess 139. Thereby, in this embodiment, the labyrinth structure is comprised by the overlap part 117 and the cyclic | annular recessed part 139. FIG.

  Next, the operation and effect of the water pump 110 according to the second embodiment of the present invention will be described.

  According to the water pump 110 according to the present embodiment, as shown in FIG. 4, the fluid flow F from the pump chamber 142 to the gap between the rotor 114 and the stator 116 can be restricted by the overlap portion 117. The fluid pressure P1 at the radially outer position in the pump chamber 142 can be maintained higher than the fluid pressure P2 in the gap between the rotor 114 and the stator 116. Thereby, the thrust thrust in the direction opposite to the fluid suction direction acting on the rotor 114 and the impeller 122 can be reduced.

  Further, by maintaining the fluid pressure P1 at the radially outer position in the pump chamber 142 higher than the fluid pressure P2 in the gap between the rotor 114 and the stator 116 as described above, the radially outer position in the pump chamber 142 is maintained. And the pressure difference between the gap between the rotor 114 and the stator 116 continuously forms a fluid flow F circulating from the pump chamber 142 to the gap between the rotor 114 and the stator 116, as shown in FIG. Can do. Thereby, the stator 116 contacts the fluid flow F formed in the gap between the rotor 114 and the stator 116, and the stator 116 can be efficiently cooled.

  Furthermore, according to the water pump 110 of the present embodiment, the stator 116 can be efficiently cooled and the thrust in the direction opposite to the fluid suction direction acting on the rotor 114 can be efficiently cooled by adding the overlap portion 117 to the rotor 114. Thrust can be reduced. Thereby, the manufacturing cost of the water pump 110 can also be reduced.

  In addition, when the labyrinth structure is configured by the overlap portion 117 and the annular recess 139 as in the present embodiment, the fluid flow F from the pump chamber 142 to the gap between the rotor 114 and the stator 116 is caused by this labyrinth structure. The regulatory effect can be enhanced. As a result, as shown in FIG. 4, the fluid pressure P <b> 1 at the radially outer position in the pump chamber 142 can be reliably maintained higher than the fluid pressure P <b> 2 in the gap between the rotor 114 and the stator 116. Become.

  Further, as in the present embodiment, when the stator coil 128 is disposed on the rotor side of the stator 116 and the overlap portion 117 is disposed at a position overlapping the stator coil 128 in the radial direction, the overlap portion 117 is The stator coil 128 can be cooled by the fluid that flows around and flows into the gap between the rotor 114 and the stator 116.

  Further, as in the present embodiment, when the overlap portion 117 is formed of a cylindrical rib, the outer peripheral portion 116 </ b> C of the stator 116 can be wrapped with the overlap portion 117 formed of the cylindrical rib. Thereby, during the rotation of the rotor 114, it is possible to always maintain a state where the overlap portion 117 overlaps the outer peripheral portion 116C of the stator 116 in the radial direction.

  Further, according to the water pump 110 of the present embodiment, the rotor 114 and the stator 116 are disposed so as to face each other in the rotation axis direction, and thereby the stator 116 sucks the rotor 114 toward the rotation axis direction stator (thrust). Directional magnet coupling). Therefore, this configuration can also reduce the thrust thrust acting on the rotor 114 in the direction opposite to the fluid suction direction. Thereby, for example, the connecting portion 145 in the fluid suction port 144 can be simplified (thinning, diameter reduction, number reduction, etc.), so that the water flow resistance at the fluid suction port 144 can be reduced by doing so, and the pump Efficiency can also be improved.

  Furthermore, according to the water pump 110 of the present embodiment, it is possible to prevent foreign matter from entering the gap between the rotor 114 and the stator 116 by the labyrinth structure including the overlap portion 117 and the annular recess 139. Thereby, acceleration of wear of the bearing member 115 can be suppressed.

  Further, according to the water pump 110 of the present embodiment, the surface applied to the thrust receiving portion of the shaft support portion 137 by the shaft 150 by reducing the thrust thrust in the direction opposite to the fluid suction direction acting on the rotor 114 as described above. Since the pressure is reduced, the frictional force in the thrust receiving portion of the shaft support portion 137 is reduced. Thereby, the amount of bearing wear in the thrust receiving portion of the shaft support portion 137 can be reduced, and the pump efficiency can be improved.

It is sectional drawing which shows the structure of the water pump which concerns on 1st embodiment of this invention. It is a principal part enlarged view of FIG. It is sectional drawing which shows the structure of the water pump which concerns on 2nd embodiment of this invention. It is a principal part enlarged view of FIG.

Explanation of symbols

10, 110 ... water pump (fluid pump), 12, 112 ... motor, 14, 114 ... rotor, 15, 115 ... bearing member, 16, 116 ... stator, 16A, 16B .. End face, 16C, 116C ... outer peripheral part, 17, 117 ... overlap part, 18, 118 ... magnet, 20, 120 ... rotor yoke, 22, 122 ... impeller, 24 ...・ Vane, 25... Connecting part, 26, 126... Stator core, 28, 128... Stator coil, 30... Salient pole, 32, 132. 36, 136 ... Stator housing, 37, 137 ... Shaft support, 38, 138 ... End housing, 38A ... Partition, 39, 139 ... Ring Recess, 40, 140 ... Circuit unit, 41 ... Switching element, 42, 142 ... Pump chamber, 44, 144 ... Fluid inlet, 46, 146 ... Fluid outlet, 50, 150 ... Shaft, 56,156 ... First water channel, 58 ... Second water channel, 60,160 ... Communication channel, 129 ... Terminal, 135 ... Connector, 145 ... Link Part, 150A ... circumferential groove, 153A ... washer, 153B ... E-ring

Claims (5)

A rotor with an impeller on a rotating shaft;
A stator arranged to face the rotor in the direction of the rotation axis across a gap;
A casing having a pump chamber in which the impeller is rotatably accommodated and a fluid flow is formed around a rotation axis by the rotation of the impeller, and the pump chamber is configured to communicate with the gap. In the fluid pump,
The outer diameter of the rotor is larger than the outer diameter of the impeller,
The rotor is formed with an overlap portion that is located radially outside the outer peripheral portion of the stator and extends to the stator side along the rotation axis direction and overlaps the outer peripheral portion of the stator in the radial direction. Features fluid pump. The stator is integrated with the stator housing by molding at least a stator coil and a stator core,
An annular recess is formed on the outer side of the stator housing in the radial direction than the stator,
2. The fluid pump according to claim 1, wherein the overlap portion is disposed in the annular recess such that a protruding front end surface of the overlap portion faces a bottom surface of the annular recess. The stator coil of the stator is disposed on the rotor side of the stator,
The fluid pump according to claim 1, wherein the overlap portion is disposed at a position overlapping with the stator coil in a radial direction.   The fluid pump according to any one of claims 1 to 3, wherein the overlap portion is configured by a cylindrical rib. A first water channel formed along the radial direction is in contact with the end surface of the stator on the rotor side,
  A second water channel formed along the radial direction is in contact with the end surface of the stator opposite to the rotor in the axial direction,
  The first water channel and the second water channel communicate with the pump chamber;
  The impeller is configured to convey the fluid in the pump chamber radially outward when rotating,
  The outer diameter of the pump chamber and the outer diameter of the first water channel and the second water channel are configured to be substantially equal,
  The radially outer position of the pump chamber and the radially outer position of the first water channel and the second water channel are communicated with each other by a communication passage extending in the rotation axis direction. The fluid pump according to any one of the above.

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