JP2006299975A - Fluid pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling structure for efficiently cooling a stator and a circuit unit. <P>SOLUTION: Even when the stator 16 is heated with the operation of a water pump 10, fluid carried from a pump chamber 42 to a first water channel 56 and a second water channel 58 has contact with both axial end faces 16A, 16B of the stator 16. So, a stator coil 28 covered with a molding resin into a watertight structure is efficiently cooled at both axial sides. The circuit unit 40 is kept watertight by a partition wall 38A, while heat from the circuit unit 40 can be transferred into the fluid in the second water channel 58 via the partition wall 38A. The stator 16 can be separated from the circuit unit 40 by the second water channel 58, and so a heat transfer passage from the stator 16 to the circuit unit 40 can be completely shut off. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fluid pump, and more particularly to an improvement of a fluid pump having a structure for cooling a stator and a circuit unit.

  Conventionally, for example, some electric water pumps used in vehicles have a structure for cooling a stator or a circuit unit (see, for example, Patent Documents 1 and 2).

  For example, Patent Document 1 discloses a structure for cooling a circuit unit. In the electric water pump described in Patent Document 1, a heat transfer member is in close contact with a partition having a high thermal conductivity that divides and partitions the stator housing portion and the fluid passage portion inside the housing. The transistor substrate is in close contact with the substrate. Thereby, the heat generated in the transistor substrate is transmitted to the partition via the heat transfer body, and further transferred to the cooling water flowing through the fluid passage portion and released together with the cooling water.

  Patent Document 2 discloses a structure for cooling the stator and the circuit unit. In the pump described in Patent Document 2, at least a part of a control circuit and at least a coil of a stator are resin-molded to form a molded stator, and at least a part of a fluid passage is formed by the molded stator. I have to. Accordingly, since the fluid sucked from the suction port flows in contact with the mold stator, the control circuit and the coil in the mold stator can be cooled by the fluid.

By the way, this type of electric water pump includes a so-called axial gap type motor in which a rotor and a stator are arranged so as to oppose each other in the rotation axis direction (see, for example, Patent Document 3).
JP 2002-364576 A JP 11-166500 A JP 2000-145682 A

  Generally, in an electric water pump, when the stator coil generates heat as the stator coil is energized, the internal resistance of the stator coil increases, and the motor efficiency (pump efficiency) decreases. Further, when the stator coil generates heat, this heat affects the circuit elements of the circuit unit, resulting in a problem that the life of the circuit elements is shortened.

  Therefore, in order to prevent the motor efficiency from being lowered and to keep the circuit element life long, a cooling structure capable of efficiently cooling the stator and the circuit unit is required for the electric water pump.

  In particular, when the stator coil is molded as described in Patent Document 2, the cooling efficiency of the stator coil is lowered because the thermal conductivity of the mold resin is low. Therefore, when the stator coil is molded in the electric water pump, a cooling structure capable of efficiently cooling the stator coil is required to prevent a reduction in motor efficiency.

  Although it is conceivable to arrange the stator coil directly in the fluid, in this case, the insulating film of the stator coil is hydrolyzed, and the occurrence of insulation failure becomes a problem.

  In addition, as described in Patent Document 3, an electric water pump including a so-called axial gap type motor is also used to prevent the motor efficiency from being lowered and to maintain the life of the circuit element for a long time. It is necessary to provide a cooling structure that can cool well.

  The present invention has been made in view of the above circumstances, and in a fluid pump including a so-called axial gap type motor, the stator and the circuit unit are efficiently cooled, thereby reducing the motor efficiency (pump efficiency). An object of the present invention is to provide a cooling structure capable of preventing and keeping the life of a circuit element long.

  In order to solve the above-mentioned problem, a fluid pump according to claim 1 is provided with a rotor having an impeller on a rotating shaft and having a magnet around the rotating shaft, and facing the magnet in the rotating shaft direction. A stator having at least the stator coil covered with a resin member, a pump chamber in which the impeller is rotatably housed, and a casing for housing the rotor and the stator. A first water channel formed along a radial direction is in contact with an end surface of the stator on the rotor side, and an end surface of the stator opposite to the rotor in the axial direction has a diameter. A second water channel formed along the direction is in contact, and the first water channel and the second water channel communicate with the pump chamber.

  Thus, in the fluid pump according to claim 1, the first water channel formed along the radial direction is in contact with the end surface on the rotor side of the stator, and the end surface on the opposite side in the axial direction from the rotor of the stator is in the radial direction. A second water channel formed along the line is in contact, and the first water channel and the second water channel communicate with the pump chamber.

  Therefore, even when the stator generates heat due to the operation of the fluid pump, the fluid conveyed from the pump chamber to the first water channel and the second water channel contacts the end surface on the rotor side of the stator and the end surface opposite to the rotor in the axial direction. The stator coil can be cooled by heat exchange between the fluid and the stator coil via the resin member.

  Further, in the fluid pump according to claim 1, since both end faces in the axial direction of the stator are in contact with the fluid as described above, even if the stator coil has a waterproof structure by being covered with a resin member, the stator is viewed from both axial directions. The coil is cooled efficiently. As a result, it is possible to prevent a reduction in motor efficiency (pump efficiency).

  At this time, as described in claim 2, the impeller is configured to convey the fluid in the pump chamber radially outward when rotating, and the outer diameter of the pump chamber and the outer diameter of the first water channel and the second water channel However, when the impeller rotates when 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. As the impeller rotates, the radially outer position of the pump chamber is pressurized, and a fluid flow is formed from the radially outer position of the pump chamber to the first water channel and the second water channel through the communication path.

  Therefore, according to the fluid pump of the second aspect, the fluid flow is formed by the pressure difference between the radially outer position of the pump chamber and the communication passage and the first and second water passages as described above. The fluid is reliably transported and comes into contact with the end surface on the rotor side and the end surface on the opposite side to the rotor in the axial direction. As a result, the stator coil can be reliably cooled.

  In the fluid pump according to claim 3, the casing includes a pump housing having a pump chamber, a stator housing that holds the stator, and an end housing that is disposed on the opposite side to the pump housing of the stator housing in the axial direction. The second water channel is formed between the stator housing and the end housing, and the communication channel is formed radially outside the stator.

  As described above, when the second water channel is formed between the stator housing and the end housing, the second water channel for flowing the fluid is formed in a hole shape, and the hole-shaped second water channel is formed in the stator housing. Therefore, when the stator housing is formed by resin molding, the stator housing can be easily molded.

  Further, if the communication path is formed on the radially outer side than the stator, the arrangement of the stator coil and the stator core is not restricted by the arrangement position of the communication path, so compared to the case where the communication path is formed in the stator, The stator coil and the stator core can be easily arranged. Thereby, the freedom degree of design of a stator and a stator housing can be raised.

  Furthermore, as described in claim 4, the end housing includes a partition wall that is in contact with the second water channel and extends along the radial direction, and a circuit for energizing the stator coil on the opposite side of the partition wall to the second water channel in the axial direction. When the unit is arranged, the circuit unit can be waterproofed by the partition wall, while the heat from the circuit unit can be transferred to the fluid in the second water channel through the partition wall. Further, since the stator and the circuit unit can be separated by the second water channel, the heat transfer path from the stator to the circuit unit can be completely blocked. As a result, the circuit unit can also be efficiently cooled, so that the life of the circuit elements provided in the circuit unit can be kept long.

  According to a fifth aspect of the present invention, the pump housing and the end housing are connected in the rotation axis direction, and the outer peripheral portion of the stator housing is held by at least one inner peripheral portion of the pump housing and the end housing. If configured, when the fluid pump is assembled, the pump housing and the end housing may be connected in the direction of the rotation axis while the outer peripheral portion of the stator housing is held by the inner peripheral portion of the pump housing or the end housing. Therefore, the fluid pump can be easily assembled.

  In particular, the end housing has a multi-functional housing design that separates the circuit unit from the pump chamber by a partition wall, contributes to cooling of the circuit unit by the partition wall, and also has a fixing function with the pump housing. This contributes to the simplification of the process and the reduction of housing processing man-hours. In addition, since the end housing constitutes a casing with the pump housing and touches the outside air, for example, when it is made of aluminum or the like, it also has an air cooling function capable of efficiently releasing heat from the circuit unit to the outside air, Contribute further by improving the cooling efficiency of the circuit unit.

  Further, as described in claim 6, when the circuit element of the circuit unit is arranged on the partition wall, the heat from the circuit element is transferred to the fluid in the second water channel via the partition wall. Therefore, the cooling efficiency for the circuit element can be increased as compared with the case where the circuit element is arranged at a position away from the second water channel. Thereby, it becomes possible to keep the lifetime of a circuit element longer.

  Furthermore, as described in claim 7, the end housing has a housing portion that houses the circuit unit, and includes a circuit element housing portion that houses the circuit element of the circuit unit separately from the housing portion. For example, even if the circuit element housed in the circuit element housing portion has lower heat resistance than the other heat generating elements in the circuit unit, the circuit element housing portion provides the Since the heat can be cut off, the temperature rise of the circuit element can be suppressed. Thereby, it becomes possible to keep the lifetime of a circuit element long.

  In addition, since the circuit element housing portion is provided, it is possible to suppress the temperature rise of the circuit element as described above, so that addition of a member such as a heat sink for cooling the circuit element becomes unnecessary, and the circuit element has heat resistance. It is not necessary to use a good and expensive one. Thereby, cost can be reduced.

  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 FIGS. 1 and 2.

  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.

  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 includes a plurality of blades 24, and rotates together with the rotor 14 to apply a centrifugal force radially outward to the fluid in the pump chamber 42, thereby causing the fluid to flow in the radial direction of the pump chamber 42. It is comprised so that it may convey outside.

  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 stator housing 36 is sandwiched and fixed between the pump housing 34 and the end housing 38. Further, 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, a first water channel 56 extending in the radial direction is formed between the stator 16 and the rotor 14, and a stator housing is provided 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.

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

  In the water pump 10 according to the present embodiment, the first water channel 56 formed along the radial direction is in contact with the end surface 16A on the rotor side of the stator 16, and the end surface 16B opposite to the rotor 14 of the stator 16 in the axial direction is The second water channel 58 formed along the radial direction is in contact with the first water channel 56 and the second water channel 58 and communicates with the pump chamber 42 through the communication channel 60.

  Therefore, even when the stator 16 generates heat with the operation of the water pump 10, the fluid conveyed from the pump chamber 42 to the first water channel 56 and the second water channel 58 is in contact with the end surface 16A on the rotor side of the stator 16 and the rotor 14 and the shaft. Since it is in contact with the end face 16B on the opposite side, the stator coil 28 can be cooled by heat exchange between the fluid via the mold resin and the stator coil 28.

  Further, in the water pump 10 according to the present embodiment, since the axially opposite end faces 16A and 16B of the stator 16 are in contact with fluid as described above, even if the stator coil 28 is covered with a mold resin to have a waterproof structure, The stator coil 28 is efficiently cooled from both axial sides. As a result, it is possible to prevent a reduction in motor efficiency (pump efficiency).

  Furthermore, according to 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. Therefore, the fluid is reliably conveyed and comes into contact with the end surface 16A on the rotor side of the stator 16 and the end surface 16B on the opposite side in the axial direction with the rotor 14. Thereby, the stator coil 28 can be reliably cooled.

  Further, as in the present embodiment, the end housing 38 includes a partition wall 38A that is in contact with the second water channel 58 and extends in the radial direction, and the stator coil 28 is energized on the opposite side of the partition wall 38A from the second water channel 58 in the axial direction. When the circuit unit 40 is arranged, the circuit unit 40 can be waterproofed by the partition wall 38A, while the heat from the circuit unit 40 can be transmitted to the fluid in the second water channel 58 via the partition wall 38A. . Moreover, since the stator 16 and the circuit unit 40 can be separated by the second water channel 58, the heat transfer path from the stator 16 to the circuit unit can be completely blocked. Thereby, since the circuit unit 40 can also be efficiently cooled, it is possible to keep the life of the switching element 41 provided in the circuit unit 40 long.

  In particular, when the switching element 41 of the circuit unit 40 is disposed in the partition wall 38A as in the present embodiment, the heat from the switching element 41 can be transferred to the fluid in the second water channel 58 via the partition wall 38A. Therefore, the cooling efficiency for the switching element 41 can be increased as compared with the case where the switching element 41 is arranged at a position away from the second water channel 58. As a result, the life of the switching element 41 can be kept longer.

  Further, when the second water channel 58 is formed between the stator housing 36 and the end housing 38 as in the present embodiment, the second water channel 58 for flowing a fluid is formed into a hole shape, and the hole shape Since there is no need to form the second water channel 58 in the stator housing 36, when the stator housing 36 is formed by resin molding, the stator housing 36 can be easily molded.

  Furthermore, if the communication path 60 is formed radially outward from the stator 16 as in the present embodiment, the arrangement of the stator coil 28 and the stator core 26 is not restricted by the arrangement position of the communication path 60. The stator coil 28 and the stator core 26 can be easily arranged as compared with the case where the communication path 60 is formed therein. Thereby, the freedom degree of design of the stator 16 and the stator housing 36 can be raised.

  Further, as in the present embodiment, when the rotor 14 and the stator 16 are arranged so as to face each other in the rotation axis direction, a so-called axial gap type fluid pump is formed, and the water pump 10 rotates in the rotation axis direction. Can be made shorter.

  Further, when the impeller 22 is formed integrally with the rotor 14 as in the present embodiment, the cost can be reduced and the assemblability can be improved as compared with the case where the impeller 22 is formed separately. Can do.

  The first water channel 56 may be formed in a groove shape on the end surface 16A on the rotor side of the stator 16, and the second water channel 58 is formed in a groove on the end surface 16B on the axially opposite side of the rotor 14 of the stator 16. It may be configured in a shape.

[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 uses an axial gap type motor 112 in which the rotor 114 and the stator 116 are arranged to face each other in the rotation axis direction. It has been.

  The rotor 114 is rotatably supported on a shaft 150 provided in the stator housing 136 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 integrally 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. The end housing 138 includes a partition wall 138A that is in contact with a later-described second water passage 158 and extends in the radial direction, and a housing portion 138B is formed on the opposite side of the partition wall 138A from the second water passage 158 in the axial direction. The housing unit 138B houses a circuit unit 140 on which a switching element 141 and the like that sequentially energize the stator coil 128 based on a control signal from an external control device are mounted. Further, the opening of the accommodating portion 138 </ b> B formed in the pump housing 134 is closed by a lid member 139.

  The pump housing 134 and the end housing 138 are connected to each other in the axial direction by a fixing member 133. In the pump housing 134 of the present embodiment, a flow velocity difference relaxation member holding portion 147 is formed adjacent to the pump chamber 142. The flow velocity difference relaxation member holding portion 147 is formed along the inner periphery of the pump housing 134, and the outer periphery of the flow velocity difference relaxation member 152 is fitted into the flow velocity difference relaxation member holding portion 147. Is held by.

  A stator holding portion 149 is formed in the pump housing 134 and the end housing 138. The stator holding portion 149 is formed along the inner peripheral portions of the pump housing 134 and the end housing 138, and the stator holding portion 149 is held by fitting the outer peripheral portion of the stator housing 136. .

  An O-ring 151 is provided between the outer peripheral portion of the stator housing 136 and the stator holding portion 149. The stator housing 136 is formed with a shaft support portion 137, and the shaft 150 is fixed to the shaft support portion 137.

  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.

  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.

  Further, in the water pump 110 of the present embodiment, a first water channel 156 extending along the radial direction is formed between the stator 116 and the rotor 114, and a stator housing is provided on the opposite side of the stator 116 from the rotor 114. A second water channel 158 extending in the radial direction is also formed between the end housing 138 and 136. With this configuration, the first water channel 156 is in contact with the end surface 116A of the stator 116 on the rotor 114 side, and the second water channel 158 is in contact with the end surface 116B on the side opposite to the rotor 114 of the stator 116 in the axial direction. .

  The first water channel 156 and the second water channel 158 communicate with the pump chamber 142 via an annular communication path 160 that extends radially outside the stator 116 along the axial direction and a center hole 154 of the flow velocity difference reducing member 152. Has been. In this embodiment, the stator 116 and the circuit unit 140 are cooled by the plurality of water channels.

  By the way, in this embodiment, as described above, the outer diameter of the rotor 114 is configured to be larger than the outer diameter of the impeller 122. For this reason, the radially outer side of the impeller side end surface 114A of the rotor 114 is in contact with the flow F around the rotation axis of the fluid in the pump chamber 142, and the generation of turbulent flow due to the speed difference between the two becomes a problem.

  Accordingly, in the present embodiment, the velocity of the flow F around the rotation axis of the fluid is at a position where the outer side in the radial direction of the impeller side end surface 114A of the rotor 114 is in contact with the flow F around the rotation axis of the fluid in the pump chamber 142. And a flow speed difference reducing member 152 for reducing the difference between the rotational speed of the rotor 114 and the rotor 114.

  More specifically, the flow velocity difference reducing member 152 is formed of an annular disk body having a central hole 154 slightly larger than the outer diameter of the impeller 122, and the impeller 122 is disposed in the central hole 154. Is located. Further, the flow velocity difference reducing member 152 is configured by a disc body so as to partition the flow F around the rotation axis of the fluid and the radially outer side from the impeller 122 on the impeller side end surface 114A of the rotor 114. Has been.

  At this time, the blade-side end surface 125A of the connecting portion 125 formed on the impeller 122 and the end surface 152A of the flow velocity difference reducing member 152 opposite to the rotor 114 are formed on substantially the same plane. Further, the end surface 152A of the flow velocity difference reducing member 152 opposite to the rotor 114 is a smooth surface.

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

  In the water pump 110 according to the present embodiment, the first water channel 156 formed along the radial direction is in contact with the end surface 116A on the rotor side of the stator 116, and the end surface 116B on the opposite side to the rotor 114 of the stator 116 in the axial direction. A second water channel 158 formed along the radial direction is in contact with the first water channel 156 and the second water channel 158 and communicates with the pump chamber 142.

  Therefore, even when the stator 116 generates heat with the operation of the water pump 110, the fluid conveyed from the pump chamber 142 to the first water channel 156 and the second water channel 158 is in contact with the rotor-side end surface 116A of the stator 116 and the rotor 114. Since it contacts the end surface 116B on the opposite side, the stator coil 128 can be cooled by heat exchange between the fluid via the mold resin and the stator coil 128.

  Further, in the water pump 110 according to the present embodiment, since both end surfaces 116A and 116B in the axial direction of the stator 116 are in contact with the fluid as described above, even if the stator coil 128 is covered with a mold resin to have a waterproof structure, The stator coil 128 is efficiently cooled from both axial sides. As a result, it is possible to prevent a reduction in motor efficiency (pump efficiency).

  Further, as in the present embodiment, the end housing 138 includes a partition wall 138A that is in contact with the second water channel 158 and extends in the radial direction, and the stator coil 128 is energized on the opposite side of the partition wall 138A from the second water channel 158 in the axial direction. When the circuit unit 140 is arranged, the circuit unit 140 can be waterproofed by the partition wall 138A, while the heat from the circuit unit 140 can be transmitted to the fluid in the second water channel 158 via the partition wall 138A. . Further, since the stator 116 and the circuit unit 140 can be separated by the second water passage 158, the heat transfer path 140 from the stator 116 to the circuit unit can be completely blocked. As a result, the circuit unit 140 can also be efficiently cooled, and the life of the switching element 141 provided in the circuit unit 140 can be kept long.

  In particular, when the switching element 141 of the circuit unit 140 is arranged on the partition wall 138A as in the present embodiment, the heat from the switching element 141 can be transferred to the fluid in the second water channel 158 via the partition wall 138A. Therefore, the cooling efficiency for the switching element 141 can be increased as compared with the case where the switching element 141 is arranged at a position away from the second water channel 158. As a result, the life of the switching element 141 can be kept longer.

  Further, when the second water channel 158 is formed between the stator housing 136 and the end housing 138 as in the present embodiment, the second water channel 158 for flowing a fluid is formed into a hole shape, and this hole shape Since it is not necessary to form the second water channel 158 in the stator housing 136, when the stator housing 136 is formed by molding, the stator housing 136 can be easily molded.

  Furthermore, when the communication path 160 is formed radially outward from the stator 116 as in the present embodiment, the arrangement of the stator coil 128 and the stator core 126 is not restricted by the arrangement position of the communication path 160, so the stator 116. The stator coil 128 and the stator core 126 can be easily arranged as compared with the case where the communication path 160 is formed therein. Thereby, the design freedom of the stator 116 and the stator housing 136 can be increased.

  Further, as in the present embodiment, the pump housing 134 and the end housing 138 are connected in the rotation axis direction, and the outer peripheral portion of the stator housing 136 is held by the inner peripheral portions of the pump housing 134 and the end housing 138. When the water pump 110 is assembled, the pump housing 134 and the end housing 138 are connected in the direction of the rotation axis while the outer periphery of the stator housing 136 is held by the inner periphery of the pump housing 134 or the end housing 138. Just do it. Therefore, the water pump 110 can be easily assembled.

  In particular, the end housing 138 of this embodiment separates the circuit unit 140 from the pump chamber 42 by the partition wall 138A, contributes to cooling of the circuit unit 140 by the partition wall 138A, and also has a fixing function with the pump housing 134. The multi-functional housing design is provided, which contributes to simplification of the structure and reduction of housing processing man-hours. In addition, since the end housing 138 forms the casing 132 with the pump housing 134 and touches the outside air, for example, when it is made of aluminum or the like, the air cooling that can efficiently release the heat from the circuit unit 140 to the outside air. It also has a function and contributes further by improving the cooling efficiency of the circuit unit 140.

  Furthermore, in this embodiment, since the stator coil 128 is covered with the mold resin and the entire stator 116 has a separate structure from the pump housing 134, it is not necessary to take measures against eddy currents in the pump housing 134. Therefore, the pump housing 134 does not need to have a composite structure of a resin partition wall member and a heat radiating metal member as in the prior art, and the structure can be simplified, so that the manufacturing cost of the pump housing 134 can be kept low.

  Further, according to the water pump 110 according to the present embodiment, the rotation of the fluid at a position where the outer side in the radial direction of the impeller side end surface 114A of the rotor 114 is in contact with the flow F around the rotation axis of the fluid in the pump chamber 142. A flow speed difference reducing member 152 is provided for reducing the difference between the speed of the flow F around the axis and the rotational speed of the rotor 114. Therefore, the flow velocity difference reducing member 152 can suppress the fluid turbulence caused by the difference between the two velocities, thereby preventing the pump efficiency from being lowered.

  In the present embodiment, the flow velocity difference reducing member 152 is fixed to the pump chamber 142. Accordingly, since the flow velocity difference reducing member 152 for suppressing fluid turbulence does not rotate, there is no need to add a new rotating member such as a bearing member, and the increase in the number of parts can be suppressed as much as possible. Become.

  If the flow velocity difference reducing member 152 is configured to be rotatable with respect to the pump chamber 142, the flow velocity difference relaxing member 152 is rotated by the energy of the flow F around the rotation axis of the fluid in the pump chamber 142. Resulting in. For this reason, the energy of the flow F around the rotation axis of the fluid in the pump chamber 142 is consumed by the rotation of the flow velocity difference reducing member 152, and the pump efficiency may be reduced.

  However, in this embodiment, the flow rate difference reducing member 152 is fixed to the pump chamber 142 as described above. Accordingly, the energy of the flow F around the rotation axis of the fluid in the pump chamber 142 is not consumed by the rotation of the flow velocity difference reducing member 152, and it is possible to prevent the pump efficiency from being lowered.

  In this embodiment, the flow velocity difference reducing member 152 is configured to partition the flow F around the rotation axis of the fluid and the radially outer side of the impeller 122 at the impeller side end surface 114A of the rotor 114. Accordingly, the flow F around the rotation axis of the fluid in the pump chamber 142 does not contact the outer side in the radial direction from the impeller 122 at the impeller side end surface 114A of the rotor 114, so that the fluid turbulence caused by the contact between the two is reliably suppressed. can do.

  Further, in the present embodiment, the blade-side end surface 125A of the connecting portion 125 formed on the impeller 122 and the end surface 152A on the opposite side of the rotor 114 of the flow velocity difference reducing member 152 are formed on substantially the same plane. . Accordingly, there is no step between the blade-side end surface 125A of the connecting portion 125 and the end surface 152A of the flow velocity difference reducing member 152 opposite to the rotor 114, and therefore the flow velocity difference reducing member from the impeller 122 side (radially inner side). The fluid transported to 152 is smoothly transported radially outward of the flow velocity difference reducing member 152 without colliding with the inner diameter portion of the flow velocity difference relaxing member 152. Thereby, troubles, such as new turbulent flow generation by adding flow velocity difference alleviating member 152, can be prevented.

  In the present embodiment, the flow velocity difference reducing member 152 is formed in an annular shape around the rotation axis, and the inner diameter of the flow velocity difference reducing member 152 is larger than the outer diameter of the impeller 122. Therefore, even when the impeller 122 is integrally formed with the rotor 114 as in the present embodiment, when the flow velocity difference reducing member 152 is assembled to the water pump 110, the impeller 122 is disposed inside the flow velocity difference reducing member 152. Thus, the flow velocity difference reducing member 152 can be disposed on the impeller side of the rotor 114 in the rotation axis direction. Thereby, it can prevent that the assembly property of the water pump 110 is impaired by adding the flow velocity difference alleviating member 152.

  Further, when the rotor 114 and the stator 116 are arranged so as to face each other in the rotation axis direction as in the present embodiment, a so-called axial gap type fluid pump is formed, and the rotation axis direction of the water pump 110 is configured. Can be made shorter.

  Further, when the impeller 122 is formed integrally with the rotor 114 as in the present embodiment, the cost can be reduced and the assemblability can be improved as compared with the case where the impeller 122 is formed separately. Can do.

  In the second embodiment of the present invention, when the circuit element 143 of the circuit unit 140 has a lower heat resistance than the switching element 141, the lid member of the end housing 138, like the water pump 210 shown in FIG. A circuit element housing portion 138C (separate chamber) may be provided in 139 separately from the housing portion 138B, and the circuit element 143 may be housed in the circuit element housing portion 138C.

  With this configuration, for example, when the circuit element 143 accommodated in the circuit element accommodating portion 138C has lower heat resistance (cumulative temperature life) than the other switching elements 141 (heating elements) in the circuit unit 140. Even so, the heat from the switching element 141 can be cut off by providing the circuit element accommodating portion 138C. For this reason, the temperature rise of the circuit element 143 can be suppressed, and thereby the life of the circuit element 143 can be kept long.

  In addition, since the circuit element housing portion 138C is provided, the temperature rise of the circuit element 143 can be suppressed as described above, so that addition of a member such as a heat sink for cooling the circuit element 143 becomes unnecessary. It is also unnecessary to use an expensive material having good heat resistance. Thereby, cost can be reduced.

It is sectional drawing which shows the structure of the water pump which concerns on 1st embodiment of this invention. It is a disassembled perspective view of the structure of the water pump which concerns on 1st embodiment of this invention. It is sectional drawing which shows the structure of the water pump which concerns on 2nd embodiment of this invention. It is sectional drawing which shows the structure of the water pump which concerns on 3rd embodiment of this invention.

Explanation of symbols

10, 110, 210 ... water pump (fluid pump), 12, 112 ... motor, 14, 114 ... rotor, 14A, 114A ... impeller side end face, 15, 115 ... bearing member, 16, 116 ... stator, 16A, 16B, 116A, 116B ... end face, 18, 118 ... magnet, 20, 120 ... rotor yoke, 22, 122 ... impeller, 24 ... blade, 26, 126 ... stator core, 28, 128 ... stator coil, 129 ... terminal, 30 ... salient pole, 32, 132 ... casing, 34, 134 ... pump housing, 36, 136 ... stator housing, 37, 137 ... shaft support, 38, 138 ... end housing, 38A, 138A ... partition, 40, 140 ... circuit unit, 41, 141: switching element, 42, 142 ... pump chamber, 44 144 ... Fluid suction port, 46, 146 ... Fluid discharge port, 48 ... Nipping and fixing portion, 50, 150 ... Shaft, 56, 156 ... First water channel, 58, 158 ... Second water channel, 60, 160 ... Communication channel, 125 ... Connecting part, 125A ... Rotor side end face, 133 ... Fixing tool, 135 ... Connecting part, 138B ... Housing part, 138C ... Circuit element housing part, 139 ... Cover member, 143 ... Circuit element, 149 ... Stator holding part, 151 ... O-ring, 152 ... Flow velocity difference reducing member, 152A ... End face, 154 ... Center hole, F ... Flow

Claims (7)

A rotor having an impeller on a rotation axis and having a magnet around the rotation axis;
A stator comprising a plurality of stator coils arranged to face the magnet in the direction of the rotation axis and at least the stator coil covered with a resin member;
A fluid pump having a pump chamber in which the impeller is rotatably stored, and a casing for storing the rotor and the stator;
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 fluid pump according to claim 1, wherein 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,
2. The fluid according to claim 1, wherein the radially outer position of the pump chamber and the radially outer positions of the first water channel and the second water channel are communicated with each other by a communication passage extending in a rotation axis direction. pump. The casing includes a pump housing having the pump chamber, a stator housing that holds the stator, and an end housing that is disposed on an axially opposite side of the pump housing of the stator housing.
The second water channel is formed between the stator housing and the end housing,
The fluid pump according to claim 2, wherein the communication passage is formed radially outside the stator. The end housing includes a partition wall that is in contact with the second water channel and extends along a radial direction,
4. The fluid pump according to claim 3, wherein a circuit unit for energizing the stator coil is disposed on the opposite side of the partition to the second water channel in the axial direction. The pump housing and the end housing are connected in the rotation axis direction,
5. The fluid pump according to claim 3, wherein an outer peripheral portion of the stator housing is held by an inner peripheral portion of at least one of the pump housing and the end housing.   The fluid pump according to claim 4 or 5, wherein a circuit element of the circuit unit is disposed in the partition wall.   5. The end housing includes a housing portion that houses the circuit unit, and includes a circuit element housing portion that houses a circuit element of the circuit unit separately from the housing portion. Item 7. The fluid pump according to any one of Items 6.

Images