JP6765841B2 - Vortex pump - Google Patents

Description

This specification discloses a technique relating to a vortex pump.

Patent Document 1 discloses a vortex pump including a motor unit and a pump unit. The motor section and the pump section are provided in the housing. The housing is provided with a separation wall that separates the motor section and the pump section. Further, a bearing that supports the output shaft of the motor is fixed to the housing. The output shaft of the motor extends from the motor section to the pump section while being supported by the bearing. The pump unit is provided with a fluid suction port, a fluid discharge port, and an impeller. Further, a communication hole for communicating the motor portion and the pump portion is provided in the separation wall.

Japanese Unexamined Patent Publication No. 2006-37870

In the vortex pump of Patent Document 1, the fluid moves from the pump portion to the motor portion through the communication hole provided in the separation wall. The fluid that has moved to the motor section contributes to cooling the motor section. However, the fluid moving to the motor section may contain foreign matter. If foreign matter is scattered in the motor portion, the foreign matter may adversely affect the motor or enter the bearing supporting the shaft, which may cause deterioration of the performance of the vortex pump. There is a need for technology that reduces the adverse effects of foreign matter and suppresses deterioration in the performance of eddy current pumps. This specification discloses a technique for suppressing a performance deterioration due to a fluid moving in a motor unit in a vortex pump.

The present specification discloses a vortex pump in which a motor portion and a pump portion are provided in a housing. The motor unit includes a motor. Further, the motor unit includes a storage unit in which foreign matter that has entered the motor unit is stored. The pump unit includes a fluid suction port, a fluid discharge port, and an impeller that rotates integrally with the output shaft of the motor. Bearings that support the output shaft of the motor are fixed to the housing. In addition, the housing is provided with a separation wall that separates the motor portion and the pump portion. The separation wall is provided with a communication hole that communicates the motor unit and the pump unit.

The vortex pump is provided with a storage unit for storing foreign matter in the motor unit. By keeping the foreign matter that has entered the motor part together with the fluid in a specific place (storage part), it is possible to prevent the foreign matter from being scattered in the motor part. As a result, for example, foreign matter can be suppressed from entering the bearing, and deterioration of the performance of the vortex pump can be suppressed.

The fuel supply system using the evaporative fuel processing apparatus is shown. The perspective view of the purge pump is shown. A cross-sectional view taken along the line III-III of FIG. 2 is shown. The figure which looked at the cover from the bottom is shown. The perspective view of the impeller is shown. The bottom view of the impeller is shown. The enlarged view of the area AR of FIG. 4 is shown. The figure which looked at the cover from above is shown. A cross-sectional view taken along the line AOB of FIG. 8 is shown. The bottom view of the cover of the modified purge pump as viewed from above is shown. A cross-sectional view taken along the line AOB of FIG. 10 is shown.

The main features of the examples are listed below. The technical elements described below are independent technical elements, and exhibit their technical usefulness alone or in various combinations.

The vortex pump can be used as a purge pump for the evaporative fuel processing apparatus. The purge pump is used as a drive source for pumping the evaporated fuel generated in the fuel tank to the intake path of the internal combustion engine. The evaporative fuel processing apparatus may include a canister, a purge passage, a control valve, and the vortex pump described above. The canister adsorbs the evaporated fuel generated in the fuel tank. The purge passage is connected between the intake path of the internal combustion engine and the canister. The purge gas (gas containing evaporative fuel) sent from the canister to the internal combustion engine passes through the purge passage. The control valve controls the amount of purge gas supplied to the intake path. The vortex pump is arranged on the purge passage between the canister and the control valve.

The vortex pump includes a motor unit and a pump unit. The motor unit and the pump unit may be provided in the housing of the vortex pump. The motor unit and the pump unit may be separated by a separation wall provided in the housing. In other words, the motor unit and the pump unit may be arranged in different spaces partitioned by the separation wall. The motor unit includes a motor. Further, the motor unit may include a storage unit in which foreign matter that has entered the motor unit is stored. The pump unit includes a fluid suction port, a fluid discharge port, and an impeller. The impeller may be connected to the output shaft of the motor and rotate integrally with the output shaft. The output shaft may be supported by bearings fixed to the housing. The separation wall may be provided with a communication hole that communicates the motor unit and the pump unit.

The storage portion may be a groove (storage groove) provided on the surface of the separation wall on the motor portion side. With a simple structure (groove), foreign matter in the motor section can be stored. The reservoir may extend over the surface of the separation wall so as to surround the output shaft of the motor. Further, the storage groove may extend from the suction port toward the discharge port. The storage groove may have a constant depth, or may have a shallow groove portion having a shallow depth and a deep groove portion having a deep depth. The storage groove may be inclined from the shallow groove portion to the deep groove portion. One end of the reservoir may be the shallowest and the other end may be the deepest. The shallow groove portion may be located on the suction port side, and the deep groove portion may be located on the discharge port side.

A blade groove region may be provided along the rotation direction of the impeller on the outer peripheral portion of the surface facing the separation wall of the impeller. The rotation direction of the impeller is included in a plane orthogonal to the rotation axis direction of the impeller (rotation axis direction of the output shaft). The blade groove region may have a plurality of blades and blade grooves arranged between adjacent blades. The blade groove regions may be provided on both sides (front surface and back surface) in the rotation axis direction of the impeller. That is, the blade groove region may be provided on the surface opposite to the surface facing the separation wall of the impeller. The separation wall may be provided with a facing groove on the surface facing the blade groove region. The facing groove may extend in the direction of rotation of the impeller. The facing groove may communicate with the suction port and the discharge port. Further, in the direction of the rotation axis of the impeller, the housing on the side opposite to the separation wall with respect to the impeller may be provided with an opposing groove facing the blade groove region.

The opening of the communication hole on the motor portion side may communicate with the storage groove. When the storage groove has a shallow groove portion and a deep groove portion, the opening of the communication hole on the motor portion side may communicate with the deep groove portion. Further, the opening of the communication hole on the pump portion side may be located outside the radial end portion (outer circumference of the impeller) of the impeller. That is, the opening of the communication hole on the pump portion side may face the gap between the outer circumference of the impeller and the housing.

A fuel supply system 1 having a purge pump 10 will be described with reference to FIG. The fuel supply system 1 has a main supply path 2 for supplying fuel from the fuel tank 3 to the engine 8 and a purge supply path 4. Although the details will be described later, the purge pump 10 is a vortex pump that pumps a fluid (gas). The eddy current pump is sometimes called a Wesco pump, a cascade pump, or a regeneration pump.

A fuel pump unit 7, a supply pipe 70, and an injector 5 are arranged in the main supply path 2. The fuel pump unit 7 includes a fuel pump, a pressure regulator, a control circuit, and the like. In the fuel pump unit 7, a control circuit controls the fuel pump in response to a signal supplied from an ECU (Engine Control Unit) 6 described later. The fuel pump boosts and discharges the fuel in the fuel tank 3. The fuel discharged from the fuel pump is regulated by the pressure regulator and supplied from the fuel pump unit 7 to the supply pipe 70.

The supply pipe 70 communicates the fuel pump unit 7 with the injector 5. The fuel supplied to the supply pipe 70 flows through the supply pipe 70 to the injector 5. The injector 5 has a valve whose opening degree is controlled by the ECU 6. When the valve is opened, the injector 5 supplies the fuel supplied from the supply pipe 70 to the engine 8.

An evaporative fuel processing device 9 is provided in the purge supply path 4. The evaporative fuel processing device 9 supplies the gas (purge gas) containing the evaporative fuel generated in the fuel tank 3 to the intake pipe 80. The evaporative fuel processing device 9 includes a canister 73, a purge pump 10, a control valve 100, and communication pipes 74, 76, 78 that communicate with each other. The communication pipes 74, 76, and 78 are connected between the canister 73 and the intake pipe 80, and form a passage for purge gas (purge passage). Activated carbon (not shown) is housed in the canister 73. The activated carbon in the canister 73 adsorbs the evaporated fuel generated in the fuel tank 3. In FIG. 1, the flow direction of the gas (purge gas) from the fuel tank 3 to the intake pipe 80 is indicated by an arrow. The tank port of the fuel tank 3 is connected to a communication pipe 72 extending from the upper end of the fuel tank 3. The canister 73 and the fuel tank 3 are communicated with each other by the communication pipe 72.

The purge port of the canister 73 is connected to the purge pump 10 via a communication pipe 74. The purge pump 10 is controlled by the ECU 6. The purge pump 10 sucks in the evaporated fuel adsorbed on the canister 73, boosts the pressure, and discharges the fuel. The purge gas discharged from the purge pump 10 passes through the communication pipe 76, the control valve 100, and the communication pipe 78, and flows into the intake pipe 80. The control valve 100 is a solenoid valve controlled by the ECU 6. The ECU 6 adjusts the amount of purge gas (purge amount) supplied to the intake pipe 80 by controlling the opening degree of the control valve 100.

The communication pipe 78 (a part of the purge passage) is connected to the intake pipe 80 on the upstream side of the injector 5. The intake pipe 80 is a pipe that supplies air to the engine 8. The throttle valve 82 is arranged on the upstream side of the position where the communication pipe 78 of the intake pipe 80 is connected. The throttle valve 82 adjusts the air flowing into the engine 8 by controlling the opening degree of the intake pipe 80. The throttle valve 82 is controlled by the ECU 6.

An air cleaner 84 is arranged on the upstream side of the intake pipe 80 with respect to the throttle valve 82. The air cleaner 84 has a filter for removing foreign matter from the air flowing into the intake pipe 80. In the intake pipe 80, when the throttle valve 82 is opened, intake is performed from the air cleaner 84 toward the engine 8. The engine 8 uses the air and fuel from the intake pipe 80 for internal combustion, and exhausts the air after combustion.

In the evaporative fuel processing device 9, the evaporative fuel adsorbed on the canister 73 can be supplied to the intake pipe 80 by driving the purge pump 10. When the engine 8 is driven, a negative pressure is generated in the intake pipe 80. Therefore, even when the purge pump 10 is stopped, the evaporated fuel adsorbed on the canister 73 passes through the stopped purge pump 10 due to the negative pressure in the intake pipe 80 and enters the intake pipe 80. Is supplied to. On the other hand, when the idling of the engine 8 is stopped when the vehicle is stopped, or when the engine 8 is stopped and the vehicle runs on the motor as in a hybrid vehicle, in other words, when the drive of the engine 8 is restricted for environmental measures. A situation occurs in which the pressure inside the intake pipe 80 does not become negative. Further, when the supercharger is mounted, the supercharger causes a situation in which the pressure inside the intake pipe 80 becomes positive. Even in such a situation, the purge pump 10 can supply the evaporated fuel adsorbed on the canister 73 to the intake pipe 80. Even if the engine 8 is driven and a negative pressure is generated in the intake pipe 80, if the absolute value of the negative pressure is small, the purge pump 10 is driven to drive the purge gas to the intake pipe 80. Can be supplied to.

Next, the configuration of the purge pump 10 will be described with reference to FIGS. 2 and 3. FIG. 2 shows a perspective view of the purge pump 10 as viewed from the pump portion 50 side. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. In this embodiment, "up" and "down" are represented with reference to the vertical direction of FIG. 3, but the vertical direction of FIG. 3 is not necessarily the direction in which the purge pump 10 is mounted on the automobile.

The purge pump 10 includes a housing (upper housing 26 and lower housing 52), a motor unit 20, and a pump unit 50. The motor unit 20 includes an upper housing 26, a motor 22, and a control circuit 24. The motor 22 is, for example, a brushless motor. The upper housing 26 houses the motor 22 and the control circuit 24. The control circuit 24 converts the DC power supplied from the battery of the automobile into three-phase AC power of U-phase, V-phase, and W-phase, and supplies the DC power to the motor 22. The control circuit 24 supplies electric power to the motor 22 according to a signal supplied from the ECU 6. The motor 22 includes a cylindrical stator (not shown) and a rotor (not shown) arranged at the center of the stator. The rotor is fixed to the output shaft 30 of the motor 22. The output shaft 30 rotates about the rotation axis X.

A pump unit 50 is arranged below the motor unit 20. The pump unit 50 is driven by the motor 22. The pump unit 50 includes a lower housing 52 and an impeller 54. The output shaft 30 is connected to the impeller 54, and the impeller 54 rotates as the output shaft 30 rotates. The impeller 54 is housed in the lower housing 52. The lower housing 52 is fixed to the lower end of the upper housing 26. The lower housing 52 includes a bottom wall 52a and a cover 52b. The cover 52b includes an upper wall 52c, a peripheral wall 52d, a suction port 56, and a discharge port 58 (see FIG. 2). The bearing 42 is fixed to the lower housing 52. More specifically, the bearing 42 is press-fitted into the through hole 46 provided in the center of the upper wall 52c. The bearing 42 rotatably supports the output shaft 30.

The upper wall 52c is arranged at the lower end of the upper housing 26. The motor unit 20 and the pump unit 50 are separated by the upper wall 52c. More specifically, the space where the motor 22 is arranged and the space where the impeller 54 is arranged are separated by the upper wall 52c. The upper wall 52c is an example of the separation wall described in the claims. The peripheral wall 52d projects downward from the upper wall 52c and goes around the outer peripheral edge of the upper wall 52c. A bottom wall 52a is arranged at the lower end of the peripheral wall 52d. The bottom wall 52a is fixed to the cover 52b by bolts (not shown). The bottom wall 52a closes the lower end of the peripheral wall 52d. The space 60 is defined by the bottom wall 52a and the cover 52b. The impeller 54 is arranged in the space 60. A storage groove 44 is provided on the motor portion 20 side of the upper wall 52c. The storage groove 44 will be described later. The area AR will also be described later.

The pump unit 50 will be described with reference to FIGS. 4 to 7. FIG. 4 is a view of the cover 52b viewed from below (from the side on which the impeller 54 is arranged). The broken line 54 indicates the position where the impeller 54 is arranged. FIG. 5 shows a perspective view of the impeller 54, and FIG. 6 is a view of the impeller 54 as viewed from below. FIG. 7 is an enlarged view of the area AR of FIG. The arrow R shown in FIGS. 4 and 6 indicates the moving direction of the purge gas during the driving of the pump. That is, the arrow R indicates the rotation direction of the impeller 54.

As shown in FIG. 4, the peripheral wall 52d is provided with a suction port 56 and a discharge port 58. The suction port 56 and the discharge port 58 communicate with each other in the space 60 (see FIG. 3), and project outward from the peripheral wall 52d. The suction port 56 and the discharge port 58 are arranged parallel to each other and perpendicular to the vertical direction. The suction port 56 communicates with the canister 73 via a communication pipe 74 (see FIG. 1). The suction port 56 is provided with a suction flow path inside, and purge gas is introduced into the space 60 from the canister 73. The discharge port 58 is provided with a discharge flow path inside, and communicates with the suction port 56. The discharge port 58 sends the purge gas sucked into the space 60 to the outside of the purge pump 10 (communication pipe 76).

The upper wall 52c has an opposing groove 52e extending from the suction port 56 to the discharge port 58 along the peripheral wall 52d. Similarly, the bottom wall 52a also has an opposing groove 52f extending from the suction port 56 to the discharge port 58 along the peripheral wall 52d (see also FIG. 3). The facing groove 52e and the facing groove 52f have a constant depth at an intermediate position excluding both ends in the longitudinal direction, specifically, at a position facing the impeller 54, and at both ends in the longitudinal direction, the suction port 56 and the discharge port 56, respectively. It gradually becomes shallower as it approaches port 58. The communication hole 40 is provided on the bottom surface of the facing groove 52e at a position not facing the impeller 54. Although the details will be described later, the communication hole 40 penetrates the upper wall 52c and communicates with the space where the motor 22 is arranged (motor unit 20) and the space where the impeller 54 is arranged (pump unit 50). ..

The impeller 54 will be described. The impeller 54 has a disk shape (see FIGS. 5 and 6). Further, as shown in FIG. 3, the impeller 54 is housed in the space 60. The thickness of the impeller 54 is slightly smaller than the gap between the upper wall 52c and the bottom wall 52a of the lower housing 52. The impeller 54 faces each of the upper wall 52c and the bottom wall 52a with a small gap. Further, a small gap is provided between the outer circumference of the impeller 54 and the peripheral wall 52d. The impeller 54 has a fitting hole (not shown) fitted in the output shaft 30 at the center. As a result, the impeller 54 rotates about the rotation axis X as the output shaft 30 rotates.

As shown in FIGS. 5 and 6, the impeller 54 has a blade groove region 54f having a plurality of blades 54a and a plurality of blade grooves 54b on the outer peripheral portion. In addition, in FIGS. 5 and 6, only one blade 54a and one blade groove 54b are designated by reference numerals. The blade groove region 54f having the blade 54a and the blade groove 54b is provided on both the upper surface 54g and the lower surface 54h of the impeller 54. The upper surface 54g and the lower surface 54h can be said to be end faces of the impeller 54 in the rotation axis X direction. The blade groove region 54f arranged on the upper surface 54g is arranged so as to face the facing groove 52e. The blade groove region 54f arranged on the lower surface 54h is arranged so as to face the facing groove 52f (see also FIG. 3).

Each blade groove region 54f makes a round in the circumferential direction of the impeller 54 inside the outer peripheral wall 54c of the impeller 54. The plurality of blades 54a have the same shape. The plurality of blades 54a are arranged at equal intervals in the circumferential direction of the impeller 54 in the blade groove region 54f. One blade groove 54b is arranged between two blades 54a adjacent to each other in the circumferential direction of the impeller 54. That is, the plurality of blade grooves 54b are arranged at equal intervals in the circumferential direction of the impeller 54 inside the outer peripheral wall 54c of the impeller 54. The outer peripheral wall 54c of the plurality of blade grooves 54b closes the end portion on the outer peripheral side. The plurality of blade grooves 54b have the same shape.

As shown in FIG. 7, the plurality of blade grooves 54b arranged on the upper surface 54g of the impeller 54 are opened on the upper surface 54g side of the impeller 54, while are closed on the lower surface 54h side of the impeller 54. Similarly, the plurality of blade grooves 54b arranged on the lower surface 54h of the impeller 54 are opened on the lower surface 54h side of the impeller 54, respectively, while being closed on the upper surface 54g side of the impeller 54. The plurality of blade grooves 54b arranged on the lower surface 54h of the impeller 54 and the plurality of blade grooves 54b arranged on the upper surface 54g of the impeller 54 are blocked and do not communicate with each other.

While the purge pump 10 is being driven, the impeller 54 rotates as the output shaft 30 of the motor 22 rotates. As a result, the gas (purge gas) containing the evaporated fuel adsorbed on the canister 73 is sucked into the lower housing 52 from the suction port 56 (see also FIGS. 2 to 4). The purge gas sucked into the lower housing 52 advances in the rotation direction R as the impeller 54 rotates. A gas vortex (swirl flow) is generated in the space 57 defined by the blade groove 54b and the facing groove 52e. On the upper surface 54g side of the impeller 54, as shown by the arrow 45, the vortex flows toward the outer peripheral side of the impeller 54 along the bottom surface of the blade groove 54b and toward the center of the impeller 54 along the bottom surface of the facing groove 52e. Flows. A vortex is similarly generated in the space 59 defined by the blade groove 54b and the facing groove 52f. The purge gas advances in the rotation direction R while being boosted by the vortex flow. The purge gas that has reached the end of the discharge port 58 is discharged from the discharge port 58.

The communication hole 40 will be described with reference to FIGS. 8 and 9. FIG. 8 is a view of the cover 52b viewed from above (from the side where the motor 22 is arranged). Further, FIG. 9 shows a cross section along the line AOB of FIG. As shown in FIG. 8, a storage groove 44 is provided on the surface of the upper wall 52c so as to surround the through hole 46. The storage groove 44 extends from the suction port 56 toward the discharge port 58. The depth of the reservoir 44 is not constant. The depth of the end 44b on the discharge port 58 side of the storage groove 44 is deeper than the depth of the end 44a on the suction port 56 side of the storage groove 44. That is, the storage groove 44 includes a shallow groove portion having a shallow depth and a deep groove portion having a deep depth. Hereinafter, the end portion 44a is referred to as a shallow groove portion, and the end portion 44b is referred to as a deep groove portion. The depth of the storage groove 44 becomes deeper from the shallow groove portion 44a toward the deep groove portion 44b. That is, the storage groove 44 is inclined from the shallow groove portion 44a toward the deep groove portion 44b.

The communication hole 40 communicates with the deep groove portion 44b. That is, the communication hole 40 communicates with the storage groove 44 on the discharge port 58 side. Further, the opening on the impeller 54 side of the communication hole 40 is located outside the radial direction (direction orthogonal to the rotation axis X) of the opening on the motor 22 side of the communication hole 40 (opening to the storage groove 44). More specifically, the opening of the communication hole 40 on the impeller 54 side is located outside the outer circumference (outer peripheral wall 54c) of the impeller 54. That is, the opening of the communication hole 40 on the impeller 54 side faces the gap between the outer periphery of the impeller 54 and the peripheral wall 52d.

While the purge pump 10 is being driven, the pressure inside the pump unit 50 is higher than that inside the motor unit 20. Therefore, the gas (purge gas) in the pump unit 50 passes through the communication hole 40 and moves into the motor unit 20. As the gas moves from the pump unit 50 to the motor unit 20, the pressure inside the pump unit 50 and the pressure inside the motor unit 20 are balanced. At this time, foreign matter may move into the motor unit 20 together with the purge gas. Since the foreign matter that has moved into the motor section 20 is held in the storage groove 44, it is possible to prevent the foreign matter from being scattered in the pump section 50.

When the drive of the purge pump 10 is stopped, the pressure in the pump unit 50 decreases. As a result, the pressure in the motor unit 20 becomes higher than that in the pump unit 50, and the gas passes through the communication hole 40 and moves from the motor unit 20 to the pump unit 50. Along with the movement of the gas, foreign matter existing in the motor unit 20, for example, foreign matter that has moved from the pump unit 50 to the motor unit 20 while the purge pump 10 is being driven moves to the pump unit 50. Since the foreign matter is held in the storage groove 44, even if the gas passes through a gap other than the communication hole 40, for example, the gap of the bearing 42 and moves to the pump portion 50, the foreign matter damages the bearing 42. Can be suppressed.

As described above, in the purge pump 10, the storage groove 44 is inclined from one end (shallow groove) 44a toward the other end (deep groove) 44b. Therefore, the foreign matter in the storage groove 44 collects in the vicinity of the deep groove portion 44b. Further, the communication hole 40 communicates with the deep groove portion 44b. When the gas moves from the motor unit 20 to the pump unit 50, foreign matter can be efficiently discharged to the pump unit 50. Further, since the opening of the communication hole 40 on the pump portion 50 side is located outside the outer circumference of the impeller 54, damage to the impeller 54 by foreign matter discharged from the motor portion 20 to the pump portion 50 is suppressed. ..

Further, as described above, while the purge pump 10 is being driven, the pressure inside the pump portion 50 is higher on the discharge port 58 side than on the suction port 56 side. Therefore, the differential pressure between the motor unit 20 and the pump unit 50 increases from the suction port 56 toward the discharge port 58. By providing the communication hole 40 at a position where the differential pressure between the motor unit 20 and the pump unit 50 is large (on the discharge port 58 side), the gas passes through a gap other than the communication hole 40, for example, a gap of the bearing 42, and the pump unit 50 It is possible to prevent the motor unit 20 from moving to the motor unit 20.

The purge pump 10a will be described with reference to FIGS. 10 and 11. The purge pump 10a is a modification of the purge pump 10, and the position where the communication hole is provided is different from that of the purge pump 10. Regarding the purge pump 10a, the same reference number may be assigned to the same structure as the purge pump 10, and the description may be omitted. FIG. 10 is a view of the cover 52b viewed from above (from the side where the motor 22 is arranged), and FIG. 11 shows a cross section taken along the line AOB of FIG. The purge pump 10a can be used in the evaporative fuel processing device 9 of the fuel supply system 1 instead of the purge pump 10 (see also FIG. 1).

The purge pump 10a includes two communication holes 40a and 40b. The communication hole 40a is provided on the suction port 56 side. The communication hole 40b is provided on the discharge port 58 side. The communication hole 40a communicates with the shallow groove portion 44a, and the communication hole 40b communicates with the deep groove portion 44b. As described above, in the case of the vortex pump, the pressure in the pump portion 50 is higher on the discharge port 58 side than on the suction port 56 side. Therefore, if communication holes (communication holes 40a and 40b) are provided on both the suction port 56 side and the discharge port 58 side, the purge gas moves from the pump section 50 to the motor section 20 through the communication hole 40b, and the motor section passes through the communication hole 40a. A flow moving from 20 to the pump section 50 is formed. While driving the purge pump 10a, it is possible to reliably prevent the purge gas from passing through the gap of the bearing 42.

The purge pump 10 of the above embodiment has the following features (1) to (6). (1) A communication hole for communicating the motor unit and the pump unit is provided, and a storage groove is provided in the motor unit. (2) The storage groove extends from the suction port side toward the discharge port side. (3) The storage groove has a shallow groove portion having a shallow depth and a deep groove portion having a deep depth, and is inclined from the shallow groove portion to the deep groove portion. (4) A shallow groove portion is provided on the suction port side, and a deep groove portion is provided on the discharge port side. (5) On the motor portion side, the opening of the communication hole communicates with the deep groove portion. (6) On the pump portion side, the opening of the communication hole is located outside the outer circumference of the impeller. The main part of the technique disclosed in the present specification is to have the above-mentioned feature (1), and the features (2) to (6) can be appropriately selected as needed. Further, instead of the storage groove of the feature (1), for example, a hemispherical recess can be used as a storage part for foreign matter.

The purge pump 10 of the above embodiment is provided with communication holes on the discharge port side (high pressure side), and the purge pump 10a is provided with communication holes on the discharge port side (high pressure side) and the suction port side (low pressure side). There is. In each case, a communication hole is provided on the discharge port side. However, the position where the communication holes are provided and the number of communication holes are not limited to the above embodiment. For example, the communication holes may be provided on the suction port side, or three or more communication holes may be provided.

Although the embodiments of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above. In addition, the technical elements described in the present specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the techniques illustrated in the present specification or drawings achieve a plurality of objectives at the same time, and achieving one of the objectives itself has technical usefulness.

9: Evaporated fuel processing device 10: Vortex pump 20: Motor unit 22: Motor 26: Upper housing 30: Output shaft 40: Communication hole 42: Bearing 44: Storage unit 50: Pump unit 52: Lower housing 54: Impeller 56: Inhalation Port 58: Discharge port 52c: Separation wall 80: Intake path

Claims (7)

It is a vortex pump with a motor part and a pump part inside the housing.
The motor unit is provided with a motor and also has a storage unit for storing foreign matter that has entered the motor unit.
The pump unit includes a fluid suction port, a fluid discharge port, and an impeller that rotates integrally with the output shaft of the motor.
The housing is provided with a bearing for supporting the output shaft and a separation wall for separating the motor portion and the pump portion.
The separation wall is provided with a communication hole that communicates the motor section and the pump section.
The storage unit is composed of a storage groove provided so as to surround the output shaft.
The storage groove does not go around the output shaft, and one end is provided at the first position corresponding to the suction port and the other end is provided at the second position corresponding to the discharge port.
A vortex pump in which a communication hole is provided on the second position side in the storage groove . The vortex pump according to claim 1, wherein the storage groove is provided on the surface of the separation wall. The vortex pump according to claim 1 or 2, wherein communication holes are provided on both the first position side and the second position side in the storage groove. The vortex pump according to any one of claims 1 to 3, wherein the storage groove is inclined from a shallow groove portion having a shallow depth toward a deep groove portion having a deep depth. The vortex pump according to claim 4 , wherein the groove depth at one end of the storage groove is the shallowest and the groove depth at the other end is the deepest in the longitudinal direction in which the storage groove extends. The vortex pump according to any one of claims 3 to 5, wherein the opening on the motor portion side of the communication hole communicates with the deep groove portion. The vortex pump according to any one of claims 1 to 6, wherein the opening on the pump portion side of the communication hole is provided outside the radial end portion of the impeller.