WO2021019976A1

WO2021019976A1 - Fluid pump

Info

Publication number: WO2021019976A1
Application number: PCT/JP2020/024935
Authority: WO
Inventors: 直純村上
Original assignee: 愛三工業株式会社
Priority date: 2019-07-31
Filing date: 2020-06-25
Publication date: 2021-02-04
Also published as: JP2021025431A

Abstract

This fluid pump is provided with a pump casing (8) accommodating an impeller (14). The pump casing includes a first casing portion (4) in which a fluid intake port (2) for intake of a fluid is provided, and a second casing portion (9) in which a fluid discharge port (10) for discharging the fluid is provided. A first planar surface portion (4b) perpendicular to the axis of rotation of a motor, and a first inclined portion (4a) which is inclined with respect to the first planar surface portion are provided in the first casing portion. A second planar surface portion (6b) perpendicular to the axis of rotation of the motor, and a second inclined portion (6a) which is inclined with respect to the second planar surface portion are provided in a side wall portion (6) of the second casing portion. The first planar surface portion is in contact with the second planar surface portion and the first inclined portion is in contact with the second inclined portion, thereby defining a space, inside the pump casing, in which the impeller is disposed.

Description

Fluid pump

This application claims priority based on Japanese Patent Application No. 2019-141460 filed on July 31, 2019. The entire contents of that application are incorporated herein by reference. This specification discloses a technique relating to a fluid pump.

Japanese Unexamined Patent Publication No. 2002-276566 (hereinafter referred to as Patent Document 1) discloses a fuel pump that distributes fuel by driving an impeller connected to a motor. In the fuel pump of Patent Document 1, a motor and a pump casing are housed in a housing (motor casing). The pump casing is a member provided with a fluid suction port for sucking fluid into the pump casing (second plate) and a member provided with a fluid discharge port for discharging fluid from the inside of the pump casing (second plate). The first plate) is provided. The first plate and the second plate are respectively press-fitted into the motor casing. That is, the pump casing is formed by press-fitting the first plate and the second plate into the motor casing.

When the pump casing is formed of two members (first plate, second plate), it is required to align each member with high accuracy. For example, if the alignment of each member is insufficient, liquid leakage may occur from the inside of the pump casing, or the fluid (fuel) may not move smoothly from the fluid suction port to the fluid discharge port. That is, the pump performance of the fuel pump deteriorates. Therefore, in the case of the fuel pump of Patent Document 1, it is necessary to finish the size of the housing (motor casing) with high accuracy. It is also necessary to finish the housing with high strength so that deformation does not occur when each member is press-fitted. As a result, the manufacturing cost of the fuel pump of Patent Document 1 increases. There is a need for a technique for aligning each part (two parts forming the pump casing) with a simpler structure. The present specification provides a technique for realizing a fluid pump having a pump casing having a novel structure that has never existed before.

The first technique disclosed in this specification is a fluid pump including an impeller driven by a motor and a pump casing accommodating the impeller. In this fluid pump, the pump casing is provided with a first casing portion in which a fluid suction port for sucking fluid is provided in the pump casing, and a fluid discharge port for discharging fluid from the inside of the pump casing. It may have a second casing portion. Further, the first casing portion is provided with a first plane portion extending in a direction orthogonal to the rotation axis of the motor and a first inclined portion inclined with respect to the first plane portion, and the second casing portion is provided. , A second plane portion extending in a direction orthogonal to the rotation axis of the motor and a second inclined portion inclined with respect to the second plane portion are provided, and the first plane portion and the second plane portion come into contact with each other. , The space inside the pump casing in which the impeller is arranged may be defined by the contact between the first inclined portion and the second inclined portion.

The second technique disclosed in the present specification is the fluid pump of the first technique, and a housing surrounding the outer periphery of the pump casing may be provided in a direction orthogonal to the rotation axis of the motor. The housing may apply a force to the first casing portion and the second casing portion to prevent them from separating in the rotation axis direction of the motor.

The third technique disclosed in the present specification is the fluid pump of the first or second technique described above, and the first inclined portion and the second inclined portion may be parallel to each other.

According to the first technology, the parts constituting the pump casing (first casing portion and second casing portion) are highly accurate without being affected by the characteristics (machining accuracy, strength) of other members (housing, etc.). Can be aligned. In other words, in order to align the first casing portion and the second casing portion with high accuracy, it is not necessary to process other members with high accuracy. As a result, the manufacturing cost of the fluid pump can be reduced.

Further, in the fluid pump of the first technology, the first casing portion and the second casing portion are the first and second plane portions (planes orthogonal to the rotation axis of the motor) and the first and second inclined portions (of the motor). It is in contact with an inclined surface that is inclined with respect to a plane orthogonal to the rotation axis). The distance between the first casing portion and the second casing portion in the rotation axis direction can be controlled by the contact between the first flat surface portion and the second flat surface portion. Further, by contacting the first inclined portion and the second inclined portion, it is possible to control the relative positions of the first casing portion and the second casing portion in the direction orthogonal to the rotation axis direction of the motor (that is, axis alignment). can do). In the following description, the rotation axis direction of the motor is referred to as "axial direction", and the direction orthogonal to the rotation axis of the motor (that is, the radial direction of the motor) is referred to as "diameter direction".

The impeller used in the fluid pump may have blade grooves on the front and back surfaces. When such an impeller is used, a groove may be formed in the pump casing so as to face the blade groove to control the flow of fluid. In order to bring out the pump performance of the fluid pump as designed, it is necessary that the groove in the pump casing and the blade groove face each other as designed. As described above, the fluid pump of the first technique can satisfactorily align the first casing portion and the second casing portion in the axial direction and the radial direction. As a result, the fluid pump of the first technique can exhibit good pump performance.

As described above, in the fluid pump of the first technology, the first inclined portion and the second inclined portion are in contact with each other. When forming the pump casing (joining the first casing portion and the second casing portion), the first casing portion is brought into contact with the second inclined portion (or the second casing portion) so that the first inclined portion and the second inclined portion come into contact with each other. The casing portion is press-fitted into the first casing portion). Since the first casing portion and the second casing portion are joined by press fitting, the gap between the first casing portion and the second casing portion is satisfactorily sealed. In the fluid pump of the first technology, since the first casing portion and the second casing portion are in contact with each other on both the flat surface portion (the first flat surface portion and the second flat surface portion) and the inclined surface portion (the first inclined portion and the second inclined portion). , Except for the fluid inlet and fluid outlet, the inside of the pump casing is well sealed. That is, it is possible to suppress liquid leakage from the inside of the pump casing.

When the first casing portion and the second casing portion are not in contact with each other on the flat surface portion but only on the inclined portion, the first casing portion is referred to as the second casing portion (or the second casing portion is referred to as the first casing portion). ), It becomes difficult to control the axial distance between the first casing portion and the second casing portion to an appropriate value. That is, it becomes difficult to control the space volume in the pump casing to an appropriate value. Further, if the axial distance between the first casing portion and the second casing portion becomes long (if the press-fitting is insufficient), the sheath property of the pump casing may deteriorate. On the other hand, even if the axial distance between the first casing portion and the second casing portion is shortened (even if the press-fitting is excessive), the first casing portion and / or the second casing portion is deformed, and the sheath property of the pump casing is increased. May decrease. In the fluid pump of the first technique, since the first casing portion and the second casing portion are in contact with each other on both the flat surface portion and the inclined portion, the first casing portion is referred to as the second casing portion (or the second casing portion is referred to as the second casing portion). By simply press-fitting into 1 casing), both can be aligned and the sealing performance of the pump casing can be ensured.

According to the second technology, the housing can keep the positions of the first casing portion and the second casing portion in good condition. That is, it is possible to maintain a good contact state between the first casing portion and the second casing portion in the flat surface portion and the inclined portion.

According to the third technology, the first inclined portion and the second inclined portion come into surface contact with each other. Since the contact area between the first inclined portion and the second inclined portion is increased, the sealing property of the pump casing is further improved.

The cross-sectional view of the fuel pump is shown. An enlarged view of the range surrounded by the broken line II in FIG. 1 is shown. An enlarged view of the range surrounded by the broken line II in FIG. 1 is shown. A modified example of the joint portion between the first casing portion and the second casing portion is shown. A modified example of the joint portion between the first casing portion and the second casing portion is shown. A modified example of the joint portion between the first casing portion and the second casing portion is shown. A modified example of the joint portion between the first casing portion and the second casing portion is shown. A modified example of the joint portion between the first casing portion and the second casing portion is shown. A modified example of the joint portion between the first casing portion and the second casing portion is shown. A modified example of the joint portion between the first casing portion and the second casing portion is shown. A modified example of the joint portion between the first casing portion and the second casing portion is shown.

(Fuel pump)
The fuel pump 100 will be described as an example of the fluid pump with reference to FIGS. 1 to 3. In addition, in FIG. 1, only both end portions (pump portion 20 and pump discharge port 22) of the fuel pump 100 are shown in cross section, and the appearance (housing 46) is shown for the intermediate portion (motor portion 30). The fuel pump 100 is arranged in, for example, a fuel tank of an automobile, and supplies fuel in the fuel tank to the engine. Further, in the following description, the pump discharge port 22 side may be referred to as "upper side" or "upper side", and the fuel suction port 2 side may be referred to as "lower side" or "lower side".

As shown in FIG. 1, the motor unit 30 and the pump unit 20 are arranged in the housing 46. A motor having a rotor and a stator (for example, a brushless motor) is arranged in the motor unit 30. The rotor shaft 40 fixed to the rotor extends downward toward the pump portion 20 and engages with the impeller 14 housed in the pump casing 8. More specifically, an engaging portion 42 having a non-circular cross section (for example, a D shape) is provided at the end of the rotor shaft 40, and the impeller 14 is engaged with the engaging portion 42. The rotor shaft 40 is supported by a bearing 44 and rotates around a rotation shaft CL. When the rotor shaft 40 rotates (the motor is driven), the impeller 14 rotates in the pump casing 8. The rotary shaft CL is a rotary shaft of the motor (rotor shaft 40) and a rotary shaft of the impeller 14.

(Composition of pump part)
The pump unit 20 includes a substantially disk-shaped impeller 14 and a pump casing 8 accommodating the impeller 14, and is arranged in the housing 46. More specifically, the outer peripheral surface (diametric end surface) of the pump casing 8 is surrounded by the housing 46, and the axial end surface (lower end portion) of the pump casing 8 is exposed from the opening of the housing 46. .. That is, the pump casing 8 forms a part of the appearance of the fuel pump 100.

The pump casing 8 includes a first casing portion 4 in which the fuel suction port 2 is formed, and a second casing portion 9 in which the fuel discharge port 10 is formed. The fuel suction port 2 is an example of a fluid suction port, and the fuel discharge port 10 is an example of a fluid discharge port. The first casing portion 4 and the second casing portion 9 are joined by a joining portion 50. Specifically, a side wall portion 6 extending toward the first casing portion 4 is provided at the radial end portion of the second casing portion 9. The first casing portion 4 and the second casing portion 9 are joined by press-fitting and fixing the radial end portion of the first casing portion 4 and the side wall portion 6. By joining the first casing portion 4 and the second casing portion 9, the pump internal space 8a in which the impeller 14 is housed is formed. That is, the surface (upper surface) of the first casing portion 4 constitutes the lower surface of the pump inner space 8a, and the surface (lower surface) of the second casing portion 9 is the upper surface of the pump inner space 8a. The inner surface of the side wall portion 6 constitutes the side surface of the pump inner space 8a. A caulking portion 46a is provided at the lower end of the housing 46, and a force is applied to the second casing portion 9 side with respect to the first casing portion 4. The fixed state (press-fitting state) of the first casing portion 4 and the second casing portion 9 will be described later.

The fuel suction port 2 and the fuel discharge port 10 communicate with each other in the pump internal space 8a. In the fuel pump 100, when the impeller 14 rotates as the motor is driven, fuel is sucked from the fuel suction port 2 into the pump internal space 8a. The fuel sucked into the pump internal space 8a is boosted as the impeller 14 rotates, and is discharged from the fuel discharge port 10 to the motor unit 30. The fuel supplied to the motor unit 30 passes through the motor unit 30 and is discharged from the pump discharge port 22 to the outside of the fuel pump 100 (toward the engine).

Blade grooves

14a and 14b are formed on the front and back surfaces of the impeller 14. Further, a suction groove 5 facing the blade groove 14a is formed in the first casing portion 4, and a discharge groove 7 facing the blade groove 14b is formed in the second casing portion 9. The suction groove 5 is connected to the fuel suction port 2 and extends in an arc shape around the rotation shaft CL. Further, the discharge groove 7 is connected to the fuel discharge port 10 and extends in an arc shape around the rotation shaft CL. In the fuel pump 100, a space formed by the blade groove 14a and the suction groove 5 (suction side space) and a space formed by the blade groove 14b and the discharge groove 7 (discharge side space) as the impeller 14 rotates. ), A swirling flow occurs. The smoother the flow of the swirling flow in the suction side space and the discharge side space, the better the fuel discharge performance (pump performance) of the fuel pump 100. In other words, the more turbulent flow occurs in the intake side space and the discharge side space, the lower the fuel discharge performance of the fuel pump 100.

The joint state of the first casing portion 4 and the second casing portion 9 (side wall portion 6) will be described with reference to FIGS. 2 and 3. FIG. 2 shows a joint portion 50 between the first casing portion 4 and the side wall portion 6. As shown in FIG. 2, a first inclined portion 4a and a first flat surface portion 4b are formed at the radial end portion of the first casing portion 4. The first flat surface portion 4b is a flat surface extending in the radial direction, and makes a round in the circumferential direction. Further, the first flat surface portion 4b is located below the surface of the first casing portion 4 (lower surface of the pump inner space 8a), and is provided radially outside the first inclined portion 4a. That is, the first inclined portion 4a is a tapered surface provided between the surface of the first casing portion 4 and the first flat surface portion 4b. The first inclined portion 4a also makes a round in the circumferential direction.

A second inclined portion 6a and a second flat surface portion 6b are formed at the lower end portion of the side wall portion 6 (second casing portion 9). The second flat surface portion 6b is an end surface of the side wall portion 6, is a flat surface extending in the radial direction, and makes a round in the circumferential direction. The second flat surface portion 6b is provided on the outer side in the radial direction from the second inclined portion 6a. The second inclined portion 6a is a tapered surface provided between the second flat surface portion 6b and the inner surface of the side wall portion 6. The second inclined portion 6a also makes a round in the circumferential direction. The first inclined portion 4a and the second inclined portion 6a are in surface contact with each other to form the inclined contact portion 51. Further, the first flat surface portion 4b and the second flat surface portion 6b are in surface contact with each other to form the flat surface contact portion 52. The joint portion 50 is composed of an inclined contact portion 51 and a plane contact portion 52. As shown in FIG. 2, a gap 60 is provided between the side wall portion 6 and the radial end surface of the first casing portion 4 (the outer peripheral surface of the pump casing 8) and the housing 46. That is, the first casing portion 4 and the second casing portion 9 are not fixed to the housing 46.

In the fuel pump 100, the first casing portion 4 (first inclined portion 4a) is press-fitted into the second inclined portion 6a of the second casing portion 9 (side wall portion 6) until the

flat surfaces

4b and 6b come into contact with each other. The first casing portion 4 and the second casing portion 9 are joined to each other (the pump casing 8 is formed). Since the first casing portion 4 and the second casing portion 9 are provided with the

inclined portions

4a and 6a, when the first casing portion 4 is press-fitted into the second casing portion 9, the first casing portion 4 and the second casing portion 9 are press-fitted. The radial alignment of the portion 9 progresses (the coaxiality of the first casing portion 4 and the second casing portion 9 increases). The

inclined portions

4a and 6a are parallel to each other, and they are in surface contact with each other. When the

flat surfaces

4b and 6b come into contact with each other, the axial distance between the first casing 4 and the second casing 9 is controlled to the design value, and the relative positions of the first casing 4 and the second casing 9 in the radial direction are changed. It is controlled by the design value (the first casing portion 4 and the second casing portion 9 are coaxial).

As shown in FIG. 3, a caulking portion 46a is provided at the lower end of the housing 46. The caulking portion 46a is in contact with the lower surface of the radial end portion of the first casing portion 4, and applies a force to the first casing portion 4 in the direction of arrow 54 (upward). That is, the caulking portion 46a applies a force to the joint portion 50 to prevent the first casing portion 4 and the second casing portion 9 from being separated in the axial direction (a gap is generated between the

flat surface portions

4b and 6b). ing. The caulked portion 46a brings the

flat surfaces

4b, 6b and the

inclined portions

4a, 6a into close contact with each other, and the adhesiveness is maintained. As described above, the first casing portion 4 and the second casing portion 9 are not fixed to the housing 46. Therefore, even if the housing 46 is deformed in the radial outer portion of the pump casing 8 by providing the caulking portion 46a in the housing 46, the positional relationship between the first casing portion 4 and the second casing portion 9 does not change.

(Advantages of fuel pump 100)
In the fuel pump 100, the first casing portion 4 is simply press-fitted into the second casing portion 9 without controlling the positions, dimensions, etc. of the

casing portions

4 and 9 and other parts (for example, the housing 46). The casing portion 4 and the second casing portion 9 can be aligned with high accuracy. Further, since the first casing portion 4 and the second casing portion 9 are aligned with high accuracy, the blade groove 14a and the suction groove 5, and the blade groove 14b and the discharge groove 7 are also aligned with high accuracy. .. When the fuel pump 100 is driven, a swirling flow is satisfactorily formed between the blade groove 14a and the suction groove 5 and between the blade groove 14b and the discharge groove 7, and the pump performance as designed is realized.

On the other hand, when the

casing portions

4 and 9 are positioned with respect to other parts (for example, the housing 46) (for example, press-fitted into the housing 46), if the strength and processing accuracy of the housing 46 are insufficient, the first casing portion The alignment between 4 and the second casing portion 9 becomes insufficient. As a result, the alignment between the blade groove 14a and the suction groove 5 and / or the blade groove 14b and the discharge groove 7 becomes insufficient, and between the blade groove 14a and the suction groove 5 and / or the blade groove 14b and the discharge groove Turbulence may occur between the seven. If turbulence occurs between the blade groove 14a and the suction groove 5 (between the blade groove 14b and the discharge groove 7), the pump performance may deviate from the design value (typically, the discharge performance of the pump deteriorates). .. In the fuel pump 100, since the

casing portions

4 and 9 are in contact with the inclined contact portion 51 at the flat contact portion 52, the

casing portions

4 and 9 are aligned with each other with high accuracy, and good pump performance is realized. Has advantages.

Further, in the fuel pump 100, since the first casing portion 4 is press-fitted into the second casing portion 9 (side wall portion 6) to join the two, the two are joined at the joining portion 50 (inclined contact portion 51 and the flat contact portion 52). Good adhesion can be achieved and the sealing property of the pump internal space 8a can be improved. Further, since the caulking portion 46a applies a force upward to the first casing portion 4, for example, even if vibration is applied to the fuel pump 100, the joint state of the joint portion 50 can be maintained satisfactorily. The fuel pump 100 also has an advantage that liquid leakage from the pump internal space 8a can be suppressed for a long period of time.

(Modification example of contact part)
Hereinafter, modifications of the joint portion 50 (joint portions 50a to 50h) will be described with reference to FIGS. 4 to 11. The joint portions 50a to 50h are common in that they have an inclined contact portion and a plane contact portion. Therefore, the features common to the joint portions 50a to 50h may be omitted by assigning the same reference numbers as those of the joint portion 50. Any of the joint portions 50a to 50h can be applied as a joint portion between the first casing portion 4 and the second casing portion 9 in the pump portion 20 of the fuel pump 100.

The joint portion 50a shown in FIG. 4 includes an inclined contact portion 51, a first plane contact portion 52a, and a second plane contact portion 52b. The relationship between the inclined contact portion 51 and the first plane contact portion 52a is substantially the same as the relationship between the inclined contact portion 51 and the plane contact portion 52 of the joint portion 50 (see also FIG. 2). In the joint portion 50a, the first casing portion 4 is provided with two flat surfaces (first flat surface portion 4b and third flat surface portion 4c), and the side wall portion 6 is provided with two flat surface portions (second flat surface portion 6b). And the fourth plane portion 6c) are provided. The third flat surface portion 4c is a part of the surface of the first casing portion 4, and is provided radially inside the first inclined portion 4a. The fourth flat surface portion 6c is provided on the inner side in the radial direction from the second inclined portion 6a. The third flat surface portion 4c and the fourth flat surface portion 6c make a round in the circumferential direction.

In the joint portion 50a, the third plane portion 4c and the fourth plane portion 6c are in contact with each other to form the second plane contact portion 52b. In the joint portion 50a, the first casing portion 4 and the second casing portion 9 (side wall portion 6) are in contact with each other at three locations (inclined contact portion 51, first plane contact portion 52a, and second plane contact portion 52b). Therefore, the space 8a inside the pump can be sealed even better.

The joint portion 50b shown in FIG. 5 includes a first inclined contact portion 51a, a second inclined contact portion 51b, and a flat contact portion 52. The

inclined contact portions

51a and 51b are provided between the flat contact portion 52 and the pump internal space 8a. In the joint portion 50b, the first casing portion 4 is provided with two inclined portions (first inclined portion 4a1 and the third inclined portion 4a2), and the side wall portion 6 is provided with two inclined portions (second inclined portion 6a1). And a fourth inclined portion 6a2) are provided. The third inclined portion 4a2 is provided radially inside the first inclined portion 4a1. That is, in the radial direction, the first inclined portion 4a1 is provided between the first plane portion 4b and the third inclined portion 4a2. Further, the fourth inclined portion 6a2 is provided on the inner side in the radial direction with respect to the second inclined portion 6a1. That is, in the radial direction, the second inclined portion 6a1 is provided between the second plane portion 6b and the fourth inclined portion 6a2. The inclined portions 4a1, 4a2, 6a1, 6a2 make a round in the circumferential direction.

At the joint portion 50b, the first inclined portion 4a1 and the second inclined portion 6a1 are in contact with each other to form the first inclined contact portion 51a. Further, the third inclined portion 4a2 and the fourth inclined portion 6a2 are in contact with each other to form the second inclined contact portion 51b. The inclination angle of the first inclined contact portion 51a (angle with respect to the plane contact portion 52) is smaller than the inclination angle of the second inclined contact portion 51b. In the joint portion 50b, the first casing portion 4 and the second casing portion 9 (side wall portion 6) are in contact with each other at three locations (first inclined contact portion 51a, second inclined contact portion 51b, flat contact portion 52). The pump internal space 8a can be satisfactorily sealed.

In the joint portion 50c shown in FIG. 6, the first inclined portion 4a and the second inclined portion 6a partially contact each other to form an inclined contact portion 51, and the first plane portion 4b and the second plane portion 6b come into surface contact with each other. The plane contact portion 52 is formed. Specifically, the first inclined portion 4a and the second inclined portion 6a are non-parallel, the inclination angle of the first inclined portion 4a is larger than the inclined angle of the second inclined portion 6a, and in the vicinity of the plane contact portion 52, The first inclined portion 4a and the second inclined portion 6a are not in contact with each other. Even in such a form, there is an advantage that the first casing portion 4 and the second casing portion 9 can be aligned with high accuracy without being affected by the processing accuracy of the housing 46.

In the joint portion 50d shown in FIG. 7, similarly to the joint portion 50c, the first inclined portion 4a and the second inclined portion 6a partially contact to form the inclined contact portion 51, and the first plane portion 4b and the second inclined portion 50d are formed. The flat surface portion 6b is in surface contact to form the flat surface contact portion 52. The first inclined portion 4a and the second inclined portion 6a are non-parallel, the inclination angle of the first inclined portion 4a is smaller than the inclined angle of the second inclined portion 6a, and the first inclined portion 4a and the second inclined portion 6a are on the pump inner space 8a side. The second inclined portion 6a is non-contact. Even in such a form, there is an advantage that the first casing portion 4 and the second casing portion 9 can be aligned with high accuracy without being affected by the processing accuracy of the housing 46.

In the joint portion 50e shown in FIG. 8, a part of the surface of the first casing portion 4 also serves as the first flat surface portion 4b, and the first inclined portion 4a is provided radially outside the first flat surface portion 4b. .. The first inclined portion 4a is inclined downward from the surface of the first casing portion 4 toward the outer side in the radial direction. The second casing portion 9 (side wall portion 6) has a second flat surface portion 6b on the inner side in the radial direction, and has a second inclined portion 6a protruding downward in the radial direction from the second flat surface portion 6b. In the joint portion 50e, the inclined contact portion 51 is provided radially outside the plane contact portion 52. As described above, the inclined contact portion 51 is formed by press-fitting the first inclined portion 4a of the first casing portion 4 into the second inclined portion 6a of the side wall portion 6. Therefore, the degree of adhesion of the

inclined portions

4a and 6a in the inclined contact portion 51 is higher than the degree of adhesion of the

flat portions

4b and 6b in the planar contact portion 52. That is, the sealing property of the inclined contact portion 51 is higher than the sealing property of the flat contact portion 52. Further, as described above, a force is applied upward by the caulking portion 46a to the radial end portion of the first casing portion 4. In the joint portion 50e, the force applied from the caulking portion 46a is likely to be applied to the inclined contact portion 51 having a high sealing property, and the sealing property of the pump inner space 8a is more easily maintained.

In the joint portion 50f shown in FIG. 9, the first plane portion 4b is located above the surface of the first casing portion 4 (the lower surface of the pump inner space 8a). At the joint portion 50f, the second inclined portion 6a of the side wall portion 6 is press-fitted into the first inclined portion 4a of the first casing portion 4.

In the joint portion 50g shown in FIG. 10, a part of the surface of the first casing portion 4 also serves as the first flat surface portion 4b, and the first inclined portion 4a is provided radially outside the first flat surface portion 4b. .. The first inclined portion 4a is inclined upward from the surface of the first casing portion 4 toward the outer side in the radial direction. The second casing portion 9 (side wall portion 6) is provided with a second flat surface portion 6b on the inner side in the radial direction and a second inclined portion 6a on the outer side in the radial direction. The second inclined portion 6a is inclined upward from the second plane portion 6b toward the outer side in the radial direction. Similar to the joint portion 50e, the joint portion 50g is provided with the inclined contact portion 51 radially outward from the plane contact portion 52 (see also FIG. 8). Therefore, also in the joint portion 50g, the force applied from the caulking portion 46a is likely to be applied to the inclined contact portion 51 having a high sealing property, and the sealing property of the pump inner space 8a is further easily maintained.

The joint portion 50h shown in FIG. 11 includes an inclined contact portion 51, a first plane contact portion 52a, and a second plane contact portion 52b, similarly to the joint portion 50a (see also FIG. 4). However, the first plane contact portion 52a is located above the second plane contact portion 52b. In the joint portion 50h, the first casing portion 4 and the second casing portion 9 (side wall portion 6) are in contact with each other at three points, so that the pump internal space 8a can be satisfactorily sealed.

(Other embodiments)
In the above embodiment, the fuel pump in which the side wall portion (member forming the side surface of the pump inner space) is provided in the second casing portion has been described. However, the side wall portion may be provided on the first casing portion (a member provided with the fluid suction port).

Further, instead of the caulking portion provided on the housing, for example, a force may be applied upward to the first casing portion by sandwiching the first casing portion and the second casing portion with a clamp member or the like (first). A force may be applied to prevent the casing portion and the second casing portion from separating).

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.

Claims

The impeller driven by the motor and
Equipped with a pump casing that houses the impeller,
The pump casing has a first casing portion in which a fluid suction port for sucking fluid is provided in the pump casing and a second casing portion in which a fluid discharge port for discharging fluid from the inside of the pump casing is provided. And have
The first casing portion is provided with a first flat portion extending in a direction orthogonal to the rotation axis of the motor and a first inclined portion inclined with respect to the first flat portion.
The second casing portion is provided with a second flat portion extending in a direction orthogonal to the rotation axis of the motor and a second inclined portion inclined with respect to the second flat portion.
A fluid pump in which the space inside the pump casing in which the impeller is arranged is defined by the contact between the first flat surface portion and the second flat surface portion and the contact between the first inclined portion and the second inclined portion.
The fluid pump according to claim 1.
A housing that surrounds the outer circumference of the pump casing is provided in a direction orthogonal to the rotation axis.
The housing is a fluid pump that applies a force to the first casing portion and the second casing portion to prevent them from separating in the rotation axis direction.
The fluid pump according to claim 1 or 2.
A fluid pump in which the first inclined portion and the second inclined portion are parallel.