Electric pump

Abstract

To provide an electric pump that prevents the pump housing from shifting radially relative to the motor housing. [Solution] The electric pump comprises a shaft 12 extending in the axial direction, a rotatable rotor 13 located radially outward from the shaft 12, a stator 15 located radially outward from the rotor 13 and surrounding the rotor 13, a pump section 20 located on one axial side of the shaft 12, and a housing having a pump housing section 20h that accommodates the pump section 20. Furthermore, the pump housing section 20h has a support section 23 that supports the axial end 12b of the shaft 12.

Description

Technical Field

[0001] The present invention relates to an electric pump.

Background Art

[0002] Conventionally, an electric pump in which a pump section is connected to a motor section is known. As shown in, for example, Patent Document 1 below, the electric pump has a pump housing that houses a pump and a motor housing that houses a rotor, a stator, etc. Then, the opening of the pump housing is abutted against the opening of the motor housing and combined, and they are connected with bolts or the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a structure in which the housing of the pump section and the housing of the motor section are composed of separate members and combined, when vibration, external force, etc. are applied, the position of the housing of the pump section may shift radially with respect to the housing of the motor section and the rotor. If the housing of the pump section shifts, it may interfere with the impeller of the pump section or the like, or may have an adverse effect on the pump performance. Further, if the housing of the pump section shifts, the sealing performance with the housing of the motor section may decrease. Therefore, an object of the present invention is to provide an electric pump that can prevent the housing of the pump section from shifting radially with respect to the housing of the motor section.

Means for Solving the Problems

[0005] One embodiment of the electric pump according to the present invention comprises a motor section having a shaft extending in the axial direction, a rotatable rotor located radially outward from the shaft, and a stator surrounding the rotor; a pump section located on one axial side of the shaft; and a housing covering the motor section and the pump section, wherein the housing comprises a first housing located on the motor section side and a second housing located on the pump section side, and the second housing has a shaft fitting portion that fits with the axial end of the shaft on one side. [Effects of the Invention]

[0006] According to one aspect of the present invention, it is possible to prevent the housing of the pump section from shifting radially relative to the housing of the motor section. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a perspective view of an electric pump according to one embodiment, viewed from the other side in the axial direction. [Figure 2] Figure 2 is a cross-sectional view of an electric pump according to one embodiment, cut along its central axis. [Figure 3] Figure 3 is a perspective view showing the electric pump of one embodiment shown in Figure 1 with the control unit removed. [Figure 4] Figure 4 is a perspective view of the first housing of one embodiment, viewed from one axial side. [Figure 5] Figure 5 is an exploded perspective view of a partition wall member of one embodiment, viewed from the other side in the axial direction. [Figure 6] Figure 6 is a perspective view of a partition wall member of one embodiment, viewed from one axial direction. [Figure 7] Figure 7 is a magnified view of section A in Figure 2. [Figure 8] Figure 8 is a magnified view of section B in Figure 2. [Figure 9] Figure 9 is a perspective view of a partition wall member of one embodiment, viewed from the other side in the axial direction. [Figure 10]Figure 10 is a perspective view of the second housing of one embodiment, which houses the pump unit, viewed from the other axial side. [Figure 11] Figure 11 is a perspective view of the second housing of one embodiment, viewed from one axial side. [Figure 12] Figure 12 is an exploded perspective view of the pump section and the second housing of one embodiment, viewed from the other axial side. [Figure 13] Figure 13 is a magnified view of section C in Figure 2. [Figure 14] Figure 14 is a magnified view of part A of Figure 13. [Modes for carrying out the invention]

[0008] Hereinafter, embodiments of the electric pump 100 of this disclosure will be described with reference to the attached drawings. Each figure virtually shows the central axis J of the electric pump 100 of this embodiment. In the following description, the axial direction of the central axis J will be simply referred to as the "axial direction," the radial direction centered on the central axis J will be simply referred to as the "radial direction," and the circumferential direction centered on the central axis J will be simply referred to as the "circumferential direction." The Z-axis shown in each figure indicates the direction in which the central axis J extends.

[0009] Furthermore, in the description of this embodiment, in order to make it easier to understand the configuration of each part, the direction in which the Z-axis arrow points (upper side in the figure) will be referred to as the "other axial side." Note that the "other axial side" may sometimes be simply referred to as the "upper side." Also, in the description of this embodiment, the direction opposite to the direction in which the Z-axis arrow points will be referred to as the "one axial side." Note that the "one axial side" may sometimes be simply referred to as the "lower side." In the description of this embodiment, the upper side and lower side are convenient terms used to explain the relative positional relationship of each part. The actual arrangement may be different from the arrangement indicated by these terms.

[0010] The electric pump 100 in this embodiment, shown in Figures 1 and 2, is, for example, a water pump for cooling that sends water as a fluid (refrigerant), or an oil pump for cooling that sends oil as a fluid (refrigerant). Figure 1 is a perspective view of the electric pump 100 from diagonally above. Figure 2 is a cross-sectional view of the electric pump 100 cut along the central axis J.

[0011] The electric pump 100 of this embodiment includes a motor unit 10, a pump unit 20 located on one axial side (below) of the motor unit 10, a control unit 30 located on the other axial side (above) of the motor unit 10, and a housing H. The motor unit 10, the pump unit 20, and the control unit 30 are housed in a metal housing H. The housing H includes a first housing 11 that houses the motor unit 10, a second housing 21 that houses the pump unit 20, and a third housing 31 that houses the control unit 30. The configurations of the motor unit 10, the pump unit 20, and the control unit 30 will be described in detail below.

[0012] (Motor section 10) As shown in Figure 2, the motor unit 10 includes a shaft 12 located on the central axis J and extending in the direction of the central axis J (axial direction), a rotor 13 located radially outward from the shaft 12, and a stator 15 surrounding the rotor 13. The motor unit 10 is housed in a motor housing section 11h (Figure 4) within the first housing 11. Figure 4 is a perspective view of the first housing 11 from below.

[0013] As shown in FIG. 3, the first housing 11 has a cylindrical outer shell 11a and an upper part 11b provided above the outer shell 11a. The upper part 11b is a disc-shaped member. FIG. 3 is a perspective view showing a state in which the control unit 30 is removed from the electric pump 100 shown in FIG. 1. As shown in FIG. 4, the first housing 11 has a first opening 11k that opens toward the pump unit 20 side. A flange 11m extending radially outward is formed at the edge of the first opening 11k. The flange 11m is formed along the circumferential direction of the edge of the first opening 11k. A first surface 11n facing the pump unit 20 side is formed on the flange 11m. The first surface 11n is a flat surface without steps except for a groove for accommodating an O-ring. Further, a plurality of screw holes 11p are formed in the flange 11m. The screw holes 11p are formed at a plurality of predetermined intervals along the circumferential direction of the flange 11m.

[0014] As shown in FIG. 3, a shaft fixing portion 11c is formed on the upper part 11b of the first housing 11. The other end (upper end) in the axial direction of the shaft 12 is fixed to the shaft fixing portion 11c. The shaft fixing portion 11c is composed of a shaft fixing hole h1 formed at the center of the upper part 11b. As shown in FIG. 7, the upper end portion of the shaft fixing hole h1 has a larger diameter compared to the other portions of the shaft fixing hole h1, and an annular first step portion s1 is formed by the enlarged diameter portion. FIG. 7 is a partially enlarged view showing part A of FIG. 2.

[0015] As shown in Fig. 7, a second stepped portion 12a that spreads in a flange shape is formed at the other axial end (upper end) of the shaft 12. The second stepped portion 12a of the shaft 12 has a larger diameter compared to other portions of the shaft 12. The shaft 12 is inserted and fixed into the shaft fixing hole h1. When the shaft 12 is inserted and fixed into the shaft fixing hole h1, the second stepped portion 12a of the shaft 12 faces the first stepped portion s1 in the axial direction. More specifically, the second stepped portion 12a is in contact with the first stepped portion s1 in the axial direction. Since the second stepped portion 12a of the shaft 12 is in contact with the first stepped portion s1 in the axial direction, it is possible to prevent the shaft 12 from moving (shifting) to the one axial side (lower side) even when a pulling force acts on the shaft 12 to the one axial side (lower side). The fixing of the shaft 12 to the shaft fixing portion 11c is performed by press-fitting.

[0016] As shown in Fig. 2, a cylindrical rotor 13 is arranged on the outer side in the radial direction of the shaft 12 so as to surround the shaft 12. The rotor 13 is rotatable about the shaft 12. The rotor 13 includes a rotor core 13a, a magnet 13b, a rotor support plate 13c, a rotor support shaft 13d, and a rotor cover 13f. The rotor core 13a is formed by laminating dozens of laminated steel plates (electromagnetic steel plates).

[0017] The rotor support plates 13c are located above and below the rotor core 13a. The rotor support plates 13c sandwich the magnet 13b and the rotor core 13a from above and below. The rotor cover 13f covers the sides of the rotor core 13a. The rotor cover 13f and the two rotor support plates 13c isolate the rotor core 13a from fluids (refrigerants) such as water (waterproofing). The rotor support shaft 13d is cylindrical and extends in the axial direction. The rotor support shaft 13d is rotatably mounted on the shaft 12 via a bearing 14. In this embodiment, the bearing 14 is a sliding bearing. The impeller body 20a of the pump unit 20 is connected to the lower end of the rotor support shaft 13d. The connection between the rotor support shaft 13d and the impeller body 20a of the pump unit 20 is made by press-fitting and welding. Press-fitting ensures centering, while welding ensures connection strength. The configuration of the rotor support shaft 13d and the impeller body 20a of the pump section 20 will be described later.

[0018] A stator 15 is positioned radially outward of the rotor 13, surrounding the rotor 13. The stator 15 is assembled to the inner circumferential surface of the first housing 11 by shrink-fitting. The stator 15 has a stator core 15a, an insulator 15b attached to the stator core 15a, and a plurality of coils 15c attached to the stator core 15a via the insulator 15b. The stator core 15a is constructed by stacking dozens of ring-shaped laminated steel sheets (electromagnetic steel sheets). A coil winding section is formed inside the stator core 15a for winding each coil 15c. The coil winding section extends from the stator core 15a toward the center.

[0019] The insulator 15b is made of a protective material such as resin. The insulator 15b covers the surface of the stator core 15a. In other words, the insulator 15b protects the coils 15c by covering the inner circumferential surface of the cylindrical stator core 15a and the surface of each coil winding section. The coils 15c are made of metal windings such as copper or aluminum. The coils 15c are wound around each coil winding section of the stator core 15a.

[0020] The coil lead wires 15d of coil 15c are connected to a busbar assembly 19 located above the stator 15. The busbar assembly 19 is connected to a control unit 30, which supplies three-phase AC power to each coil 15c. The energization from the busbar assembly 19 to each coil 15c generates a magnetic flux inside each coil 15c. The busbar assembly 19 will be described further later.

[0021] A partition wall member 16, which serves as a sealing member, is provided between the rotor 13 and the stator 15. Figure 5 is a perspective view of the partition wall member 16 from above. As shown, the partition wall member 16 has a shape like an inverted cup, and the upper part of the partition wall member 16 (first partition wall 16a) is supported by the shaft 12. The partition wall member 16 has a disc-shaped first partition wall 16a located on the upper side, a cylindrical second partition wall 16b extending downward from the outer peripheral edge of the first partition wall 16a, and a third partition wall 16c extending radially outward from the peripheral edge of the second partition wall 16b. The connection portion 16p between the second partition wall 16b and the third partition wall 16c is machined into a rounded shape. The partition wall member 16 is made of a metal or resin that has sealing properties. Figure 6 is a perspective view of the partition wall member 16 from below. Although it was explained that the partition member 16 has the shape of an inverted cup, it could also be said that the partition member 16 is hat-shaped.

[0022] A fourth partition wall 16d is provided on the periphery of the third partition wall 16c, extending upward. Furthermore, a flange-shaped fixing portion 16e is provided on the periphery of the fourth partition wall 16d, extending radially outward. The first partition wall 16a, the second partition wall 16b, the third partition wall 16c, the fourth partition wall 16d, and the fixing portion 16e form a continuous structure. Multiple holes 16f for passing screws (bolts) are formed in the fixing portion 16e. In this embodiment, six holes 16f are formed. The holes 16f are provided on the radially outward side of the fixing portion 16e.

[0023] As shown in Figure 5, multiple reinforcing members 16g are provided on the outer surface of the second partition wall 16b, connected to the upper surface of the third partition wall 16c. The reinforcing members 16g are provided at predetermined intervals in the circumferential direction of the second partition wall 16b. In this embodiment, the reinforcing members 16g are reinforcing ribs. The shape of the reinforcing rib 16g is a right triangle when viewed from the circumferential direction. The parts corresponding to opposite sides of the reinforcing rib 16g are connected to the outer surface of the second partition wall 16b. The parts corresponding to adjacent sides are connected to the upper surface of the third partition wall 16c. The parts corresponding to the right angles are chamfered to match the rounded shapes of the second partition wall 16b, the third partition wall 16c, and the connecting part 16p. The second partition wall 16b and the third partition wall 16c are connected at a right angle at the connecting part 16p.

[0024] The reinforcing ribs 16g are positioned between the coils 15c that make up the stator 15. Multiple reinforcing ribs 16g maintain the right-angle connection between the second partition wall 16b and the third partition wall 16c. If the partition wall member 16 is made of metal, the reinforcing ribs 16g are made of metal and connected to the partition wall member 16 by welding or adhesive. If the partition wall member 16 is made of resin, the reinforcing ribs 16g may be made of metal or resin. If the partition wall member 16 is made of resin and the reinforcing ribs 16g are made of metal, the reinforcing ribs 16g can be integrally molded and assembled when the partition wall member 16 is molded in a mold. If the partition wall member 16 is made of resin and the reinforcing ribs 16g are also made of resin, the reinforcing ribs 16g can be molded simultaneously when the partition wall member 16 is molded in a mold, or the reinforcing ribs 16g can be provided as a separate component and joined to the partition wall member 16 by welding. The metal reinforcing ribs 16g are positioned near the coil 15c, allowing heat transferred from the coil 15c through the space to be dissipated to the fluid located inside the partition member 16. The resin reinforcing ribs 16g can be molded simultaneously with the partition member 16 when it is molded in a mold, thus reducing costs.

[0025] A through-hole 16h for the shaft 12 is formed in the center of the first partition wall 16a. A cylindrical mounting body 16j is provided on the periphery of the through-hole 16h so as to extend upward from the through-hole 16h. As shown in Figure 7, the first partition wall 16a is attached to the shaft 12 by passing the shaft 12 through the mounting body 16j and the through-hole 16h. Figure 7 is a partially enlarged view of part A in Figure 2. By attaching the first partition wall 16a to the shaft 12, the disc-shaped first partition wall 16a is positioned above the rotor 13 so as to extend radially outward from the shaft 12, and the first partition wall member 16a covers the upper side of the cylindrical rotor 13.

[0026] Furthermore, as shown in Figure 2, a second partition wall 16b, extending downward from the outer peripheral edge of the first partition wall 16a, is located between the rotor 13 and the stator 15, with the second partition wall 16b separating the rotor 13 and the stator 15. In addition, as shown in Figure 13, the lower side of the stator 15 is covered by a third partition wall 16c and a fourth partition wall 16d, which extend radially outward from the lower peripheral edge of the second partition wall 16b. The fourth partition wall 16d is fixed to the first housing 11 by a fixing portion 16e that extends radially outward in a flange-like manner from the fourth partition wall 16d. Figure 13 is a partially enlarged view showing section C of Figure 2. In other words, the lower side of the partition wall member 16 is fixed to the first housing 11 by the fixing portion 16e.

[0027] As shown in Figure 7, an O-ring mounting groove 16m is formed on the outer circumferential surface of the shaft 12 at the point where the shaft 12 fits into the mounting body 16j. An O-ring 16k is installed in the O-ring mounting groove. The O-ring 16k seals the space between the shaft 12 and the mounting body 16j. The partition member 16 appropriately separates the rotor 13 and the stator 15, sealing the space and preventing fluid from leaking from the rotor 13 to the stator 15. The second partition 16b does not contact either the rotor 13 or the stator 15. That is, as shown in Figure 8, a gap c1 is formed between the second partition 16b and the rotor 13. Also, a gap c2 is formed between the second partition 16b and the stator 15. Figure 8 is a partially enlarged view showing part B of Figure 2.

[0028] As shown in Figure 7, an auxiliary member 17 is positioned between the first partition wall 16a of the partition wall member 16 and the upper part 11b of the first housing 11. In Figure 7, the reference numeral f2 indicates the lower surface of the auxiliary member 17 (the contact surface that contacts the partition wall member 16). As shown in Figure 5, the auxiliary member 17 is disc-shaped. A through hole 17a is formed in the center of the auxiliary member 17. The mounting body 16j of the partition wall member 16 is inserted into the through hole 17a. In Figure 5, the reference numeral f1 indicates the top surface (the surface facing upwards) of the first partition wall 16a. By inserting the mounting body 16j into the through hole 17a, as shown in Figure 7, the top surface f1 of the first partition wall 16a and the contact surface f2 of the auxiliary member 17 are in contact with each other across their entire surfaces. Figure 9 is a perspective view showing the state in which the mounting body 16j of the partition wall member 16 is inserted into the through hole 17a of the auxiliary member 17 (the state in which the auxiliary member 17 is assembled on top of the partition wall member 16).

[0029] Furthermore, as shown in Figure 7, an annular recess 17b is formed on the upper surface of the auxiliary member 17. The recess 17b is formed by an annular guide wall w1 that surrounds the through hole 17a, with the through hole 17a at its center. The guide wall w1 is a wall that extends in the Z direction. The surface f3 enclosed by the guide wall w1 and facing the other side in the axial direction is the surface that receives the tip of the screw 18 (the lower end of the screw 18 in Figure 7). The surface f3 that receives the tip of the screw 13 may also be called the receiving surface f3. As shown in Figure 7, an annular space (gap) S is formed around the guide wall w1.

[0030] The lower surface (bottom surface) of the upper part 11b of the housing 11 is provided with a protrusion 11d that projects downward. The protrusion 11d is located below the shaft fixing part 11c. The protrusion 11d is annular. The protrusion 11d has a shaft fixing hole h1 in its center. As shown in Figure 7, the annular protrusion 11d is fitted into the annular recess 17b of the auxiliary member 17. In this fitting, the radial gap between the protrusion 11d and the recess 17b is very small. Because the protrusion 11d is fitted into the recess 17b, the auxiliary member 17 does not rattle radially. The protrusion 11d and the recess 17b are in a so-called spigot joint state. As shown by the white arrow (bidirectional arrow) in Figure 7, the auxiliary member 17 is movable axially (in the +Z direction and -Z direction) along the protrusion 11d.

[0031] Furthermore, as shown in Figure 3, the shaft fixing portion 11c of the housing 11 has multiple screw holes 11f that penetrate the upper part 11b of the housing 11 in the Z direction. Multiple screw holes 11f are formed in the circumferential direction with the shaft fixing hole h1 as the center. In this embodiment, three screw holes 11f are formed at equal intervals in the circumferential direction. A screw 18, which serves as a retaining member, is screwed into each screw hole 11f. As shown in Figure 5, the screw 18 is a headless micro-screw such as a fully threaded bolt or a plunger, and the entire screw 18 can be embedded in the screw hole 11f.

[0032] The lower end of the screw 18 is machined to have a chamfered or hemispherical shape. As shown in Figures 7 and 9, the lower end of the screw 18 protrudes downward from the screw hole 11f, and the lower end surface of the screw 18 is in contact with the receiving surface f3 of the recess 17b of the auxiliary member 17. A hexagonal hole or a star-shaped hole is formed at the other axial end (upper end) of the screw 18. A tool such as a hexagonal wrench or a star-shaped wrench can be inserted into the hexagonal or star-shaped hole. The screw 18 is screwed into the screw hole 11f from above the shaft fixing part 11c using a tool such as a hex wrench. At this time, whether or not the tip of the screw 18 is in contact with the receiving surface f3 of the recess 17b of the auxiliary member 17 can be determined, for example, by detecting a change in the screwing torque of the screw 18. In addition, whether or not the contact pressure (pressing force) between the tip (lower end) of the screw 18 and the receiving surface f3 is appropriate can also be determined by detecting a change in the screwing torque of the screw 18.

[0033] As shown in Figure 2, a gap S is formed around the auxiliary member 17. The gap S is an annular space centered on the shaft 12. The gap S is formed by the guide wall w1 of the auxiliary member 17, the upper part 11b of the first housing 11, the outer shell 11a of the first housing 11, and the other axial surface (top surface) of the stator 15. The busbar assembly 19 is housed in a radially outer position within the gap S, that is, near the inner surface of the outer shell 11a of the first housing 11.

[0034] The busbar assembly 19 has an annular assembly body 19a extending along the inner surface of the outer shell 11a of the first housing 11, a coil connection portion 19b, and a substrate-side projection 19c. The coil connection portion 19b and the substrate-side projection 19c are paired. In this embodiment, three such pairs are provided. The coil connection portion 19b includes a busbar (conductive rod) connected to a coil lead wire 15d extending from the coil 15c of the stator 15. As shown in Figure 2, the coil connection portion 19b is positioned radially inward, that is, toward the guide wall w1 of the auxiliary member 17.

[0035] By positioning the coil connection portion 19b radially inward, the tip of the coil connection portion 19b overlaps with the rotor 13 and the auxiliary member 17 when viewed from the axial direction. Because the coil connection portion 19b overlaps with the rotor 13 and the auxiliary member 17, there is no need to expand the air gap S that accommodates the coil connection portion 19b in the radial direction. By housing the coil connection portion 19b and the auxiliary member 17 in the air gap S, the radial miniaturization of the first housing 11 can be achieved. The air gap S is a space formed in the axial direction. By effectively utilizing the air gap S, the radial miniaturization of the first housing 11 is achieved. Furthermore, since the coil connection portion 19b is positioned lower than the height of the guide wall w1 of the auxiliary member 17, it is possible to suppress the axial enlargement of the first housing 11.

[0036] As shown in Figures 2 and 3, the substrate-side protrusion 19c is positioned inside the through-hole 11g formed in the upper part 11b of the first housing 11. In this embodiment, three through-holes 11e are formed in the upper part 11b of the first housing 11. A substrate-side protrusion 19c is positioned in each through-hole 11g. The substrate-side protrusion 19c is provided with a connection terminal 19d that connects to the busbar of the coil connection part 19b. As shown in Figure 3, the connection terminal 19d protrudes upward from the substrate-side protrusion 19c. Because the connection terminal 19d protrudes upward from the substrate-side protrusion 19c, when the control unit 30 is assembled to the upper part 11b of the first housing 11, the tip of the connection terminal 19d is electrically connected to the control unit 30.

[0037] (Pump section 20) As shown in Figures 2 and 13, the pump unit 20 is housed in a pump housing 20h located below the motor unit 10. As shown in Figure 10, the pump unit 20 is positioned in the center of the second housing 21 that forms the pump housing 20h. The second housing 21 has a support portion 23 that supports the lower end 12b of the shaft 12. Figure 10 is a perspective view of the pump unit 20 seen from above, Figure 11 is a perspective view of the second housing 21 that houses the pump unit 20 seen from below, and Figure 12 is an exploded perspective view of the second housing 21 and the pump unit 20 seen from the other axial side (above).

[0038] As shown in Figure 10, the second housing 21 has a second opening 21a facing the +Z direction. A flange 21m extending radially outward is provided on the edge (outer circumference) of the second opening 21a. A second surface 21n facing the +Z direction is formed on the flange 21m. The second surface 21n is a flat surface without any steps. In addition, a plurality of bolt holes 21p are formed on the flange 21m. The bolt holes 21p are formed at predetermined intervals in the circumferential direction of the flange 21m. In this embodiment, six bolt holes 21p are formed.

[0039] As shown in Figure 2, the flange 21m of the second housing 21 and the flange 11m of the first housing 11 are fastened together by bolts 24, with the fixing portion 16e of the bulkhead member 16 in between. O-rings 11j, 11j are located above and below the fixing portion 16e of the bulkhead member 16, respectively. As shown in Figure 13, the fastening of the flange 21m of the second housing 21 and the flange 11m of the first housing 11 results in the second surface 21n of the flange 21m and the first surface 11n of the flange 11m being in surface contact with each other, with the fixing portion 16e of the bulkhead member 16 in between.

[0040] By sandwiching the fixing portion 16e of the partition member 16 between the flange 11m of the first housing 11 and the flange 21m of the second housing 21, and fixing the flange 21m to the flange 21m, the fixing portion 16e (lower side of the partition member 16) of the partition member 16 can be fixed to the housing H. In other words, as described above, the upper side of the partition member 16 (first partition 16a) is fixed to the shaft 12, and the lower side of the partition member 16 (fixing portion 16e) is fixed to the housing H. By fixing the upper side of the partition member 16 to the shaft 12 and the lower side of the partition member 16 to the housing H, the rigidity and shape stability of the partition member 16 are improved. Improved rigidity and shape stability make it possible to make the partition member 16 thinner. Furthermore, since O-rings 11j, 11j are located above and below the fixing portion 16e of the partition member 16, the fixing portion 16e (the lower side of the partition member 16) can be sealed.

[0041] Furthermore, as shown in Figures 2 and 11, the second housing 21 has an inlet 25 connected to the pump housing 20h and a discharge port 26 located on the outer circumference of the pump housing 20h. The inlet 25 consists of a pipe 25a located coaxially with the central axis J. The inlet 25 is located on one axial end (lower end) of the shaft 12. The inlet 25 is connected to a fluid supply passage (not shown) and draws fluid from the fluid supply passage into the center of the pump housing 20h. The diameter of the inlet 25 is the same as that of the discharge port 26. The inlet 25 is provided with a support portion 23, which will be described later.

[0042] The discharge port 26 consists of a pipe 26a located parallel to the central axis J. The pipe 26a (discharge port 26) is located outside the flange 21m of the second housing 21. The lower side of the pipe 26a is open (open in the -Z direction), as shown in Figures 2 and 11. The upper side of the pipe 26a is closed. A communication port 26b is formed on the side of the pipe 26a. The communication port 26b is connected to the outlet side of the discharge flow path 21j in the pump housing 20h. The lower end of the pipe 26a (discharge port 26) is connected to a flow path (not shown), and discharges the fluid in the pump housing 20h into that flow path.

[0043] As shown in Figure 11, the discharge channel 21j is formed along the circumferential direction of the outer circumference of the second housing 21. The discharge channel 21j is formed as part of the second housing 21. The discharge channel 21j forms the inner surface of the pump housing 20h (Figure 10). As shown in Figure 2, the cross-section (cross-section perpendicular to the direction of fluid flow) of the discharge channel 21j is semicircular. The semicircular discharge channel 21j forms a curved section leading to the outermost diameter of the second housing 21. The discharge channel 21j collects the fluid sent radially outward from the pump section 20 and directs the fluid toward the discharge port 26.

[0044] As shown in Figures 12 and 13, the bottom 21c of the second housing 21 is flat. The outer circumference of the bottom 21c is connected to the inner circumference of the discharge passage 21j. A tubular projection 21d is provided in the center of the bottom 21c, which is connected to the pipe body 25a of the inlet 25. The projection 21d extends downward from the center of the bottom 21c. An inner groove 21e is formed inside the projection 21d along the circumferential direction. Since the inner diameter of the inner groove 21e is larger than the inner diameter of the pipe body 25a, the connection between the inner groove 21e and the pipe body 25a is stepped. Part of the pump section 20 is located in the inner groove 21e. The second housing 21 also has a curved section from the inlet 25 to the outermost flange 11m side.

[0045] As shown in Figures 10 and 13, a stepped portion 21f is formed on the upper inner circumference of the second housing 21 along the circumferential direction of the second housing 21. The stepped portion 21f has a first wall surface 21g facing radially inward and a second wall surface 21h facing in the other axial direction. The first wall surface 21g constitutes the inner circumferential surface of the flange 21m of the second housing 21. The first wall surface 21g is continuous with the second surface 21n of the flange 21m. The second wall portion 21h is located above the discharge passage 21j.

[0046] The third partition wall 16c and the fourth partition wall 16d of the partition wall member 16 are located on the stepped portion 21f. More specifically, as shown in Figure 13, the third partition wall 16c of the partition wall member 16 is located on the second wall surface 21h, and the fourth partition wall 16d of the partition wall member 16 is located on the first wall surface 21g. The lower portion of the partition wall member 16 (the third partition wall 16c and the fourth partition wall 16d) is located on the stepped portion 21f, thereby ensuring the shape stability of the lower portion of the partition wall member 16.

[0047] As shown in Figure 2, the pump section 20 is connected to the lower side of the rotor 13. In this embodiment, the pump section 20 is an impeller. In this embodiment, the impeller constituting the pump section 20 is made of metal. However, the impeller may be made of resin. As shown in Figure 12, the pump section 20 has an impeller body 20a, a shroud 20b, and a plurality of blades 22c. The impeller body 20a is disc-shaped with a central axis J at its center. A first through hole 20d is formed in the center of the impeller body 20a. A cylindrical fitting body 20e extending upward is formed on the edge of the first through hole 20d.

[0048] As shown in Figure 13, the pump unit 20 is connected to the rotor support shaft 13d of the rotor 13, so that the pump unit 20 rotates in conjunction with the rotation of the rotor 13. More specifically, one axial end (lower end) 13e of the sleeve-shaped rotor support shaft 13d is press-fitted into the inside of the fitting body 20e of the impeller body 20a. Furthermore, this fitting portion is welded. The impeller body 20a and the rotor support shaft 13d are connected by press-fitting and welding. The inner diameter of the fitting body 20e is approximately the same as or slightly smaller than the inner diameter of the pipe body 25a of the intake port 25.

[0049] As shown in Figure 12, the shroud 20b is a separate component from the impeller body 20a. The shroud 20b is positioned below the impeller body 20a with a gap between them. The shroud 20b is a disc shape, almost identical in shape to the impeller body 20a. A second through-hole 20f is formed in the center of the shroud 20b. A cylindrical guide body 20g extending downward is provided at the edge of the second through-hole 20f. Reference numeral 20j indicates the connection portion between the second through-hole 20f and the guide body 20g. The connection portion 20j has a rounded shape to smooth the fluid flow. As shown in Figure 13, the inner diameter of the guide body 20g is the same as the inner diameter of the pipe 25a of the intake port 25.

[0050] As shown in Figure 13, the guide body 20g is positioned to fit into an annular inner groove 21e formed inside the projection 21d of the intake port 25. However, since the guide body 20g rotates together with the shroud 20b, it does not come into contact with the inner groove 21e. In other words, there is a radial gap between the guide body 20g and the inner groove 21e. Also, the lower surface of the shroud 20b faces the bottom 21c of the second housing 21, but does not come into contact with the bottom 21c. In other words, there is an axial (Z-direction) gap between the lower surface of the shroud 20b and the bottom 21c.

[0051] As shown in Figure 12, the impeller body 20a is spaced axially apart from the shroud 20b, and the blades 20c are located between the impeller body 20a and the shroud 20b. The blades 20c are strip-shaped metal pieces curved in one direction. In this embodiment, seven blades 20c are arranged at regular intervals in the circumferential direction, with the same curvature direction for each blade 20c. Each blade 20c extends from the second through-hole 20f of the shroud 20b to the outer edge of the shroud 20b. The bottom of each blade 20c is fixed to the shroud 20b by welding. The top of each blade 20c is also fixed to the impeller body 20a by welding. The impeller body 20a and the shroud 20b are connected to each other via multiple blades 20c.

[0052] As the rotor 13 rotates, the pump unit (impeller) 20 rotates, and the centrifugal force of the pump unit 20 pushes the fluid in the pump housing 20h outwards to the outer circumference of the pump unit 20, where it is discharged through the discharge channel 21j and out of the discharge port 26 (OUT in Figure 2). When fluid is discharged from the discharge port 26, a negative pressure is created inside the pump housing 20h, causing fluid to be drawn into the pump housing 20h from the intake port 25 (IN in Figure 2). Fluid is continuously pumped out of the pump unit 20 by a similar action. The inside of the pump housing 20h and the space in which the rotor 13 is housed are in communication. Therefore, as the pump unit 20 rotates, some of the fluid in the pump housing 20h flows into the rotor 13. However, since the rotor 13 and the stator 15 are separated and sealed by the partition member 16, the fluid inside the rotor 13 does not flow (leak) into the stator 15. Furthermore, pressure fluctuations constantly occur within the pump housing 20h due to the fluid flow (discharge and suction). These pressure fluctuations also act on the partition wall member 16 facing the inside of the pump housing 20h.

[0053] As shown in Figures 2 and 13, a support portion 23 is positioned at the axial center of the pump section 20. The support portion 23 supports the lower end 12b of the shaft 12 (one side in the axial direction). The support portion 23 has a shaft fitting portion 23a and a plurality of support legs 23b. As shown in Figures 13 and 14, the shaft fitting portion 23a is located inside the fitting body 20e of the impeller body 20a. A first recess 23c is formed on the end face of the shaft fitting portion 23a on the other side in the axial direction (upper side), recessing toward the one side in the axial direction (lower side). The end portion 12b of the shaft 12 is fitted into the first recess 23c. Figure 14 is a partially enlarged view showing part A of Figure 13.

[0054] The first recess 23c is shaped to match the outer shape of the end 12b of the shaft 12. As can be seen from Figure 12, the outer shape of the end 12b of the shaft 12 consists of a circular cross-section and a notch (flat section) 12d. Therefore, the shape of the first recess 23c is shaped to match the circular cross-section and the notch 12d. If the end 12b of the shaft 12 is polygonal, the first recess 23c will also have a shape that matches the polygon. If the end 12b of the shaft 12 has a projection or keyway, the first recess 23c will also have a shape that matches the projection or keyway. Furthermore, the end 12b of the shaft 12 may be machined to snap-fit ​​into the first recess 23c. In this case, the two are joined simply by fitting the end 12b of the shaft 12 into the first recess 23c. In addition, the first recess 23c may be not just a simple hole, but may also have a stepped section created by cutting a wide groove.

[0055] As shown in Figures 12 and 14, a washer 14a is provided between the shaft fitting portion 23a and the bearing 14. The washer 14a prevents the bearing 14, which rotates with the rotor 13, from directly contacting and wearing down the fixed fitting portion 23a. Furthermore, as shown in the figures, a linear projection 14b is formed on a part of the inner circumference of the washer 14. This projection 14b is positioned so that when the end 12b of the shaft 12 passes through the washer 14, it fits into a notch 12d on the end 12b of the shaft 12. Because the projection 14b of the washer 14a is positioned on the notch 12d, the notch 12d also functions as an anti-rotation device for the washer 14a (preventing the washer 14a from rotating together).

[0056] As shown in Figure 14, a second recess 12c extending in the axial direction is formed at the end 12b of the shaft 12. In this embodiment, the second recess 12c is a screw hole. A fixing member 22, which fixes the shaft fitting portion 23a to the end 12b of the shaft 12, is screwed into the screw hole 12c. In this embodiment, the fixing member 22 is a screw or a bolt. A through hole 23e connected to the first recess 23c is formed in the center of the shaft fitting portion 23a. The through hole 23e is located below the first recess 23c. The fixing member (screw) 22 is screwed into the through hole 23e from one axial side (bottom side) to the other axial side (top side). The screw 22 has a screw head 22b at one axial end (bottom end). The screw head 22b has a screw end face 22a facing the other axial side (top side).

[0057] As shown in Figure 14, when the screw 22 is screwed into the screw hole 12c of the end 12b of the shaft 12 from the lower side of the through hole 23e, the screw head 22b comes into contact with the first end face 23g of the shaft fitting portion 23a. The first end face 23g is oriented axially to one side (downward) so as to face the screw end face 22a of the screw head 22b. In addition, an axial gap s3 is formed between the second end face 23h of the first recess 23c of the shaft fitting portion 23a and the end face 12e of the end 12b of the shaft 12. The second end face 23h is oriented axially to the other side (upward) so as to face the end face 12e of the end 12b of the shaft 12.

[0058] The screw head 22b of the screw 22 has a hole 22e (hexagonal hole, star-shaped hole, etc.) into which a tool for turning (screwing in) the screw 22 can be fitted. Tools such as hex wrenches and star wrenches can be fitted into the hole 22e. When the screw 22 is screwed into the screw hole 12c of the end 12b of the shaft 12 using a tool such as a hex wrench, and the support part 23 is fixed to the end 12b of the shaft 12, the end 12b of the shaft 12 is pulled toward the support part 23 (tension acts on the end 12 of the shaft 12 in the -Z direction). In other words, when the screw 22 is tightened, a force is generated in the axial direction that brings the end 12b of the shaft 12 and the support part 23 closer together. As shown in Figure 13, since the intake port 25 is located on the extension of one side of the axial direction of the screw 22, the screw 22 can be screwed into the end 12b of the shaft 12 using the intake port 25.

[0059] As shown in Figure 13, the shaft fitting portion 23a is supported by a plurality of support legs 23b located below the shaft fitting portion 23a. In this embodiment, three support legs 23b support the shaft fitting portion 23a. As shown in Figure 13, the support legs 23b extend from the inner wall surface of the pipe body 25a of the suction port 25 to the other axial direction. More specifically, the support legs 23b extend diagonally upward for a predetermined length from the inner wall surface of the pipe body 25a of the suction port 25, and then extend parallel to the central axis J. The upper ends of the support legs 23b pass through the first through hole 20d and the second through hole 20f of the pump section 20, respectively, and are connected to the first end face 23g of the shaft fitting portion 23a. In this embodiment, the three support legs 23b are arranged at equal intervals (120°) in the circumferential direction of the pipe body 25a with respect to the central axis J.

[0060] As shown in Figure 13, the end 12b of the shaft 12 is located above (on the other axial side) the third partition wall 16c of the partition wall member 16. In other words, the end 12b of the shaft 12 does not reach the pump section 20. Therefore, the shaft fitting portion 23a that supports the end 12b of the shaft 12 is located above (on the other axial side) the third partition wall 16c of the partition wall member 16, that is, it protrudes towards the motor housing portion 11h of the first housing 11.

[0061] In this embodiment, as shown in Figure 7, the second stage portion 12a of the shaft 12 is mounted on the shaft fixing portion 11c of the upper part 11b of the first housing 11. Therefore, as shown in Figure 13, the end portion 12b of the shaft 12 is fixed to the support portion 23 with a fixing member such as a screw 22. However, if the shaft 12 rotates together with the rotor 13, a bearing member may be newly attached to the support portion 23 instead of the screw 22. Also, the impeller constituting the pump portion 20 may be a trochoid pump, a gear pump, or a vane pump. Furthermore, in this embodiment, the shaft fitting portion 23a of the support portion 23 is located on the other axial side (upper side) of the pump portion 20, but the shaft 12 may be extended to be located on one axial side (lower side) of the pump portion 20.

[0062] (Control Unit 30) The control unit 30 supplies drive current to the motor unit 10. As shown in Figure 2, the control unit 30 includes a third housing 31 having a substrate housing chamber 30a, a substrate 32 housed in the substrate housing chamber 30a, and electronic components 33, etc. The third housing 31 is made of a metal such as aluminum or steel, which has excellent thermal conductivity. Cooling fins 31a and cable connection parts 31b are provided on the upper surface of the third housing 31. A sleeve 31c extending in one axial direction is formed on the lower side of the third housing 31. The sleeve 31c is fitted so as to cover the upper part 11b of the first housing 11 from the outside.

[0063] Electronic components 33 are mounted on the circuit board 32. The electronic components 33 include, for example, ICs, transistors, and capacitors. The electronic components 33 constitute a control circuit for controlling the electric pump 100. The circuit board 32 is mounted on the upper side of the upper part 11b of the first housing 11. Power is supplied from the circuit board 32 to the coil 15c of the stator 15 via the connection terminal 19d of the busbar assembly 19, thereby operating the stator 15.

[0064] (Effects / Actions) As shown in Figures 2 and 13, the electric pump 100 of this embodiment has a shaft fitting portion 23a in the second housing 21 located on the pump section 20 side, which fits with the axial end 12b of the shaft 12 on the motor section 10 side (lower side). By providing the shaft fitting portion 23a in the second housing 21, when the second housing 21 is assembled to the first housing 11, the shaft fitting portion 23a fits with the lower end 12b of the shaft 12. When the lower end 12b of the shaft 12 fits into the shaft fitting portion 23a, the shaft fitting portion 23a does not shift radially relative to the shaft 12. Because the radial shift of the shaft fitting portion 23a is eliminated, the position of the second housing 21 having the shaft fitting portion 23a also does not shift radially relative to the first housing 11 or the rotor 13. Since the shaft fitting portion 23a and the second housing 21 will not shift radially relative to the first housing or rotor 13, interference between the second housing and the pump section and a decrease in sealing performance can be prevented.

[0065] In this embodiment, the radial position of the second housing is determined by fitting the lower end 12b of the shaft 12 into the shaft fitting portion 23a of the second housing, thereby preventing radial displacement of the second housing. Therefore, it is not necessary to create a fitting structure between the first opening 11k of the first housing 11 shown in Figure 4 and the second opening 21a of the second housing 21 shown in Figure 10. Since it is not necessary to create a fitting structure between the first opening 11k and the second opening 21a, it is possible to provide grooves 11r (Figure 4) for assembling sealing members such as O-rings 11j while suppressing the radial size of each opening 11k and 21a. In addition, the surface 21n (Figure 10) of the second housing 21 assembled to the first housing 11 can be made of a flat surface, making it easy to process and reducing processing costs. Furthermore, since the number of times the tool contacts the surface during processing is reduced, it is easier to improve the accuracy of the processed surface, and the assembly accuracy when assembled to the first housing 11 is also improved.

[0066] In this embodiment, the shaft fitting portion 23a has a first recess 23c that is recessed on the upper side, and the shape of the first recess 23c matches the outer shape of the end portion 12b of the shaft 12. By matching the shape of the first recess 23c with the outer shape of the end portion 12b of the shaft 12, as shown in Figure 12, the outer shapes of the end portion 12b of the shaft 12 and the first recess 23c can be made not only circular in cross-section, but also notched 12d shape, polygonal shape, etc. If the shape of the end portion 12b of the shaft 12 and the first recess 23c are made notched 12d shape, polygonal shape, etc., it is possible to prevent the shaft fitting portion 23a from rotating circumferentially around the shaft 12 when the shaft fitting portion 23a is fitted to the end portion 12b of the shaft 12. By preventing the rotation of the shaft fitting portion 23a, the second housing 21 will not shift not only radially but also circumferentially relative to the first housing.

[0067] In this embodiment, as shown in Figure 14, a fixing member 22, such as a screw, is fixed to the second recess 12c of the end 12d of the shaft 12 by passing through the through hole 23e of the shaft fitting portion 23a. By fixing the shaft fitting portion 23a to the shaft 12 with the fixing member 22, it is possible to prevent the second housing 21 from shifting in the axial direction.

[0068] In this embodiment, as shown in Figure 14, the fixing member, the screw 22, passes through the through hole 23e of the shaft fitting portion 23a and is screwed into the screw hole 12c of the end portion 12d of the shaft 12. By screwing the screw 22 into the screw hole 12c of the shaft 12, the end portion 12d of the shaft 12 can be suitably fixed to the shaft fitting portion 23a. Furthermore, when the screw end face 22a of the screw 22 is in contact with the first end face 23g of the shaft fitting portion 23a, there is a gap s3 between the end face 23d of the shaft 12 and the second end face 23h of the shaft fitting portion 23a. Therefore, when the screw 22 is further tightened, the axial force of the screw 22 pulls the end portion 12b of the shaft 12 towards the shaft fitting portion 23a, generating tension between the shaft 12 and the shaft fitting portion 23a. The tension between the shaft 12 and the shaft fitting portion 23a increases the surface pressure between the second surface of the second opening 21a of the second housing 21 and the first surface 11n of the first opening 11k of the first housing 11. As the surface pressure increases, the second housing 21 is more firmly fixed to the first housing 11, thereby more effectively preventing displacement of the second housing 21 relative to the first housing 11 in any direction.

[0069] In this embodiment, as shown in Figure 3, the first housing 11 has an upper part 11b located above the stator 15 or rotor 13, and the upper part 11b has a shaft fixing part 11c, as shown in Figure 2. By fixing the end 12b of the shaft 12 to the shaft fixing part 11c, the shaft 12 will not detach (fall out) from the upper part 11b of the first housing 11 even if the shaft 12 is pulled by the axial force of the screw. Because the shaft 12 will not detach, the second housing 21 can be fixed to the first housing 11 with stronger tension, and thus the radial displacement of the second housing 21 can be more effectively prevented.

[0070] In this embodiment, as shown in Figure 7, the shaft fixing portion 11c has a first stage portion s1, and the upper end of the shaft 12 has a second stage portion 12a that faces the first stage portion s1 in the axial direction. Therefore, the second stage portion 12a of the shaft 12 is fixed so that it faces the first stage portion s1 of the shaft fixing portion 11c in the axial direction. Because the second stage portion 12a of the shaft 12 is fixed, even if the shaft 12 is pulled by the axial force of the screw 22, the end portion 12b of the shaft 12 will catch on the upper part 11b of the first housing 11, preventing it from coming off (falling out) from the shaft fixing portion 11c in one axial direction. Therefore, it is possible to increase the tension of the shaft 12, and the second housing 21 is fixed more strongly to the first housing 11. By fixing the second housing 21 more strongly to the first housing 11, it is possible to more effectively prevent the second housing 21 from shifting radially.

[0071] In this embodiment, as shown in Figure 2, the pump housing 20h has an intake port 25 located below the shaft fitting 23a. Therefore, the support portion 23 inside the pump housing 20h can be directly viewed from the intake port 25. By inserting a tool or the like while visually inspecting the inside of the pump housing 20h from the intake port 25, the installation and tightening of fixing members such as screws 22 to the shaft fitting portion 23a can be easily performed. The ease of installation and tightening allows for tightening of the screws 22 with strong axial force without requiring a high level of skill. The ease of tightening the screws 22 with strong axial force makes it possible to fix the second housing 21 more firmly to the first housing 11, thereby more effectively preventing the second housing 21 from shifting radially.

[0072] In this embodiment, as shown in Figure 13, the shaft fitting portion 23a is located on the other axial side (upper side) of the impeller body portion 23a that constitutes the pump portion 20. Therefore, the shaft fitting portion 23a does not obstruct the fluid flow in the pump portion 20 and does not adversely affect the pump performance. In other words, since the shaft fitting portion 23a is not present in the fluid flow path of the pump portion 20, the shaft fitting portion 23a does not act as resistance to the fluid flow. Alternatively, the shaft fitting portion 23a may be positioned on one axial side (lower side) of the pump portion 20. By shifting the shaft fitting portion 23a downwards from the pump portion 20, the shaft fitting portion 23a is no longer located within the pump portion 20, thereby suppressing adverse effects on the fluid flow in the pump portion 20.

[0073] In this embodiment, as shown in Figure 13, the shaft fitting portion 23a is located on the other axial side (above) of the impeller body portion 23a that constitutes the pump portion 20. Therefore, the shaft fitting portion 23a does not obstruct the fluid flow in the pump portion 20 and does not adversely affect the pump performance. Also, as shown in Figure 13, the fluid flows from the inlet 25 through the second through-hole 20f of the shroud 20b of the pump portion 20, and is carried by the blades 20c from the radially outer side of the pump portion 20 to the discharge passage 21j. Therefore, the shaft fitting portion 23a does not obstruct the fluid flow compared to the case where it is located in the center of the blades 20c. Furthermore, the support legs 23b that support the shaft fitting portion 23a have a shape that extends axially from the inner wall surface of the pipe body 25a of the inlet 25. In addition, the support legs 23b are arranged with a large gap in the circumferential direction. Therefore, the support legs 23b also do not obstruct the fluid flow.

[0074] In this embodiment, as shown in Figure 4, the first opening 11k of the first housing 11 has a planar first surface 11n including a flange 11m. On the other hand, the opening 21a of the second housing 21, which is assembled to the second opening 11k of the first housing 11, has a planar second surface 21n including a flange 21m. The first surface 11n and the second surface 21n are in contact on a planar surface. Therefore, as shown in Figure 3, it is possible to press the fixing portion 16e of the partition wall member 16 with the entire surface, and excellent sealing performance can be achieved. Furthermore, by making the first surface 11n and the second surface 21n planar, there is no need to provide a complex fitting structure (spigot) between the first opening 11k and the second opening 21a. In addition, the fixing portion 16e of the partition wall member 16 only needs to be flat like the first surface 11n and the second surface 21n, and does not require a special shape or special precision.

[0075] The embodiments described above should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the embodiments described above, and all modifications within the meaning and scope of the claims are intended to be included. For example, the first partition wall 16a of the partition wall member 16 and the auxiliary member 17 may be polygonal in shape, not just disc-shaped. Also, the recess 17b of the auxiliary member 17 and the protrusion 11d of the upper part 11b that fits therein may also be polygonal. Furthermore, the electric pump of this disclosure can have the following configuration.

[0076] (1) It is an electric pump, A motor unit having a shaft extending in the axial direction, a rotatable rotor located radially outward from the shaft, and a stator surrounding the rotor, A pump section located on one axial side of the aforementioned shaft, It has a housing that covers the motor section and the pump section, The aforementioned housing is The first housing located on the motor section side, It has a second housing located on the pump side, The second housing has a shaft fitting portion that fits with one end of the shaft on the axial side, and is an electric pump.

[0077] (2) The first housing is, A first opening that opens in one axial direction 5, It has a stator housing section that houses the stator, The checked2 housing is, A second opening that opens to the other side in the axial direction, It has a pump housing section that houses the pump section, The electric pump according to (1), wherein the second opening is in contact with the first opening on the other side of the axial direction of the second opening.

[0078] (3) The fitting portion has a first recess that is recessed on one side in the axial direction, The electric pump according to (2), wherein the first recess fits with the outer shape of the end. (4) The shaft fitting portion has a through hole that penetrates in the axial direction, The end of the shaft has a second recess that is recessed on the other side in the axial direction, The electric pump according to (1), wherein the second recess is fixed by a fixing member passing through the through hole. (5) The second recess is a screw hole extending in the axial direction, The fixing member is a screw that is screwed into the screw hole, The shaft fitting portion has a first end face facing one side in the axial direction and a second end face facing the other side in the axial direction. The screw has a threaded end face that faces the other side in the axial direction and contacts the first end face, The electric pump according to (4), wherein there is a gap between the shaft end face on one axial side of the end and the second end face.

[0079] (6) The first housing has an upper part located on the other axial side of the stator or the rotor, The electric pump according to (1), wherein the upper part has a shaft fixing portion for fixing the other end of the shaft in the axial direction. (7) The shaft fixing portion has a first stage portion, The electric pump according to (2), wherein the other end of the shaft on the axial side has a second stage that faces the first stage in the axial direction. (8) The pump housing has an intake port on one axial side of the shaft fitting portion, and is an electric pump mounted on (1).

[0080] (9) The electric pump according to claim 1, wherein the shaft fitting portion is located on the other axial side or on one axial side of the pump portion. (10) The pump section has a through hole on the radially inner side, The shaft fitting portion has support legs extending in the axial direction, The support leg is located inside the through hole, The electric pump according to (1), wherein the shaft fitting portion is located on the other axial side of the pump portion. (11) The first housing has a planar first surface that is fixed to the second housing side, The second housing has a planar second surface that is fixed to the first housing side, The second housing has a sealing member that prevents fluid from entering, The electric pump according to claim 1, wherein the sealing member has a fixing portion sandwiched between the first surface and the second surface. [Explanation of Symbols]

[0081] 100: Electric pump 10: Motor section 11: Housing 1 11b: Upper part 11c: Shaft fixing part 11h: Motor housing 11n: First face 12: Shaft 12a: Upper end of the shaft (second stage) 12b: Lower end of shaft 12c: Second recess (screw hole) 12d: Notch 12e: Shaft end face 13: Rotor 15: Status 16: Partition member (sealing member) 20: Pump section 20d: First through hole 20f: 2nd through hole 20h: Pump housing 21: Second Housing 21n: Second face 22: Screws (fixing components) 22a: Screw end face 23a: Shaft fitting section 23c: First recess 23c 23d: End face 23e: Through hole 23g: 1st end surface 23h: 2nd end surface 23h: Pump housing 25: Inlet 30: Control Unit H: Housing s1: First section s3: Gap

Claims

1. It is an electric pump, A motor unit having a shaft extending in the axial direction, a rotatable rotor located radially outward from the shaft, and a stator surrounding the rotor, A pump section located on one axial side of the aforementioned shaft, It has a housing that covers the motor section and the pump section, The aforementioned housing is The first housing located on the motor section side, It has a second housing located on the pump side, The second housing has a shaft fitting portion that fits with one end of the shaft on the axial side, and is an electric pump.

2. The first housing is, A first opening that opens on one side in the axial direction, It has a stator housing section that houses the stator, The preceding 2 housing is, A second opening that opens to the other side in the axial direction, It has a pump housing section that houses the pump section, The electric pump according to claim 1, wherein the second opening is in contact with the first opening on a surface facing the other axial direction of the second opening.

3. The shaft fitting portion has a first recess that is recessed on one side in the axial direction, The electric pump according to claim 2, wherein the first recess fits with the outer shape of the end portion.

4. The shaft fitting portion has a through hole that penetrates in the axial direction, The end of the shaft has a second recess that is recessed on the other side in the axial direction, The electric pump according to claim 1, wherein the second recess is fixed by a fixing member passing through the through hole.

5. The second recess is a screw hole extending in the axial direction, The fixing member is a screw that is screwed into the screw hole, The shaft fitting portion has a first end face facing one side in the axial direction and a second end face facing the other side in the axial direction. The screw has a threaded end face that faces the other side in the axial direction and contacts the first end face, The electric pump according to claim 4, wherein there is a gap between the shaft end face on one axial side of the end and the second end face.

6. The first housing has an upper part located on the other axial side of the stator or the rotor, The electric pump according to claim 1, wherein the upper part has a shaft fixing portion for fixing the other end of the shaft in the axial direction.

7. The shaft fixing portion has a first stage portion, The electric pump according to claim 2, wherein the other end of the shaft on the axial side has a second stage that faces the first stage in the axial direction.

8. The electric pump according to claim 1, wherein the pump housing has an intake port on one axial side of the shaft fitting portion.

9. The electric pump according to claim 1, wherein the shaft fitting portion is located on the other axial side or on one axial side of the pump portion.

10. The pump section has a through hole on the radially inner side, The shaft fitting portion has support legs extending in the axial direction, The support leg is located inside the through hole, The electric pump according to claim 1, wherein the shaft fitting portion is located on the other axial side of the pump portion.

11. The first housing has a planar first surface that is fixed to the second housing side, The second housing has a planar second surface that is fixed to the first housing side, The second housing has a sealing member that prevents fluid from entering, The electric pump according to claim 1, wherein the sealing member has a fixing portion sandwiched between the first surface and the second surface.

Images