JP5913028B2 - Electric pump - Google Patents

Description

  The present invention relates to an electric pump.

  Conventionally, as disclosed in Patent Document 1, for example, an electric pump has a pump housing assembled to a motor case in which a motor rotor and a motor stator are accommodated. The pump housing includes a first housing part (main body part in Patent Document 1) directly in contact with the motor case, and a second housing part (cover in Patent Document 1) assembled to the first housing part. Consists of. The rotary shaft of the electric pump has a motor rotor fixed to one end side and a pump rotor fixed to the other end side, and a portion of the rotary shaft between the motor rotor and the pump rotor is located in the first housing portion. The intermediate shaft support provided is rotatably supported. The pump rotor that rotates integrally with the rotary shaft is accommodated in a pump chamber formed between the first and second housing parts, and the suction port formed in the second housing part based on the rotation of the pump rotor. And fluid such as oil is fed through the discharge port.

JP 2012-26294 A

  However, in the electric pump as described in Patent Document 1, the motor stator generates heat during rotational driving, and the heat is transmitted from the motor case to the first housing portion that is in direct contact with the motor case. Thereby, the heat generated in the motor stator can be released to the first housing part without staying in the motor case, and the deterioration of the motor performance due to the heat staying in the motor case is suppressed. However, when the first housing part becomes hot due to heat transmitted from the motor case, thermal wear (a phenomenon in which wear is promoted compared to that at low temperatures) occurs in the intermediate shaft support part provided in the first housing part. This was one of the factors that hindered the extension of the service life of electric pumps.

  The present invention has been made to solve the above-described problems, and the object thereof is to suppress thermal wear at the intermediate shaft support portion of the pump housing while suppressing heat retention in the motor case. It is to provide an electric pump.

  In order to solve the above problems, the invention according to claim 1 is a motor case in which a motor rotor and a motor stator are accommodated, the motor rotor is fixed to one end side, and a pump rotor is fixed to the other end side. A rotating shaft, an intermediate shaft supporting portion that supports a portion of the rotating shaft between the motor rotor and the pump rotor, and a pump housing that houses the pump rotor and is fixed to the motor case. The pump housing includes a first housing part fixed to the motor case and a second housing part having the intermediate shaft support part, and the first and second housings. The pump chamber is formed between the first housing part, the second housing part being fixed to the first housing part, Characterized in that it is separated from the Takesu.

  In this invention, the heat generated in the motor stator is transmitted from the motor case to the first housing part, but the heat of the motor case is not directly transmitted to the second housing part separated from the motor case. As a result, by releasing heat from the motor case to the first housing part, it is possible to prevent the second housing part having the intermediate shaft support part from becoming high temperature while suppressing heat retention in the motor case, and as a result. The thermal wear at the intermediate shaft support can be suppressed.

According to a second aspect of the present invention, in the electric pump according to the first aspect, the first housing part is directly fixed to the motor case.
In the present invention, since the first housing part is directly fixed to the motor case, heat can be easily released from the motor case to the first housing part, and as a result, heat accumulation in the motor case is suitably suppressed. be able to.

  According to a third aspect of the present invention, in the electric pump according to the second aspect, the first housing portion has an insertion portion inserted into an opening end portion of the cylindrical motor case, A caulking fixing portion that protrudes inward of the motor case and press-contacts with the insertion portion of the first housing portion is formed at the opening end portion.

  In this invention, since the motor case and the insertion part of the first housing part are fixed by caulking (plastically deforming) the opening end part of the motor case, the motor case can be used without using bolts or adhesives. The first housing portion can be fixed, and as a result, it is possible to contribute to simplification of the configuration and manufacturing process of the electric pump.

  According to a fourth aspect of the present invention, in the electric pump according to the third aspect, the caulking fixing portion is provided at a position different in the axial direction with respect to a fixing portion between the first housing portion and the second housing portion. It is characterized by being.

  In this invention, the caulking pressure at the time of fixing the opening end portion of the motor case and the insertion portion of the first housing portion is less likely to affect the second housing portion fixed to the first housing portion. it can. For this reason, it can suppress that the fixed state of the 2nd housing part deteriorates by caulking pressure, and the axial shift of the intermediate shaft support part of a 2nd housing part arises.

  According to a fifth aspect of the present invention, in the electric pump according to the third or fourth aspect, a thin-walled portion that is thinner than other portions of the motor case is formed at the opening end of the motor case. The caulking fixing part is formed in the thin part.

  In this invention, since the opening end portion of the motor case is formed thin, the opening end portion can be easily plastically deformed, and as a result, the fixing operation between the motor case and the first housing portion is facilitated. .

A sixth aspect of the present invention is the electric pump according to any one of the first to fifth aspects, wherein the motor case is made of an iron-based material.
In the present invention, the motor case is formed of an iron-based material having a relatively high rigidity and a relatively small linear expansion coefficient, so that the motor stator can be stably fixed to the motor case. Also, since iron-based materials have higher thermal conductivity than, for example, resin, the heat of the motor stator is radiated well from the motor case to the outside, and as a result, the heat of the motor stator is trapped inside the motor case. Can be suppressed.

The invention according to claim 7 is the electric pump according to any one of claims 1 to 6, wherein the first housing portion is made of an aluminum-based material.
In this invention, it can contribute to the weight reduction of an electric pump. Moreover, since the aluminum-based material has a relatively high heat transfer coefficient, heat transfer from the motor case to the first housing portion is promoted, and as a result, heat retention in the motor case can be suitably suppressed.

  Therefore, according to the above-described invention, thermal wear at the intermediate shaft support portion of the pump housing can be suppressed while suppressing heat retention in the motor case.

It is sectional drawing of the electric pump of embodiment. It is a top view of the electric pump of the same form. It is sectional drawing which expands and shows a part of electric pump of another example.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
As shown in FIG. 1, the electric pump according to the present embodiment includes a substantially cylindrical motor case 11, a pump housing 12 provided on the axial output side of the motor case 11, and an axially opposite output side of the motor case 11. And a circuit case member 13 provided on the housing, and the entire housing is configured therefrom.

  The motor case 11 is made of an iron-based material, and a substantially cylindrical motor stator 14 as an armature is fixed to the inner peripheral surface thereof. A motor rotor 16 is disposed on the inner peripheral side of the motor stator 14 and is fixed to a rotary shaft 15 supported by the pump housing 12 so as to be integrally rotatable. The rotating shaft 15 is disposed at the center of the diameter of the motor case 11, and is configured such that the axis of the rotating shaft 15 and the axis of the motor case 11 are coaxial. Moreover, the rotating shaft 15 consists of stainless steel which is a nonmagnetic metal.

  The motor stator 14 and the motor rotor 16 constitute an inner rotor type brushless motor, and are a power source of the electric pump of this embodiment. The motor rotor 16 according to the present embodiment is a so-called IPM type contiguous pole rotor in which the outer peripheral surface is composed of a magnet magnetic pole and a salient pole, and the magnet 16a is embedded in the magnet magnetic pole.

  The pump housing 12 includes a first housing portion 21 assembled to the first opening end portion 11 a on the axial output side of the motor case 11 and a second housing portion 22 assembled to the first housing portion 21. ing. Both the first and second housing parts 21 and 22 are made of an aluminum-based material that is a nonmagnetic metal.

  The first housing portion 21 includes a base portion 23 located outside the motor case 11, and a substantially cylindrical insertion that extends in the axial direction from the base portion 23 and is inserted into the first opening end portion 11 a of the motor case 11. Part 24.

  As shown in FIG. 2, the base portion 23 is formed with extending portions 23 a that extend in two opposite directions (the left-right direction in FIG. 2) along the radial direction of the motor case 11. The extending portion 23a extends radially outward from the outer diameter of the motor case 11, and the extending portion 23a has a mounting hole 23b for fixing the electric pump to a predetermined mounting location with a bolt or the like. Is formed.

  The electric pump of the present embodiment is a pump for circulating oil in a vehicle transmission (not shown), and the extending portion 23a of the base portion 23 is attached to the transmission with a bolt or the like. ing.

  As shown in FIG. 1, the insertion portion 24 of the first housing portion 21 is inserted and fixed to the first opening end portion 11 a of the motor case 11. A seal ring 25 is interposed between the outer peripheral surface 24a of the insertion portion 24 and the inner peripheral surface of the motor case 11, and a sealing property between them is ensured.

  The insertion portion 24 has a substantially cylindrical shape that opens to the axially inner side (motor rotor 16 side) of the motor case 11, and has three circular concave portions (a fitting concave portion 26, an accommodating concave portion having different diameters) on the inner peripheral side thereof. 27 and a shaft support recess 28) are formed continuously along the axial direction of the rotary shaft 15. The three recesses are formed in the order of the fitting recess 26, the receiving recess 27, and the shaft support recess 28 from the inner side of the motor case 11, and the recesses 26 to 28 are open to the inner side of the motor case 11.

  Each of the recesses 26 to 28 has a circular shape when viewed in the axial direction. Among them, the fitting recess 26 has the largest diameter, the housing recess 27 is formed to have a smaller diameter than the fitting recess 26, and the shaft support recess 28 further includes It is formed with a smaller diameter than the housing recess 27. That is, the inner periphery of the insertion portion 24 has a step shape that decreases in diameter as it passes through the fitting recess 26, the housing recess 27, and the shaft support recess 28. The fitting recess 26 and the shaft support recess 28 are formed in a circular shape coaxial with the rotary shaft 15, while the housing recess 27 does not appear in the cross section of FIG. (That is, a circular shape that is eccentric to the rotating shaft 15 (that is, a circular shape that is not coaxial).

  The shaft support recess 28 extends to the base portion 23 along the axial direction of the rotary shaft 15. Further, the shaft support recess 28 is opened only on the housing recess 27 side in the axial direction of the rotary shaft 15, and the end of the shaft support recess 28 opposite to the housing recess 27 is closed. And this axial support recessed part 28 supports the edge part of the axial direction output side (counter motor rotor side) of the rotating shaft 15 rotatably.

  The second housing part 22 is assembled in the fitting recess 26 of the first housing part 21. The second housing portion 22 is formed in a substantially disk shape centered on the axis of the rotary shaft 15, and a shaft support hole 31 (intermediate for pivotally supporting the intermediate portion of the rotary shaft 15 at the center of the diameter thereof. A shaft support portion is formed through. The shaft support hole 31 is formed coaxially and with the same diameter as the shaft support recess 28 of the first housing portion 21.

  At the end of the second housing portion 22 on the side opposite to the motor rotor, a circular closing portion 32 that is inserted into the fitting recess 26 of the first housing portion 21 is formed. The shaft support hole 31 passes through the center of the closing portion 32. In addition, a notch groove 31 a is formed at the end of the shaft support hole 31 on the side of the housing recess 27.

  The closing portion 32 has an outer diameter side portion in contact with the fitting recess 26 in the axial direction, and an inner diameter side portion closes the opening of the housing recess 27 on the motor rotor 16 side. Further, the closing portion 32 is locked in the axial direction with a retaining portion 26a that is formed to project from the opening end portion (end portion on the motor rotor 16 side) of the fitting concave portion 26 to the inner peripheral side. Thereby, the movement of the closing part 32 in the axial direction is restricted, and the closing part 32 (second housing part 22) is prevented from coming out of the fitting recess 26. The retaining portion 26a has a plurality of circumferential locations (or the entire circumferential direction) of the insertion portion end surface 24f which is the end surface of the insertion portion 24 on the motor rotor 16 side in a state where the closing portion 32 is fitted in the fitting recess 26. It is formed by plastic deformation on the inner peripheral side with a jig or the like (not shown).

  The closing portion 32 and the housing recess 27 constitute a pump chamber P, and a pump rotor 33 is housed in the pump chamber P. A seal ring 34 is interposed between the closing portion 32 and the fitting recess 26 in the axial direction, and the sealing performance between them is ensured.

  The pump rotor 33 is an internal gear type composed of an inner rotor 35 fixed to the rotary shaft 15 so as to be integrally rotatable, and an outer rotor 36 disposed on the outer periphery of the inner rotor 35.

  The inner rotor 35 is fixed to the rotary shaft 15 so as to be integrally rotatable, and external teeth (not shown) are formed on the outer periphery of the inner rotor 35. The outer rotor 36 has a cylindrical shape with a circular outer peripheral surface, and is rotatably fitted to the housing recess 27. Inner teeth (not shown) that mesh with the outer teeth of the inner rotor 35 are formed on the inner periphery of the outer rotor 36. The number of teeth of the inner teeth of the outer rotor 36 is set to n (n is a natural number of 3 or more), and the number of teeth of the outer teeth of the inner rotor 35 is set to n-1.

  A cylindrical portion 37 that protrudes in a cylindrical shape along the axial direction of the rotary shaft 15 is formed on the end surface of the second housing portion 22 on the motor rotor 16 side. The inner diameter of the cylindrical portion 37 is formed larger than the diameter of the shaft support hole 31, and an oil seal 38 is interposed between the inner peripheral surface of the cylindrical portion 37 and the outer peripheral surface of the rotary shaft 15. Yes. The oil seal 38 seals between the inner peripheral surface of the cylindrical portion 37 and the outer peripheral surface of the rotary shaft 15, so that the space on the pump chamber P side and the internal space of the motor case 11 are liquid-tight. It is partitioned. The outer diameter of the cylindrical portion 37 is formed smaller than the inner diameter of the motor stator 14.

  In the housing recess 27 of the first housing portion 21, a suction port 41 and a discharge port 42 are formed at a radially outer position of the shaft support recess 28. The suction port 41 and the discharge port 42 are formed so as to penetrate from the bottom surface 27 a of the housing recess 27 to the bottom surface 23 c of the base portion 23. That is, the suction port 41 and the discharge port 42 communicate the inside of the housing recess 27 and the outside of the first housing part 21. Further, a cutout groove 27 b that connects the discharge port 42 and the shaft support recess 28 is formed in the bottom surface 27 a of the housing recess 27. The notch groove 27b is formed at a position facing the notch groove 31a on the second housing portion 22 side in the axial direction.

Here, the fixing structure of the insertion part 24 of the first housing part 21 and the first opening end part 11a of the motor case 11 in the electric pump will be described.
As shown in the enlarged view of FIG. 1, a thin portion 11 c is formed at the first opening end portion 11 a of the motor case 11. The thin portion 11c is formed over a predetermined length in the axial direction from the axial end of the motor case 11, and is formed over the entire circumference of the first opening end 11a. The thin portion 11c is formed to have a larger inner diameter than other portions of the motor case 11 (for example, the axial intermediate portion 11d), and the radial thickness T1 of the thin portion 11c is the radial direction of the axial intermediate portion 11d. It is formed thinner than the thickness T2.

  A caulking fixing portion 11e that protrudes radially inward of the motor case 11 is formed in the thin portion 11c over the entire circumferential direction of the thin portion 11c. The caulking fixing part 11e is formed by plastically deforming the thin part 11c from the outer peripheral side with a jig (not shown) after inserting the insertion part 24 into the first opening end part 11a. The outer peripheral surface 24a of the insertion portion 24 is in pressure contact. Thereby, the 1st opening end part 11a of the motor case 11 and the insertion part 24 of the 1st housing part 21 are firmly fixed.

  In addition, the press-contact part of the caulking fixing part 11e with respect to the insertion part 24 is set to the radial direction outer side of the accommodation recessed part 27 (pump chamber P). For this reason, generation | occurrence | production of the axial shift of the rotating shaft 15 by caulking is suppressed suitably. Further, the distal end portion of the insertion portion 24 is inserted to an axially inner position from the thin portion 11c, and the outer peripheral surface 24a of the distal end portion of the insertion portion 24 is the inner periphery of the axial intermediate portion 11d of the motor case 11 It is in contact with the surface in the radial direction. The seal ring 25 is interposed between the contact portions. That is, the seal ring 25 is provided corresponding to a position other than the thin portion 11c in the motor case 11 (that is, on the inner side in the axial direction than the thin portion 11c).

  In addition, the position of the portion where the caulking fixing portion 11 e of the insertion portion 24 of the first housing portion is press-contacted (the portion to be caulked and in the vicinity of the root of the insertion portion 24) is the closing portion 32 of the second housing portion 22. Are set at different positions in the axial direction of the rotary shaft 15 with respect to the portion to be fixed (that is, the fitting recess 26). Thereby, it is suppressed that the 2nd housing part 22 fixed to the fitting recessed part 26 receives the influence of the caulking pressure of the radial direction at the time of fixation with the insertion part 24 of the motor case 11 and the 1st housing part 21. ing. For this reason, it is suppressed that the fixed state of the 2nd housing part 22 deteriorates by caulking pressure, for example, and the axial shift of the shaft support hole 31 arises by it.

  In the motor case 11, a resin circuit case member 13 is assembled to the second opening end portion 11 b opposite to the first opening end portion 11 a into which the insertion portion 24 of the first housing portion 21 is fitted. Yes. The circuit case member 13 has a circular shape coaxial with the motor case 11 when viewed in the axial direction.

  As shown in FIG. 2, a plurality (four in this embodiment) of locking pieces 51 are provided on the outer peripheral surface of the circuit case member 13 in the circumferential direction. The circuit case member 13 is fixed to the motor case 11 by each of the locking pieces 51 being locked to a locking projection 52 provided on the outer peripheral surface of the motor case 11. A seal ring 50 (see FIG. 1) is interposed between the second opening end portion 11b and the circuit case member 13, and a sealing property between them is ensured. The circuit case member 13 is provided with a heat sink 53 for radiating heat generated from the circuit components 55 on the circuit board 54.

  As shown in FIG. 1, a circuit board 54 is fixed to the circuit case member 13 by, for example, heat welding. A circuit component 55 is mounted on the circuit board 54, and a coil wire 14 b drawn from the coil 14 a of the motor stator 14 is connected to the circuit board 54. The circuit case member 13 covers the circuit component 55 of the circuit board 54.

  In the electric pump having the above configuration, when a current is supplied from an external power source (not shown) to the coil 14a of the motor stator 14 via the circuit component 55 of the circuit board 54, a rotating magnetic field is generated in the motor stator 14, and the rotating magnetic field is generated. Based on this, the motor rotor 16 and the rotating shaft 15 rotate. As the rotary shaft 15 rotates, the inner rotor 35 and the outer rotor 36 of the pump rotor 33 rotate. Then, oil is sucked into the pump chamber P through the suction port 41 by the pump action of the inner rotor 35 and the outer rotor 36, and the oil sucked into the pump chamber P is outside the pump chamber P through the discharge port 42 ( That is, the ink is discharged to the outside of the first housing part 21.

  Here, in the above configuration, the rotation shaft 15 is pivotally supported at the two points of the shaft support recess 28 of the first housing portion 21 and the shaft support hole 31 of the second housing portion 22, so that the rotation of the rotation shaft 15 is stable. To do. Furthermore, since the shaft support recess 28 and the shaft support hole 31 are provided on both sides in the axial direction of the pump rotor 33 to which a load is applied (so-called both-side support), the shaft shake during rotation of the rotary shaft 15 is suppressed. It has become so.

  The bearing clearance (the clearance between the rotating shaft 15 and the shaft support recess 28 and the clearance between the rotating shaft 15 and the shaft support hole 31) includes oil sucked into the pump chamber P from the suction port 41. Part of the fluid flows in and acts as lubricating oil for the shaft support recess 28 and the shaft support hole 31. Here, on the positive pressure side (the right side in FIG. 1) from which the oil in the pump chamber P is discharged from the discharge port 42, the oil in the bearing clearance tends to be insufficient. Therefore, in the present embodiment, the cutout grooves 27b and 31a are formed on both axial sides of the pump rotor 33 on the positive pressure side (discharge port 42 side), and oil is held in the cutout grooves 27b and 31a. Therefore, a shortage of oil in the bearing clearance is suppressed even on the positive pressure side.

  In the assembly of the electric pump of the present embodiment, the first housing portion 21 is used as a reference member for assembly, and the first housing portion 21 is not shown in the drawing so that the opening direction of each of the recesses 26 to 28 faces upward in the vertical direction, for example. Install in an immovable manner.

  Next, the outer rotor 36 is assembled and accommodated on the lower side in the vertical direction with respect to the accommodating recess 27. Thereafter, the sub-assembly formed by assembling the inner rotor 35, the second housing portion 22, the oil seal 38, the rotating shaft 15 and the motor rotor 16 (after the magnet 16 a is assembled) is connected to the first housing portion 21 with the outer rotor. Assembling is performed in the same direction as 36 assembling directions (that is, vertically downward).

  Next, the motor case 11 is assembled to the insertion portion 24 of the first housing portion 21 in the same direction as the above components. At this time, first, the thin portion 11 c of the motor case 11 is extrapolated to the insertion portion 24. Thereafter, the intermediate portion in the axial direction of the thin portion 11 c is plastically deformed radially inward with a jig (not shown) and is brought into pressure contact with the outer peripheral surface 24 a of the insertion portion 24. Thereby, the caulking fixing part 11e is formed, and the motor case 11 and the insertion part 24 of the first housing part 21 are firmly fixed.

Next, the operation of this embodiment will be described.
In the pump housing 12, the first housing portion 21 is directly fixed to the motor case 11, and the second housing portion 22 fixed to the first housing portion 21 is separated from the motor case 11. Yes. The second housing portion 22 is provided with a shaft support hole 31 that pivotally supports an intermediate portion of the rotating shaft 15 (a portion between the motor rotor 16 and the pump rotor 33).

  As a result, the heat generated in the motor stator 14 during the rotational drive is transmitted from the motor case 11 to the first housing part 21, but the second housing part 22 separated from the motor case 11 has the Heat is not transmitted directly. For this reason, by releasing heat from the motor case 11 to the first housing portion 21, the second housing portion 22 having the shaft support hole 31 may become high temperature while suppressing the stay of heat in the motor case 11. As a result, thermal wear at the shaft support hole 31 can be suppressed.

  Further, in the electric pump of the present embodiment, a thin wall portion 11c is formed at the first opening end portion 11a of the motor case 11, and the thin wall portion 11c is plastically deformed to be brought into pressure contact with the insertion portion 24. The first housing portion 21 is fixed. For this reason, it becomes possible to fix the motor case 11 and the 1st housing part 21 without using a volt | bolt, an adhesive agent, etc., As a result, the structure and manufacturing process of an electric pump can be simplified. .

Next, characteristic effects of the present embodiment will be described.
(1) The pump housing 12 has a shaft support hole 31 (supporting the first housing portion 21 fixed to the motor case 11 and an intermediate portion of the rotating shaft 15 (a portion between the motor rotor 16 and the pump rotor 33). The second housing part 22 having the intermediate shaft support part) is assembled to each other, and the pump chamber P is formed between the first and second housing parts 21 and 22. The second housing portion 22 is fixed to the first housing portion 21 and is configured to be separated from the motor case 11. Thereby, the heat generated in the motor stator 14 is transmitted from the motor case 11 to the first housing part 21, but the heat of the motor case 11 is directly transmitted to the second housing part 22 separated from the motor case 11. I don't get it. As a result, by releasing heat from the motor case 11 to the first housing portion 21, the second housing portion 22 having the shaft support hole 31 may become high temperature while suppressing heat retention in the motor case 11. As a result, thermal wear at the shaft support hole 31 can be suppressed.

  (2) The insertion part 24 of the first housing part 21 is directly fixed to the first opening end part 11 a of the motor case 11. That is, since it is fixed between the insertion portion 24 of the first housing portion 21 and the first opening end portion 11a of the motor case 11 without using another member such as a heat insulating material, the motor housing 11 and the first housing It is possible to easily release the heat to the portion 21, and as a result, it is possible to suitably suppress the heat retention in the motor case 11.

  (3) The first opening end portion 11 a of the motor case 11 is formed with a thin portion 11 c that is thinner than other portions of the motor case 11. The thinned portion 11 c is formed with a caulking fixing portion 11 e that protrudes inward in the radial direction of the motor case 11 and press-contacts with the insertion portion 24 of the first housing portion 21. As a result, the thin case 11c of the motor case 11 is caulked (plastically deformed) so that the motor case 11 and the insertion portion 24 of the first housing part 21 are fixed. The motor case 11 and the first housing portion 21 can be fixed, and as a result, it is possible to contribute to simplification of the configuration and manufacturing process of the electric pump. In addition, by forming the caulking fixing portion 11e as the thin portion 11c, the first opening end portion 11a of the motor case 11 can be easily plastically deformed. As a result, the motor case 11 and the first housing portion 21 are formed. The fixing work becomes easy.

  (4) By forming the motor case 11 with an iron-based material having a relatively high rigidity and a relatively small linear expansion coefficient, the fixing of the motor stator 14 to the motor case 11 can be stabilized. In addition, since the iron-based material has a higher thermal conductivity than, for example, resin, the heat of the motor stator 14 is radiated well from the motor case 11 to the outside, and as a result, the heat of the motor stator 14 enters the motor case 11. Can be suppressed.

  (5) Since the 1st housing part 21 consists of an aluminum-type material, it can contribute to the weight reduction of an electric pump. In addition, since the aluminum material has a relatively high heat transfer coefficient, heat transfer from the motor case 11 to the first housing portion 21 is promoted, and as a result, heat retention in the motor case 11 is more suitably suppressed. be able to.

  (6) The caulking fixing portion 11e is provided at a position different in the axial direction with respect to the fixing portion between the first housing portion 21 and the second housing portion 22. Thereby, the caulking pressure in the radial direction at the time of fixing the first opening end portion 11 a of the motor case 11 and the insertion portion 24 of the first housing portion 21 is the second housing portion 22 fixed to the first housing portion 21. Can be made difficult to affect. For this reason, it can suppress that the fixed state of the 2nd housing part 22 deteriorates by caulking pressure, and the axial shift of the shaft support hole 31 arises by it, for example.

In addition, you may change embodiment of this invention as follows.
The configuration of the caulking and fixing between the first opening end portion 11a of the motor case 11 and the insertion portion 24 of the first housing portion 21 is not limited to the above embodiment, and may be appropriately changed according to the configuration. .

  For example, in the example shown in FIG. 3, the insertion portion 24 of the first housing portion 21 has a protruding portion 24 b that protrudes radially outward from the outer peripheral surface 24 a over the entire circumference of the insertion portion 24. . The outer peripheral surface of the protrusion 24 b is in contact with the inner surface of the thin portion 11 c of the motor case 11. A recess 24c that accommodates the seal ring 25 is formed on the outer peripheral surface of the protrusion 24b.

  Further, the first end 24d in the axial direction of the protruding portion 24b (the end on the distal end side of the insertion portion 24) has a thin portion 11c and an axially intermediate portion 11d (thick portion) on the inner peripheral surface of the motor case 11. Is contacted in the axial direction with respect to the step portion 11f formed between the two. Thereby, the movement to the insertion direction (upward in FIG. 3) of the insertion part 24 with respect to the motor case 11 is controlled.

  On the other hand, a caulking fixing portion 11g formed at the axial front end portion of the thin portion 11c is pressed against the second end portion 24e in the axial direction of the protruding portion 24b. The caulking fixing portion 11g is formed by bending the axial end portion of the thin portion 11c radially inward. The caulking fixing portion 11g is locked in the axial direction with respect to the second end portion 24e of the projecting portion 24b, whereby the insertion portion 24 is removed from the motor case 11 in the anti-insertion direction (downward in FIG. 3). Is suppressed. Even with such a configuration, it is possible to obtain the same effect as the above-described embodiment.

  In the above embodiment, the thin portion 11c is formed in the first opening end portion 11a of the motor case 11. However, the present invention is not particularly limited to this, and the radial thickness of the first opening end portion 11a is set to the It may be set equal to the radial thickness T2 of the axial intermediate portion 11d.

In the above embodiment, the motor case 11 is caulked and fixed to the insertion portion 24 of the first housing portion 21, but other than this, for example, the motor case 11 may be fixed by a bolt, an adhesive, or the like.
In the above embodiment, the housing recess 27 for housing the pump rotor 33 is formed on the first housing portion 21 side, but is not particularly limited thereto, and may be formed on the second housing portion 22 side. .

In the above embodiment, the second housing part 22 is press-fitted and fixed to the fitting recess 26 of the first housing part 21, but may be fixed by, for example, a bolt or an adhesive.
In the above embodiment, the first housing portion 21 is formed with the shaft support recess 28 that supports the rotary shaft 15, but the present invention is not limited to this, and the shaft support recess 28 is omitted, and the rotary shaft 15 may be supported by only the shaft support hole 31 of the second housing portion 22.

  In the above embodiment, the motor case 11 is made of an iron-based material, and the first and second housing parts 21 and 22 are made of an aluminum-based material. However, the present invention is not limited to this. 11 and the materials of the first and second housing parts 21 and 22 may be appropriately changed according to the configuration.

  In the above-described embodiment, the pump rotor 33 is an internal gear type including the inner rotor 35 and the outer rotor 36. However, the pump rotor 33 is not particularly limited to this, and the internal gear type may be used as long as fluid can be sucked and discharged. Other types of pump rotors may be used.

  In the above embodiment, the motor rotor 16 is an IPM type contiguous pole type rotor. However, the present invention is not limited to this, and is not a contiguous type (a type in which N pole / S pole magnets are alternately arranged in the circumferential direction). Alternatively, an SPM type rotor may be used.

  In the above-described embodiment, the oil pump is embodied as an electric pump. However, the oil pump may be embodied in an electric pump used for feeding fluid other than oil.

  DESCRIPTION OF SYMBOLS 11 ... Motor case, 11a ... 1st opening edge part (opening edge part), 11c ... Thin part, 11e, 11g ... Caulking fixing part, 12 ... Pump housing, 14 ... Motor stator, 15 ... Rotating shaft, 16 ... Motor rotor, DESCRIPTION OF SYMBOLS 21 ... 1st housing part, 22 ... 2nd housing part, 24 ... Insertion part, 31 ... Shaft support hole (intermediate shaft support part), 33 ... Pump rotor, P ... Pump chamber.

Claims (7)

A motor case containing a motor rotor and a motor stator;
The motor rotor is fixed to one end side, and a rotary shaft having a pump rotor fixed to the other end side;
An electric pump comprising: an intermediate shaft supporting portion that supports a portion of the rotating shaft between the motor rotor and the pump rotor; and a pump housing that houses the pump rotor and is fixed to the motor case. Because
In the pump housing, a first housing part fixed to the motor case and a second housing part having the intermediate shaft support part are assembled to each other, and the pump chamber is provided between the first and second housing parts. Made up of,
The electric pump according to claim 1, wherein the second housing part is fixed to the first housing part and is separated from the motor case. The electric pump according to claim 1,
The electric pump according to claim 1, wherein the first housing part is directly fixed to the motor case. The electric pump according to claim 2,
The first housing portion has an insertion portion inserted into an opening end portion of the cylindrical motor case,
The electric pump according to claim 1, wherein a caulking fixing portion that protrudes inward of the motor case and press-contacts with the insertion portion of the first housing portion is formed at the opening end portion of the motor case. In the electric pump according to claim 3,
The electric pump according to claim 1, wherein the caulking fixing portion is provided at a position different in an axial direction with respect to a fixing portion between the first housing portion and the second housing portion. The electric pump according to claim 3 or 4,
An electric pump characterized in that a thin portion having a thinner thickness than other portions of the motor case is formed at the opening end portion of the motor case, and the caulking fixing portion is formed in the thin portion. . In the electric pump according to any one of claims 1 to 5,
The electric pump is characterized in that the motor case is made of an iron-based material. The electric pump according to any one of claims 1 to 6,
The electric pump according to claim 1, wherein the first housing part is made of an aluminum-based material.