Electric liquid pump

Abstract

To provide a technique capable of reducing the weight of an electric liquid pump and reducing its manufacturing costs.SOLUTION: An electric liquid pump 1 comprises: an electric motor 2 having a motor rotor 20 having a shaft 21 and a magnet part 23, and a stator 25 for rotating the motor rotor 20; a liquid pump 3 having an inner rotor 30 integrated with another end of the shaft 21 and an outer rotor 35 forming a gap volume part 38; a motor case 4 having therein a first housing chamber 41 shaped like a box and housing one axial part of the motor rotor 20 and the stator 25, a second housing chamber 42 housing the other axial part of the motor rotor 20, and a partition wall 45 provided with a hole-like communication part 46 for communicating the first housing chamber 41 and the second housing chamber 42, and circulating liquid in the first housing chamber 41, the second housing chamber 42, and the hole-like communication part 46; and a body 5 having a bearing part supporting one axial part of the shaft 21. The body 5 is entirely made of thermosetting resin.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an electric fluid pump for transporting fluids such as oil. [Background technology]

[0002] BACKGROUND ART Known electric liquid pumps for transporting liquids such as oil include those in which an inner rotor and an outer rotor that realize a pump function are housed in a case (see, for example, Patent Document 1). In the electric liquid pump disclosed in Patent Document 1, a trochoid 4, which is an integral part of an inner rotor 3 and an outer rotor 2, is housed within a casing 5 and a cover 6.

[0003] Rotation of the drive shaft 10 connected to the drive source rotates the inner rotor 3 integrated with the drive shaft 10. The rotation of the inner rotor 3 rotates the outer rotor 2 meshed with the inner rotor 3. This produces a pump function that sucks in and discharges liquid. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-066975 Summary of the Invention [Problem to be solved by the invention]

[0005] In electric liquid pumps, high dimensional accuracy is required for the parts that house the inner and outer rotors and the parts that support the drive shaft. Therefore, in typical conventional electric liquid pumps, these parts are made of metal and require an additional cutting process after molding. This makes it difficult to reduce the weight of conventional electric liquid pumps and leads to high manufacturing costs. An electric fluid pump with a large mass is not suitable as an on-board electric fluid pump to be mounted on a vehicle, for example.

[0006] For example, in the technology introduced in the above-mentioned Patent Document 1, the cover 6 that supports the drive shaft 10 is made of metal, and furthermore, a bearing for supporting the drive shaft 10 is press-fitted into the cover 6. Note that in a typical electric liquid pump, a metal bearing is used as the bearing. Such a cover 6 is difficult to reduce in weight, and as a result, it is difficult to say that an electric fluid pump having such a cover 6 is sufficiently light in weight. Furthermore, the electric liquid pump introduced in Patent Document 1 requires a metal plate 8. This also makes it difficult to reduce the weight of the electric liquid pump. Therefore, even with the technology of Patent Document 1, it is difficult to say that the weight of the electric liquid pump can be sufficiently reduced and that the manufacturing costs thereof can be sufficiently reduced.

[0007] The present invention has been made in view of the above circumstances, and an object to be achieved is to provide a technique that can reduce the weight and manufacturing costs of an electric fluid pump. [Means for solving the problem]

[0008] The electric liquid pump of the present invention, which solves the above problems, an electric motor including a motor rotor having a shaft and a magnet portion integrated with one axial end of the shaft, and a stator disposed radially outside or inside the magnet portion to rotate the motor rotor; a liquid pump including: an inner rotor having external teeth and integral with the other axial end of the shaft; and an outer rotor having internal teeth that mesh with the external teeth and forming a clearance volume between the inner rotor and the outer rotor, into which liquid is sucked from a suction passage and into which liquid is discharged toward a discharge passage; a motor case having a box shape and including inside a first accommodating chamber that accommodates the stator and a portion of the motor rotor in the axial direction including the magnet portion, a second accommodating chamber that communicates with the first accommodating chamber and accommodates another portion of the motor rotor in the axial direction, and a partition wall that has a hole-like communicating portion that communicates the first accommodating chamber and the second accommodating chamber and is provided between the first accommodating chamber and the second accommodating chamber, and in which a liquid circulates between the first accommodating chamber, the second accommodating chamber, and the hole-like communicating portion; a body including a centering body portion inserted into the hole-like connecting portion and centered therein, a general body portion continuous with the centering body portion and accommodated in the second accommodation chamber, and a bearing portion formed through the centering body portion and the general body portion and supporting a part of the axial direction of the shaft at a position between the magnet portion and the inner rotor, The electric liquid pump has a body entirely made of thermosetting resin. [Effects of the Invention]

[0009] The technology of the present invention makes it possible to reduce the weight and manufacturing costs of electric liquid pumps. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is an explanatory diagram for schematically explaining the appearance of an electric liquid pump according to a first embodiment. [Figure 2] 2 is an explanatory diagram for explaining a schematic view of the electric liquid pump of the first embodiment cut at the position XX in FIG. 1. FIG. [Figure 3] 2 is an explanatory diagram for schematically explaining the electric liquid pump of the first embodiment cut at the YY position in FIG. 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] The electric liquid pump of the present invention will be described below by way of a specific example.

[0012] The electric liquid pump of the present invention comprises a motor rotor, a stator, an inner rotor, an outer rotor, a motor case, and a body. The inner rotor and outer rotor form the liquid pump, and the motor rotor and stator form an electric motor for driving the liquid pump.

[0013] The motor case and the body function as a housing for accommodating at least a portion of the liquid pump and the electric motor therein.

[0014] The body also functions as a support mechanism for supporting the liquid pump and the electric motor. In other words, the body of the electric liquid pump of the present invention functions as the cover 6 and the casing 5 introduced in the above-mentioned Patent Document 1.

[0015] In other words, the electric liquid pump of the present invention only requires a body, instead of the two components of a cover and a casing that were previously required. This reduces the number of parts required by the electric liquid pump of the present invention, which in turn reduces the number of steps required to manufacture the electric liquid pump, and ultimately reduces the manufacturing costs of the electric liquid pump.

[0016] In the electric liquid pump of the present invention, the inner rotor, the outer rotor, and the body supporting the shaft of the motor rotor are made of thermosetting resin, and liquid circulates inside the motor case. Therefore, in the electric liquid pump of the present invention, there is no need for a structure such as a metal bearing as a bearing portion for supporting the shaft of the motor rotor, for example.

[0017] That is, conventional electric liquid pumps require a bearing unit including a metal bearing as a bearing for supporting the shaft of the motor rotor. Bearings are mechanisms for smoothly rotating a shaft. For example, a typical rolling bearing has a three-layer structure consisting of an inner ring, balls, and an outer ring, and is a relatively heavy component. For this reason, it is difficult to reduce the weight of an electric fluid pump that includes such a bearing in its bearing section.

[0018] In the electric liquid pump of the present invention, the motor rotor shaft is supported by a body made of thermosetting resin, and the liquid circulating inside the motor case is also supplied between the body and the shaft, where it can function as a lubricant.

[0019] In other words, in the electric liquid pump of the present invention, by circulating liquid inside the motor case, it is possible to rotate the shaft smoothly, even though part of the body is made of thermosetting resin, which is lighter than metal, instead of bearings. As a result, the electric liquid pump of the present invention can be made lighter in weight.

[0020] Furthermore, in the electric liquid pump of the present invention, the body itself made of thermosetting resin is lightweight, which reduces the weight of the electric liquid pump as a whole. This electric liquid pump of the present invention can be said to be significantly lighter than electric liquid pumps that have metal covers, such as the electric liquid pump introduced in Patent Document 1.

[0021] Furthermore, by using a thermosetting resin body and eliminating the need for a metal body or metal cover, cutting processes for manufacturing the body and cover are no longer necessary, which further reduces the manufacturing costs of the electric liquid pump of the present invention.

[0022] As a result of the cooperation of the above, the electric liquid pump of the present invention can reduce the weight of the electric liquid pump and its manufacturing costs.

[0023] The electric liquid pump of the present invention will be described below with respect to each of its components.

[0024] In this specification, when simply referring to the radial direction or the axial direction, it means the radial direction or the axial direction of the shaft of the electric motor.

[0025] Unless otherwise specified, the numerical ranges "x to y" described in this specification include the lower limit x and the upper limit y. These upper and lower limit values, as well as the numerical values ​​listed in the embodiments, can be arbitrarily combined to form a numerical range. Furthermore, the upper and lower limit values ​​can be arbitrarily selected from within the numerical range.

[0026] The electric fluid pump of the present invention is a pump for infusing fluids such as oil and various coolants, and can be embodied, for example, as a pump mounted on a vehicle to supply oil to a drive system such as a transmission. The electric fluid pump of the present invention may be a small pump mounted on a vehicle, or a stationary pump installed in various facilities.

[0027] The electric liquid pump of the present invention comprises an electric motor, a liquid pump, a motor case, and a body.

[0028] The electric motor in the electric liquid pump of the present invention has a motor rotor and a stator. The electric motor may be a so-called inner rotor motor in which the stator is disposed radially outside the motor rotor, or a so-called outer rotor motor in which the stator is disposed radially inside the motor rotor.

[0029] The shaft is a long member that constitutes the rotating shaft of the motor rotor, and it is preferable to use a material that is difficult to deform as the material for the shaft. The shaft may be made of a magnetic material or a non-magnetic material, but is preferably made of a magnetic material in order to function as a back yoke for the magnet portion.

[0030] The shaft may have a constant radial cross section, or may have a T-shaped cross section with a sleeve of a larger diameter at one end in the axial direction, i.e., the part integrated with the magnet part, compared to the other parts. If the shaft has a sleeve, the magnet part is integrated with the sleeve. Therefore, when a sleeve is provided on the shaft, it can effectively function as a back yoke as described above, and also has the advantage of being able to reduce the magnet part by the amount of the sleeve.

[0031] The magnet portion may be any permanent magnet that can generate a magnetic field, and may be, for example, a bonded magnet.

[0032] A bonded magnet is a magnet made by binding magnetic powder with a binder. The magnetic powder can be any known material, such as SmFeN, ferrite, or neodymium. The binder can also be any known material, such as resin or elastomer. By using a bonded magnet as the magnet portion, it is possible to reduce the mass of the magnet portion by the amount of the binder.

[0033] Furthermore, by using a bonded magnet for the magnet portion, the weight of the entire motor rotor is reduced, which reduces the rotational torque of the metal motor rotor, and the thermosetting resin body without bearings has the advantage of allowing the motor rotor shaft to rotate more smoothly.

[0034] Furthermore, when a bonded magnet is used for the magnet portion, the rotational torque of the motor rotor is reduced, so a smaller stator is sufficient, which also contributes to the weight reduction of the electric liquid pump of the present invention.

[0035] The method for integrating the magnet portion and the shaft is not particularly limited; for example, they may be integrated during molding using insert molding, or a pre-molded magnet portion may be fixed to the shaft using a method such as adhesive.

[0036] The stator is a part that generates a force for rotating the rotor, and may have a known structure such as a core with a coil wound around it.

[0037] The liquid pump has an inner rotor and an outer rotor.

[0038] The inner rotor has external teeth and is integrated with the other axial end of the shaft, so that the inner rotor rotates together with the shaft.

[0039] The outer rotor has internal teeth that mesh with the external teeth of the inner rotor. In other words, the inner rotor is disposed inside the outer rotor, and the outer rotor rotates in response to the rotation of the inner rotor.

[0040] A clearance volume is formed between the inner rotor and the outer rotor. As the inner rotor and the outer rotor rotate, liquid is drawn into the clearance volume from a suction passage outside the electric liquid pump, and liquid is discharged from the clearance volume to a discharge passage outside the electric liquid pump.

[0041] The inner rotor and outer rotor for forming the clearance volume may have any shape that is generally used in liquid pumps.

[0042] Specifically, in a typical oil pump, the inner rotor and outer rotor mesh eccentrically. The inner rotor has multiple external teeth. The outer rotor is located radially outward of the inner rotor and has internal teeth that mesh with the external teeth of the inner rotor. The number of internal teeth on the outer rotor is different from the number of external teeth on the inner rotor. When the shaft rotates, the inner rotor, which is integrated with the shaft, rotates integrally with the shaft. This causes the outer rotor, which is engaged with the inner rotor, to rotate eccentrically relative to the inner rotor. As this rotation occurs, the volumes of the multiple clearance volumes formed between the inner rotor and the outer rotor repeatedly shrink and expand sequentially. This causes oil to be sucked up from the suction passage outside the electric hydraulic pump to the clearance volumes by negative pressure, and oil to be compressed from the clearance volumes to the discharge passage outside the electric hydraulic pump by compression.

[0043] The inner rotor and the outer rotor may have any general shape that can perform the above-mentioned pump function.

[0044] The motor case is a box-shaped member that houses the motor rotor having a magnet portion, the stator, and the body.

[0045] The motor case has a first housing chamber and a second housing chamber therein, and a partition wall between the first housing chamber and the second housing chamber. The partition wall has a hole-like connecting portion that connects the first housing chamber and the second housing chamber. The partition wall may have a passage that connects the first housing chamber and the second housing chamber in addition to the hole-like connecting portion.

[0046] The first housing chamber accommodates the magnet portion, the stator, and one axial end of the shaft integrated with the magnet portion. In other words, the first housing chamber accommodates the axial part of the motor rotor including the magnet portion and the stator. The first housing chamber can also be considered as a motor chamber that accommodates the part of the electric liquid pump of the present invention that functions as the electric motor.

[0047] The second housing accommodates another axial portion of the shaft, i.e., another axial portion of the motor rotor. Furthermore, the second housing accommodates a general body portion, which is part of the body. For convenience of accommodating the body, it is preferable that the end of the second housing accommodates the body opposite the first housing accommodates the body be open. Hereinafter, this opening will be referred to as a case opening, as necessary.

[0048] As described above, the first and second housing chambers are separated by a partition wall and communicate with each other through a hole-like connecting portion. Therefore, the portion of the motor rotor between the portion housed in the first housing chamber and the other axial portion housed in the second housing chamber can be said to be housed in the hole-like connecting portion. Specifically, this portion is the portion between one axial end and the other axial end of the shaft.

[0049] The body has a centering body portion and a general body portion. The centering body portion is inserted into the hole-like connecting portion to center the body relative to the motor case, and the outer shape of the centering body portion approximately matches the shape of the hole-like connecting portion. The body of the electric liquid pump of the present invention is made of a thermosetting resin, which will be described in detail later.

[0050] The general body portion is a portion that is continuous with the centering body portion and is housed in the second housing chamber of the motor case.

[0051] A bearing portion is formed through the centering body portion and the general body portion. The bearing portion is simply a through-hole without a bearing or the like. However, an oil groove may be provided in the bearing portion to improve lubrication between the shaft and the bearing portion. The bearing portion accommodates a portion of the motor rotor shaft between one end and the other end, i.e., a portion that is not integrated with either the magnet portion or the inner rotor.

[0052] An inner rotor is integrally formed on the other axial end of the motor rotor shaft. The inner rotor may be disposed outside the body, but in order to make the electric liquid pump of the present invention compact and lightweight, it is preferable to dispose it inside the body.

[0053] That is, it is preferable that a rotor accommodating chamber for accommodating the inner rotor and the outer rotor is provided at the end of the general body opposite the centering body, and the rotor accommodating chamber is connected to the bearing due to the positional relationship of the shaft, inner rotor, and outer rotor.

[0054] When the general body portion has a rotor accommodating chamber for accommodating the inner rotor and the outer rotor, it is preferable that the inner rotor and the outer rotor are also accommodated in the motor case together with the general body portion.

[0055] The general body portion and the motor case are integrated with each other by inserting the centering body portion into the hole-like connecting portion and centering them, but they may also be integrated at other portions. For example, if the second housing chamber has a case opening, the general body portion may close the case opening, and the general body portion and the motor case may be centered around the periphery of the case opening.

[0056] Furthermore, the centering portion between the general body and the motor case may also be used as a mounting portion for mounting the electric liquid pump of the present invention to a mating member, such as an oil pan, for supplying liquid to the pump. In this case, the structure for integrating the body and motor case in the electric liquid pump of the present invention and the structure for mounting the electric liquid pump of the present invention to the mating member can be made simple and compact. This contributes to further reducing the size and weight of the electric liquid pump of the present invention.

[0057] In the electric liquid pump of the present invention, the materials of the inner rotor and the outer rotor are not particularly limited, and they may be made of metal such as aluminum, or may be made of resin. At least one of the inner rotor and the outer rotor is preferably made of resin, and among such resins, a thermosetting resin is preferably used. Hereinafter, the inner rotor or the outer rotor made of resin may be referred to as a resin rotor as necessary.

[0058] By using a thermosetting resin as the material for the resin rotor, it is possible to reduce the weight of the resin rotor while maintaining its heat resistance. Although only one of the inner rotor and the outer rotor may be a resin rotor, it is preferable that both the inner rotor and the outer rotor are resin rotors. Furthermore, it is particularly preferable that both the inner rotor and the outer rotor are resin rotors and made of a thermosetting resin.

[0059] When the inner rotor and outer rotor are made of resin, the materials of the inner rotor and outer rotor may be the same or different, and may even be the same as the material of the body.

[0060] The thermosetting resin used as the material for the body and, if necessary, the inner rotor and / or outer rotor is not particularly limited, and may be selected appropriately taking into consideration the deterioration resistance and infiltration resistance to the liquid that is drawn in and discharged by the electric liquid pump of the present invention, and the seizure resistance and sliding properties of the bearing parts. For example, if the electric liquid pump of the present invention is an oil pump for a vehicle, it is preferable to use a phenolic resin as the thermosetting resin.

[0061] In the present invention, the term "made of thermosetting resin" includes not only those made of only thermosetting resin, but also those made of a mixture of thermosetting resin and various compounding agents.

[0062] The compounding agent referred to here means a material other than the thermosetting resin, and examples thereof include reinforcing fibers such as glass fiber and carbon fiber, various inorganic fillers typified by mineral powders such as talc and mica, and glass beads, as well as various additives such as antifoaming agents and pigments.

[0063] The amount of compounding agent relative to the thermosetting resin is not particularly limited, but is preferably, for example, 90% by mass or less, 70% by mass or less, or 50% by mass or less relative to 100% by mass of the thermosetting resin.

[0064] In the electric liquid pump of the present invention, the material of the motor case is not particularly limited.

[0065] The electric liquid pump of the present invention will be described below by way of a specific example.

[0066] Example 1 The electric fluid pump of the first embodiment is mounted on a vehicle and serves to suck up oil from an oil pan and supply it to a drive system such as a transmission, and the fluid in the electric fluid pump is oil.

[0067] Fig. 1 is an explanatory diagram that schematically illustrates the appearance of the electric liquid pump of Example 1. Fig. 2 is an explanatory diagram that schematically illustrates the electric liquid pump of Example 1 cut at position XX in Fig. 1. Fig. 3 is an explanatory diagram that schematically illustrates the electric liquid pump of Example 1 cut at position YY in Fig. 1. Hereinafter, in the first embodiment, the terms "upper", "lower", "left", "right", "front" and "rear" refer to the respective directions shown in the drawings. The upper and lower directions correspond to the axial direction of the motor rotor.

[0068] As shown in FIGS. 1 to 3, the electric liquid pump 1 of the first embodiment includes an electric motor 2, a liquid pump 3, a motor case 4, and a body 5.

[0069] As shown in FIGS. 2 and 3, the electric motor 2 has a motor rotor 20 and a stator 25.

[0070] The motor rotor 20 has a shaft 21 and a magnet portion 23, and its axial cross section is substantially T-shaped. Of these, the shaft 21 is a long member made of magnetic metal, and has a sleeve 21s at one end in the axial direction, the sleeve 21s having a larger diameter than the other portions.

[0071] The magnet portion 23 is a bonded magnet, which is integrated with the outer peripheral surface of the sleeve 21s and extends radially outward beyond the sleeve 21s.

[0072] The stator 25 is disposed radially outward of the magnet portion 23. The control board 7 is connected to the stator 25 via lead wires (not shown). 3, a lead wire 70 is further connected to the control board 7 and directed toward the outside of the electric liquid pump 1. The end of the lead wire 70 forms a connection terminal portion 71 for supplying power to the electric motor 2 of the first embodiment and for inputting and outputting signals.

[0073] The liquid pump 3 has an inner rotor 30 and an outer rotor 35. The inner rotor 30 and the outer rotor 35 are made of phenolic resin.

[0074] The inner rotor 30 has external teeth 31 and is integrated with the other axial end of the shaft 21, i.e., the lower end in Figures 2 and 3. Because the inner rotor 30 is integrated with the shaft 21 of the motor rotor 20, when the motor rotor 20 rotates due to the action of the stator 25 and the magnet portion 23, the inner rotor 30 rotates together with the motor rotor 20.

[0075] The outer rotor 35 has internal teeth 36 that mesh with the external teeth 31 of the inner rotor 30 , and is disposed outside the inner rotor 30 so as to surround the inner rotor 30 . A clearance volume 38 is formed between the inner rotor 30 and the outer rotor 35 to provide a pump function.

[0076] The motor case 4 is made of polyphenylene sulfide resin containing reinforcing fibers, is box-shaped, and has a case opening 40 that opens downward. A first housing chamber 41 and a second housing chamber 42 are provided inside the motor case 4. Inside the motor case 4, the first housing chamber 41 is located at the top and the second housing chamber 42 is located at the bottom, and a partition wall 45 is provided between the first housing chamber 41 and the second housing chamber 42.

[0077] The partition wall 45 is provided with a through-hole-like communicating portion 46 that passes through the partition wall 45 in the thickness direction, i.e., the vertical direction. In the electric liquid pump 1 of the first embodiment, the hole diameter of the communicating portion 46 is approximately the same as the inner diameter of the first storage chamber 41.

[0078] The first housing chamber 41 of the motor case 4 houses an upper portion of the motor rotor 20 including the magnet portion 23, and the stator 25. The stator 25 is disposed radially outward of the magnet portion 23 so as to surround the magnet portion 23.

[0079] The inner portion of the stator 25, i.e., the portion of the stator 25 on the motor rotor 20 side, is exposed to the first housing chamber 41. The outer portion of the stator 25 is outside the first housing chamber 41 and is embedded in the wall portion of the motor case 4.

[0080] In the electric liquid pump 1 of the first embodiment, the portion of the motor case 4 above the first housing chamber 41 is divided into an upper and lower section, with a board chamber 48 formed between them.

[0081] The board chamber 48 is liquid-tightly isolated from the first housing chamber 41 and the second housing chamber 42, and a control board 7 for the stator 25 is disposed in the board chamber 48. The control board 7 is electrically connected to the stator 25 by lead wires extending from the first housing chamber 41 to the board chamber 48. For this reason, a communication path (not shown) through which the lead wires pass is formed in the portion of the motor case 4 between the first housing chamber 41 and the board chamber 48. However, the gap between the communication path and the lead wires is liquid-tightly sealed at the boundary between the first housing chamber 41 and the board chamber 48. Therefore, the board chamber 48 in the electric liquid pump 1 of the first embodiment is liquid-tightly isolated from the first housing chamber 41 and the second housing chamber 42.

[0082] The hole-like communicating portion 46 and the second accommodating chamber 42 are continuous, and the portion of the motor rotor 20 other than the portion accommodated in the first accommodating chamber 41 is accommodated in the hole-like communicating portion 46 or the second accommodating chamber 42.

[0083] The body 5 is made of phenolic resin. A centering body portion 51, which is a part of the body 5, is inserted into the hole-like connecting portion 46. The outer shape of the centering body portion 51 is roughly the same as the hole shape of the hole-like connecting portion 46, so that the centering body portion 51 is fitted into the hole-like connecting portion 46 and is centered, i.e., positioned, with respect to the partition wall 45 and ultimately the motor case 4.

[0084] The upper portion of the general body portion 52, which is continuous with the centering body portion 51, is housed in the second housing chamber 42, which is continuous with the hole-like connecting portion 46. The outer shape of the upper portion of the general body portion 52 is slightly smaller than the inner shape of the second housing chamber 42, and a small space is formed in the outer portion of the general body portion 52 in the second housing chamber 42. This space functions as an oil circulation space.

[0085] 3, a plurality of recesses 53 are formed inside the general body portion 52. The interior of the recesses 53 communicates with the clearance volume 38 formed between the inner rotor 30 and the outer rotor 35.

[0086] A bearing portion 55 is formed to penetrate the centering body portion 51 and the general body portion 52. The bearing portion 55 is a through-hole extending in the vertical direction. A central portion of the shaft 21 of the motor rotor 20 is supported by the bearing portion 55. More specifically, the axial central portion of the shaft 21 of the motor rotor 20 is inserted into the through-hole-shaped bearing portion 55 provided in the body 5, and as a result, the bearing portion 55 supports the entire shaft 21, the magnet portion 23 integrated with one axial end of the shaft 21, and the inner rotor 30 integrated with the other axial end of the shaft 25.

[0087] The inner rotor 30 is integrated with the lower end of the shaft 21 of the motor rotor 20. The inner rotor 30 is housed together with the outer rotor 35 in a rotor housing chamber 56 provided at the end of the general body portion 52 opposite the centering body portion 51. The rotor accommodating chamber 56 is larger than the bearing portion 55, is located below the bearing portion 55, and is connected to the bearing portion 55. The bottom of the rotor accommodating chamber 56 is open. Furthermore, there is a recess 53 above the rotor accommodating chamber 56, and the interior of the recess 53 is connected to the rotor accommodating chamber 56. As described above, the inner rotor 30 and the outer rotor 35 are housed in the rotor accommodating chamber 56, and therefore it can be said that the interior of the recess 53 is also connected to the clearance volume 38 formed between the inner rotor 30 and the outer rotor 35 via the rotor accommodating chamber 56.

[0088] The lower end of the general body portion 52 is larger than the second housing chamber 42 , expands in a radial direction perpendicular to the up-down direction, and is exposed to the lower side of the motor case 4 through the case opening 40 . The lower end of the motor case 4, in other words, the peripheral edge of the case opening 40, also expands in a radial direction perpendicular to the up-down direction.

[0089] 2, through holes are formed at opposing positions in the lower end of the general body portion 52 and the periphery of the case opening 40. A fastener (not shown) is inserted into the through hole, and the lower end of the general body portion 52 is fixed to the periphery of the case opening 40 by the fastener. The lower end of the general body portion 52 can be said to close the case opening 40.

[0090] In the electric liquid pump 1 of the first embodiment, the body 5, inner rotor 30, and outer rotor 35 are made of phenolic resin, which is a type of thermosetting resin, and therefore the electric liquid pump 1 of the first embodiment is lightweight.

[0091] Furthermore, the electric liquid pump 1 of the first embodiment does not require a bearing to support the shaft 21. Therefore, the electric liquid pump 1 of the first embodiment is small and lightweight.

[0092] Furthermore, in the electric liquid pump of Example 1, the body 5 not only houses the liquid pump 3, but also supports the liquid pump 3 and the electric motor 2. Because the body 5 thus performs many functions, the number of parts in the electric liquid pump 1 of Example 1 is reduced, which in turn reduces the number of steps required to manufacture the electric liquid pump 1 and, ultimately, reduces the manufacturing costs of the electric liquid pump 1.

[0093] Furthermore, in the electric fluid pump 1 of the first embodiment, the body 5 is made of a thermosetting resin, which eliminates the need for metal cutting during manufacturing, thereby further reducing manufacturing costs.

[0094] By virtue of the cooperation described above, the electric liquid pump 1 of the first embodiment can achieve a reduction in weight and manufacturing costs.

[0095] Although the present invention has been described above, the present invention is not limited to the above-described embodiments, etc., and it is possible to implement the present invention by appropriately extracting and combining elements described in the embodiments, etc., and to make various modifications within the scope that does not deviate from the spirit of the present invention. Furthermore, the specification of the present invention discloses not only the citation relationships of the claims at the time of filing but also the technical idea of ​​appropriately combining the matters described in the claims. [Explanation of symbols]

[0096] 1: Electric liquid pump 2: Electric motor 20: Motor rotor 21: Shaft 23: Magnet section 25: Stator 3: Liquid pump 30: Inner rotor 31: Outer teeth 35: Outer Rotor 36: Inner teeth 38: Clearance volume 4: Motor case 41: First Containment Cell 42: Second Containment Cell 45: Compartment wall 46: Hole-like connecting part 48: Substrate room 5: Body 51: Centering body part 52: General body part 55: Bearing part 7: Control board

Claims

1. an electric motor including a motor rotor having a shaft and a magnet portion integrated with one axial end of the shaft, and a stator disposed radially outside or inside the magnet portion to rotate the motor rotor; a liquid pump including: an inner rotor having external teeth and integral with the other axial end of the shaft; and an outer rotor having internal teeth that mesh with the external teeth and forming a clearance volume between the inner rotor and the outer rotor, into which liquid is sucked from a suction passage and into which liquid is discharged toward a discharge passage; a motor case having a box shape and including inside a first accommodating chamber that accommodates the stator and a portion of the motor rotor in the axial direction including the magnet portion, a second accommodating chamber that communicates with the first accommodating chamber and accommodates another portion of the motor rotor in the axial direction, and a partition wall that has a hole-like communicating portion that communicates the first accommodating chamber and the second accommodating chamber and is provided between the first accommodating chamber and the second accommodating chamber, and in which a liquid circulates between the first accommodating chamber, the second accommodating chamber, and the hole-like communicating portion; a body including a centering body portion inserted into the hole-like connecting portion and centered therein, a general body portion continuous with the centering body portion and accommodated in the second accommodation chamber, and a bearing portion formed through the centering body portion and the general body portion and supporting a part of the axial direction of the shaft at a position between the magnet portion and the inner rotor, The entire body of the electric fluid pump is made of thermosetting resin.

2. 10. The electric liquid pump of claim 1, wherein the thermosetting resin comprises a phenolic resin.

3. 3. The electric liquid pump according to claim 2, wherein the thermosetting resin contains reinforcing fibers and / or inorganic fillers in an amount of 30% by mass to 90% by mass, both inclusive, when the total mass is taken as 100% by mass.

4. 3. The electric liquid pump according to claim 1, wherein the body is injection molded or compression molded.

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