Electric liquid pump

Abstract

To provide a technique capable of reducing manufacturing costs and wight of an electric liquid pump, while maintaining a performance of the pump.SOLUTION: An electric liquid pump 1 comprises: an electric motor 2 having a motor rotor 20 and a stator 25; a liquid pump 3 having an inner rotor 30 and an outer rotor 35; a motor case 4 formed into a box-shape, and having a first housing chamber 41 housing the stator 25, a second housing chamber 42 housing another axial part of the motor rotor 20, and a partition wall 45 provided between the first housing chamber 41 and the second housing chamber 42; and a body 5 having a centered body part 51 inserted in a hole-like communication part 46, a general body part 52 continued to the centered body part 51 and housed in the second housing chamber 42, and a bearing part formed to penetrate through the centered body part 51 and the general body part 52 and supporting one axial part of a shaft 21 at a position between a magnet part 23 and the inner rotor 30. The inner rotor 30 or the outer rotor 35 is 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] Known electric liquid pumps for transporting liquids such as oil include an electric motor as a drive source, and inner and outer rotors connected to the shaft of the electric motor to realize the pump function (see, for example, Patent Documents 1 to 3).

[0003] In this type of electric liquid pump, the rotation of the electric motor shaft rotates the inner rotor, which is integrated with the shaft. The rotation of the inner rotor also rotates the outer rotor, which is meshed with the inner rotor. This allows the pump to function as a pump that sucks in and discharges liquid. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-95085 [Patent Document 2] Japanese Patent Publication No. 2022-67808 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-173444 Summary of the Invention [Problem to be solved by the invention]

[0005] In an electric liquid pump, high dimensional accuracy is required for the inner rotor and outer rotor. Generally, the inner rotor and outer rotor are manufactured by processing sintered metal, which requires special equipment and know-how, and therefore only a limited number of manufacturers can manufacture inner rotors and outer rotors by processing sintered metal, making inner rotors and outer rotors made from processed sintered metal expensive.

[0006] Furthermore, in order to obtain a sintered metal, a process is required in which mixed metal powder is compressed and molded and then sintered in a sintering furnace, which poses the problem of high production costs for the sintered metal itself.

[0007] Furthermore, because the metal inner rotor and outer rotor are heavy, there is also the problem that it is difficult to reduce the weight of an electric liquid pump that uses a metal inner motor and outer rotor.

[0008] Incidentally, the above-mentioned Patent Documents 1 and 2 propose that the inner rotor and the outer rotor be made of synthetic resin. Since resin materials are easier to mold and lighter than metals, it is believed that using resin inner and outer rotors will reduce the manufacturing costs of electric liquid pumps and make the electric liquid pumps lighter.

[0009] Incidentally, Patent Documents 1 and 2 do not specifically disclose the type of resin material used for the inner rotor and outer rotor, but thermoplastic resin materials, which are commonly used as synthetic resins, have the problem that they are significantly inferior to metals in terms of chemical properties such as heat resistance and mechanical properties such as wear resistance.

[0010] In other words, if the inner rotor and outer rotor are made of resin, the performance of the inner rotor and outer rotor may be reduced, making it difficult to maintain the performance of the electric liquid pump.

[0011] The present invention has been made in consideration of the above circumstances, and its problem to be solved is to provide a technology that can reduce the manufacturing cost of an electric liquid pump and make the electric liquid pump lighter while maintaining the performance of the electric liquid pump. [Means for solving the problem]

[0012] One aspect of the electric liquid pump of the present invention that solves the above problem is: 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 the inner rotor or the outer rotor made of a thermosetting resin.

[0013] Another aspect of the electric liquid pump of the present invention that solves the above problem is: 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 integrated with the other axial end of the shaft, and an outer rotor having internal teeth that mesh with the external teeth and forming a rotor chamber 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 box-shaped case that houses the liquid pump and the shaft; The electric liquid pump has the inner rotor or the outer rotor made of a thermosetting resin. [Effects of the Invention]

[0014] According to the technology of the present invention, it is possible to reduce the manufacturing cost of an electric liquid pump and reduce the weight of the electric liquid pump while maintaining the performance of the electric liquid pump. [Brief explanation of the drawings]

[0015] [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

[0016] The electric liquid pump of the present invention will be described below by way of a specific example.

[0017] As mentioned above, conventional electric liquid pumps use inner and outer rotors made of metal. As a result, the costs required for the inner and outer rotors are high, making it difficult to reduce the manufacturing costs of electric liquid pumps.

[0018] Patent Documents 1 and 2 disclose that the inner rotor and outer rotor are made of synthetic resin, but there is a problem in that general synthetic resins are significantly inferior to metals in chemical and mechanical properties.

[0019] Furthermore, Patent Document 3 introduces a technique of blending carbon fiber or glass fiber into the resin material used for the inner rotor and outer rotor. Also, paragraph

[0015] of Patent Document 3 introduces that engineering plastics are suitable as the resin material.

[0020] It is believed that blending reinforcing fibers such as carbon fiber or glass fiber into the resin material improves the wear resistance of the inner and outer rotors made of that resin material.In addition, engineering plastics have better heat resistance than general thermoplastic resins.

[0021] Although Patent Document 3 does not disclose what materials are suitable as engineering plastics, because engineering plastics are also thermoplastic resins, they become plasticized at high temperatures. Therefore, inner and outer rotors made of engineering plastics also do not have sufficient heat resistance, and there are concerns about durability.

[0022] In the electric liquid pump of the present invention, the inner rotor or the outer rotor is made of a thermosetting resin.

[0023] Thermosetting resin is lighter than metal, so the electric liquid pump of the present invention, which uses an inner rotor or outer rotor made of thermosetting resin, can reduce the weight of the inner rotor and outer rotor, and ultimately reduce the weight of the entire electric liquid pump.

[0024] Furthermore, since thermosetting resin is cheaper and has better formability than sintered metal, using this thermosetting resin as the material for the inner rotor or outer rotor can reduce the manufacturing cost of the inner rotor or outer rotor that is made of thermosetting resin, and ultimately reduce the manufacturing cost required for the entire electric liquid pump.

[0025] Furthermore, thermosetting resins polymerize when heated to form a polymer network structure, and once hardened, they do not soften even when heated again. This gives thermosetting resins superior heat resistance compared to thermoplastic resins. By using such a thermosetting resin as the material for the inner rotor or outer rotor, the one made of thermosetting resin can be given excellent durability.

[0026] Therefore, the electric liquid pump of the present invention can reduce the manufacturing cost and weight while maintaining the performance of the electric liquid pump.

[0027] The electric liquid pump of the present invention will be described below with respect to each of its components. 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.

[0028] 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.

[0029] 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.

[0030] The electric liquid pump of the present invention comprises an electric motor, a liquid pump, and a case, the case of which may comprise a motor case and a body.

[0031] The electric motor includes a shaft, a magnet, and a stator. The electric motor in the electric liquid pump of the present invention 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.

[0032] 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.

[0033] 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.

[0034] The magnet portion may be any permanent magnet that can generate a magnetic field, and may be, for example, a bonded magnet.

[0035] A bonded magnet is a magnet made by binding magnetic powder with a binder. The magnetic powder may be any known material such as SmFeN, ferrite, or neodymium. 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.

[0036] Furthermore, by using a bonded magnet for the magnet portion, the weight of the entire motor rotor, including the magnet portion, can be reduced, which has the advantage of reducing the rotational torque of the motor rotor compared to when a metal motor rotor is used, and allowing the motor rotor shaft to rotate smoothly using a body without bearings.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] The liquid pump has an inner rotor and an outer rotor.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] The inner rotor and outer rotor for forming the clearance volume may have any shape that is generally used in liquid pumps.

[0045] 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.

[0046] The inner rotor and the outer rotor may have any general shape that can perform the above-mentioned pump function.

[0047] In the electric liquid pump of the present invention, the inner rotor or the outer rotor is made of a thermosetting resin.

[0048] By using a thermosetting resin as the material for the inner or outer rotor, it is possible to reduce the manufacturing cost of the inner or outer rotor made of a thermoplastic resin, while maintaining the heat resistance of the inner or outer rotor made of a thermosetting resin, and further reduce its weight. Hereinafter, the inner or outer rotor made of a thermosetting resin may be referred to as a resin rotor, as necessary.

[0049] Either the inner rotor or the outer rotor may be a resin rotor, and it is more preferable that both the inner rotor and the outer rotor are resin rotors. The resin rotor may be made of a thermosetting resin, and even if the inner rotor and outer rotor are made of resin, the materials of the inner rotor and the outer rotor may be the same or different. The thermosetting resin material of the resin rotor will be described in detail later.

[0050] The case may be any type that is box-shaped and can accommodate the liquid pump and shaft described above, but it is preferable that the case be equipped with the motor case and body described below.

[0051] The motor case is a box-shaped member that houses the motor rotor having the magnet portion, the other part of the stator, and the body.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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 material of the body of the electric liquid pump of the present invention is not particularly limited, but it is preferably made of a thermosetting resin, which will be described in detail later.

[0057] 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.

[0058] 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.

[0059] In addition, when the case of the electric liquid pump of the present invention does not include the motor case and the body, the case may have a bearing in the bearing portion. When the case in the electric liquid pump of the present invention comprises a motor case and a body, and the body has a through-hole bearing portion formed through the centering body portion and the general body portion, the bearing can be eliminated as described below, which has the advantage of enabling further weight reduction of the electric liquid pump.

[0060] When the case comprises a motor case and a body, the bearing portion formed through the centering body portion and the general body portion accommodates the portion of the motor rotor shaft between one end and the other end, i.e., the portion that is not integrated with either the magnet portion or the inner rotor.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] When the case includes the motor case and body, the liquid drawn into the liquid pump circulates inside the motor case, specifically, through the first and second chambers and the hole-like connecting portion. By circulating the liquid inside the motor case, a metal bearing or other structure is not required as a bearing portion of the electric liquid pump.

[0067] That is, a typical electric fluid pump requires a bearing portion including a metal bearing as a bearing for supporting the shaft of the electric motor. A bearing is a mechanism 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 component with a relatively large mass.

[0068] When the electric liquid pump of the present invention is configured such that liquid circulates inside the motor case, the liquid circulating inside the motor case is also supplied between a through-hole-shaped bearing portion provided in the body and the shaft supported by the bearing portion, and can function as a lubricant.

[0069] Therefore, in the electric liquid pump of this aspect of the present invention, it is possible to eliminate the need for bearings and to rotate the shaft smoothly. As a result, the electric liquid pump of this aspect of the present invention has the advantage of being lightweight.

[0070] The material of the body is not particularly limited, but it is preferably made of a thermosetting resin similar to the material of the resin rotor. The material of the body may be the same as or different from the material of the resin rotor.

[0071] The thermosetting resin used for the resin rotor and, if necessary, the body is not particularly limited, and may be selected appropriately taking into consideration the deterioration resistance and infiltration resistance of the liquid sucked in and discharged by the electric liquid pump of the present invention, the seizure resistance and sliding properties of the bearing portion, etc. 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] In the electric liquid pump of the present invention, the material of the motor case is not particularly limited.

[0076] The electric liquid pump of the present invention will be described below by way of a specific example.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] As shown in FIGS. 2 and 3, the electric motor 2 has a motor rotor 20 and a stator 25.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] In the electric liquid pump 1 of the first embodiment, the inner rotor 30, the outer rotor 35 and the body 5 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.

[0102] Furthermore, thermosetting resin is less expensive and more moldable than sintered metal, so using thermosetting resin as the material for inner rotor 30, outer rotor 35, and body 5 can reduce the manufacturing costs of inner rotor 30, outer rotor 35, and body 5. This significantly reduces the manufacturing cost of electric liquid pump 1 of the first embodiment.

[0103] Furthermore, by using a thermosetting resin as the material for the inner rotor 30 and the outer rotor 35, excellent durability is imparted to the inner rotor 30 and the outer rotor 35. This improves the durability of the electric liquid pump 1 of the first embodiment itself.

[0104] 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.

[0105] Furthermore, in the electric liquid pump of the first embodiment, the body 5 has the function of accommodating the liquid pump 3 and also the function of supporting the liquid pump 3 and the electric motor 2 . As the body 5 performs many functions in this way, the number of parts in the electric liquid pump 1 of the first embodiment is reduced, which 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.

[0106] As a result of the above cooperation, the electric liquid pump 1 of the first embodiment can reduce the manufacturing cost and weight while maintaining the performance of the electric liquid pump.

[0107] 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]

[0108] 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, An electric liquid pump, wherein the inner rotor or the outer rotor is made of a thermosetting resin.

2. 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 rotor chamber 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 box-shaped case that houses the liquid pump and the shaft; An electric liquid pump, wherein the inner rotor or the outer rotor is made of a thermosetting resin.

3. 3. The electric liquid pump according to claim 1, wherein the inner rotor and the outer rotor are made of a thermosetting resin.

4. 3. The electric liquid pump according to claim 1, wherein the thermosetting resin includes a phenolic resin.

5. 5. The electric liquid pump according to claim 4, 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 of the thermosetting resin is taken as 100% by mass.

6. 3. The electric liquid pump according to claim 1, wherein the inner rotor and the outer rotor are formed by injection molding or compression molding.

Images