JP6574595B2 - Electric pump device - Google Patents

Description

  The present invention relates to an electric pump device used, for example, with an electric oil pump that controls the flow of oil.

  Electric oil pumps are becoming mainstream as pumps for supplying oil to automatic transmissions of vehicles. For example, as shown in Patent Document 1 and Patent Document 2, the electric oil pump is composed of a motor unit and a pump unit, and the inner rotor of the pump is fixed to the rotating shaft of the motor, and the inner rotor is rotated by the motor. It is.

  The motor unit includes a motor main body including a stator and a rotor as main components, and a substrate provided on one end side in the axial direction, on which electronic components for mounting a motor drive circuit are mounted. The motor body and the substrate are covered with a metal or resin case. In particular, recently, a case has been proposed in which the main part is constituted by a cover of a resin molded product, and a connector for electrically connecting the substrate and the outside is integrated with the resin cover.

  On the other hand, the pump unit includes an inner rotor fixed to the rotating shaft of the motor and an outer rotor arranged around the inner rotor, and the inner rotor and the outer rotor are housed in a metal pump body. The resin motor mold is a cup-shaped member whose bottom surface is open, and the metal pump body is a cup-shaped member whose top surface is open, and the two are combined and fixed so that the opening faces each other. Thus, the motor unit and the pump unit are sealed by the resin motor mold and the metal pump body.

  In this case, the stator of the motor is fixed to the resin motor mold by molding, and an insert nut is fixed to the outside of the stator in the resin motor mold. By screwing the tip of the bolt inserted from the pump body side into the insert nut, the resin motor mold and the metal pump body are fixed.

JP 2014-126005 A JP 2012-241593 A

  Since this type of electric oil pump is often used in an automatic transmission of a vehicle and the like, it is subjected to vibration for a long period of 10 years or more, and therefore, excellent vibration resistance performance is required. Usually, the resin motor mold and the metal pump body are fixed by fastening the tip of a bolt that penetrates the metal pump body to the insert nut of the resin motor mold.

  However, in the prior art, only the insert nut is fastened to the metal pump body, and therefore it is the resin motor mold that bears the mechanical strength of the electric oil pump. In particular, since a heavy metal stator is supported only by the motor mold resin, if acceleration is applied to the electric oil pump, the inertia of the stator cannot be supported by the motor mold resin and the motor mold cracks or breaks. There is a risk that vibration or noise may occur in the resin motor mold.

  In particular, the board provided in the motor part is located away from the vehicle etc. where the electric oil pump is fixed, and the electronic parts are cantilevered via pin-like terminals etc. with respect to the board. In many cases, when the resin motor mold is vibrated for a long time, the joint between the electronic component and the substrate or the terminal may be broken.

  Such problems occur not only in the electric oil pump but also in electric pumps that send out other fluids, and more excellent vibration resistance performance has been required.

  The present invention has been proposed to solve the above-described problems of the prior art. The objective of this invention is providing the electric pump apparatus which improved the vibration-proof performance, maintaining the structure which resin-molds a stator.

The electric pump device according to the present invention has the following configuration.
(1) Motor rotor.
(2) A metal stator disposed around the motor rotor.
(3) A resin motor mold covering the metal stator.
(4) A metal pump body that houses the pump-side outer rotor and the pump-side inner rotor and at least partially contacts the metal stator.
(5) A bolt for fixing the resin motor mold and the metal pump body.
(6) A bolt insertion portion that is provided in the metal stator and inserts the bolt.
(7) The bolt is inserted into the bolt insertion portion to fasten the resin motor mold, the metal stator, and the metal pump body.

According to the present invention, since the metal stator and the metal pump body are fixed by bolting in a state where the resin motor mold and the metal stator are fixed, the metal stator has the strength of the resin motor mold. As a result, the vibration resistance of the resin motor mold can be improved. Further, by fastening the metal stator and the metal pump body, the metal members can be firmly fastened, so that the vibration resistance of the entire apparatus can be improved.
In particular, when the metal stator and the metal pump body are brought into direct contact with each other, the contact area between the metals increases, and the metal stator can be tightened more firmly, and the vibration resistance can be further improved.

It is a disassembled perspective view of the electric pump apparatus of 1st Embodiment. It is the front view which carried out the cross section of the resin-made motor mold parts of a 1st embodiment. It is an expanded sectional view of the insert nut part of a 1st embodiment. It is the perspective view which removed the resin motor mold in a 1st embodiment. It is the perspective view which compared 1st Embodiment and the prior art. It is the graph which compared the resonance point of 1st Embodiment and a prior art. It is the graph which compared the acceleration of 1st Embodiment and a prior art. The perspective view of the state which removed the resin-made motor molds of 2nd Embodiment. Sectional drawing of 2nd Embodiment.

[1. First Embodiment]
[1.1 Configuration]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. In the present embodiment, the axis refers to an axis that runs in the longitudinal direction of the rotary shaft 1 and passes through the center of the rotary shaft 1. Indicates direction. Further, the cross-sectional view of FIG. 2 shows the cross section of the rotary shaft 1 portion and the cross section of the bolt 7 portion in one view for easy understanding of the internal structure of this embodiment.

  As shown in the exploded perspective view of FIG. 1, the electric pump device of the present embodiment includes a motor part M and a pump part P. The motor unit M includes a columnar motor rotor 2 fixed to one rotating shaft 1 provided at the center of the electric pump device, and a metal stator 3 (hereinafter referred to as a stator 3) disposed around the motor rotor 2. ). The motor rotor 2 and the stator 3 are housed in a resin motor mold 4 (hereinafter referred to as a motor mold 4).

  The motor mold 4 is a rectangular cylindrical member in the present embodiment, and as shown in the cross-sectional view of FIG. 2, a first space portion 5 having an open bottom surface is provided at the lower portion thereof. The motor rotor 2 and the stator 3 are accommodated in the part 5. The stator 3 is accommodated in the motor mold 4 so that the lower surface thereof and the lower surface of the motor mold 4 are flush with each other. The stator 3 may be embedded in the motor mold 4 by molding, or the stator 3 and the motor mold 4 may be fixed with an adhesive. Further, it may be press-fitted or fitted inside the first space portion 5. The stator 3 is configured such that the motor rotor 2 is rotatably disposed inside thereof, and a gap is left between the inner peripheral surface of the stator 3 and the outer peripheral surface of the motor rotor 2 so that they can rotate without contacting each other. .

  The outer peripheral shape of the stator 3 is an annular shape in accordance with the outer peripheral shape of the motor rotor 2, but in the present embodiment, the outer shape in the radial direction from the annular surface according to the shape of the four corners of the rectangular motor mold 4. A protrusion 6 is provided toward the end. A bolt insertion portion 8 for inserting a bolt 7 for fixing the motor portion M and the pump portion P passes through each protrusion 6 in parallel with the rotary shaft 1. As shown in the enlarged view of FIG. 3, an insert nut 9 corresponding to the bolt fastening portion of the present invention is embedded in the same direction as the rotary shaft 1 at a position corresponding to the bolt insertion portion 8 in the motor mold 4. The insert nut 9 is formed by placing a metal nut in the mold of the motor mold 4 and embedding the metal nut inside the resin when the motor mold 4 is molded, that is, by an insert molding method. Embedded in the motor mold 4.

  Above the support plate 10, a second space 12 having an upper surface opened is provided. The substrate 13 is fixed so as to close the upper surface opening of the second space 12. An electronic component 14 for controlling the motor unit M and the like are provided on the lower surface of the substrate 13. In FIG. 1, a capacitor mounted on the lower surface of the substrate 13 is shown as an example of the electronic component 14.

  The board 13 is inserted into a plurality of through holes 15 provided therein, and set screws (not shown) are inserted therein, and screw holes provided in a support portion of the cylindrical substrate 13 raised from the support plate 10 at the tips of the set screws. By being screwed into 17, the motor mold 4 is fixed. An inverter cover 18 that seals the second space 12 together with the substrate 13 is provided on the upper surface of the substrate 13. The inverter cover 18 is fixed to the motor mold 4 by screwing a set screw (not shown) into a screw hole 19 provided on the upper outer periphery of the motor mold 4.

  As shown in the sectional view of FIG. 2, the pump part P includes an inner rotor 20 fixed to the rotary shaft 1 and an outer rotor 21 disposed on the outer side, and the outer rotor 21 and the inner rotor 20 are made of metal. It is accommodated in a pump body 22 (hereinafter referred to as pump body 22). In the present embodiment, the pump body 22 includes a cylindrical rotor storage portion 23 whose outer periphery is a quadrangle and whose upper and lower sides are open inside, and the outer periphery is a circular shape inside the rotor storage portion 23. The outer rotor 21 is rotatably accommodated. Although not shown, an inner gear that forms the outer wall of the compression chamber of the pump is formed on the inner periphery of the outer rotor 21, and the outer gear of the inner rotor 20 inserted inside the outer rotor 21 is against this inner gear. Engage and rotate.

  A square block-shaped pump cover 24 is fixed to the bottom of the pump body 22, and the rotor storage portion 23 is sealed by the pump cover 24. A pair of ports 25 for allowing oil to circulate inside the pump is opened at a location facing the compression chamber of the pump in the pump cover 24. Although the pump cover 24 is provided separately from the pump body 22 in the present embodiment, it can be produced integrally with the pump body 22 according to the position of the port 25 and the shape of the pump.

  In the four corners of the rectangular pump body 22, bolt insertion portions 26 penetrate in the same direction as the rotary shaft 1 in accordance with the positions of the bolt insertion portions 8 provided in the four protruding portions 6 provided in the stator 3. Yes. Four bolt insertion portions 27 extending in the same direction as the rotary shaft 1 are provided outside the port 25 provided in the pump cover 24 in accordance with the position of the bolt insertion portion 26 of the pump body 22. The bottom surface of the pump cover 24 is provided with four recesses 28 for hiding the head of the bolt 7 in accordance with the position of the bolt insertion portion 27.

  The motor part M and the pump part P are fixed by bolts 7. Specifically, the protrusions 6 at the four corners of the stator 3 face the four corners of the pump body 22, and a pump cover 24 containing the stator 3 and the rotor inside is overlaid on the pump body 22. The pump cover 24 is closed, and the four bolts 7 are sequentially passed from the bottom surface of the pump cover 24 into the bolt insertion part 27 of the pump cover 24, the bolt insertion part 26 of the pump body 22, and the bolt insertion part 8 of the stator 3. Screw the tip of the bolt 7 into the insert nut 9.

In this case, the order of assembly is not particularly limited, and is performed as follows, for example.
(1) Place the pump body 22 on the pump cover 24.
(2) Fit the outer rotor 21 inside.
(3) The inner rotor 20 is assembled into the outer rotor 21 with the inner rotor 20 and the motor rotor 2 fixed to the rotary shaft 1.
(4) Fit the stator 3 outside the motor rotor 2.
(5) Cover the motor mold 4 in which the board 13 and the inverter cover 18 are assembled in advance from the outside.
(6) Screw the tips of the four bolts 7 through the pump cover 24, the pump body 22 and the stator 3 into the insert nut 9.

  After fixing the motor part M and the pump part P with the bolts 7, the fixing bolts are inserted into the insertion holes 29 provided at the four corners of the pump cover 24 from the surface side (pump body 22 side) of the pump cover 24. The fixing bolt is fixed to a member for fixing the electric pump device, for example, a vehicle body.

[1.2 Effects]
The operational effects of the first embodiment having the above-described configuration are as follows.

(1) In this embodiment, since the stator 3 and the pump body 22 are fixed by bolting in a state where the motor mold 4 and the stator 3 are fixed, the metal stator 3 is a strength member of the motor mold 4. As a result, the vibration resistance of the motor mold 4 can be improved. Further, since the stator 3 and the pump body 22 are fastened, the metal members can be firmly fastened, so that the vibration resistance of the entire apparatus can be improved.

(2) In the present embodiment, since the stator 3 and the pump body 22 are in direct contact with each other, the contact area between the metals increases, the metal can be tightened more firmly, and the vibration resistance can be further improved.

(3) In the present embodiment, the motor mold 4 and the stator are provided by three or more bolts 7 arranged at predetermined intervals in the circumferential direction, specifically, four bolts 7 arranged diagonally of the electric pump device. 3 and the three members of the pump body 22 are fastened, so that the tightening force can be equally applied to each part in the circumferential direction of the electric pump device, the fastening strength is high, and there is an advantage that no distortion due to fastening occurs in each part of the device. is there.

(4) On the outer periphery of the stator 3 having a circular cross section, a protrusion 6 is provided in the circumferential direction of the rotating shaft 1, and a bolt insertion part 8 is provided on the protrusion 6. The fastening bolt 7 can be arranged without increasing the diameter, and the apparatus can be downsized. Further, since there is a space for filling the resin of the motor mold 4 in a portion other than the protruding portion 6, it is possible to increase the thickness of the resin and improve its strength while reducing the overall size.

(5) In this embodiment, the projecting portion 6 is provided corresponding to the square corner portion of the pump body 22, and the bolt insertion portion 26 is provided on the projecting portion 6. By effectively utilizing the space resulting from the difference in the shape of the pump body 22, the entire apparatus can be fastened, leading to a reduction in the size of the apparatus.

(6) In this embodiment, the substrate 13 on which the electronic component 14 is mounted is fixed to the motor mold 4, and the electronic component 14 to which stress is applied to the joint portion with the substrate 13 is mounted, but the stator 3 is mounted on the pump body 22. Since the motor mold 4 does not vibrate with respect to the pump body 22 even if a large acceleration is applied to the electric pump device, the motor mold 4 and the substrate 13 disposed therein are greatly vibrated. Will not be added. As a result, since a large stress is not applied to the joint portion of the electronic component 14 mounted on the substrate 13 with the substrate 13, there is no possibility that the joint portion is destroyed. In particular, even in an electric pump device in which vibration is applied over a long period of time, such as an in-vehicle electric pump device, the failure of the terminals of the electronic component 14 being broken or the solder welds being peeled off is reduced.

(7) Since the bolt 7 inserted from the pump cover side is fastened to the motor mold 4 through the pump body 22, the motor mold 4, the stator 3, and the pump body 22 are not fixed to the vehicle side. Since the three members are fastened, there is an advantage that the assembly of the electric pump device is completed before fixing to the vehicle. In particular, since the internal device can be sealed by the motor mold 4 and the pump body 22, no foreign matter is mixed in during storage and transportation of the device, and there is no dropout or damage of components inside the device at the time of mounting on the vehicle.

[1.3 Comparative Example]
Comparing the present embodiment shown in FIG. 5 (a) with the conventional electric pump device shown in FIG. 5 (b), the resonance frequencies when vibration is applied from three directions of XYZ are compared. Table 1 and the graph of FIG. A measurement point is the location of the electronic component 14 mounted in the center of the board | substrate 13 provided in the motor mold 4 shown in FIG.

  As can be seen from Table 1, in the electric pump device of the present embodiment, the primary resonance frequency is increased in the two directions of the X axis and the Y axis. In general, when an electric pump device is mounted on a vehicle, if the primary resonance frequency is close to 2 kHz, the electric pump device resonates with the running vibration of the vehicle, so that the primary resonance frequency increases as in this embodiment. It becomes possible to suppress vibration.

Similarly, when comparing the acceleration of 2 kHz at the measurement point when a predetermined acceleration is applied from the three directions of XYZ, it is as shown in the following Table 2 and the graph of FIG.

  As can be seen from Table 2, in the electric pump device of this embodiment, it can be seen that the acceleration is reduced in any direction (particularly, the two directions of the X axis and the Y axis).

[2. Second Embodiment]
A second embodiment will be described with reference to FIGS. In the second embodiment, three members of the motor mold 4, the stator 3 and the pump body 22 are fastened from both sides using the first bolt 7 and the second bolt 31.

  In the present embodiment, insert nuts 9 as first bolt fastening portions are embedded in two diagonal positions of the motor mold 4, and the first bolt 7 inserted from the bottom surface of the pump cover 24 is inserted into the pump body 22 and It is inserted into the stator 3 and screwed into the insert nut 9 of the motor mold 4 to be fixed. Screw holes 19 as second bolt fastening portions are provided at two remaining diagonal positions of the pump body 22, and the second bolt 31 inserted from the upper side of the motor mold 4 is inserted into the stator 3, so that the pump body It is screwed into the screw hole 19 of 22 and fixed.

  The electric pump device of the present embodiment fixed by the first bolt 7 and the second bolt 31 has a pump in the insertion holes 29 provided at the four corners of the pump cover 24 as in the first embodiment. A fixing bolt is inserted from the surface side of the cover 24, and the fixing bolt is fastened to the vehicle body or the like.

  According to this embodiment having such a configuration, the three members of the motor mold 4, the stator 3 and the pump body 22 are fastened from both sides using a plurality of bolts 7 and bolts 31. These three bolts 31 are integrated together, and then the electric pump device can be fixed to the vehicle side with the bolts 7 from the pump body 22 side. As a result, the electric pump device can be easily attached to the vehicle.

  In this embodiment, in order to fasten the three members of the motor mold 4, the stator 3, and the pump body 22 from both sides, four bolt fastening portions are formed with the insert nut 9 of the motor mold 4 and the screw hole 19 of the pump cover 24. Can be dispersed. As a result, there are fewer gaps such as screw holes and recesses 28 provided in one member, the thickness of the motor mold 4 and the pump cover 24 can be sufficiently secured, and excellent fastening strength can be secured.

[3. Other Embodiments]
The present invention is not limited to the above embodiment. The above embodiments are presented as examples, and can be implemented in various other forms. Various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope, gist and equivalent range of the invention. An example is shown below.

(1) The bolt insertion portion provided in the stator 3 or the pump body 22 may be a circular through hole with a closed periphery as in the illustrated embodiment, but other parts are notched like a U-shaped cross section. You may have. The number and location of the bolts 7 and / or bolts 31 that fix the motor unit M and the pump unit P are not limited to the illustrated embodiment, and may be smaller or larger.

(2) All the bolts 31 are inserted from the motor mold 4 side, and the motor mold 4, the stator 3, the pump body 22, and the pump cover 24 are fixed. The pump cover 24 and the vehicle are fixed by another bolt C. . If it does in this way, it will become unnecessary to use the insert nut 9, and the shaping | molding process of the resin-made motor mold 4 will become easy. Since the bolt fastening portion only needs to be screwed into the metal pump body 22 or pump cover 24, the number of parts can be reduced.

(3) When the insert nut 9 is provided on the motor mold 4 and fastened with the bolt 7 from the pump cover 24 side, the assembly of the device and the vehicle can be achieved by using the bolt 7 and the bolt that fastens the pump cover 24 and the vehicle. Can be fixed with a small number of bolts and tightening steps. The pump cover 24 can also be used as a member such as a vehicle body, and the bolt 7 can be inserted from the member such as the vehicle body, or a bolt fastening portion can be provided on the member such as the vehicle body.

DESCRIPTION OF SYMBOLS 1 ... Rotary shaft, 2 ... Motor rotor, 3 ... Stator, 4 ... Motor mold, 5 ... 1st space part, 6 ... Projection part, 7 ... Bolt, 8 ... Bolt insertion part, 9 ... Insert nut, 10 ... Support plate , 12 ... 2nd space part, 13 ... Board | substrate, 14 ... Electronic component, 15 ... Through-hole, 16 ... Board | substrate support part, 17 ... Screw hole, 18 ... Inverter cover, 19 ... Screw hole, 20 ... Inner rotor, 21 DESCRIPTION OF SYMBOLS ... Outer rotor, 22 ... Pump body, 23 ... Rotor accommodating part, 24 ... Pump cover, 25 ... Port, 26 ... Bolt insertion part, 27 ... Bolt insertion part, 28 ... Recessed part, 29 ... Insertion hole, 31 ... Bolt.

Claims (10)

A motor rotor;
A metal stator disposed around the motor rotor;
A resin motor mold covering the metal stator;
A metal pump body that houses the pump-side outer rotor and the pump-side inner rotor, and is at least partially in contact with the metal stator;
A bolt for fixing the resin motor mold and the metal pump body;
A bolt insertion portion provided in the metal stator for inserting the bolt;
With
The electric pump device, wherein the bolt is inserted into the bolt insertion portion to fasten the resin motor mold, the metal stator, and the metal pump body. A motor rotor having a rotating shaft, and a metal stator arranged around the motor rotor;
A resin motor mold that is disposed on the outer periphery of the motor rotor and the metal stator and covers the periphery of the metal stator so that the bottom surface of the metal stator is exposed;
A pump-side inner rotor fixed to the rotating shaft; a pump-side outer rotor disposed on the outer periphery of the pump-side inner rotor;
A metal pump body that is at least partially in contact with the metal stator and houses the pump-side inner rotor and the pump-side outer rotor;
In the metal stator and the metal pump body, at a position avoiding the motor rotor, the pump-side inner rotor and the pump-side outer rotor, a bolt insertion portion provided along the axial direction of the rotating shaft,
A bolt fastening portion provided at a position corresponding to the bolt insertion portion in the resin motor mold;
A bolt inserted into the bolt insertion portion, the screw portion at the tip thereof being screwed into the bolt fastening portion,
The electric pump device in which the resin motor mold, the metal stator, and the metal pump body are fixed by the bolts.   The bolt fastening portion provided in the resin motor mold is an insert nut fixed to the resin motor mold, and the screw portion of the bolt inserted into the bolt insertion portion from the metal pump body side is the insert nut. The electric pump device according to claim 2, wherein the electric pump device is screwed into the electric pump device.   The bolt screwed into the insert nut from the metal pump body side penetrates the bolt insertion part of the metal pump body and the metal stator from the member side fixing the electric pump device, and the tip thereof is a resin motor The electric pump device according to claim 3, wherein the electric pump device is screwed into an insert nut of the mold. A motor rotor having a rotating shaft, and a metal stator arranged around the motor rotor;
A resin motor mold that is disposed on the outer periphery of the motor rotor and the metal stator and covers the periphery of the metal stator so that the bottom surface of the metal stator is exposed;
A pump-side inner rotor fixed to the rotating shaft; a pump-side outer rotor disposed on the outer periphery of the pump-side inner rotor;
A metal pump body that is at least partially in contact with the metal stator and houses the pump-side inner rotor and the pump-side outer rotor;
In the metal stator and the resin motor mold, a bolt insertion portion provided along the axial direction of the rotating shaft at a position avoiding the motor rotor, the pump-side inner rotor and the pump-side outer rotor,
A bolt fastening portion provided at a position corresponding to the bolt insertion portion in the metal pump body;
A bolt inserted into the bolt insertion portion, the screw portion at the tip thereof being screwed into the bolt fastening portion,
The electric pump device in which the resin motor mold, the metal stator, and the metal pump body are fixed by the bolts. A first bolt fastening portion is provided in the resin motor mold, and a thread portion of a first bolt tip inserted into the bolt insertion portion from the metal pump body side is screwed into the first bolt fastening portion,
The metal pump body is provided with a second bolt fastening portion, and a screw portion at the tip of the second bolt inserted into the bolt insertion portion from the resin motor mold side is screwed into the second bolt fastening portion. The electric pump device according to claim 1. A cross section perpendicular to the axial direction of the rotating shaft of the metal stator is annular,
On the outer periphery of the metal stator having an annular cross section, a protrusion is provided in the radial direction of the rotating shaft,
The electric pump device according to any one of claims 1 to 6, wherein the projecting portion is provided with the bolt insertion portion. A cross section perpendicular to the axial direction of the rotating shaft of the metal stator is annular,
The cross section orthogonal to the axial direction of the rotating shaft of the metal pump body is a quadrangle,
The bolt insertion portion or the bolt fastening portion is provided in a portion protruding from the outer periphery of the metal stator in the square corner portion of the metal pump body,
On the radially outer side of the rotating shaft in the resin motor mold and the metal stator, the protrusion is provided corresponding to the square corner portion of the metal pump body,
The electric pump device according to claim 7, wherein the protruding portion is provided with the bolt insertion portion or the bolt fastening portion. A substrate on which electronic components are mounted on the resin motor mold is fixed,
The electric pump device according to any one of claims 1 to 8, wherein an electronic component that applies stress to a joint portion with the substrate in a state where acceleration applied to the electric pump device is transmitted to the substrate. .   At least three bolts that are screwed into the bolt fastening portion through the bolt insertion portion, the corresponding bolt fastening portion, and the bolt insertion portion are provided at different positions in the circumferential direction of the rotating shaft. The electric pump device according to any one of claims 1 to 4.

Images