JP2008267236A - Manufacturing method for internal gear electric oil pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for an internal gear type electric oil pump, reducing a generation ratio of abnormal noise when a drive gear and a driven gear are rotated, or reducing loudness of the abnormal noise. <P>SOLUTION: The internal gear electric oil pump 1 has an electric motor 2, the drive gear 3, the driven gear 4, and a pump body 5. A gear shaft part 31 of the drive gear 3 is rotatably supported by a rotation support hole 53 formed to the pump body 5, an output shaft 21 of the electric motor 2 is engaged with a gear engaged hole 32 of the drive gear 3. The electric motor 2 is assembled to the pump body 5 by fastening a plurality of bolts so that a positional of the output shaft 21 of the electric motor 2 is shifted to a suction port 51 side of the pump body 5 within a range of a clearance by engagement with a plurality of positioning pins 55 or engagement of a shaft-like projection 23 with a shaft hole 56 while the pump body 5 is relatively pressed against the electric motor 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a manufacturing method of an internal gear type electric oil pump that feeds oil by rotating a drive gear and a driven gear by an electric motor.

  As an oil pump that supplies oil of a desired pressure to a hydraulic control circuit such as an automatic transmission, an internal gear type electric motor that uses an electric motor to rotationally drive a drive gear that meshes with an internal tooth of a driven gear by an external tooth. There is an oil pump. This electric oil pump can supply oil (hydraulic oil) to the automatic transmission even when the engine is stopped, particularly in a hybrid vehicle or the like.

For example, Patent Document 1 includes a casing in which a gear chamber having a suction port and a discharge port is formed, and an external drive gear and an internal drive gear that are meshed with each other and disposed in the gear chamber. An internal gear type oil pump is disclosed in which hydraulic oil is pressurized and fed by rotation of a gear and a driven gear.
Further, when assembling the electric oil pump, in consideration of assemblability, the gear shaft portion formed on the drive gear is inserted into the rotation support hole formed on the pump body, and the drive gear and the driven gear are inserted into the pump body. A pump body is formed by being housed inside, and an electric oil pump is assembled by fastening the pump body and the electric motor with a plurality of bolts.

By the way, even if each component is positioned and assembled, there is a minute micron order between the positioned components due to the dimensional tolerances set in the assembly part of each component, the processing accuracy of each component, etc. In most cases, there are clearances, misalignments, and the like.
Also, in the internal gear type electric oil pump, when the oil is fed by the drive gear and the driven gear, the oil pressure at the discharge port is higher than the oil pressure at the suction port. In the pump body, a force is applied from the side where the discharge port is formed toward the side where the suction port is formed. Therefore, especially when the center of the output shaft of the electric motor is slightly displaced from the center of the gear shaft portion of the drive gear on the side where the discharge port is formed, and the electric oil pump is assembled, When the drive gear and the driven gear rotate, there is a possibility that an abnormal noise is generated. And when this abnormal noise is generated when the electric oil pump is operated when the engine is stopped, particularly in a hybrid vehicle or the like, it becomes conspicuous.

JP 2004-28006 A

  The present invention has been made in view of such a conventional problem, and is an internal gear type electric oil capable of reducing the rate of occurrence of abnormal noise or the magnitude of abnormal noise when the drive gear and the driven gear rotate. It is intended to provide a method for manufacturing a pump.

The present invention relates to an electric motor, a drive gear that rotates in response to rotation of the output shaft of the electric motor, a driven gear that meshes with an external tooth of the drive gear by an internal tooth, and the driven gear and the drive gear. An internal gear type having a suction port for sucking oil and a pump body for discharging the oil by relative rotation of the driven gear and the drive gear. In the method of manufacturing the electric oil pump of
The drive gear has a gear shaft portion that is rotatably supported by a rotation support hole formed in the pump body, and the output shaft of the electric motor has an engagement surface that is chamfered in parallel to the axial direction. And engaged with a gear engaged hole formed in the drive gear by the engagement surface,
The pump body has an accommodation hole for accommodating the driven gear and the drive gear in a state in which the outer peripheral surface of the driven gear is slid, and the suction port and the discharge port are located in the accommodation hole. A bottom portion facing the side surfaces of the drive gear and the driven gear, each formed in an arc shape at positions on both sides via the output shaft of the electric motor;
The pump body and the electric motor are assembled by tightening a plurality of bolts in a state in which the pump body and the electric motor are positioned by engagement with a plurality of positioning pins or engagement between a shaft-like protrusion and a shaft hole.
When assembling the electric motor with the pump body in which the gear shaft portion is inserted into the rotation support hole and the drive gear and the driven gear are accommodated in the accommodation hole, the drive gear The output shaft of the electric motor is inserted into the gear engaged hole, and the pump body and the electric motor are positioned by engagement with the plurality of positioning pins or engagement between the shaft-like protrusion and the shaft hole. In this state, the output shaft of the electric motor is displaced toward the suction port side of the pump body within the clearance due to the engagement by the plurality of positioning pins or the engagement between the shaft-shaped protrusion and the shaft hole. The pump body and the electric motor are tightened by tightening the plurality of bolts in a state where the pump body is pressed relatively to the electric motor. There to carry out with a set to the manufacturing method of the internal gear electric oil pump, wherein (claim 1).

In the manufacturing method of the present invention, when assembling the internal gear type electric oil pump, the device is designed to stabilize the engagement state between the drive gear accommodated in the pump body and the output shaft of the electric motor. ing.
Specifically, the drive gear of the present invention has a gear shaft portion that is inserted into a rotation support hole formed in the pump body, and the gear shaft portion is rotatably supported by the pump body. In this state, the drive gear is rotated by receiving the rotation of the output shaft of the electric motor. The pump body and the electric motor are assembled by tightening a plurality of bolts in a state where the pump body and the electric motor are positioned by engagement with a plurality of positioning pins or engagement between the shaft-like protrusion and the shaft hole.

By the way, between the gear shaft portion and the rotation support hole, between the plurality of positioning pins and the pump body and the electric motor, or between the shaft-like protrusion and the shaft hole, there is a minute amount due to the dimensional tolerance of each component, processing accuracy, etc. Mostly there is clearance.
In the present invention, the gear shaft portion of the drive gear is inserted into the rotation support hole of the pump body, the drive gear and the driven gear are accommodated in the accommodation hole of the pump body, and the drive gear and the driven gear are arranged in the pump body. Then, the pump body and the electric motor are combined in a state in which the pump body and the electric motor are positioned by engagement with a plurality of positioning pins or engagement between the shaft-like protrusion and the shaft hole.

  Further, in this state of positioning, the pump body is pressed relatively to the electric motor so that the output shaft of the electric motor is displaced toward the suction port side of the pump body. At this time, the output shaft of the electric motor is displaced toward the suction port side of the pump body within a clearance range due to engagement by a plurality of positioning pins or engagement between the shaft-like protrusion and the shaft hole. And in the state which performed this position shift, a some bolt is tightened and a pump body and an electric motor are assembled | attached, and an electric oil pump is manufactured.

When operating the electric oil pump manufactured in this way, the drive gear is configured such that the oil pressure at the discharge port formed at the bottom of the housing hole of the pump body is the oil pressure at the suction port formed at the bottom of the housing hole of the pump body. Higher than the clearance between the gear shaft of the drive gear and the rotation support hole of the pump body and the clearance between the output shaft of the electric motor and the gear engaged hole of the drive gear. The position is shifted to
At this time, as described above, the output shaft of the electric motor is in a state of being displaced toward the suction port.

  Therefore, when the drive gear rotates in response to the rotation of the output shaft of the electric motor, both the shaft center of the gear shaft portion of the drive gear and the shaft center of the output shaft of the electric motor are on the inlet side. In this state, the amount of positional deviation between the axial centers of the two can be reduced. Thus, the position of the shaft center of the gear shaft portion of the drive gear and the shaft center of the output shaft of the electric motor when the drive gear rotates and the driven gear rotates following the rotation of the drive gear in the accommodation hole. It is possible to reduce the occurrence rate of abnormal noise or the size of abnormal noise caused by a large deviation.

  Therefore, according to the manufacturing method of the present invention, it is possible to manufacture an internal gear type electric oil pump that can reduce the generation rate or the size of abnormal noise when the drive gear and the driven gear rotate. Can do.

A preferred embodiment of the present invention described above will be described.
In the present invention, the internal gear type electric oil pump may supply hydraulic oil as oil to the control circuit of the automatic transmission.
The output shaft of the electric motor is formed with a pair of engaging surfaces having two parallel widths, and the gear engaged hole has a pair of engaged surfaces facing the pair of engaging surfaces. A mating surface can be formed (claim 2).
In this case, the rotation of the output shaft of the electric motor and the gear engaged hole of the drive gear is prevented by the width of the two surfaces. Then, when the drive gear rotates upon receiving the rotation of the output shaft of the electric motor, the operating point of the driving force is changed from the contact portion between one engagement surface and one engaged surface to the other engagement surface. Even when switching to the contact portion with the other engaged surface, both the shaft center of the gear shaft portion of the drive gear and the shaft center of the output shaft of the electric motor are displaced toward the suction port. By being in the performed state, the occurrence rate of abnormal noise or the size of abnormal noise can be reduced.

Further, when the pump body and the electric motor are assembled, the electric motor is held on a holding base, and the pump body is provided on the clamp portion of the pressing clamp with respect to the electric motor. It is preferable to press with a predetermined pressing force by the repulsive force.
In this case, the pump body is pressed against the electric motor with an appropriate pressing force, and the output shaft of the electric motor is engaged with the plurality of positioning pins or the shaft-like protrusion and the shaft toward the suction port side of the pump body. It is possible to appropriately shift the position within the clearance due to the engagement with the hole.

Preferably, the pressing clamp is a toggle clamp, and the elastic body is a compression spring.
In this case, it is easy for the operator to manually operate the toggle clamp, and the pump body can be easily pressed against the electric motor.

  The pump body includes a body main body formed with the housing hole, the suction port, and the discharge port, and a body cover that faces the body main body and maintains the drive gear and the driven gear in the housing hole. The body main body and the body cover, and the body cover and the electric motor are all positioned by engagement with the plurality of positioning pins or engagement between the shaft-like protrusion and the shaft hole. And when assembling the body cover and the electric motor, the body body, the body cover, and the body cover with the plurality of bolts in a state of pressing the body body relative to the electric motor, It is preferable that the electric motor is fastened together.

In this case, the pump body can be easily formed by arranging the drive gear and the driven gear in the housing hole of the body main body and positioning and combining the body main body and the body cover. Then, the body cover and the electric motor are positioned and aligned with each other, and the body main body is pressed relative to the electric motor, so that the clearance between the body main body and the body cover is determined, and the body cover and the electric motor The output shaft of the electric motor can be displaced toward the suction port side of the body main body within the range of the clearance due to the positioning.
In a state in which this positional deviation is performed, the body main body, the body cover, and the electric motor are fastened together with a plurality of bolts, so that the occurrence rate of abnormal noise or the size of abnormal noise can be reduced. A contact gear type electric oil pump can be easily manufactured.

  The pump body includes a body main body in which the accommodation hole, the suction port, and the discharge port are formed. The mounting portion of the electric motor faces the body main body and has the drive gear and the drive hole in the housing hole. A cover portion for maintaining the driven gear is integrated, and the body main body and the cover portion are positioned by engagement with the plurality of positioning pins or engagement between the shaft-shaped protrusion and the shaft hole. Yes, when assembling the body main body and the electric motor integrated with the cover portion, the body main body is pressed relative to at least one of the electric motor and the cover portion. Thus, the body body and at least one of the electric motor and the cover part can be tightened by the plurality of bolts.

In this case, the drive gear and the driven gear are arranged in the housing hole of the body main body, the body main body and the body cover integrated with the electric motor are positioned and combined, and the electric motor and at least one of the cover portion are combined. By relatively pressing the body main body, the output shaft of the electric motor can be displaced toward the suction port side of the body main body within the clearance range due to the positioning of the body main body and the cover portion.
In a state where the positional deviation is performed, the body main body and at least one of the electric motor and the cover portion are tightened with a plurality of bolts, whereby the occurrence rate of abnormal noise or the size of the abnormal noise can be reduced. An internal gear type electric oil pump can be easily manufactured.

Further, the gear shaft portion of the drive gear can be rotatably supported in the rotation support hole formed in the body main body (Claims 6 and 9).
Further, the gear shaft portion of the drive gear can be rotatably supported in the rotation support hole formed in the body cover (or the cover portion).
In these cases, the drive gear and the driven gear can be easily disposed between the body main body and the body cover (or cover portion).

Hereinafter, an embodiment according to a manufacturing method of an internal gear type electric oil pump of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the internal gear type electric oil pump 1 manufactured in this example includes an electric motor 2, a drive gear 3 that rotates in response to the rotation of the output shaft 21 of the electric motor 2, and a drive It has a driven gear 4 that meshes with the outer teeth 30 of the gear 3 by the inner teeth 40 and rotates in a driven manner. In addition, the electric oil pump 1 rotatably accommodates the driven gear 4 and the drive gear 3, and the suction port 51 for sucking oil and the discharge port for discharging oil by the relative rotation of the driven gear 4 and the drive gear 3. A pump body 5 formed with 52 is also provided.

As shown in FIGS. 2 and 3, the drive gear 3 has a gear shaft portion 31 that is rotatably supported by a rotation support hole 53 formed in the pump body 5. The output shaft 21 of the electric motor 2 has an engagement surface 211 chamfered parallel to the axial direction, and is engaged with a gear engaged hole 32 formed in the drive gear 3 by the engagement surface 211. Yes.
The pump body 5 is formed with an accommodation hole 54 for accommodating the driven gear 4 and the drive gear 3 while the outer peripheral surface 41 of the driven gear 4 is slid. The suction port 51 and the discharge port 52 are formed in an arc shape at positions on both sides through the output shaft 21 of the electric motor 2, which are bottom portions facing the side surfaces of the drive gear 3 and the driven gear 4 in the accommodation hole 54. .

  As shown in FIGS. 1 and 5, the pump body 5 and the electric motor 2 are positioned by engagement with a plurality of positioning pins (knock pins) 55 or engagement between the shaft-like protrusions 23 and the shaft holes 56. These are assembled by tightening a plurality of bolts 60. In FIG. 5, the bolt 60 is indicated by an arrow and a two-dot chain line.

In the manufacturing method of this example, the pump body 5 and the electric motor 2 are assembled as follows.
First, as shown in FIGS. 2 and 4, the gear shaft portion 31 of the drive gear 3 is inserted into the rotation support hole 53 of the pump body 5, and the drive gear 3 and the driven gear 4 are inserted into the accommodation hole 54 of the pump body 5. The pump body 5 and the electric motor 2 are positioned and combined. At this time, the output shaft 21 of the electric motor 2 is inserted into the gear engaged hole 32 of the drive gear 3, and the pump body is engaged by the engagement by the plurality of positioning pins 55 or the engagement between the shaft-like protrusion 23 and the shaft hole 56. 5 and the electric motor 2 are positioned.

As shown in FIGS. 1, 5, and 6, the output shaft 21 of the electric motor 2 is engaged with the plurality of positioning pins 55 toward the suction port 51 side of the pump body 5 or the shaft-like protrusions 23 and the shaft holes 56. The pump body 5 and the electric motor 2 are tightened by tightening a plurality of bolts 60 in a state where the pump body 5 is relatively pressed against the electric motor 2 so as to be displaced within a clearance range due to engagement with the electric motor 2. As a result, the electric oil pump 1 is manufactured.
5 and 6, the pressing direction by the pressing clamp 72 described later is indicated by an arrow P, and the suction port 51 side of the pump body 5 is indicated by an arrow E. The bolt 60 is indicated by an arrow and a two-dot chain line.

Below, it explains in full detail with FIGS. 1-18 about the manufacturing method of the internal gear type electric oil pump 1 of this example.
The electric oil pump 1 of this example supplies hydraulic oil as oil to the control circuit of the automatic transmission. The electric oil pump 1 of this example is used for an automatic transmission in a hybrid vehicle, and even when the engine is stopped, the electric motor 2 is operated to supply hydraulic oil to the control circuit of the automatic transmission. It is something that can be done.

  As shown in FIG. 4, the electric motor 2 of this example has a base plate (frame end) 22 as an attachment portion fixed to the motor body 20, and the output shaft 21 protrudes from the base plate 22. As shown in FIG. 2, a pair of engaging surfaces 211 having two widths parallel to each other are formed at the tip of the output shaft 21 of the electric motor 2 of this example. The gear engaged hole 32 of the drive gear 3 is formed with a pair of engaged surfaces 321 facing the pair of engaging surfaces 211.

As shown in FIGS. 1 and 4, the pump body 5 of this example has a body main body 61 formed with a rotation support hole 53, an accommodation hole 54, a suction port 51, and a discharge port 52, and the body main body 61. The housing hole 54 includes a body cover 62 for maintaining the drive gear 3 and the driven gear 4. Pipes for allowing oil to pass through are respectively connected to the suction port 51 and the discharge port 52 of the body main body 61.
As shown in FIG. 4, the body main body 61 and the body cover 62 are formed with insertion holes 601 and 602 through which the bolts 60 are inserted, respectively, and the threaded portion of the bolt 60 is formed in the base plate 22 of the electric motor 2. The screw hole 201 for screwing is formed.

  As shown in FIGS. 1 and 4, the body main body 61 and the body cover 62 are positioned with respect to each other by engagement via two positioning pins 55. The body cover 62 and the electric motor 2 are positioned by engagement (so-called inlay fitting) between the shaft-like protrusion 23 formed in the electric motor 2 and the shaft hole 56 formed in the body cover 62. Further, a sealing member 63 such as a packing and an O-ring for preventing oil leakage is disposed on the facing portion of the body main body 61 and the body cover 62 and on the facing portion of the body cover 62 and the base plate 22 of the electric motor 2. . A sliding sealing member 64 is also disposed between the communication shaft hole 561 formed in communication with the shaft hole 56 of the body cover 62 and the output shaft 21 of the electric motor 2.

Further, as shown in FIG. 2, in the body main body 61, the rotation support hole 53 is formed at a position eccentric from the central portion at the bottom of the accommodation hole 54. Further, the rotation center of the drive gear 3 that pivotally supports the gear shaft portion 31 in the rotation support hole 53 is offset from the rotation center of the driven gear 4 that is rotatably slidably disposed in the accommodation hole 54. Then, the outer teeth 30 of the drive gear 3 mesh with the inner teeth 40 of the driven gear 4, and the driven gear 4 is driven to rotate in accordance with the rotation of the drive gear 3, whereby the drive gear 3 and the driven gear 4 are connected from the suction port 51. The oil that has flowed into the space 45 formed in the above can be boosted and discharged from the discharge port 52. In the figure, the rotation directions of the drive gear 3 and the driven gear 4 are indicated by arrows R.
In the drive gear 3, the gear shaft portion 31 and the gear engaged hole 32 are formed so as to have the same axis, and the gear engaged hole 32 is formed through the drive gear 3. Yes (see FIG. 1).

In this example, as shown in FIGS. 1, 5, and 6, when the electric oil pump 1 is assembled, a pressing clamp that presses the holding base 71 that holds the electric motor 2 and the body main body 61 of the pump body 5. A clamp jig 7 having 72 is used.
The holding base 71 has a holding block 711 that engages at an appropriate place on the outer periphery of the electric motor 2, and the plurality of holding blocks 711 of this example are engaged with appropriate places on the base plate 22 of the electric motor 2. It is formed.

  As shown in FIG. 6, the pressing clamp 72 of this example is a toggle clamp 72 that is used by operating the operation lever 722 by an operator. The clamp portion 721 of the toggle clamp 72 is provided with a plurality of compression coil springs 73 as elastic members 73 for applying a predetermined pressing force, and a tip plate 74 is provided at the tip of the compression coil spring 73. .

In the manufacturing method of this example, when the internal gear type electric oil pump 1 is assembled, the engagement state between the drive gear 3 accommodated in the pump body 5 and the output shaft 21 of the electric motor 2 is determined. Striving to stabilize.
By the way, between the gear shaft portion 31 of the drive gear 3 and the rotation support hole 53 of the body main body 61, between the plurality of positioning pins 55 and the body main body 61, and between the shaft-shaped protrusion 23 and the shaft hole 56, There is a minute clearance depending on the dimensional tolerance of each part, machining accuracy, etc.

  In this example, as shown in FIGS. 2 and 4, the gear shaft portion 31 of the drive gear 3 is inserted into the rotation support hole 53 of the body main body 61 and the drive gear 3 and the housing gear 54 are inserted into the accommodation hole 54 of the body main body 61. The driven gear 4 is accommodated, and the drive gear 3 and the driven gear 4 are arranged in the body main body 61. The pump body 5 is formed by combining the body main body 61 and the body cover 62 by positioning with a plurality of positioning pins 55.

Next, as shown in FIG. 5, the body cover 62 in the pump body 5 and the base plate 22 in the electric motor 2 are combined in a state where the positioning is performed by the engagement between the shaft-like protrusion 23 and the shaft hole 56. And the temporary assembly which performed this combination is set to the holding stand 71 of the clamp jig | tool 7 (refer FIG. 6).
Next, as shown in FIGS. 1 and 6, the toggle clamp 72 is operated so that the output shaft 21 of the electric motor 2 is displaced toward the suction port 51 of the pump body 5 with respect to the electric motor 2. 61 is pressed with a predetermined pressing force by the repulsive force of a plurality of compression coil springs 73 provided in the clamp part 721 of the pressing clamp 72. At this time, the body cover 62 is also pressed through the plurality of positioning pins 55.
In addition, the predetermined pressing force by the plurality of compression coil springs 73 can be set to a magnitude of 20 to 40 N, for example.

  As a result, the output shaft 21 of the electric motor 2 is connected to the body main body 61 within the clearance range due to the positioning of the body main body 61 and the body cover 62 and within the clearance range due to the positioning of the body cover 62 and the base plate 22 of the electric motor 2. The position can be shifted toward the suction port 51. Then, in a state where this positional deviation is performed, the body main body 61, the body cover 62, and the electric motor 2 are fastened together by the plurality of bolts 60. Thus, the electric oil pump 1 can be manufactured by integrating the pump body 5 and the electric motor 2.

When the electric oil pump 1 manufactured in this way is operated, the drive gear 3 has the oil pressure at the discharge port 52 formed at the bottom of the housing hole 54 of the body main body 61 formed at the bottom of the housing hole 54 of the body main body 61. Since the oil pressure at the suction port 51 is higher, the clearance between the gear shaft portion 31 of the drive gear 3 and the rotation support hole 53 of the body main body 61 and the pair of engagement surfaces 211 on the output shaft 21 of the electric motor 2 are obtained. In the range of the clearance between the pair of engaged surfaces 321 in the gear engaged hole 32 of the drive gear 3, the position is shifted toward the suction port 51.
At this time, as described above, the output shaft 21 of the electric motor 2 is in a state of being displaced toward the suction port 51 side.

  Therefore, when the drive gear 3 rotates in response to the rotation of the output shaft 21 of the electric motor 2, either the shaft center of the gear shaft portion 31 of the drive gear 3 or the shaft center of the output shaft 21 of the electric motor 2 is selected. However, it is in a state of being displaced toward the suction port 51, and the amount of displacement between the axial centers of both can be reduced. Accordingly, when the drive gear 3 rotates and the driven gear 4 rotates following the rotation of the drive gear 3 in the accommodation hole 54, the drive gear 3 rotates smoothly, and the gear shaft portion 31 of the drive gear 3 is rotated. The generation rate of abnormal noise or the magnitude of abnormal noise caused by a large positional deviation between the axis center of the output shaft 21 and the axis center of the output shaft 21 of the electric motor 2 can be reduced.

  Therefore, according to the manufacturing method of the present example, the internal gear type electric oil pump 1 that can reduce the generation rate or the size of the abnormal noise when the drive gear 3 and the driven gear 4 rotate is provided. It can be manufactured easily.

  7 to 12 show a state in which the operating point of the driving force from the output shaft 21 to the drive gear 3 is switched when the drive gear 3 rotates in response to the rotation of the output shaft 21 of the electric motor 2. 2 when the output shaft 21 of the electric motor 2 is displaced to the suction port 51 side (invention product A) and when the output shaft 21 of the electric motor 2 is displaced to the discharge port 52 side (comparative product). B).

As shown in FIGS. 7 to 10, in the invention product A, when the drive gear 3 rotates, the drive gear 3 is attracted to the suction port 51 side to be displaced, and the output shaft 21 of the electric motor 2. Is also displaced toward the suction port 51.
In Invention A, it is considered that the direction of action of the driving force from the output shaft 21 to the drive gear 3 is in the following state.

  That is, as shown in FIGS. 7 and 8, the driving force is directed from the contact portion (engagement corner) of one engagement surface 211 located on the suction port 51 side to the suction port 51 side on the output shaft 21. Act. As shown in FIG. 9, when the drive gear 3 rotates about 90 °, the operating point of the driving force is switched to the contact portion (engagement angle portion) of the other engaging surface 211, and the driving force is changed to the other engaging force. It acts again from the contact portion of the mating surface 211 toward the suction port 51. Thus, it is considered that the switching of the contact portion of the engaging surface 211 and the operating point of the driving force is repeated every time the drive gear 3 rotates about 180 °.

7 is when the rotational position of the drive gear 3 is 0 °, FIG. 8 is when the drive gear 3 is rotated about 45 °, FIG. 9 is when the drive gear 3 is rotated about 90 °, and FIG. 3 shows a case where 3 rotates about 135 °.
7 to 10, the direction in which the driving force by the output shaft 21 is applied is indicated by an arrow F, and the rotation direction of the drive gear 3 is indicated by an arrow R.

As described above, in the product A in which the output shaft 21 of the electric motor 2 is displaced to the suction port 51 side and assembled, the gear shaft portion 31 of the drive gear 3 is rotated when the drive gear 3 is rotated. The amount of positional deviation between the shaft center and the shaft center of the output shaft 21 of the electric motor 2 is reduced. In the invention A, the driving force is considered to always act toward the suction port 51 side.
Therefore, in Invention A, it is considered that the rate of occurrence of abnormal noise or the size of abnormal noise can be reduced when the drive gear 3 and the driven gear 4 rotate.

On the other hand, as shown in FIGS. 11 and 12, in the comparative product B, when the drive gear 3 rotates, the drive gear 3 is sucked toward the suction port 51 and is displaced, while the electric motor 2 The output shaft 21 is displaced toward the discharge port 52 side.
In the comparative product B, it is considered that the operating point and the operating direction of the driving force from the output shaft 21 to the drive gear 3 are as follows.

That is, as shown in FIG. 11, the driving force acts from the contact portion (engagement corner) of one engagement surface 211 located on the discharge port 52 side in the output shaft 21 toward the discharge port 52 side. (The figure shows a state rotated by 45 °). Then, as shown in FIG. 12, when the drive gear 3 is rotated by about 90 ° (FIG. 12 shows a state rotated by 135 °), the operating point of the driving force is the contact portion (engagement of the other engagement surface 211). The driving force acts from the contact portion of the other engagement surface 211 toward the discharge port 52 again. Thus, it is considered that the switching of the contact portion of the engaging surface 211 and the operating point of the driving force is repeated every time the drive gear 3 rotates about 180 °.
11 and 12, the direction in which the driving force by the output shaft 21 is applied is indicated by an arrow F, and the rotation direction of the drive gear 3 is indicated by an arrow R.

As described above, in the comparative product B in which the output shaft 21 of the electric motor 2 is displaced to the discharge port 52 side and assembled, the gear shaft portion 31 of the drive gear 3 is rotated when the drive gear 3 is rotated. The amount of positional deviation between the shaft center and the shaft center of the output shaft 21 of the electric motor 2 increases. Further, in the comparative product B, the driving force is considered to always act toward the discharge port 52 side.
For this reason, in the comparative product B, it is considered that the occurrence rate of abnormal noise or the magnitude of abnormal noise when the drive gear 3 and the driven gear 4 rotate increases.

  Further, as shown in FIG. 13, the pump body 5 includes a body main body 61 in which a rotation support hole 53, an accommodation hole 54, a suction port 51 and a discharge port 52 are formed, and the base plate 22 of the electric motor 2 has a body main body 22. A cover 65 for maintaining the drive gear 3 and the driven gear 4 in the accommodation hole 54 facing the 61 can also be integrated. In this case, the body main body 61 and the cover portion 65 can be positioned by engagement with a plurality of positioning pins 55 or engagement between the shaft-like protrusion 23 and the shaft hole 56.

And when assembling the body main body 61 and the electric motor 2 in which the cover portion 65 is integrated, the output shaft 21 of the electric motor 2 is displaced toward the suction port 51 side of the body main body 61. The body main body 61 and at least one of the electric motor 2 and the cover portion 65 are tightened by the plurality of bolts 60 in a state where the body main body 61 is relatively pressed against at least one of the electric motor 2 and the cover portion 65. Can do. Also in this case, it is possible to manufacture the internal gear type electric oil pump 1 that can reduce the generation rate or the size of the abnormal noise.
Further, as shown in FIG. 14, the gear shaft portion 31 of the drive gear 3 can be rotatably supported in a rotation support hole 53 formed in the body cover 62 (or the cover portion 65).

(Confirmation test)
15 to 18 show the results of measuring the vibration generated when the drive gear 3 and the driven gear 4 are rotated (four times in this example) for the invention product A and the comparison product B. In each figure, the horizontal axis represents time, and the vertical axis represents the magnitude of vibration (vibration value).

The average value (dB) of the vibration values is 52.3 dB (result 1), 54.1 dB (result 2), 62.2 dB (result 3), and 53.6 dB (result 4) for the comparative product B. On the other hand, for Invention A, the values were 43.6 dB (Result 1), 48.3 dB (Result 2), 54.1 dB (Result 3), and 48.6 dB (Result 4).
From this result, according to the electric oil pump 1 (invention A) in which the output shaft 21 of the electric motor 2 is assembled with the position shifted to the suction port 51 side, the output shaft 21 of the electric motor 2 is connected to the discharge port 52 side. It can be seen that the magnitude of noise when the drive gear 3 and the driven gear 4 rotate can be reduced as compared with the electric oil pump (comparative product B) assembled with the position shifted to the right.

Cross-sectional explanatory drawing which expands and shows the principal part of the internal gear type electric oil pump in an Example. Explanatory drawing which shows the periphery of the drive gear and driven gear in an Example in the state seen from the axial direction of the electric motor. Explanatory drawing which shows the periphery of the suction inlet and discharge outlet in an Example in the state seen from the axial direction of the electric motor. The perspective explanatory view which shows the state which positions and combines the body main body, the body cover, and the electric motor in an Example. The perspective explanatory view which shows the state which presses a body main body with respect to an electric motor, when assembling a body main body, a body cover, and an electric motor in an Example, and inserting a some volt | bolt. Plane explanatory drawing which shows the state which presses a body main body with respect to the electric motor in an Example. Explanatory drawing which shows the action state of the driving force from the output shaft of an electric motor to a drive gear about invention (in 0 degree rotation) in an Example. Explanatory drawing which shows the action state of the driving force from the output shaft of an electric motor to a drive gear about invention (in 45 degree rotation) in an Example. Explanatory drawing which shows the action state of the driving force from the output shaft of an electric motor to a drive gear about the invention (at the time of 90 degree rotation) in an Example. Explanatory drawing which shows the action state of the driving force from the output shaft of an electric motor to a drive gear about the invention (at the time of 135 degree rotation) in an Example. Explanatory drawing which shows the action state of the driving force from the output shaft of an electric motor to a drive gear about the comparative product (at the time of 45 degree rotation) in an Example. Explanatory drawing which shows the action state of the driving force from the output shaft of an electric motor to a drive gear about the comparative product (at the time of 135 degree rotation) in an Example. Explanatory drawing which shows typically the principal part of the other electric oil pump in an Example. Explanatory drawing which shows typically the principal part of the other electric oil pump in an Example. The graph which shows the result 1 which measured about the vibration which arises when a drive gear and a driven gear rotate about an invention and a comparative product in a confirmation test. The graph which shows the result 2 which measured about the vibration produced when a drive gear and a driven gear rotate about an invention and a comparative product in a confirmation test. The graph which shows the result 3 which measured about the vibration produced when a drive gear and a driven gear rotate about an invention and a comparative product in a confirmation test. The graph which shows the result 4 which measured about the vibration produced when a drive gear and a driven gear rotate about an invention and a comparative product in a confirmation test.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric oil pump 2 Electric motor 21 Output shaft 211 Engagement surface 22 Mounting part (base plate)
23 Shaft-shaped projection 3 Drive gear 30 External tooth 31 Gear shaft portion 32 Gear engaged hole 321 Engaged surface 4 Driven gear 40 Internal tooth 41 Outer peripheral surface 5 Pump body 51 Suction port 52 Discharge port 53 Rotation support hole 54 Receiving hole 55 Positioning pin 56 Shaft hole 60 Bolt 61 Body body 62 Body cover 65 Cover 7 Clamp jig 71 Holding stand 72 Press clamp (Toggle clamp)
721 Clamp part 73 Elastic member (compression coil spring)

Claims (10)

An electric motor, a drive gear that rotates in response to the rotation of the output shaft of the electric motor, a driven gear that meshes with the external teeth of the drive gear by internal teeth, and the driven gear and the drive gear can rotate. An internal gear-type electric oil pump that is housed and has a suction port for sucking oil and a pump body for discharging oil by relative rotation of the driven gear and the drive gear. In the method of manufacturing
The drive gear has a gear shaft portion that is rotatably supported by a rotation support hole formed in the pump body, and the output shaft of the electric motor has an engagement surface that is chamfered in parallel to the axial direction. And engaged with a gear engaged hole formed in the drive gear by the engagement surface,
The pump body has an accommodation hole for accommodating the driven gear and the drive gear in a state in which the outer peripheral surface of the driven gear is slid, and the suction port and the discharge port are located in the accommodation hole. A bottom portion facing the side surfaces of the drive gear and the driven gear, each formed in an arc shape at positions on both sides via the output shaft of the electric motor;
The pump body and the electric motor are assembled by tightening a plurality of bolts in a state in which the pump body and the electric motor are positioned by engagement with a plurality of positioning pins or engagement between a shaft-like protrusion and a shaft hole.
When assembling the electric motor with the pump body in which the gear shaft portion is inserted into the rotation support hole and the drive gear and the driven gear are accommodated in the accommodation hole, the drive gear The output shaft of the electric motor is inserted into the gear engaged hole, and the pump body and the electric motor are positioned by engagement with the plurality of positioning pins or engagement between the shaft-like protrusion and the shaft hole. In this state, the output shaft of the electric motor is displaced toward the suction port side of the pump body within the clearance due to the engagement by the plurality of positioning pins or the engagement between the shaft-shaped protrusion and the shaft hole. The pump body and the electric motor are tightened by tightening the plurality of bolts in a state where the pump body is pressed relatively to the electric motor. Method for producing internal gear electric oil pump which is characterized in that the attached set.   2. The output shaft of the electric motor according to claim 1, wherein the output shaft of the electric motor is formed with a pair of engaging surfaces having two parallel widths, and the gear engaged hole is opposed to the pair of engaging surfaces. A method of manufacturing an internal gear type electric oil pump, wherein a pair of engaged surfaces are formed.   3. When assembling the pump body and the electric motor according to claim 1 or 2, the electric motor is held on a holding base, and the pump body is clamped to a clamp portion of a press clamp with respect to the electric motor. A method for manufacturing an internal gear type electric oil pump, wherein pressing is performed with a predetermined pressing force by a repulsive force of an elastic body provided in the inner gear.   4. The method of manufacturing an internal gear type electric oil pump according to claim 3, wherein the pressing clamp is a toggle clamp, and the elastic body is a compression spring. 5. The pump body according to claim 1, wherein the pump body includes a body main body in which the accommodation hole, the suction port, and the discharge port are formed, and the drive gear and the body in the housing hole facing the body main body. It consists of a body cover for maintaining the driven gear,
The body body and the body cover, and the body cover and the electric motor are all positioned by engagement with the plurality of positioning pins or engagement between the shaft-like protrusion and the shaft hole.
When assembling the body main body and the body cover and the electric motor, the body main body and the plurality of bolts are used while the body main body is relatively pressed against the electric motor. A manufacturing method of an internal gear type electric oil pump, wherein a body cover and the electric motor are fastened together.   6. The method of manufacturing an internal gear type electric oil pump according to claim 5, wherein the gear shaft portion of the drive gear is rotatably supported in the rotation support hole formed in the body main body.   6. The method of manufacturing an internal gear type electric oil pump according to claim 5, wherein the gear shaft portion of the drive gear is rotatably supported in the rotation support hole formed in the body cover. In any one of Claims 1-4, the said pump body consists of a body main body which formed the said accommodation hole, the said suction inlet, and the said discharge outlet,
A cover portion for maintaining the drive gear and the driven gear in the accommodation hole is integrated with the mounting portion of the electric motor so as to face the body body,
The body body and the cover portion are positioned by engagement with the plurality of positioning pins or engagement between the shaft-shaped protrusion and the shaft hole,
When assembling the body main body and the electric motor integrated with the cover portion, the body main body is relatively pressed against at least one of the electric motor and the cover portion, A method of manufacturing an internal gear type electric oil pump, wherein the body main body and at least one of the electric motor and the cover part are fastened by the plurality of bolts.   9. The method of manufacturing an internal gear type electric oil pump according to claim 8, wherein the gear shaft portion of the drive gear is rotatably supported in the rotation support hole formed in the body body.   9. The method of manufacturing an internal gear type electric oil pump according to claim 8, wherein the gear shaft portion of the drive gear is rotatably supported in the rotation support hole formed in the cover portion.

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