JP6914777B2 - motor - Google Patents

Description

The techniques disclosed herein relate to motors.

Patent Document 1 discloses a pump assembly including a fuel pump and an electric motor. A resin outlet cover is arranged at one end of the pump assembly. The outlet cover is provided with a square terminal mounting hole through which the terminal of the electric motor penetrates.

The outlet cover is provided with a thin-walled portion and a thick-walled portion in the vicinity of the terminal mounting hole. At the time of resin molding, the flow of the resin becomes slow in the thin-walled portion, and the flow of the resin becomes fast in the thick-walled portion. As a result, the flow of the resin is controlled so that the weld extending from the terminal mounting hole does not occur at the corner of the terminal mounting hole.

Japanese Unexamined Patent Publication No. 2009-62813

In the above technique, the position of the weld is controlled, but it is difficult to suppress the weld itself. The present specification provides a technique for suppressing welds generated in a resin layer arranged in a motor.

The techniques disclosed herein relate to motors. The motor may include a rotor, a core, a bearing portion that supports the shaft of the rotor, and a stator that includes a resin layer that covers the core. The resin layer has an end face portion arranged apart from the end face of the rotor and extends from the end face portion toward the rotor side, covers the outer surface of the bearing portion, and supports the bearing portion. It may be provided with a bearing. The end face portion includes, around the support portion, a portion of the support portion in the rotation direction of the rotor that suppresses the flow of resin from the end face portion toward the support portion during molding of the resin layer. May be.

When molding the resin layer, the resin flowing through the space in the molding mold for molding the end face portion flows into the space in the molding mold for molding the support portion. In this case, if the timing at which the resin reaches the space for molding the support portion is different in the rotation direction of the rotor, the resins merge in the space for molding the support portion, and a weld is generated. According to the above configuration, in the rotation direction of the rotor, the restraining portion is provided at a location where the resin from the gate can reach the space for forming the support portion from the space for forming the end face portion relatively early. By arranging the resin, it is possible to reduce the difference in the timing at which the resin reaches the space for forming the support portion in the rotation direction of the rotor. As a result, it is possible to suppress the resin from merging in the space for forming the support portion and suppress the weld generated in the support portion.

The thickness of the resin may be smaller at the restraining portion than at other portions when viewed along the rotation direction of the rotor. According to this configuration, by reducing the thickness of the resin, the flow path of the resin at the time of resin molding can be made smaller than other portions. This makes it possible to slow down the resin that passes through the restraint portion during resin molding. As a result, it is possible to reduce the difference in the timing at which the resin reaches the space for molding the support portion.

The resin layer may further include a gate-corresponding portion corresponding to the end of the gate of the molding mold for molding the resin layer on the surface of the end face portion opposite to the rotor. The restraining portion may be located on a straight line connecting the gate corresponding portion and the center of the shaft. During resin molding, the resin flows from the gate into the space for molding the end face portion. Therefore, the distance between the gate and the space for forming the support portion is the shortest on the straight line connecting the gate and the center of the shaft. By arranging the restraining portion on the straight line connecting the gate corresponding portion and the center of the shaft, the flow of the resin on the straight line connecting the gate and the center of the shaft can be slowed down. Thereby, the difference in the timing at which the resin reaches the space for forming the support portion can be reduced.

The restraining portion may be separated from the end face of the rotor than other parts of the end face portion when viewed along the rotation direction of the rotor. In this configuration, in the molding die, the restraint portion can be molded by projecting the portion where the restraint portion is molded as compared with the portion where the other portion is molded.

The stator may further include an insert member arranged between the restraint and the rotor. In this configuration, the restraining portion can be molded by arranging the insert member at the time of resin molding.

The resin layer may further include a plurality of gate-corresponding points corresponding to the ends of the plurality of gates of the molding mold for molding the resin layer on the surface of the end face portion opposite to the rotor. The plurality of gate corresponding points may be arranged at equal intervals along the rotation direction of the rotor. By arranging the gates at equal intervals, it is possible to easily control the flow of the resin from the gate to the space for forming the support portion.

The vertical sectional view of the fuel pump of an Example is shown. The perspective view of the stator of an Example is shown. The plan view of the stator of an Example is shown. The figure which looked at the periphery of the bearing part of the end face part of the stator of the resin layer of 1st Example from the rotor side is shown. The cross-sectional view of the VV cross section of FIG. 3 is shown. The perspective view which shows the state which removed the resin layer of 1st Example is shown. A schematic diagram for explaining the flow of the resin near the support portion when molding the resin layer of the first embodiment is shown. A schematic diagram for explaining the flow of the resin near the support portion when molding the resin layer of the first embodiment is shown. A schematic diagram for explaining the flow of the resin near the support portion when molding the resin layer of the comparative example is shown. A schematic diagram for explaining the flow of the resin near the support portion when molding the resin layer of the comparative example is shown. The perspective view which shows the state which removed the resin layer of the stator of 2nd Example is shown. A cross-sectional view of the VV cross section of FIG. 3 of the second embodiment is shown. A view of the periphery of the bearing portion of the end face portion of the stator of the resin layer of the modified example as viewed from the rotor side is shown. A view of the periphery of the bearing portion of the end face portion of the stator of the resin layer of the modified example as viewed from the rotor side is shown.

As shown in FIG. 1, the motor unit 50 of this embodiment is used for the fuel pump 10. The fuel pump 10 is arranged in a fuel tank (not shown) and supplies fuel (for example, gasoline or the like) to an engine (not shown) of a vehicle such as an automobile. The fuel pump 10 includes a motor unit 50 and a pump unit 30. The motor unit 50 and the pump unit 30 are arranged in the housing 2. The housing 2 has a cylindrical shape with both ends open.

The pump unit 30 includes a casing 32 and an impeller 34. The casing 32 closes the opening at the lower end of the housing 2. A suction port (not shown) is provided at the lower end of the casing 32. At the upper end of the casing 32, a communication hole (not shown) for communicating the inside of the casing 32 and the motor portion 50 is provided. The impeller 34 is housed in the casing 32.

The motor unit 50 is located above the pump unit 30. The motor unit 50 is a brushless motor and is a three-phase motor. The motor unit 50 includes a rotor 54 and a stator 60. The rotor 54 includes a permanent magnet. A shaft 52 penetrates and is fixed to the center of the rotor 54. The lower end of the shaft 52 is inserted into and penetrates the central portion of the impeller 34. The shaft 52 is rotatably supported by a bearing 36, which is a bearing portion arranged in the casing 32. Further, the shaft 52 is rotatably supported with respect to the stator 60. As a result, the rotor 54 is rotatably supported with respect to the stator 60. In the embodiment, the upper and lower parts are defined in the state of FIG. That is, the pump unit 30 is located "lower" when viewed from the motor unit 50, and the motor unit 50 is located "upper" when viewed from the pump unit 30.

(Constituent configuration)
As shown in FIGS. 2, 3 and 6, the stator 60 includes a resin layer 62, a core 70, a bobbin 80, a plurality of conductors 90, a plurality of terminals 100, and a bearing portion 120. FIG. 2 shows a perspective view of the stator 60, and FIG. 3 shows a plan view of the stator 60. FIG. 6 shows a perspective view of the core 70, the bobbin 80, the conductor 90, and the terminal 100 with the resin layer 62 removed. The viewpoints of FIGS. 2 and 6 are different. The core 70 is configured by laminating a plurality of core plates 72 (see FIG. 1). In FIG. 1, the gap between the core plate 72 and the housing 2 is omitted. Further, although the core plate 72 is exposed on the side surface of the core 70, the description of the core plate 72 is omitted in FIGS. 2 and 6. A plurality of core plates 72 are laminated in the vertical direction, and each core plate 72 is formed of a magnetic material. The core plate group (72, 72, ...) Includes a stator yoke 74 and a plurality of teeth (not shown). The stator yoke 74 has a cylindrical shape that is arranged on the side surface of the stator 60. The plurality of teeth are arranged at equal intervals on the inner peripheral surface of the stator yoke 74 and extend toward the rotor 54.

The core 70 is coated with a bobbin 80. The bobbin 80 covers a portion of the core 70 other than the outer peripheral surface. A conducting wire 90 is wound around the portion of the bobbin 80 that covers the teeth.

As shown in FIG. 6, the plurality of terminals 100 include a plurality of (three in this embodiment) energization terminal group 102, a ground terminal 104, and a common terminal 106. The common terminal 106 is arranged at the lower end of the stator 60 and is electrically connected to the conductor 90 supported by the conductor support portion 89 of the bobbin 80.

The energizing terminal group 102 includes energizing terminals 102U, 102V, and 102W for supplying each of the U phase, V phase, and W phase to the conducting wire 90. The energizing terminals 102U, 102V, and 102W are attached to the bobbin 80 via the support member 103 (see FIG. 1). The energizing terminals 102U, 102V, and 102W are electrically connected to the conducting wire 90 supported by the conducting wire supporting portion 88 of the bobbin 80. The ground terminal 104 is electrically connected to the housing 2.

(Structure of resin layer)
The resin layer 62 covers the entire bobbin 80, the conducting wire 90, and the common terminal 106, and the lower end portions of the energizing terminal group 102 and the ground terminal 104. The resin layer 62 is a so-called insert molding in which a combination with a plurality of terminals 100 including a core 70, a bobbin 80, a conducting wire 90, and a support member 103 as shown in FIG. 6 is arranged in a molding mold to perform resin molding. Placed by.

As shown in FIGS. 2 and 3, the resin layer 62 includes an outer wall 64, a partition wall 66, a connector 68, and a discharge port 11. The outer wall 64, the partition wall 66, the connector 68, and the discharge port 11 are integrally molded. "Integrally molded" means that the outer wall 64, the partition wall 66, the connector 68, and the discharge port 11 are molded by one resin molding, and no joint appears in any of the portions. The outer wall 64 covers the upper end portion, the lower end portion, and the inner peripheral portion of the core 70. The energizing terminals 102U, 102V, 102W and the grounding terminal 104 project upward from the upper end of the outer wall 64. A partition wall 66, a connector 68, and a discharge port 11 are arranged at the upper end of the outer wall 64. The discharge port 11 has a cylindrical shape. The discharge port 11 communicates with the pump unit 30 via the inside of the core 70. The partition wall 66 covers the energizing terminal group 102 from the outer peripheral side. The connector 68 is a connector for connecting the terminals 102U, 102V, 102W, 104 and the external terminal.

With reference to FIGS. 3 to 5, the outer wall 64 of the resin layer 62 includes an end face portion 110, a support portion 112, and a concave groove 114 located on the upper end side of the resin layer 62. FIG. 4 is a view of the vicinity of the support portion 112 of the lower end surface 110a of the end surface portion 110 as viewed from below, and FIG. 5 is a cross-sectional view of the VV cross section of FIG. The end face portion 110 covers the upper ends of the rotor 54 and the core 70. The end face portion 110 is arranged so as to be separated from the upper end surface of the rotor 54. The space between the end face portion 110 and the rotor 54 is filled with the fuel discharged from the pump portion 30.

The lower end surface 110a of the end surface portion 110, that is, the surface facing the rotor 54 has a planar shape. A support portion 112 is arranged at the central portion of the end face portion 110. The support portion 112 extends downward from the lower end surface 110a along the shaft 52 toward the rotor 54. The support portion 112 has a cylindrical shape. A bearing portion 120 is arranged on the inner peripheral surface of the support portion 112. The support portion 112 covers the outer peripheral surface of the bearing portion 120 in a circle in the rotation direction R of the rotor 54. The bearing portion 120 has a bearing.

The end face portion 110 includes a concave groove 114 arranged along the end of the support portion 112 on the end face portion 110 side. The concave groove 114 is arranged in a part of the support portion 112 in the rotation direction of the rotor 54, and is arranged symmetrically with respect to the central axis CX of the shaft 52. As shown in FIG. 5, the depth of the concave groove 114 is smaller than the thickness of the end face portion 110. Therefore, in the place where the concave groove 114 is arranged, the end face portion 110 is thinner than the other places. Of the end face portions 110, a portion where the thickness is reduced due to the arrangement of the concave groove 114 is referred to as a suppression portion 116.

On the upper end surface 110b located on the opposite end side to the rotor 54 of the end surface portion 110, the gate corresponding portion 110c is arranged symmetrically with respect to the central axis CX of the shaft 52. In FIG. 4, the gate corresponding portion 110c is shown by a broken line at the position where the gate corresponding portion 110c on the upper end surface 110b is arranged on the lower end surface 110a. The gate corresponding portion 110c is located at the downstream end of the gate of the molding mold (that is, the inflow port for flowing the resin into the space in the molding mold) when the resin layer 62 is molded by resin molding. After molding the resin layer 62, when it is taken out from the molding mold, the resin solidified in the gate is connected to the gate corresponding portion 110c. At the gate corresponding portion 110c, the resin solidified in the gate is cut from the end face portion 110. At this time, the end face portion 110 remains after being cut.

The concave groove 114, that is, the restraining portion 116, connects the gate corresponding portion 110c and the central axis CX of the shaft 52 and is located on a straight line.

(Flow of resin to the support part during molding of the resin layer)
Next, with reference to FIGS. 7 and 8, the flow of the resin to the support portion 112 during molding of the resin layer 62 will be described. FIG. 7 is a perspective view schematically showing the flow of the resin in the vicinity of the support portion 112, and FIG. 8 is a plan view schematically showing the flow of the resin in the vicinity of the support portion 112. The arrows shown in FIGS. 7 and 8 indicate the direction in which the resin flows. Note that, in FIGS. 7 and 8, the top and bottom are reversed from those in FIGS. 1 to 6. When molding the resin layer 62, the core 70 shown in FIG. 6, the conducting wire 90, the plurality of terminals 100, the support member 103 (not shown), and the bearing portion 120 are arranged in a molding mold, and insert molding is performed. As shown in FIG. 7, the resin flows from the gate GT into the space (that is, the cavity) in the mold. The resin flowing in from the gate GT spreads from the end of the gate GT to the space 110x in the molding mold for molding the end face portion 110 and flows. The molding die includes a convex shape 114x for molding the concave groove 114.

Since the molding die is provided with the convex shape 114x, the flow path of the resin flowing from the gate GT and flowing toward the space for molding the support portion 112 is the resin flowing through the space 110x at the suppression point 116. It is narrower than other parts. As a result, the flow of the resin flowing through the suppression portion 116 is suppressed, and the speed becomes slow. It is possible to slow down the speed of the resin flowing a relatively short distance from the gate GT and reaching the space 112x for forming the support 112. As a result, the timing of reaching the space 112x of the resin that wraps around the suppression point 116 and reaches the space 112x, that is, the resin that flows a relatively long distance from the gate GT and reaches the space 112x, and passes through the suppression point 116. Therefore, it is possible to suppress the difference between the timing of the resin reaching the space 112x and the timing of reaching the space 112x. According to this configuration, it is possible to prevent the resins from merging in the space 112x for molding the support portion 112. As a result, the weld generated in the support portion 112 can be suppressed.

Further, since the resin flows into the space 112x for molding the support portion 112 at substantially the same timing over the entire circumference of the rotor 54 of the support portion 112 in the rotation direction, the orientation of the glass fibers in the resin is aligned with the shaft 52. Aligns along the central axis CX of. As a result, the variation in shrinkage of the resin due to the variation in the orientation of the glass fibers can be reduced along the rotation direction of the rotor 54, and the support portion 112 can be prevented from being significantly deformed from the cylindrical shape. ..

9 and 10 schematically show the flow of the resin to the support portion 112 during molding of the resin layer 62 when the suppression portion 116 is not arranged as a comparative example. FIG. 9 is a perspective view schematically showing the flow of the resin in the vicinity of the support portion 112, and FIG. 10 is a plan view schematically showing the flow of the resin in the vicinity of the support portion 112. The arrows shown in FIGS. 9 and 10 indicate the direction in which the resin flows.

When the restraint portion 116 is not arranged, the resin that linearly flows from the gate GT for a relatively short distance and reaches the space 112x first flows into the space 112x. Next, the resin that wraps around the gate GT, flows a relatively long distance, and reaches the space 112x flows into the space 112x. As a result, the resins merge in the space 112x, and a weld WL having a large variation in the orientation of the glass fibers is formed on the support portion 112.

(Second Example)
The differences from the first embodiment will be described with reference to FIGS. 11 and 12. In the second embodiment, the blocking plate 200 having a semi-cylindrical shape is arranged below the ground terminal 104. The blocking plate 200 is housed in the concave groove 114 of the end face portion 110. According to this configuration, when the resin layer 62 is molded, the blocking plate 200 suppresses the flow of the resin. As a result, similar to the resin flow of FIGS. 7 and 8, the weld generated in the support portion 112 can be suppressed and the orientation of the glass fibers can be aligned.

Although the embodiments of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above.

(1) In each of the above embodiments, the end face portion 110 includes two gate corresponding points 110c. That is, two gate GTs are arranged in the molding die. However, the number of gate corresponding points 110c, that is, the number of gate GTs may be one or three or more. When there is one gate GT, the suppression portion 116 is gradually thickened along the support portion 112 from the straight line connecting the gate GT (that is, the gate corresponding portion 110c) and the central axis CX of the shaft 52 (that is,). , The recessed groove 114 may be arranged along the support portion 112 so as to gradually become shallower). On the other hand, when there are three or more gate GTs, the suppression points are arranged at intervals along the support portion 112 from the straight line connecting each gate GT (that is, the gate corresponding point) and the central axis CX of the shaft 52. It may have been done. In this case, the three or more gate-corresponding points may be rotationally symmetric with respect to the central axis CX, that is, may be arranged at equal intervals along the rotation direction R. For example, as shown in FIG. 13, when there are three gate GTs, that is, when the end face portion 110 includes three gate corresponding points 410c, the suppression points 416 (that is, the concave groove 414) correspond to the gate. It may be arranged at a distance along the support portion 112 from the straight line connecting the portion 410c and the central axis CX of the shaft 52. The three or more gate-corresponding points 410c may be arranged rotationally symmetrically with respect to the central axis CX. According to this configuration, the flow of the resin from the gate GT to the space 112x for molding the support portion 112 can be easily predicted, and the position and size of the suppression portion 116 can be easily determined. Can be done. Thereby, the flow of the resin can be easily controlled.

(2) In each of the above embodiments, the suppression points 116 are arranged on a straight line connecting the gate corresponding points 110c and the central axis CX. However, for example, as shown in FIG. 14, when a pair of insert members 300 that block the flow of resin are arranged between the gate corresponding portion 110c and the support portion 112, the restraining portion 316 (that is, the concave groove). 314) is not arranged on a straight line connecting the gate corresponding portion 110c and the central axis CX, and may be arranged between the insert members 300. That is, at the time of molding the resin layer 62, the arrival timing of the resin reaching the space 112x for molding the support portion 112 from the gate GT of the restraint portion 316 is substantially the same over the entire circumference of the support portion 112. It suffices if it is arranged like this.

(3) In the above embodiment, the motor unit 50 is used for the fuel pump 10. However, the motor unit 50 may be used in addition to the fuel pump 10 such as a water pump.

(4) In the above embodiment, the suppression portion 116 is arranged along the end surface portion 110 side end of the support portion 112. However, the restraint portion 116 may be arranged at a position on the end face portion 110 away from the end of the support portion 112 on the end face portion 110 side. At the time of molding the resin layer 62, the restraining portion 116 so that the arrival timing of the resin reaching the space 112x for molding the support portion 112 from the gate GT is substantially the same over the entire circumference of the support portion 112. It suffices if it is arranged.

In addition, the technical elements described in the present specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the techniques illustrated in this specification or drawings achieve a plurality of objectives at the same time, and achieving one of the objectives itself has technical usefulness.

10: Fuel pump 30: Pump unit 50: Motor unit 52: Shaft 54: Rotor 60: Stator 62: Resin layer 64: Outer wall 70: Core 102: Energizing terminal group 104: Ground terminal 106: Common terminal 110: End face portion 110a: Lower end surface 110b: Upper end surface 110c: Gate corresponding part 110x: Space 112: Support part 112x: Space 114: Recessed groove 114x: Convex shape 116: Suppressing part 120: Bearing part 200: Blocking plate 300: Insert member 314: Recessed groove 316 : Suppressed part 410c: Gate corresponding part 414: Recessed groove 416: Suppressed part CX: Central axis GT: Gate R: Rotation direction

Claims (7)

With the rotor
A stator including a core, a bearing portion that supports the shaft of the rotor, and a resin layer that covers the core.
The resin layer is
An end face portion arranged apart from the end face of the rotor and
A support portion extending from the end face portion toward the rotor side, covering the outer surface of the bearing portion, and supporting the bearing portion is provided.
The end face portion includes, around the support portion, a portion of the support portion in the rotation direction of the rotor that suppresses the flow of resin from the end face portion toward the support portion during molding of the resin layer. ,
The suppression portion is a motor in which the thickness of the resin is smaller than that of other portions when viewed along the rotation direction of the rotor. With the rotor
A stator including a core, a bearing portion that supports the shaft of the rotor, and a resin layer that covers the core.
The resin layer is
An end face portion arranged apart from the end face of the rotor and
A support portion extending from the end face portion toward the rotor side, covering the outer surface of the bearing portion, and supporting the bearing portion is provided.
The end face portion includes, around the support portion, a portion of the support portion in the rotation direction of the rotor that suppresses the flow of resin from the end face portion toward the support portion during molding of the resin layer. ,
A motor in which the restraining portion is separated from the end face of the rotor than other parts of the end face portion when viewed along the rotation direction of the rotor. With the rotor
A stator including a core, a bearing portion that supports the shaft of the rotor, and a resin layer that covers the core.
The resin layer is
An end face portion arranged apart from the end face of the rotor and
A support portion extending from the end face portion toward the rotor side, covering the outer surface of the bearing portion, and supporting the bearing portion is provided.
The end face portion is a plurality of restraining points around the support portion that suppress the flow of resin from the end face portion toward the support portion at a part of the rotation direction of the rotor of the support portion during molding of the resin layer. A motor including the plurality of restraining points arranged at intervals in the rotation direction of the rotor. With the rotor
A stator including a core, a bearing portion that supports the shaft of the rotor, and a resin layer that covers the core.
The resin layer is
An end face portion arranged apart from the end face of the rotor and
A support portion extending from the end face portion toward the rotor side, covering the outer surface of the bearing portion, and supporting the bearing portion is provided.
The end face portion includes, around the support portion, a portion of the support portion in the rotation direction of the rotor that suppresses the flow of resin from the end face portion toward the support portion during molding of the resin layer. ,
The resin layer is further provided with a gate-corresponding portion corresponding to the end of the gate of the molding mold for molding the resin layer on the surface of the end face portion opposite to the rotor.
The suppression portion is a motor located between the gate corresponding portion and the shaft. The resin layer is further provided with a gate-corresponding portion corresponding to the end of the gate of the molding mold for molding the resin layer on the surface of the end face portion opposite to the rotor.
The motor according to any one of claims 1 to 4, wherein the suppression portion is located on a straight line connecting the gate corresponding portion and the center of the shaft. The motor according to any one of claims 1 to 5 , wherein the stator further includes an insert member arranged between the restraining portion and the rotor. The resin layer is further provided with a plurality of gate-corresponding points corresponding to the ends of the plurality of gates of the molding mold for molding the resin layer on the surface of the end face portion opposite to the rotor.
The motor according to any one of claims 1 to 6 , wherein the plurality of gate corresponding points are arranged at equal intervals along the rotation direction of the rotor.

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