Motor with potting section and hole provided with cap through which winding is inserted

A motor unit includes a stator including a coil formed from a wound winding that is configured by a conductive member including an insulating covering layer on the surface of the conductive member, a rotor that rotates under the influence of a rotating magnetic field generated by the stator, and a centerpiece that supports the stator and is formed with a centerpiece-side winding insertion hole through which the winding is inserted. The motor unit also includes a circuit device and a potting section. The potting section is formed using potting material, and seals a gap formed between the centerpiece-side winding insertion hole and the winding by achieving a state in which a portion of the potting section is closely adhered to the covering layer of the winding.

TECHNICAL FIELD

The present disclosure relates to a motor and a method of manufacturing a motor.

BACKGROUND ART

Japanese Patent Application Laid-Open (JP-A) No. 2015-142455 discloses a brushless motor that includes a stator including coils formed by winding windings around a stator core, a rotor that rotates under the influence of a rotating magnetic field from the stator, a circuit device that controls current flow to the windings, and a base to which the stator and the circuit device is fixed. In this brushless motor, the circuit device is fixed to an opposite side of the base to the side on which the stator is fixed. Openings are accordingly formed in the base to lead terminal ends of the windings that are wound around the stator core to the circuit device side of the base.

However, depending on the environment in which the brushless motor is used, it may be necessary to suppress water droplets adhered to the stator side of the base from infiltrating to the circuit device side through the openings formed in the base. Accordingly, in the brushless motor described in JP-A 2015-142455, an insulator is provided between the openings formed in the base and the windings inserted through the openings to suppress water droplets adhered to the stator side of the base from infiltrating to the circuit device side.

JP-A 2014-204477 also discloses a brushless motor that includes a stator including coils formed by winding windings around a stator core, a rotor that rotates under the influence of a rotating magnetic field from the stator, and a circuit device that controls current flow to the windings. In this brushless motor, terminal ends of the windings are bent and joined to circuit terminals of the circuit device.

However, the shape and wiring routing of locations of the windings between the stator core and the circuit device may influence the build shape along a rotation axis direction of the rotor.

SUMMARY OF INVENTION

Technical Problem

The present disclosure obtains a motor capable of suppressing water droplets adhered to a stator side from infiltrating to a circuit device side.

The present disclosure further obtains a motor capable of suppressing the build shape along a rotation axis direction from becoming more bulky, and a method of manufacturing a motor thereof.

Solution to Problem

A first aspect of the present disclosure is a motor including a stator, a rotor, a centerpiece, a circuit device, and a potting section. The stator includes a coil formed from a wound winding that is configured by a conductive member including an insulating covering layer on the surface of the conductive member. The rotor rotates under the influence of a rotating magnetic field generated by the stator. The centerpiece supports the stator and is formed with a centerpiece-side winding insertion hole through which the winding is inserted. The circuit device is disposed on an opposite side of the centerpiece to a side on which the stator is fixed, includes a connection portion to which the winding is connected after having passed through the centerpiece-side winding insertion hole, and controls current flow to the winding. The potting section is formed using potting material, and seals a gap formed between the centerpiece-side winding insertion hole and the winding by achieving a state in which a portion of the potting section is closely adhered to the covering layer of the winding.

According to the first aspect, the stator generates a rotating magnetic field by controlling the current flow to the winding that is connected to the connection portion of the circuit device. The rotor is rotated under the influence of the rotating magnetic field. In the first aspect, the winding is inserted through the centerpiece-side winding insertion hole formed in the centerpiece supporting the stator. Moreover, the gap formed between the centerpiece-side winding insertion hole and the winding is sealed by the potting section formed using the potting material. Water droplets adhered to the stator side can thereby be suppressed from infiltrating through the centerpiece-side winding insertion hole to the circuit device side. In particular, in the first aspect, a good state of joining between the potting section and the winding can be achieved due to the potting section being configured closely adhered to the covering layer of the winding. This enables water droplets adhered to the stator side to be suppressed from infiltrating through between the potting section and the winding to the circuit device side.

A second aspect of the present disclosure is the motor of the first aspect, wherein plural of the centerpiece-side winding insertion holes are formed in the centerpiece, and each gap formed between the plural the centerpiece-side winding insertion holes and the respective windings inserted through the plural respective centerpiece-side winding insertion holes is sealed by the single potting section.

According to the second aspect, good work efficiency can be achieved when forming the potting section to seal the respective gaps due to the configuration in which every one of the gaps is sealed by the single potting section.

A third aspect of the present disclosure is the motor of the first aspect or the second aspect, wherein a recess is formed in the centerpiece so as to open toward one side in a rotation axis direction of the rotor, and the centerpiece-side winding insertion hole is formed in a bottom of the recess.

According to the third aspect, the potting material for forming the potting section can be held inside the recess due to the configuration in which the centerpiece-side winding insertion hole is formed in the bottom of the recess. This enables good work efficiency to be achieved when forming the potting section to seal the gaps formed between the centerpiece-side winding insertion hole and the winding.

A fourth aspect of the present disclosure is the motor of the third aspect, wherein plural of the centerpiece-side winding insertion holes are formed in the bottom of the single recess.

According to the fourth aspect, even better work efficiency can be achieved when forming the potting section to seal the gap formed between the centerpiece-side winding insertion hole and the winding due to forming the plural centerpiece-side winding insertion holes in the bottom of the single recess.

A fifth aspect of the present disclosure is the motor of one of the first to the fourth aspects, wherein an insulating cap is provided between the centerpiece-side winding insertion hole and the winding, a cap-side winding insertion hole through which the winding is inserted is formed in the insulating cap, and a stator-side portion of the cap-side winding insertion hole has an inner diameter that becomes smaller on progression from the stator side to the circuit device side.

According to the fifth aspect, the state of insulation between the winding and the peripheral edge of the centerpiece-side winding insertion hole can be easily secured due to providing the insulating cap between the centerpiece-side winding insertion hole and the winding. Moreover, the winding can be easily inserted through from the stator side to the circuit-device side due to the stator-side portion of the cap-side winding insertion hole formed in the cap having an inner diameter that becomes smaller on progression from the stator side to the circuit device side.

A sixth aspect of the present disclosure is the motor of the fifth aspect, wherein a circuit-device-side portion of the cap-side winding insertion hole has an inner diameter larger than an inner diameter of the cap-side winding insertion hole at a central portion in a rotation axis direction of the rotor, and the potting section is provided on the circuit device side of the centerpiece.

According to the sixth aspect, contact area between the potting section and the covering layer formed on the winding can be increased due to making the inner diameter of the portion on the circuit-device-side of the cap-side winding insertion hole formed in the cap larger than the inner diameter of the central portion of the cap-side winding insertion hole along the rotation axis direction of the rotor. This enables the join strength between the potting section and the covering layer formed to the winding to be raised.

A seventh aspect of the present disclosure is a motor including (1) a rotor that includes a rotor magnet and that is supported so as to be capable of rotating about an axis, and (2) a stator. The stator includes (i) a stator core disposed facing the rotor magnet along a rotation radial direction of the rotor, and (ii) a winding. The winding includes a first extension that extends with respect to the stator core toward one side in a rotation axis direction of the rotor, a second extension that extends toward a rotation radial direction outside of the rotor from an end of the first extension on the one side in the rotation axis direction of the rotor, and a third extension that extends toward the one side in the rotation axis direction of the rotor from an end at the rotor rotation radial direction outside of the second extension, and that is connected to a circuit device. The winding forms a coil around the stator core, and a boundary between the first extension and the second extension is disposed at the one side in the rotation axis direction of the rotor with respect to a boundary between the second extension and the third extension.

According to the seventh aspect, a magnetic field around the stator core arises due to current flow from the circuit device to the winding forming the coil. Namely, the stator causes generation of the rotating magnetic field. The rotor is rotated about the axis by interaction between the rotating magnetic field and the magnetic field of the rotor magnet. In the seventh aspect, the boundary between the first extension and the second extension on a section of the winding extending from the stator core is disposed at the one side in the rotation axis direction of the rotor with respect to the boundary between the second extension and the third extension on this extension section. Thereby, a location on the stator at the rotor rotation radial direction outside can be disposed closer to a member disposed at the one side of the stator in the rotor rotation axis direction than in a configuration in which the boundary between the first extension and the second extension and the boundary between the second extension and the third extension are disposed at the same position in the rotation axis direction of the rotor. As a result, the build shape of the motor in the rotation axis direction can be suppressed from becoming bulky.

An eighth aspect of the present disclosure is the motor of the seventh aspect, wherein the second extension is inclined toward another side in the rotation axis direction of the rotor on progression toward the rotor rotation radial direction outside.

According to the eighth aspect, the second extension, which is the location between first extension and the third extension, is inclined as described above. Due to adopting such a configuration, the length of the second extension can be made shorter than in cases in which the second extension is curved. This enables the wiring routing of the windings for the portion extending from the stator core as far as the circuit device to be suppressed from increasing in length.

A ninth aspect of the present disclosure is a method applicable to manufacturing the motor of the seventh aspect or the eighth aspect. This motor manufacturing method includes: forming a coil by winding a winding around the stator core to form the coil around the stator core; bending a winding by pressing a section of the coil-forming winding extending out from the stator core so as to form the first extension, the second extension, and the third extension such the boundary between the first extension and the second extension is disposed on the one rotation axis direction side of the rotor with respect to the boundary between the second extension and the third extension; and connecting the winding by connecting the third extension to the circuit device.

In the ninth aspect, first the coil wound around the stator core is formed by winding the winding around the stator core (coil forming process). Then the portion of winding forming the coil and extending out from the stator core is pressed. The first extension that extends with respect to the stator core toward one side in a rotation axis direction of the rotor, the second extension that extends toward a rotation radial direction outside of the rotor from an end of the first extension on the one side in the rotation axis direction of the rotor, and the third extension that extends toward the one side in the rotation axis direction of the rotor from an end at the rotor rotation radial direction outside of the second extension, are formed thereby. The boundary between the first extension and the second extension is also thereby disposed on the one rotation axis direction side of the rotor with respect to the boundary between the second extension and the third extension (winding bending process). Then the third extension of the winding is connected to the circuit device (winding connection process). The motor of the seventh or eighth aspect is manufactured by performing the above processes, and is capable of suppressing the build shape of the motor in the rotation axis direction from becoming bulky.

A tenth aspect of the present disclosure is a motor manufacturing method of the ninth aspect, further including turning the winding after bending the winding by swinging the second extension about the third extension so as to dispose the third extension at a position corresponding to the centerpiece-side winding insertion hole, and attaching the stator to the centerpiece. The stator is supported by a centerpiece formed with a centerpiece-side winding insertion hole through which the third extension is inserted.

According to the tenth aspect, after performing the winding bending process, the third extension of the winding is disposed at a position corresponding to the centerpiece-side winding insertion hole formed in the centerpiece by swinging the second extension of the winding about the third extension (winding turning process). Then, the stator is attached to the centerpiece (stator attaching process). Thus in the tenth aspect, the third extension of the winding can be inserted easily into the centerpiece insertion hole formed in the centerpiece when the stator is attached to the centerpiece by performing the winding turning process.

DESCRIPTION OF EMBODIMENTS

Explanation follows regarding a motor according to an exemplary embodiment of the present disclosure, with reference toFIG. 1toFIG. 5.

As illustrated inFIG. 1, a motor unit10, serving as a motor in the present exemplary embodiment, includes a stator12, a rotor14, a centerpiece16, a circuit device18, and a cover20. The stator12generates a rotating magnetic field. The rotor14is rotated by the rotating magnetic field generated by the stator12. The centerpiece16supports the rotor14, the stator12, and the like. The circuit device18controls rotation of the rotor14by controlling current flow to windings26configuring part of the stator12. The cover20covers the circuit device18. Note that the arrow Z direction, the arrow R direction, and the arrow C direction respectively indicate a rotation axis direction, a rotation radial direction, and a rotation circumferential direction of the rotor14in the drawings, as appropriate. Further, in the following, unless specifically stated otherwise, simple reference to the axis direction, the radial direction, or the circumferential direction refers to the rotation axis direction, the rotation radial direction, and the rotation circumferential direction of the rotor14.

As illustrated inFIG. 1andFIG. 2, the stator12is configured by wrapping the windings26around predetermined locations of a stator core24that is formed from a magnetic metal with an insulator22attached thereto.

The stator core24includes an annular section24A formed in a ring shape and plural (twelve in the present exemplary embodiment) teeth24B. The teeth24B project toward the radial direction outside from an outer circumferential portion of the annular section24A, and are disposed at even intervals around the circumferential direction. The windings26are wound around each of the respective teeth24B. The windings26each include an insulating covering layer on the surface of a conductive member that has been formed into a linear shape (wire shape). A coil28is thus respectively formed around each of the teeth24B.

As illustrated inFIG. 2, in each of the windings26that are formed into the coils28, a section of the windings26leading out from the stator core24side is bent into a predetermined shape (roughly an N-shape). Specifically, the section of each winding26leading out from the stator core24side includes a first extension26A and a second extension26B. The first extension26A extends toward one side in the axis direction of the stator core24. The second extension26B extends toward the radial direction outside from an end on the one axis direction side of the first extension26A, and is inclined toward the other side in the axis direction on progression toward the radial direction outside. The section of each winding26leading out from the stator core24side also includes a third extension26C. The third extension26C extends toward the one axis direction side from a radial direction outside end of the second extension26B, and an end of the third extension26C on the one axis direction side is connected by solder to a circuit board44(seeFIG. 3) configuring part of the circuit device18. In the present exemplary embodiment, an inner bent portion26D at a boundary between the first extension26A and the second extension26B is disposed at the one axis direction side of an outer bent portion26E at a boundary between the second extension26B and the third extension26C.

As illustrated inFIG. 1, the rotor14is configured including a rotor housing30formed in substantially a bottomed circular cylinder shape and a rotor magnet32fixed to the rotor housing30. The rotor housing30includes a bottom wall30A formed in a disc shape and a circumferential wall30B. The circumferential wall30B is bent so as to extend toward the one axis direction side from an outer circumferential edge of the bottom wall30A. The rotor magnet32is fixed to the radial direction inside face of the circumferential wall30B. A pair of bearings34are fixed to an axial center portion of the rotor housing30by press fitting or the like. The pair of bearings34are inserted into an axial member36fixed to the centerpiece16, described below. The rotor housing30is thus supported by the axial member36through the pair of bearings34, such that the rotor magnet32fixed to the rotor housing30and the stator12are disposed facing each other in the radial direction.

The centerpiece16, serving as a first member, is formed from an aluminum alloy or the like. A boss portion16A is provided to the centerpiece16so as to project toward the other axis direction side. The axial member36is fixed into the boss portion16A by press fitting. The stator12is fixed to the other axis direction side of the centerpiece16by, for example, stator fixing bolts38. Moreover, the circuit device18, described below, is fixed to the one axis direction side of the centerpiece16by circuit device fixing bolts40. A groove16B applied with a sealant50(seeFIG. 9), described below, is formed in the centerpiece16on an outer circumferential portion on the other axis direction side of the centerpiece16.

As illustrated inFIG. 3andFIG. 4, an elongated recess16C is formed in the centerpiece16. The elongated recess16C is open toward the one axis direction side, and is curved in a bow shape as viewed along the axial direction. Plural (three in the present exemplary embodiment) centerpiece-side winding insertion holes16D are formed in the bottom16C1of the recess16C. The third extensions26C of the windings26are inserted through the centerpiece-side winding insertion holes16D. The plural centerpiece-side winding insertion holes16D formed in the bottom16C1of the recess16C are disposed spaced apart along the length direction of the recess16C. Note that the recess16C and the centerpiece-side winding insertion holes16D of the same number as the number of the third extensions26C of the windings26are formed in the centerpiece16.

As illustrated inFIG. 5, a communication hole16E is formed in an outer circumferential portion of the centerpiece16. The communication hole16E places a space between the centerpiece16and the cover20, this being a space where the circuit device18is disposed (seeFIG. 1), in communication with the space outside this space. One side of the communication hole16E opens toward the one axis direction side onto the space where the circuit device18is disposed. The other side of the communication hole16E opens toward the radial direction outside onto the space outside of the space where the circuit device18is disposed. The end of the communication hole16E on the side of the space where the circuit device is disposed is closed off by a filter42that is formed from a material that is gas-permeable but does not let liquid readily pass through. Note that GORETEX (registered trademark) or the like is an example of a material that may be employed for the filter42.

As illustrated inFIG. 1andFIG. 5, the circuit device18is disposed on the opposite side of the centerpiece16to the side on which the stator12is fixed. The circuit device18is configured including the circuit board44and plural circuit elements46that configure a control circuit to control current flow to the stator12(windings26).

The circuit board44is formed in a rectangular sheet shape with its thickness direction along the axis direction. The circuit board44is configured by conductive patterns formed on a board body formed from an insulating material. As illustrated inFIG. 3andFIG. 4, connection portions44A are provided on the circuit board44. Ends of the third extensions26C of the windings26that have passed through the centerpiece-side winding insertion holes16D formed in the centerpiece16are connected by solder to the connection portions44A. Note that power is supplied to the circuit board44through a connector48attached to the centerpiece16(seeFIG. 1).

As illustrated inFIG. 1, the cover20, serving as a second member, is formed in the shape of a bottomed box that is open at the side of the centerpiece16. The cover20is joined to the centerpiece16using the interposed sealant50(seeFIG. 9), so as to form the space the circuit device18is disposed in between the cover20and the centerpiece16. Specifically, the cover20includes a bottom wall20A, a side wall20B, and a flange20C. The bottom wall20A extends in the radial direction and faces the circuit board44fixed to the centerpiece16along the axis direction. The side wall20B is bent so as to extend from an outer circumferential edge of the bottom wall20A toward the centerpiece16. The flange20C extends toward the radial direction outside from the centerpiece-16-side end of the side wall20B. The flange20C is formed with a protrusion20D that corresponds to the groove16B formed in the centerpiece16.

As illustrated inFIG. 4, a cap52formed from an insulating material is attached to a peripheral edge of each of the centerpiece-side winding insertion holes16D in the centerpiece16. Each cap52is tube shaped and formed with a cap-side winding insertion hole52A at the axial center thereof. The third extension26C of the respective winding26is inserted into the cap-side winding insertion hole52A.

A portion on the stator12side (on the other axis direction side) of the cap-side winding insertion hole52A is formed with a funnel shape that gradually narrows on progression toward the one axis direction side. An inner diameter D1of the other-axis-direction-side portion of the cap-side winding insertion hole52A thus gradually decreases on progression toward the one axis direction side. An inner diameter D2of a portion on the circuit device18side (on the one axis direction side) of the cap-side winding insertion hole52A is set as a larger inner diameter than an inner diameter D3of an axis direction central portion of the cap-side winding insertion hole52A. Note that the inner diameter D3of the axis direction central portion of the cap-side winding insertion hole52A is an inner diameter substantially the same as an outer diameter D4of the windings26.

As illustrated inFIG. 3andFIG. 4, in the present exemplary embodiment, slight gaps formed between the centerpiece-side winding insertion holes16D and the caps52, and slight gaps formed between the caps52and the windings26are sealed by forming a potting section53in the recess16C formed in the centerpiece16. Note that the potting material to form the potting section53with is a silicone resin that cures readily by irradiation with ultraviolet rays.

As illustrated inFIG. 3, in the present exemplary embodiment, a single potting section53is formed in the recess16C by pouring the silicone resin into the recess16C formed in the centerpiece16and then irradiating ultraviolet rays onto the silicone resin poured into the recess16C. Each of the gaps formed at the peripheral edges of the three centerpiece-side winding insertion holes16D formed in the bottom16C1of the recess16C are thus sealed by the single potting section53. Note that an axis direction height (depth) H of the potting section53with respect to the bottom16C1of the recess16C is set to a height such that the cap52is not exposed from the potting section53.

Method of Forming Winding Terminal Ends

Explanation follows regarding a method of forming the section leading out from the stator core24side in each of the windings26formed into the coils28, with reference toFIG. 6andFIG. 7.

As illustrated inFIG. 6AtoFIG. 6C, in the present exemplary embodiment, the section leading out from the stator core24side in each of the windings26formed into the coils28is bent into a predetermined shape using a pressing apparatus. The pressing apparatus is configured including a backup54that is inserted between the respective teeth24B of the stator core24, and a first bending jig56and a second bending jig58. The windings26are sandwiched between the backup54, and the first bending jig56and the second bending jig58.

The backup54is configured by plural backup configuration blocks60that are divided from each other in the circumferential direction. The backup configuration blocks60each includes an inter-tooth insertion portion60A and an outer circumferential wall portion60B. The inter-tooth insertion portion60A includes a portion that is disposed between the respective teeth24B. The outer circumferential wall portion60B extends toward the one axis direction side from the radial direction outer side of the inter-tooth insertion portion60A. Each backup configuration block60is thus formed in substantially an L-shape in side view (as viewed from the radial direction outside). A surface S1on the one-axis-direction-side of the inter-tooth insertion portion60A is inclined toward the other axis direction side on progression toward the radial direction outside. The angle θ1of the surface S1on the one-axis-direction-side of each inter-tooth insertion portion60A is, for example, set to approximately 4 degrees with respect to the radial direction. A surface S2on the radial direction inner side of the outer circumferential wall portion60B extends along the axis direction.

The first bending jig56is formed in substantially a circular column shape. A radial direction outside end at the other-axis-direction-side of the first bending jig56is configured with a tapered portion56A that becomes narrower on progression toward the other axis direction side. An inclination angle θ3of an outer circumferential surface S3of the tapered portion56A is set to approximately 45 degrees with respect to the radial direction.

The second bending jig58is formed in an annular block shape, into which the first bending jig56is inserted. A surface S4on the other-axis-direction-side of the second bending jig58corresponds to the surface S1on the one-axis-direction-side of the inter-tooth insertion portions60A of the backup configuration blocks60. Namely, an inclination angle θ4of the surface S4on the other-axis-direction-side of the second bending jig58is set to approximately 4 degrees with respect to the radial direction. A surface S5on the radial direction outer side of the second bending jig58is slightly inclined with respect to the surface S2on the radial direction inner side of the outer circumferential wall portion60B of each backup configuration block60. Namely, an inclination angle θ5of the surface S5on the radial direction outer side of the second bending jig58is set so as to be inclined by approximately 1.5 degrees toward the radial direction inside with respect to the axis direction. The inclination angle θ5is set in consideration of spring back of the windings26from the state illustrated using double-dotted dashed lines to the state illustrated using solid lines inFIG. 2.

As illustrated inFIG. 6A, in a state after a coil forming process has been performed, in each of the windings26formed into the coils28, the section thereof that leads out from the stator core24side extends in a straight line toward the one axis direction side. After the stator12has been set in this state in the pressing apparatus, each of the backup configuration blocks60is moved toward the radial direction inside. Part of the inter-tooth insertion portion60A of each backup configuration block60is thus disposed between respective teeth24B of the stator core24.

Next, as illustrated inFIG. 6B, the first bending jig56is moved toward the other axis direction side. The base end side (the other axis direction side) of the section leading out from the stator core24side of each of the windings26formed into the coils28is thereby pressed against the outer circumferential surface S3of the tapered portion56A of the first bending jig56. This causes the section leading out from the stator core24side of each of the windings26formed into the coils28to be inclined at an angle corresponding to the outer circumferential surface S3of the tapered portion56A (i.e. approximately 45 degrees with respect to the axis direction).

Next, as illustrated inFIG. 6C, the second bending jig58is moved toward the other axis direction side. The section leading out from the stator core24side of each of the windings26formed into the coils28is thereby interposed and pressed between the other-axis-direction-side surface S4and the radial-direction-outer-side surface S5on the second bending jig58, and the one-axis-direction-side surface S1of the inter-tooth insertion portion60A and the radial-direction-inner-side surface S2of the outer circumferential wall portion60B on the respective backup configuration block60(a winding bending process). The section leading out from the stator core24side of each of the windings26formed into the coils28is bent into the state illustrated inFIG. 7Aby these processes.

Further, after this winding bending process has been performed, the second extension26B of each of the windings26is caused to swing about the third extension26C such that, as illustrated inFIG. 7B, the third extensions26C are disposed at positions corresponding to the centerpiece-side winding insertion holes16D (seeFIG. 3) formed in the centerpiece16(a winding turning process). Then, as illustrated inFIG. 8AandFIG. 8B, when attaching the stator12to the centerpiece16, to which the cap52has already been attached, the third extension26C of each winding26is inserted through the centerpiece-side winding insertion holes16D formed in the centerpiece16and through the cap-side winding insertion hole52A formed in the respective cap52(a stator attaching process). Then, as illustrated inFIG. 8C, the potting section53is formed inside the recess16C by pouring silicone resin into the recess16C formed in the centerpiece16and irradiating ultraviolet rays onto the silicone resin poured into the recess16C (a potting section forming process). Then, as illustrated inFIG. 3, the third extension26C of each winding26is connected by solder to the circuit board44configuring part of the circuit device18(a winding connection process).

Cover Attachment Process

Explanation follows regarding a process for attaching the cover20to the centerpiece16, with reference toFIG. 9. Note that the groove16B formed in the centerpiece16and the protrusion20D formed to the flange20C of the cover20are omitted from illustration inFIG. 9.

As illustrated inFIG. 9, first, a suction pump62is connected to the communication hole16E formed in the centerpiece16(a pump connecting process).

Next, the sealant50is poured into the groove16B (seeFIG. 1) formed in the centerpiece16. Note that the amount of sealant50poured into the groove16B is an amount such that the sealant50projects out of the open end of the groove16B. A portion corresponding to the groove16B may be formed on the flange20C of the cover20, and the sealant50applied to this portion corresponding to the groove16B.

Next, the suction pump62is actuated to join the flange20C of the cover20to the portion applied with the sealant50on the centerpiece16while air on the circuit device18side of the communication hole16E is sucked through the communication hole16E (a joining process).

The motor unit10of the present exemplary embodiment is manufactured through the processes described above and other processes.

Operation of Present Exemplary Embodiment

Explanation follows regarding the operation of the present exemplary embodiment.

As illustrated inFIG. 1, in the motor unit10of the present exemplary embodiment, current flow to the stator12(windings26) is controlled by the circuit device18such that the stator12generates a rotating magnetic field. The rotor14is rotated by interaction between the rotating magnetic field and the magnetic field of the rotor magnet32.

In the motor unit10of the present exemplary embodiment, as illustrated inFIG. 3, the third extension26C of each of the windings26is inserted through the centerpiece-side winding insertion holes16D formed in the centerpiece16that supports the stator12, and through the cap-side winding insertion hole52A formed in the respective cap52. Slight gaps formed between the centerpiece-side winding insertion holes16D and the caps52and slight gaps between the cap52and the windings26are sealed due to the potting section53being formed in the recess16C formed in the centerpiece16. Water droplets adhering to the stator12side can thereby be suppressed from flowing past the peripheral edges of the centerpiece-side winding insertion holes16D and infiltrating through to the circuit device18side. In particular, since the potting section53is closely adhered to the covering layer of the windings26in the present exemplary embodiment, it is possible to achieve a good state of joining between the potting section53and the windings26. This enables water droplets adhered to the stator12side to be suppressed from infiltrating through between the potting section53and the winding26to the circuit device18side.

Moreover, a configuration is adopted in the present exemplary embodiment in which gaps at the peripheral edges of the plural (three) third extensions26C are sealed by the single potting section53. This enables good work efficiency to be achieved when forming the potting section53to seal the gaps.

Moreover, since the centerpiece-side winding insertion holes16D are formed in the bottom of the recess16C formed in the centerpiece16in the present exemplary embodiment, the potting material for forming the potting section53can be held in the recess16C. This enables good work efficiency to be achieved when forming the potting section53to seal the gaps formed between the centerpiece-side winding insertion holes16D and the windings26.

Further, adopting a configuration in the present exemplary embodiment in which plural of the centerpiece-side winding insertion holes16D are formed in the bottom of a single recess16C enables even better work efficiency to be achieved when forming the potting section53to seal the gaps formed between the centerpiece-side winding insertion holes16D and the windings26.

Further, providing the insulating caps52between the centerpiece-side winding insertion holes16D and the windings26in the present exemplary embodiment enables a state of insulation between the windings26and the peripheral edges of the centerpiece-side winding insertion holes16D to be easily secured. Further, forming the portion on the stator12side of the cap-side winding insertion hole52A formed in each cap52with the inner diameter D1that is smaller on progression from the stator12side toward the circuit device18side enables the windings26to be easily inserted through from the stator12side to the circuit device18side.

Further, forming the portion on the circuit device18side of the cap-side winding insertion hole52A formed in each cap52with the inner diameter D2that is larger than the inner diameter D3of the axis direction central portion of the cap-side winding insertion hole52A in the present exemplary embodiment enables an increase in the contact area between the potting section53and the covering layer formed on the windings26. This enables the strength of the join between the potting section53and covering layer formed on the windings26to be increased. Note that as illustrated inFIG. 10, the contact area between the potting section53and covering layer formed on the windings26may also be increased by attaching the caps52to the centerpiece16in a state in which the caps52are inverted in the axis direction.

Note that although in the present exemplary embodiment, as illustrated inFIG. 3, explanation was given of an example of a configuration in which the portion on the stator12side of each of the cap-side winding insertion holes52A is formed in a funnel shape in which the inner diameter D1of the other-axis-direction-side portion of the cap-side winding insertion hole52A gradually becomes smaller on progression toward the one axis direction side, the present disclosure is not limited thereto. For example, as illustrated inFIG. 11, the portion on the stator12side of each cap-side winding insertion hole52A may be formed in a funnel shape in which an axis direction intermediate portion of this portion is configured with an inflection. Further, as illustrated inFIG. 12, the portion on the stator12side of each cap-side winding insertion hole52A may be formed in a funnel shape in which the inner circumferential face thereof is configured with a gentle curve.

Note that although explanation was given in the present exemplary embodiment of an example in which the caps52are attached to the centerpiece16, the present disclosure is not limited thereto. For example, configuration may be such that the peripheral edge of each of the centerpiece-side winding insertion holes16D formed in the centerpiece16is configured similarly to a cap, and a cap52is not provided.

As illustrated inFIG. 2, in the stator12configuring part of the motor unit of the present exemplary embodiment, the inner bent portion26D at the boundary between the first extension26A and the second extension26B of each of the windings26is disposed at the one axis direction side of the outer bent portion26E at the boundary between the second extension26B and the third extension26C. This enables locations of the stator12at the rotor rotation radial direction outside to be disposed closer to the centerpiece16than in configurations in which the inner bent portion26D and the outer bent portion26E are disposed at the same position along the rotation axis direction. As a result, the build shape of the motor unit10along the rotation axis direction can be suppressed from becoming more bulky.

Further, in the present exemplary embodiment, the second extension26B, this being a location between the first extension26A and the third extension26C of each of the windings26, is inclined toward the other axis direction side on progression toward the radial direction outside. Such configuration enables the length of the second extension26B to be shorter than in cases in which the second extension26B is curved. This enables the wiring routing for the section of the winding26extending from the stator core24as far as the circuit device to be suppressed from increasing in length. Note that inclination or no inclination of the second extension26B as described above may be appropriately set in consideration of the configuration of the portion where the stator12is to be fixed to on the centerpiece16.

Further, in the present exemplary embodiment, after the winding bending process illustrated inFIG. 6AtoFIG. 6Chas been performed, when the stator12is being attached to the centerpiece16via the winding turning process illustrated inFIG. 7B, the third extension26C of each of the windings26can be easily inserted through the respective centerpiece-side winding insertion hole16D formed in the centerpiece16, and through the respective cap-side winding insertion hole52A formed in the cap52. Note that the incorporation or not of the winding turning process into the processes for manufacturing a motor unit may be selected in consideration of the arrangement of the centerpiece-side winding insertion holes16D formed in the centerpiece16.

As illustrated inFIG. 1, in the motor unit10of the present exemplary embodiment, the circuit device18is disposed inside the space formed between the centerpiece16and the cover20. Further, the sealant50is interposed between the centerpiece16and the cover20. Water droplets are thereby suppressed from infiltrating into the space where the circuit device18is disposed between the centerpiece and the cover.

Note that when the cover20is being attached to the centerpiece16in a state in which the sealant50has been applied to the centerpiece16, as illustrated inFIG. 9, it is conceivable that the pressure between the centerpiece16and the cover20will rise when the sealant50is being squashed between the cover20and the centerpiece16. Thus the sealant50interposed between the centerpiece16and the cover20might conceivably fly out. Namely, it is conceivable that there will be a loss of the sealant50at some locations between the centerpiece16and the cover20.

However, in the present exemplary embodiment, the centerpiece is formed with the communication hole16E that communicates the space formed between the centerpiece16and the cover20with space on the outside of this space, and also a portion on the side of the outside space is open toward the radial direction outside. This enables the suction pump62to be easily connected to a portion on the opposite side of the communication hole16E to the side on which the circuit device18is disposed. Attaching the cover20to the centerpiece16as air on the circuit device18side is being sucked out by the suction pump62enables the pressure in the space between the centerpiece16and the cover20to be suppressed from increasing when the sealant50is squashed between the cover20and the centerpiece16. This enables sealant to be interposed between the centerpiece16and the cover20in a desired state.

Further, in the present exemplary embodiment, an end portion of the communication hole16E on the side of the space where the circuit device18is disposed is closed off by the filter42that has the aforementioned properties. With such a configuration, the pressure in the space between the centerpiece16and the cover20is liable to increase when the sealant50is squashed between the cover20and the centerpiece16. However, in the present exemplary embodiment, the cover20is attached to the centerpiece16as air is being sucked out from the circuit device18side using the suction pump62connected to the communication hole16E, and this enables the pressure in the space between the centerpiece16and the cover20to be suppressed from increasing when the sealant50is squashed between the cover20and the centerpiece16. This configuration provided with the filter42also enables the sealant50to be interposed between the centerpiece16and the cover20in a desired state.

Note that provision or not of the filter42may be selected as appropriate in consideration of the environment for disposing the motor unit10in, the orientation of the motor unit10, and so on.

Explanation has been given regarding an exemplary embodiment of the present disclosure. However, the present disclosure is not limited to the above, and obviously various other modifications may be implemented within a range not departing from the spirit of the present disclosure.

The disclosures of Japanese Patent Application No. 2016-045700 and Japanese Patent Application No. 2016-045701, filed on Mar. 9, 2016, are incorporated in their entirety in the present specification by reference herein.

All cited documents, patent applications, and technical standards mentioned in the present specification are incorporated by reference in the present specification to the same extent as if each individual cited document, patent application, or technical standard was specifically and individually indicated to be incorporated by reference.