Rotating electrical machine and method for manufacturing rotating electrical machine

A rotating electrical machine includes a rotor and a stator positioned circumferentially around the rotor. The stator includes multiple core elements arrayed in a circumferential direction of the rotor such that the core elements form multiple slots arrayed in the circumferential direction, and a unitary cylindrical coil resin structure including molded resin and lap wound air-core coils resin-molded in the molded resin, each of the air-core coils having an air-core, a first side portion and a second side portion extending on the opposite sides of the air-core such that the first side portion extends through a first one of the slots and the second side portion extends through a second one of the slots.

BACKGROUND

Technical Field

The disclosed embodiment relates to a rotating electrical machine, and a method for manufacturing a rotating electrical machine.

Description of Background Art

A three-phase AC rotating electrical machine has a stator with a Y-connected winding serving as the winding of each phase of a distributed winding and a lap winding.

SUMMARY

According to one aspect of the present disclosure, a rotating electrical machine includes a rotor and a stator positioned circumferentially around the rotor. The stator includes multiple core elements arrayed in a circumferential direction of the rotor such that the core elements form multiple slots arrayed in the circumferential direction, and a unitary cylindrical coil resin structure including molded resin and lap wound air-core coils resin-molded in the molded resin, each of the air-core coils having an air-core, a first side portion and a second side portion extending on the opposite sides of the air-core such that the first side portion extends through a first one of the slots and the second side portion extends through a second one of the slots.

According to another aspect of the present disclosure, a unitary cylindrical coil resin structure for a rotating electrical machine includes molded resin, and lap wound air-core coils resin-molded in the molded resin, each of the air-core coils having an air-core, a first side portion and a second side portion extending on opposite sides of the air-core. When assembled with core elements of a stator of the rotating electrical machine, the core elements are arrayed in a circumferential direction of a rotor such that the core elements form slots arrayed in the circumferential direction, the first side portion of each of the air-core coils extends through a first one of the slots, and the second side portion of each of the air-core coils extends through a second one of the slots.

According to yet another aspect of the present disclosure, a method for manufacturing a rotating electrical machine includes lap-winding air-core coils such that lap wound air-core coils form a substantially cylindrical reel shape, resin-molding the lap wound air-core coils such that a unitary cylindrical coil resin structure including molded resin and the lap wound air-core coils resin-molded in the molded resin is formed, and assembling core elements of a stator to the unitary cylindrical coil resin structure such that the core elements are arrayed in a circumferential direction of a rotor and form slots arrayed in the circumferential direction, each of the air-core coils having an air-core, a first side portion and a second side portion extending on opposite sides of the air-core such that the first side portion extends through a first one of the slots and the second side portion extends through a second one of the slots.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Rotating Electrical Machine

First, the structure of the rotating electrical machine in embodiment 1 will be described usingFIG. 1andFIG. 2.

As shown inFIG. 1andFIG. 2, a rotating electrical machine10in this embodiment is a magnet-embedded synchronous motor having a rotor20inside a stator30. That is, the rotating electrical machine10has the rotor20rotatably supported, and the substantially cylindrical stator30disposed so as to enclose a radial-direction outer circumference side of the rotor20with a magnetic air gap therebetween. Further, the rotating electrical machine10has a cylindrical frame11disposed on an outer circumference side of the stator30, a load-side bracket12disposed on a load side (the right side inFIG. 1) of the frame11, a load-side bearing13whereby an outer ring is fitted to the load-side bracket12, a counter-load side bracket14disposed on a counter-load side (the left side inFIG. 1) of the frame11, a counter-load side bearing15whereby an outer ring is fitted to the counter-load side bracket14, a shaft16(rotating shaft) rotatably supported by the load-side bearing13and the counter-load side bearing15, and an encoder17that detects a rotating position of the rotor20, disposed on a counter-load side (the left side inFIG. 1) end part of the shaft16.

The load-side bracket12and the counter-load side bracket14are connected to the frame11by bolts (not shown). On the load-side bracket12, a dust seal18is disposed on the outside of the bearing13to prevent entry of foreign matter into the interior of the rotor20. A connecting part44of a coil41of the stator30is disposed on a counter-load side end surface of a stator core32of the stator30. An external power source is connected to the connecting part44via a lead wire (not shown), and power is supplied from the external power source to the coil41via the connecting part44.

The rotor20has a substantially annular rotor core22having an axial-direction hole21that fits the shaft16, and an axial-direction permanent magnet23embedded in the rotor core22in a V-shape per pole. With this arrangement, the rotor20is structured as a field system part with an embedded magnet type structure of multiple poles (8 in this example). A load-side lateral plate8and a counter-load side lateral plate9that respectively hold and prevent the load-side end surface and counter-load side end surface of the rotor20from moving outward in the load-side direction and outward in the counter-load side direction of the rotor20are attached to the shaft16. A positioning lateral plate7of the rotor20is attached between the load-side lateral plate8and the above described load-side bearing13of the shaft16.

Structure of Stator

The stator30has the substantially annular above described stator core32having multiple slots31(48 slots in this example), and the coils41(48 coils in this example) respectively housed in the above described slots31. With this arrangement, the stator30is structured as an armature part. The stator core32is structured by arranging divided core elements33(48 core elements in this example) with a substantially fan-shaped transverse cross-section across the entire circumference, along the inner circumferential surface of the frame11. Each of the divided core elements33has a tooth34with a rectangular transverse cross-sectional shape, on the radial-direction inside. At this time, the slot31is formed between the teeth (34,34) respectively included in adjacent divided core elements (33,33). With this arrangement, the slots31are disposed across the entire circumferential-direction circumference so as to extend along the inner circumferential surface of the above described frame11. The slots31correspond to the teeth34with rectangular transverse cross-sectional shapes, and are each formed so as to be fan-shaped with the transverse cross-sectional shape narrowing toward the radial-direction inside.

At this time, the above described coils41(48 coils in this example) is formed in advance as one substantially cylindrical coil resin structure45, as shown inFIG. 3. The following describes the coil resin structure45formed by the 48 coils41, and the detailed structures of and the respective coils41, usingFIG. 4andFIG. 5.

Structure of Coil

Each of the coils41is formed as a hexagonal air-core coil, as shown inFIG. 4. That is, first a conductor42covered by a suitable insulating film (not shown) is wound multiple times (4 times, for example) into a long rectangular frame shape. Note that a flat rectangular wire with a rectangular transverse cross-sectional shape is used as the conductor42in this example. Nevertheless, the present disclosure is not limited thereto, allowing use of a lead wire with another shape (a round lead wire with a substantially circular transverse cross-sectional shape, for example). At this time, the conductor42is wound while layered from the lowermost layer in the direction of the upper layers on one of the long sides of the rectangular frame that face each other, and while layered from the uppermost layer in the direction of the lower layers on the other of the long sides. Further, at that time, the conductor42is wound while inverting the front and back so as to create a loop within a plane surface orthogonal to the plane surface of the above described rectangular frame, in the centre area of the two short sides that face each other. After the above described winding, the wound body of the conductor42is widened in the width direction and longitudinal direction as indicated by arrows (a1, a2, a3, a4) inFIG. 4, plastically deforming into a hexagonal shape, thereby achieving the above described coil41, which is a hexagonal air-core coil.

That is, the coil41has a substantially linear first linear part (41a) (one side portion in a circumferential direction) positioned on the upper right side inFIG. 4that leads to a winding start end41sof the conductor42, a substantially linear second linear part (41b) (other side portion in a circumferential direction) positioned on the lower left side inFIG. 4that leads to a winding finish end (41e) of the conductor42, inclined parts (41f,41g) that respectively connect one end of the first linear part (41a) and the second linear part (41b) (upper left side inFIG. 4), one turn part (41c) disposed in the middle area of these inclined parts (41f,41g), and another turn part (41d) (hereinafter “nose part”) that continues to the inclined parts that connect the other end of the first linear part (41a) and the second linear part (41b).

Four-Layer Layered Structure of Conductor

In each of the above described parts (41a-41g) of the coil41, the conductor42is wound multiple times (4 times in this example). As a result, in each of the above described parts (41a-41g), the conductor42is layered in multiple layers (4 layers in this example; hereinafter the same) in the radial direction (up-down direction inFIG. 4) of the stator core32. Then, the first linear part (41a) and the second linear part (41b) of the coil41are disposed away from each other so as to substantially extend along the direction that is the circumferential direction of the stator core32when the stator core32is mounted to the slots31(in other words, when the coil resin structure45is mounted to the stator core32).

Hence, during the above described mounting, the first linear part (41a) (or the second linear part (41b)) of a certain coil41included in the coil resin structure45is disposed well on the radial-direction inside (indicated by the “inner circumferential step” inFIG. 4) of each of the slots31, and the first linear part (41a) (or the second linear part (41b)) of another coil included in the coil resin structure45is disposed well on the radial-direction outside (indicated by the “outer circumferential step” inFIG. 4) of each of the slots31, as shown in the enlarged explanatory views inside the circles inFIG. 4. That is, with the coil resin structure45assembled to the stator core32, in each of the 48 coils41, the first linear part41is disposed well on the radial-direction inside (on the “inner to circumferential step” inFIG. 4) of a certain slot31while the second linear parts (41b) is disposed well on the radial-direction outside (on the “outer circumferential step” inFIG. 4) of another slot31, four slots away in the circumferential direction. To achieve such a disposition, a separation distance (L) between the first linear part (41a) and the second linear part (41b) of the respective coils41described above (refer toFIG. 3) is substantially equal to a separation distance (X) equivalent to four slots31in the substantially circumferential direction (with the difference in the inner/outer radial-direction positions described above taken into account; refer toFIG. 2) when the aforementioned coil resin structure45is mounted to the stator core32.

Pressure Molding

Further, as described above, the slot31is fan-shaped, with a transverse cross-sectional shape narrowing toward the radial-direction inside. Correspondingly, at least the first linear part (41a) and the second linear part (41b) of each of the coils41are pressure-molded in advance so that the outer shape agrees with the transverse cross-sectional shape of each of the slots31prior to being molded as described later. That is, the second linear part (41b) disposed well on the radial-direction outside of the slot31is molded into a flatter shape than the first linear part (41a) disposed well on the radial-direction inside of the slot31. Specifically, in the four layer conductor42(conductors (42-1,42-2,42-3,42-4) from the radial-direction inside toward the outside) having the first linear part (41a), the conductor (42-1) has the smallest circumferential-direction (the left-right direction in the enlarged view inFIG. 4) dimension and the largest radial-direction (the up-down direction in the enlarged view inFIG. 4) dimension. Then, the cross-sectional shape becomes increasingly flat for conductors further on the radial-direction outside, in the order of the conductor (42-2), the conductor (42-3), and the conductor (42-4), with the conductor (42-4) having the largest circumferential-direction dimension and the smallest radial-direction dimension. Similarly, in the four layer conductor42(conductors (42-5,42-6,42-7,42-8) from the radial-direction inside toward the outside) having the second linear part (41b), the conductor (42-5) has the smallest circumferential-direction dimension and the largest radial-direction dimension. Then, the cross-sectional shape becomes increasingly flat for conductors further on the radial-direction outside, in the order of the conductor (42-6), the conductor (42-7), and the conductor (42-8), with the conductor (42-8) having the largest circumferential-direction dimension and the smallest radial-direction dimension. Note that the conductor (42-5) has a larger circumferential-direction dimension and a smaller radial-direction dimension than the conductor (42-4).

Forming Coil Resin Structure

Then, as conceptually shown inFIG. 5, an air gap43where the above described tooth34of the stator core32is fitted is formed between two coils41during the above described mounting, and each of the 48 coils41is shifted in position and overlapped while extended along the circumferential direction of the stator core32during the above described mounting. This overlapping mode is repeated so as to extend across the entire circumferential direction of the stator core32during the above described mounting (equivalent to the lap-winding step). Then, the 48 coils41thus lap-wound across the entire circumferential-direction circumference are integrally resin-molded and hardened by mold resin (not shown), thereby forming one substantially cylindrical coil resin structure45made of the 48 coils41(equivalent to the resin molding step), as shown in the above describedFIG. 3.

Attaching Coil Resin Structure to Stator Core

Subsequently, the teeth34of the divided core element33are fitted (across the entire circumference of the coil resin structure45) from the outer circumference side of the coil resin structure45into each of the air gaps43between adjacent coils (41,41) of the coil resin structure45formed as described above. With this arrangement, the annular stator core32is constructed by the divided core elements33(48 elements in this example). Further, the coil resin structure45and the above described stator core32are integrally assembled while the first linear part (41a) of the coil41of the coil resin structure45is housed in the above described inner circumferential step of each of the slots31formed between the teeth (34,34) of two adjacent divided core elements (33,33), and the second linear part (41b) of the another coil41of the coil resin structure45is housed in the above described outer circumferential step of each of the slots31(equivalent to the assembly step). In this manner, the stator30is assembled.

As described above, according to the rotating electrical machine10in embodiment 1, each of the coils41has an air-core coil, and the first linear part (41a) and the second linear part (41b) are disposed in a so-called lap-winding mode in which the circumferential-direction position is sequentially shifted while the parts are separately inserted into different slots31. At this time, the coils41, which are air-core coils subjected to lap-winding and arranged around the entire circumferential-direction circumference as described above, are integrally resin-molded in advance while not inserted into the slots31to form one coil resin structure45. On the other hand, the stator core32is structured by arranging the divided core element33in multiple across the entire circumferential-direction circumference. Each of the core elements33has the tooth34, and the above described slot31is formed between two divided core elements33that are adjacent when arranged in multiple. Then, the divided core elements33are assembled from the outer circumference side of the coil resin structure45while each of the coils41included in the coil resin structure45is inserted into two corresponding slots31. With this arrangement, the stator30with the lap-wound coils41inserted into the slots31of the stator core32is manufactured.

As described above, according to this embodiment, before being individually inserted into the slots31, the coils41are constructed as one coil resin structure45and the stator core32with the divided structure is inserted into the one coil resin structure45. With this arrangement, the coils are not inserted into the slots and molded by mold resin on the main line of the manufacturing process, but rather the coils41can be prepared as one resin structure45in advance on a sub-line of the manufacturing process. By constructing the coil resin structure45at a high space factor by the coils41on a sub-line that is a separate line from the main line, it is possible to decrease the generation of heat of the coil41itself, thereby improving the cooling performance of the rotating electrical machine10.

Further, since the work is performed for assembling each of the coils41of the coil resin structure45constructed in advance on the sub-line while housing them into the slots31, the mold resin molding work is no longer necessary on the main line, making it possible to significantly reduce the manufacturing time.

Then, the stator30is structured by the assembly body of the stator core32with a divided structure such as described above and one coil resin structure45, thereby making it possible to perform disassembly easily when the rotating electrical machine10is no longer needed and is to be discarded. In particular, the iron material used on the core32side and the copper material used in the conductor42of the coil41can be easily separated, for example, making it possible to rapidly improve recyclability.

Further, in particular, according to this embodiment, each of the coils41is pressure-molded, thereby making the external shape thereof agree with the transverse cross-sectional shape of the corresponding slot31. With this arrangement, there is also the advantage of more reliably improving the space factor, which is the actual disposition capacity of the coil41that occupies the slot31, which is the disposition space of the coil41. Further, there is also the advantage of improving the cooling performance by the decrease in coil heat generation resulting from the increase in the space factor of the rotating electrical machine10.

Overview of Rotating Electrical Machine

Next, the rotating electrical machine in embodiment 2 will be described usingFIG. 6toFIG. 12. The components that are the same as those in embodiment 1 will be denoted using the same reference numerals, and descriptions thereof will be suitably omitted or simplified. As shown inFIG. 6, a rotating electrical machine10A in this embodiment has a coil resin structure60in the stator30.

The coil resin structure60, as schematically shown inFIG. 7, is formed by lap-winding the coils41(48 coils in this example, the same as described above; refer toFIG. 8described later), which are the same air-core coils as the above described embodiment 1, across the entire circumferential-direction circumference of the stator core32(refer to the aforementionedFIG. 4andFIG. 5as well), and integrally resin-molding by mold resin and hardening the lap-wound coils41. Each of the coils41is pressure-molded so that the external shape agrees with the transverse cross-sectional shape of the corresponding two slots31. A load-side end surface (41A) of the coil41is formed so as to have a partial conical surface corresponding to an inside surface (12a) by the above described pressure-molding so as to be closely fitted to the inside surface (12a) of the load-side bracket12.

Overview of Coil Resin Structure

FIG. 8shows the overall outer appearance of the coil resin structure60. The coil resin structure60, as shown inFIG. 8, has a short, cylindrical load-side coil end part62positioned on the load side (equivalent to one axial-direction side of the rotor), a short, cylindrical counter-load side coil end part63positioned on the counter-load side (equivalent to the other axial-direction side of the rotor), and a middle part64positioned between the load-side coil end part62and the counter-load side coil end part63. At this time, the coil resin structure60, as shown inFIG. 7andFIG. 8, has a nearly cylindrical reel shape overall, with the outer diameter of the middle part64smaller than the outer diameter of the above described coil end parts (62,63) on both sides.

The load-side coil end part62, as indicated by the dashed lines inFIG. 8, is an area where the portion of the turn part (41c) and the like on the above described one end side of each of the coils41is covered and contained (details described later). The counter-load side coil end part63, as indicated by the dashed lines inFIG. 8, is an area where the above described winding start end (41s), the above described winding finish end (41e), the above described nose part (41d), and the like on the above described other end side of each of the coils41are covered (details described later).

In the middle part64, multiple slot insertion parts61with a substantially rectangular plate shape, housed in the slots31of the stator core32, are arranged in the circumferential direction. Note that, as described later, this slot insertion part61is an area where the above described first linear part (41a) and the above described second linear part (41b) of each of the coils41are covered and contained.

Molding by Primary Covering and Secondary Covering

This coil resin structure60is formed by performing resin-molding by mold resin twice on the front surface of each of the coils41disposed in advance in a substantially annular shape. That is, a primary covering layer700that covers the outside of each of the coils41(refer toFIG. 9and the like described later) is generated by a first resin molding, thereby forming a primary molding50. Subsequently, a secondary covering layer800that covers the outside of the primary covering layer700(refer toFIG. 12, described later) is generated by a second resin molding, thereby forming the above described coil resin structure60. The following describes the details of the formation of the above described primary covering layer700and secondary covering layer800, in order. The primary covering layer700links to means for covering an outside of the air-core coil. The secondary covering layer800links to means for covering an outside of the means for covering an outside of the air-core coil.

Formation of Primary Molding

The following describes the above described primary molding50usingFIG. 9,FIG. 10, andFIG. 11. The primary molding50, as described above, is structured by covering the outside of each of the coils41disposed in a substantially annular shape with the primary covering layer700(refer toFIG. 11andFIG. 10). That is, the primary molding50, as shown inFIG. 9, has a load-side coil end part52corresponding to the load-side coil end part62of the above described coil resin structure60, a counter-load side coil end part53corresponding to the counter-load side coil end part63of the above described coil resin structure60, and a middle part54corresponding to the middle part64of the above described coil resin structure60, positioned between the load-side coil end part52and the counter-load side coil end part53.

When the above described primary molding50is molded, the coils41disposed in the above described substantially annular shape is set in the primary mold, which is a split mold, and mold resin is poured into the interior of the mold, thereby forming the above described primary covering layer700by mold resin on the outside of each of the coils41(equivalent to the primary covering step). With this arrangement, regardless of the position and posture of each of the coils41inside the interior space of the above described primary mold, it is possible to achieve the above described primary molding50having the load-side coil end part52and the counter-load side coil end part53with a specified outer diameter dimensions determined in advance, and further having the identically shaped slot insertion parts51with a specified outer diameter dimension determined in advance in the middle of the coil ends parts (52,53).

Middle Part

In the middle part54, multiple slot insertion parts51with a substantially rectangular plate shape, respectively corresponding to the slots insertion parts61of the above described coil resin structure60, are arranged in the circumferential direction. As shown inFIG. 10A, the second linear part (41b) of a certain coil41and the first linear part (41a) of another coil41are overlapped and layered in the radial direction in the slot insertion part51. That is, in this example, the above described second linear part (41b) is disposed on the radial-direction outside (the upper side inFIG. 10A,FIG. 10C) of the slot insertion part51, and the above described first linear part (41a) is disposed on the radial-direction inside (the lower side inFIG. 10A,FIG. 10C) of the slot insertion part51(refer toFIG. 4andFIG. 8as well). Then, by covering the outside of the layered first linear part (41a) and the second linear part (41b) with the primary covering layer700, the slot insertion part51has a substantially rectangular plate shape with multiple protrusion portions (described later).

Specifically, the slot insertion part51has outer surface parts (701a,701a) with a rectangular plane surface and the outer surface parts701b,701bwith a long, narrow rectangular plane surface, as the outer surface resulting from the primary covering layer700.

The outer surface part (701a) is respectively formed on both sides (the upper side and the lower side inFIG. 10B, the far side and the near side inFIG. 10A, and the left side and the right side inFIG. 10C) of the slot insertion part51along the circumferential direction. Each of the outer surface parts (701a) has at least one protrusion portion (701a1) (two portions in this example) resulting from the primary covering layer700, protruded from the outer surface part (701a) in the above described circumferential direction in an amount equivalent to a predetermined dimension.

The outer surface part (701b) is respectively formed on both sides (the near side and the far side inFIG. 10B, the upper side and the lower side inFIG. 10A, and the upper side and the lower side inFIG. 10C) of the slot insertion part51along the radial direction. Each of the outer surface parts701bhas at least one protrusion portion (701b1) (one portion in this example) resulting from the primary covering layer700, protruded from the outer surface part (701b) in the above described radial direction in an amount equivalent to a predetermined dimension.

Load-Side Coil End Part

The load-side coil end part52is formed into a substantially cylindrical shape having multiple protrusion portions (described later) by covering the outside of the turn part (41c) and the like on one axial-direction side of the coils41with the primary covering layer700.

Specifically, the load-side coil end part52has an outer surface part (702a) with a substantially circular plate shape, an outer surface part (702b) with an annular curved surface, and an outer surface part (702c) with an annular curved surface, as the outer surface resulting from the primary covering layer700.

The outer surface part (702a) is formed on the aforementioned other axial-direction side (corresponding to the above described counter-load side; the left side inFIG. 10BandFIG. 10A, and the near side inFIG. 10C). The outer surface part702ahas at least one protrusion portion (702a1) (two portions in this example) resulting from the primary covering layer700, protruded from the outer surface part (702a) in an amount equivalent to the same dimension as the above described protrusion portion (701a1).

The outer surface part (702b) is formed on the radial-direction outside (the near side inFIG. 10B, and the upper side inFIG. 10AandFIG. 10C). The outer surface part (702b) has at least one protrusion portion (702b1) (one portion in this example) resulting from the primary covering layer700, protruded from the outer surface part (702b) in an amount equivalent to the same dimension as the above described protrusion portion (701b1).

The outer surface part (702c) is formed on the radial-direction inside (the far side inFIG. 10B, and the lower side inFIG. 10AandFIG. 10C). The outer surface part (702c) has at least one protrusion portion (702c1) (one in this example) resulting from the primary covering layer700, protruded from the outer surface part (702c) in an amount equivalent to the same dimension as the above described protrusion portion (701b1).

Counter-Load Side Coil End Part

The counter-load side coil end part53is formed into a substantially cylindrical shape having multiple protrusion portions (described later) by covering the outside of the nose part (41d) and the like on the other axial-direction side of the coils41with the primary covering layer700.

Specifically, the counter-load side coil end part53has an outer surface part (703a) with a substantially circular plate shape, an outer surface part (703b) with an annular curved surface, and an outer surface part (703c) with an annular curved surface, as the outer surface resulting from the primary covering layer700.

The outer surface part (703a) is formed on the aforementioned one axial-direction side (corresponding to the above described load side; the right side inFIG. 10BandFIG. 10A). The outer surface part (703a) has at least one protrusion portion (703a1) (two portions in this example) resulting from the primary covering layer700, protruded from the outer surface part (703a) in an amount equivalent to the same dimension as the above described protrusion portion (701a1) and the like.

The outer surface part (703b) is formed on the radial-direction outside (the near side inFIG. 10B, and the upper side inFIG. 10A). The outer surface part703bhas at least one protrusion portion (703b1) (one portion in this example) resulting from the primary covering layer700, protruded from the outer surface part (703b) in an amount equivalent to the same dimension as the above described protrusion portion (701a1) and the like.

The outer surface part (703c) is formed on the radial-direction inside (the far side inFIG. 10B, and the lower side inFIG. 10A). The outer surface part (703c) has at least one protrusion portion (703c1) (one portion in this example) resulting from the primary covering layer700, protruded from the outer surface part (703c) in an amount equivalent to the same dimension as the above described protrusion portion (701a1) and the like.

Molding Coil Resin Structure

The covering when the coil resin structure60is molded from the above described primary molding50will now be described usingFIG. 12andFIG. 8. After the primary molding50is molded as described above, the primary molding50is set in a secondary mold, which is a split mold, and the mold resin is poured into the interior of the mold to cover each of the outer surface parts (701a,701b,702a,702b,702c,703a,703b,703c) of the primary covering layer700of the primary molding50with the secondary covering layer800at a specified thickness determined in advance, thereby forming the above described coil resin structure60(equivalent to the secondary covering step). At this time, the primary molding50is supported on the above described both radial-direction sides, the above described both circumferential-direction sides, and the above described both axial-direction sides with respect to the inner wall of the secondary mold via the aforementioned protrusion portions (701a,701b1), the protrusion portions (702a1,702b1,702c1), the protrusion portions (703a1,703b1,703c1), in the interior of the above described secondary mold. As a result, with the above-described resin pouring, the secondary covering layer800having the same thickness as the height-direction dimension of each of the protrusion portions (701a,701b1,702a1,702b1,702c1,703a1,703b1,703c1) (equivalent to the above described predetermined thickness) is formed on the entire outer front surface of the primary molding50(excluding the above described respective protrusion portions), thereby completing the above described coil structure60. Note that the height-direction dimension of each of the protrusion portions (701a,701b1,702a1,702b1,702c1,703a1,703b1,703c1) may be mutually the same or not the same.

The coil resin structure60, as described above usingFIG. 8, has the middle part64, the load-side coil end part62, and the counter-load side coil end part63. At this time, in the middle part64, the rectangular plate-shaped slot insertion part61where the outside of the primary covering layer700of the above described slot insertion part51of the primary molding50is covered by the secondary covering layer800is arranged in the circumferential direction. The load-side coil end part62is formed by covering the outside of the primary covering layer700of the above described load-side coil end part52of the primary molding50with the secondary covering layer800. The counter-load side coil end part63is formed by covering the outside of the primary covering layer700of the above described counter-load side coil end part53of the primary molding50with the secondary covering layer800.

Middle Part

As described above, in the middle part64, the slot insertion parts61with the substantially rectangular plate shape are arranged in the circumferential direction. The slot insertion part61has rectangular outer surface parts (801a,801a) and long, narrow rectangular outer surface parts (801b,801b), as the outer surface resulting from the covered above described secondary covering layer800that further covers the outside of the above described primary covering layer700.

The outer surface part (801a) is formed by further covering the outer front surface of the outer surface part (701a) resulting from the primary covering layer700of the above described primary molding50with the secondary covering layer800having a thickness equivalent to the height dimension of the protrusion portion (701a1) using the aforementioned technique, on both sides (the upper side and the lower side inFIG. 12B, the far side and the near side inFIG. 12A, and the left side and the right side inFIG. 12C) of the slot insertion part61along the circumferential direction.

The outer surface part (801b) is formed by further covering the outer front surface of the outer surface part (701b) resulting from the primary covering layer700of the above described primary molding50with the secondary covering layer800having a thickness equivalent to the height dimension of the protrusion portion (701b1) using the aforementioned technique, on both sides (the near side and the far side inFIG. 12A, the upper side and the lower side inFIG. 10A, and the upper side and the lower side inFIG. 10C) of the slot insertion part61along the radial direction.

Load-Side Coil End Part

The load-side coil end part62has an outer surface part (802a) with a substantially circular plate shape, an annular outer surface part (802b), and an outer surface part (802c) with an annular curved surface, as the outer surface resulting from the above described secondary covering layer800that further covers the outside of the above described primary covering layer700.

The outer surface part (802a) is formed by further covering the outer front surface of the outer surface part (702a) resulting from the primary covering layer700of the above described primary molding50with the secondary covering layer800having a thickness equivalent to the height dimension of the protrusion portion (702a1) using the aforementioned technique, on the above described other axial-direction side (the left side inFIG. 12AandFIG. 12B, and the near side inFIG. 12C).

The outer surface part802bis formed by further covering the outer front surface of the outer surface part (702b) resulting from the primary covering layer700of the above described primary molding50with the secondary covering layer800having a thickness equivalent to the height dimension of the protrusion portion (702b1) using the aforementioned technique, on the above described radial-direction outside (the near side inFIG. 12B, and the upper side inFIG. 12AandFIG. 12C).

The outer surface part (802c) is formed by further covering the outer front surface of the outer surface part (702c) resulting from the primary covering layer700of the above described primary molding50with the secondary covering layer800having a thickness equivalent to the height dimension of the protrusion portion (702c1) using the aforementioned technique, on the above described radial-direction inside (the far side inFIG. 12B, and the lower side inFIG. 12AandFIG. 12C).

Counter-Load Side Coil End Part

The counter-load side coil end part63has an outer surface part (803a) with a substantially circular plate shape, an outer surface part (803b) with an annular curved surface, and an outer surface part (803c) with an annular curved surface, as the outer surface resulting from the above described secondary covering layer800that further covers the outside of the above described primary covering layer700.

The outer surface part (803a) is formed by further covering the outer front surface of the outer surface part (703a) resulting from the primary covering layer700of the above described primary molding50with the secondary covering layer800having a thickness equivalent to the height dimension of the protrusion portion (703a1) using the aforementioned technique, on the above described one axial-direction side (the right side inFIG. 12AandFIG. 12B).

The outer surface part (803b) is formed by further covering the outer front surface of the outer surface part (702b) resulting from the primary covering layer700of the above described primary molding50with the secondary covering layer800having a thickness equivalent to the height dimension of the protrusion portion (702b1) using the aforementioned technique, on the above described radial-direction outside (the near side inFIG. 12B, and the upper side inFIG. 12AandFIG. 12C).

The outer surface part (803c) is formed by further covering the outer front surface of the outer surface part (703c) resulting from the primary covering layer700of the above described primary molding50with the secondary covering layer800having a thickness equivalent to the height dimension of the protrusion portion (703c1) using the aforementioned technique, on the above described radial-direction inside (the far side inFIG. 12B, and the lower side inFIG. 12AandFIG. 12C).

The same advantages as those of the above described embodiment 1 are achieved according to this embodiment structured as described above as well. That is, by constructing the coil resin structure45at a high space factor by the coils41on a sub-line that is a separate line from the main line, it is possible to decrease the generation of heat of the coil41itself, thereby improving the cooling performance of the rotating electrical machine10. Further, the mold resin molding work on the main line is no longer required, making it possible to significantly reduce the manufacturing time. Further, the rotating electrical machine10can be easily disassembled when it is no longer needed and is to be discarded. In particular, the iron material used on the stator core35side and the copper material used in the conductor42of the coil41can be easily separated, for example, making it possible to rapidly improve recyclability.

Further, according to this embodiment, the following advantages are achieved in addition to the above. That is, according to this embodiment, the coil resin structure60is manufactured by forming the primary covering layer700on the outside of the coil41, which is an air-core coil, and then further forming the secondary covering layer800on the outside thereof. In the primary covering step, the coil41is housed into the above described primary mold, resin is poured into the interior of the mold, and the coil41is covered by the primary covering layer700. At this time, the outer shape dimensions of the primary molding50that contains the coils41covered by the primary covering layer700(in other words, the shape dimensions of the space formed in the interior of the above described mold) are controlled. That is, in the interior of the primary molding50, the skew and the position of each of the coils41do not matter.

Then, the above described primary molding50is further housed into a different secondary mold, resin is poured into the interior of the mold, and the primary molding50is covered by the secondary covering layer800. As described above, the outer shape dimensions of the primary molding50are controlled by the above described primary mold with high precision (all outer shape dimensions of the primary molding50are the same, regardless of the position of the each of the coils41in the interior of the primary molding50), thereby making it possible to form the secondary covering layer800on the outside of the above described primary molding51at a uniform thickness.

As described above, the secondary covering layer800is uniformly formed on the outside of the primary molding50wherein the outer shape dimensions are controlled by the primary covering layer700with high precision. With this arrangement, it is possible to maintain the minimum required thickness in the covering layer of the resin formed on the outer circumference side of the coil41(the primary covering layer700+ the secondary covering layer800).

Further, when the winding (the conductor42) is wound during the manufacture of the coil41, which is a preliminary stage of formation of the above described primary covering layer700(or when the coil41is subsequently pressure-molded), winding lift may occur, for example, causing the coil41to stick out from the outside of the primary mold or to become distorted in shape, and therefore the primary molding50to not always achieve the preferred external dimensions with high precision (hereinafter suitably referred to as “irregular shape”). According to this embodiment 2, even in such a case, the coil41with the above described irregular shape is housed in the interior of the primary mold and the primary mold is closed, making it possible to forcibly achieve the aforementioned high-precision outer shape dimensions of the primary molding50. However, in this case, resin does not flow into areas of the coil41that are contacted and pressed by the above described primary mold, resulting in a thickness of the primary covering layer700of zero (or near that value). Nevertheless, as described above, the secondary covering layer800having a predetermined thickness is subsequently uniformly formed across the entire outside area of the primary covering layer700, thereby making it possible to reliably form the resin covering layer in these areas as well.

As a result of the above, according to this embodiment, it is possible to suppress variance in thickness in the covering layer when the coil41is covered, improving the uniformity.

Further, in particular, according to this embodiment, in the primary covering layer700, multiple protrusion portions (the protrusion portions (701a1,701b1), the protrusion portions (702a1,702b1,702c1), and the protrusion portions (703a1,703b1,703c1) are protruded from each outer surface part in an amount equivalent to a predetermined dimension on the outer surface (the outer surface part (701a) and the outer surface part701b) of the slot insertion part51, on the outer surface (the outer surface part702a, the outer surface part (702b), and the outer surface part702c) of the load-side coil end part52, and on the outer surface (the outer surface part703a, the outer surface part (703b), and the outer surface part (703c)) of the counter-load side coil end part53. Then, the secondary covering layer800is disposed so as to cover the outside of the above described primary covering layer700at a thickness equal to the above described predetermined dimensions (the height-direction dimension of each of the protrusion portions).

That is, in this embodiment, each of the outer surface parts of the primary molding50after the primary covering layer700is formed has the above described protrusion portions (701a1,701b1,702a1,702b1,702c1,703a1,703b1,703c1) having a predetermined dimension (equivalent to the thickness dimension of the secondary covering layer800). With this arrangement, when the primary molding50is housed in the secondary mold to form the secondary covering layer800, it is possible to reliably support the entire primary molding50with respect to the inner wall of the secondary mold by the above described protrusion portions (701a1,701b1,702a1,702b1,702c1,703a1,703b1,703c1), as described above.

Further, in particular, according to this embodiment, resin is poured and filled in the area around the primary molding50supported by the above described protrusion portions (701a1,701b1,702a1,702b1,702c1,703a1,703b1,703c1), thereby causing the above described secondary covering layer800to cover the outside of the above described primary covering layer700, excluding the above described protrusion portions, at a thickness equal to the above described predetermined dimension. With this arrangement, it is possible to reliably uniformly form the secondary covering layer800in the area around the primary molding50housed in the secondary mold other than the protrusion portions (701a1,701b1,702a1,702b1,702c1,703a1,703b1,703c1).

Further, in particular, according to this embodiment, in the coil resin structure60, the outer diameter of the middle part64having the slot insertion part61housed in the slots31is smaller than the outer diameter of the coil end parts (62,63) on both sides of the rotor30along the axial direction. This has the following significance.

That is, when the coils41are disposed on the stator core32as described above, the rotor20is disposed on the radial-direction inside of the portion of each of the coils41housed in the slot31(the middle part64other than the coil end parts (62,63)), and a support structure of the housing of the rotating electrical machine (10A) is disposed on the radial-direction outside of the above described slot insertion part61of the above described middle part64of each of the coils41, as shown inFIG. 6. Hence, according to this embodiment, in the coil resin structure60, the outer diameter of the middle part64where other members and structures are disposed on the radial-direction inside and outside as described above is made smaller than the outer diameter of the coil end parts (62,63) where there is no such disposition. With this arrangement, it is possible to prevent the overall rotating electrical machine (10A) from increasing in size in the radial direction, and thus decrease the size.

Next, the rotating electrical machine in embodiment 3 will be described usingFIG. 13. As shown inFIG. 13, a rotating electrical machine (10B) in this embodiment is a reluctance motor having the rotor20inside the stator30. The components that are the same as those in embodiment 1 will be denoted using the same reference numerals, and descriptions thereof will be suitably omitted or simplified.

In the rotating electrical machine (10B) shown inFIG. 13, the stator30has a stator core35. In the stator core35, similar to the above described embodiment 1, multiple divided core elements36(72 elements in this example) are arranged across the entire circumference while extending along the inner circumferential surface of the frame11of the stator30(refer to the above describedFIG. 2). Each of the divided core elements36has a tooth37with a transverse cross-section having a tapered trapezoidal shape on the radial-direction inside. Then, a slot38with a rectangular (shaped like a long rectangular) transverse cross-section is formed between the above described teeth (37,37) of adjacent divided core elements (36,36).

According to this embodiment, similar to the above described embodiment 1, the coils41(72 coils in this example) are inserted (housed) in the above described slots38(72 slots in this example). At this time, similar to the above, each of the coils41is shifted in position and lap-wound so that the air gap43where the tooth37of the divided core element36is fit is formed between two coils (41,41). Then, 72 lap-wound coils41are integrally resin-molded using mold resin (not shown), forming one substantially cylindrical coil resin structure45(not shown; refer to the above describedFIG. 8as well).

At this time, according to this embodiment, the transverse cross-sectional shape of the tooth37is tapered, and thus the transverse cross-sectional shape of the slot38is left rectangular (shaped like a long rectangle) as is. As a result, the pressure-molding with respect to the outer shape such as in the above described embodiment 1 is not performed on the first linear part (41a) and the second linear part (41b) of the coil41.

In this embodiment as well, similar to the above described embodiment 1, the teeth37of the divided core element36are fitted (across the entire circumference of the coil resin structure45) from the outer circumference side of the coil resin structure45into each of the air gaps43between adjacent coils (41,41) of the coil resin structure45. With this arrangement, the annular stator core35is constructed by the 72 divided core elements36. Further, the coil resin structure45and the above described stator core35are assembled while the first linear part of the coil41of the coil resin structure45is housed in the above described inner circumferential step of each of the slots38formed between the teeth (37,37) of two adjacent divided core elements (36,36), and the second linear part of another coil41of the coil resin structure45is housed in the above described outer circumferential step of each of the slots38. Note that while the above described first linear part in this embodiment is equivalent to the first linear part (41a) in the above described embodiment 1, each layer of the four layer conductor42has the same substantially rectangular transverse cross-sectional shape. Further, while the above described second linear part in this embodiment is equivalent to the second linear part (41b) in the above described embodiment 2, each layer of the four layer conductor42has the same substantially rectangular transverse cross-sectional shape. In this manner, the stator30is assembled.

Note that a total of 24 air gap parts25are disposed on the rotor core22of the rotor20, three per each of multiple poles (8 poles in this example) along the circumferential direction. The air gap part25curves in a convex manner on the radial-direction inside. This air gap part25can cause a difference in the magnetic path resistance of the rotor core, resulting in a reluctance torque.

The same advantages as those of the above described embodiment 1 are achieved according to this embodiment structured as described above as well. That is, by constructing the coil resin structure45at a high space factor by the coils41on a sub-line that is a separate line from the main line, it is possible to decrease the generation of heat of the coil41itself, thereby improving the cooling performance of the rotating electrical machine (10B). Further, the mold resin molding work on the main line is no longer required, making it possible to significantly reduce the manufacturing time. Further, the rotating electrical machine (10B) can be easily disassembled when it is no longer needed and is to be discarded. In particular, the iron material used on the stator core35side and the copper material used in the conductor42of the coil41can be easily separated, for example, making it possible to rapidly improve recyclability.