Brushless motor, stator, manufacturing process for a stator and manufacturing process for a brushless motor

Abstract

Brushless motor (60), comprising: a rotor (50) comprising a rotating shaft section (52) which is supported in such a way as to be rotatable about its axial line, and magnets (54) which are arranged along a circumferential direction of the rotating shaft section; a stator core (20) which is arranged radially outside the rotor (50) and which comprises: an outer annular section (40) which is formed in a ring shape, tooth sections (24) which project outwards from the outer annular section (40) in a radial direction inwards from the outer annular section (40) and are wound with conductive wire coils, and an inner annular section (41) which is formed by rotor-side surfaces extending from end sections of the tooth sections (24), wherein the end sections are adjacent to the rotor (50) along a circumferential direction of the rotor (50) and form circular, arc-shaped surfaces with the rotor (50) as the axial center, wherein projecting sections (78) on the outer annular section (40) are formed in such a way as to project in a radial direction outside of the outer annular section (40) and to be arranged at equal intervals around a circumferential direction from the outer annular section (40) when viewed along an axial direction from the outer annular section (40); and a stator housing (70) formed in a cylindrical shape to cover the stator core (20) in a radial direction outside the stator core (20), and which is integrated together with the stator core (20) by a plurality of plastic deformation sections (72) formed on an outer circumferential section of the stator housing (70) at locations pointing towards the projecting sections (78), and wherein the plurality of plastic deformation sections (72) are arranged at equal intervals along a circumferential direction from the outer circumferential section of the stator housing (70) along the axial direction of the outer annular section (40), wherein: the outer annular section (40) is formed from a plurality of yoke-forming sections (22) which form an annular yoke (40) and are segmented in a circumferential direction from the yoke (40), wherein the tooth sections (24) each project outwards from the yoke-forming sections (22) in a radial direction inwards of the yoke (40); each of the majority of the nucleus formation sections (14) is equipped with the yoke formation section (22) and the tooth section (24); the stator housing (70) is integrated together with the majority of core formation sections (14); the stator core (20) furthermore has a plurality of insulators (18) and each of the insulators (18) has a plurality of insulating sections (32) and comprising connecting sections (34), wherein the insulating sections (32) are integrated with the respective core-forming sections (14) and insulate between the respective tooth sections (24) and the winding sections (26), and wherein each of the connecting sections (34) is formed in a ring shape and together connects the plurality of insulating sections (32); and the majority of insulators (18) are formed such that the stiffness of the connecting section (34) of one of the insulators (18) is essentially the same as the stiffnesses of each of all the other connecting sections (34).

Description

Background of the invention: Technical field

[0001] The present invention relates to a brushless motor and a stator. State of the art

[0002] A brushless motor, described in the Japanese patent application JP 2011-142 811 A, is designed to comprise a housing (stator housing) formed in a cylindrical shape with a base, a stator core located radially inside the housing and supported by the housing, and a rotor located radially inside the stator core. A brief explanation of the technology described in this referenced document is as follows: a recess extending axially along the housing is provided on an outer circumferential section of the stator core, and at a point on the housing facing the recess, a plastic deformation section is formed in the direction of the recess, with a projecting profile extending radially inside the housing.The inner diameter at the point in the housing where the plastic deformation section is formed is accordingly reduced, thereby enabling the integration of the housing and the stator core together.

[0003] DE 10 2012 100 158 A1 discloses a stator for rotating electrical machines and a method for manufacturing it.

[0004] US 2010 / 0 007 236 A1 discloses a stator core made of ring-shaped elements.

[0005] EP 1 499 000 B1 discloses a segmented stator for an electric motor, in particular for a pump unit.

[0006] CH 693 014 A5 discloses a rotor for an electric micromotor, comprising a permanent magnet which is rigidly connected to the shaft of the rotor.

[0007] JP 2011- 101 464 A a method for producing a laminated core with a precise layer thickness (product thickness) and a manufacturing apparatus for this purpose. Summary

[0008] However, in the embodiment described in the reference document above, destruction of the circular shape of the stator core is conceivable if the outer circumferential section of the stator core is pressed against the housing section due to the formation of the plastic deformation section on the outer circumferential section of the housing. Furthermore, in the embodiment described in the reference document above, the clamping force in the circumferential direction between the housing and the stator core is high, since the point on the housing where the plastic deformation section is formed engages with the recessed section formed on the outer circumferential section of the stator core; however, the clamping force in the axial direction is comparatively low.

[0009] Taking into account the above circumstances, the present invention achieves a brushless motor that is capable of improving the circularity of the stator core and improving the fastening force between the housing and the stator core.

[0010] A brushless motor according to a first aspect of the present invention has the features of claim 1. In particular, the motor comprises: a rotor comprising a rotating shaft section which is supported to be rotatable about its axial line, and magnets which are arranged along a circumferential direction of the rotating shaft section; a stator core which is arranged radially outside the rotor and which comprises an outer annular section formed in a ring shape, tooth sections which project from the outer annular section in a direction of an inner radial direction from the outer annular section and are wound with conductive wire coils, and an inner annular section which is formed by rotor-side surfaces extending from end sections of the tooth sections.which are adjacent to the rotor along a circumferential direction of the rotor and which form circular, arcuate surfaces with the rotor as the axial center, wherein projecting sections on the outer annular section are formed to project in the direction of an outer radial direction from the outer annular section and to be arranged at equal intervals around a circumferential direction from the outer annular section when viewed along an axial direction from the outer annular section; and a stator housing formed in a cylindrical shape to cover the stator core from the radial outer direction of the stator core, and which is integrated together with the stator core by several plastic deformation sections formed on an outer circumferential section of the stator housing at locations which point in the direction of the projecting sections,and wherein the majority of plastic deformation sections are arranged at equal intervals along a circumferential direction from the outer circumferential section when viewed along the axial direction from the outer annular section.

[0011] According to the first aspect, the brushless motor consists of the rotor, the stator core, and the stator housing, which are designed as described above. The rotor with magnets is rotated around its axial center by the rotating shaft section through a rotating magnetic field that arises in the stator core and the housing when a current is passed through the coil wires.

[0012] Furthermore, in the first aspect, the stator core is formed with the outer annular section, the toothed sections, and the inner annular section as described above, and the stator core is integrated or assembled together with the housing. The rotor-side surfaces of the inner annular section form circular, arcuate surfaces with the rotor as the axial center. Accordingly, it is possible to form the plastic deformation sections on the outer circumferential section of the housing in a state in which a metal core, formed in a circular column shape (or, for example, a circular cylinder shape) corresponding to an inner diameter of the circular, arcuate surfaces, is positioned along the radial inner direction of the inner annular section.The circular shape of the inner annular section of the stator core is accordingly maintained, although points of the housing where the plastic deformation sections are formed press the outer annular section (protruding sections) from the stator core.

[0013] Furthermore, the protruding section formed on the outer annular section of the stator core points towards the plastic deformation section formed on the outer circumferential section of the housing. Thus, when the plastic deformation section is formed on the outer circumferential section of the housing, stress is concentrated at the points on the housing where the plastic deformation section is formed and at the points on the outer annular section of the stator core where the protruding sections are formed. The tightness of the fit between the points on the housing where the plastic deformation sections are formed and the points on the outer annular section of the stator core where the protruding sections are formed is accordingly increased, thereby improving the clamping force between the housing and the stator core.

[0014] Furthermore, the projecting sections formed on the outer annular section are arranged at equal intervals around the circumference of the outer annular section when viewed along the axial direction, and the majority of the plastic deformation sections are arranged at equal intervals around the circumference of the outer annular section of the housing when viewed along the axial direction. The outer sections of the stator core are accordingly pressed uniformly around the circumference of the housing by the housing.

[0015] As explained above, the circular shape of the stator core and the clamping force between the housing and the stator core can be improved accordingly. A brushless motor designed with this in mind, in particular, has an outer annular section formed by several yoke sections, which together form an annular yoke and are segmented in a circumferential direction by the yoke. The tooth sections of each yoke section project outwards towards the inside in the radial direction of the yoke. Each of the multiple core sections is equipped with the yoke section and the tooth section. The stator housing is integrated with the multiple core sections. The stator core further comprises multiple insulators, and each insulator includes multiple insulating and connecting sections.The insulating sections are integrated into the respective core-forming sections and insulate between the respective tooth sections and the winding sections. Each of the connecting sections is formed in a ring shape and connects the majority of insulating sections. The majority of the insulators are formed such that the stiffness of the connecting section of one of the insulators is essentially the same as the stiffnesses of each of the other connecting sections.

[0016] According to this principle, the stator of the brushless motor is manufactured using the following technique. First, the core formation sections are integrated with the insulation sections of each insulator, forming several sub-assemblies. Next, coil wires are wound onto each of the respective tooth sections of these sub-assemblies, forming several stator formation sections. These stator formation sections are then connected to each other via connecting sections. The multiple stator formation sections are then assembled. Finally, the housing, which is located on the outer radial side of the yoke, is integrated along with the majority of the core formation sections (the stator core). The stator of the brushless motor is thus manufactured using the above technique.In the present invention, the stiffnesses of the connecting sections of the plurality of insulators are essentially the same. In other words, the supporting stiffnesses for the stator-forming sections of the connecting sections are essentially the same. The arrangement of the plurality of stator-forming sections is thus prevented from being unbalanced due to differences between the stiffnesses of the respective connecting sections. Therefore, the circular shape of the stator core can be improved in the present invention.

[0017] It should be noted that the specification of the stiffnesses of the respective connection sections, which are essentially the same, is not limited to cases where the stiffnesses of the respective connection sections are completely identical. The stiffnesses of the respective connection sections can easily vary within a range in which the above operation and the advantageous effects are achieved.

[0018] A brushless motor according to a second aspect of the present invention is a brushless motor according to the first aspect, wherein the projecting sections are provided at locations which point towards the tooth sections.

[0019] The housing sections formed by the plastic deformation segments press against the outer annular section (protruding segments) of the stator core, and a pressing force through these housing sections is transmitted via the tooth segments and the inner annular section to the metal core, which is located radially inward of the inner annular section. In the second aspect, the protruding segments on the outer annular section are formed at points facing the tooth segments. The metal core is thus able to support the aforementioned pressing force perpendicularly. This increases the tightness of the fit between the housing sections where the plastic deformation segments are formed and the protruding segments on the outer annular section of the stator core.As a result, the fastening force between the housing and the stator core can be increased even further.

[0020] A brushless motor according to a third aspect of the present invention is the brushless motor according to the first aspect or according to the second aspect, wherein 3 xn (n = 1, 2, 3 etc.) individual or 4 xn (n = 1, 2, 3 etc.) individual plastic deformation sections are formed on the outer circumferential section of the stator housing.

[0021] In the third aspect, the plastic deformation sections are formed in a plurality of three or a plurality of four locations on the outer circumferential section of the housing. The supporting force of the stator core from the housing can be made uniform if the plastic deformation sections are formed in a plurality of three locations. The supporting force of the stator core from the housing can also be made uniform if the plastic deformation sections are formed in a plurality of four locations, and it is also possible to easily control the machining process when a tool comes into contact with the outer circumferential section of the housing to form the plastic deformation sections.

[0022] A brushless motor according to the fourth aspect of the present invention is the brushless motor according to the first aspect or according to the second aspect, wherein: the stator core is formed with a segmented structure, which is formed by arranging m individual core-forming sections in a ring shape, and there are mxn (n = 1, 2, 3 etc.) individual of the plurality of plastic deformation sections, which are formed on the outer circumferential section of the stator housing.

[0023] In the fourth aspect, the stator core is formed with a segmented structure, which is created by arranging m individual core formation sections, and m times an integer number of individual plastic deformation sections (locations) are formed on the outer circumferential section of the housing. The supporting force of the stator core by the housing can thus be made uniform.

[0024] A brushless motor according to a fifth aspect of the present invention is the brushless motor according to the fifth aspect, wherein: the connecting sections of the plurality of insulators are arranged adjacent to each other in a radial direction from the insulator and the stiffnesses of the connecting sections are adapted to be substantially the same to each other by adapting at least one factor from the group consisting of the wall thickness in the axial direction, the wall thickness in the radial direction and a cross-sectional profile of each of the connecting sections.

[0025] According to the fifth aspect, the stiffnesses of the respective connection sections can be easily adjusted by adjusting the wall thickness in the axial direction, the wall thickness in the radial direction, or the cross-sectional profile of each of the connection sections.

[0026] A brushless motor according to a sixth aspect of the present invention is the brushless motor according to the fifth aspect, wherein: the stiffnesses of each of the connecting sections are adapted to be substantially the same to each other by selecting materials for the respective connecting sections such that a Young's modulus or modulus of elasticity of the material of one of the connecting sections is lower than a Young's modulus of the material of another of the connecting sections, which is arranged outside in the radial direction of the one connecting section.

[0027] The sixth aspect allows the stiffness of each connection section to be easily adjusted by selecting the materials for each connection section.

[0028] A brushless motor according to a seventh aspect of the present invention is the brushless motor according to one of the fifth to the sixth aspects, wherein: the stiffnesses of each of the connecting sections are adapted to be substantially the same to each other by providing at least one of the connecting sections with a rib extending in a radial direction.

[0029] In the seventh aspect, the stiffnesses of the respective connection sections can be easily adjusted by providing the rib, which extends in a radial direction, to the connection section.

[0030] A brushless motor according to an eighth aspect of the present invention is the brushless motor according to one of the fifth to the seventh aspects, wherein: the stiffnesses of each of the connecting sections are adapted to be substantially the same to each other by providing a recess in at least one of the connecting sections.

[0031] Regarding the eighth aspect, the stiffness of the respective connection sections can be easily adjusted by providing a recess in the connection section. Balance in terms of stiffness in the circumferential, radial, and axial directions of the connection sections can also be easily achieved by appropriately selecting the location and number of recesses.

[0032] A brushless motor according to the ninth aspect of the present invention is the brushless motor according to the fifth aspect, wherein: the stiffnesses of each of the connecting sections are adapted to be substantially the same to each other by arranging the connecting sections adjacent to each other in an axial direction of the connecting sections and by producing the cross-sectional profile of each of the connecting sections as the same to each other.

[0033] In the ninth aspect, the respective connecting sections are arranged adjacent to each other in the axial direction thereof, and the cross-sectional profiles of the respective connecting sections are manufactured to be identical to each other, thereby enabling a section of a brushless motor to be made even more compact in the radial direction of the stator.

[0034] A stator according to a tenth aspect of the present invention comprises, in particular: core-forming sections and a stator housing. The core-forming sections comprise yoke-forming sections, which form an annular yoke and which are segmented in a circumferential direction of the yoke, and tooth sections, which project from the yoke-forming sections inwards in a radial direction of the yoke. The stator housing is formed in a circular cylindrical shape with an inner diameter that exceeds an outer diameter of the annularly arranged core-forming sections. The stator housing is formed using a soft magnetic metal and is integrated with the core-forming sections by forming a plastic deformation section on an outer circumferential surface of the stator housing by applying pressure inwards in a radial direction from the stator housing.

[0035] In the tenth aspect, the stator housing is formed in a circular, cylindrical shape, and a path of magnetic flux through the stator housing is ensured even if the yoke sections do not reliably make contact with each other from the ring-shaped core sections. In the present invention, a coil wire is easily wound onto the tooth sections because the yoke is formed in a segmented structure by arranging core sections in a ring shape. Specifically, the present invention enables a stator that is easily wound with coil wire while still ensuring the specific path of magnetic flux.

[0036] A method for manufacturing a stator according to an eleventh aspect of the present invention comprises in particular: a core assembly process in which core-forming sections are arranged in a ring shape, each of the core-forming sections comprising a yoke-forming section and a tooth section, the yoke-forming sections forming an annular yoke and being segmented in a circumferential direction from the yoke, and the tooth sections projecting from the yoke-forming sections in an inner radial direction from the yoke; a metal core build-up process in which a metal core having an outer diameter corresponding to an inner diameter of the annularly arranged core-forming sections is inserted into an inner circumferential section of the annularly arranged core-forming sections;and a crimping process which integrates a stator housing and the core formation sections by arranging a metallic stator housing formed in a circular cylindrical shape with an inner diameter exceeding an outer diameter of the annularly arranged core formation sections along an outer circumferential section of the core formation sections and forming a plastic deformation section along a circumferential direction on an outer circumferential surface of the stator housing.

[0037] In the eleventh step, the core formation sections are first arranged in a ring shape. Then, the metal core, with an outer diameter corresponding to the inner diameter of the ring-shaped core formation sections, is inserted into the inner circumferential section of the core formation sections. Next, the metallic stator housing, with an inner diameter exceeding the outer diameter of the ring-shaped core formation sections, is positioned along the outer circumferential surface of the core formation sections. Finally, the stator housing and the core formation sections are integrated by forming a plastic deformation section along the circumferential direction on the outer circumferential surface of the stator housing.

[0038] The plastic deformation section is formed on the outer circumferential surface of the stator housing after the metal core is inserted into the inner circumferential section by the core-forming sections. Consequently, the arrangement of the ring-shaped core-forming sections is not disturbed, even when the external force for forming the plastic deformation section is transferred to the ring-shaped core-forming sections. In fact, the circular shape of the ring-shaped core-forming sections can be improved.

[0039] A method for manufacturing a stator according to a twelfth aspect of the present invention is that according to the eleventh aspect, further comprising: a housing measurement process which measures a deformation of the stator housing; and a metal core selection process which selects a metal core according to the deformation of the stator housing which is measured in the housing measurement process; and wherein, in the crimping process, a deformation correction and crimping processes are carried out to integrate the stator housing and the core formation sections together while correcting the deformation of the stator housing.

[0040] In the twelfth step, the core-forming sections are first arranged in a ring shape. The deformation of the metallic stator housing is then measured. A metal core is selected according to the stator housing deformation and inserted into the inner circumferential section formed by the ring-shaped core-forming sections. The stator housing is then aligned along the outer circumferential surface of the ring-shaped core-forming sections, and the plastic deformation section is formed along the circumferential direction of the outer circumferential surface of the stator housing. As a result, according to this step, the stator housing and the core-forming sections can be integrated, while any deformation of the stator housing is corrected.

[0041] A method for manufacturing a stator according to a thirteenth aspect of the present invention is that according to the eleventh aspect or according to the twelfth aspect, wherein: in the metal core build-up process, the outer circumferential surface of the metal core and the inner circumferential surface of the core formation sections are brought into contact with each other by widening a diameter of the metal core.

[0042] In the thirteenth aspect, the outer circumferential surface of the metal core and the inner circumferential surface of the core-forming sections are brought into contact by expanding the diameter of the metal core. The stator housing and the core-forming sections are then integrated by forming a plurality of plastic deformation sections on the outer circumferential surface of the housing at equal intervals along the circumferential direction of the housing. The plastic deformation sections are formed on the outer circumferential surface of the housing in a state in which the outer circumferential surface of the metal core and the inner circumferential surface of the core-forming sections are in contact, specifically in a state in which the circular shape of the inner circumferential section of the core-forming sections is ensured by the metal core. The circular shape, or rather,The roundness of the inner circumferential section of the core formation sections is accordingly maintained, even though the external force for forming the plastic deformation section is applied to the outer circumferential surface of the casing.

[0043] Furthermore, when an external force is applied to the outer circumferential surface of the housing to form the plastic deformation sections, the metal core assists the external force. Specifically, the diameter of the inner circumferential section of the core formation sections does not decrease when the external force is applied to the outer circumferential surface of the housing to form the plastic deformation sections. This increases the tightness of the fit between the areas of the housing where the plastic deformation sections are formed and the outer circumferential section of the core formation sections, thereby increasing the clamping force between the housing and the core formation sections.

[0044] As explained above, the method for manufacturing a stator according to the present aspect allows for an improvement in the circular shape of the core formation sections and the fastening force between the housing and the core formation sections.

[0045] A method for manufacturing a stator according to a fourteenth aspect of the present invention is that according to the thirteenth aspect, wherein: in the metal core build-up process, an outer circumferential surface of the core formation sections and an inner circumferential surface of the stator housing are brought into contact with each other by further expanding the diameter of the metal core; and in the crimping process, several of the plastic deformation sections on the outer circumferential surface of the stator housing are formed in a contacting state with the outer circumferential surface of the core formation sections and the inner circumferential surface of the stator housing.

[0046] In the fourteenth aspect, after the outer circumferential surface of the metal core and the inner circumferential section of the core-forming section have been brought into contact by expanding the diameter of the metal core, the outer circumferential surface of the core-forming sections and the inner circumferential surface of the housing are then brought into contact by a further expansion of the diameter of the metal core. The plastic deformation sections are then formed on the outer circumferential surface of the stator housing, with the outer circumferential surface of the core-forming sections and the inner circumferential surface of the stator housing in a state of contact.Due to the formation of plastic deformation sections on the outer circumferential surface of the stator housing with the outer circumferential surface of the core formation sections and the inner circumferential surface of the stator housing in a contact state, the tightness of the fit between the areas of the stator housing formed by the plastic deformation sections and the outer circumferential surface of the core formation sections is further increased. As a result, the clamping force between the stator housing and the core formation sections can be increased even further.

[0047] A method for manufacturing a stator according to a fifteenth aspect of the present invention is the method for manufacturing a stator according to the thirteenth or fourteenth aspect, wherein the diameter of the metal core is compressed when a pressing force exceeding a specific value is applied to the outer circumferential surface of the stator housing to form the plastic deformation section.

[0048] In the fifteenth aspect, when the external force (press force) is applied to form the plastic deformation sections on the outer circumferential surface of the housing, the press force is supported by the metal core. Furthermore, the diameter of the metal core decreases when the press force exceeds a specific value. The stator housing and the core formation sections can therefore be integrated with a desired clamping force.

[0049] A method for manufacturing a brushless motor according to a sixteenth aspect of the present invention comprises, in particular, a housing assembly process and a crimping process. In the housing assembly process, a stator housing, formed in a circular, cylindrical shape with an inner diameter exceeding the outer diameter of a stator main body, is arranged radially on the outside of the stator main body. The stator main body comprises several core formation sections, several tooth sections, several wire coils, and several insulators.The multiple core formation sections comprise several yoke formation sections, which form an annular yoke and are segmented circumferentially by the yoke. Each of the multiple tooth sections projects from the respective yoke formation sections inwards in a radial direction of the yoke and is integrated together with the yoke formation sections. The multiple wire coils, which form a plurality of winding sections, are wound on the respective tooth sections to form multiple phases. In the crimping process, the housing and the stator main body are integrated together by forming a plastic deformation section on an outer circumferential section of the housing by applying a machining force to specific points on the outer circumferential section of the housing that point towards the respective yoke formation sections.The machining force corresponds to a stiffness of at least one stiffness which refers to a specific position on the stator main body, and / or a stiffness of the respective points of the housing, and the circular shape of the stator main body is adapted by integrating the housing and the stator main body together.

[0050] In the sixteenth aspect, the stator for a brushless motor is manufactured using the housing assembly process and the crimping process described above. During the crimping process, the machining force is transferred to specific points on the outer circumferential section of the housing that point towards the multiple yoke sections. The pressing force at the points on the housing where the plastic deformation sections are formed on the yoke sections can be adjusted accordingly. Specifically, in the present invention, the circular shape of the stator main body is adjusted by modifying the pressing force, thereby improving the circular shape of the stator core.

[0051] A method for manufacturing a brushless motor according to a seventeenth aspect of the present invention is that according to the sixteenth aspect, wherein: the stator body further comprises several insulators, which include a plurality of insulating sections and a connecting section, wherein the plurality of insulating sections are integrated with the respective core-forming sections and insulate between the tooth section and the winding section, and the connecting section is formed in a ring shape and connects the plurality of insulating sections together. In the crimping process, the machining force, which corresponds to the stiffness of the connecting sections of the respective plurality of insulators, is applied to the housing.

[0052] The seventeenth aspect improves the circular shape of the stator main body, even if the respective stiffnesses of the connecting sections differ from each other.

[0053] A method for manufacturing a brushless motor according to an eighteenth aspect of the present invention is that according to the seventeenth aspect, wherein: the respective connecting sections of the majority of the insulators are arranged adjacent to one another in a radial direction of the insulators; and during the crimping process, a weaker machining force is applied to the places of the housing which point in the direction towards the yoke-forming sections of the core-forming sections which are connected to the connecting section which is arranged in the outer radial direction, than a machining force which is applied to places of the surface which point in the direction towards the yoke-forming sections of the core-forming sections which are connected to the connecting section which is arranged in the inner radial direction.

[0054] In the eighteenth aspect, the pressing force is adjusted to a greater or lesser degree, taking into account a reaction force from the deformation of each of the connection sections, when the areas of the stator housing where the plastic deformation sections are formed press against the respective core-forming sections. The arrangement of the core-forming sections can thus be prevented from being disturbed when the stator housing and the stator core are integrated together, thereby allowing the circular shape of the stator core to be improved.

[0055] In the eighteenth aspect, the stator main body, in which the stiffnesses of the respective connection sections of the majority of the insulators are essentially the same, is integrated together with the stator housing during the crimping process. Thus, the machining force applied to the stator housing when one of the plastic deformation sections is formed can be made the same as the machining force applied to the stator housing when another of the plastic deformation sections is formed. Accordingly, the present invention enables easy process control of the crimping process.

[0056] A method for manufacturing a brushless motor according to a nineteenth aspect of the present invention comprises, in particular: a housing assembly process, a metal core assembly process, and a crimping process. In the housing assembly process, a stator housing, formed in a circular, cylindrical shape with an inner diameter exceeding the outer diameter of a stator main body, is arranged radially on the outside of the stator main body. The stator main body comprises several core formation sections, several tooth sections, several wire coils, and several insulators.The multiple core formation sections comprise several yoke formation sections, which form an annular yoke and are segmented circumferentially by the yoke. Each of the multiple tooth sections projects radially inward from its respective yoke formation section and is integrated with the yoke formation sections. The multiple wire coils, forming multiple winding sections, are wound on the respective tooth sections to create multiple phases. In the metal core build-up process, a metal core, equipped with sensors to detect contact pressure against each of the core formation sections, is inserted radially inward from the stator body.In the crimping process, the housing and the stator main body are integrated by forming a plastic deformation section on an outer circumferential section of the housing. This is achieved by applying a machining force at specific points on this outer circumferential section, which points towards the majority of the crimping sections. The machining force corresponds to the sensor's initial values, and the circular shape of the stator main body is adjusted by integrating the housing and the stator main body together.

[0057] In the nineteenth aspect, the stator for a brushless motor is manufactured through the housing assembly process, the metal core build-up process, and the crimping process, as described above. In this aspect, when the core-forming sections are in contact with the metal core, the sensors provided on the metal core output the contact pressure against each of the core-forming sections. The circularity of the stator body is adjusted by modifying the machining force on the outer circumferential section of the housing based on these output values, thereby improving the circularity of the stator core.

[0058] A method for manufacturing a brushless motor according to a twentieth aspect of the present invention comprises, in particular, a housing assembly process and a crimping process. In the housing assembly process, a stator housing, which is formed in a circular, cylindrical shape with an inner diameter exceeding the outer diameter of a stator main body, is arranged on an outer surface in a radial direction from the stator main body. The stator main body comprises several core formation sections, several tooth sections, several wire coils, and several insulators.The multiple core formation sections comprise several yoke formation sections, which form an annular yoke and are segmented circumferentially by the yoke. Each of the multiple tooth sections projects inward from the respective yoke formation sections in the radial direction of the yoke and is integrated together with the yoke formation sections. The majority of the wire coils, which form multiple winding sections, are wound on the respective tooth sections to form multiple phases. During the crimping process, the housing and the stator main body are integrated together by forming a plastic deformation section on an outer circumferential section of the housing. This is achieved by applying a machining force to the outer circumferential section of the housing at points facing the majority of the yoke formation sections.The machining force corresponds to an alignment of the majority of core formation sections, and the circular shape of the stator main body is adjusted by integrating the housing and the stator main body together.

[0059] In the twentieth aspect, the stator for a brushless motor is manufactured using the housing assembly and crimping processes described above. In this aspect, the machining force is applied according to the alignment of the multiple core formation sections with the outer circumferential section of the housing. The circularity of the stator body is adjusted by modifying this machining force, thereby improving the circularity of the stator core. Brief description of the drawings

[0060] Embodiments of the present invention will be described in detail based on the following figures, wherein: Fig. 1A is a top view showing a brushless motor according to a first exemplary embodiment; Fig. 1B is a perspective view showing a stator according to the first exemplary embodiment; Fig. 2A is a perspective view showing a stator formation section of a U-phase; Fig. 2B is a perspective view showing a stator formation section of a V-phase; Fig. 2C is a perspective view showing a stator formation section of a W-phase; Fig. 2D is an enlarged top view showing a section of ring-shaped nucleation sections; Fig. 3A is a perspective view depicting a process in which the multiple stator formation sections, which are in the Fig. 2A to Fig. 2C represents being assembled together; Fig. 3B is a perspective view, which represents a state in which assembly is further advanced than in the Fig. 3A; Fig. 4A is an enlarged cross-sectional view showing connection sections of insulators according to the first exemplary embodiment; Fig. 4B is an enlarged top view and an enlarged cross-sectional view, which represent connection sections of insulators according to a first modified exemplary embodiment; Fig. 4C is an enlarged cross-sectional view showing connection sections of insulators according to a second modified exemplary embodiment; Fig. 4D is an enlarged perspective view showing connection sections of insulators according to a third modified exemplary embodiment; Fig. 4E is an enlarged cross-sectional view showing a connecting section of insulators according to a fourth modified exemplary embodiment; Fig. 5 is a vertical cross-sectional view which represents a state in which a metal core has been inserted in the inner radial direction of the stator core; Fig. 6A is a vertical cross-sectional view which represents a state in which an outer circumferential surface of a variable core holding section has been brought into contact with a circular, arcuate, inner, annular section by widening the diameter of the variable core holding section from the metal core; Fig. 6B is a top view which represents a state in which an outer circumferential surface of the variable core holding section has been brought into contact with a circular, arc-shaped inner annular section by widening the diameter of the variable core holding section from the metal core; Fig. 7 is a vertical cross-sectional view showing a state in which the metal core has been inserted and the stator core and stator housing have been adjusted using a crimping tool; Fig. Figure 8 shows a perspective cross-sectional view of the metal core, the stator core, the stator housing, and the crimping tool, which is shown in the Fig. 7 are shown when viewed from one side in an axial direction of the stator core; Fig. 9 is a vertical cross-sectional view showing the metal core, the stator core, the stator housing and the crimping tool when the crimping tool is operated by a machining force of a press; Fig. 10A is a top view showing the stator core and stator housing when the crimping tool is operated by a machining force of a press; Fig. 10B is an enlarged top view, which shows a section defined by the simply dotted, dashed line of the Fig. is surrounded by 10A; Fig. 11 is a vertical cross-sectional view showing the metal core, the stator core and the stator housing when the metal core has been removed; Fig. 12A an enlarged top view corresponding to the Fig. 10B is which represents a location where a plastic deformation section is formed in a stator according to a modified example; Fig. 12B an enlarged top view corresponding to the Fig. 10B is which represents a location where a plastic deformation section is formed in a stator according to another modified example; Fig. 13 a top view corresponding to the Fig. 10A is, which represents a stator core and a slightly deformed stator housing when a crimping tool is operated by a machining force of a press; Fig. 14 an enlarged top view corresponding to the Fig. 10A is which represents a stator core and a stator housing of varying thickness when a crimping tool is operated by a machining force of a press; Fig. 15 a top view accordingly Fig. 10A is which represents a stator core, a stator housing and a metal core when a crimping tool is operated by a machining force of a press; Fig. 16 is an enlarged top view, which shows an enlargement of a plurality of nucleation sections with a variation in positioning in a circumferential direction; Fig. 17 is a perspective view showing a stator according to a second exemplary embodiment; Fig. Figure 18A is a perspective view showing a stator formation section of a U-phase, which is located in the Fig. 17 is shown; Fig. Figure 18B is a perspective view showing a stator formation section of a V-phase, which is located in the Fig. 17 is shown; Fig. Figure 18C is a perspective view showing a stator formation section of a W-phase, which is located in the Fig. 17 is shown; Fig. Figure 19A is a perspective view depicting a process in which the majority of the stator formation sections, which are in the Fig. 17 are shown, assembled together; Fig. 19B is a perspective view, which represents a state in which assembly is further along than in the Fig. 19A is advanced; Fig. 19C is a perspective view showing a process in which a stator housing is arranged on the outer circumferential side of the ring-shaped core-forming sections; Fig. 20A is a horizontal cross-sectional view, which represents a brushless motor that is connected to the one in the Fig. 17 is equipped with the stator shown; Fig. Figure 20B is a vertical cross-sectional view showing a brushless motor with the stator located in the Fig. 17 is shown, equipped; Fig. 21 a drawing to explain a way in which a wire is wound as a coil by a flyer machine; Fig. 22 is a horizontal cross-sectional view which represents a process in which a plastically deformable groove is formed in an outer circumferential surface of the stator housing; Fig. 23 is an enlarged horizontal cross-sectional view showing a stator housing and a draw-in section formed on a core-forming section; Fig. 24 is an enlarged top view showing ring-shaped nucleation sections; Fig. 25 is an enlarged top view showing the core formation sections and a stator housing after a plastic deformation groove has been formed on the outer circumferential surface of the stator housing; Fig. 26 is a top view showing ring-shaped nucleation sections according to a modified exemplary embodiment; Fig. 27A is an enlarged top view showing ring-shaped nucleation sections according to the modified exemplary embodiment; Fig. 27B an enlarged top view according to the Fig. 27A is which represents the core formation sections according to the modified exemplary embodiment after the formation of the plastic deformation groove on the outer circumferential surface of the stator housing; Fig. 28A is a lateral cross-sectional view and a horizontal cross-sectional view, which represent a process of introducing a metal core into an inner circumferential section of the ring-shaped core-forming sections and a process of forming a plastic deformation groove on the outer circumferential surface of the stator housing; Fig. 28B is a horizontal cross-sectional view showing a process of forming the plastic deformation groove on the outer circumferential surface of the stator housing; Fig. 28C is a perspective view showing a process of forming the plastic deformation groove on the outer circumferential surface of the stator housing; Fig. 28D is a horizontal cross-sectional view showing a stator formed by removing the metal core from the inner circumferential section of the core formation sections after forming the plastic deformation groove on the outer circumferential surface of the stator housing; Fig. 28E is a perspective view showing a stator formed by removing a metal core from the inner circumferential section of the core formation sections after forming the plastic deformation groove on the outer circumferential surface of the stator housing; Fig. 29A is a horizontal cross-sectional view showing a state in which a deformed stator housing is arranged along outer circumferential sections of ring-shaped core formation sections; Fig. 29B is a horizontal cross-sectional view showing a state in which a metal core is inserted into an inner circumferential section of ring-shaped core-forming sections; Fig. 29C is a horizontal cross-sectional view showing a process in which a plastic deformation groove is formed on an outer circumferential surface of the stator housing; and Fig. Figure 29D is a horizontal cross-sectional view, which represents a state after the plastic deformation groove has been formed on the outer circumferential surface of the stator housing. Detailed description of the invention

[0061] The following is an explanation regarding a first exemplary embodiment of the present invention.

[0062] As it is in the Fig. As shown in Figure 1A, a brushless motor 60 of the first exemplary embodiment is a brushless motor of the inner rotor type and is configured to comprise a stator 10 which generates a rotating magnetic field, and a rotor 50 which is rotated by the rotating magnetic field of the stator 10. As shown in the Fig. As shown in Figure 1B, the stator 10 is configured to comprise a stator housing 70, which serves as a casing, and a stator main body 11, which includes a stator forming section of a U-phase 12U, a stator forming section of a V-phase 12V, and a stator forming section of a W-phase 12W. The following section first provides an explanation of the stator housing 70, then an explanation of the stator forming sections 12U, 12V, 12W and the rotor 50, and finally an explanation of a manufacturing process for the stator 10 and the brushless motor 60. Stator housing 70

[0063] As it is in the Fig. 1A and the Fig. As shown in Figure 1B, the stator housing 70 is formed in a thin-walled, circular, cylindrical shape and is integrally formed along its circumference using a soft magnetic metal (such as copper, aluminum alloy, or copper alloy). An inner diameter D1 of the stator housing 70 before the formation of the plastic deformation sections 72 is defined to be larger than an outer diameter D2 of a stator core 20 (ring-shaped core-forming sections 14U, 14V, 14W).

[0064] Furthermore, several plastic deformation sections 72 are arranged at equal intervals along a circumferential direction of the stator housing 70 on an outer circumferential surface (12 plastic deformation sections 72 in the present exemplary embodiment). The formation of the plastic deformation sections 72 on the stator housing 70 results in a reduction of the inner diameter of the stator housing 70 at the locations where the plastic deformation sections 72 are formed and at the locations formed by the plastic deformation sections 72 that abut the stator core 20. The stator housing 70 and the stator core 20 are thus integrated together, forming an integrated arrangement.

[0065] Furthermore, the plastic deformation sections 72 are formed at points which project towards projecting sections 78U, 78V, 78W, which are each formed at yoke-forming sections 22U, 22V, 22W, which will be described in detail later. Stator circuits 12U, 12V, 12W

[0066] As it is in the Fig. As shown in Figure 2A, a stator formation section of a U-phase 12U is formed with several core formation sections 14U, a coil wire 16U, and an insulator 18U. The several core formation sections 14U form a core 20, together with the several core formation sections of a V-phase 14V and the several core formation sections of a W-phase 14W, which will be described later (see Figure 2A for each). Fig. 1A). The core formation sections 14U each comprise several yoke formation sections 22U, several tooth sections 24U and several metal core contact sections 25U.

[0067] As it is in the Fig. 2A and the Fig. As shown in 2D, the multiple yoke-forming sections 22U, together with the multiple yoke-forming sections of a V-phase 22V and the multiple yoke-forming sections of a W-phase 22W, which will be described later, form a yoke 40 and are each circular arc-shaped. The multiple tooth sections 24U are integrally formed with the respective yoke-forming sections 22U and project from the yoke-forming sections 22U in a radial inward direction from the yoke 40.

[0068] Furthermore, projecting sections 78U are formed at points on the yoke-forming sections 22U that point towards the tooth sections 24U. These sections project outwards in a radial direction from the yoke-forming sections 22U and extend axially from the yoke-forming sections 22U. Additionally, recessed sections 80U with a U-shaped groove are formed at intermediate sections of the projecting sections 78U (intermediate sections in the circumferential direction from the yoke-forming sections 22U). These recessed sections 80U are open in the radial outward direction from the yoke-forming sections 22U and extend axially from the yoke-forming sections 22U.

[0069] At an end section of the tooth sections 24U near the rotor 50 (see Fig. 1A) The metal core contact sections 25U are provided, which extend outwards along the circumferential direction of the rotor 50 (alongside ring-shaped magnets 54S, 54N). The metal core contact sections 25U together with the metal core contact sections of a V-phase 25V and the metal core contact sections of a W-phase 25W, which are described later, form an inner ring-shaped section 41, and surfaces of the metal core contact sections 25U, 25V, 25W on the side of the rotor 50 each form arc-shaped surfaces R.

[0070] As it is in the Fig. As shown in Figure 2A, the coil wire 16U forms the U-phase and comprises several winding sections 26U and several crossing wires 28U. The several winding sections 26U are wound concentrically on the tooth sections 24U, with insulator sections 32U, which will be described later, arranged between them. The winding sections 26U are each connected to one another by the several crossing wires 28U. The crossing wires 28U are laid out (encased) around an outer circumferential surface of a connecting section 34U, which is formed in the insulator 18U, which will be described later. Connection sections 30U at both ends of the coil wire 16U lead from the tooth sections 24U to one side of a first axial direction (the side of arrow Z1) out of the stator 10.

[0071] The insulator 18U is made of a resin and comprises multiple insulator sections 32U and a connecting section 34U, which are integrated together. The number of multiple insulator sections 32U provided is the same as the number of multiple tooth sections 24U mentioned above. Each of the multiple insulator sections 32U comprises a main insulator body section 32U1 and an extending section 32U2. The main insulator body sections 32U1 are integrated with the respective surfaces of the multiple core-forming sections 14U mentioned above, for example, by integral casting or interlocking assembly. The main insulator body sections 32U1 insulate between the tooth sections 24U formed on the core-forming sections 14U and the winding sections 26U.The extending sections 32U2 are positioned further in a radial inward direction than the core-forming sections 14U and extend from the insulator main body section 32U1 to the side of the first axial direction (the side of arrow Z1) from the yoke 40.

[0072] The connecting section 34U is located on the side of the first axial direction of the multiple insulator sections 32U (the Z1 side). The connecting section 34U is formed in a ring shape and connects the multiple insulator sections 32U (or, more precisely, the extension end sections on the Z1 side of the extending sections 32U2) and is positioned further towards the radial inner direction than the core-forming sections 14U. Several retaining sections 36U, formed in a projection, are located between the multiple insulator sections 32U on an outer circumferential surface of the connecting section 34U and project outwards in the radial outer direction of the insulator 18. The retaining sections 36U hold the crossing wires 28U, mentioned above, on the connecting section 34U from one side of a second axial direction (side of arrow Z2).Several recesses 38U, which open in the direction of the second axial direction (side of arrow Z2), are formed between the several insulator sections 32U at the connecting section 34U.

[0073] The stator formation section of a V-phase 12V, which is located in the Fig. The stator section shown in Figure 2B has essentially the same configuration as the stator section of a U-phase 12U mentioned above. Specifically, the stator section of a V-phase 12V is formed by including the multiple yoke sections of a V-phase 22V, the multiple tooth sections 24V, the multiple metal core contact sections 25V, a coil wire 16V, and an insulator 18V. The multiple yoke sections 22V, the multiple tooth sections 24V, the metal core contact sections 25V, the coil wire 16V, and the insulator 18V correspond to the aforementioned multiple yoke sections 22U, the multiple tooth sections 24U, the multiple metal core contact sections 25U, the coil wire 16U, and the insulator 18U (see Figure 2B for each). Fig. 2A). Projecting sections 78V and recessed sections 80V correspond to the projecting sections 78U and recessed sections 80U mentioned above. It should be noted that in the stator forming section of a V-phase 12V, a connecting section 34V is formed in a ring shape and has a smaller diameter than the connecting section of a U-phase 34U mentioned above (cf. Fig. 2A). Furthermore, holding sections 36V hold the crossing wires 28V from the side of the first axial direction (the side of arrow Z1) to the connecting section 34V and are positioned further towards the radial inner direction than the core forming sections 14V.

[0074] The stator formation section of a W-phase 12W, which is located in the Fig. The stator section of a U-phase 12U, as shown in Figure 2C, has essentially the same configuration as the stator section of a U-phase 12U mentioned above. Specifically, the stator section of a W-phase 12W is configured to include the multiple yoke sections of a W-phase 22W, the multiple tooth sections 24W, the multiple metal core contact sections 25W, a coil wire 16W, and an insulator 18W. The multiple yoke sections 22W, the multiple tooth sections 24W, the multiple metal core contact sections 25W, the coil wire 16W, and the insulator 18W correspond to the multiple yoke sections 22U, the multiple tooth sections 24U, the multiple metal core contact sections 25U, the coil wire 16U, and the insulator 18U mentioned above (see Figure 2C for each). Fig. 2A). Projecting sections 78W and recessed sections 80W also correspond to the projecting sections 78U and recessed sections 80U mentioned above. It should be noted that in the stator forming section of a W-phase 12W, a connecting section 34W is formed in a ring shape and has a smaller diameter than the connecting section of a V-phase 34V mentioned above (cf. Fig. 2B). The aforementioned recesses (cf. recesses 38U in the Fig. 2A) are omitted from the connection section 34W. Furthermore, retaining sections 36W hold the crossing wires 28W from the side of the first axial direction (the side of arrow Z1) to the connection section 34W and are positioned further towards the inside of the radial direction than the core-forming sections 14W.

[0075] As it is in the Fig. As shown in Figure 1A, after the several stator formation sections 12U, 12V, 12W are assembled together, as will be described in detail later, they are held by the outer circumferential sections thereof by the stator housing 70 to form the stator 10. Furthermore, the annular yoke 40 of the stator 10 is formed by the several yoke formation sections 22U, 22V, 22W.

[0076] The projecting sections 78U, 78V, 78W, which are formed on the respective yoke-forming sections 22U, 22V, 22W, which form the yoke 40, are arranged at equal intervals along the circumferential direction when viewed from the axial direction of the yoke 40.

[0077] As it is in the Fig. 3A, Fig. 3B and Fig. As shown in Figure 4A, the multiple deformation sections 34U, 34V, 34W are arranged radially inside the yoke 40, with radial gaps, and are coaxial with the yoke 40. The retaining sections of a V-phase 36V are fitted against the inner circumferential surface of the connecting section of a U-phase 34U, and the retaining sections of a W-phase 36W are fitted against the inner circumferential surface of the connecting section of a V-phase 34V. The multiple connecting sections 34U, 34V, 34W are thus held in a radially separated state. Specifically, the holding sections 36U, 36V, 36W are provided between the multiple connecting sections 34U, 34V, 34W in the radial direction and take on the role of spacers shaped with a projection to hold the multiple connecting sections 34U, 34V, 34W in a state separated from each other in the radial direction.

[0078] A cross-sectional area, viewed in the axial direction of the stator, at locations where the retaining sections 36U and the recesses 38U are not formed by the connecting section of a U-phase 34U, a cross-sectional area, viewed in the axial direction of the stator, at locations where the retaining sections 36V and the recesses 38V are not formed by the connecting section of a V-phase 34V, and a cross-sectional area, viewed in the axial direction of the stator, at locations where the retaining sections 36W are not formed by the connecting section of a W-phase 34W, are identical to each other. The stiffness of the connecting section of a V-phase 34V is accordingly higher than that of the connecting section of a U-phase 34U, and the stiffness of the connecting section of a W-phase 34W is accordingly higher than that of the connecting section of a V-phase 34V.

[0079] Furthermore, as described above, in the state in which the several deformation sections 34U, 34V, 34W are arranged such that gaps exist between them in the radial direction of the yoke 40, the crossing wires of a V-phase 28V pass through the interior of the recesses 38U, which are formed at the connecting section of a U-phase 34U (are received inside the recesses 38U), and the crossing wires of a W-phase 28W pass through the interior of the recesses 38U, which are formed at the connecting section of a U-phase 34U, and the recesses 38V, which are formed at the connecting section of a V-phase 34V (are received inside the recesses 38U and the recesses 38V). Rotor 50

[0080] As it is in the Fig. As shown in Figure 1A, the rotor 50 is designed to comprise a rotating shaft section 52, which is arranged radially inward of the stator 10 and is supported to be rotatable about a shaft axis, as well as magnets 54S, 54N, which are arranged along a circumferential direction of the rotating shaft section 52. More precisely, the rotating shaft section 52 is formed by applying a surface treatment, such as carbon immersion machining, to a rod-shaped steel element. The rotating shaft section 52 is also supported by a shaft bearing element, which is not shown in the drawings. South pole magnets 54S and north pole magnets 54N are arranged alternately along the circumferential direction around the rotating shaft section 52. The magnets 54S, 54N are attached to the rotating shaft section 52 by a support element 56. Manufacturing process of the stator 10 and the brushless motor 60

[0081] Next, an explanation of a manufacturing process for the stator 10 and the brushless motor 60, which are designed as described above, will follow.

[0082] First, as is stated in the Fig. As shown in Figure 2A, the nucleation sections 14U are integrated onto the insulator sections 32U of the insulator 18U to form a subarray of a U-phase 42U. Similarly, as shown in the Fig. As shown in Figure 2B, the core-forming sections 14V are integrated with the insulator sections 32V of the insulator 18V to form a sub-arrangement of a V-phase 42V. Furthermore, as shown in the Fig. As shown in Figure 2C, the core-forming sections 14W are integrated with the insulator sections 32W of the insulator 18W to form a sub-arrangement of a W-phase 42W. Sub-arrangements 42U, 42V, and 42W are thus formed for each of the U-phase, V-phase, and W-phase (the process of forming a sub-arrangement).

[0083] Next, as it says in the Fig. 2A shows a flyer machine (not shown in the drawings) used to wind the coil wire 16U onto each of the tooth sections 24U of the sub-arrangement of a U-phase 42U from the radial outer direction, wherein the stator forming section of a U-phase 12U is formed with several winding sections 26U which are formed on the sub-arrangement 42U.

[0084] In a similar way to how it is described in the Fig. As shown in Figure 2B, the aforementioned spinning vane machine is used to wind the 16V coil wire onto each of the 24V tooth sections of the 42V sub-arrangement from the radial outer direction, with the stator forming section of a 12V V-arrangement being formed with several 26V winding sections formed on the 42V sub-arrangement. Furthermore, as shown in the Fig. As shown in Figure 2C, the aforementioned spinning vane machine is used to wind the coil wire 16W onto each of the tooth sections 24W of the sub-arrangement of a W-phase 42W from the radially outer direction, wherein the stator forming section of a W-phase 12W is formed with several winding sections 26W which are formed on the sub-arrangement 42W.

[0085] If the above is carried out, as described in the Fig. As shown in Figure 2A, the multiple crossing wires 28U are laid out along the outer circumferential surface of the connecting section 34U. The multiple crossing wires 28U are also held on the connecting section 34U by the retaining sections 36U formed in a projection from the side of the second axial direction (side of arrow Z2). In a similar manner, as shown in the Fig. As shown in Figure 2B, the multiple crossing wires 28V are laid out along the outer circumferential surface of the connecting section 34V. The multiple crossing wires 28V are also held by the retaining sections 36V formed in a projection on the side of the first axial direction (the side of arrow Z1) on the connecting section 34V. Furthermore, as shown in the Fig. As shown in Figure 2C, the multiple crossing wires 28W are laid out along the outer circumferential surface of the connecting section 34W. The multiple crossing wires 28W are also held by the retaining sections 36W formed in a projection on the side of the first axial direction (the side of arrow Z1) on the connecting section 34W.

[0086] As it is in the Fig. As shown in Figure 2A, the connection sections 30U lead from the tooth sections 24U at the two end faces of the coil wire 16U to the side of the first axial direction (the side of arrow Z1) from the stator 10. Similarly, as shown in the Fig. As shown in Figure 2B, the 30V connection sections at the two end sides of the coil wire 16V from the tooth sections 24V towards the side of the first axial direction of the stator 10. Furthermore, as shown in the Fig. As shown in Figure 2C, the connection sections 30W at the two end sides of the coil wire 16W extend from the tooth sections 24W towards the side of the first axial direction of the stator 10. The stator forming sections 12U, 12V, 12W are thus formed for each of the U-phase, the V-phase and the W-phase (the process of forming a stator forming section).

[0087] Then, as is stated in the Fig. 3A and the Fig. 3B is shown in a state in which the core formation sections 14V of the stator formation section of a V-phase 12V are offset by a specific angle in the circumferential direction with respect to the core formation sections 14W of the stator formation section of a W-phase 12W, the stator formation section of a V-phase 12V is mounted on the stator formation section of a W-phase 12W from the side of the first axial direction (the side of the arrow Z1). Then, in a state in which the core formation sections 14U of the stator formation section of a U-phase 12U are offset by a specific angle in the circumferential direction with respect to the core formation sections 14V of the stator formation section of a V-phase 12V, the stator formation section of a U-phase 12U is mounted on the stator formation section of a V-phase 12V and the stator formation section of a W-phase 12W from the side of the first axial direction (the side of the arrow Z1).

[0088] When the above is carried out, the multiple nucleation sections 14U, 14V, 14W are arranged in a ring shape, and as shown in the Fig. In 2D representation, both of the inner circumferential ends of each of the multiple yoke sections 22U, 22V, 22W are in contact with the inner circumferential ends of the adjacent yoke sections 22U, 22V, 22W on both sides (core assembly process).

[0089] Furthermore, as stated in the Fig. 3A and the Fig. As shown in Figure 3B, the retaining sections of a V-phase 36V are attached against the inner circumferential surface of the connecting section of a U-phase 34U, and the retaining sections of a W-phase 36W are attached against the inner circumferential surface of the connecting section of a V-phase 34V. The multiple connecting sections 34U, 34V, 34W are accordingly held separately from one another in the radial direction by the retaining sections 36U, 36V, 36W formed in a projection.

[0090] Furthermore, the crossing wires of a V-phase 28V pass through the interior of the recesses 38U formed at the connection section of a U-phase 34U, and the crossing wires of a W-phase 28W pass through the interior of the recesses 38U and the interior of the recesses 38V formed at the connection section of a V-phase 34V.

[0091] The following is an explanation of a process for integrating the stator housing 70 and the stator core 20 (the stator main body 11).

[0092] As it is in the Fig. As shown in Figure 5, the stator housing 70 is arranged radially outside the stator core 20, specifically along the yoke 40 of the stator core 20 (housing arrangement process). It should be noted that the inner diameter D1 of the stator housing 70 before the formation of the plastic deformation sections 72 (see Figure 5) is... Fig. 1A) is larger than the outer diameter D2 of the stator core 20 (see Fig. 1A), however, there is only a slight difference between D1 and D2. Thus, it seems that in the Fig. 5, that the inner diameter D1 of the stator housing 70 and the outer diameter D2 of the stator core 20 are compatible.

[0093] Next, variable core holding sections 102 of a metal core 100 are introduced on the inner circumferential side of the inner annular section 41 of the stator core 20, and as described in the Fig. 6A and the Fig. As shown in 6B, by widening a diameter of the respective variable core holding sections 102, the outer circumferential surfaces of the variable core holding sections 102 come into contact with the arc-shaped surfaces R of the metal core contact sections 25U, 25V, 25W.

[0094] Subsequently, by further widening the diameter of the respective variable core holding sections 102, the outer circumferential surface of the yoke 40 (the projecting sections 78U, 78V, 78W, which are formed on the yoke-forming sections 22U, 22V, 22W) comes into contact with the inner circumferential surface of the stator housing 70 (metal core build-up process). It should be noted that, in order to insert the variable core holding sections 102 into the inner annular section 41, the outer diameter of the variable core holding sections 102 is sufficiently narrowed to correspond to the inner diameter of the inner annular section 41.

[0095] As a brief explanation regarding the design of the metal core 100, the metal core 100 has basic design elements consisting of twelve individual variable core holding sections 102, which are arranged in a ring shape, as well as an upper lateral holding section 104 and a lower lateral holding section 106. The upper lateral holding section 104 and the lower lateral holding section 106 support the variable core holding sections 102 and allow the twelve individual variable core holding sections 102 to widen outwards towards the side of the outer diameter. The outer circumferential surfaces of the variable core holding sections 102 are formed as circular arc shapes to correspond to the circular arc surfaces R of the metal core contact sections 25U, 25V, 25W, and cam sections 102A are formed on the inner circumferential sections of the variable core holding sections 102.Furthermore, the retaining section of the upper side 104 and the retaining section of the lower side 106 are formed in circular disk shapes and are formed with inclined surfaces 104A, 106A on their respective outer circumferential sections. The cam sections 102A of the variable core retaining sections 102 are clamped between the inclined surface 104A of the retaining section of an upper side 104 and the inclined surface 106A of the retaining section of a lower side 106. Additionally, there is a through-hole formed by a central section in a radial direction between the retaining section of an upper side 104 and the retaining section of a lower side 106, and a shaft section 108 is inserted into the through-hole. The retaining section of an upper side 104 and the retaining section of a lower side 106 are accordingly able to slide along the shaft section 108.Accordingly, a design is achieved in which the twelve individual ring-shaped variable core holding sections 102 move in the radial direction to widen the diameter of the holding section of an upper side 104 and the holding section of a lower side 106, which slide along the shaft section 108 and approximate the separation between the holding section of the upper side 104 and the holding section of the lower side 106.

[0096] Furthermore, a spring 110 is inserted into the shaft section 108, and the spring 110 biases the retaining section of the lower side 106 towards the side of the retaining section of the upper side 104. The variable core retaining sections 102 thereby press the core-forming sections 14U, 14V, 14W with a specific pressing force F1. The pressing force F1 (the driving force of the spring 110) is set such that the variable core retaining sections 102 are compressed radially inwards when the pressing force applied to the outer circumferential section of the stator housing 70 exceeds a specific value when the plastic deformation sections 72 are formed on the stator housing 70. It should be noted that a positioning template 112 is attached to the shaft section 108 to perform positioning of the variable core holding sections 102 in relation to the stator core 20 and the stator housing 70.

[0097] Next, as stated in the Fig. 7 and the Fig. Figure 8 shows the stator housing 70, the stator core 20 and the metal core 100 inserted into a crimping tool 114.

[0098] The following is a brief description of the crimping tool 114. The crimping tool 114 comprises the following basic elements: a circular, cylindrical base section 116, which supports the stator core 20 and the metal core 100; twelve individual punches 118, which are arranged at equal intervals along the circumference of the base section 116; and a pressing section 120. The punches 118 are mounted in such a way as to be able to move along the radial direction of the upper end section of the base section 116. The pressing section 120 moves the punches 118 radially inward from the base section 116. Twelve individual, recessed grooves (not shown in the drawings) are formed on the upper end section of the base section 116, which are arranged at equal intervals around the circumference extending along the radial direction of the base section 116.By receiving the punches 118 in these recessed grooves, the punches 118 are enabled to slide in the radial direction of the base section 116. The punches 118 are formed with rectangular block shapes, and one end of each punch 118 is designed as a contact section which comes into contact with the outer circumferential surface of the stator housing 70. Furthermore, as shown in the . Fig. As shown in Figure 10B, a pair of projecting sections 118A are provided on the contact section such that they project in the direction of the radial inner direction of the stator housing 70 and the stator core 20 when viewed along the axial direction of the stator housing 70 and the stator core 20. Furthermore, each of the pair of projecting sections 118A is arranged through the stator housing 70 such that it points in the direction of the respective projecting section 78U, 78V, 78W and spans the respective recessed section 80U, 80V, 80W formed on the projecting section 78U, 78V, 78W provided on the core-forming section 14U, 14V, 14W. As shown in the Fig. 7 and the Fig. As shown in Figure 8, the other end of each of the punches 118 is formed by an inclined surface 118B, which extends obliquely towards one end (the contact section) of the side of the punch 118, increasing in angle towards the side of the press section 120. Furthermore, the press section 120 is formed in a circular, cylindrical shape, and a tapered surface 120A is formed at a position on the inner circumferential surface of the press section 120 on the side of the base section 116. The inner diameter of the tapered surface 120A widens towards the side of the base section.The tapered surface 120A is in contact with the inclined surface 118B, which is formed at the other end of the punches 118, in a configuration such that twelve individual punches 118 are caused to slide inwards in the radial direction from the base section 116, making the separation between the press section 120 and the base section 116 narrower.

[0099] As it is in the Fig. 9, the Fig. 10A and the Fig. As shown in Figure 10B, a machining force F2 is applied to the press section 120 by a press, and the projecting sections 118A of the punch 118 are pressed against the outer circumferential section of the stator housing 70. The twelve individual plastic deformation sections 72 are thereby formed on the outer circumferential section of the stator housing 70 at equal intervals around the circumference (crimping process). The diameter of the stator housing 70 is accordingly reduced at the points where the plastic deformation sections 72 are formed, and these points press against each of the core-forming sections 14U, 14V, 14W. As a result, the stator housing 70 and the stator core 20 (the stator main body 11 (see Figure 10B)) are crimped. Fig. 1B)) integrated together.

[0100] In the present exemplary embodiment, an adaptation is made such that, according to the stiffness of the connecting sections 34U, 34V, 34W of the insulators 18U, 18V, 18W (see Fig. 1B) a machining force F3 is applied from the projection sections 118A of the punch 118 to the stator housing 70 when the plastic deformation sections 72 are formed at locations which point towards the yoke-forming sections of a U-phase 22U, a machining force F4 is applied from the projection sections 118A to the stator housing 70 when the plastic deformation sections 72 are formed at locations which point towards the yoke-forming sections of a V-phase 22V, and a machining force F5 is applied from the projection sections 118A to the stator housing 70 when the plastic deformation sections 72 are formed at locations which point towards the yoke-forming sections of a W-phase 22W.More precisely, F3, F4, and F5 are set such that when each of the core-forming sections 14U, 14V, 14W is pressed at points on the stator housing 70 where the plastic deformation sections 72 are to be formed, each of the core-forming sections 14U, 14V, 14W moves inwards by the same distance as each other in the radial direction. Even more precisely, taking into account reaction forces due to the deformation of each of the connecting sections 34U, 34V, 34W, which have different stiffnesses, the machining force F4 is set higher than the machining force F3, and the machining force F5 is set higher than the machining force F4. It should be noted that the machining forces F3, F4, and F5 can be determined by calculation or by performing tests.

[0101] When the stator housing 70 and the stator core 20 are integrated using the machining forces F3, F4, F5, deformation in the arrangement of the core-forming sections 14U, 14V, 14W (the stator-forming sections 12U, 12V, 12W) is prevented, and thus the circularity of the stator core 20 (of the stator main body 11) is improved. In other words, the stator housing 70 functions as an adjusting element to adapt the circularity of the stator core 20 (of the stator main body 11) when the stator housing with the plastic deformation sections 72 is formed by applying the machining forces F3, F4, F5 described above.

[0102] Next, as it says in the Fig. As shown in Figure 11, the crimping tool 114 is removed from the stator housing 70, the stator core 20, and the metal core 100. Then, the diameter of the variable core retaining sections 120 is compressed by releasing the tension of the spring 110, and the metal core 100, which was inserted into the stator core 20, is removed from the stator core 20.

[0103] The stator housing 70 and the stator core 20 (the stator main body 11) are integrated together by the processes described above, thereby forming the stator 10. The brushless motor 60 is manufactured by arranging a rotor radially inside the stator 10 (rotor assembly process). Operation and advantageous effects of the present exemplary embodiment

[0104] The following is an explanation regarding the operation and advantageous effects of the present exemplary embodiment.

[0105] As it is in the Fig. As shown in Figure 1A, the brushless motor 60 of the present exemplary embodiment is configured as described above, comprising the rotor 50, the stator core 20, and the stator housing 70. A current is passed through the coil wires 16, and the rotor 50, which includes the magnets 54S, 54N, is rotated about the rotating shaft section 52 as the central axis by the rotating magnetic field generated in the stator core 20 and the stator housing 70.

[0106] Furthermore, in the present exemplary embodiment, the stator core 20 is configured to comprise the yoke 40, the tooth sections 24, and the inner annular section 41, and the stator core 20 is integrated with the stator housing 70. The surface of the inner annular section 41 on the rotor 50 side (the inner circumferential surfaces of the metal core contact sections 25U, 25V, 25W) is formed with the arcuate surfaces R, which are centered on the axis of the rotor 50. In the process of integrating the stator housing 70 and the stator core 20 (the stator main body 11), it is thus possible to attach the metal core 100, which has a diameter corresponding to the inner diameter of the arcuate surfaces R, along the radial direction inside the inner annular section 41 (see Figure 1). Fig. 5) to arrange, wherein the plastic deformation sections 72 are formed on the outer circumferential sections of the stator housing 70. Consequently, the roundness or circular shape of the inner annular section 41 of the stator core 20 is maintained, although the yoke 40 of the stator core 20 (the projecting sections 78U, 78V, 78W) is pressed by the stator housing 70 at points where the plastic deformation sections 72 are formed.

[0107] In the present exemplary embodiment, the projecting sections 78U, 78V, 78W, which are formed on the yoke sections 22U, 22V, 22W of the stator core 20, further point towards the plastic deformation sections 72 on the outer circumferential sections of the stator housing 70. When the plastic deformation sections 72 are formed on the outer circumferential sections of the stator housing 70, a reaction force is thus concentrated at the locations of the stator housing 70 where the plastic deformation sections 72 are formed, and at locations where the projecting sections 78U, 78V, 78W are formed on the yoke sections 22U, 22V, 22W of the stator core 20.The tightness of the fit between the places where the plastic deformation sections 72 are formed and the places of the yoke formation sections 22U, 22V, 22W, where the protruding sections 78U, 78V, 78W are formed, is accordingly increased, thereby improving the fastening force between the stator housing 70 and the stator core 20.

[0108] In the present exemplary embodiment, the projecting sections 78U, 78V, 78W are furthermore arranged at equal intervals around the circumference of the yoke 40 when viewed along the axial direction of the yoke 40, and the plastic deformation sections 72 of the stator housing 70 are arranged at equal intervals around the circumference of the yoke 40 when viewed along the axial direction of the yoke 40. The yoke 40 is accordingly pressed uniformly around its circumference by the stator housing 70.

[0109] To summarize the above, the brushless motor 60 of the present exemplary embodiment improves the roundness of the stator core 20 and improves the fastening force between the stator housing 70 and the stator core 20.

[0110] Furthermore, according to the present exemplary embodiment, the projecting sections 78U, 78V, 78W, which are formed on the yoke-forming sections 22U, 22V, 22W, are arranged at positions that point towards the tooth sections 24. The variable core-holding sections 102 (see Fig. 5) are accordingly capable of supporting a pressing force which is applied by the punches 118 through the stator housing 70 perpendicularly to the yoke-forming sections 22U, 22V, 22W. The tightness of the fit between the locations where the plastic deformation sections 72 are formed on the stator housing 70 and the locations where the projecting sections 78U, 78V, 78W of the stator core 20 are formed is correspondingly increased. As a result, in the present exemplary embodiment, the clamping force between the stator housing 70 and the stator core 20 can be increased even further.

[0111] In the present exemplary embodiment, the plastic deformation sections 72 are further formed on the outer circumferential section of the stator housing 70 at a multiple of 3 or a multiple of 4 (twelve individual locations). The load-bearing capacity for the stator core 20 exerted by the stator housing 70 can thereby be made uniform around the circumference of the stator housing 70, and control of the manufacturing process can be facilitated by bringing the punches 118 into contact with the outer circumferential section of the stator housing 70 to form the plastic deformation sections 72.

[0112] In the present exemplary embodiment, the stator core 20 is furthermore formed with a segmented structure by twelve individual core-forming sections 14U, 14V, 14W, and the plastic deformation sections 72 are formed at twelve individual points by the outer circumferential section of the stator housing 70. The supporting force for the core-forming sections 14U, 14V, 14W by the stator housing 70 can accordingly be made uniform.

[0113] In the manufacturing process of the stator 10 of the present exemplary embodiment, the stator housing 70, which is formed in a circular, cylindrical shape with an inner diameter larger than the outer diameter of the stator core 20, is arranged along the yoke 40 of the stator core 20 by the housing assembly process. The formation of burrs, which is caused by the sliding contact between the inner circumferential surface of the stator housing 70 and the outer circumferential surface of the stator core 20 (the projecting sections 78U, 78V, 78W), can thus be prevented. It is therefore possible to prevent problems such as motor oscillation and short circuits.

[0114] Furthermore, as stated in the Fig. 6A to the Fig. As shown in Figure 11, the metal core build-up process is carried out. The stator housing 70 and the stator core 20 are then integrated together by the crimping process through the formation of several plastic deformation sections 72 on the outer circumferential section of the stator housing 70. The plastic deformation sections 72 are thus formed on the outer circumferential surface of the stator housing 70 in a state in which the roundness of the inner annular section 41 (the metal core contact sections 25U, 25V, 25W) is ensured by the variable core retaining sections 102 in a contact state between the outer circumferential surface of the variable core retaining sections 102 and the arc-shaped surfaces R of the metal core contact sections 25U, 25V, 25W.The roundness of the inner annular section 41 is accordingly maintained even when the external force is applied to the stator housing 70 to form the plastic deformation sections 72.

[0115] In the present exemplary embodiment, the external force is further applied to the outer circumferential section of the stator housing 70 by the punches 118 to form the plastic deformation sections 72, and this external force is supported by the variable core retaining sections 102 of the metal core 100. Specifically, the inner annular section 41 of the stator core 20 is not compressed in the radial direction when the external force is applied to the outer circumferential surface of the stator housing 70. The tightness of the fit is accordingly increased between the locations on the stator housing 70 where the plastic deformation sections 72 are formed and the yoke 40 of the stator core 20 (the projecting sections 78U, 78V, 78W), and the clamping force between the stator housing 70 and the stator core 20 is increased.

[0116] To summarize the above, the manufacturing process of a stator of the present exemplary embodiment makes it possible to improve the roundness of the stator core 20 and to increase the fastening force between the stator housing 70 and the stator core 20.

[0117] Furthermore, after the outer circumferential surface of the variable core holding sections 102 and the arc-shaped surfaces R of the metal core contact sections 25U, 25V, 25W have been brought into contact by widening the diameter of the variable core holding sections 102, the outer circumferential surface of the yoke 40 of the stator core 20 (the projecting sections 78U, 78V, 78W) is brought into contact with the inner circumferential surface of the stator housing 70 by further widening of the variable core holding sections 102. The plastic deformation sections 72 are then formed on the outer circumferential surface of the stator housing 70 in a state of contact between the outer circumferential surface of the yoke 40 (the projecting sections 78U, 78V, 78W) and the inner circumferential surface of the stator housing 70.The tightness of the fit between the areas of the stator housing 70 where the plastic deformation sections 72 are formed and the yoke 40 of the stator core 20 (the projecting sections 78U, 78V, 78W) is accordingly increased even further. As a result, in the present exemplary embodiment, the clamping force between the stator housing 70 and the stator core 20 can be increased even more.

[0118] In the present exemplary embodiment, the drive of the spring 110 is further adjusted such that the variable core retaining sections 102 contract in the radial direction when the external force (pressing force) on the outer circumferential surface of the stator housing 70 for forming the plastic deformation sections 72 exceeds a specific value. The stator housing 70 and the stator core 20 can thus be integrated together by a desired fastening force.

[0119] The following is an explanation regarding the characteristic operation and the advantageous effects of the present exemplary embodiment.

[0120] As it is in the Fig. As shown in Figure 10A, in the present exemplary embodiment the machining forces F3, F4, F5 are set taking into account the reaction force caused by the deformation of the connecting sections 34U, 34V, 34W (see Figure 10A). Fig. 1B) is caused when each of the core-forming sections 14U, 14V, 14W is pressed through the locations on the stator housing 70 where the plastic deformation sections 72 are formed. Deformation with respect to the positioning of the core-forming sections 14U, 14V, 14W (the stator-forming sections 12U, 12V, 12W) can thus be prevented if the stator housing 70 and the stator core 20 are integrated together, thereby making it possible to improve the roundness of the stator core 20 (the stator main body 11).

[0121] It should be noted that the present exemplary embodiment illustrates a case in which the recessed sections 80U, 80V, 80W are formed on the projecting sections 78U, 78V, 78W by the yoke-forming sections 22U, 22V, 22W; however, the present invention is not limited to this. For example, as described in the Fig. As shown in Figure 12A, the recessed sections 80U, 80V, 80W are not formed on the projecting sections 78U, 78V, 78W. Consequently, whether or not the recessed sections 80U, 80V, 80W are formed on the projecting sections 78U, 78V, 78W can be adjusted appropriately, taking into account factors such as the contact pressure between the projecting sections 78U, 78V, 78W and the stator housing 70.

[0122] In the present exemplary embodiment, a further explanation has been given of an example in which the punches 118, which comprise the pair of projecting sections 118A, are used to form the plastic deformation sections 72 on the outer circumferential section of the stator housing 70; however, the present invention is not limited thereto. As described in the Fig. As shown in Figure 12B, the plastic deformation sections 72 can be formed by a configuration in which the punches 122, which are designed to narrow towards the side of the guide end, are pressed against the stator housing 70 at points facing the recessed sections 80U, 80V, 80W. In such cases, the clamping force between the stator housing 70 and the stator core 20 is further increased. Modified examples

[0123] The following is an explanation regarding stators according to modified examples of the exemplary embodiment described above. It should be noted that a fundamentally similar design to that of the exemplary embodiment described above will be designated with the same reference numerals as those of the embodiment described above, and further explanation will be omitted.

[0124] As it is in the Fig. As shown in Figure 4B, the stator, according to the present modified example, has the feature that the stiffnesses of each of the connecting sections 34U, 34V, 34W of the insulators 18U, 18V, 18W are the same relative to each other. More precisely, the connecting section of a U-phase 34U, which is formed with the largest inner and outer diameter of the majority of connecting sections 34U, 34V, 34W, is designed with a plate thickness (wall thickness) in the radial direction as T1. Furthermore, a width in the axial direction of the connecting section of a U-phase 34U, where the retaining sections 36U and the recesses 38U are not formed, is given as W1.

[0125] A plate thickness in the radial direction of the connecting section 34V, which is arranged radially inside the connecting section of a U-phase 34U, is T2, which is thinner than T1, and a width in the axial direction of the connecting section of a V-phase 34V, where the retaining sections 36V and the recesses 38V are not formed, is W2, which is narrower than a width W1.

[0126] A plate thickness in the radial direction of the connecting section 34W, which is arranged in the radial direction inside the connecting section of a V-phase 34V, is furthermore T3, which is thinner than T2, and a width in the axial direction of the connecting section of a W-phase 34W, where the retaining sections 36W are not formed, is W3, which is narrower than the width W2.

[0127] By adjusting the plate thicknesses T1, T2, T3 and the widths W1, W2, W3 of the connecting sections 34U, 34V, 34W in the manner explained above, the respective stiffnesses of each of the connecting sections 34U, 34V, 34W are made similar to each other.

[0128] In the modified examples described above, a further explanation was given of an example in which the stiffnesses of each of the connecting sections 34U, 34V, 34W are made essentially the same by adjusting the plate thicknesses T1, T2, T3 and the widths W1, W2, W3 of the connecting sections 34U, 34V, 34W. However, the stiffnesses of the connecting sections 34U, 34V, 34W can be made similar to each other using a different method. For example, as in a second modified example, which is described in the Fig. As shown in Figure 4C, the stiffness of each of the connection sections 34U, 34V, 34W is adjusted to be equal to each other by varying the materials of the connection sections 34U, 34V, 34W. In the second modified example, the stiffnesses of each of the connection sections 34U, 34V, 34W are adjusted by, for example, using an aluminum alloy as the material of the connection section of a U-phase 34U, using polyacetal as the material for the connection section of a V-phase 34V, and furthermore, using a polyamide fiber composite as the material of the connection section of a W-phase 34W. In other words, the stiffness of the connection sections 34U, 34V, 34W is adjusted by using materials such that the closer the respective connection section is to the radial inner direction, the more material is used that has a lower Young's modulus.exhibits a modulus of elasticity.

[0129] In a third modified example, as in the Fig. As shown in 4D, the stiffnesses of each of the connection sections 34U, 34V, 34W can be further adjusted by providing a rib 124 which extends in the direction of the radial outer direction of the connection section 34U at an end section of a side of a second axial direction (side of arrow Z2) of the connection section of a U-phase 34U, and by providing several recesses 126 in the outer circumferential section of the connection section of a W-phase 34W, namely by adjusting the cross-sectional profile of each of the connection sections 34U, 34V, 34W.

[0130] In a fourth modified example, as it appears in the Fig. As shown in Figure 4E, the stiffnesses of each of the connecting sections 34U, 34V, 34W can be adjusted to be the same by adjusting the inner and outer diameters of each connecting section 34U, 34V, 34W to be the same, by arranging each connecting section 34U, 34V, 34W so that they are adjacent to each other in their axial directions, and by additionally adjusting the cross-sectional profile of each connecting section 34U, 34V, 34W to be the same. The cases in which the connecting sections 34U, 34V, 34W are arranged in this way also result in an even more compact stator 10 in the radial direction. Operation and beneficial effects of the modified examples

[0131] In the stators according to the modified examples described above, because the stiffnesses of each of the connection sections 34U, 34V, 34W of the insulators 18U, 18V, 18W are set to be the same, the machining forces F3, F4, F5, which are in the Fig. Figure 10A shows the forces required to form the plastic deformation sections 72 on the outer circumferential sections of the stator housing 70, provided that the same machining forces are applied to each other. The modified examples can therefore easily control the machining process when the stator core 20 (the stator main body 11) and the stator housing 70 are integrated together.

[0132] It should be noted that, although the in the Fig. The embodiments shown in Figures 4B to 4E in the modified examples above have been given as ways to make the stiffnesses of each of the connecting sections 34U, 34V, 34W of the plurality of insulators 18U, 18V, 18W equal to each other, but the present invention is not limited thereto. Other methods can be used to make the stiffnesses of each of the connecting sections 34U, 34V, 34W equal to each other, or the embodiments shown in the above are not limited to these. Fig. The elements shown in 4B to 4E can be combined in a suitable manner.

[0133] Furthermore, an explanation was given in the above exemplary embodiment and in the modified examples of embodiments in which the stator formation section of a U-phase 12U is supported by the connecting section 34U, the formation section of a V-phase 12V is supported by the connecting section 34V, and the formation section of a W-phase 12W is supported by the connecting section 34W, the present invention being not limited thereto. For example, an embodiment can be produced such that one connecting section supports the stator formation section of a U-phase 12U, the formation section of a V-phase 12V, and the formation section of a W-phase 12W. Thus, there is no requirement for a connecting section to be provided for each of the phases. Other manufacturing processes for the stator 10

[0134] The following is an explanation regarding other methods for manufacturing the stator 10 with reference to the Fig. 13 to 16.

[0135] The in the Fig. 13 and Fig. The manufacturing process shown in Figure 14 includes a crimping process with a feature of taking into account the stiffness of places on the stator housing 70 which are pressed by the punches 118, and of adjusting the machining force applied by each of the punches 118 to the outer circumferential section of the stator housing 70.

[0136] As it is in the Fig. As shown in Figure 13, in situations where the stator housing 70 has an elliptically shaped deformation in its profile when viewed along an axial direction, the deformation at a pressed location P1, when the outer circumferential section of the stator housing 70 is pressed from the outside inwards in a long radial direction, is less than the deformation at a location P2, when the outer circumferential section of the stator housing 70 is pressed from the outside inwards in a short radial direction. In other words, the stiffness at location P1 in the long radial direction of the stator housing 70 is higher than the stiffness at location P2 in the short radial direction of the stator housing 70. Accordingly, a machining force F6 pressing location P1 is set higher than the machining force F9 pressing location P2.Furthermore, an adjustment is made such that an intermediate section between point P1 and point P2 of the stator housing 70 is pressed by machining forces F7 and F8, which are less than the machining force F6 but greater than the machining force F9. It should be noted that the machining forces F6, F7, F8, and F9 are determined based on data from the profile of the stator housing 70.

[0137] As it is in the Fig. As shown in Figure 14, in cases where the wall thickness of the stator housing 70 is not constant along its circumference and several points on the stator housing 70 are pressed inwards in the radial direction, the deformation at the pressed points is less where the stator housing 70 has a thick wall than at points where the stator housing 70 has thin walls. In other words, the stiffness of the thick-walled sections is higher than that of the thin-walled sections of the stator housing 70. The machining force F6, which presses the thick-walled sections of the stator housing 70, is therefore set higher than the machining forces F7, F8, and F9, which press the thin-walled sections of the stator housing 70. It should be noted that the machining forces F6, F7, F8, and F9 are determined based on data regarding the thickness of each section of the stator housing 70.

[0138] In the Fig. In the manufacturing process described in Figure 15, the stator 10 is produced by inserting a metal core 128 equipped with sensors 130 that detect contact pressure against the metal core contact sections 25U, 25V, 25W from the core formation sections 14U, 14V, 14W. First, an embodiment of the metal core 128 is described, wherein the metal core 128 is configured to comprise a base section 132 formed in a circular rod shape and twelve individual sensors 130 attached to the outer circumferential sections of the base section 132. The twelve individual sensors 130 are arranged at equal intervals along a circumferential direction of the base section 132. It should be noted that the sensors 130 are pressure sensors that output a signal when they are pressed inwards in the radial direction of the base section 132.Following the execution of the housing assembly process described above, the metal core 128 is inserted into the radial inner direction of the stator main body 11, specifically into an area surrounded by the metal core contact sections 25U, 25V, and 25W (metal core assembly process). Subsequently, the twelve individual plastic deformation sections 72 of the stator housing 70 are formed at equal intervals along the circumference of the stator housing 70 by the projecting sections 118A of the punches 118, which press the outer circumferential section of the stator housing 70 (crimping process).The areas of the stator housing 70 where the plastic deformation sections 72 are formed are thereby narrowed in diameter, and when these areas press against each of the core-forming sections 14U, 14V, 14W, the metallic core contact sections 25U, 25V, 25W of each of the core-forming sections 14U, 14V, 14W press against the respective sensors 130. Furthermore, in the present exemplary embodiment, the machining forces F6, F7, F8, F9, which are applied by the punches 118 to the outer circumferential section of the stator housing 70, are adjusted based on the output values ​​of each of the sensors 130. It should be noted that in the present exemplary embodiment, the machining forces F6, F7, F8, F9 are adjusted such that the output values ​​of the respective sensors 130 become the same.

[0139] In the Fig. In the manufacturing process described in Figure 16, a feature of the crimping process described above is the adjustment of the machining force applied by each of the punches 118 to the outer circumferential sections of the stator housing 70, taking into account the orientation of the core-forming sections 14U, 14V, 14W. More precisely, a machining force F5 applied to locations on the stator housing 70 that point towards the core-forming sections 14U, 14V, 14W and are offset further radially outwards than a reference circle S is set higher than a machining force F3 applied to locations on the stator housing 70 that point towards the core-forming sections 14U, 14V, 14W and are offset further radially inwards than the reference circle S.It should be noted that a machining force F4, which is applied to the stator housing 70 at points which point towards the core formation sections 14U, 14V, 14W which are not offset with respect to the reference circuit S, is a lower machining force than the machining force F5 and a greater force than the machining force F3.

[0140] In accordance with the manufacturing process described above, the roundness of the stator core 20 can be improved by adjusting the machining force applied by the punches 118 to the stator housing 70, taking into account the stiffness of each section of the stator housing 70, the output values ​​of the sensors 130 and / or the alignment of the core forming sections 14U, 14V, 14W.

[0141] The following is an explanation of a second exemplary embodiment of the present invention with reference to the drawings.

[0142] As it is in the Fig. Figure 17 shows a stator 210 of the second exemplary embodiment for use in an inner rotor brushless motor and is configured to comprise a stator housing 270 as well as a stator forming section of a U-phase 212U, a stator forming section of a V-phase 212V and a stator forming section of a W-phase 212W, as shown in the Fig. 18A to 18C is shown.

[0143] As it is in the Fig. As shown in Figure 17, the stator housing 270 is formed in a thin-walled, circular, cylindrical shape and is integrally formed along its circumference using a soft magnetic metal (such as “iron” or similar). As shown in the Fig. As shown in Figure 19C, the inner diameter D1 of the stator housing 270 is larger than the outer diameter D2 of the core formation sections 214U, 214V, 214W, which are arranged in a ring shape, as will be described in detail later. As shown in the Fig. As shown in Figure 17, a plastic deformation groove 272 is formed on an outer circumferential surface of the stator housing 270 as a plastic deformation section by continuous formation around the circumferential direction of the stator housing 270 (in the present exemplary embodiment, there is a single plastic deformation groove 272 formed around the circumferential direction of the stator housing 270). Due to the formation of the plastic deformation groove 272, the inner diameter of the stator housing 270 is reduced (to less than the inner diameter D1) at the location where the plastic deformation groove 272 is formed.

[0144] As a result, the core formation sections 214U, 214V, 214W (the stator formation sections 212U, 212V, 212W), which are arranged in a ring shape, are integrated with the stator housing 270.

[0145] As it is in the Fig. As shown in Figure 18A, the stator formation section of a U-phase 212U is designed in a similar manner to the stator formation section 12U of the first exemplary embodiment, and thus similar design parts are designated with the same reference numerals, and further explanation is omitted.

[0146] At points on the yoke-forming sections 222U that point towards the tooth sections 24U, U-shaped, grooved recess sections 280U are formed, which open radially outwards from the yoke-forming sections 222U and extend axially from the yoke-forming sections 222U. As shown in the Fig. As shown in Figure 23, the recess sections 280U are configured with bottom surfaces 282 and pairs of side walls 284. The bottom surfaces 282 point outwards in the radial direction from the yoke-forming sections 222U, and the pairs of side walls 284 extend outwards in the radial direction of the yoke-forming sections 222U from two end sections of the bottom surface 282, the two end sections being arranged circumferentially from the yoke-forming sections 222U of the bottom surface 282. The depth of the recess sections 280U is set such that the stator housing 270, which is formed with the plastic deformation groove 272 (the location of the stator housing 270 where the plastic deformation groove 272 is formed), is not in contact with the bottom surface 282.Furthermore, the width W in the circumferential direction of the recessed sections 280U (a width dimension of the opening) is set smaller than the wall thickness T of the stator housing 270 before the formation of the plastic deformation groove 272.

[0147] As it is in the Fig. As shown in Figure 24, before being held by the stator housing 270, an angle θ1, formed between one end and the other end in the circumferential direction by an outer circumferential section of the yoke sections 222U, is set to a more acute angle than an angle θ2, formed between one end and the other end in the circumferential direction by an inner circumferential section of the yoke sections 222U. Specifically, the end sections of a circumferential direction of the yoke sections 222U, 222V, 222W are adjusted to abut each other at their respective inner circumferences. Furthermore, as shown in the Fig. 24 and the Fig. As shown in Figure 25, the angle θ1 and the angle θ2 of the yoke sections 222U are set at more acute angles (approximately 30° or less in the present exemplary embodiment) than an angle θ3 (360° / the number of teeth (twelve in the present exemplary embodiment)).

[0148] The stator formation section of a V-phase 212V, which is located in the Fig. The section shown in Figure 18B is designed similarly to the stator formation section 12V of the first exemplary embodiment, and therefore a further explanation of similar parts of an embodiment is omitted. The recessed sections 280V, which are provided on the yoke formation sections 222V, correspond to the recessed sections 280U described above.

[0149] The stator formation section of a W-phase 212W, which is located in the Fig. The section shown in 18C is similarly designed to the stator formation section 12W of the first exemplary embodiment, and therefore a further explanation of the identical parts of this embodiment is omitted. The recessed sections 280W, which are provided on the yoke formation sections 222W, correspond to the recessed sections 280U described above.

[0150] Then, as is stated in the Fig. As shown in Figure 17, after the assembly of the several stator formation sections 212U, 212V, 212W, as described in detail later, the stator 210 is designed such that its outer circumferential section is held by the stator housing 270. The several yoke formation sections 222U, 222V, 222W are each arranged between pairs of adjacent yoke formation sections on both sides of the stator housing.

[0151] The positioning and design of the multiple connection sections 34U, 34V, 34W is similar to that of the first exemplary embodiment.

[0152] The stator 210, which is configured as described above, forms a rotor 50 together with the rotor 50, as shown in the Fig. 20A and the Fig. Figure 20B shows a brushless motor 260 of the inner rotor type. The brushless motor 260 is designed such that the rotor 50 rotates when a rotating magnetic field is generated by the stator 210. It should be noted that the brushless motor 260 is, for example, a motor of the 8-pole, 12-slot type. Circuit devices 90 for controlling the rotation of the brushless motor 260 are provided on a circuit board 92 inside the stator housing, and the two ends of the stator housing are closed by a base element 94 and a cover 98, which are equipped with a connector section 96 to which an external connector, not shown in the drawings, is connected.

[0153] The following is an explanation regarding a method for manufacturing the stator 210, which is designed as described above.

[0154] Similar to the first exemplary embodiment, the sub-arrangements 242U, 242V, 242W are formed for each of the U-phase, the V-phase and the W-phase (the process of forming sub-arrangements).

[0155] Next, as it says in the Fig. 18A shows a spinning wing machine 200 (cf. Fig. 21) is used to wind the coil wire 16U onto each of the tooth sections 24U of the sub-arrangement of a U-phase 242U from the radial outer direction, forming a stator section of a U-phase 212U with a plurality of winding sections 26U formed on the sub-arrangement 242U. It should be noted that the flyer machine 200, as described in the Fig. Figure 21 shows a wing 201 which winds the coil wires 16 in a circular motion in such a way as to go around the circumference of the tooth sections 24, a variable shaper 202 which aligns the orientation of the coil wires 16 which are wound on the tooth sections 24, and a drive circuit 203 which controls the other elements.

[0156] In a similar way to how it is in the Fig. As shown in Figure 18B, the stator forming section of a V-phase 212V is formed with the majority of winding sections 26V, which are formed on the sub-arrangement of a V-phase 242V. As shown in the Fig. As shown in Figure 18C, the stator formation section of a W-phase 212W is also formed with the majority of winding sections 26W, which are formed on the sub-arrangement of a W-phase 242W.

[0157] When the above is carried out, several crossing wires 28U are laid out along the outer circumferential surface of the connecting section 34U, similar to the first exemplary embodiment. The several crossing wires 28U are also held by the connecting section 34U on the side of the second axial direction (side of arrow Z2) by the retaining sections 36U formed in a projection. Similarly, several crossing wires 28V are laid out along the outer circumferential surface of the connecting section 34V. The several crossing wires 28V are also held by the connecting section 34V on the side of the first axial direction (side of arrow Z1) by the retaining sections 36V formed in a projection. Furthermore, several crossing wires 28W are laid out along the outer circumferential surface of the connecting section 34W.The multiple crossing wires 28W are also held from the side of the first axial direction (the side of arrow Z1) by the connecting section 34W through the retaining sections 36W formed in a projection.

[0158] Furthermore, as stated in the Fig. As shown in Figure 18A, the connection sections 30U at the two ends of the coil wire 16U are led from the tooth sections 24U to the side of the first axial direction (the side of arrow Z1) from the stator 210. Similarly, as shown in the Fig. As shown in Figure 18B, the 30V connection sections are led out of the stator 210 from the 24V tooth sections at the two ends of the 16V coil wire. Furthermore, as shown in the Fig. As shown in Figure 18C, the connection sections 30W are led out from the tooth sections 24W at the two ends of the coil wire 16W towards the side of the first axial direction from the stator 210. The stator forming sections 212U, 212V, 212W are thus formed for each of the U-phase, the V-phase and the W-phase (the process of forming a stator forming section).

[0159] Then, as is stated in the Fig. 19A and the Fig. As shown in Figure 19B, similar to the first exemplary embodiment, the stator formation section of a V-phase 212V is mounted to the stator formation section of a W-phase 212W from the side of the first axial direction (the side of arrow Z1). Then, the stator formation section of a U-phase 212U is mounted to the stator formation section of a V-phase 212V and to the stator formation section of a W-phase 212W from the side of the first axial direction (the side of arrow Z1).

[0160] When the above is carried out, the multiple core-forming sections 214U, 214V, 214W are arranged in a ring shape, and each of the multiple yoke-forming sections 222U, 222V, 222W is, as shown in the Fig. 24 is shown, between a pair of yoke sections, which are adjacent on both sides, such that the inner circumferential sections of the multiple yoke sections 222U, 222V, 222W are in contact with the inner circumferential sections of the adjacent yoke sections on both sides (core assembly process).

[0161] Furthermore, as stated in the Fig. 19A and the Fig. Figure 19B shows the several connecting sections 34U, 34V, 34W held in a radially separated state by the retaining sections 36U, 36V, 36W formed in a projection.

[0162] Furthermore, when the above is carried out, the crossing wires of a V-phase 28V pass through the interior of the recesses 38U formed at the connection section of a U-phase 34U, and the crossing wires of a W-phase 28W pass through the interior of the recesses 38U formed at the connection section of a U-phase 34U, and the interior of the recesses 38V formed at the connection section of a V-phase 34V.

[0163] Furthermore, as stated in the Fig. As shown in Figure 19C, the stator housing 270 is arranged along the outer circumferential sections of the several core-forming sections 214U, 214V, 214W, which are arranged in a ring shape. Then, as shown in the Fig. As shown in Figure 22, a roller body 204 with a larger outer diameter than the width W (groove width) is brought into contact with the stator housing 270 by a press in the circumferential direction from the recessed sections 280U, 280V, 280W, and a plastic deformation groove 272 is formed. The plastic deformation groove 272 is formed by pressing the roller body 204 against the outer circumferential surface of the stator housing 270 with a specific pressure and by rolling the roller body 204 along the circumferential direction of the stator housing 270. The plastic deformation groove 272 is formed such that its depth gradually deepens when the roller body 204 is rolled several times around the circumferential direction of the stator housing 270.Furthermore, the inner diameter of the stator housing 270 is reduced at the locations formed by the plastic deformation groove 272 by the formation of the plastic deformation groove 272. As a result, the stator housing 270 and the multiple core formation sections 214U, 214V, 214W, which are arranged in a ring shape, are integrated together (the multiple core formation sections 214U, 214V, 214W are held by the stator housing 270) (crimping process).

[0164] The stator 210 is designed according to the processes described above. It should be noted that the connection sections 30U, 30V, and 30W are connected to each other by a buzz bar, which is not shown in the drawings. Operation and advantageous effects of the present exemplary embodiment

[0165] The following is an explanation regarding the operation and advantageous effect of the present exemplary embodiment.

[0166] As it is in the Fig. As shown in Figure 17, in the stator 210 of the present exemplary embodiment, a magnetic transmission path through the stator housing 270 is ensured due to the integral formation of the stator housing 270 along its circumference, without the need to verify contact between each of the yoke-forming sections 222U, 222V, 222W and the ring-shaped core-forming sections 214U, 214V, 214W. Furthermore, because the yoke 240 is formed in a segmented structure with the core-forming sections 214U, 214V, 214W arranged in a ring shape, the coil wires 16 can be easily wound onto the tooth sections 24U, 24V, 24W without the need for a technology such as a nozzle device.As explained above, in the present embodiment a stator 210 can be obtained in which the coil wires 16 are loosely wound, while still ensuring the desired path of a magnetic flux.

[0167] Furthermore, in the present exemplary embodiment, the recessed sections 280U, 280V, 280W are formed on the yoke-forming sections 222U, 222V, 222W of the core-forming sections 214U, 214V, 214W. Thus, when pressure is applied towards the inside of the core-forming sections 214U, 214V, 214W by forming the plastic deformation groove 272 on the stator housing 270, the core-forming sections 214U, 214V, 214W move towards the axial center and come into contact with each of the respective adjacent yoke-forming sections 222U, 222V, 222W. As a result, as shown in the Fig. Figure 23 shows a reaction force acting on the yoke sections 222U, 222V, 222W to compress them in their circumferential direction. The width of the depression sections 280U, 280V, 280W is thus narrowed by this reaction force. In other words, narrowing the width of the depression sections 280U, 280V, 280W prevents unpredictable deformation of the yoke sections 222U, 222V, 222W and maintains contact between them. As a result, this exemplary embodiment is capable of reliably controlling the path of a magnetic flux.

[0168] Furthermore, in the present exemplary embodiment, the recessed sections 280U, 280V, 280W are formed with the aforementioned side walls 284. Accordingly, it is easier to maintain a space between the stator housing 270 and the lower surface 282 of the recessed sections 280U, 280V, 280W, even though the plastic deformation groove 272 is formed on the stator housing 270. As a result, due to the narrower width of the recessed sections 280U, 280V, 280W, unpredictable deformation of the yoke sections 222U, 222V, 222W can be further prevented, and the contact between each of the yoke sections 222U, 222V, 222W is maintained with greater reliability. As a result, in the present exemplary embodiment, the path of a magnetic flux can be ensured with even greater certainty.

[0169] As it is in the Fig. As shown in Figure 23, in the present exemplary embodiment, the widths of the recessed sections 280U, 280V, 280W are set narrower than the wall thickness of the stator housing 270 before the formation of the plastic deformation groove 272. Consequently, a space can be left even more securely between the stator housing 270 and the lower surfaces 282 of the recessed sections 280U, 280V, 280W, even when the plastic deformation groove 272 is formed on the stator housing 270. As a result of narrowing the widths of the recess sections 280U, 280V, 280W, unpredictable deformation of the yoke sections 222U, 222V, 222W is further prevented, and the contact between the yoke sections 222U, 222V, 222W can be maintained even more reliably. The present exemplary embodiment is thus capable of reliably ensuring the path of the magnetic flux.

[0170] Furthermore, in the present exemplary embodiment, the recessed sections 280U, 280V, 280W are provided at locations facing the tooth sections 24U, 24V, 24W. Accordingly, a magnetic flux is transferred from the tooth sections 24U, 24V, 24W to the yoke sections 222U, 222V, 222W through the locations where the recessed sections 280U, 280V, 280W are formed. In this exemplary embodiment, the magnetic flux can be transferred to the yoke sections 222U, 222V, 222W, while the influence of the recessed sections 280U, 280V, 280W is minimized.

[0171] In the present exemplary embodiment, furthermore, as described in the Fig. As shown in Figure 24, the angle θ1, which is formed between one end and the other end in the circumferential direction of the outer circumferential section of the yoke sections 222U, 222V, 222W, is set at an even more acute angle than the angle θ2, which is formed between one end and the other end in the circumferential direction of the inner circumferential section of the yoke sections 222U, 222V, 222W. The inner circumferential sections of the yoke sections 222U, 222V, 222W are accordingly in contact with each other in the annular arrangement of the core-forming sections 214U, 214V, 214W. When the plastic deformation groove 272 is formed on the stator housing 270 (see Figure 24), the angle θ1 is formed between the outer circumferential section of the yoke sections 222U, 222V, 222W. Fig. 25), a contact is established between adjacent yoke sections 222U, 222V, 222W at a point which gradually increases from the inner circumferential sections of the yoke sections to the outer circumferential sections thereof. In the present exemplary embodiment, the contact state between the adjacent yoke sections 222U, 222V, 222W can be stabilized, and thus the path of a magnetic flux can be ensured with even greater certainty.

[0172] Furthermore, angles θ1 and θ2 are set at a smaller acute angle (approximately 30° or less in the present exemplary embodiment) than angle θ3 (360° / the number of teeth (12 in the present exemplary embodiment)). Thus, when the plastic deformation groove 272 is formed on the stator housing 270, abrupt contact at a single point between the inner circumferential section and the outer circumferential section of the yoke sections 222U, 222V, 222W is prevented. In other words, contact is established at a position that gradually increases from the inner circumferential section towards the outer circumferential section of the yoke sections 222U, 222V, 222W.As a result, the contact state between the adjacent yoke formation sections 222U, 222V, 222W can be further stabilized, and thus the path of a magnetic flux can be ensured with greater safety.

[0173] Furthermore, in the present exemplary embodiment, as described in the Fig. As shown in Figure 22, the plastic deformation groove 272 on the stator housing 270 is formed by rolling the roller body 204 several times around the circumference of the stator housing 270. Because the depth of the plastic deformation groove 272 gradually increases as the roller body 204 is rolled several times around the circumference of the stator housing 270, a stable plastic deformation groove 272 is achieved. In this exemplary embodiment, the contact state between the stator housing 270 and the yoke-forming sections 222U, 222V, 222W of the core-forming sections 214U, 214V, 214W can be stabilized, thus ensuring the desired path of magnetic flux.

[0174] The plastic deformation groove 272 is further formed by bringing the roller body 204, with a larger outer diameter than the width W, into contact in the circumferential direction from the recessed sections 280U, 280V, 280W against the stator housing 270. Accordingly, a space is more reliably left between the stator housing 270 and the recessed sections 280U, 280V, 280W after the plastic deformation groove 272 has been formed. As a result of the narrowing of the recess sections 280U, 280V, 280W, unpredictable deformation of the yoke sections 222U, 222V, 222W is prevented, and the contact between the yoke sections 222U, 222V, 222W is maintained. The present exemplary embodiment is thus capable of ensuring the path of a magnetic flux with even greater reliability.

[0175] It should be noted that, although an explanation has been given for the present exemplary embodiment in which the plastic deformation groove 272 is formed by bringing the roller body 204, with a larger outer diameter than the width W in a circumferential direction, into contact with the recessed sections 280U, 280V, 280W against the stator housing 270, the present invention is not limited thereto. The plastic deformation groove 272 can, for example, be formed using a roller body with a smaller outer diameter than the width W in the circumferential direction by adjusting the machining force for pressing against the outer circumferential surface of the stator housing 270.

[0176] Furthermore, in the present exemplary embodiment, the plastic deformation groove 272 on the stator housing 270 is formed by rolling the roller body 204 several times around the circumferential direction of the stator housing 270, although the present invention is not limited thereto. For example, the plastic deformation groove 272 can be formed by rolling the roller body 204 around the circumferential direction of the stator housing 270 with a single rotation.

[0177] In the present exemplary embodiment, the angle θ1 in the circumferential direction between one end and the other end of the outer circumferential section of the yoke sections 222U, 222V, 222W, and the angle θ2 between one end and the other end of the inner circumferential section of the yoke sections 222U, 222V, 222W, are furthermore set at smaller acute angles (approximately 30° or less in the present exemplary embodiment) than 360° / the number of teeth (twelve in the present exemplary embodiment), the present invention not being limited thereto. The angle θ1 and the angle θ2 can be set in a suitable manner taking into account the properties of the desired stator.

[0178] Furthermore, in the present exemplary embodiment, angle θ1 is set at a more acute angle than angle θ2, although the present invention is not limited to this. For example, angle θ1 and angle θ2 can be set to be essentially the same relative to each other.

[0179] In the present exemplary embodiment, the width of the recessed sections 280U, 280V, 280W is furthermore set smaller than the wall thickness of the stator housing 270 before the formation of the plastic deformation groove 272, whereby the present invention is not limited thereto. For example, a configuration can be produced in which the width of the recess sections 280U, 280V, 280W is set larger than the wall thickness of the stator housing 270 before the formation of the plastic deformation groove 272. In cases of such a configuration, an excess amount of material is prepared for the recess sections 280U, 280V, 280W to become narrower if there is an unpredictable deformation of the yoke-forming sections 222U, 222V, 222W, and the contact condition between the yoke-forming sections 222U, 222V, 222W is maintained.As a result, it is possible to ensure the path of a magnetic flux with even greater certainty.

[0180] Next, an explanation of modified examples of the second exemplary embodiment as described above will follow, with reference to the Fig. 26, the Fig. 27A and the Fig. 27B. It should be noted that elements similar to those of the second exemplary embodiment are designated by the same reference numerals as those of the second exemplary embodiment and no further explanation is given.

[0181] As it is in the Fig. As shown in Figure 27B, a stator 310 according to the present modified example has a projecting section 312 with a curved surface 316 formed in a projection, which is formed at one end in a circumferential direction by the yoke-forming sections 322, and a recessed section 414 with a curved surface 122 formed in a recess, which is formed at the other end in a circumferential direction by the yoke-forming sections 322. More precisely, as shown in the Fig. As shown in Figure 27A, the projecting section 312 is formed at a point on one end side of the yoke-forming section 322 and extends radially outwards from the yoke-forming section 322. The projecting section 312 extends outwards towards the other end side of the adjacent yoke-forming section 322, and one side of a guide end in a projection direction of the projecting section 312 is formed by the curved surface 316 with a radius of curvature R1. Furthermore, a countersinking section 318 is also formed, which lowers inwards radially from the yoke-forming section 322 at a point on one side of a base end of the projecting section 312 and outwards radially from the yoke-forming section 322.Furthermore, a point on the side of the guide end of the projecting section 312 and in the radial direction outwards from the yoke-forming section 322 is positioned further towards the outside of the radial direction than an outer circumferential surface 320 of the yoke-forming section 322.

[0182] The recessed section 414 is further formed at a point on the other end side of the yoke-forming section 322 and on the radial outer direction of the yoke-forming section 322. More precisely, the recessed section 414 is open in the direction towards the other end side of the yoke-forming section 322, and the recessed section 414 is formed with the curved surface 422 with radius of curvature R2, which is essentially the same as the radius of curvature R1 of the curved surface 316 of the projecting section 312.

[0183] As it is in the Fig. As shown in Figure 26, several core formation sections 314U, 314V, 314W, each equipped with the projecting section 312 and the recessed section 414, are arranged in a ring shape, and a stator housing 270 (see, for example, Figure 26) is arranged in a ring shape. Fig. 17) is arranged along an outer circumferential section of the several ring-shaped core-forming sections 314U, 314V, 314W. A plastic deformation groove 272 is then formed on the stator housing 270 (see, for example, Fig. 17) As a result, the inner diameter of the stator housing 270 is reduced at the point where the plastic deformation groove 272 is formed, and the inner circumferential surface of the stator housing 270 is pressed against the side of the guide end by the projecting sections 312 and in the radial outer direction by the yoke-forming sections 322. Then, as described in the Fig. As shown in Figure 27B, adjacent projecting sections 312 and recessed sections 414 are brought into contact with each other by reducing the diameter at the points on the side of the guide end of the projecting sections 312 and in the radial outer direction of the yoke-forming sections 322, thereby integrating the stator housing 270 and the several ring-shaped core-forming sections 314U, 314V, 314W together.

[0184] In the stator 310 according to the modified example described above, the adjacent projecting sections 312 and the recessed sections 414 of the yoke sections 322 are positioned in contact with each other by forming the plastic deformation groove 272 on the outer circumferential surface of the stator housing 270. A localized contact state between the adjacent yoke sections 322 is thus prevented in contrast to the cases in which the projecting sections 312 and the recessed sections 414 are not formed on the yoke sections 322 in the configuration described above (a contact surface area is increased by the contact between the curved surfaces 316, 422).As a result, the contact state between the adjacent yoke sections 322 is stabilized in the present modified example, thus enabling a path of magnetic flux to be ensured with greater certainty. Furthermore, the roundness of the stator 310 is improved by stabilizing the contact state between the adjacent yoke sections 322.

[0185] It should be noted that in the present modified example, the radius of curvature R1 of the curved surface 316 of the projecting section 312 and the radius of curvature R2 of the curved surface 422 of the recessed section 414 are essentially the same, although the present invention is not limited thereto. There may be a difference in the radii of curvature of the two surfaces within a region in which the aforementioned advantageous effects are achieved. Furthermore, as long as there are sections that come into contact with each other at the curved surfaces of the adjacent yoke-forming sections 322, other sections may come into contact with each other as flat planes.

[0186] An explanation has been given regarding a second exemplary embodiment of the present invention; however, the present invention is not limited to the above, and obviously various other modifications are possible within a range which do not deviate from the idea of ​​the present invention.

[0187] The following is an explanation of a third exemplary embodiment of the present invention. Each section of the stator 410 of the present exemplary embodiment is essentially the same as that of the stator 210 of the second exemplary embodiment. With regard to the manufacturing process, the process of forming a sub-assembly, the process of forming the stator-forming section, and the process of assembling the core of the stator 410, these are equally similar to those of the first and second exemplary embodiments, and further explanation thereof is therefore omitted. In the manufacturing process of the stator 410, as described in the Fig. 19C and the Fig. As shown in Figure 28A, after arranging the stator housing 270 along the outer circumferential section of the several ring-shaped core formation sections 214U, 214V, 214W, a metal core 306 with an outer diameter corresponding to the inner diameter of the ring-shaped core formation sections 214U, 214V, 214W (in the present exemplary embodiment, the outer diameter of the metal core 306 is essentially the same as the inner diameter of the core formation sections 214U, 214V, 214W) is inserted into the inner circumferential section of the core formation sections 214U, 214V, 214W (metal core build-up process).

[0188] Then, a roller body 204 is positioned in contact with the stator housing 270 using a press, and the plastic deformation groove 272 is formed. As described in the Fig. 28A, the Fig. 28B and the Fig. As shown in Figure 28C, the outer diameter of the roller body 204 is larger than the width W of a circumferential direction (groove width) of the recessed sections 80U, 80V, 80W, which are formed in the yoke-forming sections 22U, 22V, 22W of the core-forming sections 214U, 214V, 214W. The plastic deformation groove 272 is then formed by pressing the roller body 204 against the outer circumferential surface of the stator housing 270 with a specific pressure and rolling the roller body 204 along the circumferential direction of the stator housing 270. The plastic deformation groove 272 is formed by rolling the roller body 204 along the circumferential direction of the stator housing 270 over several rotations (multiple times) such that the depth of the plastic deformation groove 272 gradually becomes deeper.Furthermore, by forming the plastic deformation groove 272, the inner diameter of the stator housing 270 is reduced at the locations where the plastic deformation groove 272 is formed. As a result, the stator housing 270 and the several ring-shaped core-forming sections 214U, 214V, 214W are integrated together (the several core-forming sections 214U, 214V, 214W are held by the stator housing 270) (crimping process).

[0189] Next, as it says in the Fig. 28D and the Fig. 28E shows the metal core 306 away from the inner circumferential section of the core-forming sections 214U, 214V, 214W.

[0190] The stator 410 is formed using the processes described above. It should be noted that connection sections 30U, 30V, and 30W are interconnected, for example, by a buzz bar, which is not shown in the drawings. The stator 410 is manufactured using the techniques described above. Operation and advantageous effects of the present exemplary embodiment

[0191] The following is an explanation regarding the operation and advantageous effects of the present exemplary embodiment.

[0192] As it is in the Fig. As shown in Figures 28A to 28E, in the present exemplary embodiment, after the metal core 306 has been inserted into the inner circumferential section of the core-forming sections 214U, 214V, 214W, the plastic deformation groove 272 is then formed on the outer circumferential surface of the stator housing 270. Thus, even when the external force for forming the plastic deformation groove 272 is transmitted to the annularly arranged core-forming sections 214U, 214V, 214W, the arrangement of the annularly arranged core-forming sections 214U, 214V, 214W is not removed or displaced. In fact, in the present exemplary embodiment, the roundness of the annularly arranged core-forming sections 214U, 214V, 214W can be improved.

[0193] It should be noted that, although an explanation has been given for the present exemplary embodiment in which the metal core 306 is inserted into the inner circumferential section of the core-forming sections 214U, 214V, 214W after the stator housing 270 is arranged along the outer circumferential section of the several annularly arranged core-forming sections 214U, 214V, 214W, the present invention is not limited thereto. The stator housing 270 can, for example, be arranged along the outer circumferential section of the core-forming sections 214U, 214V, 214W after the metal core 306 has been inserted into the inner circumferential section of the core-forming sections 214U, 214V, 214W.

[0194] Next, an explanation will be given regarding another manufacturing process for the stator 410, which is designed as described above.

[0195] In this manufacturing process, after completion of the subassembly forming process, the stator formation section forming process, and the core assembly process, the deformation of the stator housing 370 is first measured by a housing measurement process, and then the stator housing 370 is arranged along its outer circumferential section by the several ring-shaped core formation sections 214U, 214V, 214W, as shown in the Fig. 29A. It should be noted that in the present exemplary embodiment, the stator housing 370 has an inner diameter which is deformed into a substantially elliptical shape (with the direction of the long axis indicated by arrow L and the direction of the short axis indicated by arrow S). It should be noted that in the Fig. 29A to 29C the deformation is excessive.

[0196] Next, as it says in the Fig. As shown in Figure 29B, a metal core 308 is selected to match the deformation of the stator housing 370, which was measured by the housing measurement process described above. The selected metal core 308 is then inserted into the inner circumferential section of the annularly arranged core-forming sections 214U, 214V, 214W (process of selecting and constructing the metal core). More precisely, the metal core 308, having a substantially elliptical cross-section, is inserted into the inner circumferential section of the annularly arranged core-forming sections 214U, 214V, 214W in an orientation with its short diameter oriented along the direction of the long diameter of the housing 370 (the direction of arrow L) and its long diameter oriented along the direction of the short diameter of the stator housing 370 (the direction of arrow S).

[0197] Next, as it says in the Fig. As shown in Figure 29C, the roller body 204 is pressed against the outer circumferential surface of the stator housing 370 with a specific pressure, and the roller body 204 is rolled around a circumferential direction by the stator housing 370. As a result, as shown in the Fig. Figure 29D shows the stator housing 370 and the core formation sections 214U, 214V, 214W integrated together, while a deformation of the stator housing 370 is corrected (deformation correction process and crimping process).

[0198] Next, the metal core 308 is removed from the inner circumferential section of the core-forming sections 214U, 214V, 214W, thereby forming the stator 410.

[0199] As explained above, in the present manufacturing process the stator housing 370 and the core formation sections 214U, 214V, 214W can be integrated together, while any deformation or twisting of the stator housing 370 is corrected.

Claims

[1] Brushless motor (60), comprising: a rotor (50) comprising a rotating shaft section (52) which is supported in such a way as to be rotatable about its axial line, and magnets (54) which are arranged along a circumferential direction of the rotating shaft section; a stator core (20) which is arranged radially outside the rotor (50) and which comprises: an outer annular section (40) which is formed in a ring shape, tooth sections (24) which project outwards from the outer annular section (40) in a radial direction inwards from the outer annular section (40) and are wound with conductive wire coils, and an inner annular section (41) which is formed by rotor-side surfaces extending from end sections of the tooth sections (24), wherein the end sections are adjacent to the rotor (50) along a circumferential direction of the rotor (50) and form circular, arc-shaped surfaces with the rotor (50) as the axial center, wherein projecting sections (78) on the outer annular section (40) are formed in such a way as to project in a radial direction outside of the outer annular section (40) and to be arranged at equal intervals around a circumferential direction from the outer annular section (40) when viewed along an axial direction from the outer annular section (40); and a stator housing (70) formed in a cylindrical shape to cover the stator core (20) in a radial direction outside the stator core (20), and which is integrated together with the stator core (20) by a plurality of plastic deformation sections (72) formed on an outer circumferential section of the stator housing (70) at locations pointing towards the projecting sections (78), and wherein the plurality of plastic deformation sections (72) are arranged at equal intervals along a circumferential direction from the outer circumferential section of the stator housing (70) along the axial direction of the outer annular section (40), wherein: the outer annular section (40) is formed from a plurality of yoke-forming sections (22) which form an annular yoke (40) and are segmented in a circumferential direction from the yoke (40), wherein the tooth sections (24) each project outwards from the yoke-forming sections (22) in a radial direction inwards of the yoke (40); each of the majority of the nucleus formation sections (14) is equipped with the yoke formation section (22) and the tooth section (24); the stator housing (70) is integrated together with the majority of core formation sections (14); the stator core (20) furthermore has a plurality of insulators (18) and each of the insulators (18) has a plurality of insulating sections (32) and comprising connecting sections (34), wherein the insulating sections (32) are integrated with the respective core-forming sections (14) and insulate between the respective tooth sections (24) and the winding sections (26), and wherein each of the connecting sections (34) is formed in a ring shape and together connects the plurality of insulating sections (32); and the majority of insulators (18) are formed such that the stiffness of the connecting section (34) of one of the insulators (18) is essentially the same as the stiffnesses of each of all the other connecting sections (34). [2] Brushless motor (60) according to claim 1, wherein the projecting sections (78) are provided at locations which point towards the tooth sections (24). [3] Brushless motor (60) according to claim 1 or 2, wherein 3 × n (n = 1, 2, 3 etc.) individual or 4 × n (n = 1, 2, 3 etc.) individual plastic deformation sections (72) are formed by the plurality of plastic deformation sections (72) on the outer circumferential section of the stator housing (70). [4] Brushless motor (60) according to claim 1 or 2, wherein the stator core (20) is formed with a segmented structure, which is formed by arranging m individual core formation sections (14) in a ring shape, and wherein there are m × n (n = 1, 2, 3 etc.) individual plastic deformation sections (72) formed on the outer circumferential section of the stator housing (70). [5] Brushless motor (60) according to claim 1, wherein the connecting sections (34) of the plurality of insulators (18) are arranged to be adjacent to each other in a radial direction of the insulators (18), and the stiffnesses of the plurality of connecting sections (34) are adapted to be substantially the same as each other by adapting at least one factor from the group consisting of the wall thickness in the axial direction, the wall thickness in the radial direction and the cross-sectional profile of each of the connecting sections (34). [6] Brushless motor (60) according to any one of claims 1 to 5, wherein the stiffnesses of the majority of the connecting sections (34) are adapted to be substantially the same as each other by selecting materials for the respective connecting sections (34) such that a Young's modulus or E-modulus of the material of one of the connecting sections (34) is lower than the Young's modulus of the material of another of the connecting sections (34), which is arranged outside in the radial direction of the one connecting section (34). [7] Brushless motor (60) according to one of claims 1 to 6, wherein the stiffnesses of the plurality of connecting sections (34) are adapted to be substantially the same to each other by providing at least one of the connecting sections (34) of the plurality of connecting sections (34) with a rib extending in a radial direction. [8] Brushless motor (60) according to any one of claims 1 to 7, wherein the stiffnesses of the plurality of the connecting sections (34) are adapted to be substantially the same as any other by providing a recess in at least one of the connecting sections (34) of the plurality of the connecting sections (34). [9] Brushless motor (60) according to claim 1, wherein the stiffnesses of the plurality of connecting sections (34) are adapted to be substantially the same as each other by arranging the connecting sections (34) adjacent to each other in an axial direction of the connecting sections (34) and producing the cross-sectional profile of each of the connecting sections (34) in the same way relative to each other. [10] Stator (10), comprising: a plurality of nucleus-forming sections (14) comprising yoke-forming sections (22) which form an annular yoke (40) and are segmented in a circumferential direction from the yoke (40), and tooth sections (24) which project inwards from the yoke-forming sections (22) in a radial direction of the yoke (40); and a stator housing (70) formed in a circular, cylindrical shape with an inner diameter exceeding the outer diameter of the annularly arranged core-forming sections (14), formed using a soft magnetic metal and integrated with the core-forming sections (14) by forming a plastic deformation section (72) on an outer peripheral surface of the stator housing (70) by applying inward pressure in a radial direction from the stator housing (70); and a plurality of insulators (18) and each of the insulators (18) has a plurality of insulating sections (32) and connecting sections (34), wherein the insulating sections (32) are integrated with the respective nucleation sections (14) and insulate between the respective tooth sections (24) and the winding sections (26), wherein each of the connecting sections (34) is formed in a ring shape and together connects the majority of insulating sections (32); wherein the majority of insulators (18) are formed such that the stiffness of the connecting section (34) of one of the insulators (18) is essentially the same as the stiffnesses of each of all the other connecting sections (34). [11] Method for manufacturing a stator (10) comprising: a core assembly process in which core formation sections (14) are arranged in a ring shape, each of the core formation sections (14) comprising a yoke formation section (22), a tooth section (24) and an insulator (18), wherein the yoke formation sections (22) form an annular yoke (40) and are segmented in a circumferential direction from the yoke (40) and wherein the tooth sections (24) project out from the yoke formation section (22) in a radial direction inwards from the yoke (40); and the insulator (18) has a plurality of insulating sections (32) and connecting sections (34), wherein the insulating sections (32) are integrated with the respective core-forming sections (14) and insulate between the respective tooth sections (24) and the winding sections (26), and wherein each of the connecting sections (34) is formed in a ring shape and together connects the plurality of insulating sections (32); and the majority of insulators (18) are formed such that the stiffness of the connecting section (34) of one of the insulators (18) is essentially the same as the stiffnesses of each of all the other connecting sections (34), a metal core formation process in which a metal core (100) with an outer diameter corresponding to an inner diameter of the ring-shaped nucleation sections (14) is introduced into an inner circumferential section of the ring-shaped nucleation sections (14); and a crimping process which integrates a stator housing (70) and the core formation sections (14) together by arranging a metallic stator housing (70) formed in a circular cylindrical shape with an inner diameter exceeding an outer diameter of the annularly arranged core formation sections (14), along an outer circumferential section of the annularly arranged core formation sections (14) and forming a plastic deformation section (72) along a circumferential direction on an outer circumferential surface of the stator housing (70). [12] Method for manufacturing a stator (10) according to claim 11, further comprising: a housing measurement process which measures the deformation of the stator housing (70); and a metal core selection process which selects a metal core (100) according to the deformation of the stator housing (70) which is measured in the housing measurement process; and wherein During the crimping process, deformation correction and crimping processes are performed to integrate the stator housing (70) and the core formation sections (14) together while correcting the deformation of the stator housing (70). [13] Method for manufacturing a stator (10) according to claim 11 or 12, wherein in the metal core build-up process an outer circumferential surface of the metal core (100) and an inner circumferential surface of the core formation sections (14) are brought into contact with each other by widening a diameter of the metal core (100). [14] Method for manufacturing a stator (10) according to any one of claims 11 to 13, wherein: In the metal core build-up process, an outer circumferential surface of the core formation sections (14) and an inner circumferential surface of the stator housing (70) are brought into contact with each other by further expanding the diameter of the metal core (100); and During the crimping process, a majority of the plastic deformation sections (72) on the outer circumferential surface of the stator housing (70) are deformed in contact with the outer circumferential surface of the core formation sections (14) and the inner circumferential surface of the stator housing (70). [15] Method for manufacturing a stator (10) according to any one of claims 11 to 14, wherein the diameter of the metal core (100) is compressed when a pressing force exceeding a specific value is applied to the outer circumferential surface of the stator housing (70) to form the plastic deformation section (72). [16] Method for manufacturing a brushless motor (60), comprising: a housing arrangement process in which a stator housing (70), which is formed in a circular cylindrical shape with an inner diameter which exceeds an outer diameter of a stator (10) produced according to the method of claim 11, is arranged on an outside in a radial direction of the stator (10) produced according to the method of claim 11, a crimping process which integrates the stator housing (70) and the stator (10) by forming a plastic deformation section (72) on an outer circumferential section of the stator housing (70) by applying a machining force to an outer circumferential section of the housing (70) at respective locations, which point towards the majority of yoke formation sections (22), wherein the processing force corresponds at least to a stiffness of the connection sections (34) on the stator (10) and / or a stiffness of the respective location of the housing (70), and wherein the crimping process adapts the circular shape of the stator (10) by integrating the housing (70) and the stator (10) together. [17] Method for manufacturing a brushless motor (60) according to claim 16, wherein the machining force, which corresponds to the stiffnesses of the connecting sections (34) of the insulators (18), is applied to the stator housing (70) in the crimping process. [18] Method for manufacturing a brushless motor (60) according to claim 17, wherein: the respective connecting sections (34) of the plurality of insulators (18) are arranged adjacent to each other in a radial direction of the insulators (18); and In the crimping process, a weaker processing force is applied to the points which point towards the yoke formation sections (22) of the core formation sections (14) which are connected to the connecting section (34) which is arranged on the outside in the radial direction, than a processing force which is applied to points which point towards the yoke formation sections (22) from the core formation sections (14), which are connected to the connecting section (34) which is arranged inwards in the radial direction. [19] Method for manufacturing a brushless motor (60), comprising: a housing arrangement process in which a stator housing (70), which is formed in a circular cylindrical shape with an inner diameter which exceeds an outer diameter of a stator (10) produced according to the method of claim 11, is arranged on an outside in a radial direction of the stator (10) produced according to the method of claim 11, a metal core build-up process in which a metal core (128), which is provided with sensors (130) for detecting a contact pressure against each of the core-building sections (14), is inserted on an inner side in a radial direction from the stator (10); and a crimping process which integrates the housing (70) and the stator (10) together by forming a plastic deformation section (72) on an outer circumferential section of the housing (70) by applying a machining force to the outer circumferential section of the housing (70) at respective points which point towards the majority of the yoke formation sections (22), wherein the machining force corresponds to the output values ​​of the sensors (130) and the crimping process adapts the circular shape of the stator (10) by integrating the housing (70) and the stator (10) together. [20] Method for manufacturing a brushless motor (60), comprising:a housing assembly process in which a stator housing (70), which is formed in a circular cylindrical shape with an inner diameter exceeding an outer diameter of a stator (10) manufactured according to the method of claim 11, is arranged on an outer side in a radial direction of the stator (10) manufactured according to the method of claim 11; a crimping process which together integrates the housing (70) and the stator (10) by forming a plastic deformation section (72) on an outer circumferential section of the housing (70) by applying a machining force to the outer circumferential section of the housing (70) at respective locations which point towards the plurality of yoke-forming sections (22);wherein the processing force corresponds to an alignment of the majority of core formation sections (14) and wherein the crimping process adapts the circular shape of the stator (10) by integrating together the housing (70) and the stator (10).

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