Rotor for synchronous motor

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A FLAT ROLLED

MAGNETIC STEEL

SHEET

FORMING AN INTEGRAL,

PERIPHERAL CONNECTING

PORTIONS CUT

CUT THE OUTER PERPHERAL

CONNECTING PORTIONS

ARE INNER

PERIPHERAL CONNECTING

PORTIONS CUT

CUT THE INNER PERPHERAL

CONNECTING PORTIONS

STACKING, CAULKING

AN INTEGRAL, LAMINATED

ROTOR CORE

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ROTOR FOR SYNCHRONOUS MOTOR laminated core members disposed around a rotating shaft alternately in a circumferential direction, which can facili

This is a Divisional Application of U.S. Ser. No. 08/873, tate positioning or fixing processes of the permanent mag 879, filed Jun. 11, 1997, now U.S. Pat. No. 5,786,650 which nets and laminated core members in an assembling process is a continuation of Ser. No. 08/318,676, filed Oct. 14, 1994, So as to improve productivity, and also can improve now abandoned. mechanical Strength and thus performance and reliability of a high Speed or high torque motor.

TECHNICAL FIELD To accomplish the above objects, the present invention The present invention relates to a rotor for a Synchronous provides a rotor for a Synchronous motor comprising a shaft; motor, which includes a plurality of permanent magnets aatplurality generally of permanent magnets disposed around the shaft equal intervals, a plurality of core members disposed around a shaft and magnetized alternately in a disposed around the shaft while holding each of the perma circumferential direction, and a plurality of laminated core nent magnets therebetween members disposed around the shaft while holding each as to form magnetic poles;inSupporting a circumferential direction, So means for fixedly permanent magnet therebetween in the circumferential Supporting the permanent magnets and the core members direction So as to form magnetic poles. 15 onto the Shaft; and connecting means for fixedly connecting

BACKGROUND ART the core members located at desired positions around the shaft with each other in a relative arrangement of a finished

In the field of Synchronous motors, a rotor as mentioned rotor assembly.

above, which includes permanent magnets magnetized in a In the rotor according to the present invention, the con circumferential direction and laminated core members each necting means enables the core members located at desired forming a magnetic pole between the permanent magnets, positions to be integrally handled in a State in which they are the magnets and the core members being alternately dis already relatively positioned. Accordingly, the productivity posed around a shaft, has been used. In this type of con for assembling a rotor is significantly improved, and, after ventional rotor, each laminated core member is generally being assembled, the mechanical Strength of a rotor Structure formed by Stacking a plurality of core-laminations made of 25 is improved because the connecting means assists the Sup magnetic materials. Such as Silicon Steel plates. Each core port of the core members and the permanent magnets against lamination may have recesses and projections, which are an external force Such as a centrifugal force. formed at corresponding positions on respective axial end In a preferred embodiment of the present invention, each faces of core-lamination and can be engaged with each other. of the core members is a laminated core member formed by The core-laminations can be joined to each other by, e.g., axially Stacking and joining a plurality of core-laminations preSS-fitting the core-laminations together while aligning the made of magnetic materials, and the connecting means recesses and projections of the adjacent core-laminations. comprises at least one integral core-lamination made of a Each permanent magnet is held between a pair of adjacent magnetic material, the integral core-lamination including laminated core members and brought into close contact with Sections which are inserted between the core-laminations of the Side faces of the latter. The permanent magnet may be 35 the laminated core members located at the desired positions positioned and fixedly Supported in a radial direction by and are joined to adjacent core-laminations. In this case, the outer and inner hooks protruding from the Side faces of each integral core-lamination may include core-lamination Sec laminated core member at Outer and inner peripheral regions tions having shapes generally the same as those of the thereof. A rod member may be inserted into an axial through core-laminations of the laminated core members and the hole formed generally at the center of each laminated core 40 number thereof being the same as the number of magnetic member. Each rod member may be connected to annular end poles So as to be inserted and joined between the core plates which are arranged at both axial ends of the laminated laminations, and also include connecting portions extended core member and fixed to the rotating shaft. In this manner, from the core-lamination Sections So as to annularly connect the laminated core members and the permanent magnets are all of the core-lamination Sections in a predetermined fixedly held in the rotor against external force Such as 45 arrangement, whereby all of the core-lamination Sections are centrifugal force, by the end plates, the rod members and the connected in Such a relative arrangement of a finished rotor hookS. assembly that a Space for locating each permanent magnet is This type of rotor uses a plurality of permanent magnets defined between adjacent core-lamination Sections, So as to and laminated core members, the number of which corre form an integral laminated rotor core. Alternatively, the sponds to the number of magnetic poles, therefore it has 50 integral core-lamination may include core-lamination Sec problems in that the work of positioning or fixing the tions having shapes being generally the same as those of the permanent magnets and laminated core members is core-laminations of the laminated core members and the complicated, increased working time and Skilled workers are number thereof being half the number of magnetic poles So required, and thus improvement of perSonnel requirements as to be inserted and joined between the core-laminations, and productivity is prevented. Further, the accuracy of 55 and connecting portions extended from the core-lamination positioning the permanent magnets and laminated core Sections So as to annularly connect all of the core-lamination members depends on the mechanical Strength and proceSS Sections in a predetermined arrangement, whereby all of the ing accuracy of the rod members and end plates. laminated core members forming the same magnetic poles Consequently, in the case of high Speed motorS or high are fixedly connected in Such a relative arrangement of a torque motors, additional means for improving the mechani 60 finished assembly rotor that a Space for locating one lami cal Strength of the whole Structure of the rotor is required in nated core member forming another magnetic pole and two order to accurately hold the permanent magnets and lami permanent magnets is defined between adjacent core nated core members in predetermined positions. lamination Sections.

DISCLOSURE OF THE INVENTION 65 BRIEF DESCRIPTION OF THE DRAWINGS An object of the preset invention is to provide a rotor for The foregoing and the other objects, features, and advan a Synchronous motor including permanent magnets and tages of the present invention will be described with refer

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ence to the embodiments shown in the accompanying FIG. 22 is an illustration of stamped products formed at drawings, in which, respective Steps according to the manufacturing process FIG. 1A is a Side view of a rotor according to an shown in FIG. 21; and embodiment 1 of the present invention; FIG. 23 is an illustration showing a manufacturing pro FIG. 1B is a sectional view taken along line I-I of FIG. cess of the integral laminated rotor core shown in FIG. 14 by 1A; Stamped products formed at respective Steps thereof. FIG. 2A is a perspective view of an integral laminated BEST MODE OF CARRYING OUT THE rotor core of the rotor shown in FIG. 1A; INVENTION

FIG. 2B is a perspective view of a part taken along line 1O In the following description of embodiments, the same or II-II of FIG. 2A; Similar components are represented by the same reference FIG. 3A is a plan view of a core-lamination of the integral numerals.

laminated rotor core shown in FIG. 2A, Embodiment 1 FIG. 3B is a sectional view taken along line III-III of Referring to the drawings, FIGS. 1A and 1B show a rotor FIG. 3A; 15 10 for a synchronous motor according to the embodiment 1

FIG. 4 is a plan view of an integral core-lamination of the of the present invention. The rotor 10 includes a shaft 12, a integral laminated rotor core shown in FIG. 2A, plurality (six in this embodiment) of permanent magnets 14 FIG. 5A is a side view of a rotor according to an disposed around the Shaft 12 at generally equal intervals and embodiment 2 of the present invention; magnetized alternately in a circumferential direction, and a FIG. 5B is a sectional view taken along line V-V of FIG. plurality (six in this embodiment) of laminated core mem 5A; bers 16 disposed around the shaft 12 while holding each FIG. 6 is a perspective view of an integral laminated rotor permanent magnet 14 therebetween in the circumferential core of the rotor shown in FIG. 5A; direction So as to form magnetic poles. Each permanent 25 magnet 14 is held between and brought into close contact

FIG. 7 is a plan view of a core-lamination of the integral with laminated rotor core shown in FIG. 6; the Side faces of adjacent laminated core members 16. Each laminated core member 16 includes outer hooks 18

FIG. 8 is a plan view of an integral core-lamination of the protruding from both side faces at Outer peripheral regions integral laminated rotor core shown in FIG. 6; thereof. Therefore, each permanent magnet 14 is positioned FIG. 9 is a plan view of an integral core-lamination of a in a radial direction by the outer hook 18 of the laminated rotor according to an embodiment 3 of the present invention; core member 16 and fixedly Supported against centrifugal FIG. 10 is a perspective view of an integral laminated force. The laminated core members 16 are respectively rotor core using the integral core-lamination shown in FIG. provided with rod holes 20 axially penetrating through the 9; generally center portions of the core members, and rod FIG. 11A is a perspective View of an integral laminated 35 members 22 are inserted into respective rod holes 20. These rotor core of a rotor according to an embodiment 4 of the rod members 22 are connected to a pair of annular end plates present invention; 24 arranged at both axial ends of the laminated core mem FIG. 11B is a schematic view of a laminated construction bers 16. Each end plate 24 is fixed to the shaft 12 by shrink of the integral laminated rotor core shown in FIG. 11A; fitting or bonding.

FIG. 12A is a perspective view of an integral laminated members As shown in FIGS. 2A and 2B, the laminated core rotor core of a rotor according to an embodiment 5 of the formed 16 forming six magnetic poles of the rotor 10 are present invention; by Stacking a plurality of core-laminations 26 made FIG. 12B is a schematic view of a laminated construction of magnetic materials. Such as Silicon Steel plates and joining of the integral laminated rotor core shown in FIG. 12A; 45 3B, them to each other. As more clearly shown in FIGS. 3A and the core-lamination 26 has a generally Sector shape in a

FIG. 13 is a plan view of an integral core-lamination of a plan view, which includes an arcuate inner edge 28 adapted rotor according to an embodiment 6 of the present invention; to surround the shaft 12, an outer edge 30 with a predeter FIG. 14 is a Sectional view of a rotor according to an mined curved-out shape adapted to be opposed to a Stator embodiment 7 of the present invention; (not shown), and both sides 32 adapted to be brought into FIG. 15A and 15B are plan views of integral core 50 contact with the permanent magnet 14. The core-lamination laminations of a rotor shown in FIG. 14; 26 is provided at both sides 32 thereof with outer hook FIG. 16A is a perspective view of two integral laminated elements 18' extended from the outer edge 30, and at the rotor cores of the rotor shown in FIG. 14, center thereof with a rod hole element 20'. When the FIG. 16B is a perspective view of a part taken along line core-laminations 26 are Stacked in an exactly Superimposed XVI-XVI of FIG. 16A; 55 manner, the outer hook elements 18' and the rod hole FIG. 17 is a plan view of a modification of a core elements 20' are axially joined and form the outer hook 18 and the rod hole 20. The core-lamination 26 is provided on lamination of the integral laminated rotor core shown in respective axial end faces thereof with a receSS 34 and a FIG. 16; projection 36 formed at a corresponding position, the pro FIG. 18 is a sectional view of a rotor according to an 60 jection being able to be fitted into the receSS. The core embodiment 8 of the preset invention; laminations 26 are Stacked in Such a manner that the receSS FIGS. 19A and 19B are plan views of integral core 34 and the projection 36 of the adjacent core-laminations 26 laminations of a rotor shown in FIG. 18; are aligned with each other, and after that the core FIG. 20 is a sectional view of a rotor according to an laminations 26 are joined together by a press-fitting process embodiment 9 of the present invention; 65 using, e.g., a press machine (not shown). FIG. 21 is a flow chart showing a manufacturing proceSS As shown in FIGS. 2A and 2B, a plurality of integral of the integral laminated rotor core shown in FIG. 11A; core-laminations 38 are inserted or arranged at predeter

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S 6 mined positions in a laminated construction formed by the whereby the productivity is remarkably improved in the core-laminations 26 of each laminated core member 16. AS Subsequent Step of fitting to the shaft 12. shown in FIG. 4, the integral core-lamination 38 includes six core-lamination Sections 40 each having the Same shape as Embodiment 2 the core-lamination 26. Each core-lamination Section 40 is 5

Stacked and joined together with the large number of core FIGS. 5A and 5B show a rotor 50 according to an laminations 26 in the above-mentioned manner to form the embodiment 2 of the present invention. The rotor 50 laminated core member 16. The core-lamination section 40 includes an integral laminated rotor core 52 which has a includes connecting portions 46 extended in the circumfer structure similar to the integral laminated rotor core 48 of the ential direction from both sides 42 at an inner edge 44 of the embodiment 1. As shown in FIG. 6, the integral laminated core-lamination Section. The core-lamination Sections 40 are rotor core 52 includes a plurality of laminated core members 56 which are formed by Stacking and joining the large mutually connected through the connecting portions 46 in number of core-laminations 54. These laminated core mem Such a relative arrangement that a Space for locating the permanent magnet 14 is defined between the adjacent core berS 56 are connected together by integral core-laminations lamination Sections 40. In this manner, the integral core 15 58 which are inserted into the predetermined positions in the lamination 38, of which all core-lamination sections 40 are laminated Structure of the core-laminations 54 and joined annularly connected, is formed. together with the latter. As shown in FIG. 7, the core In the illustrated embodiment, four integral core lamination 54 has Substantially the same shape as the core-lamination 26 of the embodiment 1, except that inner laminations 38 are arranged at two positions dividing the hooks 64' are extended laminated length of the core-laminations 26 of each lami both sides 60 at an innerinedge a circumferential direction from nated core member 16 into three generally equal parts, two inner hooks 64 of the laminated62. The inner hooks 64 form integral core-laminations being arranged at each of the two a plurality of core-laminationscore member 56 by stacking positions. When the large number of core-laminations 26 cooperate with outer hookS 66 So as toThe 54. inner hooks 64 position and fixedly and the four integral core-laminations 38, which are Support the permanent magnet 14.

arranged in this manner, are joined together by a preSS-fitting 25 process, the laminated core members 16 are mutually con As shown in FIG. 6, two integral core-laminations 58 are nected in Such a relative arrangement of a finished assembly arranged at two positions dividing the laminated length of that a Space for locating the permanent magnet 14 is defined each laminated core member 56 into three generally equal between the adjacent laminated core members 16 as shown parts, in the same manner as the embodiment 1. Of course, in FIG. 1B, whereby an integral laminated rotor core 48 is other numbers or arrangements of the integral core formed (see FIG. 2A). It should be noted that a different laminations 58 may be adopted. As shown in FIG. 8, the number of the integral core-laminations 38 may be provided integral core-lamination 58 includes a plurality of core lamination Sections 68 each having the same shape as the other than the above-mentioned number, but preferably a core-lamination

Small number are provided as long as the mechanical 54. Each core-lamination section 68 is Strength of the connecting Structure between the laminated 35 Stacked and joined together with the large number of core core members can be maintained, from the Viewpoint of the laminations 54 So as to form the laminated core member 56. reduction of magnetic leakage. Also, the integral core The core-lamination Section 68 includes connecting portions laminations 38 may have various arrangements in the lami 74 extended in the circumferential direction from both sides nated Structure other than the above-mentioned 70 at an outer edge 72 of the core-lamination section. The arrangement, but preferably have a regular and Symmetrical 40 core-lamination Sections 68 are mutually connected through arrangement in order to obtain an entirely balanced Strength. the connecting portions 74 in Such a relative arrangement The connecting portions 46 of the integral core that a Space for locating the permanent magnet 14 is defined lamination 38 are formed relatively thin as long as the between the adjacent core-lamination Sections 68. mechanical Strength can be maintained, in order to prevent In the rotor 50 including the integral core-laminations 58, magnetic leakage as much as possible. AS shown in FIG. 1B, 45 the connecting portions 74 for forming the integral lami in the integral laminated rotor core 48, the connecting nated rotor core 52 are provided on the Outer peripheral edge portions 46 of the integral core-lamination 38 are abutted region adapted to be opposed to a Stator, therefore the onto the inner Surfaces of the permanent magnets 14, which magnetic leakage performance and the influence for mag are opposed to the shaft 12, and cooperate with the outer netic flux distribution in an air-gap between the Stator and hooks 18 of the laminated core members 16 so as to position 50 rotor are inferior to Some extent to the embodiment 1. and fixedly Support the permanent magnets 14. However, the connecting portions 74 reinforce the Support Consequently, the laminated core members 16 do not require of the permanent magnets against an external force Such as inner hooks as used in a conventional Structure, and the a centrifugal force, and thereby improve the mechanical magnetic leakage caused by the inner hooks can be elimi Strength of the rotor Structure.

nated. Thus, it has been observed that the magnetic leakage 55 Embodiment 3 in the integral laminated rotor core 48 is, as a whole, about the same as that in the conventional Structure. The rotor according to the present invention may use an The integral laminated rotor core 48 having the above integral core-lamination 76 as shown in FIG. 9, in order to mentioned Structure makes it possible to integrally handle form an integral laminated rotor core. The integral core the laminated core members 16 with the same number (six 60 lamination 76 includes a plurality of core-lamination Sec in this embodiment) as the number of magnetic poles in a tions 78 which have substantially the same shape as the State in which they are previously positioned relative to each core-lamination 26 of the embodiment 1. Each core other. Accordingly, in the assembling process of the rotor 10, lamination Section 78 includes outer peripheral connecting the permanent magnets 14 can be held between the lami portions 84 extended in the circumferential direction from nated core members 16 merely by inserting and fitting the 65 both sides 80 at an outer edge 82 and inner peripheral permanent magnets 14 into the Spaces for locating perma connecting portions 88 extended in the circumferential nent magnets defined in the integral laminated rotor core 48, direction from both sides 80 at an inner edge 86. The

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core-lamination Sections 78 are mutually connected through lamination Section, and is Supported by an annular connect the outer and inner peripheral connecting portions 84 and 88 ing portion 108 adapted to surround the shaft 12 through the in Such a relative arrangement that a Space 90 for locating a first connecting portion 106. In this manner, the core permanent magnet is defined between the adjacent core lamination Sections 102 are mutually connected in Such a lamination sections 78. relative arrangement that a Space for locating a permanent Each core-lamination section 78 of the integral core magnet 14 is defined between the adjacent core-lamination Sections 102.

lamination 76 is stacked and joined with the core laminations 26 of the embodiment 1. An integral laminated In the case of using the integral core-laminations 100 of rotor core 94 as shown in FIG. 10 is formed in this manner, the embodiment 6 in place of the integral core-laminations which includes a plurality of laminated core members 92 58 in the integral laminated rotor core 52 of the embodiment connected to each other. In the case of using the integral 2, the magnetic leakage through the first connecting portions core-lamination 76, the magnetic leakage performance and 106 and the annular connecting portion 108 is extremely the influence on magnetic flux distribution in an air-gap are reduced, because the first connecting portions 106 are dis inferior to Some extent to the embodiment 1, because the posed at the region having low magnetic flux density from Structure has the Outer peripheral connecting portions 84. 15 the Viewpoint of magnetic flux flow (shown as arrows in However, the mechanical Strength of the integral laminated FIG. 13) when the permanent magnets 14 are assembled in rotor core 94 is more stable than that of both the above the integral laminated rotor core 52. The effect of this embodiments. Also, the productivity for assembling the embodiment on preventing magnetic leakage is extremely rotor is better than both of the above embodiments. Superior in comparison with the effect of the embodiment 1. It is noted that a plurality of first connecting portions 106

Embodiment 4 may be extended in parallel from the general center region

An integral laminated rotor core 96 as shown in FIG. 11A ofSuch the inner edge 104 of the core-lamination section 102 to an extent that the magnetic leakage is not increased. In is formed by replacing two of four integral core-laminations this case, the stiffness of the laminated core member 56 38 of the inner periphery connecting type (FIG. 4), in the 25 (FIG. 6) against revolution about the first connecting portion integral laminated rotor core 48 of the embodiment 1, with 106 is increased.

the integral core-laminations 76 of the inner and outer peripheries connecting type (FIG. 9). From the viewpoint of Embodiment 7 rotor balance, it is preferred that one integral core In the above-mentioned embodiments, there is a problem lamination 38 is directly Superimposed on one integral as to how the magnetic leakage can be inhibited, which is core-lamination 76 as shown in FIG. 11B and they are caused by the connecting portions of the integral core arranged at two positions that divide the laminated length of lamination used for forming the integral laminated rotor rotor into three generally equal parts. The integral laminated core. In this respect, by integrating only the laminated core rotor core 96 has a mechanical strength greater than that of members of the same pole instead of integrating all lami the integral laminated rotor core 48 of the embodiment 1 and 35 nated core members of the rotor, the magnetic leakage can a magnetic performance Superior to that of the integral be substantially eliminated.

laminated rotor core 94 of the embodiment 3. A rotor 110 as shown in FIG. 14 includes a plurality of Embodiment 5 laminated core members 112, 114, both being formed by

Stacking the large number of core-laminations 54, in the

An integral laminated rotor core 98 as shown in FIG. 12A 40 Same manner as the embodiment 2. The laminated core is formed by adding two integral core-laminations 58 of the members 112 and 114 are alternately magnetized by the outer periphery connecting type (FIG. 8) to the integral permanent magnets 14. In the illustrated embodiment, three laminated rotor core 48 of the embodiment 1, which includes laminated core members 112 establishing N-poles are mutu four integral core-laminations 38 of the inner periphery ally connected through first integral core-laminations 116 connecting type (FIG. 4). In the illustrated embodiment, 45 which are inserted and joined to the predetermined positions from the Viewpoint of rotor balance, two mutually Superim in a laminated Structure, and three laminated core members posed integral core-laminations 58 are arranged at a gener 114 establishing S-poles are mutually connected through ally center position between the positions of the two integral Second integral core-laminations 118 which are inserted and core-laminations 38 as shown in FIG. 2B (see FIG. 12B). joined to the predetermined positions in a laminated Struc The integral laminated rotor core 98 has a mechanical 50 ture.

Strength and a magnetic performance generally equal to As shown in FIGS. 15A and 15B, the first integral those of the integral laminated rotor core 96 of the embodi core-lamination 116 has the same Structure as the Second ment 4. integral core-lamination 118, and both include three core Embodiment 6 lamination Sections 120 each having the same shape as the 55 core-lamination 54. Each core-lamination section 120

FIG. 13 shows an integral core-lamination 100 with a includes a first connecting portion 124 extended in a radially different shape, used to form an integral laminated rotor core inward direction from a generally center of an inner edge according to the present invention. The integral core 122 of the core-lamination Section, and is Supported by an lamination 100 includes a plurality of core-lamination sec annular connecting portion 126 adapted to Surround the shaft tions 102, each of which has the same shape as the core 60 12 (FIG. 14) through the first connecting portion 124. In this lamination 54 of the embodiment 2 (FIG. 7). Each core manner, the core-lamination Sections 120 are mutually con lamination section 102 is inserted into the predetermined nected in Such a relative arrangement that a Space for position in the laminated Structure of the large number of locating two permanent magnets 14 (FIG. 14) and one core-laminations 54 and joined together with the latter. Each another pole's core-lamination section 120 is defined core-lamination Section 102 includes a first connecting por 65 between the adjacent core-lamination Sections 120. tion 106 extended in a radially inward direction from As shown in FIGS. 16A and 16B, four first integral generally the center of an inner edge 104 of the core core-laminations 116 are mutually Superimposed and

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arranged at a position Spaced a distance of generally one connecting portions 142 and an annular connecting portion third of a laminated length from one axial end face of the 144 both having higher strength. The inner diameter of the laminated core member 112 establishing a N-pole, and the annular connecting portion 144 is generally equal to the core-lamination Sections 120 thereof are joined together outer diameter of the shaft 136. Therefore, the annular with the large number of core-laminations 54 by a press connecting portion 144 is closely fit to the shaft 136, fitting process. Also, four Second integral core-laminations whereby the mechanical strength of the rotor 134, particu 118 are mutually Superimposed and arranged at a position larly the Strength against radial load applied to the Shaft 136, Spaced a distance of generally one-third of a laminated can be further improved.

length from one axial end face of the laminated core member 114 establishing a S-pole, and the core-lamination Sections Embodiment 9 120 thereof are joined together with the large number of In the rotor of the embodiments 1 to 8, it is possible to core-laminations 54 by a press-fitting process. In this form manner, an integral laminated rotor core 128 for N-poles and Side bya high-power multi-Section rotor by disposing axially an integral laminated rotor core 130 for S-poles are formed. the same structure. Forofexample,

Side a plurality integral laminated rotor cores with

Then, the integral laminated rotor core 128 for N-poles and integral laminated rotor cores 48 asin shown

the in FIG. 20, two embodiment 1 are the integral laminated rotor core 130 for S-poles are disposed axially side by Side through a circular plate mem assembled together in Such a manner that the respective ber 146, and are fixedly installed to the shaft 12 through the three laminated core members 112 and 114 are positioned rod members 22 and the end plates 24, whereby a high alternately in a circumferential direction, and that the annu lar connecting portions 126 of the respective integral core power rotor 148 can be formed. In this case, the permanent magnets 14 of the embodiment 1 may be used as they are, laminations 116 and 118 do not interfere with each other.

or longer permanent magnets having overall lengths corre

After that, the permanent magnets 14 are inserted between sponding to the total length of two integral laminated rotor the respective adjacent laminated core members 112, 114. In cores 48 may be used.

this state, the integral laminated rotor cores 128 and 130 are fixedly installed onto the shaft 12 through the rod members 25 Manufacturing Process 22 and the end plates 24 in the same manner as the embodiments 1 to 6, whereby the rotor 110 shown in FIG. The integral laminated rotor cores of the rotors according 14 is formed. to the embodiments 1 to 9 can be conveniently manufactured In the rotor 110, the laminated core members 112, 114 of by one progressive die machine which can carry out various the same magnetic poles are respectively integrated, processes while choosing desired press-Stations, from the therefore, in comparison with the Structures of the embodi Viewpoint of maintaining productivity. A manufacturing ments 1 to 6, in which all laminated core members are process for an integral laminated rotor core 96 according to integrated, the assembling productivity is inferior to some the embodiment 4 is schematically described, by way of extent but the magnetic leakage is Substantially eliminated. example, with reference to FIGS. 21 and 22. In this case, an Of course, it has a Superior workability in comparison with 35 integral core-lamination 76 of inner and outer peripheries the conventional Structure in which all laminated core mem connecting type (FIG. 9) is formed as a basic shape by bers are separated. The integral core-laminations 116, 118 Stamping a flat rolled magnetic Steel sheet, at a first Station may have various arrangements and different numbers of the S1. The integral core-lamination 76 is conveyed Succes laminated core members 112, 114, other than those men Sively to following Stations by a conveying device of the tioned above. However, it is necessary to eliminate a mutual 40 progressive die machine. At a neXt Station S2, whether to cut contact between the annular connecting portions 126 of the outer peripheral connecting portions 84 or not is decided. If integral core-laminations 116, 118 when the integral lami the integral core-lamination was not cut at the outer portions nated rotor core 128 for N-poles is assembled with the 84, it is conveyed to the last station S4 so as to be used as integral laminated rotor core 130 for S-poles. Further, a well the integral. core-lamination 76. Further at a next station S3, balanced arrangement as a whole is required. 45 whether to cut inner peripheral connecting portions 88 or not The connecting construction between the core-lamination is decided. If the integral core-lamination was not cut at the sections 120 of the integral core lamination 116, 118 is not inner portions 88, it is conveyed to the last station S4 so as to be used as an integral core-lamination 38 of inner periph restricted as the first and annular connecting portions 124 ery connecting type (FIG. 4), and if the integral core and 126 as mentioned above, but may use connecting 50 lamination was cut at the inner portions 88, it is conveyed to portions 132 each having a shape easily made by a Stamping the last Station process, as shown in FIG. 17. In the case of using this shape, while keeping S4 So as to be used as Six core-laminations 26 the connecting portions 132 must be formed So as to S4, the integralthe core-laminations relative arrangement. At the last Station 76, the integral core eliminate any contact with the adjacent core-laminations 54 laminations 38 and the core-laminations 26 are collected of another pole. 55 into the above-mentioned Stacking arrangement, and are Embodiment 8 joined with each other by preSS-fitting, So as to form the A rotor 134 shown in FIG. 18 includes a shaft 136 made integral laminated rotor core 96.

of a non-magnetic material Such as a StainleSS Steel. Further, FIG. 23 shows a manufacturing process for an integral a first integral core-lamination 138 shown in FIG. 19A is laminated rotor core 128 for N-poles and an integral lami used to connect the laminated core members 112 for N-poles 60 nated rotor core 130 for S-poles according to the embodi with each other, and a Second integral core-lamination 140 ment 7, which uses the above progressive die machine. First, shown in FIG. 19B is used to connect the laminated core an integral core-lamination (identical to the integral core members 114 for S-poles with each other. Each of the lamination 100 in the embodiment 6), of which all core integral core-laminations 138,140 has a structure similar to lamination Sections 120 are connected by an annular con that of each integral core-lamination 116,118 in the embodi 65 necting portion 126, is formed as a basic shape by Stamping ment 7, but, regarding the connecting construction between a flat rolled magnetic Steel sheet, at a first Station S1. At a the core-lamination Sections, includes a plurality of first next station S2, whether to cut every other one of first

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connecting portions 124 of the core-lamination Sections 120 at least one integral core-lamination made of a magnetic or not is decided. If the integral core-lamination was not cut, material being the same as that of each of Said core it is conveyed to a next station S3. Further at the next station laminations, and including a desired number of core S3, whether to cut first connecting portions 124 of the lamination Sections locally inserted and fixed between remaining three core-lamination Sections 120 or not is Said core-laminations forming each of Said laminated decided. If the integral core-lamination was cut at the core members located at desired positions around Said stations S2 and S3, it is conveyed to the last station S4, after shaft, and located at a position between Said end plates removing the annular connecting portion 126, So as to be axially dividing the laminated length of the core used as Six Separated core-laminations 54 while keeping the laminations into generally equal parts allowing mag relative arrangement. If the integral core-lamination was cut netic and mechanical balance to be maintained, and at the station S2 and was not cut at the station S3, it is also including connecting portions extended from Said desired number of core-lamination Sections So as to conveyed to the last Station S4 So as to be used as a first annularly connect all of Said core-lamination Sections, integral core-lamination 116 and three Separated core wherein Said connecting portions of Said at least one laminations 54 while keeping the relative arrangement. If integral core-lamination are extended in a circumfer the integral core-lamination was not cut at the Station S2 and 15 ential direction from both sides of respective ones of was cut at the station S3, it is conveyed to the last station S4 Said core-lamination Sections on Outer edges remote So as to be used as a Second integral core-lamination 118 and from said shaft whereby said laminated core members three separated core-laminations 54 while keeping the rela located at desired positions are fixedly connected with tive arrangement. At the last Station S4, the first integral each other in a relative arrangement of a finished rotor core-laminations 116, the Second integral core-laminations assembly, and 118 and the core-laminations 54 are collected into the wherein Said at least one integral core-lamination is above-mentioned Stacking arrangement, and are joined with formed with a central opening of diameter greater than each other by press-fitting, So as to respectively form the that of Said shaft, Such that a gap is defined between integral laminated rotor core 128 for N-poles and the inte Said at least one integral core-lamination and Said Shaft gral laminated rotor core 130 for S-poles in a relative 25 So Said at least one core-lamination and Said core arrangement of a finished assembly. members are Supported against external force only by AS is clear from the above description, the present inven Said end plates and Said rod members.

tion provides an integral laminated rotor core in which 2. A rotor as Set forth in claim 1, wherein Said at least one laminated core members forming magnetic poles are con integral core-lamination connects all of Said laminated core nected with each other, by inserting at least one integral members.

core-lamination into the laminated Structure of the laminated 3. A rotor as Set forth in claim 1, wherein Said at least one core members. Therefore, the work of positioning or fixing integral core-lamination includes Said core-lamination Sec permanent magnets and laminated core members in an tions having shapes being generally the Same as those of Said assembling process of a rotor is facilitated, and productivity core-laminations of Said laminated core members and a is significantly improved. Further, the mechanical Strength 35 number thereof being the same as a number of magnetic of a rotor is improved by the integral laminated rotor core. poles So as to be joined to adjacent ones of Said core Consequently, the performance and reliability of high Speed laminations, whereby all of Said core-lamination Sections are or high torque motors can be improved by using the rotor connected in Such a relative arrangement of a finished rotor according to the present invention. assembly that a Space for locating each permanent magnet is The present invention has been described in relation to the 40 defined between adjacent core-lamination Sections, So as to various embodiments shown in the attached drawings, but is form an integral laminated rotor core.

not restricted by the above descriptions, and various changes 4. A rotor as Set forth in claim 1, wherein Said at least one and modifications can be carried out without departing from integral core-lamination and Said core-laminations are the Spirit and Scope of the invention recited in the appended 45 respectively formed by Stamping Same materials into pre claims. determined shapes by one progressive die machine which We claim: can carry out various processes while choosing desired 1. A rotor for a Synchronous motor comprising: preSS-Stations, and Said laminated core members are formed a shaft; by press-fitting and joining Said integral core-lamination and a plurality of permanent magnets disposed around Said 50 with Said core-laminations, both of which have been Stamped, shaft at generally equal intervals, each other in a last preSS-Station of Said progressive die machine, whereby Said laminated core members located at a plurality of laminated core members each formed by desired positions are connected with each other in a relative axially Stacking and joining a plurality of core arrangement of a finished rotor assembly.

laminations made of magnetic materials, Said laminated 5. A rotor as Set forth in claim 1, wherein Said at least one core members being disposed around Said Shaft while 55 integral core-lamination comprises a plurality of groups of holding each of Said permanent magnets therebetween integral core-laminations, Said groups being Substantially in a circumferential direction, So as to form magnetic equally spaced between Said end plates So as to divide Said poles; laminated length of the core laminations into Several Sub Supporting means for fixedly Supporting Said permanent Stantially equal parts.

magnets and Said laminated core members onto Said 60 6. A rotor as Set forth in claim 5, wherein each group of shaft, Said Supporting means including a pair of end integral core-laminations consists of at least two plates disposed at both axial ends of Said laminated laminations, and two Such groups divide Said laminated core members and fixed to Said Shaft and a plurality of length of the core laminations into three parts. rod members penetrating through Said laminated core members and joined at both ends to Said end plates, and k k k k k