Abstract: A lanced strip of generally thin ferromagnetic material adapted to be edgewise wound into a core for a salient pole dynamoelectric machine. A continuous yoke section of the lanced strip extends generally lengthwise thereof and includes a pair of generally opposite edges, and a set of spaced apart notches in one of the opposite edges with each notch having an arcuate edge therein, respectively. A set of spaced apart teeth are integral with the other of the opposite edges and extend generally laterally from the yoke section, and the teeth includes a set of free end sections each having another arcuate edge defining at least a part thereof and with respective ones of the first named and another arcuate edges having a common centerpoint, respectively.A core for a salient pole dynamoelectric machine is also disclosed.

Abstract: An amortisseur bar interconnection arrangement for a synchronous dynamoelectric machine rotor in which amortisseur bars embedded in the various rotor poles are interconnected by a pair of segmented conductive strips disposed about the circumference of the rotor hub. The amortisseur bars for each pole are supported by a pair of conductive rotor pole end laminations. When the rotor poles are attached to the rotor hub, the end laminations each physically engage a segmented conductive strip disposed in an annular recess formed on the circumference of the rotor hub, thereby completing the electrical connection between the various amortisseur bars. The segmented conductive strips are backed by a compressible resilient pad which maintains sufficient engagement force between the end laminations and the conductive strip to ensure a solid electrical connection therebetween.

Abstract: A motor comprises magnetic poles constituted by a permanent magnet magnetized in its radial direction and a core having salient poles placed inside or outside the magnetic poles wherein the magnetic flux distribution of the permanent magnet is controlled so that the cogging torque characteristic of the motor is rendered to be a specified condition.

Abstract: A salient-pole rotary electric machine comprises a stator including a stator core formed with a plurality of ventilation ducts spaced apart by a predetermined distance in its axial direction and extending in its radial direction, and a stator winding would around the stator core, and a rotor including a rotor shaft, a rotor rim rotatable together with the rotor shaft, a plurality of salient field poles disposed on the outer periphery of the rotor rim in circumferentially spaced apart relation and extending in the axial direction of the rotor rim, and cooling gas passages defined between every adjacent salient field poles. In the rotary electric machine, a closure member is bured in each of the cooling gas passages between the salient field poles to extend from one of the axial ends to the center of the cooling gas passage, and the closure members are disposed between the adjacent salient field poles in a relation alternate with each other in the axial direction of the salient field poles.

Abstract: An armature for a DC motor includes a plurality of circumferentially spaced armature segments having salient poles with arcuate surfaces and air pockets formed within the poles adjacent to but not intersecting the surfaces, sized and located to reduce cogging due to variations in reluctance. The armature segments are preferably bridged by flux links carrying prewound electrical coils arranged in a circular path. Corresponding lamina in each armature segment are formed of a unitary stamping in which the segments are interconnected by removable flexible joints.

Abstract: A frequency generator comprises a cylindrical rotor to which an annular multipolar magnet is fixed on the inner wall thereof. The multipolar magnet includes a plurality of magnetizable sectors arranged in a circumferential direction thereof, and adjacent magnetizable sectors are magnetized alternately in reverse polarity. Within the rotor, two disk-shaped magnetic plates are supported fixedly with a predetermined space axially. On the peripheries of respective magnetic plates, a plurality of salient poles are formed with a predetermined pitch in a circumferential direction thereof. The salient poles of each magnetic plate respectively constitute a salient-pole line. Between the two salient-pole lines, a generating coil is wound in a circumferential direction thereof. To each first and second salient poles to be paired, the magnetizable sectors of different polarity of the multipolar magnet are faced in divergence relatively in the circumferential direction.

Abstract: A three-phase motor is disclosed which has six salient teeth for a two-pole motor or twelve salient teeth for a four-pole motor. The motor stator has at least three main field windings on the salient teeth to form either two or four poles, with the teeth being equal in number to at least three times the number of the poles. Each main field winding includes on one tooth a first coil connected in series with the second coil on another tooth, so that at a given instant, pole faces of opposite polarity are established on these two teeth. The coils of the at least three main field windings are wound and connected so that each coil is a one-third pitch of three adjacent teeth, with pole faces of the same polarity at a given instant. The end result is that these three main field windings establish a uniform rotating field to provide driving force to a rotor.

Abstract: A rotor for a synchronous motor, having a plurality of first magnetic poles formed by a plurality of permanent magnets respectively and disposed at practically equal circumferential intervals on the outer circumference of a yoke fixed to a rotatable motor shaft, and a second magnetic pole projecting radially from the yoke adjacently to each first magnetic pole and the second magnetic pole wherein the shape of the pole face of each first magnetic poles are in a circular arc and the shape of the pole face of each of second magnetic pole is determined by a given equation so that the magnetic flux distribution established by a pair of the first magnetic pole and the second magnetic pole is substantially equivalent to a sinusoidal magnetic flux distribution in the sweeping effect by the armature coils of each phase of the stator.

Abstract: A rotor for a salient-pole machine comprises a rotor rim rotatable with a rotary shaft and magnetic poles fixedly connected at prescribed intervals to the rotor rim on its outer periphery. Axially extending ventilation grooves are formed on the rotor rim between respective adjacent poles. The pole is connected to the rotor rim by means of a dovetail joint consisted of a dovetail groove on the rotor rim and a dovetail tenon on the bottom of the pole. The ventilation groove has a sectional profile in the perpendicular to the rotary shaft which is defined by connecting necessary lengths required in the material strength of groups of lines respectively originating from the corners of the dovetail groove.

Abstract: A rotor has permanent magnets mounted on a core having a pair of opposing air gaps formed therein. Preferably, the permanent magnets are a material sold under the mark "NEOMAX", with an extremely high flux density, as compared to previously available permenant magnets. The contour of the air gap follows the contour of the naturally occurring flux lines which result from the mounting of the permanent magnets. The resulting rotor has a more efficient magnetic structure, with better overall characteristics than were available heretofore. The rotor may be used with any driven shaft system such as: motors, generators, dynamometers, and combinations thereof.

Abstract: An inside-out salient pole core for a dynamo-electric machine. The core has an edgewise wound yoke including an edgewise and helically wound strip of generally thin ferromagnetic material having at least one edge defining an outer circumferential surface on the edgewise wound yoke and extending generally axially thereacross. A set of salient pole pieces is secured to the edgewise wound core at least generally adjacent its outer circumferential surface, and extends generally outwardly from the outer circumferential surface about a set of preselected pitch axes, respectively.

Abstract: In a two-phase salient pole variable reluctance motor in which the number of stator poles is four or a multiple of four, alternate stator poles carry windings of different phases and each stator pole has an elongated pole shoe, so that the pole tips of each adjacent pair of stator poles are closely spaced. Each rotor pole has an iron depletion layer in the vicinity of its poleface surface which defines a saturating zone, across which the greater part of the magnetomotive force produced by stator windings is developed by uniform flux build-up with rotor angle throughout almost the entire duration of pole overlap. A working stroke approximating a stator pole pitch is achieved.

Abstract: A permanent magnet electric machine such as, for example, a motor or generator, including a permanent magnet field member, an armature having salient magnetic poles and armature windings. A greatest common division of the number of magnetic poles of the field member and the salient magnetic poles having the armature windings differs from the number of magnetic poles. A group of grooves is formed between the salient magnetic poles having an interval of 2/3M.pi., with M being an integer which is not a multiple of three. To reduce the occurrence of cogging torque, auxiliary grooves are provided on the surface of the salient poles at positions which are spaced apart from positions of the grooves by (.pi./3)K+(.pi./6), in terms of electrical angle, with K being an integer.

Abstract: A rotor for a synchronous motor, having a plurality of first magnetic poles (19) formed by a plurality of permanent magnets respectively and disposed at practically equal circumferential intervals on the outer circumference of a yoke (18) fixed to a rotatable motor shaft (14), and a second magnetic pole (18a) projecting radially from the yoke (18) adjacently to each first magnetic pole (19) so as to form a pair of a first magnetic pole (19) and the second magnetic pole (18a), wherein the shape of the pole face of each second magnetic pole (18a) is decided so that the magnetic flux distribution established by a pair of the first magnetic pole (19) and the second magnetic pole (18a) is practically equivalent to a sinusoidal magnetic flux distribution in the sweeping effect by the armature coils of each phase of the stator (11).

Abstract: An electrical motor has one or more capacitors inside the motor. Particularly, a half-pitch capacitor induction motor is shown, wherein the stator winding has a plurality of coils, one each on a tooth of the stator, and an auxiliary or capacitor winding includes a plurality of coils, one each on different ones of the teeth of the stator. The stator coils are spaced around the periphery of the stator such that spaces are provided between the coils, and one or more capacitors are provided in such spaces. These capacitors are mounted on an insulator board which provides physical mounting of the capacitors and also provides electrical connection to the capacitors to connect them all in parallel. The capacitors are then connected to the auxiliary winding. By this means, a small-sized motor without an elongated end bell permits mounting the capacitors inside the motor frame instead of outside in the usual cylindrical metal container.

Abstract: An armature for a DC motor comprises a laminated core defining poles extending generally axially, each pole comprising a body portion with a winding thereabout and a plurality of axially disposed tooth portions, each tooth portion exhibiting a primary skew of its laminations in one direction while the tooth portions of each pole exhibit a smaller secondary skew in the opposite direction. The primary skew is produced by arms extending circumferentially from radial body portions in consecutive laminations which become progressively longer on one side and shorter on the other side of the body portions. Magnetic force fluctuations between the armature and field magnets of the case are modified so as to produce less audible noise with armature rotation.

Abstract: A magnetic coil assembly for a dynamoelectric machine comprises a magnetic field coil, a magnetic field pole core adapted to be mounted on a rotor of the dynamoelectric machine and an electrical insulation placed around the magnetic field coil. The electrical insulation is disposed only in the region between the pole core and the straight coil side portions of the magnetic coil less the coil end portion or the end turns of the coil. The magnetic pole is bevelled at the corners thereof to provide a sufficient insulting distance between the coil and the pole.

Abstract: A single-phase brushless motor which can be manufactured at low cost and which can be started at any rotary position. The motor includes a rotary magnet having a plurality of magnetic poles and a stator armature having a plurality of poles, each of which is wound with a coil carrying a driving current. Each of the poles is divided circumferentially into at least two sectors, the cross sections of which at points where the magnetic flux density is a maximum being different from one another. A single position detector detects the rotary position of the rotary magnet relative to the stator armature, and the driving currents in each of the coils are controlled in accordance with the output of the position detector. In preferred embodiments, the poles have links which join them to a generally cylindrical central core. Holes are formed in at least some of the sectors of each of the poles, having different diameters.

Abstract: An electrical machine is disclosed, capable of functioning as either a motor or generator, which has a salient pole rotor (23) and a stator having multiple phase windings (21) each comprising a concentrated, full pitch winding with one stator slot per pole per phase. The pole faces (27) of the salient poles of the rotor may be tapered to produce an air gap which increases from the front to the back of the pole face to counter the effect of armature reaction MMF. The taper of the pole faces is selected such that the resultant total flux density in the air gap from field and armature currents is quasi-rectangular. The quasi-rectangular flux densities rotating in the air gap produce quasi-rectangular phase voltages and currents when the machine is operated as a generator, and, when operated as a motor, the machine is adapted to accept quasi-rectangular supply currents or voltages of the type readily produced by variable frequency converter power supplies.

Abstract: A small capacitor motor comprises a rotor, a stator core disposed in concentric relationship with the rotor and stator coils wound on the stator core. The stator core comprises a ring-shaped core part, surrounding the core of the rotor and having an axial thickness substantially equal to the axial thickness of the core of the rotor. A plurality of coil winding core parts each radially extends from the periphery of the ring-shaped core part and has an axial thickness less than the axial thickness of the ring-shaped core part. The stator coils are mounted on these radial extensions.

Abstract: A reluctance motor comprises a stator having two salient poles and a rotor also having two poles and being of soft magnetic material. The stator poles support windings which when current is being supplied generate a magnetic field which tends to set the rotor (16) in a stable position of equilibrium in which the rotor pole and the stator pole coincide. Either or both of the rotor poles and/or either or both of the stator poles are designed so as at high flux density to cause a constriction of the flux in a part of the cross section of the flux path to displace the position of equilibrium and when the flux density is moderate to distribute the flux generally uniformly over the said cross section.

Abstract: Cooling medium flows from the rotor of a rotary electric machine from a rotor side towards an air gap side between the rotor and stator of the machine, wherein provision is made of guide vanes such that the cooling medium flows in a direction opposite to the direction in which the rotor rotates, reducing the angular momentum of the coolant to zero, to increase circulation efficiency.

Abstract: A unique design and construction is presented for the rotor of a dynamoelectric machine. The rotor is comprised of two end plates, bar means for holding the end plates together, a stack of pole laminations, electrical conductors wrapped about the laminations and an insulator means. The end plate contains apertures about its periphery such that the rotor can be balanced about two axis perpendicular the rotor axis of rotation by inserting masses/weights into the apertures. The insulator means electrically insulates the electrical conductors from the ends of the stack laminations, the rotor end plates and the rotor shaft. The insulator means by its unique shape further acts as a guide to position electrical conductors about the laminations during pole winding. In one embodiment the insulator means acts as a thermal insulator protecting electrical conductors when the bar means are welded to the end plates.

Abstract: A larger number of keys (L) are formed in the outer cylindrical surface of a rotor rim than is strictly necessary for fixing pole pieces (P) thereto. The keys are regularly spaced around the rim. This arrangement makes it possible to avoid having adjacent rim segments offset to each other by an angle which is equal to the pole pitch or at best to the half pole pitch as has previously been the case. The overlap between segments may now be at the pitch of the fixing keys. This can be used to increase the overlap factor, thereby increasing the mechanical strength of the rim against centrifugal forces.

Abstract: An interpole for a locomotive traction motor comprising a magnetizable pole piece and a magnetizing coil of wire surrounding the piece wherein the wire is coated with electrically insulative polyphenylene sulfide and the pole and coil are potted in a polyphenylene sulfide foam which constrictively engages the pole and is fused to the wire coating.

Abstract: An electric rotary machinery including a rotor of salient-pole type provided with salient magnetic poles to achieve a fan effect of driving air radially, the fan effect being limited by air flow limiting members attached to the rotor, a stator cooperating with the rotor, an air circulating passage through which air is circulated to cool both the rotor and stator, and electric fans. Cooling air is driven mainly by the electric fans.

Abstract: An electrical connection system is provided for the salient poles of a hydrogenerator rotor. The system provides for identically wound salient poles to be connected in a manner that achieves opposite electromagnetic polarity of adjacent salient poles while eliminating the requirements of crossover connections during final assembly of the poles to the rotor or during field replacement of salient poles.

Abstract: A device for cooling a salient-type rotor by ventilation, in which ventilation ducts are formed in the radial direction in the magnetic cores on both sides thereof relative to the circumferential direction so as to communicate with the ventilation ducts in the rim. The cooling air supplied through the ventilation ducts in the rim is also permitted to flow through the ventilation ducts in the magnetic cores between the adjacent cores so that the ventilation resistance is reduced, the stator coils and the stator cores are efficiently cooled, and the field coils wound around the magnetic cores are efficiently cooled from the outer side and from the inner side thereof.

Abstract: An end portion of a free conductor bar of a pole-face winding for the rotor of a large dynamoelectric machine includes a flat at its radially outermost extremity. The end fits loosely within an oversized hole in an amortisseur ring. The presence of the flat displaces the contact line between the end portion and the hole from a thin bridge region of the amortisseur ring to two lines of contact displaced inward into the body of the material of the amortisseur ring. The reduced contact force and the repositioning of the contact location avoids cracking in the amortisseur rings of large dynamoelectric machines.

Abstract: A method of locking coiled conductors in slots of a dynamoelectric machine rotor by placing deformable locking members over selected axially limited areas of the coiled conductors and driving the ends of the locking members under tips of salient rotor poles to secure the locking members firmly in position against the outer surfaces of the conductors. In one form of the invention preformed sheets of insulating material are positioned around the coiled conductors and under the deformable locking members to insulate the coils from the sides of the rotor poles and from the locking members. An aspect of the invention includes the combination in a dynamoelectric machine rotor of a plurality of deformable locking members positioned to secure coiled conductors in rotor slots and to secure preformed sheets of insulating material between the outer surfaces of the conductors and the locking members when they are arranged in their coil-locking positions.

Abstract: A rotational speed indication signal generator comprises a magnetic circuit and a plurality of generating coils radially arranged with respect to the rotary shaft of a rotor. Each of the generating coils is wound around a radial projection of a circular disk made of a magnetic material so that the axis of the generating coils is normal to the rotary shaft. The generating coils are electrically connected in series in such a manner that a noise voltage induced across one coil caused by external flux has opposite poloraity to that of a noise voltage induced across another coil positioned opposite with respect to the rotary shaft. The electrical connection of the generating coils has a given circular direction while a lead wire connected to the last coil in the series connection has a circular direction opposite to the direction of the series connection.

Abstract: A self-cooled rotating electrical machine is provided with multiple axial and radial coolant passages. Wedges within the interpolar spaces of a salient pole rotor provide an axial coolant path which receives coolant deflected by vanes on the end of the wedges. Coolant expelled at the center of the wedges passes through axial passages in the stator and through a gap between the rotor and stator. Impeller tabs on the ends of the wedges force coolant around stator windings. Recirculation of coolant is prevented by shrouds attached to the ends of the wedges.

Abstract: In a dynamoelectric machine wherein cooling air is sent into spaces between magnetic poles of a salient pole type rotor in parallel with an axis of the rotor, an air chamber is provided in the vicinity of axial ends of the poles of the rotor and adapted to rotate the air therewithin together with the rotor, whereby the cooling air flows from the outside of the rotor through the air chamber into the spaces between the poles.

Abstract: A direct current dynamoelectric machine characterized by having a plurality of salient field poles each comprising a rigid laminated base member, a relatively more flexible laminated face member, and a plurality of permanent magnet sub-assemblies mounted between and adhered, respectively, to the base member and face member. The magnet sub-assemblies each comprise a plurality of rare earth permanent magnet bars arranged in a predetermined configuration and compressed between a pair of flat magnetically permeable metal plates to which the bars are adhered with a partially cured adhesive.

Abstract: A liquid cooling system for a dynamoelectric machine's rotor winding. Concentrically arranged intake and outtake coolant pipes extend a desired axial distance within a centrally arranged bore in the rotor. Both pipes are joined to a distribution block also disposed in the rotor bore. The distribution block transmits coolant from the intake pipe to arcuately-shaped coolant distribution manifolds through radially-directed pipes and transmits coolant from arcuately-shaped coolant collection manifolds to the outtake pipe through radially-directed pipes. The manifolds are fluidly connected to the rotor winding either by rigid non-conducting tubing having bends therein for permitting thermal expansion thereof or flexible insulation tubing such as Teflon.RTM..

Abstract: A Salient pole generator includes a laminated rotor having an integral amortisseur winding and end supports. The rotor laminations have amortisseur winding and clamping openings adjacent the shaft portion of the poles. The end supports are cast to the stack of lamination as an inverted U-shaped member aligned with each pole. Each member has an outer amortisseur winding base portion and a pair of inwardly projecting side arms. The outer base portion includes integral coil support and fan projections and an inner inclined interior wall. The coil is wound about the pole, and the support side arms, and defines a radial air slot between the end pole lamination and the interior of the coil. The air slot has the inlet opening at the shaft and an inclined discharge opening at the outer end of the winding. The fan projections promote the movement of air through the slot and thus, over the backside of the winding and the end faces of the poles.

Abstract: A turbine type synchronous motor capable of starting directly and asynchronously when coupled to a work-performing machine is constructed with a drum rotor of high mass, made of solid magnetic material containing iron, and having no damper winding. The field windings, short-circuited or closed through a resistance during starting, are radially disposed in insulated slots which are closed by insulated wedges wherein the insulation is of highly temperature resistant material.

Abstract: The rotor assembly comprises a shaft, a rim structure, and a spider for connecting the rotor rim to the shaft. The spider structure incorporates a number of rigid arms which are secured to and extend radially from the shaft. The ends of the rigid arms are secured such that free radial motion of the rotor rim is permitted with respect to the spider, but angular motion between the rotor rim and the spider is prevented. The rotor assembly further contains a plurality of flexible cross beams and associated floating arms. The cross beams extend between adjacent spider arms, while the floating arms are firmly connected between the middle section of the cross beams and the inner surface of the rotor rim. The cross beams flex in and out in radial directions as the rotor rim contracts and expands, respectively, due to centrifugal or thermal forces.

Abstract: A laminated pole for an electrical machine with salient poles is disclosed. The laminated pole includes a pole body having a plurality of pole sheets, and a pole end plate having a plurality of individual sheets. The pole sheets are layered and pressed one against another. The individual sheets are welded one to another, and may also be welded to a connecting pin. The connecting pin protrudes from the pole end plate in an axial direction and is used as a bearing or support member for a pole coil of the electrical machine. The individual sheets and the pole sheets are made from the same sheet material, have the same outside contour, and are punched with the same punching tool. Laminated pole end plates according to the present invention are cheaper to manufacture and suffer less pulsation losses and eddy current losses than solid pole end plates.

Abstract: A cooling system for a rotary electric machine having a stator including a stator core and a stator frame for supporting the stator core and a rotor including a yoke, a plurality of salient magnetic poles mounted on the periphery of the yoke and shield plates bridging the tips of the adjacent magnetic poles wherein the cooling system comprises groups of air-discharging and air-charging ducts radially penetrating the stator core, each group of the ducts being axially aligned with a predetermined distance from each other and air-discharging windows formed in the shield plates at predetermined axial positions thereof, and the axial area of each group of the air-discharging ducts is larger than the axial area of the air-discharging window of the corresponding shield plate thereby increasing the flow rate of the cooling air through the rotary machine.

Abstract: A new and improved winding and pole construction is provided for a hydrogenerator field coil, comprising: a pole cap, and a winding having concentric inner and outer helices of conductor. The conductor has a central bore extending its length, whereby coolant is circulated therethrough. Each helix comprises a plurality of turns of concentric layers of conductor, bottom lead-outs and top lead-outs. The inner helix may be connected hydraulically in parallel and electrically in series to the outer helix. In one embodiment of the invention, the top lead-outs of the inner helix are accessed through an access port cut in the top of the pole cap. In this embodiment, a portion of each turn is skewed one conductor thickness so that the lead-outs may be proximate the access port with a minimum of available winding cross-sectional area not used. In an alternate embodiment, the access port is located in the rotor rim with a portion of each turn skewed by one conductor thickness toward the rim.

Abstract: In a synchronous electric machine with salient poles in its rotor, which are supported by a lamination chain, one sided large enlargements of the lamination chain deviating from a circular shape are prevented by straps arranged between the hub body and the lamination chain, the attachment of the straps at the lamination chain, with the machine standing still, being with a play which corresponds approximately to the mean expansion of the lamination chain at the runaway speed. If this play is taken up through expansion of the lamination chain due to one-sided forces, then the straps prevent further expansion. The invention is of advantage especially for slowly rotating hydroelectric generators.

Abstract: In a dynamoelectric machine having armature conductors located in the air-gap separating rotor and stator, the conductors are secured to the stator structure. Conductor fastening means are provided which maintain the armature conductors and their support members in compression in all modes of operation of the machine.

Abstract: A rotor for electric rotating machines has a plurality of salient poles arranged in spaced relation in axial direction on the outer periphery of the rotor rim. Adjacent salient poles have opposed slots in the axial direction, into which a shielding member is fitted to bridge between said adjacent poles. The shielding member includes a plurality of rod members fitted over the entire length of said slots to extend across said opposed slots. While the rotor is running, the centrifugal force acts on each of said rod members thereby pressing the rod members against the outer periphery side wall of the slot. As a result, the centrifugal force is dispersed substantially uniformly over the entire length of the slot wall.

Abstract: A support device for a field winding of a field spider includes first and second support members which bear at least partially against free coil surfaces of adjacent field coils. The first and second support members mutually support one another against the field coils with various devices provided to urge the first and second support members apart. The support members may either be angled or flat with the flat support members crossing one another.

Abstract: A rotor, for a synchronous salient-pole electrical machine, having a rim built up in annular layers consisting of segments provided with recesses forming slots on the rim circumference, in which like poles are mounted and which form a plurality of groups distributed in series over the rim circumference, the distances between the adjacent slots in all the groups being the same and different than equal distances between the adjacent slots of different groups. In some of the segments the adjacent recesses are spaced from each other by a distance equal to the distance between the slots within a group.

Abstract: A salient pole includes a flat coil made up of a multilayer winding of round wire. The wire includes an adhesive layer which is cured after winding to consolidate the winding. The winding is within a U-shaped channel which is impregnated with resin to fill any gaps. The flat coil fits over a pole core and is fixed thereto by means of spacers which axially space the coil from the pole core and radially space the coil from the machine casing.

Abstract: A rotor for electric rotating machines has a plurality of salient poles arranged at certain intervals with each other along the outer periphery of the rotor rim. Each of the shield plates of the rotor has a plurality of reinforcing ribs arranged between adjacent salient poles and extending along the periphery of the rotor. The eddy currents flowing in the shield plates are reduced, thus reducing the eddy current losses.

Abstract: A stepping motor comprising a plurality of stages which may be selectively activated to effect stepping movement of the motor, and which are mounted along a common rotor shaft to achieve considerable reduction in motor size and minimum diameter, whereby sequential activation of the stages results in successive rotor steps with direction being determined by the particular activating sequence followed.

Abstract: A ventilation system is provided for dynamoelectric machines such as hydro generators having salient pole rotors and in which the rotor and stator have separate ventilation systems sealed from the air gap. The stator ventilation system includes radial vent ducts with longitudinal ducts in the stator core extending between adjacent radial vent ducts. The longitudinal ducts are sealed from the air gap and are disposed in the region of the stator windings, preferably extending through the teeth. Ventilating air flows radially inward through the vent ducts, longitudinally through the longitudinal ducts from one vent duct to the next, and radially outward to the external circuit where it is circulated through coolers, by means of a blower or otherwise.