Abstract: A stator unit for an electric motor, in particular an external rotor motor, includes a stator with a stator laminate stack and stator windings and a stator bushing and a stator flange which is formed at one end. A housing flange of a housing for accommodating a motor controller or the like is fastened on the stator flange, and with motor connection contacts, which run from the stator through through-openings in the housing flange, and with fastening means, which run through fastening holes in the housing flange and are fastened in the stator. A sealing disk is arranged between the stator and the housing flange. The sealing disk has sealing regions made from elastic plastic, which are arranged and designed in such a way that direct and/or indirect sealing of the through-openings and/or the fastening holes is provided against the ingress of moisture.

Abstract: A disk drive device comprises a hub on which a magnetic recording disk is to be mounted; a base rotatably supporting the hub through a bearing unit; a sintered core fixed to the base, the sintered core having a ring portion and nine teeth that extend radially from the ring portion; coils wound around nine teeth; and a cylindrical magnet fixed to the hub. The sintered core is formed by heat-treating an iron powder. At least one of (a) the surfaces of particles of the iron powder and (b) the surfaces of the sintered core is insulated.

Abstract: A plastic package motor, including at least a plastic package stator (1) including at least a stator core, a stator winding, and a housing, a rotor (2), a rotating shaft (3), a bearing (4), and at least one end cover. The stator winding is wrapped on the stator core. The housing is disposed outside the stator core and the stator winding, and is made of resin. The rotor (2) is disposed in a cavity (5) of the housing. A bearing housing (9) is disposed at the center of the end cover and operates to receive the bearing (4). The bearing (4) operates to support the rotating shaft (3). A flanging (8) axially protrudes from an outer edge of the end cover. The flanging (8) is received in the cavity (5) and is fit with inner wall of the cavity (5) whereby implementing radial locating, and causing the bearing housing (9) of the end cover to partially enter the cavity (5).

Abstract: A fan motor for circulating cooled air including: a stator assembly having a stator core having teeth ends protruded annularly outwardly and coils wound on the teeth ends of the stator core and molded out of resin to have a donut-like shape having a bearing insertion hole formed to be passed vertically through the center thereof; a bearing assembly adapted to be insertedly fixed into the bearing insertion hole of the stator assembly; and a rotor fan assembly having a rotor having a cup-shaped case, a rotor shaft formed in the center of the case in such a manner as to be passed vertically through the center of the case, and magnetic poles formed along the inner periphery of the case, and a fan having a hub coupled to the top end periphery of the rotor shaft of the rotor and blades disposed around the hub.

Abstract: The rotor assembly contains a number of polar anisotropic ring magnets sequentially stacked, a number of supporting rings within the stacked ring magnets, and an axle threading through the supporting rings. The ring magnets are of a same diameter and length. Each supporting ring contains three co-centric rings: an inner steel ring, a middle rubber ring, and an outer steel ring. The supporting rings are positioned with substantially equal spacing and with a gap away from each aperture of the stacked ring magnets, so that additional weight elements could be positioned and adhered within the gap. The periodic positioning of a number of supporting rings could significantly reduce the weight of the motor assembly with much improved steadiness. Additionally, the middle rubber rings of the supporting rings provide a buffer mechanism for absorbing vibration and noise reduction.

Abstract: An electric motor assembly including a stator assembly and a rotor assembly extending through the stator assembly. A first end cap is located adjacent to a first end of the stator assembly and includes a bearing insert supporting a first end bearing for receiving an end of a rotor shaft. A second end cap is located adjacent to a second end of the stator assembly. An endbell is formed separately from the second end cap and is positioned within the second end cap. The endbell supports a bearing for a second end of the rotor shaft. An overmold material extends through the stator assembly. The overmold material may form the first end cap, supporting the bearing insert therein, and extends within and substantially fills an annular space within the second end cap.

Abstract: A motor is disclosed, the motor including a stator core formed with a cylindrical space at an inner surface and formed at an inner circumferential surface with a plurality of teeth protruding toward a center, a cylindrical rotor rotatably mounted at the space and formed with a plurality of pockets for inserting a permanent magnet, a rotation shaft coupled to the center of the rotor and receiving a rotation force generated by interaction between the stator core and the rotor, a nut member connecting the rotor to the rotation shaft by press-fitting the rotor at a periphery to an axial direction of the rotation shaft and press-fitting the rotation shaft at an inner circumferential surface to the axial direction of the rotation shaft, and a key unit inhibiting a slip between the rotor and the nut member.

Abstract: The invention relates to a DC current machine, in particular a DC current motor for driving a blower of a motor vehicle, with a pole housing forming the stator of the machine, a rotor that is rotatably mounted in two bearing plates, and with a brush support for supplying current to the rotor. According to the invention, a support is integrated into the brush support, with de-tensioning for the electrical connecting cables of the machine, which means that a secure fastening, de-tensioning, and insulation of the connecting cables is achieved without additional components and without additional expense in the assembly of the machine.

Abstract: A stator comprises a ferromagnetic core having teeth. The stator also comprises first and second insulator members. The first and second insulating members collectively encircle each of the teeth of the core. The first insulating member comprising a plurality of mounting bosses spaced circumferentially from each other about the axis. Each of the mounting bosses has first and second retaining surfaces. The first and second retaining surfaces face axially opposite directions from each other and are exposed and are unobstructed by the second insulating member.

Abstract: An electric compressor provided with an integral inverter, incorporated with a motor and provided in a receiving space surrounded by a compressor housing with a motor drive circuit that includes the inverter. At least some of electric parts including the motor drive circuit are covered by a resin charged into the receiving space, and a part of a region which is in the receiving space and into which the resin can be charged is filled with a light-weight material different from the charged resin. In the structure of the resin covering section for such a motor drive circuit, the amount of resin charged is significantly reduced, and the entire compressor is reduced in weight and cost.

Abstract: A ripple spring is provided having one or more layers laminated together, where the one or more layers form a symmetrical stack.

Abstract: The invention provides an electrical connection for an electric motor having a casing which houses a drive device, embodied especially a stator in a casing interior. The drive device is contacted via a conductor, embodied especially in the form of a pin. The conductor is guided from the exterior into the interior of the casing via a casing opening. A cylindrical sealing element is provided on the casing opening in the casing interior to seal the conductor from the casing opening. The sealing element is provided with a continuous collar and a through-opening through which the conductor extends and in which the conductor is sealed in the through-opening via at least one radial sealing lip that is formed in the through-opening on the sealing element and that rests on a surface of the conductor. The conductor is then sealed towards the housing via at least one axial sealing lip that is formed on the collar and that rests on an inside of the casing.

Abstract: A motor having a structure capable of achieving an enhancement in durability and a washing machine, to which the motor is applied. The motor includes a stator including a plurality of stator cores arranged in a circumferential direction, and coils respectively wound around the stator cores, and a rotor rotatably arranged inside or outside the stator. The rotor includes a plurality of rotor cores arranged in a circumferential direction of the rotor, a plurality of magnets each disposed between neighboring ones of the rotor cores, a molded body having a bridge to support the plurality of rotor cores and the plurality of magnets, and a coupler including coupling ribs outwardly extending from an outer circumferential surface of the bridge in a radial direction of the rotor, and coupling grooves formed at inner ends of the rotor cores supported by the bridge, to receive the coupling ribs, respectively.

Abstract: A three-phase rotary electrical machine including a stator including a stator core including split cores, a rotor, a bobbin attached to each of the split cores, a winding being wound around each split core to which the bobbin is attached, and a bobbin unit including three of the bobbins which are arranged in a circumferential direction of a rotation axis as one unit, wherein the bobbin positioned at a center of the bobbin unit are formed in a bendable manner integrally with the bobbins positioned adjoining to the bobbin positioned at the center, the bobbin unit is sealed with the bobbin unit positioned adjoining thereto, and a cooling passage extending in the axial direction is provided at each clearance between the windings for three phases.

Abstract: A motor having a structure capable of achieving a reduction in magnetic flux leakage occurring at a rotor and a washing machine, to which the motor is applied. The motor includes a stator including a plurality of stator cores arranged in a circumferential direction, and coils respectively wound around the stator cores, and a rotor rotatably arranged inside the stator. The rotor includes a plurality of rotor cores arranged in a circumferential direction of the rotor, a plurality of magnets each disposed between neighboring ones of the rotor cores such that the magnet extends in an axial direction of the rotor outwardly of upper and lower surfaces of the neighboring rotor cores, and a molded body to support the plurality of rotor cores and the plurality of magnets. The molding body includes a shaft hole, to which a motor shaft is coupled.

Abstract: In a stator manufacturing method to manufacture a stator in which divided-core assemblies are arranged in a cylindrical shape, each of which includes a divided-core member having a teeth portion on which a coil is wound. In this method, the divided-core assemblies are inserted in the cylindrical shape into a fixed mold, resin sheets containing glass fibers or carbon fibers are disposed on coil-end portions of the cylindrically-arranged divided-core assemblies, and a slide part of a movable mold applies pressure to and molds the resin sheets, thereby combining the divided core assemblies into a single unit. The movable mold is operated to position the divided-core assemblies in place by a cylindrical part and then apply pressure to and mold the resin sheets by the slide part.

Abstract: An electric motor has a stator, a rotor and brush gear. The rotor includes a shaft, a rotor core fixed to the shaft, a commutator fixed to the shaft, and rotor windings wound on the rotor core and electrically connected to the commutator. The brush gear includes at least two arcuate brushes for making sliding contact with the commutator. The commutator and brush gear are disposed within a space formed in the rotor core to minimize the axial length of the motor.

Abstract: An electric motor has a stator, a rotor and brush gear. The rotor includes a shaft, a rotor core fixed to the shaft, a commutator fixed to the shaft, and rotor windings wound on the rotor core and electrically connected to the commutator. The brush gear includes at least two arcuate brushes for making sliding contact with the commutator. The commutator and brush gear are disposed within a space formed in the rotor core to minimize the axial length of the motor.

Abstract: An electric motor for a power tool includes a stator and an armature disposed in the stator. The armature includes a lamination stack having slots therein; an armature shaft extending coaxially through the lamination stack; a plurality of magnet wires wound in the slots of the lamination stack; a commutator disposed on the armature shaft to which ends of the magnet wires are electrically coupled; and thermally conductive plastic at least partially encasing the magnet wires, the thermally conductive plastic having a base polymer that is a blend of at least two polymers.

Abstract: A brushless motor for washing machine of this invention is a motor suitable for application to a drum-type washing machine. The brushless motor for washing machine comprises a stator and a rotor. The stator includes a mounting section for fixing to a water tub, a stator core, a winding and a winding insulation material. The rotor includes a motor pulley for connection to a belt, a rotatably supported motor shaft, a rotor core and a magnet. At least one of the stator and the rotor has a mold portion formed of a resin material.

Abstract: An electric motor has a wound stator and a permanent magnet rotor. The rotor includes a shaft, a hub fixed on the shaft, a plurality of rotor core segments and magnets fixed around the hub. The rotor core segment includes at least two rotor blocks inwardly extending from the innermost portion thereof. The hub includes a plurality of hub blocks equidistantly and outwardly extending from the outer surface thereof. The rotor blocks of each rotor core segment engage with at least one hub block to fix the rotor core segment to the hub. The number of rotor blocks is greater than the number of hub blocks.

Abstract: A brushless motor for washing machine applicable to a drum-type washing machine is provided with a rotary drum having an axis of rotation in a horizontal direction or an inclined direction, and power is transmitted to the rotary drum via a pulley and a belt. The brushless motor for washing machine comprises a stator and a rotor, and the rotor includes a rotor mold portion formed of a resin material on both end surfaces in an axial direction of a rotor core. The rotor mold portion has a resin protrusion projecting in an annular shape in the axial direction.

Abstract: The present invention relates to a motor including: a housing formed in such a manner as to locate a stator assembly inside a mold and to perform an insert injection molding, the housing having a hollow portion formed at the inside thereof and power terminal pins exposed above the hollow portion; a printed circuit board adapted to mount an integrated circuit device thereon and having a shaft insertion hole formed at the center thereof and power terminal pin holes formed at the corresponding positions to the power terminal pins; and an end cover adapted to be coupled to the housing in such a. manner as to be located on the top of the printed circuit board and having a motor shaft coupling portion formed at the center thereof.

Abstract: Disclosed is a stator of an EPS motor, the stator including a stator core including a plurality of teeth protrusively formed toward a center of an inner circumferential surface, a plurality of coils wound on the teeth at a predetermined counts, an insulator coupled to an upper surface and a bottom surface of the stator core to insulate the coil from the stator core, and an insulation tube situated nearest to a coil wound on an adjacent stator core and inserted into a coil wound on an outmost side of the teeth.

Abstract: A mill drive system with a transmission arranged beneath a milling table and with at least one planetary and/or spur gear stage as well as a vertical shaft position is provided. In addition, an electric motor is integrated in a housing of the transmission and is connected to a lubricant supply circuit of the transmission. A rotor and a stator of the electric motor have vertically extending axes. Cooling of the motor is performed by a lubricant circulating through the transmission. Furthermore, a lubricating-oil-proof sheath for rotor and/or stator windings of the electric motor for sealing with respect to the lubricant is provided. In addition, the mill drive system includes a converter with a regulation device for backlash-free speed regulation of the electric motor.

Abstract: A pump motor includes a stator, a rotor and a housing accommodating the stator and the rotor. The stator has a plurality of teeth, each of the teeth being provided with a cap portion at its tip end. The rotor is arranged inside the stator in an opposing relationship with the cap portion of each of the teeth. The housing includes a fluid path defined therein. The fluid path includes a substantially annular gap axially extending between the stator and the rotor. The cap portion includes a first opposing surface and a second opposing surface provided in an opposing relationship with the rotor to define a portion of the fluid path, the distance between the first opposing surface and an outer circumferential surface of the rotor being greater than the distance between the second opposing surface and the outer circumferential surface of the rotor.

Abstract: A stator for an electric motor, in particular for an external rotor motor, has a basic body (3) with a laminated stator core and with stator coils arranged on the laminated stator core. Each of the stator coils has a winding wire start and a winding wire end. Each winding wire start is attached to contact pins. The basic body (3) is extrusion-coated with a sleeve made from plastic, from which contact pins at least partially protrude. In order to reduce the manufacturing costs, a contact holder (2) encased in the sleeve together with the basic body (3) is pushed via the free ends of the contact pins onto the basic body (3), wherein the contact holder (2) encases the contact pins with a sealing section (11) in a gap-free, sealing manner.

Abstract: An end cap mounted on the stator clement is provided with the same cut-out as arranged on the stator segment so that both parts can be secured on a retainer system for winding processing. The end cap are arranged to retain insulating materials.

Abstract: The present invention provides a motor (M) including a case (1) storing an armature (3) having a winding wire (2) wound thereon on the inner circumferential side, in which the case (1) includes an opening part (1a) for inserting a terminal (5) for connecting the winding wire (2) to an external power source, and the terminal (5) is integrated into a resin for forming a cap (6) for air-tightly closing the opening part (1a) by insert molding, with one end (5a) of the terminal (5) being protruded into the case (1) and the other end (5b) of the terminal (5) being protruded out of the case (1).

Abstract: The present invention provides a motor (M) including a rotor (1), a stator (S) having a winding wire (2) wound thereon, and an outer cylinder (3) for holding the stator (S) fitted into the inner circumference thereof. The stator (S), the outer cylinder (3), and a terminal (4) having one end (4a) connected to the winding wire (2) are integrated together by a mold resin (12) by insert molding while closing one end side of the outer cylinder (3) by the mold resin (12), and protruding the other end (4b) of the terminal (4) out of the motor (M) through the mold resin (12).

Abstract: A rotor for an electric motor, that includes a main body on which a support surface is formed, to which a permanent magnet element is attached. The main body is partially surrounded by a joining sleeve having chamber walls. The chamber walls together with the support surfaces form a chamber in which the permanent magnet element is arranged. The joining sleeve fixes the position of the permanent magnet element in a radial direction on the main body and a locking element is molded onto the main body. The locking element closes the chamber fixing the position of the permanent magnet element in the axial direction on the main body.

Abstract: An electromechanical device includes a rotor having a magnetic back yoke with a cylindrical shape, and at least one rotor magnet arranged along an outer periphery of the magnetic back yoke in a cylindrical manner, a stator having at least one air-core magnetic coil arranged along an outer periphery of the rotor in a cylindrical manner, and a coil back yoke with a cylindrical shape disposed on an outer periphery of the magnetic coil arranged in a cylindrical manner, and a casing adapted to cover the stator and the rotor, wherein at least a part of the casing is formed of carbon fiber reinforced plastic.

Abstract: An encapsulated stator includes a driving module coupled to a shaft tube. The driving module includes a silicon steel plate unit. A coil unit is wound around the silicon steel plate unit. A jacket is mounted to an outer periphery of the silicon steel plate unit of the driving module. The jacket includes an inner face and an outer face opposite to the inner face. The inner face of the jacket faces the driving module. An encapsulant is bonded to the driving module, the jacket, and the shaft tube. The encapsulant encapsulates the driving module. The encapsulant partially encapsulates the outer face of the jacket.

Abstract: A starter motor for an engine includes a motor casing made of electrically conductive material and an end bracket fixed to one end of the motor casing. The end bracket comprises a base with brush cages integrally formed therewith, brushes mounted in the brush cages and a conductor electrically connected to the brushes and motor casing. The base is a single piece made of electrically insulating material and coaxial mounting holes are formed in the base and motor casing for fasteners to fix the starter motor to a housing of the engine.

Abstract: A rotating portion of a motor includes a rotor holder including a cylindrical portion arranged to be coaxial or substantially coaxial with a central axis, a plurality of magnets arranged in a circumferential direction on an inner circumferential surface of the cylindrical portion, and a resin portion arranged on a surface of the rotor holder. The resin portion includes a plurality of ribs arranged at regular or substantially regular intervals in the circumferential direction along the inner circumferential surface of the cylindrical portion, and an outer tubular portion arranged to cover an outer circumferential surface of the cylindrical portion. Each rib and the outer tubular portion are arranged to be defined by a single monolithic member such that each rib and the outer tubular portion are continuous with each other. Each magnet is preferably arranged between a separate pair of adjacent ones of the ribs.

Abstract: Embodiments of the invention provide an electric machine module including an electric machine which can include a stator assembly. The stator assembly can include stator end turns. Some embodiments can provide a housing at least partially enclosing the electric machine and the housing can at least partially define a machine cavity. Further, at least one baffle can be coupled to the housing at a region near the stator end turns, so that the at least one baffle surrounds a portion of a perimeter of the stator end turns.

Abstract: A stator structure and a stator manufacturing method which are configured so that the stress occurring in resin-molded sections or insulators of the stator can be reduced. The structure of the stator is provided with coils formed by winding conductors, and also with stator cores provided with teeth to which the coils are mounted through the insulators. The coils mounted to the insulators are resin-molded and integrated with the insulators. Spaces which continue in the radial direction of the stator cores are formed between the insulators and end surface of the stator cores in the axial direction thereof. The insulators and the side surfaces of the teeth of the stator cores are adhered or welded (fusion bonded) to each other.

Abstract: A stator of a rotary electrical machine includes a core unit configured by a plurality of core assemblies, around which wires are respectively wound to form the coils, including low voltage side terminals, which connect first ends of the coils, and a bus ring attached to the core unit so as to connect second ends of the coils to electricity supply wires by high voltage side terminals. Each terminal accommodating portion is individually formed relative to each of the core assemblies at an external side of the coils. Each of the terminal accommodating portions is filled with an insulating resin material in a state where at least one of a connecting portion of the first end and each of the low voltage side terminals and a connecting portion of the second end and each of the high voltage side terminals is accommodated within each of the terminal accommodating portions.

Abstract: A voltage regulator negative electrode terminal is mounted to an axially outer end surface of a rear bracket so as to be in a state of electrical connection with the rear bracket by fastening a flange portion to a mounting pedestal of the rear bracket using a voltage regulator fixing second screw. A screw loosening restricting lug is disposed so as to project from a floor portion of a protective cover so as to face the voltage regulator fixing second screw so as to have a predetermined clearance in an axial direction.

Abstract: Due largely to their high torque-to-current and torque-to-volume ratios, permanent magnet (PM) motors and generators are increasingly being used in a wide range of high performance applications, such as industrial drives, robotics, computer peripherals, and automotive applications. The present invention utilizes stator modularity to enable cost efficiency by significantly decreasing stator core manufacturing costs, and coil forming and fixturing costs in several ways. Minimizing costs extend to a novel, lightweight, support structure that does not require the usual encasement structure. The approach presents a challenge to mitigating cogging torque via popular methods; therefore a novel anti-cogging approach was developed that is a natural outgrowth of the modular layout instead of being negatively impacted by. The result is a low cost PM machine design and method with low cogging torque.

Abstract: Disclosed herein is a switched reluctance motor including: a rotor formed with a plurality of salient poles; a rotor core having the rotor coupled thereto; and a stopper formed integrally with the rotor core by an insert special molding method.

Abstract: The stator of an electric motor includes a stator lamination bundle which is provided with windings which pass through this and which in the regions projecting beyond the stator lamination bundle form end-windings. An end-winding shielding which is electrically conductively connected to the stator lamination bundle is provided. This shielding is formed by segmented and distanced shielding sections which in each case shield at least one end-winding completely or partly.

Abstract: A molded motor includes a stator, a resin casing, a rotor, a pair of bearings, a pair of bearing retainers, a resin bracket cover, and a control board. The rotor includes a shaft. The bearings are arranged to rotatably support the shaft. The bearing retainers are made of an elastic electrically insulating body. The bearing retainers are arranged to cover the bearings at radial outer sides of the bearings and to hold the bearings in place. The bracket cover is arranged to cover the open side of the casing. One of the bearings is attached to the bracket cover through one of the bearing retainers. The other bearing is attached to a bottom wall portion of the casing through the other bearing retainer.

Abstract: A rotor assembly for an electromechanical device includes a molded wire support. The wire support has a body including a first side spaced from a second side and a hole extending through the sides and configured to receive a shaft. The body includes a wall about the hole extending to the first side. At least one end turn support extends outwardly from the wall and is configured to support wires. A molded pocket extends into the wall from the second side without penetrating through to the first side.

Abstract: Disclosed is a stator capable of reducing stress generated in the resin mold of the stator. A stator is provided with a coil formed by coiling a flat conductor, a split stator core provided with a teeth unit for inserting the coil, and a resin mold, which has resin covering the coil ends of the coil inserted into the split stator core. In the stator, an insulator is formed between the split stator core and the coil by way of insert molding, and the resin mold has a cavity, formed in the radial direction of the stator, in between the coil and the end face of the split stator core.

Abstract: A fuel pump includes a pump portion for pumping fuel. The fuel pump further includes a magnet having magnetic poles circumferentially alternate with each other. The fuel pump further includes an armature on a radially inside of the magnet. The armature includes a rotor core provided with a coil formed of a wire. The armature is rotatable for driving the pump portion. A commutator, which is in a substantially disc shape, is provided to an axial end of the armature for rectifying electricity supplying to the coil. The rotor core has an axial end having an outer circumferential periphery defining a commutator-side collar portion extending toward the commutator. The coil is formed by winding the wire between an outer circumferential periphery of the commutator and the commutator-side collar portion.

Abstract: A stator for a brushless, electronically commutated electric motor having a stator core wound with stator windings and control electronics for controlling the stator windings. The stator core together with the stator windings are enclosed in a molded encapsulation made of a plastic material of a defined thermal conductivity (?St). The temperature sensor is arranged on the outside at the encapsulation, and the control electronics are designed such that they calculate the temperature in the region of the stator windings on the basis of the temperature detected by the temperature sensor taking into account a specific stator temperature profile stored in a memory. Furthermore, the invention relates to a brushless, electronically commutated electric motor having a stator as described above.

Abstract: An electromechanical device includes: a center shaft; a rotor having a rotor magnet disposed around an outer periphery of the center shaft; and a stator disposed on an outer periphery of the rotor, wherein the center shaft is formed of a carbon-fiber-reinforced plastic, and when projection is performed in a radial direction from the center shaft toward the rotor magnet, an angle between a direction of carbon fiber in the carbon-fiber-reinforced plastic and a direction of the center shaft is 45°.

Abstract: An electric machine has a stator which carries a polyphase coil winding, wherein coil ends are connected in a predetermined manner to a plurality of electric connection conductors. The electric machine comprises a power connection unit having a plurality of terminal conductors which are constructed separate from the connection conductors and which by a first end portion are bondingly connected or connectable to the connection conductors and by a second end portion are connected or connectable to the electrical energy source. The power connection unit is constructed as a plastic composite element, in which the terminal conductors are embedded at least over a portion of their length in a plastic shell so as to be spaced apart from one another, and wherein first end portions of the terminal conductors project out of the plastic shell.

Abstract: A rotor for a motor or generator is produced by placing separated magnets around the diameter of the potential rotor, placing separated segments of magnetic backing material behind the magnets, and embedding the whole in molding material in a mold in such a way that the segments thrust outwards against the magnets and the magnets thrust outwards against the mold during placement of the molding material.