Electric motor

Abstract

Electric motor, whereby is designed as an asynchronous motor, whereby casting compound is provided to achieve high electrical insulation strength between lines of different phases of the stator winding and the stator windings are fully encapsulated with the potting compound using negative pressure or vacuum, wherein coils of a coil group, the coils of which run at least partially through adjacent slots in the stator core, run in different directions in the region of the winding head, viewed in the circumferential direction, where both winding heads are fully potted, i.e. surrounded by potting compound on all sides, where no coil is continued in the winding head beyond the next ninth slot.

Description

The invention relates to an electric motor.In asynchronous motors which can be supplied with three-phase current, it is known to draw three-phase windings into a stator housing and then to insulate the phase windings from one another with insulating paper.The textbook "Technologie des Elektronikaus", Verlag Technik GmbH, Berlin, 1990, 1st edition, Author Prof. Tzscheuschler et al., page 172, page 2.4.31 may be mentioned by way of example in this context.U.S. Pat. No. 3,075,250 A discloses winding end caps made of plastic as the closest prior art.From GB 306 099 A an improved dynamoelectric machine is known.U.S. Pat. No. 3,470,409 A discloses a concentric stator coil winding for a polyphase dynamoelectric machine.DE 690 05 912 T2 discloses a stator of an electric motor.The end-face protruding regions of the coil windings are also called winding heads.The lines belonging to the individual phases come close to one another at some points, especially in the winding head, which are also referred to below as crossing points.The number of such points is kept as small as possible by the skilled person by selecting suitable winding schemes.The invention is therefore based on the object of developing an electric motor, wherein the production is to be simple and cost-effective and the efficiency is to be improved.According to the invention, the object is achieved in the electric motor according to the features specified in claim 1, 2 or 8.Essential features of the invention in the case of the electric motor are that the electric motor is designed as an asynchronous motor, wherein the stator windings are encapsulated with an encapsulation compound, in particular to achieve high electrical insulation resistance between lines of different phases of the stator winding.It is advantageous in this case that the stator winding may have a large number of crossing points and no insulating paper is necessary in the winding head. This is because the potting compound performs the task of electrically insulating. Thus, surprisingly, despite the outlay for casting compound, an inexpensive asynchronous motor can be produced overall. It is furthermore advantageous that the efficiency of the motor can be improved, since a winding scheme can now be used which separates a matching coil group in the region of the winding head.In addition, the winding head can be implemented with a smaller amount of material, line lengths and in particular copper, because the three coils of a coil group can now no longer be guided over one another in parallel, but rather the one of the three coils of a coil group can be guided in the other direction in each winding head.In an advantageous embodiment, the electric motor can be operated in one or more phases, in particular in three phases. It is advantageous here that the coils can be drawn into the stator laminated core and an upper and lower winding head can be produced in which the coil groups can be separated and the coils can be oriented in the circumferential direction or along the circumferential direction.In an advantageous embodiment, the potting compound comprises epoxy resin, in particular based on bisphenol. It is advantageous here that a substance which absorbs particularly mechanical oscillations, which is electrically insulating and can be cured quickly can be used.In an advantageous embodiment, no paper, in particular insulating paper, is used in the winding head in the stator. It is advantageous in this case that work and material can be saved. This is because the effort involved in introducing paper as a phase separator is high and can be saved by the invention.In an advantageous embodiment, coils of a coil group whose coils in the stator laminated core run at least partially through adjacent slots in the region of the winding head in different directions, as seen in the circumferential direction. It is advantageous here that a higher efficiency can be produced.In an advantageous embodiment, the winding, in particular the slot and winding head, is cast, in particular fully cast, and are therefore surrounded by casting compound on all sides. It is advantageous that a high protection type can be achieved. This is because the stator winding package is protected all around.In an advantageous embodiment, the stator comprises a laminated core comprising grooves for receiving coil regions. It is advantageous here that a known, cost-effective stator can be used.Further advantages are evident from the dependent claims.List of reference characters1, 2, 3, 36 slots 100 of upper winding head 101 of lower winding head 102 region of the slots of the stator laminated core U1 end point of the line of the stator winding of phase U U2 end point of the line of the stator winding of phase U V1 end point of the line of the stator winding of phase V V2 end point of the line of the stator winding of phase V Z1 end point of the line of the stator winding of phase Z2 end point of the line of the stator winding of phase ZThe invention will now be explained in more detail with reference to the drawings:FIG. 1 shows a winding scheme according to the invention for the stator windings.The stator lamination stack comprises the slots numbered 1 to 36 which extend in the axial direction. The stator laminated core is designed in a die-cut stack.The region of the upper and lower winding head ( 100, 101) is shown. Three associated coils, for example those coils which belong to phase U and extend in the region 102 of the slots of the stator laminated core through adjacent slots with the numbers 10, 11, 12 which are not guided together and parallel in the winding head, but only the coils which extend through the slots 10, 11 are guided together and parallel in the upper winding head. The coil running through the groove 12 is laid in the other direction in the upper winding head 100, as viewed in the circumferential direction.By this division of the associated coil group in the winding head, a better efficiency is achievable.No coil has to be carried on in the winding head than to the next ninth slot. Thus, less winding wire is needed and the ground of the motor is lower with equal power. Thus, the efficiency is improved.In the invention, no paper is used for insulation between the leads of the stator windings. In order to achieve the necessary insulation, the stator is cast with a casting compound. After curing of the casting compound, the insulation is achieved.Since the insulation of the casting compound is very good, even a winding scheme can be used which can be provided with many crossing points.Despite the potting compound, the production according to the invention can be applied to asynchronous motors.Not only is the insulation improved by means of the potting compound, but the noise emission is also reduced, in particular not only in the case of mains operation, but also in the case of converter operation, that is to say in the case of an electric motor supplied by the converter. In addition, the heat generated by the stator windings is dissipated better.The electric motor has a high protection type overall by means of the potting compound.The winding head is completely cast and thus surrounded by casting compound.In further embodiments according to the invention, an epoxy resin is used as casting compound, in particular based on bisphenol A. A two-component epoxy casting resin which is solvent-free is preferably used.In further embodiments according to the invention, the casting is carried out with reduced pressure or vacuum. The risk of air inclusions can thus be reduced.In further embodiments according to the invention, the stator laminated core comprises the slots numbered instead of 36 a different number N of slots. The winding scheme is correspondingly implemented.In further exemplary embodiments according to the invention, the stator laminated core is not designed as a stamped core, but rather is clamped and / or welded.

Claims

Electric motor, wherein it is designed as an asynchronous motor, wherein potting compound is provided to achieve high electrical insulation resistance between lines of different phases of the stator winding, and the stator windings are fully potted with the potting compound using negative pressure or vacuum, wherein coils of a coil group, the coils of which in the stator laminated core run at least partially through adjacent slots, run in different directions in the region of the end winding, as seen in the circumferential direction, wherein both end windings are fully potted, that is to say are surrounded by potting compound on all sides, wherein no coil is continued in the end winding than to the next ninth slot.Electric motor, wherein it is designed as an asynchronous motor, wherein potting compound is provided to achieve high electrical insulation resistance between lines of different phases of the stator winding and the stator windings are fully potted with the potting compound using reduced pressure or vacuum, coils of a coil group, the coils of which in the stator laminated core run at least partially through adjacent slots, run in the same directions in the region of the end winding as viewed in the circumferential direction, wherein both end windings are fully potted, that is to say are surrounded by potting compound on all sides, wherein no coil is passed on in the end winding as compared to the next ninth slot.Electric motor according to at least one of the preceding claims, characterized in that no paper, in particular insulating paper, is used for separating lines, in the stator, in particular in the winding head of the stator.Electric motor according to at least one of the preceding claims, characterized in that the electric motor can be operated in one or polyphase fashion, in particular in three phases.Electric motor according to at least one of the preceding claims, characterized in that casting compound comprises epoxy resin, in particular based on bisphenol.Electric motor according to at least one of the preceding claims, characterized in that the stator comprises a laminated core comprising grooves for receiving coil regions.Electric motor according to at least one of the preceding claims, characterized in that the motor is designed as a rotary or linear motor.Use of casting compound for achieving high electrical insulation resistance between lines of different phases of the stator winding of an electric motor, wherein the electric motor is designed as an asynchronous motor, wherein casting compound is provided for insulation and the stator windings provided in slots are fully cast with the casting compound using negative pressure or vacuum, wherein both end windings are fully cast, i.e. are surrounded by casting compound on all sides, wherein no coil is continued in the end winding than to the next ninth slot.

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