DE102009020481B4 - Reluctance motor - Google Patents

Abstract

Reluctance motor (1) with a rotor (3) and a stator (5), wherein individual, free-standing stator poles (6) are formed on the stator (5) and are surrounded by windings (7), wherein winding bodies (9) are further arranged between the stator (5) and the windings (7) and/or the stator (5) is accommodated in an externally encompassing stator housing (10) and the stator housing (10) runs in sections at a distance from the stator (5), characterized in that the stator housing (10) designed as a bent sheet metal part is divided into two parts and that the spacing is in any case formed on the housing part provided with an upper bridge (11).

Description

The invention relates to a reluctance motor according to the feature of the preamble of claim 1.

Reluctance motors of the type in question are known. For example, the DE 103 37 916 A1 There, a reluctance motor is shown and described which, in order to reduce the noise emission when the motor is in operation, has a stator cover which forms a winding body and which surrounds the free-standing stator poles and serves as a support for the stator winding provided. It is also known to accommodate reluctance motors of the type in question in a stator housing, in particular consisting of a wall surrounding the stator and bridges provided at each end of the stator for supporting the rotor axis.

High electromagnetic forces cause vibrations in the stator. The energization of the motor causes micro-movements in the stator and in the winding, for example electrostriction in the iron, forces between the copper wires of the winding and electromagnetic interactions between the rotor and stator. The frequency of these forces depends on the speed of the motor. Depending on the frequency, resonances can be excited in the system. Resonance effects can therefore occur in high-speed motors.

From the US 6144137 A A reluctance motor with an outer housing is known, which can be designed as an aluminum part. The stator housing is designed as a one-piece cylinder part, which is connected to separate bearing flanges by means of a screw connection. JPH 11-41884 A A reluctance motor is known in which projections are formed on the stator that project radially outwards and rest against an inner side of the one-piece cylindrical stator housing or in which radially inwardly projecting formations are formed on the stator housing and rest against an outer surface of the stator. EN 602 11 603 T2 A reluctance motor is known in which the stator has a large number of evenly distributed recesses distributed over the circumference, starting from a circular circumferential line, so that a system with respect to a circular circumferential edge is only possible with regular interruptions on the inside of the stator housing. The stator is also housed in a shrink sleeve, with the remaining free spaces serving to conduct coolant.

From the JP 2006-180611 A A casing for windings of a stator is known, whereby a stator winding is fitted into a winding body by means of liquid filling material. The filling material hardens into a casing part in order to achieve a tight and firm connection. From the CN 2686194 Y A cover for a stator winding is also known, which is attached to the winding on one side by means of a corrugated formation. JPH10-309053 A It is known to form ribs on the inside of a cover cap for a stator tooth, with which the cover rests on an outer surface of the stator tooth.

Based on the prior art presented, the invention addresses the problem of achieving effective decoupling with a simple design of the stator housing.

This object is achieved in the subject matter of claim 1, whereby the stator housing, which is designed as a bent sheet metal part, is divided into two parts and the spacing is in any case formed on the housing part provided with an upper bridge. Movements as a result of resonance vibrations of a part, such as the winding body and/or the stator housing, which movements would lead to a collision with the stator, are prevented and the unpleasant noises that would otherwise accompany them are eliminated.

By spacing the winding body and/or the stator housing from the stator in sections, resonance is achieved outside the speed range. Full-surface contact between the winding body and/or the stator housing and the stator is avoided.

The winding body and/or the stator housing can have projections associated with the stator for section-by-section spacing. In an alternative or combined embodiment, the stator has projections formed on the stator associated with the winding body and/or the stator housing. The projections pointing outwards or inwards with respect to the rotor axis passing through the stator form support areas spaced apart from one another. In this context, it is preferred that no flat contact is provided, but rather a point-like or linear contact of the winding body and/or the stator housing on the stator.

In a further preferred embodiment, the projections run in the axial direction of the rotor, i.e. parallel to the rotor axis or at least oriented along such a parallel axis, that means possibly taking up an acute angle of 0.5° to 30°. In this context, it is further provided that the projections are designed as ribs, so that a particularly linear arrangement is achieved. The ribs run in the form of web-like elevations compared to the adjacent wall area of the winding body and/or the stator housing or the stator when the projections are arranged on the stator.

Resonance effects in the speed range of the reluctance motor are further avoided by a further development in which the spaced-apart area, which is located directly opposite the stator, is 20% to 98% in cross-section relative to a circumferential line. Accordingly, support is provided on the opposite area, correspondingly support of the winding body and/or the stator housing on the stator in cross-section relative to a circumferential line in the support area of approximately 2% to 80%, preferably 2% to 10%, which, with an exemplary circumference of the section of the stator housing enclosing the stator of 250mm, results in a combined contact area of approximately 10mm to 15mm, which contact area is further distributed evenly or alternatively irregularly over the circumference by the preferably provided rib-like projections. The respective support surface is selected to be small in the circumferential direction in such a way that a point-like or line-like contact is achieved. For example, projections are formed on the winding body and/or stator housing, the respective circumferential extent of which is equal to or smaller than the wall thickness of the winding body and/or the stator housing, with a preferred wall thickness of the winding body and/or the stator housing of 1 mm to 5 mm, which results in a circumferential extent of each projection of 5 mm or less. In this context, it is further provided that the circumferential extent of the projections corresponds to a tenth to a half of the wall thickness of the winding body and/or the stator housing, so that with a preferred wall thickness of 1 mm to 5 mm, a circumferential extent of a projection of 0.1 mm to 2.5 mm results, this in particular in connection with the formation of projections on the winding body and in relation to a winding body wall thickness.

In an alternative or combined embodiment, projections are formed on the winding body and/or stator housing, the circumferential extent of which is equal to or greater than the wall thickness of the winding body and/or the stator housing, so that, with reference to the aforementioned preferred wall thickness, a circumferential extent of each projection of 5 mm or more results. In this regard, it is also preferred that the circumferential extent of the projections corresponds to 1.5 to 10 times the wall thickness of the winding body and/or the stator housing. This results in a preferred circumferential extent of each projection of 1.5 mm to 50 mm with a preferred wall thickness as mentioned above. Projections formed in this way are assigned in particular to the stator housing, with their circumferential extent being in relation to the housing wall thickness.

The stator housing is designed as a bent sheet metal part and is divided into two parts, the spacing being formed in any case on the housing part provided with an upper bridge. In a further preferred embodiment, the spacing is also provided on the housing part provided with a lower bridge, which bridges are clamped, for example, to secure the stator housing to the stator. Accordingly, this clamping of the stator housing bridge to the stator is designed favorably with regard to the aforementioned resonance effects by section-by-section spacing of the housing section surrounding the stator, with the projections provided for this purpose for spacing being more preferably formed on the stator itself. In a preferred embodiment of the stator as a stator package, consisting of stator sheets of the same contour arranged one above the other, these projections spaced apart from the stator housing are formed by punching along the outer contour during the manufacture of the stator sheets.

In a preferred embodiment, the winding body is designed as an electrically insulating plastic injection-molded part. This carries the stator windings and acts as an electrical insulator for the stator.

The distances between the non-touching surfaces lying directly opposite each other are also chosen to be large enough that there can be no contact between these surfaces even under extreme conditions, i.e. even in situations in which the surfaces freely stretched between the projections bend due to vibrations, and further bend in an almost radial direction with respect to the rotor rotation axis. In this context, the circumferential length between two contact areas corresponds to one to fifty times the circumferential extension of a projection, so that with a preferred circumferential extension of a projection of around 1 mm to 5 mm, a support-free circumferential length between two contact areas of, for example, 1 mm to 50 mm results.

The numerical ranges indicated in each case exclude - unless otherwise are given as examples - all intermediate values are limited, in particular in one-tenth increments from the lower and/or upper limit to the other limit. "And" here means that both limits are shifted by one or more tenths towards the limit, i.e. limited.

• 1 in perspektivischer Darstellung einen Reluktanzmotor mit einem Stator und einem als Brücke ausgebildeten, an dem Stator festgelegten Statorgehäuseteil;
• 2 die Seitenansicht hierzu;
• 3 den Schnitt gemäß der Linie III - III in 2;
• 4 die Herausvergrößerung des Bereiches IV in 3;
• 5 die Herausvergrößerung des Bereiches V in 3.

The invention is explained in more detail below with reference to the accompanying drawing, which represents only one embodiment. It shows:

• 1 in perspective view a reluctance motor with a stator and a stator housing part designed as a bridge and fixed to the stator;
• 2 the side view of this;
• 3 the section according to line III - III in 2 ;
• 4 the enlargement of area IV in 3 ;
• 5 the enlargement of area V in 3 .

Presented and described is initially with reference to 1 a reluctance motor 1 in the form of a four-two reluctance motor. The corresponding two-phase motor has a rotor 3 that is fixedly mounted on a rotor shaft 2. This has two diametrically opposed rotor poles 4. When the reluctance motor 1 is in operation, the rotor 3 rotates about a geometric rotor axis x defined by the rotor shaft 2.

The stator 5 surrounding the rotor 3 has four stator poles 6, each of which forms an angle of 90° to one another in the direction of rotation of the rotor 3. These each carry windings 7 that form coils.

For electrical insulation of the windings 7 from the stator 5, the stator poles 6 and the stator walls 8 extending between the stator poles 6 in the circumferential direction are covered by a winding body 9 designed as a plastic injection-molded part. This is shown in cross section in 3 shell-like design to line the stator area flanking the windings.

The stator 5 is further accommodated in a stator housing 10 which surrounds it on the outside, of which only a bridge 11 covering one end face of the stator 5 is shown in the drawings. The side of the stator 5 opposite this bridge 11 is covered by another bridge of similar construction, although not shown.

The bridge 11, as well as the further bridge provided, serve to support the rotor shaft 2, for which purpose a central receiving opening 12 is provided in the bridge 11. A ball bearing or the like can be inserted into this to support a rotor shaft section.

The bridge 11 further comprises a collar 13 which runs around the rotor axis x. This collar 13 surrounds the associated end section of the stator 5, resting partially on its outer surfaces.

The stator 5 is formed from a package of identically designed stator sheets 14. These are formed by punching in such a way that in the assembled stator 5, four stator outer surfaces 15 are formed on the outside of the wall, each enclosing an angle of 90° to one another in plan view, which are assigned to the stator poles 6 pointing radially inwards. The corner areas adjoining the stator outer surfaces 15 in the circumferential direction of the stator 5 are rounded, for example with a radius oriented towards the rotor axis x.

As can be seen particularly from the enlarged illustration in 4 As can be seen, the stator outer surfaces 15 are provided with projections and recesses with respect to a cross section through the stator 5, so that an interrupted support surface for the bridge-side collar 13 is produced. The projections 16 have a radial height a with respect to the rotor axis x, which corresponds approximately to 0.5 times the material thickness of the collar 13 of the bridge 11, which is designed as a sheet metal part. The width b of such a projection 16, viewed transversely thereto, i.e. in the circumferential direction, corresponds approximately to 10 times the height a.

For each stator outer surface 15, three projections 16 are provided which are evenly spaced from one another in the circumferential direction, wherein the free distance between two adjacent projections 16 corresponds approximately to the projection width b.

The circumferential extent of each projection 16, resulting from the addition of the projection width b and twice the value of the height a, corresponds in the illustrated embodiment to approximately ten times the wall thickness of the collar 13. Each projection 16 extends in a spatially parallel alignment to the rotor axis x over the entire stator outer surface 15, that is, starting from the bridge 11 up to the opposite end region receiving the further bridge.

Due to the above-described design of the projections 16, the collar 13 of the stator housing 10 extends in sections at a distance from the stator 5, which distance is defined by the projection height a. This spacing is maintained in the rounded corner areas of the stator 5, so that the collar section assigned to the rounded area extends freely at a distance from the stator 5.

Due to the design described above, there is only linear contact between the stator housing 10, in particular its collar 13, and the stator 5. The distances between the projections 16 are selected such that no resonances are excited in the speed range of the motor 1. In addition, the distances between the non-touching, directly opposite surfaces are selected so large due to the projection height a that even if the sections of the collar 13 freely stretched between the projections 16 bend due to vibrations, there is no contact with the stator 5, this is the case with a preferred arrangement of the bridge 11 on the stator 5 in a press fit.

The winding body 9 also does not lie completely against the facing wall of the stator 5 or the stator poles 6. Rather, the winding body is supported on the associated stator wall via projections 17 arranged on the outside of the wall and running parallel to the rotor axis x, which projections 17 are designed as ribs. These are made of the same material and are formed in one piece on the winding body 9 and act like crush ribs, which provide a linear contact of the winding body 9 on the associated stator wall.

As can be seen from the enlarged view in 5 As can be seen, the rib-like projections 17 are designed in the shape of a circular segment in cross-section, with a width c measured in the root area of the projections 17 on the winding body wall 18 in the circumferential direction, which corresponds to approximately one third of the thickness of the wall 18. The height d viewed transversely to the projection height c further corresponds to approximately half the width dimension c of the projection 17, which results in a circumferential extension of a projection 17 viewed in cross-section, which corresponds to approximately half the value of the wall thickness of the wall 18.

The projections 17 are spaced apart from one another in the circumferential extension of the winding body wall 18, wherein in the illustrated embodiment this distance between two adjacent projections 17 corresponds approximately to ten times the circumferential extension of a projection 17.

As can also be seen from the illustrations, the winding body 9 is supported in the area of the surface assigned to a stator pool 6 by two projections 17 spaced apart from one another in the circumferential direction, while three projections 17 spaced apart from one another are provided in the circumferential direction for support on the stator wall 8. This results in an area viewed in the circumferential direction that is spaced apart from the stator 5, which in cross-section is approximately 85% based on a circumferential line, so that the winding body 9 is supported on the stator 5 over approximately 15% of its circumferential extent.

This also provides a linear contact with the stator 5 with respect to the winding body 9, wherein the surfaces or distances between the rib-like projections 17 are dimensioned such that a resonance is achieved outside the speed range.

The reluctance motor 1 described above is characterized by a high natural resonance. Undesirable resonance effects in the speed range of the motor are avoided, as are other mechanical noises such as rattling. The motor is noise-minimized due to the point- or line-shaped contact of the stator housing 10 or the bridge 11 and the winding body 9 on the stator 5 and the resulting reduced vibration level.

All disclosed features are (in themselves) essential to the invention. The disclosure content of the associated/attached priority documents (copy of the prior application) is hereby fully included in the disclosure of the application, also for the purpose of including features of these documents in the claims of the present application.

List of reference symbols

1

Reluctance motor

2

Rotor shaft

3

rotor

4

Rotor poles

5

stator

6

Stator poles

7

Windings

8th

Stator wall

9

Winding body

10

Stator housing

11

Bridge

12

Receiving opening

13

collar

14

Stator laminations

15

Stator outer surfaces

16

head Start

17

head Start

18

Winding body wall

a

Height

b

Width

c

Width

d

Height

x

Rotor axis

Claims (14)

Reluctance motor (1) with a rotor (3) and a stator (5), wherein individual, free-standing stator poles (6) are formed on the stator (5) and are surrounded by windings (7), wherein winding bodies (9) are further arranged between the stator (5) and the windings (7) and/or the stator (5) is accommodated in an externally encompassing stator housing (10) and the stator housing (10) runs in sections at a distance from the stator (5), characterized in that the stator housing (10) designed as a bent sheet metal part is divided into two parts and that the spacing is in any case formed on the housing part provided with an upper bridge (11). Reluctance motor according to Claim 1 , characterized in that the winding body (9) and/or the stator housing (10) associated with the stator (5) has projections (16, 17) for section-wise spacing. Reluctance motor according to one of the preceding claims, characterized in that the stator (5) has projections (16, 17) formed on the stator (5) associated with the winding body (9) and/or the stator housing (10). Reluctance motor according to one of the Claims 2 or 3 , characterized in that the projections (16, 17) extend in the axial direction of the rotor (3). Reluctance motor according to one of the Claims 2 until 4 , characterized in that the projections (16, 17) are designed as ribs. Reluctance motor according to one of the preceding claims, characterized in that a spaced-apart region which is located directly opposite the stator (5) is, in cross-section relative to a circumferential line, 20% to 98%. Reluctance motor according to one of the Claims 2 until 6 , characterized in that projections (16, 17) are formed on the winding body (9) and/or stator housing (10), the circumferential extent of which is equal to or smaller than the wall thickness of the winding body (9) and/or the stator housing (10). Reluctance motor according to Claim 7 , characterized in that the circumferential extension of the projections (16, 17) corresponds to one tenth to one half of the wall thickness of the winding body (9) and/or the stator housing (10). Reluctance motor according to one of the Claims 2 until 6 , characterized in that projections (16, 17) are formed on the winding body (9) and/or stator housing (10), the circumferential extent of which is equal to or greater than the wall thickness of the winding body (9) and/or the stator housing (10). Reluctance motor according to Claim 9 , characterized in that the circumferential extension of the projections (16, 17) corresponds to 1.5 to 10 times the wall thickness of the winding body (9) and/or the stator housing (10). Reluctance motor according to one of the preceding claims, characterized in that the stator (5) is formed from a package of identically designed stator sheets (14) which are formed by punching in such a way that in the assembled stator (5) on the outside of the wall there are four stator outer surfaces (15) which in plan form an angle of 90° to one another and which are assigned to the stator poles (6) pointing radially inwards, wherein the corner regions adjoining the stator outer surfaces (15) in the circumferential direction of the stator (5) are rounded. Reluctance motor according to Claim 11 , characterized in that due to the projections (16) a collar (13) of the stator housing (10) extends in sections at a distance from the stator (5), wherein the distance is defined by a projection height (a) and this spacing is maintained in the rounded corner regions of the stator (5), so that the collar section assigned to a rounded region extends freely at a distance from the stator (5). Reluctance motor according to one of the preceding claims, characterized in that the winding body (9) is designed as a plastic injection-molded part. Reluctance motor according to one of the preceding claims, characterized in that a circumferential length between two contact areas corresponds to one to fifty times the circumferential extension of a projection (16, 17).

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