DE7319454U - SMALL ELECTRIC MOTOR - Google Patents

Description

Papst-Motoren KG - 1 - April 22, 1977

7742 St. Georgen / Schw. 'T

Flektro-Kieinmotor

The innovation relates to a small electric motor with a bell-like rotor, which has an electro-motor-driven, hollow-cylindrical solid part on one end face the bottom of the rotor bell is connected to the coaxial shaft of the rotor.

Such motors are used in large numbers in various embodiments, usually the embodiment such a motor as a so-called external rotor motor in it, that the active, solid, hollow cylindrical part is pressed or cast into the surrounding housing made of a die-cast aluminum alloy.

The aim of the innovation is to use simple constructive measures to create an electric motor or its parts mentioned at the beginning to train in such a way that the production is simplified and cheaper at the same time.

This is achieved according to the invention in that the shaft of the rotor and the electromotive active, hollow cylindrical Solid part are fixed in a mutually coaxial position by means of an adhesive connection.

In a further development of the innovation it is provided that the adhesive connection is provided on one end face of the hollow cylindrical part.

According to the innovation, the bottom of the rotor bell has a groove that deepens in the axial direction along its circumference into which the end face of the hollow cylinder is glued, the circumferential groove particularly advantageously accommodates one end of the hollow cylinder with radial play.

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Because the radial width of the annular groove is a few tenths of a millimeter (preferably c. 2 to 0.4 mm) smaller than the radial thickness of the hollow cylinder, that is, it is larger than its part assigned to the groove possible, when inserting or gluing this hollow cylindrical solid part, to center it precisely relative to the housing bottom, but in particular to the rotor shaft, and to achieve perfect alignment of the active, cylindrical solid part and the rotor shaft during the gluing process.

Through the groove is for the production of practical and advantageously at the same time also provided a bed for the Klebwerkstoff dose, in which fund in which dips) the end face of the hollow cylinder, the thus interconnected components for the required running characteristics usually have accurately machined and the Red a '.. ": h can still be balanced, in a costly manner in two planes, the invention would allow cheap, relatively imprecise parts, for example a die-cast part for the bottom of the red bell, to be used without machining _The rotor shaft and the hollow cylindrical solid part are fixed coaxially to one another by means of a device according to the invention and glued in this position, any remaining eccentricities of the parts, in particular in the variant described below, are irrelevant because the decisive parts, Shaft and the active, massive hollow (which can be machined cheaply and precisely before assembly) ring are exactly concentric to one another and the decisive mass of the solid cylindrical part can therefore practically not cause any unbalance effects. Any imbalance can therefore practically only occur on the light, almost flat case bottom and can be easily compensated there.

Since the casing of the rotor bell is essentially only formed by the hollow cylindrical Tsil (16), the rotor bell can Reduce to a rotor base part, which is made of conductive metal 1 part 1, especially as a die-cast part made of an aluminum alloy, but can also be formed from titanium, for example.

Y319454

In a further development of the invention, it is proposed that the adhesive material be an adhesive that does not change in practice either in its volume or in its shape due to hardening, preferably a fully polymerizing two-component adhesive. The subject of the invention, which is relatively large in volume, could cause weak points due to an adhesive that changes in volume or shape (with an expression of force!) When it hardens, or - due to a time lag (which may only appear later) - eccentricities receive. Known adhesives that act centering in an eccentric annular gap seem to be disadvantageous here. A two-component adhesive with the properties described above has surprisingly proven itself in tests with an exemplary embodiment under different operating conditions, particularly with regard to the stresses caused by temperature changes.

The task is due to another further development of the innovation: de, in the simplest way in the area of the groove the rotor bell or the rotor base without other disadvantages with the largest possible inner diameter to provide. To maintain safety distances or for technical reasons or required dimensions of the winding head, this inner diameter should not in any case smaller than the clear width of the hollow cylindrical solid part

^be · _r '! , + practical

One solution is that the part of the magnetic steel hollow cylinder (16) inserted into the groove (15b) is offset and a smaller part radial wall thickness than the immediately adjoining one Part of the hollow cylinder.

However, it is even more advantageous if the wall thickness of the Groove (15a) inserted part of the hollow cylinder (16) in the direction is steadily tapered towards the depth of the groove, preferably on the inside of the cylinder. Because such a taper on the front side of the hollow cylinder is easier to manufacture than a paragraph In diameter. Since the walls of the groove must not be very thin for reasons of casting technology, the cylinder wall thickness is tapered by expanding the inside diameter of the cylinder

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advantageous, because then there is one, also in terms of casting technology favorable, conically increasing strength of the inner groove wall in the direction of the groove depth, namely, if desired, from an extremely small initial wall thickness at the groove opening; this can easily be realized in terms of casting technology, if the increase in wall thickness is strong enough. Because when the hollow cylinder is immersed in the adhesive material Partially filled groove this in the series production process easily up and there on the less steep groove wall much faster overflows, were advantageously on the groove base over the circumference distributed, small-area surveys on which the hollow cylinder can partially rest.jThe drawing and the following description of which represents an exemplary embodiment of FIG Invention, with still other developments of the invention and advantages are explained.

The figure shows a partially schematically simplified representation an external rotor motor designed according to the invention. This consists essentially of the one carried by the bearing tube (1) Stator core 2 with winding located therein, whose End windings 3 and 4 are visible, as well as from the rotor bell 5, which is attached to the rotor shaft 6, which in known Manner is carried by the tube 1 by means of the bearings 7 and 9. This is attached in a flange plate 11, which means Thread 12 can be screwed into a (not shown) holder. The rotor bell 5 consists of a Si 1 uniin die-cast bottom part 14, which has a circumferential groove 15a or 15b, in which the designed as a hollow cylinder 16, ferromagnetic Part of the rotor is glued in, here for example a ring made of hysteresis material.

The profile of the groove 15a or 15b is based on the cross section of the inserted Part of the hollow cylinder 16 adapted in each case. In the Figure shows two embodiments for the groove profile.

In the embodiment shown on the left, the radial Width of the groove 15a steadily tapers towards the depth of the groove, namely by chamfering on the inside d ^ s Zy-1 In the S.

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In the embodiment shown on the right, the part of the hollow cylinder 16 inserted into the groove 15b is offset on its inside and has a slightly straight wall thickness inside the groove than the part directly adjoining the outside of the groove.

The embodiment shown on the left a of the groove 15 has the Disadvantage that if the adhesive is not as good as it is heated, a thrust effect could occur, which would affect the ferromagnetic part 16 would like to slide out of the groove 15a of the aluminum part 5. However, such a disadvantage was not observed with the above-mentioned adhesive.

In the case of the variant 15b shown on the right, in contrast in addition, the detached part of the ferromagnetic ring 16, when heated, tends to be even more firmly on the inner wall of the groove 15b of the Tensioned aluminum floor.

It is essential that the nominal dimensions for the inner and outer diameter of the groove as well as for the inner and outer diameter of the groove are used during manufacture to choose the outer diameter of the part of the honing cylinder 16 to be inserted into the groove in such a way that - in the radial direction seen - both on the outside and on the inside a sufficient distance of a few tenths of a millimeter is provided so that there is enough space for centering when gluing in.

Other characteristics and details of the Invention are characterized in the subclaims.

In the illustration on the left, a side wall of the part of the hollow cylinder 16 located in the groove has a groove-like depression 19, which contains metal glue.

Instead or in addition, as shown on the right, in a side wall of the groove, preferably in the radial direction seen outer side wall, a groove-like, circumferential Be arranged recess 17, in which there is metal adhesive.

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Such depressions increase at least (in the sense of a form fit connection) the strength of the adhesive connection according to the invention.

The metal 1 adhesive located in the area of the groove 15a or 15b between the wall of the groove on the one hand and the associated part of the hollow cylinder on the other hand is indicated by a broad black line.

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Claims (1)

Papst Motors KG - 7 - \ g . 5. 73 St. Georgen 055-HDP / Pe Pat. + HGM DT-151 Expectations 1.) Small electric motor with a bell-like rotor, which is an electric motor having active, hollow cylindrical solid part, on one end of which the bottom of the rotor bell is connected to the coaxial shaft of the rotor, characterized, that the shaft of the rotor (6) and the electromotive active, hollow cylindrical solid part (16) in a mutually coaxial position by an adhesive connection are fixed. Z.) Small electric motor according to claim 1, characterized by that the adhesive connection is provided on one end face of the hollow cylindrical part (16). 3.) Small electric motor according to claim 1 or 2, characterized in that that the bottom of the rotor bell has a groove (15) extending in the axial direction in its circumference, in which the end face of the hollow cylinder (16) is clipped in 4.) Small electric motor according to claim 3, characterized in that the groove (15) is one end of the Hollow cylinder (16) receives with radial play. 5.) Small electric motor according to one of claims 1-4, characterized, that the adhesive material by hardening neither in his Volume is still practically changing in its shape adhesive, preferably a polymerizing two-component adhesive. 7319454 07/28/77 I I> ι I ι ι - May 8-19, 1973 6.) Small electric motor according to claim 4 or characterized in, that the inserted into the groove 15b part of the magnetic steel hollow cylinder (16) is offset and a lower radial Wall thickness than the immediately adjoining part of the Hollow cylinder. 7.) .Electric small motor according to claim 4 od ^ r δ, characterized in that the wall thickness of the part inserted into the groove 15a of the hollow cylinder (16) steadily in the direction of the depth of the groove is increasingly tapered, preferably on the inside of the cylinder. 8.) Small electric motor according to one of claims 4-7, characterized in that that at least one side wall of the groove, preferably in the outer side wall (seen in the radial direction) Groove-like, circumferential recess 17 is arranged in the adhesive material is located. 9.) Small electric motor according to one of claims 4-8, characterized in that that one or both side walls of the part of the hollow cylinder (16) located in the groove have a groove-like depression (19), in which there is adhesive material. 10.) Small electric motor according to one of claims 1-9, characterized, e.g. that the annular groove (15) was distributed around the circumference of the groove base, has short points which rise axially from the groove bottom by a fraction of the groove depth. 11.) Electric motor according to one of claims 1-10, characterized in that 7319454 28.i7.77 I 1 <1 1 (1 - May 9-19, 1973 that the shell of the rotor bell essentially only through the hollow cylindrical part (16) is formed. 12. Small electric motor according to one of claims 1 - 11, dadurcr, characterized in that the rotor bell has an outer barrel r housing forms. 7319454 07/28/77