DE2222666A1 - ELECTRICAL MACHINE, IN PARTICULAR SMALL ENGINE, AND DEVICE FOR MANUFACTURING THIS MACHINE - Google Patents

Description

R.876
January 18, 1972 Sa / Kb

Attachment to
Patent and
Utility model registration

R03ERT BOSCH GMBH, 7 Stuttgart 1

Electric machine, in particular small motor, and device for producing this machine

The invention relates to an electrical machine, in particular a small motor, with permanent magnetic, im Cross-section of ring segment-shaped field magnets, each other Gegenliegend.an the inner wall of a composite of two shells, forming part of a motor housing, annular iron back yoke body are arranged in a position in which the parting plane leading through the back yoke body lies in the magnetically neutral plane of the motor, with the field magnets being overmoulded with plastic on the shells of the return path body are held.

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309847/0160

Robert Bosch GmbH R. 8 7 6 Sa / Kb

Stuttgart

So that between the inner wall of the annular iron back yoke body and the convex outer surface of the field magnet creates a magnetically optimally conductive connection, the two mutually facing surfaces of these parts should have the same radius as possible. With field magnets some of them are relatively small in relation to the motor armature this requirement can still be achieved with a reasonable amount of effort. For the sake of an improved Armature flux, which brings with it a higher motor efficiency, on the other hand, the greatest possible over striving for coverage angle. In the production of permanent magnetic field magnets with a large overlap angle results However, the difficulty that the inner wall of the return path body to provide facing lateral surface of the magnet body with the required radius, because with increasing The overlap angle, the shrinkage that occurs after pressing and the associated form deviation do not affect the grip is to get.

It has already been proposed that the finished magnetic body in an additional and expensive operation accordingly be ground to the requirements.

In a known electrical machine of the type mentioned at the beginning, the field magnets are so in the iron back yoke body arranged that the joints of the yoke shells in the area of the permanent magnets, preferably in their center lie. As a result, the dimensional tolerances of the ring segment shaped ge n permanent magnets can be intercepted so that always there is an equal air gap between the rotor and the magnet, influencing the air gap between the Back-yoke body and the field magnet is not

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Robert Bosch GmbH R. 8 7 6 Sa / Kb

Stuttgart 2222666

possible. Next is the removal of the finished ring-shaped Magnet system from the injection mold difficult because it has to be drawn off from a cylindrical mold core, which is especially due to the shrinking effect occurring after spraying is problematic

The invention is based on the object of developing such electrical machines in such a way that they can be increased in a simple manner the efficiency is achieved and at the same time a economic production of the magnet system should be guaranteed.

According to the invention this is achieved in that the field magnets are divided in the parting plane of the yoke body, and that the component forming the magnet system consists of two halves is composed, each half containing a back yoke body shell and the magnetic parts associated therewith. Due to the division of the field magnets and the associated increased pressing accuracy, the outer circumferential surfaces of the subsegments abut the inner wall of the iron back yoke body achieved, as it is possible with field magnets with a small overlap angle, although the field magnets at to find the engine according to the invention use, a can have a large overlap angle, further a division of the magnet system is made possible so that individual Shells are pressed that are easily removed from the injection mold can be.

Further advantages in the assembly of the machine result if, in a further development of the invention, the two halves of the Components are built in mirror image to one another and can be put together in a suitable manner.

In a further embodiment of the invention, those facing each other are located Longitudinal edges of the back yoke body shells at a distance

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Robert Bosch GmbH R. 8 7 6 Sa / Kb

Stuttgart

from each other. By a corresponding width of the air gap thus formed in the magnetically neutral plane of the motor The armature transverse field can be influenced in the yoke body. Then, after overmoulding with plastic, the motor housing halves are placed obtained with a view to the further assembly of the motor compared to the annular housing after the encapsulation have significant advantages in the known machine.

Appropriately, each back yoke body shell are one half of the north pole and one half of the south pole of the assigned to both field magnets formed magnet system.

A further simplification of the assembly of the motor is given, if in an embodiment of the invention to the rucks chlußköroerschalen End shields and mounts for bearing elements for the motor shaft are molded on.

With a view to good engine ventilation, it is also provided that the receptacles for the bearing elements are overmolded Ribs are connected to the yoke body shells.

The recordings for the Lagereler.ente advantageously have niches for lubricant carriers.

A brush support bar, which is customary in the known motors, can be omitted if, according to a further development of the invention on each motor housing half between the collector-side receptacle for the bearing element and the one injected into this half Back yoke shell guide means for carbon brushes are molded on.

So that the carbon brushes can be pressed against the collector via levers mounted next to brush holders, the Brush holder in a side wall an open-edged slot for a spring-loaded lever, which is attached to the The end of the carbon brush facing away from the collector rests.

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Robert Bosch GmbH R. 8 7 6 Sa / Kb

Stuttgart

A simple storage of the brush pressure lever is achieved when it is close to its facing away from the carbon brush End rests on a bearing edge molded onto the motor housing half and if further between the A spring engages both support points of the lever on the carbon brush and the bearing edge.

So that the two motor housing halves are easily connected to each other can be, it is particularly advantageous if on the inner surfaces of flange-like flaps of the one Housing half pegs are provided which are perpendicular to these surfaces and the housing halves that are joined together extend through their associated recesses in the other housing half and lock there.

This is a useful link between the two Motor housing parts achieved in that the pins are slotted in their axial direction, made of a resilient material exist and have a larger diameter at their free ends than the recesses assigned to them.

The pins are preferably molded onto the housing halves.

Further advantages with regard to the motor mounting are given if the motor housing halves have holding means for more Engine components are molded on.

A relief when installing the finished motor at its destination is given if the motor housing shells Means for fixing and / or fastening the motor in its operating position are molded on.

The invention is described below on the basis of exemplary embodiments explained in more detail. Show it:

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Fig. 1 shows the cross section through a field magnet system as it

is used in the engine according to the invention, FIG. 2 shows a motor housing half with one half of the field magnet system according to FIG. 1 in perspective Depiction,

FIG. 3 is a plan view of the motor housing half according to FIG. with inserted bearing elements for the built-in

Motor armature,
Fig. 4 shows a possible arrangement of the brush guide and the

Brush pressing device in partial section, FIG. 4a a partial view of the brush guide according to FIG. ¹ J in

Direction of arrow A in Fig. ¹ J, but without pressure lever and carbon brush,
Fig. 5 is a plan view of a drive motor, the ab-

A worm gear is assigned on the drive side, with the motor and gear being housed in a single housing and one housing half being removed,
FIG. 6 shows a cross section through the complete housing according to FIG.

5 and "

7 shows a cross section through a Soritz mold for production of magnet system halves or motor housing shells.

In the field magnet system 10 (Fig. 1) one not shown DC motor consists of the ring-shaped iron return path

11 from two shells 11a on their inner lateral surfaces opposite one another, two permanent magnetic ones, in cross section ring segment-shaped field magnets 12 are arranged. Every magnet

12 is composed of two magnet parts 12a in such a way that the parting line 13 extends radially between the two parts 12a. The parting line 13 lies in the plane in which the parting line IM between the two shells 11a of the iron return body lies. The field magnet system 10 itself consists of two halves 15 constructed in mirror image to one another. Each half 15 contains a backflow body shell 11a, on its inner

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Robert Bosch GmbH 1. ^{y ö} Sa / Kb

Stuttgart

A magnetic part 12a of the two magnetic poles 12 is arranged at a distance from one another. The magnet parts 12a are connected to the yoke body shells 11a assigned to them by overmolding with plastic IJ . In order to ensure that the magnet parts 12a are held securely on the yoke body shells 11a, the magnet parts 12a can, for example, be provided with recesses in their areas embedded in the plastic. into which the plastic can penetrate during injection. The plastic 17 connects the magnet parts 12a and the yoke body ehale 11a connecting these parts in a bridge-like manner to form a half-shell 15 which, together with a second, identical half-shell, results in a motorized part, namely the field magnet system 10. The longitudinal edges l8 / of the half-shells 15 ″, which rest against one another after they have been joined, are formed by side surfaces of the magnet parts 12a and plastic layers 19. The plastic layers 19 / fill a gap created by the longitudinal edges of the yoke body shells lla opposite the longitudinal edges or side surfaces of the Magnet parts 12a are set back. "When two half-shells 15 are fitted together in the manner shown in FIG. 1 and thus form the magnet system 10, the magnet parts 12a of magnetic poles of the same name rest against one another. The longitudinal edges of the yoke body shells 11a facing one another are at a distance from one another. The area of the mutually facing longitudinal edges of the shells 11a therefore lies in the magnetically neutral zone of the motor or magnet system 10. Furthermore, the field magnets 12 are also divided in the area that remains between the mutually facing longitudinal edges of the yoke body shells 11a. The entire magnet system 10 accordingly has a parting line / which lies exactly in its magnetically neutral zone.

In Fig. 2, one half 15 of the field map system is shown, to which further engine components are injected during the encapsulation

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Robert Bosch GmbH R. 8 7 6 Sa / Kb

Stuttgart

have been, so that a complete motor housing half 110 is present, in which one half of the field magnet system is integrated. By fitting two of these together Motor housing halves 110 with a corresponding arrangement of magnet parts 12a are then used to form the motor housing. Every Motor housing half 110 has halves of end shields 111, ■ in which receptacles 112 for bearing elements 113 for the Motor shaft 114 (Fig. 3) are provided. These recordings also have niches 115 for lubricant carriers arranged in these feed the lubricant continuously to the bearing point. The end shield halves 111 are over Ribs 116, likewise injection-molded, are connected to the magnet system half 15. These ribs 116 also support the Magnet parts 12a in the axial direction of the motor. Between the collector-side end shield half 111 and half of the Magnet system 15 are provided in the motor half 110 guide grooves 117 for carbon brushes. The depth of the grooves 117 is slightly larger than half the thickness of the brushes, so that they can move easily after joining two motor housing halves 110.

However, it is also possible that on each motor housing half one brush holder 217 each, which is closed in the circumferential direction is injected (Fig. 4 and Fig.4a). In a side wall 217a an open-edged slot 218 is then provided through which a pressure lever 219 extends with one end on the from the collector 216 of the motor facing away from the end of a Carbon brush 220 rests. The other end of the lever 219 lies on a bearing-cutting edge-shaped, molded-on support nose 221 on. By means of a tension spring 222, which engages between the support lug 221 and the lever 219, this direction of the arrow becomes

loaded, so that the carbon brush 220 on the collector 216 remains applied. The lever 219 itself is bent from a stiff wire in the present case. However, he can also take off cut out of a sheet metal or made of plastic.

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Robert Bosch GmbH R. # 76 Sa / Kb.

Stuttgart

On the motor housing half 110 (Pig. 2 and 3) are further molded flange-like tabs 150, which extend parallel to The separating plane of the magnet system 15 and its inner, when the motor housing halves 110 are joined together, extend to the other half facing surfaces are at least approximately in this parting plane. On the inner surfaces of the tabs 150 are also two locking pins 151, which are arranged diagonally opposite one another and are preferably injection-molded onto the tabs 150, are provided. These Latching pins 151 are essentially perpendicular to the mutually facing surfaces of the tabs 150 and are on their free ends thicker than the diameter of recesses 152, which are also provided in the tabs 150 and the Latching pins 151 are assigned to the other second housing half required to form a complete motor housing. The locking pins 151 are provided at their free ends with a cross slot running in the axial direction, so that her thickened head can be pressed together resiliently. When joining two housing halves, you can press the locking pins 151 of one housing half through the recesses assigned to them in the other housing half until the thickened head of the locking pin on the other side of the Laopes 150 comes out again, spreads and thereby the two motor housing halves are locked together.

However, it is also possible, when manufacturing the motor housing halves according to FIGS. 2 to 4, to attach to the halves at the same time Corresponding halves of a gear housing 210 are to be molded on (FIG. 5). In addition to spraying recordings for bearing elements 211 for the motor shaft 212, the receptacles for the bearing elements of the worm wheel 213 and Recordings for adjusting means 214, 215 to limit the longitudinal play of the motor shaft 212 are injection-molded. In the gearbox an adjusting screw 214 is provided for this purpose, with which the motor shaft 212 can be pushed against a stop plate 215 which is inserted in a receptacle of the motor housing. Can continue

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Robert Bosch GmbH R. ^{8 7} δ Sa / Kb

Stuttgart

one injection-molded half-shell 216 of the engine and gearbox housing in their edge areas with a circumferential groove 217 and the other half-shells 218 with one that fits into the groove 217 Sealing edge 219 be provided (Fig. 6).

When injecting the motor housing halves, additional holding means for additional motor components, such as interference suppression elements, Rectifier and brush pressure spring are also molded on.

Furthermore, during the injection molding process, tabs 220 with recesses 221 can be attached to the magnet system halves 15 (FIG. 1) or also to the Motor housing halves 110 (Fig. 2) are molded on, which are used when installing the motor at its place of installation for motor mounting and fixation serve.

Finally, it is also conceivable to have engine characteristics that are usually noted on a rating plate, which was previously in a further operation on the motor housing must be attached to the housing with a corresponding design of the injection mold.

An injection mold 316 (FIG. 7) for producing the magnet system halves 15 or the housing halves 110 or 210 has a lower part 317 and an upper part 318. The lower part 317 has a cross-section semicircular core 319, the radius r of which is the radius of the motor armature plus the air gap width between armature and corresponds to the inner surface of the field magnets. When collapsed, mold 316 extends spaced from the core and concentrically therewith the inner wall 322 of a cavity in the upper part 3l8. The radius R of this inner wall 320 is greater than 'the sum of the following dimensions including the permitted Tolerances:

1. Radius of the core 319 »

2. maximum thickness of the magnet parts 12a and

3. maximum thickness of the yoke body shell 11a.

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Robert Bosch GmbH ff R. g 7 5 Sa / Kb '*

Stuttgart

This ensures that _s if the magnetic members 12a and the short-circuit body shell are in together driven mold 316 inserted 11a in the position shown in Fig. 7 manner in the mold part 317 and a resilient holding-down device 320, these parts firmly presses on the core 319, between the outer surface a gap remains between the return body shell and the inner wall 322. This gap, the width of which is measured radially to the yoke body shell 11a, depends on the thickness tolerances of the magnet parts 12a and the shell 11a, is also filled with plastic 17 during the SpritζVorganges so that the parts coming out of the mold always have the same outer radius. This feature can be implemented independently of the radius r of the device core, so that machines of different types can be held with the same fastening means engaging the circumference of the housing.

So that the between the mutually facing side surfaces of the magnet parts 12a of the same half-shell 15 is not unnecessarily large Plastic 17 must be injected, the mold core 319 has a Extension 321, which extends between the spaced apart magnet parts 12a.

It can also prove to be advantageous if the depth of the receptacles, e.g. for the bearing elements or the interference suppression means is dimensioned so that they are clamped together in their receptacles by fastening two housing shells to one another. This means that it is perpendicular to the parting plane of the motor housing halves measured, for example, the bearing elements protrude further from their recordings than they were taken up by these recordings will.

Another advantage of the motor according to the invention can be seen in the fact that its housing is divided in the axial direction so that all can be introduced particularly easily into the housing parts to be assembled.

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Claims (1)

Robert Bosch GmbH R. 8 7 6 Sa / Kb Stuttgart Expectations / 1.j Electric machine, in particular small motor, with permanent magnetic field magnets with the shape of a ring segment in cross-section, the opposite to each other on the inner wall of a composed of two shells, forming part of a motor housing, annular iron back yoke body are arranged in a position in which the parting plane leading through the back yoke grains lies in the magnetically neutral plane of the motor, with the field magnets being overmoulded with plastic on the shells of the back yoke body are held, characterized in that the field magnets (12) in the parting plane of the back yoke body (11) are divided, and that the component (10) forming the field magnet system is composed of two halves (15), each half containing a yoke body shell (Ha) and the magnetic parts (12a) assigned to it. 2. Machine according to claim 1, characterized in that the the two halves (15) of the component (10) are mirror images of one another and can be fitted together in a suitable manner. 3. Machine according to claim 2, characterized in that the mutually facing longitudinal edges of the Ruckschlussköroerschale (lla) with an assembled magnet system (10) at a distance lie apart. -13- 309847/0160 Robert Bosch GmbH ¹ R. ^ 7 5 'Sa / Kb Stuttgart 2222666. ¹ J. Machine according to one of Claims 1 to 3, characterized in that each back yoke body shell (11a) has one half of the North Pole and a half of the South Pole of the by the two field magnets (12) formed magnet system are assigned. 5. Machine according to one of claims 1 to 4, characterized in that that on each half (15) of the component forming the magnet system (10) halves of end shields (111) with Recordings (112) for bearing elements (113) of the motor shaft (14) are injection-molded so that complete motor housing halves (110) are formed. 6. Machine according to claim 5, characterized in that perpendicular to the parting plane of the motor housing halves (110) measured the bearing elements (113) further from their receptacles (112) a Housing halves (110) protrude when they are received by the receptacles (112). 7. Machine according to one of claims 5 or 6, characterized in that that the halves of the end shields (111) are connected to the halves (15) of the magnet system (10) via ribs (II6). 8. Machine according to one of claims 5 to 7, characterized in that that the receptacles (112) for the bearing elements (113) each with a niche (115) for lubricant carriers are provided. 309847/0160 Robert Bosch GmbH R. 8 7 6 'Sa / Kb 9. Machine according to one of claims 5 to 8, characterized in that that on each motor housing half (110) between the collector-side receptacle (112) for the bearing element (113) and the back yoke shell (11a) injected in this half guide means (117) for carbon brushes are molded on. 10. Machine according to claim 9 »characterized in that the guide means are designed as a brush holder (217), a brush holder (217) being provided on each motor housing half (110). 11. Machine according to claim 10, characterized in that in a side wall (217a) of the brush holder (217) Open-edged slot (218) for a spring-loaded lever (219) is provided, which rests on the end of the carbon brush (220) facing away from the collector. 12. Machine according to claim 11, characterized in that the lever (219) close to its facing away from the carbon brush (220) End rests on a bearing edge (221) molded onto the motor housing half (110) and that between the two A spring (222) engages the support points of the lever (219) on the carbon brush (220) and the bearing cutter (221). 309847/0160 " ^{± 5} ~ Robert Bosch GmbH 'R. 8 7 6 Sa / Kb Stuttgart 2222666 13. Machine according to one of claims 5 to 12, characterized in that that on each motor housing half (110) flange-like tabs (150) are injection-molded, which are parallel to the parting plane of the magnet system (10) and their inner, when the motor housing halves (110) are joined together, the other The surfaces facing the motor housing half (110) lie at least approximately in this parting plane. Ik. Machine according to claim 13j, characterized in that pins (151) are provided on the inner surfaces of the flange-like tabs (150) of one housing half (110), which are perpendicular to these surfaces and which are associated with them when the housing halves (110) are joined Recesses (152) extend in the other housing half (110) and lock there. 15. Machine according to claim 14, characterized in that the Pins (151) are slotted in their axial direction, made of a resilient material and at their free ends have a larger diameter than the recesses (152) assigned to them. 16. Machine according to one of claims I ¹ I or I5, characterized in that the pins (151) are injection-molded onto the motor housing halves (110). 30 984 7/0 160 ~ ^l6 ~ -16-Robert Bosch GmbH ^{R 8 7 6} Sa / Kb 17. Machine according to one of claims 5 to 16, characterized in that that one half (210) of a gear housing is injection-molded onto each motor housing half (110). 18. Machine according to claim 17, characterized in that the gear housing halves (210) next to injected receptacles For bearing elements (211) injected mounts for adjustment means (214,215) to limit the longitudinal play of the motor shaft (212). 19. Machine according to one of claims 5 to 18, characterized in that that holding means for further engine components are molded onto the engine housing halves (110). 20. Machine according to one of claims 5 to 19 »characterized in that that on the motor housing shells (110) means (220, 221) for fixing and / or fastening the motor in its Operating position are molded. 21. Device for producing a motor housing half according to one of claims 5 to 20 with a core on which the Magnet parts are applied and with an inner wall located at a distance from the core when the device is closed, characterized in that the distance between the inner wall (32 2) and the core (319) is greater than the sum of the maximum thickness of the magnet parts (12a) and the maximum 309847/0160 -17- -17-Robert Bosch GmbH R. 37g Sa / Kb Thickness of the yoke body shells (lla), including the permitted tolerances. 22. The device according to claim 21, characterized in that regardless of the radius (r) of the device core (319) Inner wall (32 2) of the device (316) always has the same "radius (R). 23. The device according to claim 21, characterized in that the mold core (319) has a projection (321) which extends between the spaced apart magnet parts (12a) extends. 2k. Device according to one of the claims. 21 to 23, characterized in that the injection mold (316) is provided with the characteristic data of the motor, preferably in the area of the inner wall (322). 309847/0160 Blank page