JPH0847186A - Electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently reduce the noise level of a machine by means of the hard fastening of a stator between housing half parts and to improve the engagement of a stator bedding iron core between the housing half parts within the range a fastening screw. SOLUTION: Individual bedding boards 11a of the stator bedding iron core 11, which are fastened between contact faces 31 provided for the housing half parts 13 and 14 and a centering face, are mutually connected by at least two welding seams 32 which are arranged symmetrically on the both sides of, with respect to a fastening screw 15 providing small intervals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-phase alternating-current generator for use in electric machines, in particular motor vehicles, which is provided with a two-part housing screwed to each other by tightening screws. A housing serves for supporting the rotor and for clamping the stator, the laminated core of the stator consisting of individual laminated plates which are connected to each other on the outer peripheral surface by rigid longitudinal joints, in particular welded seams,
The present invention relates to a type in which the stator is housed by at least a plurality of individual laminated plates located in the outer edge region thereof by a contact surface and a centering surface provided on at least one of the two housing halves.

[0002]

2. Description of the Prior Art A three-phase AC generator of this type is known from German Utility Model Specification No. 9107542. In this known construction, the laminated cores are connected to each other by welding seams provided on the outer peripheral surface.

Published German patent application No. 4121
In the known three-phase AC generator according to the specification No. 734, only some of the laminated thin plates in the middle of the stator laminated iron core are provided with forming portions on the outer peripheral surface in the range where the tightening screws are located. The part is housed between two housing halves with a contact surface and a centering surface. further,
In order to bind the stator laminated core, instead of the weld seam provided on the outer peripheral surface, the laminated core is riveted to each other at a plurality of points, or via a groove-shaped punched ridge provided on the individual laminated plate. It is also known that they combine with each other.

The disadvantage of the above-mentioned known means is that it is not sufficiently rigid in the region of the clamping screw, in the region of clamping of the stator core, especially between the two housing halves of the machine. That is, the vibration excitation propagates to the housing through this tightening range. The magnetically generated vibrations thus emitted outward in the form of sound waves, together with bearing noise and ventilation noise, create an additional significant noise level over a range of machine speeds of any magnitude. .

[0005]

The object of the present invention is to improve an electric machine of the type mentioned at the outset such that the noise level of the machine is sufficient by virtue of the tight clamping of the stator between the two housing halves of the machine. It is an object of the invention to provide an electric machine which, while being reduced, has an improved fit of the stator laminated core between the two housing halves in the region of the clamping screw.

[0006]

In order to solve this problem, according to the structure of the present invention, the individual laminated plate of the stator laminated iron core is tightened between the contact surface and the centering surface provided on both housing half portions. Are connected to each other by at least two longitudinal joints, preferably welded seams, which are symmetrically spaced apart on both sides with respect to the clamping screw.

[0007]

The electric machine according to the present invention has the following advantages. That is to say, in the region of the contact surface and the centering surface of the stator core provided on both housing halves, the rigid lamination of the lamination plate by two longitudinal joints each preferably formed as a weld seam. Forming a plate composite, which is defined and clamped tightly between the two housing halves by clamping screws which are arranged symmetrically with respect to the plate composite, respectively. . This has the following additional advantages. That is, the laminated core of the stator is no longer elastically pressed against the contact surface and the centering surface by the screw fastening of the housing halves, but is housed between the housing halves with little tension. Furthermore, such a binding of the laminated core of the stator with paired welded seams allows for a correct stator clamping of the fit and radial centering without play.

[0008] The measures described in claims 2 and below enable advantageous refinements of the electric machine according to claim 1. It is particularly advantageous if the contact surface and the centering surface provided on the two housing halves are designed as annular sections and are arranged symmetrically with respect to the clamping screw. Another advantageous means is provided for radially fixing the stator. In this case, at least one of the two housing halves is symmetrical with respect to the tightening screw, and the annular section of each housing half is in press-fit contact with the outer peripheral surface of the laminated core of the stator. The part is an annular section with a centering surface, which has a moment of resistance against radial forces higher than the circumferential extent of the housing half located between them.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings.

The three-phase AC generator used in an automobile, which is shown in a longitudinal sectional view in FIG. 1, mainly has a stator 10. The stator 10 is formed as a layered laminated core 11. The laminated core 11 holds a three-phase stator coil 12. The laminated core 11 is tightened between the housing halves 13 and 14 by a tightening screw 15. Both housing halves 13, 14 form a bearing shield on the end face side. A relatively large drive side bearing 16 is inserted on the drive side into this bearing shield,
On the brush side, a relatively weak slip ring bearing 17 is inserted. In the stator 10, the claw pole type rotor 18 is provided.
Is arranged. The claw pole type rotor 18 is composed of two claw pole plates 19 and 20, and a magnetic flux guide piece 21 clamped and fixed between the claw pole plates 19 and 20. An exciting coil 22 is attached to the magnetic flux guide piece 21. The claw pole type rotor 18 is press-fitted onto the rotor shaft 23, and the rotor shaft 23 is housed in both bearings 16 and 17. The rotor shaft 23 has a threaded projection 24 at the drive end for fixing the drive disk. Further, on the rotor shaft 23, one fan plate 25, 26 for fixing the heat loss of the three-phase AC generator is fixed on both sides of the claw pole type rotor 18. The exciting coil 2 is attached to the brush-side end of the rotor shaft 23.
The slip ring device for powering 2 is fixed. This slip ring device is connected to a regulator 28 and a rectifying unit (not shown) via a carbon brush of a brush holder 27. By means of this rectifying unit, the three-phase alternating current formed is converted into direct current for powering the vehicle's on-board power supply and the charging battery.
The regulator 28 and the rectifying component unit are further surrounded by a pot-shaped cover cap 29. This cover cap 29 is likewise fixed to the brush-side housing half 14 and houses the electrical connection 30 of the generator.

FIG. 2 shows the fastening points of the laminated core 11 of the stator between the housing halves 13 and 14. In this case, the individual laminated plate 1 in which the laminated core 11 is tightened
1a is a contact surface 3 provided on the housing halves 13 and 14
In the range 1), they are rigidly connected to one another by welding seams 32 symmetrically on each side with respect to the clamping screw 15. Due to the axial protrusions 33 provided on the housing halves 13 and 14 in the range where the tightening screw 15 is located,
The contact surface 31 and the centering surface 34, which is visible in FIG. 1 and which is radially adjacent to the contact surface 31, are arranged symmetrically with respect to the clamping screw 15 as annular sections. In combination with FIG. 2, it can be seen from FIG. 3 that, in a part of the laminated core 11, the weld seams 32 are paired with each other and are circumferentially displaced from each other by a tooth pitch of, for example, 10 ° with respect to the tightening screw 15. It can be seen that they extend in parallel. Furthermore, it can be seen from FIG. 3 that the weld seam 32 is laid in the groove 35. The grooves 35 have the outer diameter of the laminated core 11 and are arranged above the tooth centers of the individual laminated plates having the internal tooth rows. Like the tightening screw 15, the weld seam 32 also extends at a right angle to the end surface 11 b of the laminated core 11. Between the two weld seams 32 shown in FIG. 3, three stator teeth 36 of the three-phase stator coil 12 are provided.
It can be seen that the angular division of the weld seam 32, which has, for example, 20 °, is not harmonious with the pole pitch T of the generator since

FIG. 4 and FIG. 5 show a part of a three-phase AC generator having a stator fastening portion in a second embodiment of the present invention. In this case, the same reference numerals are used for the same components as in the first embodiment. Second
In the example, both housing halves 13 at this location,
The 14 configurations are slightly different. What is important in this case is that the stator 10 in both housing halves 13 and 14 is fixed in position in the radial direction by press fitting. In this case, a centering surface 34 with a slightly smaller diameter, which is provided symmetrically with respect to the clamping screw 15 over an annular section 37 provided in the housing halves 13, 14, has a slightly smaller diameter.
The outer peripheral surface of the individual layered plate 11a on the outer side of 1 is covered by press fitting. For this purpose, both housing halves 13, 14 are formed in the annular section 37 of the centering surface 34 by a radial increase 38 in the region of the clamping screw 15. The increased diameter portion 38 is provided in the circumferential range 3 of the housing halves 13 and 14 located therebetween.
9 has a higher resistance moment to the radial force. On the one hand, the centering surface 3 to the laminated core 11
The circumferential range 39 of the housing halves 13 and 14 located between the tightening points is elastically bent in the radial direction when 4 is pressed, while on the other hand heat loss is derived from the laminated core 11 by the air flow. In order to achieve the above, the walls of the housing halves 13 and 14 surrounding the laminated core 11 are provided with an air gap 40 to the outer peripheral surface of the laminated core 11 in the circumferential range 39 located between the centering surfaces 34. There is. Due to the increased diameter portion 38 provided at the tightening portion of the laminated core 11, the housing half portion 1 on the centering surface 34
The radial resistance moments 3 and 14 are at least twice as large as the circumferential range 39 located therebetween.

FIGS. 6 to 8 show a half portion of the bearing shield on the driving side of the three-phase AC generator, that is, the upper portion of the housing half portion 13 as a third embodiment of the present invention. FIG. 6 shows a plan view of the housing half 13 as seen from the stator side, taken along line VI-VI in FIG. 7. Figure 7
6 shows a cross-sectional view of the housing half 13 along the line VII-VII of FIG. 6, and FIG.
Corresponding cross-sections along the line II-VIII are shown. In this case as well, the contact surface 31 and the centering surface 34 are formed symmetrically with respect to the tightening screw 15 over the respective annular sections 37 at the tightening points. An annular section 37 with a centering surface 34 is in this case shown in FIG.
And as in the embodiment shown in FIG. 2, the web 41 is oriented substantially radially for the purpose of radial reinforcement.
Via the bearing hub 42 of the housing half 13. The webs 41 are arranged in pairs and symmetrically on either side of the clamping screw 15. Between each annular section 37 with the contact surface 31 and the centering surface 34, the housing half 13 is provided on the end side with segmented ventilation openings 43, 44. In this case, the ventilation openings 43 on the outer side in the radial direction project into this circumferential area 39 in order to reduce the radial resistance moment of the circumferential area 39 located radially outside (FIG. 8). Airflow can enter through the inner vent openings 44. This air flow is guided to the winding head of the stator 10 via a radial fan plate 26 attached to the machine rotor, and from this location to the outer ventilation openings 43 and the air gap 40 of the laminated core 11. Derived outward on the upper side.

A relatively long circumferential range 3 between each tightening point
In a relatively high power electric machine, such as the one in which 9 is located, the walls of the housing halves 13 and 14 each have an annular section 37 with a contact surface 31 and a centering surface 34 as shown in FIG. It is advantageous to have further radial projections 45 each directed inward in the circumferential region 39 located between the two. This radial projection 45 additionally clamps the laminated sheet on the end face side of the laminated core 11 in the radial and / or axial direction. In addition, the housing half 1 of the electric machine, manufactured from aluminum die casting
At the time of molding 3, 14, as shown in FIGS. 4 and 5, the notch 48 is machined in the annular section 37 in the range of the threaded hole 46 or the through hole 47 for the tightening screw 15. Is advantageous. As a result, in each toroidal section 37, the centering surface 34 is divided into two centering surfaces 34a symmetrically spaced with respect to the clamping screw 15.

The present invention is not limited to the embodiment shown, in order to obtain a correct fit, a low tension and a stator clamp as rigid as possible against excitation. That is, instead of the axially extending paired weld seams 32, the weld seams extend parallel in pairs but are arranged to intersect axially. That can also be advantageous. In this case, in order to further reinforce the laminated core 11 of the stator, paired parallel weld seams 32 are crossed in opposite directions with respect to adjacent pairs of weld seams. further,
A plurality of axial and radial fixings of the stator 10 on the housing halves 13 and 14 are carried out in different angular ranges on the circumferential surface of the stator, for example with eight axial contacts and four radial fixing points. You can also On the basis of the bending-rigid partial annular section 37 and the bending-elastically located circumferential area 39 designed for cooling air guidance, the intent is compared with the known 360 ° tightening. At the same time a vibratingly rigid, compact and clear stator contact for the tightening force transfer and a good contact connection for the heat transfer from the stator 10 to the housing halves 13 and 14 are obtained. The advantage is that noise reduction is also obtained. Housing half 1
The partial axial tightening of the stator between 3, 14 further allows a play-free fit without a tedious heat-critical shrink fit. A housing half made of aluminum, for example, and a stator 10 made of steel sheet, for example.
Due to the flexural elastic bearing shield area between the respective stator clamping points, the different coefficients of thermal expansion of the two lead to very little stator deformation when the temperature changes. Also, with the arrangement according to the invention, the production of the laminated core 11 and the housing halves 13, 14 is also cheaper than the conventional means due to the improved error compensation.

Instead of welded seams, the laminated sheets of the laminated core 11 are in some other form partially rigidly connected to each other by longitudinal joints, for example via riveting, joining by punching ridges in individual laminated sheets, gluing, etc. can do.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a generator used in an automobile showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a tightening portion of a stator.

FIG. 3 is a transverse cross-sectional view showing a part of a stator laminated core provided with a pair of weld seams.

FIG. 4 is a vertical sectional view of a tightening portion according to a second embodiment of the present invention.

5 is a front view of a cross section taken along line IV-IV in FIG. 4. FIG.

FIG. 6 is a plan view of a contact portion and a centering portion of a housing half according to a third embodiment of the present invention.

FIG. 7 is a vertical cross-sectional view of the reinforcing rib taken along line VV of FIG.

8 is a vertical cross-sectional view taken along line VI-VI of FIG.

[Explanation of symbols]

10 stator, 11 laminated iron core, 11a individual laminated plate, 11b end face, 12 stator coil, 1
3,14 Housing half, 15 Tightening screw, 1
6 drive side bearings, 17 slip ring bearings,
18 claw pole type rotor, 19 and 20 claw pole plate, 2
DESCRIPTION OF SYMBOLS 1 magnetic pole guide piece, 22 excitation coil, 23 rotor shaft, 24 threaded protrusion, 25, 26 fan plate,
27 Brush Holder, 28 Regulator, 29
Cover cap, 30 connection part, 31 contact surface,
32 Weld seams, 33 Protrusions, 34, 34a Centering surface, 35 Grooves, 36 Stator teeth, 3
7 annular section, 38 increased diameter section, 39 circumferential range,
40 air gaps, 41 webs, 42 bearing hubs, 43,44 vent openings, 45 radial projections, 46 threaded holes, 47 through holes, 48 notches

Claims (14)

[Claims] 1. An electric machine comprising a two-part housing screwed together by means of a tightening screw, said housing acting to support a rotor and to tighten a stator, said stator comprising: In the outer peripheral surface of the laminated core, said stator being connected to each other by rigid longitudinal joints, said stator being at least a plurality of individual laminated plates located in the outer edge region thereof, at least in both housing halves. In the type of housing accommodated by the contact surface and the centering surface provided on one housing half, both housing half (13, 1)
4) The stator laminated core (11) clamped between the contact surface (31) and the centering surface (34)
Individual laminated plates (11a) of the invention are connected to each other by at least two longitudinal joints (32) which are symmetrically spaced on both sides with respect to the clamping screw (15). Let's say an electric machine. 2. The longitudinal joints formed as welded seams (32) have an unequal angular pitch in the circumferential direction and at least about one tooth pitch on both sides with respect to the tightening screw (15). The electric machine according to claim 1, wherein the electric machines are offset from each other and extend parallel to each other. 3. A weld seam (32) is laid in a groove (35), said groove (35) being the outside diameter of the laminated core (11) and having an individual tooth sequence (11a). 3. The electric machine according to claim 1, wherein the electric machine is arranged above the tooth centers of the electric machines. 4. The electric machine according to claim 1, wherein the weld seam (32) extends axially at right angles to the end face of the laminated core (11). 5. The angle division of the weld seam (32) is inconsistent with the magnetic pole pitch T of the machine.
The electric machine according to claim 1. 6. The contact surface (31) and the centering surface (34) are formed as an annular section (37) of both housing halves (13, 14), and the tightening screw (15) is 2. The electric machine according to claim 1, which is arranged symmetrically with respect to the pair of weld seams (32). 7. The radial fastening of the stator (11) on the tightening screw (15) comprises the annular section (37).
7. The electric machine according to claim 6, wherein the electric machine is arranged in the contact hole and is in contact with the outer peripheral surface of the laminated core (11) of the stator by press fitting. 8. At least one of the two housing halves (13, 14) is an annular section (37) of the centering surface (34) between which the housing halves (13, 14) are located. 8. The electric machine according to claim 7, which has a higher resistance moment to radial forces than the circumferential extent (39). 9. The radial resistance moment in the centering surface (34) is at least twice as great as the radial resistance moment in the circumferential range (39) of the housing halves (13, 14) located between them. The electric machine according to claim 8, wherein the electric machine is formed into a rib. 10. Both housing halves (13, 14)
The wall surrounding the laminated core (11) of the stator has an air gap (40) with respect to the outer peripheral surface of the laminated core (11) in the circumferential range (39) between the centering surfaces (34).
Any one of claims 7 to 9 extending with
The electric machine according to the item. 11. The annular section (37) having a centering surface (34) defines the housing halves (13,
An electric machine according to claim 8, which is connected to the bearing hub (42) via a radially oriented web (41) for the purpose of radial reinforcement of (14). 12. A radially oriented web (41)
Electric machine according to claim 11, characterized in that each extends in pairs and symmetrically on both sides of the clamping screw (15). 13. Both housing halves (13, 14).
With air flow openings (43, 44) in the area located between said annular sections (37) with contact surfaces (31) and centering surfaces (34). 11. The electric machine according to item 11. 14. Both housing halves (13, 14)
The walls of each contact surface (31) and each centering surface (3
4) has in the circumferential range (39) located in the circumferential direction (39) each one further inwardly directed projection (45), said projection (45) being a laminated core (11) of the stator. 11. The electric machine according to claim 10, wherein is additionally radially and / or axially clamped.