CN1813388A - Device, in particular electrical machine, comprising components mutually connected via an interference fit - Google Patents

Abstract

The invention concerns a device (10), in particular and electrical machine, comprising components (16, 18) mutually connected via an interference fit (10). At least one external component (18), in particular a housing, and at least one internal component (16), in particular a stator, are interlocked via an interference fit. Bars (32) transmitting the forces of the interference fit are arranged between the external component (16) and the internal component (18). Said bars (32) are subjected at least partly to a plastic deformation and/or the external component (18) is elastically deformed, thereby easily compensating the tolerances. It is easy to compensate tolerance.

Description

Devices, especially electric machines, having components connected to each other by a press fit

Background technique

The invention relates to a device, in particular an electric machine, according to the preamble of claim 1 , having components connected to one another by a press fit.

Known from DE 102 61 617 disclosed later is a device, in particular an electrical machine, which has components connected to each other by a press fit, wherein at least one outer component, in particular a housing, and at least one inner component, in particular a stator, are pressed together Mates connect with each other. The components are connected to one another via elastic clamping sleeves.

Devices are known in which the stator is pressed directly into the housing with interference without using additional components between the stator and the housing. The shell is deep drawn. The stator is a lamination pack which consists of stamped sheets or individual metal sheets and carries the stator windings of the electric machine. Since the outer circumferential surface of the lamination pack is rougher than the inner circumferential surface of the housing, stresses may arise during assembly. This can cause bearing damage, short circuits and/or cause the motor to seize.

Contents of the invention

According to claim 1, the device according to the invention, in particular the motor, having components connected to each other by a press fit has the advantage that when the inner component is pressed into the outer component, it is no longer directly between the two components. relative movement between the guide rail and one of the members, preferably between the guide rail and the outer member. The result is that at least the stresses that develop during assembly can be reduced. For this purpose, a guide rail transmitting a press-fit force is arranged between the at least one outer part and the at least one inner component, wherein the guide rail is at least partially plastically deformable and/or the outer part is elastically deformable.

The guide rail is preferably arranged extending in the installation direction. The assembly direction can run linearly, but also helically or the like.

In the case of stronger pressure couples, the guide rail is slightly deformed or flattened during pressing in, which makes it possible to compensate for larger tolerances. Simultaneously or in another way of compensating for tolerances, the housing can be deformed in the elastic range, whereby larger tolerances of the inner and outer components can likewise be easily compensated. In the case of geometrical changes due to thermal expansion, the housing acts as an elastic element, thus maintaining the prestress of the press fit to a large extent.

Another advantage is that the at least one outer member has an inner circumference and the at least one inner member has an outer circumference, the outer circumference of the inner member and the inner circumference of the outer member substantially form a gap, and the guide rail Distributed on the inner and outer circumferences. Direct contact of the inner component and the outer component is avoided by this gap. However, the inner and outer components can always be partially in contact.

Preferably, the housing is deep-drawn, since it can be manufactured advantageously in this way and is more easily deformed during assembly due to the relatively thin wall thickness. If, for example, the housing has a circular cross section, it is easily deformed into a polygonal shape in the elastic range, whereby large tolerances in the diameter of the inner and outer parts can be compensated and the retention of the prestressing force in the event of thermal expansion is enhanced.

At one end, the guide rail has a bevel or bend for insertion, which makes it easier to assemble the part.

The guide rails are preferably arranged in grooves of the inner component and/or the outer component extending in the assembly direction, so that they have a clearly defined installation position. For this purpose, it is also advantageous to fasten the guide rail to the inner or outer component before assembly.

Finally, it is also advantageous if the guide rail has a circular cross-section before assembly, since this makes it easier to position the guide rail. If the guide rail is made of a softer material than the components to be assembled, in particular copper, preferably copper wire, the guide rail is essentially a plastically deformable guide rail.

If the guide rail is a rib on a sleeve or an extruded rib or a local raised position, it has the following advantages:

- overcome large manufacturing tolerances by adaptable extrusion regions, in particular by the formation of local elevations on the housing surface;

- a greater heat transfer between the stator and the housing through a greater number of extruded ribs;

- use of components that are easy to construct, thereby reducing production costs;

- Fewer components are used to install the composite structure, thereby reducing equipment costs and thus overall manufacturing costs;

- Stator with laminated core, without additional material gaps in the outer area (no flux loss in the laminated core);

- application of known installation and production procedures;

- matching of the stator circumference due to manufacturing tolerances (length compensation in the open area);

- Mechanical, adhesive-free and process-reliable displacement;

- large variance in the required clamping force due to the number and arrangement of the extruded ribs (not only in high-power but also in low-power motors);

- There are no flux losses at the yoke ring of the stator, since for example there are no longitudinal slots when only copper rails are used.

Circumferential tolerances can easily be compensated for if the sleeve has an axially extending slit.

The sleeve can be easily assembled if the sleeve has an inwardly directed collar.

Further advantages and preferred developments of the device according to the invention emerge from the subclaims and the description.

Description of drawings

An exemplary embodiment is shown in the drawing and explained in more detail in the following description.

Fig. 1 shows a motor in longitudinal section according to the section line I-I in Fig. 2,

Figure 2 shows a motor in cross-section according to the section line II-II in Figure 1,

Fig. 3 The motor according to Fig. 1 with another component,

Fig. 4 The motor according to Fig. 3 with a variable member,

Figure 5 Part of a front view of a sleeve.

Detailed ways

1 and 2 show a device in the form of an electric machine 10 in a longitudinal or cross section. The motor 10 is an electric motor (commutator motor, electronically commutated DC motor, AC motor, three-phase motor, etc.), a generator or the like. If the electric machine 10 is used as an electric motor, it can be used, for example, in a drive for windshield regulators, blowers, clutch regulators, speed controllers, wipers for motor vehicles.

The electric machine 10 comprises a rotor 12 arranged on a shaft 14 , which is supported in bearings 15 . 1 , 15 . 2 arranged at both ends of the electric machine 10 . Furthermore, the electric machine 10 includes a stator 16 which is arranged around the rotor 12 and is itself fastened in a housing 18 . The housing 18 is preferably deep drawn and may be made of Galfan ^(R) , which is a melt-dip refined steel plate, or another material suitable for deep drawing. The stator 16 is substantially annular and has plate lugs 20 arranged on the circumference and directed inwards. The stator 16 comprises a lamination pack 19 of punched laminations or individual metal sheets. Around the lug 20 , which extends in the axial direction of the electric machine 10 , a winding 22 is arranged in a known manner. Winding 22 is the field winding in the case of an electronically commutated motor, for example. In the case of a generator, voltage or current can be tapped off at winding 22 . An electrical connection 24 is shown schematically, wherein possible electronics can also be located in the interior of the electric machine 10 .

The stator 16 and the housing 18 are members connected to each other by a press fit, wherein the stator 16 is an inner member and the housing 18 is an outer member, and the two are engaged with each other by a press fit. Housing 18 has an inner circumference 26 and stator 16 has an outer circumference 28 . Housing 18 and stator 16 or outer circumference 28 and inner circumference 26 form a gap 30 . Of course, the stator 16 and the housing 18 can also be partially in contact in order to enable a direct electrical connection.

A guide rail 32 transmitting a press-fit force is arranged between the housing 18 and the stator 16 . In the present exemplary embodiment, three guide rails are provided which are arranged uniformly on the inner or outer circumference 26 , 28 . Of course, other numbers and a non-uniform distribution are also possible. The guide rails extend at least part of the length of the laminated core pack 19 and are arranged to extend essentially in the direction of installation corresponding to the arrow of section line II ( FIG. 1 ). Of course, other curves, for example a helical curve, are also possible. The guide rail 32 is preferably arranged in a groove 34 which is formed on the outer circumference 28 of the stator 16 and which likewise extends in the assembly direction corresponding to the arrow of the section line II ( FIG. 1 ). Alternatively or additionally, such a groove 34 can be formed on the inner circumference 26 of the housing 18 . As best seen in FIG. 2 , guide rail 32 protrudes from slot 34 . At each end 36 of the guide rail 32 , which points in the assembly direction II, the guide rail 32 has a bevel or—as indicated in FIG. 1—a bend 38 pointing inward or away from the inner circumference 26 of the housing 18 .

Insertion into the housing 18 is thereby facilitated. Via this bend 38 , possibly also by means of an additional gluing process, the guide rail 32 is fastened to the stator 16 before assembly. The bend 38 also provides a measure by which the guide rail cannot slip off during assembly. Alternatively, the guide rail can also be fixed on the inner circumference 26 of the housing 18 . In this case, the bevel or bend 38 points outward, or away from the outer circumference 28 of the stator 16 .

The guide rail 32 is made of a softer material compared to the components to be assembled, ie the stator 16 and/or the housing. In this embodiment, the guide rail is made of copper, preferably copper wire or a copper alloy, and can also be made of aluminum or an aluminum alloy. Alternatively, guide rail 32 may be made of another material, such as steel. The guide rail 32 ideally has a circular cross section before assembly. This is particularly advantageous since existing copper wires can be used, which need only be cut to the required dimensions.

Before assembly, the guide rails 32 are arranged in the lamination pack 19 or in the slots of the stator 16 . The stator 16 is then pressed into the housing 18 together with the guide rail 32 . To this end, the guide rail 32 is at least partially plastically deformed and/or the housing 18 is elastically deformed. If the guide rail 32 deforms plastically and/or the housing 18 deforms elastically, the components do not scrape along each other in a stress-forming manner.

Instead of the motor 10 having a stator 16 and a housing 18 as mutually engaged parts, the guide rail 32 can also be applied to other devices having inner and outer members which are mutually engaged by press-fitting. The members also do not have to have a circular cross-section. Round or angular cross sections are also possible.

A particularly advantageous configuration is indicated in FIG. 3 . The guide rail 32 is a web or a partial projection on a sleeve 40 or on an open peripheral surface. They are evenly distributed over the circumference of the sleeve 40 . The guide rail 32 is arranged in such a way that the volume of the recess approximately corresponds to the volume of the elevation. In this way, the sleeve 40 can be formed from a flat cut-out without cutting. Furthermore, the sleeve 40 has an axially extending slit 42 . The sleeve 40 has an inwardly pointing collar 38 (see FIG. 1 ) on an end face with which the sleeve protrudes into the housing 18 . The remaining parts are the same as in FIGS. 1 and 2 and also have the same reference numerals, so refer to the above embodiment.

The guide rail 32 points inwards. As a result, the guide rail 32 rests against the stator and is compressed during assembly. The smooth surface of the sleeve 40 —in this case the surface on the outside—rests against the housing 18 . The guide rail 32 may have an angle other than zero relative to the rotor axis direction. If the guide rails are parallel to the axial direction, ie have an angle of zero degrees, the stator 16 tends not to be twisted relative to the housing 18 when it is pressed in. Due to the application in EC motors, and the exact configuration between the phases of the working magnets and the phases of the plate lugs 20 , the stator 16 can be accurately positioned in the housing 18 .

Handling is made very easy by the use of a sleeve 40 with an axial collar 38 . The sleeve 40 is made of a malleable material such as aluminum, copper, lead, brass, etc., so that it can be easily manufactured and integrated in a mass production process. During assembly, first the sleeve 40 surrounds the stator 16 , and then the unit thus formed is pushed together into the housing 16 . An axial collar 38 prevents movement of the sleeve 40 in a direction opposite to the pressing-in direction.

FIG. 4 shows a sleeve 44 , in which, opposite to the sleeve 40 , only the guide rail 32 points outward. As a result, the sleeve 44 can bear against the stator 16 with its smooth inner surface.

What is important in the exemplary embodiment of FIGS. 3 and 4 is that the stator 16 is clamped radially towards the housing 18 by means of an open cylindrical sleeve made of an extensible material via local projections or guide rails 32 . In this case, the shaping of the guide rail 32 or the extruded web is preferably the result of the plastic deformation of a planar cutout which is then formed into the sleeve 40 . Finally the stator 16 is clamped in the housing 18 via sleeves 40 , 44 or open rings. In this case, the collar 38 is arranged at the front as viewed in the pressing-in direction. The sleeve 40 preferably has a split 42 or slot after pressing in. In this case it is advantageous if both the stator 16 and the housing 18 have a cylindrical shape on the housing surfaces facing each other.

In FIG. 5 a sleeve 46 facing away is partially shown. The guide rails 32 are arranged on both sides in the sleeve 46 . The guide rails 32 can be arranged mirror-image or offset. In the case of one or more opposing pairs of guide rails or ribs, the advantage is that the guide rails 32 can be considered as centering means. The original pressing function is thus not hindered. The centering between the stator 16 and the housing 18 can be shifted by one or more slots on the outer side of the stator 16 and by one or more slots on the inner side of the housing 18 . The guide rail 32 is then brought into the slot.

Claims (14)

1. A device (10), in particular an electric machine, having components (16, 18) connected to each other by a press fit, wherein at least one outer component (18), in particular a housing, and at least one inner component (16), in particular a stator, are passed through A press-fit mutual engagement, characterized in that a guide rail (32) transmitting a press-fit force is arranged between the at least one outer component and the at least one inner component (16, 18), wherein the guide rail (32) at least partially Plastic deformation, and/or elastic deformation of the outer member (18). 2. The device (10) according to claim 1, characterized in that the guide rail (32) is arranged substantially extending in the assembly direction (II). 3. The device according to claim 1 or 2, characterized in that the at least one outer component (18) has an inner circumference (26) and the at least one inner component (16) has an outer circumference (28) , the outer circumference (28) of the inner member (16) and the inner circumference (26) of the outer member (18) basically form a gap (30), the guide rail (32) is distributed on the inner circumference and the outer circumference, and the gap (30 ) is at least partially interrupted. 4. The device (10) as claimed in claim 1, characterized in that the outer part (18) is deep-drawn. 5. The device (10) as claimed in claim 1, characterized in that the guide rail (32) is made of a material that is softer than the components (16, 18) to be assembled. 6 . The device ( 10 ) according to claim 1 , characterized in that the guide rail ( 32 ) consists of copper, preferably copper wire, or of aluminum or aluminum wire. 7. The device (10) as claimed in claim 1, characterized in that the guide rail is fastened to the inner part (16) or outer part (18) before assembly. 8. The device (10) as claimed in claim 1, characterized in that the guide rail (32) has a substantially circular cross section before assembly. 9. According to the device (10) according to any one of the preceding claims, it is characterized in that the guide rail (32) has a bevel or a bend (38) at one end (36) for placing the inner part (16) ) into the outer member (18). 10. The device (10) according to any one of the preceding claims, characterized in that the guide rail (32) is arranged in the assembly direction (II) of the inner component (16) and/or the outer component (18) Extended slot (34). 11. The device (10) according to claim 1, characterized in that the guide rail (32) is a web on a sleeve (40, 44, 46). 12. The device (10) according to claim 11, characterized in that the guide rails (32) point inwardly and/or outwardly on the sleeves (40, 44, 46). 13. Device (10) according to claim 11 or 12, characterized in that the sleeve (40, 44, 46) has an axially extending opening (42). 14. Device (10) according to claim 11, characterized in that the sleeve (40, 44, 46) has an inwardly directed collar (42).

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