DE102005037464A1 - Stator of electrical machine e.g. passenger vehicle generator, has laminated core, which comprises a winding whereby damping mass is arranged in interdental spaces in between external teeth at the outer circumference - Google Patents

Abstract

Stator of an electrical machine has a laminated core, which comprises a winding (12). A damping mass (15) is arranged in the interdental spaces (13) in between the external teeth (11) at the outer circumference whereby only one part of the interdental spaces is filled with the damping mass. An independent claim is also included for the electrical machine.

Description

State of technology

The The invention relates to a stator of an electric machine according to to the preamble of claim 1 and an electric machine according to the preamble of claim 7.

It It is known that in the case of car generators, the stator is usually the Component with the largest share at the sound emission of the magnetically excited noise. Cause for this is that the laminated core of the stator by magnetic forces in the air gap is excited to mechanical vibrations and these vibrations on the winding as well as on connected components, e.g. Bearing shields, transferred become.

It are different possibilities known to reduce the vibrations of the stator, such as through a high manufacturing accuracy of the stator and the end shields or the minimization of the stimulating forces by a suitable design the shape of the claw poles. Such measures are complex and accordingly expensive.

A another possibility To reduce the vibration amplitude, is the mechanical damping of the Laminations by attaching suitable damping material to the laminated core purposefully increase. It is known e.g. the laminated core not as usual directly to clamp in the end shields, but between laminated core and End shields a layer for damping and / or insulation to lay. This affects however, the mechanical strength of the connection. In the election of the damping material have to because of the required high mechanical strength compromises regarding the damping behavior To be received. The layer obstructs the heat conduction from the stator to the end shield, causing the cooling of the stator is deteriorated. It creates a high production cost when introducing the damping mass in the end shields as well as during joining of the stator.

Advantages of invention

It a stator of an electric machine is proposed in which on the outside diameter in interdental spaces between external teeth one damping mass is arranged. Advantageously, it turns out that in the most diverse noise is critical Vibration forms of the stator noise reduction is possible. Compared to a stationary stator are energized electric machine at typical frequencies induced deformations in the stator. In a car generator, for example, at frequencies around 1300 Hz an oval oscillation on, in which the cross section of the stator is deformed oval. at a higher one Frequency around 1800 Hz, a triangular vibration occurs at which the Cross-section of the stator is deformed into a triangle. In such Deformations become the circumferentially arranged on the stator surface outer teeth against each other emotional. The deformation of the stator moves in time between end positions to the beat of the oscillation frequency back and forth how can be shown with finite element calculations. In the movement the stator areas are bent more or less strongly. These swinging movements bump the air particles surrounding the stator. The vibration amplitudes are typically in the range of a few microns. The resulting Alternating pressure of the air propagates and becomes in the ear as audible sound perceived.

The in the interstices arranged damping mass is also deformed by the movement. By doing so Resulting internal friction in the damping material Energy is withdrawn from the vibrating stator, causing the vibration amplitudes be reduced and the radiated noise is reduced. The spaces can be completely or only partially with damping mass filled be. It is appropriate, no damping mass in screw passages provided.

The damping mass is preferred between external teeth an outer circumference arranged. It turns out that especially the external teeth depending on the position of the oscillation phase aufzubiegen or. Through the damping mass can Advantageously, the cyclical movement of the external teeth can be used to increase the damping. The mechanical strength of the connection between stator and end shield will not be affected. It can be an optimal choice of material for the damping mass without consideration stability to be hit. The heat dissipation between stator and end shield is not obstructed. The assembly of the Stators in the end shields is not complicated.

In a cheap one Embodiment, only a part of the interdental spaces may be filled.

In another cheap Design, the damping mass over a total axial length a tooth space extend. Alternatively, the damping mass only about one Part of an axial length a tooth space extend.

In another cheap Embodiment, the damping mass radially over the outer teeth protrude.

In a cheap one Design, the outer teeth means on to the adhesion the damping mass to improve. This can e.g. a profiling of the tooth flanks be, with a form-fitting Connection of the damping mass with the external tooth brought can be.

The individual measures can also be combined with each other. This makes it possible for the Arrangement of the damping mass optimal to the current vibration characteristics of the given Adjust stator. It is also possible, the Selection of the material for the damping mass ever according to requirement with regard to the one to be damped Frequency range.

ever according to quantity and costs it is possible that Introducing the damping mass mechanically or manually, e.g. to insert into the interdental spaces, gluing, injecting or the like.

It is also an electric machine with a rotor and a stator, proposed at the stator in interdental spaces between the external teeth a damping mass is arranged. Preferably, the electric machine is a generator for a Motor vehicle.

drawing

Further Embodiments, Aspects and advantages of the invention are also independent of their summary in claims, without restriction the general public from a subsequently illustrated with reference to a drawing embodiment the invention.

Hereinafter shows

1 a section of a preferred stator with a damping mass in spaces of external teeth;

2 . 2a : a stator without deformation, 2 B : a stator at an oval oscillation, and c: a stator at a triangular oscillation.

description of the embodiment

The 1 shows a section of a preferred stator 10 a graphically not further illustrated electric machine while 2a a view of an undeformed circular stator 10 with external teeth 11 shows that radially on a laminated core 14 are arranged 2 B a stator 10 with an oval deformed cross-section at an induced by magnetic excitation of the electric machine oval oscillation at about 1300 Hz and 2c a stator 10 with a triangularly deformed cross section at a triangular vibration induced by magnetic excitation of the electric machine at about 1700 Hz. The vibration amplitude is in the range of a few micrometers.

The stator 10 has a laminated core 14 on, that's a winding 12 having. In interdental spaces 13 the outer teeth 11 is between the external teeth 11 a damping mass 15 arranged. At an inner periphery in its stator bore, the stator 10 not shown inner teeth, which carry the stator winding.

The damping mass 15 is between external teeth 11 disposed on an outer periphery and preferably extends over an axial length of a tooth space 13 , By a relative movement of the external teeth 11 the vibration energy is due to internal friction in the damping mass 15 at least partially destroyed.

Claims (7)

Stator of an electric machine with a laminated core ( 14 ), which is a winding ( 12 ), characterized in that in interdental spaces ( 13 ) between external teeth ( 11 ) on an outer circumference a damping mass ( 15 ) is arranged. Stator according to claim 1, characterized in that only a part of the interdental spaces ( 13 ) with the damping mass ( 15 ) is filled. Stator according to claim 1 or 2, characterized in that the damping mass ( 15 ) over an entire axial length of a tooth space ( 13 ). Stator according to one of the preceding claims, characterized in that the damping mass ( 15 ) over only a part of an axial length of a tooth space ( 13 ). Stator according to one of the preceding claims, characterized in that the damping mass ( 15 ) radially over the external teeth ( 11 protrudes). Stator according to one of the preceding claims, characterized in that the external teeth ( 11 ) Means for improving the adhesion of the damping mass ( 15 ) exhibit. Electric machine with a damping mass and with a rotor and a stator ( 10 ), wherein the stator ( 10 ) a winding ( 12 ) having, according to one of the preceding claims, characterized in that the damping mass ( 15 ) in interdental spaces ( 13 ) between external teeth ( 11 ) is arranged on an outer periphery.