KR20070023754A - Hammer brush for an electric machine - Google Patents

Abstract

The invention relates to a hammer brush (22) comprising a leaf spring (36) and for pivotably supporting a brush holder (24) of an electric machine (10). The leaf spring 36 has a fixing section 38 for fixing to the brush holder 24, an arm connected to the fixing section and an end of the arm 40 to which the carbon brush 30 is fixed, the fixing section 38. A section 44 that is bent toward. The section 44 is bent and elastically formed toward the side of the arm 40, away from the carbon brush 30.

Leaf spring, brush holder, fixed section, carbon brush, arm

Description

Hammer brush for an electric machine

The present invention relates to a hammer brush for an electric machine according to the preamble of claim 1.

The hammer brush in this manner for pivotally supporting the brush holder of the electric machine generally comprises two leaf springs, which spring is fixed to the brush holder, connected to the fixing section and the carbon brush is fixed Arm and a section that is turned toward the fixed section at the end of the arm. In order to ensure the pressing force of the carbon required for the commutator, a prestress of the hammer brush is required. When radially assembling the hammer brush, the prestressed hammer brush is expanded by a section supported by the commutator, formed by coupling means. In particular, a large bending load is generated on the leaf spring of the hammer brush in the first contact of the coupling means and the commutator. Thus, the surface of the commutator can be damaged.

Hammer brushes for electric machines comprising the features of claim 1 have the advantage that the assembly of the hammer brush holder is simplified, the positioning of carbon relative to the commutator is improved, and the elastic force error is reduced. In addition, a leaf spring is provided in the hammer brush for pivotally supporting the brush holder of the electric machine, which leaf spring is fixed in the brush holder for fixing, an arm connected to the fixing section and fixed with a carbon brush, and the arm An elastic section bent toward the fixed section at the end of the. The section bends toward the side of the arm, away from the carbon brush.

Preferably the elastic section is at least acutely bent with respect to the arm. This provides a precisely defined elastic force.

If the arm and the elastic section are connected to each other by an arch, it is preferable to the spring characteristic curve.

At the end of the resilient section, a carbon arc is bent away by an arm, preferably an arcuate region, which is formed so that the hammer brush is simply joined into the part.

If a reinforcement is provided along the arm, which is a bead, bent edge or additional plate, this prevents the tilting of the carbon induced through the rotational moment due to the elastic force.

The brush holder with two hammer brushes spaced from the brush holder, arranged in the brush holder, is simply assembled. The carbon brushes face each other and the elastic sections face away from each other. In the case of the brush holder of the above manner, if the arms are arranged substantially parallel to each other in the non-assembled state, the bearing capacity for the commutator in the assembly is very small and is provided only at the end of the assembly process.

The effect of this simple assembly is also seen in electric machines with at least one hammer brush of the above manner. The same applies for an electric machine with a brush holder in this manner, the brush holder being first placed in the recess with the hammer brush, the hammer brush contacting a commutator arranged in the recess, the recess being in contact with the elastic section. It has two side walls. In addition, assembly is simplified when a mating slope for the elastic section of the arm is formed on the side wall.

Other advantages and preferred refinements are set forth in the dependent claims and the description.

Embodiments are illustrated in the drawings and described in detail in the detailed description below.

1 is a longitudinal sectional view of an electric motor;

FIG. 2 is a rectifier of the electric motor along line II-II of FIG. 1.

3 shows the rectifying device of FIG. 2 in an assembled position.

In figure 1 a longitudinal cross-sectional view of an electric motor 10, which may be a generator, is shown simply. The electric motor 10 can be used in a vehicle such as a seat adjuster, window lifter, wiper drive, fan, and the like. The electric motor 10 includes a housing 12 and an armature 14 disposed in the housing. The armature 14 comprises a shaft 16 and an armature packet 17 which includes armature windings not shown in detail. The armature winding is connected to the commutator 20 by a winding 18. At the circumference of the commutator 20, two hammer brushes 22 are provided on the radially opposite sides. The hammer brush 22 is disposed in the brush holder 24. The commutator 20, hammer brush 22 and brush holder 24 form a commutator 26. The commutator 20 and a portion of the hammer brush 22 are arranged in a recess 28, which can be arranged, for example, in the gear housing.

2 shows a side view of the rectifier 26 from the left in relation to the longitudinal sectional view of FIG. 1. The brush holder 24, preferably made of plastic, extends substantially parallel to the shaft 16, which is not shown in detail in FIG. 2. However, it may also extend perpendicular to the shaft 16. The brush holder 24 is first placed in the recess 28. The hammer brush 22 contacts the commutator 20 disposed in the recess 28 by the carbon brush 30. The hammer brush 22 contacts two side walls 32 parallel to each other of the recess 28. The outer edges of the side walls 32 each have an inserting inclination 34 which serves as a joining means, towards each other.

The hammer brushes 22 for pivotally supporting the brush holders 24 each comprise a leaf spring 36. Each leaf spring 36 includes a fixing section 38, which is fixed to the brush holder 24 by the fixing section. The electric supply of the hammer brush 22 is effected by a fixing section 38 or an additional strip. An arm 40 in the form of a leaf spring is connected to the fixing section 38. The carbon brush 30 is also fixed to the arm 40.

An elastic section 44 is connected to the fixing section 38 or brush holder 24 towards or towards the end of the arm 40 by an arch 42, preferably having a radius of 1 to 3 mm. . The bent section 44 is bent at an acute angle of 5 to 25 degrees relative to the arm 40 in the unassembled state (FIG. 3). The elastic section 44 bends toward the side of the arm 40, away from the carbon brush 30. At the end of the bent section 44 is formed an arcuate region 46, preferably bent away from the arm 40 at approximately the height of the carbon brush 30. Region 46 substantially corresponds to a semicircle.

A reinforcement 48 is disposed between the securing section 38 and the arch 42 along the arm 40. The reinforcement 48 may be formed of beads or bent along the arm 40 as both side edges. The plate can also be welded, for example.

As shown in FIG. 3, the arms 40 are arranged substantially parallel to each other, at least in an unassembled state. The carbon brushes 30 face each other and the elastic sections 44 face away from each other. The arm 40 is used for preliminary positioning of the carbon brush 30. Upon insertion of the brush holder 24 or hammer brush 22, the first section 44 which is bent is pressed together and fixed by the arcuate region 46 in contact with the insertion slope 34. This may be such that the carbon brush 30 is pressed against the commutator 20 only in the radial direction without being ground in contact with the commutator. This does not scratch the surface. However, it may be possible for the carbon brush 30 to be roughly ground along the surface of the commutator 20. Since the arm 40 is pivoted only by the positional displacement between the commutator 20 and the brush holder 24, it prevents the tilting which causes the failure of the carbon brush 30, which can be introduced by the rotational moment due to the elastic force. The reinforcement may be disposed.

The hammer brush 22 may also be disposed in the recess 28 itself. The engagement ramp 34 is arranged on a corresponding part, for example a plastic carrier or gear cover.

Claims (10)

A hammer brush 22 for pivotally supporting a brush holder 24 of an electric machine 10 comprising a leaf spring 36, the leaf spring being A fixing section 38 for fixing to the brush holder 24, An arm 40 to which the carbon brush 30 is fixed, connected to the fixing section 38, and A hammer brush for an electromechanical machine comprising a section 44 that is bent at the end of the arm 40 toward the stationary section 38. The hammer (44) for the electromechanical machine, characterized in that the section (44) is bent and elastically oriented towards the side of the arm (40), away from the carbon brush (30). 2. Hammer according to claim 1, characterized in that the elastic section (44) is at least acute angled with respect to the arm (40). 3. Hammer according to one of the preceding claims, characterized in that the arm (40) and the elastic section (44) are connected to each other by an arch (42). 4. The arcuate region 46 according to claim 1, wherein at the end of the elastic section 44, an arcuate region 46 is formed, which is curved away from the arm 40 at the height of the carbon brush 30. Hammer for an electric machine, characterized in that. 5. Hammer according to one of the preceding claims, characterized in that a reinforcement (48) is provided along the arm (40) in the form of beads, folded side edges or additional plates. A brush holder comprising at least two hammer brushes 22 according to any one of claims 1 to 5, spaced from the brush holder 24, disposed in the brush holder 24, comprising: 30) the brush holder facing each other and the elastic sections 44 facing away from each other. 7. Brush holder according to claim 6, characterized in that the arms (40) are arranged parallel to each other at least in an unassembled state. An electrical machine with at least one hammer brush (22) according to any of the preceding claims. In the electrical machine (10) comprising a brush holder (24) according to claim 6 or 7, The brush holder 24 is first disposed in the recess 28 together with the hammer brush 22, and the hammer brush 22 contacts the commutator 20 disposed in the recess 28, and The electrical machine, characterized in that the recess (28) comprises two side walls (32) in contact with the elastic section (44). 10. The electric machine according to claim 9, wherein a coupling slope (34) for the hammer brush (22) is formed on the side wall (32).

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