Brush structure for increasing the ripple current of the motor

Abstract

A brush structure for increasing a ripple current of a motor according to the present invention contacts a commutator including commutator bars separated annularly by a plurality of slits as being able to be slid. The brush structure of the present invention comprises: a first ripple groove part which satisfies a condition of R2>R1 where slit width between the commutator bars is L and a curvature radius of the commutator is R1 and a curvature radius of a brush surface contacting the commutator bar is R2 and the brush surface facing the commutator bar is formed to be concave along a length direction of the brush; and a second ripple groove part which is extended along a direction of going away from the commutator bar from the first ripple groove part, and constitutes a staircase shape by being formed narrower than the width of the first ripple groove part. Thus, the first ripple groove part and the second ripple groove part divides the brush into two segments along a rotation direction of the brush.

Description

[0001] Cross reference of related applications [0002] This application claims the rights and interests of Korean Patent Application No. 10-2015-0103009 filed with the Korean Intellectual Property Office on July 21, 2015, and the disclosure of the application is incorporated herein by reference in its entirety. Technical field [0003] One or more embodiments of the present invention relate to a motor including a brush, and more specifically, to a brush structure for increasing the ripple current of the motor. Background technique [0004] Generally speaking, an electric motor includes a rotor and a stator. The rotor includes a commutator, which is configured to rotate with the output shaft of the electric motor. The stator contains brushes that are configured to supply current to the commutator. Generally speaking, the commutator includes a plurality of pieces separated from each other and arranged around the output shaft of the motor. The brushes supply current to the commutat...

AI Technical Summary

Problems solved by technology

[0012] However, when using the disclosed brush structure, due to factors such as a roughness mismatch between the fine surfaces of the commutator and the brush during the approximately 1000 cycles after the brush begins to slide frictionally around the commutator Excessive generation of noise, which may not be satisfactory to the user or operator

Additionally, after multiple uses of the disclosed brush structures, the ripple grooves formed in the brush due to wear may disappear, and thus the effect of increasing the ripple current may also disappear.

Furthermore, since the initial contact area between the commutator and the brushes is relatively large, the maximum value of the ripple current is relatively low, and therefore an additional circuit is necessary to amplify the ripple current

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