End cap assembly for suppressing electromagnetic interference and motor having the same

Patent metadata

Field	Value
Publication number	US-10277098-B2
Application number	US-201514820010-A
Country	US
Kind code	B2
Filing date	Aug 6, 2015
Priority date	Aug 6, 2014
Publication date	Apr 30, 2019
Grant date	Apr 30, 2019

Abstract

An end cap assembly for an electric motor has a brush assembly, a circuit board, an inductor and a grounded metal element. The brush assembly has a plurality of brushes. The circuit board is fixed relative to the brush assembly. The inductor is electrically connected to the circuit board. The grounded metal element is positioned between the brushes and the inductor to absorb high frequency electromagnetic radiation transmitted from the brushes to the inductor.

First claim

The invention claimed is:

1. An end cap assembly comprising:
a brush assembly having a plurality of brushes;
a circuit board fixed relative to the brush assembly;
an inductor electrically connected to the circuit board; and
a grounded metal element positioned between the brushes and the inductor, the metal element being configured to substantially obstruct a route from the brushes to the inductor to absorb high frequency electromagnetic interference signals transmitted from the brushes;
wherein the inductor is mostly covered by the metal element, the metal element comprises a base plate and two side plates extending from two long sides of the base plate, respectively, the base plate and the side plates cooperatively defining a receiving space to receive the inductor such that the inductor is mostly covered by the metal element, the brush assembly comprises an insulating bracket to which the metal element is fixed;
wherein one side plate of the metal element bends outwardly to form a fixing tab, a fixing hole is formed in the fixing tab and a fixing post is formed on the insulating bracket and engages the fixing hole to fix the metal element to the insulating bracket.

2. The end cap assembly of claim 1 , wherein the metal element is made of copper.

3. The end cap assembly of claim 1 , wherein the metal element is elongated and has a U-shaped cross section.

4. The end cap assembly of claim 1 , wherein a flange is formed on another side plate of the metal element, and a flange is formed at a center of the insulating bracket, the flange of the another side plate lapping on the flange of the insulating bracket.

5. The end cap assembly of claim 1 further comprising an end cap receiving the brush assembly and the circuit board, a plurality of latch blocks being formed on an outer circumference of the brush assembly, and a plurality of latches being defined in a circumferential wall of the end cap and arranged to respectively engage with the latch blocks.

6. A motor comprising:
a stator having a housing and a magnet disposed on a wall of the housing;
a rotor having a shaft, a rotor core and a commutator fixed on the shaft; and
the end cap assembly of claim 1 , the metal element of the end cap assembly electrically contacting the housing.

7. The motor of claim 6 , wherein the housing has an open end at which the end cap assembly is disposed, a portion of an edge of the open end of the housing corresponding to the metal element is bent inwards to form a crimp, the crimp electrically contacting the metal element to the housing.

8. The motor of claim 6 , wherein the metal element is elongated and has a U-shaped cross section defining the receiving space in which the inductor is received such that the inductor is mostly covered by the metal element.

9. The motor of claim 6 , wherein a flange is formed on the other side plate of the metal element, and a flange is formed at a center of the insulating bracket, the flange of the other side plate lapping on the flange of the insulating bracket.

10. The motor of claim 6 , further comprising an end cap receiving the brush assembly and the circuit board, a plurality of latch blocks being formed on an outer circumference of the brush assembly, and a plurality of latches being defined in a circumferential wall of the end cap and arranged to respectively engage with the latch blocks.

Assignees

• Johnson Electric Int Ag

Inventors

• Lai Chi Wai
• Luo Qing Bin
• Xu Gong Wu
• Wei xin peng
• Ren Xiao Lin
• Tian gui hong
• Zhang Hong Wei
• Han Xia

Classifications

• H02K5/148

  Slidably supported brushes · CPC title

• H02K23/66

  Structural association with auxiliary electric devices influencing the characteristic of, or controlling, the machine, e.g. with impedances or switches · CPC title

• H02K11/026 Primary

  Suppressors associated with brushes, brush holders or their supports · CPC title