Brush holder assembly and commutator motor comprising said brush holder assembly

A brush holder assembly comprising:

• a brush holder formed in a disk shape by molding of insulating resin, and including a pair of box fixing sections each including a groove formed from an outer peripheral side toward inside;
• and
• brush box assemblies each having a brush box which houses a brush therein, each of the brush box assemblies being disposed in the groove in the box fixing section,
• wherein
• the brush box assembly is formed of box-like metal, and has a plurality of mounting legs,
• each of the box fixing sections of the brush holder has a pair of fixing wall sections, the groove formed to be sandwiched between the fixing wall sections, and a plurality of mounting holes, and
• the mounting legs are inserted into the respective mounting holes, and the brush box assemblies are fixed,
• wherein
• each of the brush box assemblies comprises:
• the brush;
• a brush spring for pressing the brush;
• a metal cover plate formed with the plurality of mounting legs and disposed on one side surface of a sliding section of the brush, and covering the groove of the box fixing section;
• and
• a metal brush case having a U-shaped cross-section, and housing the brush,
• wherein
• the metal brush case has three surfaces including:
• a bottom surface facing the groove and having two ends;
• and
• two side surfaces, the two side surfaces extending from the two ends of the bottom surface respectively and facing the fixing wall sections,
• the metal brush case of each of the brush box assemblies faces the brush holder through gaps in a noncontact manner so that an entirety of each surface of the three surfaces of the metal brush case does not contact any part of the brush holder.