Electric power tool, in particular a grinding or polishing machine

Abstract

An electric power tool is described, and which includes a housing in which a drive, a fan unit and an electronics device are accommodated, and wherein an air stream for cooling the drive to be generated with the aid of the fan unit through at least one air inlet opening and at least one air duct being formed within the housing, and wherein the air duct extends from the air inlet opening to the drive, and which allows a directed supply of air to flow to the drive, with the air inlet opening being arranged in an end region of the electric power tool.

1 . An electric power tool, and in particular a grinding or polishing machine, comprising: a housing in which a drive, a fan unit and an electronics device are accommodated, and wherein an air stream for cooling the drive is generated with the aid of the fan unit when ambient air is drawn into the housing through at least one air inlet opening, and wherein at least one air duct is formed within the housing and extends in the flow direction of the air stream from the air inlet opening to the drive, and which allows a directed supply of air to the drive, with the air inlet opening being arranged in an end region of the electric power tool which, when a workpiece is being processed with the electric power tool, is averted from the workpiece which is to be processed, and wherein the housing of has a double-walled design with a housing inner wall and a housing outer wall, which is at a predetermined distance from the said housing inner wall, at least in sections, with the air duct being delimited by the housing outer wall and the housing inner wall, and wherein the housing has a multi-part design which includes at least two half-shells. 
     
     
         2 . An electric power tool as claimed in  claim 1 , and wherein the electronics unit is mounted in the housing in such a way that it is separated from the air duct by the housing inner wall at least in part. 
     
     
         3 . An electric power tool as claimed in  claim 1 , and wherein the housing inner wall at least partially delimits a substantially closed chamber which is at least partially accommodated within the housing outer wall. 
     
     
         4 . An electric power tool as claimed in  claim 3 , and wherein the housing outer wall is in the form of a casing surface having a substantially cylindrical body which forms, at least in part, a handle part of the electric power tool. 
     
     
         5 . An electric power tool as claimed in  claim 4 , and wherein the air inlet opening is formed at an end face of the housing and is defined by the space between the housing outer wall and the housing inner wall. 
     
     
         6 . An electric power tool as claimed in  claim 5 , and wherein the drive comprises an electric motor having a collector and a means for making electrical contact with the collector, and wherein the air duct conducts an air stream which is directed to the means for making electrical contact with the collector. 
     
     
         7 . An electric power tool as claimed in  claim 6 , and wherein the air inlet opening has a plurality of supporting ribs which are substantially parallel to one another. 
     
     
         8 . An electric power tool as claimed in  claim 7 , and wherein the supporting ribs extend between the housing outer wall and the housing inner wall in order to support the said walls against one another. 
     
     
         9 . An electric power tool as claimed in  claim 8 , and wherein the housing outer wall projects beyond the respective supporting ribs at least in sections. 
     
     
         10 . (canceled)