Electric grinding machine

Abstract

An electric grinding machine includes a housing, an electric motor disposed in the housing, a motor end plate disposed in the housing and provided for disposal of the electric motor, and an airflow generating member connected to the electric motor. The housing is formed with at least one inlet hole. The motor end plate is formed with at least one opening without being shielded by the electric motor, and at least one first annular structure disposed at a side distanced from the electric motor. The airflow generating member rotates with the electric motor, so that a heat dissipation airflow generated in the housing enters from the at least one inlet hole and flows through a surface of the electric motor, and passes through the opening. The airflow generating member is formed with at least one second annular structure matched with the at least one first annular structure.

What is claimed is: 
     
         1 . An electric grinding machine, comprising:
 a housing, formed with at least one inlet hole;   an electric motor, provided in the housing;   a motor end plate, provided in the housing, the electric motor located on the motor end plate, and the motor end plate formed with at least one opening without being shielded by the electric motor and at least one first annular structure disposed at a side distanced from the electric motor; and   an airflow generating member, connected to the electric motor, the airflow generating member generating a heat dissipation airflow in the housing along with rotation of the electric motor, the heat dissipation airflow entering from the at least one inlet hole and flowing through a surface of the electric motor, and passing through the at least one opening, the airflow generating member formed with at least one second annular structure matched with the at least one first annular structure, and a plurality of dust-blocking points jointly defined by the at least one first annular structure and the at least one second annular structure.   
     
     
         2 . The electric grinding machine as claimed in  claim 1 , wherein a number of the at least one first annular structure and a number of the at least one second annular structure are N and N+1, respectively, and N is greater than or equal to one. 
     
     
         3 . The electric grinding machine as claimed in  claim 2 , wherein the airflow generating member comprises a base and a plurality of fan blades disposed on the base, the plurality of fan blades are located at a surface of the base same as the at least one second annular structure, and closer to an edge of the base than the at least one second annular structure. 
     
     
         4 . The electric grinding machine as claimed in  claim 3 , wherein the at least one opening is disposed close to a surface edge of the electric motor, and the at least one first annular structure is arranged within a projection range of the electric motor. 
     
     
         5 . The electric grinding machine as claimed in  claim 4 , wherein the electric motor comprises a rotor and a stator disposed around the rotor, and a part of the stator is exposed on the surface of the electric motor. 
     
     
         6 . The electric grinding machine as claimed in  claim 5 , wherein the electric grinding machine comprises a control circuit board disposed in the housing and connected to the electric motor, and the at least one inlet hole is close to the control circuit board. 
     
     
         7 . The electric grinding machine as claimed in  claim 6 , wherein the housing comprises an outlet hole facing the airflow generating member. 
     
     
         8 . The electric grinding machine as claimed in  claim 7 , wherein the airflow generating member is disposed between an eccentric block and the motor end plate. 
     
     
         9 . The electric grinding machine as claimed in  claim 8 , wherein the at least one first annular structure is not in contact with the airflow generating member, and the at least one second annular structure is not in contact with the motor end plate. 
     
     
         10 . The electric grinding machine as claimed in  claim 1 , wherein the housing comprises an outlet hole facing the airflow generating member. 
     
     
         11 . The electric grinding machine as claimed in  claim 1 , wherein the motor end plate is formed with a plurality of openings disposed along with an edge of the electric motor. 
     
     
         12 . The electric grinding machine as claimed in  claim 1 , wherein the airflow generating member is disposed between an eccentric block and the motor end plate. 
     
     
         13 . The electric grinding machine as claimed in  claim 12 , wherein the at least one first annular structure is not in contact with the airflow generating member, and the at least one second annular structure is not in contact with the motor end plate.