An electric sander motor includes a motor main body (100), a power axial shaft (210) and a sleeve (220). The motor main body (100) includes a rotor (110) and a stator (120) surrounding the rotor (110). The power axial shaft (210) includes an axial hole (211) extending along a central axis of the power axial shaft (210). The sleeve (220) includes one open end and another closed end extended outward to form an eccentric axial shaft (221) penetrating through the axial hole (211). A central axis of the eccentric axial shaft (211) is parallel with a central axis of the sleeve (220) and spaced apart therefrom. The power axial shaft (210) penetrates through the rotor (110), and the sleeve (220) is outside the motor main body (100). The assembly is facilitated by assembling the power axial shaft (210) and the sleeve (220) onto the motor main body (100) sequentially.

An electric sander motor includes a motor main body (100), a power axial shaft (210) and a sleeve (220). The motor main body (100) includes a rotor (110) and a stator (120) surrounding the rotor (110). The power axial shaft (210) includes an axial hole (211) extending along a central axis of the power axial shaft (210). The sleeve (220) includes one open end and another closed end extended outward to form an eccentric axial shaft (221) penetrating through the axial hole (211). A central axis of the eccentric axial shaft (211) is parallel with a central axis of the sleeve (220) and spaced apart therefrom. The power axial shaft (210) penetrates through the rotor (110), and the sleeve (220) is outside the motor main body (100). The assembly is facilitated by assembling the power axial shaft (210) and the sleeve (220) onto the motor main body (100) sequentially.

The present disclosure relates to a floor surfacing machine (100) comprising drive wheels (171, 172) and a planetary head (140) with one or more satellite grinding heads (120), A first drive motor (110) is arranged to drive the planetary head (140) and a second drive motor (130, 430) is arranged to drive the one or more satellite grinding heads (120). The first drive motor (110) is arranged to be directly powered only by means of a re-chargeable internal electrical power source (310) comprised in the floor surfacing machine (100).

The present disclosure relates to a floor surfacing machine (100) comprising drive wheels (171, 172) and a planetary head (140) with one or more satellite grinding heads (120), A first drive motor (110) is arranged to drive the planetary head (140) and a second drive motor (130, 430) is arranged to drive the one or more satellite grinding heads (120). The first drive motor (110) is arranged to be directly powered only by means of a re-chargeable internal electrical power source (310) comprised in the floor surfacing machine (100).

An electric work machine in one aspect of the present disclosure includes an electric power input terminal, a motor, a circuit board, a first heat dissipation plate, and a second heat dissipation plate. The circuit board includes a first surface and an electronic circuit on the first surface. The electronic circuit controls supply of AC power to the motor. The electronic circuit includes an electronic component that generates Joule heat. The first heat dissipation plate is spaced from the first surface by a first distance in parallel to the first surface. The second heat dissipation plate is spaced from the first surface by a second distance in parallel to the first surface. The second heat dissipation plate is thermally coupled with the first heat dissipation plate. The second distance is smaller than the first distance.

An electric work machine in one aspect of the present disclosure includes an electric power input terminal, a motor, a circuit board, a first heat dissipation plate, and a second heat dissipation plate. The circuit board includes a first surface and an electronic circuit on the first surface. The electronic circuit controls supply of AC power to the motor. The electronic circuit includes an electronic component that generates Joule heat. The first heat dissipation plate is spaced from the first surface by a first distance in parallel to the first surface. The second heat dissipation plate is spaced from the first surface by a second distance in parallel to the first surface. The second heat dissipation plate is thermally coupled with the first heat dissipation plate. The second distance is smaller than the first distance.

A power tool is provided including a housing defining a cavity therein, where the housing includes a motor case and a handle portion extending along a longitudinal axis of the housing from the motor case; an electric motor having a drive shaft and mounted within the motor case; a partitioning wall extending radially and separating the motor case portion from the non-motor case portion of the housing; and a bearing pocket with an open end facing the motor case portion formed in the partitioning wall and a main body extending away from the electric motor for receiving a rotor bearing. The handle portion includes two elongate walls extending from the partitioning wall, a circuit board supported by the two elongate walls and including a motor drive circuit, and two covers secured to the two elongate walls to cover the circuit board.

A power tool is provided including a housing defining a cavity therein, where the housing includes a motor case and a handle portion extending along a longitudinal axis of the housing from the motor case; an electric motor having a drive shaft and mounted within the motor case; a partitioning wall extending radially and separating the motor case portion from the non-motor case portion of the housing; and a bearing pocket with an open end facing the motor case portion formed in the partitioning wall and a main body extending away from the electric motor for receiving a rotor bearing. The handle portion includes two elongate walls extending from the partitioning wall, a circuit board supported by the two elongate walls and including a motor drive circuit, and two covers secured to the two elongate walls to cover the circuit board.

A wafer polishing head is provided. The wafer polishing head includes a carrier head, a plurality of piezoelectric actuators disposed on the carrier head, and a membrane disposed over the plurality of piezoelectric actuators. The plurality of piezoelectric actuators is configured to provide mechanical forces on the membrane and generate an electrical charge when receiving counterforces of the mechanical forces through the membrane. A wafer polishing system and a method for polishing a substrate using the same are also provided.

A surface processing device includes a machining mechanism and a driving mechanism driving the machining mechanism to polish a workpiece. The machining mechanism includes a machining assembly and a first transmission shaft eccentrically coupled with the machining assembly at a first end. The first transmission shaft rotates to bring the machining assembly into revolving around the first transmission shaft. The driving mechanism includes a motor connected to a second end of the first transmission shaft for outputting power to the machining mechanism. The surface processing device provides smooth machining without the noise of a pneumatically-powered tool.