Abstract: A random orbital sanding tool includes a power motor, a driving spindle connected to the power motor, an eccentric block connected to the driving spindle, a tool holder disposed on the eccentric block, and a sanding pad connected to the tool holder and indirectly driven by the power motor. The random orbital sanding tool includes a friction ring disposed on the tool holder, the friction ring contacts a surface of the eccentric block facing the sanding pad, the friction ring stops rotation of the tool holder and the sanding pad by a friction force exerting on the surface of the eccentric block when the power motor stops operation, the friction ring includes a base part protruding into a gap between the tool holder and the eccentric block, a sleeve part diverged and extended from the base part.

Abstract: A dust suction device includes a dust collection barrel, a supporting ring and a dust suction assembly, the barrel includes an inner space, an assembling opening communicating with the space, and at least two connectors disposed on the barrel, the opening has an opening diameter. The ring is placed at the opening, and has a ring outer diameter larger than the opening diameter, and a ring inner diameter. The assembly includes a shell and at least two connecting structures formed on an outer surface of the shell and used to restrict the assembly from separating from the barrel, the shell has at least one shell outer diameter smaller than the opening diameter, but larger than the ring inner diameter, the assembly has a use state by using the ring as a base and stacked above the barrel, and a storage state of being placed in the space.

Abstract: A dustproof structure of a grinding tool holder, which comprises a shaft portion and a counterweight portion connected to one end of the shaft portion. The counterweight portion comprises an eccentric block connected to the shaft portion, at least one bearing mounted in the eccentric block, a dustproof ring, and a grinding member assembling head assembled with the bearing. The eccentric block is formed with an assembly port for disposing the bearing and the dustproof ring, the dustproof ring is located on a side of the bearing facing the grinding member assembling head, and formed with a first continuous concave-convex structure on a side away from the bearing, the grinding member assembling head is formed with a second continuous concave-convex structure on a side facing the dustproof ring, the first and second continuous concave-convex structures match with each other and define dust blocking dots.

Abstract: A grinding machine tool for reducing hotness of a casing, includes a casing and a drive assembly. The casing is divided into a head and a body; includes casing parts; includes an air inlet provided on the body and an air outlet provided on a side of the head; and forms a motor cover on the head, and the motor cover does not contact the casing parts to form an airflow passage in the casing. The drive assembly includes a circuit board, a motor placed into the motor cover, and an airflow generating member rotating synchronously with the motor. When the airflow generating member rotates, it generates a first heat dissipation airflow passing through the airflow passage and dissipating heat of the circuit board and the head, and a second heat dissipation airflow dissipating heat on a side of the motor facing the airflow generating member.

Abstract: An air guider disposed in a grinding machine tool. The grinding machine tool comprises a casing and a motor disposed in the casing. The casing comprises a head for disposing the motor and a body formed with at least one air inlet. The air guider comprises a main body, and an ascending diversion portion integrally formed with the main body, the main body is disposed at a junction between the head and the body, the ascending diversion portion comprises a main guide surface to guide a first heat dissipation airflow entering from the air inlet to flow toward a top of the motor, and two auxiliary guide surfaces respectively disposed on two sides of the main guide surface to generate a second heat dissipation airflow.