A small-scale shredder typically refers to a machine with a power rating under 2 kilowatts, featuring a compact size, and is either desktop or portable. The terminology for small high-speed shredders varies depending on the application, such as laboratory shredders or household shredders. The shredding process involves a sealed shredding chamber with sharp-edged blades rotating at high speeds, powered directly by the shredder's lower motor shaft. Materials are shattered upon impact with the rapidly spinning shredder blades. Generally, after some time of use, the seal at the upper bearing section of the shredder may gradually develop gaps, allowing finer dust to enter the motor's bearing, resulting in increased noise and vibration, as well as a rapid rise in temperature.

In practical applications, due to the use of ultra-high-speed DC motors, heat generation is also relatively high, primarily occurring at the carbon brushes, commutators, and housing. During operation, the carbon brushes make contact with the commutator surface, transmitting the external power source (usually DC excitation current) to the stator windings (excitation winding) through slip rings (rotating with the rotor). This serves the purpose of reversing the current, allowing the DC current to flow into one end of the rotor, thereby causing the motor to rotate in one direction. The good contact between the carbon brushes and the rotor provides electrical power to the rotor. However, due to prolonged frictional contact with the commutator, the carbon brushes wear down. When the length of the carbon brushes reaches the point of replacement, the supporting spring behind them no longer functions, potentially leading to poor contact between the carbon brushes and the commutator, causing the粉碎机 to fail to start upon power application. To address these issues, simply replace the carbon brushes and clean the rotor head with alcohol.