OVER-ROTATION PREVENTING METHOD AND DEVICE

摘要

PURPOSE:To prevent the over-rotation of a refrigerator by functioning an electromagnetic friction brake by the abrupt stop command from a rotation detector upon reaching to the setting rotation slightly higher than the rated rotation while interrupting the current to be fed to a motor for driving the compressor. CONSTITUTION:When the generator is no load due to the disconnection of the electric circuit to reach to the setting rotation slightly higher than the rated rotation and a rotor 35 associated with a magnet will reach to the setting rotation, a rotation detector 44 will transmit an electric command to a relay 46 while an electric contact 47a will close an electric circuit 41 to feed the current to an electromagnet 38 thus to attract a brake member 37 and to function as the friction brake. At the same time an electric contact 47b will close the circuit to fully close an electromagnetic cut-off valve 8 thus to block the supply of the fluid to the refrigerator. While an electric contact 47c will open the circuit to interrupt the current supply to a motor 3. Since said operations are performed on the basis of the electric command, it causes to time lag thus to prevent the over-rotation of the refrigerator.