| 摘要 |
An overspeed prevention device of a traveling motor of a crawler type excavator is provided to prevent a traveling motor from being damaged by overspeed by hydraulic oil supplied excessively. An overspeed prevention device of a traveling motor of a crawler type excavator comprises variable capacity type first and second hydraulic pumps(1,2), right and left traveling motors(3,5) and working devices(4,6) connected to the first and second hydraulic pumps, a control valve(21) including changeover valves(7,8) controlling hydraulic oil, a straight traveling valve(10) changed over with the supply of signal pressure to secure the straight traveling of equipment, speed control valves(13,14) controlling the swash plate swivel angle of the right and left traveling motors, 1-speed/2-speed changeover valves(15) outputting control signals to change over the speed control valves, and an overspeed prevention logic valve(16) controlling the control signals supplied to the speed control valves according to the load pressure occurring in a working device. |
