At the same time, constant engine speed stabilizes output displacement of hydraulic pump and then stabilizes travel speed and vibratory frequency in turn, so that compaction quality is increased.
同时，发动机转速的恒定也使液压泵输出排量稳定，进而保证了行走速度和振动频率的稳定，提高了压实质量。
2
The concern of pump is the increased thermal cycling and vibratory loads.