The impulse motion and the unbalanced vibration of the pump generate certain structural noise which could be significantly expressed in frequency spectrum.
泵的脉动运动与不平衡振动产生了结构噪声，结构噪声在频谱中清晰显示出来。
2
However, the heavier unbalanced radial force existed in the traditional two-gear's gear pump is a chief factor to affect the pump's service life.
但是传统的二齿轮式齿轮泵存在较大的不平衡径向力，成为制约齿轮泵寿命的主要因素。
3
The common gear pump has such merits as simple structure, low cost, insensitive oil pollution, etc. but it has such demerits as high flow pulsation, unbalanced radial force, strong noise, etc.