Effect of Trapped Volume on Volumetric Efficiency and Optimization of a Micro Two-dimensional Piston Pump

doi:10.3969/j.issn.1004-132X.2026.07.006

Abstract

Abstract:

This study investigates the effects of reverse flow， axial leakage， and circumferential leakage on the volumetric efficiency of a micro two-dimensional （2D） piston pump through theoretical analysis， numerical simulation， and experimental testing. The results indicate that reverse flow is the primary cause of volumetric efficiency loss. Reducing the trapped volume can significantly decrease reverse flow and enhance volumetric efficiency； specifically， the efficiency increases by 13.31% at a working pressure of 35 MPa.

Key words: two-dimensional piston pump, volumetric efficiency, trapped volume, reverse flow

摘要：

结合理论分析、数值理论及实验测试，深入探讨了倒灌、轴向泄漏、周向泄漏等因素对微型二维活塞泵容积效率的影响。研究结构表明，倒灌现象是造成容积效率下降的主要因素；减小滞留容积可有效减小倒灌流量、提高容积效率，35 MPa压力下的容积效率较原滞留容积时提高13个百分点。

关键词: 二维活塞泵, 容积效率, 滞留容积, 倒灌

CLC Number:

TH137

ZHOU Xiaoyun, ZHOU Jiajian, CHEN Yong, RUAN Jian. Effect of Trapped Volume on Volumetric Efficiency and Optimization of a Micro Two-dimensional Piston Pump[J]. China Mechanical Engineering, 2026, 37(7): 1580-1586.

周小云, 周家健, 陈勇, 阮健. 滞留容积对微型二维活塞泵容积效率的影响与优化[J]. 中国机械工程, 2026, 37(7): 1580-1586.

Figures/Tables 17

Fig.1 Structure of a micro 2D piston pump

Fig.2 Cross-section and dimensions of the pump core

Fig.3 Volumetric efficiency test bench.

Tab.1 Design parameters of the pump

描述	值	描述	值
凸轮导轨行程h/mm	0.8	同心环长度L_s/mm	8
间隙高度δ/μm	1.5	活塞长度L_p/mm	9
配流槽所占角度φ_g/（°）	45	配流槽长度L_g/mm	6
配流窗口宽度B_w/mm	2.4

Fig.4 Basic principles of motion and flow distribution

Fig.5 Pressure of left piston chamber under different load pressures

Fig.6 Flow discharged from the left piston chamber through the distribution port.

Fig.7 Proportion of reverse flow in the theoretical flow

Fig.8 Axial external leakage flow

Fig.9 Axial internal leakage flow

Fig.10 Proportion of axial leakage flow in the theoretical flow

Fig.11 Circumferential leakage flow

Fig.12 Proportion of reverse flow in the circumferential leakage flow

Fig.13 Theoretical results and experimental results of volumetric efficiency

Fig.14 Errors between theoretical efficiency and experimental efficiency

Fig.15 Discharge flow rate of distribution windows before and after improvement

Fig.16 Impact of different trapped volumes on volumetric efficiency（n=6000 r/min）

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