正齒輪泵齒數與齒輪外形效應之實驗研究

Experimental study of Gear Pumps considering Gear tooth number and shape

周群智(Chun-Chih Chou)

指導教授 ： 張財壽

國立虎尾科技大學/工程學院/動力機械工程系機械與機電工程碩士班/碩士(2017年)

摘要

本研究以實驗方式量測外接式正齒輪泵並分析其流量、效率以及壓力脈動特性。首先針對10齒及14齒齒輪泵量測其流量及出口壓力等參數進行分析討論。接著修改齒輪非工作輪廓齒形，增加齒輪困油容積，量測修改後齒形壓力脈動變化與流量等數據，分析並比較兩者差異。結果顯示，就單齒輪泵特性而言，相同出口壓力時，流量與容積效率隨著轉速增加而提升；相同轉速時，流量與容積效率隨著出口壓力增加而下降；機械效率與總效率趨勢相近，在空載壓力時特別低，在給予出口壓力後會明顯上升。10齒泵，因齒空容積較大，空載壓力時，輸出流量較14齒泵大，在高出口壓力時，則較14齒泵低，因側面間隙較大的關係，流量與容積效率較低，機械效率隨出口壓力增加而提升的幅度較大，總效率與14齒齒輪泵相近。修改後齒形雖能降低最大困油壓力，但亦造成瞬時壓力脈動的增加。

關鍵字

齒輪泵 ； 齒輪外形 ； 實驗量測 ； 質量流率 ； 效率 ； 壓力脈動

並列摘要

Volumetric efficiency, discharge characteristics and pressure pulsation of spur gear pumps is experimentally measured in this thesis. First of all, the discharge, outlet pressure and other parameters of 10-tooth and 14-tooth gear pump are measured. Then non-working tooth shape of the gear is modified to increase the trapped-oil volume. The pressure pulsation and discharge of before and after modification of the tooth shape are analyzed and compared. The results show that, the discharge and volumetric efficiency of the pump will increase as the rotational speed increases at a fixed outlet pressure. Moreover, at the same rotational speed, the discharge and volumetric efficiency will decreases as the outlet pressure increases. The mechanical and overall efficiency have a similar trend and are particularly low with a no-load pressure. They increases significantly with a given outlet pressure larger than 2 MPa. The discharge of gear pump with 10-tooth is larger than that of 14-tooth with a no-load pressure because the tooth space of the former is larger. Caused by the larger axial clearance, the discharge of the 14-tooth pump becomes less with a higher outlet pressure. Mechanical efficiency will increase with a steeper slope when the outlet pressure increases. The overall efficiency trend is similar to that of 14-tooth gear pump. Modification of the tooth shape can reduce the maximum trapped oil pressure by 80%, but increases instantaneous pressure pulsation.

並列關鍵字

Gear pumps ； Gear shape ； Flow rate ； Pressure pulsation

參考文獻

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