无另置困油缓冲槽的轴向两段式齿轮泵

An External Gear Pump with Axial Stepped-gear Structure and Without Additional Trapped-oil Relief-grooves

为解决齿轮泵现有另置困油缓冲槽所存在的问题,提出了一种具有两种重合度的轴向两段式齿轮泵,重合度大于1的齿轮段的困油负荷流量,由重合度为1的齿轮段的困油缓冲流量来平衡,从而实现困油现象的充分缓解。重点给出了重合度为1的齿轮段脱开缝隙的3D特征测量方法;由困油负荷流量等于困油缓冲流量,建立了困油压力式。最后,进行了实例演示和PumpLinx软件验证。结果表明,两段式齿宽比的灵活调整,弥补了现有另置缓冲槽不可调缓冲能力的不足,工况适用性强;考虑气穴压力的困油压力式,修正了困油膨胀时的负压情况,适用于任何结构下的困油压力计算。得出了该泵能有效缓解困油现象,而无需另置缓冲槽,且结构简单、加工方便的重要结论。

In order to solve the problems in the existing gear pump with another trapped oil buffer groove,an external gear pump with axial stepped-gear structure for realizing two different contact ratios is proposed;the trapped-oil load flow from the gear section with a contact ratio greater than 1 is balanced by the trapped-oil relief flow from the gear section with a contact ratio equal to 1,and the trapped-oil phenomenon will be fully alleviated;then the relief gap from the gear section with a contact ratio equal to 1 is calculated by 3D feature method,and the trapped-oil pressure formula is derived by making the trapped-oil load flow equal to the trapped-oil relief flow;finally,an example is demonstrated and validated by PumpLinx software.The results show that the flexible adjustment of the two section gear width ratio makes up for the shortage of the non-adjustable buffer capacity of the existing buffer groove,and has strong applicability to working conditions;the trapped oil pressure formula considering cavitation pressure corrects the negative pressure when the trapped oil expands,which is applicable to the trapped oil pressure calculation under any structure.It is concluded that the pump can effectively alleviate the trapped-oil phenomenon,doesn’t need another buffer groove,has simple structure and is convenient for processing.