【正文】 但隨著建模的開發(fā)和計算,這個VPT有可能有助于開發(fā)新一代有更高性能的柱塞泵樣機(jī)。(3)柱塞泵是最復(fù)雜的液壓元件,因此建模和仿真也需要一些假設(shè)來簡化建模。根據(jù)模型的類型(如動態(tài)模型和液壓模型),相應(yīng)的仿真結(jié)果顯示柱塞泵的預(yù)測性能,所以更多的特征可以通過VPT研究。在柱塞上的這個最大應(yīng)力大約是222 。應(yīng)力和應(yīng)變能描述強(qiáng)度和變形程度。曲線在圖13顯示力的趨勢，它開始于一個非常小的值,當(dāng)斜盤的角到達(dá)5176。,15176。,5176。在柱塞泵中,柱塞用于吸油和排油，所以流體作用于活塞力是可變的和復(fù)雜的。因為配流盤上兩個腰形孔之間有一定的距離所以輸出流量是不連續(xù)的。流量脈動清晰的顯示在曲線中。泵的輸出流量和壓力被直接使用于液壓系統(tǒng)來驅(qū)動負(fù)載。因此,液壓接口,動態(tài)界面和柔性體界面是根據(jù)工作環(huán)境建立的。另外，求解器可以模擬泵和得到柱塞和軸的受力結(jié)果和變形結(jié)果。在有限元軟件環(huán)境中柱塞的撓性能被動態(tài)模型讀到并且被集結(jié)在整個泵模型上。由于一個泵有九個柱塞,所以整個泵模型包括9個綜合活塞模型,如圖6所示。因為兩種不同的孔的不同角度是180176。這個單元包括三個重要的泄漏，柱塞和缸體間, 滑靴和斜盤之間板和缸體和配流盤之間,這是在方程式（8）（10）中描述。基于泵部件之間的運動關(guān)系和流體對泵的影響，柱塞泵的液壓模型從基本的流量模型開始。為了構(gòu)建液壓模型,有一些假設(shè)如下：（1）柱塞泵運行穩(wěn)定和中間軸的旋轉(zhuǎn)速度定義常數(shù)。在動態(tài)軟件,所有這些運動副和運動參數(shù)被添加到相應(yīng)的部分。至于斜盤式柱塞泵顯示在圖 2(a), 三維結(jié)構(gòu)模型(圖2(b))在erical CAD軟件中建立。B點的軌跡可以描述活塞的運動。 (3)斜盤傾角的變化由旋轉(zhuǎn)驅(qū)動在一個定義的工作范圍內(nèi)。有幾種假說如下。該泵性能已被分析，斜盤傾角指標(biāo)的優(yōu)化通過VPT顯示了改善產(chǎn)品的可能性。它對于泵的優(yōu)化是非常有用的。一個柱塞泵的虛擬樣機(jī)在2002年由德國的亞琛技術(shù)大學(xué)用商業(yè)液壓和動態(tài)軟件制造。有時甚至可以取代物理模擬試驗并且節(jié)省開發(fā)成本。 虛擬樣機(jī)技術(shù)是一種新的工程技術(shù)。由于柱塞泵有復(fù)雜結(jié)構(gòu)和復(fù)合高速運動,所以做到確切的研究泵是困難的。然后一個特別的強(qiáng)調(diào)是放在動力學(xué)模型和水力模型,模擬的流量脈動、壓力脈動、運動原理、應(yīng)力和應(yīng)變分布的中間軸與柱塞的操作。流體特征被液壓軟件計算。lhydraulik und Pneumatik (O+P), 2002, 46: 6?12.[5] YU X K, WANG J. Virtual prototype of a hydraulic system based on ADAMS[M]. Beijing: Construction Machinery and Equipment, 2003. (in Chinese)[6] DEEKEN M. Simulation of the tribological contacts in an axial piston machine[J]. 214。, 15176。, 5176。Modeling and Simulation on Axial Piston Pump Based on Virtual Prototype TechnologyAbstract: A particular emphasis is placed on the virtual prototype technology (VPT) of axial piston pump. With this technology it is convenient and flexible to build a plicated 3D virtual based on real physical model. The actual kinematics pairs of the parts were added on the model. The fluid characters were calculated by hydraulic software. The shape of the parts, the flexible body of parts, etc. were improved in this prototype. So the virtual prototype of piston pump can work in puter like a real piston pump, and the flow ripple, pressure pulsation, motion principle, stress of parts, etc. can be investigated. The development of the VPT is introduced at the beginning, and the modeling process of the virtual prototype is explained. Then a special emphasis is laid on the relationship between the dynamics model and the hydraulic model, and the simulations on the flow ripple, pressure pulsation, motion principle, the stress and strain distribution of the middle shaft and piston are operated. Finally, the advantages and disadvantages of the VPT are discussed. The improved virtual prototype of piston pump more tally with the real situation and the VPT has a great potential in simulation on hydraulic ponents.Key words: virtual prototype, axial piston pump, dynamics1 Introduction?Axial piston hydrostatic pump is an important hydraulic ponent, which is widely applied both in industry and mobile machine. As the piston pump has plicated structure and posite highspeed motion, so it is difficult to do exactly research on the pump. The pump model is always simplified to a great degree. And the simplifications bring considerable deviation. With the development of puter and multibody dynamics, the virtual prototype technology (VPT) is used for studying hydraulic system and ponents. Virtual prototype technology is a new engineering technology. With the VPT plex mechanism system model can be made and its dynamics characteristic can be simulated at a very real condition by integrating modeling tools from several different fields and simulation methods. The core of VPT is the dynamics model, which have several interfaces to connect other models, such as hydraulic model and fitness element method (FEM) model. So the virtual prototype built based on VPT can simulate most of the pump performances, and the simulation results of the virtual prototype are very close to the test results of the physics prototype. Sometimes the simulation can even replace physics test and save the development cost[1]. Hydraulic virtual prototype technology integrate the advanced 3D CAD modeling method and hydraulic simulation technology to predict performance and study characteristics of a machine[1]. Because of the plicated structure and nonlinear characteristics of the hydraulicsolid coupling, it is timeconsuming and expensive with traditional tryanderror design way, and the analysis results of traditional way are not accurate enough[2]. The virtual prototype of hydraulic machine, such as the axial piston pump, is a better way to predict the performance of hydraulic ponent[3]. With the mercial hydraulic and dynamic softwares, a virtual prototype of piston pump was made by Aachen Technique University, Germany, in 2002[4]. The hydraulic characteristics and fri