****本科毕业设计(论文)
定量叶片泵的设计
学生姓名： 学生学号： 院 （系）： 年级专业： 20 机械设计制造及其自动化 指导教师： 职称:
二〇一 年 月
****本科毕业设计（论文） 摘要
摘 要
在广泛应用的各种液压设备中，液压泵是关键性的元件，它们的性能和寿命在很大程度上决定着整个液压系统的工作能力，随着时代的发展和技术的进步，液压泵性能越来越完善，在各种工业设备、行走机构以及船舶和飞机上都得到了广泛应用。因此对于叶片泵相关知识的学习和认识十分必要，特别是对于从事液压相关方面工作的人更显得尤为重要。
本设计根据现已广泛应用的叶片泵为基础，对定量叶片泵即双作用叶片泵进行设计。在设计过程中采纳了一些有关叶片泵的新技术和新观点，并用于叶片泵的设计考虑，设计中对双作用叶片泵的叶片倾角进行了探讨，并对比两种观点的优劣，选择了现今已越来越得到更多人承认的叶片倾角为零的一种观点。在定子过渡曲线的设计上也没有拘泥于传统的等加速曲线或阿基米德螺旋线等定子曲线选择，而是结合现今数控机床普及的事实大胆选用高次曲线作为定子过渡曲线的设计基础。
设计中还主要参考了YB型系列的叶片泵相关产品结构和技术参数，在相关类型的叶片泵基础上对叶片泵的定子过渡曲线和叶片前倾角等结构进行了重新设计，使叶片泵的部分或整体性能有所改善。
关键词：双作用叶片泵，叶片倾角，定子过渡曲线
注：本设计为已通过答辩并获得“优秀”等级成绩的毕业设计，特别是本文的CAD图几无错误，得到了各位答辩老师的一致好评。
由于该类设计资料稀少，作者在设计中吃了很多苦，所以在文档中隐藏了部分重要设计计算过程，如果需要请下载后（去掉背景色）阅读，谢谢!
另本文附有8张CAD图纸（装配图，左、右配流盘零件图，左、右泵体零件图，定子零件图，转子零件图，传动轴零件图），凡下载需CAD图纸的，请给我发消息，我会把图纸发到你邮箱，纯免费的哦...
Ⅰ
****本科毕业设计（论文） ABSTRACT
ABSTRACT
Widely used in various hydraulic pump is the key equipment, components, their performance and life in largely determines the hydraulic system, the ability to work with the development of The Times and the technological progress, more perfect, pump performance in various industrial equipment, walks the organization and the ship and aircraft have been widely applied. Therefore vane pump for knowledge and necessary, especially for the work in hydraulic related more appear particularly important.
This design has been widely applied to the vane pump, based on quantitative vane pump is double vane pump function design. In the design process of vane pump adopt some new technology and new ideas, and used in the design of vane pump, design of double vane pump function of blade Angle is discussed, and the comparison of two kinds of views, choose now has more and more people admit blade Angle of view a zero. In the design of the stator transition curve is not constrained the acceleration curve or Archimedes spiral such as choice, but the stator curve with universal fact CNC nowadays choose high curve as bold design of stator transition curve.
In the design of main type series of YB vane pump related products structure and technical parameters, the type of vane pump basis of the stator vane pump transition curve and blade Angle structures such as before, the design of vane pump part or whole performance improved.
Keywords: Double vane pump function ，Blade Angle ，The stator transition curve
Ⅱ
****本科毕业设计（论文） 目录
目 录
摘要·························································································································· Ⅰ ABSTRACT ············································································································ Ⅱ
前言 ···························································································································· 1 1双作用叶片泵简介 ································································································· 2
1.1双作用叶片泵组成结构 ························································································ 2 1.2 双作用叶片泵工作原理 ······················································································· 2 1.3 双作用叶片泵结构特点 ······················································································· 3 1.4 双作用叶片泵排量和流量计算 ············································································· 4
2双作用叶片泵设计原始参数 ················································································· 5 3设计方案分析与选定 ····························································································· 6
3.1 设计总体思路 ····································································································· 6 3.2泵体结构方案分析与选定····················································································· 6
3.2.1圆形叶片泵 ······························································································ 6 3.2.2方形叶片泵 ······························································································ 6 3.2.3 方案选定 ································································································· 7 3.3 叶片倾斜角方案分析选定 ···················································································· 7
3.3.1 叶片倾角对叶片受力的影响 ······································································· 7 3.3.2叶片倾角的两种观点 ·················································································· 9 3.3.3我倾向的观点····························································································11 3.3.4 叶片倾角方案选定 ····················································································11 3.4定子过渡曲线方案分析与选定············································································ 12
3.4.1双作用叶片泵性能对定子曲线的要求························································ 12 3.4.2定子曲线应具备的特性············································································· 14 3.4.3各种定子曲线的分析、比较和选择 ··························································· 15 3.4.4定子过渡曲线方案综合分析、选定 ··························································· 22
4参数的计算 ··········································································································· 23
4.1 流量计算 ·········································································································· 23
4.1.1平均理论流量··························································································· 23 4.1.2实际流量·································································································· 23 4.2功率计算 ··········································································································· 23
****本科毕业设计（论文） 目录
4.2.1输入功率轴功率 ······················································································· 23 4.2.2有效输出功率液压功率············································································· 23 4.2.3理论功率·································································································· 23 4.3 扭矩计算 ·········································································································· 23
4.3.1理论扭矩·································································································· 23 4.3.2实际扭矩·································································································· 24 4.4 双作用叶片泵设计计算参数表 ··········································································· 24
5整体设计计算 ······································································································· 25
5.1转子的设计 ········································································································ 25
5.1.1材料选择·································································································· 25 5.1.2转子半径·································································································· 25 5.1.3转子轴向宽度··························································································· 25 5.1.4转子结构尺寸设计···················································································· 26 5.2叶片的设计 ········································································································ 28
5.2.1叶片材料选择··························································································· 28 5.2.2 叶片数 ···································································································· 28 5.2.3叶片安放角 ······························································································ 29 5.2.4叶片的厚度 ······························································································ 29 5.2.5叶片的长度 ······························································································ 29 5.2.6叶片的结构尺寸设计 ················································································ 30 5.2.7叶片的强度校核 ······················································································· 30 5.3定子的设计 ········································································································ 31
5.3.1定子材料选择··························································································· 31 5.3.2定子短半径 ······························································································ 31 5.3.3定子长半径 ······························································································ 32 5.3.4定子大、小圆弧角···················································································· 32 5.3.5定子过渡曲线的幅角 ················································································ 32 5.3.6定子过渡曲线设计···················································································· 32 5.3.7校核定子曲线··························································································· 34 5.3.8定子结构尺寸设计···················································································· 37 5.4左配流盘的设计 ································································································· 38
5.4.1左配油盘封油区夹角 ················································································ 38 5.4.2左配流盘V形尖槽 ··················································································· 39 5.4.3左配流盘结构尺寸设计············································································· 40
****本科毕业设计（论文） 目录
5.5右配流盘结构设计 ····························································································· 41 5.6传动轴的设计 ···································································································· 42
5.6.1 材料选择 ································································································· 42 5.6.2 花键轴段的设计 ······················································································ 42 5.6.3校核轴段花键的挤压强度 ········································································· 44 5.6.4轴的结构设计··························································································· 44 5.6.5轴上载荷分析··························································································· 46 5.6.6按扭转切应力校核轴的强度······································································ 47 5.6.7校核轴的刚度··························································································· 48 5.7泵体的设计 ········································································································ 49
5.7.1泵体材料选择： ······················································································· 49 5.7.2左泵体结构设计 ······················································································· 50 5.7.2右泵体结构设计 ······················································································· 51 5.8盖板的设计 ········································································································ 51
6主要标准件的选用 ······························································································· 52
6.1 轴承的选择 ······································································································· 52
6.1.1 左端轴承 ································································································· 52 6.1.2右端轴承·································································································· 52 6.1.3轴承的润滑 ······························································································ 52 6.2密封件选择 ········································································································ 53
6.2.1 旋转轴唇形密封圈选择 ·········································································· 53 6.2.2 O形橡胶密封圈选择·············································································· 53 6.3 螺钉选择 ·········································································································· 54
6.3.1 定子、侧板配合螺钉选择 ········································································ 54 6.3.2 盖板螺钉选择 ·························································································· 54 6.3.3挡板螺钉·································································································· 54 6.4 螺栓的选择 ······································································································· 55 6.5 标准螺纹选择 ··································································································· 55
6.5.1吸油孔口螺纹··························································································· 55 6.5.2压油孔口螺纹··························································································· 55 6.6键的选择 ··········································································································· 55 6.7圆锥销的选择 ···································································································· 55
7各种配合的选择 ··································································································· 56
7.1滚动轴承配合 ···································································································· 56
****本科毕业设计（论文） 目录
7.1.1轴承与轴的配合 ······················································································· 56 7.1.2轴承与壳孔的配合···················································································· 56 7.1.3配合表面粗糙度和形位公差······································································ 57 7.2花键轴配合 ········································································································ 57 7.3转子叶片槽配合 ································································································· 58 7.4右侧板与左、右泵体·························································································· 58 7.5定子、左配流盘与泵壳孔配合············································································ 58 7.6端盖与泵壳孔配合 ····························································································· 59 7.7定子与转子宽度配合·························································································· 59
8主要材料及技术要求 ··························································································· 60 9噪声、寿命与维护 ······························································································· 61
9.1双作用叶片泵振动与噪声··················································································· 61
9.1.1噪声及产生原因 ······················································································· 61 9.1.2降低噪声的措施 ······················································································· 61 9.2双作用叶片泵的寿命·························································································· 62 9.3双作用叶片泵的正确使用与维护 ········································································ 63
9.3.1双作用叶片泵的正确使用 ········································································· 63 9.3.2双作用叶片泵的维护与检查······································································ 64
参考文献 ·················································································································· 65 致谢 ·························································································································· 66
****本科毕业设计（论文） 前言
前 言
液压泵是现代液压设备中的主要动力元件，它决定着整个液压系统的工作能力。在液压系统中，液压泵的功能主要是将电动机及内燃机等原动机的机械能转换成液体的压力能，向系统提供压力油并驱动系统工作。
在液压传动与控制中使用最多的液压泵主要有齿轮式、叶片式和柱塞式三大类型。其中叶片泵是在近代液压技术发展史上最早实用的一种液压泵。
叶片泵与齿轮式、柱塞式相比，叶片泵具有尺寸小、重量轻、流量均匀、噪声低等突出优点。在各类液压泵中，叶片泵输出单位液压功率所需重量几乎是最轻的，加之结构简单，价格比柱塞泵低，可以和齿轮泵竞争。
本设计对定量叶片泵的设计以YB系列的双作用叶片泵为基础，并结合现今的技术特点和最新观点进行设计，在定子过渡曲线和叶片倾角等设计上采用了一些有别于传统的设计方案，在一定程度上提高了泵的工作性能。叶片泵作为液压系统主要部件，对其的设计需要丰富的机械方面的理论知识，以及有关叶片泵的相关专业技术知识，将其作为我的设计方向，是我大学四年专业知识学习的总结和锻炼，在设计过程中也不断促使我重新认识、理解所学专业知识，对所学知识有了一次系统的巩固和提高。最重要的是在这次设计过程中，对所学理论知识与实践的结合，提高了自己的实践动手能力，并在这过程认识到自己的许多不足，我一定会在今后的学习工作中不断改进。
1
****本科毕业设计（论文） 1 双作用叶片泵简介
1 双作用叶片泵简介
1.1双作用叶片泵组成结构
组成结构：定子、转子、叶片、配油盘、传动轴、壳体等
1.2 双作用叶片泵工作原理
43251 图1-1 双作用叶片泵工作原理
图3-19 双作用叶片泵工作原理1-定子 2-压油口 3-转子 4-叶片 5-吸油口 Fig 1-1 Double-acting vane pump principle of work 1—定子；2—吸油口；3—转子；4—叶片；5—压油口
如图1-1所示。它的作用原理和单作用叶片泵相似，不同之处只在于定子表面是由两段长半径圆弧、两段短半径圆弧和四段过渡曲线八个部分组成，且定子和转子是同心的。在图示转子顺时针方向旋转的情况下，密封工作腔的容积在左上角和右下角处逐渐增大，为吸油区，在左下角和右上角处逐渐减小，为压油区；吸油区和压油区之间有一段封油区把它们隔开。这种泵的转子每转一转，每个密封工作腔完成吸油和压油动作各两次，所以称为双作用叶片泵。泵的两个吸油区和两个压油区是径向对称的，作用在转子上的液压力径向平衡，所以又称为平衡式叶片泵。
定子内表面近似为椭圆柱形,该椭圆形由两段长半径R、两段短半径r和四段过渡曲线所组成。当转子转动时,叶片在离心力和建压后>根部压力油的作用下,
2
****本科毕业设计（论文） 1 双作用叶片泵简介
在转子槽内作径向移动而压向定子内表,由叶片、定子的内表面、转子的外表面和两侧配油盘间形成若干个密封空间,当转子按图示方向旋转时,处在小圆弧上的密封空间经过渡曲线而运动到大圆弧的过程中,叶片外伸,密封空间的容积增大,要吸入油液;再从大圆弧经过渡曲线运动到小圆弧的过程中,叶片被定子内壁逐渐压进槽内,密封空间容积变小,将油液从压油口压出,因而,当转子每转一周,每个工作空间要完成两次吸油和压油,所以称之为双作用叶片泵,这种叶片泵由于有两个吸油腔和两个压油腔,并且各自的中心夹角是对称的,所以作用在转子上的油液压力相互平衡,因此双作用叶片泵又称为卸荷式叶片泵,为了要使径向力完全平衡,密封空间数即叶片数>应当是双数。
1.3 双作用叶片泵结构特点
1>双作用叶片泵的转子与定子同心;
2>双作用叶片泵的定子内表面由两段大圆弧、两段小圆弧和四段定子过渡曲 线组成;
3>双作用叶片泵的圆周上有两个压油腔、两个吸油腔，转子每转一转，吸、压油各两次双作用式>。
4>双作用叶片泵的吸、压油口对称，转子轴和轴承的径向液压作用力基本平衡;即径向力平衡卸荷式>。
5>双作用叶片泵的所有叶片根部均由压油腔引入高压油，使叶片顶部可靠地与定子内表面密切接触。
6>传统双作用叶片泵的叶片通常倾斜安放，叶片倾斜方向与转子径向辐射线成倾角θ，且倾斜方向不同于单作用叶片泵，而沿旋转方向前倾，用于改善叶片的受力情况，最近观点认为倾角为0?最佳。
3
****本科毕业设计（论文） 1 双作用叶片泵简介
1.4 双作用叶片泵排量和流量计算
RV1θ3rδr0V221 图1-2 双作用叶片泵的流量计算 算图3-20 双作用叶片泵的流量计1-转子 2-叶片 3-定子 1-转子 2-叶片 3-定子
如图1-2所示，泵的排量为
Vp?2?V1?V2?Z/(2?)?B(R?r)22 (1-1)
式中 R——定子内表面长圆弧半径；
r——定子内表面短圆弧半径； B——转子或叶片宽度； Z——叶片数。
若叶片厚度为δ，且倾斜θ角安装，则它在槽内往复运动时造成叶片泵的排量损失为
B2(R?r)Z?2?cos??B(R?r)Z??cos? 双作用叶片泵的真正排量为
?Z??V?B(R?r)?(R?r)??cos????(m/rad)3 (1-2) 泵的实际流量为
?Z?q?V????pv?B(R?r)?(R?r)??cos???????pv (m/s)3 (1-3)
4
****本科毕业设计（论文） 2 双作用叶片泵设计原始参数
2 双作用叶片泵设计原始参数
设计原始参数:
额定排量：q?9.0ml/r 额定压力： 额定转速：
p?7.0MPa n?1450r/min 5
****本科毕业设计（论文） 3 设计方案分析与选定
3 设计方案分析与选定
3.1 设计总体思路
本设计为定量叶片泵的设计，叶片泵实现定量可以是定心的单作用叶片泵和双作用叶片泵，此处选择双作用叶片泵进行设计。以双作用叶片泵本身的结构特点实现定量，并参考YB型叶片泵结构，结合现有新技术和新观点进行双作用叶片泵的设计。
3.2泵体结构方案分析与选定
本设计为单级双作用叶片泵，它分为单级圆形平衡式叶片泵和单级方形平衡式叶片泵两种类型。
3.2.1圆形叶片泵
圆形叶片泵的主要结构特点和存在问题：
1>采用固定侧板，转子侧面与侧板之间的间隙不能自动补偿，高压时泄漏严重。只能工作在7.0MPa以下的中、低压。
2>进、出油道都铸造在泵体内称为暗油道>，铸造清沙困难。而且油道狭窄，高转速时由于流速过快，流动阻力大，容易出现吸空和气蚀。
3>侧板与转子均带耳轴，虽然支承定心较好，但毛坯费料，加工不方便。这种结构装配时对后泵盖联接螺钉拧紧扭矩的均匀性要求很严，否则容易导致侧板和转子的倾侧，使侧板与转子端面的轴向间隙不均匀，造成局部磨损。
3.2.2方形叶片泵
方形叶片泵主要结构特点与圆形叶片泵相比，主要有以下改进：
1>简化了结构，在同等排量的情况下，外形尺寸和重量比圆形泵大大减小。 2>取梢转子和侧板的耳轴，改善了加工工艺性，而且可节省毛坯材料。装配时即使泵盖四个螺栓的拧紧力矩不很均匀，也不致影响侧板与转子端面的均匀密合。
3>采用浮动压力侧板，提高了容积效率和工作压力。
4>进油道设在泵体，排油道设在泵盖，均为开式油道，不仅铸造方便，而且油道通畅，即使高转速工作时流动阻力也较小．
5>传动釉输入端一侧的支承较强，能够承受径向载荷，允许用皮带或齿轮直接驱动，有一定的耐冲击和振动能力。
6
****本科毕业设计（论文） 3 设计方案分析与选定
3.2.3 方案选定
综上所述，方形叶片泵具有结构紧凑，体积小，能够适应高转速和较高压力工作，耐冲击、振动能力较强等特点，因此特别适用于工程车辆液压系统。加之其加工工艺性也比圆形泵优越得多，所以在一般工业机械上也获得广泛应用，已逐步取代圆形泵。
综合考虑以上因素选定方形叶片泵为本设计的叶片泵类型。
3.3 叶片倾斜角方案分析选定
3.3.1 叶片倾角对叶片受力的影响
FtφωFFp
图3-1 叶片顶端受力分解
7
****本科毕业设计（论文） 3 设计方案分析与选定
υlF1F2T2L
图3-2 转子对叶片的作用力
定子对叶片顶部产生的反作用合力F可以分解为Fp和Ft两个分力见图3—1>，其中横向分力Ft枝叶片靠向转于榴一侧并形成转子槽对叶片的接触反力和摩擦阻力见图3-2>，对叶片的自由滑动十分不利，严重时将会造成转子槽的局部磨损，导致泄漏增加，甚至因摩擦力太大而使叶片被咬住不能伸缩滑动。此外，
Ft还使叶片悬伸部分承受弯矩作用，假如Ft力过大，或者叶片悬伸过长，叶片
还有可能折断。因此，Ft分力的存在对叶片泵的寿命和效率都很不利，设计上应设法尽量减小其数值。
由图3-1和图3-2
?FP?Fcos? (3-1) ?F?Fsin??t式中，?为合力F的作用方向与叶片间的夹角
?F1?fr?T1 (3-2) ?F?f?T?2r2式中，fr为转子槽与叶片摩擦系数。
合力F与叶片之间的夹角?越小，则分力Ft越小。最理想的情况是令叶片的方向正好与F力的作用方向一致，这时??0?,Ft?0，由Ft引起的转于对叶片的接触反力和摩擦力亦为零，叶片的伸缩滑动将完全不受转于槽阻碍。
8
****本科毕业设计（论文） 3 设计方案分析与选定
NFtAFfFnψωθ1NγOFFpαφ 图3-3 叶片倾角与作用力方向
在图3-3中，?是定子曲线接触点处法线方向与叶片方向的夹角，称为压力角，?是定子与叶片的摩擦角。由图可见，各角度之间存在如下关系 ????? (3-3)
因此，要使?角为0应使压力角等于摩擦角?。
由此得出结论；定子曲线与叶片作用的压力角?等于摩擦角?时．对叶片产生的横向作用力Ft最小，叶片与转子槽之间的相互作用力和摩擦磨损量最小，所以压力角的最优值?op为
?op?arctgf0?? (3-4)
当摩擦系数f0?0.13时，?op???7?。
如图3-3所示，在叶片向旋转方向前倾放置的情况下，吸油区定子与叶片作用的用力角?为
?????1 (3-5)
?1为叶片的倾斜角，式中?为定子曲线接触点A处的法线与半径OA的夹角，
即叶片方向与半径方向OA的夹角。
3.3.2叶片倾角的两种观点
1> 传统观点：平衡泵叶片应具有一定的前倾角?1
传统观点认为，平衡式叶片泵的叶片应该向旋转方向朝前倾斜放置。以往生产的大多数叶片泵亦按此原则设计制造，叶片前倾角其至达10??14?。这种观点的主要理由如图3-4a所示：定子对叶片作用的横向分力Ft取决于法向接触反力
9
****本科毕业设计（论文） 3 设计方案分析与选定
Fn和压力角?，即Ft?Fnsin?，为了使Fn尽可能沿叶片方向作用，以减小有害
的横向分Ft，压力角?越小越好。因此令叶片相对于半径方向倾斜一个角度?1，倾斜方向是叶项沿旋转方向朝前偏斜，使压力角?小于?角，即?????1，否则压力角???将较大。
2> 新观点：认为取叶片前倾角?1?0?更为合理
影响压力角?大小的因素包括定子曲线的形状反映为?角的大小>和叶片的倾斜角?1。实际上定子曲线各点的?角是不同的，转子旋转过程中，要使压力角除非叶片倾斜角?1能在不同转角?在定子各接触点均保持为最优值???op??，
时取不同的值，且与?保持同步反值变化，而这在结构上是不可能实现的。因此，叶片在转子上安放的倾斜角只能取—个固定平均合理值，使得运转时在定子曲线上有较多的压力角接近于最优值?op??。由计算机对不同叶片泵所作的计算表明，为使压力角?保持为最优值，相府的叶片倾斜角?1通常需在正负几度沿转子旋转方向朝后倾斜为负>的范围内变化，其平均值接近于零度；加之从制远方便考虑，所以近期开发的高性能叶片泵倾向于将叶片沿转子径向放置，即叶片的倾斜角?1?0?。
NFtFnFpθ1Nω
a>
10
ψα****本科毕业设计（论文） 3 设计方案分析与选定
NFtFnθ1ψωNOFpα
b>
图3-4 叶片前倾时压力角 a>压油区 b>吸油区
3.3.3我倾向的观点
新观点：叶片倾角为0.
理由：传统观点是靠经验得出的值，而现代通过先进的计算机技术已经能计算解决这类复杂问题，并通过计算证明了传统观点的错误。
传统观点的错误还在于：
1>在分析定子对叶项的作用力时未考感摩擦力Ff的影响，计算有害的横向分力Ft使不是以反作用合力F为依据，而是以法向接触反力Fn为依据，因而得出压力角?越小越好的错误结论。实际上由于存在摩擦力Ff，当压力角??0?时，定子对叶顶的反作用合力F并不沿叶片方向作用，即并非处于最有利的受力状态，这时转子槽对叶片的接触反力和摩擦力并不为零。
2>忽视了平衡式叶片泵的叶片在吸油区和压油区受力情况大不相同，而且吸油区叶片受力较压油区严重得多的现实，错误地把改善叶片受力的着眼点放在压油区而不是吸油区。叶片向前倾角?1有利于成小压力角的结论实际上只适用于压油区。相反，由图3-4b可见，在吸油区叶片前倾反而使压力角?增大，变为
?????1，使受力情况更加恶劣。
3.3.4 叶片倾角方案选定
综上，设计的平衡式叶片泵的叶片前倾角选择?1?0?。
11
****本科毕业设计（论文） 3 设计方案分析与选定
3.4定子过渡曲线方案分析与选定
平衡式叶片泵定子大、小圆弧之间过渡曲线的形状和性质决定了叶片的运动状态，对泵的性能和寿命影响很大，所以定子曲线问题主要也就是大、小圆弧之间连接过渡曲线的问题。定子曲线的设计即指的这部分过渡曲线的设计。
由于定子曲线对叶片泵的排量、输出流量的脉动、冲击振动、噪声、效率和使用寿命都有重要影响，所以定子曲线是叶片泵设计的关键之一。
3.4.1双作用叶片泵性能对定子曲线的要求
1>使输出流量脉动小 泵瞬时流量公式： Qtr?R而
dsjdtdVdtk?B?(R2?R1)?2Bt1?j?122dsjdt (3-6)
??dsjd???cos??d?(?)d?|j
由上式知泵输出流星的均匀性取决于处在一个区段定子曲线范围内各叶片径向运动速度之和是否变化，或者说取决于定子曲线相应各点的矢径变化之和
k?[j?1d?(?)d?]是否能保持为常数。最简单的情况是定子曲线的速度特性v(?)在整
个 ?角范围内保持为常数，这时只要处于吸油区的叶片数k=常数，就有常数
k?[j?1d?(?)d?]=常数，输出流量的脉动就为零。
2>使叶片不脱离定子
虽然平衡式叶片泵在进入工作状态后主要靠根部压力油的作用将叶片顶出与定子保待接触，但在泵启动之初，由于根部压力尚来建立，却只能依靠离心力使叶片伸出。在这种情况下使叶片与定子保持接触而不脱空的条件是
［?（?）-L2?］?a?0，即要求对定于曲线的径向加速度加以限制，以保证叶片
2的离心加速度大于定于曲线矢径增长的加速度。这样，在根部无油压作用的情况下，吸油区叶片的径向运动才能跟上定子曲线矢径的增长，并对定子有适当的接触压力。
值得注意的是，定子长、短半径的差值(R2?R1)对加速度值的影响很大，如果差值太大，即定子曲线的升程太大，则径向运动的速度和加速度将很大，有可能会出现叶片的离心力不足以克服加速外伸运动的惯性力，以致跟不上定子曲线矢径的增长而脱离定子的现象。 3> 叶片无冲击振动，低噪声
12
****本科毕业设计（论文） 3 设计方案分析与选定
如果定子曲线在某些点上的径向速度?发生突变，则曲线上该点的径向加速度a在理论上等于无穷大。若a???，叶片在该点将出现瞬间脱离定子的现象；若a???，则叶片对定于产生很大的冲击力，二者均会引起撞击噪声和严重磨损。有些书中把这种现象称为“硬冲”，是叶片泵正常工作所不允许的。为了消除径向速度的突变，要求定子曲线处处光滑连续，与大、小圆弧的连接点处有公共切线。
根据分斩，定子曲线加速度a(?)的急剧变化和加速度变化率（的突变也J?）会使叶片对定子的压紧力发生变化，是引起叶片振动冲击产生噪声的重要原因。把因加速度突变而引起的冲击称为“软冲”。
无冲击、低噪声对定子曲线的要求是曲线的速度?、加速度a和加速度变化率J都连续光滑变化，没有突变。此外，为了减轻闭死容积高压回流或高压喷流所引起的冲击和高压流体噪声，往往还要求扩大定子曲线的范围角?，使定子曲线具有预压缩或预扩张的功能。
4>使叶片的受力状态良好
ΦdρΨNNdφO
图3-5 定子曲线的压力角
定子曲线某点矢径?(?)与曲线该点的法线之夹角?称为定于曲线的压力角，如图3-5所示。根据高等数学的知识： tg??d?(?)?(?)d? (3-7)
当叶片沿转子径向放置时，定子曲线的压力角?也就是叶片与定子接触的
13
****本科毕业设计（论文） 5 整体设计计算
取 ?0?40?
5.4.2左配流盘V形尖槽
正因为?0??1，当相邻两叶片同时处于?0角范围内时，由两叶片、转子、定子和侧板所围成的容积cdef图中带点部分与吸、排油窗均隔离，出现闭死现象。
如果是从吸油区转向压油区，例如在平衡式叶片泵的大圆弧K段(出现闭死时cdef密闭容积内的油液仍保持与吸油腔压力p1相同的低压。随着转子向前转动，一但接通排油窗口，内于压差悬殊，压油腔的高压油将在瞬间内反冲入两叶片间的容腔。使该腔压力迅猛升高，出现所谓酌“高压回流”，造成很大的压力冲击。每转过一个?角都如比重复一次。这种周期性的高压回流液压冲击不仅导致叶片泵输出流量和输出压力的脉动，更重要的是造成定子环的径向振动，
从而产生噪声．并加快定子内曲面与叶顶的磨损，对叶片泵的正常工作影响极大。叶片泵越是工作在高压，上述闭死现象所造成的高压回流液压冲击也越严重。
如果两叶片间的容腔是从压油区转向吸油区，例如在平衡式叶片泵的小圆弧阶段出现闭死时。cdef密闭容积内的油液处于等同于压油压力p2的高压。一旦接通吸油窗口，闭死容积内的高压油将在瞬间内向吸油腔喷出，突然泄压，同样也对泵的正常工作不利，但闭死容积内储存的液体压力能有限且不是直接与泵的输出相通，高压回流影响程度较轻些。
为了减轻闭死现象的不利影响，在配流盘窗口设计V形尖槽。
配流窗口v形尖槽如图3—33所示。减缓高压回流液压冲击的v形尖槽应当开在排油窗口的进入端。当闭死容积离开吸油窗口之后，通过v形尖榴逐渐与排油窗口连通，随着转角的增加， v形尖槽的通流截面积的逐渐增大而使两叶片间容腔内的压力p逐步升高，直至完全接通排油窗口，才升压达到压油腔的压力
p2。闭死容积的升压过程与
v形尖槽的几何尺寸有关。当V形尖楷的横截面为
等边三角形时，随着v形尖槽逐渐进入两叶片间的容腔，按节流作用和油液可
压缩性计算出的闭死容腔压力P的升压过程如图3—34所示。其小，?是v
?1是v形尖槽的范围角，形尖槽的槽底倾角； ?是从尖槽算起的转角见图3—35>。
V形尖槽所占的幅角在6??17?之间，具体数值要通过实验来确定，有些泵为了达到降低噪声的效果，宁可稍许降低容积效率，设计成V形尖槽跨入封油区若干度。
取 ??10?
39
****本科毕业设计（论文） 5 整体设计计算
5.4.3左配流盘结构尺寸设计
1>整体尺寸:
定子外径??85mm，则配流盘大径Dp?85mm，考虑工艺要求和条件取配流盘宽度bzp?25mm。
2>轴孔尺寸:
左配油盘的轴孔壁作为左轴承外圈的轴向定位，由手册上查得61902型深沟球轴承外圈的安装尺寸Da?26mm，定位高度h=轴孔直径
dzp?Da?2?C (5-33) C为轴孔倒角，查《机械设计手册—第一篇》零件倒圆与倒角 GB/T 6403.4—1986>表1-5-10，得 C=1.0mm
故求得轴孔直径 dzp?Da?2?C?24mm 3>配流盘端面环槽:
配流盘端面环槽与叶片槽底部相通，由转子叶片压力油孔尺寸，各孔圆心位置rt?35mm，孔直径??3mm，取环槽分度圆rhc?35mm，环槽宽度bhc?4mm，槽深hhc?3mm
4>配油窗口:
计算得到的配油盘封油区夹角?0?40?，配流盘V形尖槽??10?，则计算配油盘吸油窗口夹角?x和压油窗口夹角?y：
?x??y??2?(?0??)?2?9?40?Da?D2?1mm,因此，左配油盘
配油窗口吸、压排油窗口需要根据转子和定子的配合安装位置确定，且配油窗口在四段过渡定子曲线上，R1?30.0mm，R2?31.035mm，则配油窗口分圆直径在??62mm上。
取左配流盘两吸油窗口宽度为5mm，且为不通孔深5mm，吸油窗口为缺口型，夹角为40?，在吸油口入口端，吸油窗口较大，扩大角度为15?。
5>螺钉孔:
由定子设计选择的螺钉型号M3?70，且定子上螺钉孔直径为?3.3，4个螺钉孔位置在分布在直径?77的圆上，分别位于过渡定子曲线中心点上。则左配油盘上螺钉孔直径为?3.3且2个螺钉孔位置分布在直径?77的圆上，在吸油窗口中心点上。
40
****本科毕业设计（论文） 5 整体设计计算
6>V形尖槽: 压油窗口V形尖槽：
平衡式叶片泵叶片当随着转子向前转动，一但接通排油窗口，由于压差悬殊，压油腔的高压油将在瞬间内反冲入两叶片间的容腔。使该腔压力迅猛升高，出现所谓酌“高压回流”，造成很大的压力冲击。每转过一个?角都如此重复一次。这种周期性的高压回流液压冲击不仅导致叶片泵输出流量和输出压力的脉动，更重要的是造成定子环的径向振动，从而产生噪声．并加快定子内曲面与叶顶的磨损，对叶片泵的正常工作影响极大。叶片泵越是工作在高压，上述闭死现象所造成的高压回流液压冲击也越严重。因此在压油窗口设计V形尖槽，尖槽夹角由上面的计算知
???10
考虑安装方便，在两压油窗口两端均布置一V形尖槽。 吸油窗口V形尖槽：
当叶片接通吸油窗口，闭死容积内的高压油将在瞬间内向吸油腔喷出，突然泄压，同样也对泵的正常工作不利，但因为闭死容积内储存的液体压力能有限且不是直接与泵的输出相通，所以影响程度较高压回流轻些。
因此，闭死容积突然泄压问题对叶片泵性能的影响不太直接，所以吸油窗口有时并不开设V型槽，此处，配流盘吸油窗口不开设V形槽。
5.5右配流盘结构设计
1>右配流盘与左配流盘大部分尺寸相同，吸、压油窗口位置也相同，不同在于，右配流盘的吸油窗口为不通孔，深为5mm，压油窗口为通孔与配流盘环形槽相通，环形槽宽8mm，深5mm.
右配流盘螺纹孔为M3，与左配流盘螺钉孔配合安装螺钉。
2>在右配流盘上开有2个?3mm的孔和2个?2mm的孔，分别为2个?2mm向叶片槽底部输送压力油的孔，使压力油进到叶片底部，叶片在压力油和离心力作用下压向定子表面，保证紧密接触以减少泄漏。转子两侧泄漏的油液经传动轴与右配流盘孔中的间隙，经另2个孔流回吸油腔。
3>配流盘轴孔根据装配情况知，
dDE?23mm?dyp?dEF?25mm (5-34) 取右侧板轴孔直径dyp?24mm
配流盘右端与右泵体配合，右端轴承6005型其尺寸为
d?D?B?25mm?47mm?12mm
41
****本科毕业设计（论文） 5 整体设计计算
故与右泵体装配的该段直径为?47mm
4>参考《机械设计手册—第10篇润滑与密封》表10-4-5,选择O形橡胶密封圈作为密封件，型号为
82.0?2.65 G GB/T3452.1—1992 46?2.65 G GB/T3452.1—1992
参考《机械设计手册—第10篇润滑与密封》轴向密封沟槽尺寸 表10-4-8
82.0?2.65 G GB/T3452.1—1992
的沟槽尺寸为
槽外直径 80.0mm+5.3mm=85.3mm；
0.25槽宽3.8?mm； ?00.10深1.97?； ?0槽内直径?78.1mm
46?2.65 G GB/T3452.1—1992
沟槽尺寸为
槽外直径50.0mm+3.6mm=53.6mm；
0.25mm； 槽宽3.8??00.10槽深1.97? ?0结合右配流盘上孔，槽等工作强度要求，右配流盘总宽45mm，和右泵体配合尺寸为15mm.
5>参考《机械设计手册—第1篇》表1-5-12配流盘与右泵体配合段倒角为
3?45?
5.6传动轴的设计
平衡式叶片泵由于叶片所受径向力平衡，故轴主要承受扭矩作用，承受的弯矩很小，故称为传动轴。
5.6.1 材料选择
轴主要承受扭矩作用，在轴上有扭转切应力，由《机械设计》表15-1选择轴常用材料中剪切疲劳极限较高的40Cr材料。
5.6.2 花键轴段的设计
42
****本科毕业设计（论文） 5 整体设计计算
图5-9 传动轴花键轴段结构
由转子设计中选择的花键轴孔直径为 d0?19mm
花键连接为多齿工作，承载能力高，对中性、导向性好，齿根较浅，应力集中小，轴的强度削弱小，平衡式叶片泵主要承受扭矩作用且对运行是对中和稳定性有一定要求，因此选择将轴段加工成花键轴，并选择为矩形花键轴。 设齿的工作高度为 h?D?d2?2C?2mm (5-35)
式中 h——花键齿工作高度，mm D——矩形花键大径，mm d——矩形花键小径，mm C——矩形花键齿倒角尺寸，mm 又由配合关系得
D?d0?2h?23mm (5-36) 由取C=1mm,得 d=17mm 取键数 N=4，键宽B=5mm 即花键轴规格为
N?d?D?B?4?17?23?5 式中 N——键数
d——矩形花键小径，mm
43