快速装卸皮带轮

现将快速装卸皮带轮的结构作一介绍。皮带轮与轴的装配形式如图所示。锥套和轮毂的锥度为1:25,锥套大端直径略大于锥孔大端直径0.5～1毫米,锥套孔尺寸比轴颈尺寸大0.1毫米左右,锥套做成单开口式。皮带轮在装配时旋转顶丝3,当顶丝到达锥套上之半丝扣底部时,由于继续旋转顶丝3,在带轮上的半丝扣的作用下,使皮带轮与锥孔产生轴向位移,并通过内锥面使开口锥套束紧,从而实现过盈配合,以传递扭矩。     

气缸套双锥内撑夹具的设计应用

为避免气缸套在车削加工中单锥内撑夹具夹紧缸套轴向移动,公司自主研发了一种气缸套双锥内撑夹具,该夹具外锥套与本体通过卡槽相连接,外锥套和内锥套通过锥面相连接,活塞杆带动内锥套移动,通过锥面使锥套向外胀紧实现夹紧。由于该双锥内撑夹具外锥套在本体卡环槽的定位,外锥套无轴向移动,使其具有定位准确、加工效率高、产品质量稳定等优点。     

锥面胀套的设计与制造

锥面胀套(包括单锥而和双锥面)的制造及使用各有其优缺点。相对来说,工作状态下双锥面胀套由两个锥面支持,外圆面的圆柱度误差要小于单锥面胀套,可以提高工件的加工精度,由于每个锥面的长度缩短,占有的径向空间随之减小,提供了较充裕的设计空间。与单锥面胀套相比,双锥面胀套可用于孔径较小、长度较大的工件的加工。根锯单锥面胀套和双锥面胀套的优点,我们设计了多级环锥面胀套。多级环锥面胀套(一般简称多锥面胀套)是由沿轴向三个或三个以上的环状锥面构成。它的结构如图1所示。其特点是胀套的内锥面和心轴的外锥面的接     

刀头装卸机构

<正> 本机构是由刀头和刀夹两部分组成,刀头与刀夹的结合面A,加工成锥面配合。刀头上旋入夹紧棒,棒上有两个两面锥凸缘,装卸刀头是依靠装在刀夹内的三片夹套左右滑动来控制的。刀头装卸动作过程如下: 装刀对,把刀头上的夹紧棒插入三片夹套内,当拉杆拉着三片夹套向右移动时,它的外爪右锥面受到刀夹体内锥面B的作用,使三片夹套边移动边向中心收拢。与此同时,三片夹套的内爪与夹紧棒上的两面锥凸缘的左锥     

改进锥堵消除主轴应力变形

通常情况下,精磨含有较大直径锥孔的主轴外圆时,都需要在主轴锥孔中装入一个与之相配的锥堵,通过乐紧锥面或者锥面自锁产生摩擦力,使锥堵起到定心并且传递转矩的作用。因此,锥堵作为一种精磨主轴外圆的专用工装,其设计、使用得当与否也会影响到主轴的制造精度。     

车削挺杆外圆的不停车夹具

我公司生产的柴油机梃杆的第一道工序为车削铸件外圆 ,尺寸要求如图 1所示 ,为了保证这道工序的质量与效率 ,我公司设计了一套不停车夹具 ,经使用效果良好。夹具主要由牙花轴 4、弹簧 2、锥面定心套 3组成 ,如图 2所示。锥面定心套与牙花轴的配合为Ｈ7/ｆ6 ;由于铸件上的圆柱孔和锥孔是同一泥芯成型的 ,同轴度比较好 ,所以工件的定心选取锥面定心套定位圆柱孔口以及牙花轴的牙花锥面定位锥孔面 ,同时牙花还起到驱动工件的作用。弹簧的钢丝直径要求不小于 1 .5ｍｍ以保证锥面定位套有足够的推力。使用前需在牙花轴靠近牙花处打出毛刺 ,以防止…     

轴和轮毂联结的两种新结构

过去,轴和轮毂多使用键联结。近来由于各种机械提出了高速化等要求,键(包括单键、双键和花键)、铆接、热压配合等联结方法,往往满足不了设计要求。最近,应用摩擦力进行联接的各种形式已普及起来。日本由西德引进了锥度涨环式摩擦联接器,现已被很多厂家应用于数控机床上。本文介绍两种联结结构,供设计者参考。 一、力锁紧锥套联连器: 结构如图1所示。锥套A、B的锥面与内锥环、外锥环的锥面均保持完全接触。拧紧锁紧螺钉使锥套A、B相互靠拢,在内、外锥环上产生压紧力P、P,由此形成使轴和轮毂联结在一起的摩擦力。当然,在内、外锥环的圆周上…     

立铣刀夹头

图示的立铣刀夹头,可使工人在更换刀具时不需站到工作台上去装卸立铣刀拉紧螺杆。使用这种夹头后装换立铣刀的动作过程如下:将铣刀套入莫氏锥套用螺钉拉紧;再将此组件装入刀体中,拧紧螺母,在其端面作用下,使莫氏锥套外锥面紧贴于刀体锥孔中。若进行一般轻度铣削也可不用螺母。更换铣刀时,可借助锥套前端面的环形槽来取下组件。安装不同规格的锥柄铣刀,可用两种刀体并更换不同的莫氏锥套来达到。     

两用活顶尖

广州重型机器厂为了提高车削加工的效率,减少更换钻套、中心钻、钻头等的辅助时间,制造了图1所示的两用活顶尖。 该顶尖上的三爪钻夹头1,通过锥杆2的内锥面,在顶尖心轴3上定位。顶尖心轴3通过圆锥滚柱轴承4、止推轴承5和双列向心球轴承6,可在顶尖套内旋转,并起活顶尖的作用。顶尖套安放在车床尾座的锥孔中。当钻夹头处于图1所示的位置时,即可在工件上打中心孔或钻孔。此时,在弹簧8的拉力作用下,夹头1通过托架7和锥杆2的内锥面而定位并被拉紧。当需要用活顶尖工作时,向外拉掉托架7,使托架连同钻夹头一起垂挂在顶尖套的螺钉上。以便用活顶尖支…     

三锥面同步器

一种三锥面同步器，属于汽车传动装置领域。本发明包括：二档齿轮、内锥环、外锥环、中间环、同步器弹簧、齿套、齿毂、滑块、一档齿轮、第一凹槽、滑块槽、第二凹槽，内锥环、中间环、外锥环由内向外依次设置构成齿轮上的摩擦环，内锥环空套在齿轮锥面上，中间环空套在内锥环上，外锥环空套在中间环上，中间环通过档位齿上的凹槽与二档齿轮、一档齿轮联接，齿套内壁有滑块槽，整个滑块嵌在齿毂凹槽内，两根同步器弹簧分别紧贴在齿毂两侧，外锥环大端面处设有凹槽。     

轧辊锥体锥度检测仪

介绍了一种检测高速线材轧机轧辊锥轴与锥套锥度的检测方法以及相应的锥体锥度检测仪。该检测仪进行锥度测量的相对误差约为10-4,可在计算机上显示出被测锥体的实际轮廓,并可进行锥轴和锥套的虚拟装配,实现了锥体的高精度选择装配。     

正弦规测量内、外锥直径尺寸公式的建立与分析

<正>弦规一般用于测量外锥面的角度,将其用于测量外锥体和内锥孔的直径值,是正弦规的一种扩大使用技术。本文建立了一套公式,对外锥体和内锥孔的直径值进行分析并用正弦规进行实践性测量,可保证锥套配合直径尺寸的测量精度。     

A study of stresses in alumina universal heads of femoral prostheses

Three-dimensional, frozen-stress photoelasticity was used to study the best shape for a proposed alumina universal head loaded on to a Vitallium cone taper spigot with a 30 degrees inclined force, as in vivo. Typical cone taper friction values were reproduced in the photoelastic models. The location of the highest tensile stresses in the Mark I shape with a flat crown was found to be on the inner surface of the crown. Changing to a torispherical surface in the Mark II shape reduced this magnitude. However, the Mark III shape with a hemispherical inner crown surface gave even lower stress there, equal to the maximum value of the hoop stress at the taper, which was measured to be fairly uniform both around and along the taper except at the ends where contact pressure concentrations were found to occur and it became reduced. Lamé axisymmetric cylinder stress predictions were found to be useful approximations to measured values and were generally overestimates of the tensile hoop stress at the head taper surface.     

颤振冷挤压降载机理与仿真研究

针对金属冷挤压成形过程中金属变形抗力大、设备吨位高而普遍振动形式降载效果不理想的问题,将颤振激励技术引入金属冷挤压成形过程中。从表面效应角度分析了颤振激励下的金属冷挤压成形过程中摩擦力的变化规律,阐明了颤振降载的基本原理。以万向节轴套零件为例,分别讨论分析了传统冷挤压模式和颤振激励冷挤压模式下的挤压力数学模型,从理论上说明了颤振冷挤压的降载机理,进一步应用Deform-3D软件建立了其有限元分析模型,对万向节轴套零件进行了受载和模具寿命分析。仿真实验结果表明,在100 Hz频率0.03 mm振幅的周期性颤振激励下,万向节轴套零件的冷挤压过程最大成形压力下降8.3%,最终成形压力下降10.1%;冲头单次最大磨损量下降,但凹模单次最大磨损量有一定程度的增加。     

特殊螺纹接头主密封优化研究

以特殊螺纹接头为研究对象,采用有限元分析的方法,分析常规锥面/锥面密封结构、变锥面密封结构以及逆向台肩3种结构主密封面上接触压力分布规律,并在此基础上提出一种改进型密封结构。有限元分析结果表明:锥面/锥面密封结构主密封面上接触压力分布不均,有效接触长度很短;变锥面密封结构和逆向台肩能够在一定程度上改善接触压力分布,但密封结构参数对接触压力分布影响很大;改进型密封结构综合了上述结构的优点,主密封面上接触压力呈现U型分布,并且在拉伸载荷作用下有着更高的稳定性。     

弹性流体静压轴承

The elasto-hydraustatic bearing is a new type of hydraustatic bearing. In action, it is similar to some conventional type of hydraustatic bearing The difference lies in the fact that in a Conventional hydraustatic bearing, the inside surface of the bearing shell must bs made to a certain configuration to prodvce the by dravstatic action. In this new type of bearing, the bearing shell is made to the form of a plain cylindrical bushing with a circumferential groove in the middle. (Fig 3-1) when the oil pressure is low, it will function as a plain sliding bearing. But when the pressure of oil is high, the bearing Shell, mostly made of some elastomer, will deform and the diameter of the bearing at the middle will be larger than the diameter at both ends. As is well known, this taper shaped bearing shell will have hydracstatic action, (Fig 3-2) Experiments show that the load carrying capacity of this kind of hrdravstatic bearing can be computed by the following empirical formula;W=0.12xDxL when the bearing bushing is made of metal, the outside of the bushing must be hollowed out(Fig3-3) to make it easier to deform.There are many advantage of this type of hydraustatic bearing. It is simple in form and very easy to make. When the pressure of the oil drops, it will foction as a plain bearing and hence is very safe and reliable. As there is no groove at the inside of the bearing shell, it will function as a squeeze film bearing under shock or vibrating load and has a high capacity.     

锥面联接的压入受力分析及其仿真

基于某设备搅拌轴上的锥面过盈联接,结合锥面角度因素和实际受力情况,建立关于压入过程中压入力和传递扭矩所需锥面间结合压力间的关系。在此基础上,使用ANSYS Workbench进行仿真,通过对锥轴施加相应的压入力,得到锥面接触面上的压力分布情况。仿真得到的结合压力与理论计算值基本吻合,也验证了锥面间结合压力与压入力之间的关系,为其实际应用提供了理论指导。     

Three-dimensional analysis of light propagation through uncoated near-field fibre probes

The near-field emission from uncoated tapered fibre probes is investigated for different probe geometries. The three-dimensional model calculations are based on Maxwell's curl equations and describe the propagation of a 10 fs optical pulse (λ = 805 nm) through tapers of different lengths and different diameters of the taper exit. The numerical evaluation is done with a finite difference time domain code. Two tapers with cone angles of 50°, with taper lengths of 1.5 µm and 1.0 µm and exit diameters of 100 nm and 520 nm, respectively, are considered. We find that without sample the short taper with large exit diameter optimizes both light transmission and spatial resolution. In the presence of a sample with a high dielectric constant, however, the spatial near-field distribution changes drastically for both taper geometries. We find a pronounced increase in spatial resolution, down to about 250 nm inside the medium. This collimation of the near-field distribution arises from interferences between emitted and reflected light from the sample surface and from a collimation effect that the field experiences in the high-index semiconductor material. The combination of high spatial resolution and transmission and collection efficiencies makes such probes interesting for spectroscopic investigations, as demonstrated by recent experiments.     

Suitability of grooved configurations for bearings and seals

Suitably designed grooves and wedges on the surface of a plain hydrodynamic sleeve can modify the load-carrying capacity, the side leakage and other characteristics. If the sleeve is to be used as a hydrodynamic seal for turbogenerators to prevent leakage of cooling gas or for other engineering applications, it must have an unbroken oil film of extent 2Π. A plain sleeve with a very small eccentricity may provide an uninterrupted film but it will have a load capacity insufficient to support even its own weight and it will also be unstable.The effects of various groove and wedge configurations on the performance characteristics of a hydrodynamic sleeve were studied. The suitability of these configurations or combinations of them for bearings or seals was investigated.     

Wall slip and hydrodynamics of two-dimensional journal bearing

In the present paper, based on the limiting shear stress model, a multi-linearity finite element algorithm and quadratic programming technique are used to study the influence of wall slip on the hydrodynamic lubrication performance of a two-dimensional journal bearing (finite length journal bearing). It is found that if the lubricated surfaces are designed as homogeneous slip surfaces, the hydrodynamic force will be decreased. If the shaft surface (rotation) is a slippery surface with very low limiting shear stress, almost no fluid load support can be generated. If the sleeve surface is designed as the homogeneous slip surface, a low fluid load support together with a small friction drag can be obtained. However, if the sleeve surface is designed as an optimized slip surface with a slip zone in the inlet region, a high load support and low friction coefficient can be obtained. Optimization of the shape and the size of the slip zone can give the journal bearing many advanced properties.