资源目录
压缩包内文档预览：
编号：122377195
类型：共享资源
大小：1.37MB
格式：ZIP
上传时间：2021-04-19
上传人：221589****qq.com
认证信息
个人认证
李**（实名认证）
湖南
IP属地：湖南
40
积分
- 关 键 词：
-
打桩
机动力
结构设计
- 资源描述：
-
打桩机动力结构设计,打桩,机动力,结构设计
- 内容简介：
-
湖 南 科 技 大 学英文文献翻译学 生 姓 名： 牛文建 学 院： 机电工程学院 专业及班级： 机械设计制造及其自动化（2）班 学 号： 103010201 指导教师： 马克新 2015 年 3 月 26 日VIBRATORY HAMMER EXCITERSAlthough there are many varitations in design and construction ,the vast majority of vibratory hammer are of the configuration like this .Briefly ,there are two main components of the system: the exciter , which produces the actual vibrating force ,and the power pack, which provides the usable energy for the motors on the hammer to spin the eccentrics. We first need to look at the exciter; it is divided into three parts; 1)Vibrator case :This contains the eccentric weights and does the actual vibration. Thus, these eccentrics must be somehow both driven and synchronized. The most common way to accomplish this is a gear system. The gears can actually function in various ways , depending upon how they are set up . Generally the eccentrics are mounted to the gear system , either partially or entirely; in either case the mounting is rigid. In some vibratory hammers, this rigidity is insured by insured by making the gear a one piece eccentric .Several types of gears have been used in vibratory hammer, including spur, helical ,and bevel. All types work best when the teeth are small but strong enough to transmit the power. Large teeth have two been used extensively in vibratory hammers over the years , but small ones are quieter , more efficient, and more reliable. Other schemes of synchronization are: a) there are no gears , and most of the time the amplitude of the system synchronizes their rotation ,each eccentric driven by its own motor , or b) the gears are synchronized by a chain and each eccentrics is driven individually . In any case , the dynamics forces generated by the eccentrics is transmitted to the case by the use of antifriction bearings , which also facilitate rotation. These can be cylindrical , spherical (“screen” bearings) ,or ball , but to work properly they must be sufficiently large for the load and adequately lubricated ,either by a pump system or well designed splash system . Geared eccentrics can be connected to the motor either by pinion, or through belts or chain drives. For the latter two the motor is mounted on the static weight ; a pinion drive require that the motor be mounted directly to the vibrator case .Pinions are used as torque converters, which make optimum used of motors at their preferred operating speeds. 2)Clamp: This connects the vibrator case to the pile and thus transmits the vibrators power from the vibrator case to the pile. Generally speaking , most clamps pinch the pile using a hydraulic cylinder and jaws , thus making a frictional connection . A few vibrators actually bolt or pin the pile to the vibrator case , as was done with the old Vulcan or MKT impact extractors . Some clamps (Foster) use some kind of leverage to enable the use of a small cylinder to generate a large force . For hydraulic clamps ,both lever and direct cylinder clamps are shown.3) Suspension: This is connected to the vibrator case by rubble or metal springs. In driving this provides additional weight to the system to force the pile into the ground without degrading the vibration of the system, although with most units additional bias weight can be attached to the suspension. In extraction the suspension system transmits static pull while dampening out vibration and thus protects the crane boom. For this to be effective the springs must be sufficiently soft and the bias weight sufficiently heavy to insure a suspension natural frequency that is much lower than the vibrators operating frequency. Occasionally additional static weight is helpful during and the weights which accomplish this (called “base weighst”) are attached to the suspension. Impact-Vibration Exciters Although impact vibration hammers share common constructional features with their vibratory relatives , there are important differences .In common with more conventional vibratory hammers, it contains counter rotating eccentrics which impart vertical vibrations ;however, these are contained in a head which is not rigidly connected to the pile but is free to some degree . This freedom enables the units to impact the pile at a rate higher than conventional impact hammers . The alternating force of the eccentrics takes the place of the air , steam ,diesel combustion or hydraulic fluid in 4 moving the head up and down like a ram, with impact at either the top , bottom,or both ends of its “stroke”. Although this can produce variations in the eccentric rotational speed of up to 40%(as opposed to the 50% or so normal for vibratory hammers), this variation generally does not impede the continuous , stable operation of the equipment. Some of the various parts of these hammer are dicussed below: Exciter/Head : The exciter of these machines is similar in general principle to strictly vibrating machines ,with eccentrics driven by motors. With impact vibration hammers ,the exciter has a constant source of amplitude within the springs ,and so the eccentrics are usually not synchronized with gears ,each one driven by a motor. Beaing life with these machine is critical ,and many of them must be used in the vibratory mode a good deal of their operation. Frame/Springs : Frame design of these machines is critical since the frame provides both the regulation of the machine and its connection to the pile. The regulating springs are generally coil springs . The machines vibration within the springs is regulated by both the springs rate and the pretensioning of the springs . The latter can be either fixed or regulated by hydraulic or electric means . Part of the machines force on the pile is also transmitted by the springs if the frame is clamped to the pile.Pile Connection: The most elementary of impact-vibration machines have no pile connection(or frame) at all and rest on the top like impact hammers .Although hydraulic clamps similar to ones in vibratory hammers can be used , other schemes to keep the frame on the pile include simply making the frame heavy than the upward springs force or bolting the machine to the pile. Power Packs for Vibratory and Impact-Vibration Equipment Turning to the power pack, a few vibrators , such as the bodine-guild resonant drivers ,some of the early Soviet vibrodrilling machines ,and some Japanese units ,drive rotating eccentrics straight from diesel or gasoline engines by mechanical couplings . However , most vibratory or impact-vibration hammers transmit energy from the prime mover to the eccentrics through either electric or hydraulic systems. Since construction site are usually remote , transportable power sources have been developed for vibratory hammers. These are referred to as power packs ( for hydraulic units) or generator sets ( for electric units) . These units are similar for both vibratory and impact-vibration equipments . Electrics system : these usually employ three-phase induction motors driven at a single frequency, which has encourage the development of many system to vary the eccentric moment and thus the driving force .In some case electric vibratory hammers can be driven from a nearby three-phase mains , obviating the need for a generator set. The hammers thus only requires a switchbox to control it . A separate , small power pack , driven with an electric motor , is required to operate the hydraulic clamp , if there is one . This can either be on the ground or mounted on the static overweight . Electric systems are less and less popular because of maintenance and reliability consideration. Hydraulic system: for a varity of reason hydraulic system have become dominant, and the major manufactures , such as Vulcan ,ICE ,and MKT, employ hydraulic drive almost exclusively. These system use a diesel engine to drive a hydraulic pump ,which In turn drives the motor on the exciter . A reservoir of varying size is used to store hydraulic fluid in case of leakage , fluid low , both in starting and stopping the 6 machine and during operation .Beyond these basic , these are specific differences between the various hydraulic power packs available; They are : 1) Pump Driven or Gearbox :the hydraulic pump is connected to the engine through a pump drive; sometimes this pump drive is a gearbox as well , acting as a speed changer to optimize the pump , while in others a direct drive is employed , eliminating gear losses. 2) Clamp Pumps :some units have separate pumps for the hydraulic clamp and some integrate these into the main power source .Impact-vibration hammers that do mot have a clamp on them do not have a clamp on them do not need a clamp circuit. 3) Variation of Frequency and Force :Both of these can be varied either by using varied displacement pumps in the power pack or by simply varying the engine speed. Variable disable displacement pumps can have very sophisticated flow control mechanisms. 4) Control Type : These units can employ air ,electric, or manual controls for the hydraulic circuitry .Manual controls are the simplest; however ,they confine the operate the machine . Remote controls allow more economical and there is better access to the parts for severice. 5) Enclosure : some power packs have a sheets metal enclosure and some do not . The principal advantage of an enclosed power pack is protection from weather and criminal activity . Enclosures are also helpful if they provide sound deadening , although many do not. Open power packs are more economical and there is better access to the parts of service. 6) Open and Close Loop Hydraulic System: Both appear on power pack in this application . Closed loop systems allow for better controlled starting , running ,and stopping of themechines , but have traditionally been more complicated, and the power packs less adaptable to other applications. In some cases, the crane hydraulic system can be employed to power the vibratory hammer. Although this eliminates the external power pack and diesel engine , all of the control and operating features of these integral power units are the same. 振动打桩机激振器虽然在设计和施工中有很多变化，但绝大多数的振动桩锤结构都像这样。简单的说，打桩机系统由两个核心组件构成：激振器产生激振力；电源箱提供能源使得位于振动桩锤上的马达带动偏心块旋转。 我们首先看一看激振器，它由三部分组成； 1）激振箱 ：包含偏心块，它能产生振动。因此这些偏心块一定是以某种方式被同步驱动。 最常被用来实现这种同步驱动的是齿轮系统。齿轮有多种运用方式，这取决于它们是怎样被安装的。通常齿轮系统被整体或局部的安装在激振器中，无论哪一种情况下，它都是被精确的安装。在某些振动桩锤中，齿轮配对加工以确保其精度。某些型号的齿轮被运用到振动桩锤中，包括直齿，园齿和圆锥持轮。这些齿轮齿形虽小但工作良好，强度足够传递动力。大型齿轮虽然多年来广泛的运用在振动桩锤中，但是小齿轮更轻巧、更有效也更可靠。 其他的同步方案中不存在齿轮系统，方案一：大多数的振动系统中每一个偏心块由独立的马达驱动，振幅随着旋转改变。方案二：由同步齿轮链条驱动，偏心块仍由独立的马达驱动。 无论在那种情况下，由偏心块产生的激振力由润滑轴承旋转传递到箱体内，这些轴承的滚珠可以是圆柱形、球形的，但是为良好工作，必须有足够的强度和充分的润滑，润滑是由液压系统或者是设计良好的油滴飞溅润滑来实现。 偏心块既不是通过齿轮也不是带和链传动连接到马达上的，后两者中马达是被静态安装的；齿轮传动需要马达直接被安装在激振器箱体上，齿轮被用作旋转转化原件以便充分利用马达工作转速。 2）压钳：用来连接激振器和桩锤，因此传递递激振器产生的激振力至桩锤。总的来说，大多数的压钳采用液压缸和下颚挤压桩锤而产生摩擦连接。实际上一些振动桩机采用螺栓或者螺钉将桩锤直接安装在激振器箱体上，正如一些老式的Vulcan 和MTK的冲击桩锤。一些压钳（福特斯）采用某种类型的杠杆以使缸体产生很大的挤压力，对于液压压板来说，通常采用杠杆和直压板。 3）悬架：悬架通过垫圈或金属弹簧安装在激振器箱体上，大多数的部件都可以增加偏心块重量，通过驱动这些额外增加系统重量而不减少系统的振动以使桩锤打入地面。在拔桩过程中，悬架传递静拉力而不损坏起重吊臂。为了确保悬架的振动频率低于激振器工作频率，弹簧和偏心块必须有足够弹性和重量。有时候，适当的增加悬架的重量有理由完成打桩过程。 冲击振动桩锤 尽管冲击振动打桩机和其它类型的打桩机一样都具有类似的结构，但是还是存在显著的区别。和传统的打桩桩锤相同，它包括旋转的偏心块来产生竖直方向上的激振力，但是，冲击桩锤的桩锤不是刚性的连接而是自由的还具有一定程度的自由度。这种自由连接的方式保证了冲击桩锤比传统桩锤上升的高度更高。偏心块产生可变换的激振力取代了压缩空气、柴油燃烧或者液压油驱动桩体上升或下降，在桩体上身到顶部和底部时都能产生冲击力。尽管偏心块旋转能产生高达40%的变速范围（相对于正常桩锤的50%），但是变速范围不影响设备的整体连续运行。 激振器/ 连接头：冲击桩锤的激振器与严格的振动打桩机激振器大体相似，其
- 温馨提示:
1: 本站所有资源如无特殊说明，都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
2: 本站的文档不包含任何第三方提供的附件图纸等，如果需要附件，请联系上传者。文件的所有权益归上传用户所有。
3.本站RAR压缩包中若带图纸，网页内容里面会有图纸预览，若没有图纸预览就没有图纸。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 人人文库网仅提供信息存储空间，仅对用户上传内容的表现方式做保护处理，对用户上传分享的文档内容本身不做任何修改或编辑，并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容，请与我们联系，我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
人人文库网所有资源均是用户自行上传分享，仅供网友学习交流，未经上传用户书面授权，请勿作他用。
川公网安备: 51019002004831号