The multi-motor driveDescription:The present invention concerns a drive for an escalator， which drives the stair belt and is arranged on one or both sides of the escalator at the upper and/or the lower end thereof， wherein the drive comprises a main drive wheel and at least one motor with gear and brake BACKGROUND OF THE INVENTION Different dispositions and constructional principles are known for escalator Since the drive must be designed for the maximally occurring load， a relatively large and strongly dimensioned motor with a corresponding gear is Poor efficiency at the mostly prevailing partial load and the large installation volume in the case of limited space availability within an escalator construction are disadvantages of such a These disadvantages are present to a lesser degree or not at all with multi-motor Such a drive for escalators and walkways， which comprises two individual drives or two twin drives， the output gearwheels of which drive the stair chain or the plate chain and， by way of an additional gear， the handrail， is known from DE 35 26 Such a construction is executed in different variants and correspondingly comprises a number of different gears and gear housings for the stair chain drive or the plate chain Furthermore， the individual drives are equipped with planetary gears， which causes relatively high The object of the present invention is to create an improved multi-motor drive for escalators， which can be implemented at favorable costs， which may be built up in a modular manner， and which covers a usual performance BRIEF DESCRIPTION OF THE INVENTION The drive according to the present invention distinguishes itself by several constructionally identical drive units being mountable distributed at the circumference of a main drive wheel， whereby the main drive wheel or its toothing need be dimensioned only for loading by a single drive The main drive wheel itself thus can have a smaller width， which is of great advantage for the accommodation of the drive parts in the case of an The drive units， in a number corresponding with power requirements， may be flange-mounted to a main gear housing identical for all performance This simplifies the production process for the entire constructional series， reduces the inventory and facilitates maintenance and The drive units are provided with torque transmitters and/or rotational speed transmitters for recognition of their mechanical Each of the drive units can furthermore be provided with a clutch which makes a selectable switching-in or switching-out of a drive unit The drive further comprises a frequency-setting device which is common to all drive units and by means of which different speeds can be set and which also serves as a starting A control and regulating unit produces corresponding control and regulating commands by the processing of incoming The control and regulating unit causes the switching-in and switching-out of individual drive units on the basis of actual load data from the torque transmitters， which helps to improve the electrical and mechanical efficiency and thus also reduces the energy The use of polyphase alternating current squirrel-cage motors of variable frequency and their associated control has the advantage that high torques can be produced at low rotational BRIEF DESCRIPTION OF THE DRAWINGS The invention is explained more closely in the following with the aid of an illustrative example of an embodiment thereof and is illustrated in the accompanying drawings， wherein: FIG 1 shows an escalator with a drive according to the invention at the upper end of the escalator; FIG 2 shows the drive with drive units flange-mounted on a main gear transversely to the direction of travel of the escalator; FIG 3 shows the drive with drive units flange-mounted on a main gear longitudinally of the direction of travel of the escalator; FIG 4 shows a three-dimensional illustration of the drive arrangement according to FIG 2; FIG 5 shows a three-dimensional illustration of the drive arrangement according to FIG 3; and FIG 6 shows a block schematic diagram and functional diagram of the drive with all associated DETAILED DESCRIPTION OF THE INVENTION FIG 1 shows an escalator 1 with an upper end 2， below which drive units denoted by 7 and a part of a stair chain 3 are FIG 2 shows the details of a drive， which is installed within a carrying structure 9 at the upper end 2 of the escalator Three identically constructed drive units 7 drive a toothed main drive wheel 6 by way of an output gearwheel 6 and an intermediate gearwheel 21， and are arranged and distributed about the circumference of the main drive wheel The main drive wheel 6， together with a stair chain wheel 5， are fastened on the main shaft 4 of the The drive units 7 are firmly connected to a main gear housing 8 at three planar flange-connecting openings 24 formed for this When less than three drive units 7 are needed， the unused flange-connecting opening 24 may be closed by a cover and the associated intermediate gearwheel 21 is not With this construction， the same main gear housing 8 can always be used for one， two or three needed drive units The axles of the drive units 7 are arranged transversely to the direction of movement of the escalator 1， which yields the advantage of a short machine As example of a variant， FIG 3 shows an arrangement of the drive units 7 parallel to the direction of movement of the escalator In this manner of arrangement， the drive units 7 additionally comprise a bevel gear Motor 1， clutch 2， brake 4， flywheel 5 and the output gearwheel 6， which are otherwise constructionally identical with and incorporated in the drive units 7 of FIG 2， are present for each drive unit The main gear housing 8 is likewise always the same for one， two or three drive units 7 and unused flange-connecting openings 24 can likewise be covered by a FIG 4 is a spatial illustration of the drive according to FIG 2 within the carrying structure 9 of the escalator Two stair elements 22 are illustrated in addition to the elements shown in the preceding FIG 5 is a similar spatial illustration of the drive according to FIG 3 within the carrying structure 9 of escalator The two stair elements 22 are likewise additionally The function and operation of the multi-motor drive according to the invention is to be explained more closely in the following by reference to FIG The current supply of the drive takes place as usual from local three-phase current mains 13 with phases R， S and T which are led to a main switch Following thereon， the entire drive is connected through a main relay or several relays There then follows a frequency-setting device 16， which by way of a relay control 23 with the relays S1， S2 to Sn feeds the motors 1 (M1， M2 to Mn) of the drive modules 7 at a variable frequency current and direction of rotation as provided by the frequency-setting device The motors M1， M2 to Mn are， as already shown and described in the preceding， operatively connected with the main drive wheel 6 by way of gears 3 and output gearwheels 6 and intermediate gearwheels 21， which are not further illustrated Torque transmitters 20 (L1， L2 to Ln) for the purpose of the measurement of the actual mechanical loading of the motors M1， M2 to Mn are installed at a suitable place in the transmission between the motors M1， M2 to Mn as known in the The main gear wheel 6 drives a speed transmitter 19 by way of an appropriate known transmission， which similarly is not more closely A control and regulating unit 10 contains microprocessor and relay control components， as well as signal and data inputs and First input data line 1 supplies speed values from the speed transmitter 19， which are fed as actual values to an internal regulating The second group of input data lines 2 provide measurement values from the torque transmitters 20 and， through appropriate processing， cause the switching-in and switching-out of individual drive modules A third group of input data lines 3 supplies data from transmitters 11， which essentially concern control safety contacts and mode of operation A first group of output data lines 1 leads to the relays 15 and to the frequency-setting device A second group of output data lines 2 contain control signals for the relay control 23， and the third group of output data lines 3 provides the data to control optical signals and illumination The multi-motor drive according to the invention functions as following: During starting-up of the escalator 1， the relay 15 for the drive is switched on， the frequency-setting device 16 is run up and at least one drive module 7 is switched on by way of the relay control 23 by the control and regulating unit 10 according to the choice of direction and a start-up On reaching the target speed， the drive regulation in the control and regulating unit 10 holds the speed of travel of the escalator 1 constant within close limits independently of the During the now following operation of the escalator 1， the input data lines 2 from the torque transmitters 20 supply information about the mechanical loading of the switched-in drive modules 7 (motors M1， M2 to Mn) In the case of low or no loading by transported persons， the drive power of the first motor M1 may suffice， and the further motors M2 to Mn remain switched If a full loading with a tendency to lasting overload is signalled by the torque transmitter L1， the next motor M2 is switched on after a defined The signals from the two torque transmitters L1 and L2 are now monitored in the control and regulating unit 10 and a further， not illustrated motor M3 may be switched in according to analog criteria when the load limit values of the motors M1 and M2 are The third motor， denoted by Mn in the illustration， is to indicate that， in principle， a greater number of drive modules 7 can be For practical and economic reasons， however， the number of drive modules 7 will probably remain restricted to three or at most The procedure is reversed when the mechanical loading The no longer needed motors 1 are then switched off in the sequence beginning with the motor Mn switched on If a uniform wear of the drive modules 7 is desired， this can be taken into consideration by way of an additional measurement of the switched-on times of the individual drive modules 7 and the individual drive modules 7 can thus be switched on and off selectably and not according to an always identical As already mentioned， the number of the drive modules 7 is not limited to the illustrated three Drive modules 7 produced in large quantities can be very favorable in price， so that it could be feasible to provide a greater number， for example 4 to 6， drive modules With appropriately adapted control programs in the control and regulating unit 10， the greater amount of data resulting therefrom can be processed without The use of direct current motors for the drive modules 7 is also possible in principle with appropriately-adapted control and regulating techniques as known in the Alternating current motors with squirrel cage armatures are preferably used because of their simple mode of construction and ease of Moreover， efficient and likewise cheap frequency-setting devices or frequency converters are Normal spur gearwheels， by means of which an optimum mechanical efficiency is achieved， may be used for the drive arrangement according to FIG Cone wheel gears， by means of which a practically equal efficiency is achieved by comparison with spur gearwheels， are advantageously used as bevel gears 3 for the drive arrangement according to FIG The main gear housing 8 can be so constructed that both drive arrangements， those according to FIG 2 as well as those according to FIG 3， can be The main drive housing 8 then correspondingly has twice as many flange-connecting openings The intermediate gearwheels 21 can be the same at the same position for both drive The drive arrangement according to the invention can also be used for other kinds of conveying equipment， for example for walkways and mercalators in horizontal and oblique
Crane Work Needs More TechniqueAbstractCrane work needs more Construction of tower cranes are the main vertical transportation equipment and also a measure of construction companies and equipment strength of the important logo， in today's increasingly competitive construction market， to meet the construction needs of many construction companies have bought the tower With the tower crane at the construction site of the widely used by the tower crane accident also caused more and more to people's lives and property brought about great According to national statistics， the departments concerned， the tower crane accident rate reached 77 Its security problem is still the urgency of the construction Loose training， testing and oversight requirements for the people who work around construction cranes have fostered a false sense of security in our The recent deadly tower-crane collapse at a congested New YorkCity building site should be a wake-up call for us to question and step up our current safety Training and testing is king when it comes to But the construction industry is putting unqualified personnel in the seats of construction cranes， even with today's In many places， no experience is necessary after passing a standardized One week of study will give some people enough knowledge to pass a certification examination， and then they can jump into the cab of a Imagine that a commercial airline pilot had the same training as a certified crane How would you feel the next time you decided to fly? In California， it takes more hours of training to wield a pair of scissors in a hair salon than to operate potentially dangerous lifting How does this make sense?Riggers and signal persons also need standard training and testing to ensure safety under the Employers usually allow any craft to signal a crane on a jobsite， despite best practices that require only qualified people do How is it then that uncertified and untrained people are allowed to signal and rig under the hook of a licensed or certified operator?Tower cranes are particularly risky as urban sites become more congested， and the risk of a catastrophic event is very high during climbing Yet most tower-crane climbing crews are trained in a non-traditional manner， via secondhand knowledge that has been passed down over The problem with this type of hand-me-down knowledge is that it changes over the years， leaving out small-but-important details along the This "osmosis" of knowledge leads crews to develop their own tricks for climbing cranes， often forsaking basic safety in an attempt to save time and In many cases， there are no safety devices or alarms to warn of a serious Climbing crews are subjected to pressures that affect safety-critical decision- It is not uncommon for climbs to continue with damaged or leaking hydraulic systems， out-of-adjustment or jammed guide rollers， often working in the dark and for extended This "MacGyver" method of climbing， where every jump becomes a new adventure， should not be the Climbing-frame designs vary among manufacturers， but the operational steps are similar in The climbing process is relatively straightforward， with a mixture of physical work and technical It is not complex; it is more about knowing the proper sequence of what needs to be done and then following the steps， one by one， making sure each step has been successfully completed before moving onto the It is essential that everyone know exactly what is going on and what the dangers are at every That's why the industry needs standardized training， testing and oversight for this work， including a practical assessment of Technicians should have model-specific training directly from the manufacturer， along with a level of practical Inspectors， too， should be required to have specific technical They should be independent from all aspects of installation and maintenance to allow for objective Key personnel on erection crews should have standard training and When these needs are satisfied， crane operations should be carried out in strict accordance with the manufacturers' instructions， engineering principals and governmental But industry stakeholders and lawmakers need to step up their lax standards to protect the New York City residents， who have seen their homes turned into dust and debris， would be shocked at the way the industry deals with these 起重机的工作需要更多的科学技术摘要 塔式起重机是建筑施工垂直运输的主要设备，也是衡量一个建筑施工企业装备实力的重要标识，在当今竞争日益激烈的建筑市场，为满足施工需要，很多施工企业都购置了塔式起重机。随着塔式起重机在施工现场的广泛使用，由塔式起重机引发的伤亡事故也越来越多，给人民的生命财产带来重大损失。据国内有关部门统计资料表明，塔式起重机的事故率已达77%。其安全问题仍然是建筑施工中的忧患……起重机的工作需要更多的科学技术松散的培训，测试和监督的要求， 周围的建筑起重机给这些工作的人树立了一种虚假的安全感，在我们的行业。最近塔式起重机倒塌在一个繁忙的纽约市建筑地盘应敲响警钟，提醒我们问题的存在，并加强我们目前安全的做法。当谈到安全问题时，训练和测试是关键。不过，建造业是把不合格人员放在建筑起重机的驾驶位上，甚至没有通过今天的测试。在许多地方，没有任何经验必须合格的通过标准化的测试。一周的学习将给予一些人足够的知识足以通过认证考试，然后他们可以跳转到的起重机的驾驶室。想象一下一个商业航空公司飞行员和一个认证的起重机操作员有相同的训练。你会如何感觉，下一次你决定要坐飞机？在加利福尼亚州，掌握一对剪刀在头发沙龙比操作有潜在危险的起重机械需要更多的时间训练。如何，这是否合理？装配工人和发信号的人也需要标准的培训和测试，以确保安全下钩。雇主通常允许任何工人发信号指挥起重机上工地 ，尽管最佳做法是需要合格的人这样做。怎么能允许那么无证和未受过训练的人来代替有工作证或经核证的操作者呢？塔式起重机是特别危险的，尤其是在市区用地变得更加拥挤时。攀登行动更是一个风险的行动，其灾难性非常高。然而，大多数塔式起重机攀登员的训练，在一个非传统的方式，通过二手知识已流传一段时间。问题与这种类型的现成的知识是，多年来，留下来的非常少，但最重要的细节却丢失了。这种“渗透”的知识，导致操作者只能发展自己的技巧攀登起重机，往往放弃基本的安全，企图以节省时间和能源在许多情况下没有安全装置或警报来提醒严重的问题的存在。攀登人员容易遭受到影响安全性至关重要的决策所带来的压力。攀登时，使用损坏或泄漏的液压系统，没有任何的调整，这并不鲜见。在黑暗中工作和延长工作时间是时有发生的。这种攀登方法，其中的每一次攀登都会成为新的冒险，不应该作为规范被采纳。攀爬架的设计，在制造商之间存在不同，但设计的步骤在原则上是相似的。攀登过程中是相对比较明了的，配合着的体力劳动和技术程序。这是并不复杂，它是更多地了解知道正确的序列需要做什么，然后按照下列步骤，一个又一个，确保每一步在做下一步前成功完成。这是十分重要，每个人都清楚的知道事情进展的怎么样，在每一个阶段存在什么样的危险。这就是为什么业界需要规范的培训，测试和监督，其中包括一个实际的评估能力。技术人员应该随着实际经验的提升，直接从制造商哪里获得标准训练。视察员同样也也须有具体的技术培训。他们应独立于安装和维修的各方面，这由客观决定。架设的关键人员应该有标准的训练和测试当这些需要得到满足，起重机作业应进行严格按照有关制造商的指示，工程原则和政府的法律。但业内人士和国会议员，要加强他们的宽松标准，以保障公众利益。看到自己的家园变成了尘埃和碎片的纽约市居民，会对处理这些问题的方式感到震惊。
