【正文】 。式中——系數(shù)，取=；——系數(shù)，取=。由上可知電動(dòng)機(jī)不會(huì)過熱。3)啟動(dòng)時(shí)間的驗(yàn)算電動(dòng)機(jī)的啟動(dòng)時(shí)間按下式計(jì)算： 式中 ——平均啟動(dòng)轉(zhuǎn)矩，；——系數(shù)，取=；——飛輪矩，；——靜阻力矩。則。由起重機(jī)的允許啟動(dòng)時(shí)間，可知啟動(dòng)時(shí)間滿足啟動(dòng)條件。 減速器的驗(yàn)算減速器的輸出功率按啟動(dòng)時(shí)的功率確定： （）已知，而 （）其中 （）所以減速器的輸出功率。綜上所述，減速器驗(yàn)算通過。 選擇制動(dòng)器 運(yùn)行機(jī)構(gòu)制動(dòng)器的力矩應(yīng)根據(jù)滿載順風(fēng)下坡的工況，能使起重機(jī)安全平穩(wěn)的制動(dòng)來確定。1，制動(dòng)力矩的計(jì)算 式中 ——起重機(jī)靜力矩，；——制動(dòng)時(shí)間，取小車制動(dòng)時(shí)間，＝6s。則制動(dòng)力矩為。2，選擇制動(dòng)器查表選用制動(dòng)器型號(hào)：，制動(dòng)輪直徑，制動(dòng)力矩，質(zhì)量。3，驗(yàn)算制動(dòng)時(shí)間 式中 ——按需要調(diào)接后的制動(dòng)器的制動(dòng)力矩，取。則符合制動(dòng)要求。 啟動(dòng)和制動(dòng)打滑驗(yàn)算一般懸臂式龍門起重機(jī)打滑驗(yàn)算都通不過，但在運(yùn)行過程中可通過改變小車位置使主動(dòng)輪的最小輪壓增加，調(diào)整制動(dòng)力矩或通過加壓鐵的方式增加輪壓，從而避免起重機(jī)打滑。參考文獻(xiàn)[1] ［Ｍ］.北京：中國(guó)鐵道出版社，1997.[2] ［Ｍ］.北京：人民鐵道出版社，1978.[3] 陳道南，［Ｍ］.北京：冶金工業(yè)出版社，2003.[4] ［Ｍ］. 北京：中國(guó)鐵道出版社，1985.[5] ［Ｍ］.北京：冶金工業(yè)出版社，1988.[6] 最新起重機(jī)械設(shè)計(jì)、制造、安裝調(diào)試、維護(hù)新工藝、新技術(shù)與常用數(shù)據(jù)及質(zhì)量檢驗(yàn)標(biāo)準(zhǔn)實(shí)用手冊(cè)［Ｍ］.廣州：廣州音像出版社，2004.[7] 陳瑋璋, ［Ｍ］. 北京：人民交通出版社，1986[8] ［Ｍ］. 北京：高等教育出版社，.[9] 濮良貴，［Ｍ］.北京：高等教育出版社，.[10] 吳宗澤，［Ｍ］. 北京：高等教育出版社，.[11] GB381183起重機(jī)設(shè)計(jì)規(guī)范［Ｍ］. 北京：.[12] 楊黎明，［Ｍ］. 北京：.[13]伊萬琴柯，起重運(yùn)輸機(jī)械計(jì)算[M]. 北京：中國(guó)鐵道出版社，1982.[14]坂本種芳，[M]. 北京：中國(guó)鐵道出版社，1987. [15]曲中謙，實(shí)用軸承手冊(cè)[M].沈陽：遼寧科學(xué)技術(shù)出版社，2001.致 謝通過本次設(shè)計(jì)使我學(xué)習(xí)到了很多新的知識(shí)，提高了我的學(xué)習(xí)能力。在周為民老師嚴(yán)格，認(rèn)真和負(fù)責(zé)的指導(dǎo)才使得設(shè)計(jì)能夠按時(shí)保質(zhì)的完成。在此向周為民老師表示崇高的敬意和衷心的謝意！同時(shí)感謝四年以來辛苦傳授知識(shí)給我的老師們，你們給予的不僅僅是知識(shí)，還有很多的做人道理，這些都是我一生用之不竭的財(cái)富。感謝各位老師！在學(xué)習(xí)的幾年中，很多同學(xué)也給了我無私的幫助，是你們令我度過了一個(gè)美好而充實(shí)的大學(xué)生活。感謝各位同學(xué)！最后，感謝各位評(píng)委老師審閱我的設(shè)計(jì)，并提出寶貴意見。謝謝！學(xué)生簽名：日 期：第88頁，共88頁附錄英文原文 Calculation method and control value of static stiffness of tower craneLanfeng Yu*Research Institute of Mechanical Engineering, Southwest JiaoTong University, Chengdu, Sichuan, 610031, P. R. China(Manuscript Received August 31, 2006。 Revised November 30, 2007。 Accepted December 13, 2007)AbstractThe static stiffness of tower cranes is studied by using the proposed formulations and finite element method in this paper. A reasonable control value based on theoretical calculation and finite element method is obtained and verified via collected field data. The results by finite element method are pared with the collected field data and that by the proposed formula. Corresponding to theoretical formulations and field data, it is found that the results by finite element method are closer to the real data.Keywords: Tower crane。 Static stiffness。 Control value。 Static displacement1. IntroductionSagirli, Bococlu and Omurlu (2003) realized the simulation of a rotary telescopic crane by utilizing an experimental actual system for geometrical and dynamical parameters [1]. With the intention of paring the real system and the model and of verifying the sufficiency of the model accuracy, various scenarios were defined corresponding to different loading and operating conditions. Of the scenarios defined, impulse response, time response and static response are used to experimentally gather such system parameters and variables as damping coefficient, cylinder displacements, and stiffness of the telescopic boom, respectively. Following are the simulations for two dissimilar scenarios which are static response and impulse response and the results that were presented. Barrett and Hrudey (1996) performed a series of tests on a bridge crane to investigate how the peak dynamic response during hoisting is affected by the stiffness of the crane structure, the inertial properties of the crane structure, the stiffness of the cablesling system, the payload mass, and the initial conditions for the hoisting operation [2]. These factors were varied in the test program, and time histories were obtained for displacements, accelerations, cable tension, bridge bending moment, and end truck wheel reactions. Values for the dynamic ratio, defined as peak dynamic value over corresponding static value, are presented for displacements, bridge bending moment, and end truck wheel reactions. A two degree of freedom analytical model is presented, and theoretical values for the dynamic ratio are calculated as a function of three dimensionless parameters that characterize the crane and payload system. Grierson (1991) considered the design under static loads whereby the members of the structure are automatically sized by using mercial steel sections in full conformance with design standard provisions for elastic strength/ stability and stiffness [3]. This problem was illustrated for the leastweight design of a steel mill crane framework prised of a variety of member types and subject to a number of load effects. Huang et al (2005, 2006, 2007) analyzed the static and dynamic characteristics of mechanical and structural systems using fuzzy and neural network methods [411]. For static stiffness of a tower crane, the requirements of GB 38111983 “Design rules for cranes” and GB/T 137521992 “Design rules for tower cranes” of China are as follows. “Under the rated load, the horizontal static displacement of the tower crane body △x at the connection place with the jib (or at the place of rotary column with the jib) should be no larger than H/100. In which H is the vertical distance of the tower body of the railmounted tower crane from the jib connection place to the rail surface, and the vertical distance from the jib connection place of the attached tower crane to the highest adhesion point”.In this paper a special research on the static stiffness of tower cranes was carried out aimed at relieving the overstrict control on the static stiffness (△x H/100) in the rules above, so as to meet the requirement for revising GB/T 38111983 “Design rules for cranes”. The remainder of this paper is organized as follows. Section 2 gives the suggested control value of static stiffness of a tower crane. Section 3 verifies the static stiffness control value. Theoretical calculation method of static displacement of the tower body corresponding to the static stiffness control value is provided in Section 4. Section 5 pares various methods for calculatio