中英文翻譯--頻譜分析在轉(zhuǎn)子動平衡中的應用

1、<p><b>　　中文2420字</b></p><p>　　本科畢業(yè)論文（設計）</p><p><b>　　相關(guān)中英文翻譯資料</b></p><p>　　資料題目：頻譜分析在轉(zhuǎn)子動平衡中的應用</p><p><b>　　學生姓名：</b></p>

2、<p><b>　　所在院系：機電學院</b></p><p>　　所學專業(yè)：機電技術(shù)教育</p><p><b>　　指導老師：</b></p><p>　　APPLICATION OF FREQUENCY SPECTRUM ANALYSIS IN THE ROTATOR MOVING EQUILIBRIU

3、M</p><p><b>　　ABSTRACT</b></p><p>　　The experimental equipment is developed to simulate the rotator vibration. The running state of machine is simulated by using different running co

4、nditions. The vibration caused by non-equilibrium mass is analyzed and discussed for first order with focus load. The effective method is found out by using frequency spectrum analysis. </p><p>　　INTRODUCTIO

5、N </p><p>　　In the conventional island of nuclear power plant, turbine generator set is a very important equipment in which the core thermal energy is transferred into electric energy. When the turbine gener

6、ator set has run for long time, the original equilibrium of system would be upset because of the remnant deformed of the metal, abrasion or damaging of the components etc. As a result, the vibration will be increased. So

7、 it is necessary to adjust the equilibrium at spot. On the other hand, a large turbin</p><p>　　We could have a definitely view for the vibration type, vibration power source and vibration property by analyzi

8、ng the vibration of the turbine generator set or doing some special experiment. When the vibration signal is obtained, the frequency spectrum could be used to analysis the vibration signal in order to diagnose quickly. U

9、sing frequency spectrum analysis, the electrical signal of vibration that is obtained by the vibration sensor and has a wide frequency range will be decomposed into sev</p><p>　　The vibration caused by rotat

10、or mass non-equilibrium with concentrated load is discussed and analyzed in this paper. And an effective method to prevent the vibration is presented by using frequency spectrum analysis. </p><p>　　1 EXPERIM

11、ENTAL EQUIPMENT </p><p>　　The experimental system consists of the motor, shaft coupling and rotor etc.. Its structure is very simple. The rotor is driven by the motor directly. Its rotating speed could be ad

12、justed in a wide range. The system could be operated smoothly and reliably. The rated current of the motor is 2.5 A, the output power is 250 W. </p><p>　　The field excitation of the motor is provided by the

13、220 V AC power source which is commutated by the speed regulator, the armature current of the motor is also provided by the same power source. It is adjusted by the compressor governor. Through adjusting the output volta

14、ge of compressor governor, the motor could be of step-less speed regulated at the range 0～10000 r/min, the rate of velocity increasing could be 800 r/min. </p><p>　　The length of the experimental equipment i

15、s 1200 mm, the width is 108 mm, the mass is about 45 kg, the diameter of the shaft is 9.5 mm, the length of the shaft is 500 mm and the maximum deflection is less than 0.005～0.015 mm. Any position along the axial directi

16、on could be selected as experimental abutment point. The diameter and mass of the experimental rotating table is φ 76×19 mm and 600 g, respectively. The arrangement of experimental equipment is shown in Fig.1.</p

17、><p>　　Fig. 1 The arrangement of experimental equipment</p><p>　　The electrical vortex sensors are used to measure the relatively displacement or vibration for axis to bearing pedestal. They are in

18、stalled in the x and y directions at the sensor support, respectively. They do not touch the shaft, and could be used to directly measure the vibration signal of the rotation shaft. The flashing phase-measurer is used to

19、 measure the rotator speed and the phase of the shaft. </p><p>　　2 THE FREQUENCY SPECTRUM ANALYSIS OF VIBRATION SIGNAL </p><p>　　The real vibration of turbine generator set is the most of simple

20、 harmonic periodic motion. Its wave type is also made of many simple harmonic motion. In order to analysis the vibration, we should study the wave type, the frequency composition of the vibration, and the amplitudes. Fre

21、quency can be used as x-axis to describe the vibration in the frequency-domain. The method decomposing the vibration into its various frequency components in frequency components in the frequency domain is called fr</

22、p><p>　　In the frequency spectrum of rotator vibration, the different frequency is often corresponding to the different reason. If we can find the frequency composition of the vibration signal, the reason of vi

23、bration will be discovered. </p><p>　　There are about 80% accidents caused by rotator non-equilibrium in the vibration accidents of turbine generator set happened in the spot, and 90% accidents caused by rot

24、ator mass non-equilibrium. In the experiments described in this paper we study the vibration caused by rotator mass non-equilibrium by using the method of frequency spectrum analysis and the influence coefficient method

25、of finding equilibrium to determine the position of rotator mass non-equilibrium. </p><p>　　3 EXPERIMENTAL RESULTS AND ANALYSIS </p><p>　　The Bode diagram shown as Fig. 2 is about the horizontal

26、 vibration characteristics of rotator. It shows that the critical velocity of rotator is about 2605 r/min, the maximum amplitude of rotator corresponding to the bearing shell is 371 μm, the amplitude of select frequency

27、(AMP-1X) is 360 μm, and the phase difference (PHA-1X) is -36°. The mark position in Fig. 3 is the maximum value of vibration, and also is the position where the phase angle changes. When the rotator speed is smaller

28、 than 215</p><p>　　Fig. 2 The Bode diagram of rotator horizontal vibration characteristic</p><p>　　The phase changeis slightly greater than 90°. According to the eccentric forced vibration

29、theory for single free dimension, the case in the Fig.2 is caused by resonance. The maximum amplitude occurs at the position where the phase change is slightly greater than 90°, because of the damping. In this case,

30、 the angle frequency of rotator speed equals to that of exciting force, that is, . The angle frequency of rotator speed can be considered as first order critical rotator speed. The critical rotat</p><p>　　Th

31、e experiments have been done under the condition of constant temperature. So supporting rigidity is the main influence factor. The experiments have been done by using the method of adding the non-equilibrium mass. The lo

32、cation adding non-equilibrium mass is determined by influence coefficient method that finding equilibrium. The non-equilibrium mass can change the system stiffness. But, according to , when the △m is very small, will al

33、most not change. If mm increases,will be decreased. The fi</p><p>　　The frequency spectrum figures show that the amplitude is obviously large when the frequency is one times (1X). It is monotonously increasi

34、ng before the speed reaches critical rotator speed. The cases of frequency two times (2X), three times (3X) and four times (4X) all exist, but these amplitudes are very small and can be neglected. It is impossible that r

35、otating table or system axis appear crosswise cracking when the experimental velocity is not high enough. The main reason causing vibration i</p><p>　　The result that the second adding non-equilibrium mass i

36、s shown in Fig. 4. From this case, we can see: the 1X component is very obvious in the frequency spectrum. There are components for 2X, 3X, 4X, but their amplitudes are very small. They are not the main components of vib

37、ration. The 1X amplitude changes very small when change the system stiffness. </p><p>　　This is determined by the location of adding non-equilibrium mass. The vibration amplitude can be effectively controlle

38、d only by calculation to find out the non-equilibrium point and non-equilibrium mass, then adding the same equilibrium mass at its opposite direction. </p><p>　　Fig. 3 The frequence spectrum diagram of the f

39、irst adding non-equilibrium mass</p><p>　　Fig. 4 The frequence spectrum diagram of the second adding non-equilibrium mass</p><p>　　4 CONCLUSION </p><p>　　(1) In the frequency spectr

40、um figure, the one times frequency 1X components is too large. When the malfunction about bearing pedestal stiffness and axis joint join defect is not considered. The reason why the vibration is greater is the rotator no

41、n-equilibrium mass. </p><p>　　(2) The one times frequency 1X amplitude is decreased by changing system stiffness. The decreasing amplitude is determined by the location of adding non-equilibrium mass. </p

42、><p>　　(3) The location of non-equilibrium mass is determined by the influence coefficient method. It is needed to find the non-equilibrium point and non-equilibrium mass by calculation. Then add the same equil

43、ibrium mass at the opposite direction.</p><p>　　(4) The adding non-equilibrium mass is so small that it can not cause the large change of the system first order critical velocity.</p><p>　　頻譜分析在

44、轉(zhuǎn)子動平衡中的應用</p><p><b>　　摘 要</b></p><p>　　在模擬旋轉(zhuǎn)機械振動的實驗裝置上，通過不同的選擇來模擬機器的運行狀態(tài)，對單跨集中載荷情況下轉(zhuǎn)子由于不平衡質(zhì)量引起的振動進行了分析和討論，并用頻譜分析的方法找到了有效的解決辦法。</p><p><b>　　介紹</b></p>

45、<p>　　在傳統(tǒng)的島嶼核電站中，汽輪發(fā)電機組是一種非常重要的核熱能轉(zhuǎn)換成電能的設備。當汽輪發(fā)電機組經(jīng)長時間運轉(zhuǎn)后,原來的系統(tǒng)平衡會因金屬的殘余變形、部件的磨損或損壞而遭到破環(huán)。結(jié)果,系統(tǒng)的機械振動將會因此增加。所以因此有必要進行現(xiàn)場平衡調(diào)整。另一方面,一個大型汽輪發(fā)電機組在制作工序中也需要調(diào)整平衡、調(diào)試、安裝和運行?，F(xiàn)場動平衡技術(shù)是消除汽輪發(fā)電機組劇烈振動的一種重要的手段。</p><p>　　我們可

46、以通過對汽輪發(fā)電機組的振動進行分析或做一些特殊的實驗明確了解振動的類型、振動動力源和振動特性。當獲得振動信號之后，頻譜可以用來分析振動信號，以便迅速診斷。利用頻譜分析由振動感應器獲得的電機的振動信號，并將廣泛的頻率范圍分解為幾個主要的頻率成分。不同頻率成分對汽輪發(fā)電機組有著不同的影響。頻譜分析是研究汽輪發(fā)電機組振動的一個非常有用的方法。</p><p>　　本文將對由于集中載荷引起的轉(zhuǎn)子質(zhì)量不平衡進行討論和分析，

47、并且給出了一個利用頻譜分析有效防止振動的方法。</p><p><b>　　1 實驗設備</b></p><p>　　實驗系統(tǒng)由電機、聯(lián)軸器及轉(zhuǎn)子等構(gòu)成，它的結(jié)構(gòu)是非常簡單的。轉(zhuǎn)子由電機直接驅(qū)動，它的轉(zhuǎn)速可進行大范圍調(diào)節(jié)。該系統(tǒng)可以順利、可靠的運作。電機的額定電流為2.5 A,輸出功率是250 W。</p><p>　　電動機的外部勵磁由220

48、 V交流電源經(jīng)調(diào)節(jié)器整流后提供的,發(fā)動機的電樞電流也是相同的電源提供的。它是由壓縮機調(diào)節(jié)器進行調(diào)整控制，通過調(diào)整壓縮機輸出電壓，電動機的速度可逐步減少調(diào)節(jié)至范圍0 ? 10000轉(zhuǎn)/分，速度遞增可達800 r /分。</p><p>　　實驗設備的長度是1200毫米,寬度為108毫米,質(zhì)量是大約45公斤, 軸的直徑是9.5毫米，軸的長度500毫米,最大撓度小于0.005～ 0.015毫米。可以選擇沿軸向的任何位置

49、作為實驗的支承點。實驗用轉(zhuǎn)盤的直徑和質(zhì)量分別為φ76×19毫米,重600克。實驗設備的安裝如圖1所示。</p><p><b>　　圖1實驗設備的安裝</b></p><p>　　電渦流傳感器是用來測量中軸相對軸承底座的位移或振動的。傳感器分別被安裝在X和Y方向提供信號傳遞。它們不接觸軸,但可以直接用于測量轉(zhuǎn)動軸的振動信號。閃動相位測量儀是用來測量轉(zhuǎn)子速度和

50、傳動軸的相位。</p><p>　　2 振動信號頻譜分析</p><p>　　輪機發(fā)電機組真正的振動的是最簡單的諧波周期運動。它的波型也是由許多簡單的諧波運動構(gòu)成。為了分析振動,我們應該學習振動的的波型、頻率組成和振幅。在頻域中頻率可以被看作X軸來描述振動。在頻域中將振動分解成各種頻率成分的方法叫做頻譜分析。頻譜分析的目的是為了將振動信號分解成不同的信號成分。所以振動被分解成為諧波運動包括

51、不同的振幅、頻率和階段。</p><p>　　在轉(zhuǎn)子振動的頻譜中,不同的頻率通常是對應于不同的原因。如果我們能找到振動信號的頻率成分，也就會發(fā)現(xiàn)引起振動的原因。</p><p>　　在輪機發(fā)電機組工作現(xiàn)場有大約80%的振動事故是由轉(zhuǎn)子不平衡引起的,90%的事故是由轉(zhuǎn)子質(zhì)量不平衡引起的。在本文中所描述的實驗中我們會采用頻譜分析的方法研究轉(zhuǎn)子質(zhì)量平衡引起的振動和用影響系數(shù)法找出轉(zhuǎn)子質(zhì)量不平衡的

52、位置。</p><p><b>　　3 實驗結(jié)果及分析</b></p><p>　　圖2所示伯德圖是關(guān)于轉(zhuǎn)子的橫向振動特性。圖示轉(zhuǎn)子的臨界速度約是2605 r /分鐘,轉(zhuǎn)子相對應軸承殼最大限度的振幅為371μm,選擇頻率(AMP-1X)是360μm、相位差(PHA-1X)是-36°。在圖2中標記位置是最大幅度的振動,也就是振動相位變化的位置。當轉(zhuǎn)子速度小于2

53、152 r /分鐘,相對相位是-130°。當轉(zhuǎn)子速度增加到2605 r /分鐘,振幅將增加到最大值。也就是說, 在旋轉(zhuǎn)速度范圍2152 ～ 2605 r /分內(nèi)振幅迅速增加。</p><p>　　圖2 轉(zhuǎn)子橫向振動特性伯德圖</p><p>　　相變略大于90°。根據(jù)單一自由維度的偏心受迫振動理論可知圖2中的情況是由共振引起的。受阻尼影響最大的振幅發(fā)生位置的相變略大于9

54、0°。在這種情況下,轉(zhuǎn)子速度旋轉(zhuǎn)角頻率等于激振力的角頻率,也就是說,。轉(zhuǎn)子旋轉(zhuǎn)角頻率速度可視為一階臨界轉(zhuǎn)子速度。轉(zhuǎn)子的旋轉(zhuǎn)速度取決于轉(zhuǎn)子的材質(zhì)、幾何形狀、大小、結(jié)構(gòu)和支撐條件等，與外部條件無關(guān)，影響因素主要是溫度和支撐剛度。</p><p>　　該實驗在恒溫條件下完成，因此支承剛度是主要影響因素。這個實驗通過添加非平衡質(zhì)量完成。添加非平衡質(zhì)量的位置取決于用影響系數(shù)法尋找平衡。不平衡質(zhì)量可以改變系統(tǒng)剛度。

55、但是,根據(jù),當質(zhì)量變化非常小時的,幾乎沒有改變。如果轉(zhuǎn)子質(zhì)量增加,將減少。系統(tǒng)的一階臨界旋轉(zhuǎn)速度將會下降。這些可從實驗中獲知。</p><p>　　頻譜的數(shù)字顯示頻率為1倍時振幅明顯很大。在旋轉(zhuǎn)速度達到臨界速度之前它是單調(diào)增加的。對所有平衡情況的頻率兩倍、三倍、四倍時都存在，但這些振幅的存在很小,可以忽略不計。當試驗速度遠不夠高的情況下系統(tǒng)軸出現(xiàn)橫向裂縫裂的情況是不可能的。引起振動主要的原因是繞軸旋轉(zhuǎn)的轉(zhuǎn)盤不統(tǒng)一

56、。</p><p>　　圖3、4的頻譜圖是通過添加不同的轉(zhuǎn)子質(zhì)量使系統(tǒng)分別達到平衡。圖3顯示了一階臨界轉(zhuǎn)子速度基本上沒有改變,為 2312 r /分,但振幅頻率下降。頻率的一倍下降到145μm、垂直振幅下降到134μm。在圖4中它們分別為116μm和87μm。如圖3是橫向振幅減少到145μm、垂直振幅從360μm下降至134μm。</p><p>　　第二次增加非平衡質(zhì)量的結(jié)果如圖4所示。

57、在從這種情況下，我們可以看到：在頻譜中1倍頻率的組成部分是非常明顯的。2倍， 3倍， 4倍頻率的部分也同樣存在，但其幅度是非常小的。它們不是振動的主要組成部分。當更改系統(tǒng)剛度時，1倍頻率的幅度變化是非常小的。</p><p>　　這是由添加不平衡質(zhì)量的位置所決定的。我們可以只通過計算來找出非均衡點和非平衡質(zhì)量有效的控制振幅,然后在其相反的方向添加相同的平衡質(zhì)量。</p><p>　　圖3

58、頻率頻譜首次加入不平衡質(zhì)量圖</p><p>　　圖4 頻率頻譜第二次加入不平衡質(zhì)量圖</p><p><b>　　4 結(jié)論</b></p><p>　?。?）在頻譜圖，一次頻率一倍的部分太大。當有關(guān)軸承座剛度和軸心聯(lián)合的障礙不考慮時，振動變大的原因是轉(zhuǎn)子不平衡質(zhì)量。</p><p>　　（2）通過改變系統(tǒng)剛度降低了一倍