Severity: Notice
Message: Use of undefined constant APP_ID - assumed 'APP_ID'
Filename: database/translate.php
Line Number: 64
Backtrace:
File: D:\database\translate.php
Line: 64
Function: _error_handler
File: D:\wwwroot\blfsy.com\application\controllers\news.php
Line: 240
Function: lang
File: D:\wwwroot\blfsy.com\index.php
Line: 315
Function: require_once
Severity: Notice
Message: Use of undefined constant APP_ID - assumed 'APP_ID'
Filename: database/translate.php
Line Number: 69
Backtrace:
File: D:\database\translate.php
Line: 69
Function: _error_handler
File: D:\wwwroot\blfsy.com\application\controllers\news.php
Line: 240
Function: lang
File: D:\wwwroot\blfsy.com\index.php
Line: 315
Function: require_once
Severity: Notice
Message: Use of undefined constant SEC_KEY - assumed 'SEC_KEY'
Filename: database/translate.php
Line Number: 69
Backtrace:
File: D:\database\translate.php
Line: 69
Function: _error_handler
File: D:\wwwroot\blfsy.com\application\controllers\news.php
Line: 240
Function: lang
File: D:\wwwroot\blfsy.com\index.php
Line: 315
Function: require_once
Severity: Notice
Message: Use of undefined constant APP_ID - assumed 'APP_ID'
Filename: database/translate.php
Line Number: 64
Backtrace:
File: D:\database\translate.php
Line: 64
Function: _error_handler
File: D:\wwwroot\blfsy.com\application\views\news\knowledgePage.php
Line: 24
Function: lang
File: D:\wwwroot\blfsy.com\application\controllers\news.php
Line: 248
Function: view
File: D:\wwwroot\blfsy.com\index.php
Line: 315
Function: require_once
Severity: Notice
Message: Use of undefined constant APP_ID - assumed 'APP_ID'
Filename: database/translate.php
Line Number: 69
Backtrace:
File: D:\database\translate.php
Line: 69
Function: _error_handler
File: D:\wwwroot\blfsy.com\application\views\news\knowledgePage.php
Line: 24
Function: lang
File: D:\wwwroot\blfsy.com\application\controllers\news.php
Line: 248
Function: view
File: D:\wwwroot\blfsy.com\index.php
Line: 315
Function: require_once
Severity: Notice
Message: Use of undefined constant SEC_KEY - assumed 'SEC_KEY'
Filename: database/translate.php
Line Number: 69
Backtrace:
File: D:\database\translate.php
Line: 69
Function: _error_handler
File: D:\wwwroot\blfsy.com\application\views\news\knowledgePage.php
Line: 24
Function: lang
File: D:\wwwroot\blfsy.com\application\controllers\news.php
Line: 248
Function: view
File: D:\wwwroot\blfsy.com\index.php
Line: 315
Function: require_once
2024-04-18
Severity: Notice
Message: Use of undefined constant APP_ID - assumed 'APP_ID'
Filename: database/translate.php
Line Number: 64
Backtrace:
File: D:\database\translate.php
Line: 64
Function: _error_handler
File: D:\wwwroot\blfsy.com\application\views\news\knowledgePage.php
Line: 27
Function: lang
File: D:\wwwroot\blfsy.com\application\controllers\news.php
Line: 248
Function: view
File: D:\wwwroot\blfsy.com\index.php
Line: 315
Function: require_once
Severity: Notice
Message: Use of undefined constant APP_ID - assumed 'APP_ID'
Filename: database/translate.php
Line Number: 69
Backtrace:
File: D:\database\translate.php
Line: 69
Function: _error_handler
File: D:\wwwroot\blfsy.com\application\views\news\knowledgePage.php
Line: 27
Function: lang
File: D:\wwwroot\blfsy.com\application\controllers\news.php
Line: 248
Function: view
File: D:\wwwroot\blfsy.com\index.php
Line: 315
Function: require_once
Severity: Notice
Message: Use of undefined constant SEC_KEY - assumed 'SEC_KEY'
Filename: database/translate.php
Line Number: 69
Backtrace:
File: D:\database\translate.php
Line: 69
Function: _error_handler
File: D:\wwwroot\blfsy.com\application\views\news\knowledgePage.php
Line: 27
Function: lang
File: D:\wwwroot\blfsy.com\application\controllers\news.php
Line: 248
Function: view
File: D:\wwwroot\blfsy.com\index.php
Line: 315
Function: require_once
引起电动机振动的原因很多,产生振动的部位和振动的特征又各不相同,如果把电动机各种原围引起的振动特征和有关因素加以分析,将有助于电动机振动异常的识别和诊断。电动机常见的异常振动有以下几种。
一、定于异常产生的电磁振动
(1)振动频率为电源频率的2倍;
(2)切断申源,电磁振动立即消失;
(3)振动可以在定子机座和轴承上测得;
(4)振动与机座刚度和电动机的负载有关。
其产生的主要原因有:
(1)定子三相磁场不对称;
(2)定子铁心和定子线圈松动,将使定子电磁振动和电碱噪声加大,在这种情况下,振动频谱图中,电磁振动除了2f的基本成分外,还可出现4f、6f,8f的谐波成分;
(3)电动机座底脚螺栓松动,其结果相当于机座刚度降低,使电动机在接近2f的频率范围发生共振,因而使定子振动增大,结果产生异常振动。
二、气隙不均匀引起的电磁振动
这有两种情况:一种是静态不均匀;另一种是动态的不均匀,两者的振动特征并不完全相同。
1.静态气隙偏心产生的电磁振动特征
(1)电磁振动频率是电源频率f0的2倍。
(2)振动随偏心值的增大而增加,与电动机负荷关系也是如此。
(3)气隙僧心产生的电磁振动与定子异常产生的电磁振动较难区分。
2.动态气隙偏心产生的电磁振动特征
(1)转子旋转频率和旋转磁场同步转速频率的电磁振动都可能出现。
(2)电磁振动以1/2sf0周期在脉动,因此,在电机负载增加,s如大时,其脉动节拍加快。
(3)电动机往往发生与脉动节拍相一致的电磁噪声。
三、转子导体异常引起的电磁振动
转子绕组异常引起的电磁振动的特征:
(1)转子绕组异常引起电磁振动与转子动态偏心所产生的电磁振动的电磁力和振动波形相似,现象相似,较难判别。
(2)电动机负载增加时,这种振动随之增加,当负载超过50%以上时较为显著。
(3)若对电动机定子电流波形或振动波形作频谱分析,在频谱图中,基频两边出现±2sf的边频,根据边频与基频幅值之间的关系,可判断故障的程度。
四、转子不平衡产生的振动
电动机转子失衡原因有:转子零郜件脱落和移位,绝缘收缩造成转子线圈移位、松动,联轴器不平衡,冷却风扇与转子表面结垢等,以上因素对高速电动机尤为敏感。转子失衡产生的振动有如下特征:
(1)振动频率和转速频率相等。
(2)振动幅值随转速增高而加大,但与电动机负载无关。
(3)振动以径向为,轴向较小。
五、滚动轴承异常产生的机械振动
由于滚动轴承损坏、设计和制造中的误差,在运行中会出现机械振动。
1.滚动轴承损坏
滚动轴承因负载过重、润滑不良、安装不正确、轴电流、异物进入等原因,将会出现磨损、表面剥落、点蚀、碎裂、锈蚀等故障。轴承的损坏,加工和装配的误差、以及滚动轴承自身结构都会引起振动,振动作为一种信息,预示轴承运行状态是否正常。
2.加工和装配不良引起振动
(1)振动幅值以轴向为。
(2)振动频率和旋转频率相同。
3.轴承非线性特性引起振动
(1)振动频率是旋转频率的整数或分数倍;
(2)振动是轴向的;
(3)振动与转速密切相关。
六、滑动轴承振动
1.油膜涡动弓起异常振动
(1)振动频率略低于转于旋转频率的一半,通常为0.42~0.48f;
(2)油膜涡动的振动是径向的;
(3)油膜涡动往往是突然出现的,诊断的方法是油膜涡动后,改变润滑油的黏度和温度,振动就能减轻或消失。
2.油膜振荡产生异常振动
(1)振动频率等于转子一阶临界转速,工作转速接近一防临界转速2倍的大型高速柔性转子电动机,极易发生油膜振荡;
(2)油膜振荡是一种径向振动;
(3)减少转子不平衡、降低润滑油的黏度和提高油温,能使油膜振荡消失。
七、安装、调整不良引起的机械振动
1.安装时轴线不对中引起振动
(1)轴心线偏差越大,振动也越大;
(2)振动中2倍旋转频率的部分增加;
(3)电机单独运行时,这些振动将消失。
2.联轴器配合不良引起的振动
(1)振动频率与电机旋转频率相同;
(2)连接机械和电机端振动相位相反;
(3)电机单独运行时振动将消失。
(来源:电力讲坛)
Severity: Notice
Message: Use of undefined constant APP_ID - assumed 'APP_ID'
Filename: database/translate.php
Line Number: 64
Backtrace:
File: D:\database\translate.php
Line: 64
Function: _error_handler
File: D:\wwwroot\blfsy.com\application\views\news\knowledgePage.php
Line: 36
Function: lang
File: D:\wwwroot\blfsy.com\application\controllers\news.php
Line: 248
Function: view
File: D:\wwwroot\blfsy.com\index.php
Line: 315
Function: require_once
Severity: Notice
Message: Use of undefined constant APP_ID - assumed 'APP_ID'
Filename: database/translate.php
Line Number: 69
Backtrace:
File: D:\database\translate.php
Line: 69
Function: _error_handler
File: D:\wwwroot\blfsy.com\application\views\news\knowledgePage.php
Line: 36
Function: lang
File: D:\wwwroot\blfsy.com\application\controllers\news.php
Line: 248
Function: view
File: D:\wwwroot\blfsy.com\index.php
Line: 315
Function: require_once
Severity: Notice
Message: Use of undefined constant SEC_KEY - assumed 'SEC_KEY'
Filename: database/translate.php
Line Number: 69
Backtrace:
File: D:\database\translate.php
Line: 69
Function: _error_handler
File: D:\wwwroot\blfsy.com\application\views\news\knowledgePage.php
Line: 36
Function: lang
File: D:\wwwroot\blfsy.com\application\controllers\news.php
Line: 248
Function: view
File: D:\wwwroot\blfsy.com\index.php
Line: 315
Function: require_once
Severity: Notice
Message: Use of undefined constant APP_ID - assumed 'APP_ID'
Filename: database/translate.php
Line Number: 64
Backtrace:
File: D:\database\translate.php
Line: 64
Function: _error_handler
File: D:\wwwroot\blfsy.com\application\views\news\knowledgePage.php
Line: 36
Function: lang
File: D:\wwwroot\blfsy.com\application\controllers\news.php
Line: 248
Function: view
File: D:\wwwroot\blfsy.com\index.php
Line: 315
Function: require_once
Severity: Notice
Message: Use of undefined constant APP_ID - assumed 'APP_ID'
Filename: database/translate.php
Line Number: 69
Backtrace:
File: D:\database\translate.php
Line: 69
Function: _error_handler
File: D:\wwwroot\blfsy.com\application\views\news\knowledgePage.php
Line: 36
Function: lang
File: D:\wwwroot\blfsy.com\application\controllers\news.php
Line: 248
Function: view
File: D:\wwwroot\blfsy.com\index.php
Line: 315
Function: require_once
Severity: Notice
Message: Use of undefined constant SEC_KEY - assumed 'SEC_KEY'
Filename: database/translate.php
Line Number: 69
Backtrace:
File: D:\database\translate.php
Line: 69
Function: _error_handler
File: D:\wwwroot\blfsy.com\application\views\news\knowledgePage.php
Line: 36
Function: lang
File: D:\wwwroot\blfsy.com\application\controllers\news.php
Line: 248
Function: view
File: D:\wwwroot\blfsy.com\index.php
Line: 315
Function: require_once