传动联轴器的扭矩和温度测试

• 关键词：传动联轴器,扭矩
• 摘要：Ariel公司曾和RBTS公司合作为澳大利亚的一家公司某个项目技术服务。自项目开始以来, 设备一直运行在设计范围内的负载和速度下，但与煤矿的甲烷增压压缩机耦合时，弹性元件多次发生故障。此压缩机由天然气发动机驱动。 最初的扭振模型分析结果是一阶扭振固有频率(TNF)低于800rpm (在额定扭矩下30°C 时是720 RPM ，100°时是 620 RPM)。

Torque Talk December 2012 
Torque & Temperature in a Drive Coupling
传动联轴器的扭矩和温度测试

    Ariel公司曾和RBTS公司合作为澳大利亚的一家公司某个项目技术服务。自项目开始以来, 设备一直运行在设计范围内的负载和速度下，但与煤矿的甲烷增压压缩机耦合时，弹性元件多次发生故障。此压缩机由天然气发动机驱动。 最初的扭振模型分析结果是一阶扭振固有频率(TNF)低于800rpm (在额定扭矩下30°C 时是720 RPM ，100°时是 620 RPM)。

Ariel Corporation was working on an issue with Rotor Bearing Technology & Software, Inc. (RBTS) for a company in Australia. Since its start up, the customer had experienced multiple elastomeric element failures in the drive coupling on their large coal bed methane booster compressor at loads and speeds in the design operating range. This compressor unit is driven by a natural gas engine. 
The analytical torsional model initially predicted the first mode torsional natural frequency (TNF) to be below 800 RPMs (720 RPM at 30°C and 620 at 100° element temperature at rated engine torque).

     Ariel公司的 Tom Stephens在现场使用两个TorqueTrak仪器同时进行测试: 一个用于联轴器的动态转矩，另外一个用于耦合器元件的温度测试。因为这些元件都是旋转联轴器组件的一部分, Ariel公司决定使用遥测方式从内部温度传感器传输信号。测试数据表明联轴器实际工作时过硬不灵活，设计的临界转速在800-850RPM之间。系统运转在临界转速或接近临界转速，导致了联轴器的弹性元件过热。在固有频率下激发的扭振，造成联轴器的损坏。

    该图显示了动态扭矩和热变化的关系。温度值在零以下，表示该联轴器正在冷却。反之，温度值在零以上，则表示它正在升温。参阅这张图表，为了防止弹性元件过热，我们可以看到扭矩水平必须保持在11000lb-ft以下。
Ariel's Tom Stephens performed site testing with two TorqueTrak instruments simultaneously: one for coupling dynamic torque, and one for coupling element temperature. Because these elements are part of the rotating coupling assembly, Ariel decided to use telemetry to transmit the signal from their internal temperature sensor. The measurement data indicated the coupling was acting much stiffer than originally modeled with the fundamental twist critical speeds between 800 - 850 RPM. Operating at, or even near, the critical speed was causing the coupling's elastomeric elements to heat up. The drive train's fundamental twist mode of vibration was being excited by the inherent unsteady torque demand from the compressor which resulted in damaging levels of torsional vibration in the drive coupling.
The plot shows the coupling element heat generation under different vibratory torque levels - a value below zero indicates that the coupling is cooling down and above zero indicates that it is heating up. Referring to this chart, to prevent the elastomeric elements from overheating, one can see that the vibratory torque level must remain below about 11,000 ft-lbs P-P.

    根据这些数据，对联轴节做了简单的改动调整，降低了传动系统的基本扭转频率，从根本上改善了压缩机的可靠性。在这个应用中，BINSFELD的TorqueTrak提供了遥测方案，使Ariel和RBTS可以同时监测联轴节的扭矩和温度，帮助他们发现问题、解决问题，这确实是一个非常成功的案例。
Armed with this data, a slight modification was made to the setup of the coupling assembly which resulted in lowering the drive train's fundamental twist frequency and ultimately improved compressor reliability. Binsfeld's TorqueTrak products provided the required telemetry solution to facilitate the simultaneous monitoring both torque and temperature on a rotating coupling assembly which were essential to enabling Ariel and RBTS to fully understand the problem and arrive at a solution.