无油线性压缩机的频率特性和活塞偏移特性研究

针对线性压缩机随工况和热负荷变化而引起共振频率和活塞中心位置偏移量改变的问题,建立了关于压缩机共振频率的线性等效模型和傅里叶变换计算模型.两种模型用来预测线性压缩机的共振频率,后者同时用来计算活塞中心位置偏移量,模型中考虑了不同行程、不同排气压力对共振频率的影响以及不同行程、不同排气压力和不同运行频率对活塞中心位置偏移...

Frequency characteristics and piston offset characteristics of oil-free linear compressor

Here,aiming at the problem of resonance frequency and piston offset’variation caused by working conditions and heat load’change in linear compressor,linear equivalent model and Fourier transformation calculation one of linear compressor resonance frequency were established.Both of them were used to predict resonance frequency of linear compressor and the latter was also used to predict piston central position offset.Effects of stroke and discharge pressure on resonance frequency were considered in models,and effects of stroke,discharge pressure and operating frequency on piston offset were also considered in models.To verify the effectiveness of models,a testing system was constructed to measure resonance frequency and piston offset of linear compressor.The test results were compared with the calculated ones.Results showed that compared with Fourier transformation calculation model,the linear equivalent model can predict resonance frequency more accurately;resonance frequency gradually decreases with increase in stroke and increases with increase in discharge pressure.Tests showed that piston offset of linear compressor is almost a constant with increase in stroke and gradually increases with increase in discharge pressure;piston offset values predicted with Fourier transformation calculation model under different strokes are higher than the actual test ones,but piston offsets under different strokes and discharge pressures can be predicted by using this model to calculate the compressor’s offsets at the position of top dead center(TDC),the error is less than 10%.