Under the rotor compressor bearing centering position impact on performance

Compressor rotor under the performance impact of 2019 - bearing centering position 06 - 28 Yao Xiaoyong Chen Xianquan ( Zhuhai ling of compressor co. , LTD. ) 1 introduction rotary compressor because of its excellent performance, compact structure, less parts, long working life, widely used in room air conditioning, refrigeration equipment, automotive air conditioning and compressed gas device. As rotary compressor pump body components of the heart, the assembly after the performance directly affects the whole performance of the compressor. Since the accuracy of pump body parts at micron level, assembly parts between minor changes will lead to pump body rotation is not smooth, and even have serious production lines, leading to a sharp drop in the performance of compressor. In recent years, each big business enterprise of research models and compressors for key process centering compressor pump body assembly, carried out extensive research, and proposed the corresponding solution, including the bearing on the pump body and the bias Angle of centering cylinder, cylinder and roller, the minimum clearance value, centering under multiple cylinder clearance compensation, etc, but all research has focused on the bearing and cylinder, to influence the compressor operation on the relationship between the bearing and the bearing did not see have related research. Figure 1 pump body stress analysis in this paper, the stress of the crankshaft from the compressor runtime analysis, established the loading condition of the crankshaft and the stress of the upper and lower bearings and contact model, and the compressor simulation software simulation analysis of the changes on the loading direction and size of the crankshaft. 2 test analysis of crankshaft in rotary compressor drive roller rotation, through the vane of blocking cylinder internal cavity is divided into two cycles, due to the refrigerant after cavity compressed form a larger pressure within the cavity. Than when the pressure in the high-pressure vane ( Spring pressure) Big two orders of magnitude, so the internal stress of the roller main cavity for continuously compressed the gas forces of change, the direction for the roller run dynamic minimum clearance, and the sliding vane and the perpendicular bisector of roller contact, from the high side tended to low voltage side, as shown in figure 1. Through the simulation software according to the above model for simulating a practical compressor, and the simulation results are shown in figure 2. Figure in the lower left corner of the irregular closed graph and the stress variation of crankshaft, including the origin and irregular graphics midpoint attachment said under the current state of stress, attachment force size (length said The longer the length, the greater the force) ； Attachment with the direction of axis Angle of crankshaft stress. Can be seen from the figure 2, the crankshaft in the compressor running under periodic load, and along the direction of the lower left to achieve maximum load due to the operation of the compressor, the length of crank shaft is always in contact with the upper and lower bearing, in order to avoid the biggest stress in the crankshaft with a strong friction with upper and lower bearings, bearing centering will under the bearing under assumptions need to be the biggest crankshaft stress direction bias, this state compressor performance will achieve the optimal effect. The following validated by test. Crankshaft stress simulation diagram in figure 2 pump body is the same type of compressor test, the pump body assembly when installed in different centering position respectively, and in the same test under the condition of the compressor performance, the results are shown in table 1. （ 1) From the Angle of bearing centering distribution in three quadrants contrast data ( Centering on the fourth quadrant pump body directly stuck) , only centering in the third quadrant of the compressor test does not jump stop; （ 2) Centering on the third quadrant of the compressor and centering in the second quadrant, compared to the average power consumption of about 8% lower power consumption. As shown in table 1, the test results of the middle and lower bearing centering in the third quadrant, which mentioned in the foregoing analysis of the bearing centering will under the bearing's biggest crankshaft stress direction bias, the point of view, bearing centering in the third quadrant, indeed has a more significant performance advantages compared to other quadrants. But the third quadrant still has a large range, the same quadrant of the different centering position may still cause large fluctuations in the compressor performance, therefore the following further tests have been carried out, to achieve the optimum centering position. Further test, the test results are shown in table 2, the results show that: ( 1) Centering in the third quadrant, but in different regions have an impact on the compressor performance; （ 2) Compare the situation of centering in different angles and concentricity, found centering Angle for 245 & deg; , the concentricity of 7, the lowest average power consumption of compressor, The results and the stress of the pump body runtime analysis results; （ 3) Under the same centering Angle, concentricity in 2. 8 ~ 7μ; Between the power fluctuation is not sensitive, more than 14 & mu; Will power can significantly increase; （ 4) In the third quadrant location near the fourth quadrant centering, abnormal compressor prone to power on the high side, so to avoid centering on this interval. Three conclusions based on the pump body internal stress of the crankshaft rotating compressor runtime analysis, and the compressor simulation software simulation analysis of the changes on the loading direction and size of the crankshaft. And thus it is concluded that the bearing centering effect on power consumption when the compressor is running, the conclusions are as follows: ( 1) Under the same conditions, when bearing centering will bearing the largest crankshaft stress direction under the bias of compressor performance will achieve a better effect; （ 2) Under the same conditions, in the same centering Angle, concentricity in 2. 8 ~ 7μ; Between the power fluctuation is not sensitive, more than 14 & mu; Will power can significantly increase; （ 3) Centering in the third quadrant near the fourth quadrant, the compressor is prone to failure, must avoid centering on this interval. References [ 1] Ma Guoyuan, hong-qi li, etc. Rotary compressor. Beijing: mechanical industry publishing house, 2001. ( 2] Chien-hua wu. Computer simulation and performance analysis of R410A rotary compressor. Xi 'an: xi 'an jiaotong university institute of compressor 2005. Source: the appliance of science and technology, no. 8