Experiment Investigation Of Dynamic Characteristics And High Speed Dynamic Balance Of A Aeroengine Flexible Rotor

Rotor is an important component of aeroengine. With the development of science and technology, the performance of turbine shaft aeroengine is constantly improved, its power turbine rotor is developing towards high speed and large length-to-diameter ratio, specified operating speed is generally over bending critical speed, structure is becoming more and more complex. The dynamic characteristics of power turbine rotor are particular, for example, rotor is rather sensitive to unbalance, vibration caused by unbalance of rotor is an important cause of whole engine vibration, therefore, high speed dynamic balance must be finished before it is used in engine and balance is extraordinary difficulty. The dynamic characteristics and high speed dynamic balance investigation of power turbine rotor of a new-type turbine shaft aeroengine is carried out in this paper, main purpose is to solve a key technique during model development, focal point is experiment investigation. The investigation achievements of this paper are directly used in model development and possess significant national defense and engineering use value. The main contents of this paper are following:(1)Being aimed at the structure characteristics of power turbine rotor, such as hollow, thin wall, large length-to-diameter ratio, with elastic support and squeeze film damper, torque tube is assembled in inner hole of transmission shaft, two stage power turbine disks locate at one end of the rotor, finite element calculation model is set up in order to calculate dynamic characteristics of power turbine rotor. The dynamic characteristics of power turbine rotor, such as critical speeds, vibration modes and steady unbalance responses, are systematically calculated and analyzed respectively. The influences of elastic support and three main components that is transmission shaft, torque tube and power turbine disks on dynamic characteristics of the rotor are calculated and analyzed.(2)The experiment investigation of dynamic characteristics of power turbine rotor used in engine are carried out on high speed rotating test rig, the experiment results verify the correction of calculation model. The influences of the three main components that is transmission shaft, torque tube and power turbine disks and other factors on dynamic characteristics are researched by experiment. The overspeed experiment of 105% specified operating speed of whole power turbine rotor is finished.(3)An effective means of placing balance weight is advanced to overcome the difficulty that test weight or balance weight can't directly be placed on transimission shaft of dynamic turbine rotor during high speed dynamic balance, this is a technological method by precise balance collars (auxiliary balance tool) to achieve high speed dynamic balance of slender flexible rotor. A set of precise balance collars are designed and processed according to precision demond of dynamic balance. The strength calibration of collars is finished by using finite element method. The experiments of checking and verifying balance collars are accomplished through two simulate shafts. The influences of balance collars on dynamic characteristics of power turbine rotor are calculated and analyzed. At last, the optimization design of balance collars is achieved, one of the difficult problems of high speed dynamic of power turbine rotor is effectively solved.(4)The investigation of high speed dynamic balance technique of power turbine rotor used in engine is accomplished on high speed rotating test rig, a multispeed, multiplane, balance step by step influence coefficient method is put forward. The use behaviors and balance behaviors of the balance collars are verified to be very ideal during experiments. The principles to determine three balance essential factors(measure plane, balance plane and balance speed) are advanced. The balance procedures and balance technologies are standardized. The balance judgement criteria (balance judgement bases) are put forward. An method for estimating unbalance of torque tube is advanced. The modification opinions about technique demonds of design blueprint about low speed and high speed dynamic balance are raised and are adopted during model development.(5)It is analyzed and investigated that the effect of high speed dynamic balance technique of power turbine rotor in reducing vibration of whole turbine shaft aeroengine.(6)The experiment research about the unfavorable influence on high speed dynamic balance precision of power turbine rotor caused by assembly imbalance is fulfilled, the balance program of power turbine module is advanced and the experiment research of power turbine module is brought to success.