Rotor Dynamics Research On Flexible Shaft Submersible Motor

With the development of economy,consumption of oil is increasing.The electric submersible pump become an important production equipment in no rod pump lifting mode.Submersible motor is the power source of the all system,the performance and quality of submersible motor is play an important role to the whole system to work normally.Submersible motor usually work in the hundreds or even thousands of metres oil Wells,bearing wear and stator friction is an important factor to cause electrical failure.These two factors are mainly caused by the motor vibration,so research the rotor dynamics of a flexible shaft oil motor is a crucial role to solve the problem of failure of oil motor.This thesis mainly analyzes the following research:Firstly,the application background and significance of the submersible motor are introduced,and the structural characteristics of the submersible motor are detailed.The current research status of submersible motor in design,temperature rise and electromagnetism is described in detail.The research method and application of rotor dynamics of oil submersible motor are introduced in detail.According to the paraments and principle of the submersible motor to design electromagnetic of motor.In this way,determining the size of submersible motor structure.After that we use Ansoft to build two-dimensional model of submersible motor,and the no-load and load simulation of the designed motor is performed.The simulation results verify the rationality that each parameter of the submersible motor.Secondly,a rotor dynamics model of the flexible shaft submersible motor is established.Through the analytical calculation and finite element simulation,calculating the viscous friction loss between the submersible motor rotor and the lubricating oil,in order to obtain the viscous friction coefficient and friction.As we all know,the results of the finite element simulation can calculate the friction loss accurately and conveniently,so in this way we can obtain the motor speed and the influence of temperature on the friction loss of viscous friction.Analying the electromagnetic force of the motor,and using the ansoft to establish the three-dimensional eccentricity model of submersible motor.Using that model to obtain the simulation curve of the electromagnetic force received by the submersible motor under the normal working speed.Finally,modal analysis is carried out on the rotor system of the flexible shaft submersible motor.Using Solidworks to establish 3d modeling of the flexible shaft submersible motor.And then the model was imported into Ansys after the constraint conditions were determined,meanwhile,using modal analysis method analyzing the dynamic characteristics that different pitch rotor system of submersible motor.Besides modal analyzing the rotor system composed of single rotor series of different lengths.and according to the simulation results to determine the length of the single rotor,so that resonance can be avoided when the motor is running normally.