Simulation Analysis And Experimental Test Of Over Speed Broken Process In Vehicle Motor Commutator

Commutator is an important component of automotive motor,affects the life and performance of the motor directly.The commutator changes the direction of the current,and rotates at high speed in a certain temperature conditions,withstands centrifugal force and thermal stress when the motor working.Especially when the motor is idling,the commutator withstands the great centrifugal force at the maximum speed.Then the molding compound may resulting in micro-cracks,as the crack growth,eventually resulting in the accident of copper bar flying out.How to use the scientific analysis method to analyze the over-speed broken process of the commutator and optimize the commutator design has become an important issue for the commutator manufacturers.In this context,a commutator of a motor starter motor is studied in this paper.Combining the fracture mechanics and finite element method,used the ABAQUS software to simulate the over-speed broken process of the commutator.According to the FEA result,discussed the role of each component,optimized the design of the commutator,and verified the accuracy of the finite element model by the over-speed broken test.Firstly,the material parameter database of each component is established.Obtained the basic mechanical properties of silver-copper alloy,glass fiber reinforced ring and molding compound by tensile test.And obtained the fracture mechanics parameters such as fracture toughness and critical crack opening displacement of the molding compound by three-point bending crack opening test.Secondly,used the FEA software ABAQUS,to establish the finite element model of the commutator over-speed process and simulate the broken process.Used the smeared cracking model to simulate the crack generation and expansion.Verified and improved the FEA model by test.Then according to the FEA result,discussed the effect,stress distribution and displacement of each component of the commutator,and optimized the structure design.Finally,simulated for the optimized design to determine the feasibility.Produced samples for over-speed test.Compared with the simulation results,it is found that the over-speed performance of the commutator is obviously improved.It is proved that finite element simulation can be used to study and improve the over-speed performance of commutator.