| Facing with increasingly severe energy crisis and environmental pollution issues,the popularization of hybrid electric vehicles (HEV) is paid more attention by thegovernments and enterprises for its high fuel utilization rate and good transmissionperformance. As a key component of HEV, the power split device (PSD) is functionedto couple multi-resources of energy and distribute energy, whose transmissionperformance has a vital influence on power performance and ride comfort of vehicles.As the special structure and complicated working conditions, planetary bevel-geartransmission in PSD is more likely to generate axial offset error, which has a seriouseffect on the capability of PSD. This paper focuses on the planetary bevel-geartransmission in PSD, and analyzes the influences of axial offset error on dynamiccharacteristics of the transmission. The results provide theoretical and practicalsignificances for understanding the complex dynamic performance of planetarybevel-gear transmission and recognizing the axial offset error fault, which can offervaluable references for developing PSD with high transmission characteristics.(1) The mathematical model of straight bevel gear pair with axial offset error isestablished according to the mathematical model with backlash for spur gear pair. Therelationship of axial offset, non-normal backlash and efficient tooth width is deduced.And some dynamic responses are obtained based on the accurate bevel gear meshstiffness with axial offset error, which lays a foundation for the verification of thefollowing multi-body dynamics model.(2) The time-varying mesh stiffness of straight bevel gear pair is crucial to themathematical model considering axial offset error. A method that the mesh stiffness ofstraight bevel gear pair is replaced by the mesh stiffness of its virtual spur gear pair isproposed in this paper according to the key effect. The mesh stiffness considering fivekinds of deformation for virtual spur gear pair is calculated by numerical method. Theresults show a good agreement with the meshed stiffness calculated by FEA method,which validates the proposed method.(3) The multi-body dynamic model of a straight bevel gear pair with axial offset error is established on ADAMS software. The dynamic angular velocity and relativedisplacement under two different working conditions are investigated. The resultsshow a good conformance with the one deduced from mathematical model in shape,rage of motion, and period trend, which reveal the feasibility of investigating dynamiccharacteristics of straight bevel gear pair in multi-body dynamics method.(4) The multi-body dynamics model with axial offset error of planetarybevel-gear transmission is built and the influences of different axial offset value anddifferent planet gear number with axial offset error on dynamic transmissionperformance are investigated. The simulation results show that the offset error reducesthe transmission continuity and causes an impact on dynamic meshing force, andplanet gear offset leads to severe load sharing problem of sun gear. The resultsprovide valuable references on fault detecting of bevel-gear transmission with axialoffset. |
PDF Full Text Request