Design And Analysis Of Wheel Set Suspension With Six-arm Structure Based On Hydro Pneumatic Spring

With the continuous breakthrough and improvement of motor technology,there are also new choices for driving methods.The motor is integrated into the vehicle hub to form an independent drive unit,replacing the engine and transmission mechanism of the traditional drive method,and the wheel-to-wheel drive also makes differential steering possible.Due to the traditional drive and steering mechanism,the development of the suspension system is greatly restricted,and the degree of freedom of the suspension is restricted.Aiming at the problem that the traditional suspension can not meet the new driving mode only considering single vertical degree of freedom,a six-arm structure wheelset suspension based on oil and gas spring is designed,which not only meets the wheel drive mode of hub motor,but also breaks the limit of freedom.The main work of this paper is as follows.In this paper,according to the suspension requirements,a six-arm structure wheelset suspension model is designed in Solidworks software.The structure and characteristics of the suspension are analyzed and summarized.Based on the oil-gas spring,the feasibility of the design of the six-arm structure suspension was analyzed.The good nonlinear characteristics of the oil and gas springs bring about the process of improving the suspension performance,but bring repeatability and uncertainty to the design work.Aiming at this problem,the corresponding mathematical modeling of the oil-gas spring is carried out.Through the structural design and theoretical analysis of the proposed external single-chamber oil-gas spring,the mathematical model of the oil-gas spring is established,and the nonlinear characteristic curve of the oil-gas spring is obtained.At the same time,the factors affecting the nonlinear characteristics of the oil-gas spring are studied.Considering factors such as piston area,oneway orifice,normally open orifice,initial pressure of air chamber,area of air chamber,initial height of air chamber,etc.,the appropriate parameters are selected to make the suspension meet the ideal performance requirements.In this paper,the performance of the suspension under six degrees of freedom is analyzed,and the variation law of the oil-gas spring and the motion trajectory of the ball head at the lower end of the oil-gas spring are obtained.However,due to the complex structure of the suspension and the nonlinear characteristics of the oil and gas spring,there is an instability problem during the horizontal steering of the wheelset.Finally,on the basis of the six-arm suspension,it is supplemented by four extension springs.The simulation results show that within a certain range,the resultant moment of the suspension is basically maintained around 0 · 8),and it has a strong self-stabilizing ability.The wheelset suspension with six-arm structure designed in this paper breaks the limitation of the degree of freedom of the traditional suspension,and has the characteristics of unitization and modularization,which makes it have great flexibility and applicability.It can be combined with in-wheel motor wheel-to-wheel drive mode as an independent module,which not only has the function of driving,but also has the characteristics of suspension.