The research status of the solution method of the dynamic equation of gear transmission system, because the gear meshing stiffness changes with time, even without considering the influence of other nonlinear factors, the gear transmission system is also the parameterized excitation forced vibration system. Generally, the dynamic equation of a gear system is a second-order differential equation with multiple degrees of freedom. There are four main types of dynamic equations depending on the dynamic model:
(1) Linear time invariant system dynamics equation;
(2) Dynamic time equations of linear time-varying systems;
(3) Nonlinear time-invariant system dynamic equations;
(4) Dynamic equations of nonlinear time-varying systems.
In addition, according to the purpose of analysis, it can be divided into homogeneous and non-homogeneous equations. The former is a free vibration equation and is mainly used to analyze the inherent characteristics of the system, namely the natural frequency, modality and stability zone. The latter is used to analyze the dynamic response of the system under internal and external incentives. Linear time-invariant systems, also known as linear vibration systems, can be analyzed and solved using conventional linear vibration theory and methods. The linear time-varying system, that is, the system dynamics equation has a linear time-varying coefficient, which is mainly considering the time-varying stiffness coefficient caused by the meshing stiffness of the gear with time. Due to the periodicity of the time-varying mesh stiffness, the system is a parametrically excited vibration system with a periodic coefficient.
The nonlinear time-invariant system is a general constant-coefficient nonlinear vibration system. It mainly considers various nonlinear factors and takes the meshing stiffness as a constant to consider the influence of nonlinear factors on the dynamic characteristics of the system. Considering the influence of time-varying mesh stiffness and nonlinear factors on the dynamic characteristics of the system, it is also necessary to use the theory and method of nonlinear vibration to analyze. The solution of the nonlinear vibration system often varies from problem to problem. So far, there is no unified general solution. In the nonlinear research of gear system, the following solutions are mainly used:
(1) Numerical integration method for finding the solution of the vibration period;
(2) Quantitative analysis of nonlinear vibration;
(3) state space method;
(4) Direct integration method for seeking system dynamic response.
For multi-degree-of-freedom nonlinear systems, numerical methods are very effective. The direct integration method is a stepwise numerical integration method. It does not need to transform the dynamic equation into another form, and is an effective method for analyzing the dynamic response of a nonlinear system.
(Finish)
The central motor we are referring to here is a central Ebike Motor used on lithium-ion assisted Electric Bicycles, while the common one is the motor used on lithium-ion mountain assisted bicycles. It was developed and put into use after the hub motor, and compared to the hub motor, the technology of the central motor is not yet very mature, so there is still a long way to go in terms of performance stability. But the central motor has a characteristic that hub motors do not have, which is its instantaneous starting assistance function, so it also has a corresponding market. The most common method is to install a center mounted motor on a mountain Electric Bike to meet the bumpy road conditions in the mountains, so both hub motors and center mounted motors have their advantages and disadvantages. The choice of motor depends entirely on which aspect of its functionality you value.Generally speaking, the central motor is used to assist mountain bikes, and hub motors are more common on urban series of assist bicycles.
Electric Bicycle Motor ,Mid Motor,Ebike Motor
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