Driver Seat Differential Pneumatic System with Air Damping

摘要

The paper shows a possibility of tuning vibration isolation properties of a mechanical system by means of two pneumatic springs in a differential configuration, which are connected by a throttle valve. The springs are inserted into the guiding mechanism. They are attached to the mechanism parts and to the supporting platform. Vibrations of the vibration isolated mass, transferred from the kinematic excitation of the base, are intended to be minimized. Vibration isolation by means of pneumatic springs is utilized in many technical systems, e.g. in suspension of heavy machinery and systems characterized by interaction with humans, such as driver seats, ambulance couches, etc. The pneumatic springs provide the option of change of the stiffness, by which the adaption of the natural frequency of the system to the exciting frequency can be achieved. In cases of application of the object vibration isolation, they can change the load characteristics in a relative large range. In the studied case of differential spring configuration, the springs are connected with air pipes to the throttle valve. The air being exchanged during the motion period comes through the valve, the cross-section of which determines the time constant of the pneumatic sub-system thus creating a hysteresis of load characteristic of the spring support. This brings an additional, controllable damping to such a system that is profitable in most vibration isolation cases.