BELLOWS DRIVES OF CURVILINEAR MOTION OF WALKING MACHINE LEG
This article focuses on the improvement of the drives of mobile walking devices using pneumatic-mechanical converters containing a sealed elastic bellows chamber enabled to be connected to the pneumatic line of power supply pressure. Functioning analysis of chamber bellows drives revealed the limitations of their use as leg drives of the walking device, which are associated with the design that limits performance capability. Modern drives of curved movement in the desired direction use excess pressure of energy carrier for lifting the leg and expansion pressure for its straightening. Power characteristics of a cone bellows drive with a center track rod of curvilinear movement of a walking device are studied. Its advantages and disadvantages in comparison with cylindrical bellows drive are revealed. It is shown that the maximum bending angle of the cone bellows is more than one and a half times greater than the bending angle of the cylindrical bellows. Bellows drives of a curvilinear movement with an inextensible center track rod have low power characteristics, which does not allow them to be used as leg drives of a walking device. The idea and a new device for its implementation are proposed. New drive consists of an annular bellows, along the axis of which two plugs are fixed at the ends, forming a sealed cavity that can be connected to the pressure device. A flexible spring-load rod is fixed on the plugs along the bellows axis and an inextensible flexible shell is fixed along the bellows perimeter, which restricts the bellows axial tension. Excess pressure buildup in the working chamber bends the bellows due its unstable symmetrical arrangement (lifting of the working tool). Further pressure buildup leads to bellows axial stretching, force interaction with the inextensible shell and straightening of the bellows. Simulation cone bellows: dust guard of front shock absorber M-2141. Inextensible shell material: polyester.