IN INFLUENCE OF THE NEAR- RESONANCE OPERATING MODE OF A TWO-MASS VIBRATION HARDENING UNIT ON THE FOUN-DATION AND SPECIFIC POWER COSTS

In mechanical engineering, large-sized parts are produced by casting from carbon steels, cast irons with internal cavities, having a low safety margin without the use of strengthening methods. For example, such parts are turbopump housings, gearboxes, and turbines. In aircraft construction, large-sized parts of complex spatial shape are used, such as wing panels, fuselage, chassis compartment, operating under alternating dynamic loads with limited mass and safety margin. It is not always possible to apply modern methods of strengthening such parts due to the presence of cavities and the complexity of their spatial surface shape. This problem is solved by the vibration impact hardening (VI) method. The disadvantage of (VI) is large volumes of the tool environment and high energy costs. Modern (VI) operate in a superresonant mode with rigid fastening of parts and have one dynamic system. The article presents the results of studies of a two-mass dynamic system of a vibration-hardening unit, which incorporates the advantages of near-resonance and super-resonance modes, which reduce the disadvantages of modern (VU). The first mass is a part with elastic elements, which operates in an environment of intense vibrations in a near-resonance mode. The second mass is a tool environment with a container, which operates in a super-resonance mode. Various operating modes of the machine are created by changing the air pressure in the pneumatic rubber-cord chambers (PRC), as well as by compressing them. Such a layout of the experimental model of the vibration-hardening unit during tests showed a decrease in power consumption per unit of vibration amplitude by 35-40% when operating in a mode close to resonance compared to the pre- and super-resonance regions of the modes. The amplitude of base vibrations changed insignificantly.