砥石車の締付圧が回転破壊周速に及ぼす影響

抄録

This report shows that the bursting speed of rotating wheel fluctuates by several percents according to the intensity of clamping pressure, through theoretical analysis and experiments. From the discussion on results of the preliminary experiments measuring the stress distribution in the wheel, a model is presented, in which the frictional force μp acting on flange-wheel interface due to clamping force resists the radial displacement caused by centrifugal force, and the stress solution is derived from the two-dimensional elastic theory. This solution lies between the stress values on surface and central plane of wheel getting from the three-dimensional analysis by the finite element method, and is fairly applicable as an approximate one to a thin wheel whose thickness is under 20% of the outer radius. The non-dimensional maximum value of circumferential stress σ_θ working on the arbor hole edge, which acts as a trigger for wheel bursting, reduces with the increase of the parameter μp/ρω²γ_o² (ω; angular velocity, γ_o; outer radius, ρ; density) from the value of free-sustained hollow disc often referred to compare with the experimental values. Then, the stress resulting from ring-like axial pressure p does not exert a powerfull effect on the σ_θ distribution in rotating wheel. In the wheel bursting experiment under two levels of the clamping pressure, there is brought the difference of 7% in bursting speed.