糸の流体潤滑について

第6報　潤滑中における油剤の粘度変化

抄録

The instant changes of the viscosity of the lubricant among the asperities have been studied.
1) When the change of viscosity of lubricant by increasing temperature is considered, the following formula is derived: where f_i: frictional force acting on the unit length of fibre or yarn η₀: apparent viscosity of lubricant U: sliding speed R_i: load acting on the unit length of fibre or yarn k₁, k₂, B: constants N: constant (frictional index) K: constant concerning the elastic property of asperity L: size of the unit asperity m: constant concerning η=η₀e^-mt (relation between viscosity and temperature) δ: density of lubricant c: specific heat of lubricant
On the tension of fibre or yarn sliding around a cylinder, the following formula is derived from the above formula: where T: final tension of fibre or yarn T₀: initial tension of fibre or yarn b_l, b₂: constants
As the above result is quite consistent with the experimental result, the decreasing viscosity of lubricant by increasing temperature has an influence on the frictional force.
2) When the change of viscosity of lubricant by increasing pressure is considered, the following formula is derived: where k₃: constant k: constant concerning μ=μ₀e^kp (relation between viscosity and pressure)
On the tension of fibre or yarn sliding around a cylinder, the following formula is derived from the above formula: where a_l, a₂: constants
Comparing the a_??_ove result with the experimental result, it seems that the effect of increased pressure on the frictional force is negligible.