| Budget Amount *help |
¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2000: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1999: ¥500,000 (Direct Cost: ¥500,000)
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| Research Abstract |
In this study, the effects of contact stress o_H, applied D.C.voltage V_0, maximum electric current I_0 applied to close circuit formed by metal to metal contact and surface roughness R_y, on electric current I between lubricated roller surfaces were investigated by measuring the electric current between lubricated roller surfaces under various o_H, V_0 and I_0. The effects of V_0, I_0 and R_y on the amount of wear and fatigue life were also determined by carrying out the two roller tests under various V_0 and I_0. Furthermore, the surface failure mode of rollers of different surface roughnesses under various V_0 was investigated.
The main results obtained from this investigation are summarized as follows.
(1) The electric current I between lubricated roller surfaces tends to increase with an increase of contact stress o_H irrespective of surface roughness R_y, applied voltage V_0 and maximum electric current I_0 applied to close circuit formed by metal to metal contact, but becomes almost constant for larger o_H values. The minimum o_H value at which the I value becomes almost constant decreases with increases of R_y, V_0 and I_0 values.
(2) The amounts of wear of rollers with different surface roughnesses are almost equal irrespective of V_0 value for V_0≦10V and I_0≦0.4A.For V_0>10V and I_0>0.4A, the amounts of wear tend to increase with increases of V_0 and I_0, but the rate of increase becomes smaller with an increase of R_y.
(3) Fatigue life N_c of rollers decreases with an increases of R_y irrespective of V_0. The N_c values are almost equal irrespective of R_y and V_0 for V_0≦10V.For V_0≧20V, the N_c values tend to decrease with an increase of V_0, but the effect of V_0 on N_c becomes smaller with an increase of R_y.
(4) The surface failure of rollers is pitting, in which the pits fan out to the rolling direction, irrespective of o_H, V_0 and I_0.
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