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Abstract: The
instantaneous thermal elastohydrodynamic lubrication (EHL) of the mesh
of a pair of helical gears is simulated by the pseudo-steady state
thermal EHL of two tapered rollers in opposite orientation
approximately. The behavior of pseudo-steady state thermal EHL is
investigated by multilevel method and sequential sweeping method. It is
found from the numerical results that, firstly, pressure, film
thickness, temperature of the film and gears surfaces are different at
different positions on the meshing line of the helical gears, especially
the distribution of temperature. The lowest temperature rise is nearly
zero, however the highest can exceed 100 K in the con-tact area. That is
because that the distributions of pressure and film thickness depend
strongly on the distribution of the equivalent radius in the direction
of the roller length, and the distribution of temperature depends
strongly on the local slide/roll ratio in the direction of the roller
length. Secondly, the high pressures and temperatures in the ends can be
decreased by the end modifications, but the pressure and temperature
there are still higher than those in the middle, and the film
thick-nesses there are smaller than that in the middle. The place in
which the pressure and temperature is high and the film is thin is
corresponding to the place where pitting and scoring are most likely to
occur.
Key words: Helical gears
Thermal elastohydrodynamic lubrication
Tapered rollers
Opposite orientation
Pseudo-steady state
CLC No: TH117.22
山东省自然科学基金(Z2003F01)和青岛市科技发展基金(04-2JZ-112)资助项目. Received 20051215, received in revised form 20060625
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