| 摘要 |
A method of stepping up the speed of a rotary motion from a first speed, supplied to an input shaft (26), to a second speed delivered by an output shaft (28), comprises transmitting said rotary motion from said input shaft (26), via a drive gear (34) of said input shaft (26), the drive gear (34) being helical and having a first helix angle (?in), to a layshaft arrangement, so as to generate a first axial thrust (F1) of the input shaft (26) in a first axial direction; transmitting said rotary motion from said layshaft arrangement, via a driven gear (44) of said output shaft (28), said driven gear (44) being helical and having a second helix angle (?out) that is larger than said first helix angle (?in), to said output shaft (28), so as to generate a second axial thrust (F2) of the output shaft (28) in a second direction, said second direction being substantially opposite to said first direction; and applying said first axial thrust (F1) and said second axial thrust (F2) to the same location of an axially rigid support structure (50), such that said first and second axial thrusts (F1, F2) counter-act and at least partly cancel out in said support structure (50). |
