| 摘要 |
A pitch change mechanism (100:200) for a bladed rotor comprises a driving sleeve (110:210), a drive shaft (102:202), a first pitch-changing element (130:230), a second pitch-changing element (150:250), and a plurality of blade drive gears (180). The driving sleeve (110:210) has, in axial sequence, a first helical connection portion (133:233) and a second helical connection portion (153:253). The driving sleeve (110:210) is positioned concentrically with and surrounding the drive shaft (102:202). The first pitch-changing element (130:230) has a first end (132:232) drivingly engaged with the first helical connection portion (133:233), and a first ring gear portion (140:240) at a second opposite end (138:238), while the second pitch-changing element (150:250) has a first end (152:252) drivingly engaged with the second helical connection portion (153:253), and a second ring gear portion (160:260) at a second opposite end (158:258). The plurality of blade drive gears (180) are arranged in a circumferential array around a longitudinal axis of the drive shaft (102:202). The first pitch-changing element (130:230) is positioned axially adjacent to the second pitch-changing element (150:250) with the first ring gear portion (140:240) facing the second ring gear portion (160:260). Each of the first and second pitch-changing elements (130:230,150:250) is positioned concentrically over the driving sleeve (110:210), such that axial movement of the driving sleeve (110:210) causes the first helical connection portion (133:233) to rotate the first pitch-changing element (130:230) in a first rotational direction (144), and simultaneously causes the second helical connection portion (153:253) to rotate the second pitch-changing element (150:250) in an opposite second rotational direction (164), with the contra-rotation of the first and second pitch-changing elements (130:230,150:250) causing a rotation of the plurality of blade drive gears (180) positioned between and meshingly coupled to each of the first ring gear portion (140:240) and the second ring gear portion (160:260). |
