Patent ID: 6338691
Filing Date: 2002-01-15
Classification: F16H,Y10T

Abstract:
A planetary gear transmission comprising:a cylindrical transmission housing having a longitudinal central axis, a first end and a second end; a planet gear carrier mounted for rotation within said transmission housing carrying a first set of rotatably mounted planet gears and a second set of rotatably mounted planet gears longitudinally spaced from said first set of planet gears toward said second end of said transmission housing; said planet gears of said first set each having a helical cut with a same sense and a same angle; said planet gears of said second set each having a helical cut with a same sense and a same angle opposite to the sense and the angle of the helical cut of said planet gears of said first set; a first cylindrical shaped ring gear disposed on said transmission housing and mounted for movement in a direction of said longitudinal central axis of said transmission housing and restrained from circumferential movement in a circumferential direction of said transmission housing; said first cylindrical shaped ring gear having a helical cut with a sense and an angle opposite to the sense and the angle of said helical cut of said planet gears of said first set; said planet gears of said first set engaging said first ring gear for rotation in said first ring gear upon rotation of said planet gear carrier; a second cylindrical shaped ring gear disposed on said transmission housing and mounted for movement in the direction of the longitudinal central axis of said transmission housing and restrained from circumferential movement in the circumferential direction of said transmission housing; said second cylindrical shaped ring gear having a helical cut with a sense and an angle opposite to the sense and the angle of the helical cut of said planet gears of said second set; said planet gears of said second set engaging said second ring gear for rotation in said second ring gear upon rotation of said planet gear carrier; a first ring gear member disposed between said first cylindrical shaped ring gear and said second cylindrical shaped ring gear for transmitting force in the direction of the longitudinal central axis of said transmission housing between said first cylindrical shaped ring gear and said second cylindrical shaped ring gear; a sun gear shaft mounted for rotation within said transmission housing, said sun gear shaft having an axis parallel to and coincident with said longitudinal central axis of said transmission housing; said sun gear shaft having a first end adjacent to the first end of said transmission housing and a second end adjacent to the second end of said transmission housing; a first sun gear mounted on said sun gear shaft restrained from axial movement on said sun gear shaft toward said first end of said sun gear shaft and further mounted on said sun gear shaft for transmission of rotational power between said first sun gear and said sun gear shaft; said first sun gear having a helical cut with a sense and an angle opposite to the sense and the angle of the helical cut of said planet gears of said first set; said first sun gear engaging said planet gears of said first set for transmitting rotational power between said first sun gear and said planet gears of said first set; a second sun gear mounted on said sun gear shaft restrained from axial movement on said sun gear shaft toward said second end of said sun gear shaft and further mounted on said sun gear shaft for transmission of rotational power between said second sun gear and said sun gear shaft; said second sun gear having a helical cut with a sense and angle opposite to the sense and the angle of the helical cut of said planet gears of said second set; said second sun gear engaging said planet gears of said second set for transmitting rotational power between said second sun gear and said planet gears of said second set; the respective helical cuts on said first cylindrical shaped ring gear and said second cylindrical shaped ring gear having senses and angles whereby rotation of said planet gears of said first set and said planet gears of said second set engaging respectively said first cylindrical shaped ring gear and said second cylindrical shaped ring gear establishes forces forcing said first cylindrical shaped ring gear and said second cylindrical shaped ring gear toward one another in the direction of the longitudinal central axis of said transmission housing.