Patent ID: 8771126
Filing Date: 2014-07-08
Classification: F16H

Abstract:
1. A traction drive mechanism comprising a first planetary roller mechanism and a second planetary roller mechanism that are connected in series, the first planetary roller mechanism including a plurality of first planetary rollers rotatably supported by a first carrier, the first planetary rollers being held in contact between a first sun roller and a first ring roller, the second planetary roller mechanism including a plurality of second planetary rollers rotatably supported by a second carrier, and the second planetary rollers being held in contact between a second sun roller and a second ring roller, wherein in which N 1 is the number of the first planetary rollers, N 2 is the number of the second planetary rollers, ρ 1 is the ratio between the inner diameter of the first ring roller and the outer diameter of the first sun roller, and ρ 2 is the ratio between the inner diameter of the second ring roller and the outer diameter of the second sun roller, and provided that N when a value of a smaller one of (0.204×(ρ 1 +1)×(ρ 2 +1)+3.123) and (7+4×3 0.5 ) is min[0.204×(ρ 1 +1)×(ρ 2 +1)+3.123, 7+4×3 0.5 ], or provided that N when a value of a smaller one of (0.185×(ρ 1 +1)×(ρ 2 +1)+1.320) and (7+4×3 0.5 ) is min[0.185×(ρ 1 +1)×(ρ 2 +1)+1.320, 7+4×3 0.5 ], or provided that N when a value of a smaller one of (0.234×(ρ provided that N when a value of a smaller one of (0.278×(ρ