Patent ID: 6743137
Filing Date: 2004-06-01
Classification: F16H

Abstract:
Eccentric gear for providing a speed difference between two machine elements (3, 4) which are rotatably mounted in relation to a reference member (2) and individually rotatable around a common geometrical symmetry axis (C), including a first pair of co-operating gear rims (6, 7), one of which is eccentric in relation to the symmetry axis (C) and one of which is in the form of a male-like gear rim (6) formed with out-turned teeth, and the other one is in the form of a female-like gear rim (7) which formed with in-turned teeth and has a larger diameter than the male gear rim (6) in order to enable engagement of only one or a few of the teeth of the male gear rim in the female gear rim, one of the gear rims being arranged to roll against the other one, and a second pair of mutually co-operating gear rims in the form of male and female gear rims (8, 9), one of which is rigidly connected to a homologous gear rim in the first pair of gear rims and situated along a geometric axis (X) being common for these two gear rims, which axis is eccentric in relation to the symmetry axis (C), while the other gear rim in the second pair of gear rims is rotatable in relation to the homologous gear rim thereof in the first pair of gear rims, the number of teeth in the individual male gear rim (6, 8) in each one of the two pairs of gear rims (6, 7; 8, 9) being smaller than the number of teeth in the co-operating female gear rim (7, 9), and wherein the teeth of the first and second pairs of gear rims are involute-shaped, the contact points between individual teeth extending helically along the gear rims.