US 5,632,705 AGranted

Epicyclic roller gear including two rings having an internal profile and a rolling element capable of rolling on the inner side of the rings

AssigneeNeugart GmbH & Co.

InventorsVasile Ifrim, Annedore Ifrim

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Abstract

An epicyclic roller gear (100) has two rings (1 and 4) provided with an inner profile. One ring (1) is fixed and the other ring (4) is parallel or coaxial to the first ring (1) and is rotatably mounted with respect thereto. The number of teeth on the two rings is different. Both rings (1 and 4) have at least two parallel internal profiles (1.1, 1.2, 4.1 and 4.2) which are offset in the circumferential direction by a fraction of the pitch of the profile or teeth. When each ring has two mutually offset internal profiles, they are mutually offset by half the pitch of the teeth, so that in this case the gaps of the one tooth system are occupied by the teeth of the second, adjacent tooth system. This results in a high contact ratio with the corresponding complementary profiles of a rolling element, preferably a roller carrier (5) with rotatable rollers which roll in the gaps between the teeth of the internal profiles. Because the rings have a different number of teeth, there results a relative rotation during each revolution of the rolling element. By providing sections having a different number of teeth and/or teeth of different shapes in the circumferential direction, the output speed can be varied, and if required the output may even be stopped for a short time or its direction of rotation may be reversed. This in turn may be used to convert, through the gear (100), a reciprocal movement acting on such a ring into a rotary motion in a single direction (FIG. 2).

An epicyclic roller gear (100) comprising first and second rings (1, 4), each ring having an inner side with an internal profile having teeth, wherein the first ring (1) is fixed and the second ring (4) is coaxial to the first ring (1) and is rotatably mounted with respect thereto, the number of internal teeth on the first and second rings (1, 4) is different, at least one rotatable rolling element (5) which is capable of rolling on the toothed inner sides of the first and second rings (1, 4) and having alternate external gaps and projections which mesh with the internal profile of both rings, said rolling element (5) being engaged with the internal profiles of the rings, wherein the rolling element is rotatably mounted on an arm (5.1, 5.2) which is rotatable about an axis of the rings (1, 4) to drive the rolling element in a circumferential direction along the inner sides of the rings (1, 4) so that, based on the different numbers of teeth on the inner side of each of the two rings (1, 4), the rotatable ring (4) is movable relative to the fixed ring (1), characterized in that the internal profile on each of the two rings (1, 4) includes at least two internal tooth systems (1.1, 1.2;

4.1, 4.2) which are disposed parallel to each other and are offset in the circumferential direction by a fraction of the pitch of the teeth, wherein the internal tooth systems within each ring have the same profile and pitch, and the internal tooth systems of the two rings differ from one another, the alternate external gaps and projections of the rolling element including a plurality of axially adjacent external gaps and projections which are complementary to the internal tooth systems of the rings (1, 4), said complementary gaps and projections being mutually offset in the circumferential direction according to the offset of the internal tooth systems on the rings, each projection of the rolling element engages one internal tooth system of one of the first and second rings and is applied in a forward direction and an axially adjacent projection simultaneously engages the adjacent internal tooth system of the same ring and is applied in an opposite direction, and as the rolling element rolls this engagement of the axially adjacent projections thereof alternates continuously.

Abstract

Claims23