Two-Stage Speed Increaser Arrangement And Gear Train For A Clockwork

A two-stage speed increaser arrangement comprising force transmission members having a first pitch surface (100A), a second pitch surface (100B), a third pitch surface (100a), and a fourth pitch surface (100b), wherein, in a first stage, the third pitch surface (100a) rolls along the first pitch surface (100A), and, in a second stage, the fourth pitch surface (100b) rolls along the second pitch surface (100B), such that the first pitch surface (100A) and the third pitch surface (100a) have a common first line segment (102A) and the second pitch surface (100B) and the fourth pitch surface (100b) have a common second line segment (102B), wherein both stages have at least one respective tooth contact region, arranged spaced apart with respect to the line segments (102A, 102B), along which the force transmission members of the first and second stages are engaged, and the first and second pitch surfaces (100A, 100B) have a fixed relative position at the first and second line segments (102A, 102B), and the third and fourth pitch surfaces (100a, 100b) also have a fixed relative position at the first and second line segments (102A, 102B),

• characterised in that
• considering an orthogonal coordinate system in a plane (104) perpendicular to the second line segment (102B), wherein an origin (T1) of the orthogonal coordinate system is a projection of the second line segment (102B) to the plane (104),
• and considering that the Y axis of the coordinate system is pointing in the direction of a projection point (T0) of a point (D) of the first line segment (102A) to the plane (104), the following Formula 1 is satisfied at all times for the arrangement, in a coordinate system defined for each point (D) of the first line segment (102A):
• x(((y′+d)x—x′y)(x2+y2−y)+d2xy)≥0, Formula 1
• wherein
• d is the distance of the projection point (T0) from the origin (T1),
• x and y are the coordinates of a projection point (K), as projected to the plane (104), of an arbitrary tooth contact point (P) within any tooth contact region of the first pitch surface (100A) and the third pitch surface (100a), and
• x′ and y′ are the coordinates of a projection point (K′), as projected to the plane (104), of an arbitrary tooth contact point (P′) within any tooth contact region of the second pitch surface (100B) and the fourth pitch surface (100b).