This drive consists of a pinion of helical teeth and a rack of straight teeth.

The rack is stationary. The green curve is locus of a point on pinion pitch circle (a space cycloid?).

Pinion: Helix angle B1 = 30 deg., left hand Rack: Helix angle B2 = 0 deg.

Angle between pinion axle and rack moving direction is L = 30 deg.