Planetary-type of gear and procedure and apparatus for its production

Claim 1

A gear having a housing (2, 5, 10, 21), an input main shaft (9) and an output mean shaft (1, 22), which main shafts are coaxially mounted in the housing with respect to each other, a toothed path (18) fixedly connected with and coaxial with said input main shaft and having a diametrical pitch (D A ), a toothed path (4) fixedly connected with and coaxial with said output main shaft and having a diametrical pitch (D B ), said housing having a toothed path (3) in the form of a gear ring with internal teeth which is fixedly connected to the housing and coaxial with said main shafts and has a diametrical pitch (D H ), and there being mounted on one (9) of said main shafts a sun wheel which carries the toothed path (18) of said input main shaft and around the circumference of which two or more planet wheels (6) are evenly distributed, which have a first toothed path (19) having a diametrical pitch (D P1 ) which meshes with the toothed path (18) of said input main shaft (9) and with the toothed path (3) of the housing, and a second toothed path (20) having a diametrical pitch (D P2 ) coaxial with said first toothed path (19) and axially offset with respect thereto and having a different pitch diameter and a different number of gear teeth than said first toothed path, said second toothed path (20) being integral with said first toothed path and meshing with the toothed path (4) of the output main shaft, both toothed paths (19, 20) of each planet wheel (6) having a predetermined peripheral angular offset with respect to each other, said angular offset being dependent both on the relative angles of the planet wheels (6) at the center of the gear, and on the number of teeth pitch diameters of all the toothed paths (3, 4, 18, 19, 20), the planet wheels (6) being placed in a predetermined rotational position with respect to each other in mesh with the toothed paths (4, 18) of the main shafts (9, 1, 22) and with the toothed path (3) of the housing (2, 5, 10, 21), the toothed path (18) of said input main shaft having a first number of gear teeth; the second toothed path (20) of said planet wheels having a second number of gear teeth, the second number being larger than the first number; the first toothed path (19) of said planet wheels having a third number of gear teeth, the third number being larger than the second number; the toothed path (4) of the output main shaft having a fourth number of gear teeth, the fourth number being larger than the third number; and the toothed path (3) of the housing having a fifth number of gear teeth, the fifth number being larger than the fourth number, the relationship between said gear teeth being such that the gear provides a large reduction of the r.p.m. of said input main shaft, and being such that, the ratio of the r.p.m. of the input main shaft (N A ) to the r.p.m. of the output main shaft (N B ) is determined by the formula: ##EQU2##