GB1451328A - Variable output mechanical transmission - Google Patents

Abstract

1451328 Toothed gearing; variable-speed gearing J H KERR 15 Aug 1973 [31 Aug 1972] 38563/73 Headings F2D and F2Q An infinitely variable transmission comprises two similar pairs of intermeshed, non-circular, spur wheels providing cyclic variations of velocity ratio, coaxial first wheels of each pair being interconnected by means including epicyclic gearing whereby the phase relationship of the wheels may be adjusted to alter the overall transmission ratio of the apparatus, the second wheels of each pair being associated with respective wheels of a bevel differential gear, and a planetary bevel pinion and carrier of the differential being associated with a shaft assembly having an overrunning clutch and a further spur wheel in mesh with a final spur wheel on a shaft coaxial with the first wheels. Limiting ranges are specified for various dimensional and functional characteristics of the non-circular gear pairs, and typical examples of such pairs are illustrated in Fig. 1. One embodiment of transmission has three pairs of non- circular wheels 3, 7; 22, 25 and 5, 9, Fig. 45, of which one wheel of each pair is driven by an input shaft 1. The number of teeth on control wheels 2, 24, 4 and pinions 29 carried by a cage 32 is such that the phase relationship of the wheels 3, 22, 5 may be varied by rotary adjustment of the cage on the shaft 1. The wheel 9 is fixed to one side wheel 10 of the bevel differential, the wheels 7, 25 are coupled by overrunning clutches 16, 27 with the other side wheel 8, and the planetary bevel pinion 13 is mounted on a carrier 11 coupled to an output shaft 21 by spur wheels 19, 20. The wheels 3, 22, 5 may drive four similar assemblies 7, 25, 9, 8, 10, 19 &c. equally spaced around the common axis of the shafts 1, 21. In a further embodiment the two wheels 5, 22, Fig. 48, drive a bevel wheel 10 through wheels 9, 25 and overrunning clutches 16, 27, and the wheel 3 drives a bevel wheel 8 through the wheel 7. Planetary bevel pinions 13, 62 are coupled with the shaft 63 through a bevel wheel 64, and with a non-circular spur wheel pair 66, 71 through a bevel wheel 65. The shaft 63 is coupled through overrunning clutches 87, 88 with two further non-circular spur wheel pairs 67, 70 and 68, 69, and the phase relationship between the wheels 69. 70, 71 is varied by rotary adjustment of a cage 78. The motion of the assembly of wheels 69, 70, 71 is compounded with the rotation of the input shaft 1 by epicyclic gearing 80, 81, 82, 83, 84. An idler gear 86 interconnects the planetary bevel pinion carrier with the carrier of at least one other similar bevel assembly. Further embodiments are described in which the coaxial input and output shafts, one rotatable within the other, project from one end of the apparatus, and are interconnected by epicyclic gearing, and in which adjustment of the control cage to alter the phase relationship of the non-circular wheels is effected by an electric motor (Figs. 50, 51, 53, not shown) or by centrifugal means responsive to input speed (Fig. 54, not shown). Another embodiment (Fig. 58, not shown) employs a friction brake arrangement to adjust the cage for controlling phase relationship. Fig. 59 shows an embodiment in which rotary adjustment of the cage 32 on the input shaft 1 alters the phase relationship between non- circular wheels 3, 3A keyed to the input shaft and other non-circular wheels 22, 5 and 5A keyed together, and 22A. The other wheels 7, 7A, paired with 3, 3A are keyed to bevel wheels 65, 8, and the other wheels 25, 9, 9A, 25A paired with 22, 5, 5A, 22A are connected through overrunning clutches with bevel wheels 10, 64. The carrier for the planetary bevel pinions 13, 62 is keyed to the shaft 12 which drives the output through spur wheels 19, 20.