GB636163A - Gearing for the transmission of rotary motion - Google Patents

Abstract

636,163. Cam gearing for transmitting rotary motion; differential gearing. NICHOLLS, K. H. March 2, 1946, No. 20284/48. Divided out of 636,109. [Classes 80 (ii) and 80 (iii)] In cam gearing in which positive rotary motion is transmitted between three relatively rotable members, two of which are formed with opposed cam surfaces adapted upon relative rotation to oscillate one or more connecting members, such as balls or rollers, freely mounted in the other member and engaging the said cam surfaces, the two cam members are provided with a first pair of axially opposed cam surfaces to provide a primary track of wave form for one set of connecting members and a second pair of cam surfaces to define a secondary track for a second set of connecting members which is out of phase with the primary track, and these cam surfaces are all formed as surfaces of revolution or parts of such surfaces. As shown two sets of balls 27, 126 carried by a supporting member 25 engage respectively with pairs of cam surfaces 24b, 23a and 24a, 23a on cam members 24 and 23. These cam surfaces are formed as ordinary slant surfaces and a single surface 23a on member 23 serves for both primary and secondary surfaces, whilst the surfaces 24a and 24b are out of phase. By holding one of the three members 23, 24, 25 rotary motion may be transmitted between the other two at a reduced or increased speed or the gearing may be used as a differential having two input members and one output or vice versa. The cam surfaces may be grooved or hollow, or of conical form about axes inclined to the axis of the gear, or of parts of internal and external cylindrical surfaces about axes at right angles to the gear axis, and the connecting members may take the form of push rods or slides or rollers of plain, conical, or barrel shape. Two or more of such gear units may be coupled together and the various members adapted to be locked or freed to provide different ratios of transmission or they may be used as a succession of differentials for adding or subtracting a number of different and varying quantities.