GB436667A - Improvements in variable speed power transmission mechanism - Google Patents

Abstract

436,667. Variable-speed gearing. WHARTON, W., The Gables, Kendal, Westmorland. April 23, 1934, Nos. 12151/34 and 7161/35. [Class 80 (ii)] [See also Group XXIX] A variable-speed gear comprises two epicyclic trains having a common casing, one of which trains acts as an ordinary driving train, while the other has a variable fluid or friction coupling arranged between two of its elements to produce the reaction for the driving train. In the form shown in Fig. 1, the driving shaft 9 carries a sun-wheel 3 gearing with planets 5, which with integral stepped planets 5<1> are rotatable on spindles 12 in a rotatable casing 1. The planets 5<1> mesh with a sun 4 fixed on the driven shaft 10. The spindles 12 also loosely carry stepped planets 8, 8<1> which mesh respectively with a further sun-wheel 6 fixed on the driven shaft 10 and with a sun-wheel 7 fixed to a sleeve 11 connected to the driven shaft through the variable resistance coupling. There is a forward drive on the sun 4, and as the sleeve 11 tends to rotate faster than the shaft 10, a forward drive is transmitted through the coupling, reaction being obtained from the sun 6. In the form shown in Fig. 2, the driving shaft 21 carries a sun-wheel 70 gearing with planets 72 mounted on a carrier 74 connected through a reversing train 75, 76, 80 to the driven shaft 23. The annulus 71 engaging the planets 72 acts as a carrier for stepped planets 31, 31<1> respectively engaging a further sun-wheel 28 fixed on the driving shaft 21 and a sun-wheel 29 on a sleeve 30 carrying bevel planets 34 engaging a bevel wheel 35 on the driving shaft and a bevel 36 on a sleeve 37 carrying the vanes 38 of an adjustable hydraulic coupling whose casing 25 is secured to the driving shaft 21. Owing to the bevel gearing 34, 35, 36 the vanes 38 will, in the absence of fluid resistance, rotate relatively to the casing 25 at twice the relative velocity between the sleeve 30 and shaft 21. The vanes 38 of the coupling are pivoted on arms 39, Fig. 4, radiating from the sleeve 37 and are urged outwards towards the vanes 26 on the casing 25 by plungers 50 acting through links 51 and cranks 38<1>. The plungers 50 are forced outwardly by liquid pressure entering the cylinders 49 from a space 48, in which pressure is produced by pumps 40 operated by an eccentric 43 on the sleeve 30. The pumps 40 supply liquid to the space 48 through non-return valves 47. A roller freewheel clutch 53, 54, 55 has its inner member 55 connected through a sleeve 56 to the friction disc 59 of a friction clutch whose presser plate 60 may be disengaged by pivoted levers 62 operated by a sliding collar 67. When the clutch is engaged the reaction on the carrier 74 is taken through the freewheel clutch on to the gear casing. A fixed or variable interposed between the sun-wheel 29 and the hydraulic coupling. Specification 192,244, [Class 69 (ii)], is referred to in the first Provisional Specification.