GB866582A - Improvements in and relating to change speed reversing gearing employing epicyclic gear trains - Google Patents

Abstract

866,582. Change-speed gear. SELF-CHANGING GEARS Ltd. June 19, 1959 [June 20, 1958], No. 19838/58. Class 80 (2). A change-speed and reverse. gear for a railcar or earth mover, providing three ratios in both forward and reverse directions, comprises a three-speed planet gear 40 in series behind an hydraulic torque converter or coupling 8 and a reverse planet gear 14, the planet trains being disposed around the output shaft 1 and controlled by selective engagement of friction brakes 29, 38, 51, 58 and a direct drive clutch 41. The reverse gear has two sun-ring planet trains in the first of which an input sun. 15 is driven through the torque converter 8 and a one-way clutch 20, whilst its planet-carrier 23 is connected to the ring 33 of the second train and to the drum of the reverse brake 29. The ring gear 17 of the first train and planet-carrier 27 of the second are fast with an intermediate output shaft 28 whilst the second sun 30 may be braked at 38. The first train acts alone on engagement of the brake 29 for reverse, and both trains are compounded on engagement of the brake 38 for reduced forward drive. The three-speed gear provides reduced, direct and overdrive ratios. The intermediate output shaft 28 of the preceding reverse gear forms the input member carrying the planets 43 of the front train, the sun 42 of which may be braked at 51 and is connected to the sun 53 of the rear train whilst the ring gear 45 of the front train and the planet carrier 54 of the rear are fast with the output shaft 1. Application of the brake 51 causes the front train to overdrive alone; applying the brake 58 to the ring gear 56 gives compounded reduced, whilst a clutch 41 between the ring gear 56 and output shaft 1 gives direct drive. The reverse brake 29 is of higher capacity than the other brakes and is of the overlap-type described in Specification 805,597. The direct drive clutch 41 is operated by fluidpressure at 68 acting through a crank 66 and thrust bearing 65 on the presser plate 62. A lubrication system, Fig. 2 (not shown), comprises a pump which draws oil from the sump and supplies it to the torque converter under pressure. The outflow from the converter passes through a filter, pressure control valve and heat-exchanger to the duct 79 (Fig. 1), to lubricate the gearing, a pressure relief valve 84 being provided.