GB457646A - Improvement in stepwise change speed gears - Google Patents

Abstract

457,646. Change-speed gearing. JONSSON, G. E., Huddinge, Sweden. July 6, 1936, No. 18713. [Class 80 (ii)] A pair of speed-changing multi-disc friction clutches 12, 13 are arranged between the driven shaft 10 and the change-speed gear, which is of the kind having one-way roller clutches 9, 21, which permit overrunning in some of the lower speeds whilst higher speeds are driving. The gearing provides four speeds and reverse, one of which is an overdrive, either included in the gear itself (Fig. 1), or comprised in a separate three element epicyclic train 30, Fig. 2, arranged in front of the gear. In Fig. 1, a centrifugal friction clutch 3 provides automatic change from lowto second - speeds. Low - speed from the driving shaft 1 is by way of a common main friction disc-clutch 4, manually operated, and driving a sleeve 5, pinion 6, free - wheel countershaft pinion 7, return pair 20, 19, one-way clutch 21 and a sliding dog-clutch pinion 22, which, for reverse, can be engaged through an idler with a countershaft pinion 23. The main disc-clutch 4 also drives the centrifugal clutch 3 which latter, at a predetermined speed, begins to drive the countershaft through an inner shaft 5 and second-speed pair 17, 18, the one-way clutch 9 overrunning. The sliding dog-clutch reverse-pinion 22 is splined to a sleeve 24, which constitutes a forward extension of a clutch housing 11, which is integral with the driven shaft 10 and forms the common driven member of the multi-disc clutches 12, 13. In low- and second-speeds, the drive passes directly to the driven shaft from the final gearwheel 19, through the one-way clutch 21 and the sleeve and housing-assembly 24, 11. Engagement of the multi-disc clutch 12 clutches the driven shaft 10 directly to the inner driving shaft 2, producing direct-drive, with overrun in both one-way clutches 9, 21. Engagement of the multi-disc clutch 13 and disengagement of that 12, produces overdrive through the gear-pairs 17,18 and 16, 15, the driving members of the clutch 13 being splined to a loose sleeve 14, integral with the pinion 15. The detached overdrive form shown in Fig. 2, dispenses with the automatic centrifugal clutch 3, Fig. 1, and with the overdrive pair 15, 16, the second-speed pinion 17 being integral with the driving sleeve 14 of the multi-disc clutch 13, which is now used for bringing in second-speed. Direct-drive is through the multi-disc clutch 12, as before, the first pinion 6 being integral with the inner driving shaft 2b. The over-driving unit which drives the main gear provides a direct drive to the gear-driving shaft 2b, from the usual main-clutch 4, through a one-way roller clutch 35, and an overdrive by braking a loose sun-wheel 31, secured to a brake-drum 32. Planet-wheels 30 are carried by the main driving shaft 2a, the annulus 34 being integral with the inner driving shaft 2b of the following changespeed gear. The multi-disc clutches 12, 13 and the overdrive brake-band 33 are preferably engaged by oil-pressure developed by a pump on a cross-shaft 36, the clutch-means comprising pistons 25 and 26, the former acting directly on the clutch 12, the latter acting through rods 27 on the clutch 13. Oil reaches the pistons through a distributing-valve (not shown) and annular passages 37, 39.