GB829052A - Improvements relating to change-speed gear clutch devices - Google Patents

Abstract

829,052. Friction clutches. DAIMLERBENZ A.G. Jan. 6, 1958 [Jan. 17, 1957], No. 497/58. Class 80 (2). Gears 3, 4 are selectively clutched to a shaft 5 by sliding a selector sleeve 6 either left or right from the position shown so that torque-responsive cam means 10, 11 between the hub and the shaft tend to force friction surfaces 12 in the sleeve into engagement with truncated cone friction surfaces 13 on synchronizing rings 14 axially slidable upon the hubs of the gears, cam means 18, 19 between each ring 14 and its associated gear urging the ring against the selector sleeve and baulking completion of clutch engagement until the speeds of rotations of the surfaces 12, 13 have been synchronized. The cam surfaces 10, 11, Fig. 3, are provided on teeth 8 projecting inwards and outwards from the sleeve 6 and the shaft hub. The surfaces 10 are inclined slightly to the normal through the shaft axis, and the surfaces 11 are more steeply inclined. The cam surfaces 18, 19 between the synchronizing rings 14 and the associated gears 3, 4 may be of the sinusoidal curve type, as shown in Fig. 2, and springs 16 bias the rings to their centre positions. On initiating clutch engagement by movement of the selector sleeve 6, axially parallel surfaces 9 on the teeth 8 between the sleeve and shaft hub, which are engaged in the neutral position shown, are slidden out of engagement, and the slightly inclined cam surfaces 10 engage, to obtain torque assisted axial movement of the sleeve. When one of the pairs of friction surfaces 12, 13 engage, the co-operating synchronizing ring 14 has been biased by its spring 16 to the position shown, with the proud portions of the cam surfaces 18, 19 just engaged. Transmission of torque through these cam surfaces 18, 19 opposes axial movement of the synchronizing ring 14 away from the position shown until the speeds of rotation of the sleeve and the gear have been synchronized, when the cam surfaces 18, 19 slide into full engagement with the proud portions of one lying in the dwell points of the other. The axial engaging movement of the sleeve 6 is then completed, and the more sharply inclined cam surfaces 11 on the teeth 8, 9 give an increased torque assisted axial bias to the sleeve 6 for complete clutch engagement. A ball detent 25 retains the clutch sleeve 6 in the engaged position when the torque transmitted is reduced. Wipers 21 in skewed slots 20 in the synchronizing rings 14 scrape away oil from the friction clutch surfaces 12 of the selector sleeve 6 when the associated clutch is disengaged.