| 摘要 |
1509374 Clutch combinations; differential gear GKN TRANSMISSIONS Ltd 27 May 1975 [28 May 1974] 23526/74 Headings F2C F2D and F2W A cone friction clutch 31, 32 in parallel with a multiplate viscous shear coupling 25 is engaged by an increase of pressure within the liquid in the coupling. The viscous shear coupling has interleaved plates 10, 11 in an enclosure 25 filled with liquid to an extent such that the pressure therein rises rapidly as the temperature exceeds a predetermined value (e.g. 100‹ C.). The temperature rise is caused by prolonged slip in the coupling. The plates 10, 11 which may be perforated, are splined at 22, 23 to relatively rotatable cylinders 13, 14. The clutch cones 31, 32 are integral with plates 27, 33 respectively splined to the cylinders 13, 14. The plate 27 is urged away from the plate 33 by a spring ring 42 and is acted upon the the liquid pressure within the coupling 25. When the pressure in the coupling 25 increases beyond a predetermined value the plate 27 moves left against the bias of the spring 42 to engage its conical surface 31 with the coned surface of the plate 33. The viscous liquid may have a viscosity between 5000 and 100,000 centistokes and preferably between 30,000, 60,000 centistokes at 25‹ C. and zero shear rate. The coupling is filled to the desired extent by completely filling the coupling and then heating to the predetermined temperature to expel a quantity of liquid from the coupling prior to replacing a filling plug 18. One or both sets of plates 10, 11 of the coupling may be axially movable and one of the sets of plates may be lined with friction material. Differential gear.-An interaxle differential gear (131) Fig. 3 (not shown) of a four wheel drive vehicle comprises an input shaft (52) fast with a planet carrier (49) carrying planet pinions which mesh with a ring gear (50) and a sun gear (51) respectively connected directly to a first output shaft (132) and through a sleeve (57) and chain-and-sprocket gear (56) to a second output shaft (135). The sleeve (57) and ring gear (50) are interconnected by a viscous shear coupling and parallel friction clutch of the type described above to limit relative rotation between the output shafts (132, 135). |
