| 摘要 |
<p>1537345 Axle drive assemblies EATON Ltd 10 Aug 1976 [11 Aug 1975] 33251/76 Heading B7H A drive system for a vehicle having at least three driven axles includes means for driving all axles at low speed and for disconnecting drive from at least one axle at higher speed. In a vehicle having three rear drive axles (R1-R3, Fis. 1, not shown) the foremost axle includes an assembly 11 which allows that axle to be disconnected from the engine. The assembly is connected at 19 to a main drive shaft (M1, Fig. 1) and transfers drive via shaft 15, 17 and coupling 25 to a further axle assembly on the second axle which is in turn connected to the third axle. A toothed gear 33 is rotatably mounted on shaft 15 and meshes with a pinion 39 which drives the differential 51 of the foremost axle. A clutch member 67 rotationally fast with shaft 15 is axially movable to engage the gear 33 so allowing the foremost axle to be driven. Movement of the clutch member may be affected manually or automatically. The second axle assembly includes a torque divider so that the second and third axles are driven by the output from the foremost axle. Apparatus for engaging the clutch member 67 and gear 33 automatically includes a magnetic sensor (101, Fig. 3, not shown) for detecting the speed of rotation of gear 33 and hence the vehicle speed, a circuit for comparing the sensor signals with a reference value, a time delay circuit for preventing rapid engagement and disengagement of the clutch member, and a pneumatically actuated shifting fork controlled by a solenoid valve. The apparatus operates to engage the foremost axle when the vehicle speed is below a pre-determined value and to disengage the axle drive when the speed exceeds this value. The drive disengagement facility may be fitted to the second axle. One of the axles may be arranged to be lifted from ground contact when desired, the axle being lifted by springs and returned by an inflatable cushion.</p> |
