| 摘要 |
<p>EP--93044 A The differential drive has a rotatable driving shaft (12), a coaxial driven shaft (16) and a speed reducing drive (64,22). This has gears (64) rotatable with the drive and driven shafts to produce a reduced speed coupling. A clutch (22) controls the drive, shiftable from a first condition engaging the shafts for rotation together, to a second condition driving the driven section through the gear to drive the latter at reduced speed. - The gear transmission can be a planetary gear set and the clutch can have an electromagnetic actuator (46) to shift the clutch. (1/2) USAB- US4484495 A The differential drive mechanism includes a driving member and a driven member. A planetary gearset drivingly connects the driving member and driven member to drive the driven member at a speed lower than that of the driven member when the electromagnetic actuator is energised. When the electromagnetic actuator is not energised, a clutching member engages the driven member to cause the latter to be driven at the same speed as that of the driving member. - The electromagnetic actuator includes a coil which is wrapped around the driving member and is connected to appropriate engine speed and/or acceleration sensors. The coil is enclosed within a housing which includes a projecting portion that is slidably received in an aperture defined within an armature. Because of the sliding engagement of the armature on the projecting portion, the armature is able to slide toward and away from the coil, but is restrained against rotation relative to it. The armature is provided with friction material which is adapted to engage the engagement face when the armature is moved toward the coil.</p> |
