| 摘要 |
<p>A gear change device for a motor vehicle comprises a first and a second primary shaft (1A, 1B) coaxial with respect to each other, selectively connectable to the driving shaft of the motor vehicle by means of a double clutch engagement device, and a first and a second secondary shaft (2A, 2B), whose axes are parallel and spaced from the common axis of said primary shafts, and having respective output pinions (u', u") intended to mesh with the gear wheel of a differential. The gear change device further comprises a plurality of gear selector devices (S 17, S26, S34, S4R) for rotatably coupling each of said freely rotatable gear wheels (I, II, III, IV, V, VI, VII, R') with the shaft (2A, 2B) on which it is mounted, as well as at least one rotatable actuator drum, for controlling said selector devices, having a plurality of cam tracks. The selector devices include respective fork-like actuator members (F 1/7 , F 3/5 ; G 4/R , G 2/6 ) slidably mounted in a direction parallel to the axes of the primary and secondary shafts (1A, 1B, 2A, 2B) and each having a cam follower element (p 1 , p 2 , q 1 , q 2 ) engaged in a respective cam track of the respective actuator drum (T F , T G ). Each pair of cam tracks adjacent to each other provided on an actuator drum controls fork-like actuator members which are associated to different secondary shafts and which have the cam follower elements thereof engaged on said drum in positions angularly spaced with respect to each other. Each of said fork-like actuator members (F 1/7 , F 3/5 ; G 4/R , G 2/6 ) has an extended body with a fork-shaped end and the opposite end carrying the respective cam follower element (p 1 , p 2 , q 1 , q 2 ). The body of each fork-like actuator member ( F 1/7 , F 3/5 ; G 4/R , G 2 , 6 ) is slidably mounted on a pair of guide rods (301, 302) spaced from each other and parallel to the axes of said primary and secondary shafts (1A, 1B, 2A, 2B). There are provided two pairs of cam tracks (f 1 , f 2; g 1 , g 2 ) and two pairs of fork-like actuator members ( F 1/7 , F 3/5 ; G 4/R , G 2/6 ) respectively associated to the two secondary shafts (2A, 2B), the two actuator members associated to the same secondary shaft being slidably mounted on the same pair of guide rods (301, 302).</p> |
