| 摘要 |
<p>An automatic transmission (1) with five forward speeds comprises a main transmission unit (2) and an auxiliary transmission unit (5). The auxiliary transmission unit (5) comprises a first planetary gear (s3) and a second planetary gear (s4) which is located on the side of the rear casing. The ring gear (r3) of the first planetary gear (s3,25) is connected to the output element (23) of the main transmission unit (2), the carrier (cr3) is directly connected to the transmission output (12) and also to the sun gear (s3) via a multi-disc clutch (c3), which is located on the side of the rear casing. The hydraulic servo of the multidisc clutch (c3) is connected to an integral casing through a band brake (b4), arranged around the outer circumference of the servo. The ring gear (r4) of the second planetary gear (s4) is connected to the transmission output (12), the carrier (cr4) is connected to the integral casing through a multi-disc brake (b5), the sun gear (s4) is connected to the first sun gear (s3). The multi-disc brake (b5) and related hydraulic servo arranged on the rear casing side of the secondary planetary gear (s4). The rear casing forms part of the hydraulic servo for the multidisc brake. The auxiliary transmission unit (5) can be given a compact three-speed construction to establish five forward speeds while retaining a feasible mount on a vehicle, or it can be easily modified into a two-speed version by removing the second planetary gear (s4) and the brake (b5) for the 1st speed. This at a reasonable cost by making most of the component parts common. <IMAGE></p> |
