摘要 |
A hydraulic-mechanical transmission for a heavy vehicle as shown in FIG. 5 includes a hydraulic variable-displacement pump (I) supplying fluid under pressure to two hydraulic, variable-displacement motors (II, III), controlled by valves (64, 65). It further includes a planetary gear (IV) enclosed in a casing (1) which can be driven by one of the motors (II) through a pinion (51) and an external ring gear (10). The second motor (III) can drive the casing (1) which latter is mounted direct on the motor shaft (40). A planet carrier (2) can be coupled to the casing (1) by a clutch (33) or is freely movable in the casing. A sun gear (31) is mounted on an output shaft (3), while the planet gears (20) engage with an internal gear (11) of the casing. Three speeds and torques are available by respectively driving the planetary gear by either motor or by both motors together and by alternately coupling the planet carrier to the casing or having it freely rotating by operation of the clutch.
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