A seven-front, two-back, four-degree-of-freedom planetary transmission

Abstract

The invention discloses a planetary transmission with seven forward gears, two reverse gears and four degrees of freedom, and belongs to the technical field of transmissions. The planetary transmission comprises an input shaft, an output shaft, planetary rows, clutches and brakes. The four planetary rows are distributed in parallel. The input shaft is coaxially and fixedly connected with a first sun gear and a second sun gear. A first planetary carrier is fixedly connected with a second gear ring, the second gear ring is fixedly connected with a third sun gear, a second planetary carrier is fixedly connected with a fourth sun gear, and a fourth planetary carrier is fixedly connected with the output shaft. An outer hub of the first clutch is fixedly connected with a third gear ring, and aninner hub of the first clutch is fixedly connected with a fourth gear ring. An outer hub of the second clutch is fixedly connected with a third planetary carrier, and an inner hub of the second clutchis fixedly connected with the fourth sun gear. An outer hub of the third clutch is fixedly connected with a fourth gear ring, and an inner hub of the third clutch is fixedly connected with the thirdplanetary carrier. An inner hub of the first brake is fixedly connected with a first gear ring, and an inner hub of the second brake is fixedly connected with the third gear ring. An outer hub of thefirst brake and an outer hub of the second brake are fixed to a transmission shell. By the adoption of the planetary transmission, the number of control parts can be reduced, and the power is improved.

Description

technical field [0001] The invention belongs to the technical field of transmissions, and in particular relates to a seven-front, two-back, four-degree-of-freedom planetary transmission. Background technique [0002] The speed change mechanism of the automatic transmission changes the speed and torque output by the hydraulic torque converter, and outputs the changed speed and torque through the output shaft to meet actual needs. The more gears there are in the automatic transmission, the smoother the shift, and the better its power performance and fuel economy, so try to use a scheme that achieves more gears. [0003] Existing heavy-duty vehicles are mainly based on three-degree-of-freedom planetary transmissions. In order to realize multi-gear, at least five operating elements are required, and some transmissions even have six or seven operating elements. Most of the power loss of planetary transmissions is also caused by the operating elements. Power loss occurs. When th...

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Problems solved by technology

[0003] Existing heavy-duty vehicles are mainly based on three-degree-of-freedom planetary transmissions. In order to realize multi-gear, at least five operating elements are required, and some transmissions even have six or seven operating elements. Most of the power loss of planetary transmissions is also caused by the operating elements. power loss generation

When the planetary transmission uses five operating elements, two operating elements need to be engaged when the three degrees of freedom work, and the remaining three elements are opened, resulting in power loss

[0004] The realization of multi-degree-of-freedom planetary transmission gears is achieved by combining different operating parts. Too many operating parts will take up too much space, and when the operating parts are not combined, there will be belt row loss, so the more operating parts are not the better

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