Transmission Clutch Unit with Planetary Gear Reverse Lock
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Solution Overview
Problem
Agricultural work vehicle transmission systems require a complex double-clutch arrangement with four friction clutches for reversing and preselection, which increases installation space and costs, while some applications do not need prolonged reverse operation without traction interruption, necessitating a simpler and cost-effective solution.
Innovation Solution
A transmission-clutch unit with only three clutches, featuring a modular design with concentric output shafts and a planetary gear system that allows for compact structure and direct reverse drive, using a reverse clutch to lock the ring gear, enabling constant reversing without traction interruption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a double-clutch arrangement with four friction clutches is used for reversing and preselection, then the functionality of constant reversing without traction interruption is achieved, but the installation space and costs increase
Solution Approach 1:
The patent extracts the preselection function from the clutch arrangement and implements it through a reversible planetary gear unit with a reverse clutch. This separates the reversing function (handled by the reverse clutch) from the preselection function (handled by the planetary gear mechanism), allowing the system to achieve constant reversing without requiring four friction clutches. The extraction of the preselection mechanism reduces the number of clutches needed while maintaining the same operational capability.
Solution Approach 2:
The reversible planetary gear unit serves multiple functions: it provides reversing capability, enables preselection of gear stages, and allows for constant reversing operations. By making the planetary gear unit multi-functional, the patent eliminates the need for separate dedicated components for each function, thereby reducing the overall number of clutches from four to three or fewer, while maintaining installation space efficiency and operational performance.
2Device complexity
If a reversible planetary gear unit is used for reversing, then installation space is reduced, but the complexity of controlling the planetary gear stages increases
Solution Approach 1:
The patent implements preselection of gear stages through the reversible planetary gear unit before actual gear changing occurs. The planetary gear stages are prepared in advance, allowing smooth transitions without interruption of traction. This preliminary action simplifies the control sequence by pre-positioning the gear stages, making the overall control process more manageable despite the mechanical complexity of the planetary gear mechanism.
Solution Approach 2:
The reversible planetary gear unit acts as an intermediary mechanism between the clutch arrangement and the final drive. It mediates the power flow and gear stage transitions, providing a buffer that simplifies the control of the overall system. The planetary gear unit absorbs some of the control complexity by providing inherent mechanical advantages in stage transitions, reducing the burden on the clutch control system.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The three-clutch system reduces installation space and costs while maintaining the functionality of constant reversing, ensuring smooth shifting behavior and equal vehicle speed in both directions, even with different gear ratios, by adjusting input speed through engine power compensation.
Implementation Method 1
a reverse clutch (32), for locking the ring gear (30) against rotation in relation to a fixed housing (34) of the transmission-coupling unit (10), for reversing drive connection of the input shaft (12) with the second output shaft (18)
Implementation Method 2
a planetary gear train (26) with a ring gear (30) and a planetary gear carrier (28), the ring gear (30) being able to be locked against rotation
Data Source
AI summary
The invention relates to a gearbox-clutch unit (10), comprising: an input shaft (12) for driving the gearbox-clutch unit (10); a first and a second output shaft (16, 18) which are connectable for driving to a gearbox unit downstream in terms of force flow; a first and a second clutch (20, 22) with a common clutch driving element (24), wherein, as needed, the first output shaft (16) is drivingly connectable via the first clutch (20) to the input shaft (12), and the second output shaft (18) is drivingly connectable thereto via the second clutch (22); and a planetary gear unit (26) with a ring gear (30) and a planet carrier (28). The ring gear (30) is lockable against rotation with respect to a stationary housing (34) of the gearbox-clutch unit (10) via a reverse clutch (32) for a reversing driving connection of the input shaft (12) to the second output shaft (18).