Magnetic-Electric Tractor Transmission for Smooth Shifting Under Load
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Solution Overview
Problem
Agricultural towing vehicles face challenges with complex and inefficient transmission arrangements, particularly under high towing loads, as existing solutions like dual clutch transmissions and continuously variable transmissions are cumbersome and noisy, with high inertia and complexity.
Innovation Solution
A transmission arrangement combining an electrically power-split continuously variable transmission with a dual clutch transmission unit, featuring a magnetic-electric epicyclic gear stage with a rotatable modulation ring, allowing for efficient speed adjustment and reduced physical moments of inertia, enabling smoother shifting and improved controllability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a continuously variable transmission with power-split system and variable hydraulic path is used, then continuous speed variation is achieved, but the structural design becomes complex with high inertia and disruptive noise
Solution Approach 1:
The patent replaces the traditional mechanical continuously variable transmission with a magnetic-electric epicyclic gear stage. The magnetic-electric system uses electromagnetic fields instead of mechanical linkages to achieve continuous speed variation, eliminating the complex hydraulic paths and mechanical variators while maintaining the ability to continuously vary speed ratio.
Solution Approach 2:
The patent changes the operating parameters of the magnetic-electric epicyclic gear stage, specifically varying the excitation current to the electromagnetic coil to achieve continuous speed variation. This allows the transmission ratio to be adjusted continuously by changing the magnetic field strength rather than through mechanical reconfiguration.
2Adaptability or versatility
If the number of gear stages is increased by combining transmission devices and units, then the transmission range is extended, but the device complexity increases
Solution Approach 1:
The magnetic-electric epicyclic gear stage serves multiple functions simultaneously: it provides continuous speed variation, achieves reverse gear operation, and covers a wide transmission range all within a single integrated unit. This eliminates the need for separate transmission devices and multiple gear stages to achieve the same functionality.
Solution Approach 2:
The patent introduces dynamic control capabilities to the transmission system through the magnetic-electric system. The transmission ratio can be dynamically adjusted during operation without discrete gear changes, and the system can dynamically switch between forward and reverse operations, providing adaptability without increasing structural complexity.
3Reliability
If a dual clutch transmission is used, then shifting under load is enabled, but the inertia and noise increase
Solution Approach 1:
The patent replaces the dual clutch mechanical system with a magnetic-electric control system. The electromagnetic coil controls the engagement and disengagement of the epicyclic gear stage components through magnetic fields, eliminating the need for heavy clutch assemblies and reducing the overall moving mass and inertia of the transmission 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 solution simplifies the transmission arrangement, reduces complexity and noise, enhances shifting speed, and improves controllability, allowing for efficient operation under high loads without interruptions in tractive power, while minimizing weight and installation space.
Implementation Method 1
a magnetic modulation ring (62) between them. The modulation ring (62) is either rotationally fixedly connected to a clutch drive shaft (92) of the clutches (82, 84) or can be drive-connected. An electric motor (52) coupled to the input shaft (44) generates electrical power, which can be partially or fully transmitted to the stator (56) of the epicyclic gear stage (58). The stator (56) of the epicyclic gear stage (58) can be controlled to achieve rotation of the modulation ring (62).
Implementation Method 2
The electric motor (52) coupled to the input shaft (44) generates electrical power, which can be partially or fully transmitted to the stator (56) of the epicyclic gear stage (58). The stator (56) of the epicyclic gear stage (58) can be controlled to achieve rotation of the modulation ring (62).
Data Source
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AI summary
The invention relates to a transmission arrangement (30) for a drive train (20) of an agricultural tractor (10) comprising a transmission unit (40) and a transmission unit (80) downstream in the power flow. The transmission unit (40) includes a mechanical transmission branch (64) and a variable transmission branch (66) with a magnetic-electric planetary gear stage (58) comprising an inner rotor (60), an outer stator (56), and a rotatable magnetic modulation ring (62) between them. The modulation ring (62) is rotationally fixed to a clutch drive shaft (92) of the clutches (82, 84) or can be driven by a drive. Electrical power from an electric machine (52) coupled to the input shaft (44) can be transmitted to the stator (56) of the planetary gear stage (58). The stator (56) can be controlled to achieve rotation of the modulation ring (62).The invention further relates to an agricultural tractor (10) comprising such a transmission arrangement (30).