Cardan Coupling Startup Transmission for Agricultural Balers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Large and heavy flywheels in agricultural balers require significant energy to accelerate, often stalling older tractors due to their high inertia, and existing solutions like hydraulic systems are costly and complex.
Innovation Solution
A cardan coupling with a torque-limiter and switchable transmission means that allows partial transmission during startup and full transmission during running, enabling the flywheel to be driven by a tractor without stalling, using a gearbox or clutch with fluid cooling to manage torque and rotational speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a large and heavy flywheel is used to transmit high power, then the power transmission capability is improved, but the tractor stalls during startup due to high inertia
Solution Approach 1:
A cardan coupling is introduced as an intermediary component between the PTO and the flywheel. This cardan coupling allows angular misalignment and provides a mechanical advantage that reduces the startup torque requirement, enabling the tractor to rotate the heavy flywheel without stalling while still transmitting high power during operation.
Solution Approach 2:
The system changes the operational parameters by allowing the PTO to operate at higher rotational speeds during startup than during normal operation. The cardan coupling's geometry and the transmission means enable the PTO to reach a minimum operational speed quickly, then transition to full power transmission as the flywheel accelerates.
2Device complexity
If a direct connection is used between PTO and flywheel, then the device complexity is reduced, but the tractor stalls during startup
Solution Approach 1:
The cardan coupling serves as a minimal yet effective intermediary that prevents stalling while maintaining structural simplicity. It introduces only the necessary complexity to resolve the startup problem without adding excessive components.
Solution Approach 2:
The system transitions from a static direct connection to a dynamic cardan coupling that adapts its torque transmission characteristics during startup. The cardan coupling's angular movement and the transmission means enable smooth acceleration without stalling.
3Reliability
If a hydraulic system is used to rotate the flywheel, then the startup problem is solved, but the system becomes costly and complex
Solution Approach 1:
The patent replaces the proposed hydraulic system with a purely mechanical solution using a cardan coupling and transmission means. This mechanical approach solves the startup problem without introducing hydraulic components, reducing both cost and complexity while maintaining reliability.
4Power
If the PTO rotational speed is reduced to match the flywheel, then the power transmission is optimized, but the tractor stalls during startup
Solution Approach 1:
The system allows the PTO rotational speed parameter to vary during startup, operating at higher speeds initially to prevent stalling, then transitioning to optimized speeds for power transmission. The cardan coupling and transmission means enable this dynamic parameter adjustment.
Solution Approach 2:
The startup process involves periodic action where the PTO first accelerates to a minimum operational speed, then the transmission means engage to transfer power to the flywheel. This staged approach allows the system to transition from startup mode to power transmission mode without stalling.
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
An agricultural baler comprising a flywheel that is connected via a cardan coupling to a PTO of a tractor, the cardan coupling comprising a torque-limiter adapted for disengaging the flywheel from the PTO when a predetermined torque is exceeded, wherein the cardan coupling further comprises transmission means that are switchable between a startup state and a running state, in the startup state the transmission means being configured to only partially transmit rotational movement of the PTO to the flywheel while in the running state the transmission means being configured to fully transmit rotational movement of the PTO to the flywheel.