PTO Driveline Eccentric Pump for Wet Clutch Cooling
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Solution Overview
Problem
The existing power take-off (PTO) drivelines for agricultural and industrial vehicles face challenges in providing a sufficient and efficient flow of cooling/lubricating fluid to wet clutches, leading to issues such as wear and overheating.
Innovation Solution
A PTO driveline with an eccentric formation on the input shaft that oscillates a pumping piston, creating a fluid circulation circuit including the wet clutch and a housing reservoir, utilizing a non-return valve arrangement to ensure fluid delivery and cut-off when the clutch is disengaged to reduce drag, along with a brake and free play device for limited rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a wet clutch is supplied with cooling/lubricating fluid from a reservoir, then wear of the clutch is reduced and overheating is prevented, but the complexity of the fluid supply system increases
Solution Approach 1:
The pump housing is integrated with the clutch housing to form a single unified component. This merging eliminates the need for separate pump and housing structures, reducing overall system complexity while maintaining the fluid circulation function for clutch cooling and lubrication.
Solution Approach 2:
The housing structure serves multiple functions simultaneously: it acts as the pump housing containing the pumping mechanism, the clutch housing providing structural support for the clutch assembly, and the fluid reservoir storing the cooling/lubricating fluid. This multi-functionality reduces the number of separate components needed.
2Reliability
If cooling/lubricating fluid is continuously supplied to the wet clutch, then the clutch is protected from wear and overheating, but drag increases when the clutch is disengaged
Solution Approach 1:
The fluid supply system transitions from a static continuous supply to a dynamic controlled supply. The pump is activated only when the clutch is engaged, and the control mechanism adjusts fluid flow based on clutch engagement status. This dynamic operation eliminates unnecessary fluid circulation and associated drag when the clutch is disengaged.
Solution Approach 2:
The control mechanism receives feedback from the clutch engagement state and adjusts fluid supply accordingly. When the clutch is engaged, the pump operates to supply cooling/lubricating fluid; when disengaged, the pump stops or reduces flow. This feedback-based control optimizes fluid supply to match actual clutch needs.
3Volume of moving object
If a compact fluid supply system is designed, then the driveline becomes more space-efficient, but the fluid flow capacity may be reduced
Solution Approach 1:
The pump mechanism is nested within the housing structure, with the pumping chamber formed inside the housing volume. The fluid reservoir is also integrated into the housing, creating a nested arrangement where multiple functional elements occupy overlapping or adjacent spaces. This nesting maximizes space utilization without compromising fluid flow capacity.
Solution Approach 2:
The system utilizes three-dimensional space efficiently by arranging components in multiple dimensions rather than linear sequences. The fluid circulation paths are routed through available volumetric space within the housing, and the pump mechanism is positioned to optimize fluid intake and discharge pathways in three-dimensional space, maintaining flow capacity despite compact dimensions.
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
This solution provides a compact, efficient, and economic fluid supply system that reduces wear and overheating, allowing for reliable operation and easy manual engagement/disengagement of the clutch while minimizing drag and facilitating implement attachment.
Implementation Method 1
a PTO wet clutch (12) which when engaged delivers power to a PTO output shaft (13), the driveline having an eccentric formation (34) on the input shaft (11) which oscillates a pumping piston (31) when the input shaft rotates
Implementation Method 2
The oscillating piston draws the fluid from the reservoir via a non-return valve arrangement
Data Source
Figure 1
Figure 1A
Figure 2
AI summary
A vehicle PTO driveline (10) in which a PTO input shaft (11) drives a PTO wet clutch (12) which when engaged drives a PTO output shaft (13). The driveline has an eccentric formation (34) on the input shaft which oscillates a pumping piston (31) when the input shaft rotates, which piston pumps cooling/lubricating fluid from a reservoir (25c) to the wet clutch. The piston is connected with the eccentric formation by a ring (33) which surrounds the eccentric formation and a hollow tube (32) which is attached to the ring and which carries the piston at a lower end, the piston oscillating inside a chamber (31a) when the input shaft rotates. The chamber is connected with the fluid reservoir and the oscillating piston pumps the fluid along the hollow tube into the ring which then delivers the fluid into internal passages (38) in the input shaft from where the fluid flows to the wet clutch.