Clutch Lubrication Control for Forward-Reverse Shift Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional hydraulic transmission systems for work vehicles face issues with excessive lubrication of the forward-backward switching clutch, leading to malfunctions due to drag or slip, as it is always lubricated like other clutches, despite having high sensitivity and low usage frequency.
Innovation Solution
A system that includes a forward-backward switching clutch connected to a first transmission hydraulic line, main transmission clutches connected in parallel, and auxiliary transmission clutches connected to a second transmission hydraulic line, with a lubricating oil supply portion that intermittently supplies oil to the forward-backward switching clutch only when operated, using solenoid-driven control valves and a clutch lubrication valve unit to regulate oil flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the forward-backward switching clutch is always lubricated like other clutches, then wear prevention and cooling are achieved, but excessive lubrication causes malfunction due to drag or slip and adversely affects clutch performance
Solution Approach 1:
The lubrication system for the forward-backward switching clutch is made dynamic by controlling the lubrication valve to supply lubricant only during clutch engagement periods. This dynamic control allows the system to provide necessary lubrication when needed while avoiding excessive lubrication that causes drag or slip, thereby resolving the contradiction between wear prevention and performance maintenance.
Solution Approach 2:
The system changes the lubrication parameter (lubricant flow rate) based on the operational state of the clutch. By detecting whether the clutch is engaged or disengaged and adjusting the lubrication accordingly, the system optimizes lubrication levels to prevent wear during engagement while avoiding the harmful effects of excessive lubrication, thus improving reliability without generating drag or slip.
2Device complexity
If a single lubrication circuit is used for all clutches, then system complexity is reduced, but the forward-backward switching clutch receives excessive lubrication due to its low usage frequency and high sensitivity
Solution Approach 1:
The lubrication circuit is segmented into two separate circuits: one for the forward-backward switching clutch and another for the other clutches. This segmentation allows independent control of lubrication for each clutch type, enabling the system to provide appropriate lubrication levels tailored to each clutch's specific requirements without increasing overall system complexity significantly.
Solution Approach 2:
The system applies different lubrication qualities to different clutches based on their specific needs. The forward-backward switching clutch receives intermittent lubrication controlled by a lubrication valve during engagement periods, while other clutches receive continuous lubrication. This local differentiation in lubrication quality resolves the contradiction between system simplicity and performance optimization.
3Ease of operation
If intermittent lubrication is applied to the forward-backward switching clutch, then clutch performance and sensitivity are improved, but wear prevention may be insufficient compared to continuous lubrication
Solution Approach 1:
The lubrication valve is activated in advance before clutch engagement to ensure lubricant is supplied to the friction surfaces just before contact occurs. This preliminary action ensures that the friction surfaces are properly lubricated for wear prevention while the lubrication is discontinued after engagement to avoid excessive lubrication that would affect operation sensitivity, thus resolving both concerns.
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
Prevents malfunctions and maintains clutch performance by ensuring appropriate lubrication and cooling of the forward-backward switching clutch, while continuously lubricating and cooling the main and auxiliary transmission clutches, thus addressing the issue of excessive lubrication and improving operational sensitivity and longevity.
Implementation Method 1
The plurality of clutches may include a forward-backward switching clutch configured to determining a rotation direction of a driving force
Implementation Method 2
appropriate lubricating for wear prevention, cooling, and so on is required
Implementation Method 3
a method of using a hydraulic pressure for vehicle shifting, i.e., a method of using a hydraulic transmission
Implementation Method 4
maintaining a clutch performance appropriately by absorbing a frictional heat
Data Source
AI summary
Proposed is a system for operating and lubricating a clutch of a work vehicle. The system includes a forward-backward switching clutch portion connected to a first transmission hydraulic line, a main transmission clutch portion connected to the first transmission hydraulic line so as to be disposed in parallel with the forward-backward switching clutch portion, an auxiliary transmission clutch portion connected to a second transmission hydraulic line disposed in parallel with the first transmission hydraulic line, and a lubricating oil supply portion configured to supply oil as a lubricant to each clutch friction element. The lubricating oil supply portion includes a clutch lubrication valve unit, and is configured to always allow oil supply to the clutch friction elements of each of the main transmission clutch portion and the auxiliary transmission clutch portion, and is configured to intermittently allow oil supply to the clutch friction element of the forward-backward switching clutch portion.