Transmission Power Take-Off Lubrication Valve Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Increased power output in vehicle transmissions leads to higher temperatures in the power take off unit, causing a deficiency in lubrication and cooling for the main gearbox due to the inability to exclusively control the lubrication circulation system for the power take off unit.
Innovation Solution
A pneumatically or electrically controlled engagement mechanism with a valve member that blocks the lubricant inlet to the power take off unit when disengaged, allowing for an on/off-function and preventing lubricant flow, thereby ensuring efficient lubrication and cooling for the main gearbox.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If more lubricant is derived to the power take off unit for cooling and lubrication, then the power take off unit can handle increased power output, but the lubrication and cooling of the main gearbox becomes deficient
Solution Approach 1:
The lubrication circulation system is made dynamically controllable through a control valve that responds to engagement signals. When the power take off unit is engaged, the valve opens to allow lubricant flow; when disengaged, the valve closes to prevent flow. This dynamic control resolves the contradiction by ensuring lubricant is directed to the power take off unit only when needed, maintaining main gearbox lubrication reliability while enabling increased power output capability.
2Reliability
If the lubrication circulation system runs continuously for the power take off unit, then cooling and lubrication is always available, but energy is wasted pumping lubricant to unused components
Solution Approach 1:
The lubrication circulation to the power take off unit is made periodic rather than continuous. The control valve opens the lubricant inlet only during periods when the power take off unit is engaged and closes it when disengaged. This periodic action eliminates energy waste associated with pumping lubricant to inactive components while maintaining reliable cooling and lubrication during operational periods.
3Ease of operation
If a separate control system for the lubrication circulation system is added to the power take off unit, then lubrication can be controlled exclusively for the power take off unit, but the device complexity increases
Solution Approach 1:
The control valve is integrated into the existing engagement mechanism of the power take off unit. The same actuator that controls engagement also controls the lubricant inlet valve, merging two control functions into a single system. This eliminates the need for separate control components while providing exclusive control capability for the power take off unit's lubrication circulation.
Data Source
Figure 1a~1b
Figure 2a~2b
AI summary
Transmission (1) comprising a main gearbox (2) and a power take off unit (3), wherein the power take off unit (3) can be engaged with, respectively disengaged from, the main gearbox (2) through an engagement mechanism (4) having at least a first position engaging the main gearbox (2) and the power take off unit (3) and a second position disengaging the power take off unit (3) from the main gearbox (2), wherein the power take off unit (3) is provided with at least one lubricant inlet (5). The transmission (1) is characterised in, that said engagement mechanism (4) comprises a valve member (6), whereby when said engagement mechanism (4) is positioned in its second position, the valve member (6) is blocking said lubricant inlet (5), and thereby preventing lubricant to flow through the lubricant inlet (5) into the power take off unit (3), whereby when said engagement mechanism (4) is positioned in its first position, the lubricant inlet (5) is open and lubricant can flow through the lubricant inlet (5) into the power take off unit (3).