Torque Splitter Decouples CVT Pump Speed From Engine
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fluid pressure systems in continuously variable transmissions (CVTs) face inefficiencies due to the need for larger pumps at lower speeds and excess energy throttling at higher speeds, leading to unnecessary fluid pumping and energy losses.
Innovation Solution
A torque splitting device is used to connect the power source to both the pump and a variable load, allowing the pump to operate with torque proportional to the engine torque, decoupling velocity from pump operation, and an auxiliary pump provides offset pressure to maintain line pressure, minimizing unnecessary high-speed pumping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pump is sized to supply sufficient flow at lower input speeds, then the system can maintain adequate fluid supply across the full operating range, but the pump creates excess energy losses when operating at higher input speeds due to throttling and bypassing unneeded fluid
Solution Approach 1:
The pump's operating characteristics are made dynamic by coupling it to the torque splitting device, which allows the pump speed to vary independently from the power source speed. This enables the pump to operate at optimal speeds regardless of the power source's rotational speed, eliminating the need to size the pump for the worst-case scenario and reducing energy losses during high-speed operation.
Solution Approach 2:
The torque splitting device acts as an intermediary between the power source and the pump, decoupling their speed relationships. This mediator allows the pump to receive power at a speed appropriate for its flow requirements rather than being directly driven at the power source's varying speed, thereby eliminating excessive pumping and throttling losses.
2Device complexity
If a conventional pump is used that is always driven directly by the power source, then the system structure is simple, but the pump continues to operate at high speed even when not needed, causing unnecessary energy consumption
Solution Approach 1:
The system introduces dynamic control of pump operation through the torque splitting device, allowing the pump to be disengaged or operated at reduced speed when full power source speed is not required. This dynamic operation reduces energy consumption while the auxiliary pump provides a compact solution for maintaining minimum system pressure.
Solution Approach 2:
The pumping function is segmented into two independent pumps: a main pump driven by the torque splitting device for variable flow requirements, and an auxiliary pump for maintaining minimum pressure. This segmentation allows each pump to operate independently at optimal efficiency points, reducing total energy consumption.
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 configuration reduces energy consumption and minimizes pumping losses by ensuring the pump supplies only the required fluid flow, maintaining efficient operation across varying speeds and pressures.
Implementation Method 1
A pump for a supply fluid flow and/or pressure... The pump may provide fluid flow within the operating pressure range of the system
Data Source
AI summary
A product may include a power source, and a pump may be driven by the power source. A variable load may be driven by the power source and may be supplied with a fluid from the pump. A torque splitting device may have an input from the power source and may provide an output to each of the pump and the variable load.