Variable Torque Constant Actuator for Vehicle Transmission
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Solution Overview
Problem
Existing electrical actuators for vehicle transmission systems face challenges in reducing holding current while maintaining quick transition capabilities, requiring contradictory design elements that result in complexity and cost.
Innovation Solution
An electrical actuator with a static converter and control system that allows the torque constant to assume different values, enabling a single physical architecture to operate in multiple modes by modifying commutation cell control, reducing electromagnetic torque and current consumption through a fixed reduction ratio and variable torque constant settings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the motor is dimensioned for high holding torque (high constant K), then holding current is reduced, but transition speed decreases
Solution Approach 1:
The patent applies dynamics by making the torque constant K variable rather than fixed. The control system dynamically adjusts K between a first value (higher) for holding operations and a second value (lower) for transition operations. This allows the motor to optimize performance for each operational phase: using higher K to reduce holding current and lower K to increase transition speed, thereby resolving the contradiction between energy efficiency and speed performance.
Solution Approach 2:
The patent changes the parameter K (torque constant) based on operational requirements. By controlling the electrical machine to operate with different torque constant values - a first value during holding and a second value during transitions - the system adapts its electromagnetic characteristics to match the desired performance outcome, simultaneously achieving low holding current and fast transitions.
2Speed
If the motor is dimensioned for high transition speed (low constant K), then response time improves, but holding current increases
Solution Approach 1:
The system dynamically switches the torque constant K based on the operational phase. During transitions, a lower K value enables higher speeds and faster response. During holding, a higher K value reduces the current required to maintain position. This dynamic adaptation resolves the contradiction by allowing the motor to be optimized for speed when needed and for energy efficiency when holding.
Solution Approach 2:
The control system modifies the torque constant parameter K according to the operational state. By setting K to a second value (lower) during transitions for speed performance, and to a first value (higher) during holding for current reduction, the system achieves both fast response and low energy consumption without compromise.
3Quantity of substance
If a fixed-ratio reduction gearbox is used, then motor size is reduced, but device complexity and cost increase
Solution Approach 1:
The patent extracts the variable ratio functionality from the mechanical gearbox and relocates it to the electrical control domain. Instead of using a mechanically variable ratio gearbox with wear takeup systems, the invention uses a fixed-ratio gearbox combined with electronic control that adjusts the torque constant K to achieve variable effective ratio. This removes the complex mechanical components while preserving the beneficial effects of ratio adaptation.
Solution Approach 2:
The patent replaces the mechanical variable ratio gearbox system with an electrical control system that adjusts the torque constant. The mechanical complexity of variable ratio gearboxes and wear takeup systems is substituted by electronic control of the electrical machine's electromagnetic characteristics, achieving the same functional outcome with reduced mechanical complexity.
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
The solution achieves a 25-50% reduction in holding torque and current consumption, allowing for faster actuator displacement and reduced energy draw from the electrical source, while maintaining effective transmission system control.
Implementation Method 1
an electrical machine (6) comprising an armature and an inductor, the machine being such that the ratio between a variable representing the electromagnetic torque T exerted on the machine and a variable representing the current I flowing in the electrical circuit of the armature involves a constant K
Implementation Method 2
a static converter comprising a plurality of commutation cells, the static converter being arranged so as to electrically connect the electrical circuit of the armature to an electrical energy source
Data Source
AI summary
An actuator for a vehicle transmission system, comprising: an electrical machine comprising an armature and an inductor, a static converter comprising a plurality of commutation cells, the static converter being arranged so as to electrically connect the electrical circuit of the armature to an electrical energy source, and a system for controlling the commutation cells of the static converter, said system being configured so that the torque constant of the electrical machine can assume at least two different values depending on the control applied to said cells.