Dog Clutch Actuation With Spring-Isolated Torque Transfer
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Solution Overview
Problem
Existing clutch devices experience decreased responsiveness due to long meshing times and frictional forces when transmitting torque between transmission units with differing rotational speeds, affecting vehicle performance.
Innovation Solution
A clutch device with an electric actuator unit and a rotational translation unit that converts rotational motion into translational motion, utilizing a fork and dog clutch mechanism with a movement restriction portion and a spring to bias the fork base, allowing torque transmission without passing through a spring, thereby enhancing responsiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a spring is used to bias the fork base in existing clutch devices, then the fork base can be biased in the axial direction, but the torque transmission path passes through the spring causing frictional forces and reduced responsiveness
Solution Approach 1:
The patent extracts the spring from the torque transmission path while maintaining its biasing function. The spring is repositioned to only bias the fork base without being involved in torque transmission, eliminating frictional losses during torque transfer between transmission units.
Solution Approach 2:
The patent introduces a movement restriction portion as an intermediary element that connects the fork base to the nut. This intermediary allows the spring to maintain its biasing function while preventing direct torque transmission through the spring, thereby reducing energy loss.
2Productivity
If the dog clutch translates with the fork to mesh with the first transmission unit, then torque can be transmitted between transmission units, but the meshing process takes time reducing responsiveness
Solution Approach 1:
The patent applies preliminary action by using the spring to continuously bias the fork base toward the engaged position, keeping the dog clutch pre-positioned for rapid meshing. This eliminates the need for the fork to travel the full distance during torque transmission, reducing meshing time.
Solution Approach 2:
The patent introduces dynamic elements including the rotational translation unit that converts rotary motion to linear motion, and the spring-loaded fork base that dynamically adjusts position. This dynamic system enables faster response compared to static biasing mechanisms.
3Ease of operation
If the rotational translation unit converts rotational motion to translational motion, then the fork can be translated to engage the dog clutch, but the mechanism complexity increases
Solution Approach 1:
The patent replaces complex mechanical actuation systems with a rotational translation unit that converts rotary motion from a motor to linear motion of the fork. This substitution simplifies the control mechanism while maintaining precise engagement capability.
Solution Approach 2:
The rotational translation unit serves multiple functions: it converts rotary to linear motion, provides controlled translation of the fork, and integrates with the spring mechanism to enable both engagement and disengagement operations through a single actuator system.
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 clutch device achieves rapid and reliable torque transmission by applying thrust greater than frictional forces, reducing waiting times and power consumption, and preventing impact transmission to components.
Implementation Method 1
The rotational translation unit includes a shaft and a nut. The shaft is configured to rotate when receiving torque from the rotary electric motor. The nut has an annular or tubular shape, is provided radially outward of the shaft, and is configured to translate in an axial direction relative to the shaft in accordance with rotation of the shaft.
Implementation Method 2
The electric actuator unit includes a spring provided between the nut and the fork base and configured to bias the fork base in the axial direction relative to the nut.
Implementation Method 3
The clutch device achieves rapid and reliable torque transmission by applying thrust greater than frictional forces
Data Source
AI summary
A rotational translation unit includes a shaft and a nut. The shaft rotates when receiving torque from a rotary electric motor. The nut is provided radially outward of the shaft, and translates in an axial direction relative to the shaft when the shaft rotates. A fork includes a fork base and a movement restriction portion. The fork base is provided radially outward of the nut, and is movable in the axial direction relative to the nut. The movement restriction portion restricts relative movement of the fork base in the axial direction relative to the nut. An electric actuator unit includes a spring provided between the nut and the fork base to bias the fork base in the axial direction relative to the nut.