Torque Limiter Coil Spring Mechanism for Vehicle Door Actuator
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vehicle door opening and closing mechanisms face issues with excessive force input, leading to potential deformation or damage of components, resulting in increased size, cost, and weight to withstand such forces.
Innovation Solution
A power transmission mechanism incorporating a coil spring with a drive gear and inner shaft, which functions as a torque limiter to interrupt excessive force transmission by enlarging its inner diameter and separating from the inner shaft, preventing rotational force transmission when a predetermined torque is exceeded.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If components are designed with increased strength to withstand excessive input force, then reliability improves, but device complexity, size, cost, and weight increase
Solution Approach 1:
A coil spring is introduced as an intermediary torque-limiting mechanism between the drive shaft and driven shaft. When excessive torque is applied, the coil spring becomes loosened and separates from the inner shaft, interrupting power transmission and protecting the motor from damage without requiring the entire system to be designed for high-strength tolerance.
Solution Approach 2:
The coil spring's physical state changes from a tight, engaged condition during normal operation to a loosened, separated condition when excessive torque is applied. This parameter change allows the system to automatically limit torque transmission, protecting components without requiring them to be oversized for maximum force承受能力.
2Power
If the coil spring is tightly engaged with the inner shaft, then power transmission efficiency improves, but torque limiting capability deteriorates
Solution Approach 1:
The engagement between the coil spring and inner shaft is designed to be dynamic rather than static. During normal operation, the coil spring maintains tight engagement for efficient power transmission. When excessive torque occurs, the engagement automatically changes as the coil spring becomes loosened and separates, providing both efficient operation and protective torque limiting.
Solution Approach 2:
The coil spring serves dual functions: it acts as a power transmission element during normal operation and as a torque-limiting safety mechanism when excessive force is applied. This merging of functions eliminates the need for separate clutch or limiter mechanisms, simplifying the overall system design.
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 enhances performance by preventing component damage and reducing the size, cost, and weight of the mechanism while effectively managing excessive force inputs.
Implementation Method 1
a coil spring; an inner shaft which is connected to the drive shaft and is disposed to be inserted into a coil portion of the coil spring so that the coil portion of the coil spring is configured to come into close contact with an outer peripheral surface thereof
Implementation Method 2
a bottomed cylindrical outer member that is disposed at the outside of the coil portion with a gap interposed therebetween and is provided to be relatively rotatable with respect to the inner shaft so that both end portions of a wire forming the coil spring are locked thereto
Data Source
AI summary
A torque limiter (120) includes a coil spring (124), an inner shaft which is connected to a drive shaft (58) and is disposed to be inserted into a coil portion of the coil spring (124) so that the coil portion of the coil spring (124) is configured to come into close contact with an outer peripheral surface, a bottomed cylindrical outer member (122) which is disposed at the outside of the coil portion with a gap interposed therebetween and is provided relatively rotatable with respect to the inner shaft so that both end portions of a wire forming the coil spring (124) are locked thereto, and a drive gear (123) which is integrally formed with a plate portion (122a) of the outer member (122) and is configured to transmit a rotational force to the screw shaft.