Braking Device for Movable Door Leaf Using Variable Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional braking devices for movable door leaves with electric braking motors and generators face challenges in maintaining a consistent speed, leading to noise issues due to varying door leaf speeds, requiring large gear ratios and voltage ranges that are difficult to manage effectively.
Innovation Solution
The implementation of a continuously variable transmission unit, controlled mechanically, allows the braking motor and generator to operate at a speed independent of the door leaf's rotation speed, using a belt and bevel gears system where the axial distance between bevel gears is adjusted by centrifugal force, maintaining belt tension and optimizing the transmission ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed gear ratio transmission is used to connect the door leaf axis with the braking motor shaft, then the braking motor can provide sufficient damping at low door leaf speeds, but the motor speed becomes excessively high at high door leaf speeds, resulting in considerable noise
Solution Approach 1:
The patent applies a continuously variable transmission (CVT) mechanism that dynamically adjusts the transmission ratio between the door leaf axis and braking motor shaft. As the door leaf speed varies, the CVT automatically changes the gear ratio to maintain the braking motor speed within an optimal range, preventing excessive noise while ensuring sufficient damping torque at all speeds.
Solution Approach 2:
The transmission ratio parameter is made variable rather than fixed. The CVT system continuously modifies the transmission ratio based on the operating conditions, allowing the braking motor to operate at consistent speeds regardless of door leaf speed variations, thereby eliminating noise while maintaining damping effectiveness.
2Force
If a large gear ratio is used to maintain sufficient damping at low door leaf speeds, then the braking effect is improved, but the motor speed increases by a large factor at high door leaf speeds, requiring the braking device to be designed for a relatively large speed range
Solution Approach 1:
The system transitions from a static fixed gear ratio to a dynamic continuously variable transmission system. The CVT adjusts the transmission ratio in real-time based on door leaf speed, providing high torque multiplication at low speeds for effective damping while limiting motor speed at high door leaf speeds, thus reducing the required motor speed range.
3Use of energy by moving object
If the generator is designed to deliver sufficient voltage at lower leaf speeds, then power supply is adequate, but at high leaf speeds the voltage becomes excessively high, requiring the charging circuit to be designed for a large voltage range
Solution Approach 1:
The CVT system dynamically controls the generator speed by adjusting the transmission ratio. This ensures the generator operates within an optimal speed range regardless of door leaf speed, producing consistent voltage output that simplifies charging circuit design while maintaining adequate power supply for control functions.
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 solution reduces noise and improves efficiency by maintaining a consistent output speed, independent of the door leaf's speed, and allows for a simpler and cost-effective design that manages the large speed and voltage variations encountered in door operation.
Implementation Method 1
the axial distance between bevel gears of at least one bevel gear pair, fixedly rotatably connected to the drive shaft or the output shaft, and thus the radial distance of a belt portion, looping around the respective bevel gear pair, from the drive shaft or the output shaft, is continuously variable, in particular if at least one mass, which is put in rotation along with the drive or output shaft, is radially displaceable by the centrifugal force acting on it
Implementation Method 2
a belt and bevel gears system where the axial distance between bevel gears is adjusted by centrifugal force, maintaining belt tension
Implementation Method 3
an electric braking motor, operated as a generator, for generative damping of the movement of the door leaf
Data Source
AI summary
A braking device for a movable door leaf comprises an electric braking motor to damp movement of the door leaf; a motor shaft coupleable with an axis of rotation of the door leaf; and a control unit to control the electric braking motor. A generator provides power to the control unit. A continuously variable transmission unit between the axis of rotation of the door leaf and either the motor shaft of the electric braking motor or the separate generator is controlled by a mechanical control such that the motor shaft of the electric braking motor and/or the separate generator, can be driven at a rotational speed independent of the rotational speed of the rotational axle of the door leaf. Also included is a door closer, having a rotatable door closer axis, coupleable with a door leaf, cooperating with a mechanical energy storage device, and a correspondingly designed braking device.