Motor Pretensioned Roller Shade Torque Assistance
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Solution Overview
Problem
Motorized roller shades face high torque and power requirements when rolling up, especially due to the inefficiency of conventional torsion springs, which provide more assistance at the beginning than during the rolling up cycle, and existing pretensioning methods are either incorrectly set or lose tension over time.
Innovation Solution
A motor pretensioned roller shade system with a counterbalancing spring that is pretensioned by the motor to a preset amount, using planetary gears and a clutch to lock the pretension, ensuring consistent torque assistance throughout the rolling up and down cycles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a conventional torsion spring is used to counterbalance the roller shade, then the spring provides torque assistance at the beginning of the rolling up cycle, but the torque assistance progressively reduces in a linear fashion and becomes insufficient during the remainder of the rolling up cycle
Solution Approach 1:
The spring is pretensioned during installation to a specific amount (e.g., 90 degrees) before the roller shade is first used. This preliminary action stores elastic potential energy in the spring that is gradually released throughout the rolling up cycle, providing consistent torque assistance from start to finish rather than just at the beginning.
Solution Approach 2:
The patent changes the initial tension parameter of the spring by pretensioning it to a specific angle during installation. This parameter adjustment ensures that the spring maintains optimal torque characteristics throughout the entire operational cycle, transforming the torque delivery profile from linearly decreasing to sustained assistance.
2Speed
If the roller shade is rolled up quickly to reduce usage time, then the operation is faster, but the battery drains more quickly due to higher power requirements
Solution Approach 1:
The spring acts as a counterweight system that stores and releases mechanical energy to offset the weight of the shade material. By pretensioning the spring, it provides continuous counterbalancing force throughout the rolling up cycle, reducing the motor's power requirements and allowing faster operation without proportional increases in energy consumption.
3Ease of operation
If field pretensioning is performed during installation, then the spring can be adjusted to provide torque assistance, but the pretension is often set incorrectly leading to customer dissatisfaction
Solution Approach 1:
The system includes a motorized mechanism that can automatically pretension the spring to the correct amount during installation or servicing. The motor rotates the spring to a predetermined angle (e.g., 90 degrees) based on programmed parameters, eliminating the need for manual field adjustment and ensuring precise, consistent pretension settings without requiring technician expertise.
4Ease of manufacture
If the roller tube is made larger to accommodate the spring mechanism, then the spring can be installed, but the overall size of the roller shade increases
Solution Approach 1:
The spring is nested within the existing roller tube structure by winding it around the roller tube itself. The spring's coils are arranged concentrically around the tube, utilizing the internal space efficiently. This nesting approach allows the spring mechanism to be installed without significantly increasing the external dimensions of the roller tube.
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 system reduces the torque and power required to roll up the shade by maintaining consistent assistance throughout the cycle, minimizing battery drain and ensuring reliable operation even after accidental knocks or reinstallation.
Implementation Method 1
As the roller shade is unraveled, tension builds up in the spring. The tension is released when the roller shade is rolled up, thereby assisting the motor in lifting the shade material.
Implementation Method 2
a clutch adapted to translate rotational motion from the motor to the spring and lock the spring
Implementation Method 3
The motor drive unit may further comprise one or more planetary gears.
Data Source
AI summary
A roller shade comprising a motor pretensioned counterbalancing spring that lowers the torque load on the motor of the roller shade throughout the rolling up or rolling down cycles. The roller shade comprises a motor drive unit including a motor adapted to drive a drive wheel through a clutch. The motor drive unit further comprises a first spring carrier adapted to be stationary during operation of the motor and a second spring carrier adapted to rotate during operation of the motor. The motor drive unit further comprises a counterbalancing spring connected at its first end to the first spring carrier and at its second end to the second spring carrier. The counterbalancing spring is pretensioned using the motor prior to inserting the motor drive unit into the roller tube by driving the drive wheel and thereby rotating the second end of the counterbalancing spring with respect to the first end of the counterbalancing spring. The clutch translates rotational motion from the motor to the drive wheel, but locks rotational motion from the drive wheel thereby locking the pretension in the counterbalancing spring.