Actuating drive having a wound flat spring as a restoring spring, which flat spring is designed as a constant-force spring and acts directly on an actuation connection point of the actuating drive
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Solution Overview
Problem
Existing actuating drives for heating, ventilation, or cooling systems are often heavy, complex, and require a substantial installation depth due to the use of solid drive springs with steep characteristic curves, which complicates their design and manufacturing, and the integration of multiple toothed wheels.
Innovation Solution
The use of a wound flat spring with a simpler and more lightweight design, where the spring axis is radially spaced apart from the actuation axis and aligned parallel to it, allowing for a compact and flexible actuating drive with a constant or reduced number of windings, and a free spring end fastened tangentially to the shaft portion, enabling easier reversal of direction and reduced stress on the gear unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If solid cylindrical helical springs are used as restoring springs, then the actuating drive can provide restoring force, but the actuating drive becomes heavy and requires substantial installation depth
Solution Approach 1:
The patent changes the physical parameters of the spring by using a wound flat spring instead of a solid cylindrical helical spring. This parameter change results in a lighter spring with fewer windings (6-25) compared to solid springs, directly reducing the weight of the actuating drive while maintaining the restoring force function.
2Force
If solid cylindrical helical springs with steep characteristic curves are used, then restoring force is provided, but the actuating drive becomes complex and requires overdimensioning of the motor
Solution Approach 1:
The patent changes the spring characteristic from a steep curve (solid helical spring) to a flatter curve (wound flat spring). This parameter change in the spring's force-displacement characteristic simplifies the overall drive system, eliminating the need for overdimensioning the motor and reducing device complexity.
3Ease of operation
If multiple toothed wheels are integrated into the actuating drive, then the drive mechanism can be implemented, but the manufacturing and design becomes complicated
Solution Approach 1:
The patent extracts the drive spring from the complex gear train system and positions it independently at the actuation connection point. This separation simplifies the manufacturing and design by reducing the number of integrated toothed wheels and their interactions, while the spring still provides the necessary restoring torque through its direct connection to the actuation element.
4Force
If the spring axis is aligned with the actuation axis, then the spring can act on the actuation element, but the installation depth increases
Solution Approach 1:
The patent changes the spatial arrangement by aligning the spring axis parallel to but radially spaced apart from the actuation axis, rather than coincident with it. This dimensional change allows the wound flat spring to act tangentially on the shaft portion, providing restoring torque while reducing the installation depth in the axial direction.
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 design results in a more compact, cost-effective, and reliable actuating drive with a consistent restoring torque, allowing for even return in reverse operation and simplified assembly, reducing the need for overdimensioning the motor and minimizing installation height.
Implementation Method 1
The actuating drive has, as a restoring spring, a wound flat spring for providing a restoring torque acting on the actuation element
Data Source
AI summary
Various embodiments of the teachings herein include an actuating drive comprising: a drive element; an actuation element; and a restoring spring. The drive element drives the actuation element indirectly about an actuation axis. The actuation element includes a shaft portion concentric to the actuation axis and extends at least partially circumferentially. The restoring spring includes a wound flat spring providing a restoring torque on the actuation element, acting tangentially on the shaft portion, and a free spring end tangentially fastened to the shaft portion. The free spring end is radially externally disposed with respect to the spring axis and fastened tangentially to the shaft portion. The spring is mounted rotatably so the spring axis is radially spaced apart from the actuation axis and aligned parallel to the actuation axis.