HVAC Actuator Planetary Gear Layout for Higher Actuating Force
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric actuators for heating, ventilation, and air conditioning systems in motor vehicles face limitations in gear reduction ratio due to the need for a hollow drive wheel, leading to inadequate actuating forces or oversized motors, increasing cost and footprint.
Innovation Solution
The electric actuator features a planetary gear set with a pinion connected to the rotor, allowing for a higher gear reduction ratio by optimizing the diameter of the pinion and drive socket, while maintaining a compact footprint by not requiring the motor to be hollow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the drive wheel is made hollow to allow the flap shaft to pass through, then the axial footprint of the actuator is reduced, but the gear reduction ratio is limited and the electric motor must be oversized to achieve sufficient actuating forces
Solution Approach 1:
The movable element shaft is nested within the solid drive wheel by passing through a central bore, allowing the shaft to traverse the drive wheel without requiring the drive wheel to be hollow. This nesting arrangement maintains the full structural integrity and diameter of the drive wheel, enabling a higher gear reduction ratio while keeping the actuator compact.
Solution Approach 2:
The drive socket is positioned at a distance from the electric motor along the axial direction, creating a linear arrangement where the shaft passes through the drive wheel and connects to the movable element. This dimensional arrangement allows the shaft to pass through the drive wheel in the axial direction without compromising the drive wheel's structural diameter, thereby achieving both compact footprint and high actuating force.
2Force
If the diameter of the drive wheel is increased to achieve a higher gear reduction ratio, then the actuating force is improved, but the footprint of the electric motor increases
Solution Approach 1:
The shaft is nested within the drive wheel through a central bore, allowing the drive wheel to maintain its full diameter for high gear reduction ratio without requiring a hollow structure. This enables the use of a larger diameter drive wheel to achieve higher actuating forces while keeping the motor footprint compact.
Solution Approach 2:
The drive mechanism is segmented into distinct components: the electric motor, the planetary gear set with drive wheel, and the drive socket positioned at a distance along the axis. This segmentation allows optimization of each component's dimensions independently, enabling a compact motor with a larger diameter drive wheel for high reduction ratio and force output.
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 enables the actuator to provide increased actuating forces with a compact design, optimizing the magnetic circuit of the motor and reducing costs by allowing smaller motors to achieve significant forces.
Implementation Method 1
an electric motor comprising: a stator, a rotor extending along an axis
Implementation Method 2
a drive mechanism comprising: a planet carrier, at least one planet gear held by the planet carrier, the planet gear being suitable for being rotated by the pinion, an output ring gear suitable for being rotated by the at least one planet gear
Data Source
AI summary
The present invention relates to an electric actuator (50) suitable for driving a movable element for a heating, ventilation and/or air conditioning system for a motor vehicle, including an electric motor (2) comprising a stator (3), a rotor (4) extending along an axis (X), a pinion (5) rigidly connected to the rotor (4), a drive mechanism (6) comprising: a planet carrier (7), at least one planet gear (8) held by the planet carrier (7), the planet gear (8) being suitable for being rotated by the pinion (5), an output ring gear (11) suitable for being rotated by the at least one planet gear (8), a drive socket (12) rigidly connected to the output ring gear (11) and suitable for driving the movable element, the drive socket (12) being at a distance from the electric motor (2) along the direction of the axis (X) of the rotor (4).