Ventilation fan humidity sensor and case
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Solution Overview
Problem
Conventional ventilation fans struggle to prevent water and dust from intruding into humidity sensors, despite effective prevention of such intrusion into the motor's rotary shaft.
Innovation Solution
The ventilation fan design includes a housing with a suction port and exhaust port, an orifice guiding air through an air exhaust channel, a humidity sensor, and a humidity sensor case with double-layered caps to prevent water and dust ingress, ensuring the humidity sensor can accurately detect air humidity without interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional motor protection structure with bearing housing and ribs is used, then the rotary shaft is protected from water and dust intrusion, but the humidity sensor remains exposed to water and dust intrusion
Solution Approach 1:
The patent applies nesting by placing the humidity sensor inside a dedicated sensor case that is itself positioned within the motor housing. The sensor case includes nested caps (first cap inside second cap) creating multiple protective layers, similar to nested dolls, where each layer provides additional protection while maintaining sensor functionality.
Solution Approach 2:
The patent segments the housing into distinct functional zones: the motor housing with its protective structure for the rotary shaft, and a separate sensor case with its own protective caps for the humidity sensor. This segmentation allows each component to have optimized protection suitable to its specific requirements.
2Measurement precision
If the humidity sensor is exposed to air flow for accurate detection, then humidity measurement is enabled, but water and dust can intrude into the sensor
Solution Approach 1:
The patent applies local quality by creating different protective characteristics in different parts of the sensor case. The first and second caps provide different levels and types of protection, with the first cap offering primary protection and the second cap providing additional protection, while both allow air flow for humidity detection.
Solution Approach 2:
The sensor case acts as an intermediary structure between the external environment and the humidity sensor. It mediates by allowing beneficial air flow to reach the sensor while blocking harmful water and dust particles, thus protecting the sensor without isolating it from necessary air contact.
3Object-affected harmful factors
If a protective structure is added around the humidity sensor, then water and dust intrusion is prevented, but the device complexity increases
Solution Approach 1:
The sensor case serves multiple functions: it protects the humidity sensor from water and dust intrusion, provides structural support, maintains proper air flow paths, and integrates with the existing motor housing. This multi-functionality reduces the need for additional separate protective components.
Solution Approach 2:
The patent merges the protective function with the housing structure itself. The sensor case is integrated into the motor housing design, combining the protection function with the existing structural framework rather than adding completely separate protective elements.
Data Source
AI summary
A ventilation fan humidity sensor and case includes a ventilation fan and a housing in which a suction port and an exhaust port are provided, a blowing part that guides air to the exhaust port from the suction port, an orifice that guides air sucked from the suction port to the blowing part via an air exhaust channel that communicates the suction port and the exhaust port, a humidity sensor for detecting humidity of air in the housing, and a humidity sensor case for accommodating the humidity sensor. The humidity sensor case includes a sensor base with a box shape having an opening, a first sensor cap that has a first ventilation hole and covers the opening, and a second sensor cap that has a second ventilation hole and covers the opening inside the first sensor cap.