Gear Ventilation Sealing Element for Power Tools
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Solution Overview
Problem
Existing power tools with lubricated gears face issues with lubricant loss due to capillary action, leading to ventilation problems when using oil or grease-like lubricants, as the filter becomes saturated and obstructs airflow, preventing pressure equalization.
Innovation Solution
A labyrinth-like sealing element is introduced in the ventilation duct to allow air circulation while preventing lubricant escape, featuring an orifice with two separate flow channels to ensure reliable ventilation and prevent lubricant congestion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a felt filter is used in the ventilation duct, then ventilation is provided, but lubricant is absorbed by capillary action and leaks from the gear chamber
Solution Approach 1:
The sealing element is divided into multiple sealing lips (first, second, and third sealing lips) that segment the ventilation duct into separate pathways. This segmentation allows air to pass through while creating multiple barriers that prevent lubricant from reaching the felt filter, thus maintaining ventilation while preventing lubricant loss.
Solution Approach 2:
The sealing element acts as an intermediary component between the gear chamber and the felt filter. It introduces a new structure with multiple sealing lips that mediates the interaction between air flow and lubricant, allowing air to pass while blocking lubricant from reaching the felt filter.
2Loss of substance
If the gear chamber is sealed, then lubricant loss is prevented, but pressure equalization with the atmosphere is blocked
Solution Approach 1:
The sealing element provides different sealing qualities at different locations within the ventilation duct. The multiple sealing lips create localized sealing zones that allow air to pass through while preventing lubricant from escaping, thus maintaining both sealing and pressure equalization functions.
Solution Approach 2:
The sealing element dynamically adapts to pressure changes within the gear chamber. The flexible sealing lips can deform slightly to maintain sealing effectiveness while still allowing air to pass through, enabling the system to maintain sealing while accommodating pressure fluctuations for equalization.
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
Ensures safe and permanent ventilation in power tools without lubricant loss, maintaining airflow while preventing grease accumulation and ensuring reliable pressure equalization, even under temperature and operational fluctuations.
Implementation Method 1
there is a risk that the felt will become soaked with oil due to capillary action and the gear will leak after a short time (oil loss due to capillary action)
Data Source
Figure 1
Figure 2a~3
AI summary
The power tool comprises a lubricated gear arranged in a sealed gear box (23) which is provided in a fluidic connection with the atmosphere by a venting channel (26). A sealing element (40) is arranged in the venting channel, where the sealing element extends the venting channel in a maze like manner. The sealing element is directly connected to an opening (30) of the venting channel in the gear box.