Hydraulic Pulse Unit Air Separator for Power Wrench Efficiency
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Solution Overview
Problem
Existing power wrenches with hydraulic pulse units face efficiency decline and eventual loss of impulse generation due to air leakage, which increases air percentage in the oil volume, leading to friction losses and overheating, and enlarging the oil chamber to mitigate this results in increased dimensions and weight, which is not acceptable.
Innovation Solution
Incorporating a centrifugal air separator within the pulse unit to extract air from the oil and a separate air collecting chamber, utilizing loop-shaped grooves and centrifugal action to separate and gather air, maintaining a low air percentage and high efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the oil chamber volume is substantially increased to maintain low air percentage during extended operation, then the pulse generation efficiency is maintained for prolonged service intervals, but the outer dimensions and weight of the pulse unit increase
Solution Approach 1:
The patent extracts air from the oil volume using a centrifugal separator that removes air bubbles from the hydraulic oil during operation. This allows the oil chamber to be filled completely without air while automatically removing infiltrated air, resolving the contradiction between maintaining efficiency and minimizing size.
Solution Approach 2:
The patent introduces a centrifugal separator as an intermediary device between the oil chamber and the hydraulic circuit. This separator acts as a mediator that continuously removes air from the oil, allowing the system to maintain low air percentage without requiring excessive oil chamber volume.
2Reliability
If a centrifugal air separator is added to extract air from oil, then the service interval is extended by maintaining low air percentage, but the device complexity increases
Solution Approach 1:
The patent merges the centrifugal separator with the existing pulse unit structure, integrating the air removal function into the hydraulic system without requiring a completely separate system. The separator is positioned within the oil chamber to utilize existing space and fluid flow paths.
Solution Approach 2:
The patent uses the existing hydraulic oil flow and centrifugal force generated by the pulse unit's operation to drive the separation process. The hydraulic system's own dynamics are utilized to separate air from oil without requiring additional power sources or complex control mechanisms.
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 air separator effectively maintains high pulse frequency and torque output for extended service intervals while keeping the pulse unit dimensions small, preventing efficiency decline and mechanical wear, thus enhancing tool accessibility and operational economy.
Implementation Method 1
a separator (37) for extracting air from oil by centrifugal action
Data Source
AI summary
A power wrench has a rotation motor, and a hydraulic pulse unit. The pulse unit includes an inertia drive unit connected to the motor. The inertia drive unit includes an oil chamber with an impulse generating mechanism, and an output spindle extending into the oil chamber to receive torque impulses. The inertia drive unit has a cylindrical member defining the oil chamber, a rear end wall, and an air separator element co-rotating with the wall and having a substantially axially facing surface which together with a congruent surface on the rear end wall forms oil passages in the form of a clearance gap through which oil mixed with air is circulated between one or more oil inlet openings, past one or more air outlet openings, to one or more oil outlet openings. Air is extracted from the oil and is gathered in a centrally located air collecting chamber.