Scroll Pump Anti-Rotation Counterweight for Vibration Reduction
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Solution Overview
Problem
Existing scroll pumps suffer from vibrations due to unbalanced mass caused by the linear reciprocating motion of the anti-rotation device, which is not adequately compensated for in current designs.
Innovation Solution
Incorporating a counterweight that moves in a substantially linear direction and is constrained to be out of phase with the reciprocating motion of the anti-rotation device's body portion, thereby compensating for the imbalance and reducing vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a flexing arrangement anti-rotation device is used to allow orbiting motion, then the pump becomes more compact, but unbalanced mass is generated causing vibrations
Solution Approach 1:
The patent applies the counterweight principle by adding a balancing mass that moves in opposition to the unbalanced mass generated by the flexing anti-rotation device. This counterweight is constrained to move along a guide in a direction opposite to the body portion's motion, thereby compensating for the unbalanced mass and reducing vibrations while maintaining the compact flexing arrangement design.
2Reliability
If a bellows arrangement is used as anti-rotation device, then rotational movement is resisted, but the pump becomes physically big for its displacement
Solution Approach 1:
The patent extracts the essential function of the bellows (resisting rotation while allowing orbiting motion) and replaces it with a more compact flexing arrangement consisting of a body portion and constrained arms. This extraction eliminates the need for a long bellows while maintaining the anti-rotation function, thereby reducing pump size.
3Ease of operation
If the body portion of anti-rotation device moves linearly reciprocatingly, then orbiting motion is allowed, but unbalanced mass is created leading to vibrations
Solution Approach 1:
The patent directly addresses this contradiction by introducing a counterweight that moves in opposition to the body portion's linear reciprocating motion. The counterweight is constrained by a guide to move along a path opposite to the body portion, creating equal and opposite forces that cancel out the unbalanced mass and reduce vibrations while preserving the ease of orbiting motion.
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 counterweight effectively reduces vibrations by counteracting the unbalanced mass, ensuring smoother operation and reduced mechanical noise.
Implementation Method 1
the flexing arrangement provides an unbalanced mass associated with the movement of the body portion of the anti-rotation devices which introduces vibration to the pump
Implementation Method 2
said at least one counterweight moves in a reciprocating motion that is out of phase with, and at least partially compensates for, movement of said body portion
Data Source
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AI summary
A scroll pump (10), anti-rotation device and method are disclosed. The scroll pump has: a motor (18); two interleaving scrolls (22, 20) mounted such that rotation of the motor imparts an orbital motion to one scroll with respect to the other; and an anti-rotation device (50) mounted to at least one of the two scrolls and configured to impede relative rotational movement between the two scrolls, the anti-rotation device comprising a body portion (53) configured to move in a substantially linearly reciprocating motion in response to the relative orbiting motion of the scrolls. The scroll pump comprises at least one counterweight (46) mounted such that movement of the at least one counterweight is constrained to a same substantially linear direction as the reciprocating motion of the body portion of the anti-rotation device and configured such the at least one counterweight (46) moves in a reciprocating motion that is out of phase with, and at least partially compensates for, movement of the body portion (53) in response to rotation of the rotor.