Scroll Compressor Slider Balance Weight Design
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Solution Overview
Problem
The existing scroll compressor with a balance-weighted slider experiences increased power loss due to viscous drag from lubricant stirring, leading to performance deterioration, especially at high speeds, due to the balance weight portion projecting outside the orbital bearing.
Innovation Solution
A scroll compressor design where the slider, positioned on the inner peripheral side of the orbital bearing, serves as a balance weight with its center of gravity eccentric in the opposite direction to the main shaft's axis, reducing centrifugal force and minimizing lubricant stirring, thus reducing power loss and improving performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a balance weight portion is positioned on the outer peripheral side of the orbital bearing to counterbalance centrifugal force, then the sealing force between scroll laps is improved, but the balance weight portion stirs the lubricant at high speed causing increased power loss due to viscous drag
Solution Approach 1:
The invention merges the balance weight function with the slider component. The slider, which is already positioned on the inner peripheral side of the orbital bearing and necessary for the follower crank mechanism, is designed with an off-center center of gravity to provide the balance weight effect. This integration eliminates the need for a separate balance weight portion that would project outside the orbital bearing, thereby avoiding lubricant stirring while maintaining centrifugal force counterbalancing and sealing force.
2Stability of the object's composition
If the balance weight portion projects to the outer side of the orbital bearing to provide counterbalancing, then centrifugal force cancellation is achieved, but the rotational movement of the balance weight portion increases lubricant agitation and viscous drag
Solution Approach 1:
The balance weight function is merged into the slider component. The slider's center of gravity is positioned off-center relative to its rotation axis, allowing it to provide centrifugal force counterbalancing while remaining confined within the orbital bearing's inner peripheral side. This eliminates the harmful effect of the balance weight portion projecting outside and stirring the lubricant.
Solution Approach 2:
The slider acts as an intermediary component that fulfills multiple functions: it provides the follower crank mechanism functionality by guiding the eccentric shaft portion, and simultaneously serves as the balance weight by having its center of gravity positioned to counterbalance centrifugal forces. This intermediary role resolves the contradiction by achieving centrifugal balance without the need for a separate projecting balance weight portion.
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 reduces power loss due to viscous drag, enhances compressor performance, particularly at high speeds, and simplifies the design for reduced manufacturing costs and compact size, while maintaining effective sealing and refrigeration capacity.
Implementation Method 1
the center of gravity of the balance-weighted slider is eccentric in a direction opposite to the direction in which the orbiting scroll is eccentric. Hence, part or the whole of the centrifugal force acting on the orbiting scroll is cancelled out by the centrifugal force acting on the balance-weighted slider
Implementation Method 2
an orbital bearing provided to the orbiting scroll and rotatably supporting the slider
Implementation Method 3
a main shaft including an eccentric shaft portion at one end and being configured to transmit a rotational driving force to the orbiting scroll; the center axis of the slider being eccentric in one direction from an axis of rotation of the main shaft
Data Source
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AI summary
A scroll compressor includes a compressing mechanism unit 20 including a fixed scroll 3 that is fixedly provided in a shell 1 and an orbiting scroll 4 that moves around the fixed scroll 3, the compressing mechanism unit 20 compressing fluid; a main shaft 7 including an eccentric shaft portion 7a at one end thereof and that transmits a rotational driving force to the orbiting scroll 4; a slider 30 having a slide groove 31 in which the eccentric shaft portion 7a is slidably fitted; and an orbital bearing 14 provided to the orbiting scroll 4 and that rotatably supports the slider 30. The slider 30 is provided on the inner peripheral side of the orbital bearing 14 when seen in a direction of a center axis O1 of the slider 30. The center axis O1 of the slider 30 is eccentric in one direction from an axis of rotation O of the main shaft 7. A center of gravity G of the slider 30 is eccentric in a direction opposite to the one direction from the axis of rotation O of the main shaft 7.