Scroll Compressor Balance Weight Sealing and Thrust Bearing
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Solution Overview
Problem
In conventional scroll compressors, the active load support between the balance weight and the frame weakens sealing, leading to excessive oil flow into the back-pressure chamber, causing performance degradation due to oil agitation.
Innovation Solution
A scroll compressor design featuring a crank shaft with an eccentric pin and a flange portion, a balance weight mounted on the flange to cancel imbalance, a sealing member for sealing between the revolving scroll and the flange, and a thrust bearing between the frame and the flange, which reduces oil flow into the back-pressure chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the balance weight is housed inside the frame to reduce its weight, then the balance weight can be made lighter and positioned closer to the revolving scroll, but sealing between the revolving scroll and balance weight is weakened causing excessive oil flow into the back-pressure chamber
Solution Approach 1:
The invention divides the sealing function into two separate components: a sealing member for sealing between the revolving scroll and flange portion, and a thrust bearing for supporting axial load between the flange portion and frame. This segmentation allows each component to perform its specific function effectively without compromising sealing performance when the balance weight is housed inside the frame.
Solution Approach 2:
The invention introduces a flange portion as an intermediary component between the crank shaft and the balance weight. The flange portion provides a sealing surface for the sealing member and a load-bearing surface for the thrust bearing, enabling the balance weight to be positioned inside the frame while maintaining proper sealing and load support functions.
2Reliability
If oil is supplied to sliding portions including the balance weight area, then lubrication is improved, but oil excessively flows into the back-pressure chamber causing agitation loss and performance decrease
Solution Approach 1:
The invention segments the lubrication system by providing oil supply passages that deliver oil to specific sliding portions (crank shaft bearing, revolving scroll bearing) while the sealing member and thrust bearing configuration prevents excessive oil from reaching the back-pressure chamber, thus maintaining lubrication effectiveness while reducing oil agitation loss.
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 design improves performance by minimizing oil flow into the back-pressure chamber, reducing oil agitation loss and enhancing sealability, thus improving the overall efficiency of the scroll compressor.
Implementation Method 1
a centrifugal force is caused on a crank shaft by the revolution movement of a revolving scroll, and a balance weight is fitted to the crank shaft to cancel imbalance caused by this centrifugal force
Implementation Method 2
a pump mechanism is fitted to the lower end portion of a crank shaft, and an oil supply hole is provided inside the crank shaft, penetrating along the axial direction. Oil supplied by this pump mechanism is supplied, inside the frame, to the respective sliding portions
Implementation Method 3
a thrust bearing provided between the frame and the flange portion
Implementation Method 4
a sealing member that provides sealing between the revolving scroll and the flange portion
Data Source
AI summary
A scroll compressor is provided which includes: a revolving scroll, a fixed scroll, an autorotation preventing mechanism, a frame, a crank shaft provided with an eccentric pin portion which is eccentric with respect to an axis, the crank shaft being provided with a flange portion at a lower portion of the eccentric pin portion, the flange portion being larger than the diameter of the eccentric pin portion, a balance weight mounted on the flange portion, a sealing member performing sealing between the revolving scroll and the flange portion, and a thrust bearing arranged between the frame and the flange portion. The scroll compressor reduces the amount of oil flowing into a back pressure chamber, thereby improving the performance of the scroll compressor.