Screw Compressor Bearing Assembly with Inverted Positioning

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Solution Overview

Problem

Existing bearing assemblies for screw compressors require complex adjustment processes and higher manufacturing costs due to the need for precise head spacing alignment, which is challenging with preadjusted bearings and can be prone to misalignments.

Innovation Solution

A bearing assembly comprising an angular contact ball bearing and a cylindrical roller bearing, where the angular contact ball bearing is positioned closer to the shaft's center of mass, allowing for preadjusted delivery with a disc system that sets the axial bearing clearance, enabling precise head spacing measurement and installation without additional adjustment, reducing manufacturing and assembly efforts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If preadjusted bearings are used to set head spacing, then manufacturing costs and adjustment complexity are reduced, but the precision of axial dimensions and susceptibility to misalignments increase

Engineering Contradiction:

Improvemanufacturing cost and assembly complexityVSAvoidaxial dimension accuracy and alignment precision

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The bearing assembly is preadjusted during manufacturing to set the correct head spacing, eliminating the need for complex field adjustments. The angular contact ball bearing and cylindrical roller bearing are positioned and secured with locking elements before delivery, so the head spacing is predetermined and requires no additional adjustment during compressor assembly.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Locking elements are introduced as intermediary components to secure the bearings in their predetermined positions. These locking elements prevent axial displacement and misalignment of the bearings relative to each other and to the shaft, thereby maintaining the preadjusted head spacing accuracy during operation.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If the cylindrical roller bearing is positioned closer to the shaft center of mass, then assembly is simplified, but head spacing accuracy and efficiency are reduced

Engineering Contradiction:

Improveassembly simplicityVSAvoidcompressor efficiency

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The conventional arrangement is inverted by positioning the angular contact ball bearing closer to the shaft center of mass instead of the cylindrical roller bearing. This inverted configuration optimizes the load distribution and mechanical efficiency of the compressor while still allowing for simplified assembly through the preadjusted design and locking elements.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS10711836B2Bearing assembly for supporting a screw-compressor rotor and method for assembling a screw compressor

Publication Date: 2020.07.14 AB SKF SKF PATENT DEPARTMENT

AI summary

A bearing assembly for supporting a screw-compressor rotor includes a shaft having a center of mass, at least one angular contact ball bearing mounted on the shaft, and at least one cylindrical roller bearing mounted on the shaft. A spacing from the angular contact ball bearing to the center of mass is shorter than a spacing from the cylindrical roller bearing to the center of mass.