Eccentric Bearing Cartridges for Rotor-Concentric Compressor Gearboxes

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Solution Overview

Problem

Current centrifugal compressor systems require redesign and increased costs when changing operational speeds, as the gearbox and compressor package must be altered to accommodate different pinion gear tooth counts, disrupting rotor concentricity and efficiency.

Innovation Solution

The integration of eccentric cartridges within a fixed gearbox design that supports rotor bearings and seals, allowing for multiple impeller speeds by varying the eccentricity between the inner and outer surfaces of the cartridges, enabling interchangeability of pinions with different gear tooth counts without altering the gearbox dimensions or package design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the gearbox and compressor package are redesigned to accommodate different pinion gear tooth counts, then multiple impeller speeds can be achieved, but engineering costs and downtime increase

Engineering Contradiction:

Improveimpeller speed variationVSAvoidengineering time and downtime

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The system is divided into modular components: a fixed gearbox housing and interchangeable pinion-rotor assemblies. Each pinion-rotor assembly can be independently replaced to change impeller speeds, eliminating the need to redesign the entire gearbox when speed requirements change.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The fixed gearbox housing is designed with universal mounting features and sufficient internal clearance to accommodate multiple pinion sizes with different gear tooth counts. This allows a single gearbox design to support multiple impeller speeds through component interchangeability rather than redesign.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If the gearbox design is altered to accommodate different pinion gear tooth counts, then multiple impeller speeds are possible, but device complexity increases

Engineering Contradiction:

Improvepinion interchangeabilityVSAvoidgearbox design complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The gearbox is segmented into a fixed housing structure and removable pinion-rotor subassemblies. This segmentation allows the housing to remain simple and fixed while the interchangeable subassemblies handle the variability, reducing overall system complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The pinion-rotor assembly acts as an intermediary component between the fixed gearbox housing and the impeller. By placing the variability in this intermediate component rather than in the housing itself, the design maintains simplicity in the main structure while achieving adaptability.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Speed

If different pinions with varying gear tooth counts are used, then multiple impeller speeds can be achieved, but rotor concentricity is disrupted

Engineering Contradiction:

Improveimpeller speedVSAvoidrotor concentricity

Core Design Contradiction:

SpeedVSManufacturing precision

Solution Approach 1:

Each pinion-rotor assembly is pre-assembled and pre-aligned as a complete unit before installation into the gearbox. The bearing seats and mounting features are precisely positioned during assembly, ensuring rotor concentricity is established beforehand and maintained when the assembly is installed in the fixed housing.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Multiple pinion-rotor assemblies are manufactured as identical copies with standardized mounting interfaces and bearing seat positions. This copying approach ensures that regardless of which assembly is installed, the rotor concentricity geometry remains consistent, maintaining precision across different speed configurations.

Inventive Principle:

Principle #26Copying

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 solution maintains rotor concentricity and allows for multiple impeller speeds with a single gearbox design, reducing engineering costs and downtime by enabling the use of different pinions within the same compressor system without redesigning the gearbox or package components.

Implementation Method 1

the inner surface is eccentric relative to the outer surface to align the rotational axis with a center axis of the bearing assembly

Methodology Applied

Scientific EffectEccentricity: Eccentric

Data Source

PatentUS11795976B2Systems and methods for integrally geared centrifugal compressor to maintain rotor concentricity with differing pinion gear tooth counts

Publication Date: 2023.10.24 INGERSOLL RAND IND US INC

AI summary

Integrally geared centrifugal compressor systems are described that include eccentric cartridges that house bearings and seals to maintain rotor concentricity for a variety of pinons integrated in a fixed gearbox design to provide multiple impeller speeds with a single gearbox design. In an aspect, a system includes, but is not limited to, a pinion configured to be rotated by a bull gear about a rotational axis; a rotor coupled to the pinion; and an eccentric cartridge configured to house a bearing assembly through which the rotor extends to support rotation of the rotor, the eccentric cartridge having an outer surface and an inner surface, wherein the inner surface is eccentric relative to the outer surface to align the rotational axis with a center axis of the bearing assembly.