Multi-Stage Progressing Cavity Rotor–Stator Coupling for High Solids

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Solution Overview

Problem

Conventional progressing cavity devices face limitations in handling high solid content fluids and require frequent buffing to achieve a proper fit between the rotor and stator, which can lead to inefficiencies and wear.

Innovation Solution

The implementation of conically tapered surfaces on the rotor and stator, allowing for adjustable clearance and the ability to shift the rotor's position, along with slidable drive connectors, enables efficient handling of high solid content fluids and reduces the need for frequent buffing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional progressing cavity devices use a fixed fit between rotor and stator, then manufacturing precision is improved, but the device cannot handle high solid content fluids effectively and requires frequent buffing

Engineering Contradiction:

Improveability to handle high solid content fluidsVSAvoidneed for frequent buffing

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies the dynamics principle by making the rotor position adjustable relative to the stator through conical tapered surfaces. The rotor can be shifted axially to change the clearance between rotor and stator surfaces, allowing the device to adapt to different operating conditions including high solid content fluids, while eliminating the need for frequent buffing to maintain proper fit.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the physical parameter of clearance between rotor and stator by introducing conical tapered surfaces with specific taper angles (e.g., 5-15 degrees). This allows the clearance to be adjusted by shifting the rotor position, transforming the fixed fit into a variable parameter that can be optimized for different fluid conditions, particularly high solid content fluids.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the rotor and stator are fitted with a clearance fit to improve fluid handling, then the ability to handle high solid content fluids is improved, but wear increases and operational efficiency decreases

Engineering Contradiction:

Improvefluid handling capabilityVSAvoiddevice lifespan

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The conical tapered surfaces enable dynamic adjustment of rotor position, allowing the clearance to be optimized for fluid handling while maintaining control over the gap size. This prevents excessive wear by allowing the rotor to be positioned to minimize clearance when handling less challenging fluids, while still permitting larger clearance when needed for high solid content fluids.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The adjustable rotor position mechanism allows the device to self-adjust to optimal clearance settings based on operating conditions. The conical surfaces enable the rotor to be shifted to appropriate positions without external intervention, allowing the system to maintain optimal performance and minimize wear automatically.

Inventive Principle:

Principle #25Self-service

3Adaptability or versatility

If conventional devices use a fixed rotor position, then device complexity is reduced, but adaptability to different fluid conditions and operational flexibility are limited

Engineering Contradiction:

Improveadjustable clearance for different fluid conditionsVSAvoidstructure with conical tapered surfaces and slidable connectors

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces controlled complexity through conical tapered surfaces and slidable drive connectors that enable rotor position adjustment. While the structure becomes more complex, this complexity is justified by the significant gain in adaptability to different fluid conditions. The conical surfaces provide a simple geometric solution that enables continuous adjustment of rotor position without requiring complex mechanisms.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The conical tapered surfaces and adjustable rotor position mechanism provide multi-functionality, allowing the same device to handle various fluid conditions (from low to high solid content) by simply adjusting the rotor position. This universal design eliminates the need for multiple specialized devices, making the added structural complexity worthwhile by providing broad adaptability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS20250290507A1Progressing cavity devices and assemblies for coupling multiple stages of progressing cavity devices

Publication Date: 2025.09.18 NAT OILWELL VARCO LP

AI summary

A progressing cavity device includes a stator including a first end, a second end, and an inner surface formed from a metallic material that extends between the first end and the second end, and a rotor rotatably disposed in the stator, the stator including a first end, a second end, and an outer surface formed from a metallic material that extends between the first end and the second end, wherein the outer surface of the rotor contacts the inner surface of the stator, wherein the inner surface of the stator includes a conical taper extending between the first end and the second end, wherein the outer surface of the rotor includes a conical taper extending between the first end and the second end.