Variable Speed Transmission With Speed-Summing Gear for Compressors

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing systems require complex and costly variable frequency drivers to modulate the rotational speed of large compressors, which are inefficient and cumbersome, especially in industrial applications where compressors need to operate within a specific speed range.

Innovation Solution

A system comprising a constant-speed driver, a variable speed transmission with a speed summing gear arrangement and a continuous variable transmission device, allowing the rotational speed of the load to be modulated while maintaining the driver's constant speed, using a magnetic or hydro viscous coupling to transmit power and adjust torque.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a variable frequency driver is used to modulate the rotational speed of large compressors, then the rotational speed can be adjusted, but the system becomes complex, costly and cumbersome

Engineering Contradiction:
Improverotational speed modulation capabilityVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The power transmission is segmented into two separate paths: a main power path that transmits the majority of power at constant speed, and a modulation path that transmits a fraction of power through a variable speed transmission device. This segmentation allows speed modulation without requiring the entire system to be variable speed capable, thereby reducing overall system complexity while maintaining adaptability.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If a variable frequency driver is used to modulate the rotational speed of large compressors, then the rotational speed can be adjusted, but the system becomes costly and cumbersome

Engineering Contradiction:
Improverotational speed modulation capabilityVSAvoidpower handling capability
Core Design Contradiction:
Adaptability or versatilityVSPower

Solution Approach 1:

Instead of modulating the entire power flow, only a fraction (typically less than 50%, preferably less than 30% or 20%) of the power from the constant-speed driver is routed through the variable speed transmission device. This partial action approach enables rotational speed modulation while keeping the variable frequency driver smaller, less costly, and less cumbersome, as it only needs to handle a portion of the total power.

Inventive Principle:
Principle #16Partial or excessive action

3Use of energy by moving object

If a constant-speed driver is used, then the driver operates efficiently at constant speed, but the rotational speed of the load cannot be modulated

Engineering Contradiction:
Improvedriver efficiencyVSAvoidload speed modulation capability
Core Design Contradiction:
Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

A variable speed transmission device is introduced as an intermediary between the constant-speed driver and the load. This intermediary component enables the load speed to be modulated while the driver continues to operate at its efficient constant speed. The intermediary handles the speed conversion and modulation functions, allowing the driver to maintain optimal operating conditions while providing adaptable load speed control.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables efficient modulation of the rotational speed of variable-speed loads, reducing the need for complex variable frequency drivers and improving power transmission efficiency by maintaining the driver's constant speed, suitable for large compressors and other turbomachines.

Implementation Method 1

A magnetic or hydro viscous coupling to transmit power and adjust torque

Methodology Applied
Scientific EffectMagnetic coupling: Magnetic Field

Implementation Method 2

A magnetic or hydro viscous coupling to transmit power and adjust torque

Methodology Applied
Scientific EffectViscous friction: Friction

Data Source

PatentEP3482100B1Variable speed transmission and system using same
Publication Date: 2023.08.30 NUOVO PIGNONE TECH SRL
  • EP3482100B1 patent drawingFigure 1~2
  • EP3482100B1 patent drawingFigure 3
  • EP3482100B1 patent drawingFigure 3A~3B

AI summary

The system (1) comprises: a driver (3); a rotating load (5) configured to be driven into rotation by the driver (3); a controller (12), for controllably changing a rotation speed of the load (5); and a variable speed transmission (11), arranged between the driver (3) and the load (5). The variable speed transmission (11) comprises a speed summing gear arrangement (21) with a first input shaft (23), a second input shaft (25) and an output shaft (27). The output shaft (27) is drivingly coupled to the rotating load (5). The first input shaft (23) is drivingly coupled to the driver (3). A continuous variable transmission device (43; 143; 243; 343) is mechanically coupled to the driver (3) and to the second input shaft (25) of the speed summing gear arrangement (21). The continuous variable transmission device (43; 143; 243; 343) is functionally coupled to the controller (12).