Variable speed transmission with auxiliary driver and system using same

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing systems require complex and costly variable frequency drivers to modulate the rotational speed of large compressors driven by constant-speed electric motors, which are inefficient and cumbersome.

Innovation Solution

A system comprising a main driver at constant rotational speed, a controller, and a variable speed transmission with a speed summing gear arrangement, including an auxiliary driver to modulate the load's rotational speed, allowing the main driver to operate at a fixed speed while adjusting the load's speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

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

Engineering Contradiction:

Improverotational speed modulationVSAvoidsystem complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system divides the speed control function into two independent inputs: the main driver provides the base rotational speed, while the auxiliary driver provides speed modulation through the differential gear arrangement. This segmentation eliminates the need for a complex variable frequency driver, as each component operates independently at simpler control requirements.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A differential gear arrangement is introduced as an intermediary mechanical device between the main driver and the load. This intermediary combines the rotational speeds of two drivers in a mechanical summation, enabling speed modulation without electronic power conversion and thereby reducing system complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If a variable frequency driver is used to modulate the rotational speed of the load, then the rotational speed can be adjusted, but the cost increases

Engineering Contradiction:

Improverotational speed modulationVSAvoidsystem cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent replaces the electronic variable frequency driver system with a mechanical differential gear arrangement. This mechanical substitution eliminates the need for expensive power electronic converters, reducing manufacturing costs while maintaining the capability for rotational speed modulation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If a variable frequency driver is used to modulate the rotational speed of the load, then the rotational speed can be adjusted, but power conversion losses increase

Engineering Contradiction:

Improverotational speed modulationVSAvoidpower conversion losses

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

By replacing the variable frequency driver with a mechanical differential gear system, the patent eliminates power conversion losses associated with electronic converters. The mechanical transmission directly transmits power from the drivers to the load with minimal energy loss, while still enabling speed modulation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 eliminates the need for variable frequency drivers, reduces power requirements for the auxiliary driver, and enhances energy efficiency by allowing precise control of the load's speed while minimizing power conversion losses.

Implementation Method 1

a variable speed transmission, arranged between the main driver and the load and comprised of a speed summing gear arrangement having a first input shaft, a second input shaft and an output shaft

Methodology Applied

Scientific EffectSpeed summing gear arrangement: Gear

Data Source

PatentUS10948053B2Variable speed transmission with auxiliary driver and system using same

Publication Date: 2021.03.16 NUOVO PIGNONE TECH SRL

AI summary

The system comprises: a main driver configured for rotating at a substantially constant rotational speed; a rotating load configured to be driven into rotation by the main driver; a controller, for controllably adjusting a load rotational speed; a variable speed transmission, arranged between the main driver and the load and comprised of a speed summing gear arrangement having a first input shaft, a second input shaft and an output shaft; an auxiliary driver, mechanically coupled to the second input shaft of the speed summing gear arrangement. The first input shaft of the speed summing gear arrangement is drivingly coupled to the main driver. The output shaft of the speed summing gear arrangement is drivingly coupled to the rotating load. The speed of the output shaft is a combination of a speed of the main driver and of a speed of the auxiliary driver.