Stackable Nut Torquing Assembly for Recessed Terminal Nuts

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Solution Overview

Problem

Accessing and tightening terminal nuts in industrial machines, such as electric generators, is challenging due to their difficult location, requiring time-consuming and costly processes like removing retaining rings and end windings.

Innovation Solution

A nut torqueing device with a stackable nut engaging assembly, including a nut engaging element, riser elements, and a transmission system with a ratchet interface, allowing for rotational power transmission to torque the nut from a rotational power source without disassembling the machine.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional tools (wrenches, socket sets) are used to access terminal nut, then the nut can be tightened, but the process requires removing retaining rings and end windings which is time-consuming and expensive

Engineering Contradiction:
ImproveAccessibility of terminal nutVSAvoidTime required for disassembly and assembly
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The tool is divided into multiple separable components: a base engagement element that interfaces with the terminal nut, extendable rod sections that can be stacked to reach the nut through the limited space, and a handling element. This segmentation allows the tool to be assembled in different configurations to access the deeply recessed terminal nut without requiring disassembly of the generator components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The tool employs nested rod sections that can be extended or collapsed like a telescoping structure. The rod sections store within each other when not in use and extend sequentially to reach the terminal nut located approximately 7-13 cm from the outer surface and 33-43 cm from the axial end of the retainer ring, enabling access through the constrained space without removing end windings or retaining rings.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of operation

If conventional tools are used to access terminal nut, then the nut can be tightened, but the tool must be transportable and manually operated in a difficult location

Engineering Contradiction:
ImproveAccessibility of terminal nutVSAvoidTool structure complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The tool is divided into multiple separable components: a base engagement element that interfaces with the terminal nut, extendable rod sections that can be stacked to reach the nut through the limited space, and a handling element. This segmentation allows the tool to be assembled in different configurations to access the deeply recessed terminal nut without requiring disassembly of the generator components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The tool incorporates a ratchet mechanism that allows unidirectional rotation and locking, enabling the operator to apply torque in one direction while the ratchet prevents backward movement. This dynamic feature simplifies operation in the constrained space by eliminating the need for precise bidirectional control, making the tool easier to operate despite its extended reach capability.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If a telescoping tool is used to reach the terminal nut, then access is improved, but torque transmission becomes difficult due to the extended length

Engineering Contradiction:
ImproveAccessibility of terminal nutVSAvoidTorque transmission capability
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The tool incorporates a ratchet mechanism that allows unidirectional rotation and locking, enabling the operator to apply torque in one direction while the ratchet prevents backward movement. This dynamic feature simplifies operation in the constrained space by eliminating the need for precise bidirectional control, making the tool easier to operate despite its extended reach capability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The tool design incorporates curved or angled sections in the rod configuration to navigate around the end windings and reach the terminal nut from an accessible angle. This curved path allows torque to be applied more effectively by aligning the force vector optimally, compensating for the extended length and maintaining torque transmission efficiency.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 tightening of terminal nuts without disassembling the generator, saving time and costs by providing a compact, stackable solution that transmits torque through a series of interlocked elements, allowing for one-directional rotation to secure the nut.

Implementation Method 1

a ratchet interface between a pair of adjacent stackable elements of the nut engaging assembly allowing rotation of the nut engaging element in only one direction

Methodology Applied
Scientific EffectRatchet mechanism: Ratchet

Implementation Method 2

a transmission configured to transmit rotational power from a rotational power source to the transmission engaging element of the nut engaging assembly to torque a nut engaged by the nut engaging element

Methodology Applied
Scientific EffectMechanical power transmission: Gear

Implementation Method 3

a rest of the plurality of stackable elements are rotationally interlocked

Methodology Applied
Scientific EffectMechanical interlocking: Mechanical Fastener

Data Source

PatentEP3300837B1Nut torquing device for recessed nut
Publication Date: 2021.04.07 GENERAL ELECTRIC CO
  • EP3300837B1 patent drawingFigure 1
  • EP3300837B1 patent drawingFigure 2
  • EP3300837B1 patent drawingFigure 3

AI summary

A nut torqueing device (100) for a recessed nut is disclosed. The nut torqueing device includes a nut engaging assembly (102,104) to engage a nut in a recess. The nut engaging assembly includes: a nut engaging element (102,130) to engage the nut in the recess, at least one stackable riser element (132) to stackably connect to one of the nut engaging element and an adjacent stackable riser element (132,132C,132D,132F) therebelow, and a transmission engaging element (104,140) to stackably connect to an uppermost one of the at least one stackable riser element. A ratchet interface (104,106,130) within the nut engaging assembly allows rotation of the nut engaging element in only one direction, while other stackable elements rotationally interlock. A low profile transmission extends within a small space to transmit rotational power (108) to the nut engaging assembly. The nut torqueing device is applicable with a terminal nut of an electric generator.