Multi-Jackbolt Tensioner with Planetary Gear Torque Multiplication

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Solution Overview

Problem

The existing Multi-Jackbolt Tensioners (MJTs) require time-consuming individual tightening of each jackbolt, and existing tensioning apparatuses are either unsuitable for large jackbolts or impractical for simultaneous tensioning across multiple MJTs, lacking compactness and sufficient torque.

Innovation Solution

A compact tensioning apparatus featuring a housing with planetary gears, a ring gear, and spindle gears that work in conjunction with a power transfer assembly including a worm drive, allowing simultaneous and efficient tightening of multiple jackbolts by rotating the spindle gears to apply torque uniformly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a handheld apparatus is made large enough to tighten large jackbolts, then torque capability is improved, but portability and ease of operation deteriorate

Engineering Contradiction:

Improvetorque capabilityVSAvoidportability

Core Design Contradiction:

ForceVSEase of operation

Solution Approach 1:

The apparatus divides the torque application function across multiple planetary gears arranged in a polar array, each engaging with a separate jackbolt. This segmentation allows the system to distribute the total torque requirement across multiple smaller gear units, maintaining compact size while achieving high total torque output through parallel action.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The planetary gears are nested within a compact housing structure, with each planetary gear unit containing its own gear train. The entire assembly fits within a portable form factor, with the planetary gears nested concentrically around a central drive mechanism, maximizing space utilization while maintaining torque capability.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Productivity

If individual jackbolts are tightened separately with hand tools, then device complexity is reduced, but productivity and time efficiency deteriorate

Engineering Contradiction:

Improvetightening speedVSAvoidapparatus structure

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The apparatus merges multiple torque application functions into a single integrated device. The planetary gears, drive gear, and housing are combined into one unified apparatus that can simultaneously engage and tighten multiple jackbolts, eliminating the need for multiple separate hand tool operations.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The apparatus is designed as a universal tensioning device that can simultaneously perform multiple tightening operations on different jackbolts. The polar array configuration allows the same apparatus to tighten jackbolts at different positions and orientations, providing multi-functionality in a single device.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Productivity

If planetary gears are used to enable simultaneous tensioning, then productivity is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improvesimultaneous tensioning capabilityVSAvoidmanufacturing complexity

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

Each planetary gear unit is designed as a standardized module with specific local characteristics optimized for its position in the polar array. The modular design allows each unit to be manufactured independently using standard gear cutting processes, then assembled into the final apparatus, reducing overall manufacturing complexity.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The planetary gears and their components are pre-assembled and pre-tested as modular units before final integration into the apparatus. This preliminary assembly allows for quality control and adjustment to be performed on individual modules, simplifying the final assembly process and reducing manufacturing complexity.

Inventive Principle:

Principle #10Preliminary action

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 and simultaneous tensioning of multiple jackbolts with improved compactness and torque application, reducing operator effort and time required for large-scale MJT installations.

Implementation Method 1

one or more planetary gears retained within the housing for meshing with the drive gear

Methodology Applied

Scientific EffectGear meshing: Gear

Implementation Method 2

one or more planetary gears retained within the housing for meshing with the drive gear; a ring gear encircling the one or more planetary gears and meshing therewith

Methodology Applied

Scientific EffectMechanical advantage: Mechanical Advantage

Implementation Method 3

A compact tensioning apparatus featuring a housing with planetary gears, a ring gear, and spindle gears that work in conjunction with a power transfer assembly including a worm drive

Methodology Applied

Scientific EffectWorm drive: Worm Drive

Data Source

PatentUS11518008B2Apparatus for simultaneously applying torque to a plurality of jackbolts of a multi jackbolt tensioner

Publication Date: 2022.12.06 SUPERBOLT INC

AI summary

A tensioning apparatus is adapted to simultaneously tension a number of jackbolts of a multi jackbolt tensioner. The tensioning apparatus may be made compact by overlapping gear disks of the spindle gears and further act as a torque multiplier between the other gears of the tensioning apparatus. The tensioning apparatus can be part of a combination with a power transfer assembly.