Bearing Preload Assembly Using Threaded Adjustment on Shafts

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Solution Overview

Problem

Current methods for preloading bearings in large-scale applications, such as wind turbines and gear drives, require precise and accurate preload spacers, which often necessitate on-site regrinding and depend heavily on installer skill, leading to inefficiencies.

Innovation Solution

A preloading apparatus featuring a shaft with strategically placed apertures, keyway channels, and intermeshing threaded members, along with pawl and ratchet arrangements and linear actuators, allows for precise and repeatable preload adjustments, minimizing the need for regrinding and improving installer independence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a preload spacer is clamped to provide the preload force, then the bearing assembly can be preloaded, but the height of the spacer requires incredible accuracy (micron level) and often requires on-site regrinding

Engineering Contradiction:

Improvepreload force accuracyVSAvoidspacer manufacturing complexity

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The invention replaces the static, precision-machined spacer with a dynamic adjustment mechanism consisting of threaded members that allow the preload force to be adjusted on-site. The threaded members convert rotational motion into precise linear displacement, enabling accurate preload application without requiring micron-level spacer manufacturing.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention changes the parameter control method from fixed geometric dimensions (spacer height) to adjustable mechanical parameters (threaded member rotation). This allows the preload force to be precisely controlled through rotational adjustment rather than relying on extremely precise linear dimensions.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If a preload spacer with micron-level accuracy is used, then the appropriate preload force can be achieved, but the process becomes inefficient and dependent on installer skill

Engineering Contradiction:

Improvepreload force accuracyVSAvoidpreload process efficiency

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The threaded members are designed to be self-adjusting, where the installer simply needs to rotate the members to achieve the desired preload. The mechanism itself provides the precision adjustment capability, eliminating the need for skilled regrinding operations and reducing dependency on installer expertise.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The apparatus allows preliminary setup and adjustment to be performed on-site before final installation. The threaded members can be pre-adjusted to the correct preload specification, and then the entire assembly can be installed as a unit, improving overall process efficiency.

Inventive Principle:

Principle #10Preliminary action

3Manufacturing precision

If on-site regrinding is performed to achieve accurate preload, then the correct preload force can be obtained, but the process time increases and installer skill becomes critical

Engineering Contradiction:

Improvepreload force accuracyVSAvoidpreload adjustment time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The invention replaces the traditional mechanical grinding process with a threaded adjustment mechanism. Instead of removing material through grinding to achieve the correct spacer height, the system uses threaded members to mechanically adjust the preload through controlled displacement, dramatically reducing adjustment time and eliminating the need for skilled grinding operations.

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

Enables accurate and efficient preload application with minimal adjustments, reducing the reliance on installer skill and enhancing the efficiency of the preload process in large-scale bearing installations.

Implementation Method 1

linear actuators, allows for precise and repeatable preload adjustments

Methodology Applied

Scientific EffectLinear actuator: Linear Motor

Implementation Method 2

pawl and ratchet arrangements and linear actuators, allows for precise and repeatable preload adjustments

Methodology Applied

Scientific EffectRatchet mechanism: Ratchet

Implementation Method 3

pawl and ratchet arrangements and linear actuators, allows for precise and repeatable preload adjustments

Methodology Applied

Scientific EffectMechanical advantage: Mechanical Advantage

Implementation Method 4

intermeshing threaded members, along with pawl and ratchet arrangements and linear actuators, allows for precise and repeatable preload adjustments

Methodology Applied

Scientific EffectThreaded mechanism: Screw

Data Source

PatentEP3423724B1Apparatus and method for preloading bearing assemblies

Publication Date: 2021.07.28 THE TIMKEN CO(US)

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AI summary

An apparatus (10) for preloading a bearing assembly (14) on a shaft (12) includes a first annular threaded member (56) positioned about the shaft (12) and a second annular threaded member (68) positioned about the shaft (12). The first and second threaded members (56,68) have intermeshing threads such that rotation of the second threaded member (68) causes axial translation of the first threaded member (56) to apply a first axial force to the bearing assembly (14) to preload the bearing assembly (14). An actuator is operable to rotate the second threaded member (68) relative to the first threaded member (56) to apply the first axial force to the bearing assembly (14).