Torque Estimation via Bearing Deflection Sensing

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Solution Overview

Problem

Existing power train systems for work machines, such as tractors, face challenges in measuring torque without altering the structure of drive line components, which complicates and increases costs, compromising the optimized design of torque-carrying components.

Innovation Solution

A non-intrusive torque estimation method using a sensor to detect the displacement of driving and driven gears supported by bearing assemblies, which measures deflection caused by torque transmission, allowing for simplified and effective determination of over-torque conditions without modifying the power train structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If torque measurement devices are installed in the power train, then torque measurement capability is improved, but device complexity and manufacturing cost increase significantly

Engineering Contradiction:
Improvetorque measurement capabilityVSAvoidpower train structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical torque measurement devices with a simplified system using standard sensors that detect bearing deflections. The bearing assemblies serve dual purposes: supporting the input shaft and sensing torque-induced deflections. This substitution eliminates the need for complicated mechanical torque measurement apparatus while achieving accurate torque estimation through deflection sensing.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent makes the bearing assemblies multi-functional by having them perform both their traditional support function and a new torque sensing function. The same bearing assemblies that support the input shaft also detect torque levels through deflection measurements, eliminating the need for separate torque measurement devices and reducing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If torque measurement devices are installed in the power train, then torque measurement capability is improved, but manufacturing cost increases significantly

Engineering Contradiction:
Improvetorque measurement capabilityVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces expensive specialized torque measurement devices with inexpensive standard sensors. The system uses off-the-shelf sensors to detect bearing deflections, which are then converted to torque estimates. This substitution dramatically reduces manufacturing costs while maintaining accurate torque measurement capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The bearing assemblies serve themselves by performing dual functions: supporting the input shaft and sensing torque. This self-service approach eliminates the need for separate torque measurement devices, reducing component count and manufacturing complexity. The existing bearing structures are utilized for sensing purposes without requiring additional specialized components.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If alterations are made to torque carrying elements for measurement, then torque measurement capability is improved, but the optimized design of power train components is compromised

Engineering Contradiction:
Improvetorque measurement capabilityVSAvoidtorque carrying ability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent avoids altering torque carrying elements by substituting mechanical measurement devices with a deflection sensing approach. Standard sensors mounted on housings detect bearing deflections without requiring modifications to the torque carrying components themselves. This substitution preserves the original optimized design and torque carrying capacity of the power train components.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces bearing deflections as an intermediary measurement parameter. Instead of directly measuring torque or altering torque carrying elements, the system uses bearing deflections as an indirect indicator of torque levels. The sensors detect deflections of the bearing assemblies, which respond to torque without compromising the structural integrity or optimized design of the torque carrying components.

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

This approach enables cost-effective and simplified torque estimation, allowing for the detection of over-torque conditions and control of engine power output, thereby extending the longevity of drive components by avoiding excessive loading.

Implementation Method 1

a sensor detects displacement of one of said driving and driven gears in response to bearing deflections reacting to the level of torque transmitted by the driving gear

Methodology Applied
Scientific EffectDeflection: Deformation

Data Source

PatentEP2930485B1Torque estimation for work machine power train
Publication Date: 2019.06.05 CNH IND ITALIA SPA
  • EP2930485B1 patent drawingFigure 1
  • EP2930485B1 patent drawingFigure 2
  • EP2930485B1 patent drawingFigure 3

AI summary

A work machine having a diesel engine driving a plurality of ground movement devices (38, 39) to tow an agricultural implement (10). A torque estimating system is employed to determine the level of torque in the drive train between the diesel engine (24) and the ground movement devices (38, 39). The torque estimation device is a sensor (62) determining the axial and radial deflection of an input shaft (40) as a function of the torque transmitted between a pair of adjacent gears (42, 44) in the power train.