Drive Axle Gear Detection Using Rotary Angle Encoder

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Solution Overview

Problem

Existing drive axles in agricultural vehicles, such as forage harvesters and combine harvesters, face challenges in gear detection and fault diagnosis due to the complexity and susceptibility to faults of multiple electrical components in manual transmissions, making error identification and maintenance difficult.

Innovation Solution

A drive axle with a simplified gear detection system using a rotary angle sensor kinematically coupled to the actuating element via mechanical guide means, which generates an angle signal indicating the selected gear level, reducing the number of electrical components and allowing detection of multiple positions with a single sensor, thus simplifying fault diagnosis and maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple pushrod switches are used to detect gear positions, then gear recognition capability is improved, but device complexity and susceptibility to faults increase

Engineering Contradiction:
Improvegear recognition capabilityVSAvoidnumber of electrical components
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Multiple pushrod switches are merged into a single rotary angle encoder that detects the position of a single actuating element. The encoder integrates the functionality of multiple switches by measuring the cumulative rotational angle, thereby reducing the number of electrical components while maintaining gear recognition capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The rotary angle encoder serves multiple functions: it detects the position of the actuating element, determines the selected gear stage, and provides a unified signal for all gear positions. This multi-functional component replaces multiple specialized switches, reducing system complexity.

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

2Measurement precision

If multiple pushrod switches with wiring are installed, then gear position detection is improved, but ease of repair and fault diagnosis deteriorate

Engineering Contradiction:
Improvegear position detectionVSAvoidfault diagnosis difficulty
Core Design Contradiction:
Measurement precisionVSEase of repair

Solution Approach 1:

The complex wiring system associated with multiple switches is extracted and replaced by a single encoder output. This eliminates the need for multiple wiring connections, making fault diagnosis simpler as there is only one sensor to check rather than multiple switches and their associated wiring.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The rotary angle encoder acts as an intermediary that converts the mechanical position of the actuating element into an electrical signal. This single intermediary component simplifies the system architecture, making it easier to diagnose faults compared to multiple direct switch-wiring connections.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If a single rotary encoder is used with mechanical guide means, then device complexity is reduced, but measurement precision must be maintained

Engineering Contradiction:
Improvenumber of electrical componentsVSAvoidgear position detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The mechanical guide means translate the linear or angular movement of the actuating element into rotational movement of the encoder shaft. This mechanical transformation ensures that a single rotary encoder can accurately track the position throughout the entire range of motion, maintaining measurement precision while reducing component count.

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

Solution Approach 2:

The mechanical guide means change the parameter of motion from linear/displaced movement to rotational movement, which is the native measurement parameter of the rotary encoder. This parameter transformation allows the encoder to accurately detect all actuator positions with a single component.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2947353B1Drive axle for a vehicle
Publication Date: 2020.09.02 CLAAS INDUSTRIETECHNIK GMBH
  • EP2947353B1 patent drawingFigure 1
  • EP2947353B1 patent drawingFigure 2
  • EP2947353B1 patent drawingFigure 3~4

AI summary

A drive axle for a vehicle, in particular for an agricultural harvesting machine, with an integrated gearbox (2) which can be shifted into several gear stages (N, G1, Gn) by means of at least one movable actuating element (3, 4) and with a sensor arrangement for detecting the engaged gear stage (N, G1, Gn) is characterized in that the sensor arrangement has a rotary angle encoder which is kinematically coupled to the at least one actuating element (3, 4) via mechanical guide means (7, 8, 9, 21) in order to generate an angle signal (S) depending on the position of the at least one actuating element (3, 4) which indicates the engaged gear stage (N, G1, Gn) of the gearbox (2).