Torque Motor Actuator Armature Stop Design

Solution Overview

Problem

Existing torque motor actuators face high manufacturing and calibration costs due to the use of small diameter, high length-to-diameter ratio stop screws and threaded holes in magnetic pole pieces, which are difficult to tap and adjust, limiting armature rotational displacement and requiring costly calibration.

Innovation Solution

A torque motor actuator with an armature stop made of non-magnetic material, such as a pin or rivet, that is press-fit or riveted into the armature, allowing for controlled rotational displacement without the need for expensive threaded stop screws and anaerobic sealants, reducing manufacturing and calibration costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If threaded stop screws with high length-to-diameter ratio are used to limit armature rotation, then armature rotational displacement is effectively limited, but manufacturing cost and calibration cost increase significantly

Engineering Contradiction:

Improvearmature rotational displacement limitationVSAvoidmanufacturing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent replaces expensive, precision-manufactured threaded stop screws with simple, non-magnetic pins or rivets that are press-fit into the armature. These simpler components achieve the same rotational limitation function at lower manufacturing cost and without requiring complex threading operations in the magnetic pole pieces.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The invention extracts the stop function from the magnetic pole pieces (by removing threaded holes from the magnetic material) and relocates it to the armature itself. The non-magnetic pin or rivet is press-fit into the armature, separating the rotational limitation function from the magnetic circuit components.

Inventive Principle:

Principle #2Taking out (Extraction)

2Manufacturing precision

If threaded stop screws are used to limit armature rotation, then armature rotational displacement is controlled, but calibration and adjustment become difficult and costly

Engineering Contradiction:

Improvearmature rotational displacement controlVSAvoidcalibration difficulty

Core Design Contradiction:

Manufacturing precisionVSEase of repair

Solution Approach 1:

The patent replaces expensive, precision-manufactured threaded stop screws with simple, non-magnetic pins or rivets that are press-fit into the armature. These simpler components achieve the same rotational limitation function at lower manufacturing cost and without requiring complex threading operations in the magnetic pole pieces.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Manufacturing precision

If small diameter stop screws are used in magnetic pole pieces, then armature rotation is limited, but the magnetic material becomes difficult to tap and manufacture

Engineering Contradiction:

Improvearmature rotation limitationVSAvoidmagnetic pole piece manufacturability

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The invention extracts the stop function from the magnetic pole pieces (by removing threaded holes from the magnetic material) and relocates it to the armature itself. The non-magnetic pin or rivet is press-fit into the armature, separating the rotational limitation function from the magnetic circuit components.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces expensive, precision-manufactured threaded stop screws with simple, non-magnetic pins or rivets that are press-fit into the armature. These simpler components achieve the same rotational limitation function at lower manufacturing cost and without requiring complex threading operations in the magnetic pole pieces.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

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

The solution provides a cost-effective and efficient method to limit armature rotation, simplifying the calibration process and reducing the complexity of manufacturing, while maintaining effective armature position control.

Implementation Method 1

The coils are controllably energized to generate a magnetic force that is transmitted through the pole pieces and across air gaps into which portions of the armature extend. The magnetic force acts on and controls the rotational position of the armature.

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The armature stop extends from the first arm, and comprises a non-magnetic material. The armature stop is configured, upon rotation of the armature, to selectively engage one of the first or second magnetic pole pieces to thereby limit armature rotation.

Methodology Applied

Scientific EffectPhysical contact and mechanical constraint: Mechanical Fastener

Data Source

PatentUS9711269B2Torque motor actuator with an armature stop

Publication Date: 2017.07.18 HONEYWELL INTERNATIONAL INC

AI summary

A torque motor actuator includes a first magnetic pole piece, a second magnetic pole piece, an armature, and an armature stop. The second magnetic pole piece is spaced apart from the first magnetic pole piece to define an armature gap. The armature is disposed in the armature gap and is spaced apart from the first and second magnetic pole pieces. The armature includes a magnetically permeable material and has a central portion, a first arm, and a second arm. The armature is rotationally mounted at the central portion, and the first and second arms extend, in opposite directions, from the central portion. The armature stop extends from the first arm, and comprises a non-magnetic material. The armature stop is configured, upon rotation of the armature, to selectively engage one of the first or second magnetic pole pieces to thereby limit armature rotation.