HVAC Adjustment Lever with Conical Clearance Compensation

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Solution Overview

Problem

Existing adjustment devices in HVAC applications suffer from inaccurate rotation and noise due to axial and radial clearances caused by manufacturing processes and design tolerances, leading to idling and vibratory issues.

Innovation Solution

A collar with a conical surface is integrated on the driving part of the shaft, and elastically deformable elements are circumferentially arranged on the handgrip to engage the conical surface, producing a reaction force that biases the handgrip against the shaft, eliminating clearances and noise by aligning it with the theoretical axis of rotation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If standard manufacturing processes and design tolerances are used, then manufacturing cost and ease of assembly are improved, but axial and radial clearances are generated causing inaccurate rotation and noise

Engineering Contradiction:
Improveease of manufactureVSAvoidrotation accuracy
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The conical surface acts as an intermediary element between the handgrip and the shaft. The elastically deformable elements engage with this conical surface to transmit and distribute the biasing force, mediating the clearance compensation between the handgrip and shaft components.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The elastically deformable elements change their physical state from undeformed to deformed, altering their dimensional parameters to compensate for clearances. The elastic deformation allows the elements to adapt to varying clearance conditions while maintaining precise alignment.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If standard manufacturing processes and design tolerances are used, then manufacturing simplicity is improved, but noise and vibratory movement are generated due to clearances

Engineering Contradiction:
Improvedevice complexityVSAvoidnoise
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The conical surface serves as a mediator that distributes the contact force from multiple elastically deformable elements, ensuring uniform pressure application and preventing localized vibrations that would generate noise.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The elastically deformable elements provide beforehand cushioning by being pre-biased against the shaft through the conical surface engagement. This elastic cushioning absorbs vibrations and prevents noise before they can propagate through the system.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Manufacturing precision

If clearance compensation mechanisms are added, then rotation accuracy and noise elimination are improved, but device complexity increases

Engineering Contradiction:
Improverotation accuracyVSAvoiddevice complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The conical surface performs multiple functions: it provides a geometric reference for alignment, distributes contact forces from the elastically deformable elements, and enables clearance compensation. This multi-functionality reduces the need for separate components, offsetting the added complexity.

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

Solution Approach 2:

The clearance compensation mechanism is segmented into distinct functional elements: the conical surface for force distribution and the elastically deformable elements for adaptive alignment. This segmentation allows each element to be optimized independently while working together as an integrated system.

Inventive Principle:
Principle #1Segmentation

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 solution ensures a perfect assembly and complete elimination of noise associated with component clearances, enhancing the precision and operation of the adjustment device.

Implementation Method 1

a plurality of elastically deformable elements is provided on said handgrip, which elements are circumferentially arranged along said handgrip, wherein each of said elastically deformable elements is suitable to engage said conical surface in such a way as to produce a reaction force acting on the handgrip

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2479634B1Adjustment lever, particularly for automotive HVAC applications, with clearance recovery
Publication Date: 2013.12.11 DENSO THERMAL SYST SPA
  • EP2479634B1 patent drawingFigure 1~2
  • EP2479634B1 patent drawingFigure 3~4
  • EP2479634B1 patent drawingFigure 5~6

AI summary

An adjustment device (1), comprising a support (3) through which a through bore (5) is formed; a shaft (11) mounted through the through bore and having a shoulder portion (17) suitable to axially engage the support; and a handgrip (19) snap-fitted on the shaft in such a way as to axially lock the shaft relative to the support, by co-operating with the shoulder portion. A collar (31) concentric with the bore and having a conical surface (33) on the free end thereof is disposed on the support. A plurality of elastically deformable elements (191) is disposed on the handgrip, which are arranged circumferentially along said handgrip, wherein each of the elastically deformable elements is adapted to engage the conical surface in such a way as to produce a reaction force acting on the handgrip, this reaction force having an axial component directed away from the support and a centripetal radial component.