Adjustable Encoder Shaft Clamp for Slip-Free Disc Coupling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional methods for securing a motor shaft to a rotatable encoder disc often result in relative rotation, leading to inaccurate rotational information, which is detrimental in applications requiring exceptional accuracy.

Innovation Solution

An encoder assembly with a clamp that is securely fixed to both the encoder disc and the motor shaft, featuring an arcuately extending body with an adjustment mechanism to modify the clamping path and a radially extending cutout for bending, ensuring synchronous rotation and minimizing contact to prevent slipping or dragging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional methods are used to secure the motor shaft to the encoder disc, then the assembly is simple to manufacture, but relative rotation occurs leading to inaccurate rotational information

Engineering Contradiction:
Improverotational information accuracyVSAvoidclamp structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The clamp incorporates an adjustment mechanism that allows dynamic modification of the clamping path to precisely match the motor shaft dimensions. This dynamic adaptability ensures accurate coupling without relative rotation while maintaining a manageable structural complexity through controlled adjustability rather than fixed rigid design.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The clamp's clamping path parameters can be modified through the adjustment mechanism to optimize the fit between the clamp and motor shaft. By changing geometric parameters of the clamping interface, the system achieves precise rotational coupling that eliminates relative rotation and ensures accurate encoder readings.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the clamp is made adjustable to fit different shaft sizes, then adaptability improves, but the device complexity increases

Engineering Contradiction:
Improveclamp fit adjustmentVSAvoidadjustment mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The adjustment mechanism serves multiple functions: it adjusts the clamping path to fit different motor shaft sizes, ensures precise positioning to prevent relative rotation, and maintains secure coupling under vibrational loads. By consolidating these functions into a single mechanism, the design achieves high adaptability without proportionally increasing overall device complexity.

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

Solution Approach 2:

The clamp transitions from a static fixed-size design to a dynamic adjustable design that can adapt to various shaft dimensions. This dynamic capability provides universal fit for different motor shafts while the adjustment mechanism remains relatively simple through the use of standard mechanical adjustment components.

Inventive Principle:
Principle #15Dynamics

3Reliability

If the clamp contacts the encoder disc over a large area, then securement is improved, but slipping or dragging during rotation may occur

Engineering Contradiction:
Improvesecurement strengthVSAvoidslipping or dragging
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The clamp design concentrates contact at specific localized points: the inner face contacts the motor shaft at a precise clamping location, and the boss contacts the encoder disc at a specific axial position. This localized contact approach provides sufficient securement strength while minimizing surface area contact that could cause slipping or dragging during rotation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The contact surfaces are segmented into discrete, well-defined areas rather than continuous large surfaces. The clamp's inner face provides a localized clamping contact on the shaft, and the boss provides a localized contact point on the encoder disc, creating segmented contact zones that reduce friction-related issues while maintaining secure coupling.

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

The solution ensures accurate determination of motor shaft rotation and related parameters by eliminating relative rotation between the shaft and encoder disc, enhancing precision and reliability in applications with heavy vibrations.

Implementation Method 1

The body defines a radially extending cutout therein. The cutout extends from one of the inner and outer faces and facilitates bending of the body in association with arcuate expansion or contraction of the gap and modification of the clamping path.

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4286799A1Rotary encoder shaft clamp
Publication Date: 2023.12.06 NIDEC MOTOR CORP
  • EP4286799A1 patent drawingFigure 1
  • EP4286799A1 patent drawingFigure 2
  • EP4286799A1 patent drawingFigure 3

AI summary

An encoder includes a rotatable encoder disc. A clamp is fixed to the encoder disc to rotate therewith. The clamp includes an arcuately extending body presenting a radially inner face and arcuately spaced apart ends defining a gap therebetween. The inner face extends along a clamping path and engages a rotating component to secure the clamp to the rotating component to rotate therewith. The clamp includes an adjustment mechanism for modifying an arcuate extent of the gap by shifting the ends relative to one another and, in turn, modifying the clamping path. The body defines a radially extending cutout facilitating bending of the body in association with expansion or contraction of the gap and modification of the clamping path. The clamp includes a raised boss extending from a front face thereof. The boss presents a contact face spaced axially from the front face and fixedly engaging the encoder disc.