Encoder Rotation Restricting Member Axial Press-Fit Mounting

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Solution Overview

Problem

Conventional methods for attaching a rotary encoder to a rotating subject require screwing processes, which are inefficient, costly, and difficult to automate, limiting mass production and general applicability.

Innovation Solution

A rotation restricting member with a coupling part, convex fixing parts, and attaching parts that allow for secure locking without screws, enabling easy axial attachment and facilitating mechanical mounting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a member for preventing rotation is fixed to the stator by screws, then the stator is securely locked to the measured subject, but the screwing process deteriorates working efficiency and restricts mass production

Engineering Contradiction:
Improvelocking reliabilityVSAvoidworking efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention extracts and eliminates the screwing process from the attachment method. The rotation restricting member is designed to be attached to the stator without any screws, using a simple press-fit or snap-fit mechanism instead, thereby removing the time-consuming screwing operation while maintaining secure locking.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the screw-mechanical fastening system with a deformation-based mechanical interlocking system. The rotation restricting member utilizes elastic deformation of its attachment portions to engage with the stator, substituting the threaded mechanical connection with a more efficient elastic-mechanical connection.

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

2Reliability

If a member for preventing rotation is fixed to the stator by screws, then the stator is securely locked to the measured subject, but the process is extremely troublesome and increases cost when attached in the field

Engineering Contradiction:
Improvelocking reliabilityVSAvoidease of attachment
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention extracts and eliminates the screwing process from the attachment method. The rotation restricting member is designed to be attached to the stator without any screws, using a simple press-fit or snap-fit mechanism instead, thereby removing the time-consuming screwing operation while maintaining secure locking.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The rotation restricting member is designed to be self-attaching to the stator through its elastic deformation mechanism. The attachment portions automatically engage with the stator body when pressed into place, making the attachment process self-serviceable and eliminating the need for complex tools or procedures.

Inventive Principle:
Principle #25Self-service

3Reliability

If a joint is used to couple the rotor and shaft, then relative rotation is prevented, but the method is difficult to apply to encoders with ordinary shaft coupling and lacks generality

Engineering Contradiction:
Improverotation preventionVSAvoidapplicability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention designs the rotation restricting member with universal applicability to encoders with ordinary shaft coupling. The member can be attached to the stator and adapt to various encoder configurations without requiring specialized joint structures, assembly spaces, or modifications to the motor shaft, thereby achieving broad versatility.

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

Solution Approach 2:

Instead of modifying the motor shaft or rotor to accommodate a special joint structure, the invention inverts the approach by attaching the rotation restricting member to the encoder stator. This allows the solution to work with standard motor shafts and rotors, enhancing adaptability and generality.

Inventive Principle:
Principle #13The other way round (Inversion)

4Reliability

If a joint is used to couple the rotor and shaft, then relative rotation is prevented, but fixture onto the angle measurement device still requires a screwing process

Engineering Contradiction:
Improverotation preventionVSAvoidmounting efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention extracts and eliminates the screwing process from the attachment method. The rotation restricting member is designed to be attached to the stator without any screws, using a simple press-fit or snap-fit mechanism instead, thereby removing the time-consuming screwing operation while maintaining secure locking.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the screw-mechanical fastening system with a deformation-based mechanical interlocking system. The rotation restricting member utilizes elastic deformation of its attachment portions to engage with the stator, substituting the threaded mechanical connection with a more efficient elastic-mechanical connection.

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

Data Source

PatentEP2288877B1Encoder having rotation restricting member
Publication Date: 2015.07.08 DR JOHANNES HEIDENHAIN GMBH
  • EP2288877B1 patent drawingFigure 1~2
  • EP2288877B1 patent drawingFigure 3~4
  • EP2288877B1 patent drawingFigure 5~6

AI summary

There is provided an encoder having a rotation restricting member that is generally applicable, does not require a process such as screwing when attached to the encoder, and can be easily attached in a short period of time. Further, the rotation restricting member can be attached only from a specific one direction, and can be mounted mechanically. The encoder includes a rotor that is coupled to a rotation axis (19) of a measured subject (3); a stator (2) that rotatably supports the rotor; and a rotation restricting member (1) that locks the stator to the measured subject (3), the rotation restricting member (1) including: a coupling part (11) that functions as a base; a convex fixing part (15) that extends along the rotation axis from the coupling part (11) toward the stator (2); and an attaching part (13) that extends in any direction from the coupling part (11) or is formed integrally with the coupling part (11), and the stator (2) having, at least on an attachment surface, a concave fixing part (21) that is concave in a direction along the rotation axis, wherein the convex fixing (15) part is inserted or press fitted into the concave fixing part (21) so as to be locked thereto.