Rotary Tool Coupling Design with Parallel Torque Sections

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Solution Overview

Problem

Existing rotary tool coupling connections are complex and costly to produce due to the requirement of obliquely inclined surfaces for torque and clamping sections, which complicates manufacturing and increases production expenses.

Innovation Solution

A coupling connection design where torque and clamping sections extend parallel to the axis of rotation, with separate stop surfaces providing axial protection, allowing for simpler production and assembly by forming these sections through puncture methods, eliminating the need for obliquely inclined surfaces and additional fastening means like screws.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If obliquely inclined surfaces are used for torque and clamping sections to form a dovetail connection, then axial tightening and pull-out protection are achieved, but manufacturing complexity and production costs increase

Engineering Contradiction:
Improveaxial tightening and pull-out protectionVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The coupling connection is divided into three independent functional elements: torque sections (for torque transmission), clamping sections (for radial clamping force), and stop surfaces (for axial pull-out protection). This segmentation allows each element to be optimized independently and manufactured separately, eliminating the need for complex obliquely inclined dovetail surfaces while achieving all required functions.

Inventive Principle:
Principle #1Segmentation

2Reliability

If obliquely inclined surfaces are used for torque and clamping sections, then form fit effective in axial direction is achieved, but production costs increase

Engineering Contradiction:
Improveform fit effectivenessVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The axial form fit function is extracted from the torque and clamping sections and assigned to a separate stop surface element. This allows the torque and clamping sections to have simple cylindrical or flat surfaces that are easy to manufacture, while the stop surfaces provide the necessary axial form fit and pull-out protection through simple axial-facing surfaces.

Inventive Principle:
Principle #2Taking out (Extraction)

3Power

If torque sections and clamping sections are arranged one after the other in circumferential direction with oblique inclination, then torque transmission and radial clamping are achieved, but manufacturing complexity increases

Engineering Contradiction:
Improvetorque transmissionVSAvoidstructural complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

Different local regions of the coupling connection are assigned different functional qualities: torque sections have surfaces optimized for torque transmission, clamping sections have surfaces optimized for radial clamping force, and stop surfaces have axial-facing surfaces for axial protection. This local differentiation allows each region to be simple in its own right while the overall system achieves complex functionality.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3129180B1Rotary tool, in particular a drill, and cutting head for a rotary tool of this type
Publication Date: 2020.06.03 KENNAMETAL INC
  • EP3129180B1 patent drawingFigure 1A~1B
  • EP3129180B1 patent drawingFigure 2A~2C
  • EP3129180B1 patent drawingFigure 3A~3B

AI summary

A rotary tool designed as a modular drill, extending in an axial direction along an axis of rotation. It comprises two coupling parts: a carrier; and a cutting head that is attached to the carrier so as to be exchangeable. The carrier includes pin receiving means, into which a coupling pin of the cutting head is introduced in a clamping manner and so as to be reversibly exchangeable. The pin receiving means and the coupling pin have torque sections and clamping sections that correspond to one another and are oriented parallel to the axis of rotation. In addition, to prevent axial pull-out, stop surfaces are provided on the pin receiving means and on the coupling pin, the stop surfaces being effective in an axial direction and corresponding to one another. These stop surfaces preferably extend horizontally and therefore perpendicular to the axis of rotation.