Angularly Displaceable Bearing Retaining Drill Bits

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing rotary drill designs face challenges in securely and efficiently rotating bits due to the limitations of traditional retaining mechanisms, which often result in relative angular displacement and inadequate load transfer between the bits and the shafts.

Innovation Solution

A bearing assembly with an angularly displaceable outer member and a recess system that uses spherical retainers to interlock the bits with the shafts, forming a continuous or separate retention channel for secure rotational coupling and load transfer, preventing relative angular displacement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional retaining mechanisms are used to secure bits to shafts, then the structure is simple, but relative angular displacement occurs and load transfer is inadequate

Engineering Contradiction:
Improveload transfer capabilityVSAvoidbearing assembly structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The bearing outer member is divided into multiple segments that can independently displace angularly relative to each other. This segmentation allows the bearing to accommodate angular misalignment while maintaining secure retention of the bit on the shaft, thereby improving load transfer capability without requiring overly complex external mechanisms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bearing outer member is designed with dynamic angular displacement capability, allowing it to adapt its orientation in response to operational loads and misalignments. This dynamic behavior enables the bearing to maintain optimal contact and load transfer while preventing relative angular displacement between the bit and shaft, resolving the contradiction between reliability and structural simplicity.

Inventive Principle:
Principle #15Dynamics

2Reliability

If traditional retaining mechanisms are used, then the installation process is simple, but the retention of bits during rotation is inadequate

Engineering Contradiction:
Improvebit retention stabilityVSAvoidbearing assembly manufacturing
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The bearing assembly employs a nested structure where the outer member contains the inner member, which in turn retains the bit. The spherical retainers are nested within the bearing's internal geometry. This nested arrangement provides robust bit retention during rotation while maintaining a compact design that is relatively straightforward to manufacture using conventional machining processes.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Stability of the object's composition

If conventional bearing designs are used, then the structure is straightforward, but relative angular displacement between bit and shaft occurs

Engineering Contradiction:
Improveangular position stabilityVSAvoidbearing outer member design
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The bearing outer member is designed with dynamic angular displacement capability, allowing it to adapt its orientation in response to operational loads and misalignments. This dynamic behavior enables the bearing to maintain optimal contact and load transfer while preventing relative angular displacement between the bit and shaft, resolving the contradiction between reliability and structural simplicity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The bearing's angular position parameters are made variable through the angularly displaceable outer member design. This allows the bearing to adjust its geometric parameters in real-time to maintain stable angular positioning of the bit relative to the shaft, improving stability without requiring overly complex control mechanisms.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2588705B1Bearing assembly for rotary drills
Publication Date: 2020.03.04 SKF USA INC
  • EP2588705B1 patent drawingFigure 1
  • EP2588705B1 patent drawingFigure 2
  • EP2588705B1 patent drawingFigure 3

AI summary

A bearing assembly is for a rotary drill, the drill including a base with a shaft and a bit. The bearing assembly includes a bearing having a central axis and including an inner member disposeable on the shaft and an outer member disposed about the inner member. The outer member is angularly displaceable about the axis with respect to the inner member and having an outer circumferential surface and a recess extending generally radially inwardly from the outer surface. At least one and preferably a plurality of retainer members are each disposed at least partially within the bearing outer member recess and is configured to engage with the bit so as to rotatably couple the bit with the shaft. Preferably, each retainer member includes a generally spherical ball rollable through a passage and into the bearing recess during installation into the recess.