Modular Bearing Assembly for Thin Ring Gear Power Transmission

Solution Overview

Problem

Conventional cross roller bearings used in power transmission devices for industrial equipment face challenges such as increased installation costs and size limitations, making it difficult to implement thin and light designs, especially when dealing with larger ring gears, due to their structural limitations and high unit prices.

Innovation Solution

A module bearing system that includes a module outer wheel, a bearing rotor, and a part-assembly type module inner wheel, allowing for adjustable installation based on load demands and enabling compact, efficient guidance of linear and curved motions by using a combination of separate parts assembled to apply preload to the bearing rotor, thereby reducing installation costs and enabling thin and light axial implementation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cross roller bearings are used to support ring gears, then high rigidity and operational accuracy are achieved, but installation costs sharply increase and the diameter of the ring gear is limited

Engineering Contradiction:

Improveoperational accuracyVSAvoidinstallation cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The bearing system is divided into multiple module bearings (first module bearing, second module bearing, third module bearing) that can be selectively assembled. Each module bearing contains a limited number of rollers (e.g., 2-4 rollers), and multiple modules are combined to achieve the required load capacity. This segmentation allows cost-effective scaling - small ring gears use fewer modules while large ring gears use more modules, avoiding the need to purchase expensive large-size cross roller bearings.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The bearing configuration is made dynamic and adaptable through selective assembly. Different numbers of module bearings can be installed depending on the load requirements and ring gear size. The system transitions from a fixed-size bearing approach to a flexible modular approach where the bearing capacity can be adjusted by adding or removing modules, optimizing both cost and performance for each application.

Inventive Principle:

Principle #15Dynamics

2Strength

If cross roller bearings are used to support ring gears, then high rigidity is achieved, but the diameter of the ring gear is limited due to manufacturing size limitations

Engineering Contradiction:

ImproverigidityVSAvoidring gear diameter range

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The bearing system is divided into multiple module bearings (first module bearing, second module bearing, third module bearing) that can be selectively assembled. Each module bearing contains a limited number of rollers (e.g., 2-4 rollers), and multiple modules are combined to achieve the required load capacity. This segmentation allows cost-effective scaling - small ring gears use fewer modules while large ring gears use more modules, avoiding the need to purchase expensive large-size cross roller bearings.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The module bearing design creates a universal bearing unit that can be applied to ring gears of various diameters. The standardized module bearing structure with outer ring, inner ring, and roller assembly can be replicated and combined in different quantities to suit different application requirements, making the same basic design universally applicable across a wide range of ring gear sizes.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Strength

If cross roller bearings are used, then loads in axial and radial directions are supported, but the bearing protrudes from the ring gear making thin and light implementation difficult

Engineering Contradiction:

Improveload support capabilityVSAvoidaxial height

Core Design Contradiction:

StrengthVSLength of stationary object

Solution Approach 1:

The module bearing employs a nested structure where the inner ring is positioned inside the outer ring, and rollers are contained within the annular space between them. The first, second, and third module bearings are nested within the ring gear structure, with the bearing components fitted into recesses or mounting features of the ring gear. This nesting minimizes the axial protrusion of the bearing from the ring gear surface, enabling thin and light implementation while maintaining load support capability.

Inventive Principle:

Principle #7Nested doll (Nesting)

Data Source

PatentUS11371553B2Module bearing and power transmission device including same

Publication Date: 2022.06.28 SEJIN IGB CO LTD

AI summary

A module bearing and a power transmission device including the module bearing. A module bearing includes a module outer wheel supported by and in contact with a side wall of a gear to guide rotational or linear motion of the gear, a bearing rotor rotatably disposed radially inward of the module outer wheel, and a part-assembly type module inner wheel disposed radially inward of the module outer wheel with the bearing rotor interposed therebetween and connected to the bearing rotor, in which a plurality of separate parts are manufactured and assembled into the part-assembly type module inner wheel to apply a preload to the bearing rotor.