Modular Differential Pivot Bearing for Low-Friction Planet Gear Alignment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing terminal block differentials require complex stabilization measures or multiple planet gears for proper alignment, leading to increased friction and reduced service life, especially in high-speed applications.

Innovation Solution

The terminal block differential relocates the guidance of planet gears to their pivot point, using a plain bearing pivot axle to reduce friction and simplify assembly, allowing for a single planetary gear design that is space-saving, cost-effective, and robust, with additional features like positive locking elements and symmetric pivot bearings to enhance stability and prevent tilting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If planetary gears are guided by guide elements (slots) in the walls, then the planetary gears can be positioned, but friction increases and service life decreases

Engineering Contradiction:
Improveservice lifeVSAvoidfriction
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the slot-based guide elements with a pivot bearing system. The planetary gear is mounted on a pivot bearing that rotates on a bearing axle, substituting the sliding friction mechanism with a rolling/rotating bearing mechanism. This eliminates the harmful friction effect while maintaining the positioning and guidance function of the planetary gear.

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

2Stability of the object's composition

If multiple planetary gears are used for proper alignment, then stability improves, but device complexity increases

Engineering Contradiction:
Improvealignment stabilityVSAvoidnumber of planetary gears
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent segments the guidance function from the planetary gear itself by introducing a separate pivot bearing system. The pivot bearing is mounted on the cage column and provides the necessary guidance and stability, allowing the use of a single planetary gear instead of multiple gears for alignment purposes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pivot bearing acts as an intermediary element between the planetary gear and the cage column. It provides the necessary guidance and support functions, enabling a single planetary gear to maintain proper alignment and stability without requiring multiple gears or complex stabilization measures.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If additional stabilization walls are inserted, then planetary gear alignment improves, but device complexity and space requirements increase

Engineering Contradiction:
Improveplanetary gear alignmentVSAvoidstructural complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent extracts the guidance function from the cage walls by removing the need for additional stabilization walls and slots. The pivot bearing system independently provides the necessary alignment and guidance, simplifying the overall structure by taking out the complex wall-based guidance mechanism.

Inventive Principle:
Principle #2Taking out (Extraction)

4Device complexity

If a single planetary gear is used, then device complexity reduces, but stability and alignment precision worsen

Engineering Contradiction:
Improvenumber of componentsVSAvoidalignment precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The pivot bearing serves as an intermediary that compensates for the reduced number of planetary gears. It provides precise guidance and positioning for the single planetary gear, ensuring alignment precision is maintained despite the simplified configuration.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the parameters of the pivot bearing system to optimize performance. The pivot bearing is designed with specific dimensions and mounting characteristics that ensure precise alignment and stable operation of the single planetary gear, compensating for the reduced redundancy.

Inventive Principle:
Principle #35Parameter changes

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

This design significantly extends the service life of the terminal block differential, especially in high-speed applications, by reducing friction and simplifying assembly, while maintaining robustness and stability through mechanical preload and symmetric force distribution.

Implementation Method 1

the pivot bearing is designed as a plain bearing. This allows the modular differential to be constructed in a space-saving, cost-effective, and simple manner

Methodology Applied
Scientific EffectFriction reduction through plain bearing: Friction

Implementation Method 2

the pivot bearing has a bearing axle onto which the planetary gear is axially mounted. Using the bearing axle as a pivot bearing significantly reduces friction, so that the specified modular differential is particularly durable, especially in high-speed applications

Methodology Applied
Scientific EffectPlain bearing support: Friction

Implementation Method 3

the bearing axis opposite the cage column has a positive locking element that blocks axial movement of the planetary gear away from the cage wall in at least one rotational position of the planetary gear and permits it in at least one other rotational position of the planetary gear

Methodology Applied
Scientific EffectMechanical locking: Mechanical Fastener

Implementation Method 4

the pivot bearing and the additional pivot bearing are arranged symmetrically to the cage column. This distributes the drive forces symmetrically across the two planetary gears, significantly reducing the risk of jamming of the two planetary gears

Methodology Applied
Scientific EffectSymmetric force distribution:

Implementation Method 5

the pivot bearing resting against the slot end with a mechanical preload. In this way, the terminal block differential is subjected to mechanical tension, which compensates for tolerances and prevents unintentional play

Methodology Applied
Scientific EffectMechanical preload:

Data Source

PatentEP4325089A1Clamping component differential
Publication Date: 2024.02.21 DOUBLEEAGLE IND (CHINA) LTD
  • EP4325089A1 patent drawingFigure 1
  • EP4325089A1 patent drawingFigure 2
  • EP4325089A1 patent drawingFigure 3

AI summary

The invention relates to a modular building block differential (2) comprising: - a differential cage (10) extending in a longitudinal direction (4), a transverse direction (6) transverse to the longitudinal direction (4), and a vertical direction (8) transverse to the longitudinal direction (4) and transverse to the transverse direction (6), with a cage base (12) extending in the longitudinal direction (4) and the transverse direction (6), from which a first cage wall (14) and a second cage wall (16) extend in the vertical direction (8), spaced apart from each other in the transverse direction (6), and with a cage column (18) extending in the vertical direction (8) and held against the cage walls (14, 16), - a first sun gear (48) placed on the cage base (12), which is configured to drive a first output shaft through the cage base (12), - a planet gear (50) which engages with the first sun gear (48), - a cover (62),which is held on the cage walls (14, 16) opposite the cage floor (12) in the vertical direction (8), and - a second sun gear (48) held between the cage column (18) and the cover (62) and engaged with the planet gear (50), which is arranged to drive a second output shaft through the cover (62), characterized in that the planet gear (50) is rotatably held on a pivot bearing (44) of the cage column (18).