Plunging Joint Torque Capacity Groove Design

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Solution Overview

Problem

Existing plunging joints in motor vehicles face limitations in transmitting torque without increasing the joint's size, which restricts the installation space and efficiency, and often require complex cutting processes for larger angles, leading to potential axial misalignment issues.

Innovation Solution

The introduction of a groove in the ball tracks allows for the use of larger balls, increasing torque transmission capacity without altering the joint's geometry, using a sliding joint design with grooves that facilitate assembly and allow for a higher connection strength ratio, enabling the use of larger balls within the existing dimensions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If larger balls are used to increase torque transmission capacity, then the torque transmission capability is improved, but the joint size increases which affects installation space

Engineering Contradiction:
Improvetorque transmission capabilityVSAvoidjoint size
Core Design Contradiction:
PowerVSVolume of moving object

Solution Approach 1:

The patent introduces a groove dimension in the ball track that extends along the longitudinal axis of the inner hub. This additional dimensional space allows larger diameter balls to be accommodated without increasing the radial or transverse dimensions of the joint, thereby increasing torque capacity while maintaining the same external joint size

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The groove is introduced locally in specific regions of the ball track where additional space is needed to accommodate larger balls. The groove depth varies along the longitudinal axis, being deeper in regions where larger balls are positioned and shallower or absent in other regions, allowing optimized ball sizing in different locations without uniformly increasing joint dimensions

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If plunging joints are designed for larger angles, then the deflection capability is improved, but the manufacturing complexity increases requiring cutting processes

Engineering Contradiction:
Improvedeflection angle capabilityVSAvoidmanufacturing process complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent modifies the geometric parameters of the ball track by introducing a groove with specific depth and longitudinal extent. This parameter change enables the joint to accommodate larger deflection angles while maintaining a manufacturing process that uses forming rather than cutting, as the groove can be integrated into the forming process

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2591245B1Joint
Publication Date: 2018.09.05 NEUMAYER TEKFOR ENG GMBH
  • EP2591245B1 patent drawingFigure 1
  • EP2591245B1 patent drawingFigure 1a
  • EP2591245B1 patent drawingFigure 2

AI summary

The invention relates to a joint, comprising an inner hub, which has a longitudinal axis and inner ball raceways, wherein the inner ball raceways have a raceway base and raceway flanks connected to the raceway base at the sides of the raceway base, an outer hub, which has a longitudinal axis and outer ball raceways, wherein the outer ball raceways have a raceway base and raceway flanks connected to the raceway base at the sides of the raceway base, wherein the inner hub has an end facing the outer hub and an end facing away from the outer hub, wherein the inner ball raceways and the outer ball raceways are associated with each other in pairs, a cage, which has windows distributed circumferentially and which is arranged between the inner hub and the outer hub, and balls, which are arranged in the windows of the cage and in the pairs of the inner ball raceways and the outer ball raceways and which the cage holds in a plane. According to the invention, at least one groove is provided in the raceway base of the inner ball raceways and/or in the raceway base of the outer ball raceways.