Torque Transmission Unit Axial Spring Actuation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Dry multi-plate clutches in motor vehicle drive trains experience significant friction losses and require higher power input due to high tangential forces, leading to increased clutch actuation force and reduced controllability, especially in hybrid systems where torque transmission is inefficient.

Innovation Solution

A torque transmission unit with axially displaceable disk carriers and a spring device that allows lamellae to move axially, reducing the impact of frictional forces by using elastic sections and spring elements to support disk carrier segments, thereby minimizing the actuation force required for torque transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If dry multi-plate clutches are used to transmit torque on a small diameter, then the required torque can be transmitted, but friction losses increase significantly

Engineering Contradiction:
Improvetorque transmission capabilityVSAvoidfriction losses
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The clutch assembly is segmented into multiple friction plates and steel plates stacked alternately, allowing torque distribution across multiple friction surfaces. This segmentation enables effective torque transmission on a compact diameter while managing friction losses through the multiplicity of contact surfaces.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A torque transmission element with splined shaft toothing acts as an intermediary between the disk carrier and the transmission input shaft. This intermediary component enables form-fitting torque transmission while allowing axial displacement of the disks, reducing direct frictional contact during engagement and disengagement phases.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Power

If teeth are used for form-fitting connection between disks and clutch components, then torque transmission is improved, but frictional forces increase during axial movement

Engineering Contradiction:
Improvetorque transmission efficiencyVSAvoidclutch actuation force
Core Design Contradiction:
PowerVSEase of operation

Solution Approach 1:

The connection between disks and clutch components transitions from static to dynamic during engagement. The disks are axially displaceable on the splined shaft toothing, allowing them to move dynamically during engagement and disengagement while maintaining form-fitting torque transmission. This dynamic capability reduces the actuation force required compared to rigid fixed connections.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The axial position parameter of the disks is changed during engagement and disengagement operations. By allowing axial displacement of the disks along the splined shaft, the system changes the geometric parameter of disk position to facilitate smoother engagement with reduced frictional resistance, thereby lowering the required actuation force.

Inventive Principle:
Principle #35Parameter changes

3Volume of moving object

If the clutch diameter is reduced to save space, then packaging is improved, but tangential forces increase leading to higher friction losses

Engineering Contradiction:
Improveclutch assembly sizeVSAvoidfriction losses from tangential forces
Core Design Contradiction:
Volume of moving objectVSLoss of energy

Solution Approach 1:

The clutch is designed as a compact multi-plate assembly with multiple friction surfaces stacked axially, enabling high torque transmission capacity within a small radial diameter. The segmentation into multiple plates compensates for the reduced diameter by increasing the number of friction contact surfaces, thereby managing tangential forces and friction losses in a space-constrained application.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The design compensates for reduced radial diameter by utilizing the axial dimension more effectively. Multiple friction plates are stacked axially to provide sufficient friction surface area for torque transmission, transferring the torque transmission capability from the radial dimension to the axial dimension, thus achieving compact packaging without excessive tangential forces.

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

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 configuration reduces the axial actuation forces needed for torque transmission, enhances controllability, and improves energy efficiency while maintaining a cost-effective and durable connection, allowing for efficient torque transfer with reduced frictional losses.

Implementation Method 1

at least one axially acting spring device, with which at least one lamella can be displaced axially in addition to the sliding movement in relation to the torque transmission element

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the friction surfaces of the disks touch and torque can be transmitted between the disks assigned to the drive and the disks assigned to the output through friction

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3728889B1Torque transmission unit and drive train
Publication Date: 2022.07.20 SCHAEFFLER TECHNOLOGIES AG & CO KG
  • EP3728889B1 patent drawingFigure 1~2
  • EP3728889B1 patent drawingFigure 3
  • EP3728889B1 patent drawingFigure 4~5

AI summary

The invention relates to a torque transmission unit for frictionally transmitting a torque for a drive train of a motor vehicle, and to the drive train itself. The torque transmission unit is designed in particular as a clutch device for a drive train of a motor vehicle and is used to frictionally transmit a torque for a drive train of a motor vehicle and comprises: a disk carrier (10) having a plurality of disks (20), which can be pressed together with counter disks (30) of the torque transmission unit to form a friction pack (31); and a torque transmission element (60), by means of which a torque can be transmitted from the disk carrier (10) to a machine element that is or can be connected to the disk carrier (10), such as a transmission input shaft (80). The disks (20) are arranged on the disk carrier (10) so as to be axially slidable by performing a sliding movement on a shaped element, in particular on a toothing, of the disk carrier (10). The torque transmission unit also has at least one axially acting spring device (70), by means of which at least one disk (20) can be axially moved relative to the torque transmission element (60) in addition to the sliding movement.