Hybrid Module Input Shaft Rotary Union Actuation

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Solution Overview

Problem

Existing hybrid module designs for vehicle drive trains have actuating devices for separating clutches that are large and complex, leading to high manufacturing and assembly costs, potentially affecting functionality and service life.

Innovation Solution

A compact actuating device is achieved by integrating a hydraulic duct within the input shaft, forming a rotary feedthrough, and using a concentric actuating cylinder with the separating clutch, allowing for a radial and axial deflection of hydraulic medium, and connecting sections of the hydraulic duct via radial and axial holes, which simplifies production and assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional actuating device with a separate pressure cylinder is used for the separating clutch, then the clutch can be actuated reliably, but the actuating device becomes large and complex with high manufacturing and assembly costs

Engineering Contradiction:
Improveclutch actuation reliabilityVSAvoidactuating device complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pressure cylinder is merged with the input shaft to form an integrated actuating device. The hydraulic duct is formed directly in the input shaft, and the actuating piston is accommodated within the input shaft, combining previously separate components into a single unified structure that reduces complexity while maintaining actuation reliability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The input shaft is given multiple functions: it serves as both the rotational transmission element and as the housing for the actuating device. The input shaft accommodates the actuating piston, contains the hydraulic duct, and provides the structural framework for clutch actuation, thereby reducing the need for separate dedicated components

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of operation

If a separate pressure cylinder is used for actuating the separating clutch, then the actuation function is clear, but the manufacturing and assembly costs increase

Engineering Contradiction:
Improveclutch actuation functionVSAvoidmanufacturing and assembly cost
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

By integrating the pressure cylinder functionality into the input shaft through formed hydraulic ducts and accommodating the actuating piston within the input shaft, the number of separate manufactured parts is reduced, lowering manufacturing and assembly costs while preserving the clutch actuation function

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The hydraulic duct is segmented into multiple sections (first section in the input shaft, second section in the housing wall) connected by radial gaps, allowing each section to be manufactured and positioned independently while maintaining the overall actuation function

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If the hydraulic duct is formed as a single integrated component, then manufacturing is simplified, but the hydraulic medium flow path becomes more complex

Engineering Contradiction:
Improvehydraulic duct productionVSAvoidhydraulic flow path
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The hydraulic duct is divided into multiple sections: a first section formed in the input shaft containing radial and axial holes, and a second section formed in the housing wall, connected via a radial gap. This segmentation simplifies manufacturing of each section while the overall flow path remains functional

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The hydraulic flow path utilizes both radial and axial dimensions through strategically placed holes in different orientations. The radial holes provide radial flow paths while axial holes provide axial flow paths, creating a three-dimensional flow network that manages complexity through spatial distribution

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 design results in a cost-effective, compact, and reliable hybrid module with a long service life, reducing stress on the rotor bearing and enabling one-piece manufacturing of the housing, while maintaining efficient torque transmission.

Implementation Method 1

a hydraulic duct (15), which hydraulic duct is hydraulically coupled to an actuating piston (16)

Methodology Applied
Scientific EffectHydraulic pressure: Pressure Increase

Implementation Method 2

a separating clutch (8) which separating clutch is arranged radially within a sleeve-shaped torque transmission area (10) of the carrier (7)

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3826873B1Hybrid module comprising a input shaft having a rotary union, and actuation unit for one of multiple clutches, and drive train
Publication Date: 2022.09.07 SCHAEFFLER TECHNOLOGIES AG & CO KG
  • EP3826873B1 patent drawingFigure 1
  • EP3826873B1 patent drawingFigure 2

AI summary

The invention relates to a hybrid module (1) for a drive train (2) of a motor vehicle, comprising a housing (3), an electric machine (4) accommodated in the housing (3), an input shaft (5), a carrier (7) rotationally coupled to a rotor (6) of the electric machine (4), a disconnect clutch (8) operatively introduced between the input shaft (5) and the carrier (7), wherein the disconnect clutch (8) is arranged with multiple friction elements (9a, 9b) radially inside a sleeve-type torque transmission region (10) of the carrier (7) coupled to the rotor (6), a hydraulic actuation unit (11) provided for engaging and disengaging the disconnect clutch (8), and two sub-clutches (12, 13) which each have multiple friction elements (9a, 9b) arranged radially inside the torque transmission region (10) of the carrier (7), and which are rotationally fixed to the carrier (7) by their first clutch component (14b, 14c), wherein the actuation unit (11) has a hydraulic conduit (15) which is hydraulically coupled to an actuating piston (16) accommodated inside the housing (3) on the input shaft (5), and which is introduced into the input shaft (5), forming, at least in part, a rotary union. The invention also relates to a drive train (2) comprising said hybrid module (1).