Activation Solution for Dual Functional Clutch Pack for Limited Slip Differential
(2025) MMKM05 20242Innovation
- Abstract (Swedish)
- Limited-slip differentials (LSD) are normally placed in high-end and race cars to improve the handling, by reducing the differential speed and balancing the torque between the driving wheels. However, electrical-activated LSD struggles to continuously eliminate the differential speed over extended periods of time. To overcome this, BorgWarner proposed a dual-functional clutch pack, featuring two different clutch packs in series, providing two driving modes normal and overclocked mode.
This master thesis aims to develop an activation mechanism for the dual-functional clutch pack. The mechanism should separate, engage, and disengage the secondary clutch pack. The project also aims to analyze the boundary conditions, and customer... (More) - Limited-slip differentials (LSD) are normally placed in high-end and race cars to improve the handling, by reducing the differential speed and balancing the torque between the driving wheels. However, electrical-activated LSD struggles to continuously eliminate the differential speed over extended periods of time. To overcome this, BorgWarner proposed a dual-functional clutch pack, featuring two different clutch packs in series, providing two driving modes normal and overclocked mode.
This master thesis aims to develop an activation mechanism for the dual-functional clutch pack. The mechanism should separate, engage, and disengage the secondary clutch pack. The project also aims to analyze the boundary conditions, and customer requirements as well as evaluate the concept’s potential to meet the requirements within the operational constraints.
The double diamond methodology was used for the product development and 14 concepts
were generated, evaluated through screening and scoring matrices, and reduced to 4 concepts. These 4 concepts were further developed and a second evaluation led to the final concept. This concept utilizes two disc springs, creating a nonlinear force-deformation relationship, used to separate, engage, and disengage the secondary clutch pack, providing two driving modes. The final concept was validated through calculations for response time and torque as well as finite element analysis (FEA) as an assessment of the strength of the concept.
The selected activation mechanism met the requirements for response time and hold time
in overlock mode. The torque transfer reached 49% in normal mode 54% and in overlock
mode of the requirements. The torque was primarily limited by the actuator’s constraints in minimizing energy consumption to prevent overheating at unlimited lock time, which led to 67% of the maximal clutch force could be used. Despite this, the dual-functional clutch had better overlock performance than the BorgWarner generic limited-slip differential.
The final concept is promising, but improvements are necessary to meet all the requirements. Future improvements should focus on utilizing more of the actuator capacity, improve the disc spring properties, and including a self-locking system to remove the load on the actuator during overlock mode. This work provides a foundation for further investigation into the dual-functional clutch pack. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9182462
- author
- Winterfeldt, Erik LU
- supervisor
- organization
- course
- MMKM05 20242
- year
- 2025
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Limited-slip differential, dual-functional clutch pack, disc spring, differential, vehicles.
- language
- English
- id
- 9182462
- date added to LUP
- 2025-01-22 15:17:06
- date last changed
- 2025-01-22 15:17:06
@misc{9182462,
abstract = {{Limited-slip differentials (LSD) are normally placed in high-end and race cars to improve the handling, by reducing the differential speed and balancing the torque between the driving wheels. However, electrical-activated LSD struggles to continuously eliminate the differential speed over extended periods of time. To overcome this, BorgWarner proposed a dual-functional clutch pack, featuring two different clutch packs in series, providing two driving modes normal and overclocked mode.
This master thesis aims to develop an activation mechanism for the dual-functional clutch pack. The mechanism should separate, engage, and disengage the secondary clutch pack. The project also aims to analyze the boundary conditions, and customer requirements as well as evaluate the concept’s potential to meet the requirements within the operational constraints.
The double diamond methodology was used for the product development and 14 concepts
were generated, evaluated through screening and scoring matrices, and reduced to 4 concepts. These 4 concepts were further developed and a second evaluation led to the final concept. This concept utilizes two disc springs, creating a nonlinear force-deformation relationship, used to separate, engage, and disengage the secondary clutch pack, providing two driving modes. The final concept was validated through calculations for response time and torque as well as finite element analysis (FEA) as an assessment of the strength of the concept.
The selected activation mechanism met the requirements for response time and hold time
in overlock mode. The torque transfer reached 49% in normal mode 54% and in overlock
mode of the requirements. The torque was primarily limited by the actuator’s constraints in minimizing energy consumption to prevent overheating at unlimited lock time, which led to 67% of the maximal clutch force could be used. Despite this, the dual-functional clutch had better overlock performance than the BorgWarner generic limited-slip differential.
The final concept is promising, but improvements are necessary to meet all the requirements. Future improvements should focus on utilizing more of the actuator capacity, improve the disc spring properties, and including a self-locking system to remove the load on the actuator during overlock mode. This work provides a foundation for further investigation into the dual-functional clutch pack.}},
author = {{Winterfeldt, Erik}},
language = {{eng}},
note = {{Student Paper}},
title = {{Activation Solution for Dual Functional Clutch Pack for Limited Slip Differential}},
year = {{2025}},
}