Master Thesis Project at CEVT

Title: CAE tool to evaluate park lock mechanism in a DCT transmission

China Euro Vehicle Technology AB, CEVT, is a development centre for future cars of the Geely Group. CEVT covers all aspects of passenger car development – from the total architecture, powertrain and driveline components, to top hat engineering as well as the vehicles’ exterior design. The company is located in Gothenburg & Trollhättan and in Hangzhou & Cixi in China.

Background

A dual clutch transmission (DCT) is a type of automated transmission that uses two separate concentric clutches to manage odd and even gear sets. The base design of a DCT transmission is in reality a manual transmission, however the way in which the transmission is operated by the driver is the same as an automatic transmission. When the driver selects parked position (P), the park lock mechanism fitted to the DCT transmission engages in order to lock up the transmission. There are complex and mandatory requirements for this mechanism: engagement of park lock until “engagement speed”, prevent the vehicle from rolling down a hill, disengage the park lock after the vehicle has been parked on a hill, once engaged the park lock needs to stay engaged. Due to the fact that the park lock is considered as a key component for the safe operation of the vehicle its design should be robust enough to meet all design criteria.

The park lock fastens the transmission’s output shaft by engaging a pawl into a notched wheel on the shaft (ratchet) stopping it and prevent its rotation. The functionality of the park lock is highly affected by a number of operational conditions like coefficient of friction between the pawl and the ratchet, vehicle speed, slope at which the car is standing among many others.

Scope

The main purpose of the thesis work is to create a CAE tool to quickly evaluate design changes of a DCT park lock mechanism. The outcome of the CAE tool will allow CEVT to evaluate different pawl and ratchet geometries in different types of vehicles and determine the following information:

  • Static torque
  • Dynamic torque
  • Snap torque
  • Actuator spring preload
  • Friction limits
  • Pull out forces

Thesis overview

  • Literature study
  • Goals/milestone definition
  • Documentation: document the results in a thesis report and make a final presentation.

Prerequisites

  • Car enthusiast, interested to further work in the automotive industry
  • Preferably driver’s license type B

The duration of the thesis work is 20 weeks.

Suitable Student Background

Master’s student in automotive/mechanical/mechatronics engineering or applied physics. Please apply with CV and cover letter.

Starting dateNumber of students

January 20171

Contact persons

Alejandro Martinez, +46 72-184 38 11,

Application:

Please apply for this thesis project through our web site:

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