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VR-Pulley Achieves Project Milestone

March 2009 - IP News Feature

IP can now announce the successful completion of first engine trials of its innovative Variable Ratio Crank Pulley with engine-stop climate drive.

The VR-Pulley technology enables delivery of Belt-Integrated Starter/Generator (B-ISG) functions, passenger comfort and CO2 benefits with a major improvement in system economics.

IP’s innovative technology addresses current B-ISG issues of high cost electrical machinery, high belt loads leading to increased engine friction losses and the need for special energy storage e.g. super-capacitors.

These tests have demonstrated that the first concept design is capable of delivering the following functions:

  • High torque engine cranking with a B-ISG device - the prototype successfully cranks a 2.0l diesel engine with a 3:1 drive ratio within the pulley
  • Seamless transition to normal 1:1 drive after completion of cranking – delivered via passive mechanism
  • Engine-off drive for conventional FEAD ancillary systems driven by ISG via passive freewheeling function
  • FEAD over-run decoupling for gear shift belt squeal elimination – normally incorporated into alternator pulley

Click here to see VR-Pulley on test

Experience gained during the initial prototype build and test phase is being used to develop a production intent specification. It is now considered possible to achieve a drive ratio of up to 3.5:1 for cranking and cold engine cranking via the FEAD belt also looks feasible.

VR-Pulley now becomes a major enabling technology for the next generation of highly cost effective Micro-Hybrid systems with increased functionality.

Spurred by the success of these trials, IP has developed a re-optimised Micro-Hybrid machine that works in harmony with VRCP. This motor/generator device with integrated on-board power electronics takes advantage of the high pulley ratio available for engine cranking to achieve significantly higher re-generation power capability with much lower cost and mass compared to current high torque devices.

Download the vr-pulley press release