TRW launches dual stage transmission oil pumps

TRW Automotive Holdings Corp has announced that it has started production of its dual stage pump technology across two major European vehicle platforms.

The dual stage pump is TRW's latest innovation in pump technology. It is highly suitable for wet dual clutch transmissions due to its ability to integrate two external gear pumps in a compact single housing. The first stage is a low-pressure pump which cools and lubricates the wet clutches with oil. The second stage is a high-pressure pump that serves as a hydraulic pressure source to actuate the clutches, shift forks and other elements.

An electric motor runs the pump at variable speeds, operating only on-demand and reducing viscous friction losses, leading to a highly efficient solution.

Gregor Eipert, global sales lead for TRW's Transmission Motor Pump Unit business, commented: "TRW has been working on the integration of electric motors, pumps and electronics for many years and has produced millions of highly integrated motor pump units for various applications.

"By using sintering technologies, the TRW dual stage pump offers an efficient and cost effective solution for state-of-the-art dual wet clutch transmissions. Our customers also benefit from the integrated dual stage pump which utilizes just one pump and one electric motor to provide the same functionality as comparable systems which need two pumps and two electric motors."

TRW has produced over 40 million pumps to date, including eight million transmission oil pumps. The company has proven experience with different liquid formulations for powertrain, drivetrain and transmission applications and can offer the full range of pumps, from low to high pressure applications (0 – 200 bar). The company says it continues to innovate in this area and new pump developments are underway such as variable displacement pumps with either an external gear or pendular design.