Controlled pumps make engines more efficient
Stuttgart/Germany, September 2009—The controlled MAHLE pendulum-slider oil pump supplies lubricating oil to the engine as and when needed. Overall, this enables a CO2reduction potential of up to two percent in the New European Driving Cycle (NEDC) and three percent under actual driving conditions.
Engine accessories such as the oil pump and the coolant pump are essential for engine operation. However, the engine power required to operate these pumps is lost for the powertrain of the vehicle. This is why attempts are made to minimize losses in the engine accessories. Controlled oil pumps are a smart solution in this regard. They require little drive energy because they supply only as much lubricating oil as the engine needs and at the correct pressure—unlike non-controlled oil pumps. The patented MAHLE pendulum-slider oil pump is ideally suited for efficient control of volume and pressure.
Patented pendulum-slider oil pump
With an overall efficiency of 65 to 70 percent and a volumetric efficiency of more than 92 percent, the pendulum-slider oil pump converts an extremely high proportion of the drive energy into delivery output. Thus, compared with other pump types such as the external-gear pump and the vane pump, it operates with a considerably greater efficiency. This is made possible by the internal structure of the pump: Rather than using sliding gaskets to seal off individual pump cells, this pump uses pendulums supported in the outer rotor of the pump, which enables a rolling motion without sliding in grooves on the internal rotor.
By employing this principle, the pump not only operates with very little friction but is also resistant to abrasive particles, which can enter the oil during engine operation. Consequently, the pendulums are protected against excessive wear and the pendulum-slider pump retains a high level of efficiency during the entire service life of the engine. Depending on its installation size, this versatile pump is suitable for high speeds of up to 14,000 rpm, is quick to provide just the right pressure, and can be positioned in various locations.
The delivery pressure and displacement volume are created by adjusting a slider that surrounds two rotors, which are positioned off-center with respect to one another. The pump is suitable for single-stage, multiple-stage, and fully variable control operations. The fully variable control principle offers the greatest CO2 savings potential.
In the future, controlled pumps will be used to convey coolant as well. In contrast to oil pumps, coolant pumps operate with an impeller. Because of the controlled operation and minimal mechanical wear of this type of MAHLE coolant pump, the coolant circuit can also be a contributing factor to reduced CO2emissions in the driving cycle.
The MAHLE Group is one of the top 30 automotive suppliers and the globally leading manufacturer of components and systems for the internal combustion engine and its peripherals. Around 45,000 employees work at over 100 production plants and eight research and development centers. In 2008, MAHLE generated sales in excess of EUR 5 billion (USD 7.3 billion).