Tandem pump

from Wikipedia, the free encyclopedia

The tandem pump is used in diesel engines for the purpose of transport fuel pump . The term tandem contained in the name already indicates a multiple function: This pump combines the vacuum pump for the brake booster and the fuel pump for the diesel . A tandem pump achieves a so-called rough vacuum with pressures around 5 kPa to 20 kPa (ie a negative pressure of around −80 kPa to −95 kPa) .

The pump has the principle of a single vane cell in the vacuum part. In the diesel part, a bi-locking vane principle with lifting disc is often used, which is characterized by its durability.

Overspeed is a problem. Overspeed occur, for example, when downshifting if the speed is too high for the selected gear. The wings can then lift off the lifting disc and then hit hard again. This leads to damage to the vanes and the lifting disc.

Leaks due to negligence in the production of the pumps are the most common defect. The pump is then damp or wet with leaking fuel. If there is no obvious fault, the performance of the pump can be checked by measuring the fuel pressure achieved.