MCE-5 VCRi: Pushing back the fuel consumption reduction limits

Hydraulic pushers

Hydraulic pushers maintain MCE‑5 VCRi moving parts in contact with each other. These pushers make it possible to adapt to dimensional dispersion, heterogeneous thermal expansion of the crankcase, and distortion under load of the parts in the MCE‑5 VCRi gear system.

The hydraulic pushers play a vital role both for the industrialization of the engine (that they make possible) and in controlling noise emissions. Indeed, the hydraulic pushers allow the gear teeth to be at minimum clearance when the forces they transmit change direction and pass through the zero point. When the transmitted forces are at their maximum, the hydraulic pushers allow the gearwheel-rack center-to-center distance to increase substantially, so that the risk of interference between the teeth is eliminated. Regardless of the distortion of the fixed or mobile MCE‑5 VCRi parts, the hydraulic pushers lastingly guarantee their correct operation without noise emissions.

The hydraulic pushers operate between 40 to 60 bar of pressure depending on engine temperature. This pressure is provided by the pressure accumulator that is housed in the engine’s oil sump. This accumulator provides minimum variations in pressure at all pusher positions, guaranteeing that the latter supply a constant force regardless of their position on their stroke (0.4 mm maxi).

Hydraulic pushers are positioned on the crankcase side

The hydraulic pushers are essential to the industrialization
of the MCE‑5 VCRi and to preventing noise emissions

The hydraulic pushers automatically manage the dimensional dispersion, distortion under load and
heterogeneous thermal expansion of the parts making up the MCE‑5 VCRi gear system

The main characteristics of the MCE‑5 VCRi hydraulic pushers