To provide the required force at the brakes of a passenger car, the assistance of some power device is required. When a driver presses the brake pedal they will ‘feel’ assistance from the braking system without which the brake pedal would feel very hard. Servo-assisted braking has become almost universal and most brake servos require vacuum for their operation.
Vacuum pumps can be reciprocating or rotary devices and are made from a combination of aluminium, steel and plastic parts. Vacuum pumps are usually mounted directly on the vehicle’s engine. On a single vane vacuum pump an eccentrically mounted rotor guides a vane, which rotates around a unique generated profile. At each end of the vane, floating tips maintain sealing efficiency. To lubricate internal components and to ensure sealing of moving parts, the pump requires oil feed via the engine lubrication circuit. The oil is then exhausted back into the engine together with the air from the booster. Main features and benefits of WABCO vacuum pumps are:
low power consumption
low oil flow
unique generated profile bore with effect of smooth progression of accelerations for internal components resulting in low power consumption and low vibration
modular design reduces component cost and tooling investment with a range of standard components different design and capacity pumps available
