For consistent, optimal system pressure and high-precision power support

The energy- and fuel-saving Varioserv® power steering pump supplies exactly the right amount of oil that is needed for operating hydraulic steering systems in passenger cars and light commercial vehicles.

Up to 50%

reduction of power consumption


Save up to 0.3l / 100 km

fuel consumption

Flexible design

Modular assembly system

Our wide-ranging production program includes various pump designs and model series. We would also be happy to customize our solutions optimally to your individual wishes and requirements. Evamo's highly flexible modular assembly system makes most anything possible.

Because of our flexible construction method, we can implement customer-specific requirements in the production of the Varioserv® power steering pump. This gives us the option of installing customer-specific drive components or brackets in order to adapt the pump to the assembly space.

Individual product request
The energy-saving Varioserv power steering pump for passenger cars consists of a robust housing with a pressed-in suction connection and integrated volume flow control.


Variable displacement pump with reduced energy expenditure

The Varioserv® power steering pump is powered via a motor belt drive. The hub or belt pulley is pressed onto the shaft. Mounting the pump to the engine bracket is done either directly or via a pump bracket.

The Varioserv® power steering pump consists of a housing with a pressed-in intake port as well as an integrated volume flow control, valve screw with a pressure connection thread, cover, front plate, shaft and rotor set. The rotor set is comprised of the outer ring, rotor, eleven radially-guided blades and the cam ring. The pump shaft is installed in the housing and in the cover with plain bearings.

Contrary to the double-stroke rotor set of standard vane pumps, the cam ring in the single-stroke Varioserv® is adjustable and generates an adjustable geometric delivery volume via the varying eccentricity.

The cam ring adjustment is speed-dependent. This only results in the decreasing pump space generating a reduced geometric delivery volume. At higher speeds, the reduced power consumption leads to significantly lower energy consumption, whereby fewer cooling measures are required in the steering system.

The volume flow control limits the supplied volume flow to a fixed value and a pressure control valve in the valve pistons controls the system pressure.

Technical data

Details about the
Varioserv® power steering pump

Details about the
Varioserv® power steering pump
  • [1] - 
    Suction port
  • [2] - 
    Rotor with vanes
  • [3] - 
  • [4] - 
    Cam ring
  • [5] - 
  • [6] - 
    Outer ring
  • [7] - 
    Pressure port
  • [A] - 
    Concentrical bearing of cam ring for minimum delivery capacity
  • [B] - 
    Eccentrical bearing of cam ring for maximum delivery capacity
Max. theorectical displacement (cm³/rev) 9.6 or 13
Max. controlled flow (dm³/min) 7-14
Max. rotation speed (rpm) 9,000
Max. pressure (bar) 135
Weight (kg) 1,0
Max. oil temperature (°C) 135
Drive Belt drive (optionally customized)
Drive direction of rotation optionally clockwise or counterclockwise