Ensuring steering capability if the engine fails

The RKP radial piston pump automatically controls the oil flow in the pressure line leading to the steering system in case of a failure of an engine-dependent pump.

Emergency steering pump

if the engine fails


High efficiency level

with low weight



Modular assembly system

Our wide-ranging production program includes various pump designs and model series. Depending on the requirement, the RKP can be equipped with 8 or 16 pistons.

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.

Individual product request
Thanks to its innovative design, the RKP radial piston pump can be individually equipped with 8 or 16 pistons.


Hydraulic pump for steering systems with emergency steering equipment

The RKP can be equipped with either 8 or 16 pistons which are moved by two cams. It can be driven via a gear or coaxially via the interconnection of a coupling. It can also be driven via a V-belt pulley with the outboard bearing.

The radial piston pump is assigned to the second oil circuit for dual circuit steering systems and must be vehicle-driven. It is recommended for installation on the transmission or the drive axle.

The RKP is also vehicle-driven for a partial dual circuit steering system with a control valve and it is assigned to the steering oil circuit as a second oil pump.

When the engine is running, the radial piston pump conveys directly into the return line. If the engine fails, and with it the power steering pump, the emergency steering pump oil flow is rerouted automatically through a sequence valve into the pressure line leading to the steering system.

The volume flow that is controlled via the holes in the pistons as well as two reed valves is nearly constant after reaching the control speed. However, it can be fixed to the values 25 dm3/min or 50 dm3/min.

The pressure is limited by a valve located outside of the pump.

In case of a counterclockwise or clockwise drive, the RKP conveys in one direction. This ensures the emergency steering feature as well as for both forward and backwards driving.

Technical data

Details about the
RKP radial piston pump

Details about the 
RKP radial piston pump
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  • [2] - 
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    Eccentric shaft
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Models 8604 8605 8607
Max. theorectical displacement (cm³/rev) 13 16 32
Max. controlled flow (dm³/min) 16 25 50
Max. speed (rpm) 5,000
Max. pressure (bar) 185
Max. oil temperature (°C) 130
Weight (kg) 5.5
Safety valve possible with or without valve
Drive direct
Drive rotation of direction both sides