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Video History-Suspension 1
Video History-Suspension 2
Video History-Suspension 3
Video History-Suspension 4
Video History-Suspension 5
Video History-Suspension 6
Video History-Suspension 7

Video Undercarriage 1
Video Undercarriage 2
Video Steering Wheel 1
Video Steering Wheel 2
Video Steering Lock
Video Steering
Video Safety Steering
Video Rack Pinion Steering
Video Steering Ratio 1
Video Steering Ratio 2
Video Steering Ratio 3
Video Ball Steering
Video Worm Roller Steering
Video Hydraulic Power Steer. 1
Video Hydraulic Power Steer. 2
Video Electr. Power Steer. 1
Video Electr. Power Steer. 2
Video Electr.-hydraulic Pump
Video Torque (power steer.)
Video Electr. Stab. Program
Video Finger Steering
Video One-piece Track Rod
Video Four Wheel Steering 1
Video Four Wheel Steering 2
Video Four Wheel Steering 3
Video Dry Joint
Video History
Video Suspension control 1
Video Wheel positions
Video Suspension
Video Spring systems
Video Electr. Air Suspension
Video Center of Gravity
Video Oblique/lateral drift angle
Video Elasto-kinematics
Video Elk Test
Video Wheel Bearing 1
Video Wheel Bearing 2
Video Wheel Bearing 3
Video Wheel Bearing 4
Video Ind. pulse sensor
Video Wheel sensor 2
Video Transversal Axis
Video Suspension Carrier
Video Below View
Video Adj. suspension
Video Stabilizer 1
Video Stabilizer 2
Video Double-wishbone 1
Video Double-wishbone 2
Video Double-wishbone 3
Video Air suspension truck
Video McPherson Strut 1
Video McPherson Strut 2
Video McPherson Strut 3
Video McPherson Strut 4
Video Trailing Arm
Video Twist-beam Rear Axle
Video Space Arms
Video Multilink Axle
Video Semi-trailing Arm Axle
Video Rear-wheel Drive
Video Electr. Stab. Program
Video ABS/ESP-Hydr. Unit
Video One-arm Swing. Fork
Video Formula-3 Racing Car
Video Pend. Wheel Suspen.
Video Torson Crank Suspen.
Video DeDion Axle 1
Video DeDion Axle 2
Video Rigid Axle 1
Video Rigid Axle 2
Video Rigid Axle 3
Video Rigid Axle 4
Video Rigid Axle 5
Video Self steering axle
Video Track rod joint
Video Springs
Video Coil Spring 1
Video Coil Spring 2
Video Coil Spring 3
Video Leaf Spring
Video Torsion Bar Spring
Video Rubber Suspension
Video Hydropn. Suspension
Video Air Suspension 1
Video Air Suspension 2
Video Shock Absorber 1
Video Shock Absorber 2
Video Shock Absorber 3
Video Shock Absorber 4
Video Shock Absorber 5
Video Single-tube Damper 1
Video Single Tube Damper 2
Video Double-tube Damper
Video Shock Absorber Piston
Video Friction Absorber
Video Tyres
Video Wheel Positions

Video Tyre Calculation
Video Inch -> mm
Video Slip
Video Axle Load Distrib.
Video Payload Distrib.
Video Roller Resistance 2

Video Wheel suspension 1
Video Wheel suspension 2
Video Wheels 1
Video Suspension 1
Video Suspension 2
Video Suspension 5
Video Steering 1
Video Steering 2

          A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Electric Hydraulic Pump


It is a valid question, why one converts, in some modern, hydraulically supported systems, first of all, mechanical energy into electric energy (generator), then this into hydraulic energy. The latter is the job of this pump. The relatively complicated method is worthwhile and sometimes even delivers fuel savings. The electric pump is urgently necessary then, when its function should also be guaranteed when the internal combustion engine is switched off.The reasons for the fuel saving are relatively simple. In the case of the customary power steering, a pump is constantly driven. Although this pump only generates high pressures if the steering wheel is moved, it also nevertheless, consumes energy constantly, e.g., during long highway journeys. Apart from that, the space up front, in the engine compartment is limited for the ribbed belt drive. An electric pump can be installed, in principle, anywhere and is active only when required. Additionally, the steering control must only request pressure so often, that this drops below a certain value. Naturally, even more power-saving can be achieved by supporting the steering forces directly with an electric motor. In addition, the feed rate regulation is simpler.

Hydraulic pumps are evident in the automobile more and more often. They move convertible or folding roofs, the roofs of campers or numerous other movable car body parts. They are also used in the all-wheel-drive sector, e.g., for the activating of differential locking and/or for multiple-disc clutches. In fact, wherever the force of the largest, (as far as size and weight are concerned) electric motor is still not sufficient. An electric motor which drives a hydraulic pump can be smaller than one which substitutes for the complete hydraulic system.

How it works

The supply unit in the above figure is clearly divided, with the electric motor on the left, the pump in the middle, and the reservoir on the right. It can be assumed, that the motor has permanent magnets in the stator. The armature drives, at high RPMs and a low stroke, both pistons. Both have O-ring seals and move either to the right or to the left. Two check valves complete the relatively simple construction. With 12V-equipment, pressures of approx. 200 bar are possible, but no high transport capacity. The pump shown above is capable of developing approx. 70 bar pressure and 1.17 cm³ per armature rotation. 10/09               Top of page               Index
2001-2015 Copyright programs, texts, animations, pictures: H. Huppertz - E-Mail
Translator: Don Leslie - Email:

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