Start-Stop Solutions with Hydraulics

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Wheel Loader with Hydraulic Start-Stop System [1]
In this new post, iEditor would like to open a new topic about hydraulic start-stop solution. You’ll see how hydraulic start-stop solutions help on/off-highway machines save energy, what the difference between each solution developed by three typical suppliers.

1Start-Stop Overview


WWhat is Start-Stop
Start-Stop, in brief, is a kind of technology to control the engine to shut off when it is in idle condition and to restart the engine when it is needed to back to work.


Start-Stop Technology Concept

WWhy is Start-Stop
Both in On-highway and Off-highway industry, high-ratio of the machine duty cycle is in idle condition, it means the machine is waiting. Like the car waits for traffic ights, wheel loader waits for dumping material, but the engine at this time is still running, fuel is still consuming whereas no work is done.


Start-Stop Technology On/Off-highway Industry [2] [3]
Start-stop technology can help control the engine to stop when it is not used, in this way, fuel consumption can be saved significantly.Meanwhile, the engine can be waken up very fast when it’s needed to back to work.


2Start-Stop Hydraulics
Start-Stop is not a new concept, it has been applied on vehicles for a long time with electronic or mechanical solutions. While hydraulic solutions for start-stop do have its own advantages. Three typical suppliers – Rexroth, Poclain and Linde have all proposed their own hydraulic solutions.
Rexroth HSS

Rexroth HSS Solution [2]
This solution consists of an A10VO pump, a BODAS control unit, an automatic start-stop valve manifold, and four reservoirs. [2]


Rexroth HSS System Components [2]
The core component, a swivel-mounted A10VO, charges the accumulator with pressure during operation. When the diesel engine is to be restarted from stop mode, the accumulator is discharged by the swiveled pump acting as a motor to generate the necessary torque to start the engine. The start process is much shorter than one with an electric starter motor, making the machine ready for work immediately. [2]


Wheel Loader with Rexroth HSS System [2]


Poclain CleanStart


Poclain Start-Stop Solution [3]
Poclain Start-Stop solution mainly focuses on public transportation, consisting of a hydraulic starter (1), which directly drives the engine crankshaft and enables greater responsiveness with a start-up in less than 0.5 seconds, the hydraulic pump (2), a sequence valve (3), the hydraulic accumulator (4) , the tank (5) and the electronic control unit (6), which ensures the accumulator filling and draining sequences, provides system status updates and sends diagnostics.


Linde Start-Stop

Linde Start-Stop Solution on Telehandler [5]
Linde Start-Stop system consists of an electrically controlled MPR 50 medium pressure pump, Linde Hydraulics electronic control unit (LINC), an accumulator and a valve block. The working principle is similar to the two above. [4]


Linde Start-Stop System Components [5]
The MPR 50 hydraulic pump, acting as a starter motor, restarts the diesel engine so quickly that power is available almost immediately after depressing the accelerator pedal. [5]



Linde Start-Stop System Response Testing [4]




REFERENCES[1] Artur Gabriel, Atlas Weyhausen | Hydraulics & Pneumatics.
[2] Bosch Rexroth Website. www.boschrexroth.com.
[3] Poclain Hydraulics Website. www.poclain-hydraulics.com.
[4] Linde Hydraulics Website. www.linde-hydraulics.com.
[5] Christian Bischoff, Linde Hydraulics GmbH & Co. KG | Hydraulics & Pneumatics.

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[3]. This post reprint should be noted with “iHydrostatics Original”.