In the following the basic design is described. A wide variety of standard functions is additionaly available.
In basic design the engine test bed is not supposed to be run unattended, if internal faults of the test bed or external faults may lead to dangerous situations.
Loading system |
air-cooled electromagnetic eddy-current brake |
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periodically only very short |
8000 r.p.m. |
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see provisional "Load-carrying capacity" |
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The engine test bed consists of the braking and measuring unit and the control unit (evaluation, display and control unit with MP Computer). Often the control unit is swivelling mounted over the braking and measuring unit. In another design the control unit is contained in an operator's desk stand and the braking and measuring unit is connected by cables and plugs to the control unit.
The engine to be tested is connected to the brake by a special cardan shaft. Mobile supports (truck RWB or universal engine support) holding the engine are moved to the braking and measuring unit and fixed to it by one or two screws. While moving the engine on its support to the braking and measuring unit, the engine is connected to the brake by sliding together the multiple-spline parts of the cardan shaft.
The cardan shaft is positioned in a solid protective housing fixed to the braking and measuring unit. The brake is protected against accidental contact by means of a protective grating.
A foundation or fastening to the floor are not required, but an even floor surface.
If the control unit is mounted over the braking and measuring unit:
Weight: |
approx. 385 kg |
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This design is especially suitable for easy transport by a pallet truck.
In case of a separate operator's desk stand:
Weights: |
braking and measuring unit: approx. 335 kg |
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Other supply voltages are possible. |
The control unit contains:
Protection class of the control unit: IP 55
Loading of the engine by the brake is controlled by limiting the brake speed. This is achieved by manually entering the desired speed value (analog input) at a manually operated input potentiometer. This potentiometer acts through a fast response analog control circuit with thyristor amplifier. The amplifier controls the current magnetizing the eddy current brake.
The input potentiometer is installed in a separate hand-control housing and connected to the control unit via a spiral cable in such a way, that it can be operated from any point near the engine, if the control unit is positioned in an appropriate location.
A speed-stabilizing function of the MP Computer with numerical input of the desired value can be optionally superimposed to the manual speed adjustment and allows fast and precise adjustment of the speed.
Speed measurement: digital incremental pick-up non-sensitive for sense of rotation.
Torque measurement: analog measurement of the reactive torque at the stator of the brake by strain gage load cell.
The MP Computer displays the following measured and calculated values simultaneously via LED’s 20 mm high:
Speed |
display range |
9999 |
r.p.m. |
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display resolution |
1 |
r.p.m. |
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display resolution |
0.5 |
Nm |
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calibration value |
250 |
Nm |
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display resolution |
0,1 |
kW |
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9.999 |
kWh |
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or |
99.99 |
kWh |
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or |
999.9 |
kWh |
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or |
9999 |
kWh |
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0.001 |
kWh |
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or |
0.01 |
kWh |
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or |
0.1 |
kWh |
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or |
1 |
kWh |
The work counter (kWh) can be set On/Off or reset.
Setting On/Off of the work counter controls at the same time the determination of the specific fuel consumption (additional equipment).
Subject to change !