| ME
244L |
Department
of Mechanical Engineering |
| Dynamic
Systems and Controls Lab |
The
University of Texas at Austin |
|
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| Home-Made
Prony Brake |
Updated
for Summer 2002 |
|
| Return
to PMDC Lab Exercise 2 |
Go
to Document Map |
| The
Prony brake (see Chapter 12 of Figliola and Beasley) was invented in 1821
by French engineer Gaspard Prony (1755—1839). A Prony brake, shown
below, provides a means for applying an adjustable load torque to the output
shaft of a prime mover (e.g., IC engine, electric motor, etc.). The power
output is dissipated as heat in the braking material. By adjusting the 'brake
force', the torque level can be changed. By combining the measurement of
this torque with a speed measurement, the power output can also be measured
and this is a common combination in a dynamometer setup. |
Standard
Prony Brake Arrangement
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For this
laboratory, we have constructed a 'home-made' Prony brake using an off-the-shelf
'quick-grip' clamp and two wooden brake pads. This arrangement is illustrated
below. For the relatively low power and torque application with the PMDC
motors used in this lab, this quick solution works well.
To get a
sense of scale in the figure below, the shaft diameter is about 0.25 inches,
and the Quick-Grip is about 8 inches long (Quick-Grip is a registered
trademark from American Tool Companies, Inc.). The model used is the "Micro
Bar Clamp and Spreader", #530062.
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Send
comments to: Prof R.G. Longoria, Department of Mechanical Engineering, The
University of Texas at Austin
at r.longoria@mail.utexas.edu
| Last updated
August 2, 2002 |