Product category:
Gauges, Indicators and Instruments
News Release from: Dynaspede Integrated Systems | Subject: Di_Vector based test bench
Edited by the Engineeringtalk Editorial
Team on 19 March 2002
Novel concept in testing transmission
elements
Dynaspede was commissioned by a large tractor manufacturer to design and implement a Di_Vector based test bench for full load endurance testing of transaxles.
Dynaspede was commissioned by a large tractor manufacturer to design and implement a Di_Vector based test bench for full load endurance testing of transaxles The results from the test rig have satisfied them enough to go in for another one to cater to their expansion project
This concept has started attracting attention and admiration from professionals in the "automobile" and "off-highway vehicles" industry.
The basic concept of "Di_Vector technology" revolves around independent control of two vectors: torque and velocity (bidirectional speed).
In conventional terms, any prime mover capable of running a test component at its rated speed against its rated torque has to develop a mechanical power equal to the product of torque and (angular) speed.
The power rating of the test unit therefore, determines the power needed from the prime mover motor.
Further, the loading device has to absorb this full power and will be similarly rated for safely dissipating this power or regenerating part of it back into the electrical system.
Thus, the installed power capacity of the test bench will be greater than the combined power of these two devices plus the power required to account for losses in the test component and other elements in the test set up.
Significantly, even in regenerative forms of testing, the actual energy saving is severely limited by conversion efficiency involved in two stages of energy transformation - from electrical to mechanical and back to electrical form of energy.
The well known 4-square technique of testing, is based on an ingenious engineering concept to include the test element as part of a rotating closed mechanical loop within which, any amount of mechanical power can be established and circulated without the need for external power - except to supplement small frictional losses in such a synchronously driven loop.
Although 4-square form of testing has gained wide acceptance in engineering circles, the difficulty in introducing an infinitely adjustable torque into such a closed loop has so far restricted its popularity for general applications.
Di_Vector addresses to this problem by redefining this scheme to include an easy means of introducing and controlling the system torque and speed, independently of one another by using prime mover with a speed control device for driving and a independent torquing mechanism for loading the test unit.
The speed control provides a means of externally driving the test unit at desired testing speeds.
Since the prime mover (motor) is responsible only for speeds (and not torque), the driving power, demanded from it is only to the extent of overcoming the frictional and other losses in free running this loop.
In order to load the test unit, a twist is introduced between its input and output shafts (of the test device) in such a way that this twisting moment (torque) is developed and maintained within the loop, both under static and dynamic conditions.
Dynaspede's proprietary "Torquer" unit, does exactly this function of introducing a controlled bidirectional torque into the Di_Vector loop.
The system torque (which is the torque experienced by the test unit) introduced through this unit does not interfere the free running state of the Di_Vector loop while it maintains the preapplied torque in the Di_Vector loop.
PLC/PC based intelligent control systems and dedicated engineering software (developed internally) properly orchestrate all sequencing, data logging, online processing, recording and display of test results in user friendly formats.
The Di_Vector technique is eminently suited for endurance or validation tests on a variety of power transmission elements besides transaxles, that include gearboxes, belts, chains, shafts, couplings and slip clutches, with the advantages already mentioned above.
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