1 Scope
This part of ISO 10767 specifies a procedure for the determination of a rating of the source flow ripple, source impedance and pressure ripple levels generated by positive-displacement hydraulic motors, including bi-directional motors. Ratings are obtained as the following:
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a) the source flow ripple amplitude, in cubic metres per second, over ten individual harmonics of motoring frequency;
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b) the source impedance amplitude, in newton seconds per metre to the power of five [(N·s)/m5], and phase, in degrees, over ten individual harmonics of motoring frequency;
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c) the anechoic pressure ripple amplitude, in pascals, over ten harmonics of motoring frequency;
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d) the overall root mean square (r.m.s.) anechoic pressure ripple, in pascals;
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e) the blocked acoustic pressure ripple amplitude, in pascals, over ten harmonics of motoring frequency;
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f) the overall root mean square (r.m.s.) blocked acoustic pressure ripple, in pascals.
This part of ISO 10767 is applicable to all types of positive-displacement motor operating under steady-state conditions, irrespective of size, provided that the motoring frequency is in the range from 50 Hz to 400 Hz.