◆ Vol.21 Comparison of Servo-valve and HySerpack (5)

As explained in previous section, there is no stick-slip on the oil pump. Now you should wonder how about stick-slip effect on the cylinder.

The stick-slip phenomenon is discussed a little in Section 8 that it is avoided due to the oil flow mechanism of Q1=Q0 as shown below. On top of this, any oil pump have all by itself the slight output fluctuation defined as ripples.  The ripple works like the Dither signal on the cylinder and reduces the stick-slip effect.  The internal oil leakage of oil pump, which has long been regarded as one of the flaws, now helps reduce the stick slip effect of oil plums, and the fluctuation of output which has been thought as the worst flaw of oil pump helps to get red of the stick-slip of the cylinder.

Thus the Dither signal, which is essential to the servo-valve system, is not required for HySerpack.

HySerpack is unique because it is developed based on totally unconventional thought and ideal apart from the conventional fluid oil system.