Bent axis and in-line axial piston motors are both high performance designs featuring high efficiency at high operating pressures. But which is best? To answer this question, a comparison of relative performance advantages is required.

Bent axis designs can be ‘bent’ to angle of up to about 40°. Whereas the swash plate angle on an in-line design is typically limited to less than 20°. This means the maximum to minimum displacement range or stroke ratio of a variable-displacement bent axis motor is around twice that of an in-line design. This gives a variable bent axis motor a wider operating torque/speed range than an in-line motor of the same displacement (remember, increasing motor displacement increases output torque and reduces output speed; and vice versa).… continue reading »

In The Hydraulic Troubleshooting Handbook I define and explain 12 principles for troubleshooting anything successfully. And I use examples from various fields of endeavor, in addition to hydraulics, including medicine and IT.

Troubleshooting Principle #5 is: Never Take Anyone Else’s Word For It. And I observed a good example of the application of this principle recently when, after moving from one side of the country to the other, I was having trouble with my broadband connection.

I was on the telephone to a technician in my ISP’s support department. Keep in mind these guys are professional troubleshooters–by remote. The technician wanted to check my modem’s settings, so he guided me through the necessary steps until we reached a point where a password was required for access.… continue reading »

As every hydraulics user who’s been around for a while knows, hydraulic component manufacturers are notorious for the smoke and mirrors they use to deny warranty claims.

Now, this is NOT to say all warranty claims are legitimate. In fact, it’s very safe to say they’re not. But when a hydraulic component fails prematurely, what IS needed is accurate information, i.e. better answers than ‘it’s contamination’.

And the reason why is illustrated by the following story about a client of mine who had suffered a series of failures involving a particular brand of radial piston motor. When he first went to the motor manufacturer about the problem – and to pursue a warranty claim, he was told the failures were caused by contamination.… continue reading »