AAK Hydraulic Cartridge Directional Valve Spool Smoothness within Ra0.2

Derya is from Türkiye. Most of the customers in Türkiye who contact AAK are
dealers of hydraulic cartridge valves, but Derya operates a hydraulic equipment
manufacturing company. At the beginning of this year, they developed an
aviation hydraulic power unit that requires high-precision hydraulic cartridge
directional control valves, especially the surface finish of the valve spool to
be controlled within Ra0.3. Derya customized the hydraulic cartridge
directional control valve with a manufacturer in China that had been
cooperating for 3 years. 2 months later, the debugging of the aviation
hydraulic power unit was not smooth, due to the insensitive opening and closing
performance of the hydraulic cartridge directional control valve and equipment
operation hysteresis. The engineer found that the surface finish of the
hydraulic cartridge directional control valve spool from the original
manufacturer exceeded Ra0.5. The original hydraulic cartridge valve
manufacturer stated that they can only produce more valve spools and select
them one by one. Derya realized that the manufacturing quality of the original
hydraulic cartridge valve manufacturer was unstable, so he had to choose a new
manufacturer for the hydraulic cartridge directional control valve. However, 2
months had passed since then, Derya was in a hurry.

Derya found AAK on Google and left a message:
1. How long does it take for AAK to customize the hydraulic cartridge
directional control valve?
2. Is it possible for AAK to control the smoothness of the valve spool of each
hydraulic cartridge directional control valve within Ra0.3?

After communication, it was learned that he was facing the dilemma of
customizing a hydraulic cartridge directional control valve. I provided him a
customer case of a hydraulic cartridge directional control valve previously
customized for a Russian customer, with a surface finish of Ra0.2 on the valve
spool and a video of how we handled the surface finish of the valve spool.
Derya had no concerns anymore and requested AAK to make samples. After 50 days,
AAK sent 20 samples of hydraulic cartridge directional control valves.

4 weeks later, Derya informed us via email that their aviation hydraulic power
unit had been successfully tested and was on its way to deliver to the
customer. The smoothness of the AAK hydraulic cartridge directional control
valve spool was controlled at Ra0.2 and satisfied their engineers.

For AAK hydraulic cartridge directional control valve spool components, the
first is to choose suitable materials. For this model, we use 20CrNi2MoV high
permeability carbon bearing steel, which has wear-resistant performance and can
better protect the smoothness of the valve spool. Then it is polished and
precision processed, and AAK uses a Taiwan centerless grinder. The process
setting for centerless grinding is done by AAK this way: Firstly, the surface
error and feed speed of the grinding wheel are set, and the surface error value
of the hydraulic cartridge directional control valve spool is set to within
2μm, the feed speed of the grinding wheel is set at 400mm/min. The relative
vibration between the grinding wheel and the valve spool, as well as the
contact stiffness between the valve spool, guide wheel components, and support
plate, can be more smoothly controlled, ensuring that the surface finish of
each hydraulic cartridge directional control valve spool can be controlled
within Ra0.2 after processing.

AAK hydraulic cartridge directional control valve, the spool smoothness
controlled within Ra0.2, you can also give it a try!

AAK HYDRAULIC VALVES (635) 2024-07-25

https://www.aakindustry.com/info , -detail/cartridge-directional-valves-aak635

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